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Sample records for canals mexico city

  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. Microbiological indicators of water quality in the Xochimilco canals, Mexico City Indicadores microbiológicos de la calidad del agua de los canales de Xochimilco de la Ciudad de México

    Directory of Open Access Journals (Sweden)

    Luis Alfredo Juárez-Figueroa

    2003-10-01

    Full Text Available OBJECTIVE: To quantify microbiology indicators of fecal contamination in the effluents of two waste water treatment plants and in samples collected in several canals in Xochimilco. MATERIAL AND METHODS: A cross sectional study was performed. Ten sites, 5 from plant effluents and 5 from canals, were selected for sampling during November and December 2001. Fecal coliforms and enterococci were quantified by membrane filtration, male specific (F+ and somatic coliphages by double agar layer technique, and Cryptosporidium oocysts and Giardia cysts by concentration with Envirocheck filter followed by immunofluorescence microscopy quantification.The average of organisms counts from effluents and canal water were compared with t Student test. RESULTS: Treated water discharge in canals showed a low count of Fecal Coliforms (average 40.4/100 ml, enterococci (average 58.8/100 ml and Cryptosporidium oocysts (average 13.2/100 l, while coliphages and Giardia cyst rendered higher counts (average 1467.5/100 ml and 1199.8/100 l, respectively suggesting the water treatment methods could fail to remove these agents. A significant lower count of Giardia cysts (average 45/100 l and no Cryptosporidium oocysts were found in irrigation canals, which suggests a natural clearance of these pathogens. Strains of Escherichia coli isolated in one of the canals contaminated with sewage had antimicrobial multi-resistance that was transferred by conjugation suggesting that resistance is encoded in a plasmid potentially transferable to other pathogenic bacteria. CONCLUSIONS: Cost effective and culturally acceptable waste treatment methods will require careful planning and consultation if they are to be adopted and mantained by local populations.OBJETIVO: Cuantificar diversos indicadores de contaminación fecal en los efluentes de dos plantas de tratamiento de aguas residuales y en muestras recogidas en varios canales de Xochimilco. MATERIAL Y MÉTODOS: Estudio transversal

  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. FUEL CELL BUS DEMONSTRATION IN MEXICO CITY

    Science.gov (United States)

    The report discusses the performance of a cull-size, zero-emission, Proton Exchange Membrane (PEM) fuel-cell-powered transit bus in the atmospheric environment of Mexico City. To address the air quality problems caused by vehicle emissions in Mexico City, a seminar on clean vehic...

  5. Earthquake Damage in Mexico City, Mexico, September 19, 1985

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On September 19, 1985, a magnitude 8.1 earthquake occurred off the Pacific coast of Mexico. The damage was concentrated in a 25 km2 area of Mexico City, 350 km from...

  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. Emissions from forest fires near Mexico City.

    Science.gov (United States)

    R.J. Yokelson; S.P. Urbanski; E.L. Atlas; D.E. Toohey; E.C. Alvarado; J.D. Crounse; P.O. Wennberg; M.E. Fisher; C.E. Would; T.L. Campos; K. Adachi; P.T. Buseck; W.M. Hao

    2007-01-01

    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...

  8. Improving Air Quality in Metropolitan Mexico City : An Economic Valuation

    OpenAIRE

    The Mexico Air Quality Management Team

    2002-01-01

    Mexico City has for years experienced high levels of ozone and particulate air pollution. In 1995-99 the entire population of the Mexico City metropolitan area was exposed to annual average concentrations of fine particulate pollution (particulates with a diameter of less than 10 micrometers, or PM10) exceeding 50 micrograms per cubic meter, the annual average standard in both Mexico and t...

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

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

    In 1992, the United Nations described Mexico City's air as the most polluted on the planet. Six years later, that air earned Mexico the reputation of “the most dangerous city in the world for children” — a reputation Mexico has been working hard to improve. But despite more than a decade of stringent pollution control ...

  10. 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)

  11. Teenagers’ access to contraception in Mexico City

    OpenAIRE

    Sofía Gómez-Inclán; Luis Durán-Arenas

    2017-01-01

    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 mechan...

  12. [Demography of Mexico City. The same problems with less population].

    Science.gov (United States)

    Camposortega Cruz, S

    1991-01-01

    The Mexico City metropolitan area currently extends over 4451.2 sq km, completely covering the Federal District and 27 municipios in the state of Mexico. The current population of the Mexico City metropolitan area is estimated at about 16.1 million and its growth rate at approximately 2%/year. The crude birth rate is 24/1000 and the crude death rate 6/1000. The metropolitan Mexico City population represents 18.6% of the total Mexican population. Mexico's other large cities fall far behind in total population, Guadalajara with 3.16 million, Monterrey with 2.77 million, and Puebla with 1.5 million. Mexico City is 1 of the 5 largest cities of the world. Estimates of the current Mexico City population differ substantially from projections completed in the 1980s, which calculated populations of 19-22 million. The explanation of the difference lies primarily in overestimation of the metropolitan population in the 1980 census, the basis for the projections. Preliminary data from the 1990 census, data from the 1987 National Fertility and Health Survey, vital statistics, and some data on internal migration allow a preliminary correction of calculations relating to Mexico's population dynamics. During the 20th century, Mexico City's population has grown from 345,000 in 1900 to 1,029,000 in 1930, 3,136,000 in 1950, 9,045,000 in 1970, and 15,785,000 in 1990. The most rapid growth occurred in 1930-70, when the population grew by more than 5% annually. The growth rate declined to 3.65% between 1970-80 and according to preliminary estimated to 1.92% in 1980-90. Factors explaining the declining growth rate may include the fertility decline in Mexico City, reorientation of migration away from Mexico City and toward inntermediate cities with under 1 million inhabitants, and departures from Mexico City caused by the 1985 earthquakes, private and public decentralization policies, pollution, and other factos which have reduced the attractiveness of the capital. The reevised

  13. Ozone's Threat Hits Back Mexico City

    Science.gov (United States)

    Velasco, E.; Retama, A.; Guzman, D.

    2016-12-01

    Last March the Mexican authorities activated after 13 years the environmental alarm when ozone (O3) reached 210 ppb. The emergency measures created confusion among the public, who had lost memory of previous air quality crisis. Despite Mexico City has experienced a significant progress towards achieving cleaner air during the last 20 years, a recent relaxation in traffic regulations and meteorology favorable for photochemical activity triggered this new episode. All criteria pollutants of primary origin have been controlled and are in compliance with the Mexican Air Quality Standards. However, O3 and fine particles still exceed the standard threshold concentrations. For instance, 49-64% of the days have exceeded the 1-hour O3 standard of 95 ppb during the last 5 years. The current control policies, which responded to the integration of air quality information by authorities and scientists, have apparently started to lose effectiveness. Although precursor gases, such as alkanes and aromatics have shown an important decrease, reactive olefins have gained importance. The increase of motor-vehicles in recent years seems to fuel again the atmosphere's reactivity. This paper analyses the effectiveness of the emergency measures during the crisis based on the knowledge obtained from previous large field studies and the comprehensive data collected by the local air quality monitoring network. It is 10 years from MILAGRO, the last interdisciplinary study that examined the air pollution of the most populous city in North America. We call for a new collaborative research initiative based on a major field measurement campaign with the target of revealing new insights into the meteorology, emission of primary pollutants and precursor gases, photochemical production and formation of secondary particles in the atmosphere of Mexico City to improve its air quality, as well as of similar cities in the developing world.

  14. Improving air quality in metropolitan Mexico City : an economic valuation

    OpenAIRE

    Cesar, Herman; Victor H. Borja-Aburto; Dorland, Kees; Munoz Cruz, Roberto; Brander, Luke; Cropper, Maureen; Gonzalez Marinez, Ana Citlalic; Olaiz-Fernandez, Gustavo; Martinez Bolivar, Ana Patricia; Olsthoorn, Xander; Rosales-Castillo, Alberto; Soto Montes de Oca, Gloria; Torres-Meza, Victor; Uribe Ceron, Ricardo; van Beukering, Pieter

    2002-01-01

    Mexico City has for years experienced high levels of ozone and particulate air pollution. In 1995-99 the entire population of the Mexico City metropolitan area was exposed to annual average concentrations of fine particulate pollution (particulates with a diameter of less than 10micrometers, or PM10) exceeding 50 micrograms per cubic meter, the annual average standard in both Mexico and the United States. Two million people were exposed to annual average PM10 levels of more than 75 micrograms...

  15. 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.

  16. 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.

  17. [Teenagers' access to contraception in Mexico City].

    Science.gov (United States)

    Gómez-Inclán, Sofía; Durán-Arenas, Luis

    2017-01-01

    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. A qualitative study was conducted with focus groups technique in a middle and high school of Mexico City. 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. 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. 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

    Objective To describe the approval process and implementation of the 100% smokefree law in Mexico City and a competing federal law between 2007 and 2010. Methods Reviewed smokefree legislation, published newspaper articles and interviewed key informants. Results 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. Conclusions 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. PMID:21059606

  19. 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.

  20. 76 FR 73595 - Healthcare Technology, Policy & Trade Mission: Mexico City, Mexico, May 13-16, 2012

    Science.gov (United States)

    2011-11-29

    ... healthcare technology in Mexico's top hospitals and other healthcare institutions; (3) create a business... International Trade Administration Healthcare Technology, Policy & Trade Mission: Mexico City, Mexico, May 13-16... Commercial Service (CS) is organizing an executive-led healthcare technology policy and trade mission to...

  1. Rapid ethnographic assessment of breastfeeding practices in periurban Mexico City

    National Research Council Canada - National Science Library

    Guerrero, M L; Morrow, R C; Calva, J J; Ortega-Gallegos, H; Weller, S C; Ruiz-Palacios, G M; Morrow, A L

    1999-01-01

    Before carrying out a breastfeeding promotion programme in a periurban area of Mexico City, we conducted a rapid ethnographic study to determine the factors associated with absence of exclusive breastfeeding...

  2. 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.

  3. Ozone exposure among Mexico City outdoor workers.

    Science.gov (United States)

    O'Neill, Marie S; Ramirez-Aguilar, Matiana; Meneses-Gonzalez, Fernando; Hernández-Avila, Mauricio; Geyh, Alison S; Sienra-Monge, Juan José; Romieu, Isabelle

    2003-03-01

    In researching health effects of air pollution, pollutant levels from fixed-site monitors are commonly assigned to the subjects. However, these concentrations may not reflect the exposure these individuals actually experience. A previous study of ozone (O3) exposure and lung function among shoe-cleaners working in central Mexico City used fixed-site measurements from a monitoring station near the outdoor work sites as surrogates for personal exposure. The present study assesses the degree to which these estimates represented individual exposures. In 1996, personal O3 exposures of 39 shoe-cleaners working outdoors were measured using an active integrated personal sampler. Using mixed models, we assessed the relationship between measured personal O3 exposure and ambient O3 measurements from the fixed-site monitoring station. Ambient concentrations were approximately 50 parts per billion higher, on average, than personal exposures. The association between personal and ambient O3 was highly significant (mixed model slope p < 0.0001). The personal/ambient ratio was not constant, so use of the outdoor monitor would not be appropriate to rank O3 exposure and evaluate health effects between workers. However, the strong within-worker longitudinal association validates previous findings associating day-to-day changes in fixed-site O3 levels with adverse health effects among these shoe-cleaners and suggests fixed-site O3 monitors may adequately estimate exposure for other repeated-measure health studies of outdoor workers.

  4. [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 obesity in Mexico City adolescents, increases the risk of premature development of coronary atherosclerosis and diabetes mellitus in this population.

  5. 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.

  6. 78 FR 7670 - Safety Zone; Indian Street Bridge Construction, St. Lucie Canal, Palm City, FL

    Science.gov (United States)

    2013-02-04

    ...The Coast Guard is establishing a temporary safety zone on the St. Lucie Canal, Palm City, Florida to provide for the safety of life and vessels on a narrow waterway during bridge construction for the Indian Street Bridge. Persons and vessels are prohibited from entering, transiting through, anchoring in, or remaining within the safety zone unless authorized by the Captain of the Port Miami or a designated representative.

  7. [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 (Mexico City reported 11 deaths (0.03% of the total maternal deaths) associated with "non-spontaneous 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.

  8. 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,

  9. Illegal sales of cigarettes to minors--Mexico City, Mexico, 1997.

    Science.gov (United States)

    1997-05-23

    Because of the increasing prevalence of tobacco use among youth in the United States and Mexico, in 1996 the United States-Mexico Binational Commission (US-MBC) Health Working Group identified prevention of tobacco use, with an emphasis on adolescents, as one of its four priority health concerns. From 1970 to 1990, annual death rates for the leading causes of smoking-related deaths in Mexico nearly tripled and, in 1992, an estimated 10,253 persons in Mexico died as a result of smoking-related diseases, 9% of all deaths that year. In addition, from 1988 to 1993, the prevalence of current smoking among minors aged 12-17 years increased from 6.6% to 9.6%, respectively (in Mexico City, the 1993 prevalence was 12.8%), and in 1993, 72% of adult smokers in Mexico reported becoming regular smokers before age 18 years. Although since 1984 the General Health Law of Mexico has prohibited the sale of tobacco products to minors aged cigarette smoking among children and adolescents and in support of the goals of the US-MBC, during 1997 the General Directorate of Epidemiology (GDE) in the Secretariat of Health (SOH) conducted a survey of tobacco outlets in Mexico City to assess the percentage of retailers willing to sell cigarettes to minors. This report summarizes the results of the survey, which indicate that virtually no surveyed retailers asked minors attempting to purchase cigarettes about their age and that most retailers sold cigarettes to minors.

  10. 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

  11. 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.

  12. 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.

  13. [Sanitary control of food in Mexico city].

    Science.gov (United States)

    Sartí-Gutiérrez, E J; Parrilla-Cerrillo, C; Vázquez-Barojas, S; Kawashima-Hashimoto, L; Farías-Rodríguez, A; García-Juárez, C

    1989-01-01

    This work was undertaken as to avoid health risks to tourism in the "XIIth Soccer World Cup, Mexico 86". The above project was carried out through proper quality control of foods, drinking water as well as a definite care of personal hygiene of all those involved in the catering business (132 restaurants were included). The mentioned report informs only of the work of the National Public Health Laboratory in the Sanitary Epidemiological Program. The following products were analyzed: 133 water samples, 272 animated and nonliving surfaces, and 399 foods. Twenty seven percent of water samples were rejected, as well as 85% of the different surfaces and 60% of the food samples. High counts of mesophilic aerobics, followed by coliforms, S. aureus and Salmonella sp., were the principal specimens encountered. Therefore, it was suggested the permanent development of a sanitary epidemiological program.

  14. [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.

  15. Childhood acute leukemias are frequent in Mexico City: descriptive epidemiology.

    Science.gov (United States)

    Pérez-Saldivar, María Luisa; Fajardo-Gutiérrez, Arturo; Bernáldez-Ríos, Roberto; Martínez-Avalos, Armando; Medina-Sanson, Aurora; Espinosa-Hernández, Laura; Flores-Chapa, José de Diego; Amador-Sánchez, Raquel; Peñaloza-González, José Gabriel; Alvarez-Rodríguez, Francisco Javier; Bolea-Murga, Victoria; Flores-Lujano, Janet; Rodríguez-Zepeda, María Del Carmen; Rivera-Luna, Roberto; Dorantes-Acosta, Elisa María; Jiménez-Hernández, Elva; Alvarado-Ibarra, Martha; Velázquez-Aviña, Martha Margarita; Torres-Nava, José Refugio; Duarte-Rodríguez, David Aldebarán; Paredes-Aguilera, Rogelio; Del Campo-Martínez, María de Los Ángeles; Cárdenas-Cardos, Rocío; Alamilla-Galicia, Paola Hillary; Bekker-Méndez, Vilma Carolina; Ortega-Alvarez, Manuel Carlos; Mejia-Arangure, Juan Manuel

    2011-08-17

    Worldwide, acute leukemia is the most common type of childhood cancer. It is particularly common in the Hispanic populations residing in the United States, Costa Rica, and Mexico City. The objective of this study was to determine the incidence of acute leukemia in children who were diagnosed and treated in public hospitals in Mexico City. Included in this study were those children, under 15 years of age and residents of Mexico City, who were diagnosed in 2006 and 2007 with leukemia, as determined by using the International Classification of Childhood Cancer. The average annual incidence rates (AAIR), and the standardized average annual incidence rates (SAAIR) per million children were calculated. We calculated crude, age- and sex-specific incidence rates and adjusted for age by the direct method with the world population as standard. We determined if there were a correlation between the incidence of acute leukemias in the various boroughs of Mexico City and either the number of agricultural hectares, the average number of persons per household, or the municipal human development index for Mexico (used as a reference of socio-economic level). Although a total of 610 new cases of leukemia were registered during 2006-2007, only 228 fit the criteria for inclusion in this study. The overall SAAIR was 57.6 per million children (95% CI, 46.9-68.3); acute lymphoblastic leukemia (ALL) was the most frequent type of leukemia, constituting 85.1% of the cases (SAAIR: 49.5 per million), followed by acute myeloblastic leukemia at 12.3% (SAAIR: 6.9 per million), and chronic myeloid leukemia at 1.7% (SAAIR: 0.9 per million). The 1-4 years age group had the highest SAAIR for ALL (77.7 per million). For cases of ALL, 73.2% had precursor B-cell immunophenotype (SAAIR: 35.8 per million) and 12.4% had T-cell immunophenotype (SAAIR 6.3 per million). The peak ages for ALL were 2-6 years and 8-10 years. More than half the children (58.8%) were classified as high risk. There was a positive

  16. Childhood acute leukemias are frequent in Mexico City: descriptive epidemiology

    Directory of Open Access Journals (Sweden)

    Bekker-Méndez Vilma

    2011-08-01

    Full Text Available Abstract Background Worldwide, acute leukemia is the most common type of childhood cancer. It is particularly common in the Hispanic populations residing in the United States, Costa Rica, and Mexico City. The objective of this study was to determine the incidence of acute leukemia in children who were diagnosed and treated in public hospitals in Mexico City. Methods Included in this study were those children, under 15 years of age and residents of Mexico City, who were diagnosed in 2006 and 2007 with leukemia, as determined by using the International Classification of Childhood Cancer. The average annual incidence rates (AAIR, and the standardized average annual incidence rates (SAAIR per million children were calculated. We calculated crude, age- and sex-specific incidence rates and adjusted for age by the direct method with the world population as standard. We determined if there were a correlation between the incidence of acute leukemias in the various boroughs of Mexico City and either the number of agricultural hectares, the average number of persons per household, or the municipal human development index for Mexico (used as a reference of socio-economic level. Results Although a total of 610 new cases of leukemia were registered during 2006-2007, only 228 fit the criteria for inclusion in this study. The overall SAAIR was 57.6 per million children (95% CI, 46.9-68.3; acute lymphoblastic leukemia (ALL was the most frequent type of leukemia, constituting 85.1% of the cases (SAAIR: 49.5 per million, followed by acute myeloblastic leukemia at 12.3% (SAAIR: 6.9 per million, and chronic myeloid leukemia at 1.7% (SAAIR: 0.9 per million. The 1-4 years age group had the highest SAAIR for ALL (77.7 per million. For cases of ALL, 73.2% had precursor B-cell immunophenotype (SAAIR: 35.8 per million and 12.4% had T-cell immunophenotype (SAAIR 6.3 per million. The peak ages for ALL were 2-6 years and 8-10 years. More than half the children (58.8% were

  17. 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.

  18. Orthopoxvirus antibodies in grey squirrels (Sciurus aureogaster) in Mexico City, Mexico.

    Science.gov (United States)

    Martínez-Duque, Paola; Avila-Flores, Rafael; Emerson, Ginny L; Carroll, Darin S; Suzán, Gerardo; Gallardo-Romero, Nadia F

    2014-07-01

    Serum from Mexican grey squirrels (Sciurus aureogaster) from Mexico City reacted to Orthopoxvirus by enzyme-linked immunosorbent assay. Real-time PCR based on oral swabs and scabs did not detect viral DNA. Antibody prevalence was 30% (n=366), providing the first evidence of Orthopoxvirus antibodies in Mexican wild rodents.

  19. Rapid ethnographic assessment of breastfeeding practices in periurban Mexico City.

    OpenAIRE

    Guerrero, M.L.; Morrow, R C; Calva, J.J.; Ortega-Gallegos, H.; Weller, S. C.; Ruiz-Palacios, G M; Morrow, A.L.

    1999-01-01

    Before carrying out a breastfeeding promotion programme in a periurban area of Mexico City, we conducted a rapid ethnographic study to determine the factors associated with absence of exclusive breastfeeding. The responses to pilot interviews were used to develop a standardized questionnaire regarding reasons for infant feeding choice, sources of advice, and barriers to breastfeeding. We interviewed a random sample of 150 mothers with a child < 5 years of age; 136 (91%) of them had initiated ...

  20. 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)

  1. 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.

  2. Sociodemographic and Clinical Characteristics of Centenarians in Mexico City

    Directory of Open Access Journals (Sweden)

    Valdés-Corchado Pedro

    2017-01-01

    Full Text Available Background. There is little evidence about the demography and health status of adults aged 100 years and over in Latin America and there are no studies in Mexico. Objectives. To describe the demographic characteristics and health status of centenarians residing in Mexico City. Methods. This is a cross-sectional study using a population base of 393 community-dwelling centenarians in Mexico City. A comprehensive geriatric assessment was performed, including demographic information and health status. Results. The mean age of centenarians was 101.82 ± 2.02 years, of whom 44 (9.1% were semisupercentenarians (105–109 years old and 5 (0.2% were supercentenarians (≥110 years old. The female/male ratio was 3.2 : 1. Twelve (4.5% reside in nursing homes. Women versus men have unfavorable conditions given their criteria: being without a partner, dependence in 1 or more basic activities, dependence in 1 or more instrumental activities, hypertension, cancer, and Parkinson’s disease. Nevertheless, as compared to other populations, Mexican centenarians report having good self-perception of health (78.9%, polypharmacy (17.8%, low rate of pain (11.4%, diabetes (4.8%, and dyslipidemia (1.8%. Conclusions. This is the first study in Latin America that describes the social and clinical characteristics of centenarians in Mexico City. This population has a high percentage of malnutrition and osteoarthrosis, a high self-perception of health, low frequency of diabetes, dyslipidemia, cardiovascular disease, and a high frequency of “escapers” (24%.

  3. Sociodemographic and Clinical Characteristics of Centenarians in Mexico City

    Science.gov (United States)

    Pedro, Valdés-Corchado; Arturo, Ruiz-Hernández; Alejandro, Pérez-Moreno

    2017-01-01

    Background There is little evidence about the demography and health status of adults aged 100 years and over in Latin America and there are no studies in Mexico. Objectives To describe the demographic characteristics and health status of centenarians residing in Mexico City. Methods This is a cross-sectional study using a population base of 393 community-dwelling centenarians in Mexico City. A comprehensive geriatric assessment was performed, including demographic information and health status. Results The mean age of centenarians was 101.82 ± 2.02 years, of whom 44 (9.1%) were semisupercentenarians (105–109 years old) and 5 (0.2%) were supercentenarians (≥110 years old). The female/male ratio was 3.2 : 1. Twelve (4.5%) reside in nursing homes. Women versus men have unfavorable conditions given their criteria: being without a partner, dependence in 1 or more basic activities, dependence in 1 or more instrumental activities, hypertension, cancer, and Parkinson's disease. Nevertheless, as compared to other populations, Mexican centenarians report having good self-perception of health (78.9%), polypharmacy (17.8%), low rate of pain (11.4%), diabetes (4.8%), and dyslipidemia (1.8%). Conclusions This is the first study in Latin America that describes the social and clinical characteristics of centenarians in Mexico City. This population has a high percentage of malnutrition and osteoarthrosis, a high self-perception of health, low frequency of diabetes, dyslipidemia, cardiovascular disease, and a high frequency of “escapers” (24%). PMID:28904969

  4. Model assessing the impact of biomass burning on air quality and photochemistry in Mexico City

    Science.gov (United States)

    Lei, W.; Li, G.; Wiedinmyer, C.; Yokelson, R. J.; Molina, L. T.

    2010-12-01

    Biomass burning is a major global emission source for trace gases and particulates. Various multi-platform measurements during the Mexico City Metropolitan Area (MCMA)-2003 and Megacity Initiative: Local and Global Research Observations (MILAGRO)-2006 campaigns suggest significant influences of biomass burning (BB) on air quality in Mexico City during the dry season, and the observations show emissions from BB impose viable yet highly variable impacts on organic aerosols (OA) in and around Mexico City. We have developed emission inventories for forest fires surrounding Mexico City based on measurement-estimated emission factors and MODIS fire counts, and for garbage fires in Mexico City based on in situ-measured emission factors and the population distribution and socioeconomic data. In this study, we will comprehensively assess the impact of biomass burning on the aerosol loading, chemical composition, OA formation and photochemistry in Mexico City using WRF-Chem. Analysis of the model results, in conjunction with concurrent field measurements, will be presented.

  5. Decriminalization of abortion in Mexico City: The effects on women's reproductive rights

    OpenAIRE

    Becker, Davida

    2013-01-01

    In April 2007, the Mexico City legislature passed landmark legislation decriminalizing elective abortion in the first 12 weeks of pregnancy. In Mexico City, safe abortion services are now available to women through the Mexico City Ministry of Health's free public sector legal abortion program and in the private sector, and over 89,000 legal abortions have been performed. By contrast, abortion has continued to be restricted across the Mexican states (each state makes their own abortion laws) a...

  6. 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.

  7. Prevalence of Human Papillomavirus in Women from Mexico City

    Science.gov (United States)

    López Rivera, María Guadalupe; Flores, Maria Olivia Medel; Villalba Magdaleno, José D'Artagnan; Sánchez Monroy, Virginia

    2012-01-01

    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. PMID:22811590

  8. 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.

  9. Prevalence of human papillomavirus in women from Mexico City.

    Science.gov (United States)

    López Rivera, María Guadalupe; Flores, Maria Olivia Medel; Villalba Magdaleno, José D'Artagnan; Sánchez Monroy, Virginia

    2012-01-01

    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. 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). 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. 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.

  10. Satellite observations of aerosol and CO over Mexico City

    Science.gov (United States)

    Massie, Steven T.; Gille, John C.; Edwards, David P.; Nandi, Sreela

    The development of remote sensing satellite technology potentially will lead to the technical means to monitor air pollution emitted from large cities on a global basis. This paper presents observations by the moderate resolution imaging spectroradiometer (MODIS) and measurements of pollution in the troposphere (MOPITT) experiments of aerosol optical depths and CO mixing ratios, respectively, in the vicinity of Mexico City to illustrate current satellite capabilities. MOPITT CO mixing ratios over Mexico City, averaged between January-March 2002-2005, are 19% above regional values and the CO plume extends over 10° 2 in the free troposphere at 500 hPa. Time series of Red Automatica de Monitoreo Ambiental (RAMA) PM10, and (Aerosol Robotic Network) AERONET and MODIS aerosol optical depths, and RAMA and MOPITT CO time series are inter-compared to illustrate the different perspectives of ground based and satellite instrumentation. Finally, we demonstrate, by examining MODIS and MOPITT data in April 2003, that satellite data can be used to identify episodes in which pollution form fires influences the time series of ground based and satellite observations of urban pollution.

  11. Adolescent alcohol use and alcohol use disorders in Mexico City.

    Science.gov (United States)

    Benjet, Corina; Borges, Guilherme; Méndez, Enrique; Casanova, Leticia; Medina-Mora, María Elena

    2014-03-01

    To estimate the prevalence, sex, age distribution, and socio-demographic correlates of any alcohol use, consumption patterns, and any alcohol use disorder in a representative sample of Mexican adolescents. 3005 youth (52.1% female) aged 12-17 from a stratified multistage area probability sample were representative of adolescents residing in the Mexico City Metropolitan Area. Alcohol use and disorder and their socio-demographic correlates were evaluated with the World Mental Health adolescent version of the Composite International Diagnostic Interview. Data were post-stratified to the total Mexico City adolescent population. 59% has used alcohol, this proportion increasing significantly with age. By age 17, 82.5% has used alcohol. Consumption patterns are mostly of low/moderate quantity or infrequent high quantity. Lifetime DSM-IV alcohol use disorder criteria are met by 3.8%, reaching 8.1% for 16-17 years-olds. While males have greater frequency and quantity of drinking, there are no gender differences for alcohol use disorders. Non-school attending youth have twice the odds of a lifetime (OR=2.0, 95% CI=1.13-3.53) and 12-month disorder (OR=2.1, 95% CI=1.10-4.15). Low parental monitoring is associated with 1.72 times the odds of a lifetime disorder (95% CI=1.10-2.68). Over a third of 12 year-olds had ever drunk an alcoholic beverage in their lifetime suggesting that the prevention of alcohol use and disorders must begin in late childhood. Initiatives to foment parental monitoring and to prevent, identify, and treat alcohol use problems in non-school attending youth in particular should be a priority for the wellbeing of Mexico City adolescents. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. Reference values of olfactory function for Mexico City inhabitants.

    Science.gov (United States)

    Guarneros, Marco; Hudson, Robyn; López-Palacios, Martha; Drucker-Colín, René

    2015-01-01

    Olfactory testing is useful in the differential diagnosis of age-related pathologies. To provide baseline reference values for clinical use in Mexico City we investigated the relation between olfactory capabilities and the principal population parameters of age, sex, and smoking habits in a large sample of healthy inhabitants. We applied the internationally recognized and commercially available Sniffin' Sticks test battery to 916 men and women from across the adult life span. The Sniffin' Sticks test evaluates three key aspects of olfactory function: 1) ability to detect an odor, 2) to discriminate between odors, and 3) to identify odors. We found a significant decline in olfactory function from the 5th decade of age, and that detection threshold was the most sensitive measure of this. We did not find a significant difference between men and women or between smokers and non-smokers. In confirmation of our previous studies of the negative effect of air pollution on olfactory function, Mexico City inhabitants had poorer overall performance than corresponding subjects previously tested in the neighboring but less polluted Mexican state of Tlaxcala. Although we basically confirm findings on general demographic patterns of olfactory performance from other countries, we also demonstrate the need to take into account local cultural, environmental and demographic factors in the clinical evaluation of olfactory performance of Mexico City inhabitants. The Sniffin' Sticks test battery, with some adjustment of stimuli to correspond to Mexican culture, provides an easily administered means of assessing olfactory health. Copyright © 2015 IMSS. Published by Elsevier Inc. All rights reserved.

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

    OpenAIRE

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

    2011-01-01

    Objective To evaluate the economic impact of Mexico City's 2008 smoke-free law—The Non-Smokers' Health Protection Law on restaurants, bars and nightclubs. Material and methods 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 wa...

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

    OpenAIRE

    Lucas W. Davis

    2017-01-01

    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 ...

  15. Some aspects of boundary layer evolution in Mexico City

    Science.gov (United States)

    Raga, G. B.; Baumgardner, D.; Kok, G.; Rosas, I.

    Measurements of chemical species and meteorological parameters were made at a site located 440 m above the mean basin level of Mexico City, over a two-week period in November during Project Azteca. Data from three of the stations of Mexico City's air quality monitoring network (Red Automática de Monitoreo Ambiental, RAMA) were also used to estimate the dilution in concentration experienced by pollutants as they are transported upslope during the course of the day. Both carbon monoxide and sulfur dioxide show a dilution of up to 50%, while ozone is usually more concentrated at the elevated site. These comparisons clearly highlight the intrinsic differences between primary and secondary gases, which are supported also by time-space, cross correlation analysis. The thermal mesoscale wind circulation dominates concentrations of pollutants at the research site: upslope during the day and downslope during the night. The data present clear evidence that downslope flows during the night contribute to ozone concentration at basin sites.

  16. Knowledge of ischemic stroke among a Mexico City population.

    Science.gov (United States)

    Góngora-Rivera, Fernando; Gutiérrez-Jiménez, Eugenio; Zenteno, Marco Antonio

    2009-01-01

    Knowledge of risk factors (RF) and warning signs of stroke by the general population is fundamental to implement efficient preventive measures and provide timely treatment. The objective of this study was to assess this knowledge in a sample population of Mexico City. Personal interview was conducted in a multifamily building complex in Mexico City. The questionnaire included sociodemographic and comorbidity factors. Knowledge was determinated according to the number of correct answers. Chi-square and Wilcoxon rank tests were performed and significant variables were included in a multivariate logistic regression model using level of knowledge as the dependent variable. A total of 330 subjects were interviewed. Of the respondents, 66.7% named one RF associated with ischemic stroke, whereas only 12.1% identified 3 or more; one warning sign was identified by 36.7% and only 2.1% identified 3 or more. The factors associated with knowledge of RF were history of hypertension, educational level, and family history of ischemic stroke. Educational level and a family history of stroke were also associated with knowledge of warning signs. A Family history of ischemic stroke was the most important way to receive information about RF and warning signs of ischemic stroke. The study shows the need for informing the public about prevention and early detection of ischemic stroke.

  17. 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.

  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. Comparison of Ozone Production Regimes between Two Mexican Cities: Guadalajara and Mexico City

    Directory of Open Access Journals (Sweden)

    Isao Kanda

    2016-07-01

    Full Text Available Ozone concentrations have been increasing in the Guadalajara Metropolitan Area (GMA in Mexico. To help devise efficient mitigation measures, we investigated the ozone formation regime by a chemical transport model (CTM system WRF-CMAQ. The CTM system was validated by field measurement data of ground-level volatile organic compounds (VOC and vertical profiles of ozone in GMA as well as in the Mexico City Metropolitan Area (MCMA. By conducting CTM simulations with modified emission rates of VOC and nitrogen oxides (NOx, the ozone formation regime in GMA was found to lie between VOC-sensitive and NOx-sensitive regimes. The result is consistent with the relatively large VOC/NOx emission ratio in GMA compared to that in MCMA where the ozone formation regime is in the VOC-sensitive regime.

  20. 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

  1. 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

    2008-01-01

    Background 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. Methodology/Principal Findings 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. Conclusions/Significance There is a need for improvement of wastewater treatment systems, as well as more efficient monitoring, regulation

  2. Microbiological implications of periurban agriculture and water reuse in Mexico City.

    Directory of Open Access Journals (Sweden)

    Marisa Mazari-Hiriart

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: There is a need for improvement of wastewater treatment systems, as well as more efficient

  3. Prevalence trends of oral squamous cell carcinoma. Mexico City's General Hospital experience

    OpenAIRE

    Hernández Guerrero, Juan Carlos; Jacinto Alemán, Luís Fernando; Jiménez Farfán Farfán, María Dolores; Macario Hernández, Alejandro; Hernández Flores, Florentino; Alcántara Vázquez, Avissai

    2013-01-01

    Objective: Recent reports suggest an increase in oral squamous cell carcinoma (OSCC) frequency. To improve programs in public health, it is necessary to understand the epidemiological conditions. The aim of this study was to analyze the trend in gender, age, anatomic zone and OSCC stage from Mexico City?s General Hospital patients from 1990 to 2008. Study design: A retrospective review of all OSCC cases diagnosed by the Pathology Department of the Mexico City General Hospital was performed. D...

  4. 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)

  5. Raindrop size distributions and storm classification in Mexico City

    Science.gov (United States)

    Amaro-Loza, Alejandra; Pedrozo-Acuña, Adrián; Agustín| Breña-Naranjo, José

    2017-04-01

    Worldwide, the effects of urbanization and land use change have caused alterations to the hydrological response of urban catchments. This observed phenomenon implies high resolution measurements of rainfall patterns. The work provides the first dataset of raindrop size distributions and storm classification, among others, across several locations of Mexico City. Data were derived from a recent established network of laser optical disdrometers (LOD) and retrieving measurements of rainrate, reflectivity, number of drops, drop diameter & velocity, and kinetic energy, at a 1-minute resolution. Moreover, the comparison of hourly rainfall patterns revealed the origin and classification of storms into three types: stratiform, transition and convective, by means of its corresponding reflectivity and rainrate relationship (Z-R). Finally, a set of rainfall statistics was applied to evaluate the performance of the LOD disdrometer and weighing precipitation gauge (WPG) data at different aggregated timescales. It was found that WPG gauge estimates remain below the precipitation amounts measured by the LOD.

  6. Racism and mental health among university students in Mexico City.

    Science.gov (United States)

    Ortiz-Hernández, Luis; Compeán-Dardón, Sandra; Verde-Flota, Elizabeth; Flores-Martínez, Maricela Nanet

    2011-01-01

    To assess whether differences exist in experiences of discrimination, perceptions of physical attractiveness, socioeconomic position, and mental health according to student's skin color. The population included students from a public university in Mexico City. The following three groups were created based on skin color: white, light brown, and brown. By means of regression models, we evaluated whether differences in mental health according to skin color could be due to experiences of discrimination, perceptions of physical attractiveness, and/or socioeconomic position. Students with brown skin had lower levels of self-esteem and vitality and higher levels of fatigue and alcohol consumption. These differences were explained by more frequent experiences of discrimination and because students with brown skin perceived themselves as less attractive. This is one of the first studies to document the possible effects of racism on mental health among the urban population. Verification of these findings in representative samples is required.

  7. [Sanitary quality of ham eaten in Mexico City].

    Science.gov (United States)

    Sartí-Gutiérrez, E J; Parrilla-Cerrillo, M C; Saldate-Castañeda, O; Rodríguez-Peralta, M C

    1989-01-01

    Microbiological results of 2,539 hams were analyzed (counts of mesophilic aerobes, Salmonella sp. and S. aureus) at the National Public health Laboratory from 1979 to 1987. In 58.7 percent of the cases the hams were not acceptable for human consumption, due to any of the above mentioned microbiological determinations. The main cause was the finding of high levels of mesophilic aerobes (57.5%), followed by Salmonella sp (4.4%) and S. aureus (0.43%). Raw, cooked and smoked hams presented the highest counts of mesophilic aerobes. Virginia, american style and blade hams presented the most elevated frequencies of Salmonella sp. Baked ham was the one in better sanitary conditions. The conclusion is that the quality of hams in Mexico City is bad.

  8. Obesity and overweight in IMSS female workers in Mexico City.

    Science.gov (United States)

    Vázquez-Martínez, José Luis; Gómez-Dantés, Héctor; Gómez-García, Felipe; Lara-Rodríguez, María de los Angeles; Navarrete-Espinosa, Joel; Pérez-Pérez, Gabriela

    2005-01-01

    To estimate the prevalence and risk factors for overweight (OW) and obesity (OB) in women working at the Mexican Social Security Institute (IMSS, per its abbreviation in Spanish) in Mexico City, using two different classification criteria. A cross-sectional study was performed from July 1999 to September 2000. It included 588 women 20 to 65 years of age and who were working at the IMSS. The criteria used to estimate the prevalence of OW and OB were the WHO criteria and the Mexican Official Norm (NOM) for the integrated management of obesity in Mexico. The frequency of OB, according to WHO criteria, was 27.6% (26% adjusted) and for OW 43.2% (40.2% adjusted). According to the NOM, the levels of OB in those with short height ( 1.50 m. Comparison of BMI between the two height groups showed no differences. The risk factor associated with OB and OW was age. Education and exercise were protective factors. The high prevalences detected in this particular working group highlight the importance of prevention and control of OB in health personnel because it can result in a high number of disability and premature retirement due to disease. The use of the NOM criteria for the identification of women at risk may be useful for early detection of high-risk groups.

  9. Decriminalization of abortion in Mexico City: the effects on women's reproductive rights.

    Science.gov (United States)

    Becker, Davida; Díaz Olavarrieta, Claudia

    2013-04-01

    In April 2007, the Mexico City, Mexico, legislature passed landmark legislation decriminalizing elective abortion in the first 12 weeks of pregnancy. In Mexico City, safe abortion services are now available to women through the Mexico City Ministry of Health's free public sector legal abortion program and in the private sector, and more than 89 000 legal abortions have been performed. By contrast, abortion has continued to be restricted across the Mexican states (each state makes its own abortion laws), and there has been an antichoice backlash against the legislation in 16 states. Mexico City's abortion legislation is an important first step in improving reproductive rights, but unsafe abortions will only be eliminated if similar abortion legislation is adopted across the entire country.

  10. 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

  11. Bus, minibus, metro inter-comparison of commuters’ exposure to air pollution in Mexico City

    National Research Council Canada - National Science Library

    Gómez-Perales, J.E; Colvile, R.N; Fernández-Bremauntz, A.A; Gutiérrez-Avedoy, V; Páramo-Figueroa, V.H; Blanco-Jiménez, S; Bueno-López, E; Bernabé-Cabanillas, R; Mandujano, F; Hidalgo-Navarro, M; Nieuwenhuijsen, M.J

    2007-01-01

    Commuters' exposure measurements were taken for PM.sub.2.5, carbon monoxide (CO) and benzene in minibuses, buses and metro during morning and evening rush hours during January-March 2003 in Mexico City. For PM.sub...

  12. Physiological effects of the Mexico City atmosphere on lichen transplants on oaks

    Energy Technology Data Exchange (ETDEWEB)

    Zambrano, A.; Nash, T.H. III; Gries, C.

    1999-10-01

    Two lichen species, Usnea ceratina Ach. and Everniastrum neocirrhatum (Hale M. Wirth) Hale ex Sipman, were transplanted for 54 d into an oak forest (Quercus rugosa) in the vicinity of Mexico City to assess their ability to survive near a highly polluted urban environment. Net photosynthesis based on dry weight and chlorophyll b decreased respectively ca. 30 and 25% compared with control samples in a less polluted site, ca. 100 km north of Mexico City. There was no interspecific difference in the response of carbon fixation, but E. neocirrhatum was more sensitive to chlorophyll b degradation near Mexico City than U. ceratina. Chlorophyll a was also degradated (ca. 15%) near Mexico City. Changes in total carotenes were mostly dependent on species and time rather than on location. High concurrent levels of ozone and sulfur dioxide in the air are discussed as possible causes of the decline in the lichen photosynthesis and chlorophyll content.

  13. Measurements of Natural Radioactivity in Submicron Aerosols in Mexico City.

    Science.gov (United States)

    Gaffney, J. S.; Marley, N. A.; Sterling, K.; Sturchio, N. C.

    2003-12-01

    Natural radionuclides can be useful in evaluating the transport of ozone and aerosols in the troposphere. Beryllium-7, which is produced by cosmic ray interactions in the upper troposphere and lower stratosphere and becomes adsorbed on fine aerosols, can be a useful indicator of upper air transport into a region. Lead-210 is produced by the decay of radon-222 out-gassed into the lower atmosphere from ground-based uranium deposits. Potassium-40, found in soils, can act as a measure of wind-blown dust and also comes from burning of wood and other biomass that is enriched in this natural radioisotope. Thus, both lead-210 and potassium-40 can aid in identification of aerosols sourced in the lower atmosphere. As part of our continuing interest in the lifetimes and sources of aerosols and their radiative effects, we report here measurements of fine aerosol radioactivity in Mexico City, one of the largest megacities in the world. Samples were collected on quartz fiber filters by using cascade impactors (Sierra type, Anderson Instruments) and high-volume air samplers from the rooftop of the main laboratory of El Centro Nacional de Investigacion y Capacitacion Ambiental (CENICA). By using stage 4 of the impactor and timers, we were able to collect integrated samples of sizes > 1 micrometer and < 1 micrometer over 12-hr time periods daily for approximately one month in April 2003. Samples were counted at the University of Illinois at Chicago by using state-of-the-art gamma counting (beryllium-7, 477.6 keV; potassium-40, 1460.8 keV; lead-210, 46.5 keV). The beryllium-7 data indicate one possible upper-air transport event during April 2003. As expected, the lead-210 data indicate very little soil contribution to the fine aerosol. The potassium-40 data showed an increase in fine aerosol potassium during Holy Week that might be attributed to local combustion of biomass fuels. The data will be presented and discussed in light of future data analysis and comparison with other

  14. Women's work, fertility, and competing time use in Mexico City.

    Science.gov (United States)

    Smith, S K

    1981-01-01

    This study suggests that the degree to which work and childcare are competing uses of time is an important determinant of the female labor force participation (FLFP) fertility relationships in less developed countries. A negative relationship may be found where work and childcare are competing uses of time, and no relationship (or even a positive relationship) where they are not. Several measures of competing time use are developed. The competing time use hypothesis is tested using sample survey data from Mexico City. Focus is on correlation, not causation. A basic assumption is that FLFP and fertility decisions are made jointly and depend on income, prices, tastes, wages, employment opportunities, and current family size. The empirical work deals with the direction and significance of partial correlations between FLFP and fertility and whether these correlations vary predictably according to the degree to which work and childcare are competing uses of time. The data were drawn from a multistage, stratified, clustered probability sample of married Mexican women living in the Mexico City Metropolitan Area. All women were living with their husbands at the time of the interview in early 1971. Sample size was 798. The empirical results provide strong support for the hypothesis that a negative FLFP fertility relationship will exist only if work and childcare are competing uses of time. When no distinction was made regarding competing time use, there was no significant FLFP fertility relationship. Women who had worked at some time since marriage had very similar levels of fertility to women who had not. When distinctions regarding competing time use were made, large fertility differences were evident. Workers for whom market work and childcare cannot be performed simultaneously had significantly lower fertility than nonworkers; workers for whom market work and childcare could be performed simultaneously had similar or higher fertility than nonworkers. Full time workers

  15. A Pathological Study of the Epidemiology of Atherosclerosis in Mexico City

    OpenAIRE

    Joel Rodríguez-Saldaña; Marcela Rodriguez-Flores; Carlos Cantú-Brito; Jesús Aguirre-Garcia

    2014-01-01

    Objective. To examine the frequency and patterns of association of cardiovascular risk factors with atherosclerosis in five different arterial territories at post-mortem in Mexico City. Methods. We obtained five arterial territories arteries (circle of Willis, coronary, carotid, renal, and aorta) of 185 men and women 0 to 90 years of age who underwent autopsy at the Medical Forensic Service of Mexico City. We determined the prevalence and extent of atherosclerotic lesions by histopathology ac...

  16. UV-B Measurements in Mexico City: Comparison with Modeled UVB and Black Carbon

    Science.gov (United States)

    Marley, N. A.; Gaffney, J. S.; Frederick, J. E.

    2004-12-01

    Ultraviolet-B radiation (UV-B) represents a chemically important region of the sun's spectrum. At the earth's surface, UV-B can initiate a number of important photochemical reactions (e.g., ozone photolysis) that lead to the formation of OH radicals. Where levels of nitrogen oxides are high and reactive hydrocarbons are found, as in Mexico City and other megacities, UV-B can initiate photochemical smog formation. We used a broadband instrument to obtain UV-B measurements in Mexico City during the Mexico City Metropolitan Area 2003/Mexico City Megacity 2003 field study. We then used a simple radiation model for the Mexico City latitude, altitude, and time of year to construct UV-B contours for comparison with our results. Early morning discrepancies involve reductions in UV-B that are consistent with the presence of significant levels of BC in the Mexico City environment. During most afternoons, UV-B reductions were dominated by clouds. The results are discussed in terms of the potential impacts of BC on UV-B and downwind photochemical processes. The authors wish to thank the researchers at Centro Nacional de Investigación en Calidad Ambiental (CENICA), Mexico City. This work was supported by the U.S. Department of Energy, Atmospheric Science Program (Marley and Gaffney), and the U.S. Environmental Protection Agency (Frederick). We also wish to acknowledge Drs. Mario and Luisa Molina for their help in organizing and directing the Mexico City Metropolitan Area 2003 field study, during which these data were collected.

  17. Abusive Head Trauma at a Tertiary Care Children's Hospital in Mexico City. A Preliminary Study

    Science.gov (United States)

    Diaz-Olavarrieta, Claudia; Garcia-Pina, Corina A.; Loredo-Abdala, Arturo; Paz, Francisco; Garcia, Sandra G.; Schilmann, Astrid

    2011-01-01

    Objectives: Determine the prevalence, clinical signs and symptoms, and demographic and family characteristics of children attending a tertiary care hospital in Mexico City, Mexico, to illustrate the characteristics of abusive head trauma among this population. Methods: This is a cross-sectional descriptive study of infants and children under 5,…

  18. Effect of Canal Bank Filtration on Quality of Water Long Hyderabad City

    Directory of Open Access Journals (Sweden)

    IMDAD ALI KANDHAR

    2016-07-01

    Full Text Available The focus of the present study was to examine the effect of canal bank filtration on the quality of water and the geological settings along the banks of canals at the shallow depth aquifers. The four Model wells were drilled at different locations of the Line channel, Pinyari and phulali canals in the study area. The samples of soil were collected throughout drilling of the model wells for the analysis of grain size distribution .In addition to this, canal water and model well water samples were collected and analyzed for the water quality characteristics during winter and summer seasons. The analysis of soil and water samples reveals that the ground water is influenced by the grain size distribution, hydraulic conductivity and the location of the model Wells. The model well that has higher percentage of 0.075 mm of grain size distribution(hydraulic conductivity between 10-25 ft/day was more suitable for the filtration of the canal water through its banks, followed by 0.15 mm of grain size distribution (hydraulic conductivity > 25ft/ day. Moreover, the present study also shows that the canal water filtration is suitable in terms of total alkalinity, nitrate-nitrogen, total iron and pH to get the potable water at the location near upstream of the canal, especially in the summer season.

  19. Thermodynamic characterization of Mexico City aerosol during MILAGRO 2006

    Directory of Open Access Journals (Sweden)

    C. Fountoukis

    2009-03-01

    Full Text Available Fast measurements of aerosol and gas-phase constituents coupled with the ISORROPIA-II thermodynamic equilibrium model are used to study the partitioning of semivolatile inorganic species and phase state of Mexico City aerosol sampled at the T1 site during the MILAGRO 2006 campaign. Overall, predicted semivolatile partitioning agrees well with measurements. PM2.5 is insensitive to changes in ammonia but is to acidic semivolatile species. For particle sizes up to 1μm diameter, semi-volatile partitioning requires 15–30 min to equilibrate; longer time is typically required during the night and early morning hours. Aerosol and gas-phase speciation always exhibits substantial temporal variability, so that aerosol composition measurements (bulk or size-resolved obtained over large integration periods are not reflective of its true state. When the aerosol sulfate-to-nitrate molar ratio is less than unity, predictions improve substantially if the aerosol is assumed to follow the deliquescent phase diagram. Treating crustal species as "equivalent sodium" (rather than explicitly in the thermodynamic equilibrium calculations introduces important biases in predicted aerosol water uptake, nitrate and ammonium; neglecting crustals further increases errors dramatically. This suggests that explicitly considering crustals in the thermodynamic calculations is required to accurately predict the partitioning and phase state of aerosols.

  20. [Fluoride urinary excretion in Mexico City's preschool children].

    Science.gov (United States)

    Juárez-López, María Lilia Adriana; Hernández-Guerrero, Juan Carlos; Jiménez-Farfán, Dolores; Molina-Frechero, Nelly; Murrieta-Pruneda, Francisco; López-Jiménez, Georgina

    2008-01-01

    The assessment of urinary fluoride excretion during dental developing stage has been reported for different countries with community fluoride programs. Also, one of the factors that could influence on retention and excretion of fluoride is the deficient nutrition so the aim of this study was to determine fluoride urinary excretion by a group of preschool children with and without malnutrition. Urinary samples from 24 hours were collected from 60 preschool children selected by convenience from Iztapalapa area of Mexico City, 30 with malnutrition and 30 with standard nutritrional status by weight for age. The samples were analyzed by fluoride especific electrode. Orion 720A. The average concentration of fluoride in urine from preschool children with and without malnutrition were 0.89 +/- 0.4 mg/L and 0.80 +/- 0.3 mg/L, respectively. The mean of 24 hours total fluoride excreted were 367 +/- 150 microg/24 hrs. in malnutrition children and 355 +/- 169 microg/24 hrs. for those with standard nutritional status. There were no differences statistically significant between groups. The urinary fluoride excretion for children with and without malnutrition were in the optimal range of fluoridation for the prevention of caries decay. Malnutrition was no associated with changes on fluoride orine concentration and excretion rates.

  1. 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)

  2. Reformulated gasolines: The experience of Mexico City Metropolitan Zone

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

    The introduction of several reformulated gasolines into the Mexico City Metropolitan Zone (MCMZ) in the middle 1986 is an example of using fuel composition to improve, in theory, the air quality. However, although these changes have resulted in an important reduction of lead airborne concentrations, a worsened situation has been created. Ozone levels in the atmosphere MCMZ have presented a sudden rise since the introduction of the first reformulated gasoline, reaching in the 1990`s an annual average of 1,700 exceedances to the Mexican Ozone Air Quality Standard (0.11 ppm not to be exceeded 1 hr. a day one day a year). The authors examine the tendency on ozone air quality in MCMZ in relation with the changes in gasoline composition since 1986. The authors also discuss the importance to perform an air quality impact analysis before the introduction of reformulated gasolines in countries where the local economy do not allow to change the old car fleet not fitted with exhaust treatment devices.

  3. Rapid ethnographic assessment of breastfeeding practices in periurban Mexico City.

    Science.gov (United States)

    Guerrero, M L; Morrow, R C; Calva, J J; Ortega-Gallegos, H; Weller, S C; Ruiz-Palacios, G M; Morrow, A L

    1999-01-01

    Before carrying out a breastfeeding promotion programme in a periurban area of Mexico City, we conducted a rapid ethnographic study to determine the factors associated with absence of exclusive breastfeeding. The responses to pilot interviews were used to develop a standardized questionnaire regarding reasons for infant feeding choice, sources of advice, and barriers to breastfeeding. We interviewed a random sample of 150 mothers with a child health, growth, and hygiene were the main reasons for the type of feeding selected; cost, comfort, and the husband's opinion were less important. Physicians were ranked as the most important source of advice. Reduction or cessation of breastfeeding occurred on the doctor's advice (68%); or when the mothers encountered local folk illnesses such as "coraje" (52%) or "susto" (54%), which are associated with anger or fright; or had "not enough milk" (62%) or "bad milk" (56%); or because of illness of the mother (56%) or child (43%). During childhood illnesses and conditions, breastfeeding was reduced and the use of supplementary foods was increased. This study emphasizes the importance of cultural values in infant feeding choices, defines specific barriers to breastfeeding, and provides a basis for interventions to promote exclusive breastfeeding in the study population.

  4. Thermodynamic Characterization of Mexico City Aerosol during MILAGRO 2006

    Energy Technology Data Exchange (ETDEWEB)

    Fountoukis, C.; Nenes, A.; Sullivan, A.; Weber, R.; VanReken, T.; Fischer, M.; Matias, E.; Moya, M.; Farmer, D.; Cohen, R.C.

    2008-12-05

    Fast measurements of aerosol and gas-phase constituents coupled with the ISORROPIA-II thermodynamic equilibrium model are used to study the partitioning of semivolatile inorganic species and phase state of Mexico City aerosol sampled at the T1 site during the MILAGRO 2006 campaign. Overall, predicted semivolatile partitioning agrees well with measurements. PM{sub 2.5} is insensitive to changes in ammonia but is to acidic semivolatile species. For particle sizes up to 1 {micro}m diameter, semi-volatile partitioning requires 30-60 min to equilibrate; longer time is typically required during the night and early morning hours. When the aerosol sulfate-to-nitrate molar ratio is less than unity, predictions improve substantially if the aerosol is assumed to follow the deliquescent phase diagram. Treating crustal species as 'equivalent sodium' (rather than explicitly) in the thermodynamic equilibrium calculations introduces important biases in predicted aerosol water uptake, nitrate and ammonium; neglecting crustals further increases errors dramatically. This suggests that explicitly considering crustals in the thermodynamic calculations is required to accurately predict the partitioning and phase state of aerosols.

  5. 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

  6. 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.

  7. Connecting family needs and TBI caregiver mental health in Mexico City, Mexico.

    Science.gov (United States)

    Doyle, Sarah T; Perrin, Paul B; Díaz Sosa, Dulce María; Espinosa Jove, Irma Guadalupe; Lee, Gloria K; Arango-Lasprilla, Juan Carlos

    2013-01-01

    This study examined relationships between caregiver mental health and the extent to which needs were met in families of individuals with traumatic brain injury (TBI) in Mexico City, Mexico. Sixty-eight TBI caregivers completed Spanish versions of instruments assessing their own mental health and whether specific family needs were met. Twenty-seven per cent of caregivers reported clinically significant depression levels, 40% reported below-average life satisfaction and 49% reported mild-to-severe burden. Several of the most frequently met family needs were in the emotional support domain, whereas the majority of unmet needs were in the health information domain. Family needs and caregiver mental health were significantly and highly related. When family needs were met, caregiver mental health was better. The strongest pattern of connections in multivariate analyses was between family instrumental support (assistance in the completion of daily life tasks) and caregiver burden, such that caregivers with less instrumental support had greater burden. Additional results suggested that instrumental support uniquely predicted caregiver satisfaction with life, burden and depression. Interventions for TBI caregivers, especially in Latin America, should help family members determine how best to meet their health information and instrumental needs, with the former being likely to improve caregiver mental health.

  8. 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

  9. The New Suburbs: Evolving travel behavior, the built environment, and subway investments in Mexico City

    OpenAIRE

    Guerra, Erick

    2013-01-01

    Mexico City is a suburban metropolis, yet most of its suburbs would be unfamiliar to urbanists accustomed to thinking about US metropolitan regions. Mexico City’s suburbs are densely populated—not thinly settled—and its residents rely primarily on informal transit rather than privately-owned automobiles for their daily transportation. These types of dense and transitdependent suburbs have emerged as the fastest-growing form of human settlement in cities throughout Latin America, As...

  10. 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.

  11. Diabetes and Cause-Specific Mortality in Mexico City

    Science.gov (United States)

    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

    2016-01-01

    Background 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. Methods 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. Results 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

  12. 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

  13. Comparison of PAN and Black Carbon Levels in Mexico City: 1997 and 2003

    Science.gov (United States)

    Gaffney, J. S.; Marley, N. A.

    2004-12-01

    Peroxyacetyl nitrate (PAN) is a secondary oxidant formed by the oxidation of hydrocarbons in the presence of nitrogen dioxide. PAN is a good indicator compound for hydrocarbon reactivity that leads to ozone formation. Black carbon (BC) is formed by incomplete combustion processes such as diesel soot formation and is a good indicator of primary carbonaceous aerosols in urban areas. We used a fast-response luminol method to measure PAN and BC during the Mexico City Metropolitan Area 2003/Mexico City Megacity 2003 field study in April 2003. We compare these results with our previous PAN measurements in Mexico City during February 1997, made with a gas chromatograph-electron capture detector system. The decreased PAN levels observed in 2003 are consistent with the application of emissions controls on spark ignition gasoline-fueled vehicles, leading to lower levels of the nitrogen oxides and reactive volatile hydrocarbons needed to form PAN. Black carbon data for Mexico City in 2003, taken with a seven-channel aethalometer, are compared with data from 1997, estimated from thermal analyses as elemental carbon (EC). The comparison indicates little change in the levels of BC/EC over the six-year period. This observation is consistent with the application of minimal controls to diesel engines, the likely major source of BC in the Mexico City megacity complex during this period. The authors wish to thank the researchers at Centro Nacional de Investigación en Calidad Ambiental (CENICA), Mexico City. This work was supported by the U.S. Department of Energy, Atmospheric Science Program. We also wish to acknowledge Drs. Mario and Luisa Molina for their help in organizing and directing the Mexico City Metropolitan Area 2003 field study, during which these data were collected.

  14. Quantification of local and global benefits from air pollution control in Mexico City.

    Science.gov (United States)

    Mckinley, Galen; Zuk, Miriam; Höjer, Morten; Avalos, Montserrat; González, Isabel; Iniestra, Rodolfo; Laguna, Israel; Martínez, Miguel A; Osnaya, Patricia; Reynales, Luz M; Valdés, Raydel; Martínez, Julia

    2005-04-01

    Complex sociopolitical, economic, and geographical realities cause the 20 million residents of Mexico City to suffer from some of the worst air pollution conditions in the world. Greenhouse gas emissions from the city are also substantial, and opportunities for joint local-global air pollution control are being sought. Although a plethora of measures to improve local air quality and reduce greenhouse gas emissions have been proposed for Mexico City, resources are not available for implementation of all proposed controls and thus prioritization must occur. Yet policy makers often do not conduct comprehensive quantitative analyses to inform these decisions. We reanalyze a subset of currently proposed control measures, and derive cost and health benefit estimates that are directly comparable. This study illustrates that improved quantitative analysis can change implementation prioritization for air pollution and greenhouse gas control measures in Mexico City.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

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

    OpenAIRE

    Alvarado Ibarra Martha; Aguilar Andrade Carolina; Báez Islas Pamela Elena; Cervantes Sánchez Israel; Chávez Aguilar Lénica Anahí; Choque Condori Diana Ingrith; de la Rosa Cano María Luisa; Espitia Ríos María Flores Villegas Luz Victoria; García Camacho Alinka Socorro; Gómez Rosas Patricia; Grimaldo Gómez Flavio Adrián; Hernández Ruiz Eleazar; Loera Fragoso Sergio José; Mena Zepeda Verónica; Merino Pasaye, Laura Elizabeth

    2017-01-01

    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 disc...

  1. Mexico City's Petroleos Mexicanos explosion: disaster management and air medical transport.

    Science.gov (United States)

    Urquieta, Emmanuel; Varon, Joseph

    2014-01-01

    Mexico City is the largest metropolitan area in the Americas and 1 of the largest in the world; its geographic location and uncontrolled population and industrial growth make this metropolis prone to natural and human-made disasters. Mass casualty disaster responses in Mexico City tend to have complications from multiple logistical and operational challenges. This article focuses on the experiences and lessons learned from an explosion that occurred in a government building in Mexico City and the current status of mass casualty disaster risks and response strategies in Mexico City as well as air medical evacuation, which is a critical component and was shown to be extremely useful in the evacuation of 15 critically ill and polytraumatized patients (Injury Severity Score > 15). Several components of the public and privately owned emergency medical services and health care systems among Mexico City pose serious logistical and operational complications, which finally will be addressed by a joint emergency preparedness council to unify criteria in communications, triage, and incident/disaster command post establishment. Copyright © 2014 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

  2. 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

  3. Primary and Secondary Organic Carbon Downwind of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiao-Ying; Cary, R.; Laulainen, Nels S.

    2009-09-18

    In order to study particulate matter transport and transformation in the Megacity environment, fine particulate carbons were measured simultaneously at two supersites, suburban T1 and rural T2, downwind of Mexico City during the MILAGRO field campaign in March 2006. Organic carbon (OC), element carbon (EC), and total carbon (TC=OC+EC) were determined near real-time by the Sunset semi-continuous field analyzer at both sites. The semi-empirical EC tracer method was used to derive primary organic carbon (POC) and secondary organic carbon (SOC). Diurnal variations of primary and secondary carbons were observed at T1 and T2, which resulted from boundary layer inversion and impacted by local traffic patterns. The majority of organic carbons at T1 and T2 were secondary. The SOC% (SOC%=SOC/TC*100%) at T1 ranged from 1.2 - 100% with an average of 80.7 ± 14.4%. The SOC% at T2 ranged from 12.8 - 100% with an average of 80.1 ± 14.0%. The average EC to PM2.5 percentage (ECPM%=EC/PM2.5*100%)) and OCPM% were 6.0 % and 20.0% over the whole sampling time. The POC to PM percentage (POCPM%) and SOCPM% were 3.7% and 16.3%, respectively. The maximum ECPM% was 21.2%, and the maximum OCPM% was 57.2%. The maximum POCPM% was 12.9%, and the maximum SOC% was 49.7%. The SOC and POC during T1 to T2 transfer favourable meteorological conditions showed similar characteristics, which indicated that transport between the two supersites took place. Strong correlations between EC and carbon monoxide (CO) and odd nitrogens (NO and NOx) were observed at T1. This indicated that EC had proximate sources such as local traffic emissions. The EC/CO ratio derived by linear regression analysis when parameters are in μgC/m3 and μg/m3, respectively, was 0.0045. A strong correlation was also seen between OC and SOC vs. the sum of oxidants such as O3 and NO2 or O3, NO2 and SO2, suggesting the secondary nature of carbons observed at T1.

  4. Bisphenol a exposure in Mexico City and risk of prematurity: a pilot nested case control study

    OpenAIRE

    Mercado-García Adriana; Lamadrid-Figueroa Héctor; Sánchez Brisa N; Hu Howard; Meeker John D; Cantonwine David; Fortenberry Gamola Z; Calafat Antonia M; Téllez-Rojo Martha

    2010-01-01

    Abstract Background Presence of Bisphenol A (BPA) has been documented worldwide in a variety of human biological samples. There is growing evidence that low level BPA exposure may impact placental tissue development and thyroid function in humans. The aim of this present pilot study was to determine urinary concentrations of BPA during the last trimester of pregnancy among a small subset of women in Mexico City, Mexico and relate these concentrations to risk of delivering prematurely. Methods...

  5. Impact of Mexico City emissions on regional air quality from MOZART-4 simulations

    Directory of Open Access Journals (Sweden)

    L. K. Emmons

    2010-07-01

    Full Text Available An extensive set of measurements was made in and around Mexico City as part of the MILAGRO (Megacity Initiative: Local and Global Research Observations experiments in March 2006. Simulations with the Model for Ozone and Related Chemical Tracers, version 4 (MOZART-4, a global chemical transport model, have been used to provide a regional context for these observations and assist in their interpretation. These MOZART-4 simulations reproduce the aircraft observations generally well, but some differences in the modeled volatile organic compounds (VOCs from the observations result from incorrect VOC speciation assumed for the emission inventories. The different types of CO sources represented in the model have been "tagged" to quantify the contributions of regions outside Mexico, as well as the various emissions sectors within Mexico, to the regional air quality of Mexico. This analysis indicates open fires have some, but not a dominant, impact on the atmospheric composition in the region around Mexico City when averaged over the month. However, considerable variation in the fire contribution (2–15% of total CO is seen during the month. The transport and photochemical aging of Mexico City emissions were studied using tags of CO emissions for each day, showing that typically the air downwind of Mexico City was a combination of many ages. Ozone production in MOZART-4 is shown to agree well with the net production rates from box model calculations constrained by the MILAGRO aircraft measurements. Ozone production efficiency derived from the ratio of Ox to NOz is higher in MOZART-4 than in the observations for moderately polluted air. OH reactivity determined from the MOZART-4 results shows the same increase in relative importance of oxygenated VOCs downwind of Mexico City as the reactivity inferred from the observations. The amount of ozone produced by emissions from Mexico City and surrounding areas has been quantified in the

  6. 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.

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

    Science.gov (United States)

    Campos, Paola A; Falb, Kathryn L; Hernández, Sara; Díaz-Olavarrieta, Claudia; Gupta, Jhumka

    2017-01-01

    To document the frequency and forms of street harassment and examine the association between street harassment experiences and perceptions of social cohesion. Baseline survey data collected among women seeking care in public health clinics in Mexico City were used for analysis. 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). Findings indicate reducing street harassment may have important implications for improving women's perceived social cohesion and their safety in Mexico City.

  8. 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.

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

    Science.gov (United States)

    Auvinet, G.; Méndez-Sánchez, E.; Juárez-Camarena, M.

    2015-11-01

    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.

  10. 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.

  11. The production and persistence of ΣRONO2 in the Mexico City plume

    Directory of Open Access Journals (Sweden)

    H. B. Singh

    2010-08-01

    Full Text Available Alkyl and multifunctional nitrates (RONO2, ΣANs have been observed to be a significant fraction of NOy in a number of different chemical regimes. Their formation is an important free radical chain termination step ending production of ozone and possibly affecting formation of secondary organic aerosol. ΣANs also represent a potentially large, unmeasured contribution to OH reactivity and are a major pathway for the removal of nitrogen oxides from the atmosphere. Numerous studies have investigated the role of nitrate formation from biogenic compounds and in the remote atmosphere. Less attention has been paid to the role ΣANs may play in the complex mixtures of hydrocarbons typical of urban settings. Measurements of total alkyl and multifunctional nitrates, NO2, total peroxy nitrates (ΣPNs, HNO3 and a representative suite of hydrocarbons were obtained from the NASA DC-8 aircraft during spring of 2006 in and around Mexico City and the Gulf of Mexico. ΣANs were observed to be 10–20% of NOy in the Mexico City plume and to increase in importance with increased photochemical age. We describe three conclusions: (1 Correlations of ΣANs with odd-oxygen (Ox indicate a stronger role for ΣANs in the photochemistry of Mexico City than is expected based on currently accepted photochemical mechanisms, (2 ΣAN formation suppresses peak ozone production rates by as much as 40% in the near-field of Mexico City and (3 ΣANs play a significant role in the export of NOy from Mexico City to the Gulf Region.

  12. 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

  13. 3 CFR - Mexico City Policy and Assistance for Voluntary Population Planning

    Science.gov (United States)

    2010-01-01

    ... Population Planning Presidential Documents Other Presidential Documents Memorandum of January 23, 2009 Mexico City Policy and Assistance for Voluntary Population Planning Memorandum for the Secretary of State the... subsequently extended the policy to “voluntary population planning” assistance provided by the Department of...

  14. Cluster Analysis of the Wind Events and Seasonal Wind Circulation Patterns in the Mexico City Region

    Directory of Open Access Journals (Sweden)

    Susana Carreón-Sierra

    2015-07-01

    Full Text Available The residents of Mexico City face serious problems of air pollution. Identifying the most representative scenarios for the transport and dispersion of air pollutants requires the knowledge of the main wind circulation patterns. In this paper, a simple method to recognize and characterize the wind circulation patterns in a given region is proposed and applied to the Mexico City winds (2001–2006. This method uses a lattice wind approach to model the local wind events at the meso-β scale, and hierarchical cluster analysis to recognize their agglomerations in their phase space. Data of the meteorological network of Mexico City was used as input for the lattice wind model. The Ward’s clustering algorithm with Euclidean distance was applied to organize the model wind events in seasonal clusters for each year of the period. Comparison of the hourly population trends of these clusters permitted the recognition and detailed description of seven circulation patterns. These patterns resemble the qualitative descriptions of the Mexico City wind circulation modes reported by other authors. Our method, however, permitted also their quantitative characterization in terms of the wind attributes of velocity, divergence and vorticity, and an estimation of their seasonal and annual occurrence probabilities, which never before were quantified.

  15. 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…

  16. 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

  17. 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

  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. Summary of air pollution impacts on forests in the Mexico City air basin

    Science.gov (United States)

    Mark E. Fenn; L.I. de Bauer; Tomás Hernández-Tejeda

    2002-01-01

    Oxidant air pollution symptoms were first reported in bioindicator plants in the Mexico City Air Basin (MCAB) in 1971 (de Bauer 1972). Classic injury symptoms on well-known bioindicator plants strongly supported the presumption that symptoms were caused by photochemical oxidants, of which ozone (O3) is the primary pollutant. Symptoms in indicator...

  20. Mexico City basin wind circulation during the MCMA-2003 field campaign

    Directory of Open Access Journals (Sweden)

    B. de Foy

    2005-01-01

    Full Text Available MCMA-2003 was a major field campaign investigating the atmospheric chemistry of the Mexico City Metropolitan Area (MCMA in April of 2003. This paper describes the wind circulation patterns during the campaign both within the Mexico City basin and on the regional scale. ''Time roses'' are introduced to concisely analyze the diurnal wind patterns. Three episode types were identified that explain the conditions encountered: ''O3-South'', ''Cold Surge'' and ''O3-North''. These can be diagnosed from a combination of synoptic and basin observations based on whether the day was predominantly cloudy, or whether the O3 peak was in the north or south of the basin. O3-South days have weak synoptic forcing due to an anti-cyclone over the eastern Pacific. Strong solar heating leads to northerly flows in the basin and an evening shift due to a gap flow from the south-east. Peak ozone concentrations are in the convergence zone in the south of the city. Cold Surge days are associated with ''El Norte'' events, with strong surface northerlies bringing cold moist air and rain. Stable conditions lead to high concentrations of primary pollutants and peak ozone in the city center. O3-North days occur when the sub-tropical jet is closer to Mexico City. With strong westerlies aloft, the circulation pattern is the same as O3-South days except for a wind shift in the mid-afternoon leading to ozone peaks in the north of the city. This classification is proposed as a means of understanding pollutant transport in the Mexico City basin and as a basis for future meteorological and chemical analysis. Furthermore, model evaluation and design of policy recommendations will need to take into account the three episode types.

  1. Community Policing in Latin America: Lessons from Mexico City

    National Research Council Canada - National Science Library

    Markus-Michael Müller

    2010-01-01

    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...

  2. Effect of air pollution on olfactory function in residents of Mexico City.

    Science.gov (United States)

    Hudson, Robyn; Arriola, Aline; Martínez-Gómez, Margarita; Distel, Hans

    2006-01-01

    To our knowledge there has been no study of the effect of everyday air pollution on olfactory function. It was therefore the aim of this study to compare the olfactory performance of long-term residents of Mexico City, an environment with high air pollution, with the olfactory performance of residents of the Mexican state of Tlaxcala, a region geographically similar to Mexico City but with low air pollution. Healthy volunteers [82 Mexico City subjects (MEX), 86 Tlaxcala subjects (TLX)] 20-63 years of age and balanced for age and gender between the two localities were tested for the perception of the odors of everyday beverages presented in squeeze bottles. When tested with ascending concentrations of stimuli in a three-way oddball paradigm, residents of Tlaxcala detected the odors of instant coffee and of an orange drink at significantly lower concentrations than residents of Mexico City. They also performed significantly better in discriminating between the two similar-smelling Mexican beverages horchata and atole in an oddball test. Significant differences between the two populations in overall olfactory performance were apparent in three of the four age classes (20- to 29-, 30- to 39-, and 40- to 49-year-old subjects) but not in the 50-63 years age class. About 10% of MEX subjects compared to about 2% of TLX subjects were judged to have poor olfactory function; all were from the older age classes (mean age: 48.6 years). Thus, air pollution in Mexico City appears to have a substantial impact on olfactory function even in young and middle-aged residents.

  3. 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

  4. Towards sustainable urban distribution using city canals; the case of Amsterdam

    NARCIS (Netherlands)

    dr. J.H.R. van Duin; Dr. L.J. Kortmann; Dr. L.M. van de Kamp

    2017-01-01

    This study investigates whether a system of hub locations distributing goods across the water to the city of Amsterdam can be a potential future solution to guarantee same-day delivery to shopkeepers. A simulation model was developed to analyse the logistics performances and to optimise the number

  5. Towards sustainable urban distribution using city canals: the case of amsterdam

    NARCIS (Netherlands)

    van Duin, Ron; Kortmann, L.J.

    2017-01-01

    This study investigates whether a system of hub locations distributing goods across the water to the city of Amsterdam can be a potential future solution to guarantee same-day delivery to shopkeepers. A simulation model was developed to analyse the logistics performances and to optimise the number

  6. Partners in coffeeshops, canals and commerce : Marketing the city of Amsterdam

    NARCIS (Netherlands)

    Kavaratzis, M.; Ashworth, G.J.

    The position of Amsterdam as an international centre of business, culture and tourism has recently been threatened by increasingly fierce inter-urban competition. The desire to improve Amsterdam's attractiveness to local and international audiences, and to retune the city's international image, has

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

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

    2011-02-03

    Feb 3, 2011 ... But despite more than a decade of stringent pollution control measures, a haze hangs over the city most days, obscuring the surrounding snow-capped mountains and endangering the health of its inhabitants. Many factors have contributed to this situation: industrial growth, a population boom (from three ...

  8. [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.

  9. Global radiation attenuation by air pollution and its effects on the thermal climate in Mexico City

    Science.gov (United States)

    Jáuregui, E.; Luyando, E.

    1999-05-01

    Solar radiation attenuation in Mexico City is estimated by comparing global radiation intensity observed at a station in the downtown area, relative to that observed in a cleaner rural air at a site 8 km northeast of the airport. On average, the city receives on clear days during the dry season 21.6% less solar energy than the rural surroundings. Similar values of attenuation are observed during the rainy season when aerosol concentration is abated by a wash-out effect. As expected, solar dimming shows an inverse relation to wind and temperature. Attenuation reaches its maximum (25-35%) with prevailing weak winds (1-2 m/s) and high noon relative humidity. In the city, variation of global radiation by the day of week, shows that solar attenuation is highest on Tuesdays, while on Saturdays solar dimming by smog was less. Since a similar weekly variation (with lower values) was observed at the rural site, the conclusion was that the smog layer affects the solar radiation climate in rural areas beyond the immediate city limits. The declining annual mean of maximum temperatures observed near the limits of the Mexico City basin, suggests that the smog layer is affecting the radiation and thermal climate of a vast region downwind of the capital city.An attempt is made to show that while in the industrial and downtown areas the day time heat island effect dominates over the cooling effect of aerosols, in other suburban and rural sites downwind and away from the warm air mass, the reflecting properties of the smog layer seem to prevail resulting in an observed decreasing trend in maximum temperatures. From the above it may be concluded that maximum temperatures continue to rise in downtown Mexico City in spite of the attenuation due to absorption and reflection of incoming solar energy by the smog layer.

  10. Detection of mumps virus genotype H in two previously vaccinated patients from Mexico City.

    Science.gov (United States)

    Del Valle, Alberto; García, Alí A; Barrón, Blanca L

    2016-06-01

    Infections caused by mumps virus (MuV) have been successfully prevented through vaccination; however, in recent years, an increasing number of mumps outbreaks have been reported within vaccinated populations. In this study, MuV was genotyped for the first time in Mexico. Saliva samples were obtained from two previously vaccinated patients in Mexico City who had developed parotitis. Viral isolation was carried out in Vero cells, and the SH and HN genes were amplified by RT-PCR. Amplicons were sequenced and compared to a set of reference sequences to identify the MuV genotype.

  11. 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.

  12. Mexico City air pollution adversely affects olfactory function and intranasal trigeminal sensitivity.

    Science.gov (United States)

    Guarneros, Marco; Hummel, Thomas; Martínez-Gómez, Margaríta; Hudson, Robyn

    2009-11-01

    Surprisingly little is known about the effects of big-city air pollution on olfactory function and even less about its effects on the intranasal trigeminal system, which elicits sensations like burning, stinging, pungent, or fresh and contributes to the overall chemosensory experience. Using the Sniffin' Sticks olfactory test battery and an established test for intranasal trigeminal perception, we compared the olfactory performance and trigeminal sensitivity of residents of Mexico City, a region with high air pollution, with the performance of a control population from the Mexican state of Tlaxcala, a geographically comparable but less polluted region. We compared the ability of 30 young adults from each location to detect a rose-like odor (2-phenyl ethanol), to discriminate between different odorants, and to identify several other common odorants. The control subjects from Tlaxcala detected 2-phenyl ethanol at significantly lower concentrations than the Mexico City subjects, they could discriminate between odorants significantly better, and they performed significantly better in the test of trigeminal sensitivity. We conclude that Mexico City air pollution impairs olfactory function and intranasal trigeminal sensitivity, even in otherwise healthy young adults.

  13. [Perception of health risks due to air pollution among adolescents in Mexico City].

    Science.gov (United States)

    Catalán-Vázquez, Minerva; Riojas-Rodríguez, Horacio; Jarillo-Soto, Edgar C; Delgadillo-Gutiérrez, Héctor Javier

    2009-01-01

    Analyze the relations established between air pollution and health-disease-death in a sample of students in Mexico City. Survey of 1274 students from 14 secondary schools in five areas in Mexico City was conducted between March and April of 2003. We used a multi-stage sampling, based in a basic geostatistical areas (AGEB). A total of 84.4% believed that Mexico City has a high, or very high air pollution; that valuation decreases as it approaches the most immediate place in which the students live. The health risks range from effects on respiratory health, 66.9%, to other effects on daily life, 2.2%. The predictors that air pollution is perceived as serious/very serious are: 1) that they associate it with the possibility of causing death (OR= 1.35, 95% CI=1.02-1.77), and 2) that they attend schools located in the La Merced zone, (OR= 2.23, 95% CI= 1.56-3.21). Determinants of perception, such as gender, zone where the school is located and the differences in air quality perceived in the city/area/schools, suggest that focalizing components must be involved in environmental policies, in order to make environmental programs more effective at the local level.

  14. Towards sustainable urban distribution using city canals: the case of amsterdam

    OpenAIRE

    van Duin, Ron; Kortmann, L.J.

    2017-01-01

    This study investigates whether a system of hub locations distributing goods across the water to the city of Amsterdam can be a potential future solution to guarantee same-day delivery to shopkeepers. A simulation model was developed to analyse the logistics performances and to optimise the number of hub locations and required fleet size. The simulation tests have shown that two hub locations are sufficient when they are equipped with two vessels. Conclusion of this study is that a waterborne...

  15. 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)

  16. Identification of Enteric Viruses in Foods from Mexico City.

    Science.gov (United States)

    Parada-Fabián, José Carlos; Juárez-García, Patricia; Natividad-Bonifacio, Iván; Vázquez-Salinas, Carlos; Quiñones-Ramírez, Elsa Irma

    2016-09-01

    Foodborne viruses are a common and, probably, the most under-recognized cause of outbreaks of gastroenteritis. Among the main foods involved in the transmission of human enteric viruses are mollusks, and fruits and vegetables irrigated with wastewater and/or washed with non-potable water or contaminated by contact with surfaces or hands of the infected personnel during its preparation. In this study, 134 food samples were analyzed for the detection of Norovirus, Rotavirus, and Hepatitis A virus (HAV) by amplification of conserved regions of these viruses. From the 134 analyzed samples, 14 were positive for HAV, 6 for Norovirus, and 11 for Rotavirus. This is the first report in Mexico where emphasis is given to the presence of HAV and Norovirus on perishable foods and food from fisheries, as well as Rotavirus on frozen vegetables, confirming the role of vegetables and bivalve mollusks as transmitting vehicles of enteric viruses.

  17. Remote Sensing and Water Quality Indicators in the West Flood Canal Semarang City: Spatio-temporal Structures of Lansat-8 Derived Chlorophyll-a and Total Suspended Solids

    Science.gov (United States)

    Subiyanto, Sawitri

    2017-12-01

    One of the waters that has been contaminated by industrial waste and domestic waste is the waters of West Flood Canal in Semarang City which is the estuary of the river system, which passes through the Western City of Semarang which is dense with residential and industrial. So, it is necessary to have information about the assessment of water quality in the estuary of the West Flood Canal. Remote sensing technology can analyze the results of recording the spectral characteristics of water with water quality parameters. One of the parameters for assessing water quality is Chlorophyll-a and Total Suspended Solid, can be estimated through remote sensing technology using multispectral Lansat-8 Satellite images data from April, June, and August, 2017 and there are three selected algorithms. Based on the results of TSS and Chlorophyll-A processing, the TSS shows values greater than or equal to 100 which can be said that West Flood Canal is damaged (hypertrophic). While the chlorophyll-a shows a value less than 100 indicating Eutrophic status (threatened). This is caused by the number of suspended materials in the water surface and also because of the disturbance of water vegetation in the form of weeds that destroy the function of the actual West Canal Flood.

  18. The need for standards and codes to ensure an acoustically comfortable environment in multifamily housing buildings in Mexico City

    Science.gov (United States)

    Kotasek Gonzalez, Eduardo; Rodriguez Manzo, Fausto

    2002-11-01

    It is clear that almost all kinds of buildings require protection against noise and undesirable sounds, however, there are some countries where this is not yet regulated, such is the case of Mexico. Mexico City, the biggest city in the world could also be the noisiest. This is a problem which is today being debated; in fact there is no doubt that this has an important influence on the acoustic comfort conditions of dwellings, besides the habits and culture of the inhabitants, which are very different from those in the Anglo-Saxon countries. These are all details that must be taken into account in the design of an acoustic comfort standard for buildings in cities like Mexico. In this paper we deal with this problem and it suggests some recommendations to consider in a proposed acoustic comfort standard or code to be applied in the design of multifamily housing buildings in Mexico City.

  19. The avoidable health effects of air pollution in three Latin American cities: Santiago, São Paulo, and Mexico City.

    Science.gov (United States)

    Bell, Michelle L; Davis, Devra L; Gouveia, Nelson; Borja-Aburto, Víctor H; Cifuentes, Luis A

    2006-03-01

    Urban centers in Latin American often face high levels of air pollution as a result of economic and industrial growth. Decisions with regard to industry, transportation, and development will affect air pollution and health both in the short term and in the far future through climate change. We investigated the pollution health consequences of modest changes in fossil fuel use for three case study cities in Latin American: Mexico City, Mexico; Santiago, Chile; and São Paulo, Brazil. Annual levels of ozone and particulate matter were estimated from 2000 to 2020 for two emissions scenarios: (1) business-as-usual based on current emissions patterns and regulatory trends and (2) a control policy aimed at lowering air pollution emissions. The resulting air pollution levels were linked to health endpoints through concentration-response functions derived from epidemiological studies, using local studies where available. Results indicate that the air pollution control policy would have vast health benefits for each of the three cities, averting numerous adverse health outcomes including over 156,000 deaths, 4 million asthma attacks, 300,000 children's medical visits, and almost 48,000 cases of chronic bronchitis in the three cities over the 20-year period. The economic value of the avoided health impacts is roughly 21 to 165 billion Dollars (US). Sensitivity analysis shows that the control policy yields significant health and economic benefits even with relaxed assumptions with regard to population growth, pollutant concentrations for the control policy, concentration-response functions, and economic value of health outcomes. This research demonstrates the health and economic burden from air pollution in Latin American urban centers and the magnitude of health benefits from control policies.

  20. Political structure, political-clientelist networks and electoral oscillations in Mexico City

    Directory of Open Access Journals (Sweden)

    Héctor Tejera

    2017-07-01

    Full Text Available The supremacy of the prd as the ruling party in Mexico City has led the consolidation of a po­litical elite associated to different party factions. This elite supports its influence in a political structure of control, based in patronage networks. Linking participant observation and in-depth interviews, analysis of georeferenced clusters of electoral behavior, and comparison between case studies, the article shows the effects of the action of these networks in the electoral field; dem­onstrating all the above by studying the electoral conflicts in two political delegations in the aforementioned city.

  1. 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.

  2. Presence of polycyclic aromatic hydrocarbons (PAHs) in apple in rural terrains from Mexico City.

    Science.gov (United States)

    Salinas, Rutilio Ortiz; González, Gilberto Díaz; Bermudez, Beatriz Schettino; Tolentino, Rey Gutiérrez; Vega Y León, Salvador

    2010-08-01

    This paper describes PAH concentrations in apple crops that are growing in rural terrains in Mexico City. The concentrations of individual PAHs showed great variability, there being low and high molecular weight compounds in dry (high molecular weight for Tlahuac 7.06 microg/g and Milpa Alta 3.96 microg/g) and wet months (high molecular weight for Tlahuac 11.25 microg/g and Milpa Alta 12.05 microg/g). Some PAHs indicators and cross plot ratios Ant/(Ant + Phe) and Flu/(Flu + Pyr) define fossil fuels and vegetation combustion as the source of contamination over the cuticle of the apples. It is likely that deposition (dry and wet) is the principal source o f contamination over the apple surface. This study reveals the presence of PAHs in apples due to the high air contamination of Mexico City.

  3. 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.

  4. 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.

  5. 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

  6. 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…

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

    OpenAIRE

    Campos, Paola A; Falb, Kathryn L.; Sara Hernández; Claudia Díaz-Olavarrieta; Jhumka Gupta

    2017-01-01

    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 low...

  8. Sweetened beverages intake, hyperuricemia and metabolic syndrome. The Mexico City Diabetes Study.

    OpenAIRE

    Rubén López-Molina; Socorro Parra-Cabrera; Ruy López-Ridaura; María E González-Villalpando; Ele Ferrannini; Clicerio González-Villalpando

    2013-01-01

    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...

  9. A Historical Perspective on Crime in Twentieth-Century Mexico City

    OpenAIRE

    Piccato, Pablo

    2003-01-01

    This paper is an overview of perceptions of crime in Mexico City during the twentieth century. After a brief review of quantitative evidence and the main sources on crime, the paper surveys police and judicial corruption as the common denominator of public perceptions of crime, punishment, and the judiciary. The paper then discusses gender violence and juvenile delinquency as two criminal practices that have characterized the impact of crime in everyday life. Based on a review of evidence abo...

  10. An Approach to Litter Generation and Littering Practices in a Mexico City Neighborhood

    OpenAIRE

    Cecilia E. Muñoz-Cadena; Pedro Lina-Manjarrez; Irma Estrada-Izquierdo; Eva Ramón-Gallegos

    2012-01-01

    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 cou...

  11. Preschool and Educational Technology: Evaluating a Tablet-Based Math Curriculum in Mexico City

    OpenAIRE

    Garduno, Ana Eugenia

    2016-01-01

    This study examines the effect of an intervention called Native Numbers on the development of number sense and quantitative skills in low-SES preschool children (ages 5 to 6) in Mexico City, using a randomized control trial (RCT). Native Numbers (NN) is a math curriculum built as an application for iPads that includes activities on number concepts, relations, ordering and counting. The study was conducted in 2014, with eight participating schools and an analytic sample of 249 students. The in...

  12. The chemo and the mona: inhalants, devotion and street youth in Mexico City.

    Science.gov (United States)

    Gigengack, Roy

    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 fiend's point of view"). Even if inhalant use is globally associated with economic inequality and deprivation, there is a marked lack of ethnography. Incomprehension and indignation have blocked our understanding of inhalant use as a form of marginalised drug use. The current explanation models reduce inhalant consumption to universal factors and individual motives; separating the practice from its context, these models tend to overlook gustatory meanings and experiences. The paper is informed by long-term, on-going fieldwork with young street people in Mexico City. Fieldwork was done from 1990 through 2010, in regular periods of fieldwork and shorter visits, often with Mexican colleagues. We created extensive sets of fieldnotes, which were read and re-read. "Normalcy" is a striking feature of inhalant use in Mexico City. Street-wise inhabitants of popular neighbourhoods have knowledge about inhalants and inhalant users, and act accordingly. Subsequently, Mexico City's elaborate street culture of sniffing is discussed, that is, the range of inhalants used, how users classify the substances, and their techniques for sniffing. The paper also distinguishes three patterns of inhalant use, which more or less correlate with age. These patterns indicate embodiments of street culture: the formation within users of gusto, that is, an acquired appetite for inhalants, and of vicio, the inhalant fiends' devotion to inhalants. What emerges from the ethnographic findings is an elaborate street culture of sniffing, a complex configuration of shared perspectives and embodied practices, which are shaped by and shaping social exclusion. These findings are relevant to appreciate and address the

  13. Costs of treating diarrhoea in a children's hospital in Mexico City.

    OpenAIRE

    Phillips, M; Kumate-Rodríguez, J.; Mota-Hernández, F.

    1989-01-01

    The treatment received by children aged under 5 years with diarrhoea was studied in the Hospital Infantil de México (Federico Goméz), Mexico City. The costs of treatment were calculated and estimates were made of how these had changed since the establishment of an oral rehydration unit in the hospital in 1985. The results indicate that drug treatment of outpatients was generally appropriate and inexpensive. In contrast, the cost of drugs for inpatients was considerably higher. The seriousness...

  14. Satellite-derived land surface parameters for mesoscale modelling of the Mexico City basin

    OpenAIRE

    De Foy, B.; Molina, L. T.; Molina, M. J.

    2006-01-01

    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 epis...

  15. Satellite-derived land surface parameters for mesoscale modelling of the Mexico City basin

    OpenAIRE

    De Foy, B.; Molina, L. T.; Molina, M. J.

    2006-01-01

    International audience; 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 o...

  16. Rapid ventilation of the Mexico City basin and regional fate of the urban plume

    Directory of Open Access Journals (Sweden)

    B. de Foy

    2006-01-01

    Full Text Available Urban areas can be large emitters of air pollutants leading to negative health effects and environmental degradation. The rate of venting of these airsheds determines the pollutant loading for given emission levels, and also determines the regional impacts of the urban plume. Mexico City has approximately 20 million people living in a high altitude basin with air pollutant concentrations above the health limits most days of the year. A mesoscale meteorological model (MM5 and a particle trajectory model (FLEXPART are used to simulate air flow within the Mexico City basin and the fate of the urban plume during the MCMA-2003 field campaign. The simulated trajectories are validated against pilot balloon and radiosonde trajectories. The residence time of air within the basin and the impacted areas are identified by episode type. Three specific cases are analysed to identify the meteorological processes involved. For most days, residence times in the basin are less than 12 h with little carry-over from day to day and little recirculation of air back into the basin. Very efficient vertical mixing leads to a vertically diluted plume which, in April, is transported predominantly towards the Gulf of Mexico. Regional accumulation was found to take place for some days however, with urban emissions sometimes staying over Mexico for more than 6 days. Knowledge of the residence times, recirculation patterns and venting mechanisms will be useful in guiding policies for improving the air quality of the MCMA.

  17. 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.

  18. Presence of polycyclic aromatic hydrocarbons (PAHs) in top soils from rural terrains in Mexico City.

    Science.gov (United States)

    Ortiz, Rutilio; Vega, Salvador; Gutiérrez, Rey; Gibson, Richard; Schettino, Beatriz; Ramirez, María de Lourdes

    2012-03-01

    A soil survey was carried out to determine the levels and sources and concentrations of 16 polycyclic aromatic hydrocarbons in 2 semi-rural terrains in Mexico City (Tlahuac and Milpa Alta) during 2008-2009. PAH determination was made by Soxhlet extraction and chromatographic clean-up with final analysis by gas chromatography with a flame ionization detector. The concentrations in Tlahuac were 9.13 mg/kg (dry season) and 11.22 mg/kg (wet season) and in Milpa Alta were 11.43 mg/kg (dry season) and 35.77 mg/kg (wet season). The variation of total PAH concentrations are due to environmental and anthropogenic conditions within Mexico City and also the addition of compost to the soils. According to Mexican regulations BaP, DaA, BbF and Ind were within the permissible limit (2 mg/kg) for agricultural and residential soils and BkF was close to the limit (8 mg/kg). The total PAH concentrations do however surpass the permissible European limit of 1,000 μg/kg and there is probably some risk to human health, in spite of measures aimed at decreasing contamination in Mexico City. Long term monitoring of soils will be necessary.

  19. [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.

  20. 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

  1. 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.

  2. 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

  3. The T1-T2 study: evolution of aerosol properties downwind of Mexico City

    Science.gov (United States)

    Doran, J. C.; Barnard, J. C.; Arnott, W. P.; Cary, R.; Coulter, R.; Fast, J. D.; Kassianov, E. I.; Kleinman, L.; Laulainen, N. S.; Martin, T.; Paredes-Miranda, G.; Pekour, M. S.; Shaw, W. J.; Smith, D. F.; Springston, S. R.; Yu, X.-Y.

    2007-03-01

    As part of a major atmospheric chemistry and aerosol field program carried out in March 2006, a study was conducted in the area to the north and northeast of Mexico City to investigate the evolution of aerosols and their associated optical properties in the first few hours after their emission. The focus of the T1-T2 aerosol study was to investigate changes in the specific absorption αABS (absorption per unit mass, with unit of m2 g-1) of black carbon as it aged and became coated with compounds such as sulfate and organic carbon, evolving from an external to an internal mixture. Such evolution has been reported in previous studies. The T1 site was located just to the north of the Mexico City metropolitan area; the T2 site was situated approximately 35 km farther to the northeast. Nephelometers, particle soot absorption photometers, photoacoustic absorption spectrometers, and organic and elemental carbon analyzers were used to measure the optical properties of the aerosols and the carbon concentrations at each of the sites. Radar wind profilers and radiosonde systems helped to characterize the meteorology and to identify periods when transport from Mexico City over T1 and T2 occurred. Organic and elemental carbon concentrations at T1 showed diurnal cycles reflecting the nocturnal and early morning buildup from nearby sources, while concentrations at T2 appeared to be more affected by transport from Mexico City. Specific absorption during transport periods was lower than during other times, consistent with the likelihood of fresher emissions being found when the winds blew from Mexico City over T1 and T2. The specific absorption at T2 was larger than at T1, which is also consistent with the expectation of more aged particles with encapsulated black carbon being found at the more distant location. In situ measurements of single scattering albedo with an aircraft and a ground station showed general agreement with column-averaged values derived from rotating shadowband

  4. 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.

  5. 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.

  6. 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.

  7. Two new synanthropic species of Anyphaena Sundevall (Araneae: Anyphaenidae) associated to houses in Mexico City.

    Science.gov (United States)

    Durán-Barrón, César G; Pérez, Tila M; Brescovit, Antonio D

    2016-04-12

    The family Anyphaenidae is composed by 56 genera and 542 species worldwide (World Spider Catalog 2015). These spiders, known as "ghost spiders", are wandering hunters living in a variety of environments, from forests to deserts, and can be quite abundant in different crops such as cotton, sorghum and rice (Brescovit 1996; Young & Edwards 1990; Taylor & Pfannenstiel 2008). They typically live on vegetation, among dead leaves or under loose bark and rocks (Richman & Ubick 2005) but synanthropic associations have been reported for a few species (Jiménez 1998; Guarisco 1999; Durán-Barrón et al. 2009). The genus Anyphaena has 81 species widely distributed in Asia, Central Europe, North America and Mexico (Brescovit 1996; Richman & Ubick 2005; World Spider Catalog 2015). The species from Noth America and Mexico were revised by Platnick (1974) who recognized four species groups (accentuata, celer, pectorosa and pacifica). Platnick (1977), Platnick & Lau (1975) and Brescovit & Lise (1989) complemented the revision of the genus in Central America. Presently, there are 27 species of Anyphaena recorded in Mexico (World Spider Catalog 2015), 24 of them from the celer group. Here, two new species of Anyphaena are described based in material collected during an inventory of spiders associated to houses in Mexico City, carried out by Durán-Barrón et al. (2009). Both species have the diagnostic characters of the members of the pacifica group as defined by Platnick (1974), such as the lack of leg coxal spurs and the presence of a lightly sclerotized atrium in the female epigynum. These species represent the first record of the pacifica group in Mexico. The occurrence of Anyphaenidae associated to houses was reported in Mexico by Durán-Barrón et al. (2009), who recorded Anyphaena obregon Platnick & Lau, 1975 and Hibana futilis (Banks, 1898) as frequent inhabitants inside houses. The species herein described are reported solely from urban areas and can be also characterized as

  8. 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

  9. A Cross-Sectional Study of Prisoners in Mexico City Comparing Prevalence of Transmissible Infections and Chronic Diseases with That in the General Population: e0131718

    National Research Council Canada - National Science Library

    Sergio Bautista-Arredondo; Andrea González; Edson Servan-Mori; Fenella Beynon; Luis Juarez-Figueroa; Carlos J Conde-Glez; Nathalie Gras; Juan Sierra-Madero; Ruy Lopez-Ridaura; Patricia Volkow; Stefano M Bertozzi

    2015-01-01

      Objectives To describe patterns of transmissible infections, chronic illnesses, socio-demographic characteristics and risk behaviors in Mexico City prisons, including in comparison to the general...

  10. 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.

  11. A Brief Overview of INTEX-B and OVOC Observations Over Mexico City, Gulf of Mexico, and the Pacific Ocean

    Science.gov (United States)

    Singh, H. B.; Apel, E.; Brune, W.; Carmichael, G.; Cohen, R.; Crawford, J.; Czech, E.; Emmons, L.; Flocke, F.; Fried, A.; Fuelberg, H.; Heikes, B.; Jacob, D.; Pierce, B.

    2007-12-01

    INTEX-B/MILAGRO* was a major international atmospheric chemistry field campaign completed in the spring of 2006 (March 1-May 15). Airborne measurements of a large number of oxygenated volatile organic chemicals (OVOC) were carried out over Mexico City, Gulf of Mexico, and the Pacific Ocean using the NASA DC-8 and NSF/NCAR C-130. OVOC measurements included acetone, methylethyl ketone, methanol, ethanol, acetaldehyde, propanal, formaldehyde, organic peroxides, PANs, and organic nitrates. Complementary measurements of several tracers (CO, HCN) were also made. Throughout the troposphere mixing ratios of several OVOC were strongly correlated with each other as well as with tracers of fossil and biomass/biofuel combustion. The composition of these air masses also indicated a large shift of reactive nitrogen into the PAN reservoir during transport thereby limiting ozone formation. Several 3-D models (GEOS-Chem, MOZART, RAQMS, STEM) were used to simulate these observations with partial success. Some of these OVOC have also been retrieved from satellite observations in the upper troposphere and these data are compared. An analysis of the distribution and sources of OVOC based on INTEX-B/MILAGRO and some satellite observations will be presented. *INTEX-B: Intercontinental Chemical Transport Experiment-B; MILAGRO: Megacity Initiative: Local and Global Research Observations

  12. Urban-Architectural vision of aesthetic paradigm and commerce, Historic Center, Mexico-City.

    Directory of Open Access Journals (Sweden)

    Maria Guadalupe Valiñas

    2017-01-01

    Full Text Available The aim of the article is to show a current perspective Historic center of Mexico City and its problematic is that excessive trade in this space harms the urban architectural heritage and then the aesthetics of it is hampered by his use trade in. The problem is to investigate this space to analyze how antagonistically articulates the relationship between trade and aesthetics in it. This place is the center of the city and the country, it is saturated with trade in its various forms, from commercial plazas, passages, markets, up to the street vendors, these elements in their relationship affect the damage of the Historic Center the Mexico City and contribute to the deterioration of the urban architectural aesthetics of the space. The main contributions of this work reflect the different adverse effects from trade to the detriment of the aesthetic aspect, which should be evaluated as depopulation, converting housing in warehouses, upholstering informal trade public space and damage to the landmarks in the area. The usefulness of the project is growing in relation to the direction they should take public policies to preserve that heritage for the sake of seeking environmental, social and economic welfare equitably strengthen the aesthetic appearance, which itself should be one of the main features of historical center given the cultural and historical significance of the site.

  13. 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

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

    Science.gov (United States)

    Davis, Lucas W

    2017-02-02

    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.

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

    Science.gov (United States)

    Li, G.; Lei, W.; Bei, N.; Molina, L. T.

    2012-09-01

    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.

  16. Mexico City air quality research initiative, volume 3, modeling and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Mauzy, A. [ed.] [Los Alamos National Lab., NM (United States)

    1994-06-01

    The objective of the modeling and simulation task was to develop, test, and apply an appropriate set of models that could translate emission changes into air quality changes. Specifically, we wanted to develop models that could describe how existing measurements of ozone (O{sub 3}), carbon monoxide (CO), and sulfur dioxide (SO{sub 2}) would be expected to change if their emissions were changed. The modeling must be able to address the effects of difference in weather conditions and changes in land use as well as the effects of changes in emission levels. It must also be able to address the effects of changes in the nature and distribution of the emissions as well as changes in the total emissions. A second objective was to provide an understanding of the conditions that lead to poor air quality in Mexico City. We know in a general sense that Mexico City`s poor air quality is the result of large quantities of emissions in a confined area that is subject to light winds, but we did not know much about many aspects of the problem. For example, is the air quality on a given day primarily the result of emissions on that day...or is there an important carryover from previous nights and days? With a good understanding of the important meteorological circumstances that lead to poor air quality, we learn what it take duce an accurate forecast of impending quality so that we can determine the advisability of emergency measures.

  17. 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.

  18. Sources and sinks of carbon dioxide in a neighborhood of Mexico City

    Science.gov (United States)

    Velasco, E.; Perrusquia, R.; Jiménez, E.; Hernández, F.; Camacho, P.; Rodríguez, S.; Retama, A.; Molina, L. T.

    2014-11-01

    Cities are the main contributors to the CO2 rise in the atmosphere. The CO2 released from the various emission sources is typically quantified by a bottom-up aggregation process that accounts for emission factors and fossil fuel consumption data. This approach does not consider the heterogeneity and variability of the urban emission sources, and error propagation can result in large uncertainties. These uncertainties might lead to unsound mitigation policies. Monitoring systems of greenhouse gases (GHG) based on independent methods are needed to validate the accuracy of the estimated emissions. In this context, direct measurements of CO2 fluxes that include all major and minor anthropogenic and natural sources and sinks from a specific district can be used to evaluate emission inventories. This study reports and compares CO2 fluxes measured directly using the eddy covariance (EC) method with emissions taken from the gridded local emissions inventory for the footprint covered by the EC flux system for a residential/commercial neighborhood of Mexico City. The flux measurements were conducted over 15-month period. No seasonal variability was found, but a clear diurnal pattern with morning and evening peaks in phase with the rush-hour traffic was observed. After adding contributions from human and soil respiration obtained by bottom-up approaches, and subtracting the CO2 sequestrated by vegetation calculated by applying biomass allometric equations and a growth predictive model to trees inventoried within the studied domain, results show that the current emissions inventory over-predicts 2.8 times the average daily flux measured on weekdays. Using traffic emissions data from a 2-year older inventory the difference decreased to 30%, suggesting that the traffic load for this part of the city is probably highly overestimated in the current emissions inventory. This study is expected to contribute to the verification capabilities of the GHG mitigation management of Mexico

  19. HIV prevalence, sociodemographic characteristics, and sexual behaviors among transwomen in Mexico City.

    Science.gov (United States)

    Colchero, M Arantxa; Cortés-Ortiz, María Alejandra; Romero-Martínez, Martín; Vega, Hamid; González, Andrea; Román, Ricardo; Franco-Núñez, Aurora; Bautista-Arredondo, Sergio

    2015-01-01

    To present results from HIV testing, knowledge of HIV status and socioeconomic factors associated with the probability of having a HIV positive result among transwomen (TW) in Mexico. In 2012, we conducted an HIV seroprevalence survey to 585 TW in Mexico City in three strata: gathering places, the Condesa HIV Clinic and in four detention centers. We estimated the prevalence of HIV in each strata and applied a probit model to the overall sample to analyze factors associated with the probability of a HIV positive result. The prevalence of HIV was 19.8% in meeting places; 31.9% in detention centers and 64% among the participants of the clinic. Age, low education and number of sexual partners was positively associated with HIV. Results from the study provide relevant information to design HIV prevention interventions tailored to the needs of the TW population.

  20. Dietary intake, lung function and airway inflammation in Mexico City school children exposed to air pollutants

    Science.gov (United States)

    2009-01-01

    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 Mexico City. PMID:20003306

  1. 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.

  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. 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

  4. 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

  5. Dietary factors and the risk of gastric cancer in Mexico City.

    Science.gov (United States)

    Ward, M H; López-Carrillo, L

    1999-05-15

    Dietary factors play an important role in gastric cancer risk but have not been investigated extensively in Mexico. The authors conducted a population-based case-control study of gastric cancer in the Mexico City, Mexico, metropolitan area in 1989-1990. A total of 220 patients with histologically confirmed gastric adenocarcinomas were interviewed. Controls were an age-stratified random sample of residents of the Mexico City metropolitan area. The dietary questionnaire was a 70-item semiquantitative food frequency adapted for the Mexican diet. Odds ratios were calculated for quartiles of consumption of food groups and were adjusted for age, gender, calories, chili pepper intake, cigarette smoking, socioeconomic status, added salt, and history of peptic ulcer disease. There was approximately a threefold increased risk of gastric cancer for frequent consumption (highest quartile) of both fresh meat (odds ratio (OR) = 3.1) and processed meat (OR = 3.2). Odds ratios were also significantly elevated for frequent consumption of dairy products (OR = 2.7) and fish (OR = 2.2). The authors observed a decreasing gradient of risk with increasing frequency of vegetable consumption due to a significant inverse trend for the yellow and orange vegetables. High intake of citrus fruits showed a slight inverse association. Consumption of salty snacks more than twice per month was associated with an 80 percent increased risk, and there was a significant positive trend. These findings are consistent with many studies around the world that indicate important roles for salt, processed meats, and vegetable consumption in gastric cancer risk.

  6. M Protein Gene Type Distribution among Group A Streptococcal Clinical Isolates Recovered in Mexico City, Mexico, from 1991 to 2000, and Durango, Mexico, from 1998 to 1999: Overlap with Type Distribution within the United States

    Science.gov (United States)

    Espinosa, Luz Elena; Li, Zhongya; Barreto, Demostenes Gomez; Jaimes, Ernesto Calderon; Rodriguez, Romeo S.; Sakota, Varja; Facklam, Richard R.; Beall, Bernard

    2003-01-01

    To examine the type distribution of pathogenic group A streptococcal (GAS) strains in Mexico, we determined the emm types of 423 GAS isolates collected from ill patients residing in Mexico (Durango or Mexico City). These included 282 throat isolates and 107 isolates from normally sterile sites. Of the other isolates, 38 were recovered from other miscellaneous infections. A total of 31 different emm types were found, revealing a broad overlap between commonly occurring emm types in Mexico and the United States. The information obtained in this study is consistent with the possibility that multivalent, M type-specific vaccines prepared for GAS strain distribution within the United States could theoretically protect against the majority of GAS strains causing disease in the two cities surveyed in Mexico. PMID:12517875

  7. 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.

  8. 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.

  9. 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.

  10. Archaeomagnetic Investigation at Chapultepec, Mexico City: Case Study of Classical Settlers

    Science.gov (United States)

    Lopez, V.; Romero, E.; Soler-Arechalde, A. M.; Espinosa, G.

    2007-05-01

    During the restoration campaign at the Chapultepec Park in Mexico City downtown, a teotihuacan settlement was found at the south flank of Chapultepec Hill. Samples represent a kind of irregular home kilns with a hole in their central part bounded by andesite rocks. Alternating field demagnetization had been employed. Rock magnetic measurements which included: Hysteresis, continuous susceptibility and isothermal remanence experiments revealed that some spinels, most probably magnetite or Ti-poor Titanomagnetites are responsible for the remanence. An archeomagnetic date obtained here is of 525 AD which is in good agreement with other evidences of the Teotihuacan Classic Metepec period (450-600 AD).

  11. 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.

  12. [The beginnings of trauma management in Mexico City. 1847-1914].

    Science.gov (United States)

    Carreón-Bringas, Rosa María; Rodríguez-Paz, Carlos Agustín

    2005-01-01

    We describe how surgical trauma was managed in Mexico City from 1847 to 1912. Management included minimal interventions, generally ending with the patient's death. Other more radical procedures such as abdomen trauma proposed in 1874 anld performed in 1898 are also described. A variety of techniques employed and type of trauma cases registered that yielded more radical attitudes that brought about the creation of public emergency rooms (the Cruz Verde) and military surgical rooms in railroad cars that oversaw the care of soldiers during the revalutionary period are discussed.

  13. [Risky eating behaviors in student population in Mexico City: trends 1997-2003].

    Science.gov (United States)

    Unikel-Santoncini, Claudia; Bojórquez-Chapela, Ietza; Villatoro-Velázquez, Jorge; Fleiz-Bautista, Clara; Medina-Mora Icaza, María Elena

    2006-01-01

    The main purpose of this study was to identify the trends of risky eating behaviors among student population in Mexico City in the period 1997-2003 and its relationship with sex age and family head educational level. Data from the 1997 (N = 9,755), 2000 (N = 3,286) and 2003 (N = 3,062) Drug and Alcohol Prevalence in Student Population of Mexico City Survey's were analyzed. These are representative data of students of junior high, high school and technical schools in Mexico City, with a mean age of 14.5 years (SD = 1.9). Eating behaviors were assessed with a brief questionnaire developed following DSM-IV diagnostic criteria. Risky eating behaviors and the number of risk indicators were compared by sex, age and family head educational level. The results showed an overall increase in the percentage of males (from 1.3% in 1997 to 3.8% in 2003), and females (3.4% in 1997 to 9.6% in 2003) who showed 3 or more risky eating behaviors. The analysis by age groups showed an increase in all but 16-17 year old males, and in all females, being 12-13 year old males and 18-19 year old females the most affected. Regarding the type of risk indicators in both sexes and across all age groups, an increase in preoccupation towards gaining weight and the use of purging and restrictive methods to loose weight was observed. Body weight overestimation decreased in males, while in females showed an increase along with binges in the 2000 survey but showed a decrease after that (2003 survey). The relationship between the family head educational level and risky eating behaviors did not show a regular pattern among males, while a positive relationship between both variables was found among females. A first overall view of the situation of risky eating behaviors among adolescent students in Mexico City and the changes observed in the period studied. An increase of these behaviors was observed along the period of study, being younger males and older females the most affected, as well as women

  14. [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) (pchildren, strategy that might contribute to mitigate childhood obesity.

  15. 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.

  16. 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.

  17. [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.

  18. Measurements of CO 2 fluxes from the Mexico City urban landscape

    Science.gov (United States)

    Velasco, Erik; Pressley, Shelley; Allwine, Eugene; Westberg, Hal; Lamb, Brian

    In a densely populated section of Mexico City, an eddy covariance (EC) flux system was deployed on a tall urban tower to obtain direct measurements of CO 2 emissions from an urban neighborhood located in a subtropical megacity. The measured fluxes and boundary layer conditions satisfy EC assumptions of stationarity, and cospectral analyses of the turbulence measurements exhibit the required boundary layer patterns for acceptable flux measurements. Results from a field experiment conducted during April 2003 show that the urban surface is a net source of CO 2. The CO 2 flux measurements showed a clear diurnal pattern, with the highest emissions during the morning (up to 1.60 mg m -2 s -1), and the lowest emissions during nighttime. The measured fluxes were closely correlated to traffic patterns in the area. The mean daily flux was 0.41 mg m -2 s -1, which is similar to that observed in European and US cities.

  19. PCBs and PAHs in surficial sediments from aquatic environments of Mexico City and the coastal states of Sonora, Sinaloa, Oaxaca and Veracruz (Mexico)

    Science.gov (United States)

    Piazza, Rossano; Ruiz-Fernández, Ana Carolina; Frignani, Mauro; Zangrando, Roberta; Bellucci, Luca Giorgio; Moret, Ivo; Páez-Osuna, Federico

    2008-06-01

    Concentrations of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were measured in 13 surficial sediment samples collected at three lacustrine locations in the surroundings of Mexico City and four coastal areas of the States of Sinaloa, Sonora, Oaxaca and Veracruz. Total PCB concentrations span the interval 3.18 621 ng g-1. The highest values (63.7 621 ng g-1) were found in Mexico City, which is a highly anthropogenically impacted area, whereas low concentrations (3.18 12.9 ng g-1) were characteristic of seven places, some of them subject to intense hydrodynamics. In these latter cases, values increase by 18 73 times if normalised against the fine fraction (silt plus clay) content in sediment. Two samples from Mexico City exceed the ERM (Effect Range Median) guidelines and are likely to cause adverse effects. Samples contain only lower chlorinated PCBs (mainly 2-, 3- and 4-CB), thus suggesting that the most used PCB commercial mixture was Aroclor 1242. The homologue composition of the sample taken close to the nuclear power plant of Laguna Verde is identical to this commercial mixture. PAHs in the same samples have relatively low concentrations (14.9 287 ng g-1), well below ERL (Effect Range Low) guidelines. The composition of PAH mixtures accounts for the influence of both petrogenic and pyrolitic sources, with these latter prevailing at some places in Mexico City.

  20. [Comparison of climacteric symptoms among women in Mexico City and women of a Mayan community of Yucatan].

    Science.gov (United States)

    Carranza-Lira, Sebastián; Quiroz González, Byanca Nerea; Alfaro Godinez, Hugo César; May Can, Ana María

    2012-10-01

    to compare the climacteric symptoms between women from Mexico City and those from a Mayan community of the state of Yucatan. In two groups of women, Group I) Spanish-speaking women from Mexico City and Group II) Maya speaking women from the state of Yucatan, 22 climacteric symptoms were evaluated using an analog visual scale (AVS) and the SUMEVA index. For statistical analysis t student test was used as well as Chi squared. 105 women, 50 of Mexico City and 55 of Maxcanu, Yucatan were studied. When comparing the groups no difference was found in age (52.5 +/- 6.5 vs 53.7 +/- 6.2, for group I and II respectively), the body mass index was significantly smaller in group I (29.7 +/- 5.0 vs 34.0 +/- 6.0, p culture influence can be the responsible.

  1. 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...

  2. Teotihuacan: completion of map of giant ancient city in the valley of Mexico.

    Science.gov (United States)

    Millon, R

    1970-12-04

    The detailed archeological map of Teotihuacán, near Mexico City, demonstrates what the prehistoric city was like from its densely crowded center to its more sparsely settled peripheries. The city's population lived in crowded one-story apartment compounds, grouped into neighborhoods based at least partly on occupation. At its height the city had a minimum population of 75,000, a probable population of 125,000, and a possible population of more than 200,000. Those involved in craft production and associated activities may have numbered in the tens of thousands. The scope and intensity of urbanization at Teotihuacán is not paralleled in other contemporary New World centers. The growth potential of the obsidian and other industries, the rise of Teotihuacán as a market and trade center, and its attraction as a religious center may have combined in a self-generating process that led to the creation of Teotihuacán's unique urban society.

  3. [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.

  4. American trypanosomiasis and associated risk factors in owned dogs from the major city of Yucatan, Mexico.

    Science.gov (United States)

    Jiménez-Coello, Matilde; Acosta-Viana, Karla; Guzmán-Marín, Eugenia; Bárcenas-Irabién, Alejandra; Ortega-Pacheco, Antonio

    2015-01-01

    The American trypanosomiasis is a zoonosis caused by the protozoa Trypanosoma cruzi (T. cruzi). The disease is widely distributed throughout the American continent, affecting a wide range of hosts, including dogs. It is present in the canine population in the State of Yucatan, Mexico. However, no significant studies in owned dogs have been performed in the metropolitan area of Merida. A transversal study was conducted in 370 owned dogs from Merida, Yucatan, Mexico. A cross-sectional study including 370 dogs was performed in a major city of Yucatan, Mexico, to detect IgG antibodies against T. cruzi. A commercial ELISA test kit was used and a chi-square test used to evaluate associated risk factors; odds ratio (OR) and 95 % confidence interval (CI) were also estimated. The indirect ELISA and western blot (WB) tests were used to detect specific immunoglobulin G antibodies against T. cruzi in serum samples. A prevalence of 12.2 % was found; age and area of residence were statistically associated with seropositivity in dogs (p <0.05). Results from the present study suggests the presence and abundance of the vector in urban conditions where a high number of seropositive cases of T. cruzi cases were found.

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Thayer, G.R.; Hardie, R.W. [Los Alamos National Lab., NM (United States); Barrera-Roldan, A. [Instituto Mexicano de Petroleo, Mexico City (Mexico)

    1993-12-31

    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{sub 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{sub x}. The relationship between ozone levels and the hydrocarbon and NO{sub 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.

  8. 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.

  9. Prevalence trends of oral squamous cell carcinoma. Mexico City's General Hospital experience.

    Science.gov (United States)

    Hernández-Guerrero, Juan-Carlos; Jacinto-Alemán, Luís-Fernando; Jiménez-Farfán, María-Dolores; Macario-Hernández, Alejandro; Hernández-Flores, Florentino; Alcántara-Vázquez, Avissai

    2013-03-01

    Recent reports suggest an increase in oral squamous cell carcinoma (OSCC) frequency. To improve programs in public health, it is necessary to understand the epidemiological conditions. The aim of this study was to analyze the trend in gender, age, anatomic zone and OSCC stage from Mexico City's General Hospital patients from 1990 to 2008. A retrospective review of all OSCC cases diagnosed by the Pathology Department of the Mexico City General Hospital was performed. Demographic data, in addition to anatomic zone and histological degree of differentiation were obtained. Central tendency, dispersion and prevalence rate per 100,000 individuals were determined. A total of 531 patients were diagnosed with OSCC; 58.4% were men, giving a male:female ratio of 1.4:1, and the mean age was 62.5 ± 14.9 years. The predominant anatomic zone was the tongue (44.7%), followed by the lips (21.2%) and gums (20.5%). The most frequent histological degree was moderately differentiated in 325 cases (61.2%). The rates of OSCC prevalence showed similar patterns in terms across time. A significant correlation (P = 0.007) between anatomic zone and age was observed. According to our results, the prevalence of OSCC does not show important variations; however, a relationship between age and anatomic zone was observed. These data could be used as parameters for the diagnosis of OSCC as well as for the development and dissemination of preventive programs for the early detection of oral cancer.

  10. Presence and prevalence of Batrachochytrium dendrobatidis in commercial amphibians in Mexico City.

    Science.gov (United States)

    Galindo-Bustos, Miguel Angel; Hernandez-Jauregui, Dulce María Brousset; Cheng, Tina; Vredenburg, Vance; Parra-Olea, Gabriela

    2014-12-01

    In Mexico City, native and exotic amphibians are commonly sold through the pet trade. This study investigates the presence of Batrachochytrium dendrobatidis (Bd) in native amphibians being sold at two commercial markets and at a herpetarium in Mexico City. A total of 238 individuals (6 genera and 12 species) were tested for Bd using real-time polymerase chain reaction (PCR) analysis. There were 197 Bd-positive individuals (prevalence 82%) from five species of amphibians. Hyla eximia from the markets had very high Bd prevalence (100%; 76/76 and 99%; 88/89) but those from the herpetarium were Bd negative (0/12). Ambystoma mexicanum from the herpetarium also had a high Bd-positive prevalence (80%; 28/35). Though A. mexicanum is nearly extinct in the wild, a commercial market continues to flourish through the pet trade. Now that captive colonies of A. mexicanum are currently used for reintroduction programs, the authors recommend quarantine to reduce spread of Bd via movement of infected animals in the trade and between colonies and via disposal of wastewater from captive collections.

  11. A pathological study of the epidemiology of atherosclerosis in Mexico city.

    Science.gov (United States)

    Rodríguez-Saldaña, Joel; Rodriguez-Flores, Marcela; Cantú-Brito, Carlos; Aguirre-Garcia, Jesús

    2014-01-01

    Objective. To examine the frequency and patterns of association of cardiovascular risk factors with atherosclerosis in five different arterial territories at post-mortem in Mexico City. Methods. We obtained five arterial territories arteries (circle of Willis, coronary, carotid, renal, and aorta) of 185 men and women 0 to 90 years of age who underwent autopsy at the Medical Forensic Service of Mexico City. We determined the prevalence and extent of atherosclerotic lesions by histopathology according to the classification of the American Heart Association as early (types I-III) and advanced (types IV-VI), and according to the degree of stenosis and correlated with cardiovascular risk factors. Results. Atherosclerotic lesions were identified in at least one arterial territory in 181 subjects (97.8%), with involvement of two ore more territories in 178 subjects (92.2%). Advanced lesions were observed in 36% and 67% of subjects under 15 and between 16 and 35 years, respectively. Any degree of atherosclerosis was associated with the presence of diabetes mellitus, hypertension, overweight, obesity, and smoking, and to a greater extent with the presence of two or more risk factors (P disease in subjects without known risk factors.

  12. A Pathological Study of the Epidemiology of Atherosclerosis in Mexico City

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    Joel Rodríguez-Saldaña

    2014-01-01

    Full Text Available Objective. To examine the frequency and patterns of association of cardiovascular risk factors with atherosclerosis in five different arterial territories at post-mortem in Mexico City. Methods. We obtained five arterial territories arteries (circle of Willis, coronary, carotid, renal, and aorta of 185 men and women 0 to 90 years of age who underwent autopsy at the Medical Forensic Service of Mexico City. We determined the prevalence and extent of atherosclerotic lesions by histopathology according to the classification of the American Heart Association as early (types I–III and advanced (types IV–VI, and according to the degree of stenosis and correlated with cardiovascular risk factors. Results. Atherosclerotic lesions were identified in at least one arterial territory in 181 subjects (97.8%, with involvement of two ore more territories in 178 subjects (92.2%. Advanced lesions were observed in 36% and 67% of subjects under 15 and between 16 and 35 years, respectively. Any degree of atherosclerosis was associated with the presence of diabetes mellitus, hypertension, overweight, obesity, and smoking, and to a greater extent with the presence of two or more risk factors (P<0.001. However, emerging and advanced athersoclerosis was observed in 53% and 20% people with no risk factors. Conclusions. The study shows a high prevalence of atherosclerosis in all age groups and both sexes. There is considerable development of atherosclerotic disease in subjects without known risk factors.

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

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    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

  14. 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

  15. 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.

  16. Fast airborne aerosol size and chemistry measurements above Mexico City and Central Mexico during the MILAGRO campaign

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    P. F. DeCarlo

    2008-07-01

    Full Text Available The concentration, size, and composition of non-refractory submicron aerosol (NR-PM1 was measured over Mexico City and central Mexico with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS onboard the NSF/NCAR C-130 aircraft as part of the MILAGRO field campaign. This was the first aircraft deployment of the HR-ToF-AMS. During the campaign the instrument performed very well, and provided 12 s data. The aerosol mass from the AMS correlates strongly with other aerosol measurements on board the aircraft. Organic aerosol (OA species dominate the NR-PM1 mass. OA correlates strongly with CO and HCN indicating that pollution (mostly secondary OA, SOA and biomass burning (BB are the main OA sources. The OA to CO ratio indicates a typical value for aged air of around 80 μg m−3 (STP ppm−1. This is within the range observed in outflow from the Northeastern US, which could be due to a compensating effect between higher BB but lower biogenic VOC emissions during this study. The O/C atomic ratio for OA is calculated from the HR mass spectra and shows a clear increase with photochemical age, as SOA forms rapidly and quickly overwhelms primary urban OA, consistent with Volkamer et al. (2006 and Kleinman et al. (2008. The stability of the OA/CO while O/C increases with photochemical age implies a net loss of carbon from the OA. BB OA is marked by signals at m/z 60 and 73, and also by a signal enhancement at large m/z indicative of larger molecules or more resistance to fragmentation. The main inorganic components show different spatial patterns and size distributions. Sulfate is regional in nature with clear volcanic and petrochemical/power plant sources, while the urban area is not a major regional source for this species. Nitrate is enhanced significantly in the urban area and immediate outflow, and is strongly correlated with CO indicating a strong urban source. The importance

  17. An overview of the MILAGRO 2006 Campaign: Mexico City emissions and their transport and transformation

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    L. T. Molina

    2010-09-01

    Full Text Available MILAGRO (Megacity Initiative: Local And Global Research Observations is an international collaborative project to examine the behavior and the export of atmospheric emissions from a megacity. The Mexico City Metropolitan Area (MCMA – one of the world's largest megacities and North America's most populous city – was selected as the case study to characterize the sources, concentrations, transport, and transformation processes of the gases and fine particles emitted to the MCMA atmosphere and to evaluate the regional and global impacts of these emissions. The findings of this study are relevant to the evolution and impacts of pollution from many other megacities.

    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, and enlisting over 450 scientists from 150 institutions in 30 countries. Three ground supersites were set up to examine the evolution of the primary emitted gases and fine particles. Additional platforms in or near Mexico City included mobile vans containing scientific laboratories and mobile and stationary upward-looking lidars. Seven instrumented research aircraft provided information about the atmosphere over a large region and at various altitudes. Satellite-based instruments peered down into the atmosphere, providing even larger geographical coverage. The overall campaign was complemented by meteorological forecasting and numerical simulations, satellite observations and surface networks. Together, these research observations have provided the most comprehensive characterization of the MCMA's urban and regional atmospheric composition and chemistry that will take years to analyze and evaluate fully.

    In this paper we review over 120 papers resulting from the MILAGRO/INTEX-B Campaign that have been

  18. The time evolution of aerosol composition over the Mexico City plateau

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    J. Hubbe

    2008-03-01

    Full Text Available The time evolution of aerosol concentration and chemical composition in a megacity urban plume was determined based on 8 flights of the DOE G-1 aircraft in and downwind of Mexico City during the March 2006 MILAGRO field campaign. A series of selection criteria are imposed to eliminate data points with non-urban emission influences. Biomass burning has urban and non-urban sources that are distinguished on the basis of CH3CN and CO. In order to account for dilution in the urban plume, aerosol concentrations are normalized to CO which is taken as an inert tracer of urban emission, proportional to the emissions of aerosol precursors. Time evolution is determined with respect to photochemical age defined as −Log10 (NOx/NOy. The geographic distribution of photochemical age and CO is examined, confirming the picture that Mexico City is a source region and that pollutants become more dilute and aged as they are advected towards T1 and T2, surface sites that are located at the fringe of the City and 35 km to the NE, respectively. Organic aerosol (OA per ppm CO is found to increase 7 fold over the range of photochemical ages studied, corresponding to a change in NOx/NOy from nearly 100% to 10%. In the older samples the nitrate/CO ratio has leveled off suggesting that evaporation and formation of aerosol nitrate are in balance. In contrast, OA/CO increases with age in older samples, indicating that OA is still being formed. The amount of carbon equivalent to the deduced change in OA/CO with age is 56 ppbC per ppm CO. At an aerosol yield of 5% and 8% for low and high yield aromatic compounds, it is estimated from surface hydrocarbon observations that only ~9% of the OA formation can be accounted for. A comparison of OA/CO in Mexico City and the eastern U.S. gives no evidence that aerosol yields are higher in a more polluted environment.

  19. Surface water quality in a water run-off canal system: A case study in Jubail Industrial City, Kingdom of Saudi Arabia

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    Zia Mahmood Siddiqi

    2016-06-01

    Full Text Available Water quality in a run-off canal system in an industrial area was evaluated for a range of physical and chemical properties comprising trace metals (including mercury (Hg, chromium (Cr, iron (Fe, manganese (Mn, salinity, pH, turbidity, total dissolved solids, total suspended solids, chemical oxygen demand (COD, and dissolved oxygen. High concentrations of potassium (K (1.260–2.345 mg/l and calcium (Ca (19.170–35510 mg/l demonstrated that the salinity in the water was high, which indicates that industrial effluents from fertilizer manufacturing and Chlor-alkali units are being discharged into the canal system. Almost all the metal concentrations in water and sediment were within the thresholds established by the local regulatory body. Concentrations of Cr (0.0154–0.0184 mg/l, Mn (0.0608–0.199 mg/l, Fe (0.023–0.035 mg/l, COD (807–916 mg/l, and turbidity (633 ± 15–783 ± 22 NTU were high where the canal discharges into the Persian Gulf; these discharges may compromise the health of the aquatic ecosystem. There is concern about the levels of Hg in water (0.00135–0.0084 mg/l, suspended sediment (0.00308–0.0096 mg/l, and bed sediment (0.00172–0.00442 mg/l because of the bio-accumulative nature of Hg. We also compared the total Hg concentrations in fish from Jubail, and two nearby cities. Hg contents were highest in fish tissues from Jubail. This is the first time that heavy metal pollution has been assessed in this water run-off canal system; information about Hg is of particular interest and will form the basis of an Hg database for the area that will be useful for future investigations.

  20. Ozone predictabilities due to meteorological uncertainties in the Mexico City basin using ensemble forecasts

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    N. Bei

    2010-07-01

    Full Text Available The purpose of the present study is to investigate the sensitivity of ozone (O3 predictions in the Mexico City Metropolitan Area (MCMA to meteorological initial uncertainties and planetary boundary layer (PBL parameterization schemes using state-of-the-art meteorological and photochemical prediction models through ensemble forecasts. The simulated periods (3, 9, 15 and 29 March 2006 represent four typical meteorological episodes ("South-Venting", "O3-North", "O3-South" and "Convection-North", respectively in the Mexico City basin during the MCMA-2006/MILAGRO campaign. Our results demonstrate that the uncertainties in meteorological initial conditions have significant impacts on O3 predictions, including peak time O3 concentrations ([O3], horizontal and vertical O3 distributions, and temporal variations. The ensemble spread of the simulated peak [O3] averaged over the city's ambient monitoring sites can reach up to 10 ppb. The increasing uncertainties in meteorological fields during peak O3 period contribute to the largest unpredictability in O3 simulations, while the impacts of wind speeds and PBL height on [O3] are more straightforward and important. The magnitude of the ensemble spreads varies with different PBL schemes and meteorological episodes. The uncertainties in O3 predictions caused by PBL schemes mainly come from their ability to represent the mixing layer height; but overall, these uncertainties are smaller than those from the uncertainties in meteorological initial conditions.

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

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    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.

  2. 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.

  3. Spatio-temporal and neighborhood characteristics of two dengue outbreaks in two arid cities of Mexico.

    Science.gov (United States)

    Reyes-Castro, Pablo A; Harris, Robin B; Brown, Heidi E; Christopherson, Gary L; Ernst, Kacey C

    2017-03-01

    Little is currently known about the spatial-temporal dynamics of dengue epidemics in arid areas. This study assesses dengue outbreaks that occurred in two arid cities of Mexico, Hermosillo and Navojoa, located in northern state of Sonora. Laboratory confirmed dengue cases from Hermosillo (N=2730) and Navojoa (N=493) were geocoded by residence and assigned neighborhood-level characteristics from the 2010 Mexican census. Kernel density and Space-time cluster analysis was performed to detect high density areas and space-time clusters of dengue. Ordinary Least Square regression was used to assess the changing socioeconomic characteristics of cases over the course of the outbreaks. Both cities exhibited contiguous patterns of space-time clustering. Initial areas of dissemination were characterized in both cities by high population density, high percentage of occupied houses, and lack of healthcare. Future research and control efforts in these regions should consider these space-time and socioeconomic patterns. Copyright © 2017. Published by Elsevier B.V.

  4. 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

  5. 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.

  6. Measurements of Criteria Pollutants in Suburban Locations in the Mexico City Metropolitan Area

    Science.gov (United States)

    Fentanes, O.; Sanchez, A.; Garcia, A.; Martinez, A.

    2004-12-01

    In the town of Santa Ana in the southern part of the Mexico City Metropolitan Area (MCMA) at an approximate height of 370 meters above the Valley of Mexico, a series of criteria pollutants (nitrogen dioxide, ozone, sulfur dioxide, and carbon monoxide) and meteorological parameters (wind speed and direction, temperature and relative humidity) were measured during the MCMA-2003 field campaign during April 2003. Santa Ana is considered a border site, agriculture being the predominant activity. The generated data in Santa Ana was compared with those from two representative atmospheric monitoring stations from the southeast zone (CENICA Supersite) and southwest (Revolucion Station) of Mexico City. The carbon monoxide and ozone concentrations measured in Santa Ana are atypical for a rural area. The sulfur dioxide and nitrogen dioxide concentrations are characteristic of the local activity. The average obtained during the measurement time for carbon monoxide was 0.86 ppm, the presence of the contaminant was within a 0.3 to 1.5 ppm range, 5 to 95 percentile, and does not follow the observed behavior of the monitoring stations that are located inside the urban area, although during the night (10 pm to 6 am) the carbon monoxide in Santa Ana was preset in levels from 0.4 to 1.5 ppm, 5 to 95 percentiles, average 0.92 ppm, above the reported concentrations at Revolucion Station, levels from 0.1 to 1.7 ppm, 5 to 95 percentiles; average 0.72 ppm. The presence of this contaminant can be attributed to transportation and accumulation phenomena. The ozone daytime behavior is similar to the one observed in the CENICA and Revolucion stations, but with a lower magnitude, the daily maximum generally occuring 2 or 3 hours after the urban stations. The one-hour average maximum values were 133 ppb in Santa Ana area and 188 ppb in the city. During the night the average concentrations were 37 ppb in Santa Ana and 17 ppb in the urban area. Nevertheless, the ozone average value in Santa Ana

  7. Flux Measurements of Trace Gases, Aerosols and Energy from the Urban Core of Mexico City

    Science.gov (United States)

    Velasco, E.; Molina, L.; Lamb, B.; Pressley, S.; Grivicke, R.; Westberg, H.; Jobson, T.; Allwine, E.; Coons, T.; Jimenez, J.; Nemitz, E.; Alexander, L. M.; Worsnop, D.; Ramos, R.

    2007-05-01

    As part of the MILAGRO field campaign in March 2006 we deployed a flux system in a busy district of Mexico City surrounded by congested avenues. The flux system consisted of a tall tower instrumented with fast-response sensors coupled with eddy covariance (EC) techniques to measure fluxes of volatile organic compounds (VOCs), CO2, CO, aerosols and energy. The measured fluxes represent direct measurements of emissions that include all major and minor emission sources from a typical residential and commercial district. In a previous study we demonstrated that the EC techniques are valuable tools to evaluate emissions inventories in urban areas, and understand better the atmospheric chemistry and the role that megacities play in global change. We measured fluxes of olefins using a Fast Olefin Sensor (FOS) and the EC technique, fluxes of aromatic and oxygenated VOCs by Proton Transfer Reaction-Mass Spectroscopy (PTR-MS) and the disjunct eddy covariance (DEC) technique, fluxes of CO2 and H2O with an open path Infrared Gas Analyzer (IRGA) and the EC technique, fluxes of CO using a modified gradient method and a commercial CO instrument, and fluxes of aerosols (organics, nitrates and sulfates) using an Aerodyne Aerosol Mass Spectrometer (AMS) and the EC technique. In addition we used a disjunct eddy accumulation (DEA) system to extend the number of VOCs. This system collected whole air samples as function of the direction of the vertical wind component, and the samples were analyzed on site using gas chromatography / flame ionization detection (GC-FID). We also measured fluxes of sensible and latent heat by EC and the radiation components with a net radiometer. Overall, these flux measurements confirm the results of our previous flux measurements in Mexico City in terms of the magnitude, composition, and distribution. We found that the urban surface is a net source of CO2 and VOCs. The diurnal patterns show clear anthropogenic signatures, with important contributions from

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

    Science.gov (United States)

    Wood, E. C.; Canagaratna, M. R.; Herndon, S. C.; Onasch, T. B.; Kolb, C. E.; Worsnop, D. R.; Kroll, J. H.; Knighton, W. B.; Seila, R.; Zavala, M.; Molina, L. T.; Decarlo, P. F.; Jimenez, J. L.; Weinheimer, A. J.; Knapp, D. J.; Jobson, B. T.; Stutz, J.; Kuster, W. C.; Williams, E. J.

    2010-09-01

    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 ratio. Although not succesful in reproducing the atmospheric observations presented, modeling P(SOA)/P(Ox) can serve as a useful test

  9. Variability of winter and summer surface ozone in Mexico City on the intraseasonal timescale

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    B. S. Barrett

    2016-12-01

    Full Text Available Surface ozone concentrations in Mexico City frequently exceed the Mexican standard and have proven difficult to forecast due to changes in meteorological conditions at its tropical location. The Madden–Julian Oscillation (MJO is largely responsible for intraseasonal variability in the tropics. Circulation patterns in the lower and upper troposphere and precipitation are associated with the oscillation as it progresses eastward around the planet. It is typically described by phases (labeled 1 through 8, which correspond to the broad longitudinal location of the active component of the oscillation with enhanced precipitation. In this study we evaluate the intraseasonal variability of winter and summer surface ozone concentrations in Mexico City, which was investigated over the period 1986–2014 to determine if there is a modulation by the MJO that would aid in the forecast of high-pollution episodes. Over 1 000 000 hourly observations of surface ozone from five stations around the metropolitan area were standardized and then binned by active phase of the MJO, with phase determined using the real-time multivariate MJO index. Highest winter ozone concentrations were found in Mexico City on days when the MJO was active and in phase 2 (over the Indian Ocean, and highest summer ozone concentrations were found on days when the MJO was active and in phase 6 (over the western Pacific Ocean. Lowest winter ozone concentrations were found during active MJO phase 8 (over the eastern Pacific Ocean, and lowest summer ozone concentrations were found during active MJO phase 1 (over the Atlantic Ocean. Anomalies of reanalysis-based cloud cover and UV-B radiation supported the observed variability in surface ozone in both summer and winter: MJO phases with highest ozone concentration had largest positive UV-B radiation anomalies and lowest cloud-cover fraction, while phases with lowest ozone concentration had largest negative UV-B radiation anomalies

  10. Variability of winter and summer surface ozone in Mexico City on the intraseasonal timescale

    Science.gov (United States)

    Barrett, Bradford S.; Raga, Graciela B.

    2016-12-01

    Surface ozone concentrations in Mexico City frequently exceed the Mexican standard and have proven difficult to forecast due to changes in meteorological conditions at its tropical location. The Madden-Julian Oscillation (MJO) is largely responsible for intraseasonal variability in the tropics. Circulation patterns in the lower and upper troposphere and precipitation are associated with the oscillation as it progresses eastward around the planet. It is typically described by phases (labeled 1 through 8), which correspond to the broad longitudinal location of the active component of the oscillation with enhanced precipitation. In this study we evaluate the intraseasonal variability of winter and summer surface ozone concentrations in Mexico City, which was investigated over the period 1986-2014 to determine if there is a modulation by the MJO that would aid in the forecast of high-pollution episodes. Over 1 000 000 hourly observations of surface ozone from five stations around the metropolitan area were standardized and then binned by active phase of the MJO, with phase determined using the real-time multivariate MJO index. Highest winter ozone concentrations were found in Mexico City on days when the MJO was active and in phase 2 (over the Indian Ocean), and highest summer ozone concentrations were found on days when the MJO was active and in phase 6 (over the western Pacific Ocean). Lowest winter ozone concentrations were found during active MJO phase 8 (over the eastern Pacific Ocean), and lowest summer ozone concentrations were found during active MJO phase 1 (over the Atlantic Ocean). Anomalies of reanalysis-based cloud cover and UV-B radiation supported the observed variability in surface ozone in both summer and winter: MJO phases with highest ozone concentration had largest positive UV-B radiation anomalies and lowest cloud-cover fraction, while phases with lowest ozone concentration had largest negative UV-B radiation anomalies and highest cloud

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

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    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

  12. Mexico.

    Science.gov (United States)

    Semaan, Leslie

    The text explores Mexico's history, geography, art, religion, and lifestyles in the context of its complex economy. The text focuses on Mexico's economy and reasons for its current situation. Part I of this teaching unit includes: Teacher Overview, Why Study Mexico, Mexico Fact Sheet, Map of Mexico, the Land and Climate, History, Government,…

  13. The ditches of México City and implications on residential buildings of the XVIII century

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    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.

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

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    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.

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

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    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

  16. An exploration of measures for comparing measurements with the results from meteorological models for Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Williams, M.D.; Brown, M.J.

    1995-12-31

    Los Alamos National Laboratory and Instituto Mexicano del Petroleo have completed a joint study of options for improving air quality in Mexico City. We used a three-dimensional, prognostic, higher-order turbulence model for atmospheric circulation (HOTMAC) to treat domains that include an urbanized area. We tested the model against routine measurements and those of a major field program. During the field program, measurements included: (1) lidar measurements of aerosol transport and dispersion, (2) aircraft measurements of winds, turbulence, and chemical species aloft, (3) aircraft measurements of skin temperatures, and (4) Tethersonde measurements of winds and ozone. We made both graphical and statistical comparisons and we have reported some of the comparisons to provide insight into the meaning of statistical parameters including the index of agreement.

  17. Absorbance and color change of LLDPE samples exposed to natural weathering in Aguascalientes City, Mexico

    Science.gov (United States)

    González-Mota, R.; Soto-Bernal, J. J.; Rosales-Candelas, I.; Vega-Dúran, J. T.

    2007-03-01

    The degradation of weather exposed linear low density polyethylene (LLDPE) specimens, with and without pigments, in Aguascalientes City, Ags. Mexico, during 269 days, was studied. Spectroscopic methods, ultraviolet (UV) spectroscopy and colorimetry, were used to determine the degradation of the specimens. The material used is not pure since they are samples of finished product that contain additives such as anti-oxidants, stabilizers, catalysts. One of the samples contains orange color pigment and the other sample is colorless. The plots describing the absorption bands attributable to the polymeric material show a similar profile in both samples. The bands attributable to pigment do show a considerable decrease in absorbance. The results suggest that the orange pigment has been degrading, as it can also be observed in the color change, while the polymeric material doesn't show any degradation.

  18. Stress from an administrative perspective in public transport drivers in Mexico City: Minibus and metrobus

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    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.

  19. An Approach to Litter Generation and Littering Practices in a Mexico City Neighborhood

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    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.

  20. Crisis, Xenophobia and Repatriation. The Spanish Immigrants in the City of Mexico, 1910-1936

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    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.

  1. 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.

  2. Secular trend in blood lead levels in a cohort of Mexico City children.

    Science.gov (United States)

    Rothenberg, S J; Schnaas, L; Perroni, E; Hernández, R M; Karchmer, S

    1998-01-01

    We determined the secular trend in blood lead levels in a cohort of 104 children born in Mexico City between 1987 and 1993. We grouped children by the calendar year in which they reached 6 mo of age and measured blood lead levels every 6 mo until they attained 36 mo of age. The overall geometric mean blood lead level was 9.6 microg/dl (range = 1.5-59.5 microg/dl). A repeated measures analysis of variance revealed a highly significant linear trend in blood lead level with year (p pottery significantly elevated blood lead levels (p = .028). The downward trend in blood lead levels during the time period of study corresponded to the reduction in various sources of lead exposure.

  3. Costs of treating diarrhoea in a children's hospital in Mexico City.

    Science.gov (United States)

    Phillips, M.; Kumate-Rodríguez, J.; Mota-Hernández, F.

    1989-01-01

    The treatment received by children aged under 5 years with diarrhoea was studied in the Hospital Infantil de México (Federico Goméz), Mexico City. The costs of treatment were calculated and estimates were made of how these had changed since the establishment of an oral rehydration unit in the hospital in 1985. The results indicate that drug treatment of outpatients was generally appropriate and inexpensive. In contrast, the cost of drugs for inpatients was considerably higher. The seriousness of the cases justified much of this additional expense for inpatients, but there is evidence that the costs could be reduced further without jeopardizing the quality of the care. Diagnostic tests were relatively expensive, frequently failed to identify diarrhoeal etiology, and their results correlated poorly with the treatment prescribed. The oral rehydration unit resulted in significant savings by causing a 25% fall in the number of inpatients with diarrhoea. PMID:2766450

  4. Emergency contraception in Mexico City: what do health care providers and potential users know and think about it?

    Science.gov (United States)

    Langer, A; Harper, C; Garcia-Barrios, C; Schiavon, R; Heimburger, A; Elul, B; Renoso Delgado, S; Ellertson, C

    1999-10-01

    Emergency contraception promises to reduce Mexico's high unwanted pregnancy and unsafe abortion rates. Because oral contraceptives are sold over-the-counter, several emergency contraceptive regimens are already potentially available to those women who know about the method. Soon, specially packaged emergency contraceptives may also arrive in Mexico. To initiate campaigns promoting emergency contraception, we interviewed health care providers and clients at health clinics in Mexico City, ascertaining knowledge, attitudes, and practices concerning the method. We found limited knowledge, but nevertheless cautious support for emergency contraception in Mexico. Health care providers and clients greatly overestimated the negative health effects of emergency contraception, although clients overwhelmingly reported that they would use or recommend it if needed. Although providers typically advocated medically controlled distribution, clients believed emergency contraception should be more widely available, including in schools and vending machines with information prevalent in the mass media and elsewhere.

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

    Science.gov (United States)

    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

    2005-04-04

    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. Population-based data. Hospitals: In San Salvador, El Salvador, Hospital Nacional de Niños "Benjamin 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. 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) 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 Salvadorian 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. 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.

  6. Age and archaeological implications of Xitle volcano, southwestern Basin of Mexico-City

    Science.gov (United States)

    Siebe, C.

    2000-12-01

    The Pedregal lavas are fresh, well-exposed basaltic flows erupted from the Xitle scoria-and-cinder cone in the southwestern part of the Basin of Mexico. These lavas cover an area of 70 km2 and were emplaced over pyramids and other buildings (e.g. Cuicuilco and Copilco archaeological sites). Today, a part of Mexico-City (including the National University) is built on the flows. Initial strombolian activity produced an ash fallout layer, which was immediately followed by effusive emplacement of lava flows. The Xitle cone grew on the north-facing slope of Ajusco volcano, and lava flowed down to the N-NE until it reached the basin floor. More than 30 radiocarbon dates have been obtained by several workers on charcoal samples from beneath the lava, and several ages for the eruption have been proposed from these dates. Most dated samples were not directly produced by Xitle's eruption but instead are artifacts of human activity that predates the eruption. Thus, these ages (mostly about 2000 BP) are older than the eruption. A new age of 1670±35 years BP (AD 245-315) obtained on charcoal samples collected just beneath the lavas is favored for the Xitle eruption. These samples originated by ignition of vegetation during the emplacement of hot scoriaceous tephra. The new age is within the Classic period of Mesoamerican archaeology, whereas the earlier reported ages are at the end of the Preclassic. The new age carries important implications for the timing of population shifts within the Basin of Mexico.

  7. 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.

  8. Assessing the regional impacts of Mexico City emissions on air quality and chemistry

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    M. Mena-Carrasco

    2009-06-01

    Full Text Available The impact of Mexico City (MCMA emissions is examined by studying its effects on air quality, photochemistry, and on ozone production regimes by combining model products and aircraft observations from the MILAGRO experiment during March 2006. The modeled influence of MCMA emissions to enhancements in surface level NOx, CO, and O3 concentrations (10–30% increase are confined to distances <200 km, near surface. However, the extent of the influence is significantly larger at higher altitudes. Broader MCMA impacts (some 900 km Northeast of the city are shown for specific outflow conditions in which enhanced ozone, NOy, and MTBE mixing ratios over the Gulf of Mexico are linked to MCMA by source tagged tracers and sensitivity runs. This study shows that the "footprint" of MCMA on average is fairly local, with exception to reactive nitrogen, which can be transported long range in the form of PAN, acting as a reservoir and source of NOx with important regional ozone formation implications. The simulated effect of MCMA emissions of anthropogenic aerosol on photochemistry showed a maximum regional decrease of 40% in J[NO2→NO+O], and resulting in the reduction of ozone production by 5–10%. Observed ozone production efficiencies are evaluated as a function of distance from MCMA, and by modeled influence from MCMA. These tend to be much lower closer to MCMA, or in those points where modeled contribution from MCMA is large. This research shows that MCMA emissions do effect on regional air quality and photochemistry, both contributing large amounts of ozone and its precursors, but with caveat that aerosol concentrations hinder formation of ozone to its potential due to its reduction in photolysis rates.

  9. Location and Mapping of an Ethyl Acetate Plume in Mexico City

    Science.gov (United States)

    Rogers, T.; Grimsrud, E.; Knighton, W.; Velasco, E.; Lamb, B.; Westberg, H.; Jobson, T.; Alexander, M.; Prazeller, P.; Herndon, S.; Kolb, C.

    2004-12-01

    A major goal of the 2003 Mexico City Metropolitan Area (MCMA) field campaign was to gain a better understanding of the dispersion and transport of volatile organic compounds (VOCs) in this urban airshed. Continuous monitoring of VOCs in the atmosphere and identification and quantification of their emission sources is complicated by two factors: first, there are hundreds of different VOC species released daily in the MCMA atmosphere, and second, few real time (1-10 second) measurement techniques have been available to provide the high resolution spatial and/or temporal data usually required to locate VOC emission sources and measure their flux strength. A relatively new technique, Proton Transfer Reaction Mass Spectometery (PTR-MS) provides this capability and was used to locate and quantify a significant source of ethyl acetate in the Iztapalapa region of Mexico City. Two PTR-MS systems were deployed during the 2003 MCMA campaign, the MSU PTR-MS was operated on-board the Aerodyne Mobile Laboratory while the PNNL instrument located on the roof at the National Center for Environmental Research and Training (Centro Nacional de Investigacion y Capacitacion Ambiental or CENICA). The uniqueness of the ethyl acetate signature allowed the MSU PTR-MS on-board the mobile lab to track the ethyl acetate plume back to its source. A short movie documenting the plume mapping and location of the source of the ethyl acetate emission will be shown. Knowing of the plume source location and the local meteorological conditions, the time resolved responses from the PNNL PTR-MS at the CENCIA location have been applied to a simple plume model to estimate the plume's emission flux strength.

  10. [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.

  11. Monoterpene and isoprene emissions from typical tree species in forests around Mexico City

    Science.gov (United States)

    Dominguez-Taylor, P.; Ruiz-Suarez, L. G.; Rosas-Perez, I.; Hernández-Solis, J. M.; Steinbrecher, R.

    The isoprenoid emission of sacred fir ( Abies religiosa (Kunth) Schltdl. & Cham.), patula pine ( Pinus patula Schiede, Schltdl. & Cham.) and net-leaf oak ( Quercus rugosa Née) was investigated in Mexico City during the years 2002 and 2003. Chemical compound specific emission factors were obtained for different months of the year. Net-leaf oak is an isoprene emitter whereas the other tree species emit monoterpenes. α-Pinene and linalool are the main compounds emitted from sacred fir and patula pine, respectively. In general, the emission of monoterpenes is temperature dependent, whereas α-pinene emission of sacred fir is controlled by light and temperature like the isoprene emission of net-leaf oak. All isoprenoids show a strong seasonality which is plant species specific. Emission factors for the conifers were high in October and low in April (sacred fir: 6.07μgCg-1dwh-1 in October and 0.02μgCg-1dwh-1 in April; patula pine: 4.22μgCg-1dwh-1 in October and 1.13μgCg-1dwh-1 in June). Isoprene emission potential of net-leaf oak was very variable in the different seasons with low source strengths in July (rainy season: 1.19μgCg-1dwh-1) and November (cold/dry season: 18.50μgCg-1dwh-1) but high in May (warm/dry season: 66.27μgCg-1dwh-1). The results indicate that present biogenic emission inventories of the Mexico City area have to be revised by using the new emission factors of native tree species including the seasonal impact.

  12. 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.

  13. 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.

  14. [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.

  15. Risk factors for pre-eclampsia/eclampsia among working women in Mexico City.

    Science.gov (United States)

    Cerón-Mireles, P; Harlow, S D; Sánchez-Carrillo, C I; Núñez, R M

    2001-01-01

    This study examined risk factors for pre-eclampsia/eclampsia in a population-based sample of pregnant working women in Mexico City. Over a 3-month period, all women who gave birth at three major hospitals and who had worked for at least 3 months during pregnancy were interviewed. After excluding mothers with multiple gestations or infants with birth defects, and previous diagnoses of hypertension, chronic renal disease or diabetes, 131 of 2,436 women (5.4%) had been diagnosed with pre-eclampsia and/or eclampsia. The frequency was much higher among women of low socio-economic status: 12% of uninsured women (SSA) compared with 4.2% of private sector employees (IMSS) and 1.3% of public sector employees (ISSSTE). After adjusting for education, women working in services (OR = 1.68, 95% CI = 1.01, 2.81) and in retail (OR = 1.99, 95% CI = 1.18, 3.37), primiparae (OR = 2.64, 95% CI = 1.65, 4.21) and women whose pregestational weight was > or = 55 kg (OR = 2.02, 95% CI = 1.34, 3.04) were at increased risk. Efforts to develop and evaluate intervention programmes should target hospitals serving the uninsured (SSA) if reduction in the number of preventable maternal deaths in Mexico is to be achieved. Such programmes should also target service and retail workers and identify women with poor glycaemic control early in pregnancy.

  16. 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.

  17. MGEA5-14 polymorphism and type 2 diabetes in Mexico City.

    Science.gov (United States)

    Cameron, E A; Martinez-Marignac, V L; Chan, A; Valladares, A; Simmonds, L V; Wacher, N; Kumate, J; McKeigue, P; Shriver, M D; Kittles, R; Cruz, M; Parra, E J

    2007-01-01

    A family-based study has recently reported that a variant located in intron 10 of the gene MGEA5 increases susceptibility to Type 2 Diabetes (T2D). We evaluated the distribution of this SNP in a sample of T2D patients (N = 271) and controls (N = 244) from Mexico City. The frequency of the T allele was higher in the cases (2.6%) than in the controls (1.8%). After adjusting for age, sex, BMI, education, and individual ancestry the odds ratio was 1.60 but the 95% confidence interval was wide and overlapped 1 (0.52-4.86, P-value : 0.404). In order to characterize the distribution of the MGEA5-14 polymorphism in the relevant parental populations, we genotyped this variant in European (and European Americans), West African, and Native American samples. The T-allele was present at a frequency of 2.3% in Spain, 4.2% in European Americans, and 13% in Western Africans, but was absent in two Native American samples from Mexico and Peru. Given the low frequency of the T-allele, further studies using large sample sizes will be required to confirm the role of this variant in T2D.

  18. 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 km2 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 hm3 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.

  19. Random walks along the streets and canals in compact cities: Spectral analysis, dynamical modularity, information, and statistical mechanics

    Science.gov (United States)

    Volchenkov, D.; Blanchard, Ph.

    2007-02-01

    Different models of random walks on the dual graphs of compact urban structures are considered. Analysis of access times between streets helps to detect the city modularity. The statistical mechanics approach to the ensembles of lazy random walkers is developed. The complexity of city modularity can be measured by an informationlike parameter which plays the role of an individual fingerprint of Genius loci. Global structural properties of a city can be characterized by the thermodynamic parameters calculated in the random walk problem.

  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. Processing of soot in an urban environment: case study from the Mexico City Metropolitan Area

    Science.gov (United States)

    Johnson, K. S.; Zuberi, B.; Molina, L. T.; Molina, M. J.; Iedema, M. J.; Cowin, J. P.; Gaspar, D. J.; Wang, C.; Laskin, A.

    2005-11-01

    Chemical composition, size, and mixing state of atmospheric particles are critical in determining their effects on the environment. There is growing evidence that soot aerosols play a particularly important role in both climate and human health, but still relatively little is known of their physical and chemical nature. In addition, the atmospheric residence times and removal mechanisms for soot are neither well understood nor adequately represented in regional and global climate models. To investigate the effect of locality and residence time on properties of soot and mixing state in a polluted urban environment, particles of diameter 0.2-2.0 μm were collected in the Mexico City Metropolitan Area (MCMA) during the MCMA-2003 Field Campaign from various sites within the city. Individual particle analysis by different electron microscopy methods coupled with energy dispersed x-ray spectroscopy, and secondary ionization mass spectrometry show that freshly-emitted soot particles become rapidly processed in the MCMA. Whereas fresh particulate emissions from mixed-traffic are almost entirely carbonaceous, consisting of soot aggregates with liquid coatings suggestive of unburned lubricating oil and water, ambient soot particles which have been processed for less than a few hours are heavily internally mixed, primarily with ammonium sulfate. Single particle analysis suggests that this mixing occurs through several mechanisms that require further investigation. In light of previously published results, the internally-mixed nature of processed soot particles is expected to affect heterogeneous chemistry on the soot surface, including interaction with water during wet-removal.

  2. Embedding Observation into the Context of Cultural Musicology: Some Moments in Mexico City

    Directory of Open Access Journals (Sweden)

    Gisa Jähnichen

    2015-08-01

    Full Text Available Narrative analysis needs narration. In cultural musicology, a term worth being taken up in succession and contemporary modification of ethnomusicology or anthropology of music, observation is an essential skill that most elaborately reveals itself in narration. Moreover, narrations include personal features and thoughts that are often avoided in academic writings. However, they offer a wide potential for narrative analysis. This paper is to exemplarily discuss theoretical issues on cultural musicology taking a holistic approach that includes analytic description, heuristics, source interpretation by means of the so called objective hermeneutics, and phenomenology. In 2008, outlines of some small stories put exemplarily together were written down in German, and part of a story collection was published in 2009. The city being observed is Mexico City that was visited in September 2006. This paper is to review the original narrations in an extended version under the aspect of their academic effectiveness after having developed further analytical tools in the last 5 years. Besides questioning conservative academic rules of reporting outcomes, this paper also reflects on the possibilities of intense methodological developments during a relatively short time. The topics of discussion include dealing with and presenting cultural heritage (Danzas de los Voladores, history of sound preservation (Songs of the Cora Indians, music in social movements and holistic approaches to research.

  3. [Heterogeneity in the expression of female sexual commerce in Mexico City].

    Science.gov (United States)

    Uribe-Salas, Felipe; Hernández-Avila, Mauricio; Conde-González, Carlos; Juárez-Figueroa, Luis

    2007-01-01

    To evaluate the relationships among the socio-economic, demographic, and sexual behavior characteristics of commercial sexual workers (CSW) and their work site. A sampling frame was constructed in the Delegación Cuauhtémoc, México City, which included massage parlors, bars, and street points. During 1993,women were selected who answered a questionnaire that inquired about socio-economic and demographic characteristics and sexual behavior, and who gave a blood sample for evaluating the seroprevalence of the herpes simplex virus type 2 (HSV-2), which was evaluated using a Western blot test. Characteristics such as age, education, socio-economic level, sexual behavior, and seroprevalence indicators were related with the work site variable. This last variable was associated with the women's sexual behavior and with the prevalence of antibodies against HSV-2. Socio-economic and sexual behavior characteristics of the women studied, measured at the individual level, were significantly related with social processes such as the organization of commercial sex in Mexico City. This organization is heterogeneous, taking on different expressions depending on the type of work site.

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

    Directory of Open Access Journals (Sweden)

    R. R. Boullosa

    2011-12-01

    Full Text Available 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 tranquility and its possible relation with the sound environment-; secondly, to identify some zones or places that have a particular sound environment - positive or negative. Natural sounds emerged as an important part of the sound identity of the Vallarta region and they seem to be highlyappreciated even when the sound levels are high. Sounds related to nature emerged in all interviews: bird calls, sound of wind rustling through trees, sound of breaking sea waves, etc. The interviewees identified places or zones with a negative sonic identity due to disagreeable or high intensity sounds; traffic flow, and mostly the urban bus, is to be blamed for in the main (some mentioned radios at high volume. A series of sound levels (dBA re 20 μPa at threedifferent times of the year: February, April, and October, 2009 were measured in some locations mentioned by the interviewees. The average sound levels found on those locations considered as having a disagreeable identity were the highest.

  5. New Magnetic and Geochemical Results on Topsoils of the Mexico City Metropolitan Area

    Science.gov (United States)

    Martínez-Pichar, E.; Soler-Arechalde, A. M.; Morton, O.; Hernandez, E.; Lozano-Santa-Cruz, R.; Gonzalez, G.; Beramendi, L.; Urrutia-Fucugauchi, J. H.

    2008-05-01

    The Metropolitan Area of Mexico city is a region well known for intense industrial and commercial activity. The potential sources of the heavy metal pollutants are assumed to be petroleum processing, production of iron material, manufacturing, coal combustion, commercial and automobile exhaust. New samples were collected from industrial, roadside, residential and public parks in the urban areas around the city and added to two previous field campaigns (2003 and 2005). Localities selected for the study represent, presumably, different heavy metal pollution levels and sources. At each sampling point, the top 2 cm layer of the soil profile was collected with a stainless steel trowel and stored in a plastic bag. The elements Fe, Cu and Zn concentrations were determined by EDXRF (Philips PW1400 apparatus) on bulk- sample pressed, boric-acid backed pellets. Metal concentrations of Pb, Ni, Cr, and V were analyzed by ICP-MS with a VG Elemental PQ3 instrument. Magnetic mineralogy in bulk soil samples was investigated by low-field susceptibility using a Kappabridge KLY2. Remanent magnetizations (ARM and IRM) and Hysteresis loops of micro samples had been carried out at room temperature. Bivariate analysis on different ratios of magnetic parameters was employed to characterize the pollution sources.

  6. [Financing of drug addiction programs in Mexico City: 1990-1994].

    Science.gov (United States)

    Parada-Toro, I M; Hernández-Peña, P; Arredondo-López, A; Becerra-Posada, F

    2000-01-01

    To analyze the financial flows in the drug dependency programs in México City, their financial source, and the way how funding monies are spent. A discrete number of institutions devoted to drug dependency control in Mexico City was selected. Analysis of financial flows was carried out using the National Health Accounts methods. Questionnaires to quantify resources were applied to health service managers and users. In addition to collection of financial flow data, we calculated the expenditures per user for each institution. For the period 1990-1993, expenditures were estimated from financial budgets allocated to each program in 1990, at constant values to eliminate the effects of inflation. Financial sources identified were: the federal budget allocation (50-90%), user fees (10-20%), and non-governmental organization contributions (15-80%). Even though budgets in participant institutions have increased in the last four years, they are still inadequate to cover the large demand of services. It is important to identify new ways to increase the availability of resources as well as to ensure their efficient use. Continuing financial analysis of these programs will allow the assessment of changes to guide optimal financial decision making.

  7. Measurements of CO{sub 2} fluxes from the Mexico City urban landscape

    Energy Technology Data Exchange (ETDEWEB)

    Velasco, E.; Pressley, S.; Allwine, E.; Westberg, H.; Lamb, B. [Washington State University, Pullman (United States). Department of Civil and Environmental Engineering

    2005-12-01

    In a densely populated section of Mexico City, an eddy covariance (EC) flux system was deployed on a tall urban tower to obtain direct measurements of CO{sub 2} emissions from an urban neighbourhood located in a subtropical megacity. The measured fluxes and boundary layer conditions satisfy EC assumptions of stationarity, and cospectral analyses of the turbulence measurements exhibit the required boundary layer patterns for acceptable flux measurements. Results from a field experiment conducted during April 2003 show that the urban surface is a net source of CO{sub 2}. The CO{sub 2} flux measurements showed a clear diurnal pattern, with the highest emissions during the morning (up to 1.60 mg m{sup -2} s{sup -1}), and the lowest emissions during nighttime. The measured fluxes were closely correlated to traffic patterns in the area. The mean daily flux was 0.41 mg m{sup -2} s{sup -1}, which is similar to that observed in European and US cities. (author)

  8. 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

  9. Chemically-resolved aerosol eddy covariance flux measurements in urban Mexico City during MILAGRO 2006

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    R. Zalakeviciute

    2012-08-01

    Full Text Available As part of the MILAGRO 2006 field campaign, the exchange of atmospheric aerosols with the urban landscape was measured from a tall tower erected in a heavily populated neighborhood of Mexico City. Urban submicron aerosol fluxes were measured using an eddy covariance method with a quadrupole aerosol mass spectrometer during a two week period in March, 2006. Nitrate and ammonium aerosol concentrations were elevated at this location near the city center compared to measurements at other urban sites. Significant downward fluxes of nitrate aerosol, averaging −0.2 μg m−2 s−1, were measured during daytime. The urban surface was not a significant source of sulfate aerosols. The measurements also showed that primary organic aerosol fluxes, approximated by hydrocarbon-like organic aerosols (HOA, displayed diurnal patterns similar to CO2 fluxes and anthropogenic urban activities. Overall, 47% of submicron organic aerosol emissions were HOA, 35% were oxygenated (OOA and 18% were associated with biomass burning (BBOA. Organic aerosol fluxes were bi-directional, but on average HOA fluxes were 0.1 μg m−2 s−1, OOA fluxes were −0.03 μg m−2 s−1, and BBOA fluxes were −0.03 μg m−2 s−1. After accounting for size differences (PM1 vs PM2.5 and using an estimate of the black carbon component, comparison of the flux measurements with the 2006 gridded emissions inventory of Mexico City, showed that the daily-averaged total PM emission rates were essentially identical for the emission inventory and the flux measurements. However, the emission inventory included dust and metal particulate contributions, which were not included in the flux measurements. As a result, it appears that the inventory underestimates overall PM emissions for this location.

  10. Seroepidemiology of Toxoplasma gondii in pregnant women in Aguascalientes City, Mexico: a cross-sectional study.

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Terrones-Saldívar, María Del Carmen; Hernández-Tinoco, Jesús; Muñoz-Terrones, María Daniela Enriqueta; Gallegos-González, Roberto Oswaldo; Sánchez-Anguiano, Luis Francisco; Reyes-Robles, Martha Elena; Jaramillo-Juárez, Fernando; Liesenfeld, Oliver; Estrada-Martínez, Sergio

    2016-07-01

    We determined the seroprevalence and correlates of Toxoplasma gondii infection in pregnant women in Aguascalientes City, Mexico. A cross-sectional survey. Pregnant women were enrolled in the central Mexican city of Aguascalientes. We studied 338 pregnant women who attended prenatal care in 3 public health centres. Women were examined for IgG/IgM antibodies to T. gondii by using commercially available enzyme immunoassays, and an avidity test. Multiple analyses were used to determine the association of T. gondii seropositivity with the characteristics of the pregnant women. Of the 338 pregnant women studied, 21 (6.2%) had IgG antibodies to T. gondii, and 1 (4.8%) of them was also positive for IgM antibodies to T. gondii. Avidity of IgG antibodies to T. gondii was high in the IgM-positive sample. Logistic regression analysis of sociodemographic, behavioural and housing variables showed that T. gondii seropositivity was associated with white ethnicity (OR=149.4; 95% CI 10.8 to 2054.1; pAguascalientes City have a low seroprevalence of T. gondii infection. However, this low prevalence indicates that most pregnant women are at risk for a primary infection. Factors associated with T. gondii exposure found in this study, including food hygiene, may be useful to determine preventive measures against T. gondii infection and its sequelae. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  11. High seroprevalence of Toxoplasma gondii infection in inmates: A case control study in Durango City, Mexico

    Science.gov (United States)

    Hernández-Tinoco, J.; Sánchez-Anguiano, L. F.; Ramos-Nevárez, A.; Cerrillo-Soto, S. M.; Sáenz-Soto, L.; Liesenfeld, O.

    2014-01-01

    Purpose The seroprevalence of infection with the parasite Toxoplasma gondii and the association with risk factors has not been determined in inmates. Through a case-control study, 166 inmates from a state correctional facility in Durango City, Mexico and 166 age- and gender-matched non-incarcerated subjects were examined for the presence of anti-T. gondii IgG and IgM antibodies using enzyme-linked immunoassays. Results Seroprevalence of anti-T. gondii IgG antibodies was higher in inmates (35, 21.1%) than in controls (14, 8.4%) (OR = 2.90; 95% CI: 1.43–5.94; P = 0.001). Anti-T. gondii IgM antibodies were detected in two (1.2%) inmates and in seven (4.2%) controls (P = 0.17). Multivariate analysis of socio-demographic, incarceration, and behavioral characteristics of inmates revealed that T. gondii seropositivity was associated with being born out of Durango State (OR = 3.91; 95% CI: 1.29–11.79; P = 0.01). In addition, T. gondii seroprevalence was higher (P = 0.03) in inmates that had suffered from injuries (17/56: 30.4%) than those without such history (18/110: 16.4%). Conclusions The seroprevalence of T. gondii infection in inmates in Durango City is higher than the seroprevalences found in the general population in the same city, indicating that inmates may represent a new risk group for T. gondii infection. Further research on T. gondii infection in inmates is needed. PMID:24678408

  12. 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.

  13. Risk factors for gastroenteritis associated with canal swimming in two cities in the Netherlands during the summer of 2015: A prospective study.

    Science.gov (United States)

    Joosten, Rosa; Sonder, Gerard; Parkkali, Saara; Brandwagt, Diederik; Fanoy, Ewout; Mughini-Gras, Lapo; Lodder, Willemijn; Ruland, Erik; Siedenburg, Evelien; Kliffen, Suzanne; van Pelt, Wilfrid

    2017-01-01

    Urban canal swimming events are popular in the Netherlands. In 2015, two city canal swimming events took place, in Utrecht (Utrecht Singel Swim, USS) and in Amsterdam (Amsterdam City Swim, ACS). This prospective study characterizes the health risks associated with swimming in urban waters. Online questionnaires were sent to 160 (USS) and 2,692 (ACS) participants, with relatives of participants who did not swim completing the questionnaire as a control. Swimming water specimens and stool specimens of diarrheic participants in the ACS group were analysed. A total of 49% of USS and 51% of ACS swimmers returned their questionnaires. Nine percent of USS swimmers and 4% of non-swimmers reported gastrointestinal complaints (aRR 2.1; 95% CI: 0.3-16), while a total of 31% of ACS swimmers and 5% of non-swimmers reported gastrointestinal complaints (aRR 6.3; 95% CI: 4.1-9.5). AGI risk among ACS participants was directly related to increasing number of mouthfuls of water swallowed. Various norovirus genotypes were detected in five out of seven stool specimens taken from ACS participants and in all three tested ACS water samples. We conclude that the AGI risk among open-water swimmers in urban areas depends on the circumstances around the event. The epidemiological curve, the statistical association between swimming and AGI, and the microbiological evidence for norovirus in stool and water specimens suggest that AGI outbreak after the ACS event was due to water contamination by multiple norovirus strains, which is possibly linked to sewage overflow due to prior heavy rainfall. There is need for more targeted preventive measurements and recommendations for organizers, municipal authorities and participants to prevent this reoccurring in the future.

  14. 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.

  15. Formation of semivolatile inorganic aerosols in the Mexico City Metropolitan Area during the MILAGRO campaign

    Directory of Open Access Journals (Sweden)

    V. A. Karydis

    2011-12-01

    Full Text Available One of the most challenging tasks for chemical transport models (CTMs is the prediction of the formation and partitioning of the major semi-volatile inorganic aerosol components (nitrate, chloride, ammonium between the gas and particulate phases. In this work the PMCAMx-2008 CTM, which includes the recently developed aerosol thermodynamic model ISORROPIA-II, is applied in the Mexico City Metropolitan Area in order to simulate the formation of the major inorganic aerosol components. The main sources of SO2 (such as the Miguel Hidalgo Refinery and the Francisco Perez Rios Power Plant in the Mexico City Metropolitan Area (MCMA are located in Tula, resulting in high predicted PM1 (particulate matter with diameter less than 1 μm sulfate concentrations (over 25 μg m-3 in that area. The average predicted PM1 nitrate concentrations are up to 3 μg m−3 (with maxima up to 11 μg m−3 in and around the urban center, mostly produced from local photochemistry. The presence of calcium coming from the Tolteca area (7 μg m−3 as well as the rest of the mineral cations (1 μg m−3 potassium, 1 μg m−3 magnesium, 2 μg m−3 sodium, and 3 μg m−3 calcium from the Texcoco Lake resulted in the formation of a significant amount of aerosol nitrate in the coarse mode with concentrations up to 3 μg m−3 over these areas. PM1−10 (particulate matter with diameter between 1 and 10 μm chloride is also high and its concentration exceeds 2 μg m−3 in Texcoco Lake. PM1 ammonium concentrations peak at the center of Mexico City (2 μg m−3 and the Tula vicinity (2.5 μg m−3. The performance of the model for the major inorganic PM components (sulfate, ammonium, nitrate, chloride, sodium, calcium, and magnesium is encouraging. At the T0 measurement site, located in the

  16. Formation of semivolatile inorganic aerosols in the Mexico City Metropolitan Area during the MILAGRO campaign

    Science.gov (United States)

    Karydis, V. A.; Tsimpidi, A. P.; Lei, W.; Molina, L. T.; Pandis, S. N.

    2011-12-01

    One of the most challenging tasks for chemical transport models (CTMs) is the prediction of the formation and partitioning of the major semi-volatile inorganic aerosol components (nitrate, chloride, ammonium) between the gas and particulate phases. In this work the PMCAMx-2008 CTM, which includes the recently developed aerosol thermodynamic model ISORROPIA-II, is applied in the Mexico City Metropolitan Area in order to simulate the formation of the major inorganic aerosol components. The main sources of SO2 (such as the Miguel Hidalgo Refinery and the Francisco Perez Rios Power Plant) in the Mexico City Metropolitan Area (MCMA) are located in Tula, resulting in high predicted PM1 (particulate matter with diameter less than 1 μm) sulfate concentrations (over 25 μg m-3) in that area. The average predicted PM1 nitrate concentrations are up to 3 μg m-3 (with maxima up to 11 μg m-3) in and around the urban center, mostly produced from local photochemistry. The presence of calcium coming from the Tolteca area (7 μg m-3) as well as the rest of the mineral cations (1 μg m-3 potassium, 1 μg m-3 magnesium, 2 μg m-3 sodium, and 3 μg m-3 calcium) from the Texcoco Lake resulted in the formation of a significant amount of aerosol nitrate in the coarse mode with concentrations up to 3 μg m-3 over these areas. PM1-10 (particulate matter with diameter between 1 and 10 μm) chloride is also high and its concentration exceeds 2 μg m-3 in Texcoco Lake. PM1 ammonium concentrations peak at the center of Mexico City (2 μg m-3) and the Tula vicinity (2.5 μg m-3). The performance of the model for the major inorganic PM components (sulfate, ammonium, nitrate, chloride, sodium, calcium, and magnesium) is encouraging. At the T0 measurement site, located in the Mexico City urban center, the average measured values of PM1 sulfate, nitrate, ammonium, and chloride are 3.5 μg m-3, 3.5 μg m-3, 2.1 μg m-3, and 0.36 μg m-3, respectively. The corresponding predicted values are 3.7

  17. An emission processing system for air quality modelling in the Mexico City metropolitan area: Evaluation and comparison of the MOBILE6.2-Mexico and MOVES-Mexico traffic emissions.

    Science.gov (United States)

    Guevara, M; Tena, C; Soret, A; Serradell, K; Guzmán, D; Retama, A; Camacho, P; Jaimes-Palomera, M; Mediavilla, A

    2017-04-15

    This article describes the High-Elective Resolution Modelling Emission System for Mexico (HERMES-Mex) model, an emission processing tool developed to transform the official Mexico City Metropolitan Area (MCMA) emission inventory into hourly, gridded (up to 1km2) and speciated emissions used to drive mesoscale air quality simulations with the Community Multi-scale Air Quality (CMAQ) model. The methods and ancillary information used for the spatial and temporal disaggregation and speciation of the emissions are presented and discussed. The resulting emission system is evaluated, and a case study on CO, NO2, O3, VOC and PM2.5 concentrations is conducted to demonstrate its applicability. Moreover, resulting traffic emissions from the Mobile Source Emission Factor Model for Mexico (MOBILE6.2-Mexico) and the MOtor Vehicle Emission Simulator for Mexico (MOVES-Mexico) models are integrated in the tool to assess and compare their performance. NOx and VOC total emissions modelled are reduced by 37% and 26% in the MCMA when replacing MOBILE6.2-Mexico for MOVES-Mexico traffic emissions. In terms of air quality, the system composed by the Weather Research and Forecasting model (WRF) coupled with the HERMES-Mex and CMAQ models properly reproduces the pollutant levels and patterns measured in the MCMA. The system's performance clearly improves in urban stations with a strong influence of traffic sources when applying MOVES-Mexico emissions. Despite reducing estimations of modelled precursor emissions, O3 peak averages are increased in the MCMA core urban area (up to 30ppb) when using MOVES-Mexico mobile emissions due to its VOC-limited regime, while concentrations in the surrounding suburban/rural areas decrease or increase depending on the meteorological conditions of the day. The results obtained suggest that the HERMES-Mex model can be used to provide model-ready emissions for air quality modelling in the MCMA. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. 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.

  19. 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.

  20. Oral health status in older adults with social security in Mexico City: Latent class analysis

    Science.gov (United States)

    Heredia-Ponce, Erika; Cruz-Hervert, Pablo; Juárez-Cedillo, Teresa; Cárdenas-Bahena, Ángel; García-Peña, Carmen

    2014-01-01

    Objective: To explore the oral health status through a latent class analysis in elderly social security beneficiaries from Southwest Mexico City. Material and Methods: 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. Results: 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. Conclusion: 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. PMID:24596632

  1. Association of TCF7L2 polymorphisms with type 2 diabetes in Mexico City.

    Science.gov (United States)

    Parra, E J; Cameron, E; Simmonds, L; Valladares, A; McKeigue, P; Shriver, M; Wacher, N; Kumate, J; Kittles, R; Cruz, M

    2007-04-01

    Polymorphisms within the transcription factor 7-like 2 gene (TCF7L2) have been associated with type 2 diabetes (T2D) in several recent studies. We characterized three of these polymorphisms (rs12255372, rs7903146 and the microsatellite DG10S478) in an admixed sample of 286 patients with T2D and 275 controls from Mexico City. We also analyzed three samples representative of the relevant parental populations: Native Americans from the state of Guerrero (Mexico), Spanish from Valencia and Nigerians (Bini from the Edo region). In order to minimize potential confounding because of the presence of population stratification in the sample, we evaluated the association of the three TCF7L2 polymorphisms with T2D by using the program admixmap to fit a logistic regression model incorporating individual ancestry, sex, age, body mass index and education. The markers rs12255372, rs7903146 and DG10S478 are in tight disequilibrium in the Mexican sample. We observed a significant association between the single-nucleotide polymorphism (SNP) rs12255372 and the microsatellite DG10S478 with T2D in the Mexican sample [rs12255372, odds ratio (OR) = 1.78, p = 0.017; DG10S478, OR = 1.62, p = 0.041]. The SNP rs7903146 shows similar trends, but its association with T2D is not as strong (OR = 1.39, p = 0.152). Analysis of the parental samples, as well as other available data, indicates that there are substantial population frequency differences for these polymorphisms: The frequencies of the T2D risk factors are more than 20% higher in European and West African populations than in East Asian and Native American populations.

  2. Impact of environmental and social attitudes, and family concerns on willingness to pay for improved air quality: a contingent valuation application in Mexico City

    National Research Council Canada - National Science Library

    Filippini, Massimo; Martínez-Cruz, Adán L

    2016-01-01

    ...) for improved air quality among residents of Mexico City Metropolitan Area (MCMA). Findings from this paper illustrate heterogeneity in WTP associated with environmental and social attitudes, and family concerns...

  3. Spectral Optical Properties of the Polluted Atmosphere of Mexico City (Spring-Summer 1992)

    Science.gov (United States)

    Vasilyev, O. B.; Contreras, A. Leyva; Valazquez, A. Muhlia; Peralta-Fabi, R.; Ivlev, L. S.; Kovalenko, A. P.; Vasilyev, A. V.; Jukov, V. M.; Welch, Ronald M.

    1995-01-01

    A joint Mexican, Russian, and American research effort has been initiated to develop new methods to remotely sense atmospheric parameters using ground-based, aircraft, and satellite observations. As a first step in this program, ground-based spectrophotometric measurements of the direct solar radiation have been obtained for the extremely polluted Mexico City atmosphere for the period of April-June 1992. These observations were made at more than 1300 channels in the spectral range of 0.35-0.95 microns. In the UltraViolet (UV) portions of the spectrum (e.g., 0.35 microns), aerosol optical thicknesses were found to range between 0.6 and 1.2; in the visible portion of the spectrum (e. g., 0.5 microns) they ranged from 0.5 to 0.8; and in the Near-Infrared (NIR) spectra (e.g., 0.85 micron), values of 0.3 - 0.5 were found. Applying a Spectral Optical Depth (SOD) model of tau(lambda) = C + A(lambda(sup -varies as), values of 1.55 less than varies as less than 1.85 were obtained for polluted, cloudless days, with values of 1.25 less than varies as less than 1.60 on days with haze. The aerosol particles in the polluted Mexico City atmosphere were found to be strongly absorbing, with a single-scattering albedo of 0.7 - 0.9 in the UV, 0.6 - 0.8 in the visible portion of the spectrum, and 0.4 - 0.7 in the NIR. These values are possibly consistent with a high soot concentration, contributed both by vehicular traffic and heavy industry. Analysis of the measured aerosol SOD using the optical parameters of an urban aerosol model pemiits the concentration of aerosol particles to be estimated in the vertical column; a maximum value of 3 x 10(exp 9) 1/sq cm was found. This concentration of aerosol particles exceeds that found in most other regions of the globe by at least an order of magnitude. Near the ground the aerosol size distributions measured using an optical particle counter were found to be strongly multimodal.

  4. 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

  5. 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

  6. Radiocarbon ages of Holocene Pelado, Guespalapa, and Chichinautzin scoria cones, south of Mexico City: implications for archaeology and future hazards

    Science.gov (United States)

    Siebe, Claus; Rodríguez-Lara, Virgilio; Schaaf, Peter; Abrams, Michael

    Pelado, Guespalapa, and Chichinautzin monogenetic scoria cones located within the Sierra del Chichinautzin Volcanic Field (SCVF) at the southern margin of Mexico City were dated by the radiocarbon method at 10,000, 2,800-4,700, and 1,835 years b.p., respectively. Most previous research in this area was concentrated on Xitle scoria cone, whose lavas destroyed and buried the pre-Hispanic town of Cuicuilco around 1,665+/-35 years b.p. The new dates indicate that the recurrence interval for monogenetic eruptions in the central part of the SCVF and close to the vicinity of Mexico City is Pelado); and total erupted volumes range between 1 and 2 km3/cone. An average eruption rate for the entire SCVF was estimated at 0.6 km3/1,000 years. These findings are of importance for archaeological as well as volcanic hazards studies in this heavily populated region.

  7. Effect of aerosols and NO2 concentration on ultraviolet actinic flux near Mexico City during MILAGRO: measurements and model calculations

    OpenAIRE

    G. G. Palancar; B. L. Lefer; Hall, S.R.; Shaw, W. J.; Corr, C. A.; S. C. Herndon; J. R. Slusser; Madronich, S.

    2013-01-01

    Urban air pollution absorbs and scatters solar ultraviolet (UV) radiation, and thus has a potentially large effect on tropospheric photochemical rates. We present the first detailed comparison between actinic fluxes (AF) in the wavelength range 330–420 nm measured in highly polluted conditions and simulated with the Tropospheric UltravioletVisible (TUV) model. Measurements were made during the MILAGRO campaign near Mexico City in March 2006, at a ground-based station near Mexico City (the T1 ...

  8. 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.

  9. Primary and secondary contributions to aerosol light scattering and absorption in Mexico City during the MILAGRO 2006 campaign

    OpenAIRE

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

    2009-01-01

    A photoacoustic spectrometer, a nephelometer, an aetholemeter, 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 ...

  10. 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.

  11. Mexican Seismic Alert System's SAS-I algorithm review considering strong earthquakes felt in Mexico City since 1985

    Science.gov (United States)

    Cuellar Martinez, A.; Espinosa Aranda, J.; Suarez, G.; Ibarrola Alvarez, G.; Ramos Perez, S.; Camarillo Barranco, L.

    2013-05-01

    The Seismic Alert System of Mexico (SASMEX) uses three algorithms for alert activation that involve the distance between the seismic sensing field station (FS) and the city to be alerted; and the forecast for earthquake early warning activation in the cities integrated to the system, for example in Mexico City, the earthquakes occurred with the highest accelerations, were originated in the Pacific Ocean coast, whose distance this seismic region and the city, favors the use of algorithm called Algorithm SAS-I. This algorithm, without significant changes since its beginning in 1991, employs the data that generate one or more FS during P wave detection until S wave detection plus a period equal to the time employed to detect these phases; that is the double S-P time, called 2*(S-P). In this interval, the algorithm performs an integration process of quadratic samples from FS which uses a triaxial accelerometer to get two parameters: amplitude and growth rate measured until 2*(S-P) time. The parameters in SAS-I are used in a Magnitude classifier model, which was made from Guerrero Coast earthquakes time series, with reference to Mb magnitude mainly. This algorithm activates a Public or Preventive Alert if the model predicts whether Strong or Moderate earthquake. The SAS-I algorithm has been operating for over 23 years in the subduction zone of the Pacific Coast of Mexico, initially in Guerrero and followed by Oaxaca; and since March 2012 in the seismic region of Pacific covering the coasts among Jalisco, Colima, Michoacan, Guerrero and Oaxaca, where this algorithm has issued 16 Public Alert and 62 Preventive Alerts to the Mexico City where its soil conditions increase damages by earthquake such as the occurred in September 1985. This work shows the review of the SAS-I algorithm and possible alerts that it could generate from major earthquakes recordings detected by FS or seismometers near the earthquakes, coming from Pacific Ocean Coast whose have been felt in Mexico

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

    Science.gov (United States)

    Rodriguez Lopez, Juan Miguel; Heider, Katharina; Scheffran, Jürgen

    2017-04-01

    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 as a result of a semi-automatic classification, dividing the land cover data into urban and non-urban classes. The second data set details an alternative view of the phenomena of urbanization by concentrating on illegal settlements in the conservation zone. It was based on voluntary complaints about environmental and land use offences filed at the Procuraduria Ambiental y del Ordenamiento Territorial del Distrito Federal (PAOT), which is a governmental entity responsible for reviewing and processing grievances on five basic topics: illegal land use, deterioration of green areas, waste, noise/vibrations, and animals. Anyone can file a PAOT complaint by phone, electronically, or in person. The complaint ends with a resolution, act of conciliation, or recommendation for action by other actors, such as the police or health office. The third data about unemployment was extracted from Mexico׳s National Census 2010 database available via public access.

  13. [Sensitization to Casuarina equisetifolia and Pinus spp pollen in patients with allergic rhinitis and asthma in Mexico City].

    Science.gov (United States)

    Velasco-Medina, Andrea Aida; Velázquez-Sámano, Guillermo

    2014-01-01

    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 countries have been demonstrated their relevance as aeroallergens. To estimate the frequency of sensitization to Casuarina equisetifolia and Pinus spp pollen. A transversal, descriptive trial was done at Hospital 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. 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. 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 corroborate sensitization in our population.

  14. What Does Latin American Social Medicine Do When It Governs? The Case of the Mexico City Government

    Science.gov (United States)

    Laurell, Asa Cristina

    2003-01-01

    Latin American social medicine (LASM) emerged as a movement in the 1970s and played an important role in the Brazilian health care reform of the 1980s, both of which focused on decentralization and on health care as a social right. The dominant health care reform model in Latin America has included a market-driven, private subsystem for the insured and a public subsystem for the uninsured and the poor. In contrast, the Mexico City government has launched a comprehensive policy based on social rights and redistribution of resources. A universal pension for senior citizens and free medical services are financed by grants, eliminating routine government corruption and waste. The Mexico City policy reflects the influence of Latin American social medicine. In this article, I outline the basic traits of LASM and those of the prevailing health care reform model in Latin America and describe the Mexico City social and health policy, emphasizing the influence of LASM in values, principles, and concrete programs. PMID:14652327

  15. What does Latin Aamerican social medicine do when it governs? The case of the Mexico City government.

    Science.gov (United States)

    Laurell, Asa Cristina

    2003-12-01

    Latin American social medicine (LASM) emerged as a movement in the 1970s and played an important role in the Brazilian health care reform of the 1980s, both of which focused on decentralization and on health care as a social right. The dominant health care reform model in Latin America has included a market-driven, private subsystem for the insured and a public subsystem for the uninsured and the poor. In contrast, the Mexico City government has launched a comprehensive policy based on social rights and redistribution of resources. A universal pension for senior citizens and free medical services are financed by grants, eliminating routine government corruption and waste. The Mexico City policy reflects the influence of Latin American social medicine. In this article, I outline the basic traits of LASM and those of the prevailing health care reform model in Latin America and describe the Mexico City social and health policy, emphasizing the influence of LASM in values, principles, and concrete programs.

  16. Ozone causes needle injury and tree decline in Pinus hartwegii at high altitudes in the mountains around Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    de la l. Bauere, M.deL.; Tejeda, T.H.; Manning, W.J.

    1985-08-01

    Needles of P. hartwegii were examined for a two-year period at 22 plots at Ajusco, D.F., south of Mexico City, at 3000 m. Ozone injury symptoms, consisting of extensive yellow banding and mottling, were observed on mature needles. These also became evident on new needles as they matured. This resulted in premature needle loss, reduction in cone and seed production, loss of tree vigor, bark beetle infestations, and tree decline and death. P. montezumae var. lindleyi and a few P. hartwegii trees in the same area were less susceptible. The most severe ozone injury to P. hartwegii occurs west to southwest of Mexico City in the mountain forest reserve of Desierto de los Leones, at 3500 m. Based on observations, the authors feel that needle injury and decline of P. hartwegii at high elevations in the mountains around Mexico City is caused primarily by ozone and not acid rain. It resembles the ozone-caused decline of ponderosa pine in the San Bernardino Mountains in California.

  17. Satellite-derived land surface parameters for mesoscale modelling of the Mexico City basin

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    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.

  18. 'Without a plan' but 'keeping on track': views on contraception, pregnancy and abortion in Mexico City.

    Science.gov (United States)

    Juarez, Fatima; Bayer, Angela M

    2011-01-01

    Despite increased use of modern contraception among Mexican women, there has been a significant increase in abortions. Little is known about the experiences behind these trends. This study examines decision-making around contraception, pregnancy, childbearing and abortion. We carried out 26 in-depth interviews with 23- to 35-year-old females and males in Mexico City. Interviewees described reproductive planning 'without a plan' and sporadic contraceptive use. Linking of reproductive preferences and contraceptive use occurred only after raising a child for a few years or after experiencing an abortion. Interviewees described side effects of hormonal contraceptives and the intrauterine device (IUD) and problems with condoms. Only 8% of participants disagreed with abortion completely. Those with mixed views opposed abortion for pregnancies resulting from lack of responsibility or due to personal problems or concerns about one's future. However, these more controversial reasons were the primary motivations for terminating pregnancies. Females and males expressed that females made most decisions related to contraception, pregnancy and abortion. Further research could explore the reasons behind reproductive planning 'without a plan', 'on and off' contraceptive use and abortion beliefs and experiences that are somewhat contradictory.

  19. A Multiscale Four-Dimensional Data Assimilation System Applied in the Mexico City Valley

    Science.gov (United States)

    Parra, D.; Hernandez, F.; Gonzalez, J. I.; Ortiz, E.; Hoyos, L. F.

    2007-05-01

    Several modeling studies have shown that four-dimension data assimilation (FDDA) has the ability to improve the simulations of wind, temperature, moisture and mixed layer depth. These works concluded that modeling with FDDA can produce spatially consistent solutions without degrading important dynamical processes. Additionally, it is widely recognized that MM5 with FDDA can be used to develop realistic three-dimensional fields that are completely suited as inputs to air quality or diagnostic meteorological models. In this work, MM5 and FDDA were used to model the weather conditions in the Mexico City Metropolitan Area (MCMA). The surface information was obtained from "Red Automática de Monitoreo Atmosférico (RAMA)" data bases. Sounding data were obtained from "Servicio Meteorológico Nacional". Four simulation domains were used with spatial resolutions of 27, 9, 3, and 1 Km2 respectively. In this work, 15 surface weather stations and 30 sounding points were employed. With this technique, weather predictions have correlation levels higher than 80%. Additionally, these predictions were used as input of the photochemical model MCCM and an important influence on pollutants concentration and dispersion predictions was observed.

  20. Morbidity following Mexico City's 1985 earthquakes: clinical and epidemiologic findings from hospitals and emergency units.

    Science.gov (United States)

    Sánchez-Carrillo, C I

    1989-01-01

    Medical records of 822 inpatients and outpatients cared for by the Department of the Federal District medical services during the 1985 Mexico City earthquakes were reviewed. Record incompleteness varied between 92.8 percent and 14.0 percent for the various study variables. No gender differences were detected among the groups; more than 70.0 percent of the patients were ages 15 to 64 years. Multiple traumatic injuries were frequent for inpatients across age groups, while simple contusions were more frequent among outpatients. Multiple head traumas, thorax-abdomen multiple traumas, and simple fractures of an arm or leg were more frequently recorded for inpatients than for outpatients. Head wounds with contusions; simple contusion of the thorax-abdomen, arms, and legs; and psychological trauma were more frequently recorded for outpatients. Although a great many records were incomplete, the data may reflect what actually happened to these patients, given the similarity of the findings with other reports of disasters. Improved record keeping during emergencies is needed to standardize the quantity and the reliability of the data so that statistical and medical care requirements are soundly based. The use of standard questionnaires for data collection is stressed to facilitate the management of clinical and epidemiologic activities. Longitudinal studies are needed to determine patterns of physical injuries, psychological trauma, and survival.

  1. Characteristics of specific reading disability in children from a neuropsychological clinic in Mexico City

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    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.

  2. [Working conditions in outpatient clinics adjacent to private pharmacies in Mexico City: perspective of physicians].

    Science.gov (United States)

    Díaz-Portillo, Sandra P; Reyes-Morales, Hortensia; Cuadra-Hernández, Silvia Magali; Idrovo, Álvaro J; Nigenda, Gustavo; Dreser, Anahí

    To analyse the working conditions of physicians in outpatient clinics adjacent to pharmacies (CAFs) and their organizational elements from their own perspective. We carried out an exploratory qualitative study. Semi-structured interviews were conducted with 32 CAF physicians in Mexico City. A directed content analysis technique was used based on previously built and emerging codes which were related to the experience of the subjects in their work. Respondents perceive that work in CAFs does not meet professional expectations due to low pay, informality in the recruitment process and the absence of minimum labour guarantees. This prevents them from enjoying the benefits associated with formal employment, and sustains their desire to work in CAF only temporarily. They believe that economic incentives related to number of consultations, procedures and sales attained by the pharmacy allow them to increase their income without influencing their prescriptive behaviour. They express that the monitoring systems and pressure exerted on CAFs seek to affect their autonomy, pushing them to enhance the sales of medicines in the pharmacy. Physicians working in CAFs face a difficult employment situation. The managerial elements used to induce prescription and enhance pharmacy sales create a work environment that generates challenges for regulation and underlines the need to monitor the services provided at these clinics and the possible risk for users. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Sweetened beverages intake, hyperuricemia and metabolic syndrome. The Mexico City Diabetes Study.

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    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.

  4. [Masculinity and sexual and reproductive health: a case study among adolescents of Mexico City].

    Science.gov (United States)

    Stern, Claudio; Fuentes-Zurita, Cristina; Lozano-Treviño, Laura Ruth; Reysoo, Fenneke

    2003-01-01

    To understand how the social construction and expression of masculinity among male adolescents and young adults are related to sexual health and reproductive risks. The study was carried out in an underserved and a popular area of Mexico City. Eighteen focal groups and 18 individual interviews were applied to a sample of males from three age groups: 10 to 14, 15 to 19, and 20 to 24 years. Data analysis was performed inductively through open codification of the verbal transcriptions. These were used to create more abstract concepts and search for relationships among them. This paper centers on interpretations of masculinity as expressed by the youngsters themselves. Our research sheds light on what youngsters do and say to "be men". Their ideas and practices produce different forms of masculinity through which risk behavior is manifested, as well as specific speech and dressing styles, and ways of courting and "going steady". These behaviors and their meanings are associated with sexual and reproductive health risk taking. The traditional model of masculinity characteristic of both social settings involves poor communication about sexuality in couple relationships, which results in infrequent protection and exposure to Sexually Transmitted Infections and unwanted pregnancies. On the other hand, their economic living conditions prevent them from fully practicing central elements of their own concept of masculinity, such as being a hard worker, a provider, and a responsible person. These unmet needs may cause frustration, aggression, and domestic violence.

  5. [Affection, kisses, and condoms: the ABC of sexual practices of female sex workers in Mexico City].

    Science.gov (United States)

    Allen, Betania; Cruz-Valdez, Aurelio; Rivera-Rivera, Leonor; Castro, Roberto; Arana-García, María Ernestina; Hernández-Avila, Mauricio

    2003-01-01

    To describe and explore the meanings of sexual practices among female sex workers (FSW) in Mexico City. A qualitative and quantitative study was carried out. The qualitative approach was conducted in 1992 and the latter from 1991 to 1992. The study population was a representative sample of FSW (n = 335) who completed a questionnaire; 52 of them also participated in six focal groups. Simple frequencies, central trend, and dispersion measures were calculated. Qualitative data were interpreted using Grounded Theory and a feminist perspective. Female sex workers accepted vaginal penetration with clients and oral penetration to a lesser extent, while anal penetration and kissing were rejected. All sexual modalities were accepted with personal partners. In their practice, FSW use psychophysical dissociation as a psychological defense mechanism and to construct their identities. Services requested by their latest clients were: 98.4% vaginal, 39.1% oral, and 7.7% anal sex. Condom use was reported by 94%. With their personal partner, 72.6% of FSW never used condoms. The week before the study, FSW worked 3.7 +/- 1.5 days on average and had sexual intercourse with 8.6 +/- 8.1 clients. Interventions are needed to promote safe sex among FSW in their private and professional lives. The English version of this paper is available at:http://www.insp.mx/salud/index.html.

  6. 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.

  7. 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.

  8. GPS and GIS study of the western slope of the Chiquihuite hill in Mexico City

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    M. Martínez–Yáñez

    2009-04-01

    Full Text Available The demographic explosion of the City of Mexico has forced the anarchical growth of urban development in its mountain slopes. The geologic risk conditions that prevail in such areas are rock falls and down slope creep. The topographic slope analysis shows that these some areas pose a high risk condition for the housing developments located down slope. A geodetic net work was thus developed for the establishment of a reference frame to detect medium and long term slope movement. The location of these benchmarks included rock out crops, structural containment civil structures and street sidewalks. This network was designed to be occupied using GPS fast static methods, with times of occupation no greater to 45 minutes per station. In order to keep short baselines to the reference station and its position errors within low levels we installed a reference GPS site (U CHI on the Southern part of Cerro del Chiquihuite. The Chiquihuite GPS network was monitored for 5 years. The GPS solutions were obtained by differential techniques with ambiguity solution and precise or bits, and using UCHI stations as a reference. The Chiquihuite GPS network does not show significant variations, except for the vertical component at station CH55. This site is likely to be affected by regional subsidence.

  9. Internally mixed soot, sulfates, and organic matter in aerosol particles from Mexico City

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    K. Adachi

    2008-11-01

    Full Text Available Soot particles, which are aggregated carbonaceous spherules with graphitic structures, are major aerosol constituents that result from burning of fossil fuel, biofuel, and biomass. Their properties commonly change through reaction with other particles or gases, resulting in complex internal mixtures. Using a transmission electron microscope (TEM for both imaging and chemical analysis, we measured ~8000 particles (25 samples with aerodynamic diameters from 0.05 to 0.3 μm that were collected in March 2006 from aircraft over Mexico City (MC and adjacent areas. Most particles are coated, consist of aggregates, or both. For example, almost all analyzed particles contain S and 70% also contain K, suggesting coagulation and condensation of sulfates and particles derived from biomass and biofuel burning. In the MC plumes, over half of all particles contained soot coated by organic matter and sulfates. The median value of the soot volume fraction in such coated particles is about 15%. In contrast to the assumptions used in many climate models, the soot particles did not become compact even when coated. Moreover, about 80% by volume of the particles consisting of organic matter with sulfate also contained soot, indicating the important role of soot in the formation of secondary aerosol particles. Coatings on soot particles can amplify their light absorption, and coagulation with sulfates changes their hygroscopic properties, resulting in shorter lifetimes. Through changes in their optical and hygroscopic properties, internally mixed soot particles have a greater effect on the regional climate of MC than uncoated soot particles.

  10. Blood groups and red cell acid phosphatase types in a Mixteca population resident in Mexico City.

    Science.gov (United States)

    Buentello, L.; García, P.; Lisker, R.; Salamanca, F.; Peñaloza, R.

    1999-01-01

    Several blood groups, ABO, Rh, Ss, Fy, Jk, and red cell acid phosphatase (ACP) types were studied in a native Mixteca population that has resided in Mexico City since 1950. Gene frequencies were obtained and used to establish admixture estimates with blacks and whites. The subjects came from three different geographical areas: High Mixteca, Low Mixteca, and Coast Mixteca. All frequencies were in Hardy-Weinberg equilibrium. The difference in the ABO frequencies was statistically significant when subjects from the three areas were compared simultaneously. Rh frequencies differed only between the High and the Low Mixteca populations. The ACP frequencies were similar between the Low Mixteca population and a previously reported Mestizo population. However, there were significant differences between the High Mixteca group and a Mestizo population, all the subjects being from Oaxaca. This is the first report of Ss, Fy, Jk, and ACP frequencies in a Mixteca population. Am. J. Hum. Biol. 11:525-529, 1999. Copyright 1999 Wiley-Liss, Inc.

  11. Years of life lost (Yll) attributable to alcohol consumption in Mexico City.

    Science.gov (United States)

    Pérez-Pérez, Eduardo; Cruz-López, Leonardo; Hernández-Llanes, Norberto Francisco; Gallegos-Cari, Andrea; Camacho-Solís, Rafael Edgardo; Mendoza-Meléndez, Miguel Ángel

    2016-01-01

    The aim of this study was to estimate the YLL attributable to alcohol consumption in Mexico City from 2006 - 2012. Vital statistics on mortality attributable to alcohol consumption from the INEGI (Instituto Nacional de Estadística y Geografía) were used to determine YLL as well as the average age of death in relation to different age ranges by sex. A total estimate of 168,607 YLL was obtained, with an average loss of 18.32 years being observed for men and 17.54 years for women. Men accounted for a higher proportion of the YLL than women. According to the ICD-10 (Tenth Revision of International Classification of Diseases), liver disease attributable to alcohol consumption was found to be responsible for more than 80% of the total YLL. There was a cyclical trend in YLL from 2006 to 2012. The YLL attributable to alcohol suggest that alcohol consumption is a public health problem that involves losses in productivity and economic costs, and the decline in YLL could be explained by the decrease in income caused by the economic crisis of 2008, just as the increase could be explained by economic improvement in 2012.

  12. [Experience and knowledge about climateric and menopause in women in Mexico City].

    Science.gov (United States)

    Velasco-Murillo, V; Navarrete-Hernández, E; Ojeda-Mijares, R I; Pozos-Cavanzo, J L; Camacho-Rodríquez, M A; Cardona-Pérez, J A

    2000-01-01

    To know the experiences and knowledge about climateric and menopause in a group of women covered by Instituto Mexicano del Seguro Social (IMSS). The purpose was to contribute for planning some strategies to increase seeking for medical care at these periods of life. Descriptive survey study in a randomized sample of women aged 50-59 years, currently users of medical services in family medicine system of IMSS en Mexico City, with a confidence interval of 95%. Mean age at menopause was 47.8 years. Most frequent climateric symptoms were: hot flushes (70.9%), depression (60.2%), insomnia (53.5%) and menstrual disturbances (37.8%). 51.1% of women seeked medical care due to climateric symptoms but only 12.1% received treatment, majority hormonals (81.6%). Past users were 14.9% and they received hormones too in 87.8%. In this survey, 83.8% of women had some knowledge about main symptoms of climateric and 90.1% knew about osteoporosis but only 37.2% had some knowledge about cardiovascular risk after menopause. The prevention of osteoporosis and coronary disease was associated with calcium and exercise; only in 1% with use of hormonals. It exists an acceptable level of information about climateric syndrome and postmenopausal osteoporosis in these women, but it is low for risk of cardiovascular disease. Probably, their information is got from the mass media communication and did not for the activities of medical institutions in health education.

  13. Airborne Bacterial Diversity from the Low Atmosphere of Greater Mexico City.

    Science.gov (United States)

    García-Mena, Jaime; Murugesan, Selvasankar; Pérez-Muñoz, Ashael Alfredo; García-Espitia, Matilde; Maya, Otoniel; Jacinto-Montiel, Monserrat; Monsalvo-Ponce, Giselle; Piña-Escobedo, Alberto; Domínguez-Malfavón, Lilianha; Gómez-Ramírez, Marlenne; Cervantes-González, Elsa; Núñez-Cardona, María Teresa

    2016-07-01

    Greater Mexico City is one of the largest urban centers in the world, with an estimated population by 2010 of more than 20 million inhabitants. In urban areas like this, biological material is present at all atmospheric levels including live bacteria. We sampled the low atmosphere in several surveys at different points by the gravity method on LB and blood agar media during winter, spring, summer, and autumn seasons in the years 2008, 2010, 2011, and 2012. The colonial phenotype on blood agar showed α, β, and γ hemolytic activities among the live collected bacteria. Genomic DNA was extracted and convenient V3 hypervariable region libraries of 16S rDNA gene were high-throughput sequenced. From the data analysis, Firmicutes, Proteobacteria, and Actinobacteria were the more abundant phyla in all surveys, while the genera from the family Enterobacteriaceae, in addition to Bacillus spp., Pseudomonas spp., Acinetobacter spp., Erwinia spp., Gluconacetobacter spp., Proteus spp., Exiguobacterium spp., and Staphylococcus spp. were also abundant. From this study, we conclude that it is possible to detect live airborne nonspore-forming bacteria in the low atmosphere of GMC, associated to the microbial cloud of its inhabitants.

  14. Active Shiga-like toxin produced by some Aeromonas spp., isolated in Mexico City

    Directory of Open Access Journals (Sweden)

    Ingrid Palma-Martínez

    2016-09-01

    Full Text Available Shiga-like toxins (Stx represent a group of bacterial toxins involved in human and animal diseases. Stx is produced by enterohemorrhagic Escherichia coli, Shigella dysenteriae type 1, Citrobacter freundii and Aeromonas spp. Stx is an important cause of bloody diarrhea and hemolytic uremic syndrome (HUS. The aim of this study was to identify the stx1/stx2 genes in clinical strains and in outer membrane vesicles (OMVs of Aeromonas spp., 66 strains were isolated from children who live in Mexico City and Shiga-like toxins effects were evaluated on Vero cell cultures.The capacity to express active, Stx1 and Stx2 toxins was determined on Vero cell cultures and the concentration of Shiga-like toxins was evaluated by lethal dose to 50% (LD50 assays, observing inhibition of damaged cells by specific monoclonal antibodies. The results obtained in this study support the hypothesis that the stx gene is another putative virulence factor of Aeromonas, and since this gene can be transferred horizontally through OMVs this genus should be included as a possible causal agents of gastroenteritis and it should be reported as part of standard health surveillance procedures.Furthermore, these results indicate that Aeromonas genus might be a potential causative agent of HUS.

  15. Intention to accept Bordetella pertussis booster vaccine during pregnancy in Mexico City.

    Science.gov (United States)

    Varan, Aiden Kennedy; Esteves-Jaramillo, Alejandra; Richardson, Vesta; Esparza-Aguilar, Marcelino; Cervantes-Powell, Patricia; Omer, Saad B

    2014-02-07

    Adult booster vaccination against pertussis can help prevent severe infections in young infants. We examined influences on intention to accept pertussis booster vaccination among pregnant women in Mexico City. We conducted a cross-sectional survey, recruiting convenience samples of pregnant women receiving prenatal care from three public healthcare centers between March and May 2012. Our primary outcome was intention to accept pertussis vaccination during pregnancy. We examined socio-demographic factors, vaccination history, pertussis knowledge, perceptions of vaccine information sources, and other potential influences on vaccine decision-making. A total of 402 pregnant women agreed to participate, of which 387 (96%) provided their intention to accept or decline pertussis vaccination. Among respondents, 57% intended to accept a pertussis booster vaccine if offered, but only 16% had ever heard of pertussis, and only 2% knew someone who had contracted this disease. Over 80% of respondents would accept pertussis vaccination if recommended by an obstetrician-gynecologist. The most frequently selected reasons to refuse pertussis vaccination were concerns that the vaccine might harm the unborn baby or pregnant woman. In multivariate analysis, rating doctors and nurses as good sources of vaccine information, and having ever heard of pertussis, were independently associated with intention to accept pertussis vaccination. Promoting patient awareness about pertussis disease and vaccine safety, and encouraging general practitioners, nurses and obstetricians to recommend pertussis booster vaccine, may increase vaccine uptake among pregnant women. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. 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)

  17. The Time Evolution of Aerosol Size Distribution Over the Mexico City Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Kleinman, Lawrence I.; Springston, Stephen R.; Wang, J. X.; Daum, Peter H.; Lee, Y.- N.; Nunnermacker, L. J.; Senum, Gunar; Weinstein-Lloyd, Judy; Alexander, M. L.; Hubbe, John M.; Ortega, John V.; Zaveri, Rahul A.; Canagaratna, Manjula R.; Jayne, J. T.

    2009-07-03

    As part of the MILAGRO field campaign, the DOE G-1 aircraft was used to make measurements over and downwind of Mexico City with the objective of determining growth characteristics of aerosols from a megacity urban source. This study focuses on number concentration and size distributions. It is found that a 5-fold increase in aerosol volume is accompanied by about a 5-fold increase in accumulation mode number concentration. There is growth in aerosol volume because there are more accumulation mode particles, not because particles are larger. Condensation and volume growth laws were examined to see whether either is consistent with observations. Condensation calculations show that the growth of Aitken mode particles into the accumulation mode size range gives the required increase in number concentration. There are minimal changes in the accumulation mode size distribution with age, consistent with observations. Volume-growth in contrast yields a population of large particles, distinctly different from what is observed. Detailed model calculations are required to translate our observations into specific information on the volatility and properties of secondary organic aerosol.

  18. 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.

  19. Primary lung cancer in Mexico city: a report of 1019 cases.

    Science.gov (United States)

    Medina, F M; Barrera, R R; Morales, J F; Echegoyen, R C; Chavarría, J G; Rebora, F T

    1996-06-01

    A retrospective study was performed in patients diagnosed with primary lung cancer, and admitted to the Instituto Nacional de Enfermedades Respiratorias between 1984 to 1992. One thousand and nineteen patients were studied, 636 males and 383 females. We found a higher incidence in the group among 61-70 years of age in both sexes. The highest percentage of tumors were from the adenocarcinoma variety, followed by the epidermoid carcinoma, while the small-cell carcinoma presented a lower incidence. Smoking has been associated with the development of lung cancer. Many of our patients were smokers. The highest frequency was in smokers with a smoking habit of more than 30 years and a rate of more than 10 cigarettes per day. However, an important part of the patients with cancer did not have a smoking habit, which led us to believe that there are other etiological possibility factors (genetic or environmental) that could be involved. Most of the cases of cancer were staged as stage IIIb and stage IV and the patients had an ECOG of 1-2. The main symptoms were coughing, sputum, dyspnea and thoracic pain. This data shows an increasing frequency of lung cancer in Mexico city as well as other countries, it also shows that it is going to be a serious health problem in the future. We consider that in order to improve the prognosis, it is necessary to increase the educational and orientation campaigns among the adult population with or without a smoking history.

  20. Variables associated with disordered eating behaviors among freshman students from Mexico City

    Directory of Open Access Journals (Sweden)

    Concepción Díaz de León-Vázquez

    2017-05-01

    Full Text Available Objective. To estimate the prevalence of disordered eating behaviors (DEB and identify their associations with demographic and psychological variables among freshman students at a public university in Mexico City. Materials and methods. A sample of 892 subjects participated in the study. Bivariate and multinomial models were performed to determine associations between DEB and covariates. Results. Of those surveyed, 6.8% of the women and 4.1% of the men exhibited DEB (p<0.05. The variables increasing the risk of eating disorders (ED for women were internal­ization of the aesthetic thin ideal (IATI, body mass index (BMI, self-esteem and physical activity, while for men they were IATI, drive for muscularity, and self-esteem. Conclu­sions. The frequency of DEB among women and men and the internalization of the thin ideal in both sexes suggest the possibility of a change in the precursor conditions for eating disorders, particularly for men, who exhibit increased risk of such behaviors.

  1. Application of high resolution geophysical prospecting to assess the risk related to subsurface deformationin Mexico City

    Directory of Open Access Journals (Sweden)

    F. A. Centeno-Salas

    2015-11-01

    Full Text Available In the eastern sector of Mexico City the sub soil consists of high contrasting sequences (lacustrine and volcanic inter bedded deposits that favor the development of erratic fracturing in the surface causing damage to the urban infrastructure. The high-resolution geophysical prospecting are useful tools for the assessment of ground deformation and fracturing associated with land subsidence phenomena. The GPR method allowed to evaluate the fracture propagation and deformation of vulcano-sedimentary sequences at different depths, the main electrical parameters are directly related with the gravimetric and volumetric water content and therefore with the plasticity of the near surface prospected sequences. The active seismology prospection consisted in a combination of Seismic Refraction (SR and Multichannel Analysis of Surface Waves (MASW for the estimation of the velocity of the mechanical compressive (P and the shear (S waves. The integration of both methods allowed to estimate the geomechanical parameters characterizing the studied sequence, the Poisson Ratio and the volumetric compressibility. The obtained mechanical parameters were correlated with laboratory measured parameters such as plasticity index, density, shear strength and compressibility and, GPR and seismic profiles were correlated with the mapped fracture systems in the study area. Once calibrated, the profiles allowed to identify the lithological contact between lacustrine and volcanic sequences, their variations of thicknesses in depth and to assess the deformation area in the surface. An accurate determination of the geometry of fracturing was of the most importance for the assessment of the geological risk in the study area.

  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. Air pollution, inflammation and preterm birth in Mexico City: study design and methods.

    Science.gov (United States)

    O'Neill, Marie S; Osornio-Vargas, Alvaro; Buxton, Miatta A; Sánchez, Brisa N; Rojas-Bracho, Leonora; Castillo-Castrejon, Marisol; Mordhukovich, Irina B; Brown, Daniel G; Vadillo-Ortega, Felipe

    2013-03-15

    Preterm birth is one of the leading causes of perinatal mortality and is associated with long-term adverse health consequences for surviving infants. Preterm birth rates are rising worldwide, and no effective means for prevention currently exists. Air pollution exposure may be a significant cause of prematurity, but many published studies lack the individual, clinical data needed to elucidate possible biological mechanisms mediating these epidemiological associations. This paper presents the design of a prospective study now underway to evaluate those mechanisms in a cohort of pregnant women residing in Mexico City. We address how air quality may act together with other factors to induce systemic inflammation and influence the duration of pregnancy. Data collection includes: biomarkers relevant to inflammation in cervico-vaginal exudate and peripheral blood, along with full clinical information, pro-inflammatory cytokine gene polymorphisms and air pollution data to evaluate spatial and temporal variability in air pollution exposure. Samples are collected on a monthly basis and participants are followed for the duration of pregnancy. The data will be used to evaluate whether ambient air pollution is associated with preterm birth, controlling for other risk factors. We will evaluate which time windows during pregnancy are most influential in the air pollution and preterm birth association. In addition, the epidemiological study will be complemented with a parallel toxicology invitro study, in which monocytic cells will be exposed to air particle samples to evaluate the expression of biomarkers of inflammation. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Heavy metal accumulation in plants and soil irrigated with wastewater from Mexico city

    Energy Technology Data Exchange (ETDEWEB)

    Mireles, A. E-mail: alibech_m@yahoo.com; Solis, C.; Andrade, E.; Lagunas-Solar, M.; Pina, C.; Flocchini, R.G

    2004-06-01

    Analysis by PIXE has been successfully employed in the study of environmental samples since it is possible to detect in a simple and fast way a high number of elements (heavier than Na) with a high sensitivity. In this work the PIXE method has been applied to study the extent of heavy metal contamination in soils and plants from Mixquiahuala, Hidalgo and Tlahuac, D.F. These two agricultural sites have been irrigated with wastewater from Mexico City for more than 50 years. The use of wastewater increased the crop productivity; however, in the areas irrigated for long periods of time, deterioration is now observed and only certain plant species can be grown. In this work, we present the range of variation that was observed for metals such as Fe, Cr, Co, Mn, Ni, Cu, Zn and Pb. Some of these elements were found at concentrations above the potentially hazardous levels in soils; however, they accumulated in plants to a lower extent, probably because of the physical and chemical properties of soils that prevent their translocation to plants.

  5. Attitudes and anticipated reactions to genetic testing for cancer among patients in Mexico City.

    Science.gov (United States)

    Romero-Hidalgo, Sandra; Urraca, Nora; Parra, Dionisio; Villa, Antonio R; Lisker, Rubén; Carnevale, Alessandra

    2009-08-01

    The aim of this study was to investigate the attitudes toward cancer predictive genetic testing in a group of non-high-risk women and men and to analyze the factors that may influence their intention to use these tests. We studied a sample of 859 outpatient women and men attending the four tertiary care hospitals of the ISSSTE (Institute of Social Security and Services for Government Employees) in Mexico City. Subjects between the ages of 30 and 74 years with no present or past history of cancer were asked to answer a questionnaire through face-to-face interview. Two different questionnaires were designed, one for women and the other for men, regarding genetic testing of a high-risk gene for breast and prostate cancer, respectively. Descriptive statistics and univariate comparisons were carried out using chi-square test, Wilcoxon's signed rank test, and Friedman test. Multivariate analysis was performed using logistic regression technique. Results showed that the majority of women attended clinics for regular check-ups and for performing screening tests to detect breast cancer, and men did not follow this pattern regarding prostate cancer. Women were more motivated to get genetic testing, more aware about its benefits, and more concerned about having cancer than men.

  6. Blood lead secular trend in a cohort of children in Mexico City. II. 1990-1995.

    Science.gov (United States)

    Rothenberg, S J; Schnaas, L; Perroni, E; Hernández, R M; Ortega, J F

    2000-01-01

    The authors determined the secular trend in blood lead levels in a cohort of 91 children born in Mexico City between 1987 and the beginning of 1993. The authors grouped children by calendar year in which they reached 36 mo of age (i.e., 1990-1995), and their blood lead levels were measured every 6 mo during a 66-mo period. The overall geometric mean blood lead level was 8.6 microg/dl (range = 1.0-61.0 microg/dl). A repeated measures analysis of variance revealed a significant downward linear trend in blood lead levels by year (p linear age effect (p pottery significantly elevated blood lead levels (p = .006), and the effect magnified as age increased (Age x Pottery Interaction [p = .014]). Although the overall downward trend in blood lead levels during the time period described corresponded to a reduction in various sources of lead exposure, there was no alteration in production, distribution, or use of leaded pottery. Currently, use of lead-glazed ceramic pottery is one of the most profound sources of lead exposure in the Mexican population.

  7. Fluoride Exposure Effects and Dental Fluorosis in Children in Mexico City.

    Science.gov (United States)

    Molina-Frechero, Nelly; Gaona, Enrique; Angulo, Marina; Sánchez Pérez, Leonor; González González, Rogelio; Nevarez Rascón, Martina; Bologna-Molina, Ronell

    2015-11-26

    BACKGROUND The objective of the present study was to determine the prevalence and severity of dental fluorosis and to evaluate exposure to fluoridated products in students in the southwest part of the Federal District (Mexico City). MATERIAL AND METHODS Students between 10 and 12 years of age who were born and raised in the study zone were evaluated. The level of dental fluorosis was determined using the modified Dean index (DI) using criteria recommended by the World Health Organization (WHO). A bivariate analysis was performed with the χ2 test, and odds ratios (OR) and 95% confidence intervals (CI) are presented. Logistic regression was performed to evaluate the association between dental fluorosis and the independent variables. RESULTS A total of 239 students were evaluated. Their mean age was 11±0.82 years, and there were 122 (51%) males. Overall, dental fluorosis was found in 59% of participants; 29.3% had very mild fluorosis, 20.9% had mild fluorosis, 6.7% had moderate fluorosis, and 2.1% had severe fluorosis. The mean fluorosis score was 0.887±0.956. In the final logistic regression model, dental fluorosis was significantly associated with frequency of brushing (OR: 0.444; 95% CI: 0.297-0.666) and with the absence of parental supervision (OR: 0.636; 95% CI: 0.525-0.771). CONCLUSIONS The association found with frequency of brushing and lack of parental supervision may be contributing to the prevalence and severity of dental fluorosis.

  8. Impact air quality by wildfire and agricultural fire in Mexico city 2015

    Science.gov (United States)

    Mendoza Campos, Alejandra; Agustín García Reynoso, José; Castro Romero, Telma Gloria; Carbajal Pérez, José Noel; Mar Morales, Bertha Eugenia; Gerardo Ruiz Suárez, Luis

    2016-04-01

    A forest fire is a large-scale process natural combustion where different types of flora and fauna of different sizes and ages are consumed. Consequently, forest fires are a potential source of large amounts of air pollutants that must be considered when trying to relate emissions to the air quality in neighboring cities of forest areas as in the Valley of Mexico. The size, intensity and occurrence of a forest fire directly dependent variables such as weather conditions, topography, vegetation type and its moisture content and the mass of fuel per hectare. An agricultural fire is a controlled combustion, which occurred a negligence can get out of control and increase the burned area or the possibly become a wildfire. Once a fire starts, the dry combustible material is consumed first. If the energy release is large and of sufficient duration, drying green material occurs live, with subsequent burning it. Under proper fuel and environmental conditions, this process can start a chain reaction. These events occur mainly in the dry season. Forest fires and agriculture fires contribute directly in the increase of carbon dioxide (CO2) into the atmosphere; The main pollutants emitted to the atmosphere by a wildfire are the PM10, PM2.5, NOx and VOC's, the consequences have by fire are deforestation, soil erosion or change of structure and composition of forests (Villers, 2006), also it affects ecosystems and the health of the population. In this study the impact of air quality for the emissions of particulate matter less than ten microns PM10, by wildfire and agricultural fire occurred on the same day and same place, the study was evaluated in Mexico City the Delegation Milpa Alta in the community of San Lorenzo Tlacoyucan, the fire occurred on 3rd March, 2015, the wildfire duration 12 hours consuming 32 hectares of oak forest and the agricultural fire duration 6 hours consumed 16 hectares of corn. To evaluate the impact of air quality the WRF-Chem, WRF-Fire and METv3

  9. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    Energy Technology Data Exchange (ETDEWEB)

    Apel, Eric; Emmons, L.; Karl, Thomas G.; Flocke, Frank M.; Hills, A. J.; Madronich, Sasha; Lee-Taylor, J.; Fried, Alan; Weibring, P.; Walega, J.; Richter, Dirk; Tie, X.; Mauldin, L.; Campos, Teresa; Weinheimer, Andrew J.; Knapp, David; Sive, B.; Kleinman, Lawrence I.; Springston, S.; Zaveri, Rahul A.; Ortega, John V.; Voss, Paul B.; Blake, D. R.; Baker, Angela K.; Warneke, Carsten; Welsh-Bon, Daniel; de Gouw, Joost A.; Zheng, J.; Zhang, Renyi; Rudolph, Jochen; Junkermann, W.; Riemer, D.

    2010-01-01

    The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to reproduce the general features of the daytime cycle of the VOC OH reactivity distribution showing that NMHCs dominate the distribution except in the afternoon hours and that the VOC OH reactivity peaks in the early morning due to high morning emissions from the city into a shallow boundary layer. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. In addition, a plume was studied in which air was advected out of the MCMA and intercepted downwind with the DOE G1 on March 18 and the NCAR C130 one day later on March 19. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind. Ozone and many OVOCs were photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial and temporal extent of the March 19 plume and to help interpret the OH

  10. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    Energy Technology Data Exchange (ETDEWEB)

    Apel, E.; Springston, S.; Karl, T.; Emmons, L.; Flocke, F.; Hills, A. J.; Madronich, S.; Lee-Taylor, J.; Fried, A.; Weibring, P.; Walega, J.; Richter, D., Tie, X.; Mauldin, L.; Campos, T.; Sive, B.; Kleinman, L.; Springston, S., Zaveri, R.; deGouw, J.; Zheng, J.; Zhang, R.; Rudolph, J.; Junkermann, W.; Riemer, D. D.

    2009-11-01

    The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to reproduce the general features of the daytime cycle of the VOC OH reactivity distribution showing that NMHCs dominate the distribution except in the afternoon hours and that the VOC OH reactivity peaks in the early morning due to high morning emissions from the city into a shallow boundary layer. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. In addition, a plume was studied in which air was advected out of the MCMA and intercepted downwind with the DOE G1 on 18 March and the NCAR C130 one day later on 19 March. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind. Ozone and many OVOCs were photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial and temporal extent of the 19 March plume and to help interpret the OH

  11. 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.

  12. Barriers to Integrating Mental Health Services in Community-Based Primary Care Settings in Mexico City: A Qualitative Analysis.

    Science.gov (United States)

    Martinez, William; Galván, Jorge; Saavedra, Nayelhi; Berenzon, Shoshana

    2017-05-01

    Despite the high prevalence of mental disorders in Mexico, minimal mental health services are available and there are large gaps in mental health treatment. Community-based primary care settings are often the first contact between patients and the health system and thus could serve as important settings for assessing and treating mental disorders. However, no formal assessment has been undertaken regarding the feasibility of implementing these services in Mexico. Before tools are developed to undertake such an assessment, a more nuanced understanding of the microprocesses affecting mental health service delivery must be acquired. A qualitative study used semistructured interviews to gather information from 25 staff in 19 community-based primary care clinics in Mexico City. Semistructured interviews were analyzed by using the meaning categorization method. In a second phase of coding, emerging themes were compared with an established typology of barriers to health care access. Primary care staff reported a number of significant barriers to implementing mental health services in primary care clinics, an already fragile and underfunded system. Barriers included the following broad thematic categories: service issues, language and cultural issues, care recipient characteristics, and issues with lack of knowledge. Results indicate that the implementation of mental health services in primary care clinics in Mexico will be difficult. However, the information in this study can help inform the integration of mental health into community-based primary care in Mexico through the development of adequate evaluative tools to assess the feasibility and progress of integrating these services.

  13. Exploratory Investigation of Concentrations of Total Gaseous Mercury in the Mexico City Metropolitan Area

    Science.gov (United States)

    Hernandez, S.; de La Rosa, D. A.; Márquez, C.; Solórzano, G.; Martínez, A.

    2004-12-01

    Total Gaseous Mercury (TGM) in ambient air at several locations within Mexico Valley Metropolitan Area (Zona Metropolitana del Valle de México, ZMVM, in Spanish) was measured during the Fall of 2002 and the first quarter of 2003. Among these locations were Tecamachalco (19°26'N; 99°13'W), San Agustín (19°31'N; 99°01'W), Xalostoc (19°31'N; 99°04'W) and Iztapalapa (19°21'N; 99°04'W). San Agustín and Xalostoc border the State of Mexico. Iztapalapa contains CENICA's monitoring station, and Mercury was one of the parameters measured here during the MCMA-2003 field campaign of the atmospheric chemistry taking place in ZMVM in April of 2003. This last site was used to monitor Mercury during three different seasons. The reported concentrations of Mercury vapor were measured continuously using cold vapor Atomic Fluorescence Spectroscopy (Tekran 2537A analyzer), with a detection limit of 0.10 ng·m-3 and a monitoring frequency of five minutes. The average TGM concentrations reported were 13.42, 10.22, 8.46 and 34.2 ng·m-3 for Iztapalapa in the months of September, October and November of 2002 and April of 2003 during the MCMA-2003 field campaign, respectively. For Tecamachalco, a concentration of 49.67 ng·m-3 was reported in January, 11.3 ng·m-3, for San Agustín in February and 31.99 ng·m-3 for Xalostoc in March of 2003.The daily maximums, 24 hourly average, for the same periods are 223.5, 78.2, 31.4 and 503.75 ng·m-3 for Iztapalapa, 118.62 ng·m-3 for Tecamachalco, 83.4 ng·m-3 for San Agustín and 261.2 ng·m-3 for Xalostoc. According to Ontario's air quality standards, the threshold value for mercury vapor in ambient air is 2 mg·m-3 on a 30 day average (Mercury situation in Canada, Report # 2, Environment Canada, May 2002). According to these criteria, then, the data reported for Mexico City are within the allowed limits for ambient air, but still 22 times higher than those reported as background concentrations at pristine locations (de la Rosa D

  14. 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

  15. Bio-climatic strategy for energy saving in corporative buildings. City Juarez, Chihuahua, Mexico; Estrategia bioclimatica para ahorro energetico en edificios corporativos. Ciudad Juarez, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Staines Orozco, E. R.

    2008-07-01

    Ciudad Juarez Chihuahua in Mexico is located in of de biggest Desert of Arid America called Chihuahuan Desert, and is there in where this border city with United State of North America and one of the border cities of greater commercial importance (a million six hundred thousands pop. approx.) has been develop to great influence of wasteful constructive systems of nonrenewable resources as they are the gas and electricity. These building take back surpassed models. In this article presents a design of a model of corporative building of five floors that counts including all a strategy from the process of architectonic design to the applications of echo passive and active Technologies (hybrid) like one of a ventilation tower, strategy that applied guarantees the significant saving to use energy. (Author)

  16. 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.

  17. 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

  18. Ambient Particulate Matter during MILAGRO in Mexico City: Main Findings, Impacts (on AQ and Climate), and Future Research Needs

    Science.gov (United States)

    Jimenez, Jose-Luis; Schauer, James J.; Molina, Luisa T.; MILAGRO Pm Team

    2010-05-01

    The MILAGRO campaign was a large international field experiments conduced in Mexico City and Central Mexico during March 2006. We present an overview of the main findings related to particulate matter and aerosol radiative properties. PM levels inside Mexico City were similar or higher than those in the most polluted North American cities, but ~5 times lower than levels in the most polluted Asian megacities During the study, PM10 and PM2.5 concentrations in the urban area of were about double the concentrations in the rural areas surrounding Mexico City. PM2.5 made up about half of the PM10 concentrations, with small amounts of mass in the PM2.5-PM1.0 range. Mineral matter made up approximately 25% of the PM10 and on average 15% and 28% of the PM2.5 in the urban and rural areas, respectively. Approximately 25% of the PM2.5 was secondary inorganic ions with the remaining PM2.5 mass being comprised of largely carbonaceous aerosol. Except for surface measurements at the central sampling sites in Mexico city, the elemental carbon mass absorption efficiency was relatively constant for aircraft and surface measurements throughout the study, contrary to expectations. Although different organic aerosol (OA) source apportionment methods had some differences, there was agreement that the dominant sources of carbonaceous aerosol were secondary OA (SOA), biomass burning, and mobile sources. The impact of biomass burning to the aerosol outflow from the region was much larger than to the surface concentrations inside the city. SOA formation from primary semivolatile and intermediate volatility precursors has the potential to close the gap in predicted vs. measured SOA, while formation from glyoxal also makes an important contribution, especially to organic oxygen. Biogenic SOA advected from the coastal mountain ranges contributes about 1 μg m-3 to concentrations in the MCMA. Primary OA from anthropogenic and biomass burning sources was found to be semivolatile, while secondary

  19. Aerosols upwind of Mexico City during the MILAGRO campaign: regional scale biomass burning, dust and volcanic ash from aircraft measurements

    Science.gov (United States)

    Junkermann, W.; Steinbrecher, R.

    2009-04-01

    During the MILAGRO Campaign March/April 2006 a series of aircraft flights with the FZK microlight D-MIFU were performed in the area southeast of Mexico City starting from Puebla airport, circling the national park area of Ixtachiuatl and Popocatepetl and scanning the Chalco valley down to Cuautla in the Cuernavaca province. All flights were combined with vertical profiles up to 4500 m a.s.l. in several locations, typically north of volcano Ixtachiuatl on the Puebla side, above Chalco or Tenago del Aire and south of volcano Popocatepetl, either at Cuautla or Atlixco. In Tenango del Aire a ceilometer was additionally operated continuously for characterization of the planetary boundary layer. The aircraft carried a set of aerosol instrumentation, fine and coarse particles and size distributions as well as a 7 wavelength aethalometer. Additionally meteorological parameters, temperature and dewpoint, global radiation and actinic radiation balance, respectively photolysis rates, and ozone concentrations were measured. The instrumentation allowed to characterize the aerosol according to their sources and also their impact on radiation transfer. Biomass burning aerosol, windblown dust and volcanic ash were identified within the upwind area of Mexico City with large differences between the dry season in the first weeks of the campaign and the by far cleaner situation after beginning thunderstorm activity towards the end of the campaign. Also the aerosol characteristics inside and outside the Mexico City basin were often completely different. With wind speeds of ~ 5 m/sec from southerly directions in the Chalco valley the aerosol mixture can reach the City within ~ 2 h. Rural aerosol mixtures from the Cuernavaca plain were mixed during the transport with dust from the MC basin. Very high intensity biomass burning plumes normally reached higher altitudes and produced pyrocumulus clouds. These aerosols were injected mainly into the free troposphere. Within the MC basin a large

  20. Trinational Library Forum Proceedings = Memorias [del] Foro Trinacional de Bibliotecas (5th, Mexico City, Mexico, February 23-25, 1995).

    Science.gov (United States)

    Instituto Tecnologico de Monterrey (Mexico).

    At the fifth Trinational Library Forum in 1995, 165 librarians from the United States, Canada, and Mexico gathered to discuss topics of international librarianship and exchanges, copyright regulations, and professional accreditation in information science. Presentations, with the full text in both English and Spanish, include: (1)…

  1. 78 FR 15341 - Auto Supply Chain Trade Mission to Mexico City and Monterrey, Mexico; September 23-26, 2013

    Science.gov (United States)

    2013-03-11

    ...). Mexican vehicle sales in 2012 increased 9 percent compared with 2011. Market realities have led to new trends in car manufacturing, including smaller car sizes and increased fuel efficiency. The aftermarket... manufacturing plants. Nissan, GM, Volkswagen, and Honda plan to increase their production in Mexico while Fiat...

  2. Evaluation of a Three-Dimensional Chemical Transport Model (PMCAMx) in the Mexico City Metropolitan Area

    Science.gov (United States)

    Tsimpidi, A. P.; Karydis, V. A.; Zavala, M.; Lei, W.; Molina, L. T.; Pandis, S. N.

    2007-05-01

    Atmospheric aerosols have adverse effects on human health, contribute to the visibility reduction and influence the energy balance of the planet. A three-dimensional chemical transport model (PMCAMx) (Gaydos et al., 2007) is used to simulate the particular matter (PM) mass composition distribution in the Mexico City Metropolitan Area (MCMA). PMCAMx uses the framework of CAMx (ENVIRON, 2002) modelling the processes of horizontal and vertical advection, horizontal and vertical dispersion, wet and dry deposition, and gas-phase chemistry. In addition to the above, PMCAMx includes three detailed aerosol modules: inorganic aerosol growth (Gaydos et al., 2003; Koo et al., 2003a), aqueous-phase chemistry (Fahey and Pandis, 2001), and secondary organic aerosol formation and growth (Koo et al., 2004). The aerosol thermodynamic model ISORROPIA has been improved as it now simulates explicitly the chemistry of Ca, Mg, and K salts and is linked to PMCAMx. The hybrid approach (Koo et al., 2003b) for modelling aerosol dynamics is applied in order to accurately simulate the inorganic components in coarse mode. This approach assumes that the smallest particles are in equilibrium while the condensation/evaporation equation is solved for the larger ones. The new CMU organic aerosol model, which is based on the splitting of the organic aerosol volatility range in discrete bins, is also used. The model predictions are evaluated against the PM and vapour concentration measurements from the MCMA-2003 Campaign (Molina et al., 2007). References Gaydos, T., Pinder, R., Koo, B., Fahey, Κ., Yarwood, G., and Pandis, S. N., (2007). Development and application of a three-dimensional Chemical Transport Model, PMCAMx. Atmospheric Environment, in press. ENVIRON (2002). User's guide to the comprehensive air quality model with extensions (CAMx). Version 3.10. Report prepared by ENVIRON International corporation, Novato, CA Gaydos, T., Koo, B., and Pandis, S. N., (2003). Development and application of

  3. Basic statistics of PM2.5 and PM10 in the atmosphere of Mexico City.

    Science.gov (United States)

    Vega, E; Reyes, E; Sánchez, G; Ortiz, E; Ruiz, M; Chow, J; Watson, J; Edgerton, S

    2002-03-27

    The high levels of fine particulate matter in Mexico City are of concern since they may induce severe public health effects as well as the attenuation of visible light. Sequential filter samplers were used at six different sites from 23 February to 22 March 1997. The sampling campaign was carried out as part of the project 'Investigación sobre Materia Particulada y Deterioro Atmosferico-Aerosol and Visibility Evaluation Research'. This research was a cooperative project sponsored by PEMEX and by the US Department of Energy. Sampling sites represent the different land uses along the city, the northwest station, Tlalnepantla, is located in a mixed medium income residential and industrial area. The northeast station, Xalostoc, is located in a highly industrialized area, Netzahualcoyotl is located in a mixed land use area, mainly commercial and residential. Station La Merced is located in the commercial and administrative district downtown. The southwest station is located in the Pedregal de San Angel, in a high-income neighborhood, and the southeast station located in Cerro de la Estrella is a mixed medium income residential and commercial area. Samples were collected four times a day in Cerro de la Estrella (CES), La Merced (MER) and Xalostoc (XAL) with sampling periods of 6 h. In Pedregal (PED), Tlalnepantla (TLA) and Netzahualcoyot1 (NEZ) sampling periods were every 24 h. In this paper the basic statistics of PM2.5 and PM10 mass concentrations are presented. The average results showed that 49, 61, 46, 57, 51 and 44% of the PM10 consisted of PM2.5 for CES, MER, XAL, PED, TLA and NEZ, respectively. The 24-h average highest concentrations of PM25 and PM10 were registered at NEZ (184 and 267 microg/m3) and the lowest at PED (22 and 39 microg/m3). The highest PM10 correlations were between XAL-CES (0.79), PED-TLA (0.80). In contrast, the highest PM2.5 correlations were between CES-PED (0.74), MER-CES (0.73) and TLA-PED (0.72), showing a lower correlation than the PM10

  4. Seasonal and diurnal trends in black carbon properties and co-pollutants in Mexico City

    Science.gov (United States)

    Retama, A.; Baumgardner, D.; Raga, G. B.; McMeeking, G. R.; Walker, J. W.

    2015-08-01

    The Mexico City metropolitan area (MCMA) is a region that continues to grow in population and vehicular traffic as well as being the largest source of short-lived climate pollutants (SLCP) in Latin America. The local city government has made significant progress in controlling some of these pollutants, i.e., ozone (O3) and carbon monoxide (CO), but particulate matter (PM2.5 and PM10) and black carbon (BC) have shown a less positive response to mitigation strategies that have been in place for almost 3 decades. For the first time, extended measurements of equivalent black carbon (eBC), derived from light absorption measurements, have been made using a Photoacoustic Extinctiometer (PAX) over a 13 month period from March 2013 through March 2014. The daily trends in workdays (Monday through Saturday) and Sunday eBC, PM2.5 and the co-pollutants CO, O3 and NOx are evaluated with respect to the three primary seasons in the MCMA: rainy, cold and dry and warm and dry. The maximum values in all of the particle and gas concentrations were significantly larger (Student's t test, P mixing of boundary layer and free tropospheric air by the formation of clouds that dilutes the concentration of the SLCPs, the decreased actinic flux that reduces the production of ozone by photochemical reactions and the heavy, almost daily rain that removes particulate matter. A significant "weekend effect" was also identified, particularly the decrease in BC due to fewer large transport vehicles that are fueled by diesel, which produces a large fraction of the BC. The other co-pollutant concentrations are also significantly less on weekends except for O3 that shows no change in maximum values from workdays to Sundays. This lack of change is a result of the balancing effects of lower precursor gases, i.e., VOCs, offset by lower concentrations of NOx, that is an O3 inhibitor. A comparison of the average maximum value of eBC measured during the 1 year period of the current study, with maximum values

  5. Seasonal trends in black carbon properties and co-pollutants in Mexico City

    Science.gov (United States)

    Retama, A.; Baumgardner, D.; Raga, G. B.; McMeeking, G. R.; Walker, J. W.

    2015-04-01

    The Mexico City Metropolitan Area (MCMA) is a region that continues to grow in population and vehicular traffic as well as being the largest source of short lived climate pollutants (SLCP) in Latin America. The local city government has made significant progress in controlling some of these pollutants, i.e. ozone (O3) and carbon monoxide (CO), but particulate matter (PM2.5 and PM10) and black carbon (BC) have shown little response to mitigation strategies that have been in place for more than two decades. For the first time, extended measurements have been made of equivalent black carbon (eBC), derived from light absorption measurements made with a Photoacoustic Extinctiometer (PAX), over a 13 month period from March 2013 through March 2014. The daily trends in workday (Monday through Saturday) and Sunday eBC, PM2.5 and the co-pollutants CO, O3 and NOx are evaluated with respect to the three primary seasons in that region: rainy, cold-dry and warm-dry. The maximum values in all of the particle and gas concentrations were significantly larger (Student's t test, Pmixing of boundary layer and free tropospheric air by the formation of clouds that dilutes the concentration of the SLCPs and the decreased actinic flux that reduces the production of ozone by photochemical reactions. A significant "weekend effect" was also identified, particularly the decrease in BC due to fewer large transport vehicles that are fueled by diesel that produces a large fraction of the BC emissions. The other co-pollutant concentrations are also significantly less on weekends except for O3 that shows no change in maximum values from workday to Sunday. As has been noted in previous studies, this lack of change is a result of the balancing effects of lower precursor gases, i.e. VOCs, offset by lower NOx that is an O3 inhibitor. A comparison of average, maximum values of eBC measured during the one year period of the current study with maximum values measured in short field campaigns in 2000 and

  6. Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

    Directory of Open Access Journals (Sweden)

    E. C. Apel

    2010-03-01

    Full Text Available The volatile organic compound (VOC distribution in the Mexico City Metropolitan Area (MCMA and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs but with a substantial contribution from oxygenated volatile organic compounds (OVOCs, predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry model and MOZART (Model for Ozone and Related chemical Tracers were able to approximate the observed MCMA daytime patterns and absolute values of the VOC OH reactivity. The MOZART model is also in agreement with observations showing that NMHCs dominate the reactivity distribution except in the afternoon hours. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height.

    A northeast transport event was studied in which air originating in the MCMA was intercepted aloft with the Department of Energy (DOE G1 on 18 March and downwind with the National Center for Atmospheric Research (NCAR C130 one day later on 19 March. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind; ozone was shown to be photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial extent and temporal evolution of the plume

  7. Neumonitis por hipersensibilidad en la ciudad de México Hypersensitivity pneumonitis in Mexico City

    Directory of Open Access Journals (Sweden)

    José G. Carrillo-Rodríguez

    2000-06-01

    Full Text Available OBJETIVO: Determinar la asociación entre la zona urbana de origen del paciente en la ciudad de México y la prevalencia de neumonitis por hipersensibilidad inducida por antígeno aviario. MATERIAL Y MÉTODOS: Se trata de un estudio de casos y controles realizado en el Instituto Nacional de Enfermedades Respiratorias, en la ciudad de México, en el año de 1999. Se estudiaron 109 casos con neumonitis por hipersensibilidad y 184 controles: de éstos, 39, con fibrosis pulmonar idiopática; 63, con tuberculosis pulmonar, y 82, con asma. La ciudad de México y las zonas conurbadas se dividieron en cinco zonas geográficas: centro, noreste, sureste, noroeste y el suroeste. Se calcularon las prevalencias de las diferentes enfermedades por zona urbana de los pacientes que participaron en el estudio; como medida de asociación, se estimó la razón de momios, con un intervalo de confianza al 95%. Asimismo, se realizó regresión logística múltiple ajustando por edad, sexo y estrato socioeconómico. RESULTADOS: Ochenta casos de neumonitis por hipersensibilidad se concentraron en el sur del noreste de las zonas conurbadas y la parte norte del sureste de la ciudad de México, 48 y 32, respectivamente (RM= 3.86, IC 95% 2.17-6.96. Treinta y seis controles de asma se localizaron en el suroeste de la ciudad de México, zona donde se ubica el Intituto Nacional de Enfermedades Respiratorias (pOBJECTIVE: To investigate the association between the urban area of origin of patients and the prevalence of hypersensitivity pneumonitis (HP, induced by avian antigens. MATERIAL AND METHODS: A case-control study was conducted in 1999 at the National Institute of Respiratory Diseases (NIRD. Cases were 109 consecutive HP patients and controls were 184 patients: 39 with idiopathic pulmonary fibrosis (IPF, 63 with pulmonary tuberculosis (PTB, and 82 with asthma. Mexico City and surrounding counties (SC were divided into 5 geographical areas: 1 Downtown; 2 North-East (NE; 3

  8. Prevalent HLA Class II Alleles in Mexico City Appear to Confer Resistance to the Development of Amebic Liver Abscess

    Science.gov (United States)

    Hernández, Eric G.; Granados, Julio; Partida-Rodríguez, Oswaldo; Valenzuela, Olivia; Rascón, Edgar; Magaña, Ulises; Escamilla-Tilch, Mónica; López-Reyes, Alberto; Nieves-Ramírez, Miriam; González, Enrique; Morán, Patricia; Rojas, Liliana; Valadez, Alicia; Luna, Alexandra; Estrada, Francisco J.; Maldonado, Carmen; Ximénez, Cecilia

    2015-01-01

    Amebiasis is an endemic disease and a public health problem throughout Mexico, although the incidence rates of amebic liver abscess (ALA) vary among the geographic regions of the country. Notably, incidence rates are high in the northwestern states (especially Sonora with a rate of 12.57/100,000 inhabitants) compared with the central region (Mexico City with a rate of 0.69/100,000 inhabitants). These data may be related to host genetic factors that are partially responsible for resistance or susceptibility. Therefore, we studied the association of the HLA-DRB1 and HLA-DQB1 alleles with resistance or susceptibility to ALA in two Mexican populations, one each from Mexico City and Sonora. Ninety ALA patients were clinically diagnosed by serology and sonography. Genomic DNA was extracted from peripheral blood mononuclear cells. To establish the genetic identity of both populations, 15 short tandem repeats (STRs) were analyzed with multiplexed PCR, and the allelic frequencies of HLA were studied by PCR-SSO using LUMINEX technology. The allele frequencies obtained were compared to an ethnically matched healthy control group (146 individuals). We observed that both affected populations differed genetically from the control group. We also found interesting trends in the population from Mexico City. HLA-DQB1*02 allele frequencies were higher in ALA patients compared to the control group (0.127 vs 0.047; p= 0.01; pc= NS; OR= 2.9, 95% CI= 1.09-8.3). The less frequent alleles in ALA patients were HLA-DRB1*08 (0.118 vs 0.238 in controls; p= 0.01; pc= NS; OR= 0.42, 95% CI= 0.19-0.87) and HLA-DQB1*04 (0.109 vs 0.214; p= 0.02; pc= NS; OR= 0.40, 95% CI= 0.20-0.94). The haplotype HLA-DRB1*08/-DQB1*04 also demonstrated a protective trend against the development of this disease (0.081 vs. 0.178; p=0.02; pc=NS; OR= 0.40, 95% CI= 0.16-0.93). These trends suggest that the prevalent alleles in the population of Mexico City may be associated with protection against the development of ALA

  9. Prevalent HLA Class II Alleles in Mexico City Appear to Confer Resistance to the Development of Amebic Liver Abscess.

    Directory of Open Access Journals (Sweden)

    Eric G Hernández

    Full Text Available Amebiasis is an endemic disease and a public health problem throughout Mexico, although the incidence rates of amebic liver abscess (ALA vary among the geographic regions of the country. Notably, incidence rates are high in the northwestern states (especially Sonora with a rate of 12.57/100,000 inhabitants compared with the central region (Mexico City with a rate of 0.69/100,000 inhabitants. These data may be related to host genetic factors that are partially responsible for resistance or susceptibility. Therefore, we studied the association of the HLA-DRB1 and HLA-DQB1 alleles with resistance or susceptibility to ALA in two Mexican populations, one each from Mexico City and Sonora. Ninety ALA patients were clinically diagnosed by serology and sonography. Genomic DNA was extracted from peripheral blood mononuclear cells. To establish the genetic identity of both populations, 15 short tandem repeats (STRs were analyzed with multiplexed PCR, and the allelic frequencies of HLA were studied by PCR-SSO using LUMINEX technology. The allele frequencies obtained were compared to an ethnically matched healthy control group (146 individuals. We observed that both affected populations differed genetically from the control group. We also found interesting trends in the population from Mexico City. HLA-DQB1*02 allele frequencies were higher in ALA patients compared to the control group (0.127 vs 0.047; p= 0.01; pc= NS; OR= 2.9, 95% CI= 1.09-8.3. The less frequent alleles in ALA patients were HLA-DRB1*08 (0.118 vs 0.238 in controls; p= 0.01; pc= NS; OR= 0.42, 95% CI= 0.19-0.87 and HLA-DQB1*04 (0.109 vs 0.214; p= 0.02; pc= NS; OR= 0.40, 95% CI= 0.20-0.94. The haplotype HLA-DRB1*08/-DQB1*04 also demonstrated a protective trend against the development of this disease (0.081 vs. 0.178; p=0.02; pc=NS; OR= 0.40, 95% CI= 0.16-0.93. These trends suggest that the prevalent alleles in the population of Mexico City may be associated with protection against the

  10. Identification of threatened areas of environmental value in the Conservation Area of Mexico City, and setting priorities for their protection

    Directory of Open Access Journals (Sweden)

    Zenia Saavedra

    2012-02-01

    Full Text Available Almost 60% of the Conservation Area of Mexico City is to the south within the Valley of Mexico; there is an extensive area of forests, scrub, wetlands, grasslands and agricultural zones. It is important for the city’s sustainability because of the environmental services provided such as aquifer recharge, carbon sequestration and biodiversity. It is being threatened by human activities despite a program of ecological regulation; this is partly because environmental problems are not always immediately visible to the government and general public in terms of the need for prompt action. The present study uses spatial evidence to identify and prioritize threatened environmentally valuable areas. Data from a variety of sources are combined, and information geo-referenced with Geographical Information Systems is verified in the field. The resultant maps show that the most threatened ecologically valuable areas are as follows: the oak wood and scrub relicts east of Milpa Alta; the forests west of Cuajimalpa, Álvaro Obregón and Magdalena Contreras; the forests of the Pelado and Malacatepec volcanoes in Tlalpan; and the forests of the Tláloc and Chichinautzin volcanoes in Milpa Alta. These results could be used by decision makers to design timely strategies to protect the Conservation Area and its supply of environmental services to Mexico City.

  11. 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.

  12. Vertical distribution of ozone and VOCs in the low boundary layer of Mexico City

    Directory of Open Access Journals (Sweden)

    E. Velasco

    2008-06-01

    Full Text Available The evolution of ozone (O3 and 13 volatile organic compounds (VOCs in the boundary layer of Mexico City was investigated during 2000–2004 to improve our understanding of the complex interactions between those trace gases and meteorological variables, and their influence on the air quality of a polluted megacity. A tethered balloon, fitted with electrochemical and meteorological sondes, was used to obtain detailed vertical profiles of O3 and meteorological parameters up to 1000 m above ground during part of the diurnal cycle (02:00–18:00 h. VOCs samples were collected up to 200 m by pumping air to canisters with a Teflon tube attached to the tether line. Overall, features of these profiles were found to be consistent with the formation of an upper residual layer during nighttime carrying over a fraction of the O3 from the previous day that contributes to the background concentration in surrounding regions. At the same time the release of heat stored in the urban surface forms a shallow unstable layer close to the ground, where the nocturnal emissions are trapped. After sunrise an O3 balance is determined by photochemical production, entrainment from the upper residual layer and destruction by titration with nitric oxide, delaying the ground-level O3 rise by 2 h. The subsequent evolution of the conductive boundary layer and vertical distribution of pollutants are discussed in terms of the energy balance, the presence of turbulence and the atmospheric stability.

  13. Aerosol Simulation in the Mexico City Metropolitan Area during MCMA2003 using CMAQ/Models3

    Science.gov (United States)

    Bei, N.; Zavala, M.; Lei, W.; de Foy, B.; Molina, L.

    2007-12-01

    CMAQ/Models3 has been employed to simulate the aerosol distribution and variation during the period from 13 to 16 April 2003 over the Mexico City Metropolitan Area as part of MCMA-2003 campaign. The meteorological fields are simulated using MM5, with three one-way nested grids with horizontal resolutions of 36, 12 and 3 km and 23 sigma levels in the vertical. MM5 3DVAR system has also been incorporated into the meteorological simulations. Chemical initial and boundary conditions are interpolated from the MOZART output. The SAPRC emission inventory is developed based on the official emission inventory for MCMA in 2004. The simulated mass concentrations of different aerosol compositions, such as elemental carbon (EC), primary organic aerosol (POA), secondary organic aerosol (SOA), nitrate, ammonium, and sulfate have been compared to the measurements taken at the National Center for Environmental Research and Training (Centro Nacional de Investigacion y Capacitacion Ambiental, CENICA) super-site. Hydrocarbon-like organic aerosol (HOA) and oxygenated organic aerosol (OOA) are used as observations of POA and SOA, respectively in this study. The preliminary model results show that the temporal evolutions of EC and POA are reasonable compared with measurements. The peak time of EC and POA are basically reproduced, thus validating the emission inventory and its processing through CMAQ/Models3. But the magnitude of EC and POA are underestimated over the entire episode. The modeled nitrate and ammonium concentrations are overestimated on most of the days. There is 1-2 hour difference between the simulated peak time of nitrate and ammonium aerosols compared to observations at CENICA. The simulated mass concentrations of SOA and sulfate are significantly underestimated. The reasons of the discrepancy between simulations and measurements are due to the uncertainties existing in the emission inventory, meteorological fields, and as well as aerosol formation mechanism in the case

  14. Mobile mini-DOAS measurement of the outflow of NO2 and HCHO from Mexico City

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    L. Molina

    2009-08-01

    Full Text Available We here present the results from mobile measurements using two ground-based zenith viewing Differential Optical Absorption Spectroscopy (DOAS instruments. The measurement was performed in a cross-section of the plume from the Mexico City Metropolitan Area (MCMA on 10 March 2006 as part of the MILAGRO field campaign. The two instruments operated in the UV and the visible wavelength region respectively and have been used to derive the differential vertical columns of HCHO and NO2 above the measurement route. This is the first time the mobile mini-DOAS instrument has been able to measure HCHO, one of the chemically most important and interesting gases in the polluted urban atmosphere. Using a mass-averaged wind speed and wind direction from the WRF model the instantaneous flux of HCHO and NO2 has been calculated from the measurements and the results are compared to the CAMx chemical model. The calculated flux through the measured cross-section was 1.9 (1.5–2.2 kg/s of HCHO and 4.4 (4.0–5.0 kg/s of NO2 using the UV instrument and 3.66 (3.63–3.73 kg/s of NO2 using the visible light instrument. The modeled values from CAMx for the outflow of both NO2 and HCHO, 1.1 and 3.6 kg/s, respectively, show a reasonable agreement with the measurement derived fluxes.

  15. Admixture in Mexico City: implications for admixture mapping of type 2 diabetes genetic risk factors.

    Science.gov (United States)

    Martinez-Marignac, Veronica L; Valladares, Adan; Cameron, Emily; Chan, Andrea; Perera, Arjuna; Globus-Goldberg, Rachel; Wacher, Niels; Kumate, Jesús; McKeigue, Paul; O'Donnell, David; Shriver, Mark D; Cruz, Miguel; Parra, Esteban J

    2007-02-01

    Admixture mapping is a recently developed method for identifying genetic risk factors involved in complex traits or diseases showing prevalence differences between major continental groups. Type 2 diabetes (T2D) is at least twice as prevalent in Native American populations as in populations of European ancestry, so admixture mapping is well suited to study the genetic basis of this complex disease. We have characterized the admixture proportions in a sample of 286 unrelated T2D patients and 275 controls from Mexico City and we discuss the implications of the results for admixture mapping studies. Admixture proportions were estimated using 69 autosomal ancestry-informative markers (AIMs). Maternal and paternal contributions were estimated from geographically informative mtDNA and Y-specific polymorphisms. The average proportions of Native American, European and, West African admixture were estimated as 65, 30, and 5%, respectively. The contributions of Native American ancestors to maternal and paternal lineages were estimated as 90 and 40%, respectively. In a logistic model with higher educational status as dependent variable, the odds ratio for higher educational status associated with an increase from 0 to 1 in European admixture proportions was 9.4 (95%, credible interval 3.8-22.6). This association of socioeconomic status with individual admixture proportion shows that genetic stratification in this population is paralleled, and possibly maintained, by socioeconomic stratification. The effective number of generations back to unadmixed ancestors was 6.7 (95% CI 5.7-8.0), from which we can estimate that genome-wide admixture mapping will require typing about 1,400 evenly distributed AIMs to localize genes underlying disease risk between populations of European and Native American ancestry. Sample sizes of about 2,000 cases will be required to detect any locus that contributes an ancestry risk ratio of at least 1.5.

  16. Obesity, eating behaviour and mental health among university students in Mexico City.

    Science.gov (United States)

    Lazarevich, Irina; Irigoyen-Camacho, María Esther; Velázquez-Alva, María del Consuelo

    2013-11-01

    Psychological factors are important in the development of obesity; however these are frequently underestimated in intervention programs. To examine the association of mental health with altered eating behavior related to weigh gain, and with abdominal obesity among college students in order to provide more comprehensive guidelines for intervention programs. A cross-sectional study was performed with 1,122 university students (from a total population of 1,820 freshmen students) at the Metropolitan Autonomous University, Mexico City. Body mass index and waist circumference (WC) were recorded. A six items questionnaire was applied to assess altered eating behavior. Self-reported questionnaires for depression (Beck Depression Inventory), anxiety (General Anxiety Disorder Scale of Carrol and Davidson), and impulsiveness symptoms (Plutchik Impulsivity Scale) were used. Multiple logistic regression models were performed. An increased WC was associated with depression symptoms (OR=1.4), female sex (OR=1.5), and age (OR=1.1). Students with altered eating behaviors showed elevated levels of impulsivity (e.g. have difficulties to stop eating, OR=4.2) and depression (e.g. have problem to eat at regular times, OR=6.98). In addition, higher WC was associated with female sex, parents' obesity, and unhealthy eating behaviors (e.g. have difficulties to stop eating, OR=1.42; and constantly feel hungry, and eat too much, OR=2.25). Although preventive programs directed at development of adequate eating habits and physical activity are considered a key component of intervention programs, strategies for the management of emotions, the promotion of positive mood and impulsivity-reduction techniques are a necessary complement for a comprehensive approach to overweight and obesity. Copyright AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

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

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    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

  18. Land subsidence in major cities of Central Mexico: Interpreting InSAR-derived land subsidence mapping with hydrogeological data

    Science.gov (United States)

    Castellazzi, Pascal; Arroyo-Domínguez, Norma; Martel, Richard; Calderhead, Angus I.; Normand, Jonathan C. L.; Gárfias, Jaime; Rivera, Alfonso

    2016-05-01

    Significant structural damages to urban infrastructures caused by compaction of over-exploited aquifers are an important problem in Central Mexico. While the case of Mexico City has been well-documented, insight into land subsidence problems in other cities of Central Mexico is still limited. Among the cities concerned, we present and discuss the cases of five of them, located within the Trans-Mexican Volcanic Belt (TMVB): Toluca, Celaya, Aguascalientes, Morelia, and Queretaro. Applying the SBAS-InSAR method to C-Band RADARSAT-2 data, five high resolution ground motion time-series were produced to monitor the spatio-temporal variations of displacements and fracturing from 2012 to 2014. The study presents recent changes of land subsidence rates along with concordant geological and water data. It aims to provide suggestions to mitigate future damages to infrastructure and to assist in groundwater resources management. Aguascalientes, Celaya, Morelia and Queretaro (respectively in order of decreasing subsidence rates) are typical cases of fault-limited land subsidence of Central Mexico. It occurs as a result of groundwater over-exploitation in lacustrine and alluvial deposits covering highly variable bedrock topography, typical of horst-graben geological settings. Aguascalientes and Toluca show high rates of land subsidence (up to 10 cm/yr), while Celaya and Morelia show lower rates (from 2 to 5 cm/yr). Comparing these results with previous studies, it is inferred that the spatial patterns of land subsidence have changed in the city of Toluca. This change appears to be mainly controlled by the spatial heterogeneity of compressible sediments since no noticeable change occurred in groundwater extraction and related drawdown rates. While land subsidence of up to 8 cm/yr has been reported in the Queretaro Valley before 2011, rates inferior to 1 cm/yr are measured in 2013-2014. The subsidence has been almost entirely mitigated by major changes in the water management

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

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    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%.

  20. 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.

  1. Prevalence and correlates of client-perpetrated abuse among female sex workers in two Mexico-U.S. border cities.

    Science.gov (United States)

    Ulibarri, Monica D; Strathdee, Steffanie A; Lozada, Remedios; Magis-Rodriguez, Carlos; Amaro, Hortensia; O'Campo, Patricia; Patterson, Thomas L

    2014-04-01

    History of abuse has been associated with greater HIV risk among women. This study examined client-perpetrated abuse among female sex workers (FSWs) in two Mexico-U.S. border cities where HIV prevalence is rising. Among 924 FSWs, prevalence of client-perpetrated abuse was 31%. In multivariate logistic regression models, intimate partner violence (IPV), psychological distress, and having drug-using clients were associated with experiencing client-perpetrated abuse. FSWs along the Mexico-U.S. border report frequently experiencing abuse from both clients and intimate partners, which may have serious mental health consequences. Our findings suggest the need for screening and gender-based violence prevention services for Mexican FSWs.

  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. 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.

  4. Of Lady-killers and ‘Men Dressed As Women’: Soap Opera, Scapegoats and the Mexico City Police Department

    OpenAIRE

    Vek Lewis

    2008-01-01

    Over two days in October 2005, police in Mexico City conducted a series of raids on male-to-female transgender (travesti) prostitutes working in the streets. The motive of the investigation was not related to sex work at all, but rather, the hunt for a serial killer responsible for the deaths of elderly women between 2003 and 2005. With few leads apart from reports by a couple of eyewitnesses that they had seen ‘a man dressed as a woman’ enter the houses of the victims, the Chief Public Prose...

  5. Exploring migratory dynamics on HIV transmission: the case of Mexicans in New York City and Puebla, Mexico.

    Science.gov (United States)

    Ruiz, Yumary; Guilamo-Ramos, Vincent; McCarthy, Katharine; Muñoz-Laboy, Miguel A; de Lourdes Rosas López, Maria

    2014-06-01

    Migration and population movement are increasingly viewed as important factors associated with HIV transmission risk. With growing awareness of the potential impact of migration on HIV transmission, several perspectives have emerged that posit differing dynamics of risk. We considered available data on the role of migration on HIV transmission among Mexican migrants in New York City and Puebla, Mexico. Specifically, we examined 3 distinct models of migratory dynamics of HIV transmission-namely, the structural model, the local contextual model, and the interplay model. In doing so, we reframed current public health perspectives on the role of migration on HIV transmission.

  6. Caries dental en escolares del Distrito Federal Dental caries in school children in Mexico City

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    MARÍA ESTHER IRIGOYEN-CAMACHO

    1997-03-01

    Full Text Available Objetivo. Presentar las estimaciones de la prevalencia y la severidad de caries dental, así como las necesidades de tratamiento de la población escolar del Distrito Federal examinada en la encuesta de caries dental que se llevó a cabo en 1988 con la finalidad de obtener datos basales sobre caries en los escolares al inicio del Programa Nacional de Fluoruración de la Sal en México. Material y métodos. La población de estudio fue seleccionada empleando un marco muestral basado en el listado de las escuelas primarias y los jardines de niños registrados por la Secretaría de Educación Pública en 1988. En el examen de la cavidad bucal de los escolares se utilizaron los criterios diagnósticos señalados por la Organización Mundial de la Salud. Resultados. Un total de 4 475 escolares de 5 a 12 años de edad participaron en el estudio. La prevalencia de caries dental en la población alcanzó 90.5%. El índice de necesidades de tratamiento fue elevado (79.6%. El promedio de los índices de caries en los escolares de 12 años de edad fue CPOD= 4.42 (desviación estándar –DE– 3.2 y CPOS= 6.53 (DE 4.8. Conclusiones. Los resultados de la encuesta subrayan la pertinencia de un programa preventivo de amplia cobertura, como el de fluoruración de la sal. Además, muestran que se requiere elaborar estrategias para mejorar el acceso de la población escolar a los servicios odontológicos del sistema de salud en México.Objective. To estimate the prevalence and severity of dental caries and the dental treatment necessities of school children in Mexico City. The studied population was surveyed for dental caries in 1988 to obtain data necessary for the National Program of Salt Fluoridation in Mexico. Material and methods. The population was selected with a sample frame based on a list of Kindergardens and primary schools registered at the Ministry of Public Education in 1988. The oral cavity examination was based on diagnostic criteria marked by the

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

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    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

  8. Mexico.

    Science.gov (United States)

    1988-02-01

    Focus in this discussion of Mexico is on the following: geography; the people; history; political conditions; the economy; foreign relations; and relations between the US and Mexico. As of July 1987, the population of Mexico numbered 81.9 million with an estimated annual growth rate of 2.09%. 60% of the population is Indian-Spanish (mestizo), 30% American Indian, 9% white, and 1% other. Mexico is the most populous Spanish-speaking country in the world and the 2nd most populous country in Latin America. Education is decentralized and expanded. Mexico's topography ranges from low desert plains and jungle-like coastal strips to high plateaus and rugged mountains. Hernan Cortes conquered Mexico in 1919-21 and founded a Spanish colony that lasted for almost 300 years. Independence from Spain was proclaimed by Father Miguel Hidalgo on September 16, 1810; the republic was established on December 6, 1822. Mexico's constitution of 1917 provides for a federal republic with a separation of powers into independent executive, legislative, and judicial branches of government. Significant political themes of the administration of President Miguel de la Madrid Hurtado, who began his 6-year term in 1982, have been restructuring the economy, liberalizing trade practices, decentralizing government services, and eliminating corruption among public servants. In 1987, estimates put the real growth of the Mexican economy at 1.5%; the gross domestic product (GDP) had shrunk by 3.5% in 1986. Yet, on the positive side, Mexico's international reserves increased to record levels in 1987 (to about $15 billion), and its current account surplus reached more than $3 billion. Mexico has made considerable progress in moving to restructure its economy. It has substantially reduced impediments to international trade and has moved to reduce the number of parastatal firms. 1987 was the 2nd consecutive year in which Mexico recorded triple-digit inflation; inflation reached 158.8%. Other problems include

  9. Cultures of space and collective and participative artistic processes. recent cases in mexico city, bogota and medellin

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    Fernando Escobar Neira

    2012-06-01

    Full Text Available this article covers different aspects related to the spacialization of some cases of collective and participative artistic practices in specific places of three latin american cities: mexico city, bogota and medellin. therefore, the article questions the presence of different social ideologies and representations concerning the artistic field in its local and global dimensions, which establish meanings for the artistic, the political and social matters and, at the same time, fight among themselves when associating with certain contemporary artistic practices and its agents and institutions. in order to do so, it is proposed a focus that, to a certain extent, is separated from art theory and history, placing itself in a constant to and fro movement between the assumptions of artistic practices and social sciences.

  10. VOC Signatures at Selected Urban Sites in Mexico City during the MCMA 2002 and 2003 Field Campaigns

    Science.gov (United States)

    Velasco, E.; Lamb, B.; Allwine, E.; Pressley, S.; Westberg, H.

    2004-12-01

    During the MCMA 2002 and 2003 field campaigns, ambient VOC concentrations were measured using automated canister sampling methods at several urban sites within Mexico City. These data, along with previously reported measurements, are examined in terms of the similarities and differences that exist for locations near the urban core, in heavily industrial areas, and at downwind urban receptor sites. Data are also compared to similar measurements for US cities. The use of ratios of compounds at different locations is valuable for highlighting the effects of dilution versus chemical aging during transport from sources to receptors. These ratios can also be used to demonstrate the effects of local industrial sources on the VOC distribution at selected locations.

  11. Anthropological Approaches to the Study of Housing Areas: Lessons from Oaxaca City, Mexico.

    Science.gov (United States)

    Murphy, Arthur D.

    The anthropological study of the city's role in the evolution of human systems requires the use of both macro and micro levels of analysis. From the macro perspective, the city is viewed as part of a wider complex society, while from the micro point of view, the city provides the context for understanding specific human institutions or processes…

  12. Emission factors of black carbon and co-pollutants from diesel vehicles in Mexico City

    Science.gov (United States)

    Zavala, Miguel; Molina, Luisa T.; Yacovitch, Tara I.; Fortner, Edward C.; Roscioli, Joseph R.; Floerchinger, Cody; Herndon, Scott C.; Kolb, Charles E.; Knighton, Walter B.; Paramo, Victor Hugo; Zirath, Sergio; Mejía, José Antonio; Jazcilevich, Aron

    2017-12-01

    Diesel-powered vehicles are intensively used in urban areas for transporting goods and people but can substantially contribute to high emissions of black carbon (BC), organic carbon (OC), and other gaseous pollutants. Strategies aimed at controlling mobile emissions sources thus have the potential to improve air quality and help mitigate the impacts of air pollutants on climate, ecosystems, and human health. However, in developing countries there are limited data on the BC and OC emission characteristics of diesel-powered vehicles, and thus there are large uncertainties in the estimation of the emission contributions from these sources. We measured BC, OC, and other inorganic components of fine particulate matter (PM), as well as carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), ethane, acetylene, benzene, toluene, and C2-benzenes under real-world driving conditions for 20 diesel-powered vehicles encompassing multiple emission level technologies in Mexico City with the chasing technique using the Aerodyne mobile laboratory. Average BC emission factors ranged from 0.41-2.48 g kg-1 of fuel depending on vehicle type. The vehicles were also simultaneously measured using the cross-road remote sensing technique to obtain the emission factors of nitrogen oxide (NO), CO, total hydrocarbons, and fine PM, thus allowing for the intercomparison of the results from the two techniques. There is overall good agreement between the two techniques and both can identify high and low emitters, but substantial differences were found in some of the vehicles, probably due to the ability of the chasing technique to capture a larger diversity of driving conditions in comparison to the remote sensing technique. A comparison of the results with the US EPA MOVES2014b model showed that the model underestimates CO, OC, and selected VOC species, whereas there is better agreement for NOx and BC. Larger OC / BC ratios were found in comparison to ratios measured in California using

  13. Risk of Giardia intestinalis infection in children from an artificially recharged groundwater area in Mexico City.

    Science.gov (United States)

    Cifuentes, Enrique; Suárez, Leticia; Espinosa, Martha; Juárez-Figueroa, Luis; Martínez-Palomo, Adolfo

    2004-07-01

    The objective of this study was to assess the risk of infection with Giardia intestinalis in children living in an area with artificial groundwater recharge and potable water reuse in Mexico City. Eligible wells and surrounding homesteads were defined by using a geographic information system. Five wells were tested for G. intestinalis cysts per 400 liters of water. A total of 750 eligible households were visited during two cross-sectional surveys. Stool samples were provided by 986 children in the rainy season study and 928 children during the dry season survey for parasitologic tests. Their guardians provided information on water, sanitation, hygiene, and socioeconomic variables. The prevalence rates of G. intestinalis infection were 9.4% in the rainy season and 4.4% in the dry season. Higher rates of infection were observed in older individuals (9.5% and 10.6%) and girls had a lower risk of infection than boys (odds ratio [OR] =0.55, 95% confidence interval [CI] = 0.34, 0.88 in the rainy season and OR = 0.47, 95% CI = 0.25, 0.90 in the dry season). During the wet season survey, a health risk was detected among those storing water in unprotected receptacles (OR = 4.00, 4.69, and 5.34 for those using uncovered jars, cisterns or tanks, and buckets, respectively), and bathing outside the dwelling, i.e., using a tap (OR = 1.93, 95% CI = 1.10, 3.39). A health risk was also detected among children from households with unsafe food hygiene practices (OR =2.41, 95% CI =1.10, 5.30) and those with no hand-washing habits (OR = 2.27, 95% CI = 1.00, 5.20). Groundwater reserves are at risk of fecal pollution, as indicated by the presence of G. intestinalis cysts. However, the endemic pattern of intestinal infection reflects low standards of personal hygiene and unsafe drinking water storage and food-related practices at household level. Prevention activities must address health education and environmental protection policies.

  14. Concentrations and properties of airborne particles in the Mexico City subway system

    Science.gov (United States)

    Mugica-Álvarez, V.; Figueroa-Lara, J.; Romero-Romo, M.; Sepúlveda-Sánchez, J.; López-Moreno, T.

    2012-03-01

    Samples of PM10 and PM2.5 were collected using High Vol and MiniVol devices on the platform of a subway station in Mexico City and in an outdoor location close to it, using such devices. Soluble extractable organic matter (SEOM) and water solubility of metals were determined. Elemental composition and solubility of trace metals were determined and individual aerosol particles were studied with scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX). The concentration levels in both sizes were similar during all days with the exception of weekends, especially on Sunday when activity decreases due to lower trains' frequency. The largest particles concentrations in the subway were found from 06:00 to 14:00 and the lowest concentrations were registered from 22:00 to 06:00. Concentrations of PM2.5 ranging between 60 μg m-3 and 93 μg m-3 (10% and 90% percentile) in the subway were 6% larger than outside, whereas PM10 were 20% larger than outside ranging from 88 μg m-3 to 145 μg m-3. Greater Fe, Cu, Ni, Cr and Mn concentrations were quantified in the subway samples as compared to the airborne particles by up to 2.5, 9, 1.8, 2.0 and 2.6 times, respectively. Even when the solubility percent of these metals in the subway PM was smaller than in the outdoor airborne particles, metals' concentrations were greater. SEM and EDS exhibit the presence of many individual particles with a large metal content in the subway samples. Correlation analysis showed the influence of outdoor PM in the subway aerosols, but characterization revealed also important differences in the presence of metals and SEOM, due to underground sources such as friction, brake system, and metals from sparking. This means that a large number of commuters are exposed during labor days to large toxic metals concentrations as they transit.

  15. Modeled and observed ozone sensitivity to mobile-source emissions in Mexico City

    Directory of Open Access Journals (Sweden)

    M. Zavala

    2009-01-01

    Full Text Available The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies and improvements in fuel quality, among others. Along with these changes, concurrent non-linear changes in photochemical levels and criteria pollutants have been observed, providing a unique opportunity to understand the effects of perturbations of mobile emission levels on the photochemistry in the region using observational and modeling approaches. The observed historical trends of ozone (O3, carbon monoxide (CO and nitrogen oxides (NOx suggest that ozone production in the MCMA has changed from a low to a high VOC-sensitive regime over a period of 20 years. Comparison of the historical emission trends of CO, NOx and hydrocarbons derived from mobile-source emission studies in the MCMA from 1991 to 2006 with the trends of the concentrations of CO, NOx, and the CO/NOx ratio during peak traffic hours also indicates that fuel-based fleet average emission factors have significantly decreased for CO and VOCs during this period whereas NOx emission factors do not show any strong trend, effectively reducing the ambient VOC/NOx ratio.

    This study presents the results of model analyses on the sensitivity of the observed ozone levels to the estimated historical changes in its precursors. The model sensitivity analyses used a well-validated base case simulation of a high pollution episode in the MCMA with the mathematical Decoupled Direct Method (DDM and the standard Brute Force Method (BFM in the 3-D CAMx chemical transport model. The model reproduces adequately the observed historical trends and current photochemical levels. Comparison of the BFM and the DDM sensitivity techniques indicates that the model yields ozone values that increase linearly with

  16. Exposure of children to air pollution in the industrial zone of Metropolitan Area of Mexico City

    Science.gov (United States)

    Mugica-Alvarez, Violeta; Quintanilla-Vega, Betsabé; De Vizcaya-Ruiz, Andrea; Alvarado-Cruz, Isabel

    2016-04-01

    An air quality monitoring in three schools located in the most important industrial zone at the Northeast of the Metropolitan Area of Mexico City (MAMC) was conducted in order to determine the exposure of children to toxics contained in PM10. Particles were analyzed for metals, polycyclic aromatic hydrocarbons (PAH), organic and elemental carbon by ICP-AES, GC-MS and TOT (Sunset lab) respectively. Average concentration of PM10 was 108.4±11.6 μg/m3. Most abundant metals were Fe, Zn and Pb with concentrations ranged by 1.1-5.4 μg/m3, 0.3-2 μg/m3, and 0.18-0.63 μg/m3 respectively; the sum of the seventeen PAHs varied from 1.4 to 3.3 ng/m3 where most abundant PAH were indene[1,2,3-c,d]pyrene, benzo[b]fluoranthene, benzo[a]anthracene, chrysene, and benzo[a]pyrene. The sum of the seven carcinogenic PAH contributed in average with the 48% of the total mixture. Carcinogenic potential of PAH were obtained using toxic equivalent factors determined by Nisbet and La Goy which varied from 0.3 to 0.6 ng/ m3 of benzo[a]pyrene equivalent (BAPeq), this value is lower than the standard proposed for the European Community of 1 ng/ m3, but higher than the standard from the United Kingdom of 0.25 ng/ m3. Principal component analysis for source apportionment showed that vehicular and industrial emissions are the main sources of PM in the zone. In general, the concentrations of particles as well as concentration of metals and PAHs are lower than concentrations measured six year before, showing that the established measures have improved the air quality. Nevertheless these PM10 concentrations exceeded frequently the Mexican Standard and children are especially susceptible due to the higher risk to develop diseases if the exposure occurs at early age.

  17. Emission factors of black carbon and co-pollutants from diesel vehicles in Mexico City

    Directory of Open Access Journals (Sweden)

    M. Zavala

    2017-12-01

    Full Text Available Diesel-powered vehicles are intensively used in urban areas for transporting goods and people but can substantially contribute to high emissions of black carbon (BC, organic carbon (OC, and other gaseous pollutants. Strategies aimed at controlling mobile emissions sources thus have the potential to improve air quality and help mitigate the impacts of air pollutants on climate, ecosystems, and human health. However, in developing countries there are limited data on the BC and OC emission characteristics of diesel-powered vehicles, and thus there are large uncertainties in the estimation of the emission contributions from these sources. We measured BC, OC, and other inorganic components of fine particulate matter (PM, as well as carbon monoxide (CO, nitrogen oxides (NOx, sulfur dioxide (SO2, ethane, acetylene, benzene, toluene, and C2-benzenes under real-world driving conditions for 20 diesel-powered vehicles encompassing multiple emission level technologies in Mexico City with the chasing technique using the Aerodyne mobile laboratory. Average BC emission factors ranged from 0.41–2.48 g kg−1 of fuel depending on vehicle type. The vehicles were also simultaneously measured using the cross-road remote sensing technique to obtain the emission factors of nitrogen oxide (NO, CO, total hydrocarbons, and fine PM, thus allowing for the intercomparison of the results from the two techniques. There is overall good agreement between the two techniques and both can identify high and low emitters, but substantial differences were found in some of the vehicles, probably due to the ability of the chasing technique to capture a larger diversity of driving conditions in comparison to the remote sensing technique. A comparison of the results with the US EPA MOVES2014b model showed that the model underestimates CO, OC, and selected VOC species, whereas there is better agreement for NOx and BC. Larger OC / BC ratios were found in comparison to ratios

  18. Oxidative capacity of the Mexico City atmosphere – Part 2: A ROx radical cycling perspective

    Directory of Open Access Journals (Sweden)

    M. J. Molina

    2010-07-01

    Full Text Available A box model using measurements from the Mexico City Metropolitan Area study in the spring of 2003 (MCMA-2003 is presented to study oxidative capacity (our ability to predict OH radicals and ROx (ROx=OH+HO2+RO2+RO radical cycling in a polluted (i.e., very high NOx=NO+NO2 atmosphere. Model simulations were performed using the Master Chemical Mechanism (MCMv3.1 constrained with 10 min averaged measurements of major radical sources (i.e., HCHO, HONO, O3, CHOCHO, etc., radical sink precursors (i.e., NO, NO2, SO2, CO, and 102 volatile organic compounds (VOC, meteorological parameters (temperature, pressure, water vapor concentration, dilution, and photolysis frequencies. Modeled HOx (=OH+HO2 concentrations compare favorably with measured concentrations for most of the day; however, the model under-predicts the concentrations of radicals in the early morning. This "missing reactivity" is highest during peak photochemical activity, and is least visible in a direct comparison of HOx radical concentrations. We conclude that the most likely scenario to reconcile model predictions with observations is the existence of a currently unidentified additional source for RO2 radicals, in combination with an additional sink for HO2 radicals that does not form OH. The true uncertainty due to "missing reactivity" is apparent in parameters like chain length. We present a first attempt to calculate chain length rigorously i.e., we define two parameters that account for atmospheric complexity, and are based on (1 radical initiation, n(OH, and (2 radical termination, ω. We find very high values of n(OH in the early morning are incompatible with our current understanding of ROx termination routes. We also observe missing reactivity in the rate of ozone production (P(O3. For example, the integral amount of ozone produced could be under-predicted by a factor of two. We argue that this uncertainty is partly accounted for in lumped chemical codes that are optimized to

  19. Oxidative capacity of the Mexico City atmosphere - Part 2: A ROx radical cycling perspective

    Science.gov (United States)

    Sheehy, P. M.; Volkamer, R.; Molina, L. T.; Molina, M. J.

    2010-07-01

    A box model using measurements from the Mexico City Metropolitan Area study in the spring of 2003 (MCMA-2003) is presented to study oxidative capacity (our ability to predict OH radicals) and ROx (ROx=OH+HO2+RO2+RO) radical cycling in a polluted (i.e., very high NOx=NO+NO2) atmosphere. Model simulations were performed using the Master Chemical Mechanism (MCMv3.1) constrained with 10 min averaged measurements of major radical sources (i.e., HCHO, HONO, O3, CHOCHO, etc.), radical sink precursors (i.e., NO, NO2, SO2, CO, and 102 volatile organic compounds (VOC)), meteorological parameters (temperature, pressure, water vapor concentration, dilution), and photolysis frequencies. Modeled HOx (=OH+HO2) concentrations compare favorably with measured concentrations for most of the day; however, the model under-predicts the concentrations of radicals in the early morning. This "missing reactivity" is highest during peak photochemical activity, and is least visible in a direct comparison of HOx radical concentrations. We conclude that the most likely scenario to reconcile model predictions with observations is the existence of a currently unidentified additional source for RO2 radicals, in combination with an additional sink for HO2 radicals that does not form OH. The true uncertainty due to "missing reactivity" is apparent in parameters like chain length. We present a first attempt to calculate chain length rigorously i.e., we define two parameters that account for atmospheric complexity, and are based on (1) radical initiation, n(OH), and (2) radical termination, ω. We find very high values of n(OH) in the early morning are incompatible with our current understanding of ROx termination routes. We also observe missing reactivity in the rate of ozone production (P(O3)). For example, the integral amount of ozone produced could be under-predicted by a factor of two. We argue that this uncertainty is partly accounted for in lumped chemical codes that are optimized to predict

  20. Family context and individual situation of teens before, during and after pregnancy in Mexico City.

    Science.gov (United States)

    Sámano, Reyna; Martínez-Rojano, Hugo; Robichaux, David; Rodríguez-Ventura, Ana Lilia; Sánchez-Jiménez, Bernarda; de la Luz Hoyuela, Maria; Godínez, Estela; Segovia, Selene

    2017-11-16

    In the last 20 years, adolescent pregnancy has become one of the most critical problems affecting women in Latin America and the Caribbean. This qualitative study was based on in-depth interviews with 29 teen mothers. All of the pregnant teens were from low- to lower-middle-class social strata in the Mexico City metropolitan area. The family (living with the girl) and the individual context of pregnant teens were analysed on the basis of data from at least three interviews: during pregnancy and at approximately 6 and 24 months following delivery. Additionally, six mothers, four fathers, and four partners of the pregnant girls of the group were interviewed. The information on the individual and family situation before, during and after the pregnancy was recorded and transcribed, then analysed in three phases, comprising pre-analysis, exploration and interpretation. The pregnant teens had a family background of teen pregnancy. The girls disclosed feelings of repression, loneliness and indifference to their parents, leading them to unprotected sexual relations without fear of pregnancy. After the pregnancy, communication improved between the girls and their parents, but became worse with their partner. Consequently, these teens returned to feeling as they did before getting pregnant. They stated that they would make their situation work for the sake of their child, and regretted dropping out of school and getting pregnant so young. Almost all said they were seeking love outside the family, which revealed a scenario of limited communication and unsatisfactory relations within the family. Understanding how communication works between parents and children is necessary to avoid teenage pregnancy, as well as early marriage or cohabitation, resulting in dropping out of school and financial constraints, which lead to great frustrations between the couple and affects the child. In addition, it is vitally important that adolescents be motivated in the family setting in order

  1. Seasonal variation of atmospheric lead levels in three sites in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Rosas, Irma; Belmont, Raul; Jauregui, Ernesto [Centro de Ciencias de la Atmosfera, UNAM, Mexico, D.F. (Mexico)

    1995-10-01

    Atmospheric lead concentrations associated to particles smaller than 10 {mu}m were measured in Mexico City, to establish changes of levels of this pollutant in three sites (industrial, commercial and residential) for 1990-1991. Moreover, an attempt was made to establish a possible link between this airborne pollutant and blood lead levels reported in children and women living near the sampling sites. A marked gradient in atmospheric lead from North to South is observed with higher and more variable mean lead values in the northern site where industry is located. Lead concentrations and their corresponding variability gradually decrease (from about 1.2 to 0.5 {mu}g m-3) toward the southern suburbs. Moreover, these values are significantly higher during the dry season than in the wet season when a marked washout effect if observed. However, the quarterly averages recorded during the sampling time do not exceed the international standard (1.5 {mu}g m-3). Lead concentrations and corresponding PM{sub 1}0 values showed a significant correlation. This results shows that lead is associated to the fine fraction of airborne particles, with high proportion of them deposited in the respiratory tract. A substantial abatement in levels of atmospheric lead is observed in 1991 with respect to the previous year. This may be explained by the introduction of improved quality gasoline in the capital city. In spite of this measure more than 30% of the evaluated population in 1991 presented blood-lead levels> 10 {mu}g dL-1. [Spanish] Durante 1991 se evaluaron en tres sitios (industrial, comercial y residencial), las concentraciones de plomo atmosferico asociado a particulas menores de 10 {mu}m, con el objeto de establecer los cambios en los niveles de este contaminante. Ademas, se trato de establecer la posible relacion de este contaminante con los niveles de plomo en sangre citados para ninos y mujeres que viven en los alrededores de los sitios de muestreo. Se observo un marcado

  2. Synergistic effect of air pollution and habitual smoking on the retention of inorganic fibers identified as ferruginous bodies in autopsy cases in Mexico City.

    Science.gov (United States)

    Salazar-Flores, Margarita; Rivera-Rodríguez, Rosa María; Vázquez-Manriquez, María Eugenia; Arenas-Huertero, Francisco

    2009-08-01

    In order to evaluate the synergistic effect of habitual smoking and air pollution in Mexico City on the retention of inorganic fibers, ferruginous bodies (FB) were quantified as markers of exposure to inorganic fibers in lung digests from 426 autopsy cases. FB were isolated from 426 lung digests from cases with several lung diseases. The results revealed more retention of FB in the smokers group than in non-smokers: 38 FB per gram (FB/g) versus 11.2 FB/g, respectively (p Mexico City increased their median to 54 FB/g. This contrasts with the median of outside residents: 11.2 FB/g (p Mexico City residents.

  3. Unpacking Mobility, Sex Trafficking, and HIV Vulnerability in Two Mexico-U.S. Border Cities

    OpenAIRE

    Goldenberg, Shira Miriam

    2011-01-01

    Background: Sex trafficking is a human rights abuse that carries particularly negative health and social consequences, including HIV and sexually transmitted infections (STIs). While HIV/STI infection and sex trafficking have been linked in Asia, the context of these associations and their applicability in Mexico is poorly understood.Aims: Aims of this dissertation were to (1) Critically review evidence linking mobility, trafficking, and HIV vulnerability in Mexico and Central America; (2) Ex...

  4. Correlates of subjective transportation deficiency among older adults attending outpatient clinics in a tertiary care hospital in Mexico City.

    Science.gov (United States)

    Navarrete-Reyes, Ana Patricia; Medina-Rimoldi, Carlos Tonatiuh; Avila-Funes, José Alberto

    2017-11-01

    Older adults frequently report problems of transportation. Little is known about the correlates of transportation deficiency in Latin America. Therefore, the aim of the present study was to determine the correlates of subjective transportation deficiency (STD) among community-dwelling older adults attending a tertiary care hospital in Mexico City. Cross-sectional study of 228 participants aged ≥70 years being followed in any of the outpatient clinics of a tertiary care hospital in Mexico City. Data were obtained through a structured questionnaire. Univariate and multivariate logistic regression analyses were carried out in order to identify the correlates of STD. The mean age of the participants was 79.8 years (SD 6.4) and 67.1% were women. STD was present in 46% of participants. The multivariate logistic regression model showed that female sex, illiteracy, mobility disability and the use of an assistive walking device had an independent and statistically significant association with STD. Female sex, illiteracy, mobility disability and the use of an assistive walking device were independent correlates of STD in the present study. Identifying the frequency and correlates of transportation deficiency in vulnerable populations will allow for the identification and implementation of useful public policies, as well as for the optimization of prevention and treatment strategies in an attempt to preserve mobility and autonomy, especially in low- and middle-income countries where previous work on transportation deficiency is lacking. Geriatr Gerontol Int 2017; 17: 1893-1898. © 2017 Japan Geriatrics Society.

  5. Automatic Monitoring of Criteria Pollutants and Meteorological Parameters in Boundary Sites of Mexico City under QA/QC Standards

    Science.gov (United States)

    Martínez, A.; Ramos, R.; Sánchez, A.; Retama, A.; Fentanes, O.; Muñoz, R.; Mar, B.; Ruiz, L. G.; Torres, R.; Torres, A.; Martínez, J.

    2007-05-01

    MILAGRO, an extensive air quality monitoring campaign, was conducted in the Mexico City Metropolitan Area (MCMA) during March 2006, in order to assess the air pollutants transport and their influence at regional and global scales. In support of this campaign a number of criteria pollutants and meteorological parameters measurements were conducted in boundary sites of the MCMA in order to determine the surface conditions in these transition sites. The boundary sites were selected based on results from previous studies, information provided systematically by the Mexico City Ambient Air Monitoring Network (Sistema de Monitoreo Atmosférico, SIMAT), pollutants trends and meteorological and climatic factors that participate in the dispersion and transport under different ventilation scenarios. Seven mobile units and two fixed stations were deployed for the continuous determination of criteria pollutants and meteorological parameters. In order to warranty the pollutants concentrations measurements' quality and comparability, calibrations and verifications were implemented at the designated monitoring sites. Data had been analyzed with statistical tools and comparisons were made against nearby SIMAT stations. Several interesting conclusions were achieved.

  6. [Health status and wellness among older adult beneficiaries of the ISSSTE and IMSS in Southwest Mexico City].

    Science.gov (United States)

    Sánchez-Garcia, Sergio; Juárez-Cedillo, Teresa; Espinel-Bermudez, Claudia; Cárdenas-Bahena, Angel; García-Peña, Carmen

    2013-01-01

    To explore the conditions of health and wellness in older adults beneficiaries to ISSSTE and IMSS of the Southwest Mexico City. Cross-sectional study samples of users to health services in primary care ISSSTE (n = 161) and IMSS (n = 176) in Southwest Mexico City. Were determined chronic health conditions, cognitive function, depressive symptoms, use of health services, nutritional status, functioning and disability and quality of life related to health. It is observed that there is a difference between samples ISSSTE vs. IMSS in comorbidity conditions (ISSSTE 53.4% vs. IMSS 57.9%), nutritional status (malnutrition risk ISSSTE 25.8% us. IMSS 36.4%; overweight ISSSTE 23.3% vs. IMSS 11.6%) (p < 0.05). There were no differences between samples IMSS us. ISSSTE in cognitive function, depression, use of health services, abdominal obesity, functioning and disability, and quality of life related to health. The conditions of health and wellness in older adults beneficiaries to ISSSTE and IMSS users are similar, with meaning in comorbidity conditions, nutritional status.

  7. 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.

  8. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Frank, R.M.; Sargentini-Maier, M.L.; Turlot, J.C.; Leroy, M.J. (Univ. Louis Pasteur, Strasbourg (France))

    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.

  10. Potential prescription patterns and errors in elderly adult patients attending public primary health care centers in Mexico City

    Directory of Open Access Journals (Sweden)

    José Antonio Corona-Rojo

    2009-08-01

    Full Text Available José Antonio Corona-Rojo1, Marina Altagracia-Martínez1, Jaime Kravzov-Jinich1, Laura Vázquez-Cervantes1, Edilberto Pérez-Montoya2, Consuelo Rubio-Poo31Division of Biological Sciences and Health, Metropolitan Autonomous University, Campus Xochimilco (UAM-X, Xochimilco, México; 2National Polytechnical Institute (IPN, México DF; 3Faculty of Higher Studies – Zaragoza (FES-Zaragoza, National Autonomous University of México (UNAM, México City, MéxicoIntroduction: Six out of every 10 elderly persons live in developing countries.Objective: To analyze and assess the drug prescription patterns and errors in elderly outpatients attending public health care centers in Mexico City, Mexico.Materials and methods: A descriptive and retrospective study was conducted in 2007. Fourteen hundred prescriptions were analyzed. Prescriptions of ambulatory adults aged >70 years who were residents of Mexico City for at least two years were included. Prescription errors were divided into two groups: (1 administrative and legal, and (2 pharmacotherapeutic. In group 2, we analyzed drug dose strength, administration route, frequency of drug administration, treatment length, potential drug–drug interactions, and contraindications. Variables were classified as correct or incorrect based on clinical literature. Variables for each drug were dichotomized as correct (0 or incorrect (1. A Prescription Index (PI was calculated by considering each drug on the prescription. SPSS statistical software was used to process the collected data (95% confidence interval; p < 0.05.Results: The drug prescription pattern in elderly outpatients shows that 12 drugs account for 70.72% (2880 of prescribed drugs. The most prescribed drugs presented potential pharmacotherapeutic errors (as defined in the present study. Acetylsalicylic acid–captopril was the most common potential interaction (not clinically assessed. Potential prescription error was high (53% of total prescriptions. Most

  11. 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

  12. 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

  13. canal24

    Data.gov (United States)

    California Department of Resources — Canal system center lines in the Central Valley of California and adjacent areas captured from 1:24,000-scale USGS topographic maps. Updates and modifications made...

  14. Characterization of Fine Particulate Matter (PM) and Secondary PM Precursor Gases in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Charles E. Kolb

    2008-03-31

    This project was one of three collaborating grants designed to understand the atmospheric chemistry and aerosol particle microphysics impacting air quality in the Mexico City Metropolitan Area (MCMA) and its urban plume. The overall effort, titled MCMA- 2006, focused on: 1) the primary emissions of fine particles and precursor gases leading to photochemical production of atmospheric oxidants and secondary aerosol particles and 2) the measurement and analysis of secondary oxidants and secondary fine particular matter (PM) production, with particular emphasis on secondary organic aerosol (SOA). MCAM-2006 pursued it goals through three main activities: 1) performance and publication of detailed analyses of extensive MCMA trace gas and fine PM measurements made by the collaborating groups and others during earlier MCMA field campaigns in 2002 and 2003; 2) deployment and utilization of extensive real-time trace gas and fine PM instrumentation at urban and downwind MCMA sites in support of the MAX-Mex/MILAGRO field measurements in March, 2006; and, 3) analyses of the 2006 MCMA data sets leading to further publications that are based on new data as well as insights from analysis and publication of the 2002/2003 field data. Thirteen archival publications were coauthored with other MCMA-2003 participants. Documented findings included a significantly improved speciated emissions inventory from on-road vehicles, a greatly enhanced understanding of the sources and atmospheric loadings of volatile organic compounds, a unique analysis of the high fraction of ambient formaldehyde from primary emission sources, a much more extensive knowledge of the composition, size distributions and atmospheric mass loadings of both primary and secondary fine PM, including the fact that the rate of MCMA SOA production greatly exceeded that predicted by current atmospheric models, and evaluations of significant errors that can arise from standard air quality monitors for ozone and nitrogen

  15. Application of neural networks to obtain the site response in Mexico City

    Directory of Open Access Journals (Sweden)

    Vargas J. Carlos A.

    2003-08-01

    Full Text Available

    We have implemented a neural network of three hidden layers with 40 neurons each layer to be used as soil/rock transfer functions for two stations in Mexico City. The net was trained with supervised learning through input and output vectors of accelerations (twelve records, from five seismic events from Guerrero and Puebla, 5.8 M 7.3, and tested with three records not taken in account in the training. The results in the frequency domain are good, finding a seismic amplification between 0.2 to 5 Hz for the Lake zone. In the time domain we obtain results that are not coincident. Due to the data and the complex of the phenomena, it is necessary to apply this tool using more records for the training net, so the phenomena can be learned better through reliable database.

    Hemos implementado una red neuronal de tres capas escondidas con 40 neuronas por capa para ser usada como funciones de trasferencia suelo/roca en dos estaciones acelerométricas en Ciudad de México. La red fue entrenada con entrenamiento supervisado por medio de vectores de aceleración de entrada y salida (doce registros de cinco eventos sísmicos localizados en la costa de Guerrero y uno al sur de Puebla, 5, 8 M 7, 3, y probada con tres registros no tornados en cuenta en el entrenamiento de la red. Los resultados obtenidos en el dominio de la frecuencia son bastante buenos, encontrándose una amplificación sísmica entre 0,2 a 5 Hz para la zona de Lago (estación RMCS. En el dominio del tiempo obtuvimos resultados que no son coincidentes.

    Oxidative capacity of the Mexico City atmosphere – Part 1: A radical source perspective

    Directory of Open Access Journals (Sweden)

    R. Volkamer

    2010-07-01

    Full Text Available A detailed analysis of OH, HO2 and RO2 radical sources is presented for the near field photochemical regime inside the Mexico City Metropolitan Area (MCMA. During spring of 2003 (MCMA-2003 field campaign an extensive set of measurements was collected to quantify time-resolved ROx (sum of OH, HO2, RO2 radical production rates from day- and nighttime radical sources. The Master Chemical Mechanism (MCMv3.1 was constrained by measurements of (1 concentration time-profiles of photosensitive radical precursors, i.e., nitrous acid (HONO, formaldehyde (HCHO, ozone (O3, glyoxal (CHOCHO, and other oxygenated volatile organic compounds (OVOCs; (2 respective photolysis-frequencies (J-values; (3 concentration time-profiles of alkanes, alkenes, and aromatic VOCs (103 compound are treated and oxidants, i.e., OH- and NO3 radicals, O3; and (4 NO, NO2, meteorological and other parameters. The ROx production rate was calculated directly from these observations; the MCM was used to estimate further ROx production from unconstrained sources, and express overall ROx production as OH-equivalents (i.e., taking into account the propagation efficiencies of RO2 and HO2 radicals into OH radicals.

    Daytime radical production is found to be about 10–25 times higher than at night; it does not track the abundance of sunlight. 12-h average daytime contributions of individual sources are: Oxygenated VOC other than HCHO about 33%; HCHO and O3 photolysis each about 20%; O3/alkene reactions and HONO photolysis each about 12%, other sources <3%. Nitryl chloride photolysis could potentially contribute ~15% additional radicals, while NO2* + water makes – if any – a very small contribution (~2%. The peak radical production of ~7.5 107 molec cm−3 s−1 is

  16. Analysis of Visible/SWIR surface reflectance ratios for aerosol retrievals from satellite in Mexico City urban area

    Directory of Open Access Journals (Sweden)

    A. D. de Almeida Castanho

    2007-10-01

    Full Text Available The surface reflectance ratio between the visible (VIS and shortwave infrared (SWIR radiation is an important quantity for the retrieval of the aerosol optical depth (τa from the MODIS sensor data. Based on empirically determined VIS/SWIR ratios, MODIS τa retrieval uses the surface reflectance in the SWIR band (2.1 µm, where the interaction between solar radiation and the aerosol layer is small, to predict the visible reflectances in the blue (0.47 µm and red (0.66 µm bands. Therefore, accurate knowledge of the VIS/SWIR ratio is essential for achieving accurate retrieval of aerosol optical depth from MODIS. We analyzed the surface reflectance over some distinct surface covers in and around the Mexico City metropolitan area (MCMA using MODIS radiances at 0.66 µm and 2.1 µm. The analysis was performed at 1.5 km×1.5 km spatial resolution. Also, ground-based AERONET sun-photometer data acquired in Mexico City from 2002 to 2005 were analyzed for aerosol depth and other aerosol optical properties. In addition, a network of hand-held sun-photometers deployed in Mexico City, as part of the MCMA-2006 Study during the MILAGRO Campaign, provided an unprecedented measurement of τa in 5 different sites well distributed in the city. We found that the average RED/SWIR ratio representative of the urbanized sites analyzed is 0.73±0.06 for scattering angles <140° and goes up to 0.77±0.06 for higher ones. The average ratio for non-urban sites was significantly lower (approximately 0.55. In fact, this ratio strongly depends on differences in urbanization levels (i.e. relative urban to vegetation proportions and types of surface materials. The aerosol optical depth retrieved from MODIS radiances at a spatial resolution of 1.5 km×1.5 km and averaged within 10×10 km boxes were compared with collocated 1-h τa averaged from sun-photometer measurements. The use of the new RED

  17. Evaluation of the imputation performance of the program IMPUTE in an admixed sample from Mexico City using several model designs

    Directory of Open Access Journals (Sweden)

    Krithika S

    2012-05-01

    Full Text Available Abstract Background We explored the imputation performance of the program IMPUTE in an admixed sample from Mexico City. The following issues were evaluated: (a the impact of different reference panels (HapMap vs. 1000 Genomes on imputation; (b potential differences in imputation performance between single-step vs. two-step (phasing and imputation approaches; (c the effect of different INFO score thresholds on imputation performance and (d imputation performance in common vs. rare markers. Methods The sample from Mexico City comprised 1,310 individuals genotyped with the Affymetrix 5.0 array. We randomly masked 5% of the markers directly genotyped on chromosome 12 (n = 1,046 and compared the imputed genotypes with the microarray genotype calls. Imputation was carried out with the program IMPUTE. The concordance rates between the imputed and observed genotypes were used as a measure of imputation accuracy and the proportion of non-missing genotypes as a measure of imputation efficacy. Results The single-step imputation approach produced slightly higher concordance rates than the two-step strategy (99.1% vs. 98.4% when using the HapMap phase II combined panel, but at the expense of a lower proportion of non-missing genotypes (85.5% vs. 90.1%. The 1,000 Genomes reference sample produced similar concordance rates to the HapMap phase II panel (98.4% for both datasets, using the two-step strategy. However, the 1000 Genomes reference sample increased substantially the proportion of non-missing genotypes (94.7% vs. 90.1%. Rare variants ( Conclusions The program IMPUTE had an excellent imputation performance for common alleles in an admixed sample from Mexico City, which has primarily Native American (62% and European (33% contributions. Genotype concordances were higher than 98.4% using all the imputation strategies, in spite of the fact that no Native American samples are present in the HapMap and 1000 Genomes reference panels. The best balance of

  18. For the good of the nation's economy: therapeutic work and public assistance at La Castañeda asylum in Mexico City, 1929-32

    National Research Council Canada - National Science Library

    Sacristán, Cristina

    2005-01-01

    Founded in 1910, by 1930 Mexico City's La Castañeda insane asylum was grappling with the problem of a massive number of chronic patients, a situation that earned it an image as a warehouse for the sick more than a place of treatment...

  19. 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)

    Particulate matter (PM) associated metals contribute to the adverse cardiopulmonary effects following exposure to air pollution. Here, we investigated how variation in the composition and size of ambient PM collected from two distinct regions in Mexico City relates to toxicity d...

  1. 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)

  2. Risk for HIV Infection among Adolescents in the Border City of Tijuana, Mexico

    Science.gov (United States)

    Martinez-Donate, Ana P.; Blumberg, Elaine J.; Hovell, Melbourne F.; Sipan, Carol L.; Zellner, Jennifer A.; Hughes, Suzanne

    2004-01-01

    Previous studies have suggested high rates of HIV infection and other sexually transmitted infections in theU.S.-Mexico border region. However, no information is available on the risk for HIV infection among Mexican adolescents living in this geographic area. This study examines the prevalence of HIV risk practices and psychosocial correlates…

  3. “The rupture generation” : nineteenth-century Nahua intellectuals in Mexico City, 1774-1882

    NARCIS (Netherlands)

    Segovia-Liga, A.

    2017-01-01

    This current dissertation explores several ideas about the construction of the Nahua intellectual tradition in 19th century-Mexico. Initially, the argument of this dissertation focuses on examining the intellectual tradition among Indigenous Peoples in Mesoamerica after the European invasion of the

  4. Determination of the atmospheric optical depth due to the El Chichon stratospheric aerosol cloud in the polluted atmosphere of Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, Ignacio [Centro Universitario de Investigaciones en Ciencia del Ambiente, Universidad de Colima, Colima, Colima, (Mexico); Kondratyev, Kirill Ya. [Academician, Counsellor Center for Ecological Safety, Russian Academy of Sciences, St. Petersburg (Russian Federation); Zenteno, Gerardo [Instituto de Geofisica, UNAM, Mexico, D.F. (Mexico)

    1996-01-01

    Direct solar radiation measurements were used to determine the aerosol optical depth (AOD) increase associated with the presence of aerosol and large particles (ash) originating from the 28 March to 4 April 1982 El Chichon eruptions (17.5 degrees N, 93.3 degrees W; Mexico) on Mexico City's polluted atmospheric aerosol layer. The results are compared with those obtained at Vancouver, British Columbia, revealing that a first AOD increase occurred in both locations during May, June, and July 1982, the Mexico City AOD decay is more extended, not reaching normal climatological values until February 1983. Meanwhile, Vancouver's AOD reached minimum values in September 1982, which subsequently increased over a period from October 1982 to September 1983. This secondary maximum was recorded in Mexico City from March to August 1983. Results suggest that the first AOD increases in May, June and July 1982, both at Vancouver and Mexico City, are due chiefly to short life-time volcanic ash particles being located near the surface. However, the second AOD increases, associated with anomalously colored twilights, corresponds to stratospheric volcanic aerosols. [Spanish] Se utilizaron mediciones de radiacion solar directa para determinar el incremento de la profundidad optica del aerosol (AOD) asociada a la presencia de aerosoles y particulas grandes (cenizas) organizadas por las erupciones de El Chichon (17.5 grados N, 93.3 grados W; Mexico) del 28 de marzo al 4 de abril de 1982 sobre la capa atmosferica contaminada de la Ciudad de Mexico. Los resultados se comparan con los obtenidos en Vancouver, Colombia Britanica, relevando que un primer aumento de AOD ocurrio en ambos lugares durante mayo, junio y julio de 1982. Sin embargo, la AOD decayo en Ciudad de Mexico mas lentamente, alcanzando los valores climatologicos normales hasta febrero de 1983. Mientras tanto la AOD para Vancouver alcanzo valores minimos en septiembre de 1982; estos subsecuentemente se incrementaron en

  5. Lead-glazed ceramic ware and blood lead levels of children in the city of Oaxaca, Mexico.

    Science.gov (United States)

    Azcona-Cruz, M I; Rothenberg, S J; Schnaas, L; Zamora-Muñoz, J S; Romero-Placeres, M

    2000-01-01

    Although Mexico substantially reduced use of leaded gasoline during the 1990s, lead-glazed pottery remains a significant source of population exposure. Most previous studies of lead in nonoccupationally exposed groups in Mexico have been conducted in the Mexico City metropolitan area. Oaxaca, a poor southern state of Mexico, has a centuries-old tradition of use of low temperature lead-glazed ceramic ware manufactured mainly by small family businesses. We measured blood lead levels in 220 8-10-y-old children (i.e., not from pottery-making families) who were students in the innercity of Oaxaca and in the mothers of all children. The geometric mean blood lead level of the children was 10.5 microg/dl (+7.0/-4.3 microg/dl standard deviation; range = 1.3-35.5 microg/dl). The corresponding mean value for the mothers was 13.4 (+9.0/-5.4 microg/dl standard deviation; range = 2.8-45.3 microg/dl). We used cutoffs that were greater than or equal to 10 microg/dl, 20 microg/dl, and 30 microg/dl, and we determined that 54.9%, 10.3%, and 3.0% of the children were at or above the respective criteria. We accounted for 25.2% of the variance in blood lead levels of the children, using maternal responses to a questionnaire that assessed possible lead sources in a linear multiple-regression model. The most important factors related to lead levels were family use of lead-glazed pottery, use of animal fat in cooking, and family income. The addition of maternal blood lead level to the model increased accounted variance in blood lead to 48.0%. In logistic-regression modeling of children's blood lead levels, we used a cutoff of greater than or equal to 10 microg/dl, and we found that use of lead-glazed pottery was the most important of all questionnaire items that were predictive of blood lead levels (odds ratio = 2.98). In Oaxaca, as is the case elsewhere in Mexico, lead-glazed ceramic ware remains a significant risk factor for elevated blood lead levels in children.

  6. The use of the electric vehicle in the metropolitan area of Mexico city; Uso de vehiculos electricos en el area metropolitana de la ciudad de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Robles, G. [Centro de Intrumentos, UNAM, Mexico, D. F. (Mexico); Sheinbaum, C. [Instituto de Ingenieria, UNAM, Mexico, D. F. (Mexico)

    1997-12-31

    A study is performed on the impact that the introduction of the electric vehicle (EV) would have in the environmental pollution of the metropolitan area of Mexico City (MAMC) for different penetration scenarios of this technology and the costs of the electric vehicle is analyzed and compared with its counterpart, the gasoline vehicle. The associated emissions of a fleet formed of EV and internal combustion engine vehicles (ICEV) were determined and the emissions reduction of the contaminants considered in the period 1995-2010 produced was analyzed. It was found that the introduction of EV could importantly reduce the carbon monoxide, methane and carbon dioxide and marginally the nitrogen oxides. It was determined that if the EV is massively produced its total cost for its entire useful life would be comparable to the cost of the ICEV. [Espanol] Se realiza un estudio sobre el impacto que tendria la introduccion de vehiculos electricos (VE) en la contaminacion ambiental del area metropolitana de la ciudad de Mexico (AMCM) para diferentes escenarios de penetracion de esta tecnologia y se analiza el costo de los vehiculos electricos en comparacion con su contraparte de gasolina. Se determinaron las emisiones asociadas a una flota compuesta de VE y vehiculos con motor de combustion interna (VMCI) y se analizo la reduccion que producia en las emisiones de los diferentes contaminantes considerados en el periodo 1995-2010. Se encontro que la introduccion de VE podria reducir de manera importante las emisiones de monoxido de carbono, metano y dioxido de carbono y marginalmente las de oxido de nitrogeno. Se determino que si los VE son producidos masivamente su costo total para toda su vida util seria comparable al correspondiente al de los VMCI.

  7. Observed trends in ground-level O3 in Monterrey, Mexico, during 1993-2014: comparison with Mexico City and Guadalajara

    Science.gov (United States)

    Hernández Paniagua, Iván Y.; Clemitshaw, Kevin C.; Mendoza, Alberto

    2017-07-01

    Here, we present an assessment of long-term trends in O3 and odd oxygen (O3 + NO2) at the industrial Monterrey metropolitan area (MMA) in NE Mexico. Diurnal amplitudes in Ox (AVd) are used as a proxy for net O3 production, which is influenced by the NO2 photolysis rate. No significant differences in the AVd are observed between weekends and weekdays, although the largest AVd values are observed at sites downwind of industrial areas. The highest O3 mixing ratios are observed in spring, with minimum values in winter. The largest annual variations in O3 are typically observed downwind of the MMA, with the lowest variations generally recorded in highly populated areas and close to industrial areas. A wind sector analysis of mixing ratios of O3 precursors revealed that the dominant sources of emissions are located in the industrial regions within the MMA and surrounding area. Significant increasing trends in O3 in spring, summer, and autumn are observed depending on site location, with trends in annual averages ranging between 0.19 and 0.33 ppb yr-1. Overall, from 1993 to 2014, within the MMA, O3 has increased at an average rate of 0.22 ppb yr-1 (p < 0. 01), which is in marked contrast with the decline of 1.15 ppb yr-1 (p < 0. 001) observed in the Mexico City metropolitan area (MCMA) for the same period. No clear trend is observed from 1996 to 2014 within the Guadalajara metropolitan area (GMA).

  8. Observed trends in ground-level O3 in Monterrey, Mexico, during 1993–2014: comparison with Mexico City and Guadalajara

    Directory of Open Access Journals (Sweden)

    I. Y. Hernández Paniagua

    2017-07-01

    Full Text Available Here, we present an assessment of long-term trends in O3 and odd oxygen (O3 + NO2 at the industrial Monterrey metropolitan area (MMA in NE Mexico. Diurnal amplitudes in Ox (AVd are used as a proxy for net O3 production, which is influenced by the NO2 photolysis rate. No significant differences in the AVd are observed between weekends and weekdays, although the largest AVd values are observed at sites downwind of industrial areas. The highest O3 mixing ratios are observed in spring, with minimum values in winter. The largest annual variations in O3 are typically observed downwind of the MMA, with the lowest variations generally recorded in highly populated areas and close to industrial areas. A wind sector analysis of mixing ratios of O3 precursors revealed that the dominant sources of emissions are located in the industrial regions within the MMA and surrounding area. Significant increasing trends in O3 in spring, summer, and autumn are observed depending on site location, with trends in annual averages ranging between 0.19 and 0.33 ppb yr−1. Overall, from 1993 to 2014, within the MMA, O3 has increased at an average rate of 0.22 ppb yr−1 (p < 0. 01, which is in marked contrast with the decline of 1.15 ppb yr−1 (p < 0. 001 observed in the Mexico City metropolitan area (MCMA for the same period. No clear trend is observed from 1996 to 2014 within the Guadalajara metropolitan area (GMA.

  9. 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

  10. Use of resistivity measurements to detect urban caves in Mexico City and to assess the related hazard

    Science.gov (United States)

    Antonio-Carpio, R. G.; Pérez-Flores, M. A.; Camargo-Guzmán, D.; Alanís-Alcantar, A.

    2004-09-01

    In the XIX century when Mexico City was much smaller than at present, there was non-regulated mining of building materials in a region of tuffs northwest of the city in an inhabited countryside. With the growth of the city during the XX century, this region was increasingly populated and in the 1970's many two-level bricks houses were built, without regard for underground caves created by the earlier extractions. Some ground sinkings in adjacent areas alarmed the residents who now are worried about this permanent hazard. An association of residents contracted a private company for a geophysical study in order to know the distribution of the caves. Resistivity measurements were taken in the area to detect the caves in order to alert city authorities. Resistivity data along most of the streets were collected with the array pole-dipole that consisted of three grounded electrodes. We performed 2-D dimensional inversions to the data in order to get a 2-D resistivity image of every street. This is similar to a resistivity cross-section of the ground but obtained from the inversion of pole-dipole and Schlumberger resistivity data simultaneously. Using the information of previous drills we modified our programming code in order to perform constrained inversion and to get more accurate resistivity models in agreement with the drills. From the resistivity models obtained for every street it was possible to produce a map which shows the horizontal distribution of the resistive bodies at a depth of 12m. These resistive bodies show coherent alignments that seem to correspond with a distributions of interconnected caves or tunnels used for extracting the sandy-tuffs. From these kind of interpretation method it was intended to get a more accurate horizontal distribution of the excavated areas in order to better know the urbanized area affected and lead the authorities to remedy the area with refill material.

  11. Use of resistivity measurements to detect urban caves in Mexico City and to assess the related hazard

    Directory of Open Access Journals (Sweden)

    R. G. Antonio-Carpio

    2004-01-01

    Full Text Available In the XIX century when Mexico City was much smaller than at present, there was non-regulated mining of building materials in a region of tuffs northwest of the city in an inhabited countryside. With the growth of the city during the XX century, this region was increasingly populated and in the 1970's many two-level bricks houses were built, without regard for underground caves created by the earlier extractions. Some ground sinkings in adjacent areas alarmed the residents who now are worried about this permanent hazard. An association of residents contracted a private company for a geophysical study in order to know the distribution of the caves. Resistivity measurements were taken in the area to detect the caves in order to alert city authorities. Resistivity data along most of the streets were collected with the array pole-dipole that consisted of three grounded electrodes. We performed 2-D dimensional inversions to the data in order to get a 2-D resistivity image of every street. This is similar to a resistivity cross-section of the ground but obtained from the inversion of pole-dipole and Schlumberger resistivity data simultaneously. Using the information of previous drills we modified our programming code in order to perform constrained inversion and to get more accurate resistivity models in agreement with the drills. From the resistivity models obtained for every street it was possible to produce a map which shows the horizontal distribution of the resistive bodies at a depth of 12m. These resistive bodies show coherent alignments that seem to correspond with a distributions of interconnected caves or tunnels used for extracting the sandy-tuffs. From these kind of interpretation method it was intended to get a more accurate horizontal distribution of the excavated areas in order to better know the urbanized area affected and lead the authorities to remedy the area with refill material.

  12. Healthcare and Social Services Providers Who Serve Sexual and Gender Minorities in a U.S.-Mexico Border City.

    Science.gov (United States)

    Loza, Oralia; Alvarez, Carlos R; Peralta-Torres, David

    2018-01-15

    Sexual and gender minorities, including lesbian, gay, bisexual, transgender, and queer (LGBTQ) individuals, experience barriers to healthcare as a result of stigma, discrimination, and poor cultural competence by healthcare and social services providers (HCSSP). The purpose of the study is to increase access to care and services for the LGBTQ community in a U.S.-Mexico border city by identifying LGBTQ-friendly HCSSP. A survey, developed based on concerns voiced in a predominantly Hispanic LGBTQ community, was administered to HCSSP and used to create a referral list, "The Purple Pages of El Paso" (PPoEP). Overall, 77 HCSSP have responded and 43 are included in the most recent version of the PPoEP. This model for developing a referral list of providers can be adapted in areas where LGBTQ communities face similar barriers to care and services. To be effective in reducing barriers to care, PPoEP must be updatable and sustainable.

  13. Developing a Hierarchical Model for the Spatial Analysis of PM10 Pollution Extremes in the Mexico City Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Alejandro Ivan Aguirre-Salado

    2017-07-01

    Full Text Available We implemented a spatial model for analysing PM 10 maxima across the Mexico City metropolitan area during the period 1995–2016. We assumed that these maxima follow a non-identical generalized extreme value (GEV distribution and modeled the trend by introducing multivariate smoothing spline functions into the probability GEV distribution. A flexible, three-stage hierarchical Bayesian approach was developed to analyse the distribution of the PM 10 maxima in space and time. We evaluated the statistical model’s performance by using a simulation study. The results showed strong evidence of a positive correlation between the PM 10 maxima and the longitude and latitude. The relationship between time and the PM 10 maxima was negative, indicating a decreasing trend over time. Finally, a high risk of PM 10 maxima presenting levels above 1000 μ g/m 3 (return period: 25 yr was observed in the northwestern region of the study area.

  14. Developing a Hierarchical Model for the Spatial Analysis of PM10Pollution Extremes in the Mexico City Metropolitan Area.

    Science.gov (United States)

    Aguirre-Salado, Alejandro Ivan; Vaquera-Huerta, Humberto; Aguirre-Salado, Carlos Arturo; Reyes-Mora, Silvia; Olvera-Cervantes, Ana Delia; Lancho-Romero, Guillermo Arturo; Soubervielle-Montalvo, Carlos

    2017-07-06

    We implemented a spatial model for analysing PM 10 maxima across the Mexico City metropolitan area during the period 1995-2016. We assumed that these maxima follow a non-identical generalized extreme value (GEV) distribution and modeled the trend by introducing multivariate smoothing spline functions into the probability GEV distribution. A flexible, three-stage hierarchical Bayesian approach was developed to analyse the distribution of the PM 10 maxima in space and time. We evaluated the statistical model's performance by using a simulation study. The results showed strong evidence of a positive correlation between the PM 10 maxima and the longitude and latitude. The relationship between time and the PM 10 maxima was negative, indicating a decreasing trend over time. Finally, a high risk of PM 10 maxima presenting levels above 1000 μ g/m 3 (return period: 25 yr) was observed in the northwestern region of the study area.

  15. Energy balance in urban Mexico City: observation and parameterization during the MILAGRO/MCMA-2006 field campaign

    Science.gov (United States)

    Velasco, Erik; Pressley, Shelley; Grivicke, Rasa; Allwine, Eugene; Molina, Luisa T.; Lamb, Brian

    2011-03-01

    The parameterization of the energy balance from a residential and commercial neighborhood of Mexico City was investigated using direct measurements of radiative and heat fluxes carried out during the MILAGRO/MCMA-2006 field campaign as a reference. The measured fluxes were used to evaluate different models of the energy balance based on parameterizations that require standard meteorological observations: ambient temperature, relative humidity, atmospheric pressure and cloudiness. It was found that these models reproduce with reasonable accuracy the diurnal features of the radiative and heat fluxes. The largest differences between modeled and observed fluxes correspond to the incoming longwave radiation, mainly due to errors in the cloudiness data. This paper contributes to the understanding of the energy partitioning in (sub)tropical urban environments, particularly in the developing world, where energy balance models have not been evaluated.

  16. HIV and STI knowledge, testing, and risk among adult crack users in Mexico city: baseline findings from a feasibility study.

    Science.gov (United States)

    Cepeda, Alice; Frankeberger, Jessica; Bailey, Jennifer L; Nowotny, Kathryn M; Natera-Rey, Guillermina; Valdez, Avelardo

    2017-03-01

    Recent research has documented crack cocaine's increasing spread in Mexico, which is likely to contribute to the rapid transmission of HIV and other sexually transmitted infections (STIs). In Mexico, crack use is increasing most rapidly in vulnerable, hard-to-reach populations, where little is known about risk behaviors. This report aims to present baseline data regarding HIV and STI knowledge and testing prevalence from an innovative projection mapping HIV intervention, in which 3-D illusions, animation, and visual text graphics and sound are projected onto buildings with health messages that were designed to disrupt everyday life and connect with the target population. Fifty-eight men and women who used crack in the past month without receiving drug treatment were recruited and interviewed before the projection mapping intervention took place. Testing instruments included a sociodemographic assessment, drug use and treatment profile, HIV and STI knowledge questionnaires, and a sex and drug risk assessment. The mean scores for respondents on the HIV Knowledge Questionnaire (10.5 out of 18, 58.3%) and STD Knowledge Questionnaire (9.5 out of 27, 35.2%) were both low. Respondents also reported high rates of sexual risk behaviors, with 73% reporting never using a condom and 64% never being tested for HIV. This report provides a portrait of STI and HIV risk among a vulnerable population in Mexico City and the need for urgent interventions to prevent the spread of STIs and HIV. The associated projection mapping intervention will seek to increase HIV and STI knowledge and reduce risk in this hard-to-reach population.

  17. Detection of pollution transport events southeast of Mexico City using ground-based visible spectroscopy measurements of nitrogen dioxide

    Directory of Open Access Journals (Sweden)

    M. Grutter

    2009-07-01

    Full Text Available This work presents ground based differential optical absorption spectroscopy (DOAS measurements of nitrogen dioxide (NO2 during the MILAGRO field campaign in March 2006 at the Tenango del Aire research site located to the southeast of Mexico City. The DOAS NO2 column density measurements are used in conjunction with ceilometer, meteorological and surface nitric oxide (NO, nitrogen oxides (NOx and total reactive nitrogen (NOy measurements to analyze pollution transport events to the southeast of Mexico City during the MILARGO field campaign. The study divides the data set into three case study pollution transport events that occurred at the Tenango del Aire research site. The unique data set is then used to provide an in depth analysis of example days of each of the pollution transport events. An in depth analysis of 13 March 2006, a Case One day, shows the transport of several air pollution plumes during the morning through the Tenango del Aire research site when southerly winds are present and demonstrates how DOAS tropospheric NO2 vertical column densities (VCD, surface NO2 mixing ratios and ceilometer data are used to determine the vertical homogeneity of the pollution layer. The analysis of 18 March 2006, a Case Two day, shows that when northerly winds are present for the entire day, the air at the Tenango del Aire research site is relatively clean and no major pollution plumes are detected. Case 3 days are characterized by relatively clean air throughout the morning with large DOAS NO2 enhancements detected in the afternoon. The analysis of 28 March 2006 show the DOAS NO2 enhancements are likely due to lightning activity and demonstrate how suitable ground-based DOAS measruements are for monitoring anthropogenic and natural pollution sources that reside above the mixing layer.

  18. 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.

  19. 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.

  20. Validity and reproducibility of a food frequency questionnaire to assess dietary intake of women living in Mexico City

    Directory of Open Access Journals (Sweden)

    HERNÁNDEZ-AVILA MAURICIO

    1998-01-01

    Full Text Available Objective. To assess the reproducibility and validity of a 116 item semi-quantitative food frequency questionnaire (FFQ, designed to assess the relation between dietary intake and chronic diseases. Material and methods. To test the reproducibility of the FFQ questionnaire, the FFQ was administered twice to 134 women residing in Mexico City at an interval of approximately one year; to assess the validity we compared results obtained by the FFQs with those obtained by four 4-day 24-hour recalls at three month intervals. Validity and reproducibility were evaluated using regression analysis and Pearson and intraclass correlation coefficients of log-e and calorie-adjusted nutrient scores. Results. Mean values for intake of most nutrients assessed by the two food frequency questionnaires were similar. However, means for the 24-hr recall were significantly lower. Intraclass correlation coefficients for nutrient intakes, assessed by questionnaires, administered one year apart, ranged from 0.38 for cholesterol to 0.54 for crude fiber. Correlation coefficients between energy-adjusted nutrient intakes, measured by diet recalls, and the first FFQ ranged from 0.12 for polyunsaturated fatty acids to 0.67 for saturated fatty acids. Regression coefficients between 24-hr recall and FFQ,s were all significant were significant for all nutrients, except for polyunsaturated fat, folic acid, vitamin E and Zinc. Conclusions. These data indicate that this semi-quantitative FFQ is reproducible and provides a useful estimate by which to categorize individuals by level of past nutrient intake. However, its application outside Mexico City or in different age and gender populations will require additional modifications and validation efforts.

  1. Effect of aerosols and NO2 concentration on ultraviolet actinic flux near Mexico City during MILAGRO: measurements and model calculations

    Directory of Open Access Journals (Sweden)

    C. A. Corr

    2013-01-01

    Full Text Available Urban air pollution absorbs and scatters solar ultraviolet (UV radiation, and thus has a potentially large effect on tropospheric photochemical rates. We present the first detailed comparison between actinic fluxes (AF in the wavelength range 330–420 nm measured in highly polluted conditions and simulated with the Tropospheric Ultraviolet-Visible (TUV model. Measurements were made during the MILAGRO campaign near Mexico City in March 2006, at a ground-based station near Mexico City (the T1 supersite and from the NSF/NCAR C-130 aircraft. At the surface, measured AF values are typically smaller than the model by up to 25% in the morning, 10% at noon, and 40% in the afternoon, for pollution-free and cloud-free conditions. When measurements of PBL height, NO2 concentration and aerosols optical properties are included in the model, the agreement improves to within ±10% in the morning and afternoon, and ±3% at noon. Based on daily averages, aerosols account for 68% and NO2 for 25% of AF reductions observed at the surface. Several overpasses from the C-130 aircraft provided the opportunity to examine the AF perturbations aloft, and also show better agreement with the model when aerosol and NO2 effects are included above and below the flight altitude. TUV model simulations show that the vertical structure of the actinic flux is sensitive to the choice of the aerosol single scattering albedo (SSA at UV wavelengths. Typically, aerosols enhance AF above the PBL and reduce AF near the surface. However, for highly scattering aerosols (SSA > 0.95, enhancements can penetrate well into the PBL, while for strongly absorbing aerosols (SSA < 0.6 reductions in AF are computed in the free troposphere as well as in the PBL. Additional measurements of the SSA at these wavelengths are needed to better constrain the effect of aerosols on the vertical structure of the AF.

  2. 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.

  3. [Environmental tobacco smoke exposure in homes of Mexico City: analysis of environmental samples and children and women hair].

    Science.gov (United States)

    Barrientos-Gutiérrez, Tonatiuh; Reynales-Shigematsu, Luz Myriam; Avila-Tang, Erika; Wipfli, Heather; Lazcano-Ponce, Eduardo

    2007-01-01

    In Mexico no evaluation of environmental tobacco smoke exposure in homes or habitants has been conducted. The objective of this study is to quantify environmental nicotine in Mexico City homes, simultaneously evaluating nicotine levels in children and women. In July 2005 a convenience sample of 41 homes was selected, 20% without smokers, 80% with smokers. Nicotine passive monitors were allocated in homes for one week, obtaining samples of hair from inhabitant non-smoking women and children. Samples were taken to the Johns Hopkins University where nicotine was extracted and analyzed using gas chromatography. A survey of opinions and behaviors related to environmental tobacco smoke was conducted. Environmental nicotine concentrations had a median of 0.08 microg/m3 (IQR 0.01-0.64), in children's hair 0.05 ng/mg (IQR 0.05-0.29), and in women's hair 0.05 ng/mg (IQR 0.05-0.19). Environmental nicotine concentrations and in children's hair were highly correlated (rS=0.49), and increased with the number of smokers at home. The majority of adults surveyed showed support towards measures of environmental tobacco smoke control. Homes are important spaces of exposure to environmental tobacco smoke. Particularly high levels of exposure were observed in children's hair, attributable to the presence of environmental nicotine at home. Integral preventive activities to eliminate active smoking and to avoid tobacco consumption at home are required.

  4. Miscarriage history and Toxoplasma gondii infection: A cross-sectional study in women in Durango City, Mexico.

    Science.gov (United States)

    Alvarado-Esquivel, C; Pacheco-Vega, S J; Hernández-Tinoco, J; Centeno-Tinoco, M M; Beristain-García, I; Sánchez-Anguiano, L F; Liesenfeld, O; Rábago-Sánchez, E; Berumen-Segovia, L O

    2014-06-01

    Through a cross-sectional study design, 326 women with a history of miscarriage were examined for anti-Toxoplasma gondii IgG and IgM antibodies in Durango City, Mexico. Prevalence association with sociodemographic, clinical, and behavioral characteristics in women with miscarriage was also investigated. Twenty-two (6.7%) of the 326 women studied had anti-T. gondii IgG antibodies and two (0.6%) were also positive for anti-T. gondii IgM antibodies. Seroprevalence of T. gondii infection was not influenced by age, birth place, occupation, educational level, or socioeconomic status. In contrast, logistic regression showed that T. gondii exposure was associated with consumption of raw or undercooked meat (OR = 6.84; 95% CI: 1.04-44.95; P = 0.04) and consumption of chicken brains (OR = 18.48; 95% CI: 1.26-269.43; P = 0.03). This is the first study on the seroepidemiology of T. gondii infection in women with a history of miscarriage in Northern Mexico. Of interest, we also observed an association of T. gondii exposure with consumption of chicken brains. Contributing factors for T. gondii exposure found in the present study should be taken into consideration for public health measures to avoid infection with T. gondii and its sequelae.

  5. Correlates of early versus later initiation into sex work in two Mexico-U.S. border cities.

    Science.gov (United States)

    Loza, Oralia; Strathdee, Steffanie A; Lozada, Remedios; Staines, Hugo; Ojeda, Victoria D; Martínez, Gustavo A; Amaro, Hortensia; Patterson, Thomas L

    2010-01-01

    To examine correlates of early initiation into sex work in two Mexico-U.S. border cities. Female sex workers (FSWs) >/=18 years without known HIV infection living in Tijuana and Ciudad Juarez who had recent unprotected sex with clients underwent baseline interviews. Correlates of initiation into sex work before age 18 were identified with logistic regression. Of 920 FSWs interviewed in Tijuana (N=474) and Ciudad Juarez (N=446), 9.8% (N=90) were early initiators (abuse as a child (42.2% vs. 18.7%, pchild abuse (adjOR=2.92). Factors associated with later initiation included less education (adjOR=0.43 per 5-year increase), migration (adjOR=0.47), and initiating sex work for better pay (adjOR=0.44) or to support children (adjOR=0.03). Different pathways for entering sex work are apparent among younger versus older females in the Mexico-U.S. border region. Among girls, interventions are needed to prevent inhalant use and child abuse and to offer coping skills; among older initiators, income-generating strategies, childcare, and services for migrants may help to delay or prevent entry into sex work. Copyright 2010 Society for Adolescent Medicine. Published by Elsevier Inc. All rights reserved.

  6. Clinicopathological characterization of primary oral and sinonasal melanoma in a referral centre in Mexico City: 2000-2012.

    Science.gov (United States)

    Maldonado-Mendoza, J; Ramírez-Amador, V; Anaya-Saavedra, G; Irigoyen-Camacho, M E; Ruíz-Godoy, L; Ruíz-García, E; Meneses-García, A

    2015-04-01

    In Mexico, there have been few studies on primary oral and sinonasal melanoma, an aggressive neoplasm with a low survival rate and few therapeutic alternatives. Further, there is limited information about its clinical and histopathological characteristics. The aim of this retrospective study was to describe the clinicopathological profile of these tumours in patients attending a major oncology reference centre in Mexico City over a 12-year period. Demographic and clinical data were obtained from the clinical charts, and histopathological features were evaluated. χ(2), Fisher's exact, and Mann-Whitney U-tests were used for analysis; significance was set at Poral melanoma (OM)); 58% were female and the median age was 66 (Q1-Q3 55.5-75) years. Compared with OM patients, SNM patients had a shorter time to diagnosis (16.7 vs. 11.7 months, P=0.022), were identified at earlier stages (33.3% vs. 58.3%, P=0.010), and all presented symptoms (66.7% vs. 100%, P=0.015). All samples showed vertical growth and 96.9% exhibited pleomorphism. A higher proportion of cases with pleomorphism developed metastases at follow-up than those without (60% vs. 12.5%, P=0.026). The present study provides valuable information that could form the basis of future studies in the search for advanced therapy modalities. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  7. 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.

  8. Statistical analysis of corn consumption for improved mycotoxin exposure estimates for the population of Veracruz City, Mexico.

    Science.gov (United States)

    Wall-Martínez, H A; Ramírez-Martínez, A; Wesolek, N; Brabet, C; Rodríguez-Jimenes, G C; García-Alvarado, M A; Salgado-Cervantes, M A; Robles-Olvera, V J; Roudot, A C

    2017-05-01

    Corn consumption was evaluated in the population of Veracruz City, Mexico, through two different dietary intake questionnaires. The selection of 300 sampling locations was completely random. The population was segregated into gender and age categories. A daily consumption questionnaire was used to determine the consumption of corn tortillas and a frequency questionnaire to determine the consumption of other corn products. A book of photographs was used to adjust criteria on the size of the portions of corn products and a probability distribution was built of the weight and content of corn for tortillas. Probability density functions (PDFs) were used to describe the consumption of each corn product. Men and those between 14 and 65 years old have the highest consumption of tortillas. Tortillas, antojitos, tacos and chilaquiles are the products that provide the largest amount of corn to the Veracruz people's diet. Even though these products are nixtamalisated, there is evidence that after a thermo-alkaline process some contaminants such as mycotoxins (like aflatoxin, which is a mutagenic, teratogenic and carcinogenic toxin) could be present in high concentrations. These results highlight the need to characterise the consumption of one of the main foods included in dietary staple in Mexico as a first step for a probabilistic risk assessment.

  9. At the Table with Hungry Ghosts: Intimate Borderwork in Mexico City

    Directory of Open Access Journals (Sweden)

    Jean Duruz

    2011-03-01

    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. 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

    Energy Technology Data Exchange (ETDEWEB)

    Voss, Paul B.; Zaveri, Rahul A.; Flocke, Frank M.; Mao, Huitimg; Hartley, Tom; DeAmicis, Pam; Deonandan, Indira; Contrerars-Jimenez, G.; Martinez-Antonio, O.; Figueroa Estrada, M.; Greenberg, David; Campos, Teresa; Weinheimer, Andrew J.; Knapp, David; Montzka, DeeDee; Crounse, J. D.; Wennberg, P. O.; Apel, Eric; Madronich, Sasha; de Foy, B.

    2010-08-04

    One of the major objectives of the Megacities Initiative: Local And Global Research 3 Observations (MILAGRO 2006) campaign was to investigate the long-range transport of 4 Mexico City Metropolitan Area (MCMA) pollution outflow and its downwind impacts on air 5 quality and climate. Four aircraft (DOE G-1, NSF/NCAR C-130, NASA-J31, and NASA 6 DC-8) made extensive chemical, aerosol, and radiation measurements above MCMA and over 7 1000 km downwind in order to characterize the evolution of MCMA pollution as it aged and 8 dispersed over the central Mexican plateau and the Gulf of Mexico. As part of this effort, 9 free-floating Controlled-Meteorological (CMET) balloons, capable of changing altitude on 10 command via satellite, characterized the MCMA outflow by performing repeated soundings 11 during the transit. In this paper, we present an analysis based on the data from two CMET 12 balloons that were launched near Mexico City on the afternoon of 18 March 2006 and floated 13 downwind with the outflow for nearly 30 hours. Continuous profile measurements made by 14 the balloons show the evolving structure of the MCMA outflow in considerable detail: its 15 stability and stratification, interaction with other air masses, mixing episodes, and dispersion 16 into the regional background. Air parcel trajectories, computed directly from the balloon 17 wind profiles, show three different transport pathways for Mexico City outflow on 18-19 18 March: (a) high-altitude advection of the top of the MCMA mixed layer, (b) low-altitude flow 19 over the Sierra Madre Oriental followed by decoupling and isolated transport over the Gulf, 20 and (c) the same decoupling scenario with entrainment into a cleaner westerly jet below the 21 plateau. The C-130 intercepted the balloon-based trajectories three times on 19 March, once 22 along each transport pathway. In all three cases, distinct peaks in the urban tracer signature 23 and LIDAR backscatter imagery provided evidence for Mexico City air

  11. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

    Science.gov (United States)

    Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

    2015-01-01

    Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize. PMID:26437425

  12. Committed dose assessment based on background outdoor gamma exposure in Chihuahua City, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Luevano G, S.; Perez T, A.; Pinedo A, C.; Renteria V, M. [Universidad Autonoma de Chihuahua, Facultad de Zootecnia y Ecologia, Perif. Francisco R. Almada Km 1, 31415 Chihuahua, Chih. (Mexico); Carrillo F, J.; Montero C, M. E., E-mail: mrenteria@uach.mx [Centro de Investigacion en Materiales Avanzados, Miguel de Cervantes 120, 31136 Chihuahua, Chih. (Mexico)

    2015-10-15

    Full text: Determining ionizing radiation in a geographic area serves to assess its effects on populations health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the committed dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, annual effective dose, and the lifetime cancer risk, 48 sampling points were randomly selected along the Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Muller counter. At the same sites, 48 soil samples were taken to obtain the activity concentrations of {sup 226}Ra, {sup 232}Th, {sup 40}K and their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Outdoor gamma dose rates ranged from 56 to 193 n Gy h{sup -1}. Results indicated that lifetime effective dose to inhabitants of Chihuahua City is in average of 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of activity concentrations in soil were 51.8, 73.1, and 1096.5 Bq kg{sup -1}, of {sup 226}Ra, {sup 232}Th and {sup 40}K, respectively. From the analysis of the spatial distribution of {sup 232}Th, {sup 226}Ra, and {sup 40}K is to north, to north-center, and to south of city, respectively. In conclusion, natural background gamma dose received by inhabitants of Chihuahua City is high and mainly due to geological characteristics of the zone. (Author)

  13. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

    Directory of Open Access Journals (Sweden)

    Sergio Luevano-Gurrola

    2015-09-01

    Full Text Available Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

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

    Directory of Open Access Journals (Sweden)

    K. S. Johnson

    2006-01-01

    Full Text Available 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 for elemental and multivariate analyses. Proton-Induced X-ray Emission (PIXE, Proton-Elastic Scattering Analysis (PESA and Scanning Transmission Ion Microscopy (STIM measurements were done to determine concentrations of 19 elements from Na to Pb, hydrogen, and total mass, respectively. The most abundant elements from PIXE analysis were S, Si, K, Fe, Ca, and Al, while the major emissions sources associated with these elements were industry, wind-blown soil, and biomass burning. Wind trajectories suggest that metals associated with industrial emissions came from northern areas of the city whereas soil aerosols came from the southwest and increased in concentration during dry conditions. Elemental markers for fuel oil combustion, V and Ni, correlated with a large SO2 plume to suggest an anthropogenic, rather than volcanic, emissions source. By subtracting major components of soil and sulfates determined by PIXE analysis from STIM total mass measurements, we estimate that approximately 50% of non-volatile PM2.5 consisted of carbonaceous material.

  15. Superfund Record of Decision (EPA Region 2): Love Canal (93rd Street School), Niagara County, City of Niagara Falls, NY. (Third remedial action), (amendment), May 1991. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1991-05-15

    The Love Canal (93rd Street) site is an inactive hazardous waste site located in Niagara Falls, New York. The 19-acre 93rd Street School site, one of several operable units for the Love Canal Superfund site, is the focus of the Record of Decision (ROD). The fill material is reported to contain fly ash and BHC (a pesticide) waste. The ROD amends the 1988 ROD, and addresses final remediation of onsite contaminated soil through excavation and offsite disposal. The primary contaminants of concern affecting the soil are VOCs including toluene and xylenes; other organics including PAHs and pesticides; and metals including arsenic, chromium, and lead.

  16. 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.

  17. [Infant morbidity caused by respiratory diseases and its relation with the air pollution in Juarez City, Chihuahua, Mexico].

    Science.gov (United States)

    Hernández-Cadena, Leticia; Barraza-Villarreal, Albino; Ramírez-Aguilar, Matiana; Moreno-Macías, Hortencia; Miller, Paul; Carbajal-Arroyo, Luz Aurora; Romieu, Isabelle

    2007-01-01

    To assess the impact of atmospheric pollutants on the respiratory health of children of different age groups in Juarez City, Chihuahua, Mexico. Data on emergency room visits between 1997 and 2001 for respiratory diseases in children less than 17 years old were obtained from hospitals in the Juarez City belonging to the Mexican Social Security Institute (IMSS). Diseases were classified into three groups according to ICD 9th and 10th codes: a) upper respiratory diseases, b) lower respiratory diseases, and c) asthma attacks. This information was stratified by age group ( 5 years). Daily air pollution data (ozone and PM10) and weather conditions were obtained from the Monitoring Network System in Juarez City. Statistical analysis was carried out using a Generalized Additive Model assuming a Poisson distribution. Ozone concentrations, but not PM 10, were statistically associated with emergency room visits for respiratory diseases, mainly among children 5 years old or younger. In this group, an increase of 20 ppb 1-hr maximum for ozone was associated with an increase of 8.3% in the number of emergency room visits for upper respiratory diseases, with a 3-day exposure lag; and an increase of 12.7% in the number of emergency room visits for lower respiratory diseases when considering a 4-day exposure lag in a maximum 8-hr mobile average. The largest effect for the complete sample and for the group 6 to 16 years of age was observed for 3-day lag (5.1% for an increase of 20 ppb 1-hr maximum for ozone). For the 6 to 16 year old group we did not find a significant effect. The wide range of risk is quite important and might represent a substantial cost for the health system as well as for the society. Our results emphasize the need to implement preventive and control measures for air pollution and avoid the worsening of the present situation.

  18. Spatial and temporal variations in inhalable CuZnPb aerosols within the Mexico City pollution plume.

    Science.gov (United States)

    Moreno, T; Querol, X; Pey, J; Minguillón, M C; Pérez, N; Alastuey, A; Bernabé, R M; Blanco, S; Cárdenas, B; Eichinger, W; Salcido, A; Gibbons, W

    2008-03-01

    We report on the CuPbZn content of PM10 and PM2.5 samples collected from three sites (urban T0, suburban T1 and rural T2) during the Mexico City MILAGRO campaign of March 2006. Daytime city centre concentrations of summation operator CuZnPb(PM10) were much higher (T0 > 450 ng m(-3)) than at the suburban site (T1 pollutants became trapped in the nightly inversion layer, but decreased at the rural site. Transient spikes in concentrations of different metals, e.g. a "copper event" at T0 (CuPM10 281 ng m(-3)) and "zinc event" at T1 (ZnPM10 1481 ng m(-3)) on the night of March 7-8, demonstrate how industrial pollution sources produce localised chemical inhomogeneities in the city atmosphere. Most metal aerosols are <2.5 microm and SEM study demonstrates the dominance of Fe, Ti, Ba, Cu, Pb and Zn (and lesser Sn, Mo, Sb, W, Ni, V, As, Bi) in metalliferous particles that have shapes including spherical condensates, efflorescent CuZnClS particles, cindery Zn, and Cu wire. Metal aerosol concentrations do not change in concert with PM10 mass, which is more influenced by wind resuspension than industrial emissions. Metalliferous particles can induce cell damage, and PM composition is probably more important than PM mass, with respect to negative health effects, so that better monitoring and control of industrial emissions would likely produce significant improvements in air quality.

  19. PBL Aerosols SE of Mexico City in the dry Season: Biomass Burning and Windblown Dust and its Impact on Photolysis Frequencies

    Science.gov (United States)

    Junkermann, W.; Grutter, M.; Baumgardner, D.; Steinbrecher, R.

    2007-05-01

    During the dry season in March 2006 airborne investigations on aerosol distributions, ultraviolet actinic radiation and ozone profiles were performed southeast of Mexico City using an ultralight aircraft as a mobile platform. The area investigated covered the rural area southeast of Mexico City, the Chalco Valley, Huexca and Atlixco south of the volcano Popocatepetl, east of Paso de Cortés to the airport of Puebla and the pass between Puebla and Mexico City north of the volcano Ixtachiuatl. The Chalco valley is the main venting valley of the Mexico City basin to the south. Intense biomass burning was observed on both slopes of the volcanoes leading to strong pyrocumulus cloud production in the northern part of the national reserve and above the motorway Puebla-Mexico. Fine particle (> 10 nm) numbers reached up to 80000/cm3 close to the burning plumes with significant reduction to ~ 30-40000/cm3 in the Chalco valley where coarse particles (> 300 nm) dominated the total mass. Dust devils transporting coarse soil particles up to elevations of more than 4000 m a.s.l. were frequently observed. Particles and air masses of pollution sources in the area can be characterized by aerosol size distributions and/or spectral absorption from multi-wavelength aethalometer measurements as well as from ozone mixing ratios and meteorological data measured onboard. The aerosol impact on photolysis rates and air chemistry is derived from vertical profiles of actinic radiation in the JO1D and JNO2 spectral regimes at 300 nm and 380 nm, respectively. Profiles were flown on both sides of the volcano ridge, south of Popocatepetl and above Tenango del Aire where aircraft measurements were supported by ceilometer aerosol vertical profiles.

  20. Negotiating Urban Citizenship: The Urban Poor, Brokers and The State in Mexico City and Khartoum

    NARCIS (Netherlands)

    Denissen, I.N.M.

    2014-01-01

    This study is about citizenship and informality in megacities. The percentage of the world population living in cities is expected to further increase in the coming decades. Urbanisation is characterised by informality in large parts of the globe. Despite urban dwellers formally having the right to

  1. Characteristics of female sex workers with US clients in two Mexico-US border cities.

    Science.gov (United States)

    Strathdee, Steffanie A; Lozada, Remedios; Semple, Shirley J; Orozovich, Prisci; Pu, Minya; Staines-Orozco, Hugo; Fraga-Vallejo, Miguel; Amaro, Hortensia; Delatorre, Adela; Magis-Rodríguez, Carlos; Patterson, Thomas L

    2008-03-01

    HIV prevalence is increasing among female sex workers (FSWs) in Tijuana and Ciudad Juarez, 2 Mexican cities on the US border. Quasilegal prostitution in both cities attracts large numbers of sex tourists. We compared FSWs with and without US clients in both cities. FSWs aged > or =18 years reporting unprotected sex with > or =1 client within the last 2 months, who were not knowingly HIV-infected, were enrolled in a behavioral intervention study. At baseline, participants underwent interviews, antibody testing for HIV and syphilis, and vaginal swabs for detecting gonorrhea and Chlamydia. Logistic regression identified factors associated with reporting >1 US client. Of 924 FSWs, 69% had US clients. Median age and duration in sex work were 32 and 4 years. Prevalence of HIV, infectious syphilis (titer > or =1:8), gonorrhea, Chlamydia, and any STI was 6%, 14%, 6%, 13%, and 27%, respectively. Compared with other FSWs, FSWs with US clients were more likely to have syphilis titers > or =1:8 (16% vs. 10%, P = 0.01), gonorrhea (8% vs. 2%, P 250 clients in the last 6 months, having syphilis titers > or =1:8, and injecting drugs. In these border cities, FSWs reporting US clients were more likely to have current STIs and to engage in higher-risk behaviors. Intensified binational prevention efforts involving both FSWs and their clients are urgently needed.

  2. Ion beam analysis of ancient Mexican colored teeth from archaeological sites in Mexico City

    Science.gov (United States)

    Rodríguez-Fernández, L.; Ruvalcaba-Sil, J. L.; Ontalba-Salamanca, M. A.; Román-Berrelleza, J. A.; Gallardo, M. L.; Grimaldi, D. M.; de Lucio, O. G.; Miranda, J.

    1999-04-01

    Infant teeth with extremely rare colored enamel regions white, blue-gray and brown, have been analyzed by Particle Induced X-ray Emission (PIXE) and Rutherford Backscattering Spectrometry (RBS). The teeth were part of human being sacrifices to deities of the Mexica culture, Mexico, corresponding to the Late Post-classic period (1325-1521 A.D.). Comparisons to normal teeth from the same historical period indicate that the colored ones present larger mean amounts of Mn and Fe, while Zn and Sr do not differ too much. Possible inorganic compounds responsible for the different colorations are indicated.

  3. Late Pleistocene-Holocene Volcanism of the Mexico Basin and Assessment of Volcanic Hazards in One of the World’s Largest Cities

    Science.gov (United States)

    Layer, P. W.; Macías, J.; Arce, J.; García, F.

    2009-12-01

    The Mexico City metropolitan area is home to more than 22 million people living in sight of, or living on, several volcanoes that either are currently active or show evidence of Late Pleistocene-Holocene activity (e.g., pyroclastic flows, debris avalanches and lahars). The volcanic rocks are located in five main belts or ranges: Sierra Nevada, Sierra de las Cruces, Sierra Guadalupe, Sierra de Santa Catarina, and the Chichinautzin Volcanic Field which surround the Mexico Basin and belong to the Trans-Mexican Volcanic Belt, preserving approx. 14 Ma of geologic history. Much attention has been devoted to the youngest of the volcanoes such as Popocatépetl in the Sierra Nevada which resumed activity in 1994-present and Chichinautzin which includes the 1600 year bp Xitle volcano. Surprisingly, the pre-Holocene history is not well constrained in the Mexico City area, due of the lack of detailed mapping coupled with high precision geochronology. Our new 40Ar/39Ar and petrologic data and detailed mapping focus on the earliest history of these volcanic systems and their temporal, spatial and geochemical evolution. For example, data from Tlaloc and Telapón volcanoes in the Sierra Nevada show at least two significant periods of edifice building (1.0 to 1.5 Ma and 0 to 400 ka) with an apparent long period of quiescence that clearly suggests that volcanism in the region did not migrate from north to south but that it has a more complex evolution that continues to pose a serious threat to the population of Mexico City. In addition, a 450 ka age, based on dome and pumice dating, constrains the timing of a major sector collapse of Iztaccíhuatl volcano that produced a Mt. St. Helens - sized debris avalanche deposit towards the present metropolitan area of the City of Puebla. In the Sierra de las Cruces Range, volcanic centers do show a north-south age progression from ~5 Ma, cumulating with the Zempoala edifice collapse approximately 900 ka, producing lahars and block and ash

  4. Survey on attitudes toward HIV-infected individuals and infection control practices among dentists in Mexico City.

    Science.gov (United States)

    Maupomé, G; Acosta-Gío, E; Borges-Yáñez, S A; Díez-de-Bonilla, F J

    2000-02-01

    The teaching of infection control is gradually being introduced at dental schools in Mexico. However, most practicing dentists have limited access to current infection control standards. Deficiencies of knowledge with regard to blood-borne pathogens such as HIV and hepatitis B virus may influence attitudes toward infected individuals and reduce compliance with infection control recommendations. The purpose of this study was to assess (1) attitudes toward HIV-infected patients and hepatitis B virus-infected patients and (2) infection control knowledge and practices among dental practitioners in Mexico City. A total of 196 dentists were interviewed by means of a questionnaire with Likert-type scales and open-ended questions (response rate, 86.1%). Most respondents had no previous social or professional contact with HIV-positive individuals. Nine percent indicated that they had knowingly treated HIV-positive patients. Perceived professional and moral obligations to treat HIV-positive patients were high. Thirty-five percent of the respondents perceived the risk of HIV infection as "considerable" to "very strong." The risk of hepatitis B infection was considered significantly higher than the risk of HIV infection (P personal protective equipment was high. Most respondents used dry heat sterilization. The principal disinfectants used were quaternary ammonium compounds, bleach, and glutaraldehyde. Fifty-four percent of the respondents acknowledged that clinical precautions reduced occupational risks. This survey revealed contradictory attitudes toward HIV-positive individuals and limited understanding of infection control recommendations. Educational and regulatory efforts are needed to promote better adherence to current infection control standards.

  5. 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 < 0.05) and 55 % (p < 0.05) reduction in the prevalence of perpetrated and experienced psychological 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).

  6. A geophysical, geochemical and remote sensing investigation of the water resources at the city of Chihuahua, Mexico

    Science.gov (United States)

    Rodriguez-Pineda, Jose Alfredo

    This doctoral dissertation is an investigation of the underground water resources of a typical urban center in and northern Mexico, the City of Chihuahua. In the first part of the investigation I analyzed by remote sensing the urban growth and the consequent water demand and supply of the city of Chihuahua over a period of 22 years (1975--1997). A linear and a regression model was successfully fit to the data and can be used to forecast future water needs based on urban growth. The second study was a gravity survey of about 200 stations and a reprocessing of about 800 earlier gravity readings in the City of Chihuahua area to define the local geologic structures. The findings were used as a first exploration step to assess groundwater resources in the area. Landsat TM imagery, 30-m resolution, was applied in conjunction with Bouguer gravity anomalies to understand and define the lateral extension of the Chihuahua, Tabalaopa Basins, and the western side of the Aldama Basin. Depth and strata thickness of these three alluvial basins were defined by gravity modeling and constrained by exploration oil well data and published stratigraphic columns. The gravity results showed that the western side of the Chihuahua Basin could be the site of potential aquifers. Also, the gravity results suggested an structural gap between the southern side of the Tabalaopa Basin and the Horcasitas Basin, likely a former course of the Chuviscar River. This gap exposes the Horcasitas Basin as another basin with promise as future groundwater source. The last part of this research focused on the groundwater pollution generated by the discharge of sewage into the Rio Chuviscar and Sacramento for decades by the City of Chihuahua. Based on a groundwater and during three consecutive years (from 1993 to 1995) the elements derived mainly from the urban sewage were identified in the Tabalaopa Aquifer. A multivariable statistical evaluation supported by a surface water sampling and analysis, and of a

  7. Isolation of Cryptococcus neoformans var. neoformans from bird droppings, fruits and vegetables in Mexico City.

    Science.gov (United States)

    López-Martínez, R; Castañón-Olivares, L R

    1995-01-01

    The presence of Cryptococcus neoformans in various natural sources, such as bird droppings, fruits and vegetables, was investigated. A total of 711 samples were analyzed; C. neoformans var. neoformans was isolated from seven out of 74 bird droppings (9.5%), with parrots as one of the most significant sources. Fruits were positive in 9.5% of the 169 samples studied, specially citrus fruits, particularly grapefruit, in which the highest frequency was found. From the 468 vegetable samples, only 20 were positive (4.2%). It is emphasized that five of the positive vegetables species are autochthonous to Mexico: avocado (Nectandra salicifolia), beet (Beta vulgaris var. quinopodiace), chayote (Sechium edule), stringbean (Cassia sp), and nopal (Opuntia ficus-indica).

  8. Prescription patterns of antihypertensives in a community health centre in Mexico City: a drug utilization study.

    Science.gov (United States)

    Alba-Leonel, Adela; Carvajal, Alfonso; Fierro, Immaculada; Castillo-Nájera, Fernando; Campos-Ramos, Oscar; Villa-Romero, Antonio; Molina-Guarneros, Juan

    2016-06-01

    Hypertension is highly prevalent; in Mexico, the 2012 National Health and Nutrition Survey reported a prevalence of hypertension of 31.5% in the adult population. Pharmacological treatment is the commonest intervention and has been shown to reduce cardiovascular mortality and morbidity, and total mortality. Accordingly, the type and number of antihypertensives used and the outcome - in terms of blood pressure (BP) control - are important. Therefore, our purpose is to learn the pattern of antihypertensive drug prescription and explore the determinants of BP control in an urban population in Mexico. A retrospective cross-sectional drug utilization study was conducted. Medical records from a community health centre were searched to identify those corresponding to patients diagnosed with hypertension; information upon antihypertensives used and control of the disease was carefully retrieved. A logistic regression model was built to know the main determinants of BP control. A sample of 345 clinical records of interest was identified. Most patients received antihypertensives (86.4%); the leading medications used were angiotensin-converting enzyme inhibitors, 63.8%; beta-blockers (26.5%), diuretics (19.8%), angiotensin-receptor blockers (15.8%) and calcium-channel blockers (6.4%). Only the age (≥55 years) and BMI (>30) of the patients, and the age of the doctors (≥55 years), had an important influence on BP control. Obesity is a particular and important determinant of uncontrolled hypertension; it is worth to act on body weight, on an individual basis. As lack of control has been also tied to elderly doctors, an education programme could be envisaged. © 2016 The Authors Fundamental & Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of Société Française de Pharmacologie et de Thérapeutique.

  9. 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

  10. Eddy Covariance Flux Measurements of Pollutant Gases in the Mexico City Urban Area: a Useful Technique to Evaluate Emissions inventories

    Science.gov (United States)

    Velasco, E.; Grivicke, R.; Pressley, S.; Allwine, G.; Jobson, T.; Westberg, H.; Lamb, B.; Ramos, R.; Molina, L.

    2007-12-01

    Direct measurements of emissions of pollutant gases that include all major and minor emissions sources in urban areas are a missing requirement to improve and evaluate emissions inventories. The quality of an urban emissions inventory relies on the accuracy of the information of anthropogenic activities, which in many cases is not available, in particular in urban areas of developing countries. As part of the MCMA-2003 field campaign, we demonstrated the feasibility of using eddy covariance (EC) techniques coupled with fast-response sensors to measure fluxes of volatile organic compounds (VOCs) and CO2 from a residential district of Mexico City. Those flux measurements demonstrated to be also a valuable tool to evaluate the emissions inventory used for air quality modeling. With the objective to confirm the representativeness of the 2003 flux measurements in terms of magnitude, composition and diurnal distribution, as well to evaluate the most recent emissions inventory, a second flux system was deployed in a different district of Mexico City during the 2006 MILAGRO field campaign. This system was located in a busy district surrounded by congested avenues close to the center of the city. In 2003 and 2006 fluxes of olefins and CO2 were measured by the EC technique using a Fast Isoprene Sensor calibrated with a propylene standard and an open path Infrared Gas Analyzer (IRGA), respectively. Fluxes of aromatic and oxygenated VOCs were analyzed by Proton Transfer Reaction-Mass Spectroscopy (PTR-MS) and the disjunct eddy covariance (DEC) technique. In 2006 the number of VOCs was extended using a disjunct eddy accumulation (DEA) system. This system collected whole air samples as function of the direction of the vertical wind component, and the samples were analyzed on site by gas chromatography / flame ionization detection (GC-FID). In both studies we found that the urban surface is a net source of CO2 and VOCs. The diurnal patterns were similar, but the 2006 fluxes

  11. Winfield Scott’s Mexico City Operation: The Genesis of American Operational Art

    Science.gov (United States)

    1989-05-12

    a major fortress, San Juan de Ulloa , with 128 guns and over 1,000 soldiers guarding the harbor. The city itself had nine forts with connecting curtain...knew the details of the 1838 the French attack of Vera Cruz and San Juan de Ulloa under the command of Admiral Baudln and the Prince de Joinville. This...honorable profession,. Manuel Dominquez, and his band of 200 men to serve as guides, couriers, and spies. Dominquez and his men developed into an effective

  12. [Depression in older adults with extreme poverty belonging to Social Program in City Juarez, Chihuahua, Mexico].

    Science.gov (United States)

    Flores-Padilla, Luis; Ramírez-Martínez, Flor Rocío; Trueba-Gómez, Rocío

    2016-01-01

    To identify depression in older adults living in extreme poverty beneficiaries of social program in City Juarez, Chihuahua. Analytical study in 941 adults > 60 years, studied variables: age, sex, marital status, education and work, extreme poverty, place of residence, asylum. Yesavage Geriatric scale was used. X², IC work, incomplete education, living in asylum, have hypertension and pulmonary diseases increase depression risk (p < 0.05). Older Adults program beneficiaries living in extreme poverty depression is greater than that reported in the literature. The support granted by the Mexican Government to social programs that benefit older adults should be planned strategically with aims on improving the long-term health.

  13. The disproportionate burden of HIV and STIs among male sex workers in Mexico City and the rationale for economic incentives to reduce risks

    OpenAIRE

    Omar Galárraga; Sosa-Rubí, Sandra G.; Andrea González; Florentino Badial-Hernández; Conde-Glez, Carlos J.; Luis Juárez-Figueroa; Sergio Bautista-Arredondo; Caroline Kuo; Don Operario; Mayer, Kenneth H

    2014-01-01

    Introduction: The objective of this article is to present the rationale and baseline results for a randomized controlled pilot trial using economic incentives to reduce HIV and sexually transmitted infection (STI) risk among male sex workers (MSWs) in Mexico City. Methods: Participants (n=267) were tested and treated for STIs (chlamydia, gonorrhoea, syphilis and HIV) and viral hepatitis (hepatitis B and C), received HIV and STI prevention education and were randomized into four groups: (1) co...

  14. Mexico City Aerosol Analysis During Milagro Using High Resolution Aerosol Mass Spectrometry at the Urban Supersite (T0) - Part 1: Fine Particle Composition and Organic Source Apportionment.

    OpenAIRE

    Aiken, A. C.; Foy, B. de; Wiedinmyer, C.; Ulbrich, I. M.; Wehrli, M. N.; Szidat, S.; Prevot, A. S. H.; Noda, J.; Wacker, L.; Volkamer, R.; Fortner, E. C.; Wang, J.; Laskin, A.; Shutthanandan, V.; Zheng, J.

    2010-01-01

    Submicron aerosol was analyzed during the MILAGRO field campaign in March 2006 at the T0 urban supersite in Mexico City with a High-Resolution Aerosol Mass Spectrometer (AMS) and complementary instrumentation. Positive Matrix Factorization (PMF) of high resolution AMS spectra identified a biomass burning organic aerosol (BBOA) component, which includes several large plumes that appear to be from forest fires within the region. Here, we show that the AMS BBOA concentration at T0 correlates wit...

  15. 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

  16. Comparison of aromatic hydrocarbon measurements made by PTR-MS, DOAS and GC-FID in Mexico City during the MCMA 2003 field experiment

    OpenAIRE

    B. T. Jobson; Volkamer, R; Velasco, E.; Allwine, G; Westberg, H.; Lamb, B.; Alexander, M.L.; C. M. Berkowitz; L. T. Molina

    2009-01-01

    A comparison of aromatic hydrocarbon measurements is reported for the CENICA supersite in the district of Iztapalapa during the Mexico City Metropolitan Area field experiment in April 2003 (MCMA 2003). Data from three different measurement methods were compared, a proton transfer reaction mass spectrometer (PTR-MS), long path measurements using a UV differential optical absorption spectrometer (DOAS), and gas chromatography-flame ionization analysis (GC-FID) of canister samples. Lab tests est...

  17. 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

  18. Factors influencing the large-scale distribution of Hg° in the Mexico City area and over the North Pacific

    OpenAIRE

    Blake, D; Vay, S.; Sachse, G.; Browell, E.; M. Avery; Dibb, J; Scheuer, E; Mao, H.; Talbot, R.; G. Huey; H. Fuelberg

    2007-01-01

    Gas-phase elemental mercury (Hg°) was measured aboard the NASA DC-8 aircraft during the Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign in spring 2006. Flights were conducted around Mexico City and on two subsequent deployments over the North Pacific based out of Honolulu, Hawaii and Anchorage, Alaska. Data obtained from 0.15–12 km altitude showed that Hg° exhibited a relatively constant vertical profile centered around 100 ppqv. Highly concentrated pol...

  19. Ethnobotanical, micrographic and pharmacological features of plant-based weight-loss products sold in naturist stores in Mexico City: the need for better quality control

    OpenAIRE

    Patricia Marta Arenas; Soledad Molares; Abigail Aguilar Contreras; Belén Doumecq; Florencia Gabrielli

    2013-01-01

    The consumption of dietary supplements and herbal mixtures to promote weight loss is a common practice in the West. This study was undertaken in Mexico City, surveying stores selling "natural products" at subway stations. The aims of this paper were as follows: to compile a record of plant products marketed as slimming aids and of retailer perceptions of these products; to review the pharmacological and ethnobotanical literature on the species declared; and to create an optical micrograph of ...

  20. Explicit modeling of organic chemistry and secondary organic aerosol partitioning for Mexico City and its outflow plume

    Directory of Open Access Journals (Sweden)

    J. Lee-Taylor

    2011-12-01

    Full Text Available The evolution of organic aerosols (OA in Mexico City and its outflow is investigated with the nearly explicit gas phase photochemistry model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere, wherein precursor hydrocarbons are oxidized to numerous intermediate species for which vapor pressures are computed and used to determine gas/part