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Sample records for mexico city atopy

  1. September 1985 Mexico City, Mexico Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The magnitude 8.1 earthquake occurred off the Pacific coast of Mexico. The damage was concentrated in a 25 square km area of Mexico City, 350 km from the epicenter....

  2. 75 FR 28555 - Executive Green ICT & Energy Efficiency Trade Mission to Mexico City, Mexico

    Science.gov (United States)

    2010-05-21

    ... Trade Mission to Mexico City, Mexico AGENCY: International Trade Administration, Department of Commerce... Trade Mission to Mexico City from September 27-29, 2010. This Executive led mission will focus on... & Energy Efficiency conference will take place at the World Trade Center in Mexico City. Relevant issues on...

  3. LCA of road infrastructure in Mexico City.

    NARCIS (Netherlands)

    Rosales Carreon, Jesus

    2007-01-01

    Vehicular traffic is a major problem in metropolitan areas and Mexico City is no exception. Located in a pollutant-trapping valley, Mexico City (one of the largest cities in the world) is famous for its size, its history, and the warmth of its people. Nev

  4. Indoor radon measurements in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa, G. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20364, 01000 Mexico, D.F. (Mexico)], E-mail: espinosa@fisica.unam.mx; Golzarri, J.I. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20364, 01000 Mexico, D.F. (Mexico); Bogard, J. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6480 (United States); Gaso, I. [Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, 11801 Mexico, D.F. (Mexico); Ponciano, G. [Facultad de Medicina, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico); Mena, M.; Segovia, N. [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico)

    2008-08-15

    Mexico City is one of the most populated cities in the world with almost 22 million inhabitants, located at an altitude of 2200 m. The old city was founded on an ancient lake and the zone is known by its high seismicity; indoor radon determination is an important public health issue. In this paper the data of indoor radon levels in Mexico City, measured independently by two research groups, both using Nuclear Track Detector systems but different methodologies, are correlated. The measurements were done during similar exposure periods of time, at family houses from the political administrative regions of the city. The results indicate a correlation coefficient between the two sets of data of R=0.886. Most of the differences between the two sets of data are inherent to houses having extreme (very high or very low indoor radon) included in the statistics of each group. The total average indoor radon found in Mexico City considering the two methods was 87Bqm{sup -3}.

  5. Lighting the city. First poetic representations of Mexico City

    Directory of Open Access Journals (Sweden)

    Claudia Kerik

    2018-01-01

    Full Text Available The first impressions that caused the changes made in Mexico City in its process of transformation into a modern city were captured by its poets drawing attention to different aspects of life in the capital. While from the popular poetry the record of the entrance of the electricity in the public road was left, from the official poetry was tried to witness the new cosmopolitan status of the Mexico City in the Porfirian era, through the fashion and the customs that were revealed in one of the main streets of the city. Comparing these poems allows us to know the initial strategies of poetic figuration of urban space that will continue to develop along different paths throughout the twentieth century until we reach our days.

  6. Correlation between obesity with atopy and family history of atopy in children

    Directory of Open Access Journals (Sweden)

    Putria Rayani Apandi

    2011-08-01

    Full Text Available Background The prevalence of childhood obesity and atopy has increased in recent decades. Research on links between obesity and atopy has shown varied results. Few previous studies have reported on the significance of family history of atopic disease in children. Objective To determine correlation between obesity with atopy and family history of atopic disease in children. Methods This cross-sectional study was conducted from April to September 2010 in the Pediatric Allergy-Immunology subdivision, Hasan Sadikin Hospital. Children aged 6−11 years were divided into four groups of 40 each: obese subjects with and without family history of atopic disease, and normal weight subjects with and without family history of atopic disease. Skin prick test was performed to determine which subjects had atopy. Chi-square test was used to analyze mutual independence, and partial Chi-square test was used to analyze correlation of obesity to atopy and family history of atopic disease in children. Environmental factors, type of childbirth, and pregnancy history were also analyzed as risk factors for atopy. Results Of 80 obese children with and without family history of atopic disease, 40 (100% and 38 (95%, respectively, were atopic. Of 80 normal weight children with and without family history of atopic disease, 39 (98% and 9 (23%, respectively, were atopic. Thus atopy was observed in 126 subjects, while the remaining 34 subjects were non-atopic. Partial test showed a correlation between obesity with atopy and family history of atopic disease (P < 0.001. There were no significant differences in risk factors for atopy by group. Conclusion Obesity correlates with atopy and family history of atopic disease in children.

  7. Subsidence Induced Faulting Hazard risk maps in Mexico City and Morelia, central Mexico

    Science.gov (United States)

    Cabral-Cano, E.; Solano-Rojas, D.; Hernández-Espriu, J.; Cigna, F.; Wdowinski, S.; Osmanoglu, B.; Falorni, G.; Bohane, A.; Colombo, D.

    2012-12-01

    Subsidence and surface faulting have affected urban areas in Central Mexico for decades and the process has intensified as a consequence of urban sprawl and economic growth. This process causes substantial damages to the urban infrastructure and housing structures and in several cities it is becoming a major factor to be considered when planning urban development, land use zoning and hazard mitigation strategies in the next decades. Subsidence is usually associated with aggressive groundwater extraction rates and a general decrease of aquifer static level that promotes soil consolidation, deformation and ultimately, surface faulting. However, local stratigraphic and structural conditions also play an important role in the development and extension of faults. Despite its potential for damaging housing, and other urban infrastructure, the economic impact of this phenomena is poorly known, in part because detailed, city-wide subsidence induced faulting risk maps have not been published before. Nevertheless, modern remote sensing techniques are most suitable for this task. We present the results of a risk analysis for subsidence induced surface faulting in two cities in central Mexico: Morelia and Mexico City. Our analysis in Mexico City and Morelia is based on a risk matrix using the horizontal subsidence gradient from a Persistent Scatterer InSAR (Morelia) and SqueeSAR (Mexico City) analysis and 2010 census population distribution data from Mexico's National Institute of Statistics and Geography. Defining subsidence induced surface faulting vulnerability within these urbanized areas is best determined using both magnitude and horizontal subsidence gradient. Our Morelia analysis (597,000 inhabitants with localized subsidence rates up to 80 mm/yr) shows that 7% of the urbanized area is under a high to very high risk level, and 14% of its population (11.7% and 2.3% respectively) lives within these areas. In the case of the Mexico City (15'490,000 inhabitants for the

  8. Atopy and development of cancer

    DEFF Research Database (Denmark)

    Skaaby, Tea; Nystrup Husemoen, Lise Lotte; Roswall, Nina

    2014-01-01

    BACKGROUND: Atopy is the familial or personal propensity to develop IgE antibodies against environmental allergens. Atopy, theoretically, could both prevent and promote the development of cancer. However, evidence from epidemiologic studies has been inconclusive. OBJECTIVE: We investigated...... the longitudinal association between atopy and the incidence of total and specific types of cancers of 5 Danish population-based studies. METHODS: Atopy was defined as serum specific IgE positivity against inhalant allergens. A total of 14,849 persons were followed up prospectively by linkage to the Danish Cancer...... Registry. We used Cox regression analysis, and risk was expressed as hazard ratios (HR) (95% CIs) for persons with atopy versus those without atopy. RESULTS: There were 1919 incident cancers (median follow-up, 11.8 years). There were no statistically significant associations between atopy and risk of any...

  9. Establishing a Water Resources Resilience Baseline for Mexico City

    Science.gov (United States)

    Behzadi, F.; Ray, P. A.

    2017-12-01

    There is a growing concern for the vulnerability of the Mexico City water system to shocks, and the capacity of the system to accommodate climate and demographic change. This study presents a coarse-resolution, lumped model of the water system of Mexico City as a whole, designed to identify system-wide imbalances, and opportunities for large-scale improvements in city-wide resilience through investments in water imports, exports, and storage. In order to investigate the impact of climate change in Mexico City, the annual and monthly trends of precipitation and temperature at 46 stations near or inside the Mexico City were analyzed. The statistical significance of the trends in rainfall and temperature, both over the entire period of record, and the more recent "climate-change-impacted period" (1970-2015), were determined using the non-parametric Mann-Kendall test. Results show a statistically significant increasing trend in the annual mean precipitation, mean temperature, and annual maximum daily temperature. However, minimum daily temperature does not appear to be increasing, and might be decreasing. Water management in Mexico City faces particular challenges, where the winter dry season is warming more quickly than the wet summer season. A stress test of Mexico City water system is conducted to identify vulnerabilities to changes in exogenous factors (esp., climate, demographics, land use). Following on the stress test, the relative merits of adaptation options that might improve the system's resilience and sustainability will be assessed.

  10. Strong advocacy led to successful implementation of smokefree Mexico City.

    Science.gov (United States)

    Crosbie, Eric; Sebrié, Ernesto M; Glantz, Stanton A

    2011-01-01

    To describe the approval process and implementation of the 100% smokefree law in Mexico City and a competing federal law between 2007 and 2010. Reviewed smokefree legislation, published newspaper articles and interviewed key informants. Strong efforts by tobacco control advocacy groups and key policymakers in Mexico City in 2008 prompted the approval of a 100% smokefree law following the WHO FCTC. As elsewhere, the tobacco industry utilised the hospitality sector to block smokefree legislation, challenged the City law before the Supreme Court and promoted the passage of a federal law that required designated smoking areas. These tactics disrupted implementation of the City law by causing confusion over which law applied in Mexico City. Despite interference, the City law increased public support for 100% smokefree policies and decreased the social acceptability of smoking. In September 2009, the Supreme Court ruled in favour of the City law, giving it the authority to go beyond the federal law to protect the fundamental right of health for all citizens. Early education and enforcement efforts by tobacco control advocates promoted the City law in 2008 but advocates should still anticipate continuing opposition from the tobacco industry, which will require continued pressure on the government. Advocates should utilise the Supreme Court's ruling to promote 100% smokefree policies outside Mexico City. Strong advocacy for the City law could be used as a model of success throughout Mexico and other Latin American countries.

  11. A Hazy Day in Mexico City

    Science.gov (United States)

    2002-01-01

    Mexico City has one of the world's most serious air pollution problems. The city is located atop a high plain at an altitude of 2200 meters, and is surrounded on three sides by mountains and snow-capped volcanoes. Since incident solar radiation does not vary significantly with season at tropical latitudes, photochemical smog is produced much of the year. In winter, air quality can worsen significantly when thermal inversions keep polluted air masses close to the surface.Atmospheric particulates (aerosols) are readily visible at oblique view angles, and differences in aerosol amount on two days are indicated by these images of central Mexico from the Multi-angle Imaging SpectroRadiometer (MISR). The images at left and center are natural color views acquired by MISR's 70-degree forward-viewing camera on April 9 and December 5, 2001, respectively. Mexico City can be identified in the center panel by the large area of haze accumulation above image center. Two small brighter patches within the hazy area indicate low fog. In the left-hand panel, the city basin appears significantly clearer, but some haze remains apparent across the Sierra Madre mountains in the lower portion of the images. On the right is an elevation field corresponding to the December 5 view. Automated MISR stereoscopic retrievals reveal the clouds at lower right to be at very high altitudes, in contrast to the low-lying haze and fog near Mexico City. When the stereo retrieval determines that a location is not covered by clouds, digital terrain elevation data are displayed instead. High clouds appear as the orange and red areas, and mountainous areas appear light blue and green. The position of the clouds within the 70-degree image are slightly southward of their location in the elevation map as a consequence of geometric parallax.Major sources of air pollutants within the basin enclosing the Mexico City urban area include exhaust from 3.5 million vehicles, thousands of industries, and mineral dust

  12. 3 CFR - Mexico City Policy and Assistance for Voluntary Population Planning

    Science.gov (United States)

    2010-01-01

    ... 3 The President 1 2010-01-01 2010-01-01 false Mexico City Policy and Assistance for Voluntary Population Planning Presidential Documents Other Presidential Documents Memorandum of January 23, 2009 Mexico... Mexico City Policy was in effect from 1985 until 1993, when it was rescinded by President Clinton...

  13. [The cholera epidemic of 1833 and mortality in Mexico City].

    Science.gov (United States)

    Velasco, M D

    1992-01-01

    The author examines the impact of the 1833 cholera epidemic in Mexico City, Mexico, on social, economic, and political aspects of life in that city. She finds that some five percent of the population died during the epidemic, and enumerates them by age and sex.

  14. A survey of 222Rn in drinking water in mexico city

    International Nuclear Information System (INIS)

    Vasquez-Lopez, C.; Zendejas-Leal, B. E.; Golzarri, J. I.; Espinosa, G.

    2011-01-01

    In Mexico City there are more than 22 millions of inhabitants (10 in the metropolitan area and 12 in the suburban zone) exposed to drinking water. The local epidemiological authorities recognised that exposure to radon contaminated drinking water is a potential health hazard, as has been considered worldwide. The United States Environmental Protection Agency has proposed a limit of 11.1 Bq l -1 for the radon level in drinking water. In Mexico a maximum contamination level of radon in drinking water has not yet even considered. In this work, a 222 Rn study of drinking water in Mexico City has revealed a range of concentrations from background level to 3.8 Bq l -1 . 222 Rn was calculated using a portable degassing system (AquaKIT) associated with an AlphaGUARD measuring system. Samples from 70 wells of the water system of the south of the Valley Basin of Mexico City and from houses of some other political administrative divisions of Mexico City were taken. (authors)

  15. Measurements of VOCs in Mexico City during the MILAGRO Campaign

    Science.gov (United States)

    Baker, A. K.; Beyersdorf, A. J.; Blake, N. J.; Meinardi, S.; Atlas, E.; Rowland, F.; Blake, D. R.

    2006-12-01

    During March of 2006 we participated in MILAGRO (Megacities Initiative: Local and Global Research Observations), a multi-platform campaign to measure pollutants in and in outflow from the Mexico City metropolitan area. As part of MILAGRO we collected whole air canister samples at two Mexico City ground sites: the Instituto Mexicano del Petroleo, located in the city, northeast of the center, and the Universidad Technologica de Tecamac, a suburban site approximately 50 km northeast of the city center. Samples were also collected in various other locations throughout Mexico City. Over 300 whole air samples were collected and analyzed for a wide range of volatile organic compounds (VOCs) including methane, carbon monoxide, nonmethane hydrocarbons (NMHCs) and halocarbons. Propane was the most abundant NMHC at both the urban and suburban locations, with mixing ratios frequently in excess of 10 parts per billion at both locations. This is likely the result of the widespread use of liquefied petroleum gas (LPG) of which propane is the major component. For most species, median mixing ratios at the urban sites were significantly greater than at the suburban site. Here we compare results from both urban and suburban locations and also examine the influence of transport on the composition of outflow from Mexico City.

  16. Internal migration and occupational achievement in Mexico city

    Directory of Open Access Journals (Sweden)

    Julio Santiago Hernández

    2015-05-01

    Full Text Available The purpose of this work is to analyze the effect of migration status on labor market insertion and occupational achievement. It is of interest to know whether the observed differences between people with a different migration status (from first-generation rural migrants to natives are due to their migratory condition per se or other sociodemographic variables associated with their status that could put migrants at disadvantage in the labor market of Mexico City. We elaborate on this by using data from the Survey on Inequality and Social Mobility in Mexico City, 2009. Unlike studies of major Mexican cities during the import substitution model, wich as sumed that upward occupational mobility rates benefited almost equally the born and raised in the city and the rural migrants our results suggest the opposite: that migrants do poorly, but not for the fact that they are migrants, but because they tend to have lower economic, cultural and social capital attributes in their families of origin due to certain factors that leave them unable to capitalize on their efforts to achieve an educational and occupational performance similar or superior to that of the natives. A suggestive finding is that, even after controlling for the disadvantageous social background, female rural migrants show a consistently unfavorable performance when compared to the native women of Mexico City.

  17. [Cholera in Mexico City during the nineteenth century].

    Science.gov (United States)

    Marquez Morfin, L

    1992-01-01

    The author draws on epidemiological and historical records for this description of the demographic impact of the fatal cholera epidemics of 1833 and 1848-1850 on the population of Mexico City, Mexico. Consideration is given to political, economic, and social factors that influenced the spread of the disease.

  18. Physical Exposure to Seismic Hazards of Health Facilities in Mexico City, Mexico

    Science.gov (United States)

    Rodriguez, S. M.; Novelo Casanova, D.

    2010-12-01

    Although health facilities are essential infrastructure during disasters and emergencies, they are also usually highly vulnerable installations in the case of the occurrence of large and major earthquakes. Hospitals are one of the most complex critical facilities in modern cities and they are used as first response in emergency situations. The operability of a hospital must be maintained after the occurrence of a local strong earthquake in order to satisfy the need for medical care of the affected population. If a health facility is seriously damaged, it cannot fulfill its function when most is needed. In this case, hospitals become a casualty of the disaster. To identify the level of physical exposure of hospitals to seismic hazards in Mexico City, we analyzed their geographic location with respect to the seismic response of the different type of soils of the city from past earthquakes, mainly from the events that occurred on September 1985 (Ms= 8.0) and April 1989 (Ms= 6.9). Seismic wave amplification in this city is the result of the interaction of the incoming seismic waves with the soft and water saturated clay soils, on which a large part of Mexico City is built. The clay soils are remnants of the lake that existed in the Valley of Mexico and which has been drained gradually to accommodate the growing urban sprawl. Hospital facilities were converted from a simple database of names and locations into a map layer of resources. This resource layer was combined with other map layers showing areas of seismic microzonation in Mexico City. This overlay was then used to identify those hospitals that may be threatened by the occurrence of a large or major seismic event. We analyzed the public and private hospitals considered as main health facilities. Our results indicate that more than 50% of the hospitals are highly exposed to seismic hazards. Besides, in most of these health facilities we identified the lack of preventive measures and preparedness to reduce their

  19. Respiratory tract toxicity in rats exposed to Mexico City air.

    Science.gov (United States)

    Moss, O R; Gross, E A; James, R A; Janszen, D B; Ross, P W; Roberts, K C; Howard, A M; Harkema, J R; Calderón-Garcidueñas, L; Morgan, K T

    2001-03-01

    The rat has been used extensively as a health sentinel, indicator, or monitor of environmental health hazards, but this model has not been directly validated against human exposures. Humans in Mexico City show upper respiratory tract lesions and evidence of pulmonary damage related to their environmental inhalation exposure. In this study, male and female F344 rats were exposed (23 hr/day) in Mexico City to local Mexico City air (MCA)* for up to seven weeks. Controls were maintained at the same location under filtered air. Prior to these exposures, several steps were taken. First, the nasal passages of normal male rats shipped from the United States and housed in Mexico City were examined for mycoplasma infection; no evidence of infection was found. In addition, a mobile exposure and monitoring system was assembled and, with an ozone (O3) exposure atmosphere, was tested along with supporting histopathology techniques and analysis of rat nasal and lung tissues. Last, the entire exposure model (equipment and animals) was transported to Mexico City and validated for a three-week period. During the seven-week study there were 18 one-hour intervals during which the average O3 concentration of MCA in the exposure chamber exceeded the US National Ambient Air Quality Standard (NAAQS) of 0.120 ppm 03 (hourly average, not to be exceeded more than once per year). This prolonged exposure of healthy F344 rats to MCA containing episodically low to moderate concentrations of 03 (as well as other urban air pollutants) did not induce inflammatory or epithelial lesions in the nasal airways or lung as measured by qualitative histologic techniques or quantitative morphometric techniques. These findings agree with those of previous controlled O3 inhalation studies, but they are in contrast to reports indicating that O3-polluted MCA causes significant nasal mucosal injury in adults and children living in southwestern Mexico City. Taken together, these findings may suggest that human

  20. Structural Damage in Mexico City

    OpenAIRE

    Hall, John F.; Beck, James L.

    1986-01-01

    This paper describes the structural damage in Mexico City caused by the September 19, 1985 earthquake. Photographs which illustrate various features of structural behavior are included. One explanation is presented as to why buildings with fundamental periods of elastic vibration considerably below the predominant two‐second period of the ground motion were most vulnerable to damage.

  1. A survey of ²²²Rn in drinking water in Mexico City.

    Science.gov (United States)

    Vázquez-López, C; Zendejas-Leal, B E; Golzarri, J I; Espinosa, G

    2011-05-01

    In Mexico City there are more than 22 millions of inhabitants (10 in the metropolitan area and 12 in the suburban zone) exposed to drinking water. The local epidemiological authorities recognised that exposure to radon contaminated drinking water is a potential health hazard, as has been considered worldwide. The United States Environmental Protection Agency has proposed a limit of 11.1 Bq l(-1) for the radon level in drinking water. In Mexico a maximum contamination level of radon in drinking water has not yet even considered. In this work, a (222)Rn study of drinking water in Mexico City has revealed a range of concentrations from background level to 3.8 Bq l(-1). (222)Rn was calculated using a portable degassing system (AquaKIT) associated with an AlphaGUARD measuring system. Samples from 70 wells of the water system of the south of the Valley Basin of Mexico City and from houses of some other political administrative divisions of Mexico City were taken.

  2. [Obesity or overweight and metabolic syndrome in Mexico City teenagers].

    Science.gov (United States)

    Cardoso-Saldaña, Guillermo C; Yamamoto-Kimura, Liria; Medina-Urrutia, Aida; Posadas-Sánchez, Rosalinda; Caracas-Portilla, Nacú A; Posadas-Romero, Carlos

    2010-01-01

    aim: To know the metabolic syndrome and its components prevalence in Mexico City adolescents sample. A cross-sectional survey was conducted in 772 men and 1078 women, 12 to 16 years old, from 8 randomly selected public junior high schools in Mexico City. Anthropometric variables, lipids, lipoproteins, Apo AI and B, glucose and insulin were determined. Prevalence of metabolic syndrome was 12.5%, 11.15% in men and 13.5% en women (p ns). The most frequently metabolic syndrome component found in México City adolescents was low HDL-C levels (38%), followed by hypertriglyceridemia (25.5%), hypertension (19.2%), central obesity (11.8%) and elevated fasting glucose (1.7). Except by the hypertriglyceridemia, higher in woman than in men, 28.2% vs. 21.6%, p metabolic syndrome components was similar between males and females. The high prevalence of biochemical and physiological factors of metabolic syndrome, associated with overweight and obesity in Mexico City adolescents, increases the risk of premature development of coronary atherosclerosis and diabetes mellitus in this population.

  3. Mexico City Air Quality Research Initiative; Volume 5, Strategic evaluation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-03-01

    Members of the Task HI (Strategic Evaluation) team were responsible for the development of a methodology to evaluate policies designed to alleviate air pollution in Mexico City. This methodology utilizes information from various reports that examined ways to reduce pollutant emissions, results from models that calculate the improvement in air quality due to a reduction in pollutant emissions, and the opinions of experts as to the requirements and trade-offs that are involved in developing a program to address the air pollution problem in Mexico City. The methodology combines these data to produce comparisons between different approaches to improving Mexico City`s air quality. These comparisons take into account not only objective factors such as the air quality improvement or cost of the different approaches, but also subjective factors such as public acceptance or political attractiveness of the different approaches. The end result of the process is a ranking of the different approaches and, more importantly, the process provides insights into the implications of implementing a particular approach or policy.

  4. Analysis of aerosol samples in Mexico City

    International Nuclear Information System (INIS)

    Martinez, T.; Lartigue, J.; Zarazua, P.; Navarrete, M.; Ramirez, A.; Avila, P.

    2000-01-01

    Total solid particles and 9 metals potentially hazardous for health were determined in Mexico City dwellings by gravimetry and X-ray fluorescence techniques, respectively. Monitoring was performed in spring and winter, on districts covering center, northeast, southeast and southwest of the City. Results show that, in general, the average concentration of metallic contaminants have increased with time and, in the particular case of lead it is higher than the indicative WHO maximum level. The total solid particles figures are also above the U.S. norm of 75 μg.m -3 . Results obtained in samples taken in the same dwelling at different seasons show that lead was not present in a measurable concentration all the time. It seems to exist a correlation between the increase in lead and the increase in total solid particles whose distribution pattern in Mexico City follows wind directions. Another relevant correlation seems to exist between lead concentration and the rate of combustion of fuel in the transport system, which varies with the zone and the season. (author)

  5. Lidar Monitoring of Mexico City's Atmosphere During High Air Pollution Episodes

    Science.gov (United States)

    Quick, C. R., Jr.; Archuleta, F. L.; Hof, D. E.; Karl, R. R., Jr.; Tiee, J. J., Jr.; Eichinger, W. E.; Holtkamp, D. B.; Tellier, L.

    1992-01-01

    Over the last two decades, Mexico City, like many large industrial and populous urban areas, has developed a serious air pollution problem, especially during the winter months when there are frequent temperature inversions and weak winds. The deteriorating air quality is the result of several factors. The basin within which Mexico City lies in Mexico's center of political, administrative and economic activity, generating 34 percent of the gross domestic product and 42 percent of the industrial revenue, and supporting a population which is rapidly approaching the 20 million mark. The basin is surrounded by mountains on three sides which end up preventing rapid dispersal of pollutants. Emissions from the transportation fleet (more than 3 million vehicles) are one of the primary pollution sources, and most are uncontrolled. Catalytic converters are just now working their way into the fleet. The Mexico City Air Quality Research Initiative in an international collaboration project between the Los Alamos National Laboratory and the Mexican Petroleum Institute are dedicated to the investigation of the air quality problem in Mexico City. The main objective of the project is to identify and assess the cost and benefits of major options being proposed to improve the air quality. The project is organized into three main activity areas: (1) modeling and simulation; (2) characterization and measurements; and (3) strategic evaluation.

  6. Libraries in the Mexico City Earthquake.

    Science.gov (United States)

    de Zamora, Rosa Maria Fernandez

    1990-01-01

    As a result of damage from the Mexico City earthquake of September 1985, some of the busiest public and special libraries had to be closed. A National Committee for the Reconstruction of Libraries was established, and international support was received through the International Federation of Library Associations and Institutions and other…

  7. Public opinion on abortion in Mexico City after the landmark reform.

    Science.gov (United States)

    Wilson, Kate S; García, Sandra G; Díaz Olavarrieta, Claudia; Villalobos-Hernández, Aremis; Rodríguez, Jorge Valencia; Smith, Patricio Sanhueza; Burks, Courtney

    2011-09-01

    This article presents findings from three opinion surveys conducted among representative samples of Mexico City residents: the first one immediately prior to the groundbreaking legalization of first-trimester abortion in April 2007, and one and two years after the reform. Bivariate and multivariate analyses were performed to assess changes in opinion concerning abortion and correlates of favorable opinion following reform. In 2009 a clear majority (74 percent) of respondents were in support of the Mexico City law allowing for elective first-trimester abortion, compared with 63 percent in 2008 and 38 percent in 2007. A significant increase in support for extending the law to the rest of Mexico was found: from 51 percent in 2007 to 70 percent in 2008 and 83 percent in 2009. In 2008 the significant independent correlates of support for the Mexico City law were education, infrequent religious service attendance, sex (being male), and political party affiliation; in 2009 they were education beyond high school, infrequent religious service attendance, and ever having been married.

  8. Atopy, but not obesity is associated with asthma severity among children with persistent asthma.

    Science.gov (United States)

    Lu, Kim D; Phipatanakul, Wanda; Perzanowski, Matthew S; Balcer-Whaley, Susan; Matsui, Elizabeth C

    2016-12-01

    Obesity is associated with an increased risk of asthma in children. Atopic sensitization is a major risk factor for asthma including severe asthma in children. It is unclear if obesity is associated with worse asthma control or severity in children and how its effects compare to atopy. We sought to examine relationships of weight status and atopy to asthma control and severity among a population of predominantly low income, minority children and adolescents with persistent asthma. A cross-sectional analysis of 832 children and adolescents, age range 5-17 years, with persistent asthma was performed. Clinical assessments included asthma questionnaires of symptoms, asthma severity score, health care utilization and medication treatment step, lung function testing, and skin prick testing as well as measures of adiposity. Data were collected between December 2010 and August 2014 from Johns Hopkins Hospital in Baltimore, MD and Children's Hospital of Boston, MA. Obesity was not associated with worse asthma control or severity in this group of predominantly low income, minority children and adolescents with persistent asthma. However, a greater degree of atopy was associated with lower lung function, higher asthma severity score, and higher medication treatment step. Atopy may be a more important risk factor for asthma severity than obesity among low-income minority children and adolescents with persistent asthma living in Northeastern cities in the United States.

  9. 76 FR 58772 - Safety & Security Trade Mission; Mexico City and Monterrey, Mexico

    Science.gov (United States)

    2011-09-22

    ... dinner at a local restaurant--group transportation will be provided. On February 1, participants will.... Group dinner at local restaurant (no host). February 1 Mexico City/Monterrey. Breakfast (no host... ability to meet certain conditions and to satisfy the selection criteria as outlined below. This mission...

  10. Atopy risk factors at birth and in adulthood.

    Science.gov (United States)

    Ferraz, Erica; Garcia, Clécia Aparecida; Bettiol, Heloísa; Caldeira, Roseane Durães; Cardoso, Viviane Cunha; Arruda, Luiza Karla; Barbieri, Marco Antônio; Vianna, Elcio Oliveira

    2011-01-01

    To study the association between atopy and variables such as weight, length, and socioeconomic level at birth and in young adulthood. A total of 2,063 subjects were investigated in a prospective birth cohort study of individuals born in Ribeirão Preto, Brazil, in 1978/1979, and examined at the age of 23-25 years. Skin prick tests (SPT) for eight common allergens in Brazil were performed. Subjects with a wheal reaction ≥ 3 mm to one or more of the eight allergens tested were considered to be atopic. We used the log-binomial model (generalized linear model) in order to assess the association between atopy and birth or adult variables. The prevalence of positive SPT was 47.6%. Male gender was associated with an increased risk of atopy (relative risk [RR] = 1.18; 95% confidence interval [95%CI] 1.07-1.30). Low level of schooling was a protective factor against atopy, with a RR = 0.74; 95%CI 0.62-0.89. Living with a smoker in childhood was also associated with lower risk of atopy (RR = 0.87; 95%CI 0.79-0.96). Birth weight, length and order, maternal age, and intrauterine growth restriction were not associated with positive SPT. This study showed that male gender was associated with an increased risk of atopy. Low socioeconomic status, assessed by low level of schooling, was a protective factor against atopy. These data agree with the hygiene hypothesis.

  11. Fungal atopy in adult cystic fibrosis.

    LENUS (Irish Health Repository)

    Henry, M

    2012-02-03

    This study set out to estimate the prevalence of atopy to a variety of common ubiquitous fungi, including A. fumigatus, in cystic fibrosis (CF), and to evaluate the investigations by which the diagnosis was made. Particular attention was paid to the usefulness of skin testing and immunoassays in detecting which patients had simple fungal atopy, and which patients were at high risk of developing allergic bronchopulmonary mycoses. This cross-sectional study included 21 adult CF patients and 20 matched controls. Serum samples were taken for the measurement of total serum IgE and specific serum IgE to nine common fungi. Immediate hypersensitivity skin prick testing to each of the fungi was also performed. Simple fungal atopy was described in subjects fulfilling the following criteria: total serum IgE > 100 KU l(-1) with specific radioimmunoassay > or = grade 1 to at least one fungus and a positive skin prick test (SPT) > or = 3 mm to the same fungus. \\'High risk\\' for developing allergic bronchopulmonary mycosis (ABPM) was described in subjects fulfilling the following criteria: total serum IgE > 200 KU l(-1) with specific radioimmunoassay > or = grade 2 to at least one fungus and a positive skin prick test (SPT) > or = 6 mm to the same fungus. The adult CF group had a significantly higher total SPT score (P=0.005) and mean total serum IgE (P<0.05) than controls. Forty-three percent of CF patients fulfilled the criteria for fungal atopy to at least a single fungus. Over half this group had an atopic tendency to more than one fungus. Nineteen percent of the CF group were at least \\'high risk\\' of developing ABPM. Skin prick testing is a better marker of fungal atopy and a better predictor of those adult CF patients at higher risk of developing ABPM than specific radioimmunoassay serum testing. There is a high prevalence of fungal atopy in the adult CF population. Total serum IgE and skin prick testing are good predictors of fungal atopy and help predict those at

  12. [The control of urban growth in Mexico City. Suppositions regarding poor planning].

    Science.gov (United States)

    Aguilar, A G; Olvera, G

    1991-01-01

    It is argued that mechanisms for planning land use and controlling urban expansion in Mexico City have failed to achieve their aims. Although in theory Mexico's urban planning process has recently attempted to go beyond purely physical aspects to include socioeconomic dimensions, it has in fact been inflexible and oriented to exclusively to technical and administrative aspects, to the detriment of social distribution goals. Planning instruments have not included important aspects such as specific mechanisms for altering employment structures or income levels or mechanisms for providing access to land or housing to the most disadvantaged groups. The urban planning process in Mexico City, instead of assuming a socially compensatory role in favor of disadvantaged groups, has maintained the status quo or discriminated in favor of the already advantaged. The spatial and technical orientation or urban planning in Mexico City does not leave room for a well-defined social policy. The population of the Mexico City metropolitan Zone increased from 3 million in 1950 to 18 million in 1985, while its total area increased from 11,750 hectares in 1940 to 125,000 in 1985. Transfer of population from the Federal District to the conurban municipios of the state of Mexico has been very significant since the 1970s. Around 20% of the total area of metropolitan Mexico City has been settled through illegal means, with communal and ejido lands accounting for a large share. Settlements on some 60% of lands in metroplitan Mexico City were illegal or irregular at some time. Low income housing is the cheapest form for the government because the frequently illegal status of settlers prevents them from making any demands for services or equipment for the 1st several years. Construction is undertaken and financed almost entirely by the settlers themselves, freeing the government of responsibility in regard to the constitutionally mandated right of all Mexicans to housing. The Urban Development

  13. The prehospital emergency care system in Mexico City: a system's performance evaluation.

    Science.gov (United States)

    Peralta, Luis Mauricio Pinet

    2006-01-01

    Mexico City has one of the highest mortality rates in Mexico, with non-intentional injuries as a leading cause of death among persons 1-44 years of age. Emergency medical services (EMS) in Mexico can achieve high levels of efficiency by offering high quality medical care at a low cost through adequate system design. The objective of this study was to determine whether the prehospital EMS system in Mexico City meets the criteria standards established by the American Ambulance Association Guide for Contracting Emergency Medical Services (AAA Guide) for highly efficient EMS systems. This retrospective, descriptive study, evaluated the structure of Mexico City's EMS system and analyzed EMS response times, clinical capacity, economic efficiency, and customer satisfaction. These results were compared with the AAA guide, according to the soc ial, economic, and political context in Mexico. This paper describes the healthcare system structure in Mexico, followed by a description of the basic structure of EMS in Mexico City, and of each tenet described in the AAA guide. The p aper includesdata obtained from official documents and databases of government agencies, and operative and administrative data from public and private EMS providers. The quality of the data for response times (RT) were insufficient and widely varied among providers, with a minimum RT of 6.79 minutes (min) and a maximum RT of 61 min. Providers did not define RT clearly, and measured it with averages, which can hide potentially poor performance practices. Training institutions are not required to follow a standardized curriculum. Certifications are the responsibility of the individual training centers and have no government regulation. There was no evidence of active medical control involvement in direct patient care, and providers did not report that quality assurance programs were in place. There also are limited career advancement opportunities for EMS personnel. Small economies of scale may not allow

  14. The economic impact of Mexico City's smoke-free law.

    Science.gov (United States)

    López, Carlos Manuel Guerrero; Ruiz, Jorge Alberto Jiménez; Shigematsu, Luz Myriam Reynales; Waters, Hugh R

    2011-07-01

    To evaluate the economic impact of Mexico City's 2008 smoke-free law--The Non-Smokers' Health Protection Law on restaurants, bars and nightclubs. We used the Monthly Services Survey of businesses from January 2005 to April 2009--with revenues, employment and payments to employees as the principal outcomes. The results are estimated using a differences-in-differences regression model with fixed effects. The states of Jalisco, Nuevo León and México, where the law was not in effect, serve as a counterfactual comparison group. In restaurants, after accounting for observable factors and the fixed effects, there was a 24.8% increase in restaurants' revenue associated with the smoke-free law. This difference is not statistically significant but shows that, on average, restaurants did not suffer economically as a result of the law. Total wages increased by 28.2% and employment increased by 16.2%. In nightclubs, bars and taverns there was a decrease of 1.5% in revenues and an increase of 0.1% and 3.0%, respectively, in wages and employment. None of these effects are statistically significant in multivariate analysis. There is no statistically significant evidence that the Mexico City smoke-free law had a negative impact on restaurants' income, employees' wages and levels of employment. On the contrary, the results show a positive, though statistically non-significant, impact of the law on most of these outcomes. Mexico City's experience suggests that smoke-free laws in Mexico and elsewhere will not hurt economic productivity in the restaurant and bar industries.

  15. Containing a contagion : crime and homosexuality in post-revolutionary Mexico City

    OpenAIRE

    Cook, Stephen Sherrard

    2008-01-01

    Primarily based upon archival resources at the Archivo Histórico del Distrito Federal (AHDF) and the Archivo General de la Nación (AGN) in Mexico City, this thesis is a social and cultural history of the criminalization and punishment of homosexuality during the 1920s and 1930s in Mexico City. The bulk of the primary historical research is based upon two separate spheres of homosexual-related criminal cases, adult and juvenile homosexual 'criminal' cases. The Archivo Histórico houses adult cr...

  16. [Availability of condoms in Mexico City].

    Science.gov (United States)

    Hernández-Girón, C; Cruz-Valdez, A; Quiterio-Trenado, M; Avila-Burgos, L; Peruga, A; Hernández-Avila, M

    2001-12-01

    At the beginning of 1999, Mexico occupied third place, after USA and Brazil, in the number of accumulated cases of AIDS (38,390 notified cases) in America. More than 80% of the cases corresponded to men between 20 and 44 years old. The transmission by sexual route has increased in both sexes, the proportion of men infected by sexual contact increased from 85% in 1991 to 90% in 1998 and in women this proportion increased from 41% in 1991 to 57% in 1998. The ratio male/female of cases of AIDS has varied from 17:1 in 1983 to 6:1 in 1998. Condom use is considered an effective method for the prevention of the transmission of STI's/HIV and therefore the availability is of paramount importance to promote use with the finality of combating these diseases. A simple randomized sampling was done in 612 establishments that included: drugstore, bars and nightclubs, hotels and motels, self-service shops and health centers in Mexico City, where am cross sectional study was performed during June and July of 1995, to evaluate the availability of condoms considering three important items: a) percent per capita required to buy an annual endowment of 100 condoms in comparison with this same indicator reported in other countries; b) physical availability, on behalf of the Secretaría de Salud, Mexico City, that considers the volume of existing condoms to be utilized for a year by the public sector in this city; c) physical availability of condoms in different evaluated locations. In order to purchase an annual supply of condoms an individual needs the assign $500 (Pesos) which represents 2.3 to 2.6% of the annual GNP per capita for 1998 and 1997 respectively. The physical availability of condoms, on behalf of the Secretaría de Salud, Mexico City, was 94.9% in health centers. In drugstores, hotels and motels, self-service shops, bars and nightclubs the availability of condoms was 100%, 82.9%, 75% and 1.2%, respectively. It has been documented that the adequate use of condom is an

  17. Urban air pollution, study of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, M [PUE-UNAM (Mexico); Guzman, F [Inst. Mexicano del Petroleo (Mexico); Navarro, B [Univ. Autonoma Metropolitana (Mexico)

    1996-12-01

    The Metropolitan Area of Mexico City (MAMC) is an outstanding case of a fast urban development with lagging, and thus insufficient, massive transportation facilities. This has given rise to a distorted transportation system that accounts for most of the air pollution problem of the city and constitutes a drag on economic development. In this paper, we first describe the MAMC geographical conditions, its growth in physical and economic terms, its transportation system, the ensuring air pollution problems together with some of the mitigation actions undertaken. Afterwards the results of a survey of the displacements of individuals within the city and the time spent on these are presented, to then draw some considerations on the negative economic impact it represents. (EG)

  18. Epidemiology of major depression in four cities in Mexico.

    Science.gov (United States)

    Slone, Laurie B; Norris, Fran H; Murphy, Arthur D; Baker, Charlene K; Perilla, Julia L; Diaz, Dayna; Rodriguez, Francisco Gutiérrez; Gutiérrez Rodriguez, José de Jesús

    2006-01-01

    Analyses were conducted to estimate lifetime and current prevalence of major depressive disorder (MDD) for four representative cities of Mexico, to identify variables that influence the probability of MDD, and to further describe depression in Mexican culture. A multistage probability sampling design was used to draw a sample of 2,509 adults in four different regions of Mexico. MDD was assessed according to DSM-IV criteria by using the Composite International Diagnostic Interview collected by trained lay interviewers. The prevalence of MDD in these four cities averaged 12.8% for lifetime and 6.1% for the previous 12 months. MDD was highly comorbid with other mental disorders. Women were more likely to have lifetime MDD than were men. Being divorced, separated, or widowed (compared to married or never married) and having experienced childhood trauma were related to higher lifetime prevalence but not to current prevalence. In addition, age and education level were related to current 12-month MDD. Data on the profile of MDD in urban Mexico are provided. This research expands our understanding of MDD across cultures.

  19. Qualitative evidence on abortion stigma from Mexico City and five states in Mexico.

    Science.gov (United States)

    Sorhaindo, Annik M; Juárez-Ramírez, Clara; Díaz Olavarrieta, Claudia; Aldaz, Evelyn; Mejía Piñeros, María Consuelo; Garcia, Sandra

    2014-01-01

    Social manifestations of abortion stigma depend upon cultural, legal, and religious context. Abortion stigma in Mexico is under-researched. This study explored the sources, experiences, and consequences of stigma from the perspectives of women who had had an abortion, male partners, and members of the general population in different regional and legal contexts. We explored abortion stigma in Mexico City where abortion is legal in the first trimester and five states-Chihuahua, Chiapas, Jalisco, Oaxaca, and Yucatán-where abortion remains restricted. In each state, we conducted three focus groups-men ages 24-40 years (n = 36), women 25-40 years (n = 37), and young women ages 18-24 years (n = 27)-and four in-depth face-to-face interviews in total; two with women (n = 12) and two with the male partners of women who had had an abortion (n = 12). For 4 of the 12 women, this was their second abortion. This exploratory study suggests that abortion stigma was influenced by norms that placed a high value on motherhood and a conservative Catholic discourse. Some participants in this study described abortion as an "indelible mark" on a woman's identity and "divine punishment" as a consequence. Perspectives encountered in Mexico City often differed from the conservative postures in the states.

  20. An analysis of a low-energy, low-water use community in Mexico City

    Science.gov (United States)

    Bermudez Alcocer, Jose Luis

    This study investigated how to determine a potential scenario to reduce energy, water and transportation use in Mexico City by implementing low-energy, low-water use communities. The proposed mixed-use community has multi-family apartments and a small grocery store. The research included the analysis of: case studies, energy simulation, and hand calculations for water, transportation and cost analysis. The previous case studies reviewed include: communities in Mexico City, Mexico, Austin, Texas, Phoenix, Arizona, New York City, New York and San Diego, California in terms of successful low-energy, low-water use projects. The analysis and comparison of these centers showed that the Multifamiliar Miguel Aleman is an excellent candidate to be examined for Mexico City. This technical potential study evaluated energy conserving measures such as low-energy appliances and efficient lighting that could be applied to the apartments in Mexico City to reduce energy-use. The use of the simulations and manual calculations showed that the application of the mixed-use concept was successful in reducing the energy and water use and the corresponding carbon footprint. Finally, this technical potential study showed taking people out of their cars as a result of the presence of the on-site grocery store, small recreation center and park on the ground floor also reduced their overall transportation energy-use. The improvement of the whole community (i.e., apartments plus grocery store) using energy-efficient measures provided a reduction of 70 percent of energy from the base-case. In addition a 69 percent reduction in water-use was achieved by using water-saving fixtures and greywater reuse technologies for the complex. The combination of high-efficiency automobiles and the presence of the on-site grocery store, small recreation center and park potentially reduced the transportation energy-use by 65 percent. The analysis showed an energy cost reduction of 82 percent reduction for

  1. Seismic Hazard Management in Mexico City

    Science.gov (United States)

    Wintergerst, L.

    2007-05-01

    Mexico City is one of the largest cities in the world. More than 8.5 million residents and 4.5 million floating population are in the city itself, but with the surrounding suburbs the number of people that could be affected by natural and man-made hazards rises to approximately 20 million. The main risk to the city as a whole is a large magnitude earthquake. Since there is reason to prepare for a credible seismic scenario of Mw = 8.2, which would exceed the damages caused during the 1985 earthquake (Mw = 8.1), we founded the Metropolitan Geologic Service (MGS) in 1998. The MGS has developed geologic and seismic hazard maps for the city (http:www.proteccioncivil.df.gob.mx). The maps include three separate risk maps for low height (3 stories), medium height (10 stories) and tall buildings (10 stories). The maps were prepared by using the maximum horizontal accelerations documented during the 1985 earthquake, and wave propagation modeling for buildings of different resonant periods (T = 0.0, 1.0 and 2.0 sec). In all cases, the risk zones were adjusted to include documented damage during the 1957, 1979 and 1985 earthquakes. All three maps show a high risk zone in the north-central portion of the city, elongated in a N-S direction, which corresponds with a narrow graben where the thickness of alluvial sediments is particularly large, and where wave amplification is accentuated. Preparation of these maps, and others used for planning, has been facilitated by the ongoing elaboration of a Dynamic Geographical Information System, which is based on geo-scientific information, includes all types of risks, and incorporates vulnerability models. From the risk management standpoint, we have elaborated the Permanent Contingency Plan for Mexico City, which in its Earthquakes chapter includes plans for coordination and for organizing attention to the population in the event of a seismic disaster. This Permanent Plan follows the philosophy of Descartes' Method, has 11 processes (6

  2. Evaluation of atopy in patients with COPD

    Directory of Open Access Journals (Sweden)

    Margarida Celia Lima Costa Neves

    2013-06-01

    Full Text Available OBJECTIVE: To determine the prevalence of atopy and to evaluate clinical, laboratory, and radiological profiles in patients with COPD. METHODS: This was a cross-sectional study involving outpatients with stable COPD (defined by the clinical history and a post-bronchodilator FEV1/FVC < 70% of the predicted value. The patients completed a questionnaire regarding clinical characteristics and atopy, after which they underwent nasal lavage cytology, skin prick testing, chest X-rays, arterial blood gas analyses, and determination of total serum IgE. RESULTS: Of the 149 subjects studied, 53 (35.6%, 49 (32.8%, and 88 (59.1% presented with nasal eosinophilia, a positive skin prick test result, and symptoms of allergic rhinitis, respectively. Correspondence analysis confirmed these findings, showing two distinct patterns of disease expression: atopy in patients with COPD that was less severe; and no evidence of atopy in those with COPD that was more severe (reduced FEV1 and hyperinflation. There was a statistically significant association between nasal eosinophilia and a positive bronchodilator response. CONCLUSIONS: Using simple and reproducible methods, we were able to show that there is a high frequency of atopy in patients with COPD. Monitoring inflammation in the upper airways can be a useful tool for evaluating respiratory diseases in the elderly and in those with concomitant asthma and COPD, a clinical entity not yet fully understood.

  3. [Scientific evidence on the legalization of abortion in Mexico City].

    Science.gov (United States)

    Gayón-Vera, Eduardo

    2010-03-01

    On April 24 2007, abortion before 12 weeks became legal in Mexico City. The arguments for this decision were: diminish the maternal morbidity and mortality, avoid a "severe health problem" and accomplish the women's physical, mental and social well being. To analyze the scientific evidences that support or reject this arguments. Retrospective study realized by bibliographic search of electronic data basis and Internet portals of interested groups. Mexico is considered by the World Health Organization, one of the countries in the world with low maternal mortality rates (abortion". In the hospitals of the Mexican Institute of Social Security, maternal deaths as consequence of induced abortions were, approximately, three every year. The evidences used as arguments in favor of abortion come from studies performed in Sub-Saharan African countries, which do not apply to Mexico. The scientific evidences show that induced abortion has important psychological sequels in women, a higher frequency of illegal drug abuse, alcoholism, child abuse, low birth weight in the following pregnancy, greater risk of subsequent miscarriage and greater mortality rate. There are no scientific evidences to support the arguments used for the legal approval of abortion in Mexico City.

  4. Energy and the environment: the case of the Metropolitan area of Mexico City

    International Nuclear Information System (INIS)

    Bazan N, G.

    1992-01-01

    The inefficient use of energy by the different types of consumers of the Metropolitan area of Mexico City (ZMCM, this means, Mexico city and the municipalities of the Estado de Mexico, which constitute a single economic population unit), is one of the main causes for the production of polluting emissions into the atmosphere, specially of nitrogen oxide, sulfur dioxide and carbon monoxide. This originates a deterioration of the environment, which injures the health of the population. As a consequence, the private and public sectors have been forced to establish programs in order to improve the use of energy, as well as to preserve the environment. (Author)

  5. Taking Control of Air Pollution in Mexico City

    International Development Research Centre (IDRC) Digital Library (Canada)

    Nancy Minogue

    la Mujer del Distrito Federal (Women's Institute of Mexico City). The researchers ... nator of workplace health, who led the project's first module. Tangible ... mountains, they say it's a good day. If they can't, they ... Empowering women to foster social and politi- ... added to attract and motivate better consumption practices and.

  6. Spatial Analysis of the Level of Exposure to Seismic Hazards of Health Facilities in Mexico City, Mexico

    Science.gov (United States)

    Moran, S.; Novelo-Casanova, D. A.

    2011-12-01

    Although health facilities are essential infrastructure during disasters and emergencies, they are also usually highly vulnerable installations in the case of the occurrence of large and major earthquakes. Hospitals are one of the most complex critical facilities in modern cities and they are used as first response in emergency situations. The operability of a hospital must be maintained after the occurrence of a local strong earthquake in order to satisfy the need for medical care of the affected population. If a health facility is seriously damaged, it cannot fulfill its function when most is needed. In this case, hospitals become a casualty of the disaster. To identify the level of physical exposure of hospitals to seismic hazards in Mexico City, we analyzed their geographic location with respect to the seismic response of the different type of soils of the city from past earthquakes, mainly from the events that occurred on September 1985 (Ms= 8.0) and April 1989 (Ms= 6.9). Seismic wave amplification in this city is the result of the interaction of the incoming seismic waves with the soft and water saturated clay soils, on which a large part of Mexico City is built. The clay soils are remnants of the lake that existed in the Valley of Mexico and which has been drained gradually to accommodate the growing urban sprawl. Hospital facilities were converted from a simple database of names and locations into a map layer of resources. This resource layer was combined with other map layers showing areas of seismic microzonation in Mexico City. This overlay was then used to identify those hospitals that may be threatened by the occurrence of a large or major seismic event. We analyzed the public and private hospitals considered as main health facilities. Our results indicate that more than 50% of the hospitals are highly exposed to seismic hazards. Besides, in most of these health facilities we identified the lack of preventive measures and preparedness to reduce their

  7. Mexico City air quality: Progress of an international collaborative project to define air quality management options

    International Nuclear Information System (INIS)

    Streit, G.E.

    1992-01-01

    Mexico City, faces a severe air pollution problem due to a combination of circumstances. The city is in a high mountain basin at a subtropical latitude. The basin setting inhibits dispersion of pollution and contributes to frequent wintertime thermal inversions which further trap pollutants near the surface. The elevation and latitude combine to provide plentiful sunshine which, in comparison to more northern latitudes, is enhanced in the UV radiation which drives atmospheric photochemistry to produce secondary pollutants such as ozone. The Area Metropolitana de la Ciudad de Mexico AMCW is defined to include the 16 delegations of the Federal District (D.F.) and 17 highly urbanized municipalities in the State of Mexico which border the D.F. The 1990 census (XI Censo General de Poblacion y Vivienda de 1990) records that slightly over 15 million people live in the AMCM. There are numerous other nearby communities which are in the airshed region of Mexico City, but which are not included in the definition and population of the AMCM. The Mexico City Air Quality Research Initiative is one project that is examining the complex relationship between air pollution, economic growth, societal values, and air quality management policies. The project utilizes a systems approach including computer modeling, comprehensive measurement studies of Mexico City's air pollutants, environmental chemical reaction studies and socioeconomic analysis. Los Alamos National Laboratory (USA) and the Mexican Petroleum Institute are the designated lead institutions

  8. Aerosol Light Absorption and Scattering in Mexico City: Comparison With Las Vegas, NV, and Los Angeles, CA.

    Science.gov (United States)

    Paredes-Miranda, G.; Arnott, W. P.; Gaffney, J. S.; Marley, N. A.; Campbell, D.; Fujita, E.

    2007-12-01

    Aerosol light scattering and absorption measurements were deployed in and near Mexico City in March 2006 as part of the Megacity Impacts on Regional and Global Environments (MIRAGE). The primary site in Mexico City was an urban site at Instituto Mexicano del Petroleo (Mexican Oil Institute, denoted by IMP). Similar campaigns were held in Las Vegas, NV in January-February, 2003; and Los Angeles, CA at numerous sites during all seasons from 2003 through 2007. The IMP site gave in-situ characterization of the Mexico City plume under favorable wind conditions. The photoacoustic instrument (PAS) used at IMP operates at 532 nm, and conveniently allowed for characterization of gaseous absorption at this wavelength as well. Light scattering measurements are accomplished within the PAS by the reciprocal nephelometery method. In Mexico City the aerosol absorption coefficient typically varies between 20 and 180 Mm-1 during the course of the day and significant diurnal variation of the aerosol single scattering albedo was observed probably as a consequence of secondary aerosol formation. We will present the diurnal variation of the scattering and absorption as well as the single scattering albedo and fraction of absorption due to gases at the IMP site and compare with Las Vegas diurnal variation. Mexico City 'breaths' more during the course of the day than Las Vegas, Nevada in part because the latitude of Mexico City resulted in more direct solar radiation. Further insight on the meteorological connections and population dynamics will be discussed.

  9. Connecting Urbanization to Precipitation: the case of Mexico City

    Science.gov (United States)

    Georgescu, Matei

    2017-04-01

    Considerable evidence exists illustrating the influence of urban environments on precipitation. We revisit this theme of significant interest to a broad spectrum of disciplines ranging from urban planning to engineering to urban numerical modeling and climate, by detailing the simulated effect of Mexico City's built environment on regional precipitation. Utilizing the Weather Research and Forecasting (WRF) system to determine spatiotemporal changes in near-surface air temperature, precipitation, and boundary layer conditions induced by the modern-day urban landscape relative to presettlement conditions, I mechanistically link the built environment-induced increase in air temperature to simulated increases in rainfall during the evening hours. This simulated increase in precipitation is in agreement with historical observations documenting observed rainfall increase. These results have important implications for understanding the meteorological conditions leading to the widespread and recurrent urban flooding that continues to plague the Mexico City Metropolitan Area.

  10. [Migration expectations among nursing students in Mexico City].

    Science.gov (United States)

    Rosales-Martínez, Yetzi; Nigenda, Gustavo; Galárraga, Omar; Ruiz-Larios, José Arturo

    2010-01-01

    To analyze the factors associated with the expectations to migrate abroad among nursing students in Mexico City. A cross-sectional study was conducted with a non-random sample of 420 students. A logistic regression model was estimated. A total of 69% of the informants expressed their intention to move abroad, to look for employment (65%) and/or to continue their studies (26%). Of those, 50% would choose Canada as their destination, followed by Spain and the United States. The variables associated with migration expectations were: age, income, having relatives abroad, and perception of poor labor conditions and low wages in Mexico. Results are consistent with international literature. Low wages, poor labor conditions and the limited possibilities for professional development in Mexico are factors that contribute to generate migration expectations among nursing students. Additionally, optimistic perceptions about the job market and the labor demand in more developed countries heighten expectations to migrate.

  11. Our experience with atopy patch tests with aeroallergens.

    Science.gov (United States)

    Celakovská, Jarmila; Ettlerová, Kvetuse; Ettler, Karel; Vanecková, Jaroslava

    2013-01-01

    Aim of our study was to evaluate the importance of atopy patch testing with aeroallergens as a diagnostic method in patients suffering from atopic dermatitis. The complet dermatological and allergological examinations were performed in 29 patients; 10 men, 19 women with the average age of 27.8 years, min. 17, max. 57 years; with the median SCORAD 24.2 points, s.d. 13.3 points. Wormwood, grass, dog dander, cat dander, dermatophagoides pharinae, dermatophagoides pteronyssinus and birch pollen were examined in diagnostic procedures. Skin prick tests, specific IgE were examined; the atopy patch tests were performed with aeroallergens for skin prick tests in concentration 1 x skin prick tests. Specific IgE and skin prick tests to one or more tested aeroallergens were positive altogether in 27 patients; atopy patch tests were positive only in one of these patients. For atopy patch testing with aeroallergens the concentration of 1 x skin prick tests is low to confirme the eczematic reaction in patients suffering from allergy to inhallant allergens.

  12. The association between atopy and factors influencing folate metabolism: is low folate status causally related to the development of atopy?

    DEFF Research Database (Denmark)

    Husemoen, LL; Toft, U.; Fenger, Mogens

    2006-01-01

    BACKGROUND: Deficiency of folate has been associated with several disorders characterized by enhanced activation of the cellular immune system (non-allergic th1 type immune response). Whether folate status is also associated with atopic disease (allergic th2 type immune response) is unknown. We....../CT individuals [odds ratio 1.76, 95% confidence interval (95% CI) 1.19-2.60]. Additionally, gene-diet interaction effects were identified. Dietary markers were negatively associated with risk of atopy in persons with the TT genotype. Total homocysteine was not related to atopy (odds ratio per 5 mumol/l = 1.......12, 95% CI 0.98-1.29). CONCLUSIONS: The results suggest that an impaired folate metabolism may be causally related to the development of atopy....

  13. Mexico City aerosol study

    International Nuclear Information System (INIS)

    Falcon, Y.I.; Ramirez, C.R.

    1987-01-01

    A major task in the field of air pollution monitoring is the development of devices for determining the mass and composition of airborne particulate matter as a function of size - and time. The sample collection device must be designed giving consideration to the nature of the aerosol and to the effects of the aerosol on human health. It has been established that particles smaller than 3.5 μm in diameter can penetrate deeply into the human respiratory system, and that larger particles are trapped in the upper respiratory passages. For these reasons, it is desirable to use a dichotomous sampler to collect particles in two size ranges, rather than to collect total particulates on a single filter. The authors discuss a study in Mexico City using a dichotomous sampler

  14. The influence of aerosols on photochemical smog in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Castro, T.; Mar, B. [UNAM, Mexico, Centro de Ciencias de la Atmosfera (Mexico); Madronich, S.; Rivale, S. [National Center for Atmospheric Research, Boulder, CO (United States); Muhlia, A. [UNAM, Mexico, Inst. de Geofysica (Mexico)

    2001-04-01

    Aerosols in the Mexico City atmosphere can have a non-negligible effect on the ultraviolet radiation field and hence on the formation of photochemical smog. We used estimates of aerosol optical depths from sun photometer observations in a detailed radiative transfer model, to calculate photolysis rate coefficients (J{sub NO2}) for the key reaction NO{sub 2}+h{nu}{yields}NO+O ({lambda}<430nm). The calculated values are in good agreement with previously published measurements of J{sub NO2} at two sites in Mexico City: Palacio de Mineria (19 degrees 25'59''N, 99 degrees 07'58''W, 2233masl), and IMP (19 degrees 28'48''N, 99 degrees 11'07''W, 2277masl) and in Tres Marias, a town near Mexico City (19 degrees 03'N, 99 degrees 14'W, 2810masl). In particular, the model reproduces very well the contrast between the two urban sites and the evidently much cleaner Tres Marias site. For the measurement days, reductions in surface J{sub NO2} by 10-30% could be attributed to the presence of aerosols, with considerable uncertainty due largely to lack of detailed data on aerosol optical properties at ultraviolet wavelengths (esp. the single scattering albedo). The potential impact of such large reductions in photolysis rates on surface ozone concentrations is illustrated with a simple zero-dimensional photochemical model. (Author)

  15. Toxocara seropositivity, atopy and wheezing in children living in poor neighbourhoods in urban Latin American.

    Directory of Open Access Journals (Sweden)

    Lívia Ribeiro Mendonça

    Full Text Available Toxocara canis and T. cati are parasites of dogs and cats, respectively, that infect humans and cause human toxocariasis. Infection may cause asthma-like symptoms but is often asymptomatic and is associated with a marked eosinophilia. Previous epidemiological studies indicate that T. canis infection may be associated with the development of atopy and asthma.To investigate possible associations between Toxocara spp. seropositivity and atopy and childhood wheezing in a population of children living in non-affluent areas of a large Latin American city.The study was conducted in the city of Salvador, Brazil. Data on wheezing symptoms were collected by questionnaire, and atopy was measured by the presence of aeroallergen-specific IgE (sIgE. Skin prick test (SPT, total IgE and peripheral eosinophilia were measured. Toxocara seropositivity was determined by the presence of anti-Toxocara IgG antibodies, and intestinal helminth infections were determined by stool microscopy.Children aged 4 to 11 years were studied, of whom 47% were seropositive for anti-Toxocara IgG; eosinophilia >4% occurred in 74.2% and >10% in 25.4%; 59.6% had elevated levels of total IgE; 36.8% had sIgE≥0.70 kU/L and 30.4% had SPT for at least one aeroallergen; 22.4% had current wheezing symptoms. Anti-Toxocara IgG was positively associated with elevated eosinophils counts, total IgE and the presence of specific IgE to aeroallergens but was inversely associated with skin prick test reactivity.The prevalence of Toxocara seropositivity was high in the studied population of children living in conditions of poverty in urban Brazil. Toxocara infection, although associated with total IgE, sIgE and eosinophilia, may prevent the development of skin hypersensitivity to aeroallergens, possibly through increased polyclonal IgE and the induction of a modified Th2 immune reaction.

  16. New information on regional subsidence and soil fracturing in Mexico City Valley

    Directory of Open Access Journals (Sweden)

    G. Auvinet

    2015-11-01

    Full Text Available In this paper, updated information about regional subsidence in Mexico City downtown area is presented. Data obtained by R. Gayol in 1891, are compared with information obtained recently from surveys using the reference points of Sistema de Aguas de la Ciudad de México (2008 and on the elevation of a cloud of points on the ground surface determined using Light Detection and Ranging (LiDAR technology. In addition, this paper provides an overview of recent data obtained from systematic studies focused on understanding soil fracturing associated with regional land subsidence and mapping of areas susceptible to cracking in Mexico City Valley.

  17. Family Structure and Female Labour Supply in Mexico City

    NARCIS (Netherlands)

    Gong, X.; van Soest, A.H.O.

    1997-01-01

    This paper investigates labour supply of the wives of the heads of households in Mexico City, with a focus on the impact of family structure. A static neoclassical structural model is used. We assume that each woman chooses her labour supply and corresponding income so that her utility is maximized,

  18. Taking control of air pollution in Mexico city | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Earlier efforts to assess the costs of pollution in Mexico City had focused on ... a range of health benefits and “savings,” including people's willingness to pay for ... $15 billion of public and private investments in air quality improvement projects.

  19. Evaluation of atopy through an expert system: description of the database.

    Science.gov (United States)

    Ray, P; Vervloet, D; Charpin, D; Gautier, V; Proudhon, H; Redier, H; Godard, P

    1995-11-01

    In order to understand the medical decisions taken during the initial visit of a new asthmatic patient, a group of experts designed an expert system which provides conclusions about severity, precipitating factors and treatment. Rules for atopy and the assessment of allergic factors have been discussed and implemented in the expert system. Conclusions about severity have been yet validated using an appropriate methodology. The aim of this study was to investigate a sample of 471 patients according to conclusions regarding atopy. A total of 471 cases report forms (CRF) was filled in for adult asthmatic outpatients, seen for the first time in our clinic without emergency situations. Data of each CRF were used by the expert system to draw conclusions. The expert system discerns three patterns for atopy, yes, possible or no. The variables known to reflect different features according to the classification of asthma as atopic or not have been studied. The variables used in the rules for atopy, obviously linked to the conclusion, were not compared. For many medical problems no unique objective solution exists and this is why a group of patients with possible atopy was introduced. Patients with atopy had less severe asthma (P = 0.01), a better FEV1 value (P = 0.0007) and showed their first symptoms of asthma earlier (P = 0.00001) than patients without atopy. The characteristics of the group studied here are consistent with the literature. This could be considered as an indirect validation of the expert system. Moreover, patients with possible atopy show intermediate findings for these variables and it is possible to suggest a 'dose-effect' relationship.

  20. Etiological relationships in atopy

    DEFF Research Database (Denmark)

    Thomsen, Simon Francis; Kyvik, Kirsten Ohm; Backer, Vibeke

    2008-01-01

    The genetics of asthma and atopy has been studied frequently in twin populations from various parts of the world. However, emphasis has been put on univariate analysis of questionnaire data, whereas clinical and intermediate traits only sporadically have been studied, especially in multivariate s...

  1. [Beliefs about chili pepper consumption and health in Mexico City].

    Science.gov (United States)

    López-Carrillo, L; Fernández-Ortega M, C; Costa-Dias, R; Franco-Marina, J; Alejandre-Badillo, T

    1995-01-01

    Eating chili peppers is a cultural tradition in Mexico. Controversial characteristics have been empirically associated to chili pepper consumption and human health. In this paper, the beliefs about the health impacts of chili pepper consumption in two independent groups of Mexico City residents are described. The results confirm, on the one hand, that there is a wide variety of health benefits and damages associated with chili pepper consumption, but on the other hand, that the levels of chili pepper consumption are not related to beliefs about its human health impact.

  2. {sup 14}C content in aerosols in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Gómez, V.; Solís, C.; Chávez, E.; Andrade, E.; Ortiz, M.E.; Huerta, A.; Aragón, J.; Rodríguez-Ceja, M. [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, México, D.F. 01000 (Mexico); Martínez, M.A. [Facultad de Ciencias, Universidad Nacional Autónoma de México (Mexico); Ortiz, E. [Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, C. P. 02200 México, D.F. (Mexico)

    2016-03-15

    {sup 14}C-AMS of total carbon was determined in aerosols (PM{sub 10} fraction), collected in Mexico City during two weeks from 21 November to 3 December 2012. Other tracers such as total carbon (TC), organic carbon (OC), elemental carbon (EC) and trace element contents were also determined. F{sup 14}C values varied from 0.39 to 0.48 with an average of 0.43. These values are slightly lower than those previously obtained for PM{sub 2.5} in 2003 and 2006 and reflect a high contribution of fossil CO{sub 2} to the carbonaceous matter in aerosols from Mexico City. In contrast, from 2006 to 2012 PM{sub 10} increased; EC, Ca, Ti and Fe concentrations remained constant, while OC, TC and K concentrations decreased. The use of potassium as an indicator of biomass burning showed that this source was negligible during this campaign. Combined analytical approaches allowed us to distinguish temporal variations of anthropogenic and natural inputs to the F{sup 14}C.

  3. Simulated Climate Impacts of Mexico City's Historical Urban Expansion

    Science.gov (United States)

    Benson-Lira, Valeria

    Urbanization, a direct consequence of land use and land cover change, is responsible for significant modification of local to regional scale climates. It is projected that the greatest urban growth of this century will occur in urban areas in the developing world. In addition, there is a significant research gap in emerging nations concerning this topic. Thus, this research focuses on the assessment of climate impacts related to urbanization on the largest metropolitan area in Latin America: Mexico City. Numerical simulations using a state-of-the-science regional climate model are utilized to address a trio of scientifically relevant questions with wide global applicability. The importance of an accurate representation of land use and land cover is first demonstrated through comparison of numerical simulations against observations. Second, the simulated effect of anthropogenic heating is quantified. Lastly, numerical simulations are performed using pre-historic scenarios of land use and land cover to examine and quantify the impact of Mexico City's urban expansion and changes in surface water features on its regional climate.

  4. Co-control of urban air pollutants and greenhouse gases in Mexico City.

    Science.gov (United States)

    West, J Jason; Osnaya, Patricia; Laguna, Israel; Martínez, Julia; Fernández, Adrián

    2004-07-01

    This study addresses the synergies of mitigation measures to control urban air pollutant and greenhouse gas (GHG) emissions, in developing integrated "co-control" strategies for Mexico City. First, existing studies of emissions reduction measures--PROAIRE (the air quality plan for Mexico City) and separate GHG studies--are used to construct a harmonized database of options. Second, linear programming (LP) is developed and applied as a decision-support tool to analyze least-cost strategies for meeting co-control targets for multiple pollutants. We estimate that implementing PROAIRE measures as planned will reduce 3.1% of the 2010 metropolitan CO2 emissions, in addition to substantial local air pollutant reductions. Applying the LP, PROAIRE emissions reductions can be met at a 20% lower cost, using only the PROAIRE measures, by adjusting investments toward the more cost-effective measures; lower net costs are possible by including cost-saving GHG mitigation measures, but with increased investment. When CO2 emission reduction targets are added to PROAIRE targets, the most cost-effective solutions use PROAIRE measures for the majority of local pollutant reductions, and GHG measures for additional CO2 control. Because of synergies, the integrated planning of urban-global co-control can be beneficial, but we estimate that for Mexico City these benefits are often small.

  5. Porcine circovirus type 2 antibody detection in backyard pigs from Mexico City.

    Science.gov (United States)

    Ramírez-Mendoza, H; Martínez, C; Mercado, C; Castillo-Juárez, H; Hernández, J; Segalés, J

    2007-08-01

    PCV2 antibodies have been found in pigs from all continents. However, this finding has been mainly studied in domestic swine reared under intensive production conditions. Mexico City, with a human population over 19 million in 2005, has both urban and rural areas. The pig production in its rural area is based on small family backyard farms. Taking into account this rather unique form of rearing pigs, the objective of this study was to determine the seroprevalence in backyard pigs from the rural area of Mexico City. A total of 695 backyard pig serum samples from 108 small family farms belonging to seven municipal areas were studied by immunoperoxidase monolayer assay technique. One hundred six out of the 108 family farms (98.14%) had at least one positive serum sample. On the other hand, 136 (19.57%), 264 (37.99%) and 248 (34.82%) pigs had low, intermediate and high titres to PCV2, respectively. Only 53 samples (7.63%) were negative for PCV2 antibodies. No apparent differences in antibody titre groups were observed among backyard pigs from the different municipal areas. In conclusion, the present study, the first one performed in this kind of extensively produced pigs, indicates that PCV2 is ubiquitous in backyard pigs from Mexico City.

  6. Urban-Rural Humidity Contrasts in Mexico City

    Science.gov (United States)

    Jáuregui, E.; Tejeda, A.

    1997-02-01

    Data from one pair of urban-suburban (Tacubaya and Airport) andone pair of urban-rural (School of Mines and Plan Texcoco) temperature and humidity measuring stations were used to illustrate specific humidity(q) contrasts in Mexico City. Results show a marked seasonal variation of q from around 7.9 g kg-1 during the dry months to 10 g kg-1 in the wet season (May-October) on both urban and suburban sites. The mean monthly contrasts for this pair of stations, albeit small, show that the city air is somewhat drier during the first half of the year. Comparison of urban and rural q on an hourly basis shows that although urban air is more humid at night the reverse is true during the afternoon. Areal distribution of q shows two centres of maximum humidity over the city at night and a corresponding minimum during the afternoon. On average the urban-rural contrasts in q were found to be somewhat smaller than the estimated uncertainty. The above results are in agreement with mid-latitude experience.

  7. NO2 and HCHO variability in Mexico City from MAX-DOAS measurements

    Science.gov (United States)

    Grutter, M.; Friedrich, M. M.; Rivera, C. I.; Arellano, E. J.; Stremme, W.

    2015-12-01

    Atmospheric studies in large cities are of great relevance since pollution affects air quality and human health. A network of Multi Axis Differential Optical Absorption Spectrometers (MAX-DOAS) has been established in strategic sites within the Mexico City metropolitan area. Four instruments are now in operation with the aim to study the variability and spatial distribution of key pollutants, providing results of O4, NO2 and HCHO slant column densities (SCD). A numerical code has been written to retrieve gas profiles of NO2 and HCHO using radiative transfer simulations. We present the first results of the variability of these trace gases which will bring new insight in the current knowledge of transport patterns, emissions as well as frequency and origin of extraordinary events. Results of the vertical column densities (VCD) valiability of NO2 and HCHO in Mexico City are presented. These studies are useful to validate current and future satellite observatopns such as OMI, TROPOMI and TEMPO.

  8. Different Implications of Paternal and Maternal Atopy for Perinatal IgE Production and Asthma Development

    OpenAIRE

    Wu, Chih-Chiang; Chen, Rong-Fu; Kuo, Ho-Chang

    2012-01-01

    Asthma is a hereditary disease associated with IgE-mediated reaction. Whether maternal atopy and paternal atopy have different impacts on perinatal IgE production and asthma development remains unclear. This paper reviews and summarizes the effects of maternal and paternal atopy on the developmental aspects of IgE production and asthma. Maternal atopy affects both pre- and postnatal IgE production, whereas paternal atopy mainly affects the latter. Maternally transmitted genes GSTP1 and FceRI-...

  9. Factors Contributing to the Catastrophe in Mexico City During the Earthquake of September 19, 1985

    OpenAIRE

    Beck, James L.; Hall, John F.

    1986-01-01

    The extensive damage to high‐rise buildings in Mexico City during the September 19, 1985 earthquake is primarily due to the intensity of the ground shaking exceeding what was previously considered credible for the city by Mexican engineers. There were two major factors contributing to the catastrophe, resonance in the sediments of an ancient lake that once existed in the Valley of Mexico, and the long duration of shaking compared with other coastal earthquakes in the last 50 years. Both of th...

  10. NO2 DOAS measurements from ground and space: comparison of ground based measurements and OMI data in Mexico City

    Science.gov (United States)

    Rivera, C.; Stremme, W.; Grutter, M.

    2012-04-01

    The combination of satellite data and ground based measurements can provide valuable information about atmospheric chemistry and air quality. In this work we present a comparison between measured ground based NO2 differential columns at the Universidad Nacional Autónoma de México (UNAM) in Mexico City, using the Differential Optical Absorption Spectroscopy (DOAS) technique and NO2 total columns measured by the Ozone Monitoring Instrument (OMI) onboard the Aura satellite using the same measurement technique. From these data, distribution maps of average NO2 above the Mexico basin were constructed and hot spots inside the city could be identified. In addition, a clear footprint was detected from the Tula industrial area, ~50 km northwest of Mexico City, where a refinery, a power plant and other industries are located. A less defined footprint was identified in the Cuernavaca basin, South of Mexico City, and the nearby cities of Toluca and Puebla do not present strong enhancements in the NO2 total columns. With this study we expect to cross-validate space and ground measurements and provide useful information for future studies.

  11. Traumatic Events and Suicide-Related Outcomes among Mexico City Adolescents

    Science.gov (United States)

    Borges, Guilherme; Benjet, Corina; Medina-Mora, Maria Elena; Orozco, Ricardo; Molnar, Beth E.; Nock, Matthew K.

    2008-01-01

    Background: We report the prevalence and associations between traumatic events and suicidal ideation, suicide plans and suicide attempts among Mexican adolescents. Methods: The data are from a representative multistage probability household survey of 3,005 adolescents aged 12 to 17 years residing in the Mexico City Metropolitan Area that was…

  12. Inhalant drug use and street youth : Ethnographic insights from Mexico City

    NARCIS (Netherlands)

    Gigengack, Roy; Preedy, Victor

    2016-01-01

    The inhalation of volatile substances with intentions of intoxication affects the lives of marginalized youths around the globe, but remains poorly understood. Based upon long-term ethnographic enquiry, this chapter describes the inhalant use of Mexico City's young street people from their

  13. Ozone, area social conditions, and mortality in Mexico City

    International Nuclear Information System (INIS)

    O'Neill, M.S.; Loomis, Dana; Borja-Aburto, V.H.

    2004-01-01

    We investigated whether the association of daily mortality and ambient ozone differs by age and area social conditions of the region of residence using a time-series analysis. The study setting was metropolitan Mexico City, a high altitude city situated in a valley, with an estimated 20 million inhabitants, large socioeconomic gradients, and ozone levels frequently exceeding international standards. We stratified daily deaths by six census-derived socioeconomic indicators, based on characteristics of the county where decedents lived. We used Poisson regression to model the association between daily mortality and ozone levels (on the day of death and the previous day) in separate models, stratified by area socioeconomic level and age, and controlling for time trends and temperature. Ozone was positively associated with total mortality [0.65% increase per 10 ppb increment, 95% confidence interval (CI): 0.02%, 1.28%] and for mortality among those over age 65 [1.39% increase per 10 ppb increment, 95% CI: 0.51%, 2.28%]. Associations between ozone and all-age mortality did not show any consistent patterns according to socioeconomic gradients. We conclude that elderly people are at higher risk for ozone-associated mortality. Though county-level social indicators in Mexico City were not strong markers of vulnerability to ozone-associated acute mortality in this analysis, complex associations between individual and area-level factors may exist that would require additional data and further analyses to elucidate

  14. Assessing air quality index awareness and use in Mexico City.

    Science.gov (United States)

    Borbet, Timothy C; Gladson, Laura A; Cromar, Kevin R

    2018-04-23

    The Mexico City Metropolitan Area has an expansive urban population and a long history of air quality management challenges. Poor air quality has been associated with adverse pulmonary and cardiac health effects, particularly among susceptible populations with underlying disease. In addition to reducing pollution concentrations, risk communication efforts that inform behavior modification have the potential to reduce public health burdens associated with air pollution. This study investigates the utilization of Mexico's IMECA risk communication index to inform air pollution avoidance behavior among the general population living in the Mexico City Metropolitan Area. Individuals were selected via probability sampling and surveyed by phone about their air quality index knowledge, pollution concerns, and individual behaviors. The results indicated reasonably high awareness of the air quality index (53% of respondents), with greater awareness in urban areas, among older and more educated individuals, and for those who received air quality information from a healthcare provider. Additionally, behavior modification was less influenced by index reports as it was by personal perceptions of air quality, and there was no difference in behavior modification among susceptible and non-susceptible groups. Taken together, these results suggest there are opportunities to improve the public health impact of risk communication through an increased focus on susceptible populations and greater encouragement of public action in response to local air quality indices.

  15. Asthma cases in childhood attributed to atopy in tropical area in Brazil.

    Science.gov (United States)

    Souza da Cunha, Sergio; Barreto, Mauricio Lima; Fiaccone, Rosemeire Leovigildo; Cooper, Philip J; Alcantara-Neves, Neuza Maria; Simões, Silvia de Magalhães; Cruz, Alvaro Augusto; Rodrigues, Laura Cunha

    2010-12-01

    This study aimed to explore the association between asthma and atopy in a cohort of children living in a large urban center in Brazil. Atopy was defined by the presence of allergen-specific IgE in serum or by a positive skin prick test. In a sample of 1 445 Brazilian children, the association between the prevalence of asthma, skin prick test positivity, and allergen-specific IgE in serum was investigated. The prevalence of asthma was 22.6%. The presence of serum allergen-specific IgE was frequent in asthmatics and nonasthmatics, and the prevalence of asthma increased only with levels of allergen-specific IgE > 3.5 kilounits/L. The proportion of asthma attributable to atopy was estimated to be 24.5% when atopy was defined by the presence of allergen-specific IgE. With a given level of specific IgE, no association between skin test reactivity and asthma was observed. Skin prick tests were less sensitive than specific IgE for detection of atopy. Most asthma cases in an urban underprivileged setting in Brazil were not attributable to atopy. This observation has important implications for understanding the risk factors for the asthma epidemic in Latin America.

  16. [Exposure to fluorides from drinking water in the city of Aguascalientes, Mexico].

    Science.gov (United States)

    Trejo-Vázquez, R; Bonilla-Petriciolet, A

    2001-08-01

    Determine the fluoride content in all the wells that supply drinking water to the city of Aguascalientes, Mexico, in order to establish the population's degree of exposure. The fluoride content of the 126 wells that supply drinking water to the city of Aguascalientes was determined, using the SPADNS method, in accordance with two Mexican regulations, NMX-AA-77-1982 and NMX-014-SSAI-1993. Using that data, we created fluoride isopleth maps showing the distribution of fluoride concentrations in the water supplies for the city of Aguascalientes. We also estimated exposure doses for the city's inhabitants. The mean analysis uncertainty was 3.9%. Seventy-three wells had a fluoride concentration of" 1.5 mg/L, which was the maximum permissible value set by the Mexican standards then in effect. All the maximum exposure doses surpassed the minimum risk level set by Agency for Toxic Substances and Disease Registry (ATSDR) of the Department of Health and Human Services of the United States of America. In the children under 1 year of age, even the minimum does was slightly higher than the ATSDR risk level. From estimating the fluoride exposure doses caused by water consumption in the city of Aguascalientes and comparing those doses with ones from other states in Mexico, we concluded that the fluoride intake in Aguascalientes represents a potential risk for inhabitants' health. The fluoride content of the city's drinking water should be reduced to 0.69 mg/L.

  17. Emerging patterns of crack use in Mexico City.

    Science.gov (United States)

    Valdez, Avelardo; Kaplan, Charles; Nowotny, Kathryn M; Natera-Rey, Guillermina; Cepeda, Alice

    2015-08-01

    Recent studies in Mexico have documented a significant increase in crack cocaine use, indicating the potential for an emerging drug epidemic. Ethnographic observations and interviews were used describe the profiles and patterns of use among street-recruited crack users in Mexico City. The data came from an international research collaboration funded by the National Institutes of Health. A polythetic typology was developed based on five dimensions central to categorizing patterns of crack use behavior: frequency of use, duration of use, context, social networks, and social contracts. Four types of users were discovered applying these dimensions: dabblers, stable users, crack heads, and old heads. Although several similarities were documented between patterns of crack use in Mexico and those in the United States and Western Europe, several key aspects distinguished crack users in this population: (1) self-regulated use; (2) non-linear progression of crack; and (3) the influence of the dimensions pertaining to setting, social networks, and social contract as contributing to understanding of the previous two. Further, we provide a discussion of how specific contextual factors in Mexico may be giving rise to these emerging patterns. Compared to the U.S. and Europe, this study finds that the majority of crack users were able to self-regulate their use without major disruption to daily social functioning. As crack use spreads in Mexico and other Latin American countries, we need to recognize the importance of social context in developing more tailored health and social responses that are specific to these developing countries. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. DURATION OF RESIDENCE IN A US CITY WITH AIR POLLUTION DOMINATED BY MOBILE SOURCES IS ASSOCIATED WITH ATOPY IN CHILDREN AGES 9-11 YEARS

    Science.gov (United States)

    The El Paso Children's Health Study examined ambient exposures to motor vehicle emissions and their effect on the prevalence of allergy and asthma among children living in a major United States-Mexico border city.

  19. Frequency of atopy in the Arctic in 1987 and 1998

    DEFF Research Database (Denmark)

    Krause, Tyra; Koch, Anders; Friborg, Jeppe

    2002-01-01

    atopy as a positive result in an assay that tests for specific IgE against the eight most common inhalant allergens in one pool (grass, birch, mugwort, dog, cat, horse, Cladosporum herbarum, house dust mite). The frequency of atopy doubled between 1987 (39 [10%] of 392) and 1998 (87 [19%] of 467; risk...

  20. Bacteriological quality of crops irrigated with wastewater in the Xochimilco plots, Mexico City, Mexico.

    Science.gov (United States)

    Rosas, I; Báez, A; Coutiño, M

    1984-05-01

    Xochimilco county plots (Mexico City), one of the most fertile agricultural areas in the Valley of Mexico, produce a large portion of the fresh vegetables consumed in the city. These plots are generally irrigated with domestic wastewater, and for this reason, it was deemed important to examine and evaluate the bacteriological quality of the water, soil, and vegetables from these plots that are harvested and marketed. The soils were also examined for the classical parameters such as nitrates, ammonia, etc., and organic matter and texture. The crops selected for this study were radishes, spinach, lettuce, parsley, and celery because they are usually consumed raw. The highest bacterial counts were encountered in leafy vegetables, i.e., spinach (8,700 for total coliform and 2,400 for fecal coliform) and lettuce (37,000 for total coliform and 3,600 for fecal coliform). Statistically significant differences in bacterial counts between rinsed and unrinsed edible portions of the crops were observed even in rinsed vegetables, and high densities of fecal coliform were detected, indicating that their consumption represents a potential health hazard. The total coliform values found in irrigation water ranged from 4 X 10(4) to 29 X 10(4), and for fecal coliform the values ranged from 5 X 10(2) to 30 X 10(2).

  1. The Autumn of Death: The 1779 Demographic Crisis in Mexico City

    Directory of Open Access Journals (Sweden)

    Manuel Miño Grijalva

    2012-10-01

    Full Text Available This article is a historical approach to the 1779 smallpox epidemic and its different manifestations both in public health and in Mexico City's demography. It introduces new statistical data which reveals, beyond testimonies, the epidemic's impact and consequences, both in schoolchildren and adults throughout the city's different parishes during September-November, 1779. Further, this research reveals an association between the epidemic and a food crisis through the effects of weather and low crops in 1778 and June, 1779.

  2. Frequency of functional bowel disorders among healthy volunteers in Mexico City.

    Science.gov (United States)

    Schmulson, Max; Ortíz, Orianna; Santiago-Lomeli, Mariana; Gutiérrez-Reyes, Gabriela; Gutiérrez-Ruiz, María Concepción; Robles-Díaz, Guillermo; Morgan, Douglas

    2006-01-01

    The frequency of functional bowel disorders (FBD) in Mexico using the Rome II criteria is unknown. The Rome II Modular Questionnaire (RII-MQ) was translated into Spanish in coordination with the Rome Committee and their Latin American program. Volunteers were recruited by advertisement in Mexico City, and administered the RII-MQ. The study population consisted of 324 healthy volunteers, with a mean age of 35.7; 66% were female. The most prevalent disorders were heartburn 35%, irritable bowel syndrome (IBS) 35%, functional bloating 21%, proctalgia fugax 21%, and functional constipation 19%. Based on gender, IBS-C was 4 times more frequent in females than males (19 vs. 4.6%) and functional bloating 3 times more frequent (10 vs. 3.7%). Differences according to occupation included a higher prevalence of ulcer-like dyspepsia (p = 0.04), IBS-C (p = 0.018) and proctalgia fugax (p = 0.034) among students. This is the first study to use RII-MQ to determine the prevalence of FBD in urban Mexico. The prevalence of IBS was significant and is related to a number of factors, including the stress of living in an overpopulated city. Selection bias is likely operative. A community-based study is warranted. Copyright 2006 S. Karger AG, Basel

  3. Typhus in Mexico City during the epoch of the Mexican Revolution, 1913-1916

    Directory of Open Access Journals (Sweden)

    América Molina del Villar

    2015-01-01

    Full Text Available This article studies the impact of the 1915-1916 typhus epidemic in Mexico City, examining its origin and propagation and placing the epidemic in the context of the great social and political vulnerability that originated with the fall of Victoriano Huerta and the capture of the city by a variety of revolutionary forces. The article focuses on the demographic impact of the epidemic, connecting its repercussions with the unhealthy conditions then prevailing in the country's capital, which could largely be attributed to poverty and the interruption of many sanitary measures due to budgetary shortfalls, armed conflict and changes of government. The article draws on sources of information from the historical archives of the Health Secretariat and the Mexico City government, as well as contemporary press reports and the bulletins issued by the Superior Health Council. This article aims to contribute to the historiography of the period from the perspective of social and demographic history.

  4. Mexico City air quality research initiative. Volume 2, Problem definition, background, and summary of prior research

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    Air pollution in Mexico City has increased along with the growth of the city, the movement of its population, and the growth of employment created by industry. The main cause of pollution in the city is energy consumption. Therefore, it is necessary to take into account the city`s economic development and its prospects when considering the technological relationships between well-being and energy consumption. Air pollution in the city from dust and other particles suspended in the air is an old problem. However, pollution as we know it today began about 50 years ago with the growth of industry, transportation, and population. The level of well-being attained in Mexico City implies a high energy use that necessarily affects the valley`s natural air quality. However, the pollution has grown so fast that the City must act urgently on three fronts: first, following a comprehensive strategy, transform the economic foundation of the city with nonpolluting activities to replace the old industries, second, halt pollution growth through the development of better technologies; and third, use better fuels, emission controls, and protection of wooded areas.

  5. [Diabetes mellitus within low socioeconomic strata in Mexico City: a relevant problem].

    Science.gov (United States)

    Avila-Curiel, Abelardo; Shamah-Levy, Teresa; Galindo-Gómez, Carlos; Cuevas-Nasu, Lucia; Moreno-Macias, Hortensia; Chávez-Villasana, Adolfo

    2007-01-01

    To evaluate the feeding and nutrition conditions and its relation with diabetes mellitus (DM-2) in adult population (> 30 years) a sample belonging to the low socioeconomic stratum of the Mexico City metropolitan area was studied. They were participants in the Second Feeding and Nutrition Survey in the Mexico City metropolitan area. (ENURBAL-2002). Information collected by the ENURBAL 2002 was used in order to evaluate the relationship between some risk factors and diabetes mellitus in adult population of low economical level. Logistical regression analysis was applied. A complete set of 1279 individuals with ages over 30 years was studied. The 9.9% (IC 95% 7.9, 12.4) had been previously diagnosed as diabetics and 3.9% (IC 95% 2.9, 5.4) were not been diagnosed but their glycemia reached diabetic levels. Total diabetes prevalence observed in this study was 13.8% (IC 95% 11.7, 16.3). People with good score on its knowledge about nutrition, as well as high total fat intake, are significant and positively associated with DM-2 (RM = 2.41, IC 95% 1.09, 5.35 and RM = 2.14 IC 95% 1.24, 3.69, respectively). Diabetes mellitus was highly prevalent among adult (> 30 years population) mainly on the lower socioeconomic stratum of Mexico City. This result is important to promote changes in life style that allow to prevent its appearance by modifying the obesigenic environment and changes in the feeding patterns.

  6. Incidence of leukemias in children from El Salvador and Mexico City between 1996 and 2000: Population-based data

    Directory of Open Access Journals (Sweden)

    Bernáldez-Ríos Roberto

    2005-04-01

    Full Text Available Abstract Background There are very few studies that report the incidence of acute leukemias in children in Latin America. This work assesses the incidence of acute leukemias, between 1996 and 2000, in children from 0–14 years old who were attended at the Mexican Social Security Institute in Mexico City and in children from 0–11 years old in El Salvador. Methods Design: Population-based data. Hospitals: In San Salvador, El Salvador, Hospital Nacional de Niños "Benjamín Bloom", the only center in El Salvador which attends all children, younger than 12 years, with oncologic disease. The Pediatric Hospital and the General Hospital of the Mexican Social Security Institute in Mexico City, the only centers in Mexico City which attend all those children with acute leukemia who have a right to this service. Diagnosis: All patients were diagnosed by bone marrow smear and were divided into acute lymphoid leukemia (ALL, acute myeloid leukemia (AML, chronic myeloid leukemia (CML, and unspecified leukemias (UL. The annual incidence rate (AIR and average annual incidence rate (AAIR were calculated per million children. Cases were stratified by age and assigned to one of four age strata: 1 Results The number of cases was 375 and 238 in El Salvador and Mexico City, respectively. AAIRs in Mexico City were 44.9, 10.6, 2.5, 0.5, and 58.4 per million children for ALL, AML, CML, UL, and total leukemias, respectively. The AAIRs in El Salvador could not be calculated because the fourth age stratum in El Salvador included children only from 0–11 years old. The incidence rates for the Salvadoran group of 0–11 year olds were 34.2, 7.1, 0.6, 0.2, and 43.2 per million children for ALL, AML, CML, UL, and total leukemias, respectively. Conclusion Reported AIRs for each age group in El Salvador were similar to those from other American countries. The AAIR of ALL in Mexico City is one of the highest reported for North America.

  7. Atopy and cause-specific mortality

    DEFF Research Database (Denmark)

    Skaaby, T; Husemoen, L L N; Thuesen, Betina Heinsbæk

    2014-01-01

    BACKGROUND: Atopy is the familial or personal propensity to develop immunoglobulin E (IgE) antibodies against common environmental allergens and is associated with high risk of allergic disease. It has been proposed that atopy may have effects on risk of cardiovascular disease and cancer...... followed by linkage to the Danish Registry of Causes of Death to obtain information on mortality status and cause of death (median follow-up time 11.3 years). The relative mortality risk was estimated by Cox regression and expressed as hazard ratios, HRs (95% confidence intervals, CIs). RESULTS: A total...... of 1776 person died during follow-up. The mortality risk for atopics vs. non-atopics was: for all-cause mortality (HR = 1.03, 95% CI: 0.90, 1.17); neoplasms (HR = 0.86, 95% CI: 0.69, 1.06); endocrine, nutritional and metabolic disorders (HR = 1.48, 95% CI: 0.71, 3.08); mental and behavioural disorders (HR...

  8. Interaction of maternal atopy, CTLA-4 gene polymorphism and gender on antenatal immunoglobulin E production.

    Science.gov (United States)

    Yang, K D; Ou, C-Y; Hsu, T-Y; Chang, J-C; Chuang, H; Liu, C-A; Liang, H-M; Kuo, H-C; Chen, R-F; Huang, E-Y

    2007-05-01

    Genetic heritability and maternal atopy have been correlated to antenatal IgE production, but very few studies have studied gene-maternal atopy interaction on antenatal IgE production. This study investigated the interaction of CTLA-4 polymorphism with prenatal factors on the elevation of cord blood IgE (CBIgE). Pregnant women were antenatally recruited for collection of prenatal environmental factors by a questionnaire. Umbilical cord blood samples were collected for CBIgE detection by fluorescence-linked enzyme assay and CTLA-4 polymorphism measurement by restriction fragment length polymorphism. A total of 1104 pregnant women initially participated in this cohort study, and 898 of them completed cord blood collection. 21.4% of the newborns had elevation of CBIgE (>or=0.5 kU/L). The CTLA-4+49A allele (P=0.021), maternal atopy (Ppaternal atopy, were significantly correlated with the CBIgE elevation in multivariate analysis. A dichotomous analysis of gene-maternal atopy interactions identified maternal atopy and CTLA-4+49A allele had an additive effect on the CBIgE elevation, especially prominent in male newborns; and in the absence of maternal atopy, CTLA-4+49GG genotype had a protective effect on CBIgE elevation in female newborns. Maternal but not paternal atopy has significant impacts on CBIgE elevation depending on gender and CTLA-4+49A/G polymorphism of newborns. Control of maternal atopy and modulation of CTLA-4 expression in the prenatal stage may be a target for the early prevention of perinatal allergy sensitization.

  9. An indoor radon survey of the X-ray rooms of Mexico City hospitals

    Energy Technology Data Exchange (ETDEWEB)

    Juarez, Faustino [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, Instituto Literario No. 100. Estado de Mexico, 50000, Mexico. Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Circuito (Mexico); Reyes, Pedro G. [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, Instituto Literario No. 100. Estado de Mexico, 50000 (Mexico); Espinosa, Guillermo [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria, Mexico D.F. Cp.04510 (Mexico)

    2013-07-03

    This paper presents the results of measurements of indoor radon concentrations in the X-ray rooms of a selection of hospitals in the metropolitan area of Mexico City. The metropolitan area of Mexico City is Mexico's largest metropolitan area by population; the number of patients requiring the use of X-rays is also the highest. An understanding of indoor radon concentrations in X-ray rooms is necessary for the estimation of the radiological risk to which patients, radiologists and medical technicians are exposed. The indoor radon concentrations were monitored for a period of six months using nuclear track detectors (NTD) consisting of a closed-end cup system with CR-39 (Lantrack Registered-Sign ) polycarbonate as detector material. The indoor radon concentrations were found to be between 75 and 170 Bq m{sup -3}, below the USEPA-recommended indoor radon action level for working places of 400 Bq m{sup -3}. It is hoped that the results of this study will contribute to the establishment of recommended action levels by the Mexican regulatory authorities responsible for nuclear safety.

  10. Human and remote sensing data to investigate the frontiers of urbanization in the south of Mexico City

    OpenAIRE

    Rodriguez Lopez, Juan Miguel; Heider, Katharina; Scheffran, J?rgen

    2016-01-01

    The data presented here were originally collected for the article “Frontiers of Urbanization: Identifying and Explaining Urbanization Hot Spots in the South of Mexico City Using Human and Remote Sensing” (Rodriguez et al. 2017) [4]. They were divided into three databases (remote sensing, human sensing, and census information), using a multi-method approach with the goal of analyzing the impact of urbanization on protected areas in southern Mexico City. The remote sensing database was prepared...

  11. Spatial and temporal variability of particulate polycyclic aromatic hydrocarbons in Mexico City

    Directory of Open Access Journals (Sweden)

    D. A. Thornhill

    2008-06-01

    Full Text Available As part of the Megacities Initiative: Local and Global Research Observations (MILAGRO study in the Mexico City Metropolitan Area in March 2006, we measured particulate polycyclic aromatic hydrocarbons (PAHs and other gaseous species and particulate properties, including light absorbing carbon or effective black carbon (BC, at six locations throughout the city. The measurements were intended to support the following objectives: to describe spatial and temporal patterns in PAH concentrations, to gain insight into sources and transformations of PAHs and BC, and to quantify the relationships between PAHs and other pollutants. Total particulate PAHs at the Instituto Mexicano del Petróleo (T0 supersite located near downtown averaged 50 ng m−3, and aerosol active surface area averaged 80 mm2 m−3. PAHs were also measured on board the Aerodyne Mobile Laboratory, which visited six sites encompassing a mixture of different land uses and a range of ages of air parcels transported from the city core. A combination of analyses of time series, back trajectories, concentration fields, pollutant ratios, and correlation coefficients supports the concept of T0 as an urban source site, T1 as a receptor site with strong local sources, Pedregal and PEMEX as intermediate sites, Pico Tres Padres as a vertical receptor site, and Santa Ana as a downwind receptor site. Weak intersite correlations suggest that local sources are important and variable and that exposure to PAHs and BC cannot be represented by a single regional-scale value. The relationships between PAHs and other pollutants suggest that a variety of sources and ages of particles are present. Among carbon monoxide, nitrogen oxides (NOx, and carbon dioxide, particulate PAHs are most strongly correlated with NOx. Mexico City's PAH/BC mass ratio of 0.01 is similar to that found on a freeway loop in the Los Angeles area and approximately 8–30

  12. Spatial and temporal variability of particulate polycyclic aromatic hydrocarbons in Mexico City

    Science.gov (United States)

    Thornhill, D. A.; de Foy, B.; Herndon, S. C.; Onasch, T. B.; Wood, E. C.; Zavala, M.; Molina, L. T.; Gaffney, J. S.; Marley, N. A.; Marr, L. C.

    2008-06-01

    As part of the Megacities Initiative: Local and Global Research Observations (MILAGRO) study in the Mexico City Metropolitan Area in March 2006, we measured particulate polycyclic aromatic hydrocarbons (PAHs) and other gaseous species and particulate properties, including light absorbing carbon or effective black carbon (BC), at six locations throughout the city. The measurements were intended to support the following objectives: to describe spatial and temporal patterns in PAH concentrations, to gain insight into sources and transformations of PAHs and BC, and to quantify the relationships between PAHs and other pollutants. Total particulate PAHs at the Instituto Mexicano del Petróleo (T0 supersite) located near downtown averaged 50 ng m-3, and aerosol active surface area averaged 80 mm2 m-3. PAHs were also measured on board the Aerodyne Mobile Laboratory, which visited six sites encompassing a mixture of different land uses and a range of ages of air parcels transported from the city core. A combination of analyses of time series, back trajectories, concentration fields, pollutant ratios, and correlation coefficients supports the concept of T0 as an urban source site, T1 as a receptor site with strong local sources, Pedregal and PEMEX as intermediate sites, Pico Tres Padres as a vertical receptor site, and Santa Ana as a downwind receptor site. Weak intersite correlations suggest that local sources are important and variable and that exposure to PAHs and BC cannot be represented by a single regional-scale value. The relationships between PAHs and other pollutants suggest that a variety of sources and ages of particles are present. Among carbon monoxide, nitrogen oxides (NOx), and carbon dioxide, particulate PAHs are most strongly correlated with NOx. Mexico City's PAH/BC mass ratio of 0.01 is similar to that found on a freeway loop in the Los Angeles area and approximately 8 30 times higher than that found in other cities. Evidence also suggests that primary

  13. Seeing Water in Early Twentieth-Century Mexico City: Henry Wellge's Perspective Plan of the City and Valley of Mexico, D.F. 1906

    OpenAIRE

    Widdifield, Stacie G.; Banister, Jeffrey M.

    2015-01-01

    We examine Henry Wellge's 1906 chromolithograph, Perspective Plan of the City and Valley of Mexico, D.F., a panoramic view that organizes the capital and its lacustrine environs through close up and distant perspectives. The Plan depicts a landscape integrated by canals, rivers, and lakes, recording a pivotal moment before modern hydraulic infrastructure would remove surface water from view. We thus interrogate this image as a visual register of hydraulic-control ideals in vogue around 1900, ...

  14. Death in Mexico City in the Eighteenth Century

    Directory of Open Access Journals (Sweden)

    Nadine Béligand

    2007-07-01

    Full Text Available Mexico City, “capital, court, and head”, core of Catholic monarchy on Earth, becomes a model for analyzing attitudes towards death in different social groups: peninsulares and criollos, religious and lay citizens, mestizos, castizos, and Indians. The capital, subject to a variety of cultural influences, is also seen as a model city; in this sense, it is one of the Ilustrado's experimental  fields. In her analysis, the author  distinguishes  between death (and all its associated beliefs and rituals and the dead (corpses, rotting,  fear of the dead. Beliefs and rituals concerning  death barely changed from the fifteenth to the eighteenth centuries, but the issue of the dead was widely discussed during this last one. However, the expelling of the dead from the cities was a slow process that did not find a definite solution until the 1850s. Traditional, archaic, and baroque attitudes towards death survived in the hygienist policies, and the Ilustrados had to confront the Church, which ever since the sixteenth century had been imprinting in people's minds an image of the city's dead as a community of ancestors identified with the community of believers, thus actually articulating social and sacred practices.

  15. Formaldehyde Surface Distributions and Variability in the Mexico City Basin

    Science.gov (United States)

    Junkermann, W.; Mohr, C.; Steinbrecher, R.; Ruiz Suarez, L.

    2007-05-01

    Formaldehyde ambient air mole fractions were measured throughout the dry season in March at three different locations in the Mexico City basin. The continuously running instruments were operated at Tenago del Aire, a site located in the Chalco valley in the southern venting area of the basin, at the Intituto Mexicano del Petroleo (IMP) in the northern part of the city and about 30 km north of the city at the campus of the Universidad Tecnològica de Tecamac (UTTEC). The technique used is the Hantzsch technology with a time resolution of 2 minutes and a detection limit of 100 ppt. Daily maxima peaked at 35 ppb formaldehyde in the city and about 15 to 20 ppb at the other sites. During night formaldehyde levels dropped to about 5 ppb or less. It is evident that the observed spatial and temporal variability in near surface formaldehyde distributions is strongly affected by local and regional advection processes.

  16. A Tale of two Cities: Photoacoustic and Aethalometer Measurements Comparisons of Light Absorption in Mexico City and Las Vegas, NV, USA

    Science.gov (United States)

    Paredes-Miranda, G.; Arnott, W. P.; Marley, N. A.; Gaffney, J. S.

    2007-05-01

    As part of the Megacity Impacts on Regional and Global Environments, MIRAGE-Mex deployment to Mexico City in the period of 30 days, March 2006, a suite of photoacoustic spectrometers (PAS; W. Arnott & G. Paredes), nephelometer scattering, and aetholemeter absorption instruments (N. Marley & J.Gaffney) were installed to measure at ground level the light absorption and scattering by aerosols at the urban site at Instituto Mexicano del Petroleo (Mexican Oil Institute, denoted by IMP). This IMP site gave in-situ characterization of the Mexico City plume under favorable wind conditions. The PAS used at IMP operates at 532 nm, and conveniently allowed for characterization of gaseous absorption at this wavelength as well. Light scattering measurements are accomplished within the PAS by the reciprocal nephelometery method. In the urban site the aerosol absorption coefficient typically varies between 20 and 180 Mm-1 during the course of the day and significant diurnal variation of the aerosol single scattering albedo was observed. The Las Vegas, NV site was located at East Charleston Street on January-February, 2003. In east Las Vegas typical westerly winds carry the city plume across the site. Comparisons of PAS aerosol light absorption and aetholemeter absorption measurements at 521 nm at both Las Vegas NV and Mexico City sites will be presented. We will also present a broad overview of the diurnal variation of the scattering and absorption as well as the single scattering albedo and fraction of absorption due to gases at the sites in relation to secondary aerosol formation.

  17. Using High-Resolution Satellite Aerosol Optical Depth To Estimate Daily PM2.5 Geographical Distribution in Mexico City.

    Science.gov (United States)

    Just, Allan C; Wright, Robert O; Schwartz, Joel; Coull, Brent A; Baccarelli, Andrea A; Tellez-Rojo, Martha María; Moody, Emily; Wang, Yujie; Lyapustin, Alexei; Kloog, Itai

    2015-07-21

    Recent advances in estimating fine particle (PM2.5) ambient concentrations use daily satellite measurements of aerosol optical depth (AOD) for spatially and temporally resolved exposure estimates. Mexico City is a dense megacity that differs from other previously modeled regions in several ways: it has bright land surfaces, a distinctive climatological cycle, and an elevated semi-enclosed air basin with a unique planetary boundary layer dynamic. We extend our previous satellite methodology to the Mexico City area, a region with higher PM2.5 than most U.S. and European urban areas. Using a novel 1 km resolution AOD product from the MODIS instrument, we constructed daily predictions across the greater Mexico City area for 2004-2014. We calibrated the association of AOD to PM2.5 daily using municipal ground monitors, land use, and meteorological features. Predictions used spatial and temporal smoothing to estimate AOD when satellite data were missing. Our model performed well, resulting in an out-of-sample cross-validation R(2) of 0.724. Cross-validated root-mean-squared prediction error (RMSPE) of the model was 5.55 μg/m(3). This novel model reconstructs long- and short-term spatially resolved exposure to PM2.5 for epidemiological studies in Mexico City.

  18. The impact of biogenic carbon emissions on aerosol absorption inMexico City

    Energy Technology Data Exchange (ETDEWEB)

    Marley, N; Gaffney, J; Tackett, M J; Sturchio, N; Hearty, L; Martinez, N; Hardy, K D; Machany-Rivera, A; Guilderson, T P; MacMillan, A; Steelman, K

    2009-02-24

    In order to determine the wavelength dependence of atmospheric aerosol absorption in the Mexico City area, the absorption angstrom exponents (AAEs) were calculated from aerosol absorption measurements at seven wavelengths obtained with a seven-channel aethalometer during two field campaigns, the Mexico City Metropolitan Area study in April 2003 (MCMA 2003) and the Megacity Initiative: Local and Global Research Observations in March 2006 (MILAGRO). The AAEs varied from 0.76 to 1.56 in 2003 and from 0.54 to 1.52 in 2006. The AAE values determined in the afternoon were consistently higher than the corresponding morning values, suggesting the photochemical formation of absorbing secondary organic aerosols (SOA) in the afternoon. The AAE values were compared to stable and radiocarbon isotopic measurements of aerosol samples collected at the same time to determine the sources of the aerosol carbon. The fraction of modern carbon (fM) in the aerosol samples, as determined from {sup 14}C analysis, showed that 70% of the carbonaceous aerosols in Mexico City were from modern sources, indicating a significant impact from biomass burning during both field campaigns. The {sup 13}C/{sup 12}C ratios of the aerosol samples illustrate the significant impact of Yucatan forest fires (C-3 plants) in 2003 and local grass fires (C-4 plants) at site T1 in 2006. A direct comparison of the fM values, stable carbon isotope ratios, and calculated aerosol AAEs suggested that the wavelength dependence of the aerosol absorption was controlled by the biogenically derived aerosol components.

  19. Metals in aerosols of the Mexico City

    International Nuclear Information System (INIS)

    Reyes L, J.

    1998-01-01

    The general purpose and scope of this work was to have a data base that includes enough information about the heavy metals which are disseminated in the atmospheric air in Mexico City, like it is what refers to its elements, its concentration and its particle size. For this were collected samples through collectors types: of the filters unit and the cascade impactor. Through the PIXE analysis for filters and films it was identified the presence of 20 elements in the majority of samples studied of the four seasons during the years 1993-1994. The metals were classified in two groups: those of natural origin and those of anthropogenic origin. (Author)

  20. Determination of radon levels in Mexico City

    International Nuclear Information System (INIS)

    Pena G, P.

    1992-01-01

    The study of the determination of radon levels in the houses room in Mexico City is part of the project Emanometry of the radon. To carry out this study, the passive method was used, which consists of: thin film dosemeter of cellulose nitrate, container of the same one and spark accountant. The method is based on the mensurations of exhibition of the number of marks of alpha track is of the open type and it allows to average the radon activity along several weeks and it presents low concentrations. This study was carried out in 4 periods of exhibition of 3 months each one. (Author)

  1. The Uses of Informality : Urban Development and Social Distinction in Mexico City

    NARCIS (Netherlands)

    Mueller, F.; Segura, R.

    “Urban informality” is a signifier that is disputed by real estate developers, politicians, and residents in undertaking strategies of social distinction and gaining particular political and economic benefits. Research in the western periphery of Mexico City distinguishes three cases of such use of

  2. Prevalence of Human Papillomavirus in Women from Mexico City

    Directory of Open Access Journals (Sweden)

    María Guadalupe López Rivera

    2012-01-01

    Full Text Available Introduction. Cervical cancer is the most common cancer among Mexican women. The goal of the present study was to determine the prevalence and distribution of HPV types in women from Mexico City. Methods. Our study was conducted in the Clinica de Especialidades de la Mujer de la Secretaría de la Defensa Nacional, Mexico. Random samples were taken from 929 healthy women requesting a cervical Papanicolaou examination. Detection and genotyping of HPV were performed by multiplex PCR, with the HPV4A ACE Screening kit (Seegene. Results. 85 of nine hundred twenty-nine women (9.1% were infected with HPV. Of HPV-positive women, 99% and 1% had high- and low-risk HPV genotypes, respectively. The prevalence of the 16 high-risk (HR HPV types that were screened was 43% : 42% (18 were HPV positive and 14% (16 were HPV positive, which includes coinfection. Multiple infections with different viral genotypes were detected in 10% of the positive cases. Abnormal cervical cytological results were found in only 15.3% of HPV-positive women, while 84.7% had normal cytological results. Conclusions. We found a similar prevalence of HPV to previous studies in Mexico. The heterogeneity of the HPV genotype distribution in Mexico is evident in this study, which found a high frequency of HPV HR genotypes, the majority of which were HPV 18.

  3. Pilot study of personality traits assessed by the Karolinska Scales of Personality (KSP) in asthma, atopy, and rhinitis.

    Science.gov (United States)

    Runeson, Roma; Wahlstedt, Kurt; Norbäck, Dan

    2011-12-01

    Asthma and atopy are common diseases. To study associations between personality and asthma, atopy, rhinitis, and personality traits were measured on the Karolinska Scales of Personality for 193 persons working in 19 buildings with suspected indoor air problems. In addition, information on history of atopy, asthma, and rhinitis was collected by postal questionnaire. In analyses, asthma was associated with higher impulsiveness scores, and atopy in non-asthmatics was associated with higher social desirability scores and lower irritability, guilt, and impulsiveness scores. Non-atopic rhinitis was associated with scores on several anxiety-related scales, while atopic rhinitis was not associated with scores on the Karolinska Scales of Personality. This exploration implies that asthma, atopy, and rhinitis may be associated with various but different personality trait scores. The finding of such personality trait associations in persons with non-asthmatic atopy raises the question of a potential role of an emotional conflict in atopy and the role of personality in asthma, atopy, and rhinitis.

  4. A Mexico City-Based Immersion Education Program: Training Mental Health Clinicians for Practice with Latino Communities

    Science.gov (United States)

    Platt, Jason James

    2012-01-01

    This article describes the philosophical foundations and educational methods of a Spanish language and cultural immersion program based in Mexico City, Mexico. The program is designed to assist U.S. graduate students in marriage and family therapy and clinical psychology programs to improve clinical service delivery with Latino clients. Utilizing…

  5. Different implications of paternal and maternal atopy for perinatal IgE production and asthma development.

    Science.gov (United States)

    Wu, Chih-Chiang; Chen, Rong-Fu; Kuo, Ho-Chang

    2012-01-01

    Asthma is a hereditary disease associated with IgE-mediated reaction. Whether maternal atopy and paternal atopy have different impacts on perinatal IgE production and asthma development remains unclear. This paper reviews and summarizes the effects of maternal and paternal atopy on the developmental aspects of IgE production and asthma. Maternal atopy affects both pre- and postnatal IgE production, whereas paternal atopy mainly affects the latter. Maternally transmitted genes GSTP1 and FceRI-beta are associated with lung function and allergic sensitization, respectively. In IgE production and asthma development, the maternal influence on gene-environment interaction is greater than paternal influence. Maternal, paternal, and/or postnatal environmental modulation of allergic responses have been linked to epigenetic mechanisms, which may be good targets for early prevention of asthma.

  6. Different Implications of Paternal and Maternal Atopy for Perinatal IgE Production and Asthma Development

    Directory of Open Access Journals (Sweden)

    Chih-Chiang Wu

    2012-01-01

    Full Text Available Asthma is a hereditary disease associated with IgE-mediated reaction. Whether maternal atopy and paternal atopy have different impacts on perinatal IgE production and asthma development remains unclear. This paper reviews and summarizes the effects of maternal and paternal atopy on the developmental aspects of IgE production and asthma. Maternal atopy affects both pre- and postnatal IgE production, whereas paternal atopy mainly affects the latter. Maternally transmitted genes GSTP1 and FceRI-beta are associated with lung function and allergic sensitization, respectively. In IgE production and asthma development, the maternal influence on gene-environment interaction is greater than paternal influence. Maternal, paternal, and/or postnatal environmental modulation of allergic responses have been linked to epigenetic mechanisms, which may be good targets for early prevention of asthma.

  7. Bacterial Exposures and Associations with Atopy and Asthma in Children.

    Directory of Open Access Journals (Sweden)

    Maria Valkonen

    Full Text Available The increase in prevalence of asthma and atopic diseases in Western countries has been linked to aspects of microbial exposure patterns of people. It remains unclear which microbial aspects contribute to the protective farm effect.The objective of this study was to identify bacterial groups associated with prevalence of asthma and atopy, and to quantify indoor exposure to some of these bacterial groups.A DNA fingerprinting technique, denaturing gradient gel electrophoresis (DGGE, was applied to mattress dust samples of farm children and control children in the context of the GABRIEL Advanced study. Associations between signals in DGGE and atopy, asthma and other allergic health outcomes were analyzed. Quantitative DNA based assays (qPCR for four bacterial groups were applied on the dust samples to seek quantitative confirmation of associations indicated in DNA fingerprinting.Several statistically significant associations between individual bacterial signals and also bacterial diversity in DGGE and health outcomes in children were observed. The majority of these associations showed inverse relationships with atopy, less so with asthma. Also, in a subsequent confirmation study using a quantitative method (qPCR, higher mattress levels of specifically targeted bacterial groups - Mycobacterium spp., Bifidobacteriaceae spp. and two different clusters of Clostridium spp. - were associated with a lower prevalence of atopy.DNA fingerprinting proved useful in identifying bacterial signals that were associated with atopy in particular. These findings were quantitatively confirmed for selected bacterial groups with a second method. High correlations between the different bacterial exposures impede a clear attribution of protective effects to one specific bacterial group. More diverse bacterial flora in mattress dust may link to microbial exposure patterns that protect against development of atopic diseases.

  8. Drinking water quality in a Mexico city university community: perception and preferences.

    Science.gov (United States)

    Espinosa-García, Ana C; Díaz-Ávalos, Carlos; González-Villarreal, Fernando J; Val-Segura, Rafael; Malvaez-Orozco, Velvet; Mazari-Hiriart, Marisa

    2015-03-01

    A transversal study was conducted at the University City campus of the National Autonomous University of Mexico (UNAM) in Mexico City, with the goal of estimating the university community preference for drinking either tap water or bottled water and the reasons for their selection. A representative sample of three university community subpopulations (students, workers/administrative staff, and academic personnel) were interviewed with respect to their water consumption habits. The results showed that 75% of the university community drinks only bottled water and that the consumption of tap water is low. The interviewees responded that the main reason for this preference is the organoleptic features of tap water independent of quality. In general, the participants in this study do not trust the quality of the tap water, which could be caused by the facilities that distribute bottled water encouraging a general disinterest in learning about the origin and management of the tap water that is distributed on campus.

  9. Final Opportunity to Rehabilitate an Urban River as a Water Source for Mexico City

    Science.gov (United States)

    Mazari-Hiriart, Marisa; Pérez-Ortiz, Gustavo; Orta-Ledesma, María Teresa; Armas-Vargas, Felipe; Tapia, Marco A.; Solano-Ortiz, Rosa; Silva, Miguel A.; Yañez-Noguez, Isaura; López-Vidal, Yolanda; Díaz-Ávalos, Carlos

    2014-01-01

    The aim of this study was to evaluate the amount and quality of water in the Magdalena-Eslava river system and to propose alternatives for sustainable water use. The system is the last urban river in the vicinity of Mexico City that supplies surface water to the urban area. Historical flow data were analyzed (1973–2010), along with the physicochemical and bacteriological attributes, documenting the evolution of these variables over the course of five years (2008–2012) in both dry and rainy seasons. The analyses show that the flow regime has been significantly altered. The physicochemical variables show significant differences between the natural area, where the river originates, and the urban area, where the river receives untreated wastewater. Nutrient and conductivity concentrations in the river were equivalent to domestic wastewater. Fecal pollution indicators and various pathogens were present in elevated densities, demonstrating a threat to the population living near the river. Estimates of the value of the water lost as a result of mixing clean and contaminated water are presented. This urban river should be rehabilitated as a sustainability practice, and if possible, these efforts should be replicated in other areas. Because of the public health issues and in view of the population exposure where the river flows through the city, the river should be improved aesthetically and should be treated to allow its ecosystem services to recover. This river represents an iconic case for Mexico City because it connects the natural and urban areas in a socio-ecological system that can potentially provide clean water for human consumption. Contaminated water could be treated and reused for irrigation in one of the green areas of the city. Wastewater treatment plants and the operation of the existing purification plants are urgent priorities that could lead to better, more sustainable water use practices in Mexico City. PMID:25054805

  10. Final opportunity to rehabilitate an urban river as a water source for Mexico City.

    Directory of Open Access Journals (Sweden)

    Marisa Mazari-Hiriart

    Full Text Available The aim of this study was to evaluate the amount and quality of water in the Magdalena-Eslava river system and to propose alternatives for sustainable water use. The system is the last urban river in the vicinity of Mexico City that supplies surface water to the urban area. Historical flow data were analyzed (1973-2010, along with the physicochemical and bacteriological attributes, documenting the evolution of these variables over the course of five years (2008-2012 in both dry and rainy seasons. The analyses show that the flow regime has been significantly altered. The physicochemical variables show significant differences between the natural area, where the river originates, and the urban area, where the river receives untreated wastewater. Nutrient and conductivity concentrations in the river were equivalent to domestic wastewater. Fecal pollution indicators and various pathogens were present in elevated densities, demonstrating a threat to the population living near the river. Estimates of the value of the water lost as a result of mixing clean and contaminated water are presented. This urban river should be rehabilitated as a sustainability practice, and if possible, these efforts should be replicated in other areas. Because of the public health issues and in view of the population exposure where the river flows through the city, the river should be improved aesthetically and should be treated to allow its ecosystem services to recover. This river represents an iconic case for Mexico City because it connects the natural and urban areas in a socio-ecological system that can potentially provide clean water for human consumption. Contaminated water could be treated and reused for irrigation in one of the green areas of the city. Wastewater treatment plants and the operation of the existing purification plants are urgent priorities that could lead to better, more sustainable water use practices in Mexico City.

  11. Final opportunity to rehabilitate an urban river as a water source for Mexico City.

    Science.gov (United States)

    Mazari-Hiriart, Marisa; Pérez-Ortiz, Gustavo; Orta-Ledesma, María Teresa; Armas-Vargas, Felipe; Tapia, Marco A; Solano-Ortiz, Rosa; Silva, Miguel A; Yañez-Noguez, Isaura; López-Vidal, Yolanda; Díaz-Ávalos, Carlos

    2014-01-01

    The aim of this study was to evaluate the amount and quality of water in the Magdalena-Eslava river system and to propose alternatives for sustainable water use. The system is the last urban river in the vicinity of Mexico City that supplies surface water to the urban area. Historical flow data were analyzed (1973-2010), along with the physicochemical and bacteriological attributes, documenting the evolution of these variables over the course of five years (2008-2012) in both dry and rainy seasons. The analyses show that the flow regime has been significantly altered. The physicochemical variables show significant differences between the natural area, where the river originates, and the urban area, where the river receives untreated wastewater. Nutrient and conductivity concentrations in the river were equivalent to domestic wastewater. Fecal pollution indicators and various pathogens were present in elevated densities, demonstrating a threat to the population living near the river. Estimates of the value of the water lost as a result of mixing clean and contaminated water are presented. This urban river should be rehabilitated as a sustainability practice, and if possible, these efforts should be replicated in other areas. Because of the public health issues and in view of the population exposure where the river flows through the city, the river should be improved aesthetically and should be treated to allow its ecosystem services to recover. This river represents an iconic case for Mexico City because it connects the natural and urban areas in a socio-ecological system that can potentially provide clean water for human consumption. Contaminated water could be treated and reused for irrigation in one of the green areas of the city. Wastewater treatment plants and the operation of the existing purification plants are urgent priorities that could lead to better, more sustainable water use practices in Mexico City.

  12. On the Sound Environment of the City of Puerto Vallarta, Jalisco, Mexico

    OpenAIRE

    Boullosa, R. R.; Alvarado Z., C.

    2011-01-01

    An exploration of the sound environment in the city of Puerto Vallarta, Jalisco, Mexico, is presented. A series of interviews were held with 19 residents, of which 7 were undergraduate students, related to the perception of sound in or around places of different zones in the so-called "Viejo Vallarta" ("Old Vallarta"). The purpose was twofold, firstly, to explore the ideas people have relating to the sounds they hear in the city -and in general, the ideas they have relating to peace and tranq...

  13. Systemic Competitiveness of SMEs in Mexico City, Mexico

    Directory of Open Access Journals (Sweden)

    Maria Luisa Saavedra García

    2015-07-01

    Full Text Available The objective of this work was to apply the model of systemic competitiveness, SMEs in Mexico City. Developing four levels of competitiveness: macro level (economic environment, meso level (regional environment, Level Goal (Environment Socioeconomic and micro Level (internal factors. Data collection was done through fieldwork and archival research. The main findings are among the major strengths of the economic environment: high level of gross domestic product, high labor productivity and fiscal autonomy, the main weaknesses: the unions and the unemployment rate; meanwhile stand between foreign investment opportunities between threats and insecurity, corruption and difficulty in business transactions. In the regional setting a positive and 1 perfect relationship between the number of economic units and per capita GDP was found. With regard to socio-cultural factors, presents lower levels of poverty and unemployment to the rest of the country. Finally, at the micro level, the competitiveness of SMEs is in direct relation to the size of the company and the industry sector shows higher competitiveness trade and services sectors.

  14. Assessment of water supply as an ecosystem service in a rural-urban watershed in southwestern Mexico City.

    Science.gov (United States)

    Jujnovsky, Julieta; González-Martínez, Teresa Margarita; Cantoral-Uriza, Enrique Arturo; Almeida-Leñero, Lucia

    2012-03-01

    Studies from the ecosystem services perspective can provide a useful framework because they allow us to fully examine the benefits that humans obtain from socio-ecological systems. Mexico City, the second largest city in the world, has faced severe problems related to water shortages, which have worsened due to increasing population. Demand for space has forced changes in land cover, including covering areas that are essential for groundwater recharge. The city has 880 km(2) of forest areas that are crucial for the water supply. The Magdalena River Watershed was chosen as a model because it is a well-preserved zone within Mexico City and it provides water for the population. The general aim of this study was to assess the ecosystem service of the water supply in the Magdalena River Watershed by determining its water balance (SWAT model) and the number of beneficiaries of the ecosystem services. The results showed that the watershed provides 18.4 hm(3) of water per year. Baseflow was dominant, with a contribution of 85%, while surface runoff only accounted for 15%. The zone provides drinking water to 78,476 inhabitants and could supply 153,203 potential beneficiaries. This work provides an example for understanding how ecosystem processes determine the provision of ecosystem services and benefits to the population in a rural-urban watershed in Mexico City.

  15. Sources and transformations of particle-bound polycyclic aromatic hydrocarbons in Mexico City

    Directory of Open Access Journals (Sweden)

    L. C. Marr

    2006-01-01

    Full Text Available Understanding sources, concentrations, and transformations of polycyclic aromatic hydrocarbons (PAHs in the atmosphere is important because of their potent mutagenicity and carcinogenicity. The measurement of particle-bound PAHs by three different methods during the Mexico City Metropolitan Area field campaign in April 2003 presents a unique opportunity for characterization of these compounds and intercomparison of the methods. The three methods are (1 collection and analysis of bulk samples for time-integrated gas- and particle-phase speciation by gas chromatography/mass spectrometry; (2 aerosol photoionization for fast detection of PAHs on particles' surfaces; and (3 aerosol mass spectrometry for fast analysis of size and chemical composition. This research represents the first time aerosol mass spectrometry has been used to measure ambient PAH concentrations and the first time that fast, real-time methods have been used to quantify PAHs alongside traditional filter-based measurements in an extended field campaign. Speciated PAH measurements suggest that motor vehicles and garbage and wood burning are important sources in Mexico City. The diurnal concentration patterns captured by aerosol photoionization and aerosol mass spectrometry are generally consistent. Ambient concentrations of particle-phase PAHs typically peak at ~110 ng m-3 during the morning rush hour and rapidly decay due to changes in source activity patterns and dilution as the boundary layer rises, although surface-bound PAH concentrations decay faster. The more rapid decrease in surface versus bulk PAH concentrations during the late morning suggests that freshly emitted combustion-related particles are quickly coated by secondary aerosol material in Mexico City's atmosphere and may also be transformed by heterogeneous reactions.

  16. Remotely-triggered Slip in Mexico City Induced by the September 2017 Mw=7.1 Puebla Earthquake.

    Science.gov (United States)

    Solano Rojas, D. E.; Havazli, E.; Cabral-Cano, E.; Wdowinski, S.

    2017-12-01

    Although the epicenter of the September 19th, 2017 Mw=7.1 Puebla earthquake is located 100 km from Mexico City, the earthquake caused severe destruction in the city, leading to life loss and property damage. Mexico City is built on a thick clay-rich sedimentary sequence and, hence, is susceptible to seismic acceleration during earthquakes. The sediment layer also causes land subsidence, at rates as high as 350 mm/yr, and surface faulting. The earthquake damage in the eastern part of the city, characterized by the collapse of several buildings, can be explained by seismic amplification. However, the damage in the southern part of the city, characterized by the collapse of small houses and surface faulting, requires a different explanation. We present here geodetic observations suggesting that the surface faulting in Mexico City triggered by the Puebla earthquake occurred in areas already experiencing differential displacements. Our study is based on Sentinel-1A satellite data from before and after the earthquake (September 17th and 29th, 2017). We process the data using Interferometric Synthetic Aperture Radar (InSAR) to produce a coseismic interferogram. We also identify phase discontinuities that can be interpreted as surface faulting using the phase gradient technique (Price and Sandwell, 1998). The results of our analysis reveal the locations and patterns of coseismic phase discontinuities, mainly in the piedmont of the Sierra de Santa Catarina, which agree with the location of earthquake's damage reported by official and unofficial sources (GCDMX, 2017; OSM, 2017). The observed phase discontinuities also agree well with the location of preexisting, subsidence-related faults identified during 10 years of field surveys (GCDMX, 2017) and coincide with differential displacements identified using a Fast Fourier Transform residual technique on high-resolution InSAR results from 2012 (Solano-Rojas et. al, 2017). We propose that the seismic energy released by the 2017

  17. A scenario of human thermal comfort in Mexico City for 2CO{sub 2} conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jauregui, Ernesto [Centro de Ciencias de la Atmosfera de la UNAM, Mexico, D.F. (Mexico); Tejeda, Adalberto [Universidad Veracruzana, Xalapa, Veracruz (Mexico)

    2001-07-01

    Applying the concept of effective temperature (ET), a scenario of human bioclimatic conditions for Mexico City is presented by using results from both GCM regional predictions for CO{sub 2} doubling and temperature trend projections from an urban station. Current and future bioclimatic maps for Mexico City and their conurbation are presented. Current environmental conditions will likely change toward a warmer atmosphere due to both the urbanization process and global greenhouse effect. The impact on the population will be more important during the warm season (March- May) when the bioclimate of the city will likely shift away from current neutrality to the next comfort scale category (ET 24-27 Celsius degrees) of warm conditions covering most of the capital city. [Spanish] A partir de la aplicacion del concepto de temperatura efectiva (ET) se presenta un escenario de las condiciones de bioclima humano para la Ciudad de Mexico y zona conurbada para la segunda mitad del proximo siglo. Se usaron resultados de predicciones regionales de modelos de circulacion general (GCM) para una duplicacion del CO{sub 2} y tambien las tendencias de temperatura de una estacion urbana. Se muestran mapas de las condiciones actuales y futuras de confort termico. La combinacion del efecto invernadero y la urbanizacion, muy probablemente impacten en la poblacion principalmente en la estacion calida (marzo a mayo), cuando se pase de la categoria de confort actual a la inmediata superior (ET 24-27 Celsius degrees) en la mayor parte de la capital del pais.

  18. The chemo and the mona : Inhalants, devotion and street youth in Mexico city

    NARCIS (Netherlands)

    Gigengack, Roy

    This paper understands inhalant use - the deliberate inhalation of volatile solvents or glues with intentions of intoxication - as a socially and culturally constituted practice. It describes the inhalant use of young street people in Mexico City from their perspective ("the vicioso or inhalant

  19. The distribution of potential West Nile virus vectors, Culex pipiens pipiens and Culex pipiens quinquefasciatus (Diptera: Culicidae), in Mexico City.

    Science.gov (United States)

    Diaz-Badillo, Alvaro; Bolling, Bethany G; Perez-Ramirez, Gerardo; Moore, Chester G; Martinez-Munoz, Jorge P; Padilla-Viveros, America A; Camacho-Nuez, Minerva; Diaz-Perez, Alfonso; Beaty, Barry J; Munoz, Maria de Lourdes

    2011-05-09

    Culex spp. mosquitoes are considered to be the most important vectors of West Nile virus (WNV) detected in at least 34 species of mosquitoes in the United States. In North America, Culex pipiens pipiens, Culex pipiens quinquefasciatus, and Culex tarsalis are all competent vectors of WNV, which is considered to be enzootic in the United States and has also been detected in equines and birds in many states of Mexico and in humans in Nuevo Leon. There is potential for WNV to be introduced into Mexico City by various means including infected mosquitoes on airplanes, migrating birds, ground transportation and infected humans. Little is known of the geographic distribution of Culex pipiens complex mosquitoes and hybrids in Mexico City. Culex pipiens pipiens preferentially feed on avian hosts; Culex pipiens quinquefasciatus have historically been considered to prefer mammalian hosts; and hybrids of these two species could theoretically serve as bridge vectors to transmit WNV from avian hosts to humans and other mammalian hosts. In order to address the potential of WNV being introduced into Mexico City, we have determined the identity and spatial distribution of Culex pipiens complex mosquitoes and their hybrids. Mosquito larvae collected from 103 sites throughout Mexico City during 2004-2005 were identified as Culex, Culiseta or Ochlerotatus by morphological analysis. Within the genus Culex, specimens were further identified as Culex tarsalis or as belonging to the Culex pipiens complex. Members of the Culex pipiens complex were separated by measuring the ratio of the dorsal and ventral arms (DV/D ratio) of the male genitalia and also by using diagnostic primers designed for the Ace.2 gene. Culex pipiens quinquefasciatus was the most abundant form collected. Important WNV vectors species, Cx. p. pipiens, Cx. p. quinquefasciatus and Cx. tarsalis, are all present in Mexico City. Hybrids of Cx. p. pipiens and Cx. p. quinquefasciatus were also collected and identified. The

  20. The distribution of potential West Nile virus vectors, Culex pipiens pipiens and Culex pipiens quinquefasciatus (Diptera: Culicidae, in Mexico City

    Directory of Open Access Journals (Sweden)

    Diaz-Perez Alfonso

    2011-05-01

    Full Text Available Abstract Background Culex spp. mosquitoes are considered to be the most important vectors of West Nile virus (WNV detected in at least 34 species of mosquitoes in the United States. In North America, Culex pipiens pipiens, Culex pipiens quinquefasciatus, and Culex tarsalis are all competent vectors of WNV, which is considered to be enzootic in the United States and has also been detected in equines and birds in many states of Mexico and in humans in Nuevo Leon. There is potential for WNV to be introduced into Mexico City by various means including infected mosquitoes on airplanes, migrating birds, ground transportation and infected humans. Little is known of the geographic distribution of Culex pipiens complex mosquitoes and hybrids in Mexico City. Culex pipiens pipiens preferentially feed on avian hosts; Culex pipiens quinquefasciatus have historically been considered to prefer mammalian hosts; and hybrids of these two species could theoretically serve as bridge vectors to transmit WNV from avian hosts to humans and other mammalian hosts. In order to address the potential of WNV being introduced into Mexico City, we have determined the identity and spatial distribution of Culex pipiens complex mosquitoes and their hybrids. Results Mosquito larvae collected from 103 sites throughout Mexico City during 2004-2005 were identified as Culex, Culiseta or Ochlerotatus by morphological analysis. Within the genus Culex, specimens were further identified as Culex tarsalis or as belonging to the Culex pipiens complex. Members of the Culex pipiens complex were separated by measuring the ratio of the dorsal and ventral arms (DV/D ratio of the male genitalia and also by using diagnostic primers designed for the Ace.2 gene. Culex pipiens quinquefasciatus was the most abundant form collected. Conclusions Important WNV vectors species, Cx. p. pipiens, Cx. p. quinquefasciatus and Cx. tarsalis, are all present in Mexico City. Hybrids of Cx. p. pipiens and Cx. p

  1. Asymmetric correlations in the ozone concentration dynamics of the Mexico City Metropolitan Area

    Science.gov (United States)

    Meraz, M.; Alvarez-Ramirez, J.; Echeverria, J. C.

    2017-04-01

    Mexico City is a megalopolis with severe pollution problems caused by vehicles and industrial activity. This condition imposes important risks to human health and economic activity. Based on hourly-sampled data during the last decade, in a recent work (Meraz et al., 2015) we showed that the pollutant dynamics in Mexico City exhibits long-term and scale-dependent persistence effects resulting from the combination of pollutants generation by vehicles and removal by advection mechanisms. In this work, we analyzed the dynamics of ozone, a key component reflecting the degree of atmospheric contamination, to determine if its long-term correlations are asymmetric in relation to the actual concentration trend (increasing or decreasing). The analysis is conducted with detrended fluctuation analysis. The results showed that the average ozone dynamics is uncorrelated when the concentration is increasing. In contrast, the ozone dynamics shows long-term anti-persistence effects when the concentration is decreasing.

  2. Contribution of garbage burning to chloride and PM2.5 in Mexico City

    Directory of Open Access Journals (Sweden)

    N. Bei

    2012-09-01

    Full Text Available The contribution of garbage burning (GB emissions to chloride and PM2.5 in the Mexico City Metropolitan Area (MCMA has been investigated for the period of 24 to 29 March during the MILAGRO-2006 campaign using the WRF-CHEM model. When the MCMA 2006 official emission inventory without biomass burning is used in the simulations, the WRF-CHEM model significantly underestimates the observed particulate chloride in the urban and the suburban areas. The inclusion of GB emissions substantially improves the simulations of particulate chloride; GB contributes more than 60% of the observation, indicating that it is a major source of particulate chloride in Mexico City. GB yields up to 3 pbb HCl at the ground level in the city, which is mainly caused by the burning of polyvinyl chloride (PVC in the garbage. GB is also an important source of PM2.5, contributing about 3–30% simulated PM2.5 mass on average. More modeling work is needed to evaluate the GB contribution to hazardous air toxics, such as dioxin, which is found to be released at high level from PVC burning in laboratory experiments.

  3. Experiences of street harassment and associations with perceptions of social cohesion among women in Mexico City

    Directory of Open Access Journals (Sweden)

    Paola A Campos

    2017-01-01

    Full Text Available Objective. To document the frequency and forms of street harassment and examine the association between street harassment experiences and perceptions of social cohesion. Materials and methods. Baseline survey data collected among women seeking care in public health clinics in Mexico City were used for analysis. Results. Nearly two-thirds (62.8% of women reported experiencing some form of street harassment in the prior month; women with street harassment experiences reported significantly lower perceived social cohesion (b=-0.46; 95%CI:0.69,-0.22. Conclusions. Findings indicate reducing street harassment may have important implications for improving women’s perceived social cohesion and their safety in Mexico City.

  4. Does atopy affect the course of viral pneumonia?

    Science.gov (United States)

    Erdem, S B; Can, D; Girit, S; Çatal, F; Şen, V; Pekcan, S; Yüksel, H; Bingöl, A; Bostancı, I; Erge, D; Ersu, R

    The presence of atopy is considered as a risk factor for severe respiratory symptoms in children. The objective of this study was to examine the effect of atopy on the course of disease in children hospitalised with viral pneumonia. Children between the ages of 1 and 6 years hospitalised due to viral pneumonia between the years of 2013 and 2016 were included to this multicentre study. Patients were classified into two groups as mild-moderate and severe according to the course of pneumonia. Presence of atopy was evaluated with skin prick tests. Groups were compared to evaluate the risk factors associated with severe viral pneumonia. A total of 280 patients from nine centres were included in the study. Of these patients, 163 (58.2%) were male. Respiratory syncytial virus (29.7%), Influenza A (20.5%), rhinovirus (18.9%), adenovirus (10%), human metapneumovirus (8%), parainfluenza (5.2%), coronavirus (6%), and bocavirus (1.6%) were isolated from respiratory samples. Eighty-five (30.4%) children had severe pneumonia. Atopic sensitisation was found in 21.4% of the patients. Ever wheezing (RR: 1.6, 95% CI: 1.1-2.4), parental asthma (RR: 1.5, 95% CI: 1.1-2.2), other allergic diseases in the family (RR: 1.8, 95% CI: 1.2-2.9) and environmental tobacco smoke (RR: 1.6, 95% CI: 1.1-3.5) were more common in the severe pneumonia group. When patients with mild-moderate pneumonia were compared to patients with severe pneumonia, frequency of atopy was not different between the two groups. However, parental asthma, ever wheezing and environmental tobacco smoke exposure are risk factors for severe viral pneumonia in children. Copyright © 2017 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.

  5. Prematurity, atopy, and childhood asthma in Puerto Ricans.

    Science.gov (United States)

    Rosas-Salazar, Christian; Ramratnam, Sima K; Brehm, John M; Han, Yueh-Ying; Boutaoui, Nadia; Forno, Erick; Acosta-Pérez, Edna; Alvarez, María; Colón-Semidey, Angel; Canino, Glorisa; Celedón, Juan C

    2014-02-01

    Puerto Rican children share a disproportionate burden of prematurity and asthma in the United States. Little is known about prematurity and childhood asthma in Puerto Rican subjects. We sought to examine whether prematurity is associated with asthma in Puerto Rican children. We performed a case-control study of 678 children aged 6 to 14 years with (n = 351) and without (n = 327) asthma living in San Juan, Puerto Rico. Prematurity was defined by parental report for our primary analysis. In a secondary analysis, we only included children whose parents reported prematurity that required admission to the neonatal intensive care unit. Asthma was defined as physician-diagnosed asthma and wheeze in the prior year. We used logistic regression for analysis. All multivariate models were adjusted for age, sex, household income, atopy (≥1 positive IgE level to common allergens), maternal history of asthma, and early-life exposure to environmental tobacco smoke. In a multivariate analysis there was a significant interaction between prematurity and atopy on asthma (P = .006). In an analysis stratified by atopy, prematurity was associated with a nearly 5-fold increased odds of asthma in atopic children (adjusted odds ratio, 4.7; 95% CI, 1.5-14.3; P = .007). In contrast, there was no significant association between prematurity and asthma in nonatopic children. Similar results were obtained in our analysis of prematurity requiring admission to the neonatal intensive care unit and asthma. Our results suggest that atopy modifies the estimated effect of prematurity on asthma in Puerto Rican children. Prematurity might explain, in part, the high prevalence of atopic asthma in this ethnic group. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  6. Microscopic Characterization of Carbonaceous Aerosol Particle Aging in the Outflow from Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Moffet, R. C.; Henn, T. R.; Tivanski, A. V.; Hopkins, R. J.; Desyaterik, Y.; Kilcoyne, A. L. D.; Tyliszczak, T.; Fast, J.; Barnard, J.; Shutthanandan, V.; Cliff, S.S.; Perry, K. D.; Laskin, A.; Gilles, M. K.

    2009-09-16

    This study was part of the Megacities Initiative: Local and Global Research Observations (MILAGRO) field campaign conducted in Mexico City Metropolitan Area during spring 2006. The physical and chemical transformations of particles aged in the outflow from Mexico City were investigated for the transport event of 22 March 2006. A detailed chemical analysis of individual particles was performed using a combination of complementary microscopy and micro-spectroscopy techniques. The applied techniques included scanning transmission X-ray microscopy (STXM) coupled with near edge X-ray absorption fine structure spectroscopy (NEXAFS) and computer controlled scanning electron microscopy with an energy dispersive X-ray analyzer (CCSEM/EDX). As the aerosol plume evolves from the city center, the organic mass per particle increases and the fraction of carbon-carbon double bonds (associated with elemental carbon) decreases. Organic functional groups enhanced with particle age include: carboxylic acids, alkyl groups, and oxygen bonded alkyl groups. At the city center (T0) the most prevalent aerosol type contained inorganic species (composed of sulfur, nitrogen, oxygen, and potassium) coated with organic material. At the T1 and T2 sites, located northeast of T0 (~;;29 km and ~;;65 km, respectively), the fraction of homogenously mixed organic particles increased in both size and number. These observations illustrate the evolution of the physical mixing state and organic bonding in individual particles in a photochemically active environment.

  7. Hygiene, atopy and wheeze-eczema-rhinitis symptoms in schoolchildren from urban and rural Ecuador.

    Science.gov (United States)

    Cooper, Philip J; Vaca, Maritza; Rodriguez, Alejandro; Chico, Martha E; Santos, Darci N; Rodrigues, Laura C; Barreto, Mauricio L

    2014-03-01

    Rural residence is protective against atopy and wheeze-rhinitis-eczema symptoms in developed countries, an effect attributed to farming and poor hygiene exposures. There are few data from developing countries addressing this question. We compared atopy and wheeze-rhinitis-eczema symptoms between urban and rural Ecuador, and explored the effects of farming and poor hygiene exposures. We performed cross sectional studies of schoolchildren living in rural and urban Ecuador. Data on symptoms and farming/hygiene exposures were collected by parental questionnaire, atopy by allergen skin prick test reactivity and geohelminth infections by stool examinations. Among 2526 urban and 4295 rural schoolchildren, prevalence was: atopy (10.0% vs 12.5%, p=0.06), wheeze (9.4% vs 10.1%, p=0.05), rhinitis (8.1% vs 6.4%, p=0.02) and eczema (5.9% vs 4.7%, p=0.06). A small proportion of symptoms were attributable to atopy (range 3.9-10.7%) with greater attributable fractions for respiratory symptoms observed in urban schoolchildren. Respiratory symptoms were associated with poor hygiene/farming exposures: wheeze with lack of access to potable water; and rhinitis with household pets, no bathroom facilities and contact with large farm animals. Birth order was inversely associated with respiratory symptoms. Area of residence and atopy had few effects on these associations. Urban schoolchildren living in Ecuador have a similar prevalence of atopy, eczema and wheeze but a higher prevalence of rhinitis compared with rural children. Some farming and poor hygiene exposures were associated with an increase in the prevalence of wheeze or rhinitis while birth order was inversely associated with these symptoms.

  8. Hygiene, atopy and wheeze–eczema–rhinitis symptoms in schoolchildren from urban and rural Ecuador

    Science.gov (United States)

    Cooper, Philip J; Vaca, Maritza; Rodriguez, Alejandro; Chico, Martha E; Santos, Darci N; Rodrigues, Laura C; Barreto, Mauricio L

    2014-01-01

    Background Rural residence is protective against atopy and wheeze–rhinitis–eczema symptoms in developed countries, an effect attributed to farming and poor hygiene exposures. There are few data from developing countries addressing this question. We compared atopy and wheeze–rhinitis–eczema symptoms between urban and rural Ecuador, and explored the effects of farming and poor hygiene exposures. Methods We performed cross sectional studies of schoolchildren living in rural and urban Ecuador. Data on symptoms and farming/hygiene exposures were collected by parental questionnaire, atopy by allergen skin prick test reactivity and geohelminth infections by stool examinations. Results Among 2526 urban and 4295 rural schoolchildren, prevalence was: atopy (10.0% vs 12.5%, p=0.06), wheeze (9.4% vs 10.1%, p=0.05), rhinitis (8.1% vs 6.4%, p=0.02) and eczema (5.9% vs 4.7%, p=0.06). A small proportion of symptoms were attributable to atopy (range 3.9–10.7%) with greater attributable fractions for respiratory symptoms observed in urban schoolchildren. Respiratory symptoms were associated with poor hygiene/farming exposures: wheeze with lack of access to potable water; and rhinitis with household pets, no bathroom facilities and contact with large farm animals. Birth order was inversely associated with respiratory symptoms. Area of residence and atopy had few effects on these associations. Conclusions Urban schoolchildren living in Ecuador have a similar prevalence of atopy, eczema and wheeze but a higher prevalence of rhinitis compared with rural children. Some farming and poor hygiene exposures were associated with an increase in the prevalence of wheeze or rhinitis while birth order was inversely associated with these symptoms. PMID:24105783

  9. Saturday Driving Restrictions Fail to Improve Air Quality in Mexico City

    Science.gov (United States)

    Davis, Lucas W.

    2017-02-01

    Policymakers around the world are turning to license-plate based driving restrictions in an effort to address urban air pollution. The format differs across cities, but most programs restrict driving once or twice a week during weekdays. This paper focuses on Mexico City, home to one of the oldest and best-known driving restriction policies. For almost two decades Mexico City’s driving restrictions applied during weekdays only. This changed recently, however, when the program was expanded to include Saturdays. This paper uses hourly data from pollution monitoring stations to measure the effect of the Saturday expansion on air quality. Overall, there is little evidence that the program expansion improved air quality. Across eight major pollutants, the program expansion had virtually no discernible effect on pollution levels. These disappointing results stand in sharp contrast to estimates made before the expansion which predicted a 15%+ decrease in vehicle emissions on Saturdays. To understand why the program has been less effective than expected, the paper then turns to evidence from subway, bus, and light rail ridership, finding no evidence that the expansion was successful in getting drivers to switch to lower-emitting forms of transportation.

  10. Childcare needs of female street vendors in Mexico City.

    Science.gov (United States)

    Hernandez, P; Zetina, A; Tapia, M; Ortiz, C; Soto, I C

    1996-06-01

    This article reports on strategies developed by female street vendors (vendedoras ambulantes) in Mexico City to ensure the care of their young children in the absence of a specific and operational government policy to fulfil this need. The information concerning child care and health was gathered by a survey of 426 street traders selected by multi-stage random cluster sampling in four of the administrative districts (delegaciones politicas) of Mexico City during 1990. It was found that, as mothers of young children, street vendors most frequently looked after their children personally on the street or left them with other members of the family. Related factors were availability of alternative child care providers in the family, the age of the children and working conditions of the mother. Children who remained on the streets with their mothers suffered more frequently from gastro-intestinal diseases and accidents than the national average. The incidence of acute respiratory diseases, however, was similar in the cases of maternal care in the street and care by family members in another environment. Existing public health measures show a greater concern for the health of food consumers than that of workers in this area. Current public policy seeks to regulate street vending activities and to concentrate traders in ad hoc areas and facilities. Our research results document the need for actions that can contribute to an improvement in the care and health conditions of these young children.

  11. The heat spells of Mexico City

    Directory of Open Access Journals (Sweden)

    Ernesto Jáuregui

    2010-06-01

    Full Text Available The warning of urban air has been documented to increase in intensity and area as cities grow (Oke, 1982. As the cities grow the so called “heat island” tends to increase the risk of more frequent heat waves as well as their impacts (IPCC, 2001. Threshold values to define a heat wave vary geographically. For the case of Mexico City located in a high inland valley in the tropics, values above 30° C (daily maximum observed for three or more consecutive days and 25° C or more as mean temperature have been adopted to define the phenomenon. These events occur at the end of the dry season during March to May when afternoon relative humidity is quite low (∼20% and thus reducing the stress. Maximum temperatute data from the Observatory of the National Meteorological Service were used. Results show that during the second half of the XXth century the frequency of heat waves as defined above has doubled from 6 events/decade to 16/decade in the 1990s with a marked increase in the last third of the last century when population of the city grew from 8.5 to 18.5 million (CONAPO, 2000. During this time the average urban/rural contrast grew considerably from about 6° C to 10° C (Jáuregui, 1986. While these heat waves may be considered as “mild”they receive attention from the media and prompt actions by the population to relieve the heat stress. Application of heat indices based on the human energy balance (PET and PMV result in moderate to strong heat stress during these events. Because climate change is expected to raise nighttime minimum temperatures more than daytime highs (as suggested by the IPCC, 2001 urban heat islands and their related heat waves are likely to be a significant health concern in days to come in large urban centers especially in the developing countries.

  12. The Chemo and the Mona: Inhalants, devotion and street youth in Mexico City

    NARCIS (Netherlands)

    Gigengack, R.A.

    2014-01-01

    This paper understands inhalant use – the deliberate inhalation of volatile solvents or glues with intentions of intoxication – as a socially and culturally constituted practice. It describes the inhalant use of young street people in Mexico City from their perspective (“the vicioso or inhalant

  13. Coupled seismic modes and earthquake hazard in Mexico City

    Science.gov (United States)

    Lomnitz, C.

    2007-05-01

    Wave-to-wave coupling can arise when an acoustic pulse selects a Rayleigh mode of the same speed and both travel together swapping energy across an interface. A similar effect may cause severe damage at distances of several hundred kilometers when an Lg wavetrain incides upon a soft remote sedimentary waveguide, as in Mexico City. Energy at a single dominant frequency is then trapped in the waveguide. When the input power exceeds the damping losses, the trapped mode reverberates in the layer for up to five minutes, causing severe resonant damage to structures.

  14. Measurement of ambient aerosols in northern Mexico City by single particle mass spectrometry

    Directory of Open Access Journals (Sweden)

    R. C. Moffet

    2008-08-01

    Full Text Available Continuous ambient measurements with aerosol time-of-flight mass spectrometry (ATOFMS were made in an industrial/residential section in the northern part of Mexico City as part of the Mexico City Metropolitan Area-2006 campaign (MCMA-2006. Results are presented for the period of 15–27 March 2006. The submicron size mode contained both fresh and aged biomass burning, aged organic carbon (OC mixed with nitrate and sulfate, elemental carbon (EC, nitrogen-organic carbon, industrial metal, and inorganic NaK inorganic particles. Overall, biomass burning and aged OC particle types comprised 40% and 31%, respectively, of the submicron mode. In contrast, the supermicron mode was dominated by inorganic NaK particle types (42% which represented a mixture of dry lake bed dust and industrial NaK emissions mixed with soot. Additionally, aluminosilicate dust, transition metals, OC, and biomass burning contributed to the supermicron particles. Early morning periods (2–6 a.m. showed high fractions of inorganic particles from industrial sources in the northeast, composed of internal mixtures of Pb, Zn, EC and Cl, representing up to 73% of the particles in the 0.2–3μm size range. A unique nitrogen-containing organic carbon (NOC particle type, peaking in the early morning hours, was hypothesized to be amines from local industrial emissions based on the time series profile and back trajectory analysis. A strong dependence on wind speed and direction was observed in the single particle types that were present during different times of the day. The early morning (3:30–10 a.m. showed the greatest contributions from industrial emissions. During mid to late mornings (7–11 a.m., weak northerly winds were observed along with the most highly aged particles. Stronger winds from the south picked up in the late morning (after 11 a.m., resulting in a decrease in the concentrations of the major aged particle types and an increase in the number fraction of fresh

  15. Winter Dew Harvest in Mexico City

    Directory of Open Access Journals (Sweden)

    Arias-Torres Jorge Ernesto

    2015-12-01

    Full Text Available This study presents experimental and theoretical results of winter dew harvest in México City in terms of condensation rate. A simplified theoretical model based on a steady-state energy balance on a radiator-condenser was fitted, as a function of the ambient temperature, the relative humidity and the wind velocity. A glass sheet and aluminum sheet white-painted were used as samples over the outdoor experiments. A good correlation was obtained between the theoretical and experimental data. The experimental results show that there was condensation in 68% of the winter nights on both condensers. The total winter condensed mass was 2977 g/m2 and 2888 g/m2 on the glass sheet and aluminum sheet white-painted, respectively. Thus, the condensed mass on the glass was only 3% higher than that on the painted surface. The maximum nightly dew harvests occurred during December, which linearly reduced from 50 g/m2 night to 22 g/m2 night as the winter months went by. The condensation occurred from 1:00 a.m. to 9:00 a.m., with maximum condensation rates between 6:00 a.m. and 7:00 a.m. The dew harvest can provide a partial alternative to the winter water shortage in certain locations with similar climates to the winter in Mexico City, as long as pollution is not significant.

  16. MEASUREMENTS OF MICROTREMORS IN BUILDINGS IN MEXICO CITY AFTER THE SEPTEMBER 19,1985 MICHOACAN EARTHQUAKE

    OpenAIRE

    Tadao, MINAMI; Toshihide, KASHIMA; Earthquake Research Institute, University of Tokyo; Building Research Institute, Ministry of Construction

    1990-01-01

    We had the opportunity to measure the microtremors of 46 buildings in Mexico City as members of the Technical Cooperation Mission that the Japan International Cooperation Agency (JICA) dispatched to work in Mexico from 19 October to 22 November 1985. Fourier analyses of the recorded microtremor data provided useful information about the dynamic properties of buildings damaged or undamaged by the 1985 Michoacan earthquake. The measured natural periods suggested that the rigidity of the undamag...

  17. Hepatitis C antibody prevalence among Mexico City prisoners injecting legal and illegal substances.

    Science.gov (United States)

    Silverman-Retana, Omar; Serván-Mori, Edson; McCoy, Sandra I; Larney, Sarah; Bautista-Arredondo, Sergio

    2017-12-01

    Hepatitis C virus (HCV) infection is highly prevalent among prisoners and this prevalence estimates reach 64% among prisoners who inject illicit drugs. Prisons are important sites for HCV transmission in the absence of access to sterile injecting equipment; hence, it can be transmitted between prisoners who share contaminated needles and syringes. We aimed to estimate the prevalence of risk factors for anti-HCV prevalence, with particular interest on injecting behavior, and to assess correlates of anti-HCV positivity among Mexico City prisoners. Cross-sectional study based on information -collected in three male and two female prisons in Mexico City during 2010-2011- about sexually transmitted infections, socio-demographics, criminal history, substance use, vitamin injection, tattooing, among others (n=3,910). Weighted multivariable adjusted logistic regression models were estimated to assess the overall and differential odds for anti-HCV due to injecting behavior. Overall prevalence of anti-HCV was 3.3%. This figure rose to 43.1% among prisoners with a history of illicit drug injection. Prisoners with history of vitamin injection showed a similar prevalence of anti-HCV (43.8%). After stratifying by substance injected, the adjusted odds ratio was 9.8 (95% CI: 4.0, 23.8) for illicit drug injection and 11.9 (95% CI: 5.8, 23.8) for illicit drug and vitamin injection. Based on data from the most populous prisons in Mexico City, this study showed that anti-HCV is highly prevalent among prisoners with history of injecting behavior. In this sense, injecting behavior per-se, independent of the substance used, is associated with increased odds of anti-HCV positivity. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Urban guides: image and space invention in Mexico City

    Directory of Open Access Journals (Sweden)

    Héctor Mendoza Vargas

    2016-03-01

    Full Text Available This article analyzes the urban guides of Mexico City from a wide time-lapse perspective, from the end ofthe eighteenth century to the nineteenth century and up to 1940, in order to detect major themes and the change of urban perception. In foreigner’s guide outlines, from 1792 to 1793, the Cathedral’s central position conferred strength to the maps inserted in such editions. It is worth noting the subliminal role of this document regarding urban perception, social behavior and the maintenance of religious devotion in the capital of New Spain. After Mexico’s independence these guides lacked novelty. During the years between 1842 and 1854, this editorial genre was reactivated in the Mexican capital. In those years the guides were included in an attempt to fulfill the increasing need for information about the city regarding political, judicial, ecclesiastical and military aspects including, as the main novelty, the continuously expansive commercial sector. While guide editions were modified in order to satisfy the consumption and preferences of the nascent urban bourgeoisie, both editors and authors detected novel concerns among readers, not only about commercial life but they also looked for pleasant and ludic experiences in the city.

  19. Non-pro-vitamin A and pro-vitamin A carotenoids in atopy development.

    Science.gov (United States)

    Rühl, R

    2013-01-01

    Carotenoids are important derivatives of the human diet and occur in high concentrations in the human organism. Various carotenoids are also present in human breast milk and are transferred to breast-fed children. The alternative to breastfeeding is supplementation with an infant milk formula, but these formulas contain only a limited variety of carotenoids. Our question is: 'What is the function of various carotenoids in human nutrition with a special emphasis on child development and the development of atopy?' In this review, the mechanisms of action of the most important non-pro-vitamin A and pro-vitamin A carotenoids: α-carotene, β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene and retinoids are discussed. In summary, the combination of carotenoids, especially lycopene, seems to be of great importance, and exclusive usage of β-carotene in infant formula may yield in an increased atopy prevalence mediated in various target organs like the skin, lungs and immune competent cells. We conclude that the determination of novel bioactive metabolites of various carotenoids, at various stages in different organs during atopy development, might be the key to understanding the potential importance of carotenoids on atopy development. Copyright © 2013 S. Karger AG, Basel.

  20. Serum IL-10, IL-17 and IL-23 levels as "bioumoral bridges" between dyslipidemia and atopy.

    Science.gov (United States)

    Manti, S; Leonardi, S; Panasiti, I; Arrigo, T; Salpietro, C; Cuppari, C

    2017-11-01

    Although several studies suggest a possible link between dyslipidemia and atopy, literature findings are still unclear. The aim of the study was to investigate the relationship between dyslipidemia and atopy in a pediatric population affected by dyslipidemia or dyslipidemia/atopic predisposition. Children with dyslipidemia, dyslipidemia and atopy as well as healthy children were recruited. Serum total IgE, IL-10, IL-17, and IL-23 levels as well as fasting lipid values (total cholesterol, LDL, HDL and triglycerides) were performed on all enrolled children. The present study evaluated 23 patients affected by dyslipidemia, 26 patients affected by atopy and dyslipidemia and, 22healthy children. Serum total IgE levels significantly related also with serum cholesterol levels: positively with total cholesterol (pdyslipidemia than patients with dyslipidemia (pdyslipidemia than patients with dyslipidemia (pdyslipidemia and atopic predisposition share the same immune pathways as well as they offer new insights in the complex crosstalk between hyperlipidemia and atopy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Atmospheric electric field effects of cosmic rays detected in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, L. X; Valdes-Galicia, J. F [Instituto de Geofisica, Universidad National Autonoma de Mexico, Mexico D.F(Mexico)

    2006-10-15

    We studied the possible effects of atmospheric electric fields, generated in thunderstorms, on the cosmic ray intensity detected at the Earth's surface by investigating the variations of the counting rates of the cosmic-ray nucleonic component, obtained from the neutron monitor installed in Mexico City, for thunderstorms during 1996 and 1997. These were years of minimum solar activity. We compare our experimental results with the general theory of cosmic ray meteorological effects by Dorman (1995). The observed intensity variation is about 0.2%. According to Dorman (1995), the effect should be between 0.27% and 0.81% on the counting rate of the neutron monitor when the atmospheric electric field intensities are around 100 to 300 Vcm-1.Our results show that either the electric field in Mexico City had less intensity than assumed by Dorman (1995), or the electric field is not uniform in time and height during the development of the thunderstorm. [Spanish] Estudiamos los posibles efectos de los campos electricos atmosfericos, generados en las tormentas electricas, sobre la intensidad de los rayos cosmicos detectados en la superficie terrestre, analizando las variaciones de las razones de conteo de la componente nucleonica de los rayos cosmicos, obtenidas por el monitor de neutrones instalado en la ciudad de Mexico, durante tormentas electricas ocurridas entre 1996 y 1997, anos del minimo solar. Comparamos nuestros resultados experimentales con la teoria general de los efectos meteorologicos en los rayos cosmicos, desarrollada por Dorman (1995). Se observo una variacion en la intensidad de alrededor de 0.2%. De acuerdo con Dorman (1995), el efecto puede estar entre 0.27 % y 0.81% en las razones de conteo del monitor de neutrones cuando las intensidades del campo electrico atmosferico se encuentran al rededor de 100 a 300 Vcm-1. Nuestros resultados muestran que los campos electricos en la ciudad de Mexico tuvieron menos intensidad que los campos electricos asumidos

  2. Biophysical, infrastructural and social heterogeneities explain spatial distribution of waterborne gastrointestinal disease burden in Mexico City

    Science.gov (United States)

    Baeza, Andrés; Estrada-Barón, Alejandra; Serrano-Candela, Fidel; Bojórquez, Luis A.; Eakin, Hallie; Escalante, Ana E.

    2018-06-01

    Due to unplanned growth, large extension and limited resources, most megacities in the developing world are vulnerable to hydrological hazards and infectious diseases caused by waterborne pathogens. Here we aim to elucidate the extent of the relation between the spatial heterogeneity of physical and socio-economic factors associated with hydrological hazards (flooding and scarcity) and the spatial distribution of gastrointestinal disease in Mexico City, a megacity with more than 8 million people. We applied spatial statistics and multivariate regression analyses to high resolution records of gastrointestinal diseases during two time frames (2007–2009 and 2010–2014). Results show a pattern of significant association between water flooding events and disease incidence in the city center (lowlands). We also found that in the periphery (highlands), higher incidence is generally associated with household infrastructure deficiency. Our findings suggest the need for integrated and spatially tailored interventions by public works and public health agencies, aimed to manage socio-hydrological vulnerability in Mexico City.

  3. Urban structure analysis of mega city Mexico City using multisensoral remote sensing data

    Science.gov (United States)

    Taubenböck, H.; Esch, T.; Wurm, M.; Thiel, M.; Ullmann, T.; Roth, A.; Schmidt, M.; Mehl, H.; Dech, S.

    2008-10-01

    Mega city Mexico City is ranked the third largest urban agglomeration to date around the globe. The large extension as well as dynamic urban transformation and sprawl processes lead to a lack of up-to-date and area-wide data and information to measure, monitor, and understand the urban situation. This paper focuses on the capabilities of multisensoral remotely sensed data to provide a broad range of products derived from one scientific field - remote sensing - to support urban managing and planning. Therefore optical data sets from the Landsat and Quickbird sensors as well as radar data from the Shuttle Radar Topography Mission (SRTM) and the TerraSAR-X sensor are utilised. Using the multi-sensoral data sets the analysis are scale-dependent. On the one hand change detection on city level utilising the derived urban footprints enables to monitor and to assess spatiotemporal urban transformation, areal dimension of urban sprawl, its direction, and the built-up density distribution over time. On the other hand, structural characteristics of an urban landscape - the alignment and types of buildings, streets and open spaces - provide insight in the very detailed physical pattern of urban morphology on higher scale. The results show high accuracies of the derived multi-scale products. The multi-scale analysis allows quantifying urban processes and thus leading to an assessment and interpretation of urban trends.

  4. Aerosol Light Absorption and Scattering at Four Sites in and Near Mexico City: Comparison with Las Vegas, Nevada, USA

    Science.gov (United States)

    Arnott, W. P.; Miranda, G. P.; Gaffney, J. S.; Marley, N. A.

    2007-05-01

    Four photoacoustic spectrometers (PAS) for aerosol light scattering and absorption measurements were deployed in and near Mexico City in March 2006 as part of the Megacity Impacts on Regional and Global Environments (MIRAGE). The four sites included: an urban site at Instituto Mexicano del Petroleo (Mexican Oil Institute, denoted by IMP); a suburban site at the Technological University of Tecamac; a rural site at "La Biznaga" ranch; and a site at the Paseo de Cortes (altitude 3,810 meters ASL) in the rural area above Amecameca in the State of Mexico, on the saddle between the volcanoes Popocatepetl and Iztaccihuatl. A similar campaign was held in Las Vegas, Nevada, USA in January-February, 2003. The IMP site gave in-situ characterization of the Mexico City plume under favorable wind conditions while the other sites provided characterization of the plume, mixed in with any local sources. The second and third sites are north of Mexico City, and the fourth site is south. The PAS used at IMP operates at 532 nm, and conveniently allowed for characterization of gaseous absorption at this wavelength as well. Instruments at the second and third sites operate at 870 nm, and the one at the fourth site at 780 nm. Light scattering measurements are accomplished within the PAS by the reciprocal nephelometery method. In the urban site the aerosol absorption coefficient typically varies between 20 and 180 Mm-1 during the course of the day and significant diurnal variation of the aerosol single scattering albedo was observed probably as a consequence of secondary aerosol formation. Comparisons with TSI nephelometer scattering at the T0 site will be presented. We will present the diurnal variation of the scattering and absorption as well as the single scattering albedo and fraction of absorption due to gases at the IMP site and compare with Las Vegas diurnal variation. Mexico City 'breaths' more during the course of the day than Las Vegas, Nevada in part because the latitude of

  5. Natural hazards and urban policies in Mexico City

    Directory of Open Access Journals (Sweden)

    François Mancebo

    2009-07-01

    Full Text Available L’agglomération de Mexico, à plus de 2 000 mètres d’altitude, adossée à la Sierra Madre et la Cordillère Volcanique est assise sur un site accueillant mais redoutable. Il s’agit d’un des endroits les plus exposés du globe, soumis à une combinaison de risques naturels, de risques technologiques souvent mal maîtrisés dus à des industries lourdes, de nuisances, de cumul des polluants et d’un épuisement des ressources locales utilisables, tout particulièrement les ressources en eau. Après le séisme dévastateur de 1985, les acteurs de l’aménagement de Mexico tentent d’intégrer risques et durabilité dans la définition de nouvelles politiques urbaines. Mais, si les risques sont bien identifiés et des réponses sont données, leur applicabilité est quasi-nulle. Une approche normative et n’incluant pas l’ensemble de l’agglomération, mais utilisant les périphéries pour améliorer la durabilité des centres (sorte de durabilité importée à l’échelle de la métropole explique cette situation. Comme dans le mythe de Sisyphe, acteurs locaux et nationaux tentent de faire remonter la pente au rocher du risque mais ce dernier finit toujours par redescendre ? C’est qu’en réalité le problème n’est pas le rocher. Le problème, c’est la pente, c’est-à-dire le substrat fait de représentations territoriales et d’usages de l’espace qui fondent la société mexicaine, sur laquelle roule le rocher.Mexico City is located at an altitude of over 2 000 metres where it occupies an attractive but hazardous site hemmed in by the Sierra Madre and volcanic mountain ranges.The site is one of the most disaster-prone locations in the world, threatened by a combination of natural hazards, poorly controlled technological hazards created by the city’s heavy industry, pollution – particularly air pollution and diminishing local resources, the most seriously threatened being water. Since the devastating earthquake

  6. Vitamin A supplementation and risk of atopy

    DEFF Research Database (Denmark)

    Kiraly, Nicholas; Balde, Aliu; Lisse, Ida Marie

    2013-01-01

    The World Health Organization recommends high-dose vitamin A supplementation (VAS) for children above six months of age in low-income countries. VAS has been associated with up-regulation of the Th2 response. We aimed to determine if VAS is associated with atopy in childhood....

  7. Overview of the 2006 MILAGRO Campaign in Mexico City: Transport and Transformation of Emissions from a Megacity

    Science.gov (United States)

    Molina, L.; MILAGRO Science Team

    2009-04-01

    Megacities (metropolitan areas with population over 10 million) and large urban centers present a major challenge for the global environment. Population growth, increasing motorization and industrialization have resulted in a higher demand for energy, greater use of fossil fuels, and more emission of pollutants into the atmosphere. As a result, air pollution has become not only one of the central environmental problems of the century, but also presents serious consequences to human health and ecosystems and economic costs to society. MILAGRO (Megacity Initiative: Local and Global Research Observations) is the first international effort to study the impact of air pollutants generated and exported by megacity. The Mexico City Metropolitan Area (MCMA) - one of the largest megacities in the world - was selected as the initial case study for MILAGRO. The measurement phase consisted of a month-long series of carefully coordinated observations of the chemistry and physics of the atmosphere in and near Mexico City during March 2006, using a wide range of instruments at ground sites, on aircraft and satellites, complemented by meteorological forecasting and numerical simulations. Together, these research observations have provided the most comprehensive characterization of Mexico City's urban and regional air pollution that will take years to analyze and evaluate fully. Initial analysis of the data is focused on understanding meteorology, emissions, urban and regional photochemistry, aerosol evolution and radiative effects - spanning the urban to regional scale transition. Many interesting aspects of atmospheric chemistry in and near the MCMA are emerging and have already added significantly to our understanding of the chemical and physical properties of the city's reactive atmosphere and the regional impacts. The information can be useful for decision-makers in Mexico in developing air quality management strategies as well as provide insights to air pollution problems in

  8. From Reproductive Rights to Responsibilization: Fashioning Liberal Subjects in Mexico City's New Public Sector Abortion Program.

    Science.gov (United States)

    Singer, Elyse Ona

    2017-12-01

    Building on medical anthropology literature that analyzes doctor-patient interactions as a charged site for the production of political subjectivities, I demonstrate how a central feature of Mexico City's new public sector abortion program involves "responsibilization." In accordance with entrenched Ministry of Health objectives, providers transmit a suite of values about personal responsibility and self-regulation through the use of birth control, hinging abortion rights to responsible reproductive subjectivity. Based on 18 months of ethnographic research across program clinics, including 75 interviews with patients and providers, I show how interrupción legal del embarazo protocols fashion "responsibilized" liberal subjects. I argue that the recent granting of abortion rights in Mexico City-ostensibly a new moment for the construction of women's citizenship-instead reflects and extends long-standing state agendas of "reproductive governance." My analysis of reproductive rights as the newest framing of ongoing population policies in Mexico adds to a critical anthropology of human rights and of liberal projects of governance. © 2016 by the American Anthropological Association.

  9. Geographically Apart, Attitudinally Very Close: A Comparison of Attitudes toward Animals between Romania and Mexico City

    OpenAIRE

    Rusu, Alina Simona; Pop, Denisa; Turner, Dennis C.

    2017-01-01

    Among other regions, Romania and Mexico (particularly Mexico City) are often cited as problematic areas in surveys and reports on the growing population of stray animals in urban areas. The aim of our study was to adapt for Romanian and Spanish languages usage of an instrument that includes significant psychological and social dimensions of the attitudes toward animals (i.e., Attitudes toward Animals questionnaire [ATA]; Fehlbaum, Waiblinger, & Turner, 2010; Turner, 2010) and compare these at...

  10. Measurements of indoor radon and radon progeny in Mexico City

    International Nuclear Information System (INIS)

    Cheng, Y.S.; Rodriguez, G.P.

    1996-01-01

    Indoor radon has been a public concern associated with increased lung cancer risks. Radon decay products interact with indoor aerosols to form progeny with different size distributions, which may influence the lung dosimetry when the progeny are inhaled. Air pollution in Mexico City is a serious problems with high particulate concentrations, but there are few reports of indoor radon measurement. The purposes of this study were to measure the aerosol concentration, radon concentration, and radon activity size distribution in the living area of three houses in Mexico City. The radon concentration was monitored by a RGM-3 radon gas monitor (Eberline, Inc., Santa Fe, NM). A graded diffusion battery was used to determine the progeny concentration and activity size distribution. The concentration and size distribution of the indoor aerosols were monitored by a quartz, crystal microbalance cascade impactor. Our measurements showed high concentrations of indoor aerosols (20-180 gg m -3 ). However, the radon concentrations-were low ( -1 ), but showed a clear diurnal pattern with peak concentrations from 2-10 AM. The activity size distributions of radon progeny were trimodal, with peaks of 0.6 nm, 4-5 nm, and 100 rim. Most activities were associated with large particle sizes. Our results indicated that indoor radon concentration was not high, due in part to a relatively high air exchange with outdoor air. The high aerosol concentration may also play an important part in the activity size distribution of radon progeny

  11. Diabetes and hypertension care among male prisoners in Mexico City: exploring transition of care and the equivalence principle.

    Science.gov (United States)

    Silverman-Retana, Omar; Servan-Mori, Edson; Lopez-Ridaura, Ruy; Bautista-Arredondo, Sergio

    2016-07-01

    To document the performance of diabetes and hypertension care in two large male prisons in Mexico City. We analyzed data from a cross-sectional study carried out during July-September 2010, including 496 prisoners with hypertension or diabetes in Mexico City. Bivariate and multivariable logistic regressions were used to assess process-of-care indicators and disease control status. Hypertension and diabetes prevalence were estimated on 2.1 and 1.4 %, respectively. Among prisoners with diabetes 22.7 % (n = 62) had hypertension as comorbidity. Low achievement of process-of-care indicators-follow-up visits, blood pressure and laboratory assessments-were observed during incarceration compared to the same prisoners in the year prior to incarceration. In contrast to nonimprisoned diabetes population from Mexico City and from the lowest quintile of socioeconomic status at the national level, prisoners with diabetes had the lowest performance on process-of-care indicators. Continuity of care for chronic diseases, coupled with the equivalence of care principle, should provide the basis for designing chronic disease health policy for prisoners, with the goal of consistent transition of care from community to prison and vice versa.

  12. Shifting corporate geographies in global cities of the South: Mexico City and Johannesburg as case studie

    Directory of Open Access Journals (Sweden)

    Parnreiter, Christof

    2013-09-01

    Full Text Available Global city research links the expansion of advanced producer services in major cities to the internationalisation of real estate markets as well as to the spread of (mainly high-rise office complexes. This research, however, has based its findings mainly on cases of the Global North. This paper examines, based on Grant and Nijman’s (2002 suggestion that the “internal spatial organisation of gateway cities in the less-developed world” reflects “the city’s role in the global political economy”, which patterns occur in two metropoles of the Global South. In addition to this, the analysis focuses especially on the driving forces behind the changes in corporate geographies. The analysis is placed in Mexico City and Johannesburg and based on real estate market data (offices as well as background documents on urban development. The outcome shows that in these cities, local transformation processes of the real estate market and office space location are indeed considerably shaped by global market dynamics. However, the findings also indicate that there is no clear scale dependence of the territorial form. In order to comprehensively understand the changes in the corporate geographies therefore, it is necessary to direct more attention to local and national dynamics. The restructuring of the built environment in both cities can only be grasped fully by considering the particular role of local and national governments. This additional entry point to an understanding of shifting corporate geographies helps to put recent dynamics of global capitalism and politics of urban neoliberalism in perspective.

  13. Protocol for a prospective longitudinal study of risk factors for hypertension incidence in a Mexico City population: the Tlalpan 2020 cohort.

    Science.gov (United States)

    Colín-Ramírez, Eloisa; Rivera-Mancía, Susana; Infante-Vázquez, Oscar; Cartas-Rosado, Raúl; Vargas-Barrón, Jesús; Madero, Magdalena; Vallejo, Maite

    2017-07-31

    Systemic hypertension (HTN) is a common risk factor for cardiovascular disease. In Mexico, HTN prevalence has increased over time and is currently 31%. Nonetheless, information about the country's HTN incidence and its associated risk factors is scarce. Understanding this condition is a priority for identifying the scope of primary prevention. The main objective of this study is to evaluate the effect of traditional and non-traditional risk factors on the incidence of HTN in a cohort of healthy Mexico City residents under biannual follow-up for 10 years. A prospective longitudinal study is proposed in which clinically healthy residents of Mexico City between 20 and 50 years old will be recruited; the participants will be evaluated every 2 years over a period of 10 years or until they develop HTN. Evaluations regarding sociodemographic, clinical, anthropometric, biochemical, diet, physical activity, stress, sleep quality, alcohol and tobacco consumption factors will be performed. The participants will be recruited from the 16 municipalities of Mexico City through promotional strategies aimed at the community and will be clinically evaluated at a tertiary care institution, Instituto Nacional de Cardiología Ignacio Chávez (National Institute of Cardiology Ignacio Chavez), located in Mexico City, Mexico. Sample size estimated for this study is 3436, and the Cox proportional hazards model will be used to estimate HRs for the association between explanatory variables and HTN using both raw and adjusted data. This study was approved by the Institutional Bioethics Committee of the Instituto Nacional de Cardiología Ignacio Chávez (National Institute of Cardiology Ignacio Chavez) under number 13-802. Findings from this study will be disseminated through scientific papers and research conferences. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise

  14. [Social representation of AIDS among students of Mexico City].

    Science.gov (United States)

    Flores-Palacios, Fátima; Leyva-Flores, René

    2003-01-01

    To analyze the social representation of AIDS in a group of high school students aged 16 to 23 years in Mexico City. A non-probabilistic, cross-sectional research was carried out in a public high school in Mexico City. Students of all grades were invited to participate in the study, which took place between 1999 and 2000. Forty-six students participated; 28% male and 72% female. This exploratory field study consisted of three phases, each to address one of three dimensions: cognitive using free association techniques, representational field using semi-structured interviews; and context attitude by means of two discussion groups. In the latter, the information was previously collected for discussion. The cognitive nucleus on AIDS included the association between sex, disease, and death. The representational field of AIDS is constructed around the transmission-prevention unit. Construct elements are virus, contagion, sex, protection, and condom. An ambivalent attitude was identified towards HIV prevention and transmission: "We are only half responsible". Situations such as "rape, blood transfusions, infected syringes" were prominent in the discussion group, deemed beyond their control to prevent transmission, thus explaining the group's ambivalent attitude towards prevention. The usefulness of condoms was associated with prevention of pregnancy rather than with prevention of sexually transmitted infections. The social representation of HIV/AIDS in young students conforms a multidimensional corpus where different elements of scientific order and common sense converge and interact, such as beliefs, myths, taboos, and fears. All of these contribute to construct the meaning of AIDS. The English version of this paper is available at:http://www.insp.mx/salud/index.html.

  15. Risk to a Changing Climate in the Mexico City Metropolitan Area

    Science.gov (United States)

    Vargas, N. D.

    2016-12-01

    The issue of climate change has dominated the atmospheric sciences agenda in recent decades. The concern about an increase in climate related disasters, mainly in large population centers, has led to ask whether they are mainly due to changes in climate or in vulnerability.The Mexico City Metropolitan Area (MCMA) is an example of megalopolis under high climate risk, where floods, landslides, health problems, high air pollution events, socioeconomic droughts are becoming important environmental and social problems. As urbanization spreads and population increases exposure to natural hazards increases, and so the magnitude of risk to a changing climate and the negative impacts. Since the late nineteenth century, in the MCMA an average maximum temperature could be around 22°C, whereas today it is about 24.5ºC. That is, the increase in the average temperature in Mexico City is around 3°C in a hundred years. But there are areas where an increase in the average temperature is similar in only thirty years. The heating rate of the city can vary depending on the change in land use. Areas that conserve forested regions in the process of urbanization tend to warm less than areas where the transformation into concrete and cement is almost complete. Thus, the climate of the MCMA shows important changes mainly in relation to land use changes. Global warming and natural climate variability were also analyzed as possible forcing factors of the observed warming by comparing low frequency variations in local temperature and indices for natural forcing. The hydrological cycle of the MCMA has also changed with urbanization. The "bubble of hot air" over the urban area has more capacity to hold moisture now than before the UHI. However, the increased risk to floods, heat or drought appears to be related not only to more frequent intense climatic hazards induced by the urbanization effect. This process also induces increased vulnerability to a changing climate. The establishment of

  16. Exploratory study of particle-bound polycyclic aromatic hydrocarbons in different environments of Mexico City

    Science.gov (United States)

    Velasco, Erik; Siegmann, Philip; Siegmann, Hans C.

    2004-09-01

    Several studies regarding particulate matter in air pollution have been performed in Mexico City, but none have focused on environment exposure to particle-bound polycyclic aromatic hydrocarbons (PPAH), which are related to the occurrence of cardiopulmonary diseases and mortality. On this account, this study presents measurements of personal exposure to PPAH in different outdoor and indoor environments, as well as along roadways in Mexico City. The measurements were done with portable sensors based on photoelectric charging and diffusion charging to determine the PPAH concentrations and the joint active surface of all particles, respectively. The use of these two sensors in parallel is a useful tool to qualitatively identify the major sources and to describe the physical and chemical characteristics of the particles. The highest exposures were found in ambient air near traffic sources, mainly at sites with great influence of diesel vehicles, such as urban transfer bus stations. Roadway measurements showed that Mexican PPAH pollution levels are between those in large cities in Europe and USA. For indoor environments such as residences, shopping centers, restaurants and hospitality venues, it was found that secondhand smoke is the major contributor, however badly calibrated pilot stoves, inefficient ventilation and faulty air-conditioning systems can be additional sources of PPAH.

  17. Mercury Levels in Pregnant Women, Children, and Seafood from Mexico City

    Science.gov (United States)

    Basu, Niladri; Tutino, Rebecca; Zhang, Zhenzhen; Cantonwine, David E.; Goodrich, Jaclyn M.; Somers, Emily C.; Rodriguez, Lauren; Schnaas, Lourdes; Solano, Maritsa; Mercado, Adriana; Peterson, Karen; Sánchez, Brisa N.; Hernández-Avila, Mauricio; Hu, Howard; Téllez-Rojo, Martha Maria

    2014-01-01

    Background Mercury is a global contaminant of concern though little is known about exposures in México. Objectives To characterize mercury levels in pregnant women, children, and commonly consumed seafood samples. Methods Use resources of the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) birth cohorts to measure total mercury levels in archived samples from 348 pregnant women (blood from three trimesters and cord blood), 825 offspring (blood, hair, urine) and their mothers (hair), and 91 seafood and canned tuna samples from Mexico City. Results Maternal blood mercury levels correlated across three trimesters and averaged 3.4μg/L. Cord blood mercury averaged 4.7μg/L and correlated with maternal blood from trimester 3 (but not trimesters 1 and 2). In children, blood, hair and urine mercury levels correlated and averaged 1.8μg/L, 0.6μg/g, and 0.9μg/L, respectively. Hair mercury was 0.5μg/g in mothers and correlated with child's hair. Mean consumption of canned tuna, fresh fish, canned sardine, and shellfish was 3.1, 2.2, 0.5, and 1.0 times per month respectively in pregnant women. Mean mercury content in 7 of 23 seafood species and 5 of 9 canned tuna brands purchased exceeded the U.S. EPA guidance value of 0.3 μg/g. Conclusions Mercury exposures in pregnant women and children from Mexico City, via biomarker studies, are generally 3-5 times greater than values reported in population surveys from the U.S., Canada, and elsewhere. In particular, mercury levels in 29-39% of the maternal participants exceeded the biomonitoring guideline associated with the U.S. EPA reference dose for mercury. PMID:25262076

  18. Association between infection with Helicobacter pylori and atopy in young Ethiopian children: A longitudinal study.

    Science.gov (United States)

    Taye, B; Enquselassie, F; Tsegaye, A; Amberbir, A; Medhin, G; Fogarty, A; Robinson, K; Davey, G

    2017-10-01

    Epidemiological evidence from developed countries indicates that Helicobacter pylori infection correlates with a reduced risk of atopy and allergic disorders; however, limited data are available from low-income countries. We examined associations between H. pylori infection in early childhood and atopy and reported allergic disorders at the age of 6.5 years in an Ethiopian birth cohort. A total of 856 children (85.1% of the 1006 original singletons in a population-based birth cohort) were followed up at age six and half years. An interviewer-led questionnaire administered to mothers provided information on demographic and lifestyle variables. Questions on allergic disease symptoms were based on the International Study of Asthma and Allergies in Children (ISAAC) core allergy and environmental questionnaire. Serum samples were analysed for total IgE levels and anti-H. pylori cytotoxin-associated gene A (CagA) IgG antibody using commercially available ELISA kits. Stool samples were analysed for H. pylori antigen using a rapid immunochromatographic test. The independent effects of H. pylori infection (measured at age of 3, 5 and 6.5 years) on prevalence and incidence of atopy and reported allergic disorders (measured at age of 6.5 years) were determined using multiple logistic regression. In cross-sectional analysis, current H. pylori infection at age 6.5 years was inversely, though not significantly, related to prevalence of atopy and "any allergic condition" at age 6.5 years. However, detection of H. pylori infection at any point up to age 6.5 years was associated with a significantly reduced odds of both atopy and "any allergic condition" (adjusted OR AOR, 95% CI, 0.54; 0.32-0.92, P = .02, and .31; 0.10-0.94, P = .04, respectively). In longitudinal analyses, H. pylori infection at age 3 was inversely associated with incidence of atopy (AOR, 95% CI, 0.49; 0.27-0.89, P = .02). Furthermore, among H. pylori-infected children, those with a Cag

  19. Report of the second joint meeting of the Working Party on Assessment of Fish Resources and the Working Party on Stock Assessment of Shrimp and Lobster Resources, Mexico City, Mexico, 26-29 November 1979

    National Research Council Canada - National Science Library

    1981-01-01

    The final formal report of the WECAFC Working Parties on Assessment of Fish Resources and on Stock Assessment of Shrimp and Lobster Resources, held in Mexico City, Mexico, 26-29 November 1979 is presented...

  20. Identification of elements in polutants of Mexico City's atmosphere, using the pixe analysis

    International Nuclear Information System (INIS)

    Diaz-Godoy, R.V.

    1990-01-01

    A review of the fundamentals and actual state in Mexico of the pixe (particle induced X- ray emission) technique are done. Elemental identification in samples of Mexico City's atmosphere taken in two sites is performed using this technique. A 3 MeV proton beam is used to irradiate the samples. Factors (Bremsstrahlung and interference) that difficult the use of the technique are discussed. The sensitivity of the method is enhanced as a main characteristic. It is shown that tje pixe technique together with an appropriate sampling system can be used to study environmental aerosols. Identified elements are bromine, lead, copper, iron, zinc, titanium, vanadium, calcium, potassium, chlorine, sulfur and silicon. Temporal variations of these elements are discussed. (Author)

  1. The policy of the rights of the government of Mexico City

    OpenAIRE

    Enríquez, Lucía

    2017-01-01

    This text deals with the analysis of the policy of the rights of the government of Mexico City which took place during the last three administrations. This government is considered as an institution identified with the political left of the country since it bases its government strategy on two core pillars: the democratization of the government and the design of new redistributive policies, mainly the social policy. With these referents, an analysis is made with the most important political g...

  2. Metals in aerosols of the Mexico City; Metales en aerosoles de la Ciudad de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Reyes L, J. [Instituto Nacional de Investigaciones Nucleares, Salazar, Estado de Mexico C.P. 52045 (Mexico)

    1998-07-01

    The general purpose and scope of this work was to have a data base that includes enough information about the heavy metals which are disseminated in the atmospheric air in Mexico City, like it is what refers to its elements, its concentration and its particle size. For this were collected samples through collectors types: of the filters unit and the cascade impactor. Through the PIXE analysis for filters and films it was identified the presence of 20 elements in the majority of samples studied of the four seasons during the years 1993-1994. The metals were classified in two groups: those of natural origin and those of anthropogenic origin. (Author)

  3. TLR-related pathway analysis : novel gene-gene interactions in the development of asthma and atopy

    NARCIS (Netherlands)

    Reijmerink, N. E.; Bottema, R. W. B.; Kerkhof, M.; Gerritsen, J.; Stelma, F. F.; Thijs, C.; van Schayck, C. P.; Smit, H. A.; Brunekreef, B.; Koppelman, G. H.; Postma, D. S.

    P>Background: The toll-like receptor (TLR)-related pathway is important in host defence and may be crucial in the development of asthma and atopy. Numerous studies have shown associations of TLR-related pathway genes with asthma and atopy phenotypes. So far it has not been investigated whether

  4. Serenity: Violence, Inequality, and Recovery on the Edge of Mexico City.

    Science.gov (United States)

    Garcia, Angela

    2015-12-01

    Over the last decade, there has been a sharp increase in drug addiction in Mexico, especially among the urban poor. During the same period, unregulated residential treatment centers for addiction, known as anexos, have proliferated throughout the country. These centers are utilized and run by marginalized populations and are widely known to engage in physical violence. Based on long-term ethnographic research in Mexico City, this article describes why anexos emerged, how they work, and what their prevalence and practices reveal about the nature of recovery in a context where poverty, drugs, and violence are existential realities. Drawing attention to the dynamic relationship between violence and recovery, pain, and healing, it complicates categories of violence and care that are presumed to have exclusive meaning, illuminating the divergent meanings of, and opportunities for, recovery, and how these are socially configured and sustained. © 2015 by the American Anthropological Association.

  5. Methacholine and adenosine 5'-monophosphate (AMP) responsiveness, and the presence and degree of atopy in children with asthma.

    Science.gov (United States)

    Suh, Dong I; Lee, Ju K; Kim, Chang K; Koh, Young Y

    2011-02-01

    The relationship between atopy and bronchial hyperresponsiveness (BHR), both key features of asthma, remains to be clarified. BHR is commonly evaluated by bronchial challenges using direct and indirect stimuli. The aim of this study was to investigate the degree of BHR to methacholine (direct stimulus) and adenosine 5'-monophosphate (AMP) (indirect stimulus) according to the presence and degree of atopy in children with asthma. We performed a retrospective analysis of data from 120 children presenting with a diagnosis of asthma. These children were characterized by skin-prick tests (SPTs), spirometry and bronchial challenges with methacholine and AMP. Atopy was defined by at least one positive reaction to SPTs, and its degree was measured using serum total IgE levels, number of positive SPTs and atopic scores (sum of graded wheal size). A provocative concentration causing a 20% decline in FEV(1) (PC(20) ) was determined for each challenge. Patients with atopy(n=94) had a significantly lower AMP PC(20) than non-atopic patients (n=26), whereas methacholine PC(20) was not different between the two groups. Among the patients with atopy, there was no association between methacholine PC(20) and any atopy parameter. In contrast, a significant association was found between AMP PC(20) and the degree of atopy reflected in serum total IgE, number of positive SPTs and atopic scores (anova trend test, p=0.002, 0.001, 0.003, respectively). AMP responsiveness was associated with the presence and degree of atopy, whereas such a relationship was not observed for methacholine responsiveness. These findings suggest that atopic status may be better reflected by bronchial responsiveness assessed by AMP than by methacholine. © 2011 John Wiley & Sons A/S.

  6. Levels and source apportionment of volatile organic compounds in southwestern area of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Rodolfo Sosa, E. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Humberto Bravo, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico)], E-mail: hbravo@servidor.unam.mx; Violeta Mugica, A. [Universidad Autonoma Metropolitana, Azcapotzalco, D.F. (Mexico); Pablo Sanchez, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Emma Bueno, L. [Centro Nacional de Investigacion y Capacitacion Ambiental, Instituto Nacional de Ecologia (Mexico); Krupa, Sagar [Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108 (United States)

    2009-03-15

    Thirteen volatile organic compounds (VOCs) were quantified at three sites in southwestern Mexico City from July 2000 to February 2001. High concentrations of different VOCs were found at a Gasoline refueling station (GS), a Condominium area (CA), and at University Center for Atmospheric Sciences (CAS). The most abundant VOCs at CA and CAS were propane, n-butane, toluene, acetylene and pentane. In comparison, at GS the most abundant were toluene, pentane, propane, n-butane, and acetylene. Benzene, a known carcinogenic compound had average levels of 28, 35 and 250 ppbC at CAS, CA, and GS respectively. The main contributing sources of the measured VOCs at CA and CAS were the handling and management of LP (Liquid Propane) gas, vehicle exhaust, asphalt works, and use of solvents. At GS almost all of the VOCs came from vehicle exhaust and fuel evaporation, although components of LP gas were also present. Based on the overall results possible abatement strategies are discussed. - Volatile organic compounds were quantified in order to perform their source apportionment in southwestern area of Mexico City.

  7. Levels and source apportionment of volatile organic compounds in southwestern area of Mexico City

    International Nuclear Information System (INIS)

    Rodolfo Sosa, E.; Humberto Bravo, A.; Violeta Mugica, A.; Pablo Sanchez, A.; Emma Bueno, L.; Krupa, Sagar

    2009-01-01

    Thirteen volatile organic compounds (VOCs) were quantified at three sites in southwestern Mexico City from July 2000 to February 2001. High concentrations of different VOCs were found at a Gasoline refueling station (GS), a Condominium area (CA), and at University Center for Atmospheric Sciences (CAS). The most abundant VOCs at CA and CAS were propane, n-butane, toluene, acetylene and pentane. In comparison, at GS the most abundant were toluene, pentane, propane, n-butane, and acetylene. Benzene, a known carcinogenic compound had average levels of 28, 35 and 250 ppbC at CAS, CA, and GS respectively. The main contributing sources of the measured VOCs at CA and CAS were the handling and management of LP (Liquid Propane) gas, vehicle exhaust, asphalt works, and use of solvents. At GS almost all of the VOCs came from vehicle exhaust and fuel evaporation, although components of LP gas were also present. Based on the overall results possible abatement strategies are discussed. - Volatile organic compounds were quantified in order to perform their source apportionment in southwestern area of Mexico City

  8. Corporative Trends in Urban Distribution of Goods in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Antun, J.P.

    2016-07-01

    The Logistics processes in urban-metropolitan distribution are constantly changing, both technological support and technical implementation in the processes themselves and in the management of these. It is necessary to monitor the substantive changes outlined in the metropolitan urban-physical distribution of goods, because they contribute to a better competitive position of companies in the market, and also to a better development of city life. It is a professional scientific and technical task that contributes, by its impact on {sup b}enchmarking{sup ,} the improvement of engineering practices in the professional community of executives in logistics and supply chains. Based on three extensive field research (ANTÚN, JP; LOZANO, A; HERNÁNDEZ, R; ALARCÓN, R et al 2007; ANTÚN, JP; LOZANO, A; MAGALLANES, R; ALARCÓN, R; GRANADOS, F 2009, ANTUN JP ALARCON R; 2014) on Logistics Distribution of Goods in Mexico City, this article presents and discusses major corporate trends on a set of key logistics processes, and bring examples from Case Studies. (Author)

  9. The deadly Morelos-Puebla, Mexico Intraslab Earthquake of 19 September 2017 (Mw7.1): Was the Earthquake Unexpected and Were the Ground Motions and Damage Pattern in Mexico City Abnormal?

    Science.gov (United States)

    Perez-Campos, X.; Singh, S. K.; Arroyo, D.; Cruz-Atienza, V. M.; Ordaz, M.; Hjorleifsdottir, V.; Iglesias, A.

    2017-12-01

    On 19 September 2017, thirty two years after the 1985 Michoacan interplate earthquake (Mw8.0), the city was once again devastated but this time by a Mw7.1 intraslab earthquake. The 2017 earthquake was located near the border of the states of Morelos and Puebla (18.410N, -98.710E; H=57 km), to SSE of Mexico City, at a hypocentral distance of about 127 km. It caused great panic in Mexico City, collapse of 44 buildings, and severely damaged many others. More than 200 persons were killed in the city. It was the second most destructive earthquake in the history of Mexico City, next only to the 1985 earthquake. A strong-motion station at CU located on basalt lava flows on main campus UNAM has been in continuous operation since 1964. PGA of 59 gal at CU during the 2017 earthquake is the largest ever, two times greater than that recorded during the 1985 earthquake (29 gal). The 2017 earthquake raised questions that are critical in fathoming the seismic vulnerability of the city and in its reconstruction. Was such an intraslab earthquake (Mw 7 at a hypocentral distance of 127 km) unexpected? Were the recorded ground motions in the city unusually high for such an earthquake? Why did the damage pattern during the earthquake differ from that observed during the 1985 earthquake? The earthquake was the closest M>5 intraslab earthquake to Mexico City ever recorded. However, Mw 5.9 events have occurred in recent years in the vicinity of the 2017 earthquake (R 145 km). Three Mw≥6.9 earthquakes have occurred since 1964 in the distance range 184-225 km. Thus, Mw and R of the earthquake was not surprising. However, a comparison of Fourier acceleration spectra at CU of 10 intraslab earthquakes with largest PGA, reduced to a common distance of R=127 km, shows that the amplitudes of the 2017 events were abnormally high in 1-2s range. Spectra of intraslab events at CU are enriched at higher frequencies relative to interplate ones because of closer distance, greater depth and higher

  10. STRONG-MOTION OBSERVATION DEMONSTRATION OF THE LONG-PATH EFFECTS FROM THE PACIFIC OCEAN TO MEXICO CITY

    OpenAIRE

    Masahiro, IIDA; Yoshinori, FURUMOTO; Hitoshi, TANIGUCHI; Carlos, GUTIERREZ; Earthquake Res. Inst., University of Tokyo; Sumitomo Heavy Industries, Ltd.; United Nations, Centre for Regional Development; National Disaster Prevention Center

    1997-01-01

    During the 1985 Michoacan earthquake (M=8.1), seismic waves were remarkably amplified in the lakebed zone of Mexico City, approximately 400 km from the epicenter, and the long duration of the lakebed seismograms was a great surprise. Many researchers thought that the origin of the long coda seen in the lakebed zone was surface waves caused by the deep Mexico basin and the soft surficial layers, but this explanation was not adequate. Another possible cause of the long coda is the long-distance...

  11. [Prevalence of hymenoptera sting allergy in veterinary medicine students from Monterey, Nuevo Leon, Mexico].

    Science.gov (United States)

    Arias Cruz, Alfredo; Monsiváis Toscano, Gina; Gallardo Martínez, Gabriela; González Díaz, Sandra Nora; Galindo Rodríguez, Gabriela

    2007-01-01

    The reported prevalence of allergic systemic reactions to hymenoptera venom occur in up to 3.3% and large local reactions occur in 17% in the general population. To investigate the prevalence of hymenoptera sting allergy in a group of veterinary medicine students from Monterrey, Nuevo Leon, Mexico. A transverse and observational study was done with 64 students of veterinary medicine. We conducted a questionnaire about the students' history of insect allergy and atopy. Skin test with allergenic extracts of bee and ant were practiced to all subjects. We performed aeroallergen skin prick test to the subjets with suspected atopy. Students age ranged from 17 to 25 years (mean 20.2) and 37 were males. Twenty students (31.3%) had clinical history of atopy and positive skin tests to aeroallergens. On the other hand, 5 students (7.8%), including 2 atopic, had suffered large local reactions, but none of them had suffered systemic reactions. Bee and ant skin tests were positive in 15.6% and 31.3% of the students respectively. There was no difference in the prevalence of hymenoptera allergy between atopic and non atopic subjects (p < 0.05). Further, the frequency of atopy in subjects with positive skin tests for bee and ant was 50%. The prevalence of large local reactions and hymenoptera sensitization found in this group was similar to that found in other epidemiologic studies.

  12. Implementation of a radiological safety management system in a hospital of Mexico City

    International Nuclear Information System (INIS)

    Martinez V, D.; Rivera M, T.; Velez D, V.

    2007-01-01

    Full text: The reflection of this work is based in some radiological accidents that its have happened in some hospital centers or of research. The over exposure of some people is due to the pursuit of the procedures, the lack of quality assurance of the equipment or the inappropriate actions of the technicians. In Mexico one has seen in several hospitals the lack of existence of a Quality Assurance Program to prevent the accidents, the execution of the same ones and those good practices and the lack of Safety Culture makes that the hospital radiological safety it is faulty. The objective of the present work is the implementation of a radiological safety management in a hospital of Mexico City. (Author)

  13. In depth analysis of the role of the mountain gap south of the Valley of Mexico on the air quality in Mexico City.

    Science.gov (United States)

    Gerardo Ruiz Suarez, Luis

    2010-05-01

    38 days of air quality observations in Tenango del Aire (TENAI), south of Mexico City during MILAGRO were analyzed. That site was managed by FQA-CCA-UNAM's team with a mobile laboratory equipped with standard air quality monitors: O3, NOx, NOy, CO, SO2 and surface meteorological parameters. Hosted additional instruments were: CH2O, column NO2 (DOAS), backscatter (Lidar) and pilot balloons. Also, an ultra light plane from IMK-IFU, equipped with O3, PM10, CN, Dew Point monitors flew around the Popocatepetl and Iztaccihuatl volcanoes and above of TENAI some days during MILAGRO. Atop of TENAI, the ultra light descended in spiral until near ground and ascended to resume its path. In addition to these measurements, UNAM team ran air quality numerical simulations using the Mesoscale Climate and Chemistry Model (MCCM) and an online coupled Wind Erosion Processor to MCCM we call WEPS-MCCM. The combined observations on the ground, the ultra light plane and the models results enabled us to carry out an in depth analysis of air quality in such important region south of Mexico City. Comparison were made with the episodes classification proposed by De Foy; Ozone North and South, Convection North and South, Cold Surge and South Venting to characterize dynamics in the Valley of Mexico. The aim was to define how well connected is TENAI with the air quality network in the MCMA. The influence of the mountain gap on ozone and PM10 levels in Mexico City is analyzed by episode type. Also, the impact of the mega city of Mexico on the nearby region to the south can be understood by observations in TENAI. More polluted episode types in TENAI are those called: Cold Surge, Ozone South and South Venting due to a wind shift occurring in early afternoon that brings back polluted air that was drained south during the morning and returns back to TENAI rich in aged air parcels. March 17 was chosen to show the integrated analysis of all variables observed and modeled (MCCM) in TENAI. In that day

  14. The possible influence of volcanic emissions on atmospheric aerosols in the city of Colima, Mexico

    International Nuclear Information System (INIS)

    Miranda, Javier; Zepeda, Francisco; Galindo, Ignacio

    2004-01-01

    An elemental composition study of atmospheric aerosols from the City of Colima, in the Western Coast of Mexico, is presented. Samples of PM 15 -PM 2.5 and PM 2.5 were collected with Stacked Filter Units (SFU) of the Davis design, in urban and rural sites, the latter located between the City of Colima and the Volcan de Colima, an active volcano. Elemental analyses were carried out using Particle Induced X-ray Emission (PIXE). The gravimetric mass concentrations for the fine fraction were slightly higher in the urban site, while the mean concentrations in the coarse fraction were equal within the uncertainties. High Cl contents were determined in the coarse fraction, a fact also observed in emissions from the Volcan de Colima by other authors. In addition to average elemental concentrations, cluster analysis based on elemental contents was performed, with wind speed and direction data, showing that there is an industrial contributor to aerosols North of the urban area. Moreover, a contribution from the volcanic emissions was identified from the grouping of S, Cl, Cu, and Zn, elements associated to particles emitted by the Volcan de Colima. - Elemental analyses of PM 15 in the City of Colima, Mexico, were done to identify possible contributions from the Volcan de Colima, an active volcano

  15. Atopy patch tests in young adult patients with atopic dermatitis and controls

    DEFF Research Database (Denmark)

    Bygum, Anette; Mørtz, Charlotte G; Andersen, Klaus Ejner

    2003-01-01

    -dependent results were obtained with Dermatophagoides pteronyssinus, grass and cat with a reproducibility rate of 0.69 to 0.81 in patients and 0.60-0.96 in controls. A unique finding was a significant positive correlation between a positive atopy patch test, allergen dose and increase in transepidermal water loss......The clinical interpretation and reproducibility of atopy patch tests was studied in 23 selected young adult patients with atopic dermatitis and 25 healthy controls using standard inhalant allergens. Non-invasive measurements were used for objective assessment of test reactions and the participants...

  16. Differential subsidence in Mexico City and implications to its Collective Transport System (Metro).

    Science.gov (United States)

    Solano Rojas, D. E.; Wdowinski, S.; Cabral-Cano, E.; Osmanoglu, B.

    2017-12-01

    Mexico City is one of the fastest subsiding metropolis in the world. At displacement rates ranging from 0 to -380 [mm/yr], the complex geological setting is subjected to differential subsidence, which has led to damage, operation interruptions, and accidents to the Collective Transport System, or Metro. The Metro plays a critical role in Mexico City, carrying more than four million passengers per day. However, no previous study has focused on the deformation monitoring along the 93 km of the Metro surface railways, mainly because of the limitations of the traditional geodetic techniques. In this study, we use high-resolution Interferometric Synthetic Aperture Radar (InSAR) observations to monitor land subsidence throughout the city and quantify differential subsidence along surface Metro lines. Our analysis is based on 34 TerraSAR-X StripMap scenes acquired from May 2011 to June 2013 and 36 COSMO-SkyMed Stripmap scenes acquired from June 2011 to June 2012. The data were processed using the StaMPS InSAR time series technique, obtaining point densities of up to 4827 points/km2. Our post-processing methodologies include the following two components: (1) Detection of differential subsidence along the metro lines by calculating subsidence gradients, and (2) Detection of apparent uplift—areas subsiding slower than their surroundings—by using spatial frequency filtering. The two analyses allow us to recognize four main consequences of differential subsidence in the Metro system: 1. Deflection in elevated railways, 2. Deflection in street-level railways, 3. Columns with decreased loading capacity, and 4. Apparent uplift affecting surrounding infrastructure. Our results aim at shortening the large gap between scientific geodetic studies and applicable engineering parameters that can be used by local authorities in the city for maintenance and new lines development.

  17. Teenagers’ access to contraception in Mexico City

    Directory of Open Access Journals (Sweden)

    Sofía Gómez-Inclán

    2017-05-01

    Full Text Available Objective. To study and understand the phenomenon of access to contraceptive methods in Mexican teenages, through the use of the Levesque model, which allows for the observation of both the system and the system and the user´s participation in the access process. Materials and methods. A qualitative study was conducted with focus groups technique in a middle and high school of Mexico City. Results. The perception of ability to access to health care is limited, teenagers do not know the mechanisms of care or supply of contraceptive methods. Prejudices of service providers provoke a negative reaction. The family is a source of information for adolescents to make decisions. Conclusions. The model allowed the assessment of access to contraceptive methods in teenagers. It were identified dif­ferent aspects that act as barriers to access and may inform health care providers about this population in their sexual and reproductive health.

  18. A Tale of Two Cities: San Diego (USA) and Tijuana (Mexico) El Niño Readiness

    Science.gov (United States)

    Stewart, C.; Kinoshita, A. M.; Nishikawa, T.; Briones-Gamboa, F.

    2016-12-01

    This research seeks to define the characteristics of an El Niño Ready City (ENRC) by comparing two neighboring cities, San Diego, United States and Tijuana, Mexico, with diverse management and social conditions, yet similar climatology. Notable El Niño years, 1982-83 and 1997-98, brought heavy precipitation and consequently significant flooding in southern California and northwest Mexico. Using the 2015-16 El Niño, we were able to investigate both Cities' historical and current preparation for hazardous events and identify lessons learned from previous events. Preparation activities include steps taken to prepare storm-related infrastructure, develop emergency protocols, establish communication and coordination efforts, and encourage public outreach and awareness. Literature, media searches, and interviews with local and regional agencies such as the San Diego Department of Transportation and Storm Water, San Diego Lifeguard Services and River Rescue Team, Tijuana State Civil Protection, and Mexican Meteorological Service Departments provided insight into the current and ongoing management for these urban Cities during the 2015-2016 El Niño. Both San Diego and Tijuana were cognizant of the 2015-2016 El Niño and anticipated above-average precipitation and had public agencies that were concerned with potential El Niño related impacts. Common challenges of inter-agency communication and coordination were noted for both Cities. By tracking the electronic media in Tijuana, we observed that local institutions respond proactively, but in a specific period of time. While, in the case of San Diego, the media analysis indicated a focus on El Niño related weather and its implications for the City as evidenced by the total number of articles related to weather across four decades. A challenge for both Cities will be to develop readiness capacities for long-term periods even if El Niño signals are weak or not present.

  19. Mexico City air quality research initiative. Volume IV. Characterization and measurement

    Energy Technology Data Exchange (ETDEWEB)

    Mauzy, A. [ed.

    1994-04-01

    This volume describes the methods and the data gathered in an attempt to measure and characterize the meteorological factors and the concentration of different pollutants in the Mexico City Metropolitan Area. The main objective of this document was to provide input for the simulation models and to obtain information that could be used to test and improve the models` performance. Four field campaigns were conducted, as well as routine monitoring, in order to obtain a database of atmospheric dynamics and air pollution characteristics. Sections include Airborne measurements, Remote sensing measurements, and Traditional (in situ) measurements.

  20. A driving cycle for vehicle emissions estimation in the metropolitan area of Mexico City.

    Science.gov (United States)

    Schifter, I; Díaz, L; Rodríguez, R; López-Salinas, E

    2005-02-01

    A driving cycle derived from driving behavior and real traffic conditions in Mexico City (MC) is proposed. Data acquisition was carried out over diverse MC routes, representing travel under congested and uncongested conditions, using the chase-car approach. Thirteen different on-road patterns, including the four main access roads to MC, trips in both directions and different timetables, a total of 108 trips spanning 1044 km were evaluated in this study. The MC cycle lasts 1360 seconds with a distance of 8.8 km and average speed of 23.4 km h(-1). Both maximum speed (73.6 km h(-1)) and maximum acceleration (2.22 km h(-1)s(-1)) are lower than those of the new vehicles certification employed in Mexico ,FTP-75 cycle., that is, the MC cycle exhibits less cruising time and more transient events than the FTP cycle. A total of 30 light duty gasoline vehicles were classified into different technological groups and tested in an FTP-75 and MC driving cycles in order to compare their emission factors A potential concern is that in Mexico manufacturers design vehicles to meet the emission standards in the FTP, but emission levels increase significantly in a more representative cycle of present driving patterns in the Metropolitan Area of Mexico City (MAMC). The use of a more representative cycle during certification testing, would provide an incentive for vehicle manufacturers to design emissions control systems to remain effective during operation modes that are not currently represented in the official test procedures used in the certification process. Based on the results of the study, the use of MC cycle, which better represents current day driving patterns during testing of vehicle fleets in emissions laboratories, would improve the accuracy of emissions factors used in the MAMC emissions inventories.

  1. [Prehospital emergency care in Mexico City: the opportunities of the healthcare system].

    Science.gov (United States)

    Pinet, Luis M

    2005-01-01

    Unintentional vehicle traffic injuries cause 1.2 million preventable deaths per year worldwide, mostly affecting the population in their productive years of life. In Mexico, unintentional vehicle traffic injuries are one of the main causes of death; in Mexico City they account for 8% of deaths. Prehospital systems are set up to provide hospital medical care to the population, by means of a complex network that includes transportation, communications, resources (material, financial and human), and public participation. These systems may be designed in a variety of ways, depending on availability, capacity and quality of resources, according to specific community needs, always abiding by laws and regulations. In Mexico, several institutions and organizations offer prehospital services without being overseen in terms of coordination, regulation and performance evaluation, despite the high rates of morbidity and mortality due to injuries and preventable conditions amenable to effective therapy during the prehospital period. Prehospital care may contribute to decrease the morbidity and mortality rates of injuries requiring prompt medical care. Emphasis is made on the importance of assessing the performance of prehospital care, as well as on identification of needs for future development.

  2. View From a Megacity: Aerosol Light Absorption and Scattering at Four Sites in and Near Mexico City.

    Science.gov (United States)

    Paredes-Miranda, G.; Arnott, W. P.; Gaffney, J. S.; Marley, N. A.

    2006-12-01

    As part of the Megacity Impacts on Regional and Global Environments, MIRAGE-Mex deployment to Mexico City in the period of 30 days, March 2006, a suite of photoacoustic spectrometers (PAS) were installed to measure at ground level the light absorption and scattering by aerosols at four sites: an urban site at Instituto Mexicano del Petroleo (Mexican Oil Institute, denoted by IMP), a suburban site at the Technological University of Tecamac, a rural site at "La Biznaga" ranch, and a site at the Paseo de Cortes (altitude 3,810 meters ASL) in the rural area above Amecameca in the State of Mexico, on the saddle between the volcanoes Popocatepetl and Iztaccihuatl. The IMP site gave in-situ characterization of the Mexico City plume under favorable wind conditions while the other sites provided characterization of the plume, mixed in with any local sources. The second and third sites are north of Mexico City, and the fourth site is south. The PAS used at IMP operates at 532 nm, and conveniently allowed for characterization of gaseous absorption at this wavelength as well. Instruments at the second and third sites operate at 870 nm, and the one at the fourth site at 780 nm. Light scattering measurements are accomplished within the PAS by the reciprocal nephelometery method. In the urban site the aerosol absorption coefficient typically varies between 40 and 250 Mm-1 during the course of the day and significant diurnal variation of the aerosol single scattering albedo was observed. Comparisons with TSI nephelometer scattering and Aetholemeter absorption measurements at the T0 site will be presented. We will present a broad overview of the diurnal variation of the scattering and absorption as well as the single scattering albedo and fraction of absorption due to gases at the IMP site. Insight on the dynamical connections will be discussed.

  3. Policy support, norms, and secondhand smoke exposure before and after implementation of a comprehensive smoke-free law in Mexico city.

    Science.gov (United States)

    Thrasher, James F; Pérez-Hernández, Rosaura; Swayampakala, Kamala; Arillo-Santillán, Edna; Bottai, Matteo

    2010-09-01

    We assessed attitudes and beliefs about smoke-free laws, compliance, and secondhand smoke exposure before and after implementation of a comprehensive smoke-free law in Mexico City. Trends and odds of change in attitudes and beliefs were analyzed across 3 representative surveys of Mexico City inhabitants: before implementation of the policy (n=800), 4 months after implementation (n=961), and 8 months after implementation (n=761). Results indicated high and increasing support for 100% smoke-free policies, although support did not increase for smoke-free bars. Agreement that such policies improved health and reinforced rights was high before policy implementation and increased thereafter. Social unacceptability of smoking increased substantially, although 25% of nonsmokers and 50% of smokers agreed with smokers' rights to smoke in public places at the final survey wave. Secondhand smoke exposure declined generally as well as in venues covered by the law, although compliance was incomplete, especially in bars. Comprehensive smoke-free legislation in Mexico City has been relatively successful, with changes in perceptions and behavior consistent with those revealed by studies conducted in high-income countries. Normative changes may prime populations for additional tobacco control interventions.

  4. Hydrogeochemical and stream sediment reconnaissance basic data for Silver City Quadrangle, New Mexico; Arizona

    International Nuclear Information System (INIS)

    1981-01-01

    Field and laboratory data are presented for 405 water samples and 736 sediment samples from the Silver City Quadrangle, New Mexico; Arizona. Uranium values have been reported by Los Alamos National Laboratory in Report GJBX-69(78). The samples were collected by Los Alamos National Laboratory; laboratory analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee

  5. Overweight, asthma symptoms, atopy and pulmonary function in children of 4-12 years of age: findings from the SCAALA cohort in Salvador, Bahia, Brazil

    OpenAIRE

    Matos, SM; Jesus, SR; Saldiva, SR; Prado, MS; D'Innocenzo, S; Assis, AM; Rodrigues, LC; Alcantara-Neves, NM; Cruz, Á, A; Simões, SdeM; Barreto, ML; SCAALA (Social Change, Asthma and Allergy in Latin America) Stud,

    2011-01-01

    : To evaluate the association between overweight and the occurrence of asthma and atopy in a cohort of children of 4-12 years of age living in the city of Salvador in 2005. : Cross-sectional study nested in a cohort. : The metropolitan region of Salvador, Bahia, Brazil. : The study included 1129 children of 4-12 years age who presented complete information on the variables used here. Skin tests for allergy, spirometry, faecal parasitology, serum IgE and anthropometric surveys were conducted. ...

  6. Aerosol effects on the photochemistry in Mexico City during MCMA-2006/MILAGRO campaign

    Directory of Open Access Journals (Sweden)

    G. Li

    2011-06-01

    Full Text Available In the present study, the impact of aerosols on the photochemistry in Mexico City is evaluated using the WRF-CHEM model for the period from 24 to 29 March during the MCMA-2006/MILAGRO campaign. An aerosol radiative module has been developed with detailed consideration of aerosol size, composition, and mixing. The module has been coupled into the WRF-CHEM model to calculate the aerosol optical properties, including optical depth, single scattering albedo, and asymmetry factor. Calculated aerosol optical properties are in good agreement with the surface observations and aircraft and satellite measurements during daytime. In general, the photolysis rates are reduced due to the absorption by carbonaceous aerosols, particularly in the early morning and late afternoon hours with a long aerosol optical path. However, with the growth of aerosol particles and the decrease of the solar zenith angle around noontime, aerosols can slightly enhance photolysis rates when ultraviolet (UV radiation scattering dominates UV absorption by aerosols at the lower-most model layer. The changes in photolysis rates due to aerosols lead to about 2–17 % surface ozone reduction during daytime in the urban area in Mexico City with generally larger reductions during early morning hours near the city center, resulting in a decrease of OH level by about 9 %, as well as a decrease in the daytime concentrations of nitrate and secondary organic aerosols by 5–6 % on average. In addition, the rapid aging of black carbon aerosols and the enhanced absorption of UV radiation by organic aerosols contribute substantially to the reduction of photolysis rates.

  7. A Methodological Approach to the Study of Urban Memory: Narratives about Mexico City

    Directory of Open Access Journals (Sweden)

    Martha de Alba

    2012-05-01

    Full Text Available This article serves a dual purpose. On the one hand, I seek to understand social representations and the collective memory of a sample of older adults, resident in the metropolitan area of Mexico City. On the other hand, I wish to reflect on the methodology used to achieve that objective, placing special emphasis on the combination of two complementary techniques: Atlas.ti, a tool used to carry out a semantic analysis of the interviews, and Alceste, a program that makes it possible to observe a classification of the terms used by respondents based on a statistical analysis of co-occurrences. The article is structured in the following order. Firstly, I explain the theoretical presuppositions that sustain the study. Secondly, I look at the methodology used, the reasons why I decided to use the software in question, and the analysis strategies for the interviews. Finally, I present the results obtained, and close with a final discussion on the relevance of the general methodology of the study for analyzing urban memory. The results indicate different levels of analysis of extensive narratives about the past experience of a great city like Mexico City; from the individual level that allows Atlas.ti up to a collective level (gender differences, location or socioeconomic status that prioritizes Alceste. I discuss the limitations of these software tools to analyze experiences that have continuity in time and space, as well in the incorporation of space as a complex category of analysis. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1202276

  8. Preventing HIV Transmission Among Partners of HIV-Positive Male Sex Workers in Mexico City: A Modeling Study.

    Science.gov (United States)

    Monteiro, João Filipe G; Marshall, Brandon D L; Escudero, Daniel; Sosa-Rubí, Sandra G; González, Andrea; Flanigan, Timothy; Operario, Don; Mayer, Kenneth H; Lurie, Mark N; Galárraga, Omar

    2015-09-01

    Mexico has a concentrated HIV epidemic, with male sex workers constituting a key affected population. We estimated annual HIV cumulative incidence among male sex workers' partners, and then compared incidence under three hypothetical intervention scenarios: improving condom use; and scaling up HIV treatment as prevention, considering current viral suppression rates (CVS, 60.7 %) or full viral suppression among those treated (FVS, 100 %). Clinical and behavioral data to inform model parameterization were derived from a sample (n = 79) of male sex workers recruited from street locations and Clínica Condesa, an HIV clinic in Mexico City. We estimated annual HIV incidence among male sex workers' partners to be 8.0 % (95 % CI: 7.3-8.7). Simulation models demonstrated that increasing condom use by 10 %, and scaling up HIV treatment initiation by 50 % (from baseline values) would decrease the male sex workers-attributable annual incidence to 5.2, 4.4 % (CVS) and 3.2 % (FVS), respectively. Scaling up the number of male sex workers on ART and implementing interventions to ensure adherence is urgently required to decrease HIV incidence among male sex workers' partners in Mexico City.

  9. Influence of solid waste and topography on urban floods: The case of Mexico City.

    Science.gov (United States)

    Zambrano, Luis; Pacheco-Muñoz, Rodrigo; Fernández, Tania

    2018-02-24

    Floods in cities are increasingly common as a consequence of multifactor watershed dynamics, including geomorphology, land-use changes and land subsidence. However, urban managers have focused on infrastructure to address floods by reducing blocked sewage infrastructure, without significant success. Using Mexico City as a case study, we generated a spatial flood risk model with geomorphology and anthropogenic variables. The results helped contrast the implications of different public policies in land use and waste disposal, and correlating them with flood hazards. Waste disposal was only related to small floods. 58% of the city has a high risk of experiencing small floods, and 24% of the city has a risk for large floods. Half of the population with the lowest income is located in the high-risk areas for large floods. These models are easy to build, generate fast results and are able to help to flood policies, by understanding flood interactions in urban areas within the watershed.

  10. Development of pollution reduction strategies for Mexico City: Estimating cost and ozone reduction effectiveness

    International Nuclear Information System (INIS)

    Thayer, G.R.; Hardie, R.W.; Barrera-Roldan, A.

    1993-01-01

    This reports on the collection and preparation of data (costs and air quality improvement) for the strategic evaluation portion of the Mexico City Air Quality Research Initiative (MARI). Reports written for the Mexico City government by various international organizations were used to identify proposed options along with estimates of cost and emission reductions. Information from appropriate options identified by SCAQMD for Southem California were also used in the analysis. A linear optimization method was used to select a group of options or a strategy to be evaluated by decision analysis. However, the reduction of ozone levels is not a linear function of the reduction of hydrocarbon and NO x emissions. Therefore, a more detailed analysis was required for ozone. An equation for a plane on an isopleth calculated with a trajectory model was obtained using two endpoints that bracket the expected total ozone precursor reductions plus the starting concentrations for hydrocarbons and NO x . The relationship between ozone levels and the hydrocarbon and NO x concentrations was assumed to lie on this plane. This relationship was used in the linear optimization program to select the options comprising a strategy

  11. Evaluation of a social marketing campaign to support Mexico City's comprehensive smoke-free law.

    Science.gov (United States)

    Thrasher, James F; Huang, Liling; Pérez-Hernández, Rosaura; Niederdeppe, Jeff; Arillo-Santillán, Edna; Alday, Jorge

    2011-02-01

    We aimed to assess the level of awareness and impact of a social marketing campaign to promote Mexico City's 2008 comprehensive smoke-free law. Four months after the smoke-free law was implemented but before the campaign launch, we collected data from a population-based, random sample of 961 inhabitants of Mexico City. We analyzed data from 786 respondents who completed follow-up at the end of the campaign to determine campaign exposure and the association between campaign exposure and changes in campaign-targeted knowledge and attitudes. Recall of any of the 5 campaign materials was 69%, with a uniform distribution of exposure to 1, 2, and 3 or more campaign materials (25%, 25%, and 19%, respectively). Exposure to a greater number of campaign materials was associated in a monotonic relation with campaign-targeted knowledge of ammonia and arsenic in cigarette smoke. In models assessing support for, perceived benefits of, and perceived right to smoke-free places, campaign exposure accounted for a positive change in half of the indicators within each of these domains. Social marketing campaigns can reinforce knowledge and attitudes that favor smoke-free laws, thereby helping to establish smoke-free norms.

  12. Early life exposures and risk of atopy among Danish children

    DEFF Research Database (Denmark)

    Thomsen, SF; Ulrik, Charlotte Suppli; Porsbjerg, C

    2006-01-01

    A large proportion of atopy develops in childhood and early life exposures are suspected to play a considerable role in the inception. The aim of this study was to examine the association between early life exposures and development of atopic disease in children. We performed a case-cohort study...... to be independent of familial predisposition to atopic disease and significantly increases the likelihood for development of atopy in genetically susceptible individuals. Parental knowledge of atopic heredity significantly influences smoking and breast-feeding habits....... of a random population-based sample of children (n = 480) 7-17 years of age, living in urban Copenhagen, Denmark. Information on breast-feeding, supplementation, wheezy bronchitis, use of antibiotics, and parental smoking during pregnancy and in early life was obtained retrospectively by questionnaire. Skin...

  13. Seroprevalence of Toxoplasma gondii infection in captive mammals in three zoos in Mexico City, Mexico.

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Gayosso-Dominguez, Edgar Arturo; Villena, Isabelle; Dubey, J P

    2013-09-01

    Antibodies to Toxoplasma gondii were determined in 167 mammals in three zoos in Mexico City, Mexico, using the modified agglutination test (MAT). Overall, antibodies to T. gondii were found in 89 (53.3%) of the 167 animals tested. Antibodies were found in 35 of 43 wild Felidae: 2 of 2 bobcats (Lynx rufus); 4 of 4 cougars (Puma concolor); 10 of 13 jaguars (Panthera onca); 5 of 5 leopards (Panthera pardus); 7 of 7 lions (Panthera leo); 2 of 3 tigers (Panthera tigris); 2 of 3 ocelots (Leopardus pardalis); 2 of 2 Sumatran tigers (Panthera tigris sumatrae); lof 2 Jaguarundi (Herpailurus jagouaroundi); but not in 0 of 2 oncillas (Leopardus tigrinus). Such high seroprevalence in wild felids is of public health significance because of the potential of oocyst shedding. Four of 6 New World primates (2 of 2 Geoffroy's spider monkeys [Ateles geoffroyi], 1 of 3 Patas monkeys [Erythrocebus patas], and 1 of 1 white-headed capuchin [Cebus capucinus]) had high MAT titers of 3,200, suggesting recently acquired infection; these animals are highly susceptible to clinical toxoplasmosis. However, none of these animals were ill. Seropositivity to T. gondii was found for the first time in a number of species.

  14. Public policy performance for social development : solar energy approach to assess technological outcome in Mexico City Metropolitan Area

    OpenAIRE

    Arenas-Aquino, A.R.; Matsumoto-Kuwabara, Y.; Kleiche Dray, Mina

    2017-01-01

    Mexico City Metropolitan Area (MCMA) is the most populated urban area in the country. In 2010, MCMA required 14.8% of total energy domestic demand, but greenhouse gas emissions accounted for 7.7% of domestic emissions. Mexico has massive renewable energy potential that could be harnessed through solar photovoltaic (PV) technology. The problem to explore is the relationship between local and federal public strategies in MCMA and their stance on energy transition concern, social empowerment, ne...

  15. [Effects of air pollution on human health and their importance in Mexico City].

    Science.gov (United States)

    Vallejo, Maite; Jáuregui-Renaud, Kathrine; Hermosillo, Antonio G; Márquez, Manlio F; Cárdenas, Manuel

    2003-01-01

    The impact of air pollution on human health is a complicated problem. In this review, we describe the main health effects of exposure to ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, lead and particulate matter. Geographical characteristics of the metropolitan area of Mexico City that favor pollutant persistence with adverse effects on the population are described; the use of the Indice Metropolitano de la Calidad del Aire (IMECA), current norms, and present programs to diminish this problem are discussed. Evidence shows that through these actions, air quality has improved. However, some pollutants such as ozone and particulate matter, still exceed the standard. To further improve air quality in the city, existing programs should continue and multidisciplinary research, both basic and applied, is required.

  16. Sensitization to Casuarina equisetifolia and Pinus spp Pollen in Patients with Allergic Rhinitis and Asthma in Mexico City

    Directory of Open Access Journals (Sweden)

    Andrea Aída Velasco-Medina

    2014-01-01

    Full Text Available Background: Pollinosis studies at Mexico City have found a considerable amount of Casuarina equisetifolia and Pinus spp pollen, its sensitization frequency is unknown. In Mexico, some allergens are not considered related to asthma or allergic rhinitis, even though reports in other coun- tries have been demonstrated their relevance as aeroallergens. Objective: To estimate the frequency of sensitization to Casuarina eq- uisetifolia and Pinus spp pollen. Patients and method: A transversal, descriptive trial was done at Hos- pital General de Mexico. Previous informed consent 142 patients with allergic rhinitis and asthma, 3 to 55 years old, were included to the study. A complete clinical evaluation, laboratory tests and skin prick tests were performed. Results: We included 142 patients, 44 children (64% males and 98 adults (73% females. We found that 8 (18.18% children and 35 (35.7% adults had a positive skin prick test to Casuarina equisetifolia. None of the patients included in the study had a positive skin prick test to Pinus spp. Conclusions: Sensitization to Casuarina equisetifolia is as important as other pollens found in Mexico City. These results suggest that it should be included when skin prick tests are performed. Pinus spp pollen is considered an aeroallergen in European countries but we did not cor- roborate sensitization in our population.

  17. CORRECTION OF VITAMIN-DEFICIENT CONDITIONS IN CHILDREN WITH ATOPY

    Directory of Open Access Journals (Sweden)

    E.A. Vishneva

    2011-01-01

    Full Text Available The most important biochemical processes in human organism are carried out with vitamins and microelements involved. Acting as biological catalysts, vitamins have an impact on metabolism and provide protection against unfavourable environmental factors. The key source of vitamins and microelements for a person is food. The content of vitamins in a diet varies and depends on a range of various reasons. However, now the diet may not fully meet vitamin and microelement requirements. The result of this is widespread prevalence of sub-clinical deficiency of vitamins and microelements. Patients from one of the risk groups, children with atopy, are especially susceptible to this condition. Hypoallergenic diet prescribed as part of the therapeutic measures, is often the cause of imbalanced and irrational nutrition. Modern vitamin complexes may solve the issue of subnormal supply of vitamins and apparent hypovitaminosis in children with allergic diseases.Key words: polyvitamin complexes, atopy, allergic diseases, subnormal supply of vitamins, children.

  18. Organochlorine pesticides residues in bottled drinking water from Mexico City.

    Science.gov (United States)

    Díaz, Gilberto; Ortiz, Rutilio; Schettino, Beatriz; Vega, Salvador; Gutiérrez, Rey

    2009-06-01

    This work describes concentrations of organochlorine pesticides in bottled drinking water (BDW) in Mexico City. The results of 36 samples (1.5 and 19 L presentations, 18 samples, respectively) showed the presence of seven pesticides (HCH isomers, heptachlor, aldrin, and p,p'-DDE) in bottled water compared with the drinking water standards set by NOM-127-SSA1-1994, EPA, and World Health Organization. The concentrations of the majority of organochlorine pesticides were within drinking water standards (0.01 ng/mL) except for beta-HCH of BW 3, 5, and 6 samples with values of 0.121, 0.136, and 0.192 ng/mL, respectively. It is important monitoring drinking bottled water for protecting human health.

  19. Determination of radon levels in Mexico City; Determinacion de niveles de radon en la Ciudad de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Pena G, P

    1992-01-15

    The study of the determination of radon levels in the houses room in Mexico City is part of the project Emanometry of the radon. To carry out this study, the passive method was used, which consists of: thin film dosemeter of cellulose nitrate, container of the same one and spark accountant. The method is based on the mensurations of exhibition of the number of marks of alpha track is of the open type and it allows to average the radon activity along several weeks and it presents low concentrations. This study was carried out in 4 periods of exhibition of 3 months each one. (Author)

  20. The contribution of the International Atomic Energy Agency to peace and development. Address at the conference of the Diplomatic Academy at the Institute of 'Matias Romero', Mexico City, Mexico, 13 October 1999

    International Nuclear Information System (INIS)

    ElBaradei, M.

    1999-01-01

    In his address at the Conference of the Diplomatic Academy at the Institute of 'Matias Romero' (Mexico City, Mexico, 13 October 1999), the Director General of the IAEA described the role of the IAEA and its contribution to peace and development, focussing in four areas: technology transfer, nuclear power and sustainable energy development, nuclear safety, and the Agency's verification system

  1. Cost of neurocysticercosis patients treated in two referral hospitals in Mexico City, Mexico.

    Science.gov (United States)

    Bhattarai, Rachana; Carabin, Hélène; Proaño, Jefferson V; Flores-Rivera, Jose; Corona, Teresa; Flisser, Ana; Budke, Christine M

    2015-08-01

    To estimate annual costs related to the diagnosis, treatment and productivity losses among patients with neurocysticercosis (NCC) receiving treatment at two referral hospitals, the Instituto Nacional de Neurologia y Neurocirugia (INNN) and the Hospital de Especialidades of the Instituto Mexicano del Seguro Social (HE-IMSS), in Mexico City from July 2007 to August 2008. Information on presenting clinical manifestations, diagnostic tests, hospitalisations, surgical procedures and other treatments received by NCC outpatients was collected from medical charts, and supplemented by an individual questionnaire regarding productivity losses and out-of-pocket expenses related to NCC. The annual average per-patient direct costs were US$ 503 (95% CI: 414-592) and US$ 438 (95% CI: 322-571) for patients without a history of hospitalisation and/or surgery seen at the INNN and the HE-IMSS, respectively. These costs increased to US$ 2506 (95% CI: 1797-3215) and US$ 2170 (95% CI: 1303-3037), respectively, for patients with a history of hospitalisation and/or surgery. The average annual per-patient indirect costs were US$ 246 (95% CI: 165-324) and US$ 114 (95% CI: 51-178), respectively, using minimum salary wages for individuals not officially employed. The total annual cost for patients who had and had not been hospitalised and/or undergone a surgical procedure for the diagnosis or treatment of NCC corresponded to 212% and 41% of an annual minimum wage salary, respectively. The disease tends to affect rural socioeconomically disadvantaged populations and creates health disparities and significant economic losses in Mexico. © 2015 John Wiley & Sons Ltd.

  2. [Itinerant physicians, the art of healing and doctors in national history (Mexico City, 1877-1911)].

    Science.gov (United States)

    Agostoni, Claudia

    2008-01-01

    The uncertainty and mistrust towards the presence and activities of academic medical practitioners in Mexico City during the Porfirio Díaz government (1877-1911) convinced these professionals that is was essential to create, strengthen and transmit a respectable, competent and homogeneous image of the profession. To this purpose they recovered, recreated and adapted the ethical maxims of the occidental medical culture to their professional work, and rescued eminent medical figures of Mexico's convulse nineteenth century from being lost in the oblivion of history. Their goal - as it will be expounded in the following pages - was to respond, oppose and neutralize the criticism and disbelief expressed by the public against their professional performance.

  3. Air Quality in Megacities: Lessons Learned from Mexico City Field Measurements

    Science.gov (United States)

    Molina, L. T.

    2014-12-01

    More than half of the world's population now lives in urban areas because of the opportunities for better jobs, access to city services, cultural and educational activities, and a desire for more stimulating human interaction. At the same time, many of these urban centers are expanding rapidly, giving rise to the phenomenon of megacities. In recent decades air pollution has become not only one of the most important environmental problems of megacities, but also presents serious consequences to human health and ecosystems and economic costs to society. Although the progress to date in combating air pollution problems in developed and some developing world megacities has been impressive, many challenges remain including the need to improve air quality while simultaneously mitigating climate change. This talk will present the results and the lessons learned from field measurements conducted in Mexico City Metropolitan Area - one of the world's largest megacities - over the past decade. While each city has its own unique circumstances, the need for an integrated assessment approach in addressing complex environmental problems is the same. There is no single strategy in solving air pollution problems in megacities; a mix of policy measures based on sound scientific findings will be necessary to improve air quality, protect public health, and mitigate climate change.

  4. Characterization of Fine Particulate Matter (PM) and Secondary PM Precursor Gases in the Mexico City Metropolitan Area

    Science.gov (United States)

    Molina, Luisa T.; Volkamer, Rainer; de Foy, Benjamin; Lei, Wenfang; Zavala, Miguel; Velasco, Erik; Molina; Mario J.

    2008-10-31

    This project was one of three collaborating grants funded by DOE/ASP to characterize the fine particulate matter (PM) and secondary PM precursors in the Mexico City Metropolitan Area (MCMA) during the MILAGRO Campaign. The overall effort of MCMA-2006, one of the four components, focused on i) examination of the primary emissions of fine particles and precursor gases leading to photochemical production of atmospheric oxidants and secondary aerosol particles; ii) measurement and analysis of secondary oxidants and secondary fine PM production, with particular emphasis on secondary organic aerosol (SOA), and iii) evaluation of the photochemical and meteorological processes characteristic of the Mexico City Basin. The collaborative teams pursued the goals through three main tasks: i) analyses of fine PM and secondary PM precursor gaseous species data taken during the MCMA-2002/2003 campaigns and preparation of publications; ii) planning of the MILAGRO Campaign and deployment of the instrument around the MCMA; and iii) analysis of MCMA-2006 data and publication preparation.

  5. Diversity-Based Characteristics of Mexican Children's Drawings: A Qualitative Analysis of Drawings Collected in Mexico City

    Science.gov (United States)

    Hass-Cohen, Noah; Chandler-Ziegler, Karina; Veeman, Thomas; Funk, Sterling

    2016-01-01

    The purpose of this study was to increase understanding of the diversity of characteristics in the drawings of children in Mexico City. The authors conducted a thematic analysis of 174 drawings from children ages 6 to 11 that revealed two main discrete themes: nature and stress. A personalized, supportive relationship with nature emerged as a…

  6. Beristain, Godoy, and the Virgin of Guadalupe. A Confrontation for Public Space in Mexico City in the Late Eighteenth Century

    Directory of Open Access Journals (Sweden)

    Gabriel Torres Puga

    2002-07-01

    Full Text Available During the festivities of the virgin of Guadalupe in 1795, a group of criollos garnished a balcony in Mexico City in order to discredit the cathedral's canon, Mariano  Beristain.  The reason for this quarrel was the recent homage paid by Beristain to Spain's ministers' chief, Manuel  Godoy, who had been  accused of insulting religion and devotion to the virgin. The complaints filed with the Inquisition against  Beristain  afford the  possibility of observing some of informal channels of expression at a time when there was a tightening of the control over the press. Moreover, these complaints illustrate the fierce dispute over control of public opinion in Mexico City at the end of the eighteenth century.

  7. The Urban Tree as a Tool to Mitigate the Urban Heat Island in Mexico City: A Simple Phenomenological Model.

    Science.gov (United States)

    Ballinas, Mónica; Barradas, Víctor L

    2016-01-01

    The urban heat island (UHI) is mainly a nocturnal phenomenon, but it also appears during the day in Mexico City. The UHI may affect human thermal comfort, which can influence human productivity and morbidity in the spring/summer period. A simple phenomenological model based on the energy balance was developed to generate theoretical support of UHI mitigation in Mexico City focused on the latent heat flux change by increasing tree coverage to reduce sensible heat flux and air temperature. Half-hourly data of the urban energy balance components were generated in a typical residential/commercial neighborhood of Mexico City and then parameterized using easily measured variables (air temperature, humidity, pressure, and visibility). Canopy conductance was estimated every hour in four tree species, and transpiration was estimated using sap flow technique and parameterized by the envelope function method. Averaged values of net radiation, energy storage, and sensible and latent heat flux were around 449, 224, 153, and 72 W m, respectively. Daily tree transpiration ranged from 3.64 to 4.35 Ld. To reduce air temperature by 1°C in the studied area, 63 large would be required per hectare, whereas to reduce the air temperature by 2°C only 24 large trees would be required. This study suggests increasing tree canopy cover in the city cannot mitigate UHI adequately but requires choosing the most appropriate tree species to solve this problem. It is imperative to include these types of studies in tree selection and urban development planning to adequately mitigate UHI. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  8. An Overview of the MILAGRO 2006 Campaign: Mexico City Emissions and their Transport and Transformation

    Energy Technology Data Exchange (ETDEWEB)

    Molina, Luisa T.; Madronich, Sasha; Gaffney, Jeffrey; Apel, Eric; de Foy, B.; Fast, Jerome D.; Ferrare, R.; Herndon, Scott C.; Jimenez, Jose L.; Lamb, Brian K.; Orsonio-Vargas, A. R.; Russell, P. B.; Schauer, James J.; Stevens, P. S.; Volkamer, Rainer M.; Zavala, Miguel A.

    2010-03-25

    The world’s population is projected to increase 33% during the next three decades, to 8.1 billion. Nearly all of the projected growth is expected to be concentrated in urban centers. These rapidly expanding urban regions and surrounding suburban areas are leading to the phenomenon of megacities (metropolitan areas with populations exceeding 10 million inhabitants). Well governed, densely populated settlements can reduce the need for land conversion and provide proximity to infrastructure and services. However, many urban areas experience uncontrolled sprawl and their activities are the leading cause of environmental problems. These mega-centers of human population are tied directly to increasing demands for energy and associated industrial activities and motorization that lead to more emission of pollutants into the atmosphere. Air pollution is one of the most important environmental challenges of this century. This challenge is particularly acute in the developing world where the rapid growth of megacities is producing atmospheric pollution of unprecedented severity and extent. MILAGRO (Megacity Initiative: Local And Global Research Observations) is the first international collaborative project to examine the behavior and the export of atmospheric pollutants generated in megacities. The Mexico City Metropolitan Area (MCMA) - one of the world’s largest megacities and North America’s most populous city -- was selected as the initial case study to characterize the sources and processes of emissions from the urban center and to evaluate the regional and global impacts of the Mexico City air pollution plume

  9. Simulation of Mexico City plumes during the MIRAGE-Mex field campaign using the WRF-Chem model

    Directory of Open Access Journals (Sweden)

    X. Tie

    2009-07-01

    Full Text Available The quantification of tropospheric O3 production in the downwind of the Mexico City plume is a major objective of the MIRAGE-Mex field campaign. We used a regional chemistry-transport model (WRF-Chem to predict the distribution of O3 and its precursors in Mexico City and the surrounding region during March 2006, and compared the model with in-situ aircraft measurements of O3, CO, VOCs, NOx, and NOy concentrations. The comparison shows that the model is capable of capturing the timing and location of the measured city plumes, and the calculated variability along the flights is generally consistent with the measured results, showing a rapid increase in O3 and its precursors when city plumes are detected. However, there are some notable differences between the calculated and measured values, suggesting that, during transport from the surface of the city to the outflow plume, ozone mixing ratios are underestimated by about 0–25% during different flights. The calculated O3-NOx, O3-CO, and O3-NOz correlations generally agree with the measured values, and the analyses of these correlations suggest that photochemical O3 production continues in the plume downwind of the city (aged plume, adding to the O3 already produced in the city and exported with the plume. The model is also used to quantify the contributions to OH reactivity from various compounds in the aged plume. This analysis suggests that oxygenated organics (OVOCs have the highest OH reactivity and play important roles for the O3 production in the aging plume. Furthermore, O3 production per NOx molecule consumed (O3 production efficiency is more efficient in the aged plume than in the young plume near the city. The major contributor to the high O3 production efficiency in the aged plume is the

  10. Effect of urban vs. rural residence on the association between atopy and wheeze in Latin America: findings from a case-control analysis.

    Science.gov (United States)

    Endara, P; Vaca, M; Platts-Mills, T A E; Workman, L; Chico, M E; Barreto, M L; Rodrigues, L C; Cooper, P J

    2015-02-01

    The association between atopy and asthma is attenuated in non-affluent populations, an effect that may be explained by childhood infections such as geohelminths. To investigate the association between atopy and wheeze in schoolchildren living in urban and rural areas of Ecuador and examine the effects of geohelminths on this association. We performed nested case-control studies among comparable populations of schoolchildren living in rural communities and urban neighbourhoods in the Province of Esmeraldas, Ecuador. We detected geohelminths in stool samples, measured recent wheeze and environmental exposures by parental questionnaire, and atopy by specific IgE (sIgE) and skin prick test (SPT) reactivity to aeroallergens. Atopy, particularly sIgE to house dust mite (HDM), was more strongly associated with recent wheeze in urban than rural schoolchildren: (urban, adj. OR 5.19, 95% CI 3.37-8.00, P children. The association between atopy and recent wheeze was attenuated by markers of geohelminth infections. Our data suggest that urban residence modifies the association between HDM atopy and recent wheeze, and this effect is explained partly by geohelminth infections. © 2014 The Authors. Clinical & Experimental Allergy Published by John Wiley & Sons Ltd.

  11. Time series analysis of Mexico City subsidence constrained by radar interferometry

    Science.gov (United States)

    Doin, Marie-Pierre; Lopez-Quiroz, Penelope; Yan, Yajing; Bascou, Pascale; Pinel, Virginie

    2010-05-01

    In Mexico City, subsidence rates reach up to 40 cm/yr mainly due to soil compaction led by the over exploitation of the Mexico Basin aquifer. The Mexico Valley, an endoreic basin surrounded by mountains, was in the past covered by large lakes. After the Spanish conquest, the lakes have almost completely disappeared, being progressively replaced by buildings of the current Mexican capital. The simplified hydrogeologic structure includes a superficial 50 to 300 m thick lacustrine aquitard overlying a thicker aquifer made of alluvial deposits. The aquitard layer plays a crucial role in the subsidence process due to the extremely high compressibility of its clay deposits separated by a less compressible sand layer where the biggest buildings of the city are anchored. The aquifer over-exploitation leads to a large scale 30m depression of its piezometric level, inducing water downwards flow in the clays, yielding compaction and subsidence. In order to quantitatively link subsidence to water pumping, the Mexico city subsidence needs to be mapped and analyzed through space and time. We map its spatial and temporal patterns by differential radar interferometry, using 38 ENVISAT images acquired between end of 2002 and beginning of 2007. We employ both a Permanent Scatterer (PS) and a small baseline (SBAS) approach. The main difficulty consists in the severe unwrapping problems mostly due to the high deformation rate. We develop a specific SBAS approach based on 71 differential interferograms with a perpendicular baseline smaller than 500 m and a temporal baseline smaller than 9 months, forming a redundant network linking all images: (1) To help the unwrapping step, we use the fact that the deformation shape is stable for similar time intervals during the studied period. As a result, a stack of the five best interferograms can be used to reduce the number of fringes in wrapped interferograms. (2) Based on the redundancy of the interferometric data base, we quantify the

  12. Inverse association between atopy and melanoma: A case-control study

    NARCIS (Netherlands)

    Marasigan, V. (Vivien); M.-A. Morren (Marie-Anne); J. Lambert; Medaer, K. (Karen); Fieuws, S. (Steffen); T.E.C. Nijsten (Tamar); Garmyn, M. (Marjan)

    2017-01-01

    textabstractHeightened cutaneous immune surveillance in atopic patients may inhibit development of melanoma. The aim of this study was to analyse the association between atopy and melanoma (development and outcome). A total of 188 cases of melanoma and 596 healthy controls were interviewed by

  13. The relationships between atopy, rhinitis and asthma: pathophysiological considerations.

    Science.gov (United States)

    Boulay, Marie-Eve; Boulet, Louis-Philippe

    2003-02-01

    A close relationship has been described between atopy, allergic rhinitis and asthma. The purpose of this work was to review recent data that have become available on the interactions between these conditions and the ways in which they influence one another. Recent findings support previous observations suggesting that atopic dermatitis and rhinitis often accompany or precede the development of asthma. Further data support the notion that early-life exposure to domestic animals, a farming environment, passive smoking, and being raised in a large family, may be protective against the development of atopy and/or allergic diseases, although this seems modulated by genetic factors. Furthermore, the appearance of house-dust-mite-specific immunoglobulin E antibodies in early childhood has been identified as a major risk factor for the development of asthma in children with atopic dermatitis; and the association between sensitization to specific allergens and airway hyperresponsiveness was reported to be the strongest for indoor allergens such as house-dust-mite and cat. Allergen exposure can increase airway responsiveness in non-asthmatic subjects with allergic rhinitis and is associated with an increase in markers of lower airway inflammation, particularly with indoor allergens. Furthermore, nasal allergen provocation can induce bronchial inflammation and vice versa, suggesting close interrelations between upper and lower airways. In summary, the recent observations on the relationships between atopy, rhinitis and asthma support the hypothesis of a unique systemic condition with variable manifestations, which may develop following an imbalance between T helper cell types 1 and 2 lymphocyte populations. The latter may be influenced by environmental exposure in early life. Upper- and lower-airway inflammatory events influence each other, supporting the concept of 'united airways'. Further studies should look at the relationships between these conditions to identify

  14. ORIGINAL ARTICLES Atopy in HIV-infected children in Pretoria

    African Journals Online (AJOL)

    Both atopic and HIV-related diseases are common in South. Africa. Atopy is a genetic .... tree mix, dog hair dander, cat hair dander, standard mite .... incidence of dermatitis;16 this may present as inflammatory or eczematous .... during intestinal nematode infections: what it takes to make a Th2 cell in vivo. Immunol Rev. 2004 ...

  15. A tale of two epidemics: gender differences in socio-demographic characteristics and sexual behaviors among HIV positive individuals in Mexico City.

    Science.gov (United States)

    Bautista-Arredondo, Sergio; Servan-Mori, Edson; Beynon, Fenella; González, Andrea; Volkow, Patricia

    2015-12-16

    To date, the HIV epidemic in Mexico has been concentrated mainly among men who have sex with men, butheterosexual transmission, particularly to women, is increasingly important. This study examine gender differences in socio-demographic characteristics and risk behaviors of HIV positive individuals in Mexico City. We analyzed data from a cross-sectional survey of 1,490 clinic patients (male:female ratio 8:1) with HIV inMexico City in 2010. We examined socio-demographic characteristics, risk behavior, and history of HIV infection.From multivariate non-linear probability (probit) models we calculated predicted probabilities by sex of several outcomes: marginalization, demographic and sexual risk behaviors. Significant differences were found between men and women. Multivariate models suggest that women had lower schooling levels; were less likely to have been employed in the past month and earn more than the minimal wage; more likely to have children, to have been sexually abused, to never have used condoms and to report having been infected by a stable partner. Additionally, women were less likely to report having a partner with a history of migration to the USA and to have engaged in transactional sex. Significant differences exist between men and women with HIV in Mexico City in terms of their socioeconomicand behavioral profiles, which translate into differences in terms of exposure to HIV infection. Women face social and economic vulnerability while men tend to have riskier sexual behavior. Gender issues must be approached in prevention and treatment efforts, using diverse methods to target those most vulnerable and at risk.

  16. The role of a peri-urban forest on air quality improvement in the Mexico City megalopolis

    International Nuclear Information System (INIS)

    Baumgardner, Darrel; Varela, Sebastian; Escobedo, Francisco J.; Chacalo, Alicia; Ochoa, Carlos

    2012-01-01

    Air quality improvement by a forested, peri-urban national park was quantified by combining the Urban Forest Effects (UFORE) and the Weather Research and Forecasting coupled with Chemistry (WRF-Chem) models. We estimated the ecosystem-level annual pollution removal function of the park’s trees, shrub and grasses using pollution concentration data for carbon monoxide (CO), ozone (O 3 ), and particulate matter less than 10 microns in diameter (PM 10 ), modeled meteorological and pollution variables, and measured forest structure data. Ecosystem-level O 3 and CO removal and formation were also analyzed for a representative month. Total annual air quality improvement of the park’s vegetation was approximately 0.02% for CO, 1% for O 3, and 2% for PM 10 , of the annual concentrations for these three pollutants. Results can be used to understand the air quality regulation ecosystem services of peri-urban forests and regional dynamics of air pollution emissions from major urban areas. - Highlights: ► Air quality regulation functions and ecosystem structure of a peri-urban forest in Mexico were quantified. ► Air pollution removal-formation dynamics were estimated using the UFORE and WRF-Chem models. ► Peri-urban forests positively contributed to air qualtiy improvement in Mexico City. ► Results can be used to quantify the ecosystem services of peri-urban forests. - Coupled models estimated air quality improvement and pollution removal-formation by peri-urban forest ecosystems in the Mexico City airshed.

  17. Analysis of Wedge-like Response in Mexico City during the September 19th, 2017 Puebla-Morelos Earthquake

    Science.gov (United States)

    Baena-Rivera, M.; Sanchez-Sesma, F. J.; Ramirez-Guzman, L.

    2017-12-01

    The September 19th, 2017 Puebla-Morelos earthquake (Mw7.1) caused severe structural and nonstructural damage in Mexico City in the Transition and border of the Lake geotechnical zones. Previously recorded ground motion had not reached similar high intensities. The Transition zone surrounds the base of mountain ranges and is composed of alluvial sands and silts, limited by layers of hard soil of the Hill Zone and highly compressible clay deposits of the Lake Zone. These transition configurations are modeled as dipping layers where the soft sediments progressively thicken away from the edge.We present a preliminary analysis of 2D SH and P-SV dipping layer models with homogeneous and lateral variations that resemble the known structure of the basin. Our results show the emergence of surface waves in the edges, and the spread of the energy, broadening the frequency range as compared to 1D models. The latter is a plausible explanation of the frequency content in the recorded ground motion in sites of observed damage. Acknowledgments: Records used in this research are obtained, processed and maintained by the Seismic Instrumentation Unit of the Institute of Engineering at the National Autonomous University of Mexico. This Project was funded by the Secretaría de Ciencia, Tecnología e Innovación (SECITI) of Mexico City. Project SECITI/073/2016.

  18. Securing water for the cities.

    Science.gov (United States)

    Satterthwaite, D

    1993-01-01

    Many cities in developing countries have grown so much that they can no longer provide adequate, sustainable water. Over pumping in Dakar and Mexico City has forced those cities to obtain water from ever more distant sources. In Dakar, the result has been saltwater intrusion. Overpumping has caused Mexico City to sink, in some areas by as much as 9 m, resulting in serious damage to buildings and sewage and drainage pipes. Other cities facing similar water problems are coastal cities in Peru (e.g., Lima), La Rioja and Catamarca in Argentina, cities in Northern Mexico, and cities in dry areas of Africa. For some cities, the problem is not so much ever more distant water supplies but insufficient funds to expand supplies. Bangkok and Jakarta both face saltwater intrusion into their overdrawn aquifers. Even through agriculture is the dominant user of water in most countries, demand concentrated in a small area exhausts local and regional sources and pollutes rivers, lakes, and coasts with untreated human and industrial waste. Most cities in Africa and Asia do not have a sewerage system. Further, most cities do not have the drains to deal with storm water and external floodwater, causing frequent, seasonal flooding. The resulting stagnant water provides breeding grounds for insect vectors of diseases (e.g., malaria). The problems in most cities are a result of poor management, not lack of water. Reducing leaks in existing piped distribution systems from the usual 60% loss of water to leaks to 12% would increase the available water 2-fold. Another way to address water shortages would be commercial, industrial, and recreational use of minimally treated waste water, such as is the case in Madras and Mexico City. Political solutions are needed to resolve inadequate water supply and waste management.

  19. Features of atopies in students from the Facultad de Odontologia at the Universidad de Costa Rica

    International Nuclear Information System (INIS)

    Alvarado Sandoval, Diana; Arce Retana, Marianela; Barquero Dawley, Maria del Mar; Caravaca Bejarano, Javier; Rivera Guadamuz, Carolina

    2014-01-01

    The prevalence and characteristics of atopies are determined in students of second to sixth year of the Career of Odontology at the Universidad de Costa Rica. The prevalence of allergies in students is determined by questionnaire. The concepts of atopy and sensitization process are explained. Different types of hypersensitivity reactions and clinical manifestations are described. Dental materials that commonly produce allergic reactions are identified. The relationship between atopy and other systemic diseases are determined. The clinical manifestation of allergic reaction is mentioned when it is triggered by drugs, food and dental materials. The second year students have shown a prevalence of 3% and the third year to more than 13%, representing a significant difference by year studied. An increase in the prevalence of allergic reactions has been according it advances in the career due to a greater exposure to dental materials [es

  20. Atopy patch tests in young adult patients with atopic dermatitis and controls: dose-response relationship, objective reading, reproducibility and clinical interpretation.

    Science.gov (United States)

    Bygum, Anette; Mortz, Charlotte Gotthard; Andersen, Klaus Ejner

    2003-01-01

    The clinical interpretation and reproducibility of atopy patch tests was studied in 23 selected young adult patients with atopic dermatitis and 25 healthy controls using standard inhalant allergens. Non-invasive measurements were used for objective assessment of test reactions and the participants were retested after 6 weeks. Ten of 19 (53%) evaluable patients with atopic dermatitis had at least one positive atopy patch test. However, there was no clear clinical relevance of the atopy patch test results when related to patient history and distribution of dermatitis. Reproducible and dose-dependent results were obtained with Dermatophagoides pteronyssinus, grass and cat with a reproducibility rate of 0.69 to 0.81 in patients and 0.60-0.96 in controls. A unique finding was a significant positive correlation between a positive atopy patch test, allergen dose and increase in transepidermal water loss and erythema, while measurement of capacitance did not distinguish between positive and negative reactions. The results of the present study do not support the routine use of atopy patch tests in the evaluation of adult patients with atopic dermatitis.

  1. Towards Providing Solutions to the Air Quality Crisis in the Mexico City Metropolitan Area: Carbon Sequestration by Succulent Species in Green Roofs.

    Science.gov (United States)

    Collazo-Ortega, Margarita; Rosas, Ulises; Reyes-Santiago, Jerónimo

    2017-03-31

    In the first months of 2016, the Mexico City Metropolitan Area experienced the worst air pollution crisis in the last decade, prompting drastic short-term solutions by the Mexico City Government and neighboring States. In order to help further the search for long-term sustainable solutions, we felt obliged to immediately release the results of our research regarding the monitoring of carbon sequestration by green roofs. Large-scale naturation, such as the implementation of green roofs, provides a way to partially mitigate the increased carbon dioxide output in urban areas. Here, we quantified the carbon sequestration capabilities of two ornamental succulent plant species, Sedum dendroideum and Sedum rubrotinctum, which require low maintenance, and little or no irrigation. To obtain a detailed picture of these plants' carbon sequestration capabilities, we measured carbon uptake on the Sedum plants by quantifying carbon dioxide exchange and fixation as organic acids, during the day and across the year, on a green roof located in Southern Mexico City. The species displayed their typical CAM photosynthetic metabolism. Moreover, our quantification allowed us to conservatively estimate that a newly planted green roof of Sedum sequesters approximately 180,000,000 ppm of carbon dioxide per year in a green roof of 100 square meters in the short term. The patterns of CAM and carbon dioxide sequestration were highly robust to the fluctuations of temperature and precipitation between seasons, and therefore we speculate that carbon sequestration would be comparable in any given year of a newly planted green roof. Older green roof would require regular trimming to mantain their carbon sink properties, but their carbon sequestration capabilities remain to be quantified. Nevertheless, we propose that Sedum green roofs can be part of the long-term solutions to mitigate the air pollution crisis in the Mexico City Metropolitan area, and other "megacities" with marked seasonal drought.

  2. Obesity increases metabolic syndrome risk factors in school-aged children from an urban school in Mexico city.

    Science.gov (United States)

    Perichart-Perera, Otilia; Balas-Nakash, Margie; Schiffman-Selechnik, Esther; Barbato-Dosal, Annarella; Vadillo-Ortega, Felipe

    2007-01-01

    To characterize the nutritional status of school-aged children from an urban public school in Mexico City, Mexico, and to assess the influence of obesity on health status in a subgroup of these children. Cross-sectional descriptive study. A nutrition screening was done for all children, including anthropometric (ie, weight, height, and waist circumference) and blood pressure assessment. In the subgroup of children, complementary dietary and biochemical assessment (ie, glucose, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, insulin, albumin, hemoglobin, and hematocrit levels) was done. Children from an urban school in Mexico City (N=561) aged 6 to 13 years. The representative subgroup (n=88) was selected based on age (9 to 12 years) and weight status (ie, normal, overweight, or obese). Descriptive statistics, correlations, mean differences tests (analysis of variance, Kruskal-Wallis and Mann-Whitney U), and chi(2) tests (categorical variables) were done with SPSS version 13 (2005, SPSS Inc, Chicago, IL). In the whole school, overweight and obesity prevalence were 27.1% and 21.4%, respectively. High systolic blood pressure was seen in 8.4% of children and 6.2% of children had prehypertension. Higher hypertension risk was seen in children with body mass index > or =95th percentile and waist circumference > or =90th percentile (88 cm). Significantly higher waist circumference, systolic blood pressure, insulin resistance indexes, and triglyceride levels were found among the obese when compared with normal-weight children. Childhood obesity prevalence is high in Mexico and it is having an influence on children's health. It is urgent to design, implement, and evaluate specific childhood obesity prevention programs.

  3. Film and social mobility: From Oaxaca to Mexico City with the Zúñiga's, father and son, 1920-1970

    Directory of Open Access Journals (Sweden)

    Mary Kay Vaughan

    2016-04-01

    Full Text Available If between 1940 and 1980 upward social mobility in Mexico City is owed to expanding opportunities for education and employment, the mass media also played a role. This essay focuses on the experiences with cinema of two men, José Zúñiga Heredia (1914-1985, a tailor who migrated from Oaxaca to Mexico City in 1939, and his son Pepe (b. 1937 who became a student, later a professor and director (1991-1993 of the Escuela de Pintura, Escultura, y Grabado La Esmeralda. I examine the role of Hollywood and Mexican film in the formation of their sensibilities, desires, aspirations, and notions of rights and dignity, and argue that cinema had an important role in the formation of a spirit of rebellion and a new masculine sensibility among male youth who entered higher education at the end of the 1950s.

  4. The Role of School in Educational Decisions during the Transition to High School Public Institutions in Mexico City context

    Directory of Open Access Journals (Sweden)

    Eduardo Rodríguez Rocha

    2016-09-01

    Full Text Available This article analyzes the role of schools in educational choices in the transition to public high schools in Mexico City. Secondary schools have the potential to influence educational choices, through the development of certain educational functions. This influence comes in different ways, and is relatively independent of adscriptive characteristics and previous academic performance of students.  Schools serve i as agents contributing to decision making, facilitating continuity on educational trajectories ii or as instances that do not develop explicit actions aimed to link their students to any of the options offered in the post-secondary educational system. While some schools teaching resources are destined to accompany their students during their decision process, others lack of them, abandoning them in this crucial educational event. The article is based on data provided by an ethnographic study conducted in seven high schools in southern Mexico City between January and July 2012

  5. Neuropsychologic status at the age 4 years and atopy in a population-based birth cohort.

    Science.gov (United States)

    Julvez, J; Torrent, M; Guxens, M; Antó, J M; Guerra, S; Sunyer, J

    2009-09-01

    Mental health has been reported to be associated with allergy, but only a few cohort studies have assessed if neurodevelopment predicts atopy. To investigate if neurobehavioral status of healthy 4-year-old children was associated with specific immunoglobulin E (IgE) at the same age and skin prick test results 2 years later. A population-based birth cohort enrolled 482 children, 422 of them (87%) provided neurobehavioral data, 341 (71%) had specific IgE measured at the age of 4 years; and 395 (82%) had skin prick tests completed at the age of 6 years. Atopy was defined as IgE levels higher than 0.35 kU/l to any of the three tested allergens at the age of 4 or as a positive skin prick test to any of the six tested allergens at the age of 6. McCarthy Scales of Child Abilities and California Preschool Social Competence Scale were the psychometric instruments used. Twelve percent of children at the age of 4 and 17% at the age of 6 were atopic. Neurobehavioral scores were negatively associated with 6-year-old atopy after adjustment for socio-demographic and allergic factors, A relative risk of 3.06 (95% CI: 1.30-7.24) was associated with the lowest tertile (scorings eczema at the age of 6, but not at the age of 4, were associated with neurodevelopment at the age of 4. Neuropsychologic functioning and later atopy are negatively associated in preschool age children.

  6. Lattice Wind Description and Characterization of Mexico City Local Wind Events in the 2001–2006 Period

    Directory of Open Access Journals (Sweden)

    Alejandro Salcido

    2015-07-01

    Full Text Available Urban transformation and expansion in Mexico City continuously affect its urban morphology, and therefore the modes of wind circulation inside it and their occurrence probabilities. Knowledge on these topics is an important issue for urban planning and for other urban studies, such as air quality assessment. In this paper, using a lattice wind model at a meso-β scale, we develop a simple description and characterization of Mexico City local wind events that occurred during the period 2001–2006, including an estimation of the occurrence probabilities. This region was modeled as a 2D lattice domain of identical cells, and wind conditions in each cell were described by four wind attributes: the horizontal velocity components, divergence, and vorticity. Models of one and four cells were applied to wind data furnished by the meteorological network of the city. Results include the following: Early morning: low intensity winds (75% from N, NW, W and SW (75%, convergent (93%, with a slight predominance of cyclonic vorticity (54%. Morning and early afternoon: winds from N, NE and E (72% with speeds from 0.5 to 3.5 m/s, slight prevailing of convergent winds (51%, and slight predominance of cyclonic vorticity (57%. Late afternoon and night: winds blowing from N, NW, and S (63% with speeds from 1.5 to 3.5 m/s (66%, convergent (90%, and cyclonic (72%.

  7. On the Chemical Characterization of Organic Matter in Rain at Mexico City.

    Science.gov (United States)

    Montero-Martinez, G.; Andraca-Ayala, G. L.; Hernández-Nagay, D. P.; Mendoza-Trejo, A.; Rivera-Arellano, J.; Rosado-Abon, A.; Roy, P. D.

    2016-12-01

    The chemical composition of the aerosol plays a central role in atmospheric processes and has influence on the hydrological cycle. Clouds form through the nucleation of water vapor on certain atmospheric aerosol particles, called cloud condensation nuclei (CCN). Also, precipitating particles scavenge some other aerosol particles on their way to the surface. Atmospheric particles are a mixture of organic and inorganic materials, both soluble and insoluble in water. Aerosol chemical characterization indicates a larger variety of compounds in urban areas respect to other regions. Thus, chemical composition of rainwater may represent an important aspect for estimating atmospheric air pollution. It has been recognized that organic species present in aerosol particles are important in the formation of cloud droplets. Therefore, the information about the organic compounds in precipitation samples may be helpful to understand their effects on the formation of clouds and rain, as well as their sources. Organic acids are ubiquitous components of aerosols and have been identified in precipitation water. In this work, preliminary results of the content of soluble organic (neutral and acidic) matter in rainwater samples collected in Mexico City during 2015 will be presented. The organic compounds content was performed by using an ionic chromatographic methodology with gradient elution; so the total amount was evaluated as the sum of four fractions: neutral/basic, mono-, bi-, and poly-acid compounds. The outcomes suggest that most of the amount of organic substances soluble in water is contained by the neutral/basic and mono-acid fractions. Regarding the total amount of water soluble organic compounds, the rain samples collected in Mexico City are in agreement with some others reported for large urban areas.

  8. Escherichia coli in settled-dust and air samples collected in residential environments in Mexico City.

    OpenAIRE

    Rosas, I; Salinas, E; Yela, A; Calva, E; Eslava, C; Cravioto, A

    1997-01-01

    Escherichia coli, an important indicator of the presence of fecal material, was isolated from indoor and outdoor environments in Mexico City. The heterogeneity of E. coli was represented by 89 serotypes, most of them coming from settled-dust indoor samples; 21% of them presented antibiotic multiresistance. The numbers of plasmids were higher among the antibiotic-resistant strains. The results of this study suggest that intestinal infections produced by environmental strains could be of more e...

  9. Vertical Profile Measurements of Volatile Organic Compounds in Southwest Mexico City with a semiautomatic sampling system

    Science.gov (United States)

    Solano-Murillo, M.; Torres-Jardón, R.; Gutiérrez-López, W.; García-Espinosa, M.

    2017-12-01

    A prototype for the simultaneous sampling of VOC at different heights using a Tethered meteorological balloon was integrated and tested in a smog urban receptor site in southwest Mexico City. A selection of COV species measured at three different heights was used to estimate the chemical aging using the expression:Δt=[ln(ER1,2)-ln(VOC1/VOC2)]/[(K1-K2)[OH

  10. Characterization of fine particle components in Mexico City

    International Nuclear Information System (INIS)

    Saitoh, K.; Sera, K.; Perales, J.G.; Garcia, F.A.; Suzuki, H.

    1999-01-01

    Particulate matter (PM-3.9 and PM-15.8) samples were collected in the three zones at the Northeast, Southwest and Southeast suburbs of Mexico City, from July to August 1998, for one week for each sampling site. The concentrations of several elements in the PM-3.9 and PM-15.8 samples were determined by Particle Induced X-ray Emission (PIXE). In the PM-3.9 samples, 21 elements were determined for each zone, and Na, Mg, Al, Si, S, K, Ca, Ti, Fe, Cu, Zn and Pb are found to be the major elemental components. On the other hand, 22 elements including P were determined on the PM-15.8 samples, and the dominant elements were the same as in the PM-3.9. Factor analysis is applied to the 28 variables (14 elements for each PM-3.9 and PM-15.8 groups) and for 21 samples (seven days for three zones) in order to identify possible sources of the particles. The result of factor analysis allows to identify five major sources, being soil the major contributor. (author)

  11. Characterization of fine particle components in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, K. [Akita Prefectural Institute of Environmental Science, Yabase-Shimoyabase, Akita (Japan); Sera, K. [Iwate Medical Univ., Cyclotron Research Center, Takizawa, Iwate (Japan); Perales, J.G.; Garcia, F.A. [Centro Nacional de Investigacion y Capacitacion Ambiental (CENICA), Av. Michoacan y la Purisima Col. Vicentina C.P. 09340 Mexico (Mexico); Suzuki, H. [Environmental Data Analysis Laboratory, System Design, Inc., Shinagawa, Tokyo (Japan)

    1999-07-01

    Particulate matter (PM-3.9 and PM-15.8) samples were collected in the three zones at the Northeast, Southwest and Southeast suburbs of Mexico City, from July to August 1998, for one week for each sampling site. The concentrations of several elements in the PM-3.9 and PM-15.8 samples were determined by Particle Induced X-ray Emission (PIXE). In the PM-3.9 samples, 21 elements were determined for each zone, and Na, Mg, Al, Si, S, K, Ca, Ti, Fe, Cu, Zn and Pb are found to be the major elemental components. On the other hand, 22 elements including P were determined on the PM-15.8 samples, and the dominant elements were the same as in the PM-3.9. Factor analysis is applied to the 28 variables (14 elements for each PM-3.9 and PM-15.8 groups) and for 21 samples (seven days for three zones) in order to identify possible sources of the particles. The result of factor analysis allows to identify five major sources, being soil the major contributor. (author)

  12. Microbiological determinations of some vegetables from the Xochimilco zone in Mexico City, Mexico.

    Science.gov (United States)

    García-Gómez, Rolando; Chávez-Espinosa, José; Mejía-Chávez, Adriana; Duránde-Bazúa, Carmen

    2002-01-01

    Vegetables intake is widely recommended because of its high content of vitamins, minerals and fiber. However, the irrigation of these vegetables, using wastewaters that have received inadequate treatment often carries unseen microbial pollution that becomes a high risk potential for humans. In the present research, two of the most consumed fresh vegetables cultivated in Mexico City were analyzed, lettuce (Lactuca sativa) and Mexican coriander (Eryngium foetidum). These vegetables are commonly consumed raw. The vegetable choice and the disinfection's method were carried out by the application of two tests to two hundred people in an aleatory form. Similarly, vegetable sampling was carried out by means of a random sampling from the cultivated areas in a chosen "chinampa" (from Náhuatl or Aztec, chinamitl, bulrush or cattail stalks lattice for hydroponics cultivation). Vegetable samples were transferred, in dark plastic bags and in cool boxes at 4 +/- 1.5 degrees C, to the laboratory. Microbiological analysis for Salmonella typhi, mesophilic microorganisms, and fecal coliforms were done according to the "NOM-093SSA1-1994" (Mexico). Results obtained demonstrated that samples treated with the most preferred disinfectant, a colloidal silver based one, had a partial elimination of pathogenic microorganisms found in both vegetables lettuce (Lactuca sativa) and coriander (Eryngium foetidum) samples (mesophyllic microorganisms from 200,000 to 96,500 UFC/g and from 175,000 to 125,000 UFC/g and fecal coliforms from 75 to 0.43 NMP/g and from 150 to 2.10 NMP/g, respectively). Salmonella typhi for all samples gave a positive result. Therefore, it was recommended to the cultivators of the Xochimilco (Náhuatl or Aztec name that means "place where flowers bloom") zone, either stop using contaminated water for irrigation or to use more efficient methods in order to eliminate pathogenic microorganisms, such as diluted chlorine solutions made with commercial cotton clothing bleachers.

  13. Atopy and contact allergy to fragrance: allergic reactions to the fragrance mix I (the Larsen mix).

    Science.gov (United States)

    Buckley, Deirdre A; Basketter, David A; Kan-King-Yu, Denis; White, Ian R; White, Jonathan L M; McFadden, John P

    2008-10-01

    The relationship between an atopic diathesis and contact sensitization to fragrances is unclear. To investigate whether there is an association between atopy and allergy to fragrance mix I (FM I). The computerized files of patients patch tested to FM I at St John's Institute of Dermatology (1980-2004) were reviewed. Demographic details recorded for all patch-tested patients included age, sex, date of testing, history of current or previous atopic eczema (AE), history of current or previous asthma nor hay fever (A/HF), family history (FH) of any type of atopy, and any positive patch tests. About 8.4% of females (1713/20 338) and 6.6% of males (903/13 734) were allergic to FM I. About 8.95% (101/1129) of females with AE were allergic to FM I versus 8.63% (619/7171) of females who had neither AE and A/HF nor FH (non-atopics) (P = 0.72). About 5.6% (40/710) of males with AE were positive to FM I versus 6.9% (427/6201) of male non-atopics (P = 0.23). There was a striking increase in AE and A/HF during this 25-year period (P < 0.0001). We found no association between atopy and allergy to FM I. There has been a marked increase in atopy in individuals referred for patch testing in the past 25 years.

  14. The polycentric structure of local labour markets in Mexico City's Metropolitan Area

    Directory of Open Access Journals (Sweden)

    José María Casado Izquierdo

    2012-11-01

    Full Text Available Commuting data at a district level and an algorithm designed to delineate self–contained areas show that Mexico City Metropolitan Area (MCMA was organized in 2007 in twelve local labour market areas. Although six exployment subcenters were identified, the MCMA is still clearly dominated by its Central Business District (CBD, being located the remaining five subcenters close to the CBD. Assessment of this spatial structure is not a positive one: diminishing co–location, decrease in speed and increase in commuting time and distance. Nevertheless, the rising percentage of intra–district commuting is a positive sign, even if this trend is not uniform throughout the metropolitan area.

  15. Climate change and its impact on water infrastructure: the case of Alcala de Henares (Spain) and Mexico City (Mexico)

    Science.gov (United States)

    Naranjo, M.; Tortajada, C.

    2012-04-01

    Climate change and its possible impacts on precipitation are still a matter of controversy due to lack of data as well as models which are considered reliable. Even though the science of climate change has advanced significantly in recent years, many uncertainties still prevail, ranging from reliable prediction of extreme river flow events to downscaling of rainfall to smaller planning areas. That is, present knowledge is still insufficient to understand and accurately predict how global changes, climate change one of them, may affect precipitation and streamflows over specific geographical units. In terms of planning and investment in urban areas, where more than 50 percent of the population live at present, freshwater supply and flood risk management have to be considered on long-term basis. This includes development of water infrastructure for drinking water supply and drainage as well as flood control which responds to the needs of the growing populations and their economies. Impacts of climate change are slow over time and take place over thousands of years. However, their study is relatively recent, mostly in terms of impacts on the hydrological cycle and therefore in terms of run-off. In the case of urban centres, the rationale is that governments will have to adapt the water infrastructure according to the expected changes and thus have to plan for them. For example, in the case of Mexico City, the way the drainage system was designed 100 years ago is very different from the way it would be done at present and the way it would be planned in about 50 years time. In the case of the city of Alcalá de Henares in the region of Madrid, the analysis of precipitations has shown a slight tendency towards a wet period from the decade of the 60´s. Due to this tendency, the calculations for the design of water infrastructures have remained virtually unchanged. In the case of this specific city, there is no indication that there will be dramatic or rapid changes in

  16. 75 FR 43939 - The Americas Business Trade Mission to Mexico

    Science.gov (United States)

    2010-07-27

    ... Mexico AGENCY: International Trade Administration, Department of Commerce. ACTION: Notice. Mission... will recruit and organize a multiple industry trade mission to Mexico City with an optional second stop... local business climate. In Mexico City, there will also be a networking reception for the delegation...

  17. Qualitative Inquiry with Women in Poverty in Mexico City: Reflections on the Emotional Responses of a Research Team

    Science.gov (United States)

    Martinez-Salgado, Carolina

    2009-01-01

    While conducting a qualitative inquiry involving in-depth interviews on the perceptions of health risks within a group of profoundly poor urban families in the southern part of Mexico City, Martinez-Salgado and her interdisciplinary team of women interviewers got involved in emotionally complex situations with the women participants in the study.…

  18. Non-methane hydrocarbons in the atmosphere of Mexico City: Results of the 2012 ozone-season campaign

    Science.gov (United States)

    Jaimes-Palomera, Mónica; Retama, Armando; Elias-Castro, Gabriel; Neria-Hernández, Angélica; Rivera-Hernández, Olivia; Velasco, Erik

    2016-05-01

    With the aim to strengthen the verification capabilities of the local air quality management, the air quality monitoring network of Mexico City has started the monitoring of selected non-methane hydrocarbons (NMHCs). Previous information on the NMHC characterization had been obtained through individual studies and comprehensive intensive field campaigns, in both cases restricted to sampling periods of short duration. This new initiative will address the NMHC pollution problem during longer monitoring periods and provide robust information to evaluate the effectiveness of new control measures. The article introduces the design of the monitoring network and presents results from the first campaign carried out during the first six months of 2012 covering the ozone-season (Mar-May). Using as reference data collected in 2003, results show reductions during the morning rush hour (6-9 h) in the mixing ratios of light alkanes associated with the consumption and distribution of liquefied petroleum gas and aromatic compounds related with the evaporation of fossil fuels and solvents, in contrast to olefins from vehicular traffic. The increase in mixing ratios of reactive olefins is of relevance to understand the moderate success in the ozone and fine aerosols abatement in recent years in comparison to other criteria pollutants. In the case of isoprene, the typical afternoon peak triggered by biogenic emissions was clearly observed for the first time within the city. The diurnal profiles of the monitored compounds are analyzed in terms of the energy balance throughout the day as a surrogate of the boundary layer evolution. Particular features of the diurnal profiles and correlation between individual NMHCs and carbon monoxide are used to investigate the influence of specific emission sources. The results discussed here highlight the importance of monitoring NMHCs to better understand the drivers and impacts of air pollution in large cities like Mexico City.

  19. Spanish Professionals in Mexico City: Narratives on Work and Labour Markets

    Directory of Open Access Journals (Sweden)

    Cristóbal Mendoza

    2008-12-01

    Full Text Available Using qualitative information, this paper studies the labour experiences of a group of skilled Spanish migrants in Mexico City. The paper identifies two types of migrants amongst the interviewed Spaniards: TNCs transferees and “migrants in the middle” (“those who are neither low-skilled migrants nor high-skilled migrants”; Conradson and Latham, 2005a. This somehow challenges assumptions about skilled workers, by showing the multiple work trajectories and experiences of highly qualified and educated workers. The article also stresses that the labour mobility of those in the middle is more horizontal and less conventional than the more typical career-path mobility of TNCs transferees. Furthermore, it is argued that labour mobility is not only related to educational background or performance in Mexico’s labour markets, but also to non-economic reasons (e.g. extensive use of social networks. Of special interest for this study are relations at the workplace as they represent a “contact zone” where “difference” is constantly encountered and negotiated (Yeoh and Willis, 2005b. For the interviewed Spaniards, workplace relations are substantially (and unexpectedly different from those in their home country. This causes tension and problems that may affect their intentions to remain in Mexico.

  20. [Food preferences and nutritional status in school-age children living in Mexico City].

    Science.gov (United States)

    Sánchez-García, Rocío; Reyes-Morales, Hortensia; González-Unzaga, Marco Aurelio

    Childhood is a basic period for the development of habits and their continuation during the course of life. The objective of this study was to identify food preferences and their variations according to the nutritional status in school-age children living in Mexico City. A cross-sectional study was carried out including 1465 school-age children attending eight public elementary schools in Mexico City. Children were asked to complete a questionnaire regarding their preferences to 70 selected different foods. Anthropometric measurements were also carried out. Parents of the children provided sociodemographic information. For each food, the preference was evaluated using a Likert scale. Frequencies were calculated for the total sample and for different nutritional status levels. Median age of children was 9 years old. Forty-eight percent of the children were overweight or obese. The most preferred foods were fruits, pizzas, flavored milk, and French fries. The least preferred foods were vegetables, whole-grain cereals, fish, meat, and panela cheese. Plain water (72%) and sugar-sweetened beverages (71%) had a high level of preference. There was no preference variation according to nutritional status. Food preference patterns of school-age children are a risk for unhealthy food consumption as well as for the increase in obesity prevalence in this population. Interventions focused on the promotion of a healthy food environment are necessary, aimed at improving food preferences from early childhood. Copyright © 2014 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

  1. Volatile organic compounds in the atmosphere of Mexico City

    Science.gov (United States)

    Garzón, Jessica P.; Huertas, José I.; Magaña, Miguel; Huertas, María E.; Cárdenas, Beatriz; Watanabe, Takuro; Maeda, Tsuneaki; Wakamatsu, Shinji; Blanco, Salvador

    2015-10-01

    The Mexico City Metropolitan Area (MCMA) is one of the most polluted megacities in North America. Therefore, it is an excellent benchmark city to understand atmospheric chemistry and to implement pilot countermeasures. Air quality in the MCMA is not within acceptable levels, mainly due to high ground levels of ozone (O3). Tropospheric O3 is a secondary pollutant formed from the oxidation of volatile organic compounds (VOCs) in the presence of nitrogen oxides and sunlight. To gain a better understanding of O3 formation in megacities, evaluate the effectiveness of already-implemented countermeasures, and identify new cost-effective alternatives to reduce tropospheric O3 concentrations, researchers and environmental authorities require updated concentrations for a broader range of VOCs. Moreover, in an effort to protect human health and the environment, it is important to understand which VOCs exceed reference safe values or most contribute to O3 formation, as well as to identify the most probable emission sources of those VOCs. In this work, 64 VOCs, including 36 toxic VOCs, were measured at four sites in the MCMA during 2011-2012. VOCs related to liquefied petroleum gas leakages exhibited the highest concentrations. Toxic VOCs with the highest average concentrations were acetone and ethanol. The toxic VOC benzene represented the highest risk to Mexican citizens, and toluene contributed the most to O3 formation. Correlation analysis indicated that the measured VOCs come from vehicular emissions and solvent-related industrial sources.

  2. Correlation of Secondary Organic Aerosol with Odd Oxygen in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Herndon, Scott C.; Onasch, Timothy B.; Wood, Ezra C.; Kroll, Jesse H.; Canagaratna, M. R.; Jayne, John T.; Zavala, Miguel A.; Knighton, W. Berk; Mazzoleni, Claudio; Dubey, Manvendra K.; Ulbrich, Ingrid M.; Jimenez, Jose L.; Seila, Robert; de Gouw, Joost A.; de Foy, B.; Fast, Jerome D.; Molina, Luisa T.; Kolb, C. E.; Worsnop, Douglas R.

    2008-08-05

    Data collected from a mountain location within the Mexico City limits are used to demonstrate a correlation between secondary organic aerosol and odd-oxygen (O3 + NO2). Positive matrix factorization techniques are employed to separate organic aerosol components: hydrocarbon-like organic aerosol; oxidized-organic aerosol; and biomass burning organic aerosol. The measured hydrocarbon-like organic aerosol is correlated with urban CO (8±1) µg m-3 ppmv-1. The measured oxidized-organic aerosol is associated with photochemical oxidation products and correlates with odd-oxygen with an apparent slope of (70-120) µg m-3 ppmv-1. The dependence of the oxidized-organic aerosol to odd-oxygen correlation on the nature of the gas-phase hydrocarbon profile is discussed.

  3. [Between the stigma and the law: legal abortion in Mexico City].

    Science.gov (United States)

    Lamas, Marta

    2014-01-01

    The present contribution is part of a research developed with qualitative social research methods. It offers part of the results attained in a study performed at a clinic belonging to Mexico City´s Government, and explores the effects on staff of the implementation of Legal Pregnancy Termination (ILE, for its initials in Spanish). The results highlights that, besides diminishing health risks in the women who abort, the use of misoprostol prompted assertive attitudes in many women, that reduced the negative effects produced by the stigma of abortion. It also acknowledges the persistence of stigma in the opinions of the health personnel. The empowering of the self-image of women who become subject to this procedure is due to the full exercise of their legal right.

  4. Antibiotic of resistence profile of Salmonella spp. serotypes isolated from retail beef in Mexico City.

    OpenAIRE

    Nova Nayarit-Ballesteros; María Salud Rubio-Lozano; Enrique Delgado-Suárez; Danilo Méndez-Medina; Diego Braña-Varela; Oscar Rodas-Suárez

    2016-01-01

    Objective. To determine the serotype and antibiotic resistance profile of Salmonella spp. isolated from retail ground beef in Mexico City. Materials and methods. A total of 100 samples of ground beef were analyzed. The pathogen was isolated by conventional methods and confirmed by PCR (invA gene, 284 bp). The antibiotic resistance profile was determined by the Kirby-Bauer method while serotyping was performed according to the Kauffman-White scheme. Results. We isolated a total of 19 strains o...

  5. Source apportionment of fine organic aerosol in Mexico City during the MILAGRO experiment 2006

    Directory of Open Access Journals (Sweden)

    E. A. Stone

    2008-03-01

    Full Text Available Organic carbon (OC comprises a large fraction of fine particulate matter (PM2.5 in Mexico City. Daily and select 12-h PM2.5 samples were collected in urban and peripheral sites in Mexico City from 17–30 March 2006. Samples were analyzed for OC and elemental carbon (EC using thermal-optical filter-based methods. Real-time water-soluble organic carbon (WSOC was collected at the peripheral site. Organic compounds, particularly molecular markers, were quantified by soxhlet extraction with methanol and dichloromethane, derivitization, and gas chromatography with mass spectrometric detection (GCMS. A chemical mass balance model (CMB based on molecular marker species was used to determine the relative contribution of major sources to ambient OC. Motor vehicles, including diesel and gasoline, consistently accounted for 49% of OC in the urban area and 32% on the periphery. The daily contribution of biomass burning to OC was highly variable, and ranged from 5–26% at the urban site and 7–39% at the peripheral site. The remaining OC unapportioned to primary sources showed a strong correlation with WSOC and was considered to be secondary in nature. Comparison of temporally resolved OC showed that contributions from primary aerosol sources during daylight hours were not significantly different from nighttime. This study provides quantitative understanding of the important sources of OC during the MILAGRO 2006 field campaign.

  6. Coverage and accessibility levels of health services in the metropolitan periphery of Mexico City

    Directory of Open Access Journals (Sweden)

    Flor López

    2012-02-01

    Full Text Available The aim of this study is two fold: first, to analyze the spatial distribution of health services that different public institutions offer in the metropolitan peripheral municipalities of Mexico City; and second, give some reasons that explain that distribution. The analysis tries to demonstrate a lack of territorial approach in the construction of the social policy in the particular case of the health sector. The spatial range of health service, coverage and accessibility in the eastern part of the State of Mexico was calculate through variables much as number of doctors, nurses, beds and medical center, that the different public institution particularly IMSS, ISSSTE and ISSEMYM, offer. Results tend to show an unequal distribution of health resources either human or material, as well as a territorial disorden in their distribution with a high concentration in urban areas. Thus, analysis shows that space plays a fundamental role as a structuring factor in the application of health policies and in the planning of such services.

  7. Adaptive pathways and coupled infrastructure: seven centuries of adaptation to water risk and the production of vulnerability in Mexico City

    Directory of Open Access Journals (Sweden)

    Beth Tellman

    2018-03-01

    Full Text Available Infrastructure development is central to the processes that abate and produce vulnerabilities in cities. Urban actors, especially those with power and authority, perceive and interpret vulnerability and decide when and how to adapt. When city managers use infrastructure to reduce urban risk in the complex, interconnected city system, new fragilities are introduced because of inherent system feedbacks. We trace the interactions between system dynamics and decision-making processes over 700 years of Mexico City's adaptations to water risks, focusing on the decision cycles of public infrastructure providers (in this case, government authorities. We bring together two lenses in examining this history: robustness-vulnerability trade-offs to explain the evolution of systemic risk dynamics mediated by feedback control, and adaptation pathways to focus on the evolution of decision cycles that motivate significant infrastructure investments. Drawing from historical accounts, archeological evidence, and original research on water, engineering, and cultural history, we examine adaptation pathways of humans settlement, water supply, and flood risk. Mexico City's history reveals insights that expand the theory of coupled infrastructure and lessons salient to contemporary urban risk management: (1 adapting by spatially externalizing risks can backfire: as cities expand, such risks become endogenous; (2 over time, adaptation pathways initiated to address specific risks may begin to intersect, creating complex trade-offs in risk management; and (3 city authorities are agents of risk production: even in the face of new exogenous risks (climate change, acknowledging and managing risks produced endogenously may prove more adaptive. History demonstrates that the very best solutions today may present critical challenges for tomorrow, and that collectively people have far more agency in and influence over the complex systems we live in than is often acknowledged.

  8. An evaluation of the hybrid car technology for the Mexico Mega City

    Science.gov (United States)

    Jazcilevich, Aron D.; Reynoso, Agustin Garcia; Grutter, Michel; Delgado, Javier; Ayala, Ulises Diego; Lastra, Manuel Suarez; Zuk, Miriam; Oropeza, Rogelio Gonzalez; Lents, Jim; Davis, Nicole

    The introduction of hybrid electric vehicle (HEV) technology in the private car fleet of Mexico City is evaluated in terms of private costs, energy, public health and CO 2 emission benefits. In addition to constructing plausible scenarios for urban expansion, emission, car fleet, and fuel consumption for year 2026 and comparing them with a 2004 base case, a time series is built to obtain accumulated economic benefits. Experimental techniques were used to build a vehicle library for a car simulator that included a Prius 2002, chosen as the HEV technology representative for this work. The simulator is used to estimate the emissions and fuel consumption of the car fleet scenarios. In the context of an urban scenario for year 2026, a complex air quality model obtains the concentrations of criterion pollutants corresponding to these scenarios. Using a technology penetration model, the hybridized fleet starts unfolding in year 2009 reaching to 20% in 2026. In this year, the hybridized fleet resulted in reductions of about 10% of CO 2 emissions, and yielded reductions in daytime mean concentrations of up to 7% in ozone and 3.4% in PM 2.5 compared to the 2004 base case. These reductions are concentrated in the densely populated areas of Mexico City. By building a time series of costs and benefits it is shown that, depending on fuel prices and using a 5% return rate, positive accumulated benefits (CO 2 benefits + energy benefits + public health benefits - private costs) will start generating in year 2015 reaching between 2.8 and 4.5 billion US Dlls in 2026. Another modernized private fleet consisting exclusively of Tier I and II cars did not yield appreciable results, signaling that a change in private car technology towards HEV's is needed to obtain significant accumulated benefits.

  9. History of nonnative Monk Parakeets in Mexico.

    Science.gov (United States)

    Hobson, Elizabeth A; Smith-Vidaurre, Grace; Salinas-Melgoza, Alejandro

    2017-01-01

    Nonnative Monk Parakeets have been reported in increasing numbers across many cities in Mexico, and were formally classified as an invasive species in Mexico in late 2016. However, there has not been a large-scale attempt to determine how international pet trade and national and international governmental regulations have played a part in colonization, and when the species appeared in different areas. We describe the changes in regulations that led the international pet trade market to shift to Mexico, then used international trade data to determine how many parakeets were commercially imported each year and where those individuals originated. We also quantified the recent increases in Monk Parakeet (Myiopsitta monachus) sightings in Mexico in both the scientific literature and in citizen science reports. We describe the timeline of increased reports to understand the history of nonnative Monk Parakeets in Mexico. As in other areas where the species has colonized, the main mode of transport is through the international pet trade. Over half a million Monk Parakeets were commercially imported to Mexico during 2000-2015, with the majority of importation (90%) occurring in 2008-2014, and almost all (98%) were imported from Uruguay. The earliest record of a free-flying Monk Parakeet was observed during 1994-1995 in Mexico City, but sightings of the parakeets did not become geographically widespread in either the scientific literature or citizen science databases until 2012-2015. By 2015, parakeets had been reported in 97 cities in Mexico. Mexico City has consistently seen steep increases in reporting since this species was first reported in Mexico. Here we find that both national and international legal regulations and health concerns drove a rise and fall in Monk Parakeet pet trade importations, shortly followed by widespread sightings of feral parakeets across Mexico. Further monitoring of introduced Monk Parakeet populations in Mexico is needed to understand the

  10. The traffic crisis and a tale of two cities: Traffic and air quality in Bangkok and Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Pendakur, V.S.; Badami, M.G.

    1995-12-31

    This paper focuses on congestion management techniques, traffic congestion levels and air quality. By using data from Bangkok and Mexico City, it illustrates the need for drastic changes in transportation policy tools and techniques for congestion management and for improving environmental quality. New approaches to investment and regulatory policy analysis and implementation are suggested. This requires the inclusion of all costs and benefits (economic and ecological) in the policy matrix so that investment and regulatory policies act in unison. Megacities are dominant in social, political and economic terms. 30 to 60% of national GDP is typically produced in these cities. Their human and motor vehicle populations have been doubling every 15-20 and 6-10 years respectively. They also have the most severe traffic congestion and air quality problems. They have the nation`s highest incidence of poverty and absolute poverty. Large portions of their populations endure severely unhealthy housing and sanitation conditions. Following are important characteristics of urban transportation systems in the megacities: the city centres are heavily congested with motorized traffic; traffic crawl rates vary from 2 to 10 km/hr; car and motorcycle ownership are increasing at annual rates of 10-12% and 15-20% respectively; significant air pollution with no relief in sight; TDM strategies are primarily creating new supply of road capacity; fairly high transit trips with substantial transit investments; weak air pollution monitoring and enforcement; and fairly cheap fuel and high costs of vehicles.

  11. Frequency of isolation of Campylobacter from roasted chicken samples from Mexico City.

    Science.gov (United States)

    Quiñones-Ramírez, E I; Vázquez-Salinas, C; Rodas-Suárez, O R; Ramos-Flores, M O; Rodríguez-Montaño, R

    2000-01-01

    The presence of Campylobacter spp. was investigated in 100 samples of roasted chicken tacos sold in well-established commercial outlets and semisettled street stands in Mexico City. From 600 colonies displaying Campylobacter morphology only 123 isolates were positive. From these isolates, 51 (41%) were identified as C. jejuni, 23 (19%) as C. coli, and 49 (40%) as other species of this genus. All of the 27 positive samples came from one location where handling practices allowed cross-contamination of the cooked product. The results indicate that these ready-to-consume products are contaminated with these bacteria, representing a potential risk for consumers, especially in establishments lacking adequate sanitary measures to prevent cross-contamination.

  12. Between Practices, Institutions and Discourses: Child Labor in Mexico City (1920-1934

    Directory of Open Access Journals (Sweden)

    Susana Sosenski

    2010-10-01

    Full Text Available This paper reveals the social action of children in Mexico City once the armed period of the Revolution was over. it analyzes the different  forms of economic participation among Mexican children and shows the various public attitudes and policies towards them. Moreover, the essay presents a quantitative and qualitative approach to urban child labor and examines the different governmental attempts to institutionalize it in schools and reformatories. The children’s role as social actors is foregrounded by studying children and teenagers as individuals who participate in their own lives, in their families’ lives, in the economic life of the country, and in the construction of the Mexican State.

  13. SURVIVAL STRATEGIES OF MICROENTREPRENEURS IN SOUTHERN MEXICO CITY: INFLUENCE OF APPRECIATED LEARNING

    Directory of Open Access Journals (Sweden)

    Arcelia López-Cabello

    2015-07-01

    Full Text Available The strategies of family reproduction are various ways in which families cope with the problems of everyday life, where the preservation of life and development of essential economic practices is ensured to optimize the material and non-material conditions of the family unit and of each of its members. Through in-depth interviews it was learned how some microentrepreneurs in Mexico City, have used their knowledge appreciated to implement various business generates economic resources to survive, but also have inherited the children. Technical and family secrets on how to make some product knowledge are transmitted from generation to generation, and part of the heritage of a family, becoming livelihood strategies.

  14. Blood lead levels in pregnant women of high and low socioeconomic status in Mexico City.

    OpenAIRE

    Farias, P; Borja-Aburto, V H; Rios, C; Hertz-Picciotto, I; Rojas-Lopez, M; Chavez-Ayala, R

    1996-01-01

    This study examined the determinants of blood lead (BPb) in 513 pregnant women in Mexico City: 311 from public hospital prenatal clinics, representing primarily women of low socioeconomic status (SES), and 202 from private hospitals, primarily women of high SES. Overall, BPb levels ranged from 1.38 to 29 micrograms/dl, with geometric means of 6.7 and 11.12 micrograms/dl for women from private and public hospitals, respectively. The crude geometric means difference obtained by t-test was 4.42 ...

  15. Aerosol climatology over the Mexico City basin: Characterization of optical properties

    Science.gov (United States)

    Carabali, Giovanni; Estévez, Héctor Raúl; Valdés-Barrón, Mauro; Bonifaz-Alfonzo, Roberto; Riveros-Rosas, David; Velasco-Herrera, Víctor Manuel; Vázquez-Gálvez, Felipe Adrián

    2017-09-01

    Climatology of Aerosol Optical Depth (AOD), Single Scattering Albedo (SSA), and aerosol particle-size distribution were analyzed using a 15-year (1999-2014) dataset from AErosol RObotic NETwork (AERONET) observations over the Mexico City (MC) basin. The atmosphere over this site is dominated by two main aerosol types, represented by urban/industrial pollution and biomass-burning particles. Due to the specific meteorological conditions within the basin, seasons are usually classified into three as follows: Dry Winter (DW) (November-February); Dry Spring (DS) (March-April), and the RAiny season (RA) (May-October), which are mentioned throughout this article. Using a CIMEL sun photometer, we conducted continuous observations over the MC urban area from January 1999 to December 2014. Aerosol Optical Depth (AOD), Ångström exponent (α440-870), Single Scattering Albedo (SSA), and aerosol particle-size distribution were derived from the observational data. The overall mean AOD500 during the 1999-2014 period was 0.34 ± 0.07. The monthly mean AOD reached a maximal value of 0.49 in May and a minimal value of 0.27 in February and March. The average α440-870 value for the period studied was 1.50 ± 0.16. The monthly average of α440-870 reached a minimal value of 1.32 in August and a maximal value of 1.61 in May. Average SSA at 440 nm was 0.89 throughout the observation period, indicating that aerosols over Mexico City are composed mainly of absorptive particles. Concentrations of fine- and coarse-mode aerosols over MC were highest in DS season compared with other seasons, especially for particles with radii measuring between 0.1 and 0.2 μm. Results from the Spectral De-convolution Algorithm (SDA) show that fine-mode aerosols dominated AOD variability in MC. In the final part of this article, we present a classification of aerosols in MC by using the graphical method proposed by Gobbi et al. (2007), which is based on the combined analysis of α and its spectral curvature

  16. [Family planning in a suburban development of Mexico City].

    Science.gov (United States)

    Gutiérrez Avila, J H; González Cortés, A; González Cortés, A

    1982-01-01

    To study the prevalence of contraceptive use among women in reproductive age, 15-50, and living in urban slums, the female population of Colonia Ajusco was surveyed. Colonia Ajusco is situated south of Mexico City; 70% of its population comes from the interior of the country; there is no drinkable water and no sewage system; housing conditions and urban services are very poor. 606 women were investigated; 58% of them were below age 36, and 53.5% were parity 4 and over. 56.4% used contraception; of these 36.7% used the IUD, 23.1% the pill, and 16.7% had been sterilized. The contraceptive method used seemed to be strictly related to the type of medical services used; women using the IUD were mostly patients of the Social Security medical services, while women using the pill were mostly clients of private physicians. There was no association between age and the method used. 88.4% of women not using contraception did not have easy availability of medical services. The percentage of women using contraception, 56.4% seems high in relation to other Latin American countries, but it is very low in relation to the percentage of contraceptive users in more developed countries (93% in England). The use of the IUD as the method of choice can be explained by several factors: the massive national advertising campaign, low cost, ease of insertion, and no need for sustained motivation to use contraception. From all studies on contraceptive prevalence in Mexico it appears that women start to regulate their fertility after the 1st child, or even after the 4th child. Women below 20 still tend to resort to illegal abortion.

  17. PROPHYLACTIС DIET OF ALLERGIC DISEASES IN CHILDREN WITH HIGH RISK OF ATOPY

    Directory of Open Access Journals (Sweden)

    V.A. Revyakina

    2007-01-01

    Full Text Available The preventive efficiency of various kinds of feedings in children of the first year of life with high risk of an allergic pathology is studied. Under observation there were 87 children from group of high risk of an allergic pathology (from birth up to 18 months. The results of this study have confirmed the importance of breast feeding for prophylaxis of an allergic pathology in children with high risk of atopy. If it is impossible, the transclation of the child on artificial feeding by an dairy admixture based on a partial hydrolysate of serumal protein, which procvides physiological needs of a growing organism, assists physiological dynamics of parameters of weight and height, allows to increase frequency of early manifestation of atopy and prevents a sensibilization to proteins of the cow milk.Key words: allergic diseases, prevention, feeding, hydrolysate of protein of the cow milk, infants.

  18. Designing Freshwater Resilience for the Mexico City Metropolitan Area

    Science.gov (United States)

    Freeman, S.; Wi, S.; Brown, C.

    2017-12-01

    There are few places in the world where the water management challenges associated with global urbanization are as fully visible as in the Greater Mexico City Metropolitan Area (MCMA). MCMA has a population of 22 million of which only 82% have daily water provision and this figure is projected by local agencies to decrease drastically in the next decade due to population growth, infrastructure degradation and climate change. The city is served by a massive water delivery system, consisting of complex network of infrastructure in the surrounding basins that provides about 40% of the supply for MCMA and is characterized by increasing land use change and competition for water. The remaining 60% of MCMA's water is sourced internally from already depleted groundwater resources whose exploitation also results in significant subsidence throughout the city, further damaging already degraded infrastructure. Consequently, there is interest and need for investments that improve the performance of the freshwater delivery system, including local resources and connected basins, in the face of change and shocks that can be only partially anticipated. The quest for such resilience is a common theme in urban infrastructure design yet practical approaches for achieving it remain nascent. In this study, we use MCMA and the Cutzamala Water supply system to demonstrate a quantitative framework to evaluate investment strategies which seek resilience for the water supply system of MCMA. Multiobjective optimization and decisions under deep uncertainty approaches are used to evaluate the best performing investment portfolios across different resilience performance metrics which encompass social equity, environmental and economic objectives. This analysis shows dynamic system responses that result from different investment portfolios, elucidating difficult planning and management decisions around tradeoffs between allocations as well as performance metrics (e.g short period of total failure

  19. Who is that masked person: the use of face masks on Mexico City public transportation during the Influenza A (H1N1) outbreak.

    Science.gov (United States)

    Condon, Bradly John; Sinha, Tapen

    2010-04-01

    This article examines three issues: (1) the use, over time, of facemasks in a public setting to prevent the spread of a respiratory disease for which the mortality rate is unknown; (2) the difference between the responses of male and female subjects in a public setting to unknown risks; and (3) the effectiveness of mandatory and voluntary public health measures in a public health emergency. The use of facemasks to prevent the spread of respiratory diseases in a public setting is controversial. At the height of the influenza epidemic in Mexico City in the spring of 2009, the federal government of Mexico recommended that passengers on public transport use facemasks to prevent contagion. The Mexico City government made the use of facemasks mandatory for bus and taxi drivers, but enforcement procedures differed for these two categories. Using an evidence-based approach, we collected data on the use of facemasks over a 2-week period. In the specific context of the Mexico City influenza outbreak, these data showed mask usage rates mimicked the course of the epidemic and gender difference in compliance rates among metro passengers. Moreover, there was not a significant difference in compliance with mandatory and voluntary public health measures where the effect of the mandatory measures was diminished by insufficiently severe penalties, the lack of market forces to create compliance incentives and sufficient political influence to diminish enforcement. Voluntary compliance was diminished by lack of trust in the government. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  20. Investigation of the correlation between odd oxygen and secondary organic aerosol in Mexico City and Houston

    Directory of Open Access Journals (Sweden)

    E. C. Wood

    2010-09-01

    Full Text Available Many recent models underpredict secondary organic aerosol (SOA particulate matter (PM concentrations in polluted regions, indicating serious deficiencies in the models' chemical mechanisms and/or missing SOA precursors. Since tropospheric photochemical ozone production is much better understood, we investigate the correlation of odd-oxygen ([Ox]≡[O3]+[NO2] and the oxygenated component of organic aerosol (OOA, which is interpreted as a surrogate for SOA. OOA and Ox measured in Mexico City in 2006 and Houston in 2000 were well correlated in air masses where both species were formed on similar timescales (less than 8 h and not well correlated when their formation timescales or location differed greatly. When correlated, the ratio of these two species ranged from 30 μg m−3/ppm (STP in Houston during time periods affected by large petrochemical plant emissions to as high as 160 μg m−3/ppm in Mexico City, where typical values were near 120 μg m−3/ppm. On several days in Mexico City, the [OOA]/[Ox] ratio decreased by a factor of ~2 between 08:00 and 13:00 local time. This decrease is only partially attributable to evaporation of the least oxidized and most volatile components of OOA; differences in the diurnal emission trends and timescales for photochemical processing of SOA precursors compared to ozone precursors also likely contribute to the observed decrease. The extent of OOA oxidation increased with photochemical aging. Calculations of the ratio of the SOA formation rate to the Ox production rate using ambient VOC measurements and traditional laboratory SOA yields are lower than the observed [OOA]/[Ox] ratios by factors of 5 to 15, consistent with several other models' underestimates of SOA. Calculations of this ratio using emission factors for organic compounds from gasoline and diesel exhaust do not reproduce the observed

  1. [Use of social marketing to increase water consumption among school-age children in Mexico City].

    Science.gov (United States)

    Carriedo, Ángela; Bonvecchio, Anabelle; López, Nancy; Morales, Maricruz; Mena, Carmen; Théodore, Florence L; Irizarry, Laura

    2013-01-01

    To increase water consumption in school children in Mexico City through a social marketing intervention. Cluster quasi-experimental design. Intervention of three months in schools, including water provision and designed based on social marketing. Reported changes in attitude, knowledge and behavior were compared pre and post intervention. Children of the intervention group (n=116) increased in 38% (171 ml) water consumption during school time, control group (n=167) decreased its consumption in 21% (140 ml) (pwater consumption among children, strategy that might contribute to mitigate childhood obesity.

  2. Factors Associated with Atopy in Toddlers: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Jolene Yung

    2015-02-01

    Full Text Available In this case-control study the association between the approaches used to feed infants, together with known family and environmental factors, and the occurrence of atopic illness in toddlers between the ages of 4 months to 3 years in Hong Kong was examined. A total of 206 subjects were recruited from April to June of 2014. The results obtained by binary logistic regression indicated that atopy is associated with boys (OR 2.072, CI 1.089–3.941, the maternal use of antibiotics in utero or while breast feeding (OR 2.276, CI 1.151–4.504, the later commencement of mixed feeding (OR 2.497, CI 1.025–6.082, breast feeding exclusively for 3 months (OR 1.972, CI 1.009–3.857, and having a mother who was diagnosed with eczema (OR 4.510, CI 1.764–11.530. Although an exclusive reliance on breast feeding has been shown to be predictive of atopy among toddlers, the positive qualities of breast milk cannot be ignored. A further study of the contents and nutritional values of breast milk is warranted.

  3. The Zapatista Social Netwar in Mexico

    Science.gov (United States)

    1998-01-01

    on the Internet. 4From a statement by Subcommandante Marcos, March 4, 1994, as reported by the Academia Mexicana de Derechos Humanos , Special...Indigenas de Mexico, Mexico City: Comisiön Nacional de Derechos Humanos , 1995. Evan, William M., "An Organization-Set Model of Interorganizational...City: Comision Nacional de Dere- chos Humanos , 1995. Meisel, James, The Fall of the Republic: Military Revolt in France, Ann Arbor: University of

  4. Water management for a megacity: Mexico City Metropolitan Area.

    Science.gov (United States)

    Tortajada, Cecilia; Castelán, Enrique

    2003-03-01

    The paper presents an overview of the present situation of the Mexico City Metropolitan Area (MCMA). The analysis indicates an urgent need to radically improve the current water supply and wastewater management practices, to become sustainable. The MCMA is one of the most rapidly growing urban centers of the world, with a population of about 21 million people, a very high rate of immigration and numerous illegal settlements. In order to meet the increasing water demand, successive governments have focused almost exclusively on supply management and engineering solutions, which have resulted in investments of hundreds of millions of USD and the construction of major infrastructure projects for interbasin water transfer. Environmental, economic and social policies associated with water management are mostly inadequate and insufficient, which is resulting in increasing deterioration in the environment, health and socioeconomic conditions of a population living in one of the largest urban agglomerations of the world. Surprisingly, however, no long-term strategies on demand-management, reuse, conservation, and improved water-management practices have been developed so far.

  5. Seasonal variations of rotifers from a high altitude urban shallow water body, La Cantera Oriente (Mexico City, Mexico)

    Science.gov (United States)

    Gutiérrez, Sergio González; Sarma, S. S. S.; Nandini, S.

    2017-11-01

    La Cantera Oriente is a shallow freshwater volcanic water body located at an altitude of 2 270 m above sea level in the Ecological Reserve of San Angel Pedregal of Mexico City (Mexico). In order to ensure the conservation of its biological heritage including zooplankton, the present work was undertaken to quantify the seasonal changes in the diversity and density of rotifers and the selected physico-chemical variables during 2013-2014. Qualitative analysis of the zooplankton samples yielded 68 rotifer species which represented 24 genera in 15 families. B rachionus calyciflorus Pallas, 1766, B. quadridentatus Hermann, 1783, Polyarthra vulgaris Carlin, 1943, Lecane closterocerca (Schmarda, 1859) and Keratella cochlearis (Gosse, 1851) were the most common species. Preston plots of species frequency-density revealed that as many as 30% of the rotifer taxa were dominant throughout the year. The species with high population densities were Brachionus quadridentatus, Lecane closterocerca, Keratella cochlearis, and Lepadella patella; their peak densities were 2 000, 1 000, 180 and 90 ind./L, all occurring in summer. Canonical correspondence analysis showed that Platyias quadricornis was related to the concentration of phosphates available in the environment and the conductivity, while B. quadridentatus was positively correlated with chlorophyll- a. The trophic status of the lake was eutrophic based on Chl- a content but oligotrophic with relation to the Brachionus: Trichocerca ratio.

  6. On the usefulness of atmospheric measurements for air quality evaluation in the context of recent urban meteorology findings in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Nunez, X.; Jazcilevich Diamant, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: xochitl@atmosfera.unam.mx

    2007-10-15

    In many cities, the main tool used to assess pollution abatement policies is the air quality information obtained from local monitoring network. However, in the context of a complex meteorology and land use such as those prevailing in Mexico City, the point-wise character and lack of detailed chemistry of this information may confer conflictive or biased information. The approach to understand the problem could be not based on solid ground. It is not until the measurement effort is complemented with detailed meteorological and air quality modeling that proper use of the information can be assured. In order to provide an example of this assertion, the usefulness of measured air quality data is gauged in a simplified manner, constructing three dimensional graphs containing local emission concentrations of nitrogen oxides (NO{sub x}), volatile organic compounds (VOC) and maximum ozone (O{sub 3}) concentrations, that we call ozone isopleths, for three sites in Mexico City. Together with corresponding wind rose data, an interpretation of the air pollution transport in the Valley of Mexico using only measured data is attempted. This interpretation, based on measured information subject to local influences, is compared with recent air quality modeling results showing that when measured data is used in conjunction with air quality modeling a better interpretation of air pollution problem can be obtained. A correct strategy to study the air quality problem, especially in the case of Mexico City where complex meteorology and land use is present, should be that both endeavors, measuring and modeling, are pursued with equal vigor. [Spanish] En muchas ciudades la herramienta principal en la evaluacion de las politicas para el control de la contaminacion es la informacion de calidad del aire proveniente de las redes locales de mediciones. Sin embargo, en el contexto de una meteorologia compleja y el uso de suelo de la Ciudad de Mexico, el caracter puntual y la carencia de

  7. The Subsidence Signature Due To Groundwater Extraction as Inferred from Remote Sensing Data in Mexico City

    Science.gov (United States)

    Patel, V.; Chen, J.

    2015-12-01

    Mexico City is facing a severe water shortage; current drought conditions in the city have led to an increase in the demand for groundwater, the pumping of which can cause significant land subsidence. In this study we explored what new information interferometric synthetic aperture radar (InSAR) data collected by the TerraSAR-X satellite could bring to water resource managers in the city so that they can efficiently and sustainably allocate water resources. Previous work done over Mexico City indicates that InSAR can be used to detect deformation due to groundwater pumping. Cabral-Cano et al. (2008) processed InSAR data acquired from ERS between 1996-2000 and from ENVISAT between 2003-2005. They compared the deformation map to geology maps of the region with information obtained by seismic methods. They found that a spatial correlation between the land deformation and the presence of young lacustrine clay beds, which indicate that the subsidence was caused by fluid pressure loss in the aquitard. They also concluded that the subsidence, for the most part, had no seasonal variation and continues to occur at near-constant, high rates. TerraSAR-­X satellite data is known to be more sensitive to small deformations than the data from satellites used in previous studies in the region because of its frequent revisit cycle, short wavelength, and accurate orbital information. For this project, we derived long sequences of crustal deformation time series from TerraSAR-­X data between May 2011 and December 2012 using the Small Baseline Subset (SBAS) method. The resulting time series was then compared to GPS data for calibration and validation. We observed a long-term deformation that was similar to those found in previous studies. The next step in our work is to determine whether the increased sensitivity of the TerraSAR-­X data allows us to detect a seasonal deformation pattern over the study area.

  8. Frequency and risk factors associated with dry eye in patients attending a tertiary care ophthalmology center in Mexico City

    Directory of Open Access Journals (Sweden)

    Martinez JD

    2016-07-01

    Full Text Available Jaime D Martinez,1 Anat Galor,2,3 Nallely Ramos-Betancourt,1 Andrés Lisker-Cervantes,1 Francisco Beltrán,1 Jorge Ozorno-Zárate,1 Valeria Sánchez-Huerta,1 Marco-Antonio Torres-Vera,1 Everardo Hernández-Quintela1 1Cornea and External Diseases Service, Asociación Para Evitar la Ceguera en Mexico (Association to prevent blindness in Mexico, Universidad Nacional Autónoma de México, Mexico City, Mexico; 2Department of Ophthalmology, Miami Veterans Affairs Medical Center, 3Cornea and External Diseases Division, Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA Purpose: The purpose of this study was to ascertain the frequency and risk factors of dry eye (DE among patients attending a tertiary care ophthalmology center in Mexico.Methods: Approximately 338 consecutive new patients attending a tertiary care ophthalmology center in Mexico City underwent an ocular surface examination, which included tear film break-up time, fluorescein corneal staining, Schirmer’s test, and evaluation of meibum quality. Symptoms of DE were evaluated by the Ocular Surface Disease Index and Dry Eye Questionnaire-5. Information on demographics, exposures, past medical and ocular history, and medications was also collected.Results: The frequency of severe DE symptoms was found to be 43% based on the Ocular Surface Disease Index and 30% based on Dry Eye Questionnaire-5. Risk factors significantly associated with increased DE symptoms included dry mouth and gastrointestinal ulcer medications. With regard to signs, aqueous tear deficiency was a less-frequent finding (22% in our population than evaporative deficiency (94%. Risk factors associated with aqueous tear deficiency were dry mouth and diuretic use. No risk factors were associated with evaporative deficiency. Risk factors associated with meibomian gland dysfunction included old age, male sex, arthritis, and use of an antihypertensive. The only risk factor associated with corneal staining was dry

  9. A comparative simple method for human bioclimatic conditions applied to seasonally hot/warm cities of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Tejeda Martinez, A. [Universidad Veracruzana, Xalapa, Veracruz (Mexico); Garcia Cueto, O.R. [Universidad Autonoma de Baja California, Mexicali, B.C. (Mexico)

    2002-01-01

    The climate of a region is an environmental resource with important implications for things such as thermal comfort, health and productivity of the population. In this work, the bioclimatic comfort was evaluated for seven seasonally warm/hot cities of Mexico by means of the following current indexes: Discomfort Index, Enthalpy Index and Heat Strain Index. Also, the periods during which it is necessary to use air conditioning in the studied cities were calculated from estimated global radiation and hourly data of temperature and relative humidity which made it possible to establish them with high precision. Finally, the useful of the Heat Strain Index is shown. It is a simple index needing available meteorological data to compare bioclimatic conditions of similar sites. [Spanish] El clima regional tiene implicaciones en el confort, la salud y la productividad de la poblacion. En este articulo se presentan las evaluaciones bioclimaticas comparativas de siete ciudades calidas de Mexico. Se aplicaron los indices bioclimaticos de disconfort, entalpia y esfuerzo frente al calor. Se calcularon los periodos para los cuales es necesario el uso de aire acondicionado, a partir de estimaciones de radiacion solar global y de temperatura y humedad horarias medias mensuales. Finalmente se muestra la utilidad y calidad del Indice de esfuerzo frente al calor, el cual requiere solo de datos climatologicos comunes para poder comparar condiciones bioclimaticas de sitios similares.

  10. Gender performativity, medicalization and health in transsexual women in Mexico City

    Directory of Open Access Journals (Sweden)

    José Arturo Granados Cosme

    2017-12-01

    Full Text Available The World Health Organization and the American Psychological Association consider transsexuality a pathology and suggest sex-gender reassignment for the biopsychic adjustment of trans people. Through the discursive analysis of experience, this study describes the processes of medicalization and gender performativity in relation to the health of a group of trans women from Mexico City. For this purpose, a qualitative study was conducted in which 10 semi-structured interviews were carried out in 2015. As part of medicalization, the pathologization of transsexuality generated psychic suffering; on the other hand, sex-gender reassignment also entailed additional risks. It is possible to conclude that in trans women, violence and exclusion constitute the primary experiences explaining their foremost health problems. Therefore, it is suggested that it is necessary for discrimination be reduced and for advancements to be made in safer medical interventions.

  11. [Gender performativity, medicalization and health in transsexual women in Mexico City].

    Science.gov (United States)

    Cosme, José Arturo Granados; Ramírez, Pedro Alberto Hernández; Muñoz, Omar Alejandro Olvera

    2017-01-01

    The World Health Organization and the American Psychological Association consider transsexuality a pathology and suggest sex-gender reassignment for the biopsychic adjustment of trans people. Through the discursive analysis of experience, this study describes the processes of medicalization and gender performativity in relation to the health of a group of trans women from Mexico City. For this purpose, a qualitative study was conducted in which 10 semi-structured interviews were carried out in 2015. As part of medicalization, the pathologization of transsexuality generated psychic suffering; on the other hand, sex-gender reassignment also entailed additional risks. It is possible to conclude that in trans women, violence and exclusion constitute the primary experiences explaining their foremost health problems. Therefore, it is suggested that it is necessary for discrimination be reduced and for advancements to be made in safer medical interventions.

  12. Temporal variations in elemental concentrations of atmospheric aerosols in Mexico City

    International Nuclear Information System (INIS)

    Aldape U, F.

    1992-05-01

    Measurements are reported of elemental concentrations of airborne particulates in Mexico City and their time variation over a one-week period in the spring of 1988. Proton-induced X-ray emission analysis, PIXE, was used to analyse the atmospheric aerosols which were bombarded with 2.5 MeV protons from the 12 MV Tandem Van de Graaff accelerator at the National Institute of Nuclear Research, ININ. Variations in the elemental concentrations were observed over the time period studied. An intercomparison was made in the case of the element lead with PIXE results obtained at the Crocker Nuclear Laboratory, CNL, University of California for the same set of samples. Excellent agreement was obtained both for the time variation of the relative concentration and the absolute lead concentrations. These results give added confidence to the protocol adopted at ININ. (Author)

  13. Basin of Mexico: A history of watershed mismanagement

    Science.gov (United States)

    Luis A. Bojorquez Tapia; Exequiel Ezcurra; Marisa Mazari-Hiriart; Salomon Diaz; Paola Gomez; Georgina Alcantar; Daniela Megarejo

    2000-01-01

    Mexico City Metropolitan Zone (MCMZ) is located within the Basin of Mexico. Because of its large population and demand for natural resources, several authors have questioned the viability of the city, especially in terms of water resources. These are reviewed at the regional and the local scales. It is concluded that a multi-basin management approach is necessary to...

  14. Association Between Depression and Elder Abuse and the Mediation of Social Support: A Cross-Sectional Study of Elder Females in Mexico City.

    Science.gov (United States)

    Vilar-Compte, Mireya; Giraldo-Rodríguez, Liliana; Ochoa-Laginas, Adriana; Gaitan-Rossi, Pablo

    2018-04-01

    We assessed the association between depression and elder abuse, and the mediation effect of social support among elder women in Mexico City. A total of 526 noninstitutionalized elder women, residing in Mexico City and attending public community centers were selected. Logistic regressions and structural equation models (SEM) were estimated. One fifth of the elderly women were at risk of depression, one third suffered some type of abuse in the past 12 months, and 82% reported low social support. Logistic models confirmed that depression was statistically associated with elder abuse and vice versa (odds ratio [OR] = 1.97 and 1.96, respectively). In both models, social support significantly reduced the association between these variables leading to study these associations through SEM. This approach highlighted that social support buffers the association between depression and elder abuse. Findings underline the relevance of programs and strategies targeted at increasing social support among urban older adults.

  15. Sustainable passenger road transport scenarios to reduce fuel consumption, air pollutants and GHG (greenhouse gas) emissions in the Mexico City Metropolitan Area

    International Nuclear Information System (INIS)

    Chavez-Baeza, Carlos; Sheinbaum-Pardo, Claudia

    2014-01-01

    This paper presents passenger road transport scenarios that may assist the MCMA (Mexico City Metropolitan Area) in achieving lower emissions in both criteria air pollutants (CO, NO x , NMVOC (non-methane volatile organic compounds), and PM 10 ) and GHG (greenhouse gas) (CH 4 , N 2 O and CO 2 ), while also promoting better mobility and quality of life in this region. We developed a bottom-up model to estimate the historical trends of energy demand, criteria air pollutants and GHG emissions caused by passenger vehicles circulating in the Mexico City Metropolitan Area (MCMA) in order to construct a baseline scenario and two mitigation scenarios that project their impact to 2028. Mitigation scenario “eff” considers increasing fuel efficiencies and introducing new technologies for vehicle emission controls. Mitigation scenario “BRT” considers a modal shift from private car trips to a Bus Rapid Transport system. Our results show significant reductions in air pollutants and GHG emissions. Incentives and environmental regulations are needed to enable these scenarios. - Highlights: • More than 4.2 million passenger vehicles in the MCMA (Mexico City Metropolitan Area) that represent 61% of criteria pollutants and 44% of GHG (greenhouse gas) emissions. • Emissions of CO, NO x and NMVOC (non-methane volatile organic compounds) in baseline scenario decrease with respect to its 2008 value because emission standards. • Emissions of PM 10 and GHG increase in baseline scenario. • Emissions of PM 10 and GHG decrease in eff + BRT scenario from year 2020. • Additional reductions are possible with better standards for diesel vehicles and other technologies

  16. Diagnosis and treatment of presumed STIs at Mexican pharmacies: survey results from a random sample of Mexico City pharmacy attendants

    OpenAIRE

    Turner, A; Ellertson, C; Thomas, S; Garcia, S

    2003-01-01

    Objectives: People in developing countries often seek medical advice for common ailments from pharmacies. As one example, pharmacists routinely diagnose and treat symptomatic sexually transmitted infections (STIs). We aimed to assess the quality of advice provided in Mexico City pharmacies by presenting hypothetical STI related syndromes and recording pharmacy attendants' suggested diagnoses and treatments.

  17. Parent Management Training-Oregon Model (PMTO™) in Mexico City: Integrating Cultural Adaptation Activities in an Implementation Model.

    Science.gov (United States)

    Baumann, Ana A; Domenech Rodríguez, Melanie M; Amador, Nancy G; Forgatch, Marion S; Parra-Cardona, J Rubén

    2014-03-01

    This article describes the process of cultural adaptation at the start of the implementation of the Parent Management Training intervention-Oregon model (PMTO) in Mexico City. The implementation process was guided by the model, and the cultural adaptation of PMTO was theoretically guided by the cultural adaptation process (CAP) model. During the process of the adaptation, we uncovered the potential for the CAP to be embedded in the implementation process, taking into account broader training and economic challenges and opportunities. We discuss how cultural adaptation and implementation processes are inextricably linked and iterative and how maintaining a collaborative relationship with the treatment developer has guided our work and has helped expand our research efforts, and how building human capital to implement PMTO in Mexico supported the implementation efforts of PMTO in other places in the United States.

  18. [Origins of institutional Pediatrics: Maternity and Childhood Hospital of Mexico City in the nineteenth century].

    Science.gov (United States)

    Baeza Bacab, Manuel Antonio

    In June of 1866, the empress Carlota founded the Maternity House in the Department of Secret Births at the Hospice of the Poor. Upon the reinstatement of a republican government, Dr. Ramon Pacheco was appointed director of the Maternity House. Shortly after, in February of 1868, Dr. Luis Fernandez Gallardo established a pavilion for sick children in the Hospital of San Andres. After realizing this pavilion didn't have the adequate conditions to operate properly, and in the need of a children's hospital in Mexico City, Dr. Pacheco merged both institutions in April 2, 1869 -with the help of Ms. Luciana Arrazola- and founded the Maternity and Childhood Hospital, the first institution for the care of ill children in the independent Mexico. Ever since it was founded, Dr. Eduardo Liceaga was in charge of the children's health. Later, with the help of the presidents Juarez, Lerdo de Tejada and Díaz, he was able to consolidate the hospital in academic and health services aspects. This noble institution closed its doors on February 5, 1905, upon its incorporation to the General Hospital of Mexico, after 36 years of working for the welfare of Mexican children. Copyright © 2017 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

  19. Guardians of health: the dimensions of elder caregiving among women in a Mexico City neighborhood.

    Science.gov (United States)

    Mendez-Luck, Carolyn A; Kennedy, David P; Wallace, Steven P

    2009-01-01

    Little is known about the family care of older adults in Mexico and the role of women in this process. To begin to fill this knowledge gap, this paper describes how a small sample of low-income women in one Mexico City neighborhood conceptualized the caregiver role and identified the forms of assistance they gave to their older relatives on a daily basis. A grounded theory approach was used to collect and analyze the data. Forty-one semi-structured qualitative interviews were conducted with female caregivers. The age of participants was between 19 and 83 years, and care recipients between 56 and 92 years. The relationship of caregiver to care recipient was wife, daughter, daughter-in-law, grand-daughter, sibling, and other relative. The mean length of time providing care was 5 years. Most participants were not employed outside the home, and the median monthly household income was 2000 pesos. We found that caregiving was a life-changing event, with 27 of 41 participants viewing themselves as guardians. Caregivers' emphasis was on care recipients' emotional needs in order to provide "the most precious gift" of "time and attention." Two forms of assistance were 'keeping company' and 'watching out' as safeguards against poor health or further decline in health. These findings increase the cultural understanding of caregiving in Mexico. Further research is needed to test the caregiving concepts identified in this study.

  20. A "Great Roads" Approach to Teaching Modern World History and Latin American Regional Survey Courses: A Veracruz to Mexico City Case Study.

    Science.gov (United States)

    Brown, James Seay, Jr.; Sullivan-Gonzalez, Douglass

    2002-01-01

    Outlines an innovative way of teaching "World History Since 1500" at Samford University (Birmingham, Alabama) called the "great roads" approach, centered upon important roads in a country's history. Presents the "Veracruz to Mexico City corridor" case study used to teach a Latin American modern history course. (CMK)

  1. Multi-Gas analysis of ambient air using FTIR spectroscopy over Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Grutter, Michel [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico (UNAM), Mexico, D.F. (Mexico)

    2003-01-01

    A Fourier Transform Infrared (FTIR) spectrometer was used to analyze the composition of ambient air at a specific site in Mexico City metropolitan area. A continuous flow of air was passed through a multi-pass cell and the absorption spectra were collected over a period of two weeks. Quantitative analysis was performed by means of the classical-least square (CLS) method using synthetically generated spectra as references and calibration sources. Ambient levels of CO, CO{sup 2}, CH{sub 4} and N{sub 2}O are reported with a time resolution of five minutes for September 2001, showing interesting results in their diurnal patterns. Comments on the precision, detection limits and signal to noise of the instrument are included for the evaluation of this technique. Water concentrations were estimated and compared with those obtained with a relative humidity sensor. The technique of extractive FTIR for ambient trace gas monitoring was utilized in Mexico for the fist time and some potential applications are given. [Spanish] Se utilizo un espectrometro en el infrarrojo por transformadas de Fourier (FTIR) para analizar la composicion de aire ambiente en un sitio de la zona metropolitana de la Ciudad de Mexico. Para ello se introdujo un flujo constante de aire a una celda de gases de paso multiple y se colectaron los espectros durante un periodo de dos semanas. Para el analisis cuantitativo, se aplico el metodo clasico de minimos cuadrados (CLS) utilizando espectros sinteticos como referencias y fuentes de calibracion. Se observaron patrones interesantes en los niveles ambientales de CO, CO{sup 2}, CH{sub 4} y N{sub 2}O, los cuales son reportados con una resolucion temporal de cinco minutos para el mes de septiembre del 2001. En la evaluacion de esta tecnica se incluyen comentarios sobre la precision, los limites de deteccion, asi como de la relacion senal/ruido del instrumento. Se estimaron concentraciones de vapor de agua a traves de sus absorciones en el infrarrojo y se

  2. Meeting Report: Institute for Social Security and Services for State Workers (ISSSTE on Acute Lymphoblastic Leukaemia, Mexico City, Mexico, 3rd to 4th October 2016

    Directory of Open Access Journals (Sweden)

    Alvarado Ibarra Martha

    2017-06-01

    Full Text Available From October 3 to 4, 2016, the fourth meeting of haematologists who belonged to the institute for social security and services for state workers (ISSSTE was held, the meeting was held in Mexico City, Mexico. Attending this working meeting, medical fellows of the specialty of Haematology and Paediatric Haematology, as well as attached doctors of both specialties that work in different hospitals in Mexico City and the rest of the country, the purpose of the attendees to this consensus was discuss, update, and homogenize the protocols of diagnostic and therapeutic approach in patients with acute lymphoblastic leukaemia of all ages. All participants appreciated the opportunity to participate in one of the most important cooperation projects of the ISSSTE and to be able to offer updated treatment protocols to this population or, failing that, to send them a Medical Center that can provide hospital care as soon as possible. Physicians took advantage of this meeting for the scientific exchange, the discussion on projects in course and were planned the development of other consensuses being the closest the one of lymphomas. As in the previous consensuses that were published in a National magazine. The coordinator of this project raised to the attendees the possibility of a publication in magazines of greater prestige international since in countries like Mexico the cooperative work is not frequent and the group of haematologists belonging to ISSSTE are working towards this goal. This consensus was considered as a very well-organized platform to support the research of young fellows in the specialty to stimulate the team work in protocols of the different haematological pathologies and to inform the world the results achieved in a population of patients attended by the ISSSTE. In agreement with the main objective of this consensus on acute lymphoblastic leukaemia once finished and discussed throughout the haematological group, the coordinator for the

  3. Antibiotic of resistence profile of Salmonella spp. serotypes isolated from retail beef in Mexico City.

    Directory of Open Access Journals (Sweden)

    Nova Nayarit-Ballesteros

    2016-05-01

    Full Text Available Objective. To determine the serotype and antibiotic resistance profile of Salmonella spp. isolated from retail ground beef in Mexico City. Materials and methods. A total of 100 samples of ground beef were analyzed. The pathogen was isolated by conventional methods and confirmed by PCR (invA gene, 284 bp. The antibiotic resistance profile was determined by the Kirby-Bauer method while serotyping was performed according to the Kauffman-White scheme. Results. We isolated a total of 19 strains of Lomita (6, Derby (4, Senftenberg (2, Javiana and Cannsttat (1 and undeter- mined (5 serotypes. The strains showed a high resistance rate to ampicillin (18/19, carbenicillin (16/19, tetracyclin (13/19, and trimethoprim-sulfamethoxazole (13/19. Multidrug resistance was observed in 14 isolates. Conclusions. Several Salmonella spp. serotypes of public health significance are circulating in ground beef sold in the major Mexican city. Some of these strains are multi-drug resistance.

  4. Early radioisotope uses in Mexico

    International Nuclear Information System (INIS)

    Segovia, N.; Tejera, A.; Bulbulian, S.; Palma, F.

    1991-10-01

    Mexico is traditionally a mining country and the first information about the presence of uranium is related to mine exploitation. Around 1945 when uranium became economically important, a rumor had spread that large amounts of black ceramics from Oaxaca were being purchased and sent abroad because of its assumed high uranium content. It was only in 1949 when minerals containing thorium and uranium were declared by law as 'National Reserves'. In those years a radium emanation plant was installed at the 'Hospital General' in Mexico City with the main purpose of carrying out radon seed implantation in tumors. In the fifties a radium dial painting facility was operating in the city of Toluca some 70 km from Mexico City. In 1955, when the National Commission of Nuclear Energy (CNEN) was founded by a government decree, two main activities were in sight: a training program on 'Radioisotope Techniques and Nuclear Instrumentation' and the creation of specialized laboratories. In this paper a general description of these events and undertakings spanning the decades 1940 to 1970 is given. (Author)

  5. Early radioisotope uses in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N; Tejera, A; Bulbulian, S; Palma, F

    1991-10-15

    Mexico is traditionally a mining country and the first information about the presence of uranium is related to mine exploitation. Around 1945 when uranium became economically important, a rumor had spread that large amounts of black ceramics from Oaxaca were being purchased and sent abroad because of its assumed high uranium content. It was only in 1949 when minerals containing thorium and uranium were declared by law as 'National Reserves'. In those years a radium emanation plant was installed at the 'Hospital General' in Mexico City with the main purpose of carrying out radon seed implantation in tumors. In the fifties a radium dial painting facility was operating in the city of Toluca some 70 km from Mexico City. In 1955, when the National Commission of Nuclear Energy (CNEN) was founded by a government decree, two main activities were in sight: a training program on 'Radioisotope Techniques and Nuclear Instrumentation' and the creation of specialized laboratories. In this paper a general description of these events and undertakings spanning the decades 1940 to 1970 is given. (Author)

  6. [Abortion and physicians in training: the opinion of medical students in Mexico City

    Science.gov (United States)

    González De León Aguirre D; Salinas Urbina AA

    1997-04-01

    This research project explores doctors' views regarding induced abortion. Abortion's penalization in Mexico greatly conditions its relevance as a social and public health problem. Physicians constitute a professional sector that can play an important role in reforming current laws on abortion. As a professional group, they have taken a conservative stance towards abortion. Their attitudes are to a great extent influenced by the medical training they receive. In this article we present results from a survey of 96 medical students from the Universidad Autónoma Metropolitana Xochimilco, in Mexico City. Data were processed with the SPSS program. Simple frequencies show that students have limited knowledge concerning the legal status of abortion and that they tolerate it with restrictions and in limited situations. Women students apparently take a more conservative stance, but statistical analysis with the c-square test did not show significant differences by gender. The article poses the need to modify doctors' training in the reproductive health field, allowing future doctors to acquire a broader view of health problems related to sexuality and reproduction. In the long run, this should also promote a kind of comprehensive health care practice in medical services, thus responding more satisfactorily to women's needs.

  7. Solar Activity, Ultraviolet Radiation and Consequences in Birds in Mexico City, 2001- 2002

    Science.gov (United States)

    Valdes, M.; Velasco, V.

    2008-12-01

    Anomalous behavior in commercial and pet birds in Mexico City was reported during 2002 by veterinarians at the Universidad Nacional Autonoma de Mexico. This was attributed to variations in the surrounding luminosity. The solar components, direct, diffuse, global, ultraviolet band A and B, as well as some meteorological parameters, temperature, relative humidity, and precipitation, were then analyzed at the Solar Radiation Laboratory. Although the total annual radiance of the previously mentioned radiation components did not show important changes, ultraviolet Band-B solar radiation did vary significantly. During 2001 the total annual irradiance , 61.05 Hjcm² to 58.32 Hjcm², was 1.6 standard deviations lower than one year later, in 2002 and increased above the mean total annual irradiance, to 65.75 Hjcm², 2.04 standard deviations, giving a total of 3.73 standard deviations for 2001-2002. Since these differences did not show up clearly in the other solar radiation components, daily extra-atmosphere irradiance was analyzed and used to calculate the total annual extra-atmosphere irradiance, which showed a descent for 2001. Our conclusions imply that Ultraviolet Band-B solar radiation is representative of solar activity and has an important impact on commercial activity related with birds.

  8. [Prevalence of irritable bowel syndrome in Veracruz City, Mexico: a community-based survey].

    Science.gov (United States)

    Valerio-Ureña, J; Vásquez-Fernández, F; Jiménez-Pineda, A; Cortázar-Benítez, L F; Azamar-Jácome, A A; Duarte-Velázquez, M E; Torres-Medina, V

    2010-01-01

    Irritable bowel syndrome (IBS) is recognized as the most frequent functional digestive disorder around the world. In Latin America and Mexico there are few studies in order to demonstrate its real prevalence in general population. To determine the prevalence of IBS in general population from Veracruz City Mexico, using the Rome II criteria. Using basic information given by bureau for planning urban services from Veracruz country, a 10% random population sample was obtained. Subjects between 16-80 years old were interviewed using a questionnaire based on Rome II criteria and a visual analogous scale in order to estimate the negative effect of IBS symptoms on daily activities. We interviewed 459 subjects with a median age of 31.2 +/- 13.6 years old detecting 78 subjects (16.9%) with IBS symptoms: 25 males and 53 females (gender prevalence of 11.3% and 22.1%, respectively). 28.2% of them had IBS with diarrhea, 50% had IBS with constipation and 21.8% alternating bowel movements, diarrhea and constipation. Negative effect of IBS symptoms on daily activities was significant. The prevalence of IBS in open population was 16.9% according to Rome II criteria, being higher in those older than 35 years old. Constipation was the predominant pattern. Further studies should evaluate associated factors of these findings.

  9. Aerosol composition and source apportionment in the Mexico City Metropolitan Area with PIXE/PESA/STIM and multivariate analysis

    OpenAIRE

    Johnson , K. S.; De Foy , B.; Zuberi , B.; Molina , L. T.; Molina , M. J.; Xie , Y.; Laskin , A.; Shutthanandan , V.

    2006-01-01

    Aerosols play an important role in the atmosphere but are poorly characterized, particularly in urban areas like the Mexico City Metropolitan Area (MCMA). The chemical composition of urban particles must be known to assess their effects on the environment, and specific particulate emissions sources should be identified to establish effective pollution control standards. For these reasons, samples of particulate matter ≤2.5 μm (PM2.5) were collected dur...

  10. Using high-resolution satellite aerosol optical depth to estimate daily PM2.5 geographical distribution in Mexico City

    OpenAIRE

    Just, Allan C.; Wright, Robert O.; Schwartz, Joel; Coull, Brent A.; Baccarelli, Andrea A.; Tellez-Rojo, Martha María; Moody, Emily; Wang, Yujie; Lyapustin, Alexei; Kloog, Itai

    2015-01-01

    Recent advances in estimating fine particle (PM2.5) ambient concentrations use daily satellite measurements of aerosol optical depth (AOD) for spatially and temporally resolved exposure estimates. Mexico City is a dense megacity that differs from other previously modeled regions in several ways: it has bright land surfaces, a distinctive climatological cycle, and an elevated semi-enclosed air basin with a unique planetary boundary layer dynamic. We extend our previous satellite methodology to...

  11. Our experiences with the use of atopy patch test in the diagnosis of cow's milk hypersensitivity.

    Science.gov (United States)

    Pustisek, Nives; Jaklin-Kekez, Alemka; Frkanec, Ruza; Sikanić-Dugić, Nives; Misak, Zrinjka; Jadresin, Oleg; Kolacek, Sanja

    2010-01-01

    Atopy patch test has been recognized as a diagnostic tool for the verification of food allergies in infants and small children suffering from atopic dermatitis. The test also has a role in the diagnosis of food allergies characterized by clinical signs associated with the digestive system. Yet, in spite of numerous studies, the test itself has hitherto not been standardized. Our study enlisted 151 children less than two years of age, who exhibited suspect skin and/or gastrointestinal manifestations of food allergy to cow's milk, and in whom tests failed to prove early type of allergic reaction. Atopy patch test was positive in 28% of the children with atopic dermatitis, 43% of the children with suspect gastrointestinal manifestation and 32% of the children with skin and gastrointestinal manifestations of food allergy. In our experience, atopy patch test is an excellent addition to the hitherto used tests for the diagnosis of food allergies. It targets specifically delayed type hypersensitivity reactions, which are difficult to confirm with other diagnostic tools. It is furthermore simple to perform, noninvasive and produces a minimum of undesired side effects. For these reasons, it should become part of the routine diagnostic toolset for food allergies to cow's milk in infants and children, and applied before a food challenge test.

  12. Mass movement processes triggered by land subsidence in Iztapalapa, the eastern part of Mexico City

    Directory of Open Access Journals (Sweden)

    M. González-Hernández

    2015-11-01

    Full Text Available Geological and structural conditions in the Basin of Mexico coupled with natural and anthropogenic factors, such as groundwater exploitation, provokes land subsidence and differential deformation. The study area is located in to the north of Iztapalapa, a municipality within Mexico City, in a site called "El Eden" with irregular topography. Where volcanic sequences overlie the lacustrine deposits of clays and silts and show displacements by the action of gravity. The displacement zone was delimited at the top of the slope by the formation of circular tensile fractures with stair -shaped geometries. At the base of the slope, compressive processes damaged housing, sidewalks and inclined light poles and trees. A NW-SE system of fractures was identified in which displacement velocities vary from a few millimeters to several centimeters per year. Which affects urban facilities. In this work a conceptual model of deformation is presented that integrates the geological and mechanical factors leading to landslide and land subsidence. A geophysical survey leads to evidence of how land subsidence processes increase the sliding slope.

  13. Fracture hydraulic conductivity in the Mexico City clayey aquitard: Field piezometer rising-head tests

    Science.gov (United States)

    Vargas, Carlos; Ortega-Guerrero, Adrián

    A regional lacustrine aquitard covers the main aquifer of the metropolitan area of Mexico City. The aquitard's hydraulic conductivity (K') is fundamental for evaluating the natural protection of the aquifer against a variety of contaminants present on the surface and its hydraulic response. This study analyzes the distribution and variation of K' in the plains of Chalco, Texcoco and Mexico City (three of the six former lakes that existed in the Basin of Mexico), on the basis of 225 field-permeability tests, in nests of existing piezometers located at depths of 2-85 m. Tests were interpreted using the Hvorslev method and some by the Bouwer-Rice method. Results indicate that the distribution of K' fits log-Gaussian regression models. Dominant frequencies for K' in the Chalco and Texcoco plains range between 1E-09 and 1E-08 m/s, with similar population means of 1.19E-09 and 1.7E-09 m/s, respectively, which are one to two orders of magnitude higher than the matrix conductivity. In the Mexico City Plain the population mean is near by one order of magnitude lower; K'=2.6E-10 m/s. The contrast between the measured K' and that of the matrix is attributed to the presence of fractures in the upper 25-40 m, which is consistent with the findings of previous studies on solute migration in the aquitard. Un imperméable régional d'origine lacustre recouvre le principal aquifère de la zone urbaine de la ville de Mexico. La conductivité hydraulique K' de cet imperméable est fondamentale pour évaluer la protection naturelle de l'aquifère, contre les différents contaminants présents en surface, et sa réponse hydraulique. Cette étude analyse et les variations de K' dans les plaines de Chalco, Texcoco et Mexico (trois des six anciens lacs qui existaient dans le Bassin de Mexico), sur la base de 225 essais de perméabilité sur le terrain, réalisés en grappes dans des piézomètres existants entre 2 et 85 m de profondeur. Les essais ont été interprétés avec la m

  14. Vitamin A supplementation and risk of atopy: long-term follow-up of a randomized trial of vitamin A supplementation at six and nine months of age.

    Science.gov (United States)

    Kiraly, Nicholas; Balde, Aliu; Lisse, Ida Marie; Eriksen, Helle Brander; Aaby, Peter; Benn, Christine Stabell

    2013-11-19

    The World Health Organization recommends high-dose vitamin A supplementation (VAS) for children above six months of age in low-income countries. VAS has been associated with up-regulation of the Th2 response. We aimed to determine if VAS is associated with atopy in childhood. Infants in Guinea-Bissau were randomly allocated VAS or placebo, either at six and nine months of age, or only at nine months of age. At six months of age, children were furthermore randomized to measles vaccine or inactivated polio vaccine. At nine months of age all children received measles vaccine. Children were revisited seven years later and skin prick testing was performed. Atopy was defined as a skin prick reaction ≥ 3 mm. 40 of 263 children (15%) were atopic. Overall VAS had no significant effect on the risk of atopy (Prevalence Ratio 1.23; 95% CI 0.69-2.18). The Prevalence Ratio was 1.60 (0.66-3.90) for males and 1.00 (0.46-2.15) for females. There was no significant effect of VAS in infancy on atopy later in childhood. The role of infant VAS in the development of atopy is still unclear.

  15. The effect of single and multiple infections on atopy and wheezing in children.

    Science.gov (United States)

    Alcantara-Neves, Neuza Maria; Veiga, Rafael Valente; Dattoli, Vitor Camilo Cavalcante; Fiaccone, Rosimeire Leovigildo; Esquivel, Renata; Cruz, Álvaro Augusto; Cooper, Philip John; Rodrigues, Laura Cunha; Barreto, Maurício Lima

    2012-02-01

    The current epidemic of asthma and atopy has been explained by alterations in immune responses related to reduction in childhood infections. However, the findings of epidemiologic studies investigating the association between infection with atopy and asthma have been inconsistent. We sought to investigate the effect of single or multiple infections (pathogen burden) on atopy and wheeze in urban children from Latin America. Specific IgE against aeroallergens (sIgE) and skin prick test (SPT) reactivity for the most common local allergens were measured in 1128 children aged 4 to 11 years. Data on wheezing and potential confounders were collected by questionnaire. Infections by 8 pathogens were assessed by using serology and stool examination. Associations of wheeze and atopic outcomes with single and multiple infections were analyzed by means of logistic regression. Negative results for Toxoplasma gondii were associated with a higher prevalence of sIgE (≥0.70 kU/L), whereas negative results for Ascaris lumbricoides, T gondii, herpes simplex virus, and EBV were associated with a higher prevalence of SPT reactivity. Children with 3 or fewer infection markers had a higher prevalence of sIgE and SPT reactivity compared with those with 4 or more infection markers. However, isolated infections or pathogen burden were not associated with the prevalence of atopic or nonatopic wheeze. The findings provide support for the idea that the hygiene hypothesis is operating in an urban Latin American context, but its expression is thus far restricted to the atopic status of patients and not the perceived asthma symptoms. Copyright © 2011 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  16. A study of indoor radon in greenhouses in Mexico City, Mexico

    International Nuclear Information System (INIS)

    Guillermo Espinosa; Allan Chavarria; Jose-Ignacio Golzarri

    2013-01-01

    Enclosed spaces in contact with soil, the main source of radon, like greenhouses have potentially high radon ( 222 Rn) concentrations. Greenhouses are frequented by visitors and also are workplaces. The study of radon concentrations in greenhouses is, thus, a relevant concern for public health and environmental radiation authorities. For this study, the radon concentrations in 12 greenhouses in different locations within Mexico City were measured using nuclear track methodology. The detectors used for the study consisted of the well-known closed-end cup device, with CR-39 Lantrack R as detector material. The measurements were carried out over a period of one year, divided into four three-month sub-periods. The lowest and highest annual mean radon concentrations found in individual greenhouses were 17.0 and 45.1 Bq/m 3 , respectively. The annual mean averaged over all 12 greenhouses was 27.3 Bq/m 3 . No significant seasonal variation was observed. Using the highest annual mean radon concentration found in an individual greenhouse, and an equilibrium factor of 0.4, the effective dose from 222 Rn and its progenies was calculated to be 339.9 nSv/h. This corresponds to an annual dose rate of 679.8 μSv/y (0.057 WLM/y) for a worker spending 4 h a day, 5 days a week, 50 weeks a year, inside the greenhouse. For a visitor spending 12 h a year inside the greenhouse the annual dose is 2.469 μSv/y. The study of indoor radon concentrations in closed buildings such as greenhouses, which are both workplaces and open to visitors, is an important public health consideration. (author)

  17. Air pollution problem in the Mexico City metropolitan zone: Photochemical pollution

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, H.B.; Alvarez, P.S.; Echeverria, R.S.; Jardon, R.T. [Centro de Ciencias de la Atmosfera (Mexico). Seccion de Contaminacion Ambiental

    1997-12-31

    Mexico City Metropolitan Zone (MCMZ) represents an example of a megacity where the air pollution problem has reached an important evolution in a very short time, causing a risk in the health of a population of more than 20 million inhabitants. The atmospheric pollution problem in the MCMZ, began several decades ago, but it increased drastically in the middle of the 80`s. It is important to recognize that in the 60`s, 70`s and the first half of the 80`s the main pollutants were sulfur dioxide and total suspended particles. However since the second half of the 80`s until now, ozone is the most important air pollutant besides of the suspended particles (PM{sub 10}) and other toxic pollutants (1--8). The purpose of this paper is to discuss the evolution of the ozone atmospheric pollution problem in the MCMZ, as well as to analyze the results of several implemented air pollution control strategies.

  18. Implementation of a radiological safety management system in a hospital of Mexico City; Implementacion de un sistema de gestion de seguridad radiologica en un hospital de la Ciudad de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Martinez V, D.; Rivera M, T. [CICATA-IPN, 11500 Mexico D.F. (Mexico); Velez D, V. [INER, 14000 Mexico D.F. (Mexico)

    2007-07-01

    Full text: The reflection of this work is based in some radiological accidents that its have happened in some hospital centers or of research. The over exposure of some people is due to the pursuit of the procedures, the lack of quality assurance of the equipment or the inappropriate actions of the technicians. In Mexico one has seen in several hospitals the lack of existence of a Quality Assurance Program to prevent the accidents, the execution of the same ones and those good practices and the lack of Safety Culture makes that the hospital radiological safety it is faulty. The objective of the present work is the implementation of a radiological safety management in a hospital of Mexico City. (Author)

  19. Health Reform in Mexico City, 2000-2006

    Directory of Open Access Journals (Sweden)

    Asa Cristina Laurell

    2008-07-01

    Full Text Available With the goal of fully guaranteeing the constitutional right to health protection, Mexico City’s leftist administration (2000-2006 undertook a reform to provide health services to people without insurance. The reform had four components: free medicine and health services; the introduction of a new service model (MAS; the strengthening, expansion, and improvement of services, and legislation to ensure that the city government become guarantor of this constitutional right. The reform resulted in 95% of eligible families being enrolled in free care; expansion of health care infrastructure with the construction of five new health care centers and a 1/3 increase in the number of public hospital beds in impoverished and disadvantaged areas; increased access to and use of health services particularly by the poor and for expensive interventions; and the legal guarantee of the continuity of this policy. The implementation of this new policy was made possible through an 80% budget increase, improvements in efficiency, and a successful fight against corruption. The health impact of the reform was seen in decline of mortality rates in all age groups between 1997 and 2005 (22% for child mortality, 11% for economically active age groups, and 7.9% for retired age groups and by a 16% decline in AIDS related mortality between 2000 and 2005. This reform contrasts with the health care reform promoted by the right wing Federal government in the rest of the country; the latter was based on voluntary health insurance, cost-sharing by families, access to a limited package of services, and gradual enrollment of the population

  20. Aerosol composition and source apportionment in the Mexico City Metropolitan Area with PIXE/PESA/STIM and multivariate analysis

    OpenAIRE

    K. S. Johnson; B. de Foy; B. de Foy; B. Zuberi; B. Zuberi; L. T. Molina; L. T. Molina; M. J. Molina; M. J. Molina; Y. Xie; A. Laskin; V. Shutthanandan

    2006-01-01

    Aerosols play an important role in the atmosphere but are poorly characterized, particularly in urban areas like the Mexico City Metropolitan Area (MCMA). The chemical composition of urban particles must be known to assess their effects on the environment, and specific particulate emissions sources should be identified to establish effective pollution control standards. For these reasons, samples of particulate matter ≤2.5 μm (PM2.5) were collected during the MCMA-2003 Field Campaign f...

  1. Maternal use of folic acid supplements during pregnancy, and childhood respiratory health and atopy

    NARCIS (Netherlands)

    Bekkers, Marga B. M.; Elstgeest, Liset E. M.; Soholtens, Salome; Haveman-Nies, Annemien; de Jongste, Johan C.; Kerkhof, Marjan; Koppelman, Gerard H.; Gehring, Ulrike; Smit, Henriette A.; Wijga, Alet H.

    Previous studies have suggested possible adverse side-effects of maternal use of folic acid-containing supplements (FACSs) during pregnancy on wheeze and asthma in early childhood. We investigated the association between maternal use of FACSs and childhood respiratory health and atopy in the first 8

  2. Atopy and new-onset asthma in young Danish farmers and CD14, TLR2, and TLR4 genetic polymorphisms: a nested case-control study

    DEFF Research Database (Denmark)

    Smit, L A M; Bongers, S I M; Ruven, H J T

    2007-01-01

    BACKGROUND: Evidence exists that exposure to high levels of microbial agents such as endotoxin in the farm environment decreases the risk of atopic sensitization. Genetic variation in innate immunity genes may modulate the response to microbial agents and thus influence susceptibility to asthma...... and atopy. OBJECTIVE: To study potential associations between single nucleotide polymorphisms (SNPs) in CD14, Toll-like receptor 2 (TLR2), and TLR4 genes, and atopy and new-onset asthma in young farmers. METHODS: A nested case-control study was conducted within a cohort of 1901 young Danish farmers. We....../-651 promoter polymorphisms are associated with atopy prevalence among young adults exposed to farm environments. Udgivelsesdato: 2007-Nov...

  3. Complete Genome Sequence of Paenibacillus larvae MEX14, Isolated from Honey Bee Larvae from the Xochimilco Quarter in Mexico City.

    Science.gov (United States)

    Peréz de la Rosa, D; Pérez de la Rosa, J J; Cossio-Bayugar, R; Miranda-Miranda, E; Lozano, L; Bravo-Díaz, M A; Rocha-Martínez, M K; Sachman-Ruiz, B

    2015-08-27

    Paenibacillus larvae strain MEX14 is a facultative anaerobic endospore-forming bacterium that infects Apis mellifera larvae. Strain MEX14 was isolated from domestic bee larvae collected in a backyard in Mexico City. The estimated genome size was determined to be 4.18 Mb, and it harbors 4,806 protein coding genes (CDSs). Copyright © 2015 Peréz de la Rosa et al.

  4. Vitamin D status, lung function and atopy in children with asthma

    International Nuclear Information System (INIS)

    Ozdogan, S.; Sari, G.; Aktan, I. H.; Aydin, B.; Irmak, C.; Cavdar, S.

    2017-01-01

    Objective: To determine the associations between serum 25-hydroxy vitamin D3 levels and pulmonary function test outcomes and atopy in children with asthma. Study Design: Cross-sectional study. Place and Duration of Study: Pediatric pulmonology outpatient clinic and pediatric outpatient clinic, from December 2012 to March 2013. Methodology: A total of 71 asthmatic children and 77 healthy controls aged 7-17 years were recruited. Vitamin D status was assessed by measuring the serum 25-hydroxy vitamin D3 levels and compared between two groups. The relationship between serum vitamin D levels and pulmonary function test outcomes and serum IgE levels and inhalant panels were also examined in asthmatic patients. Results: The serum levels of 25-hydroxy vitamin D3 were low in both the asthmatic and control participants (median = 11.8 and 9.8 ng/ml, respectively). Vitamin D levels were significantly low in the patients who had high IgE levels and high levels of specific IgE antibodies against inhalant allergens in asthmatic patients. No correlation was found between vitamin D levels and pulmonary function test outcomes in asthmatic patients (p>0.05). Conclusion: Vitamin D levels are not associated with pulmonary function test outcomes. However, low vitamin D levels are associated with atopy. (author)

  5. Heightened bronchial hyperresponsiveness in the absence of heightened atopy in children with current wheezing and low income status.

    Science.gov (United States)

    Mallol, J; Castro-Rodriguez, J A; Cortez, E; Aguirre, V; Aguilar, P; Barrueto, L

    2008-02-01

    Although global studies such as the International Study of Asthma and Allergies in Childhood (ISAAC) have provided valuable data on the prevalence of asthma in children in Latin America, there is little information on the relationship between asthma symptoms, pulmonary function, bronchial hyperresponsiveness (BHR) and atopy in the region. This study examined the relationship between self-reported wheezing in the past 12 months, pulmonary function, airway responsiveness and atopy in children from a low income population in a neighbourhood of Santiago, Chile. Two random samples (100 each) of children aged 13-14 years who participated in ISAAC phase I were selected according to whether or not they reported wheezing in the past 12 months. Spirometry, the methacholine bronchial challenge test and the prick test were performed in all individuals. Children who reported current wheezing had significantly higher BHR to methacholine compared with those without wheezing (71.6% vs 52.6%; p = 0.007) and no significant difference was found in forced expiratory volume in 1 s (116.7 (12.3)% vs 120.3 (14.5%); p = 0.11). The prevalence of atopy was not significantly different between those children who reported wheezing compared with those who did not (44.2% vs 42.3%; p = 0.89). Multiple regression analysis showed that only BHR to methacholine (OR 2.72, 95% CI 1.25 to 4.13; p = 0.01) and maternal asthma (OR 3.1, 95% CI 1.2 to 8.3, p = 0.03) were significant risk factors for current wheezing. Our results support previous findings suggesting that in adolescents from underprivileged populations, self-reported current wheezing is related to BHR but not to atopy.

  6. Diabetes and Cause-Specific Mortality in Mexico City.

    Science.gov (United States)

    Alegre-Díaz, Jesus; Herrington, William; López-Cervantes, Malaquías; Gnatiuc, Louisa; Ramirez, Raul; Hill, Michael; Baigent, Colin; McCarthy, Mark I; Lewington, Sarah; Collins, Rory; Whitlock, Gary; Tapia-Conyer, Roberto; Peto, Richard; Kuri-Morales, Pablo; Emberson, Jonathan R

    2016-11-17

    Most large, prospective studies of the effects of diabetes on mortality have focused on high-income countries where patients have access to reasonably good medical care and can receive treatments to establish and maintain good glycemic control. In those countries, diabetes less than doubles the rate of death from any cause. Few large, prospective studies have been conducted in middle-income countries where obesity and diabetes have become common and glycemic control may be poor. From 1998 through 2004, we recruited approximately 50,000 men and 100,000 women 35 years of age or older into a prospective study in Mexico City, Mexico. We recorded the presence or absence of previously diagnosed diabetes, obtained and stored blood samples, and tracked 12-year disease-specific deaths through January 1, 2014. We accepted diabetes as the underlying cause of death only for deaths that were due to acute diabetic crises. We estimated rate ratios for death among participants who had diabetes at recruitment versus those who did not have diabetes at recruitment; data from participants who had chronic diseases other than diabetes were excluded from the main analysis. At the time of recruitment, obesity was common and the prevalence of diabetes rose steeply with age (3% at 35 to 39 years of age and >20% by 60 years of age). Participants who had diabetes had poor glycemic control (mean [±SD] glycated hemoglobin level, 9.0±2.4%), and the rates of use of other vasoprotective medications were low (e.g., 30% of participants with diabetes were receiving antihypertensive medication at recruitment and 1% were receiving lipid-lowering medication). Previously diagnosed diabetes was associated with rate ratios for death from any cause of 5.4 (95% confidence interval [CI], 5.0 to 6.0) at 35 to 59 years of age, 3.1 (95% CI, 2.9 to 3.3) at 60 to 74 years of age, and 1.9 (95% CI, 1.8 to 2.1) at 75 to 84 years of age. Between 35 and 74 years of age, the excess mortality associated with previously

  7. Black carbon network in Mexico. First Results

    Science.gov (United States)

    Barrera, Valter; Peralta, Oscar; Granado, Karen; Ortinez, Abraham; Alvarez-Ospina, Harry; Espinoza, Maria de la Luz; Castro, Telma

    2017-04-01

    After the United Nations Framework Convention on Climate Change celebrated in Paris 2016, many countries should adopt some mechanisms in the next years to contribute to mitigate greenhouse gas emissions and support sustainable development. Mexico Government has adopted an unconditional international commitment to carry out mitigation actions that would result in the reduction of 51% in black carbon (BC) emissions by year 2030. However, many BC emissions have been calculated by factor emissions. Since optical measurements of environmental BC concentrations can vary according the different components and their subsequence wavelength measure, it's important to obtain more accurate values. BC is formally defined as an ideally light-absorbing substance composed by carbon (Bond et al., 2013), and is the second main contributor (behind Carbon Dioxide; CO2) to positive radiative forcing (Ramanathan and Carmichael, 2008). Recently, BC has been used as an additional indicator in air quality management in some cities because is emitted from the incomplete combustion of fossil fuels, biofuel and biomass burning in both anthropogenic and it is always emitted with other particles and gases, such as organic carbon (OC), nitrogen oxides (NOx), and sulfur dioxide (SO2). Black Carbon, PM2.5 and pollutant gases were measured from January 2015 to December 2015 at three main cities in Mexico, and two other places to evaluate the BC concentration levels in the country. The urban background sites (Mexico City, Monterrey, Guadalajara, MXC-UB, GDL-UB, MTY-UB), a sub-urban background site (Juriquilla, Queretaro, JUR-SUB) and a regional background site (Altzomoni, ALT-RB). Results showed the relationship between BC and PM2.5 in the 3 large cities, with BC/PM2.5 ratios near 0.14 to 0.09 and a high BC-CO relationship in all the year in Mexico City, who showed that mobile sources are a common, at least in cities with a non-significant biomass burning emission related to agriculture or coal

  8. Comparison of lead levels in human permanent teeth from Strasbourg, Mexico City, and rural zones of Alsace

    International Nuclear Information System (INIS)

    Frank, R.M.; Sargentini-Maier, M.L.; Turlot, J.C.; Leroy, M.J.

    1990-01-01

    A comparative study of the mean lead concentrations in enamel and dentin of human premolars and permanent molars was conducted by means of a systematic sampling procedure with energy-dispersive x-ray fluorescence analysis. In a first series of analyses, no significant statistical differences in mean lead concentrations at various levels of enamel and dentin were noted between young patients of Strasbourg and those of small villages of Alsace, nor between elderly patients living in these two locations, despite the fact that motor traffic was significantly lower in the rural zones. However, in both locations, a significantly higher concentration of lead was observed in enamel and dentin in relation to age. In a second series of analyses, the mean lead concentrations of both dental hard tissues of premolars and permanent molars of young individuals from Strasbourg, rural Alsace, and Mexico City were compared. Significantly higher mean lead concentrations were found in enamel and dentin samples from Mexico City. This was most evident for inner coronal dentin (5.7 and 6.1 times greater than in teeth of Strasbourg and rural zones of Alsace, respectively) and for pulpal root dentin (6.9 and 8.9 times greater than in teeth of Strasbourg and rural zones of Alsace). It is proposed that the higher lead concentrations are related to the higher lead content of motor gasoline and to more intense traffic conditions. The dental hard tissues appear to be of value for the study of environmental lead pollution

  9. Application of an extension of the MAI method to the Acapulco City, Mexico

    Science.gov (United States)

    Contreras, M.; Aguirre, J.

    2001-12-01

    The site effects and the source parameters, are inverted from a Fourier displacement spectra of seismograms that are corrected by geometrical spreading and regional attenuation valid for south center of Mexico(Ordaz and Singh, 1992). We used Genetic Algorithms (GA) to perform the non-linear inversion, like in the MAI method (Moya et al., 2000) . The GA have proved to produce better results than other traditional methods which are frequently trapped in a local minimum. GA is a method that mimics the evolution laws in living creatures. The best individuals reproduce and develop themselves with every generation. In our case each individual correspond to one source and the genes correspond to the source parameters. As in nature, the best source remain and are improved with each iteration. We assume that the site effect at each station are the same independently of the earthquake, because of that we can search for the combination of sources that can produce the smaller standard deviation of the estimated site effects from the different Fourier displacement earthquake spectra. Then we use the obtained site effects to generate a Fourier displacement spectra of an earthquake scenario. With this, we are able to compute the response spectra by means of random vibration theory (Reinoso et al., 1990). We apply this method to four stations located in the Acapulco City, Mexico, that recorded four earthquakes with epicenter located in the Guerrero Subduction Zone. The site effect estimated for one of the stations, called ACAZ, shows a good agreement with the estimated by Chávez-García et al. (1994) using spectral ratios between the ACAZ station and a rock reference site. Also we compare the response spectra from other earthquake, obtained by the former method and the response spectra computed using the acceleration record. We find an acceptable correlation between them. Chávez-García, J. Cuenca y M. Cárdenas (1994), "Estudio complementario de efectos de sitio en Acapulco

  10. Early incidence of occupational asthma is not accelerated by atopy in the bakery/pastry and hairdressing sectors.

    Science.gov (United States)

    Rémen, T; Acouetey, D-S; Paris, C; Hannhart, B; Poussel, M; Chenuel, B; Barbaud, A; Zmirou-Navier, D

    2013-07-01

    Occupational asthma (OA) is most likely to develop in the very early years of exposure. To describe the early incidence of OA among bakers/pastry-makers (BP) and hairdressers and to explore the role of atopy. Following a retrospective follow-up design, subjects were invited to undergo telephone interviews. Those who declared work-related respiratory or rhinitis symptoms and a sample group of others were offered a medical visit for OA investigations. Data from interviews and from medical visits were used to estimate the incidence of OA according to increasing durations of exposure. A total of 866 subjects were interviewed (mean age 25.3 years, 43.8% females), of whom 282 underwent a medical visit. Total estimated incidence rates of 'confirmed or probable' OA during the first 12 years of exposure were high in BP (2.63 per 100 person-years [py]) and in hairdressers (0.58/100 py), particularly in the first 4 years. Atopy is a strong risk factor for incidence among BP but, irrespective of the occupational sector, it does not influence the timing of OA symptoms. OA symptoms occur soon after the start of exposure. Our results suggest that atopy does not precipitate the occurrence of symptoms in two different allergen exposure settings.

  11. The effect of composition, size, and solubility on acute pulmonary injury in rats following exposure to Mexico city ambient particulate matter samples.

    Science.gov (United States)

    Snow, Samantha J; De Vizcaya-Ruiz, Andrea; Osornio-Vargas, Alvaro; Thomas, Ronald F; Schladweiler, Mette C; McGee, John; Kodavanti, Urmila P

    2014-01-01

    Particulate matter (PM)-associated metals can contribute to adverse cardiopulmonary effects following exposure to air pollution. The aim of this study was to investigate how variation in the composition and size of ambient PM collected from two distinct regions in Mexico City relates to toxicity differences. Male Wistar Kyoto rats (14 wk) were intratracheally instilled with chemically characterized PM10 and PM2.5 from the north and PM10 from the south of Mexico City (3 mg/kg). Both water-soluble and acid-leachable fractions contained several metals, with levels generally higher in PM10 South. The insoluble and total, but not soluble, fractions of all PM induced pulmonary damage that was indicated by significant increases in neutrophilic inflammation, and several lung injury biomarkers including total protein, albumin, lactate dehydrogenase activity, and γ-glutamyl transferase activity 24 and 72 h postexposure. PM10 North and PM2.5 North also significantly decreased levels of the antioxidant ascorbic acid. Elevation in lung mRNA biomarkers of inflammation (tumor necrosis factor [TNF]-α and macrophage inflammatory protein [MIP]-2), oxidative stress (heme oxygenase [HO]-1, lectin-like oxidized low-density lipoprotein receptor [LOX]-1, and inducibile nitric oxide synthase [iNOS]), and thrombosis (tissue factor [TF] and plasminogen activator inhibitor [PAI]-1), as well as reduced levels of fibrinolytic protein tissue plasminogen activator (tPA), further indicated pulmonary injury following PM exposure. These responses were more pronounced with PM10 South (PM10 South > PM10 North > PM2.5 North), which contained higher levels of redox-active transition metals that may have contributed to specific differences in selected lung gene markers. These findings provide evidence that surface chemistry of the PM core and not the water-soluble fraction played an important role in regulating in vivo pulmonary toxicity responses to Mexico City PM.

  12. Peak flow variation in childhood asthma : Relationship to symptoms, atopy, airways obstruction and hyperresponsiveness

    NARCIS (Netherlands)

    Brand, PLP; Duiverman, EJ; Postma, DS; Waalkens, HJ; Kerrebijn, KF; vanEssenZandvliet, EEM; Quanjer, PH; Sluiter, HJ; Pouw, EM; Schoonbrood, DFME; Roos, CM; Jansen, HM; DeGooijer, A; Kerstjens, HAM; vanderMark, TW; Koeter, GH; deJong, PM; Sterk, PJ; Weaver, AMJ; Dijkman, JH; Dekhuijzen, PNR; Folgering, HTM; vanHerwaarden, CLA; Overbeek, SE; Bogaard, JM; Hilvering, C; Gans, SJ; Mengelers, HJJ; vanderBruggenBogaarts, BAHA; Kreukniet, J; Kouwenberg, JM; Prinsen, JE; Gerritsen, J; Knol, K; deMonchy, JGR; Dekker, FW; Kaptein, AA; Merkus, PJFM; Pocock, SJ; Hughes, MD; Robinson, NJ; Bleecker, ER; Meyers, DA

    Although home recording of peak expiratory flow (PEF) is considered useful in managing asthma, little is known about the relationship of PEF variation to other indicators of disease activity, We examined the relationship of PEF variation, expressed in various ways, to symptoms, atopy, level of lung

  13. Variability of the Mixed-Layer Height Over Mexico City

    Science.gov (United States)

    García-Franco, J. L.; Stremme, W.; Bezanilla, A.; Ruiz-Angulo, A.; Grutter, M.

    2018-06-01

    The diurnal and seasonal variability of the mixed-layer height in urban areas has implications for ground-level air pollution and the meteorological conditions. Measurements of the backscatter of light pulses with a commercial lidar system were performed for a continuous period of almost six years between 2011 and 2016 in the southern part of Mexico City. The profiles were temporally and vertically smoothed, clouds were filtered out, and the mixed-layer height was determined with an ad hoc treatment of both the filtered and unfiltered profiles. The results are in agreement when compared with values of mixed-layer height reconstructed from, (i) radiosonde data, and (ii) surface and vertical column densities of a trace gas. The daily maxima of the mean mixed-layer height reach values > 3 km above ground level in the months of March-April, and are clearly lower (behaviour, which is characterized together with the mixed-layer-height anomalies. A clear residual layer is evident from the backscattered signals recorded in days with specific atmospheric conditions, but also from the cloud-filtered mean diurnal profiles. The occasional presence of a residual layer results in an overestimation of the reported mixed-layer height during the night and early morning hours.

  14. Infrared Absorption by Atmospheric Aerosols in Mexico City during MILAGRO.

    Science.gov (United States)

    Kelley, K. L.; Mangu, A.; Gaffney, J. S.; Marley, N. A.

    2007-12-01

    Past research in our group using cylindrical internal reflectance spectroscopy has indicated that aqueous aerosols could contribute to the radiative warming as greenhouse species (1,2). Although aerosol radiative effects have been known for sometime and are considered one of the major uncertainties in climate change modeling, most of the studies have focused on the forcing due to scattering and absorption of radiation in the uv- visible region (3). Infrared spectral information also allows the confirmation of key functional groups that are responsible for enhanced absorption observations from secondary organics in the uv-visible region. This work extends our efforts to evaluate the infrared absorption by aerosols, particularly organics, that are now found to be a major fraction of urban and regional aerosols in the 0.1 to 1.0 micron size range and to help identify key types of organics that can contribute to aerosol absorption. During the MILAGRO campaign, quartz filter samples were taken at 12-hour intervals from 5 am to 5 pm (day) and from 5 pm to 5 am (night) during the month of March 2006. These samples were taken at the two super-sites, T-0 (Instituto Mexicano de Petroleo in Mexico City) and T-1 (Universidad Technologica de Tecamac, State of Mexico). The samples have been characterized for total carbon content (stable isotope mass spectroscopy) and natural radionuclide tracers, as well as for their UV-visible spectroscopic properties by using integrating sphere diffuse reflectance spectroscopy (Beckman DU with a Labsphere accessory). These same samples have been characterized in the mid and near infrared spectral ranges using diffuse reflection spectroscopy (Nicolet 6700 FTIR with a Smart Collector accessory). Aerosol samples were removed from the surfaces of the aerosol filters by using Si-Carb sampler. The samples clearly indicate the presence of carbonyl organic constituents and the spectra are quite similar to those observed for humic and fulvic acids

  15. Popular health education and propaganda in times of peace and war in Mexico city, 1890s-1920s.

    Science.gov (United States)

    Agostoni, Claudia

    2006-01-01

    Health education and propaganda acquired importance during the late 19th and early 20th centuries in Mexico City, as physicians, hygienists, and schoolteachers attempted to teach the principles of public health to a culturally and socially heterogeneous urban population.I explore the organization of the Popular Hygiene Exhibition of 1910 and the importance of health education before and after the armed phase of the Mexican Revolution, and why children and the indigenous populations became the main recipients of health education programs.

  16. Obstructive sleep apnoea and atopy among middle aged chronic obstructive pulmonary disease and bronchial asthma patients.

    Science.gov (United States)

    Kumar, Raj; Nagar, Devender; Mallick, Adeeb; Kumar, Manoj; Tarke, Chandrakant R; Goel, Nitin

    2013-09-01

    Obstructive sleep apnoea syndrome is associated with significant morbidity. A high prevalence of obstructive sleep apnoea (OSA) symptoms has been reported in patients with asthma and chronic obstructive pulmonary disease (COPD). There are limited studies regarding relationship between atopy and OSA. To study the risk of obstructive sleep apnoea among middle aged chronic obstructive pulmonary disease and asthma patients by a home based sleep study and its association with atopy. Patients with asthma and COPD were evaluated for OSA symptoms by Epworth sleepiness scale (ESS) and Berlin questionnaire (BQ). ESS score > or = 9 was considered as high risk for OSA. Patients having high risk for OSA by ESS and BQ were further evaluated for OSA by home based sleep study. Skin prick test against common allergens was done to diagnose atopy in these patients. Among 400 patients (229, 57.25% male and 171, 42.75% female) 328 were asthmatics and 72 were COPD patients. ESS and BQ was positive in 11.25% (45/400) and 18.25% (73/400) patients respectively. ESS was positive in 10.67% (35/328) of asthma and 13.88% (10/72) of COPD patients. BQ was positive in 18.29% (60/328) of asthmatic and 18.05% (13/72) of COPD patients. Skin prick test was positive in 74.16% patients. The maximum positivity was found in asthmatics (139/155, 89.68%) compared to COPD patients (16/155, 10.32%). Skin prick test was done for 40 patients out of 73 of Asthma and COPD patients who were found positive by ESS and BQ. 72.5% patients were found to be atopic. Out of 19 patients in whom home polysomnography was done, 13 patients consented for skin prick test with common aeroallergens and 9 (69.23%) patients were found to be atopic. There is an increased risk of obstructive sleep apnoea among middle aged chronic obstructive pulmonary disease and asthma patients. Atopy could be associated with OSA. The association needs to be proved in a larger study.

  17. The future of fuel cell in Mexico in the third millennium

    Science.gov (United States)

    Ramírez-Salgado, J.; Marín-Cruz, J.; Estrada-Martínez, A.

    The warming of the earth due to green house gas emission is mainly produced by CO 2. In Mexico City, 71% of the total harmful emissions is from internal combustion engines of car and buses. Benefits from the use of fuel cells (FCs) in transportation and stationary power generating sectors will achieve satisfactory air quality standards not only in Mexico City but also throughout the country. This paper suggests a scenario for FC technology penetration in Mexico. There are two potential markets for FCs: (i) FC transportation; and (ii) stationary power plant for electrical production. In Mexico City, 3.2 million vehicles are in circulation and represent 19.5% (16.3 million) of the country's total vehicles, and 9.02 million of natural gas users are a potential market for acquiring stationary power generation by FC systems.

  18. Social conflict in response to urban sprawl in rural areas: urban reconfiguration of the Mezquital valley as influence area of the megalopolis of Mexico City

    OpenAIRE

    Carrasco, Brisa; Cadena, Edel; Campos, Juan; Hinojosa, Raquel

    2016-01-01

    The urban sprawl of metropolitan areas involves complex processes of coexistence between urban and rural dynamics, the functional redefining of central urban areas and rural areas or urban-rural surrounding transition generates land conflicts. In this paper the context of Mexico City megalopolis and its expansion process, will be discussed in the new specialization of the central city to tertiary services and increasing the value of land, it has resulted in the expulsion of the industry and s...

  19. Emission and chemistry of organic carbon in the gas and aerosol phase at a sub-urban site near Mexico City in March 2006 during the MILAGRO study

    Directory of Open Access Journals (Sweden)

    J. A. de Gouw

    2009-05-01

    Full Text Available Volatile organic compounds (VOCs and carbonaceous aerosol were measured at a sub-urban site near Mexico City in March of 2006 during the MILAGRO study (Megacity Initiative: Local and Global Research Objectives. Diurnal variations of hydrocarbons, elemental carbon (EC and hydrocarbon-like organic aerosol (HOA were dominated by a high peak in the early morning when local emissions accumulated in a shallow boundary layer, and a minimum in the afternoon when the emissions were diluted in a significantly expanded boundary layer and, in case of the reactive gases, removed by OH. In comparison, diurnal variations of species with secondary sources such as the aldehydes, ketones, oxygenated organic aerosol (OOA and water-soluble organic carbon (WSOC stayed relatively high in the afternoon indicating strong photochemical formation. Emission ratios of many hydrocarbon species relative to CO were higher in Mexico City than in the U.S., but we found similar emission ratios for most oxygenated VOCs and organic aerosol. Secondary formation of acetone may be more efficient in Mexico City than in the U.S., due to higher emissions of alkane precursors from the use of liquefied petroleum gas. Secondary formation of organic aerosol was similar between Mexico City and the U.S. Combining the data for all measured gas and aerosol species, we describe the budget of total observed organic carbon (TOOC, and find that the enhancement ratio of TOOC relative to CO is conserved between the early morning and mid afternoon despite large compositional changes. Finally, the influence of biomass burning is investigated using the measurements of acetonitrile, which was found to correlate with levoglucosan in the particle phase. Diurnal variations of acetonitrile indicate a contribution from local burning sources. Scatter plots of acetonitrile versus CO suggest that the contribution of biomass burning to the enhancement of most gas and aerosol species was not dominant and perhaps

  20. Emission and Chemistry of Organic Carbon in the Gas and Aerosol Phase at a Sub-Urban Site Near Mexico City in March 2006 During the MILAGRO Study

    Energy Technology Data Exchange (ETDEWEB)

    de Gouw, Joost A.; Welsh-Bon, Daniel; Warneke, Carsten; Kuster, W. C.; Alexander, M. L.; Baker, Angela K.; Beyersdorf, Andreas J.; Blake, D. R.; Canagaratna, Manjula R.; Celada, A. T.; Huey, L. G.; Junkermann, W.; Onasch, Timothy B.; Salcido, A.; Sjostedt, S. J.; Sullivan, Amy; Tanner, David J.; Vargas-Ortiz, Leroy; Weber, R. J.; Worsnop, Douglas R.; Yu, Xiao-Ying; Zaveri, Rahul A.

    2009-05-28

    Volatile organic compounds (VOCs) and carbonaceous aerosol were measured at a sub-urban site near Mexico City in March of 2006 during the MILAGRO study (Megacity Initiative: Local and Global Research Objectives). Diurnal variations of hydrocarbons, elemental carbon (EC) and hydrocarbon-like organic aerosol (HOA) were dominated by a high peak in the early morning when local emissions accumulated in a shallow boundary layer, and a minimum in the afternoon when the emissions were diluted in a significantly expanded boundary layer and, in case of the reactive gases, removed by OH. In comparison, diurnal variations of species with secondary sources such as the aldehydes, ketones, oxygenated organic aerosol (OOA) and water-soluble organic carbon (WSOC) stayed relatively high in the afternoon indicating strong photochemical formation. Emission ratios of many hydrocarbon species relative to CO were higher in Mexico City than in the U.S., but we found similar emission ratios for most oxygenated VOCs and organic aerosol. Secondary formation of acetone may be more efficient in Mexico City than in the U.S., due to higher emissions of alkane precursors from the use of liquefied petroleum gas. Secondary formation of organic aerosol was similar between Mexico City and the U.S. Combining the data for all measured gas and aerosol species, we describe the budget of total observed organic carbon (TOOC), and find that the enhancement ratio of TOOC relative to CO is conserved between the early morning and mid afternoon despite large compositional changes. Finally, the influence of biomass burning is investigated using the measurements of acetonitrile, which was found to correlate with levoglucosan in the particle phase. Diurnal variations of acetonitrile indicate a contribution from local burning sources. Scatter plots of acetonitrile versus CO suggest that the contribution of biomass burning to the enhancement of most gas and aerosol species was not dominant and perhaps not dissimilar

  1. Concentration levels of radon in air, indoors and outdoors in houses of Mexico City

    International Nuclear Information System (INIS)

    Pena Garcia, P.

    1992-01-01

    Concentration levels of radon in air, indoors and outdoors have been obtained in houses from Mexico City, with the purpose of relating them with the local environment. Measurements were performed both outdoors and indoors in 60 unifamiliar houses. Track detectors, LR-115, Type II, were used in several detection arrangements during four recording periods with times of exposure of three months each, with the purpose of analyzing the fluctuations due to seasonal changes. Data were obtained about the construction materials were the detection systems were located in order to establish a correlation of radon levels with the climatic parameters and the construction materials. The results of radon concentrations both indoors or outdoors were lower than the international recommendations (148 Bq/m 3 ) (Author)

  2. Emissions inventory for the Mexico City Metropolitan Area

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, V.H.P.; Renteria, J.S. [Secretaria de Medio Ambiente, Col. Tiacopac San Angel (Mexico); Hernandez, C.G. [Departamento del Distrito Federal, Col. Centro (Mexico)] [and others

    1996-12-31

    The emissions inventory bears a broad relationship to the energy balance, reflecting the dependence of the emissions with reference to the use of energy. Actually the consumption of gasoline and diesel fuel in the transport sector represents collectively, the greatest comparative expense of energy and the major contributor of the ozone precursor pollutants HC, NO{sub x} and CO, relative to the total volume of emissions in the Mexico City Metropolitan Area (MCMA). Also, the industrial sector introduces significant emissions of SO{sub 2} and NO{sub x} due to its energy consumption of fuel oils and natural gas. In contrast, the great majority of suspended particulate in the MCMA emanate from degradation processes of surface soil along the periphery of the urban zone. To the federal and local authorities charged with the design of strategies for prevention and control of atmospheric pollution, the emissions inventory is a strategic tool that reflects the relative intensity of the various emitters to the load capacity of the atmosphere. A comprehensive inventory was compiled for 1995, categorizing the emissions generated by four sectors: industry, services, transport and surface soils and vegetation, considering the following pollutants: TSP, SO{sub 2}, NO{sub x}, HC and CO. The combined pollutant emissions are 4,009,628 tons/year of which 3% are generated by the industry, 10% by the services sector, 75% by the transport sector, and 12% by surface soils and vegetation.

  3. Service use among Mexico City adolescents with suicidality

    Science.gov (United States)

    Borges, Guilherme; Benjet, Corina; Medina-Mora, Maria Elena; Orozco, Ricardo; Familiar, Itziar; Nock, Matthew K.; Wang, Philip S.

    2009-01-01

    Background We report the lifetime and 12-month prevalence and associations of mental health treatment among Mexican adolescents with suicide-related outcomes (SROs; including ideation, plans, gestures and attempts). Methods A representative multistage probability household survey of 3005 adolescents aged 12 to 17 years residing in the Mexico City Metropolitan Area was carried out in 2005. Discrete time survival analyses were used to assess the relationships between SROs and receiving treatment for emotional, alcohol, or drug problems. Results The prevalence of lifetime service use among respondents with SROs was 35% for those with ideation only, 44% for those with ideation and plan, 49% for those with gesture and 50% for those with attempt; the prevalence of 12-month service use was 10%, 24%, 6% and 21%, respectively. Timing between onset of SRO and receiving treatment for emotional, alcohol, or drug problems showed that about 50% of adolescents will have contact with a service provider before developing any SRO. Healthcare professionals were the most likely to be consulted, followed by school-based programs. Limitations This survey was limited to adolescents living in one of the largest metropolitan areas in the world and the analyses used data on retrospectively reported ages of onset that are subject to recall errors. Conclusions Most suicidal adolescents do not receive treatment, and many adolescents develop their suicidality in spite of prior contacts with service providers. Interventions to increase treatment, prevention, and monitoring are sorely needed for this vulnerable population. PMID:19411113

  4. Surface albedo measurements in Mexico City metropolitan area

    Energy Technology Data Exchange (ETDEWEB)

    Castro, T; Mar, B; Longoria, R; Ruiz Suarez, L. G [Centro de Ciencias de la Atmosfera, UNAM, Mexico, D.F. (Mexico); Morales, L [Instituto de Geografia, UNAM, Mexico, D.F. (Mexico)

    2001-04-01

    Optical and thermal properties of soils are important input data for the meteorological and photochemical modules of air quality models. As development of these models increase on spatial resolution good albedo data become more important. In this paper measurements of surface albedo of UV (295-385 nm) and visible (450-550 nm) radiation are reported for different urban and rural surfaces in the vicinity of Mexico City. It was found for the downtown zone and average albedo value of 0.05 which is in very good agreement with reported values for urban surfaces. Our albedo values measured in UV region for grey cement and green grass are of 0.10 and 0.009, respectively, and quite similar to those found at the literature of 0.11 and 0.008 for those type of surfaces. [Spanish] Las propiedades opticas y termicas de suelos son datos importantes para los modulos meteorologicos y fotoquimicos de los modelos de calidad del aire. Conforme aumenta la resolucion espacial del modelo se vuelve mas importante contar con buenos datos de albedo. En este articulo se presentan mediciones de albedo superficial de radiacion Ultravioleta (295-385 nm) y visible (450-550 nm) para diferentes superficies urbanas. Los valores medidos de albedo en la region UV para cemento gris y pasto verde son de 0.10 y 0.009, respectivamente, y son muy similares a los reportados en la literatura, 0.11 y 0.008 para este tipo de superficies.

  5. La ciudad de México a través de cuatro cuentos / Mexico City as seen through four short stories

    Directory of Open Access Journals (Sweden)

    Sofía Tierno Tejera

    2011-01-01

    Full Text Available RESUMEN: Desde el siglo XIX hasta nuestros días, la ciudad se ha convertido en protagonista de innumerables relatos. A través de cuatro cuentos sobre la ciudad de México, que abarcan desde finales del siglo XIX hasta mediados del siglo XX, analizo cómo el crecimiento de la urbe ha ido acompasado con la transformación de los temas y de las técnicas narrativas de los relatos sobre esta gran metrópoli. ABSTRACT: From the nineteenth century to today, the city has become the leading character in countless narratives. Through four short stories about Mexico City, which were written between the end of the nineteenth century and the mid fifties, I analyse how the growth of the city has run parallel to the transformation of the themes and the narrative techniques in stories about this great metropolis.

  6. Using ground-based solar and lunar infrared spectroscopy to study the diurnal trend of carbon monoxide in the Mexico City boundary layer

    Directory of Open Access Journals (Sweden)

    W. Stremme

    2009-10-01

    Full Text Available Carbon monoxide (CO is an important pollutant in urban agglomerations. Quantifying the total burden of this pollutant in a megacity is challenging because not only its surface concentration but also its vertical dispersion present different behaviours and high variability. The diurnal trend of columnar CO in the boundary layer of Mexico City has been measured during various days with ground-based infrared absorption spectroscopy. Daytime CO total columns are retrieved from solar spectra and for the first time, nocturnal CO total columns using moonlight have been retrieved within a megacity. The measurements were taken at the Universidad Nacional Autónoma de México (UNAM campus located in Mexico City (19.33° N, 99.18° W, 2260 m a.s.l. from October 2007 until February 2008 with a Fourier-transform infrared spectrometer at 0.5 cm−1 resolution. The atmospheric CO background column was measured from the high altitude site Altzomoni (19.12° N, 98.65° W, 4010 m a.s.l. located 60 km southeast of Mexico City. The total CO column within the city presents large variations. Fresh CO emissions at the surface, the transport of cleaner or more polluted air masses within the field-of-view of the instrument and other processes contribute to this variability. The mean background value above the boundary mixing layer was found to be (8.4±0.5×1017 molecules/cm2, while inside the city, the late morning mean on weekdays and Sundays was found to be (2.73±0.41×1018 molecules/cm2 and (2.04±0.57×1018 molecules/cm2, respectively. Continuous CO column retrieval during the day and night (when available, in conjunction with surface CO measurements, allow for a reconstruction of the effective mixing layer height. The limitations from this simplified approach, as well as the potential of using continuous column measurements in order to derive top-down CO emissions from a large urban area

  7. Reduced occurrence of early atopic dermatitis because of immunoactive prebiotics among low-atopy-risk infants

    NARCIS (Netherlands)

    Grueber, Christoph; van Stuijvenberg, Margriet; Mosca, Fabio; Moro, Guido; Chirico, Gaetano; Braegger, Christian P.; Riedler, Josef; Boehm, Guenther; Wahn, Ulrich

    2010-01-01

    Background: Most infants developing atopic dermatitis have a low risk for atopy. Primary prevention of atopic dermatitis is difficult. Objective: To assess the effect of supplementation of an infant and follow-on formula with prebiotic and immunoactive oligosaccharides on the occurrence of atopic

  8. [The clinico-epidemiological characteristics of cholera patients in Mexico City].

    Science.gov (United States)

    Vilchis-Guizar, A E; Uribe-Márquez, S; Pérez-Sánchez, P L

    1999-01-01

    To compare the clinical and epidemiological characteristics of cholera patients and patients with diarrhea of different etiology (controls), treated at Mexican Institute of Social Security medical units in northeast Mexico City, from 1995 to 1998. Cross-sectional analytical study design. Data were collected using the official form "Immediate Notification of Cholera Cases" that each medical unit reports to the Coordination of Community Health. Statistical analysis consisted of comparisons of means and proportions between both groups. In 4,952 notifications, there were 588 cholera cases and 4,364 controls. The age range of cases was 39 to 51 years and 54% were females. During 1995 and 1997 (years with higher proportion of cases) patients with cholera had a greater frequency of watery evacuations than controls (97% vs. 73%), "rice water" appearance (31% vs. 13%), vomiting (72% vs. 63%), muscular spasms (49% vs. 26%), dehydration (83% vs. 71%), hypovolemic shock (10% vs. 1%) and death (0.85% vs. 0.25%). These differences were statistically significant. Cholera presents a biannual cyclic behavior; greater frequencies are associated with greater severity and complications. It is necessary to increase epidemiologic surveillance and medical efforts for opportune diagnosis and treatment.

  9. Ozone concentrations at a selected high-elevation forest site downwind Mexico City

    Science.gov (United States)

    Torres-JArdon, R.

    2013-05-01

    Torres-Jardón, R.*, Rosas-Pérez, I., Granada-Macías, L. M., Ruiz-Suárez, L. G. Centro de Ciencias de la Atmósfera, UNAM, México D. F. México * rtorres@unam.mx For many years, the vegetation of forest species such as Abies religiosa in natural parks located in the southwest mountains of Mexico City has attracted much attention since these parks have been experiencing a severe decline of unclear etiology. The high ozone levels in the area and the observed naked eye macroscopic, histological and cytological injuries on these species, strongly suggest an important contribution of tropospheric ozone to this deterioration process. Apart of historical short monitoring campaigns for measuring ozone levels in these mountains, it is known just a little is known about the present exposure levels at which the local vegetation is exposed. A continuous ozone analyzer has been in operation since 2011 at a high-elevation forest site (Parque Nacional Miguel Hidalgo, PNMH; 3110 m above mean sea level) located downwind of Mexico City Metropolitan Area (MCMA), in order to characterize the local ozone diel amplitude and its seasonal trend, as well as the influence of MCMA on the local O3 concentrations. Hourly average ozone data in PNMH shows that in general, the diel of ozone concentrations in the forest site has a statistical significant correlation with the pattern of ozone levels observed in several monitoring sites (smog receptor sites) within the MCMA, although the high elevation O3 levels are relatively lower than those in the urban area (around 2200 m above mean sea level). It is possible that a part of the oxidants in the air masses are removed by sink deposition processes during the air mass transport across the hills. The diel amplitude of ozone concentrations is small in the cold season, increasing as the seasons advance to June. As in the city, the highest ozone concentrations occur in April or May and the lowest levels during the rainy season, which extends from

  10. Acceso universal al Programa de VIH/SIDA de la Ciudad de México: resultados a seis años Universal access, six years results in the Mexico City HIV/AIDS Program

    Directory of Open Access Journals (Sweden)

    Carmen Soler Claudín

    2009-02-01

    Full Text Available OBJETIVO: Analizar los resultados del Programa de Medicamentos Antirretrovirales Gratuitos del Programa de VIH/SIDA de la Ciudad de México (PVSCM en la población afectada del Distrito Federal. MATERIAL Y MÉTODOS: Se sistematizaron y analizaron datos de la Coordinación del PVSCM sobre atención médica, tratamiento antirretroviral (ARV y resultados de laboratorio especializado en un análisis retrospectivo del periodo 2001-2006, para evaluar su efecto en los pacientes atendidos. RESULTADOS. Se incluyen datos de 5 146 pacientes que recibieron tratamiento ARV. Al final del periodo, 74% de ellos permanecía vigente, 12.1% se perdió en el seguimiento y 13.9% había fallecido. CONCLUSIONES: En el Distrito Federal, durante el periodo evaluado se logró la ampliación de cobertura, eficacia en el tratamiento ARV e incremento de la sobrevida de los pacientes.OBJECTIVE: To analyze the results of the Free Antiretroviral Medication Program of the Mexico City HIV/AIDS Program among the affected population in Mexico City. MATERIAL AND METHODS: A retrospective analysis was conducted of medical attention, antiretroviral treatment and specialized laboratory results data from 2001 to 2006 from patients who sought services from the Mexico City HIV/AIDS Program. RESULTS: Data from 5 146 patients who were undergoing ARV are presented. At the end of the period studied, 74% were current, 12.2% were not found for follow-up and 13.9% had died. CONCLUSIONS: During the period evaluated, wider coverage was achieved in Mexico City as well as increased efficiency in ARV treatment and increased patient survival.

  11. Cities, Towns, Villages with 1990 Census Population (GNIS)

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data set contains points for 1600 populated places, cities and towns, in New Mexico. The points were generated from latitude and longitude coordinates contained...

  12. Incidence of leukemias in children from El Salvador and Mexico City between 1996 and 2000: Population-based data

    OpenAIRE

    Mejía-Aranguré, Juan Manuel; Bonilla, Miguel; Lorenzana, Rodolpho; Juárez-Ocaña, Servando; de Reyes, Gladys; Pérez-Saldivar, María Luisa; González-Miranda, Guadalupe; Bernáldez-Ríos, Roberto; Ortiz-Fernández, Antonio; Ortega-Alvarez, Manuel; Martínez-García, María del Carmen; Fajardo-Gutiérrez, Arturo

    2005-01-01

    Abstract Background There are very few studies that report the incidence of acute leukemias in children in Latin America. This work assesses the incidence of acute leukemias, between 1996 and 2000, in children from 0–14 years old who were attended at the Mexican Social Security Institute in Mexico City and in children from 0–11 years old in El Salvador. Methods Design: Population-based data. Hospitals: In San Salvador, El Salvador, Hospital Nacional de Niños "Benjamín Bloom", the only center ...

  13. Popular Health Education and Propaganda in Times of Peace and War in Mexico City, 1890s–1920s

    Science.gov (United States)

    Agostoni, Claudia

    2006-01-01

    Health education and propaganda acquired importance during the late 19th and early 20th centuries in Mexico City, as physicians, hygienists, and schoolteachers attempted to teach the principles of public health to a culturally and socially heterogeneous urban population. I explore the organization of the Popular Hygiene Exhibition of 1910 and the importance of health education before and after the armed phase of the Mexican Revolution, and why children and the indigenous populations became the main recipients of health education programs. PMID:16322465

  14. Community Policing in Latin America: Lessons from Mexico City

    Directory of Open Access Journals (Sweden)

    Markus-Michael Müller

    2010-04-01

    Full Text Available Community policing programmes are widely perceived and promoted as an important solution for the pressing problems of insecurity in contemporary Latin American cities, and for improving citizen-police relationships. By drawing on the results of empirical fieldwork conducted in Mexico City, the article presents a critical analysis of the local community policing effort. The article demonstrates that this policing effort is overly determined by a local context, characterized by clientelism, political factionalism and police corruption, which therefore renders its contribution to a sustainable improvement of local accountability and police legitimacy unlikely. Against this background the article calls for more empirical studies on this topic and a greater sensitivity for the embeddedness of policing programmes within a wider political context.    Resumen: Colaboración ciudadana en América Latina: Lecciones de Ciudad de México  Los programas de colaboración ciudadana son ampliamente percibidos y presentados como una importante solución para los apremiantes problemas de inseguridad en las ciudades latinoamericanas de hoy, y para mejorar las relaciones entre la ciudadanía y la policía. Basándonos en los resultados de trabajo de campo realizado en Ciudad de México, en el presente artículo se ofrece un análisis crítico del programa local de policía comunitaria y se demuestra que está excesivamente determinado por un contexto local caracterizado por el clientelismo, las lealtades políticas y la corrupción policial. Por eso, el aporte del programa a un mejoramiento sustentable de la rendición de cuentas local y de legitimidad policial es improbable. Contra este telón de fondo, en el artículo se demandan más estudios empíricos sobre el tema y una mayor sensibilidad para la integración de los programas de policía comunitaria dentro de un contexto político más amplio.

  15. Blood lead levels in pregnant women of high and low socioeconomic status in Mexico City.

    Science.gov (United States)

    Farias, P; Borja-Aburto, V H; Rios, C; Hertz-Picciotto, I; Rojas-Lopez, M; Chavez-Ayala, R

    1996-10-01

    This study examined the determinants of blood lead (BPb) in 513 pregnant women in Mexico City: 311 from public hospital prenatal clinics, representing primarily women of low socioeconomic status (SES), and 202 from private hospitals, primarily women of high SES. Overall, BPb levels ranged from 1.38 to 29 micrograms/dl, with geometric means of 6.7 and 11.12 micrograms/dl for women from private and public hospitals, respectively. The crude geometric means difference obtained by t-test was 4.42 (p Consumption of tortillas (corn bread rich in calcium) decreased BPb levels in the lower SES group, but the relationship was not statistically significant (p > 0.05). Consumption of milk products significantly (p socioeconomic status.

  16. Determination of particle size and content of metals in the atmosphere of ZMCM (Metropolitan Zone of Mexico City)

    International Nuclear Information System (INIS)

    Aldape U, F.; Flores M, J.; Diaz, R.V.; Garcia G, R.

    1994-01-01

    Inside the breathable fraction of the atmosphere of Mexico City, the presence of metals in suspended particles, is determined and quantified. The detection was carry out simultaneously in three places of the city, using collectors of the type stacking filter unit (SFU) which allow the separation of particles according to its size. The SFU detectors allow the separation in two size: 'Gross' mass from 2.5 to 1.5 μm and 'fine' mass for particles smallest than 2.5 μm. The analysis of the samples was fulfilled by means of PIXE method. Samples were irradiated with a proton beam, and based in the X-ray spectra the elements were identified and quantified, which allow to establish the temporal behavior of the concentrations per element for gross mass and fine mass in each one of the places of sampling. (Author)

  17. Evaluation of the association of acute overshift change in pulmonary function and atopy using OSHA cotton dust surveillance data.

    Science.gov (United States)

    Jennison, E; Jacobs, R R

    1994-05-01

    OSHA surveillance data were collected for 769 individuals employed in four different cotton textile mills. Current workers were asked to complete a questionnaire about personal and family history of atopy or asthma. Both surveillance and survey data were available for 502 individuals. The prevalence of atopy in the population as reported by questionnaire was 18%, while asthma was reported by 4%. Dust levels at the four mills were in compliance with the cotton dust standard during the period of surveillance. No relationship was found between a self-reported history of atopy or asthma and the magnitude or frequency of acute overshift declines in forced expiratory volume during 1 second (FEV1). Nonsmokers had annual changes in FEV1 and forced vital capacity (FVC) comparable to nonexposed populations. In one of the four mills surveyed, annual declines in FEV1 and FVC for current smokers were significantly greater than declines for smokers in the other mills or the general smoking population (p effect was also observed for subjects who were categorized as atopic (p effect from exposure to the levels of cotton dust observed in these mills.

  18. The oxidative potential and biological effects induced by PM10 obtained in Mexico City and at a receptor site during the MILAGRO Campaign

    International Nuclear Information System (INIS)

    Quintana, Raul; Serrano, Jesus; Gomez, Virginia; Foy, Benjamin de; Miranda, Javier; Garcia-Cuellar, Claudia; Vega, Elizabeth; Vazquez-Lopez, Ines; Molina, Luisa T.; Manzano-Leon, Natalia; Rosas, Irma; Osornio-Vargas, Alvaro R.

    2011-01-01

    As part of a field campaign that studied the impact of Mexico City pollution plume at the local, sub-regional and regional levels, we studied transport-related changes in PM 10 composition, oxidative potential and in vitro toxicological patterns (hemolysis, DNA degradation). We collected PM 10 in Mexico City (T 0 ) and at a suburban-receptor site (T 1 ), pooled according to two observed ventilation patterns (T 0 → T 1 influence and non-influence). T 0 samples contained more Cu, Zn, and carbon whereas; T 1 samples contained more of Al, Si, P, S, and K (p 4 -2 increased in T 1 during the influence periods. Oxidative potential correlated with Cu/Zn content (r = 0.74; p 1 PM 10 induced greater hemolysis and T 0 PM 10 induced greater DNA degradation. Influence/non-influence did not affect oxidative potential nor biological effects. Results indicate that ventilation patterns had little effect on intrinsic PM 10 composition and toxicological potential, which suggests a significant involvement of local sources. - Highlights: → Transport-related changes in PM 10 composition, oxidative potential and in vitro toxicity were studied. → Cu, Zn, and carbon levels were predominant in urban PM 10 ; receptor site PM 10 was rich in soil elements. → SO 4 -2 was the only component increased in PM 10 from the receptor during the influence periods. → PM 10 oxidative potential correlates with Cu/Zn content but not with studied biological effects. → Ventilation patterns had little effect on PM 10 composition and toxicity. - Mexico City ventilation patterns had little effect on the intrinsic PM 10 composition and toxicological potential, which suggests a significant involvement of local sources as opposed to downwind transport.

  19. Mexico City ozone concentrations as a function of readily-available meteorological parameters

    International Nuclear Information System (INIS)

    Brown, M.J.

    1994-01-01

    Daily maximum ozone concentrations measured at four sites within the Mexico City basin during the winter months are plotted as functions of different meteorological parameters that are routinely measured at surface stations. We found that ozone concentrations are most strongly correlated to the increase in daytime temperature and the maximum daytime wind speed. We also discovered that high ozone values at the sites in the southern end of the basin occur when winds come out of the northeast. In contrast, wind direction was found to be uncorrelated with high ozone values at the northern sites. From straightforward combinations of the meteorological variables, we derived some simple rules for estimating lower and upper bounds on the ozone concentration. Scatter in the data was too long to give significance to best-fit equations and statistics. Additionally, a small rawinsonde data set was used to investigate ozone's dependence on boundary-layer height and near-surface temperature gradient. Results were inconclusive, however, due to the small size of the data set

  20. Presence of polychlorinated biphenyls (PCBs) in bottled drinking water in Mexico City.

    Science.gov (United States)

    Salinas, Rutilio Ortiz; Bermudez, Beatriz Schettino; Tolentino, Rey Gutiérrez; Gonzalez, Gilberto Díaz; Vega y León, Salvador

    2010-10-01

    This paper describes the concentrations of seven polychlorinated biphenyls (PCBs) in bottled drinking water samples that were collected over 1 year from Mexico City in two sizes (1.5 and 19 L), using gas chromatography with an electron capture detector. PCBs 28 (0.018-0.042 μg/L), 52 (0.006-0.015 μg/L) and 101 (0.001-0.039 μg/L) were the most commonly found and were present in the majority of the samples. However, total concentrations of PCBs in bottled drinking water (0.035-0.039 μg/L) were below the maximum permissible level of 0.50 μg/L stated in Mexican regulations and probably do not represent a hazard to human health. PCBs were detectable in all samples and we recommend a monitoring program be established to better understand the quality of drinking bottled water over time; this may help in producing solutions for reducing the presence of organic contaminants.

  1. Georadar Archaeological Prospection at the Historical Center of the Merida City, Yucatan, Mexico.

    Science.gov (United States)

    Barba, L.; Ortiz, A.; Blancas, J.; Ligorred, J.

    2007-05-01

    This paper shows the results of the georadar archaeological prospection carried out by the Laboratorio de Prospección Arqueologica from the Instituto de Investigaciones Antropologicas (IIA) of the Universidad Nacional Autonoma de Mexico (UNAM) verifing the archaeological and historical information recovered by the Departamento de Patrimonio Arqueologico y Natural del Municipio (DPANM) del Ayuntamiento de Merida en el Centro Histerico de la Ciudad de Merida under a joint project. The Historical Center of Merida has been classified as a "zone of high patrimonial value" after the topographic data and the historical documents recovered showed a long-term occupation, non interrupted since pre-Columbian times, when T Ho was the great capital of the northern region of the Maya area. For the rehabilitation program of the Historical Center of Merida has been a great priority to verify the existence of archaeological remains, pre-Columbian or colonial, under the present streets, gardens and plazas that could be damaged during the public infrastructure works. In order to prevent any damage to the patrimony a large georadar study was carried out pulling 200 and 400 MHz antennas of the GSSI SIR System 2 for 16500 m of the city streets, focusing in the areas where infrastructure works were imminent. After the analysis of the radar data it was possible to build up a map with the location of the most noticeable archaeological remains under the pavement of the streets that confirmed many of the topographic and documental proposed places. As a final result, by the first time a city government has available information to take present urban decisions, while preventing the damage to the archaeological patrimony of the same city.

  2. Maternal Plasma Phosphatidylcholine Fatty Acids and Atopy and Wheeze in the Offspring at Age of 6 Years

    Directory of Open Access Journals (Sweden)

    Katharine C. Pike

    2012-01-01

    Full Text Available Variation in exposure to polyunsaturated fatty acids (PUFAs might influence the development of atopy, asthma, and wheeze. This study aimed to determine whether differences in PUFA concentrations in maternal plasma phosphatidylcholine are associated with the risk of childhood wheeze or atopy. For 865 term-born children, we measured phosphatidylcholine fatty acid composition in maternal plasma collected at 34 weeks’ gestation. Wheezing was classified using questionnaires at 6, 12, 24, and 36 months and 6 years. At age of 6 years, the children underwent skin prick testing, fractional exhaled nitric oxide (FENO measurement, and spirometry. Maternal n-6 fatty acids and the ratio of n-3 to n-6 fatty acids were not associated with childhood wheeze. However, higher maternal eicosapentaenoic acid, docosahexaenoic acid, and total n-3 fatty acids were associated with reduced risk of non-atopic persistent/late wheeze (RR 0.57, 0.67 and 0.69, resp. P=0.01, 0.015, and 0.021, resp.. Maternal arachidonic acid was positively associated with FENO (P=0.024. A higher ratio of linoleic acid to its unsaturated metabolic products was associated with reduced risk of skin sensitisation (RR 0.82, P=0.013. These associations provide some support for the hypothesis that variation in exposure to n-6 and n-3 fatty acids during pregnancy influences the risk of childhood wheeze and atopy.

  3. In-situ monitoring of deformation of clayey and volcanic sequences in the lacustrine plain of Iztapalapa, Mexico City

    Science.gov (United States)

    Carreon-Freyre, D.; Cerca, M.; Barrientos, B.; Gutierrez, R.; Blancas, D.

    2012-12-01

    Major cities of Central Mexico with lowering of land elevation problems are located in inter-volcanic and fault bounded basins within the central Trans-Mexican Volcanic Belt (TMVB). The most representative and studied case of ground deformation is Mexico City, where the Iztapalapa Municipality presents the highest population density. This area is located over the geological contact between the "Sierra de Santa Catarina" volcanic range and a lacustrine plain. Filling of lacustrine basins includes silty and clayey sediments as well as pyroclastic deposits (coarse and fine grained) and volcanic rocks layers. We used Ground Penetrating Radar (GPR) and MASW prospection to evaluate contrasts in the physical properties of fine grained soils and identify geometry of the deformational features and implemented a mechanical system for in situ monitoring in fractured sites. Deformational features in this basin reflect an interplay between the geological history (depositional conditions), load history, seismic activity, and faulting. Plastic mechanical behaviour predominates in these clayey sediments and differential deformation locally triggers brittle fracturing and/or subsidence of the surface. In this work we present the results of monitoring and characterization of ground deformation and fracturing in different sequences, our results show a dynamic interplay between the mechanisms of ground fracturing and the stress history of sedimentary sequences. Relating the mechanical behaviour of the studied sequences with variations of physical and geological properties should be taken into account to estimate land level lowering and risk of fracturing for urban development planning.

  4. Air emissions scenarios from ethanol as a gasoline oxygenate in Mexico City Metropolitan Area

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Carlos A. [Posgrado en Ingenieria Energetica, Universidad Nacional Autonoma de Mexico, Priv. Xochicalco s/n, Col. Centro, Apartado Postal 34, 62580 Temixco, Morelos (Mexico); Manzini, Fabio; Islas, Jorge [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Priv. Xochicalco s/n, Col. Centro, Apartado Postal 34, 62580 Temixco, Morelos (Mexico)

    2010-12-15

    The Mexican Biofuel Introduction Program states that during year 2010 the three biggest Mexican cities will have a gasoline blending with 6% ethanol available for all gasoline on-road vehicle fleet. Also in 2010 Mexican government has programmed to start the substitution of Tier 1 - the adopted US emission standards - by Tier 2, which are more stringent emission standards for motor vehicles and gasoline sulfur control requirements. How will the air emissions in the Mexico City Metropolitan Area (MCMA) be modified by using this blending? Four scenarios up to year 2030 were constructed and simulated using the Long-Range Energy Alternatives Planning model. Beginning with a BAU or reference scenario, in this scenario the current available fuel is a blending composed by 5% methyl tertiary butyl ether and 95% gasoline (MTBE5). Then, three alternative scenarios that use ethanol as an oxygenate are considered, one with the already programmed E6 blending (6% anhydride ethanol, 94% gasoline), for the sake of comparison the E10 blending (10% anhydride ethanol, 90% gasoline), and the other alternative to compare, ETBE13.7 (13.7% ethyl tertiary butyl ether, 86.3% gasoline; where ETBE is an ether composed by 48% anhydride ethanol and 52% isobutene). Emissions of carbon dioxide (CO{sub 2}), carbon monoxide (CO), nitrogen oxides (NOx), particulate matter (PM10), sulfur dioxide (SO{sub 2}), total hydrocarbons (THC), benzene, formaldehyde, acetaldehyde and 1,3-butadiene were calculated using emission factors previously calculated using the adapted US-EPA computer model called MOBILE6-Mexico. Results show that Tier 1 and Tier 2 standards effectively lowers all emissions in all studied scenarios with the exception of PM10 and CO{sub 2} emissions. The alternative scenario E10 has the most total avoided emissions by weight but it is not the best when considering some individual pollutants. The greatest environmental benefit of ethanol in its final use as a gasoline oxygenate is for

  5. No linkage and association of atopy to chromosome 16 including the interleukin-4 receptor gene

    DEFF Research Database (Denmark)

    Haagerup, A; Bjerke, T; Schiøtz, P O

    2001-01-01

    BACKGROUND: Several susceptibility genes for atopy have been suggested in recent years. Few have been investigated as intensively as the interleukin-4-receptor alpha (IL4Ralpha) gene on chromosome 16. The results remain in dispute. Therefore, in a robust design, we tested for association of type ...

  6. Contributors to ozone episodes in three US/Mexico border twin-cities.

    Science.gov (United States)

    Shi, Chune; Fernando, H J S; Yang, Jie

    2009-09-01

    The Process Analysis tools of the Community Multiscale Air Quality (CMAQ) modeling system together with back-trajectory analysis were used to assess potential contributors to ozone episodes that occurred during June 1-4, 2006, in three populated U.S.-Mexico border twin cities: San Diego/Tijuana, Imperial/Mexicali and El Paso/Ciudad Juárez. Validation of CMAQ output against surface ozone measurements indicates that the predictions are acceptable with regard to commonly recommended statistical standards and comparable to other reported studies. The mean normalized bias test (MNBT) and mean normalized gross error (MNGE) for hourly ozone fall well within the US EPA suggested range of +/-15% and 35%, respectively, except MNBT for El Paso. The MNBTs for maximum 8-h average ozone are larger than those for hourly ozone, but all the simulated maximum 8-h average ozone are within a factor of 2 of those measured in all three regions. The process and back-trajectory analyses indicate that the main sources of daytime ground-level ozone are the local photochemical production and regional transport. By integrating the effects of each process over the depth of the daytime planetary boundary layer (PBL), it is found that in the San Diego area (SD), chemistry and vertical advection contributed about 36%/48% and 64%/52% for June 2 and 3, respectively. This confirms the previous finding that high-altitude regional transport followed by fumigation contributes significantly to ozone in SD. The back-trajectory analysis shows that this ozone was mostly transported from the coastal area of southern California. For the episodes in Imperial Valley and El Paso, respectively, ozone was transported from the coastal areas of southern California and Mexico and from northern Texas and Oklahoma.

  7. First record of Hesperolabops nigriceps Reuter (Hemiptera: Miridae) on Opuntia ficus-indica in Milpa Alta, Mexico City.

    Science.gov (United States)

    Palomares-Pérez, Martín; Rodríguez-Leyva, Esteban; Brailovsky, Harry; Ramírez-Alarcón, Samuel

    2010-01-01

    In recent years a species of Hesperolabops has become a problem as a pest of nopalitos, Opuntia ficus-indica, in Milpa Alta, in the south of Mexico City, which is the most important production region of this vegetable in the country. A survey of Hesperolabops in Milpa Alta has resulted in the first report of Hesperolabops nigriceps Reuter. This occurrence should be monitored and considered in future studies in order to avoid misidentification of Hesperolabops spp. Kirkaldy native populations there, and to avoid the confusion of the damage that may be caused on O. ficus-indica.

  8. Variability of the Mixed-Layer Height Over Mexico City

    Science.gov (United States)

    García-Franco, J. L.; Stremme, W.; Bezanilla, A.; Ruiz-Angulo, A.; Grutter, M.

    2018-02-01

    The diurnal and seasonal variability of the mixed-layer height in urban areas has implications for ground-level air pollution and the meteorological conditions. Measurements of the backscatter of light pulses with a commercial lidar system were performed for a continuous period of almost six years between 2011 and 2016 in the southern part of Mexico City. The profiles were temporally and vertically smoothed, clouds were filtered out, and the mixed-layer height was determined with an ad hoc treatment of both the filtered and unfiltered profiles. The results are in agreement when compared with values of mixed-layer height reconstructed from, (i) radiosonde data, and (ii) surface and vertical column densities of a trace gas. The daily maxima of the mean mixed-layer height reach values > 3 km above ground level in the months of March-April, and are clearly lower (pollution episodes and the height of the mixed layer. The growth rate of the convective mixed-layer height has a seasonal behaviour, which is characterized together with the mixed-layer-height anomalies. A clear residual layer is evident from the backscattered signals recorded in days with specific atmospheric conditions, but also from the cloud-filtered mean diurnal profiles. The occasional presence of a residual layer results in an overestimation of the reported mixed-layer height during the night and early morning hours.

  9. Photochemistry in the Atmospheres of Denver and Mexico City

    Science.gov (United States)

    Cantrell, C. A.

    2016-12-01

    The composition of atmospheres in and downwind of urban centers has been the subject of study for decades. While early campaigns involved measurements exclusively from the ground, more recent studies have included airborne-based observations. Improved understanding has hinged critically on the development of instrumentation for better qualitifcation of pollutants, and measurement of previously unobserved species in the gas and particulate phases. Comprehensive, well-planned studies have, over time, led to more detailed understanding of chemical transformations and thus improved model representations and directions for further research. This presentation focuses on findings from two case studies of urban atmospheres, namely the MILAGRO study in the Mexico City metropolitan area and the FRAPPE study in the Denver metropolitan region. Both studies made use of extensive ground-based networks and multiple aircraft platforms. The data collected during these studies have been combined with numerical models to derive assessments of the evolution of atmospheric composition due to photochemistry, mixing, and surface processes. Here, analysis of MILAGRO data focuses on the evolution of outflow downwind of the urban region. In FRAPPE, the focus is the possible role of oil and gas exploration on urban air quality. These findings are used to assess the accuracy of current numerical models to reproduce observations, and to point toward areas possibly needing further study.

  10. Crisis, Xenophobia and Repatriation. The Spanish Immigrants in the City of Mexico, 1910-1936

    Directory of Open Access Journals (Sweden)

    Alicia GIL LÁZARO

    2011-05-01

    Full Text Available The article deals with the influence of economic crisis in migrant groups. It starts with a reflection about the current situation, putting forward a comparative view with a study case in the past, that is, the circumstances around the Spanish immigrants in Mexico City at the time of Mexican Revolution until the crisis of the Great Depression (1910-1936. Three aspects are explored: first of all, the close relationship between the spreading of the economic crisis and the increase of restrains in migratory public policies in host countries. Secondly, the concomitant growth of xenophobic attitudes in native populations and, finally, the return to the homeland as one of the essential strategies developed by immigrants to confront the crisis drawing upon the social and associative networks of migration movements.

  11. The prevalence of the metabolic syndrome did not increase in Mexico City between 1990-1992 and 1997-1999 despite more central obesity.

    Science.gov (United States)

    Lorenzo, Carlos; Williams, Ken; Gonzalez-Villalpando, Clicerio; Haffner, Steven M

    2005-10-01

    Trends in the metabolic syndrome might follow trends in obesity. We examined this hypothesis in the Mexico City Diabetes Study (MCDS), a study that showed rising trends in obesity, and the effect of the metabolic syndrome on the risk of coronary heart disease (CHD). Designed as a population-based study, the MCDS enrolled subjects in 1990-1992 (n = 2,282). Follow-up visits were held in 1993-1995 (n = 1,764) and 1997-1999 (n = 1,754). We used the revised metabolic syndrome definition of the National Cholesterol Education Program and the Framingham equations to estimate the 10-year CHD risk. In men, the age-adjusted prevalence of the metabolic syndrome was 38.9% in 1990-1992, 43.4% in 1993-1995, and 39.9% in 1997-1999; in women, the prevalences were 65.4, 65.7, and 59.9%, respectively. The prevalence did not change in men (P = 0.349) between 1990-1992 and 1997-1999, but decreased in women (P metabolic syndrome nor CHD risk has increased in Mexico City. Lower blood pressure and triglyceride values appear to have counteracted increases in central obesity and fasting glucose.

  12. A physical model of the Mexico City seismic response after the damaging M7.1 earthquake of September 19, 2017

    Science.gov (United States)

    Cruz-Atienza, V. M.; Tago, J.; Villafuerte, C. D.; Chaljub, E.; Sanabria-Gómez, J. D.

    2017-12-01

    Built-up on top of ancient lake deposits, Mexico City experiences some of the largest seismic site effects in the world. The M7.1 intermediate-depth earthquake of September 19, 2017 (S19) collapsed 43 one-to-ten story buildings in the city close to the western edge of the lake-bed sediments, on top of the geotechnically-known transition zone. In this work we explore the physical reasons explaining such a damaging pattern and the long-lasting strong motion records well-documented from past events by means of new observations and high performance computational modeling. Besides the extreme amplification of seismic waves, duration of intense ground motion in the lake-bed lasts more than three times those recorded in hard-rock a few kilometers away. Different mechanisms contribute to the long lasting motions, such as the regional dispersion and multiple-scattering of the incoming wavefield all the way from the source. However, recent beamforming observations at hard-rock suggest that duration of the incoming field is significantly shorter than the strong shaking in the lake-bed. We show that despite the highly dissipative shallow deposits, seismic energy can propagate long distances in the deep structure of the valley, promoting also a large elongation of motion. Our simulations reveal that the seismic response of the basin is dominated by surface-waves overtones, and that this mechanism increases the duration of ground motion up to 280% and 500% of the incoming wavefield duration at 0.5 and 0.3 Hz, respectively. Furthermore, our results indicate that the damage pattern of the S19 earthquake is most likely due to the propagation of the fundamental mode in the transition zone of the basin. These conclusions contradicts what has been previously stated from observational and modeling investigations, where the basin itself has been discarded as a preponderant factor promoting long and devastating shaking in Mexico City. Reference: Cruz-Atienza, V. M., J. Tago, J. D

  13. Pre-hospitalization, hospitalization, and post-hospitalization costs of patients with neurocysticercosis treated at the Instituto Nacional de Neurologia y Neurocirugia (INNN in Mexico City, Mexico

    Directory of Open Access Journals (Sweden)

    Rachana Bhattarai

    2018-05-01

    Full Text Available ABSTRACT The objective of this study was to estimate the direct costs associated with the diagnosis and treatment of neurocysticercosis (NCC during pre-hospitalization, hospitalization, and post-hospitalization periods for 108 NCC patients treated at the Instituto Nacional de Neurologia y Neurocirugia (INNN in Mexico City, Mexico. Information on clinical manifestations, diagnostic tests, hospitalizations, surgical procedures, prescription medication, and other treatments was collected via medical chart reviews. Uncertain values for costs and frequency of treatments were imputed using bootstrap techniques. The average per-patient pre-hospitalization and hospitalization costs were US$ 257 (95% CI: 185 – 329 and US$ 2,576 (95% CI: 2,244 – 2,908, respectively. Post-hospitalization costs tended to decrease over time, with estimates for the first five years post-hospitalization of US$ 475 (95% CI: 423 – 527, US$ 228 (95% CI: 167 – 288, US$ 157 (95% CI: 111 – 202, US$ 150 (95% CI: 106 – 204, and US$ 91 (95% CI: 27 – 154, respectively. NCC results in a significant economic burden for patients requiring hospitalization, with this burden continuing years post-hospitalization.

  14. [Perception over smoke-free policies amongst bar and restaurant representatives in central Mexico].

    Science.gov (United States)

    Barrientos-Gutiérrez, Tonatiuh; Gimeno, David; Thrasher, James F; Reynales-Shigematsu, Luz Myriam; Amick, Benjamin C; Lazcano-Ponce, Eduardo; Hernández-Ávila, Mauricio

    2010-01-01

    To analyze the perceptions and appreciations over smoke-free environments of restaurant and bar managers from four cities in central Mexico. Managers from 219 restaurants and bars from Mexico City, Colima, Cuernavaca and Toluca were surveyed about smoke-free environments opinions and implementation. Simultaneously, environmental nicotine was monitored. The majority of surveyed managers considered public places should be smoke-free, although more than half were concerned with potential economic loses. Implementation of smoke-free environments was more frequent in Mexico City (85.4%) than in the other cities (15.3% overall), with consequently lower environmental nicotine concentrations. Managers acknowledge the need to create smoke-free environments. Concerns over economic negative effects derived from the prohibition could explain, at least partially, the rejection of this sector towards the implementation of this type of policy.

  15. The Displacement of the Possible: Popular Experience and Gentrification at Historic Center of Mexico City

    Directory of Open Access Journals (Sweden)

    Vicente Moctezuma Mendoza

    2016-09-01

    Full Text Available This paper studies the displacement of popular sectors in the Historic Center of Mexico City as part of the gentrification process in this space. Particularly, it analyzes a form of displacement that the author defines as ‘the displacement in popular horizons of the possible’, and supposes a reinterpretation – from the characteristics of the gentrification processes in Latin America and the anthropologic fieldwork- of the definition of ‘exclusionary displacement’ proposed by Peter Marcuse. Displacement is analyzed through an ethnographic approach to some residential itineraries that account for popular sectors different rooting constructions during the second half of the twentieth century and the review of the permanence or disappearance of such conditions in the contemporary context.

  16. Neonatal vitamin A supplementation associated with increased atopy in girls

    DEFF Research Database (Denmark)

    Aage, S; Kiraly, N; Da Costa, K

    2015-01-01

    randomized controlled trial in Guinea-Bissau. METHODS: In 2002-2004, we randomized 4345 normal birthweight neonates to NVAS (50 000 IU retinyl palmitate) or placebo together with their Bacillus Calmette-Guérin vaccination. In 2013, we visited the 1692 (39%) children now aged 8-10 years who were still living...... in the study area, and 1478 (87%) were found at home. Provided consent, a skin prick test was performed, and history of allergic symptoms was recorded. Associations of NVAS and atopy (defined as skin prick test reaction of ≥3 mm) were analysed using binomial regression. RESULTS: Of the 1430 children...

  17. Characteristics of private abortion services in Mexico City after legalization.

    Science.gov (United States)

    Schiavon, Raffaela; Collado, Maria Elena; Troncoso, Erika; Soto Sánchez, José Ezequiel; Zorrilla, Gabriela Otero; Palermo, Tia

    2010-11-01

    In 2007, first trimester abortion was legalized in Mexico City, and the public sector rapidly expanded its abortion services. In 2008, to obtain information on the effect of the law on private sector abortion services, we interviewed 135 physicians working in private clinics, located through an exhaustive search. A large majority of the clinics offered a range of reproductive health services, including abortions. Over 70% still used dilatation and curettage (D&C); less than a third offered vacuum aspiration or medical abortion. The average number of abortions per facility was only three per month; few reported more than 10 abortions monthly. More than 90% said they had been offering abortion services for less than 20 months. Many women are still accessing abortion services privately, despite the availability of free or low-cost services at public facilities. However, the continuing use of D&C, high fees (mean of $157-505), poor pain management practices, unnecessary use of ultrasound, general anaesthesia and overnight stays, indicate that private sector abortion services are expensive and far from optimal. Now that abortions are legal, these results highlight the need for private abortion providers to be trained in recommended abortion methods and quality of private abortion care improved. Copyright © 2010 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

  18. Vehicle fleet emissions of black carbon, polycyclic aromatic hydrocarbons, and other pollutants measured by a mobile laboratory in Mexico City

    Directory of Open Access Journals (Sweden)

    M. Jiang

    2005-01-01

    Full Text Available Black carbon (BC and polycyclic aromatic hydrocarbons (PAHs are of concern due to their effects on climate and health. The main goal of this research is to provide the first estimate of emissions of BC and particle-phase PAHs (PPAHs from motor vehicles in Mexico City. The emissions of other pollutants including carbon monoxide (CO, oxides of nitrogen (NOx, volatile organic compounds (VOCs, and particulate matter of diameter 2.5 μm and less (PM2.5 are also estimated. As a part of the Mexico City Metropolitan Area field campaign in April 2003 (MCMA-2003, a mobile laboratory was driven throughout the city. The laboratory was equipped with a comprehensive suite of gas and particle analyzers, including an aethalometer that measured BC and a photoionization aerosol sensor that measured PPAHs. While driving through traffic, the mobile lab continuously sampled exhaust plumes from the vehicles around it. We have developed a method of automatically identifying exhaust plumes, which are then used as the basis for calculation of fleet-average emissions. In the approximately 75 h of on-road sampling during the field campaign, we have identified ~30 000 exhaust measurement points that represent a variety of vehicle types and driving conditions. The large sample provides a basis for estimating fleet-average emission factors and thus the emission inventory. Motor vehicles in the Mexico City area are estimated to emit 1700±200 metric tons BC, 57±6 tons PPAHs, 1 190 000±40 000 tons CO, 120 000±3000 tons NOx, 240 000±50 000 tons VOCs, and 4400±400 tons PM2.5 per year, not including cold start emissions. The estimates for CO, NOx, and PPAHs may be low by up to 10% due to the slower response time of analyzers used to measure these species. Compared to the government's official motor vehicle emission inventory for the year 2002, the estimates for CO, NOx, VOCs, and PM2.5 are 38% lower, 23% lower, 27% higher, and 25% higher, respectively. The

  19. 78 FR 42755 - Gulf of Mexico Fishery Management Council; Public Hearings

    Science.gov (United States)

    2013-07-17

    ...: The Gulf of Mexico Fishery Management Council (Council) will hold public hearings for Coastal... through Friday August 15, 2013 at ten locations throughout the Gulf of Mexico. The public hearings will...; Mobile, AL; Corpus Christi and Texas City, TX. Council address: Gulf of Mexico Fishery Management Council...

  20. Final report for "Characterization of Fine Particulate Matter (PM) and secondary PM Precursor Gases in the Mexico City Metropolitan Area"

    Energy Technology Data Exchange (ETDEWEB)

    Prof. Jose-Luis Jimenez

    2009-05-18

    The objectives of this funded project were (a) to further analyze the data collected by our group and collaborators in Mexico City during the MCMA-2003 field campaign, with the goal of further our understanding of aerosol sources and processes; and (b) to deploy several advanced instruments, including the newly developed high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and thermal-denuder (TD), during the MILAGRO/MAX-Mex/MCMA-2006 field campaign, and to analyze those data (together with the 2003 data) to provide additional insights on the formation and transformation of aerosols in the Mexico City area. These goals were addressed in collaboration with our project partners, MIT/Molina Center, and Aerodyne Research. Overall this project was very successful, resulting on 22+ journal papers including six “highly cited papers” and three papers that are the most cited in their respective journals (out of several thousand papers) since the year in which they were published. Multiple discoveries, such as the the underestimation of SOA in urban areas even for short photochemical ages, the demonstration that urban POA is of similar or higher volatility than urban SOA, and the first analysis of organic aerosol elemental composition in real-time have been recently published. Several dozen presentations at major US and international conferences and seminars also acknowledged this grant.

  1. A hybrid method for the estimation of ground motion in sedimentary basins: Quantitative modelling for Mexico City

    International Nuclear Information System (INIS)

    Faeh, D.; Suhadolc, P.; Mueller, S.; Panza, G.F.

    1994-04-01

    To estimate the ground motion in two-dimensional, laterally heterogeneous, anelastic media, a hybrid technique has been developed which combines modal summation and the finite difference method. In the calculation of the local wavefield due to a seismic event, both for small and large epicentral distances, it is possible to take into account the sources, path and local soil effects. As practical application we have simulated the ground motion in Mexico City caused by the Michoacan earthquake of September 19, 1985. By studying the one-dimensional response of the two sedimentary layers present in Mexico City, it is possible to explain the difference in amplitudes observed between records for receivers inside and outside the lake-bed zone. These simple models show that the sedimentary cover produces the concentration of high-frequency waves (0.2-0.5 Hz) on the horizontal components of motion. The large amplitude coda of ground motion observed inside the lake-bed zone, and the spectral ratios between signals observed inside and outside the lake-bed zone, can only be explained by two-dimensional models of the sedimentary basin. In such models, the ground motion is mainly controlled by the response of the uppermost clay layer. The synthetic signals explain the major characteristics (relative amplitudes, spectral ratios, and frequency content) of the observed ground motion. The large amplitude coda of the ground motion observed in the lake-bed zone can be explained as resonance effects and the excitation of local surface waves in the laterally heterogeneous clay layer. Also, for the 1985 Michoacan event, the energy contributions of the three subevents are important to explain the observed durations. (author). 39 refs, 15 figs, 1 tab

  2. Pollution effects on stone benches of the Eagle Warriors Precinct at the Major Temple, Mexico City

    International Nuclear Information System (INIS)

    Miranda, J.; Gallardo, M.L.; Grimaldi, D.M.; Roman-Berrelleza, J.A.; Ruvalcaba-Sil, J.L.; Ontalba Salamanca, M.A.; Morales, J.G.

    1999-01-01

    During Major Temple archaeological site excavations in Downtown Mexico City, the precinct of one of the most important Mexica military caste, the Eagle Warriors, was discovered. The ceremonial enclosure is composed of three rooms surrounded by paintings on 11 stone benches placed against the walls. Nowadays, these paintings and the stones present the effects of different deterioration processes produced by the underground water level, high humidity, and the presence of soil, water, and air pollutants. Ion beam analysis of samples from the benches and wall paintings was performed using PIXE and RBS techniques. Using enrichment factors of elements relative to iron concentrations, possible contamination by sulfur and chlorine salts was found, as well as airborne zinc scavenged by rain

  3. [Population dynamics, urban structure, and production of living space in the metropolitan zone of Mexico City].

    Science.gov (United States)

    Schteingart, M

    1989-01-01

    "In this article, an attempt is made to account for certain trends in the growth and distribution of the population, and in the structuring of living space in the metropolitan zone of Mexico City.... Among the important conclusions of this essay are those having to do with the huge growth of some political-administrative units and the relation of this phenomenon to the practices followed by private realtors, often articulated with the policies and programs set by the State's housing agencies, as well as those that associate urban growth and expansion with the development of habitational spaces within the so-called 'formal' and 'informal' housing sectors." Data are from Mexican censuses and other official sources. (SUMMARY IN ENG) excerpt

  4. The results of the Seismic Alert System of Mexico SASMEX, during the earthquakes of 7 and 19 of September 2017

    Science.gov (United States)

    Espinosa Aranda, J. M., Sr.; Cuellar Martinez, A.

    2017-12-01

    The Seismic Alert System of Mexico, SASMEX began in 1991, is integrated by the seismic alert system of Mexico City and the seismic alert system of Oaxaca. SASMEX has 97 seismic sensors which are distributed in the seismic regions of the Pacific coast and the South of the Trans-Mexican Volcanic Belt of states of Jalisco, Colima, Michoacán, Guerrero, Oaxaca and Puebla. The alert dissemination covers the cities of: Acapulco, Chilpancingo, Morelia, Puebla, Oaxaca, Toluca and Mexico City, reaching the earthquake warnings to more than 25 millions of people. SASMEX has detected correctly more than 5600 earthquakes and warned 156. Mexico City has different alert dissemination systems like several Radio and Tv commercial broadcasters, dedicated radio receivers, EAS-SAME-SARMEX radio receivers and more tha 6700 public loud speakers. The other cities have only some of those systems. The Mw 8.2 Chiapas earthquake on September 7, despite the epicentral distance far of the first seismic detections (more than 180 km) and the low amplitudes of the P waves, the earthquake warning time gave more than 90 seconds to Mexico City before the arrivals of S waves with minor damages to the city in contrast with high damages in towns in the coast. This earthquake offered an opportunity to show the developments and lacks to reduce the risk, such as the need to increase the seismic detection coverage and the earthquake warning dissemination in towns with high seismic vulnerability. The Mw 7.1 Morelos earthquake on September 19 caused thousands of damages and hundreds of deaths and injuries in Mexico City, this earthquake is the second with the most damages after the Mw 8.1 Michoacán earthquake of September 19 on 1985. The earthquake early warning gave 11 seconds after the arrivals of S waves, however the activation occurred few seconds after the P waves arrives to Mexico City, and due to the seismic focus was near to the city, the P waves were felt for the people. The Accelerographic Network

  5. Primary and secondary contributions to aerosol light scattering and absorption in Mexico City during the MILAGRO 2006 campaign

    Directory of Open Access Journals (Sweden)

    G. Paredes-Miranda

    2009-06-01

    Full Text Available A photoacoustic spectrometer, a nephelometer, an aethalometer, and an aerosol mass spectrometer were used to measure at ground level real-time aerosol light absorption, scattering, and chemistry at an urban site located in North East Mexico City (Instituto Mexicano del Petroleo, Mexican Petroleum Institute, denoted by IMP, as part of the Megacity Impact on Regional and Global Environments field experiment, MILAGRO, in March 2006. Photoacoustic and reciprocal nephelometer measurements at 532 nm accomplished with a single instrument compare favorably with conventional measurements made with an aethalometer and a TSI nephelometer. The diurnally averaged single scattering albedo at 532 nm was found to vary from 0.60 to 0.85 with the peak value at midday and the minimum value at 07:00 a.m. local time, indicating that the Mexico City plume is likely to have a net warming effect on local climate. The peak value is associated with strong photochemical generation of secondary aerosol. It is estimated that the photochemical production of secondary aerosol (inorganic and organic is approximately 75% of the aerosol mass concentration and light scattering in association with the peak single scattering albedo. A strong correlation of aerosol scattering at 532 nm and total aerosol mass concentration was found, and an average mass scattering efficiency factor of 3.8 m2/g was determined. Comparisons of photoacoustic and aethalometer light absorption with oxygenated organic aerosol concentration (OOA indicate a very small systematic bias of the filter based measurement associated with OOA and the peak aerosol single scattering albedo.

  6. Primary and secondary contributions to aerosol light scattering and absorption in Mexico City during the MILAGRO 2006 campaign

    Science.gov (United States)

    Paredes-Miranda, G.; Arnott, W. P.; Jimenez, J. L.; Aiken, A. C.; Gaffney, J. S.; Marley, N. A.

    2009-06-01

    A photoacoustic spectrometer, a nephelometer, an aethalometer, and an aerosol mass spectrometer were used to measure at ground level real-time aerosol light absorption, scattering, and chemistry at an urban site located in North East Mexico City (Instituto Mexicano del Petroleo, Mexican Petroleum Institute, denoted by IMP), as part of the Megacity Impact on Regional and Global Environments field experiment, MILAGRO, in March 2006. Photoacoustic and reciprocal nephelometer measurements at 532 nm accomplished with a single instrument compare favorably with conventional measurements made with an aethalometer and a TSI nephelometer. The diurnally averaged single scattering albedo at 532 nm was found to vary from 0.60 to 0.85 with the peak value at midday and the minimum value at 07:00 a.m. local time, indicating that the Mexico City plume is likely to have a net warming effect on local climate. The peak value is associated with strong photochemical generation of secondary aerosol. It is estimated that the photochemical production of secondary aerosol (inorganic and organic) is approximately 75% of the aerosol mass concentration and light scattering in association with the peak single scattering albedo. A strong correlation of aerosol scattering at 532 nm and total aerosol mass concentration was found, and an average mass scattering efficiency factor of 3.8 m2/g was determined. Comparisons of photoacoustic and aethalometer light absorption with oxygenated organic aerosol concentration (OOA) indicate a very small systematic bias of the filter based measurement associated with OOA and the peak aerosol single scattering albedo.

  7. Neonatal immune responses to TLR2 stimulation: Influence of maternal atopy on Foxp3 and IL-10 expression

    Directory of Open Access Journals (Sweden)

    Gold Diane R

    2006-03-01

    Full Text Available Abstract Background Maternal atopic background and stimulation of the adaptive immune system with allergen interact in the development of allergic disease. Stimulation of the innate immune system through microbial exposure, such as activation of the innate Toll-like-receptor 2 (TLR2, may reduce the development of allergy in childhood. However, little is known about the immunological effects of microbial stimulation on early immune responses and in association with maternal atopy. Methods We analyzed immune responses of cord blood mononuclear cells (CBMC from 50 healthy neonates (31 non-atopic and 19 atopic mothers. Cells were stimulated with the TLR2 agonist peptidoglycan (Ppg or the allergen house dust mite Dermatophagoides farinae (Derf1, and results compared to unstimulated cells. We analyzed lymphocyte proliferation and cytokine secretion of CBMC. In addition, we assessed gene expression associated with T regulatory cells including the transcription factor Foxp3, the glucocorticoid-induced TNF receptor (GITR, and the cytotoxic lymphocyte antigen 4 (CTLA4. Lymphocyte proliferation was measured by 3H-Thymidine uptake, cytokine concentrations determined by ELISA, mRNA expression of T cell markers by real-time RT-PCR. Results Ppg stimulation induced primarily IL-10 cytokine production, in addition to IFN-γ, IL-13 and TNF-α secretion. GITR was increased following Ppg stimulation (p = 0.07. Ppg-induced IL-10 production and induction of Foxp3 were higher in CBMC without, than with maternal atopy (p = 0.04, p = 0.049. IL-10 production was highly correlated with increased expression of Foxp3 (r = 0.53, p = 0.001, GITR (r = 0.47, p = 0.004 and CTLA4 (r = 0.49, p = 0.003, independent of maternal atopy. Conclusion TLR2 stimulation with Ppg induces IL-10 and genes associated with T regulatory cells, influenced by maternal atopy. Increased IL-10 and Foxp3 induction in CBMC of non-atopic compared to atopic mothers, may indicate an increased capacity to

  8. Management of a Dog with Poorly Regulated Diabetes Mellitus, Chronic Pancreatitis, and Suspected Atopy with Cyclosporine

    Directory of Open Access Journals (Sweden)

    Jörg M. Steiner

    2012-01-01

    Full Text Available A 3-year-and-9-months old male neutered Bichon Frise was presented for a second opinion for diabetes mellitus, weight loss, pruritus, and loss of hair. During further work-up, the dog was diagnosed with uncontrolled diabetes mellitus and concurrent diagnoses of pancreatitis and atopy were also suspected. Multiple adjustments of insulin therapy did not improve control of diabetes mellitus. Also, a variety of different treatments failed to improve pruritus. The dog was seen by a veterinary dermatologist who further suspected atopy and started treatment with cyclosporine. Pruritus improved and coincidentally serum Spec cPL and fructosamine concentrations normalized after therapy, suggesting the possibility that cyclosporine may have controlled pancreatic inflammation and improved control of diabetes mellitus. This case report would suggest that further research into autoimmunity in dogs with chronic pancreatitis is warranted. Also, a controlled study is needed and in progress before the use of cyclosporine in dogs with chronic pancreatitis or a subgroup thereof can be advocated.

  9. The San Luis Project: An Attempt to Decentralize Physics in Mexico

    Science.gov (United States)

    Will, T. A.; Valladares, A. A.

    1976-01-01

    Described is a project being conducted by the Physics Institute of the University of San Luis Potori, Mexico, in order to avoid concentrating physics education and research activities in Mexico City. (SL)

  10. Breast cancer quality of life evaluation in Mexican Women at La Raza Hospital, Mexico City: A preliminary approach

    Directory of Open Access Journals (Sweden)

    Jacobo Alejandro Gómez-Rico

    2008-11-01

    Full Text Available Jacobo Alejandro Gómez-Rico1, Marina Altagracia-Martínez1, Jaime Kravzov-Jinich1, Rosario Cárdenas-Elizalde1, Juan Carlos Hinojosa-Cruz2, Consuelo Rubio-Poo31Departments of Biological Systems and Healthcare, Biological and Health Sciences Division (DCBS, Universidad Autónoma Metropolitana–Xochimilco (UAM-X, Xochimilco, Mexico; 2La Raza Hospital of the Mexican Social Security Institute (IMSS, Mexico City, Mexico; 3Universidad Nacional Autónoma de México (UNAM, Faculty of Professional Studies, Zaragoza (FES-Zaragoza, MexicoAbstract: Breast cancer (BC is the second leading cause of death among Mexican women over 40 years of age. This study aimed to identify and examine the effects of cancer stage and surgical treatment on the quality of life (QOL of Mexican women with early stage breast cancer (ESBC treated with either modified radical mastectomy (MRM or breast conservative surgery (BCS, plus adjuvant chemotherapy. The QLQ-C30 and QLQ BR-23 questionnaires were used to assess QOL. Sociodemographic characteristics and clinical factors of 102 women with early BC were also evaluated; analysis of variance (ANOVA was performed and a statistical significance of p < 0.05 was assumed. Most women were of reproductive age. Meaningful differences in QOL as a result of surgical treatment, in women receiving BCS compared with those receiving MRM, were limited to body image. We conclude that MRM and BCS are essentially equivalent choices in terms of QOL, with the exception of the impact on body image. In general, women who received BCS had a better perceived QOL.Keywords: quality of life, breast cancer, Mexican women

  11. Patient characteristics and service trends following abortion legalization in Mexico City, 2007-10.

    Science.gov (United States)

    Mondragón y Kalb, Manuel; Ahued Ortega, Armando; Morales Velazquez, Jorge; Díaz Olavarrieta, Claudia; Valencia Rodríguez, Jorge; Becker, Davida; García, Sandra G

    2011-09-01

    Legal abortion services have been available in public and private health facilities in Mexico City since April 2007 for pregnancies of up to 12 weeks gestation. As of January 2011, more than 50,000 procedures have been performed by Ministry of Health hospitals and clinics. We researched trends in service users' characteristics, types of procedures performed, post-procedure complications, repeat abortions, and postabortion uptake of contraception in 15 designated hospitals from April 2007 to March 2010. The trend in procedures has been toward more medication and manual vacuum aspiration abortions and fewer done through dilation and curettage. Percentages of post-procedure complications and repeat abortions remain low (2.3 and 0.9 percent, respectively). Uptake of postabortion contraception has increased over time; 85 percent of women selected a method in 2009-10, compared with 73 percent in 2007-08. Our findings indicate that the Ministry of Health's program provides safe services that contribute to the prevention of repeat unintended pregnancies.

  12. Street Laborers in Mexico City: Survival, Negotiation and Urban Poverty during the Revolution

    Directory of Open Access Journals (Sweden)

    Mario Barbosa Cruz

    2010-10-01

    Full Text Available This work analyzes the survival strategies –based on negotiations with local and federal authorities– used by street laborers to face urban  poverty  in the Mexican capital during  the first three decades of the 20th  century. in general terms, I seek to describe how people who sought their sustenance in the streets, and who were not workers or craftsmen, managed to survive. By exploring their social relations,  I seek to foreground the increasing visibility of these actors in their interaction  with the authorities  during  that period, particularly with the employees of revolutionary governments. The paper, which is based on a more extensive research about street labor in Mexico City, turns to a number  of theoretical proposals  that consider reciprocal exchange networks as the base for survival during critical times such as the general supply crisis in the decade of the Revolution.

  13. An Approach to Litter Generation and Littering Practices in a Mexico City Neighborhood

    Directory of Open Access Journals (Sweden)

    Cecilia E. Muñoz-Cadena

    2012-08-01

    Full Text Available Urban litter is generated by human societies everywhere. Some litter is recyclable waste. In this study, the acronym RMSW is used to refer to recyclable municipal solid waste generated in streets. Public attitude towards RMSW generation, generators’ perceptions, and quantification of RMSW in streets were examined in a Mexico City neighborhood, where litter presence causes major environmental problems affecting the population year after year. Interviews with neighborhood residents and item counts were carried out from 2010 to 2011. In all, 58% of interviewees reported generating RMSW at variable frequencies while 42% said they did not generate this kind of waste. Laziness, lack of vigilance by municipal authorities, no litter bins in streets, and imitation were the main causes identified by interviewees as reasons for littering. Potential litter generators may be of any age, educational level or income. Interviewees’ perception of RMSW generation was compared with item counts in the neighborhood studied.

  14. Heavy metals in urban road sediments of the city of Mexicali, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Meza T, L. M.; Quintero N, M.; Valdez S, B., E-mail: montserrat.meza@uabc.edu.mx [Universidad Autonoma de Baja California, Facultad de Ingenieria, Unidad Mexicali, 21280 Mexicali, Baja California (Mexico)

    2014-07-01

    A chemical sediment characterization of urban streets in the city of Mexicali at Baja California, Mexico, was conducted to estimate the most important heavy metals along with PM{sub 10} and PM{sub 2.5} emission factors to evaluate the amount of particulate matter. Sampling was conducted from february to may 2008, following a random statistical design, in 60 sampling sites on a geo referenced map at UTM 11 North. Samples were identified and treated in the laboratory, after undergoing cracking, drying, sieving, and weighing to get less than 75 microns of sediment by using a dry method. Twelve representative samples were selected for chemical characterization using energy dispersive X-rays (EDX) and inductively coupled plasma (Icp). The most significant elements found were zinc (Zn) and lead (Pb) with concentrations ranging from 1 to 15 mg/kg and 11 to 25 mg/kg, respectively, corresponding to the third classification from a reference set of a study by US EPA in 1981-1997. The clay type known as illite was identified in four specific samples. (author)

  15. Sweetened beverages intake, hyperuricemia and metabolic syndrome. The Mexico City Diabetes Study.

    Directory of Open Access Journals (Sweden)

    Rubén López-Molina

    2013-11-01

    Full Text Available Objective. To determine prevalence of hyperuricemia and its relation with intake of sweetened beverages (SB and metabolic syndrome (MS in low income urban Mexican population. Materials and methods. A cross-sectional analysis of The Mexico City Diabetes Study, a prospective population-based investigation (1 173 participants was performed. We used logistic regression, adjusted by pertinent variables. We determined prevalence of hyperuricemia and explored associations of uric acid levels with MS and intake of SB. Results. Prevalence of hyperuricemia was 26.5 and 19.8% in males and females respectively. In an adjusted multivariate model, body mass index, waist circumference, and triglyceride were higher as uric acid quartiles increased (p menor que 0.005-0.001. The odds ratio for MS was 1.48 for 3rd uric acid quartile and 2.03 for 4th quartile. Higher consumption of SB was associated with higher uric acid levels (p menor que 0.001. Conclusion. Prevalence of hyperuricemia is high. Potential association with intake of SB, resulting in metabolic alterations should be considered.

  16. Association of atopy and tentative diagnosis of skin cancer - results from occupational skin cancer screenings.

    Science.gov (United States)

    Schäfer, I; Mohr, P; Zander, N; Fölster-Holst, R; Augustin, M

    2017-12-01

    The relationship between atopic conditions and carcinoma of the skin has been described inconsistently. Population-based data providing information on atopic diseases as well as on skin cancer are sparse. To determine the correlation between atopy and prevalence of precanceroses, non-melanoma skin cancer and malignant melanoma (MM), while taking into account known risk factors for skin cancer. Data from occupational skin cancer screenings were analysed in a cross-sectional study. Dermatologists performed whole body examinations and collected medical histories. Subjects comprised all employees (16-70 years) examined from 2006 to 2014. 'Atopy' was defined by clinical screening diagnosis and/or by participant-reported, pre-existing atopic dermatitis, allergic asthma or other specified allergies confirmed by a physician. Tentative screening diagnoses of skin cancer related to actinic keratosis, basal cell carcinoma and malignant melanoma. The study cohort comprised 90 265 employees (mean age 43 ± 11 years, 58.5% male), 30.7% of whom were ever diagnosed with an atopic disease. Persons with atopic conditions recorded in their medical history and at the time of screening had a significantly lower prevalence of actinic keratosis (AK), basal cell carcinoma (BCC) and MM. After controlling for age, sex and relevant risk factors (skin type, childhood sun burns), atopy remained significantly protective against BCC (OR 0.77) and MM (OR 0.53). Design limitations of the study include that all findings of skin cancer were based on clinical examination only and must therefore be considered tentative diagnoses. Furthermore, owing to the cross-sectional study design, causal pathways cannot be proven. However, analyses of data from such a large and general population-based cohort afford valuable insights into the relationship between atopic diseases and skin cancer. They provide the grounds for prospective cohort studies to evaluate and dissect the underlying mechanism. © 2017

  17. Lifestyle-Related Factors and Atopy in Seven Danish Population-Based Studies from Different Time Periods

    DEFF Research Database (Denmark)

    Skaaby, Tea; Husemoen, Lise Lotte Nystrup; Thuesen, Betina Heinsbæk

    2015-01-01

    drinkers versus light drinkers: 1.15; 95% CI: 1.04, 1.27), never smoking (OR for current versus never smokers: 0.73; 95% CI: 0.67, 0.80), and higher educational level (OR for educated versus uneducated: 1.27; 95% CI: 1.15, 1.41). Atopy was not associated with blood pressure, serum total cholesterol...

  18. A representative survey of indoor radon in the sixteen regions in Mexico City.

    Science.gov (United States)

    Espinosa, G; Gammage, R B

    2003-01-01

    Mexico City, also called Federal District, covers an area of 1504 km(2), and has more than 8 million inhabitants. It is located more than 2200 m above sea level in a zone of high seismic activity, and founded on an ancient lake. At present it is one of the most crowded and contaminated cities in the world, with thermal inversions. Chemical contaminants and aerosol particles in the environmental air are high most of the year. Due to these geological, environmental and socioeconomic conditions, Federal District presents very peculiar characteristics, which are important for understanding the distribution and measurements of indoor radon concentration. In this work the results of 3 year (1998-2000) measurements of indoor radon levels in the Federal District are presented. For the detector distribution and measurements, the actual political administrative divisions of the Federal District, consisting of 16 very well defined zones, was used. Nuclear track detection methodology was selected for the measurement, with a passive device close-end-cup system with CR-39 (Lantrack) polycarbonate as the detection material, with one step chemical etching, following a very well established protocol developed at the Instituto de Física, UNAM. Calibration was carried out at the Oak Ridge National Laboratory, and verification at the Instituto de Física chamber. The results show that the arithmetical mean values of the indoor radon concentration for each region of the Federal District follow a non-homogenous distribution.

  19. A representative survey of indoor radon in the sixteen regions in Mexico City

    International Nuclear Information System (INIS)

    Espinosa, G.; Gammage, R.B.

    2003-01-01

    Mexico City, also called Federal District, covers an area of 1504 km 2 , and has more than 8 million inhabitants. It is located more than 2200 m above sea level in a zone of high seismicactivity, and founded on an ancient lake. At present it is one of the most crowded and contaminated cities in the world with thermal inversions. Chemical contaminants and aerosol particles in the environmental air are high most of the year. Due to these geological, environmental and socioeconomic conditions, Federal District presents very peculiar characteristics, which are important for understanding the distribution and measurement zone of high seismic activity of indoor radon concentration. In this work the results of 3 year (1998-2000) measurements of indoor radon levels in the Federal District are presented. For the detector distribution and measurements, the actual political administrative divisions of the Federal District, consisting of 16 very well defined zones was used. Nuclear track detection methodology was selected for the measurement, with a passive device close-end-cup system with CR-39 (Lantrack(r)) polycarbonate as the detection material, with one step chemical etching, following a very well established protocol developed at the Instituto de Fisica, UNAM. Calibration was carried out at the Oak Ridge National Laboratory, and verification at the Instituto de Fisica chamber. The results show that the arithmetical mean values of the indoor radon concentration for each region of the Federal District follow a non-homogeneous distribution. (author)

  20. Sociodemographic differences among HIV-positive and HIV-negative recently pregnant women in Mexico City: A case-control study.

    Science.gov (United States)

    Aguilar-Zapata, Daniel; Piñeirúa-Menéndez, Alicia; Volkow-Fernández, Patricia; Rodríguez-Zulueta, Patricia; Ramos-Alamillo, Ubaldo; Cabrera-López, Teresita; Martin-Onraet, Alexandra

    2017-07-01

    National HIV preventive programs in Mexico focus on high-risk groups that do not consider women, apart from prenatal screening. Nonetheless, the epidemic in women is growing, and there is a need to better understand sociodemographic factors in women living with HIV (WLH). We performed a case-control study in Mexico City, including HIV+ and HIV- women with a recent pregnancy to compare their sociodemographic characteristics and describe the circumstances of diagnosis in HIV+ women, as well as prenatal screening frequency in both groups. Fifty cases and 102 controls were interviewed. HIV+ women were more frequently the only economic support of the family (20% vs 0%, P history of sexually transmitted diseases, substance abuse, history of violence, and civil status. Only 6% of controls were tested for HIV during prenatal follow-up. WLH in this study faced important social vulnerability. Targeting women living in these social contexts might increase early diagnosis and could tailor HIV prevention strategies. Prenatal coverage needs to be improved and should represent a national priority.

  1. A Cross-Sectional Study of Prisoners in Mexico City Comparing Prevalence of Transmissible Infections and Chronic Diseases with That in the General Population.

    Science.gov (United States)

    Bautista-Arredondo, Sergio; González, Andrea; Servan-Mori, Edson; Beynon, Fenella; Juarez-Figueroa, Luis; Conde-Glez, Carlos J; Gras, Nathalie; Sierra-Madero, Juan; Lopez-Ridaura, Ruy; Volkow, Patricia; Bertozzi, Stefano M

    2015-01-01

    To describe patterns of transmissible infections, chronic illnesses, socio-demographic characteristics and risk behaviors in Mexico City prisons, including in comparison to the general population, to identify those currently needing healthcare and inform policy. A cross-sectional study among 17,000 prisoners at 4 Mexico City prisons (June to December 2010). Participation was voluntary, confidential and based on informed consent. Participants were tested for HIV, Hepatitis B & C, syphilis, hypertension, obesity, and, if at risk, glucose and cholesterol. A subset completed a questionnaire on socio-demographic characteristics and risk behaviors. Positive results were delivered with counseling and treatment or referral. 76.8% (15,517/20,196) of men and 92.9% (1,779/1,914) of women participated. Complete data sets were available for 98.8%. The following prevalence data were established for transmissible infections: HIV 0.7%; syphilis: Anti-TP+/VDRL+ 2.0%; Hepatitis B: HBcAb 2.8%, HBsAg 0.15%; Anti-HCV 3.2%. Obesity: 9.5% men, 33.8% women. Compared with national age- and sex-matched data, the relative prevalence was greater for HIV and syphilis among women, HIV and Hepatitis C in men, and all infections in younger participants. Obesity prevalence was similar for women and lower among male participants. The prevalence of previously diagnosed diabetes and hypertension was lower. Questionnaire data (1,934 men, 520 women) demonstrated lower educational levels, increased smoking and substance use compared to national data. High levels of non-sterile tattooing, physical abuse and histories of sexual violence were found. The study identified that health screening is acceptable to Mexico City prisoners and feasible on a large-scale. It demonstrated higher prevalence of HIV and other infections compared to national data, though low rates compared to international data. Individual participants benefited from earlier diagnosis, treatment and support. The data collected will also

  2. A Cross-Sectional Study of Prisoners in Mexico City Comparing Prevalence of Transmissible Infections and Chronic Diseases with That in the General Population.

    Directory of Open Access Journals (Sweden)

    Sergio Bautista-Arredondo

    Full Text Available To describe patterns of transmissible infections, chronic illnesses, socio-demographic characteristics and risk behaviors in Mexico City prisons, including in comparison to the general population, to identify those currently needing healthcare and inform policy.A cross-sectional study among 17,000 prisoners at 4 Mexico City prisons (June to December 2010. Participation was voluntary, confidential and based on informed consent. Participants were tested for HIV, Hepatitis B & C, syphilis, hypertension, obesity, and, if at risk, glucose and cholesterol. A subset completed a questionnaire on socio-demographic characteristics and risk behaviors. Positive results were delivered with counseling and treatment or referral.76.8% (15,517/20,196 of men and 92.9% (1,779/1,914 of women participated. Complete data sets were available for 98.8%. The following prevalence data were established for transmissible infections: HIV 0.7%; syphilis: Anti-TP+/VDRL+ 2.0%; Hepatitis B: HBcAb 2.8%, HBsAg 0.15%; Anti-HCV 3.2%. Obesity: 9.5% men, 33.8% women. Compared with national age- and sex-matched data, the relative prevalence was greater for HIV and syphilis among women, HIV and Hepatitis C in men, and all infections in younger participants. Obesity prevalence was similar for women and lower among male participants. The prevalence of previously diagnosed diabetes and hypertension was lower. Questionnaire data (1,934 men, 520 women demonstrated lower educational levels, increased smoking and substance use compared to national data. High levels of non-sterile tattooing, physical abuse and histories of sexual violence were found.The study identified that health screening is acceptable to Mexico City prisoners and feasible on a large-scale. It demonstrated higher prevalence of HIV and other infections compared to national data, though low rates compared to international data. Individual participants benefited from earlier diagnosis, treatment and support. The data collected

  3. Frequency of viruses associated with acute respiratory infections in children younger than five years of age at a locality of Mexico City

    Directory of Open Access Journals (Sweden)

    C Cabello

    2006-02-01

    Full Text Available A locality in the district of Tlalpan, Mexico City, was selected in order to identify the viral agents in children younger than 5 years of age with acute respiratory infection (ARI. A total of 300 children were randomly selected and were included in this study for a period of 13 months. During this period nasopharyngeal exudates were collected for the isolation of viral agents. Monoclonal fluorescent antibodies were used for viral identification after cell culture. Viral infection was detected in 65% of the specimens. The respiratory syncytial virus (RSV was the most common virus agent detected. Children required an average of two consultations during the study period. Two high incidence peaks were observed, one during the summer and the other during winter; the most frequent viruses during these seasons were influenza A and RSV, respectively. The largest number of viruses was isolated in the group of children between 1 and 2 years of age and in the group between 4 and 5 years of age. This study demonstrated the presence of ARI and of different viruses in a period of 13 months, as well as the most frequent viruses in children younger than 5 years of age from a community of Mexico City.

  4. Effect of hydrocarbons and nitrogen oxides on ozone formation in smog chambers exposed to solar irradiance of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval F, J; Marroquin de la R, O; Jaimes L, J. L; Zuniga L, V. A; Gonzalez O, E; Guzman Lopez-Figueroa, F [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

    2001-01-01

    Outdoor smog chambers experiments were performed on air to determine the answer of maximum ozone levels, to changes in the initial hydrocarbons, HC, and nitrogen oxide NO{sub x}. These captive-air experiments under natural irradiation were carried out. Typically, eight chambers were filled with Mexico city air in the morning. In some of those chambers, the initial HC and/or Nox concentrations were varied by {+-}25% to {+-}50% by adding various combinations of a mixture of HC, clean air, or NO{sub x} (perturbed chambers). The O{sub 3} and NO{sub x} concentration in each chamber was monitored throughout the day to determine O{sub 3} (max). The initial HC and NO{sub x} concentration effects were determined by comparing the maximum ozone concentrations measured in the perturbed and unperturbed chambers. Ozone isopleths were constructed from the empirical model obtained of measurements of the eight chambers and plotted in a graph whose axe were the initial HC and NO{sub x} values. For the average initial conditions that were measured in Mexico City, it was found that the most efficient strategy to reduce the maximum concentration of O{sub 3} is the one that reduces NO{sub x}. [Spanish] Se realizaron experimentos de camaras de esmog con el aire de la ciudad de Mexico para determinar las respuestas de los niveles maximos de ozono a los cambios en las concentraciones iniciales de hidrocarburos, HC y oxido de nitrogeno, NO{sub x}. Por lo general, se llenaron 8 bolsas con aire matutino de la Ciudad de Mexico. En algunas camaras, las concentraciones iniciales fueron cambiadas de 25% a 50%, anadiendo varias concentraciones de una mezcla de HC, aire limpio y/o NO{sub x}. La concentracion de O{sub 3} y NO{sub x}, en cada camara, fueron monitoreadas a lo largo del dia para determinar el maximo de O{sub 3}. El efecto de los HC y el NO{sub x} fue determinado por comparacion del maximo de ozono formado en las camaras, que fueron perturbadas por adicion o reduccion de HC y/o Nox

  5. Evidence of increasing sedentarism in Mexico City during the last decade: Sitting time prevalence, trends, and associations with obesity and diabetes.

    Science.gov (United States)

    Medina, Catalina; Tolentino-Mayo, Lizbeth; López-Ridaura, Ruy; Barquera, Simón

    2017-01-01

    Sedentary behaviors such as sitting time are associated with obesity and diabetes independently of total reported physical activity. This study aimed to describe the current sitting time/day prevalence and trends and to examine the association of sitting time with sociodemographic and clinical variables in Mexico City. Two cross-sectional representative surveys in Mexico City were used for this analysis (2006: n = 1148 and 2015: n = 1329). Sedentary behavior questions from the International Physical Activity Questionnaire included time spent sitting on a weekday in the last week or on a Wednesday. Sitting time /day was divided into deciles, and participants in the highest decile (≥ 420 minutes/day) were classified within the high sitting category; others were classified in the low sitting time category. Multivariate logistic regression was used to evaluate the associations of sitting time with sociodemographic and clinical indicators, controlling for confounders and testing for potential interactions. A total of 13.7% (2006) and 14.8% (2015) adults were classified in the highest sitting time category (≥ 420 minutes/day). There was a significant increase in the average sitting time/day between the surveys (216.0 minutes in 2006 vs. 233.3 minutes in 2015, p obesity (OR = 2.37, 95% CI: 1.11, 5.09) and those with high glucose levels (survey finding) (OR = 2.34, 95% CI: 1.04, 5.25) were more likely to report sitting time in the highest category. Sitting time/day prevalence increased 8%, and average daily sitting minutes significantly increased by 8.2% (18 minutes) in the nine-year study period (2006-2015). Current public health policies should consider strategies not only for increasing physical activity levels, but also for reducing sitting time/day among the population as a measure to fight the growing epidemic of obesity and diabetes in Mexico.

  6. ADVERSE IMPACT OF HOME DAMPNESS AND LENGTH OF RESIDENCE ON ATOPY AND LUNG FUNCTION AMONG CHILDREN IN EL PASO, TEXAS, USA

    Science.gov (United States)

    The El Paso Children's Health Study examined ambient exposures to motor vehicle emissions and their effect on the prevalence of allergy and asthma among children living in a major United States-Mexico border city. In the spring of 2001, the parents of all fourth and fifth grad...

  7. Dietary intake, lung function and airway inflammation in Mexico City school children exposed to air pollutants

    Directory of Open Access Journals (Sweden)

    Díaz-Sánchez David

    2009-12-01

    Full Text Available Abstract Introduction Air pollutant exposure has been associated with an increase in inflammatory markers and a decline in lung function in asthmatic children. Several studies suggest that dietary intake of fruits and vegetables might modify the adverse effect of air pollutants. Methods A total of 158 asthmatic children recruited at the Children's Hospital of Mexico and 50 non-asthmatic children were followed for 22 weeks. Pulmonary function was measured and nasal lavage collected and analyzed every 2 weeks. Dietary intake was evaluated using a 108-item food frequency questionnaire and a fruit and vegetable index (FVI and a Mediterranean diet index (MDI were constructed. The impact of these indices on lung function and interleukin-8 (IL-8 and their interaction with air pollutants were determined using mixed regression models with random intercept and random slope. Results FVI was inversely related to IL-8 levels in nasal lavage (p 1 (test for trend p 1 and FVC as was with MDI and ozone for FVC. No effect of diet was observed among healthy children. Conclusion Our results suggest that fruit and vegetable intake and close adherence to the Mediterranean diet have a beneficial effect on inflammatory response and lung function in asthmatic children living in Mexico City.

  8. The role of feral mammals on wildlife infectious disease prevalence in two nature reserves within Mexico City limits.

    Science.gov (United States)

    Suzán, Gerardo; Ceballos, Gerardo

    2005-09-01

    Wild and feral medium-sized mammals were live trapped at two natural protected areas within the Mexico City limits to determine antibody prevalence for the most common infectious diseases (rabies, toxoplasmosis, and canine parvovirus) in dogs and cats. Mammals were trapped during the dry (March-April) and rainy seasons (July-August) of 1996 and 1997. A total of 68 individuals were captured, representing 8 species: opossums (Didelphis virginiana), ringtails (Bassariscus astutus), spotted skunks (Spilogale gracilis), weasels (Mustela frenata), rock squirrels (Spermophilus variegatus), Mexican gray squirrels (Sciurus aureogaster), feral cats (Felis catus), and feral dogs (Canis familiaris). There was marked seroprevalence for parvovirus (86.6%) and lower seroprevalences for both toxoplasma (23.9%) and rabies (17.9%). There were no significant prevalence differences among mammals in both protected areas, which were of contrasting size and isolation (i.e., small and isolated versus large and nonisolated). We suggest that high seroprevalence of these three infectious agents in wild mammals is a result of the high densities of feral dogs and cats in the two areas sampled. Feral dogs are able to maintain the infectious agents in these localities regardless of the protected area size and isolation. However, the native mammals of the small and isolated reserve are more vulnerable to infectious diseases because of small population size and genetic bottlenecks. Our results indicate that natural areas in and around Mexico City are a refugium for latent infectious agents, several of which are zoonotic. These findings suggest that conservation measures, such as eradication of feral mammals and vaccination programs, in the protected areas and surrounding areas could be beneficial.

  9. Relationship of blood and bone lead to menopause and bone mineral density among middle-age women in Mexico City.

    Science.gov (United States)

    Garrido Latorre, Francisco; Hernández-Avila, Mauricio; Tamayo Orozco, Juan; Albores Medina, Carlos A; Aro, Antonio; Palazuelos, Eduardo; Hu, Howard

    2003-04-01

    To describe the relationship of blood lead levels to menopause and bone lead levels, we conducted a cross-sectional study on 232 pre- or perimenopausal (PreM) and postmenopausal (PosM) women who participated in an osteoporosis-screening program in Mexico City during the first quarter of 1995. Information regarding reproductive characteristics and known risk factors for blood lead was obtained using a standard questionnaire by direct interview. The mean age of the population was 54.7 years (SD = 9.8), with a mean blood lead level of 9.2 microg/dL (SD = 4.7/dL) and a range from 2.1 to 32.1 microg/dL. After adjusting for age and bone lead levels, the mean blood lead level was 1.98 microg/dL higher in PosM women than in PreM women (p = 0.024). The increase in mean blood lead levels peaked during the second year of amenorrhea with a level (10.35 microg/dL) that was 3.51 microg/dL higher than that of PreM women. Other important predictors of blood lead levels were use of lead-glazed ceramics, schooling, trabecular bone lead, body mass index, time of living in Mexico City, and use of hormone replacement therapy. Bone density was not associated with blood lead levels. These results support the hypothesis that release of bone lead stores increases during menopause and constitutes an internal source of exposure possibly associated with health effects in women in menopause transition.

  10. Transportation energy use in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sheinbaum, C.; Meyers, S.; Sathaye, J.

    1994-07-01

    This report presents data on passenger travel and freight transport and analysis of the consequent energy use in Mexico during the 1970--1971 period. We describe changes in modal shares for passenger travel and freight transport, and analyze trends in the energy intensity of different modes. We look in more detail at transportation patterns, energy use, and the related environmental problems in the Mexico City Metropolitan Area, and also discuss policies that have been implemented there to reduce emissions from vehicles.

  11. Elemental contents determination in two different zones of Mexico City on the 1987-88 and 1994-95 winters

    International Nuclear Information System (INIS)

    Diaz G, R.V.

    1996-01-01

    During the 1987-1988 and 1994-1995 winters, there were taken samples of aerosols in Mexico City, in two different places, using an integral type of sampler which determines the total amount of suspended particulates; these samples were analyzed by the multi-element analysis technique called PIXE (Proton Induced X-ray Emission). One of the sites corresponds to the Alvaro Obregon area and the other to the Azcapotzalco area (a place near to the18 de Marzo Refinery). There were determined 16 elements, heavy metals, whose concentrations show differences for both sites and periods, standing out for this study the behavior of S, V and Pb. (Author)

  12. Climbing in the high volcanoes of central Mexico

    Science.gov (United States)

    Secor, R. J.

    1984-01-01

    A chain of volcanoes extends across central Mexico along the 19th parallel, a line just south of Mexico City. The westernmost of these peaks is Nevado de Colima at 4,636 feet above sea level. A subsidiary summit of Nevado de Colima is Volcan de Colima, locally called Fuego (fire) it still emits sulphurous fumes and an occasional plume of smoke since its disastrous eruption in 1941. Parictuin, now dormant, was born in the fall of 1943 when a cornfield suddenly erupted. Within 18 months, the cone grew more than 1,700 feet. Nevado de Toluca is a 15,433-foot volcanic peak south of the city of Toluca. Just southeast of Mexico City are two high volcanoes that are permanently covered by snow: Iztaccihuatl (17,342 fet) and Popocatepetl (17,887 feet) Further east is the third highest mountain in North America: 18,700-foot Citlateptl, or El Pico de Orizaba. North of these high peaks are two volcanoes, 14, 436-foot La Malinche and Cofre de Perote at 14,048 feet. This range of mountains is known variously as the Cordillera de Anahuac, the Sierra Volcanica Transversal, or the Cordillera Neovolcanica. 

  13. The oxidative potential and biological effects induced by PM{sub 10} obtained in Mexico City and at a receptor site during the MILAGRO Campaign

    Energy Technology Data Exchange (ETDEWEB)

    Quintana, Raul [Instituto Nacional de Cancerologia, Mexico City (Mexico); Serrano, Jesus [Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Mexico City (Mexico); Gomez, Virginia [Instituto de Quimica, Universidad Nacional Autonoma de Mexico, Mexico City (Mexico); Foy, Benjamin de [Earth and Atmospheric Sciences, Saint Louis University, St. Louis, MO (United States); Miranda, Javier [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Mexico City (Mexico); Garcia-Cuellar, Claudia [Instituto Nacional de Cancerologia, Mexico City (Mexico); Vega, Elizabeth [Instituto Mexicano del Petroleo, Mexico City (Mexico); Vazquez-Lopez, Ines [Instituto Nacional de Cancerologia, Mexico City (Mexico); Molina, Luisa T. [Molina Center for Energy and the Environment, CA (United States); Massachusetts Institute of Technology, Cambridge, MA (United States); Manzano-Leon, Natalia [Instituto Nacional de Cancerologia, Mexico City (Mexico); Rosas, Irma [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Mexico City (Mexico); Osornio-Vargas, Alvaro R., E-mail: osornio@ualberta.ca [Instituto Nacional de Cancerologia, Mexico City (Mexico); Department of Paediatrics, University of Alberta, 1048 RTF, 8308 114 St, Edmonton, AB T6G 2V2 (Canada)

    2011-12-15

    As part of a field campaign that studied the impact of Mexico City pollution plume at the local, sub-regional and regional levels, we studied transport-related changes in PM{sub 10} composition, oxidative potential and in vitro toxicological patterns (hemolysis, DNA degradation). We collected PM{sub 10} in Mexico City (T{sub 0}) and at a suburban-receptor site (T{sub 1}), pooled according to two observed ventilation patterns (T{sub 0} {yields} T{sub 1} influence and non-influence). T{sub 0} samples contained more Cu, Zn, and carbon whereas; T{sub 1} samples contained more of Al, Si, P, S, and K (p < 0.05). Only SO{sub 4}{sup -2} increased in T{sub 1} during the influence periods. Oxidative potential correlated with Cu/Zn content (r = 0.74; p < 0.05) but not with biological effects. T{sub 1} PM{sub 10} induced greater hemolysis and T{sub 0} PM{sub 10} induced greater DNA degradation. Influence/non-influence did not affect oxidative potential nor biological effects. Results indicate that ventilation patterns had little effect on intrinsic PM{sub 10} composition and toxicological potential, which suggests a significant involvement of local sources. - Highlights: > Transport-related changes in PM{sub 10} composition, oxidative potential and in vitro toxicity were studied. > Cu, Zn, and carbon levels were predominant in urban PM{sub 10}; receptor site PM{sub 10} was rich in soil elements. > SO{sub 4}{sup -2} was the only component increased in PM{sub 10} from the receptor during the influence periods. > PM{sub 10} oxidative potential correlates with Cu/Zn content but not with studied biological effects. > Ventilation patterns had little effect on PM{sub 10} composition and toxicity. - Mexico City ventilation patterns had little effect on the intrinsic PM{sub 10} composition and toxicological potential, which suggests a significant involvement of local sources as opposed to downwind transport.

  14. Stress from an administrative perspective in public transport drivers in Mexico City: Minibus and metrobus

    Directory of Open Access Journals (Sweden)

    Fernando Lámbarry

    2016-04-01

    Full Text Available Stress is one of the occupational diseases that affect workers worldwide, affecting their own productivity and performance (as well as that of the organizations where they work, and even their physical and mental health. According to the International Labour Organization, Mexican workers suffer from stress the most all over the world, since theirs is one of the most stressful professions. With this in mind, the aim of this research is to study the work stress in bus rapid transit drivers and minibus in Mexico City. The method used is based on an exploratory statistical factorial analysis. It is concluded that the factors which a higher influence in the onset of stress are organizational, environmental (physical/individual, inherent to the position, extra organizational and individual. Although divergent among drivers, minibus drivers are the workers who suffer the most from stress.

  15. Hydrocarbons derived from petroleum in bottled drinking water from Mexico City.

    Science.gov (United States)

    Vega, Salvador; Gutiérrez, Rey; Ortiz, Rutilio; Schettino, Beatriz; Ramírez, Maria de Lourdes; Pérez, José Jesus

    2011-06-01

    This paper describes the concentrations of polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs) derived from petroleum in bottled drinking water samples that were collected over 1 year from Mexico City in two bottle sizes (1.5 and 19 L), all brought in supermarkets. The analysis was by gas chromatography with flame ionization detection. -Concentrations of AHs (9.26-1.74 μg/L) were greater than PAHs (20.15-12.78 ng/L). Individual concentrations of PAHs such as fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene and benzo(ghi)perylene were comparable with data reported by the World Health Organization (WHO). Total concentrations of PAHs for all samples (BDW1: 12.78 μg/L, BDW2: 16.72 μg/L, BDW3: 14.62 μg/L, BDW4: 20.15 μg/L and BDW5: 13.23 ng/L) were below the maximum permissible European level of 100 ng/L; no regulations exist for AHs although their values were greater than PAHs (BDW1: 3.11 μg/L, BDW2: 8.45 μg/L, BDW3: 1.74 μg/L, BDW4: 4.75 μg/L and BDW5: 9.26 μg/L).

  16. Pet ownership is associated with increased risk of non-atopic asthma and reduced risk of atopy in childhood: findings from a UK birth cohort.

    Science.gov (United States)

    Collin, S M; Granell, R; Westgarth, C; Murray, J; Paul, E; Sterne, J A C; John Henderson, A

    2015-01-01

    Studies have shown an inverse association of pet ownership with allergy but inconclusive findings for asthma. To investigate whether pet ownership during pregnancy and childhood was associated with asthma and atopy at the age of 7 in a UK population-based birth cohort. Data from the Avon Longitudinal Study of Parents and Children (ALSPAC) were used to investigate associations of pet ownership at six time points from pregnancy to the age of 7 with asthma, atopy (grass, house dust mite, and cat skin prick test) and atopic vs. non-atopic asthma at the age of 7 using logistic regression models adjusted for child's sex, maternal history of asthma/atopy, maternal smoking during pregnancy, and family adversity. A total of 3768 children had complete data on pet ownership, asthma, and atopy. Compared with non-ownership, continuous ownership of any pet (before and after the age of 3) was associated with 52% lower odds of atopic asthma [odds ratio (OR) 0.48, 95% CI 0.34-0.68]. Pet ownership tended to be associated with increased risk of non-atopic asthma, particularly rabbits (OR 1.61, 1.04-2.51) and rodents (OR 1.86, 1.15-3.01), comparing continuous vs. non-ownership. Pet ownership was consistently associated with lower odds of sensitization to grass, house dust mite, and cat allergens, but rodent ownership was associated with higher odds of sensitization to rodent allergen. Differential effects of pet ownership on atopic vs. non-atopic asthma were evident for all pet types. Pet ownership during pregnancy and childhood in this birth cohort was consistently associated with a reduced risk of aeroallergen sensitization and atopic asthma at the age of 7, but tended to be associated (particularly for rabbits and rodents) with an increased risk of non-atopic asthma. The opposing effects on atopy vs. non-atopic asthma might be considered by parents when they are deciding whether to acquire a pet. © 2014 John Wiley & Sons Ltd.

  17. Sixty Years of Mogollon Archaeeology: Papers From the Ninth Mogollon Conference, Silver City, New Mexico, 1996, by Stephanie M Whittlesey, SRI Press, Tucson, 1999

    Directory of Open Access Journals (Sweden)

    Stephen E. Nash

    2000-11-01

    Full Text Available "The diverse papers that were presented at the 1996 Mogollon Conference reveal the geographic, intellectual, and temporal scope of contemporary Mogollon archaeology, and almost nothing of the historical controversy surrounding the Mogollon culture concept" (Whittlesey 1999:vii. With these words, Stephanie M. Whittlesey makes it clear in the preface that Sixty Years of Mogollon Archaeology: Papers From the Ninth Mogollon Conference, Silver City, New Mexico, 1996 (SRl Press 2000 contains few papers on the history of Mogollon archaeology. It might therefore be more appropri­ately titled "Current Research in Mogollon Archaeology." The volume was apparently named to honor the sixtieth anniversary of Emil Haury's 1936 publication The Mogollon Culture of Southwestern New Mexico, which described the Mogollon for the first time.

  18. Acceptance of a vaccine against novel influenza A (H1N1) virus among health care workers in two major cities in Mexico.

    Science.gov (United States)

    Esteves-Jaramillo, Alejandra; Omer, Saad B; Gonzalez-Diaz, Esteban; Salmon, Daniel A; Hixson, Brooke; Navarro, Francisco; Kawa-Karasik, Simon; Frew, Paula; Morfin-Otero, Rayo; Rodriguez-Noriega, Eduardo; Ramirez, Ylean; Rosas, Araceli; Acosta, Edgar; Varela-Badillo, Vianey; Del Rio, Carlos

    2009-11-01

    Further cases of novel influenza A (H1N1) outbreak are expected in the coming months. Vaccination has been proven to be essential to control a pandemic of influenza; therefore, considerable efforts and resources have been devoted to develop a vaccine against the influenza A (H1N1) virus. With the current availability of the vaccine, it will be important to immunize as many people as possible. However, previous data with seasonal influenza vaccines have shown that there are multiple barriers related to perceptions and attitudes of the population that influence vaccine use. The aim of the study was to evaluate the acceptance of a newly developed vaccine against pandemic (H1N1) 2009 influenza A among healthcare workers (HCW) in Mexico. We conducted a cross-sectional study among HCW in three hospitals in the two largest cities in Mexico-Mexico City and Guadalajara-between June and September 2009. A total of 1097 HCW participated in the survey. Overall, 80% (n = 880) intended to accept the H1N1 pandemic vaccine and 71.6% (n = 786) reported they would recommend the vaccine to their patients. Doctors were more likely to accept and recommend the vaccine than nurses. HCWs who intend to be immunized will be more likely to do so if they know that the vaccine is safe and effective. Knowledge of the willingness to accept the vaccine can be used to plan strategies that will effectively respond to the needs of the population studied, reducing the health and economic impact of novel influenza A (H1N1) virus.

  19. Mexico and Trilateral Air Defense, Is NORAD the Answer?

    Science.gov (United States)

    2009-02-20

    invading force in at Chapultepec Castle, or El Castillo . Defying a superior force, the heroic six embraced death by leaping from a cliff while wrapped in a...Museums in Mexico City sensationalize perceptions of US aggression. At the entrance to Mexico City’s Chapultepec Park is a daunting monument called Niños

  20. Simulations of organic aerosol concentrations in Mexico City using the WRF-CHEM model during the MCMA-2006/MILAGRO campaign

    Directory of Open Access Journals (Sweden)

    G. Li

    2011-04-01

    Full Text Available Organic aerosol concentrations are simulated using the WRF-CHEM model in Mexico City during the period from 24 to 29 March in association with the MILAGRO-2006 campaign. Two approaches are employed to predict the variation and spatial distribution of the organic aerosol concentrations: (1 a traditional 2-product secondary organic aerosol (SOA model with non-volatile primary organic aerosols (POA; (2 a non-traditional SOA model including the volatility basis-set modeling method in which primary organic components are assumed to be semi-volatile and photochemically reactive and are distributed in logarithmically spaced volatility bins. The MCMA (Mexico City Metropolitan Area 2006 official emission inventory is used in simulations and the POA emissions are modified and distributed by volatility based on dilution experiments for the non-traditional SOA model. The model results are compared to the Aerosol Mass Spectrometry (AMS observations analyzed using the Positive Matrix Factorization (PMF technique at an urban background site (T0 and a suburban background site (T1 in Mexico City. The traditional SOA model frequently underestimates the observed POA concentrations during rush hours and overestimates the observations in the rest of the time in the city. The model also substantially underestimates the observed SOA concentrations, particularly during daytime, and only produces 21% and 25% of the observed SOA mass in the suburban and urban area, respectively. The non-traditional SOA model performs well in simulating the POA variation, but still overestimates during daytime in the urban area. The SOA simulations are significantly improved in the non-traditional SOA model compared to the traditional SOA model and the SOA production is increased by more than 100% in the city. However, the underestimation during daytime is still salient in the urban area and the non-traditional model also fails to reproduce the high level of SOA concentrations in the

  1. Irrigation water quality in southern Mexico City based on bacterial and heavy metal analyses

    International Nuclear Information System (INIS)

    Solis, C.; Sandoval, J.; Perez-Vega, H.; Mazari-Hiriart, M.

    2006-01-01

    Xochimilco is located in southern Mexico City and represents the reminiscence of the pre-Columbian farming system, the 'chinampa' agriculture. 'Chinampas' are island plots surrounded by a canal network. At present the area is densely urbanized and populated, with various contaminant sources contributing to the water quality degradation. The canal system is recharged by a combination of treated-untreated wastewater, and precipitation during the rainy season. Over 40 agricultural species, including vegetables, cereals and flowers, are produced in the 'chinampas'. In order to characterize the quality of Xochimilcos' water used for irrigation, spatial and temporal contaminant indicators such as microorganisms and heavy metals were investigated. Bacterial indicators (fecal coliforms, fecal enterococcus) were analyzed by standard analytical procedures, and heavy metals (such as Fe, Cu, Zn and Pb) were analyzed by particle induced X-ray emission (PIXE). The more contaminated sites coincide with the heavily populated areas. Seasonal variation of contaminants was observed, with the higher bacterial counts and heavy metal concentrations reported during the rainy season

  2. Irrigation water quality in southern Mexico City based on bacterial and heavy metal analyses

    Science.gov (United States)

    Solís, C.; Sandoval, J.; Pérez-Vega, H.; Mazari-Hiriart, M.

    2006-08-01

    Xochimilco is located in southern Mexico City and represents the reminiscence of the pre-Columbian farming system, the "chinampa" agriculture. "Chinampas" are island plots surrounded by a canal network. At present the area is densely urbanized and populated, with various contaminant sources contributing to the water quality degradation. The canal system is recharged by a combination of treated-untreated wastewater, and precipitation during the rainy season. Over 40 agricultural species, including vegetables, cereals and flowers, are produced in the "chinampas". In order to characterize the quality of Xochimilcos' water used for irrigation, spatial and temporal contaminant indicators such as microorganisms and heavy metals were investigated. Bacterial indicators (fecal coliforms, fecal enterococcus) were analyzed by standard analytical procedures, and heavy metals (such as Fe, Cu, Zn and Pb) were analyzed by particle induced X-ray emission (PIXE). The more contaminated sites coincide with the heavily populated areas. Seasonal variation of contaminants was observed, with the higher bacterial counts and heavy metal concentrations reported during the rainy season.

  3. Early Outbreak of 2009 Influenza A (H1N1) in Mexico Prior to Identification of pH1N1 Virus

    Science.gov (United States)

    Hsieh, Ying-Hen; Ma, Stefan; Velasco Hernandez, Jorge X.; Lee, Vernon J.; Lim, Wei Yen

    2011-01-01

    Background In the aftermath of the global spread of 2009 influenza A (pH1N1) virus, still very little is known of the early stages of the outbreak in Mexico during the early months of the year, before the virus was identified. Methodology/Main Findings We fit a simple mathematical model, the Richards model, to the number of excess laboratory-confirmed influenza cases in Mexico and Mexico City during the first 15 weeks in 2009 over the average influenza case number of the previous five baseline years of 2004-2008 during the same period to ascertain the turning point (or the peak incidence) of a wave of early influenza infections, and to estimate the transmissibility of the virus during these early months in terms of its basic reproduction number. The results indicate that there may have been an early epidemic in Mexico City as well as in all of Mexico during February/March. Based on excess influenza cases, the estimated basic reproduction number R0 for the early outbreak was 1.59 (0.55 to 2.62) for Mexico City during weeks 5–9, and 1.25 (0.76, 1.74) for all of Mexico during weeks 5–14. Conclusions We established the existence of an early epidemic in Mexico City and in all of Mexico during February/March utilizing the routine influenza surveillance data, although the location of seeding is unknown. Moreover, estimates of R0 as well as the time of peak incidence (the turning point) for Mexico City and all of Mexico indicate that the early epidemic in Mexico City in February/March had been more transmissible (larger R0) and peaked earlier than the rest of the country. Our conclusion lends support to the possibility that the virus could have already spread to other continents prior to the identification of the virus and the reporting of lab-confirmed pH1N1 cases in North America in April. PMID:21909366

  4. Public policy performance for social development: solar energy approach to assess technological outcome in Mexico City Metropolitan Area.

    Science.gov (United States)

    Arenas-Aquino, Angel Raúl; Matsumoto-Kuwabara, Y; Kleiche-Dray, M

    2017-11-01

    Mexico City Metropolitan Area (MCMA) is the most populated urban area in the country. In 2010, MCMA required 14.8% of total energy domestic demand, but greenhouse gas emissions accounted for 7.7% of domestic emissions. Mexico has massive renewable energy potential that could be harnessed through solar photovoltaic (PV) technology. The problem to explore is the relationship between local and federal public strategies in MCMA and their stance on energy transition concern, social empowerment, new technology appropriation, and the will to boost social development and urban sustainability. A public policy typology was conducted through instruments of State intervention approach, based on political agenda articulation and environmental local interactions. Social equality is encouraged by means of forthright funding and in-kind support and energy policies focus on non-renewable energy subsidies and electric transmission infrastructure investment. There is a lack of vision for using PV technology as a guiding axis for marginalized population development. It is essential to promote economic and political rearrangement in order to level and structure environmental governance. It is essential to understand people's representation about their own needs along with renewable energy.

  5. Old age pensions in Mexico: Toward universal coverage

    OpenAIRE

    Willmore, Larry

    2014-01-01

    This paper chronicles the rise of social pensions in Mexico. First it summarizes the pension system prior to introduction of social pensions. Next it describes how Mexico City, the federal government, and seventeen of Mexico’s 31 states initiated social pensions, a policy supported eventually by each of the three major political parties. It concludes with thoughts on what remains to be done.

  6. The Hour of Television: The Incursion of Television and Telenovelas into Mexico City Daily Life (1958-1966

    Directory of Open Access Journals (Sweden)

    Laura Camila Ramírez Bonilla

    2015-07-01

    Full Text Available Television and television genres have a life of their own. In the Mexican case, telenovelas can be seen as the first genre authentically conceived and created for television. Since their appearance in Mexico in June 1958 on Telesistema-Canal 4, they not only recapitulated the stereotypes, myths and moral concerns of society at that time, but also became part of the daily life of their spectators, still expectant neophytes. The first melodramas were an urban phenomenon and characterized the growth of the middle class. The genre’s audience was created by its appearance and viewers actively integrated what they saw on screen into their family life. Watching telenovelas was a primordially domestic act while simultaneously being a collective one, shared among many people. Understanding this genre as a product made to provide meaning and using an analysis that demands both the study of narrative content as well an analysis of the medium itself and its spectators, this article identifies the way in which the arrival of television (and telenovelas in particular made an impact on the daily life of television viewers in Mexico City. Did the arrival of television melodramas, between 1958 and 1966, introduce a new sense of the everyday in the viewing public? How did this new sense of everyday life express itself in space, time, routines, tastes and the collective imagination of viewers? This article is supported by the audiovisual content of the first television melodramas transmitted in Mexico, their reception in television magazines and the press in general, their accompanying advertising and the experiences of middle class individuals and families who were interviewed and surveyed on the subject.

  7. Ventilation potential during the emissions survey in Toluca Valley, Mexico

    Science.gov (United States)

    Ruiz Angulo, A.; Peralta, O.; Jurado, O. E.; Ortinez, A.; Grutter de la Mora, M.; Rivera, C.; Gutierrez, W.; Gonzalez, E.

    2017-12-01

    During the late-spring early-summer measurements of emissions and pollutants were carried out during a survey campaign at four different locations within the Toluca Valley. The current emissions inventory typically estimates the generation of pollutants based on pre-estimated values representing an entire sector function of their activities. However, those factors are not always based direct measurements. The emissions from the Toluca Valley are rather large and they could affect the air quality of Mexico City Valley. The air masses interchange between those two valleys is not very well understood; however, based on the measurements obtained during the 3 months campaign we looked carefully at the daily variability of the wind finding a clear signal for mountain-valley breeze. The ventilation coefficient is estimated and the correlations with the concentrations at the 4 locations and in a far away station in Mexico City are addressed in this work. Finally, we discuss the implication of the ventilation capacity in air quality for the system of Valleys that include Mexico City.

  8. Asthma and atopy in children born by caesarean section: effect modification by family history of allergies - a population based cross-sectional study.

    Science.gov (United States)

    Kolokotroni, Ourania; Middleton, Nicos; Gavatha, Marina; Lamnisos, Demetris; Priftis, Kostas N; Yiallouros, Panayiotis K

    2012-11-16

    Studies on the association of birth by caesarean section (C/S) and allergies have produced conflicting findings. Furthermore, evidence on whether this association may differ in those at risk of atopy is limited. This study aims to investigate the association of mode of delivery with asthma and atopic sensitization and the extent to which any effect is modified by family history of allergies. Asthma outcomes were assessed cross-sectionally in 2216 children at age 8 on the basis of parents' responses to the ISAAC questionnaire whilst skin prick tests to eleven aeroallergens were also performed in a subgroup of 746 children. Adjusted odds ratios of asthma and atopy by mode of delivery were estimated in multivariable logistic models while evidence of effect modification was examined by introducing interaction terms in the models. After adjusting for potential confounders, children born by C/S appeared significantly more likely than those born vaginally to report ever wheezing (OR 1.36, 95% CI 1.07-1.71), asthma diagnosis (OR 1.41, 95% CI 1.09-1.83) and be atopic (OR 1.67, 95% CI 1.08-2.60). There was modest evidence that family history of allergies may modify the effect of C/S delivery on atopy (p for effect modification=0.06) but this was not the case for the asthma outcomes. Specifically, while more than a two-fold increase in the odds of being a topic was observed in children with a family history of allergies if born by C/S (OR 2.62, 95% CI 1.38-5.00), no association was observed in children without a family history of allergies (OR 1.16, 95% CI 0.64-2.11). Birth by C/S is associated with asthma and atopic sensitization in childhood. The association of C/S and atopy appears more pronounced in children with family history of allergies.

  9. Who presents past the gestational age limit for first trimester abortion in the public sector in Mexico City?

    Directory of Open Access Journals (Sweden)

    Biani Saavedra-Avendano

    Full Text Available To identify socio-demographic factors associated with presenting for abortion services past the gestational age (GA limit (12 weeks, and thus not receiving services, in Mexico City's public sector first trimester abortion program.We used clinical data from four high volume sites in the Interrupción Legal de Embarazo (ILE program, 2007-2015. We used descriptive statistics to quantify the proportion of women who did not receive an abortion due to presenting past the gestational age limit. We used multivariable logistic regression to identify associations between women's characteristics and presenting past the GA limit and calculated predicted probabilities of late presentation for key characteristics.Our sample included 52,391 women, 8.10% (n = 4,246 of whom did not receive abortion services due to presenting past the GA limit. Adolescents (12-17 made up 8.69% of the total sample and 13.40% of those presenting past the GA limit (p = 40 years' old respectively. Women living in Mexico City and with higher levels of education had lower odds of presenting past the GA limit, and there was an educational gradient across all age groups. In the multivariable predicted probability models, adolescents at every level of education have significantly higher probabilities of not receiving an abortion due to presenting past the gestational age limit compared with adults (among women with a primary education: 11.75% adolescents vs. 9.02-4.26% across adult age groups.Our results suggest that continued efforts are needed to educate women, especially younger and less educated women, about early pregnancy recognition. In addition, all women need information about the availability of first trimester legal abortion to ensure timely access to abortion services.

  10. On the vertical distribution of pollutants in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Perez Vidal, H. [Universidad Juarez Autonoma de Tabasco, Division Academica de Ciencias Basicas, Tabasco (Mexico); Raga, G. B. [Centro de Ciencias de la Atmosfera, UNAM, Mexico, D.F. (Mexico)

    1998-04-01

    The problem of air pollution in Mexico City is studied through the analysis of a large dataset obtained by an instrumented aircraft during February 1991. These data constitute a unique set in Mexico and provide insight into the vertical structure of the boundary layer and the pollutant species which has not been previously discussed. The results obtained on the evolution and structure of the mixed layer indicate that its height rises from 100 meters during the morning (8 am) to over 2000 meters al 5 pm. results consistently show that the maximum in ozone concentration is not observed al the surface, but al about 700 m on average about it near midday. The peak, with an average concentration over the observational period of 167 ppb, appears to be a transient feature, with concentrations becoming more uniform with height in the afternoon. The vertical profiles of nitrogen oxides and sulphur dioxide indicate that concentrations are highest during the morning and steadily decrease with height, suggesting that sources for these species are located near the surface, as was expected. There appears to be no correlation between the amount of nitrogen oxides observed during the take-off and the ozone concentrations observed during landing (2-3 hours later). When the variables are normalized by the mixed layer height the results indicate that the ozone observed is fairly independent of the nitrogen oxide concentrations observed earlier. A reduced range of values of the ratio of ozone accumulated in the mixed layer and the layer height is consistently day found during the observational period. Aerosol particles near the surface show maximum concentration during the morning hours, but in contrast, during the course of the day, there is a marked increase in their concentrations at higher levels in the boundary layer suggesting that possibly gas to particle conversion is responsible for the observed increase. [Spanish] El problema de la contaminacion del aire en la Ciudad de

  11. Abortion Legalization and Childbearing in Mexico.

    Science.gov (United States)

    Gutiérrez Vázquez, Edith Y; Parrado, Emilio A

    2016-06-01

    In 2007 abortion was legalized in the Federal District of Mexico, making it the largest jurisdiction in Latin America, outside of Cuba, to allow women to have abortions on request during the first trimester of pregnancy. While the implications of the law for women's health and maternal mortality have been investigated, its potential association with fertility behavior has yet to be assessed. We examine metropolitan-area differences in overall and parity-specific childbearing, as well as the age pattern of childbearing between 2000 and 2010 to identify the contribution of abortion legalization to fertility in Mexico. Our statistical specification applies difference-in-difference regression methods that control for concomitant changes in other socioeconomic predictors of fertility to assess the differential influence of the law across age groups. In addition, we account for prior fertility levels and change to better separate the effect of the law from preceding trends. Overall, the evidence suggests a systematic association between abortion legalization and fertility. The law appears to have contributed to lower fertility in Mexico City compared to other metropolitan areas and prior trends. The influence is mostly visible among women aged 20-34 in connection with the transition to first and second child, with limited impact on teenage fertility. There is some evidence that its effect might be diffusing to the Greater Mexico City Metropolitan area. © 2016 The Population Council, Inc.

  12. Social segregation of indigenous migrants in Mexico: An overview from Monterrey

    Directory of Open Access Journals (Sweden)

    Arun Kumar Acharya

    2012-01-01

    Full Text Available In Mexico, rural to urban migration is a clearly noticeable phenomenon. During the last few years, there has been spontaneous growth in the migration of indigenous people towards the northern cities of Mexico, especially to Monterrey, in search of employment. Once the migrants arrive in this metropolis, they face difficulties adjusting and adapting to the city environment because of hidden discrimination. The main argument and hypothesis of this paper is that indigenous people isolate themselves and segregate themselves socially due to fear of (cultural and racial discrimination and violence. For this study, data were obtained from fieldwork carried out during 2009 and 2010 in Monterrey, Mexico, where we interviewed 350 indigenous people that had moved there from different parts of the country.

  13. The impact of liquefied petroleum gas usage on air quality in Mexico City

    International Nuclear Information System (INIS)

    Gasca, J.; Ortiz, E.; Castillo, H.; Jaimes, J.L.; Gonzalez, U.

    2004-01-01

    Liquefied petroleum gas (LPG) is the main fuel used in the residential sector of the Metropolitan Zone in the Valley of Mexico (MZVM). LPG represents 16% of the total fuel consumption in the MZVM and its demand increased 14% from 1986 to 1999. Propane and butanes, the main compounds of LPG, constituted 29% of all non-methane hydrocarbons found in the air of Mexico City. Some researchers have reported that LPG losses are a significant cause of high ozone concentration in MZVM. Three analyses are carried out in this work to estimate LPG's share of responsibility for MZVM pollution problems. First, the correlation between LPG consumption and three ozone pollution indicators was calculated for the period of 1986-1999. The non-significant correlation of these indicators with LPG consumption on a monthly basis suggests that LPG associated emissions are not the foremost cause of ozone formation. Second, a simulation model is applied to three LPG related emission control strategies to estimate the reduction in the maximum ozone concentration. The most noticeable effect was obtained when both hydrocarbon (HC) and oxides of nitrogen (NO x ) emissions associated with LPG use were totally reduced. The other two strategies, that only reduce HC emissions, had a minimum effect on the ozone concentration. Third, organic compounds consumption in air samples captured and irradiated in outdoor smog chambers is used to determine the chemical loss rate of LPG associated species and aromatics in the MZVM. The smog chamber results showed that 70% of propane and n-butane remain at the end of a 1-day irradiation, therefore they remain in the MZVM atmosphere for several days being the reason for the high concentration of these compounds. LPG associated compounds only account for 18% of ozone formed but aromatics contribute 35% to ozone in smog chamber. (Author)

  14. Assessment of the ozone-nitrogen oxide-volatile organic compound sensitivity of Mexico City through an indicator-based approach: measurements and numerical simulations comparison.

    Science.gov (United States)

    Torres-Jardón, Ricardo; García-Reynoso, J Agustín; Jazcilevich, Arón; Ruiz-Suárez, L Gerardo; Keener, Tim C

    2009-10-01

    The ozone (O3) sensitivity to nitrogen oxides (NOx, or nitric oxide [NO] + nitrogen dioxide [NO2]) versus volatile organic compounds (VOCs) in the Mexico City metropolitan area (MCMA) is a current issue of scientific controversy. To shed light on this issue, we compared measurements of the indicator species O3/NOy (where NOy represents the sum of NO + NO2 + nitric acid [HNO3] + peroxyacetyl nitrate [PAN] + others), NOy, and the semiempirically derived O3/NOz(surrogate) (where NOz(surrogate) is the derived surrogate NOz, and NOz represents NOx reaction products, or NOy - NOx) with results of numerical predictions reproducing the transition regimes between NOx and VOC sensitivities. Ambient air concentrations of O3, NOx, and NOy were measured from April 14 to 25, 2004 in one downwind receptor site of photochemically aged air masses within Mexico City. MCMA-derived transition values for an episode day occurring during the same monitoring period were obtained through a series of photochemical simulations using the Multiscale Climate and Chemistry Model (MCCM). The comparison between the measured indicator species and the simulated spatial distribution of the indicators O3/ NOy, O3/NOz(surrogate), and NOy in MCMA suggest that O3 in this megacity is likely VOC-sensitive. This is in opposition to past studies that, on the basis of the observed morning VOC/NOx ratios, have concluded that O3 in Mexico City is NOx-sensitive. Simulated MCMA-derived sensitive transition values for O3/NOy, hydrogen peroxide (H2O2)/HNO3, and NOy were found to be in agreement with threshold criteria proposed for other regions in North America and Europe, although the transition crossover for O3/NOz and O3/HNO3 was not consistent with values reported elsewhere. An additional empirical evaluation of weekend/weekday differences in average maximum O3 concentrations and 6:00- to 9:00-a.m. NOx and NO levels registered at the same site in April 2004 indirectly confirmed the above results. A preliminary

  15. A new Proposal to Mexico Valley Zonification

    Science.gov (United States)

    Flores-Estrella, H. C.; Yussim, S.; Lomnitz, C.

    2004-12-01

    The effects of the Michoacan earthquake (19th September, 1985, Mw 8.1) in Mexico City caused a significant change in the political, social and scientific history, as it was considered the worst seismic disaster ever lived in Mexico. Since then, numerous efforts have been made to understand and determine the parameters that caused the special features registered. One of these efforts had began on 1960 with the work by Marsal and Masari, who published the Mexico Valley seismological and geotechnical zonification (1969), based on gravimetric and shallow borehole data. In this work, we present a revision of the studies that proposed the zonification, a description of the valley geology, and basing on it we propose a new zonification for Mexico Valley.

  16. Malignant neoplasms of the nasal cavity and paranasal sinuses: a series of 256 patients in Mexico City and Monterrey. Is air pollution the missing link?

    Science.gov (United States)

    Calderón-Garcidueñas, L; Delgado, R; Calderón-Garcidueñas, A; Meneses, A; Ruiz, L M; De La Garza, J; Acuna, H; Villarreal-Calderón, A; Raab-Traub, N; Devlin, R

    2000-04-01

    Air pollution is a serious health problem in major cities in Mexico. The concentrations of monitored criteria pollutants have been above the US National Ambient Air Quality Standards for the last decade. To determine whether the number of primary malignant nasal and paranasal neoplasms has increased, we surveyed 256 such cases admitted to a major adult oncology hospital located in metropolitan Mexico City (MMC) for the period from 1976-1997 and to a tertiary hospital in Monterrey, an industrial city, for the period from 1993-1998. The clinical histories and histopathologic material were reviewed, and a brief clinical summary was written for each case. In the MMC hospital the number of newly diagnosed nasal and paranasal neoplasms per year for the period from 1976-1986 averaged 5.1, whereas for the next 11 years it increased to 12.5. The maximal increase was observed in 1995-1997, with an average of 20.3 new cases per year (P = 0.0006). The predominant neoplasms in these series were non-Hodgkin's lymphoma, squamous cell carcinoma, melanoma, adenocarcinoma, Schneiderian carcinoma, and nasopharyngeal carcinoma. In the Monterrey hospital a 2-fold increase in the numbers of newly diagnosed nasal and paranasal neoplasms was recorded between 1993 and 1998. The predominant MMC neoplasm in this series, namely nasal T-cell/natural killer cell non-Hodgkin's lymphoma, is potentially Epstein-Barr virus related. Nasal and paranasal malignant neoplasms are generally rare. Environmental causative factors include exposure in industries such as nickel refining, leather, and wood furniture manufacturing. Although epidemiologic studies have not addressed the relationship between outdoor air pollution and sinonasal malignant neoplasms, there is strong evidence for the nasal and paranasal carcinogenic effect of occupational aerosol complex chemical mixtures. General practitioners and ear, nose, and throat physicians working in highly polluted cities should be aware of the clinical

  17. The presence of serum anti-Ascaris lumbricoides IgE antibodies and of Trichuris trichiura infection are risk factors for wheezing and/or atopy in preschool-aged Brazilian children

    Directory of Open Access Journals (Sweden)

    Alcântara-Neves Neuza M

    2010-08-01

    Full Text Available Abstract Background The elucidation of factors that trigger the development of transient wheezing in early childhood may be an important step toward understanding the pathogenesis of asthma and other allergic diseases later in life. Transient wheezing has been mainly attributed to viral infections, although sensitisation to aeroallergens and food allergens may occur at an early age. In developing countries, intestinal helminthic infections have also been associated with allergy or atopy-related disorders. Objective The aim of this study was to explore the association of Trichuris trichiura and Ascaris lumbricoides infections with wheezing and atopy in early childhood. Study design A cross-sectional study using a Portuguese-language ISAAC phase I questionnaire, adapted for preschool-aged children, nested in a cohort study of childhood diarrhoea, was conducted on 682 children. Two faecal samples per child were examined for the presence of intestinal helminthic infection. IgE antibodies against three allergenic preparations (Dermatophagoides pteronyssinus, Blomia tropicalis and common child food, as well as against A. lumbricoides antigens, were measured in a sub-sample of these children, whose parents allowed the procedure. Atopy was defined by the presence of levels of serum IgE antibodies ≥0.35 kU/L against at least one of the three tested allergenic preparations. Results Active T. trichiura infection but not A. lumbricoides infection was positively associated with wheezing in the total studied children population [adjusted OR = 2.60; CI = 1.54;4.38] and in the atopic children sub-population [adjusted OR = 3.07; CI = 1.00;9.43]. The association with atopy was also positive and statistically significant only in the brute analysis [OR = 2.13; CI = 1.03;4.40]. Anti-A. lumbricoides IgE antibodies, but not current A. lumbricoides infection, were positively associated with wheezing in atopic children [adjusted OR = 2.01; CI = 1.00;4.50] and in non

  18. Evidence of increasing sedentarism in Mexico City during the last decade: Sitting time prevalence, trends, and associations with obesity and diabetes.

    Directory of Open Access Journals (Sweden)

    Catalina Medina

    Full Text Available Sedentary behaviors such as sitting time are associated with obesity and diabetes independently of total reported physical activity. This study aimed to describe the current sitting time/day prevalence and trends and to examine the association of sitting time with sociodemographic and clinical variables in Mexico City.Two cross-sectional representative surveys in Mexico City were used for this analysis (2006: n = 1148 and 2015: n = 1329. Sedentary behavior questions from the International Physical Activity Questionnaire included time spent sitting on a weekday in the last week or on a Wednesday. Sitting time /day was divided into deciles, and participants in the highest decile (≥ 420 minutes/day were classified within the high sitting category; others were classified in the low sitting time category. Multivariate logistic regression was used to evaluate the associations of sitting time with sociodemographic and clinical indicators, controlling for confounders and testing for potential interactions.A total of 13.7% (2006 and 14.8% (2015 adults were classified in the highest sitting time category (≥ 420 minutes/day. There was a significant increase in the average sitting time/day between the surveys (216.0 minutes in 2006 vs. 233.3 minutes in 2015, p < 0.001. In 2015, men, those aged 20-49 years, those in low-intensity jobs, students, and those with a high socioeconomic level were more likely to be in the highest sitting time category. Participants with overweight/obesity (OR = 2.37, 95% CI: 1.11, 5.09 and those with high glucose levels (survey finding (OR = 2.34, 95% CI: 1.04, 5.25 were more likely to report sitting time in the highest category.Sitting time/day prevalence increased 8%, and average daily sitting minutes significantly increased by 8.2% (18 minutes in the nine-year study period (2006-2015. Current public health policies should consider strategies not only for increasing physical activity levels, but also for reducing sitting

  19. Air Quality in Mexico City: Policies Implemented for its Improvement

    Science.gov (United States)

    Paramo, V.

    2007-12-01

    Ozone and suspended particles (PM) are two pollutants in the atmosphere of Mexico City Metropolitan Area (MCMA) that still exceed the recommended Mexican health standards. The other criteria pollutants very seldom exceed their corresponding standards. In 2006, the maximum ozone concentrations were above the health standard (0.11 ppm in 1 hour) during 59 percent of the days for an average of 2.2 hours and 130 points of the Air Quality Index (Índice Metropolitano de la Calidad del Aire - IMECA). In contrast, in 1991, 98 percent of the days exceeded the ozone health standard for an average of 6.6 hours and 200 IMECA points. With regards to PM10, in 2006, 80 percent of the sampled concentrations were below the health standard of 120 µg/m3 in 24 hours. However, the annual health standard of 50 µg/m3 is still exceeded. The air quality management in the MCMA is a difficult task due to several adverse factors. The main one is the large population that increased from nearly 15 million in 1992 to more than 18 million at present. As a result, the urban area grows in the adjoined municipalities of the State of Mexico. The vehicular fleet increases also to almost 4 million and the number of industrial facilities is at present 50,000. Consequently, the fuel consumption is very high. The daily energy consumption is estimated to be 44 million liters of equivalent of gasoline. Despite the fact that the air quality has improved in recent years, the related health standards are still exceeded and therefore it is necessary to continue applying the most cost-effective actions to improve the environment quality. Some actions that have contributed most to the reduction of pollutant emissions are the following: Continuous update of the inspection and maintenance program of the vehicular fleet; substitution of the catalytic converters at the end of their useful life; self-regulation of the diesel fleet; use of alternative fuels; update the No-Driving-Day program; establishment of more

  20. Levels, Composition and Sources of PM in the Mexico City Metropolitan Area During the MILAGRO Campaign

    Science.gov (United States)

    Querol, X.; Pey, J.; Minguillon, M. C.; Perez, N.; Alastuey, A.; Moreno, T.; Bernabe, R.; Blanco, S.; Cardenas, B.

    2007-05-01

    Particle air pollution in urban agglomerations comes mostly from anthropogenic sources, mainly traffic, industrial processes, energy production, domestic and residential emissions, construction, but also a minor contribution from natural sources may be expected (bioaerosols, soil dust, marine aerosol). Once emitted into the atmosphere, this complex mixture of pollutants may be transformed as a function of the ambient conditions and the interaction among the different PM components, and also between PM components and gaseous pollutants. This system is especially complex in mega-cities due to the large emission volumes of PM components and gaseous precursors, the high variability and broad distribution of emission sources, and the possible long range transport of the polluted air masses. Speciation studies help to identify major sources of PM components with the end objective of applying plans and programs for PM pollution abatement. In this framework, concentration levels and compositions of particulate matter (PM2.5, PM10 and TSP) have been measured simultaneously at two sites in the Mexico City Metropolitan Area (T0 and CENICA) and at one site 50 km away from Mexico City (T1) during the MILAGRO campaign (1st to 31st March 2006). Spatial and time (day and night) variations have been analysed. Coarse fraction levels were higher at T1 than at CENICA and T0, contrary to what was expected. This was due to the important soil re-suspension at T1, contributing significantly to the crustal load. Moreover, crustal levels were higher during daytime than during nights at all sites, while some secondary compounds (sulphate and ammonium) presented an opposite trend. Regarding trace elements, levels of Pb, Zn and Cd were higher at T0 than at CENICA and T1, probably due to traffic contribution. Arsenic levels did not show a clear pattern, being alternatively higher at CENICA and T0. Two intense episodes of Hg particulate have been recorded, more noticeable at T1 than at the urban

  1. Transboundary water management Game-theoretic lessons for projects on the US-Mexico border*

    OpenAIRE

    Frisvold, George B.; Caswell, Margriet F.

    2000-01-01

    Of the twelve million people who live within 100 km of the US-Mexico border, 90 percent are clustered in trans boundary sister cities that share common water sources and pollution problems. New institutions created to address environmental concerns over NAFTA offer the promise of greater financial and technical assistance for water management in border cities. This paper reviews US-Mexico border water issues and institutions. Using insights from game theory, it draws policy lessons for instit...

  2. An analysis of gasoline demand elasticities at the national and local levels in Mexico

    International Nuclear Information System (INIS)

    Crotte, Amado; Noland, Robert B.; Graham, Daniel J.

    2010-01-01

    The majority of evidence on gasoline demand elasticities is derived from models based on national data. Since the largest growth in population is now taking place in cities in the developing world it is important that we understand whether this national evidence is applicable to demand conditions at the local level. The aim of this paper is to estimate and compare gasoline per vehicle demand elasticities at the national and local levels in Mexico. National elasticities with respect to price, income, vehicle stock and metro fares are estimated using both a time series cointegration model and a panel GMM model for Mexican states. Estimates for Mexico City are derived by modifying national estimates according to mode shares as suggested by, and by estimating a panel Within Groups model with data aggregated by borough. Although all models agree on the sign of the elasticities the magnitudes differ greatly. Elasticities change over time and differ between the national and local levels, with smaller price responses in Mexico City. In general, price elasticities are smaller than those reported in the gasoline demand surveys, a pattern previously found in developing countries. The fact that income and vehicle stock elasticities increase over time may suggest that vehicles are being used more intensively in recent years and that Mexico City residents are purchasing larger vehicles. Elasticities with respect to metro fares are negligible, which suggests little substitution between modes. Finally, the fact that fuel efficiency elasticities are smaller than vehicle stock elasticities suggests that vehicle stock size, rather than its composition, has a larger impact on gasoline consumption in Mexico City. (author)

  3. An analysis of gasoline demand elasticities at the national and local levels in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Crotte, Amado [Mexican Ministry of Communications and Transport, Mexico City (Mexico); Noland, Robert B. [Alan M. Voorhees Transportation Center, E. J. Bloustein School of Planning and Public Policy, Rutgers University, New Brunswick, NJ 08901 (United States); Graham, Daniel J. [Centre for Transport Studies, Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ London (United Kingdom)

    2010-08-15

    The majority of evidence on gasoline demand elasticities is derived from models based on national data. Since the largest growth in population is now taking place in cities in the developing world it is important that we understand whether this national evidence is applicable to demand conditions at the local level. The aim of this paper is to estimate and compare gasoline per vehicle demand elasticities at the national and local levels in Mexico. National elasticities with respect to price, income, vehicle stock and metro fares are estimated using both a time series cointegration model and a panel GMM model for Mexican states. Estimates for Mexico City are derived by modifying national estimates according to mode shares as suggested by, and by estimating a panel Within Groups model with data aggregated by borough. Although all models agree on the sign of the elasticities the magnitudes differ greatly. Elasticities change over time and differ between the national and local levels, with smaller price responses in Mexico City. In general, price elasticities are smaller than those reported in the gasoline demand surveys, a pattern previously found in developing countries. The fact that income and vehicle stock elasticities increase over time may suggest that vehicles are being used more intensively in recent years and that Mexico City residents are purchasing larger vehicles. Elasticities with respect to metro fares are negligible, which suggests little substitution between modes. Finally, the fact that fuel efficiency elasticities are smaller than vehicle stock elasticities suggests that vehicle stock size, rather than its composition, has a larger impact on gasoline consumption in Mexico City. (author)

  4. Association of a four-locus gene model including IL13, IL4, FCER1B, and ADRB2 with the Asthma Predictive Index and atopy in Chinese Han children.

    Science.gov (United States)

    Bai, S; Hua, L; Wang, X; Liu, Q; Bao, Y

    2018-05-11

    Asthma is a complex and heterogeneous disease. We found that gene-gene interactions among IL13 rs20541, IL4 rs2243250, ADRB2 rs1042713, and FCER1B rs569108 in asthmatic children of Chinese Han nationality. This four-locus set constituted an optimal statistical interaction model. Objective: This study examined associations of the four-gene model consisting of IL13, IL4, FCER1B, and ADRB2 with the Asthma Predictive Index (API) and atopy in Chinese Han children. Four single-nucleotide polymorphisms (SNPs) in the four genes were genotyped in 385 preschool children with wheezing symptoms using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Student's t test and x2 tests were used for this analysis. : Significant correlations were found between the four-locus gene model and the stringent and loose API (both Pfour-locus gene model with atopy (Pfour-locus gene model consisting of L13 rs20541, IL4 rs2243250, ADRB2 rs1042713 and FCER1B rs569108 was associated with the API and atopy. These findings provide an evidence of the gene model for determining a high risk of developing asthma and atopy in Chinese Han children.

  5. Mexico City normal weight children exposed to high concentrations of ambient PM2.5 show high blood leptin and endothelin-1, vitamin D deficiency, and food reward hormone dysregulation versus low pollution controls. Relevance for obesity and Alzheimer disease.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Franco-Lira, Maricela; D'Angiulli, Amedeo; Rodríguez-Díaz, Joel; Blaurock-Busch, Eleonore; Busch, Yvette; Chao, Chih-kai; Thompson, Charles; Mukherjee, Partha S; Torres-Jardón, Ricardo; Perry, George

    2015-07-01

    Millions of Mexico, US and across the world children are overweight and obese. Exposure to fossil-fuel combustion sources increases the risk for obesity and diabetes, while long-term exposure to fine particulate matter (PM2.5) and ozone (O3) above US EPA standards is associated with increased risk of Alzheimer's disease (AD). Mexico City Metropolitan Area children are chronically exposed to PM2.5 and O3 concentrations above the standards and exhibit systemic, brain and intrathecal inflammation, cognitive deficits, and Alzheimer disease neuropathology. We investigated adipokines, food reward hormones, endothelial dysfunction, vitamin D and apolipoprotein E (APOE) relationships in 80 healthy, normal weight 11.1±3.2 year olds matched by age, gender, BMI and SES, low (n: 26) versus high (n:54) PM2.5 exposures. Mexico City children had higher leptin and endothelin-1 (pMexico City APOE 4 versus 3 children had higher glucose (p=0.009). Serum 25-hydroxyvitamin DMexico City children. Leptin is strongly positively associated to PM 2.5 cumulative exposures. Residing in a high PM2.5 and O3 environment is associated with 12h fasting hyperleptinemia, altered appetite-regulating peptides, vitamin D deficiency, and increases in ET-1 in clinically healthy children. These changes could signal the future trajectory of urban children towards the development of insulin resistance, obesity, type II diabetes, premature cardiovascular disease, addiction-like behavior, cognitive impairment and Alzheimer's disease. Increased efforts should be made to decrease pediatric PM2.5 exposures, to deliver health interventions prior to the development of obesity and to identify and mitigate environmental factors influencing obesity and Alzheimer disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Emissions of black carbon and co-pollutants emitted from diesel vehicles in the Mexico City Metropolitan Area

    Science.gov (United States)

    Zavala, Miguel; Molina, Luisa T.; Fortner, Edward; Knighton, Berk; Herndon, Scott; Yacovitch, Tara; Floerchinger, Cody; Roscioli, Joseph; Kolb, Charles; Mejia, Jose Antonio; Sarmiento, Jorge; Paramo, Victor Hugo; Zirath, Sergio; Jazcilevich, Aron

    2014-05-01

    Black carbon emitted from freight, public transport, and heavy duty trucks sources is linked with adverse effects on human health. In addition, the control of emissions of black carbon, an important short-lived climate forcing agent (SLCF), has recently been considered as one of the key strategies for mitigating regional near-term climate change. Despite the availability of new emissions control technologies for reducing emissions from diesel-powered mobile sources, their introduction is still not widespread in many urban areas and there is a need to characterize real-world emission rates of black carbon from this key source. The emissions of black carbon, organic carbon, and other gaseous and particle pollutants from diesel-powered mobile sources in Mexico were characterized by deploying a mobile laboratory equipped with real-time instrumentation in Mexico City as part of the SLCFs-Mexico 2013 project. From February 25-28 of 2013 the emissions from selected diesel-powered vehicles were measured in both controlled experiments and real-world on-road driving conditions. Sampled vehicles had several emissions levels technologies, including: EPA98, EPA03, EPA04, EURO3-5, and Hybrid. All vehicles were sampled using diesel fuel and several vehicles were measured using both diesel and biodiesel fuels. Additional measurements included the use of a remote sensing unit for the co-sampling of all tested vehicles, and the installation and operation of a Portable Emissions Measurements System (PEMS) for the measurement of emissions from a test vehicle. We will present inter-comparisons of the emission factors obtained among the various vehicle technologies that were sampled during the experiment as well as the inter-comparison of results from the various sampling platforms. The results can be used to

  7. Association of indoor air pollution with rhinitis symptoms, atopy and nitric oxide levels in exhaled air

    DEFF Research Database (Denmark)

    Hersoug, Lars-Georg; Husemoen, Lise Lotte N; Thomsen, Simon Francis

    2010-01-01

    Exposure to particulate matter (PM) outdoors can induce airway inflammation and exacerbation of asthma in adults. However, there is limited knowledge about the effects of exposure to indoor PM. The aim of this study was to investigate the association of exposure to indoor sources of PM...... with rhinitis symptoms, atopy and nitric oxide in exhaled air (FeNO) as a measure of airway inflammation....

  8. Linear and regressive stochastic models for prediction of daily maximum ozone values at Mexico City atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Bravo, J. L [Instituto de Geofisica, UNAM, Mexico, D.F. (Mexico); Nava, M. M [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Gay, C [Centro de Ciencias de la Atmosfera, UNAM, Mexico, D.F. (Mexico)

    2001-07-01

    We developed a procedure to forecast, with 2 or 3 hours, the daily maximum of surface ozone concentrations. It involves the adjustment of Autoregressive Integrated and Moving Average (ARIMA) models to daily ozone maximum concentrations at 10 monitoring atmospheric stations in Mexico City during one-year period. A one-day forecast is made and it is adjusted with the meteorological and solar radiation information acquired during the first 3 hours before the occurrence of the maximum value. The relative importance for forecasting of the history of the process and of meteorological conditions is evaluated. Finally an estimate of the daily probability of exceeding a given ozone level is made. [Spanish] Se aplica un procedimiento basado en la metodologia conocida como ARIMA, para predecir, con 2 o 3 horas de anticipacion, el valor maximo de la concentracion diaria de ozono. Esta basado en el calculo de autorregresiones y promedios moviles aplicados a los valores maximos de ozono superficial provenientes de 10 estaciones de monitoreo atmosferico en la Ciudad de Mexico y obtenidos durante un ano de muestreo. El pronostico para un dia se ajusta con la informacion meteorologica y de radiacion solar correspondiente a un periodo que antecede con al menos tres horas la ocurrencia esperada del valor maximo. Se compara la importancia relativa de la historia del proceso y de las condiciones meteorologicas previas para el pronostico. Finalmente se estima la probabilidad diaria de que un nivel normativo o preestablecido para contingencias de ozono sea rebasado.

  9. Receptor Model Source Apportionment of Nonmethane Hydrocarbons in Mexico City

    Directory of Open Access Journals (Sweden)

    V. Mugica

    2002-01-01

    Full Text Available With the purpose of estimating the source contributions of nonmethane hydrocarbons (NMHC to the atmosphere at three different sites in the Mexico City Metropolitan Area, 92 ambient air samples were measured from February 23 to March 22 of 1997. Light- and heavy-duty vehicular profiles were determined to differentiate the NMHC contribution of diesel and gasoline to the atmosphere. Food cooking source profiles were also determined for chemical mass balance receptor model application. Initial source contribution estimates were carried out to determine the adequate combination of source profiles and fitting species. Ambient samples of NMHC were apportioned to motor vehicle exhaust, gasoline vapor, handling and distribution of liquefied petroleum gas (LP gas, asphalt operations, painting operations, landfills, and food cooking. Both gasoline and diesel motor vehicle exhaust were the major NMHC contributors for all sites and times, with a percentage of up to 75%. The average motor vehicle exhaust contributions increased during the day. In contrast, LP gas contribution was higher during the morning than in the afternoon. Apportionment for the most abundant individual NMHC showed that the vehicular source is the major contributor to acetylene, ethylene, pentanes, n-hexane, toluene, and xylenes, while handling and distribution of LP gas was the major source contributor to propane and butanes. Comparison between CMB estimates of NMHC and the emission inventory showed a good agreement for vehicles, handling and distribution of LP gas, and painting operations; nevertheless, emissions from diesel exhaust and asphalt operations showed differences, and the results suggest that these emissions could be underestimated.

  10. Satellite-derived land surface parameters for mesoscale modelling of the Mexico City basin

    Directory of Open Access Journals (Sweden)

    B. de Foy

    2006-01-01

    Full Text Available Mesoscale meteorological modelling is an important tool to help understand air pollution and heat island effects in urban areas. Accurate wind simulations are difficult to obtain in areas of weak synoptic forcing. Local factors have a dominant role in the circulation and include land surface parameters and their interaction with the atmosphere. This paper examines an episode during the MCMA-2003 field campaign held in the Mexico City Metropolitan Area (MCMA in April of 2003. Because the episode has weak synoptic forcing, there is the potential for the surface heat budget to influence the local meteorology. High resolution satellite observations are used to specify the land use, vegetation fraction, albedo and surface temperature in the MM5 model. Making use of these readily available data leads to improved meteorological simulations in the MCMA, both for the wind circulation patterns and the urban heat island. Replacing values previously obtained from land-use tables with actual measurements removes the number of unknowns in the model and increases the accuracy of the energy budget. In addition to improving the understanding of local meteorology, this sets the stage for the use of advanced urban modules.

  11. Investigation of OxProduction Rates in the Mexico City Metropolitan Area during MILAGRO

    Science.gov (United States)

    Dusanter, S.; Molina, L. T.; Stevens, P. S.

    2009-12-01

    Understanding the oxidative capacity of the atmosphere and the formation of secondary pollutants are important issues in atmospheric chemistry. For instance, the photochemical production of tropospheric ozone (O3) is of particular interest due to its detrimental effects on both human health and agricultural ecosystems. A detailed characterization of tropospheric O3 production rates will help in the development of effective control strategies. The 2006 Mexico City Metropolitan Area field campaign (MCMA-2006) was one of four components of MILAGRO (Megacity Initiative: Local And Global Research Observations) intended to collect information on the impact of megacity emissions on local, regional and global scales. In this presentation, rates of production of Ox (Ox = O3 + NO2) species during MCMA-2006 at the supersite T0 (Instituto Mexicano del Petroleo) will be presented using different approaches based on measured and modeled concentrations of ROx (OH + HO2 + RO2) radicals. In addition, we will examine both the reactivity of OH and the contribution of specific peroxy radicals to the oxidation rate of NO to estimate the contribution of groups of VOCs (alkanes, alkenes, aromatics, oxygenated and biogenic VOCs) to the total production rate of Ox species.

  12. Irrigation water quality in southern Mexico City based on bacterial and heavy metal analyses

    Energy Technology Data Exchange (ETDEWEB)

    Solis, C. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apdo Postal 20-364, 01000 Mexico, DF (Mexico)]. E-mail: corina@fisica.unam.mx; Sandoval, J. [Instituto de Ecologia, Universidad Nacional Autonoma de Mexico, Apdo Postal 70-275, 04510 Mexico, DF (Mexico); Perez-Vega, H. [Ciencias Agropecuarias, Universidad Juarez Autonoma de Tabasco, Ave. Universidad S/N. Zona de la Cultura, 86040 Villa Hermosa, Tabasco (Mexico); Mazari-Hiriart, M. [Instituto de Ecologia, Universidad Nacional Autonoma de Mexico, Apdo Postal 70-275, 04510 Mexico, DF (Mexico)

    2006-08-15

    Xochimilco is located in southern Mexico City and represents the reminiscence of the pre-Columbian farming system, the 'chinampa' agriculture. 'Chinampas' are island plots surrounded by a canal network. At present the area is densely urbanized and populated, with various contaminant sources contributing to the water quality degradation. The canal system is recharged by a combination of treated-untreated wastewater, and precipitation during the rainy season. Over 40 agricultural species, including vegetables, cereals and flowers, are produced in the 'chinampas'. In order to characterize the quality of Xochimilcos' water used for irrigation, spatial and temporal contaminant indicators such as microorganisms and heavy metals were investigated. Bacterial indicators (fecal coliforms, fecal enterococcus) were analyzed by standard analytical procedures, and heavy metals (such as Fe, Cu, Zn and Pb) were analyzed by particle induced X-ray emission (PIXE). The more contaminated sites coincide with the heavily populated areas. Seasonal variation of contaminants was observed, with the higher bacterial counts and heavy metal concentrations reported during the rainy season.

  13. Back to school: drop-out and return to school among youth in Mexico City

    Directory of Open Access Journals (Sweden)

    Emilio Blanco Bosco

    2014-09-01

    Full Text Available This paper addresses the return to school among youngsters in Mexico City that had dropped out of school at some point between the beginning of elementary school and the end of upper secondary level. More than a quarter of these youngsters returned to school, which supports the idea that quitting school does not equal to the end of the educational career. There is a significant association between the socioeconomic origin and the probability of an individual returning to school, although weaker (and in the opposite direction than correlation with the probability of dropping out. Complex, non-linear patterns were found between the return and the moment when the drop out occurred, which questions mainstream theories about educational decisions. It was also found that an important proportion of those who returned to school completed upper secondary education, particularly remarkable among youngsters of lower social origins. The evidence supports the idea of considering both the effects of the social structure and the individual agency, and particularly to take into account the actors’ rationality.

  14. Abortion legalization and childbearing in Mexico1

    Science.gov (United States)

    Gutierrez Vazquez, Edith Y.; Parrado, Emilio A.

    2016-01-01

    In 2007 abortion was legalized in the Federal District of Mexico, making the largest jurisdiction in Latin America, outside of Cuba, to allow women to have abortions on request during the first trimester of pregnancy. While the implications of the law for women's health and maternal mortality have been investigated, its potential association with fertility behavior has yet to be assessed. In this paper, we examine metropolitan area differences in overall and parity-specific, as well as the age pattern of childbearing between 2000 and 2010 to more precisely isolate the contribution of abortion legalization to fertility in Mexico. Our statistical specification applies difference-in-difference regression methods that control for concomitant changes in other socioeconomic predictors of fertility to assess the differential influence of the law across age groups. In addition, we account for prior fertility levels and change to better separate the effect of the law from preceding trends. Overall, the evidence suggests a systematic association between abortion legalization and fertility. The law appears to have contributed to lower fertility in Mexico City compared to other metropolitan areas and prior trends, though the influence is mostly visible among women aged 20-34 in connection with the transition to first and second child with limited impact on teenage fertility. There is some evidence that its effect might be diffusing to the greater Mexico City metropolitan area. PMID:27285423

  15. INAA of aerosol samples in Mexico City

    International Nuclear Information System (INIS)

    Martinez, T.; Lartigue, J.; Navarrete, M.; Cabrera, L.; Riveroll, M.

    2000-01-01

    Total solid particles (TSP), respirable particles (RP) PM10 and 17 metallic pollutants were measured in dwellings in the Metropolitan Zone of Mexico Valley (MZMV) by gravimetry and instrumental neutron activation analysis (INAA). Monitoring was performed in Northeast, Center, Southeast and Southwest Zones in the winter and spring seasons. In general, the average concentration of contaminants (derived from industrial activities) that we have determined have increased with time. TSP and RP PM10 are often above the US and Mexican norms. (author)

  16. Magnitude and extent of land subsidence in central Mexico revealed by regional InSAR ALOS time-series survey

    Science.gov (United States)

    Chaussard, E.; Wdowinski, S.; Amelung, F.; Cabral-Cano, E.

    2013-05-01

    Massive groundwater extraction is very common in Mexico and is well known to result in land subsidence. However, most surveys dedicated to land subsidence focus on one single city, mainly Mexico City, and thus fail to provide a comprehensive picture of the problem. Here we use a space-based radar remote sensing technique, known as Interferometric Synthetic Aperture Radar (InSAR) to detect land subsidence in the entire central Mexico area. We used data from the Japanese satellite ALOS, processed over 600 SAR images acquired between 2007-2011 and produced over 3000 interferograms to cover and area of 200,000 km2 in central Mexico. We identify land subsidence in twenty-one areas, including seventeen cities, namely from east to west, Puebla, Mexico city, Toluca de Lerdo, Queretaro, San Luis de la Paz, south of San Luis de la Paz, Celaya, south of Villa de Reyes, San Luis Potosi, west of Villa de Arista, Morelia, Salamanca, Irapuato, Silao, Leon, Aguascalientes, north of Aguascalientes, Zamora de Hidalgo, Guadalajara, Ahuacatlan, and Tepic. Subsidence rates of 30 cm/yr are observed in Mexico City, while in the other locations typical rates of 5-10 cm/yr are noticed. Regional surveys of this type are necessary for the development of hazard mitigation plans and efficient use of ground-based monitoring. We additionally correlate subsidence with land use, surface geology, and faults distribution and suggest that groundwater extraction for agricultural, urban, and industrial uses are the main causes of land subsidence. We also reveal that the limits of the subsiding areas often correlate with existing faults, motion on these faults being driven by water extraction rather than by tectonic activity. In all the subsiding locations we observe high ground velocity gradients emphasizing the significant risks associated with land subsidence in central Mexico. Averaged 2007-2011 ground velocity map from ALOS InSAR time-series in central Mexico, revealing land subsidence in 21

  17. Data on prevalence and risk factors associated with Toxocara spp infection, atopy and asthma development in Northeast Brazilian school children

    Directory of Open Access Journals (Sweden)

    Márcia B. Silva

    2016-12-01

    Full Text Available In the present article, we provide shortly, data on risk factors for acquiring Toxocara spp. infection and investigate possible associations between this infection with atopy and asthma in school children of a small town and its semi-rural areas of Northeast Brazil. The data set are composed by demographic, social and home environment variables. The detection of anti-Toxocara spp. IgG and specific IgE to aeroallergens was determined by ELISA and ImmunocAP/Phadiatrope systems, respectively. The data presented in this article are related to the article entitled “Risk factors for Toxocara spp. seroprevalence and its association with atopy and asthma phenotypes in school-age children in a small town and semi-rural areas of Northeast Brazil” (M.B. Silva, A.L. Amor, L.N. Santos, A.A. Galvão, A.V. Oviedo Vera, E.S. Silva et al., 2016 [1].

  18. Environmental conditions, immunologic phenotypes, atopy, and asthma: new evidence of how the hygiene hypothesis operates in Latin America.

    Science.gov (United States)

    Figueiredo, Camila Alexandrina; Amorim, Leila D; Alcantara-Neves, Neuza M; Matos, Sheila M A; Cooper, Philip J; Rodrigues, Laura C; Barreto, Mauricio L

    2013-04-01

    It has been proposed that improved hygiene and reduced experience of infections in childhood influences the development of allergic diseases. The mechanisms by which the hygiene operates are not well established but are underpinned by two apparently incompatible immunologic paradigms, the balance of TH1 versus TH2 cytokines and IL-10-mediated regulation of TH2 cytokines. This study defined immunologic phenotypes with the use of latent class analysis and investigated their associations with environmental factors, markers of allergy and asthma, in a Latin American population. We studied 1127 children living in urban Brazil. Data on wheeze and environmental exposures were collected with standardized questionnaires. Atopy was measured by specific IgE in serum and skin prick test reactivity to aeroallergens. Cytokines were measured in culture after the stimulation of peripheral blood leukocytes with mitogen. Infections with pathogens were assessed by serology and stool examinations. Children were classified as having high or low burden of infection. Latent class analysis was used to identify immune phenotypes on the basis of cytokine production. Logistic regression was used to evaluate the adjusted effects of environment and burden of infection on the immunologic phenotypes and the effect of the phenotypes on atopy and asthma. Three phenotypes were identified, labeled underresponsive, intermediate, and responsive. Children of more educated mothers, living in improved environmental conditions, and with a low burden of infection were significantly more likely to have the responsive phenotype. The responsive phenotype was significantly associated with an increased prevalence of atopy but not asthma. Our findings contribute to a better understanding of the immune mechanisms by which the hygiene hypothesis operates in urban Latin America. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  19. Galacto-Oligosaccharide/Polidextrose Enriched Formula Protects against Respiratory Infections in Infants at High Risk of Atopy: A Randomized Clinical Trial

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    Giusy Ranucci

    2018-03-01

    Full Text Available Background: Early nutrition affects the risk of atopy and infections through modifications of intestinal microbiota. The Prebiotics in the Prevention of Atopy (PIPA study was a 24-month randomised, double-blind, placebo-controlled trial. It aimed to evaluate the effects of a galacto-oligosaccharide/polydextrose (GOS/PDX-formula (PF on atopic dermatitis (AD and common infections in infants who were born to atopic parents and to investigate the relationship among early nutrition, gut microbiota and clinical outcomes. Methods: A total of 201 and 199 infants were randomized to receive a PF and standard formula (SF, respectively; 140 infants remained on exclusive breastfeeding (BF. Results: The cumulative incidence of AD and its intensity and duration were not statistically different among the three groups. The number of infants with at least one episode of respiratory infection (RI and the mean number of episodes until 48 weeks of age were significantly lower in the PF group than in the SF group. The number of patients with recurrent RIs and incidence of wheezing lower RIs until 96 weeks were lower in the PF group than the SF group, but similar to the BF group. Bifidobacteria and Clostridium cluster I colonization increased over time in the PF group but decreased in the SF and BF groups. Bifidobacteria had a protective role in RIs, whereas Clostridium cluster I was associated with atopy protection. Conclusion: The early administration of PF protects against RIs and mediates a species-specific modulation of the intestinal microbiota. Trial registration: clinicaltrial.gov Identifier: NCT02116452.

  20. The Prevalence of Contact Dermatitis Among Occupational and Work-related Diseases. Correlation between Atopy and Allergic or Irritative Contact Dermatitis

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    Codruta-Dana Pitis

    2015-12-01

    Full Text Available The prevalence of contact dermatitis (CD in Europe varies between 6.7% and 10.6% depending on the sector of activity. Professional CD (PCD has an important economic impact − 30% of the budget compensation for occupational disease. In Romania, the prevalence of PCD is underestimated, with an even distribution of cases with respect to the allergic or irritative mechanism. A retrospective clinical study was conducted; target population being the patients admitted in Occupational Medicine Clinic Cluj-Napoca between 2003 and 2011. Objectives of study were: specifying the prevalence range of allergic CD (ACD / irritative CD (ICD among occupational/work-related diseases, the distribution of allergic/irritative CD (A/ICD for different sectors of activity and establishing the correlation between atopy and A/ICD. We have applied allergy skin tests - prick (environmental allergens and patch (occupational allergens. Inclusion criteria were: -documented occupational exposure at skin allergens/irritants; -the atopy state; -diagnostic established at discharge. Patients with recurrent chronic urticaria, angioedema, hypereosinophilic syndrome have been excluded. Statistical analysis was done using SPSS software. The study indicated a similar prevalence for A/ICD, with similar distribution. Prevalence above average has been recorded in the metallurgy sector (A/ICD, in health care sector (ACD, respectively, textile industry (ICD. The correlation atopy-ACD has proved to be lower compared to previous reports. Regarding ICD, the diagnostic was confirmed frequently to non-atopic persons. We strongly recommend the compliance with a multidisciplinary protocol for the management of A/ICD, individualized for specific activity sectors or even work stations.

  1. Neurocysticercosis, a persisting health problem in Mexico.

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    Agnès Fleury

    Full Text Available BACKGROUND: The ongoing epidemiological transition in Mexico minimizes the relative impact of neurocysticercosis (NC on public health. However, hard data on the disease frequency are not available. METHODOLOGY: All clinical records from patients admitted in the Instituto Nacional de Neurologia y Neurocirugia (INNN at Mexico City in 1994 and 2004 were revised. The frequencies of hospitalized NC patients in neurology, neurosurgery and psychiatry services, as well as NC mortality from 1995 through 2009, were retrieved. Statistical analyses were made to evaluate possible significant differences in frequencies of NC patients' admission between 1994 and 2004, and in yearly frequencies of NC patients' hospitalization and death between 1995 and 2009. PRINCIPAL FINDINGS: NC frequency in INNN is not significantly different in 1994 and 2004. Between these two years, clinical severity of the cases diminished and the proportion of patients living in Mexico City increased. Yearly frequencies of hospitalization in neurology and psychiatry services were stable, while frequencies of hospitalization in neurosurgery service and mortality significantly decreased between 1995 and 2009. CONCLUSIONS: Our findings show a stable tendency of hospital cases during the last decade that should encourage to redouble efforts to control this ancient disease.

  2. Surface energy balance measurements in the Mexico City: a review

    Energy Technology Data Exchange (ETDEWEB)

    Tejeda Martinez, A. [Universidad Veracruzana, Xalapa, Veracruz (Mexico); Jauregui Ostos, E. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, UNAM, Mexico, D.F. (Mexico)

    2005-01-01

    During the last decade of the 20th Century, diverse campaigns for measuring the atmospheric energy balance were performed in downtown Mexico City (School of Mines and Preparatory School No. 7), in the southern suburbs (University Reserve) and in the surrounding rural areas (Plan Texcoco), in addition to a campaign carried out in 1985 in the Tacubaya district, a suburban western peripheral site. The objective was to obtain data for a better understanding of the climatic alterations due to urbanization, particularly to describe the role that the modification of the natural ground cover has played as a result of paving and the construction of urban canyons. In this paper, a review of these campaigns is presented. Energy partitioning in some areas (Tacubaya and Preparatory School No.7) is similar to that observed in urban centers of middle latitudes, whereas the major contrast was observed between Texcoco, with maximum energy consumption through evaporation, and School of Mines, where the latent heat is as low as in a desert. From the values of the correlations among the different components of energy balance, it may be possible to attempt the modeling of the diverse components of energy balance by means of regression equations starting from the net radiation. Those same coefficients distinguish the type of environment: urban, suburban or rural. [Spanish] Las primeras mediciones de balance energetico en la Ciudad de Mexico se realizaron en 1985 en un suburbio al poniente de la ciudad (el observatorio de Tacubaya). Ya en la decada de los anos noventa del siglo XX, dichas observaciones se multiplicaron tanto en el centro historico (antigua Escuela de Minas y en el edificio de la Preparatoria No. 7), como en otros sitios al sur (en terrenos de Ciudad Universitaria) y en la periferia rural (Plan Texcoco). El proposito de estas mediciones ha sido tener un mejor entendimiento de las alteraciones climaticas debidas a la urbanizacion. En este trabajo se presenta una revision

  3. Cross-Sectional Association between Length of Incarceration and Selected Risk Factors for Non-Communicable Chronic Diseases in Two Male Prisons of Mexico City.

    Science.gov (United States)

    Silverman-Retana, Omar; Lopez-Ridaura, Ruy; Servan-Mori, Edson; Bautista-Arredondo, Sergio; Bertozzi, Stefano M

    2015-01-01

    Mexico City prisons are characterized by overcrowded facilities and poor living conditions for housed prisoners. Chronic disease profile is characterized by low prevalence of self reported hypertension (2.5%) and diabetes (1.8%) compared to general population; 9.5% of male inmates were obese. There is limited evidence regarding on the exposure to prison environment over prisoner's health status; particularly, on cardiovascular disease risk factors. The objective of this study is to assess the relationship between length of incarceration and selected risk factors for non-communicable chronic diseases (NCDs). We performed a cross-sectional analysis using data from two large male prisons in Mexico City (n = 14,086). Using quantile regression models we assessed the relationship between length of incarceration and selected risk factors for NCDs; stratified analysis by age at admission to prison was performed. We found a significant negative trend in BMI and WC across incarceration length quintiles. BP had a significant positive trend with a percentage change increase around 5% mmHg. The greatest increase in systolic blood pressure was observed in the older age at admission group. This analysis provides insight into the relationship between length of incarceration and four selected risk factors for NCDs; screening for high blood pressure should be guarantee in order to identify at risk individuals and linked to the prison's health facility. It is important to assess prison environment features to approach potential risk for developing NCDs in this context.

  4. Cross-Sectional Association between Length of Incarceration and Selected Risk Factors for Non-Communicable Chronic Diseases in Two Male Prisons of Mexico City.

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    Omar Silverman-Retana

    Full Text Available Mexico City prisons are characterized by overcrowded facilities and poor living conditions for housed prisoners. Chronic disease profile is characterized by low prevalence of self reported hypertension (2.5% and diabetes (1.8% compared to general population; 9.5% of male inmates were obese. There is limited evidence regarding on the exposure to prison environment over prisoner's health status; particularly, on cardiovascular disease risk factors. The objective of this study is to assess the relationship between length of incarceration and selected risk factors for non-communicable chronic diseases (NCDs.We performed a cross-sectional analysis using data from two large male prisons in Mexico City (n = 14,086. Using quantile regression models we assessed the relationship between length of incarceration and selected risk factors for NCDs; stratified analysis by age at admission to prison was performed. We found a significant negative trend in BMI and WC across incarceration length quintiles. BP had a significant positive trend with a percentage change increase around 5% mmHg. The greatest increase in systolic blood pressure was observed in the older age at admission group.This analysis provides insight into the relationship between length of incarceration and four selected risk factors for NCDs; screening for high blood pressure should be guarantee in order to identify at risk individuals and linked to the prison's health facility. It is important to assess prison environment features to approach potential risk for developing NCDs in this context.

  5. Air quality modeling in the Valley of Mexico: meteorology, emissions and forecasting

    Science.gov (United States)

    Garcia-Reynoso, A.; Jazcilevich, A. D.; Diaz-Nigenda, E.; Vazquez-Morales, W.; Torres-Jardon, R.; Ruiz-Suarez, G.; Tatarko, J.; Bornstein, R.

    2007-12-01

    The Valley of Mexico presents important challenges for air quality modeling: complex terrain, a great variety of anthropogenic and natural emissions sources, and high altitude and low latitude increasing the amount of radiation flux. The modeling group at the CCA-UNAM is using and merging state of the art models to study the different aspects that influence the air quality phenomenon in the Valley of Mexico. The air quality model MCCM that uses MM5 as its meteorological input has been a valuable tool to study important features of the complex and intricate atmospheric flows on the valley, such as local confluences and vertical fumigation. Air quality modeling has allowed studying the interaction between the atmospheres of the valleys surrounding the Valley of Mexico, prompting the location of measurement stations during the MILAGRO campaign. These measurements confirmed the modeling results and expanded our knowledge of the transport of pollutants between the Valleys of Cuernavaca, Puebla and Mexico. The urban landscape of Mexico City complicates meteorological modeling. Urban-MM5, a model that explicitly takes into account the influence of buildings, houses, streets, parks and anthropogenic heat, is being implemented. Preliminary results of urban-MM5 on a small area of the city have been obtained. The current emissions inventory uses traffic database that includes hourly vehicular activity in more than 11,000 street segments, includes 23 area emissions categories, more than 1,000 industrial sources and biogenic emissions. To improve mobile sources emissions a system consisting of a traffic model and a car simulator is underway. This system will allow for high time and space resolution and takes into account motor stress due to different driving regimes. An important source of emissions in the Valley of Mexico is erosion dust. The erosion model WEPS has been integrated with MM5 and preliminary results showing dust episodes over Mexico City have been obtained. A

  6. Isolation of Yersinia from raw meat (pork and chicken) and precooked meat (porcine tongues and sausages) collected from commercial establishments in Mexico City.

    Science.gov (United States)

    Ramírez, E I; Vázquez-Salinas, C; Rodas-Suárez, O R; Pedroche, F F

    2000-04-01

    A total of 160 meat product samples were collected from commercial outlets in Mexico City to investigate the presence of different species of Yersinia by the 4 degrees C enrichment method after 1, 3, 5, and 7 days of incubation using alkaline treatment and isolating in cefsulodin-Irgasan-novobiocin and MacConkey agars with Tween 80. Overall, Yersinia spp. were isolated from 27% of the samples analyzed, whereas 40% of the raw and only 13% of the precooked samples were contaminated. Although 2,970 colonies showed Yersinia characteristics, only 706 (24%) actually corresponded to this genus: 49% were Yersinia enterocolitica, 25% Yersinia kristensenii, 15% Yersinia intermedia, 9% Yersinia frederiksenii, and 2% Yersinia aldovae; 10% corresponded to biotype 2, 2% to biotype 3, and 4% to biotype 4. The presence of Yersinia in raw and cooked meat products represents a health risk for consumers in Mexico, where further clinical studies are needed to assess the epidemiological importance of this pathogen.

  7. Long-range pollution transport during the MILAGRO-2006 campaign: a case study of a major Mexico City outflow event using free-floating altitude-controlled balloons

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    P. B. Voss

    2010-08-01

    Full Text Available One of the major objectives of the Megacities Initiative: Local And Global Research Observations (MILAGRO-2006 campaign was to investigate the long-range transport of polluted Mexico City Metropolitan Area (MCMA outflow and determine its downwind impacts on air quality and climate. Six research aircraft, including the National Center for Atmospheric Research (NCAR C-130, made extensive chemical, aerosol, and radiation measurements above MCMA and more than 1000 km downwind in order to characterize the evolution of the outflow as it aged and dispersed over the Mesa Alta, Sierra Madre Oriental, Coastal Plain, and Gulf of Mexico. As part of this effort, free-floating Controlled-Meteorological (CMET balloons, commanded to change altitude via satellite, made repeated profile measurements of winds and state variables within the advecting outflow. In this paper, we present an analysis of the data from two CMET balloons that were launched near Mexico City on the afternoon of 18 March 2006 and floated downwind with the MCMA pollution for nearly 30 h. The repeating profile measurements show the evolving structure of the outflow in considerable detail: its stability and stratification, interaction with other air masses, mixing episodes, and dispersion into the regional background. Air parcel trajectories, computed directly from the balloon wind profiles, show three transport pathways on 18–19 March: (a high-altitude advection of the top of the MCMA mixed layer, (b mid-level outflow over the Sierra Madre Oriental followed by decoupling and isolated transport over the Gulf of Mexico, and (c low-level outflow with entrainment into a cleaner northwesterly jet above the Coastal Plain. The C-130 aircraft intercepted the balloon-based trajectories three times on 19 March, once along each of these pathways; in all three cases, peaks in urban tracer concentrations and LIDAR backscatter are consistent with MCMA pollution. In comparison with the transport models

  8. Emissions from forest fires near Mexico City

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    R. J. Yokelson

    2007-11-01

    Full Text Available The emissions of NOx (defined as NO (nitric oxide + NO2 (nitrogen dioxide and hydrogen cyanide (HCN, per unit amount of fuel burned, from fires in the pine forests that dominate the mountains surrounding Mexico City (MC are about 2 times higher than normally observed for forest burning. The ammonia (NH3 emissions are about average for forest burning. The upper limit for the mass ratio of NOx to volatile organic compounds (VOC for these MC-area mountain fires was ~0.38, which is similar to the NOx/VOC ratio in the MC urban area emissions inventory of 0.34, but much larger than the NOx/VOC ratio for tropical forest fires in Brazil (~0.068. The nitrogen enrichment in the fire emissions may be due to deposition of nitrogen-containing pollutants in the outflow from the MC urban area. This effect may occur worldwide wherever biomass burning coexists with large urban areas (e.g. the tropics, southeastern US, Los Angeles Basin. The molar emission ratio of HCN to carbon monoxide (CO for the mountain fires was 0.012±0.007, which is 2–9 times higher than widely used literature values for biomass burning. The ambient molar ratio HCN/CO in the MC-area outflow is about 0.003±0.0003. Thus, if only mountain fires emit significant amounts of HCN, these fires may be contributing about 25% of the CO production in the MC-area (~98–100 W and 19–20 N. Comparing the PM10/CO and PM2.5/CO mass ratios in the MC Metropolitan Area emission inventory (0.0115 and 0.0037 to the PM1/CO mass ratio for the mountain fires (0.133 then suggests that these fires could produce as much as ~79–92% of the primary fine particle mass generated in the MC-area. Considering both the uncertainty in the HCN/CO ratios and secondary aerosol formation in the urban and fire emissions implies that about 50±30% of the "aged" fine particle mass in the March 2006 MC-area outflow could be from these fires.

  9. At the Table with Hungry Ghosts: Intimate Borderwork in Mexico City

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    Jean Duruz

    2011-09-01

    Full Text Available This article focuses on the project of sustaining cultural diversity within global cities’ intimate spaces. Specifically, it sketches the culinary histories of an Anglo-Australian woman (who, in 1968, settled permanently in Mexico and her male partner (who grew up in Mexico; his mother Mexican, his father Cantonese. Drawing on the tools of ‘borderwork’ (Hodge and O’Carroll, the argument positions culturally diverse landscapes of ‘Sydney’, ‘China’ and ‘Mexico City’ as distinct yet overlapping geographies. Meanwhile, analysis of curious moments in the couple’s intersecting histories contributes much fluidity to this cartography. In the process, a company of hungry ghosts appears at the dinner table – ghosts of diversity, diaspora and cosmopolitanism; nostalgia and memory; gender and ethnicity; home and belonging. The article concludes that even when borderwork is conducted amiably behind closed doors, it relies on contradictions for cultural sustenance. At the same time, its tensions resonate with possibilities for creative practice.

  10. An assessment of air pollutant exposure methods in Mexico City, Mexico.

    Science.gov (United States)

    Rivera-González, Luis O; Zhang, Zhenzhen; Sánchez, Brisa N; Zhang, Kai; Brown, Daniel G; Rojas-Bracho, Leonora; Osornio-Vargas, Alvaro; Vadillo-Ortega, Felipe; O'Neill, Marie S

    2015-05-01

    Geostatistical interpolation methods to estimate individual exposure to outdoor air pollutants can be used in pregnancy cohorts where personal exposure data are not collected. Our objectives were to a) develop four assessment methods (citywide average (CWA); nearest monitor (NM); inverse distance weighting (IDW); and ordinary Kriging (OK)), and b) compare daily metrics and cross-validations of interpolation models. We obtained 2008 hourly data from Mexico City's outdoor air monitoring network for PM10, PM2.5, O3, CO, NO2, and SO2 and constructed daily exposure metrics for 1,000 simulated individual locations across five populated geographic zones. Descriptive statistics from all methods were calculated for dry and wet seasons, and by zone. We also evaluated IDW and OK methods' ability to predict measured concentrations at monitors using cross validation and a coefficient of variation (COV). All methods were performed using SAS 9.3, except ordinary Kriging which was modeled using R's gstat package. Overall, mean concentrations and standard deviations were similar among the different methods for each pollutant. Correlations between methods were generally high (r=0.77 to 0.99). However, ranges of estimated concentrations determined by NM, IDW, and OK were wider than the ranges for CWA. Root mean square errors for OK were consistently equal to or lower than for the IDW method. OK standard errors varied considerably between pollutants and the computed COVs ranged from 0.46 (least error) for SO2 and PM10 to 3.91 (most error) for PM2.5. OK predicted concentrations measured at the monitors better than IDW and NM. Given the similarity in results for the exposure methods, OK is preferred because this method alone provides predicted standard errors which can be incorporated in statistical models. The daily estimated exposures calculated using these different exposure methods provide flexibility to evaluate multiple windows of exposure during pregnancy, not just trimester or

  11. Tourism and territorial structure in Ciudad Juarez, Mexico

    OpenAIRE

    Oswaldo Gallegos; Alvarado López López

    2012-01-01

    This paper deals with the issue of the territorial structure of tourism in Ciudad Juarez, Mexico. To do this, the study is divided into two major parts: first, theoretical aspects, given support to our analysis, and a brief history of tourism in the Northern borderlands of Mexico are presented. Then, four basic components of the territorial structure of tourism in Ciudad Juarez are examined: natural and cultural attractions, urban land-use, communications network centred around the city and v...

  12. Uniportal video-assisted thoracic surgery course in Mexico-first experience.

    Science.gov (United States)

    Céspedes-Meneses, Erick; Echavarri-Arana, José Manuel; Tort-Martínez, Alejandro; Guzmán-de Alba, Enrique; das Neves-Pereira, Joao Carlos; González-Rivas, Diego

    2016-01-01

    "The First Minimally Invasive Thoracic Surgery Uniportal Course" in Mexico was held from July 13 th to 15 th in Mexico City, at the National Institute of Respiratory Diseases (INER). Thoracic surgeons from around Mexico assisted the course. The special guests were the Spanish doctor Diego González-Rivas and the Brasilian doctor Joao Carlos das Neves-Pereira. The course included live surgery and wet lab. Demonstration of the uniportal video-assisted thoracic surgery (VATS) technique was done. The course was a success and Mexican thoracic surgeons were ready to adopt this technique.

  13. Development of an expert analysis tool based on an interactive subsidence hazard map for urban land use in the city of Celaya, Mexico

    Science.gov (United States)

    Alloy, A.; Gonzalez Dominguez, F.; Nila Fonseca, A. L.; Ruangsirikulchai, A.; Gentle, J. N., Jr.; Cabral, E.; Pierce, S. A.

    2016-12-01

    Land Subsidence as a result of groundwater extraction in central Mexico's larger urban centers initiated in the 80's as a result of population and economic growth. The city of Celaya has undergone subsidence for a few decades and a consequence is the development of an active normal fault system that affects its urban infrastructure and residential areas. To facilitate its analysis and a land use decision-making process we created an online interactive map enabling users to easily obtain information associated with land subsidence. Geological and socioeconomic data of the city was collected, including fault location, population data, and other important infrastructure and structural data has been obtained from fieldwork as part of a study abroad interchange undergraduate course. The subsidence and associated faulting hazard map was created using an InSAR derived subsidence velocity map and population data from INEGI to identify hazard zones using a subsidence gradient spatial analysis approach based on a subsidence gradient and population risk matrix. This interactive map provides a simple perspective of different vulnerable urban elements. As an accessible visualization tool, it will enhance communication between scientific and socio-economic disciplines. Our project also lays the groundwork for a future expert analysis system with an open source and easily accessible Python coded, SQLite database driven website which archives fault and subsidence data along with visual damage documentation to civil structures. This database takes field notes and provides an entry form for uniform datasets, which are used to generate a JSON. Such a database is useful because it allows geoscientists to have a centralized repository and access to their observations over time. Because of the widespread presence of the subsidence phenomena throughout cities in central Mexico, the spatial analysis has been automated using the open source software R. Raster, rgeos, shapefiles, and rgdal

  14. Inner city air pollution and respiratory health and atopy in children

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, T.; Safeca, A.F.; Leupold, W. [Univ. Children' s Hospital Dresden (Germany); Weiland, S.K.; Duhme, H.; Keil, U. [Univ. of Muenster, Inst. of Epidemiology and Social Medicine (Germany); Mutius, E. von [Univ. Children' s Hospital, Klinikum Innenstadt, Munich (Germany); Graefe, H. [Saxony State Agency for Environment and Geology, Radebeul (Germany); Csaplovics, E. [Univ. of Technology, Inst. of Photogrammetry and Remote Sensing, Dresden (Germany)

    1999-09-01

    The impact of inner city air pollution on the development of respiratory and atopic diseases in childhood is still unclear. In a cross sectional study in Dresden, Germany, 5,421 children in two age groups (5-7 yrs and 9-11 yrs) were studied according to the International Study of Asthma and Allergies in Childhood (ISAAC) phase II protocol, The prevalences of wheezing and cough as well as doctor diagnosed asthma and bronchitis were assessed by parental questionnaires. Children also underwent skin-prick testing, venepuncture for the measurement of serum immunoglobulin (Ig)E, lung function testing and a bronchial challenge test (4.5% saline) to assess airway hyperresponsiveness. Exposure was assessed on an individual basis by relating mean annual air pollution levels (SO{sub 2}, NO{sub 2}, CO, benzene, and O{sub 3}) which had been measured on a 1 km{sup 2} grid, to the home and school address of each study subject. After adjusting for potential confounding factors an increase in the exposure to benzene of 1 {mu}g{center{underscore}dot}m{sup 3} air was associated with an increased prevalence of morning cough (adjusted odds ratio (aOR): 1.15; 1.04-1.27) and bronchitis (aOR: 1.11; 1.03-1.19). Similar associations were observed for NO{sub 2} and CO. In turn, the prevalences of atopic sensitization, symptoms of atopic diseases and bronchial hyperresponsiveness were not positively associated with exposure to any of these pollutants. It is concluded that in this study a moderate increase in exposure to traffic-related air pollution was associated with an increased prevalence of cough and bronchitis, but not with atopic conditions in children. (au)

  15. Tuberculosis and systemic lupus erythematosus: a case-control study in Mexico City.

    Science.gov (United States)

    Torres-González, Pedro; Romero-Díaz, Juanita; Cervera-Hernández, Miguel Enrique; Ocampo-Torres, Mario; Chaires-Garza, Luis Gerardo; Lastiri-González, Ernesto Alejandro; Atisha-Fregoso, Yemil; Bobadilla-Del-Valle, Miriam; Ponce-de-León, Alfredo; Sifuentes-Osornio, José

    2018-04-20

    To determine, among systemic lupus erythematosus patients, factors associated with active tuberculosis. We performed a case-control study, in a tertiary-care center in Mexico City. We defined cases as systemic lupus erythematosus patients with active tuberculosis and matched them 1:1 with systemic lupus erythematosus patients without tuberculosis (controls) by age, date of systemic lupus erythematosus diagnosis, and disease duration. We analyzed clinical variables, lupus disease activity (SLEDAI-2K), and accumulated damage (SLICC/ARC-DI). We performed a nonconditional logistic regression to determine factors associated with tuberculosis. We identified 72 tuberculosis cases among systemic lupus erythematosus patients, 58% were culture confirmed. Thirty-three percent (24/72) were pulmonary only, 47.2% (34/72) extrapulmonary only, and 19.4% both. After adjustment for age, gender, and socioeconomic status, SLEDAI-2K and SLICC/ARC-DI, a 1-year cumulative dose of prednisone ≥ 3 g (odds ratios (OR), 18.85; 95% confidence interval (95% CI), 6.91-51.45) was associated with tuberculosis, and the antimalarial treatment was protective (OR, 0.13; 95% CI, 0.04-0.36). Among systemic lupus erythematosus patients, cumulative dose of prednisone is associated with tuberculosis. Further research is required to elucidate the protective effect of antimalarial drugs for tuberculosis. Preventive strategies must be implemented in patients at risk.

  16. Asthma and atopy in children born by caesarean section: effect modification by family history of allergies – a population based cross-sectional study

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    Kolokotroni Ourania

    2012-11-01

    Full Text Available Abstract Background Studies on the association of birth by caesarean section (C/S and allergies have produced conflicting findings. Furthermore, evidence on whether this association may differ in those at risk of atopy is limited. This study aims to investigate the association of mode of delivery with asthma and atopic sensitization and the extent to which any effect is modified by family history of allergies. Methods Asthma outcomes were assessed cross-sectionally in 2216 children at age 8 on the basis of parents’ responses to the ISAAC questionnaire whilst skin prick tests to eleven aeroallergens were also performed in a subgroup of 746 children. Adjusted odds ratios of asthma and atopy by mode of delivery were estimated in multivariable logistic models while evidence of effect modification was examined by introducing interaction terms in the models. Results After adjusting for potential confounders, children born by C/S appeared significantly more likely than those born vaginally to report ever wheezing (OR 1.36, 95% CI 1.07-1.71, asthma diagnosis (OR 1.41, 95% CI 1.09-1.83 and be atopic (OR 1.67, 95% CI 1.08-2.60. There was modest evidence that family history of allergies may modify the effect of C/S delivery on atopy (p for effect modification=0.06 but this was not the case for the asthma outcomes. Specifically, while more than a two-fold increase in the odds of being a topic was observed in children with a family history of allergies if born by C/S (OR 2.62, 95% CI 1.38-5.00, no association was observed in children without a family history of allergies (OR 1.16, 95% CI 0.64-2.11. Conclusions Birth by C/S is associated with asthma and atopic sensitization in childhood. The association of C/S and atopy appears more pronounced in children with family history of allergies.

  17. Experiences and opinions of health-care professionals regarding legal abortion in Mexico City: a qualitative study.

    Science.gov (United States)

    Contreras, Xipatl; van Dijk, Marieke G; Sanchez, Tahilin; Smith, Patricio Sanhueza

    2011-09-01

    This study examines the experiences and opinions of health-care professionals after the legalization of abortion in Mexico City in 2007. Sixty-four semistructured interviews were conducted between 1 December 2007 and 16 July 2008 with staff affiliated with abortion programs in 12 hospitals and 1 health center, including obstetricians/gynecologists, nurses, social workers, key decisionmakers at the Ministry of Health, and others. Findings suggest that program implementation was difficult because of the lack of personnel, space, and resources; a great number of conscientious objectors; and the enormous influx of women seeking services, which resulted in a work overload for participating professionals. The professionals interviewed indicate that the program improved significantly over time. They generally agree that legal abortion should be offered, despite serious concerns about repeat abortions. They recommend improving family planning campaigns and post-procedure contraceptive use, and they encourage the opening of primary health-care facilities dedicated to providing abortion services.

  18. [Prevention rather than cure: the emergence and first stage of the Centros de Higiene Infantil in Mexico City, 1922-1932].

    Science.gov (United States)

    Alanís, Mercedes

    2015-01-01

    This article deals with the main features of the emergence and first ten years of the Centros de Higiene Infantil, facilities run by the Departamento de Salubridad Pública from 1922 on in Mexico City with the goal of providing care for mothers from pregnancy onwards and children from birth to two years of age. It reviews the actions that gave rise to this project and how it became established. It analyzes the structure of these centers, the characteristics of the mothers and children seen there and the functions performed by doctors and nurses, stressing the notion of preventing childhood illnesses, and ends with a first assessment of the effects and limitations of these centers.

  19. Physical and chemical properties of the regional mixed layer of Mexico's Megapolis

    Directory of Open Access Journals (Sweden)

    P. Arnott

    2009-08-01

    Full Text Available The concentration of gases and aerosol particles have been measured at the mountain site of Altzomoni, 4010 m in altitude, located 60 km southeast of Mexico City, 50 km east of Puebla and 70 km northeast of Cuernavaca. The objective of this study was to evaluate the properties of gases and particles in the Regional Mixed Layer (RML of Mexico's Megapolis. Altzomoni is generally above the RML from late evening until late morning at which time the arrival of the RML is marked by increasing concentrations of CO and aerosol particles that reach their maxima in mid-afternoon. The average diurnal cycles for fourteen days in March, 2006 were evaluated during which time the synoptic scale circulation had three principal patterns: from the east (E, southwest (SW and west northwest (WNW. The original hypothesis was that air arriving from the direction of Mexico City would have much higher concentrations of anthropogenic gases and particles than air from Puebla or Cuernavaca, due to the relatively large differences in populations. In fact, not only were the average, maximum concentrations of CO and O3 (0.3 and 0.1 ppmv approximately the same for air originating from the WNW and E, but the average maximum concentrations of Peroxyacyl nitrates (PAN,PPN and particle organic matter (POM in air from the E exceeded those in air from the WNW. Comparisons of measurements from the mountain site with those made by aircraft during the same period, using the same type of aerosol mass spectrometer, show that the total masses of POM, NO3−, SO42− and NH4+ were approximately the same from aircraft measurements made over Mexico City and when winds were from the east at the mountain site. In contrast 75% of the total aerosol mass at the mountain site was POM whereas over Mexico City the fraction of POM was less than 60%. The measurements suggest the occasional influence of emissions from the nearby volcano, Popocatepetl, as well as possible incursions of biomass

  20. Testing Predictive Models of Technology Integration in Mexico and the United States

    Science.gov (United States)

    Velazquez, Cesareo Morales

    2008-01-01

    Data from Mexico City, Mexico (N = 978) and from Texas, USA (N = 932) were used to test the predictive validity of the teacher professional development component of the Will, Skill, Tool Model of Technology Integration in a cross-cultural context. Structural equation modeling (SEM) was used to test the model. Analyses of these data yielded…

  1. Measurements and receptor modeling of volatile organic compounds in Southeastern Mexico City, 2000–2007

    Directory of Open Access Journals (Sweden)

    H. Wöhrnschimmel

    2010-09-01

    Full Text Available Ambient samples of volatile organic compounds (VOCs were measured between 2000 and 2007 in Southeastern Mexico City, quantifying 13 species (ethane, propane, propylene, butane, acetylene, pentane, hexane, heptane, benzene, octane, toluene, nonane, o-xylene. These time series were analyzed for long-term trends, using linear regression models. A main finding was that the concentrations for several VOC species were decreasing during this period. A receptor model was applied to identify possible VOC sources, as well as temporal patterns in their respective contributions. Domestic use of liquefied petroleum gas (LPG and vehicle exhaust are suggested to be the principal emission sources, contributing together between 70% and 80% to the total of quantified species. Both diurnal and seasonal patterns, as well as a weekend effect were recognized in the modelled source contributions. Furthermore, decreasing trends over time were found for LPG and hot soak (−7.8% and −12.7% per year, respectively, p < 0.01, whereas for vehicle exhaust no significant trend was found.

  2. Impacts of black carbon and co-pollutant emissions from transportation sector in Mexico City

    Science.gov (United States)

    Zavala, Miguel; Almanza, Victor; Garcia, Agustin; Jazcilevich, Aron; Lei, Wenfang; Molina, Luisa

    2016-04-01

    Black carbon is one of the most important short-lived climate-forcing agents, which is harmful to human health and also contributes significantly to climate change. Transportation is one of the largest sources of black carbon emissions in many megacities and urban complexes, with diesel vehicles leading the way. Both on-road and off-road vehicles can emit substantial amounts of harmful BC-containing particulate matter (PM) and are also responsible for large emissions of carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), and many other co-emitted volatile organic compounds (VOCs). Regionally, black carbon emissions contributions from mobile sources may vary widely depending on the technical characteristics of the vehicle fleet, the quality and chemical properties of the fuels consumed, and the degree of local development and economic activities that foster wider and more frequent or intensive use of vehicles. This presentation will review and assess the emissions of black carbon from the on-road and off-road transportation sector in the Mexico City Metropolitan Area. Viable mitigation strategies, including innovative technological alternatives to reduce black carbon and co-pollutants in diesel vehicles and their impacts on climate, human health and ecosystems will be described.

  3. Connectivity, prison environment and mental health among first-time male inmates in Mexico City.

    Science.gov (United States)

    Albertie, Ariel; Bourey, Christine; Stephenson, Rob; Bautista-Arredondo, Sergio

    2017-02-01

    Research from high-income countries suggests that prison populations are affected disproportionately by mental illness. However, little research has examined mental health among prisoners in low- and middle-income countries or associations between mental health and contextual factors surrounding the prison experience among susceptible first-time inmates in these settings. The current study examines associations between connectivity, prison environment and mental health (major depression and substance use) among novice male inmates (n = 593) in three Mexico City prisons. Severe depression (46.2%), any substance use (53.8%) and heavy substance use (45.7%) were prevalent. Among key co-variates, recent visitors were protective for severe depression, conjugal visits for any substance use and prison employment for heavy substance use. Physical attacks were associated with increased prevalence of depression, sentence time served with both any and heavy substance use and overcrowding with any substance use. These findings suggest the need for routine health assessments to improve identification and treatment programmes to minimise mental health burden. Addressing demographic risk factors as well as contextual determinants, by decreasing physical violence and overcrowding and supporting outside connections for prisoners, may help improve inmate mental health.

  4. Intimate Partner Violence among Female Sex Workers in Two Mexico-U.S. Border Cities: Partner Characteristics and HIV Risk-behaviors as Correlates of Abuse.

    Science.gov (United States)

    Ulibarri, Monica D; Strathdee, Steffanie A; Lozada, Remedios; Magis-Rodriguez, Carlos; Amaro, Hortensia; O'Campo, Patricia; Patterson, Thomas L

    2010-12-01

    Intimate partner violence (IPV) has been associated with greater vulnerability to HIV infection among women. We examined prevalence and correlates of IPV among female sex workers (FSWs) in Tijuana and Ciudad Juarez, two large Mexico-U.S. border cities where HIV prevalence is rising. Participants were 300 FSWs with a current spouse or a steady partner. Participants' mean age was 33 years, and mean number of years as a sex worker was 6 years. The prevalence of IPV in the past 6 months among participants was 35%. Using multivariate logistic regression, factors independently associated with IPV included having experienced abuse as a child, a partner who had sex with someone else, and lower sexual relationship power. Our findings suggest the need for previous abuse screening and violence prevention services for FSWs in the Mexico-U.S. border region. Careful consideration of relationship dynamics such as infidelity and relationship power is warranted when assessing for IPV risk.

  5. Recent trends and challenges in three large Mexican cities: Mexico City, Guadalajara and Monterrey

    Directory of Open Access Journals (Sweden)

    Juan Manuel Ramírez Sáiz

    2009-07-01

    Full Text Available In this paper we analyze a series of factors or aspects in three large contemporary Mexican cities: multi-culturality, inequality, social and urban fragmentation, public insecurity and conflicting conceptions of what the city should be. The article offers an overview of the current situation, on the basis of the authors’ own research projects and a review of recent literature on the topic. It is therefore primarily a theoretical paper

  6. Oral health status in older adults with social security in Mexico City: Latent class analysis.

    Science.gov (United States)

    Sánchez-García, Sergio; Heredia-Ponce, Erika; Cruz-Hervert, Pablo; Juárez-Cedillo, Teresa; Cárdenas-Bahena, Angel; García-Peña, Carmen

    2014-02-01

    To explore the oral health status through a latent class analysis in elderly social security beneficiaries from Southwest Mexico City. Cross-sectional study of beneficiaries of the State Employee Social Security and Social Services Institute (ISSSTE, in Spanish) and the Mexican Institute of Social Security (IMSS, in Spanish) aged 60 years or older. Oral health conditions such as edentulism, coronal and root caries (DMFT and DFT ≥ 75 percentile), clinical attachment loss (≥ 4 mm), and healthy teeth (≤ 25 percentile) were determined. A latent class analysis (LCA) was performed to classify the oral health status of dentate patients. In total, 336 patients were included (47.9% from the ISSSTE and 52.1% from the IMSS), with an average age of 74.4 (SD = 7.1) years. The 75th percentile of the DMFT = 23 and of the DFT = 2. Of the patients, 77.9% had periodontal disease. The 25th percentile of healthy teeth = 4. A three class model is adequate, with a high classification quality (Entropy = 0.915). The patients were classified as "Edentulous" (15.2%), "Class 1 = Unfavorable" (13.7%), "Class 2 = Somewhat favorable" (10.4%), and "Class 3 = Favorable" (60.7%). Using "Class 3 = Favorable" as a reference, there was an association (OR = 3.4; 95% CI = 1.8-6.4) between being edentulous and being 75 years of age and over, compared with the 60- to 74-year age group. The oral health in elderly social security beneficiaries is not optimal. The probability of becoming edentulous increases with age. A three-class model appropriately classifies the oral health dimensions in the elderly population. Key words:Elderly, Latent class analysis (LCA), oral health, social security, Mexico.

  7. The Botanical Expedition to New Spain, 1786-1803: Mexico City's Botanical Garden and Pro­fessorship in Botany

    Directory of Open Access Journals (Sweden)

    J. Luis Maldonado Polo

    2000-07-01

    Full Text Available Thís work is about a  scientific enterprise carried out by  the Spanish Crown during the illustrated period, as a part of the ex­peditionary project to the overseas  territories. It describes the details and circumstances in which the Botanical Expedition be­gan, considering the prevailing intellectual environment at the time and the people who took a Ieading role in the cultural life of  the  incipient but  vigorous New Spain scientific community. After describing this background, the  author considers one of the Expedition's main results: the creation of  Mexico City's Botanical Garden and  Professorship in Botany,  which was the first of its kind in the American continent and contributed toes­ establish the study of Botany and related sciences in New Spain.

  8. Tourism and territorial structure in Ciudad Juarez, Mexico

    Directory of Open Access Journals (Sweden)

    Oswaldo Gallegos

    2012-02-01

    Full Text Available This paper deals with the issue of the territorial structure of tourism in Ciudad Juarez, Mexico. To do this, the study is divided into two major parts: first, theoretical aspects, given support to our analysis, and a brief history of tourism in the Northern borderlands of Mexico are presented. Then, four basic components of the territorial structure of tourism in Ciudad Juarez are examined: natural and cultural attractions, urban land-use, communications network centred around the city and visitors and tourist flows.

  9. Using tradeable permits to achieve sustainability in the world`s large cities. Policy design issues and efficiency conditions for controlling vehicle emissions, congestion and urban decentralization with an application to Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, H.C. [Instituto Tecnologico Autonomo de Mexico, Mexico City (Mexico)

    1997-07-01

    Many large cities in the world have serious ground level ozone problems, largely the product of vehicular emissions and thus the argued unsustainability of current urban growth patterns is frequently blamed on unrestricted private vehicle use. This article reviews Mexico City`s experience with vehicle use restrictions as an emissions control program and develops the conditions for optimal quantitative restrictions on vehicle use and for complementary abatement technologies. The stochastic nature of air pollution outcomes is modelled explicitly in both the static and dynamic formulations of the control problem, in which for the first time in the literature the use of tradeable vehicle use permits is proposed as a cost-effective complement to technological abatement for mobile emissions control. This control regime gives the authorities a broader and more flexible set of instruments with which to deal more effectively with vehicle emissions, and with seasonal and stochastic variation of air quality outcomes. The market in tradeable vehicle use permits would be very competitive with low transactions costs. This control policy would have very favorable impacts on air quality, vehicle congestion and on urban form and development. Given the general political resistance to environmental taxes, this program could constitute a workable and politically palatable set of policies for controlling greenhouse gas emissions from the transport sector. 7 figs., 1 appendix, 23 refs.

  10. Depressive symptoms among adolescents and older adults in Mexico City.

    Science.gov (United States)

    Sánchez-García, Sergio; García-Peña, Carmen; González-Forteza, Catalina; Jiménez-Tapia, Alberto; Gallo, Joseph J; Wagner, Fernando A

    2014-06-01

    Determine the structure of depressive symptoms among adolescents and older adults through the person-centered approach of latent class analysis (LCA). The study is based on data from two independent samples collected in Mexico City (2,444 adolescents and 2,223 older adults) which included the revised version of the CES-D. The presence or absence of depressed mood (dysphoria), diminished pleasure (anhedonia), drastic change in weight, sleep problems, thinking and concentration difficulties, excessive or inappropriate guilt, fatigue, psychomotor agitation/retardation, and suicide ideation were used in LCA to determine the structure of depressive symptoms for adolescents and older adults. Adolescents reported higher excessive or inappropriate guilt compared to older adults, while older adults had higher proportions of anhedonia, sleep problems, fatigue, and psychomotor agitation/retardation. Similar proportions were found in other symptoms. The LCA analysis showed the best fit with four latent classes (LC): LC 1, "symptoms suggestive of major depressive episode (MDE)" with prevalence of 5.9 % (n = 144) and 10.3 % (n = 230) among adolescents and older adults, respectively; LC 2, "probable MDE symptoms" 18.2 % (n = 446) and 23.0 % (n = 512); LC 3, "possible MDE" 27.7 % (n = 676) and 21.8 % (n = 485); LC 4, "without significant depressive symptoms" 48.2 % (n = 1,178) and 44.8 % (n = 996). The differences in item thresholds between the two groups (adolescents vs. older adults) were statistically significant (Wald test = 255.684, df = 1, p depressive symptoms between adolescents and older adults that merit acknowledgment, further study, and consideration of their potential clinical and public health implications.

  11. Mass movement processes associated with volcanic structures in Mexico City

    Directory of Open Access Journals (Sweden)

    Víctor Carlos Valerio

    2012-11-01

    Full Text Available Mexico City, one of the most populated areas of the world, has been affected by various hazards of natural origin, such as subsidence and cracking of the soil, seismicity, floods and mass movement processes (MMPs. Owing to the lack of space on the plain, in recent years urban growth has been concentrated particularly on the slopes of the surrounding mountain ranges, and this has significantly modified the dynamics of the relief as well as the hydrogeological conditions. The specific character of natural susceptibility to mass movements is strongly dependent on the geological–structural and morphological characteristics of the volcanic bodies that form the mountainous relief. This natural susceptibility, combined with the characteristics of vulnerability of the society, creates risk conditions that can generate severe consequences for the population and the economy. Hence, based on an inventory of mass movement processes comprising 95 data points, the present study aimed to achieve a zoning of the areas susceptible to these processes, as well as to characterize the mechanisms of instability in the volcanic structures that form the relief of the area in question. The results of this work clearly show the role of the lithology, the mode of emplacement and the morpho–structural characteristics of the volcanic structures, in the types of mass movement processes. In addition, it identifies the diverse activities of anthropogenic origin that favour slope instability in the zone: deforestation and burning of rubbish, felling of timber on the slopes for building infrastructure and dwellings, leakages of water, vibrations of vehicles, rotating machinery and the use of explosives in mining works, overloading the heads of the slopes, disturbance of the geohydrological regime, generation of rubbish tips, terracing of the slopes for cultivation, inadequate building regulations, and the use of counterproductive or ineffectual stabilization measures.

  12. Sustainable Transport: BRT experiences from Mexico and India

    DEFF Research Database (Denmark)

    Rogat, Jorge; Dhar, Subash; Joshi, Rutul

    2015-01-01

    Increasing population and urbanization is creating a steadily increasing demand for transportation in the cities of many developing countries, coinciding with rapid economic growth leading to increasing demand for higher standards of living and faster and more efficient modes of transportation...... transit (BRT). The BRT systems of Curitiba and Bogotá have subsequently been adopted all over the world with some variations. Implementation of two recent BRTs, Mexico City and Ahmedabad in India, are examined in this paper....

  13. Mexico.

    Science.gov (United States)

    1993-01-01

    The background notes on Mexico provide text and recent statistical information on the geography, population, government, economy, and foreign relations, specifically the North American Free Trade Agreement with US. The 1992 population is estimated at 89 million of which 60% are mestizo (Indian-Spanish), 30% are American Indian, 9% are Caucasian, and 1% are other. 90% are Roman Catholic. There are 8 years of compulsory education. Infant mortality is 30/1000 live births. Life expectancy for males is 68 years and 76 years for females. The labor force is comprised of 30% in services, 24% in agriculture and fishing, 19% in manufacturing, 13% in commerce, 7% in construction, 4% in transportation and communication, and .4% in mining. There are 31 states and a federal district. Gross domestic product (GDP) per capita was $3200 in 1991. Military expenditures were .5% of GDP in 1991. The average inflation rate is 19%. Mexico City with 20 million is the largest urban center in the world. In recent years, the economy has been restructured with market oriented reforms; the result has been a growth of GDP of 3.6% in 1991 from 2% in 1987. Dependence on oil exports has decreased. There has been privatization and deregulation of state-owned companies. Subsidies to inefficient companies have been stopped. Tariff rates were reduced. The financial debt has been reduced and turned into a surplus of .8% in 1992. Mexico's foreign debt has been reduced from its high in 1987 of $107 billion. Agricultural reforms have been ongoing for 50 years. Land was redistributed, but standards of living and productivity have improved only slightly. Rural land tenure regulations have been changed, and other economic reforms are expected. Mexico engages in ad hoc international groups and is selective about membership in international organizations.

  14. Aerosol Light Absorption and Scattering Assessments and the Impact of City Size on Air Pollution

    Science.gov (United States)

    Paredes-Miranda, Guadalupe

    The general problem of urban pollution and its relation to the city population is examined in this dissertation. A simple model suggests that pollutant concentrations should scale approximately with the square root of city population. This model and its experimental evaluation presented here serve as important guidelines for urban planning and attainment of air quality standards including the limits that air pollution places on city population. The model was evaluated using measurements of air pollution. Optical properties of aerosol pollutants such as light absorption and scattering plus chemical species mass concentrations were measured with a photoacoustic spectrometer, a reciprocal nephelometer, and an aerosol mass spectrometer in Mexico City in the context of the multinational project "Megacity Initiative: Local And Global Research Observations (MILAGRO)" in March 2006. Aerosol light absorption and scattering measurements were also obtained for Reno and Las Vegas, NV USA in December 2008-March 2009 and January-February 2003, respectively. In all three cities, the morning scattering peak occurs a few hours later than the absorption peak due to the formation of secondary photochemically produced aerosols. In particular, for Mexico City we determined the fraction of photochemically generated secondary aerosols to be about 75% of total aerosol mass concentration at its peak near midday. The simple 2-d box model suggests that commonly emitted primary air pollutant (e.g., black carbon) mass concentrations scale approximately as the square root of the urban population. This argument extends to the absorption coefficient, as it is approximately proportional to the black carbon mass concentration. Since urban secondary pollutants form through photochemical reactions involving primary precursors, in linear approximation their mass concentration also should scale with the square root of population. Therefore, the scattering coefficient, a proxy for particulate matter

  15. Assessment of the concentrations of U and Th in PM2.5 from Mexico City and their potential human health risk

    International Nuclear Information System (INIS)

    Mendez-Garcia, Carmen Grisel; Solis-Rosales, Corina; Rafael Chavez-Lomeli, Efrain

    2017-01-01

    This is one of the first studies in small particulate matter (PM 2.5 ) by inductively coupled plasma sector field mass spectrometry to measure the activity concentrations of isotopic uranium ( 234 , 235 and 238 U) and thorium ( 232 Th) in these fine particulates, to know their origin and their impact on human health in Mexico City. A different isotopic composition from the natural uranium composition was found. The 235 U/ 238 U atom ratio values are considered as low enrichment uranium, around 2% of 235 U enrichment. Both 235 U/ 238 U and 234 U/ 238 U ratios suggested anthropological rather natural source is impacting the composition of uranium in PM 2.5 . (author)

  16. Report on FS survey for project of introduction of highly energy-efficient trolley buses into the Mexico Metropolitan Area in FY 1997; 1997 nendo chosa hokokusho (Mexico city eno sho energy gata trolley bus donyu project FS chosa)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Traffic jam and air pollution by automobiles are currently getting severe in the Mexico Metropolitan Area. Trolley buses were introduced for improving the environment more than ten years ago. Vehicles become too old for use, and their energy efficiency is low. In this project, 200 highly energy-efficient trolley buses are introduced to replace old inefficient trolley buses, which results in the improved traffic convenience in the City and enhanced energy efficiency. The new energy-efficient trolley buses are made of energy-efficient control VVVF inverters produced and exported by MELCO (Mitsubishi Electric Corporation), energy-efficient motors by MELMEX (Mitsubishi Electric Corporation, Mexico), and bodies by MASA which is a major manufacturer of bus bodies. The objective of this research is to analyze the background of introduction of new energy-efficient trolley buses and the effects of the present project. The results of analysis are going to be utilized for future promotion of the Joint Implementation and Clean Development Mechanism. 30 refs., 30 figs., 24 tabs.

  17. Phenotypes of asthma revisited upon the presence of atopy.

    Science.gov (United States)

    Nieves, Ana; Magnan, Antoine; Boniface, Stéphanie; Proudhon, Hervé; Lanteaume, André; Romanet, Stéphanie; Vervloet, Daniel; Godard, Philippe

    2005-03-01

    Immunological studies claimed that atopic and non-atopic asthma share more similarities than differences. However, these two phenotypes of asthma are considered to be distinguishable upon distinct clinical patterns, which were not systematically assessed before in a large population. We studied characteristics discriminating atopic from non-atopic asthma among 751 asthmatic patients and 80 factors were analysed in univariate and multivariate analysis. Age, age of onset of asthma, female/male ratio were higher in non-atopic (n=200) than in atopic (n=551) asthmatics. Familial asthma, seasonal symptoms, rhinitis, conjunctivitis, allergen-triggered symptoms, improvement in altitude, exercise-induced asthma were associated with atopy. Non-atopic asthmatics displayed lower FEV(1) and FVC. Smoking was more frequent and asthma was more severe in these patients. Younger age, early onset, male sex, rhinitis and smoking were independent factors discriminating atopic from non-atopic asthma. This study establishes in a large population of asthmatics that although similarities exist between atopic and non-atopic asthma, two clinical phenotypes can still distinguish both kinds of asthma.

  18. True Love: Effectiveness of a School-Based Program to Reduce Dating Violence Among Adolescents in Mexico City.

    Science.gov (United States)

    Sosa-Rubi, Sandra G; Saavedra-Avendano, Biani; Piras, Claudia; Van Buren, S Janae; Bautista-Arredondo, Sergio

    2017-10-01

    Dating violence is a significant problem in Mexico. National survey data estimated 76 % of Mexican youth have been victims of psychological aggression in their relationships; 15.5 % have experienced physical violence; and 16.5 % of women have been the victims of sexual violence. Female adolescents perpetrate physical violence more frequently than males, while perpetration between genders of other types of violence is unclear. Furthermore, poor, marginalized youth are at a higher risk for experiencing dating violence. "Amor… pero del Bueno" (True Love) was piloted in two urban, low-income high schools in Mexico City to prevent dating violence. The intervention consisted of school-level and individual-level components delivered over 16 weeks covering topics on gender roles, dating violence, sexual rights, and strategies for coping with dating violence. The short-term impact was assessed quasi-experimentally, using matching techniques and fixed-effects models. A sample of 885 students (381 students exposed to the classroom-based curriculum of the individual-level component (SCC, IL-1) and 540 exposed only to the school climate component (SCC)) was evaluated for the following: changes in dating violence behaviors (psychological, physical and sexual), beliefs related to gender norms, knowledge, and skills for preventing dating violence. We found a 58 % (p violence, respectively, among SCC, IL-1 males compared to males exposed only to the SCC component. We also found a significant reduction in beliefs and attitudes justifying sexism and violence in dating relationships among SCC, IL-1 females (6 %; p < 0.05) and males (7 %; p < 0.05).

  19. Factors associated with condom use in the male population of Mexico City.

    Science.gov (United States)

    Hernandez-Giron, C A; Cruz-Valdez, A; Quiterio-Trenado, M; Uribe-Salas, F; Peruga, A; Hernández-Avila, M

    1999-02-01

    Sexually transmitted diseases (STDs) are an important public health problem, due to their medical, social and economic repercussions. Therefore, more knowledge is needed about the sexual behaviour that promotes their spread, in order to improve control and prevention strategies. Our aim was to determine the frequency of male condom use associated with sexual behaviour factors, a history of and knowledge about STDs in a sample of the male population in Mexico City. During 1994 a cross-sectional epidemiological study was carried out, using multi-stage sampling with conglomerates, in 1377 men from 15 to 49 years old. The mean age was 34.5 years (SD 7.5 years). Mean age at first sexual relations was 17.7 years (SD 2.8 years). The global proportion of condom use during the last sexual relation was 24.6%; use according to type of female sex partner in the last year was 18.8% with regular partners and 62.5% with occasional partners. The principal predictors of male condom use, identified through statistical modelling, were: younger age (9 years), middle and high socioeconomic level and type of sexual partners (occasional and regular). This population has risk factors for acquiring and transmitting some STDs, such as occasional sexual partners and a history of STDs. Characteristics which are important in relation to male condom use were identified, such as age (younger than 35), education (complete junior high school or more) and type of sexual partners (occasional and regular).

  20. Volatile aromatic compounds in Mexico City atmosphere: levels and source apportionment

    Energy Technology Data Exchange (ETDEWEB)

    Mugica, V. [Universidad Autonoma Metropolitana - Unidad Azcapotzalco, Mexico, D.F. (Mexico); Ruiz, M.E. [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Watson, J.; Chow, J. [Desert Research Institute, Reno, Nevada (United States)

    2003-01-01

    Samples of ambient air were simultaneously collected at three different sites of Mexico City in March of 1997 in order to quantify the most abundant volatile aromatic compounds and estimate the source contributions by application of the chemical mass balance model (CMB). Volatile aromatic compounds were around 20% of the total of non-methane hydrocarbons present in morning air samples. The most abundant volatile aromatic species in urban air were toluene and xylenes followed by 1, 2, 4 trimethylbenzene, benzene, ethylbenzene, metaethyltoluene, 1, 3, 5 trimethylbenzene, styrene, n propylbenzene, and isopropylbenzene. Sampling campaigns were carried out at crossroads, a bus station, a parking place, and areas where solvents and petroleum distillates are used, with the objective of determining people's exposure to volatile aromatic compounds. The CMB was applied for estimating the contribution of different sources to the presence of each one of the most abundant aromatic compounds. Motor vehicle exhaust was the main source of all aromatic compounds, especially gasoline exhaust, although diesel exhausts and asphalt operations also accounted for toluene, xylenes, ethylbenzene, propylbenzenes, and styrene. Graphic arts and paint applications had an important impact on the presence of toluene. [Spanish] Se colectaron simultaneamente muestras de aire ambiente en tres sitios de la Ciudad de Mexico durante el mes de marzo de 1997 con el fin de conocer las concentraciones y el origen de compuestos aromaticos utilizando el modelo de balance de masa de especies quimicas (CMB). Los compuestos aromaticos volatiles representaron alrededor del 20% del total de hidrocarburos no metalicos presentes en las muestras matutinas colectadas. Las especies aromaticas volatiles mas abundantes en el ambiente fueron el tolueno y los xilenos, seguidos por 1, 2, 4 trimetilbenceno, benceno, etilbenceno, metaetiltolueno, nporpilbenceno, isopropilbenceno, 1, 3, 5 trimetilbenceno y estireno. Se

  1. Asthma cases in childhood attributed to atopy in tropical area in Brazil Asma infantil atribuida a atopia en la zona tropical de Brasil

    Directory of Open Access Journals (Sweden)

    Sergio Souza da Cunha

    2010-12-01

    Full Text Available OBJECTIVE: This study aimed to explore the association between asthma and atopy in a cohort of children living in a large urban center in Brazil. Atopy was defined by the presence of allergen-specific IgE in serum or by a positive skin prick test. METHODS: In a sample of 1 445 Brazilian children, the association between the prevalence of asthma, skin prick test positivity, and allergen-specific IgE in serum was investigated. RESULTS: The prevalence of asthma was 22.6%. The presence of serum allergen-specific IgE was frequent in asthmatics and nonasthmatics, and the prevalence of asthma increased only with levels of allergen-specific IgE > 3.5 kilounits/L. The proportion of asthma attributable to atopy was estimated to be 24.5% when atopy was defined by the presence of allergen-specific IgE. With a given level of specific IgE, no association between skin test reactivity and asthma was observed. Skin prick tests were less sensitive than specific IgE for detection of atopy. CONCLUSIONS: Most asthma cases in an urban underprivileged setting in Brazil were not attributable to atopy. This observation has important implications for understanding the risk factors for the asthma epidemic in Latin AmericaOBJETIVO: Explorar la relación entre el asma y la atopia en una cohorte de niños que viven en un gran centro urbano de Brasil. En este estudio, se considera atopia la detección de IgE sérica específica de algún alérgeno o un resultado positivo a la prueba de punción cutánea. MÉTODOS: Se estudió la relación entre la prevalencia del asma, el resultado positivo a la prueba de punción cutánea y la detección de IgE sérica específica de algún alérgeno en una muestra de 1 445 niños brasileños. RESULTADOS: El asma registró una prevalencia de 22,6%. La presencia de IgE séricas específicas de alérgenos fue frecuente tanto en los asmáticos como en los no asmáticos, y la prevalencia del asma fue mayor solo cuando el valor detectado de la Ig

  2. Knowledge and technology transfer to improve the municipal solid waste management system of Durango City, Mexico.

    Science.gov (United States)

    Valencia-Vázquez, Roberto; Pérez-López, Maria E; Vicencio-de-la-Rosa, María G; Martínez-Prado, María A; Rubio-Hernández, Rubén

    2014-09-01

    As society evolves its welfare level increases, and as a consequence the amount of municipal solid waste increases, imposing great challenges to municipal authorities. In developed countries, municipalities have established integrated management schemes to handle, treat, and dispose of municipal solid waste in an economical and environmentally sound manner. Municipalities of developing and transition countries are not exempted from the challenges involving municipal solid waste handling, but their task is not easy to accomplish since they face budget deficits, lack of knowledge, and deficiencies in infrastructure and equipment. In the northern territory of Mexico, the municipality of Durango is facing the challenge of increased volumes of waste with a lack of adequate facilities and infrastructure. This article analyses the evolution of the municipal solid waste management of Durango city, which includes actions such as proper facilities construction, equipment acquisition, and the implementation of social programmes. The World Bank, offering courses to municipal managers on landfill operation and waste management, promoted the process of knowledge and technology transfer. Thereafter, municipal authorities attended regional and some international workshops on waste management. In addition they followed suggestions of international contractors and equipment dealers with the intention to improve the situation of the waste management of the city. After a 15-year period, transfer of knowledge and technology resulted in a modern municipal solid waste management system in Durango municipality. The actual system did not reach the standard levels of an integrated waste management system, nevertheless, a functional evaluation shows clear indications that municipality actions have put them on the right pathway. © The Author(s) 2014.

  3. Evaluation of the volatility basis-set approach for the simulation of organic aerosol formation in the Mexico City metropolitan area

    Directory of Open Access Journals (Sweden)

    A. P. Tsimpidi

    2010-01-01

    Full Text Available New primary and secondary organic aerosol modules have been added to PMCAMx, a three dimensional chemical transport model (CTM, for use with the SAPRC99 chemistry mechanism based on recent smog chamber studies. The new modelling framework is based on the volatility basis-set approach: both primary and secondary organic components are assumed to be semivolatile and photochemically reactive and are distributed in logarithmically spaced volatility bins. This new framework with the use of the new volatility basis parameters for low-NOx and high-NOx conditions tends to predict 4–6 times higher anthropogenic SOA concentrations than those predicted with the older generation of models. The resulting PMCAMx-2008 was applied in Mexico City Metropolitan Area (MCMA for approximately a week during April 2003 during a period of very low regional biomass burning impact. The emission inventory, which uses as a starting point the MCMA 2004 official inventory, is modified and the primary organic aerosol (POA emissions are distributed by volatility based on dilution experiments. The predicted organic aerosol (OA concentrations peak in the center of Mexico City, reaching values above 40 μg m−3. The model predictions are compared with the results of the Positive Matrix Factorization (PMF analysis of the Aerosol Mass Spectrometry (AMS observations. The model reproduces both Hydrocarbon-like Organic Aerosol (HOA and Oxygenated Organic Aerosol (OOA concentrations and diurnal profiles. The small OA underprediction during the rush-hour periods and overprediction in the afternoon suggest potential improvements to the description of fresh primary organic emissions and the formation of the oxygenated organic aerosols, respectively, although they may also be due to errors in the simulation of dispersion and vertical mixing. However, the AMS OOA data are not specific enough to prove that the model reproduces the organic aerosol

  4. PIXE and XRF analysis of atmospheric aerosols from a site in the West area of Mexico City

    International Nuclear Information System (INIS)

    Díaz, R.V.; López-Monroy, J.; Miranda, J.; Espinosa, A.A.

    2014-01-01

    Due to geographical factors, most of the Metropolitan Area of Mexico City features, on average, similar heights above the sea level, climate, wind speed and direction, with very uniform pollution degrees in most of the frequently studied sites. A site with different characteristics, Cuajimalpa de Morelos, was studied. It is located to the West of the urban area at 2760 m above sea level, in contrast to other sites (2240 m). Here, the wind is mostly directed towards the center of the city. Then, the site should not be affected by pollutants from the Northern/Northeastern industrial zones, so lower aerosol concentrations are expected. In this work, the elemental composition of coarse (PM 10-2.5 ) and fine (PM 2.5 ) fractions of atmospheric aerosol samples collected in Cuajimalpa is studied. The sampling period covered the cold-dry season in 2004–2005 (December 1st, 2004 to March 31, 2005), exposing polycarbonate filters with a Stacked Filter Unit of the Gent design along 24 h, every two days. The samples were analyzed with Particle Induced X-ray Emission (PIXE) and X-ray Fluorescence (XRF), to obtain elemental concentrations. The EPA code UNMIX was used to determine the number of possible influencing polluting sources, which were then identified through back-trajectory simulations with the HYSPLIT modeling software. Four sources (mostly related to soil) were found in the coarse fraction, while the fine fraction presented three main sources (fuel oil, industry and biomass burning)

  5. PIXE and XRF analysis of atmospheric aerosols from a site in the West area of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Díaz, R.V.; López-Monroy, J. [Instituto Nacional de Investigaciones Nucleares, Centro Nuclear “Nabor Carrillo”, Autopista México-Toluca, Salazar, Edo. Mex. (Mexico); Miranda, J., E-mail: miranda@fisica.unam.mx [Instituto Nacional de Investigaciones Nucleares, Centro Nuclear “Nabor Carrillo”, Autopista México-Toluca, Salazar, Edo. Mex. (Mexico); Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México, DF (Mexico); Espinosa, A.A. [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México, DF (Mexico)

    2014-01-01

    Due to geographical factors, most of the Metropolitan Area of Mexico City features, on average, similar heights above the sea level, climate, wind speed and direction, with very uniform pollution degrees in most of the frequently studied sites. A site with different characteristics, Cuajimalpa de Morelos, was studied. It is located to the West of the urban area at 2760 m above sea level, in contrast to other sites (2240 m). Here, the wind is mostly directed towards the center of the city. Then, the site should not be affected by pollutants from the Northern/Northeastern industrial zones, so lower aerosol concentrations are expected. In this work, the elemental composition of coarse (PM{sub 10-2.5}) and fine (PM{sub 2.5}) fractions of atmospheric aerosol samples collected in Cuajimalpa is studied. The sampling period covered the cold-dry season in 2004–2005 (December 1st, 2004 to March 31, 2005), exposing polycarbonate filters with a Stacked Filter Unit of the Gent design along 24 h, every two days. The samples were analyzed with Particle Induced X-ray Emission (PIXE) and X-ray Fluorescence (XRF), to obtain elemental concentrations. The EPA code UNMIX was used to determine the number of possible influencing polluting sources, which were then identified through back-trajectory simulations with the HYSPLIT modeling software. Four sources (mostly related to soil) were found in the coarse fraction, while the fine fraction presented three main sources (fuel oil, industry and biomass burning)

  6. Concentrations of benzene and toluene in the atmosphere of the southwestern area at the Mexico City Metropolitan Zone

    Energy Technology Data Exchange (ETDEWEB)

    Bravo, H.; Sosa, R.; Sanchez, P. [Universidad Autonoma de Mexico, Ciudad Universitaria (Mexico). Centro de Ciencias de la Atmosfera; Bueno, E.; Gonzalez, L. [Centro Nacional de Investigacion y Capacitacion Ambiental, Instituto Nacional de Ecologia, SEMARNAP, Mexico (Mexico)

    2002-08-01

    The Mexico City Metropolitan Zone (MCMZ) presents important emissions of hazardous air pollutants. It is well documented that the MCMZ suffers a critical air pollution problem due to high ozone and particulate matter concentrations. However, toxic air pollutants such as benzene and toluene have not been considered. Benzene has accumulated sufficient evidence as a human carcinogen, and the ratio benzene/toluene is an excellent indicator to evaluate control strategies efficiency. In order to evaluate the levels of these two air toxic pollutants in the MCMZ, ambient air samples were collected in canisters and analyzed with a gas chromatograph with a flame ionization detector, according to procedures described in the United States Environmental Protection Agency (USEPA) method TO-15. Quality assurance was performed collecting duplicate samples which were analyzed in replicate to quantify the precision of air-quality measurements. Three different sites located in the Southwestern area in the MCMZ were selected for the sampling: the University campus, a gas station, and a vertical condominium area, in the same neighborhood, which presents different activities. At these sites, grab air samples were collected during the morning hours (7-8 a.m.), while for the University area, 24 h integrated air samples were collected simultaneously, with grab samples. Benzene concentrations (24 h sampling) in the atmosphere around the University campus have similar present levels as in other cities of North America. Mean values in this site were about 1.7 ppb. A significant variation exists between the benzene and toluene concentrations in the studied sites, being the more critical values than those registered at the gas station (an average of 25.8 ppb and a maximum of 141 ppb of benzene). There is a fuel regulation for gasoline in Mexico, which allows a maximum of 1 percent of benzene. However, since more than 60 percent of vehicles do not have catalytic converters (models before 1991

  7. Haplotype and nucleotide variation in the exon 3-VNTR of the DRD4 gene from indigenous and urban populations of Mexico.

    Science.gov (United States)

    Aguirre-Samudio, Ana Julia; Cruz-Fuentes, Carlos Sabás; González-Sobrino, Blanca Zoila; Gutiérrez-Pérez, Verónica; Medrano-González, Luis

    2014-01-01

    To describe the population structure of the 48-bp variable number of tandem repeats (VNTR), located in exon 3 of the dopamine receptor D4 gene (DRD4), in 41 Tarahumara from northern Mexico, 20 Mixe from southern Mexico, and 169 people from Mexico City. Genotypes for the DRD4-VNTR were determined, from which 15 Tarahumara, eight Mixe, and 37 urban homozygous individuals were sequenced. Repeat-allele frequencies were compared with other world populations. The DRD4-VNTR variation in Mexico City appeared similar to the world mean. For the Mixe and Maya, DRD4-VNTR diversity appeared closer to South American groups whereas the Tarahumara were similar to North American groups. People from Mexico City and the Mixe exhibited attributes of a large and admixed population and an isolated population, respectively. The Tarahumara showed endogamy associated with a substructure as suggested by a preliminary regional differentiation. For the DRD4-VNTR and/or the adjacent 5'-173 bp sequence, the three populations exhibited negative Tajima's D. Two new VNTR haplotypes were discovered: one in Mexico City and another among the Tarahumara. A differentiation in the DRD4-VNTR of global relevance occurs between northern and southern populations of Mexico suggesting that the Mexican Trans-volcanic Belt has been a major frontier for human dispersion in the Americas. Ancient trespass of this barrier appears thus related to a major change in the population structure of the DRD4-VNTR. Distinctive and independent patterns of DRD4-VNTR diversity occur among the two Mexican indigenous populations by a still undefined combination of drift and selection. © 2014 Wiley Periodicals, Inc.

  8. Emerging Threat to America: Non-State Entities Fighting Fourth Generation Warfare in Mexico

    Science.gov (United States)

    2010-09-01

    warfare in Juarez, Mexico contrasts with the “peaceful” cities of Ciudad Acuña and Piedras Negras controlled by the Zetas who demonstrate 4GW tactics...Vulliamy, 2009). Within the cities of Acuna and Piedra Negras where one Pack Virus (the Zetas) has effective control of these limited geographic

  9. Retinopathy of prematurity as a major cause of severe visual impairment and blindness in children in schools for the blind in Guadalajara city, Mexico.

    Science.gov (United States)

    Zepeda-Romero, L C; Barrera-de-Leon, J C; Camacho-Choza, C; Gonzalez Bernal, C; Camarena-Garcia, E; Diaz-Alatorre, C; Gutierrez-Padilla, J A; Gilbert, C

    2011-11-01

    To determine the causes of blindness in students attending schools for the blind in Guadalajara city, Mexico and to assess the availability of screening for retinopathy of prematurity (ROP) in local neonatal intensive care units. Information on causes of blindness was obtained by interview with parents and teachers, review of records and examination. Causes of visual loss in children with a distance visual acuity of blind) were determined and classified according to the WHO's classification system for children. Of 153 children in the two participating schools, 144 were severely visual impaired or blind. Their ages ranged from 4 months to 15 years and 58% were female. ROP was the most common cause of visual loss (34.7%), followed by optic nerve lesions (17.4%) and glaucoma (14.6%). 25/59 (42.3%) children aged 0-4 years were blind from ROP compared with 6/32 (18.8%) children aged 10-15 years. 78% of children blind from ROP had psychomotor delay and less than half (46%) had not received treatment for ROP. All five privately funded neonatal intensive care units in the city regularly screen for ROP compared with only four of the 12 units in the public sector. ROP is the leading cause of blindness in children in Mexico despite national guidelines being in place. Health policies promoting primary prevention through improved neonatal care need to be implemented. Advocacy is required so that the time ophthalmologists spend screening and treating ROP is included in their job description and hence salaried.

  10. Defeating Mexico’s Drug Trafficking Organizations: The Range of Military Operations in Mexico

    Science.gov (United States)

    2012-06-08

    Nuevo Leon, Chihuahua , Baja California, and Sinaloa (see figure 2) with 60 percent of all killings in 2008 reported in three cities: Tijuana, Baja...California; Culiacan, Sinaloa; and Ciudad Juarez, Chihuahua .2 Ciudad Juarez had the highest rate of DTO related deaths; this is significant for the U.S...Northern Mexico states are: Baja California, Baja California Sur, Sonora, Chihuahua , Coahuila, Nuevo Leon, Tamaulipas, and Sinaloa (see figure 2

  11. The ditches of México City and implications on residential buildings of the XVIII century

    Directory of Open Access Journals (Sweden)

    Alejandro Jimenez Vaca

    2015-08-01

    Full Text Available Known for its canals or by its designation in the New Spain as ditches, the image of aquatic city of Mexico City was widespread in the world. It would seem that those romantic references of the city had been left alone in the lines written by the chroniclers, but when analyzing architectural plans and current cadastral can glimpse vestiges of this lakeside past. This research is done by analyzing eigh-teenth century plans, through identification of ex-isting ditches in Mexico City during this period, and its current trajectory in a plane, performing both an analysis of their influence on residential architecture, determining the characteristics of the houses in the path of the canals, by classifying canal houses, depending on the level of relationship between these two constructive general.

  12. [Distribution of aquatic birds in oxidation lagoons of La Paz city in South Baja California, Mexico].

    Science.gov (United States)

    Zamora-Orozco, Elvia Margarita; Carmona, Roberto; Brabata, Georgina

    2007-06-01

    Taxonomic composition, spatial and temporal distribution of aquatic birds in oxidation lagoons (LO) of La Paz city in south Baja California, Mexico, were determined during 24 censuses realized in two-week intervals (April/98-March/99). There are five lagoons of5 Ha each and 17 ha of terrains constantly flooded that serve as feeding areas for cattle and birds. One hundred twenty three species were observed, 75 of which were aquatic birds. A total of 46 041 observations were made (average 1 918 birds/census). Richness and abundance of aquatic birds were influenced mainly by migration of anatids and sandpipers. The first group had the greatest abundance due to its affinity towards fresh water bodies. The terrains were the favorite sites of dabbling ducks (Anas) and sandpipers. In contrast, two of the most abundant species (Oxyura jamaicensis, 12.5% of all species, and Fulica americana, 8.8 %) restricted their presence to the oxidation lagoons. LO presented a bird structure of its own and atypical, according to the dryness of the region.

  13. Microbiological implications of periurban agriculture and water reuse in Mexico City.

    Science.gov (United States)

    Mazari-Hiriart, Marisa; Ponce-de-León, Sergio; López-Vidal, Yolanda; Islas-Macías, Pilar; Amieva-Fernández, Rosa Isabel; Quiñones-Falconi, Francisco

    2008-05-28

    Recycled treated or untreated wastewater represents an important health challenge in developing countries due to potential water related microbiological exposure. Our aim was to assess water quality and health implications in a Mexico City periurban agricultural area. A longitudinal study in the Xochimilco wetland area was conducted, and 42 sites were randomly selected from 211, including irrigation water canals and effluents of treatment plants. Sample collection took place during rainy and dry seasons (2000-2001). Microbiological parameters (total coliforms, fecal coliforms, streptococci/enterococci, and bacteria other than Vibrio grown on TCBS), Helicobacter pylori, and physicochemical parameters including trihalomethanes (THM) were determined. Fecal coliforms and fecal streptococci are appropriate indicators of human or animal fecal contamination. Fecal coliform counts surpass Mexican and World Health Organization irrigation water guidelines. Identified microorganisms associated with various pathologies in humans and domestic animals comprise Escherichia coli, Klebsiella spp., Salmonella spp., Enterobacter spp., Enterococcus spp., and Pseudomonas spp; H. pylori was also present in the water. An environmental characteristic of the canal system showed high Total Organic Carbon content and relatively low dissolved oxygen concentration; residual chlorine as a disinfection control is not efficient, but THMs do not represent a problem. During the rainy season, temperature and conductivity were higher; in contrast, pH, dissolved oxygen, ammonia, and residual chlorine were lower. This is related with the continuous load of feces from human and animal sources, and to the aquatic systems, which vary seasonally and exhibit evidence of lower water quality in effluents from treatment plants. There is a need for improvement of wastewater treatment systems, as well as more efficient monitoring, regulation, and enforcement procedures for wastewater disposal into bodies of

  14. Characteristics of specific reading disability in children from a neuropsychological clinic in Mexico City

    Directory of Open Access Journals (Sweden)

    Poblano Adrián

    2002-01-01

    Full Text Available Objective. This report describes the main clinical features associated with specific reading disability (RD in a group of 778 school-age children studied in a Neuropsychological Clinic in Mexico City. Material and Methods. The study was performed retrospectively, using data abstracted from clinical records of subjects seen in 1995-1996. Children were mainly from low and middle economic strata and aged between 6 to 12 years. The following data were collected: age, gender, diagnosis, school grade, food intake, maternal complications during pregnancy, perinatal and postnatal neurological risk factors, and neurological signs and handedness. Results. Subjects with RD had a mean age of 102.9 months, were predominantly male (male female ratio, 2:1. Among the study group, 49.1% of the children were diagnosed with RD of a visuo-sensory-motor type, and 75.1% were from early school years (1st to 3rd grades; 27.6% showed evidence of malnutrition. A previous history of language disorders (49.2%, and a high frequency of perinatal risk factors and neurological soft signs were also found. Conclusions. This study shows that variables such as gender, food intake, and genetic and neurological risk factors, were associated with reading disabilities in school children.

  15. Assessing Pesticide Contamination to Fresh Water in Some Agricultural Sites, Close to Oaxaca City, Mexico

    Science.gov (United States)

    Tomas, G.

    2002-12-01

    This study presents the results of a survey on pesticides in fresh water in shallow aquifers, rivers and dams in Zaachila, Tlacolula and Etla and agricultural valleys close to Oaxaca City, SW of Mexico. In the study zones, there are generalized uses of pesticides and the impact on the water resources by inadequate use of agricultural activities. Water is used for irrigation and drinking. Surveying criteria was to sample the aquifer (production wells), its water table (dig wells) and a regional water collector (Plan Benito Juarez Yuayapan dam). A total of 14 samples were analyzed for the identification and quantification of organochlorine and organophosphorous pesticides. Method was 508-EPA. Gas chromatographer was a 5890 series II Hewlett Packard, calibrated with several patterns. Results: 10 samples are contaminated with some pesticide of the used patterns; Dieldrin, Chlordano, Malathion, Mirex were not found; Traces of organophosphorus compounds were found in 8 samples, mainly Merphos, Parathion Ethylic and Disulfoton ; There was detected traces of world-forbidden insecticides as Metoxychlor, Parathion Ethylic and Disulfoton; and In one sample (Cuilapam well #1) DDT exceeds, the Mexican maximum limit for potable water (1 mg/l),

  16. Detection of Clostridium perfringens in yearling lamb meat (barbacoa), head, and gut tacos from public markets in Mexico City.

    Science.gov (United States)

    Natividad-Bonifacio, Iván; Vázquez-Quiñones, Carlos R; Rodas-Suárez, Oscar R; Fernández, Francisco J; Rodríguez-Solis, Esteban; Quiñones-Ramírez, Elsa Irma; Vázquez-Salinas, Carlos

    2010-06-01

    No reports on the incidence of Clostridium perfringens in popularly-consumed food from Mexico City have been published; neither are there any reports that have analyzed food consumed in popular markets and less established restaurants. Therefore, this study is aimed at providing data to evaluate the relevance of C. perfringens as an etiologic agent of food-borne diseases. Of the 650 analyzed samples, 106 (16.3%) were positive for C. perfringens; 6.4% (16/250) isolates were from barbacoa, 19% (38/200) from head, and 13% (52/200) from gut tacos. The presence of C. perfringens in these popular-consumed foods demonstrates its relevance as an etiologic agent of food-borne diseases, and confirms the great sanitary risk involved in their consumption. These results may serve as a basis for the Mexican sanitary authorities to control the microbiological quality of street-made foods.

  17. Determination of particle size and content of metals in the atmosphere of ZMCM (Metropolitan Zone of Mexico City); Determinacion de tamano de particula y contenido de metales en la atmosfera de la ZMCM (Zona Metropolitana de la Ciudad de Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Aldape U, F; Flores M, J; Diaz, R V; Garcia G, R [Instituto Nacional de Investigaciones Nucleares, Mexico City (Mexico)

    1994-12-31

    Inside the breathable fraction of the atmosphere of Mexico City, the presence of metals in suspended particles, is determined and quantified. The detection was carry out simultaneously in three places of the city, using collectors of the type stacking filter unit (SFU) which allow the separation of particles according to its size. The SFU detectors allow the separation in two size: `Gross` mass from 2.5 to 1.5 {mu}m and `fine` mass for particles smallest than 2.5 {mu}m. The analysis of the samples was fulfilled by means of PIXE method. Samples were irradiated with a proton beam, and based in the X-ray spectra the elements were identified and quantified, which allow to establish the temporal behavior of the concentrations per element for gross mass and fine mass in each one of the places of sampling. (Author).

  18. Effect of Methylparathion on nitrous oxide production in Chinampa soil of Xochimilco, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Oropeza, M.; Marquez, S.; Ruiz, U.; Cabirol, N.

    2009-07-01

    Contamination of soil from pesticides is result of their bulk handling at the farmyard or following application in the field. synthetic organophosphorus compounds like chlorpyrifos and methylparathion have been used in the particulate cultivated areas, the chosen chinampa ( from Nahuatl or Aztec, chinamitl, bulrush or cattail stalks lattice for hydro-ponics cultivation) from the Xochimilco zone in Mexico City, Mexico (CICLOPLAFEST, 2006). (Author)

  19. Effect of Methylparathion on nitrous oxide production in Chinampa soil of Xochimilco, Mexico

    International Nuclear Information System (INIS)

    Rojas-Oropeza, M.; Marquez, S.; Ruiz, U.; Cabirol, N.

    2009-01-01

    Contamination of soil from pesticides is result of their bulk handling at the farmyard or following application in the field. synthetic organophosphorus compounds like chlorpyrifos and methylparathion have been used in the particulate cultivated areas, the chosen chinampa ( from Nahuatl or Aztec, chinamitl, bulrush or cattail stalks lattice for hydro-ponics cultivation) from the Xochimilco zone in Mexico City, Mexico (CICLOPLAFEST, 2006). (Author)

  20. Tobacco smoke exposure in public places and workplaces after smoke-free policy implementation: a longitudinal analysis of smoker cohorts in Mexico and Uruguay

    Science.gov (United States)

    Thrasher, James F.; Nayeli Abad-Vivero, Erika; Sebrié, Ernesto M.; Barrientos-Gutierrez, Tonatiuh; Boado, Marcelo; Yong, Hua Hie; Arillo-Santillán, Edna; Bianco, Eduardo

    2013-01-01

    Objective: To determine the prevalence, correlates and changes in secondhand smoke (SHS) exposure over the period after comprehensive smoke-free policy implementation in two Latin American countries. Methods: Data were analysed from population-based representative samples of adult smokers and recent quitters from the 2008 and 2010 waves of the International Tobacco Control Policy Evaluation Survey in Mexico (n = 1766 and 1840, respectively) and Uruguay (n = 1379 and 1411, respectively). Prevalence of SHS exposure was estimated for regulated venues, and generalized estimating equations were used to determine correlates of SHS exposure. Results: Workplace SHS exposure in the last month was similar within and across countries (range: Mexico 20–25%; Uruguay 14–29%). At the most recent restaurant visit, SHS exposure was lower where comprehensive smoke-free policies were implemented (range: Uruguay 6–9%; Mexico City 5–7%) compared with Mexican cities with weaker policies, where exposure remained higher but decreased over time (32–17%). At the most recent bar visit, SHS exposure was common (range: Uruguay 8–36%; Mexico City 23–31%), although highest in jurisdictions with weaker policies (range in other Mexican cities: 74–86%). In Uruguay, males were more likely than females to be exposed to SHS across venues, as were younger compared with older smokers in Mexico. Conclusions: Comprehensive smoke-free policies are more effective than weaker policies, although compliance in Mexico and Uruguay is not as high as desired. PMID:23172895