Different relationships between personal exposure and ambient concentration by particle size.

Science.gov (United States)

Guak, Sooyoung; Lee, Kiyoung

2018-04-06

Ambient particulate matter (PM) concentrations at monitoring stations were often used as an indicator of population exposure to PM in epidemiological studies. The correlation between personal exposure and ambient concentrations of PM varied because of diverse time-activity patterns. The aim of this study was to determine the relationship between personal exposure and ambient concentrations of PM 10 and PM 2.5 with minimal impact of time-activity pattern on personal exposure. Performance of the MicroPEM, v3.2 was evaluated by collocation with central ambient air monitors for PM 10 and PM 2.5 . A field technician repeatedly conducted measurement of 24 h personal exposures to PM 10 and PM 2.5 with a fixed time-activity pattern of office worker over 26 days in Seoul, Korea. The relationship between the MicroPEM and the ambient air monitor showed good linearity. Personal exposure and ambient concentrations of PM 2.5 were highly correlated with a fixed time-activity pattern compared with PM 10 . The finding implied a high infiltration rate of PM 2.5 and low infiltration rate of PM 10 . The relationship between personal exposure and ambient concentrations of PM 10 and PM 2.5 was different for high level episodes. In the Asian dust episode, staying indoors could reduce personal exposure to PM 10 . However, personal exposure to PM 2.5 could not be reduced by staying indoors during the fine dust advisory episode.

EXPOSURE TO CONCENTRATED AMBIENT PARTICLES (CAPS): REVIEW

Science.gov (United States)

Epidemiologic studies support a participation of fine particulate matter (PM) with a diameter of 0.1 to 2.5 microm in the effects of air pollution particles on human health. The ambient fine particle concentrator is a recently developed technology that can enrich the mass of ambi...

The contribution of waste water treatment plants to PBDEs in ambient air

International Nuclear Information System (INIS)

Martellini, Tania; Jones, Kevin C.; Sweetman, Andy; Giannoni, Martina; Pieri, Francesca; Cincinelli, Alessandra

2012-01-01

Air samples were collected at different sites in and around two wastewater treatment plants (WWTPs) located in central Italy to determine the concentrations, compositional profiles and contribution to ambient levels of eight polybrominated diphenyl ethers (PBDEs). The investigated WWTPs were selected as they treat industrial wastewater produced by local textile industries along with municipal wastewater. PBDE concentrations within the WWTPs were higher than those measured at reference sites located 4 and 5 km away with BDE-209 dominating the BDE congener composition in all air samples in 2008. Ambient PBDE concentrations measured in and around the WWTPs and estimates of emissions from aeration tanks suggest that WWTPs are sources of PBDEs to ambient air. Principal component analysis and Pearson correlations confirmed this result. The effect of distance from the plant and wind direction on atmospheric concentrations was also investigated. Although the primary fate of PBDEs in WWTPs will be partitioning to sewage sludge, this study suggests that plants can provide a measurable source of these compounds to local ambient air. - Highlights: ► Levels and distribution profiles of PBDEs in the atmosphere surrounding two WWTPs. ► Airborne polybrominated diphenyl ethers in the surrounding area of two WWTPs in Italy. ► To investigate WWTPs as sources of PBDEs to the atmosphere. ► Samples collected downwind respect to the plant showed BDE-209 as dominant congener. ► The effect of distance and wind direction on atmospheric concentrations was also investigated. - Waste water treatment plants as sources of PBDEs to the ambient air.

Ambient air quality monitoring at Universiti Tunku Abdul Rahman (UTAR) Kampar campus

Science.gov (United States)

Jie, Lim Jun; Xinxin, Guo; Ke, Wang

2017-04-01

Air Pollutant includes any substance in solid, liquid or gaseous form present in the atmosphere in concentrations which may tend to be injurious to all living creatures, property and environment. In this study, automatic continuous monitoring station was used to monitor concentration of carbon monoxide (CO), non-methane hydrocarbon (NMHC), and carbon dioxide (CO2) in the ambient air of Kampar Campus, Universiti Tunku Abdul Rahman. High-volume air sampler was also used to monitor the concentration of PM2.5 and the collected PM2.5 was further analysed for the heavy metal concentration such as Zinc (Zn), Cadmium (Cd), Copper (Cu), Arsenic (As), Aluminium (Al), and Lead (Pb) in PM2.5 using inductively coupled plasma-mass spectrometer (ICP-MS). The overall ambient air quality in the campus area is consider unhealthy as the non-methane hydrocarbon (NMHC) and carbon dioxide (CO2) average concentration obtained were far exceeding the recommended limit concentration set by United States Environmental Protection Agency (USEPA). Meteorological data was found that it does not show much relationship with the air quality data in this study. The concentration of Zn and Al were found the dominant heavy metal in the ambient air. The enrichment factor analysis also shows that the heavy metals contained in PM2.5 mainly origin from the natural source except for the Zn which it is highly contaminated by human activities.

Fission-nuclide concentrations of ambient aerosol separated by size

International Nuclear Information System (INIS)

Csepregi, T.; Kovacs, L.; Maschek, I.; Szterjopulos, K.

1984-01-01

Examinations were carried on the radionuclides in aerosol deposited on filters of an air-conditioning plant with high air flow rate. For nuclide concentration of ambient air qualitative and quantitative analyses were made by gamma spectrometry. Methods have been developed for sample preparation, size fractionation by sedimentation technique and measurement of air flow. The collected aerosol particles was separated into five size fractions from 1 to 5 μm and the aerosol fractions were analysed. The mass/size distribution of the particles processed by sedimentation has been compared with that of the ambient aerosol separated by a slot impactor Hungarian type. Because the aggregation caused by the resuspensationtechnique would be assumed, electronmicrophotos were made on processed and unprocessed aerosols. On the basis of them the particle aggregation may be negligible. Otherwise, the derivation of concentration needs to know the exact air volume. For this aim the technical parameters of the aerodynamic system have also been measured in two different ways. The paper reports on the size dependence of fission products originating from the present global late fallout for a two years monitoring period. The results are compared with the daily beta activity concentration of aerosol samples taken by an other sampling unit. (Author)

Comparison of emission inventory and ambient concentration ratios of CO, NMOG, and NOx in California South Coast Air Basin

International Nuclear Information System (INIS)

Fujita, E.M.; Croes, B.E.; Bennett, C.L.; Lawson, D.R.; Lurmann, F.W.; Main, H.H.

1992-01-01

In the present study, the author performed a top-down validation of the reactive organic gas and carbon monoxide emission inventories for California's South Coast Air Basin by comparing speciation profiles for nonmethane organic gases (NMOG) and ratios of CO/NO x and NMOG/NO x derived from early-morning (0700 to 0800) ambient measurements taken during the 1987 Southern California Air Quality Study with the corresponding ratios and speciation profiles derived from day-specific, hourly, gridded emission inventories. Twenty separate comparisons were considered for each ratio, each representing a different combination of season, emission category, and spatial and temporal averaging of emissions. It was determined that the most appropriate comparison in summer was ambient pollutant ratios with ratios derived from morning on-road motrovehicle emission inventories, and in the fall, ambient ratios with ratios derived from overnight on-road motor vehicle emission inventories with some contribution from overnight stationary-source NO x emission inventories. From these comparisons, the ambient CO/CO x and NMOG/NO x ratios are about 1.5 and 2 to 2.5 times higher, respectively, than the corresponding inventory ratios. On the assumption that inventories of NO x emissions are reasonably correct, these results indicate that on-road motor vehicle CO and NMOG emissions are significantly underestimated. Comparisons of measured CO, NMOG, and NO x concentrations and CO/NO x and NMOG/NO x ratios with air quality model predictions obtained by the California Air Resources Board show similar differences

Historical Ambient Air Quality Data Inventory

Data.gov (United States)

U.S. Environmental Protection Agency — The Historical Ambient Air Quality Data Inventory contains measured and estimated data on ambient air pollution for use in assessing air quality, assisting in...

Concentrations of persistent organic pollutants in ambient air in Durban, South Africa

CSIR Research Space (South Africa)

Batterman, S

2007-01-01

Full Text Available This paper reports on an extensive ambient air quality monitoring program in Durban (eThekwini Municipality), South Africa, on Africa’s southeast coast. Following a multi stakeholder process coordinated by the Municipality Metropolitan Health...

Ambient air quality trends in Alberta

International Nuclear Information System (INIS)

2007-01-01

This document provided an overview of ambient air pollutant trends in Alberta. The report discussed the following pollutants having effect on human and environmental health: carbon monoxide (CO), hydrogen sulphide (H2 S ), nitrogen dioxide (NO 2 ), sulphur dioxide (SO 2 ), ozone (O 3 ), fine particulate matter (PM 2 .5), benzene, and benzopyrene. Each of these pollutants was described. The report provided data on annual average concentration trends and annual 99th percentile concentration as an indicator of peak concentrations. A map illustrating air quality monitoring stations in 2006 was also provided. The findings revealed that mean annual CO levels were the lowest they have been since 1990; hydrogen sulphide concentrations have fluctuated in time since 1990; most Edmonton and Calgary area stations showed significant decreasing trends in annual average NO 2 levels since 1990; and higher SO 2 concentrations have been found in the industrial areas of Alberta, such as the Redwater and Scotford oil sands locations. tabs., figs

Ambient air pollution and cancer in California Seventh-day Adventists.

Science.gov (United States)

Mills, P K; Abbey, D; Beeson, W L; Petersen, F

1991-01-01

Cancer incidence and mortality in a cohort of 6,000 Seventh-day Adventist nonsmokers who were residents of California were monitored for a 6-y period, and relationships with long-term ambient concentrations of total suspended particulates (TSPs) and ozone (O3) were studied. Ambient concentrations were expressed as mean concentrations and exceedance frequencies, which are the number of hours during which concentrations exceeded specified cutoffs (e.g., federal and California air quality standards). Risk of malignant neoplasms in females increased concurrently with exceedance frequencies for all TSP cutoffs, except the lowest, and these increased risks were highly statistically significant. An increased risk of respiratory cancers was associated with only one cutoff of O3, and this result was of borderline significance. These results are presented in the context of setting standards for these two air pollutants.

ORGANOCHLORINE PESTICIDES IN THE AMBIENT AIR OF MEXICO

Science.gov (United States)

Recent and past use of organochlorine pesticides (OCPs) in Mexico has resulted in concentrations in ambient air that are 1-2 orders of magnitude above levels in the Great Lakes region. Atmospheric transport from Mexico and Central America may be contributing significant amounts ...

Temporal-Spatial Ambient Concentrator Estimator (T-SpACE): Hierarchical Bayesian Model Software Used to Estimate Ambient Concentrations of NAAQS Air Pollutants in Support of Health Studies

Science.gov (United States)

To fulfill its mission to protect human health and the environment, EPA has established National Ambient Air Quality Standards (NAAQS) on six selected air pollutants known as criteria pollutants: ozone (O3); carbon monoxide (CO); lead (Pb); nitrogen dioxide (NO2); sulfur dioxide ...

Profiling quinones in ambient air samples collected from the Athabasca region (Canada).

Science.gov (United States)

Wnorowski, Andrzej; Charland, Jean-Pierre

2017-12-01

This paper presents new findings on polycyclic aromatic hydrocarbon oxidation products-quinones that were collected in ambient air samples in the proximity of oil sands exploration. Quinones were characterized for their diurnal concentration variability, phase partitioning, and molecular size distribution. Gas-phase (GP) and particle-phase (PM) ambient air samples were collected separately in the summer; a lower quinone content was observed in the PM samples from continuous 24-h sampling than from combined 12-h sampling (day and night). The daytime/nocturnal samples demonstrated that nighttime conditions led to lower concentrations and some quinones not being detected. The highest quinone levels were associated with wind directions originating from oil sands exploration sites. The statistical correlation with primary pollutants directly emitted from oil sands industrial activities indicated that the bulk of the detected quinones did not originate directly from primary emission sources and that quinone formation paralleled a reduction in primary source NO x levels. This suggests a secondary chemical transformation of primary pollutants as the origin of the determined quinones. Measurements of 19 quinones included five that have not previously been reported in ambient air or in Standard Reference Material 1649a/1649b and seven that have not been previously measured in ambient air in the underivatized form. This is the first paper to report on quinone characterization in secondary organic aerosols originating from oil sands activities, to distinguish chrysenequinone and anthraquinone positional isomers in ambient air, and to report the requirement of daylight conditions for benzo[a]pyrenequinone and naphthacenequinone to be present in ambient air. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Personal and ambient exposures to air toxics in Camden, New Jersey.

Science.gov (United States)

Lioy, Paul J; Fan, Zhihua; Zhang, Junfeng; Georgopoulos, Panos; Wang, Sheng-Wei; Ohman-Strickland, Pamela; Wu, Xiangmei; Zhu, Xianlei; Harrington, Jason; Tang, Xiaogang; Meng, Qingyu; Jung, Kyung Hwa; Kwon, Jaymin; Hernandez, Marta; Bonnano, Linda; Held, Joann; Neal, John

2011-08-01

Personal exposures and ambient concentrations of air toxics were characterized in a pollution "hot spot" and an urban reference site, both in Camden, New Jersey. The hot spot was the city's Waterfront South neighborhood; the reference site was a neighborhood, about 1 km to the east, around the intersection of Copewood and Davis streets. Using personal exposure measurements, residential ambient air measurements, statistical analyses, and exposure modeling, we examined the impact of local industrial and mobile pollution sources, particularly diesel trucks, on personal exposures and ambient concentrations in the two neighborhoods. Presented in the report are details of our study design, sample and data collection methods, data- and model-analysis approaches, and results and key findings of the study. In summary, 107 participants were recruited from nonsmoking households, including 54 from Waterfront South and 53 from the Copewood-Davis area. Personal air samples were collected for 24 hr and measured for 32 target compounds--11 volatile organic compounds (VOCs*), four aldehydes, 16 polycyclic aromatic hydrocarbons (PAHs), and particulate matter (PM) with an aerodynamic diameter 0.6) was found between benzene and MTBE in both locations. These results suggest that automobile exhausts were the main contributors to benzene and MTBE air pollution in both neighborhoods. Formaldehyde and acetaldehyde concentrations were found to be high in both neighborhoods. Mean (+/- SD) concentrations of formaldehyde were 20.2 +/- 19.5 microg/m3 in Waterfront South and 24.8 +/- 20.8 microg/m3 in Copewood-Davis. A similar trend was observed for the two compounds during the saturation-sampling campaigns. The results indicate that mobile sources (i.e., diesel trucks) had a large impact on formaldehyde and acetaldehyde concentrations in both neighborhoods and that both are aldehyde hot spots. The study also showed that PM2.5, aldehydes, BTEX, and MTBE concentrations in both Waterfront South

Hanford 200 East Area ambient NO/sub x/ concentrations, February 1968 through February 1969

International Nuclear Information System (INIS)

Ramsdell, J.V.

1981-09-01

Ambient concentrations of oxides of nitrogen (NO/sub x/) were measured in the vicinity of the 200 East Area of Hanford from late February 1968 through February 1969. This report contains an analysis of the complete set to document the ambient NO/sub x/ concentrations during time periods when the Purex Plant was emitting NO/sub x/. It is not intended to represent either current ambient NO/sub x/ concentrations or concentrations during Purex Plant operation in the future. However, it does provide a reference for use in comparison of ambient NO/sub x/ concentrations during future periods of Purex emissions with those occurring in past periods. It is also of interest to compare the annual average concentrations estimated from the measurements with the national primary ambient air quality standard for NO 2 , which is 50 parts per billion (ppb) annual arithmetic mean

Personal carbon monoxide exposures of preschool children in Helsinki, Finland - comparison to ambient air concentrations

Energy Technology Data Exchange (ETDEWEB)

Alm, S.; Mukala, K.; Tittanen, P.; Jantunen, M.J. [KTL National Public Health Institute, Kuopio (Finland). Dept. of Environmental Health

2001-07-01

The associations of personal carbon monoxide (CO) exposures with ambient air CO concentrations measured at fixed monitoring sites, were studied among 194 children aged 3-6yr in four downtown and four suburban day-care centers in Helsinki, Finland. Each child carried a personal CO exposure monitor between 1 and 4 times for a time period of between 20 and 24h. CO concentrations at two fixed monitoring sites were measured simultaneously. The CO concentrations measured at the fixed monitoring sites were usually lower (mean maximum 8-h concentration: 0.9 and 2.6mgm{sup -3}) than the personal CO exposure concentrations (mean maximum 8-h concentration: 3.3mgm{sup -3}).The fixed site CO concentrations were poor predictors of the personal CO exposure concentrations. However, the correlations between the personal CO exposure and the fixed monitoring site CO concentrations increased (-0.03 -- -0.12 to 0.13-0.16) with increasing averaging times from 1 to 8h. Also, the fixed monitoring site CO concentrations explained the mean daily or weekly personal CO exposures of a group of simultaneously measured children better than individual exposure CO concentrations. This study suggests that the short-term CO personal exposure of children cannot be meaningfully assessed using fixed monitoring sites. (author)

Ambient air quality monitoring during the H1N1 influence period in Pune (India).

Science.gov (United States)

Pathak, M; Deshpande, A; Mirashe, P K; Sorte, R B; Ojha, A

2010-10-01

Ambient air quality in an urban area is directly linked with activity level in the city including transport, business and industrial activities. Maharashtra Pollution Control Board (MPCB) has established an ambient air quality network in the city including state-of-the-art continuous air quality monitoring stations which indicate short duration air quality variations for criteria and non-criteria pollutants. The influence of H1N1 outbreak in Pune hitting its worst pandemic condition, led the civic authorities to implement stringent isolation measures including closure of schools, colleges, business malls, cinema halls, etc. Additionally, the fear of such a pandemic brought the city to a stand still. It was therefore necessary to assess the impacts of such activity level on ambient air quality in the city. It has been observed that such events have positive impacts on air quality of the city. There was a decrease in PM concentration almost to the tune of 30 to 40% if the impacts of precipitation, i.e. seasonal variations, are taken into account. Similarly, the non criteria pollutants too showed a marked but unusual decrease in their concentrations in this ever growing city. The influence of these in turn led to lowered concentrations of secondary pollutants, i.e. O3. Overall, the ambient air quality of Pune was found to be improved during the study period.

Gender Disparity in Lung Function Abnormalities among a Population Exposed to Particulate Matter Concentration in Ambient Air in the National Capital Region, India

Directory of Open Access Journals (Sweden)

Chandrasekharan Nair Kesavachandran

2015-01-01

Conclusions. Since the women in this study were non-smokers, the PM in ambient air can be considered to be the major reason for the decline in lung function. The sources of PM pollutants in the study locations are large scale infrastructural development activities such as building and road construction activities. Narrowed lung airways can alter the airway caliber or resistance and flow rates proportional to the airway radius, especially in smaller airways. The present study suggests the need for policy makers and stake holders to take the necessary steps to identify PM sources and reduce the emissions of PM concentrations in ambient air.

Uncertainty associated with the gravimetric measurement of particulate matter concentration in ambient air.

Science.gov (United States)

Lacey, Ronald E; Faulkner, William Brock

2015-07-01

This work applied a propagation of uncertainty method to typical total suspended particulate (TSP) sampling apparatus in order to estimate the overall measurement uncertainty. The objectives of this study were to estimate the uncertainty for three TSP samplers, develop an uncertainty budget, and determine the sensitivity of the total uncertainty to environmental parameters. The samplers evaluated were the TAMU High Volume TSP Sampler at a nominal volumetric flow rate of 1.42 m3 min(-1) (50 CFM), the TAMU Low Volume TSP Sampler at a nominal volumetric flow rate of 17 L min(-1) (0.6 CFM) and the EPA TSP Sampler at the nominal volumetric flow rates of 1.1 and 1.7 m3 min(-1) (39 and 60 CFM). Under nominal operating conditions the overall measurement uncertainty was found to vary from 6.1x10(-6) g m(-3) to 18.0x10(-6) g m(-3), which represented an uncertainty of 1.7% to 5.2% of the measurement. Analysis of the uncertainty budget determined that three of the instrument parameters contributed significantly to the overall uncertainty: the uncertainty in the pressure drop measurement across the orifice meter during both calibration and testing and the uncertainty of the airflow standard used during calibration of the orifice meter. Five environmental parameters occurring during field measurements were considered for their effect on overall uncertainty: ambient TSP concentration, volumetric airflow rate, ambient temperature, ambient pressure, and ambient relative humidity. Of these, only ambient TSP concentration and volumetric airflow rate were found to have a strong effect on the overall uncertainty. The technique described in this paper can be applied to other measurement systems and is especially useful where there are no methods available to generate these values empirically. This work addresses measurement uncertainty of TSP samplers used in ambient conditions. Estimation of uncertainty in gravimetric measurements is of particular interest, since as ambient particulate

New Council of State degree on ambient air quality is in the making

International Nuclear Information System (INIS)

Rahnasto, O.

2000-01-01

The Finnish Ministry of the Environment is currently preparing a new Council of State decree on ambient air quality to implement EC directive 1999/30/EC relating to limit values for SO 2 , NO 2 , particulate matter and lead in the ambient air, the EC directive 2000/69/EC relating to benzene and carbon monoxide in the ambient air, and regulations in EC directive 96/62/EC on ambient air quality assessment and management. The national legislation will come into force in July 2001. Current studies based on measurements and calculations show that the SO 2 concentrations in ambient air are generally low and clearly below the limit values. The same holds good for lead. However, the new limit values for NO 2 are exceeded in the largest towns, and the 2010 limit values for particulate matter presented in the guidelines are generally exceeded in small towns, too. The 2005 limit values for particulate matter are not so strict, and it is estimated that they will be exceeded especially in years when spring dust problems are serious. The limit values for CO may at times be exceeded in areas with heavy traffic. The limit values intended to protect the vegetation and the ecosystems are not exceeded in background areas to the implementation. As for benzene, it is assumed that the concentrations will generally be below the limit value in other parts of the world as well

Citizen participatory dioxin monitoring campaign by pine needles as biomonitor of ambient air dioxin pollution

Energy Technology Data Exchange (ETDEWEB)

Komichi, I.; Takatori, A. [Environmental Research Institute Inc., Tokyo (Japan); Aoyama, T. [Musashi Institute of Technology, Yokohama (Japan). Faculty of Environment and Informations; Vrzic, B. [Maxxam Analytics Inc. HRMS Laboratory, Waterloo, ON (Canada)

2004-09-15

The needle-type leaves of Japanese black pine trees (hereafter abbreviated as pine needles) have been used as an effective bio-monitor of ambient air pollution. Miyata Laboratory of Setsunan University has reported that the pine needles accumulate PCDDs and PCDFs (hereafter abbreviated as D/F) through photosynthesis and respiration during their lifetime. On the basis of this study, we have revealed the correlation between ambient air and pine needle concentrations to be estimated at or near 1:10 by analyzing long term continuous ambient dioxin monitoring data and that of pine needles sampled from the same area as ambient air in the Kanagawa Prefecture in 1999. Since then, the citizen groups of each local area all over Japan have started monitoring the ambient air dioxin concentration levels by using pine needles. Samples analyzed during these 5 years totaled more than 650 throughout Japan. The results of these citizen participatory environmental monitoring activities are the tremendous effects achieved in reducing the dioxin levels. This occurs through observation of the dioxin emission sources such as Municipal Solid Waste Incineration Plants as well as the Industrial Waste Incineration plants, which exist in numbers exceeding several thousands in Japan. This short paper will present the results of 56 municipalities of western Japan where ambient air dioxin levels have improved steadily against local averages during these 5 years.

Seasonal variation of heavy metals in ambient air and precipitation at a single site in Washington, DC

International Nuclear Information System (INIS)

Melaku, Samuel; Morris, Vernon; Raghavan, Dharmaraj; Hosten, Charles

2008-01-01

Atmospheric samples of precipitation and ambient air were collected at a single site in Washington, DC, for 7 months (for ambient air samples) and 1 year (for wet deposition samples) and analyzed for arsenic, cadmium, chromium and lead. The ranges of heavy metal concentrations for 6-day wet deposition samples collected over the 1-year period were 0.20-1.3 μg/l, 0.060-5.1 μg/l, 0.062-4.6 μg/l and 0.11-3.2 μg/l for arsenic, cadmium, chromium and lead, respectively, with a precision better than 5% for more than 95% of the measurements. The ranges of heavy metal concentrations for the 6-day ambient air samples were 0.800-15.7 ng/m 3 , 1.50-30.0 ng/m 3 , 16.8-112 ng/m 3 , and 2.90-137 ng/m 3 for arsenic, cadmium, chromium and lead, respectively, with a precision better than 10%. The spread in the heavy metal concentration over the observation period suggests a high seasonal variability for heavy metal content in both ambient air and wet deposition samples. - High seasonal variability of heavy metals were observed in both ambient air and wet deposition samples

Quantile-based Bayesian maximum entropy approach for spatiotemporal modeling of ambient air quality levels.

Science.gov (United States)

Yu, Hwa-Lung; Wang, Chih-Hsin

2013-02-05

Understanding the daily changes in ambient air quality concentrations is important to the assessing human exposure and environmental health. However, the fine temporal scales (e.g., hourly) involved in this assessment often lead to high variability in air quality concentrations. This is because of the complex short-term physical and chemical mechanisms among the pollutants. Consequently, high heterogeneity is usually present in not only the averaged pollution levels, but also the intraday variance levels of the daily observations of ambient concentration across space and time. This characteristic decreases the estimation performance of common techniques. This study proposes a novel quantile-based Bayesian maximum entropy (QBME) method to account for the nonstationary and nonhomogeneous characteristics of ambient air pollution dynamics. The QBME method characterizes the spatiotemporal dependence among the ambient air quality levels based on their location-specific quantiles and accounts for spatiotemporal variations using a local weighted smoothing technique. The epistemic framework of the QBME method can allow researchers to further consider the uncertainty of space-time observations. This study presents the spatiotemporal modeling of daily CO and PM10 concentrations across Taiwan from 1998 to 2009 using the QBME method. Results show that the QBME method can effectively improve estimation accuracy in terms of lower mean absolute errors and standard deviations over space and time, especially for pollutants with strong nonhomogeneous variances across space. In addition, the epistemic framework can allow researchers to assimilate the site-specific secondary information where the observations are absent because of the common preferential sampling issues of environmental data. The proposed QBME method provides a practical and powerful framework for the spatiotemporal modeling of ambient pollutants.

77 FR 30087 - Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards

Science.gov (United States)

2012-05-21

... and 81 Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards; Implementation of the 2008 National Ambient Air Quality Standards for Ozone: Nonattainment Area Classifications...-9668-2] RIN 2060-AP37 Air Quality Designations for the 2008 Ozone National Ambient Air Quality...

Study of temporal variation in ambient air quality during Diwali festival in India.

Science.gov (United States)

Singh, D P; Gadi, Ranu; Mandal, T K; Dixit, C K; Singh, Khem; Saud, T; Singh, Nahar; Gupta, Prabhat K

2010-10-01

The variation in air quality was assessed from the ambient concentrations of various air pollutants [total suspended particle (TSP), particulate matter festival, post-Diwali, and foggy day (October, November, and December), Delhi (India), from 2002 to 2007. The extensive use of fireworks was found to be related to short-term variation in air quality. During the festival, TSP is almost of the same order as compared to the concentration at an industrial site in Delhi in all the years. However, the concentrations of PM(10), SO(2), and NO(2) increased two to six times during the Diwali period when compared to the data reported for an industrial site. Similar trend was observed when the concentrations of pollutants were compared with values obtained for a typical foggy day each year in December. The levels of these pollutants observed during Diwali were found to be higher due to adverse meteorological conditions, i.e., decrease in 24 h average mixing height, temperature, and wind speed. The trend analysis shows that TSP, PM(10), NO(2), and SO(2) concentration increased just before Diwali and reached to a maximum concentration on the day of the festival. The values gradually decreased after the festival. On Diwali day, 24-h values for TSP and PM(10) in all the years from 2002 to 2007 and for NO(2) in 2004 and 2007 were found to be higher than prescribed limits of National Ambient Air Quality Standards and exceptionally high (3.6 times) for PM(10) in 2007. These results indicate that fireworks during the Diwali festival affected the ambient air quality adversely due to emission and accumulation of TSP, PM(10), SO(2), and NO(2).

Characterization of ambient air pollution for stochastic health models

Energy Technology Data Exchange (ETDEWEB)

Batterman, S.A.

1981-08-01

This research is an analysis of various measures of ambient air pollution useful in cross-sectional epidemiological investigations and rick assessments. The Chestnut Ridge area health effects investigation, which includes a cross-sectional study of respiratory symptoms in young children, is used as a case study. Four large coal-fired electric generating power plants are the dominant pollution sources in this area of western Pennsylvania. The air pollution data base includes four years of sulfur dioxide and five years of total suspended particulate concentrations at seventeen monitors. Some 70 different characterizations of pollution are constructed and tested. These include pollutant concentrations at various percentiles and averaging times, exceedence measures which show the amount of time a specified threshold concentration is exceeded, and several dosage measures which transform non-linear dose-response relationships onto pollutant concentrations.

Organochlorine pesticides in the ambient air of Chiapas, Mexico

International Nuclear Information System (INIS)

Alegria, Henry; Bidleman, Terry F.; Figueroa, Miguel Salvador

2006-01-01

Organochlorine (OC) pesticides were measured in the ambient air of Chiapas, Mexico during 2000-2001. Concentrations of some OC pesticides (DDTs, chlordanes, toxaphene) were elevated compared with levels in the Great Lakes region, while those of other pesticides were not (hexachlorocyclohexanes, dieldrin). While this suggests southern Mexico as a source region for the former group of chemicals, comparably high levels have also been reported in parts of the southern United States, where their suspected sources are soil emissions (DDTs, toxaphene) and termiticide usage (chlordane). Ratios of p,p'-DDT/p,p'-DDE and trans-chlordane/cis-chlordane/trans-nonachlor (TC/CC/TN) in Chiapas suggest a mixture of fresh and weathered sources, while congener profiles of toxaphene suggest emission of old residues from soils. This is supported by air parcel back trajectory analysis, which indicated that air masses over Chiapas at the time of sampling had previously passed over areas of continuing or recent use of some OC pesticides as well as areas of past use. - Elevated levels of several organochlorine pesticides were found in the ambient air of southern Mexico

Xanthoria parietina as a monitor of ground-level ambient ammonia concentrations

DEFF Research Database (Denmark)

Olsen, Henrik Brinkmann; Berthelsen, Kasper; Andersen, Helle Vibeke

2010-01-01

Total nitrogen in transplanted and in situ lichen thalli of Xanthoria parietina were related to ambient ammonia air concentrations measured with passive ALPHA (Adapted Low-cost Passive High Absorption) diffusion samplers in Denmark. Transplants and ALPHA samplers were exposed four months in a tra...

Association between exposure to ambient air pollution and renal function in Korean adults.

Science.gov (United States)

Kim, Hyun-Jin; Min, Jin-Young; Seo, Yong-Seok; Min, Kyoung-Bok

2018-01-01

Ambient air pollution has a negative effect on many diseases, such as cardiovascular and respiratory diseases. Recent studies have reported a relationship between air pollution and renal function, but the results were limited to exposure to particulate matter (PM). This study was to identify associations between various air pollutants and renal function among Korean adults. Nationwide survey data for a total of 24,407 adults were analyzed. We calculated the estimated glomerular filtration rate (eGFR) for each individual to assess their renal function and used this to categorize those with chronic kidney disease (CKD). To evaluate exposure to ambient air pollution, we used the annual mean concentrations of four ambient air pollutants: PM with an aerodynamic diameter ≤ 10 μm (PM 10 ), nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ), and carbon monoxide (CO). We identified significant inverse relationships between the air pollutants PM 10 and NO 2 and eGFR in all statistical adjustment models (all p  ambient air pollutants were significantly related to an increased risk of CKD in the unadjusted model ( p   0.05). Exposures to PM 10 and NO 2 were significantly associated with decreases in eGFR levels, but not CKD, in Korean adults.

Measurement of Ambient Air Particle (TSP, PM10, PM2,5) Around Candidate Location of PLTN Semenanjung Lemahabang

International Nuclear Information System (INIS)

AgusGindo S; Budi Hari H

2008-01-01

Measurement analysis of ambient air particle (TSP, PM 10 , PM 2,5 ) around location candidate of PLTN (Power Station of Nuclear Energy) Semenanjung Lemahabang has been carried out. The measurement was conducted in May 2007 with a purpose to providing information about concentration of ambient air particle (TSP, PM 10 , PM 2,5 ) and diameter distribution of its air particle. The measurement was conducted in three locations i.e. 1). Balong village 2). Bayuran 3). Bondo. Concentration of TSP, PM 10 , and PM 2,5 per 24 hours in all measured locations in area candidate of PLTN exceed quality standard of national ambient air is specified by government. All measurement locations for the TSP, PM 10 , and PM 2,5 was include category of ISPU (Standard Index of Air Pollution) moderate. (author)

Assessment of SRS ambient air monitoring network

Energy Technology Data Exchange (ETDEWEB)

Abbott, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jannik, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-08-03

Three methodologies have been used to assess the effectiveness of the existing ambient air monitoring system in place at the Savannah River Site in Aiken, SC. Effectiveness was measured using two metrics that have been utilized in previous quantification of air-monitoring network performance; frequency of detection (a measurement of how frequently a minimum number of samplers within the network detect an event), and network intensity (a measurement of how consistent each sampler within the network is at detecting events). In addition to determining the effectiveness of the current system, the objective of performing this assessment was to determine what, if any, changes could make the system more effective. Methodologies included 1) the Waite method of determining sampler distribution, 2) the CAP88- PC annual dose model, and 3) a puff/plume transport model used to predict air concentrations at sampler locations. Data collected from air samplers at SRS in 2015 compared with predicted data resulting from the methodologies determined that the frequency of detection for the current system is 79.2% with sampler efficiencies ranging from 5% to 45%, and a mean network intensity of 21.5%. One of the air monitoring stations had an efficiency of less than 10%, and detected releases during just one sampling period of the entire year, adding little to the overall network intensity. By moving or removing this sampler, the mean network intensity increased to about 23%. Further work in increasing the network intensity and simulating accident scenarios to further test the ambient air system at SRS is planned

The ambient air quality accounts for the Nova Scotia Genuine Progress Index

International Nuclear Information System (INIS)

Monette, A.; Colman, R.

2004-01-01

The Nova Scotia Genuine Progress Index (GPI) is a measure of sustainable development which provides a complete and accurate picture of our well-being as a society. The GPI assigns explicit values to environmental quality, population health, livelihood security, equity, free time, and educational attainment. The Nova Scotia GPI includes 22 social, economic and environmental components, including ambient air quality. This report investigates Nova Scotia's ambient air concentrations and emissions of carbon monoxide (CO), total particulate matter (PM), sulphur dioxide (SO 2 ), nitrogen oxides (NOx), and volatile organic compounds (VOC). The costs of damages caused by the these key air pollutants are also examined. Exposure to these pollutants results in negative impacts on human health, damage to materials, agricultural crops and changes in forest productivity. From 1979 to 1996, national ambient concentrations of each of these pollutants decreased significantly. However, the national average concentration of ground-level ozone increased by 34 per cent during the same time period. In Nova Scotia, concentrations of CO, PM and SO 2 have declined dramatically since 1979, but the trends for NO 2 and ground-level ozone do not show significant declines. On a per capita basis, SOx emissions from electric power generation in the province are more than 8 times the Canadian average. The province also had higher per capita emissions of CO, PM, SOx and VOCs than all reporting OECD countries. Electric power generation is the greatest source of fuel combustion emissions in the province, followed by industrial and transportation sources. This report also described some individual actions that can be taken to reduce air pollutant emissions. 174 refs., 37 tabs., 60 figs

Status of ambient air quality at Barauni

International Nuclear Information System (INIS)

Kannan, G.K.

1993-01-01

Due to industrialization, Barauni has become a well developed industrial estate to be considered as industrial hub of Bihar. Contemporary to the industrial growth, the environmental quality also gradually deteriorated. Hence a need was felt to know the status of ambient air quality for proper planning of the future growth of industries. The ambient air quality was monitored at 16 stations in and around Barauni industrial estate during 3 major seasons for the period of one year. The results are discussed as to the status of the ambient air quality and suggestion have also been made for improvement. (author). 5 refs., 2 figs., 7 tabs

Effects of public health interventions on industrial emissions and ambient air in Cartagena, Spain.

Science.gov (United States)

Cirera, Lluís; Rodríguez, Miguel; Giménez, Joaquín; Jiménez, Enrique; Saez, Marc; Guillén, José-Jesús; Medrano, José; Martínez-Victoria, María-Aurelia; Ballester, Ferran; Moreno-Grau, Stella; Navarro, Carmen

2009-03-01

Ten years of public health interventions on industrial emissions to clean air were monitored for the Mediterranean city of Cartagena. During the 1960s, a number of large chemical and non-ferrous metallurgical factories were established that significantly deteriorated the city's air quality. By the 1970s, the average annual air concentration of sulfur dioxide (SO2) ranged from 200 to 300 microg/m3 (standard conditions units). In 1979, the Spanish government implemented an industrial intervention plan to improve the performance of factories and industrial air pollution surveillance. Unplanned urban development led to residential housing being located adjacent to three major factories. Factory A produced lead, factory B processed zinc from ore concentrates, and factory C produced sulfuric acid and phosphates. This, in combination with the particular abrupt topography and frequent atmospheric thermal inversions, resulted in the worsening of air quality and heightening concern for public health. In 1990, the City Council authorized the immediate intervention at these factories to reduce or shut down production if ambient levels of SO2 or total suspended particles (TSP) exceeded a time-emission threshold in pre-established meteorological contexts. The aim of this research was to assess the appropriateness and effectiveness of the intervention plan implemented from 1992 to 2001 to abate industrial air pollution. The maximum daily 1-h ambient air level of SO2, NO2, and TSP pollutants was selected from one of the three urban automatic stations, designed to monitor ambient air quality around industrial emissions sources. The day on which an intervention took place to reduce and/or interrupt industrial production by factory and pollutant was defined as a control day, and the day after an intervention as a post-control day. To assess the short-term intervention effect on air quality, an ecological time series design was applied, using regression analysis in generalized

Setting priorities for ambient air quality objectives

International Nuclear Information System (INIS)

2004-10-01

Alberta has ambient air quality objectives in place for several pollutants, toxic substances and other air quality parameters. A process is in place to determine if additional air quality objectives are required or if existing objectives should be changed. In order to identify the highest priority substances that may require an ambient air quality objective to protect ecosystems and public health, a rigorous, transparent and cost effective priority setting methodology is required. This study reviewed, analyzed and assessed successful priority setting techniques used by other jurisdictions. It proposed an approach for setting ambient air quality objective priorities that integrates the concerns of stakeholders with Alberta Environment requirements. A literature and expert review were used to examine existing priority-setting techniques used by other jurisdictions. An analysis process was developed to identify the strengths and weaknesses of various techniques and their ability to take into account the complete pathway between chemical emissions and damage to human health or the environment. The key strengths and weaknesses of each technique were identified. Based on the analysis, the most promising technique was the tool for the reduction and assessment of chemical and other environmental impacts (TRACI). Several considerations for using TRACI to help set priorities for ambient air quality objectives were also presented. 26 refs, 8 tabs., 4 appendices

Case report: Atrial fibrillation following exposure to ambient air pollution particles

Science.gov (United States)

CONTEXT: Exposure to air pollution can result in the onset of atrial fibrillation. CASE PRESENTATION: We present a case of a 58 year old woman who volunteered to participate in a controlled exposure to concentrated ambient particles (CAPs). Twenty minutes into the exposure, there...

77 FR 12482 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Lead Ambient Air Quality...

Science.gov (United States)

2012-03-01

... Promulgation of Air Quality Implementation Plans; Indiana; Lead Ambient Air Quality Standards AGENCY... incorporates the National Ambient Air Quality Standards (NAAQS) for Pb promulgated by EPA in 2008. DATES: This... FR 66964) and codified at 40 CFR 50.16, ``National primary and secondary ambient air quality...

FY 1994 ambient air monitoring report for McMurdo Station, Antarctica

International Nuclear Information System (INIS)

Lugar, R.M.

1994-12-01

This report presents the results of ambient air monitoring performed during the 1994 fiscal year (FY 1994) in the vicinity of McMurdo Station, Antarctica. Routine monitoring was performed during the 1993-1994 austral summer at three locations for airborne particulate matter less than 10 micrometers (PM-10) and at two locations for carbon monoxide (CO), sulfur dioxide (SO 2 ), and nitrogen oxides (NO, NO 2 , and NO x ). Selected PM-10 filters were analyzed for arsenic, beryllium, cadmium, chromium, lead, mercury, and nickel. Additional air samples were collected at three McMurdo area locations and at Black Island for determination of the airborne concentration of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Sampling site selection, sampling procedures, and quality assurance procedures used were consistent with US Environmental Protection Agency guidance for local ambient air quality networks

Ambient air pollution and semen quality.

Science.gov (United States)

Nobles, Carrie J; Schisterman, Enrique F; Ha, Sandie; Kim, Keewan; Mumford, Sunni L; Buck Louis, Germaine M; Chen, Zhen; Liu, Danping; Sherman, Seth; Mendola, Pauline

2018-05-01

Ambient air pollution is associated with systemic increases in oxidative stress, to which sperm are particularly sensitive. Although decrements in semen quality represent a key mechanism for impaired fecundability, prior research has not established a clear association between air pollution and semen quality. To address this, we evaluated the association between ambient air pollution and semen quality among men with moderate air pollution exposure. Of 501 couples in the LIFE study, 467 male partners provided one or more semen samples. Average residential exposure to criteria air pollutants and fine particle constituents in the 72 days before ejaculation was estimated using modified Community Multiscale Air Quality models. Generalized estimating equation models estimated the association between air pollutants and semen quality parameters (volume, count, percent hypo-osmotic swollen, motility, sperm head, morphology and sperm chromatin parameters). Models adjusted for age, body mass index, smoking and season. Most associations between air pollutants and semen parameters were small. However, associations were observed for an interquartile increase in fine particulates ≤2.5 µm and decreased sperm head size, including -0.22 (95% CI -0.34, -0.11) µm 2 for area, -0.06 (95% CI -0.09, -0.03) µm for length and -0.09 (95% CI -0.19, -0.06) µm for perimeter. Fine particulates were also associated with 1.03 (95% CI 0.40, 1.66) greater percent sperm head with acrosome. Air pollution exposure was not associated with semen quality, except for sperm head parameters. Moderate levels of ambient air pollution may not be a major contributor to semen quality. Published by Elsevier Inc.

Health Effects of Ambient Air Pollution in Developing Countries.

Science.gov (United States)

Mannucci, Pier Mannuccio; Franchini, Massimo

2017-09-12

The deleterious effects of ambient air pollution on human health have been consistently documented by many epidemiologic studies worldwide, and it has been calculated that globally at least seven million deaths are annually attributable to the effects of air pollution. The major air pollutants emitted into the atmosphere by a number of natural processes and human activities include nitrogen oxides, volatile organic compounds, and particulate matter. In addition to the poor ambient air quality, there is increasing evidence that indoor air pollution also poses a serious threat to human health, especially in low-income countries that still use biomass fuels as an energy resource. This review summarizes the current knowledge on ambient air pollution in financially deprived populations.

Determination and evaluation of air quality control. Manual of ambient air quality control in Germany

Energy Technology Data Exchange (ETDEWEB)

Lahmann, E.

1997-07-01

Measurement of air pollution emissions and ambient air quality are essential instruments for air quality control. By undertaking such measurements, pollutants are registered both at their place of origin and at the place where they may have an effect on people or the environment. Both types of measurement complement each other and are essential for the implementation of air quality legislation, particularly, in compliance with emission and ambient air quality limit values. Presented here are similar accounts of measurement principles and also contains as an Appendix a list of suitability-tested measuring devices which is based on information provided by the manufacturers. In addition, the guide of ambient air quality control contains further information on discontinuous measurement methods, on measurement planning and on the assessment of ambient air quality data. (orig./SR)

Low-level NOx removal in ambient air by pulsed corona technology

NARCIS (Netherlands)

Beckers, F.J.C.M.; Hoeben, W.F.L.M.; Pemen, A.J.M.; Heesch, van E.J.M.

2013-01-01

Although removal of NOx by (pulsed) corona discharges has been thoroughly investigated for high concentrations of NOx in flue gas, removal of low levels in ambient air proves to be a difficult task. (Sub) ppm NOx levels exist in traffic tunnels due to accumulation of exhaust gases. The application

Ambient air pollution and low birth weight

DEFF Research Database (Denmark)

Westergaard, Nadja; Gehring, Ulrike; Slama, Rémy

2017-01-01

(TLBW, restriction (IUGR), and suggest that some subgroups of pregnant women who are smoking, of low or high body-mass index (BMI), low socioeconomic status (SES) or asthma are more vulnerable towards...... on the association between ambient air pollution and TLBW. The adjusted odds ratio (OR) for TLBW associated with exposure to ambient air pollution were in one study higher among women who smoked during pregnancy, as compared to the OR of non-smoking women, while in the other study the association was in the opposite...... direction. The association of ambient air pollution and TLBW were higher among women characterized by extreme BMI (two studies) and low SES compared to non-obese women or women of higher SES (four studies), respectively. Only one study reported the estimated effects among asthmatic and non-asthmatic women...

Effects of concentrated ambient particles on normal and hypersecretory airways in rats.

Science.gov (United States)

Harkema, Jack R; Keeler, Gerald; Wagner, James; Morishita, Masako; Timm, Edward; Hotchkiss, Jon; Marsik, Frank; Dvonch, Timothy; Kaminski, Norbert; Barr, Edward

2004-08-01

.5 from this local urban atmosphere. Rats in the inhalation studies were exposed for 1 day or for 4 or 5 consecutive days (10 hours/day) to either filtered air (controls) or concentrated ambient particles (CAPs) delivered by a Harvard ambient fine particle concentrator. Rats were killed 24 hours after the end of the exposure. Biochemical, morphometric, and molecular techniques were used to identify airway epithelial and inflammatory responses to CAPs. Lung lobes were also either intratracheally lavaged with saline to determine cellular composition and protein in bronchoalveolar lavage fluid (BALF) or removed for analysis by inductively coupled plasma-mass spectrometry (ICPMS) to detect retention of ambient PM2.5--derived trace elements. The Harvard concentrator effectively concentrated the fine ambient particles from this urban atmosphere (10-30 times) without significantly changing the major physicochemical features of the atmospheric particles. Daily CAPs mass concentrations during the 10-hour exposure period (0800-1800) in July ranged from 16 to 895 microg/m3 and in September ranged from 81 to 755 microg/m3. In general, chemical characteristics of ambient particles were conserved through the concentrator into the exposure chamber. Single or repeated exposures to CAPs did not cause adverse effects in the nasal or pulmonary airways of healthy F344 or BN rats. In addition, CAPs-related toxicity was not observed in F344 rats pretreated with bacterial endotoxin. Variable airway responses to CAPs exposure were observed in BN rats with preexisting allergic airway disease induced by OVA sensitization and challenge. Only OVA-challenged BN rats exposed to CAPs for 5 consecutive days in September 2000 had significant increases in airway mucosubstances and pulmonary inflammation compared to saline-challenged/air-exposed control rats. OVA-challenged BN rats that were repeatedly exposed to CAPs in July 2000 had only minor CAPs-related effects. In only the September 5-day exposure

Behavior and source characteristic of PCBS in urban ambient air of Yokohama, Japan

International Nuclear Information System (INIS)

Kim, Kyoung-Soo; Masunaga, Shigeki

2005-01-01

To understand the behavior and sources of polychlorinated biphenyls (PCBs) in ambient air, gaseous and particulate phase concentrations were measured at Yokohama City, Japan, during March 2002 and February 2003. The concentration of total PCB and TEQ ranged from 62 to 250 pg/m 3 and from 2 to 14 fgTEQ/m 3 , respectively. The gas-particle partition coefficient (K p ) was obtained as a function of temperature. The relationship between the partition coefficient and the sub-cooled liquid vapor pressure (P L ) was also established (coefficients of determination for log K p versus log P L plot were >0.76, except for three samples). As a result, the partition ratio of gaseous and particulate phase PCBs can be estimated for an arbitrary temperature. Principal component analysis (PCA) was applied to the source identification of PCBs in ambient air. The concentrations of 122 congeners between tetra-CBs and deca-CB were used as input variables, and three PCs with eigenvalue more than 10 were obtained. The principal component 1 (PC 1) accounted for 43.4% of the total variance, and was interpreted as volatilization from PCB products and/or sites polluted by PCBs. The concentrations of PCB congeners were strongly related with PC 1 which showed high correlation with temperature. PC 2 accounted for 22.3%, and was interpreted as PCBs from incineration sources, while PC 3 accounted for 10.8%, but could not be interpreted. - The relationship between the gas-particle partition coefficient (K p ) and sub-cooled liquid vapor pressure was estimated using gaseous and particle phase concentration in ambient air, and was estimated source apportionment of PCBs

Influence of ambient (outdoor) sources on residential indoor and personal PM2.5 concentrations: analyses of RIOPA data.

Science.gov (United States)

Meng, Qing Yu; Turpin, Barbara J; Korn, Leo; Weisel, Clifford P; Morandi, Maria; Colome, Steven; Zhang, Junfeng Jim; Stock, Thomas; Spektor, Dalia; Winer, Arthur; Zhang, Lin; Lee, Jong Hoon; Giovanetti, Robert; Cui, William; Kwon, Jaymin; Alimokhtari, Shahnaz; Shendell, Derek; Jones, Jennifer; Farrar, Corice; Maberti, Silvia

2005-01-01

The Relationship of Indoor, Outdoor and Personal Air (RIOPA) study was designed to investigate residential indoor, outdoor and personal exposures to several classes of air pollutants, including volatile organic compounds, carbonyls and fine particles (PM2.5). Samples were collected from summer, 1999 to spring, 2001 in Houston (TX), Los Angeles (CA) and Elizabeth (NJ). Indoor, outdoor and personal PM2.5 samples were collected at 212 nonsmoking residences, 162 of which were sampled twice. Some homes were chosen due to close proximity to ambient sources of one or more target analytes, while others were farther from sources. Median indoor, outdoor and personal PM2.5 mass concentrations for these three sites were 14.4, 15.5 and 31.4 microg/m3, respectively. The contributions of ambient (outdoor) and nonambient sources to indoor and personal concentrations were quantified using a single compartment box model with measured air exchange rate and a random component superposition (RCS) statistical model. The median contribution of ambient sources to indoor PM2.5 concentrations using the mass balance approach was estimated to be 56% for all study homes (63%, 52% and 33% for California, New Jersey and Texas study homes, respectively). Reasonable variations in model assumptions alter median ambient contributions by less than 20%. The mean of the distribution of ambient contributions across study homes agreed well for the mass balance and RCS models, but the distribution was somewhat broader when calculated using the mass balance model with measured air exchange rates.

Ambient air quality predictions in the Athabasca oil sands region

International Nuclear Information System (INIS)

1996-01-01

This report presents dispersion modelling predictions for SO 2 , NOx, CO, HC and particulate matter (PM), which complement regional monitoring observations. The air quality simulation models provide a scientific means of relating industrial emissions to changes in ambient air quality. The four models applied to the emission sources in the region were: (1) SCREEN3, (2) ISC3BE, (3) ADEPT2, and (4) the box model. Model predictions were compared to air quality guidelines. It was concluded that the largest SO 2 concentrations were associated with intermittent flaring, and with the Suncor Powerhouse whose emissions are continuous. 45 refs., 36 tabs., 40 figs

Ambient air monitoring for mercury around an industrial complex

International Nuclear Information System (INIS)

Turner, R.R.; Bogle, M.A.

1991-01-01

Public and scientific interest in mercury in the environment has experienced an upsurge in the past few years, due in part to disclosures that fish in certain waters, which have apparently received no direct industrial discharges, were contaminated with mercury. Atmospheric releases of mercury from fossil fuel energy generators, waste incinerators and other industrial sources are suspected to be contributing to this problem. Such releases can be evaluated in a variety of ways, including stack sampling, material balance studies, soil/vegetation sampling and ambient air monitoring. Ambient air monitoring of mercury presents significant challenges because of the typically low concentrations (ng/m 3 ) encountered and numerous opportunities for sample contamination or analyte loss. There are presently no EPA-approved protocols for such sampling and analysis. Elemental mercury was used in large quantities at a nuclear weapons plant in Oak Ridge, Tennessee between 1950 and 1963 in a process similar to chloralkali production. Soil and water contamination with mercury were known to be present at the facility but outdoor ambient air contamination had not been investigated prior to the present study. In addition, one large building still contained original process equipment with mercury residuals. The objectives of this study were to establish a monitoring network for mercury which could be used (1) to demonstrate whether or not human health and the environment was being protected, and (2), to establish a decommissioning activities at the facility

Polycyclic aromatic hydrocarbons in ambient air, surface soil and wheat grain near a large steel-smelting manufacturer in northern China.

Science.gov (United States)

Liu, Weijian; Wang, Yilong; Chen, Yuanchen; Tao, Shu; Liu, Wenxin

2017-07-01

The total concentrations and component profiles of polycyclic aromatic hydrocarbons (PAHs) in ambient air, surface soil and wheat grain collected from wheat fields near a large steel-smelting manufacturer in Northern China were determined. Based on the specific isomeric ratios of paired species in ambient air, principle component analysis and multivariate linear regression, the main emission source of local PAHs was identified as a mixture of industrial and domestic coal combustion, biomass burning and traffic exhaust. The total organic carbon (TOC) fraction was considerably correlated with the total and individual PAH concentrations in surface soil. The total concentrations of PAHs in wheat grain were relatively low, with dominant low molecular weight constituents, and the compositional profile was more similar to that in ambient air than in topsoil. Combined with more significant results from partial correlation and linear regression models, the contribution from air PAHs to grain PAHs may be greater than that from soil PAHs. Copyright © 2016. Published by Elsevier B.V.

Summer concentrations of NMHCs in ambient air of the Arctic and Antarctic

Energy Technology Data Exchange (ETDEWEB)

Hellen, H.; Paatero, J.; Hakola, H.; Virkkula, A. [Finnish Meteorological Inst., Helsinki (Finland); Leck, C. [Stockholm Univ. (Sweden). Dept. of Meteorology

2012-11-01

Summer concentrations of C{sub 2}-C{sub 6} non-methane hydrocarbons (NMHCs) were measured in Antarctica and in the Arctic in 2008. The results show that NMHC concentrations are on average five times higher in the Arctic than in Antarctica. In Antarctica, there were few concentration peaks, but during most of the remaining time concentrations were below or close to the detection limits. Over the Arctic pack ice area north of 80 deg, concentrations of most of the measured NMHCs were always above the detection limits. No differences based on air-mass origin were detected in Antarctica, but samples collected over the central Arctic Ocean showed higher concentrations in air masses being advected from the Kara Sea and the western-central Arctic Ocean. The relatively higher NMHC-to-ethyne molar ratios calculated for samples collected over the central Arctic Ocean suggest additional alkane sources in the region. (orig.)

Ambient Air Pollution and Morbidity in Chinese.

Science.gov (United States)

Hu, Li-Wen; Lawrence, Wayne R; Liu, Yimin; Yang, Bo-Yi; Zeng, Xiao-Wen; Chen, Wen; Dong, Guang-Hui

2017-01-01

The rapid economic growth in China is coupled with a severe ambient air pollution, which poses a huge threat to human health and the sustainable development of social economy. The rapid urbanization and industrialization over the last three decades have placed China as one of countries with the greatest disease burden in world. Notably, the prevalence rate of chronic noncommunicable diseases (CND), including respiratory diseases, CVD, and stroke, in 2010 reaches 16.9%. The continuous growth of the incidence of CND urgent needs for effective regulatory action for health protection. This study aims to evaluate the impact of rapid urbanization on status of ambient air pollution and associated adverse health effects on the incidence and the burden of CND and risk assessment. Our findings would be greatly significant in the prediction of the risk of ambient air pollution on CND and for evidence-based policy making and risk management in China.

Secondary organic aerosol formation from ambient air in an oxidation flow reactor in central Amazonia

Science.gov (United States)

Palm, Brett B.; de Sá, Suzane S.; Day, Douglas A.; Campuzano-Jost, Pedro; Hu, Weiwei; Seco, Roger; Sjostedt, Steven J.; Park, Jeong-Hoo; Guenther, Alex B.; Kim, Saewung; Brito, Joel; Wurm, Florian; Artaxo, Paulo; Thalman, Ryan; Wang, Jian; Yee, Lindsay D.; Wernis, Rebecca; Isaacman-VanWertz, Gabriel; Goldstein, Allen H.; Liu, Yingjun; Springston, Stephen R.; Souza, Rodrigo; Newburn, Matt K.; Lizabeth Alexander, M.; Martin, Scot T.; Jimenez, Jose L.

2018-01-01

Secondary organic aerosol (SOA) formation from ambient air was studied using an oxidation flow reactor (OFR) coupled to an aerosol mass spectrometer (AMS) during both the wet and dry seasons at the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) field campaign. Measurements were made at two sites downwind of the city of Manaus, Brazil. Ambient air was oxidized in the OFR using variable concentrations of either OH or O3, over ranges from hours to days (O3) or weeks (OH) of equivalent atmospheric aging. The amount of SOA formed in the OFR ranged from 0 to as much as 10 µg m-3, depending on the amount of SOA precursor gases in ambient air. Typically, more SOA was formed during nighttime than daytime, and more from OH than from O3 oxidation. SOA yields of individual organic precursors under OFR conditions were measured by standard addition into ambient air and were confirmed to be consistent with published environmental chamber-derived SOA yields. Positive matrix factorization of organic aerosol (OA) after OH oxidation showed formation of typical oxidized OA factors and a loss of primary OA factors as OH aging increased. After OH oxidation in the OFR, the hygroscopicity of the OA increased with increasing elemental O : C up to O : C ˜ 1.0, and then decreased as O : C increased further. Possible reasons for this decrease are discussed. The measured SOA formation was compared to the amount predicted from the concentrations of measured ambient SOA precursors and their SOA yields. While measured ambient precursors were sufficient to explain the amount of SOA formed from O3, they could only explain 10-50 % of the SOA formed from OH. This is consistent with previous OFR studies, which showed that typically unmeasured semivolatile and intermediate volatility gases (that tend to lack C = C bonds) are present in ambient air and can explain such additional SOA formation. To investigate the sources of the unmeasured SOA-forming gases during this campaign

Health Effects of Ambient Air Pollution in Developing Countries

OpenAIRE

Mannucci, Pier Mannuccio; Franchini, Massimo

2017-01-01

The deleterious effects of ambient air pollution on human health have been consistently documented by many epidemiologic studies worldwide, and it has been calculated that globally at least seven million deaths are annually attributable to the effects of air pollution. The major air pollutants emitted into the atmosphere by a number of natural processes and human activities include nitrogen oxides, volatile organic compounds, and particulate matter. In addition to the poor ambient air quality...

75 FR 65572 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Ohio Ambient Air Quality...

Science.gov (United States)

2010-10-26

... Promulgation of Air Quality Implementation Plans; Ohio; Ohio Ambient Air Quality Standards AGENCY... Ohio Administrative Code (OAC) relating to the consolidation of Ohio's Ambient Air Quality Standards... apply to Ohio's SIP. Incorporating the air quality standards into Ohio's SIP helps assure that...

Redox Toxicology of Ambient Air Pollution

Science.gov (United States)

Ambient air pollution is a leading global cause of morbidity and mortality. Millions of Americans live in areas in which levels of tropospheric ozone exceed air quality standards, while exposure to particulate matter (PM2.5) alone results in 3.2 million excess deaths annually wor...

Association between ambient air pollution and pregnancy rate in women who underwent IVF.

Science.gov (United States)

Choe, S A; Jun, Y B; Lee, W S; Yoon, T K; Kim, S Y

2018-04-05

Are the concentrations of five criteria air pollutants associated with probabilities of biochemical pregnancy loss and intrauterine pregnancy in women? Increased concentrations of ambient particulate matter (PM10), nitrogen dioxide (NO2), carbon monoxide (CO) during controlled ovarian stimulation (COS) and after embryo transfer were associated with a decreased probability of intrauterine pregnancy. Exposure to high ambient air pollution was suggested to be associated with low fertility and high early pregnancy loss in women. Using a retrospective cohort study design, we analysed 6621 cycles of 4581 patients who underwent one or more fresh IVF cycles at a fertility centre from January 2006 to December 2014, and lived in Seoul at the time of IVF treatment. To estimate patients' individual exposure to air pollution, we computed averages of hourly concentrations of five air pollutants including PM10, NO2, CO, sulphur dioxide (SO2) and ozone (O3) measured at 40 regulatory monitoring sites in Seoul for each of the four exposure periods: period 1 (start of COS to oocyte retrieval), period 2 (oocyte retrieval to embryo transfer), period 3 (embryo transfer to hCG test), and period 4 (start of COS to hCG test). Hazard ratios (HRs) from the time-varying Cox-proportional hazards model were used to estimate probabilities of biochemical pregnancy loss and intrauterine pregnancy for an interquartile range (IQR) increase in each air pollutant concentration during each period, after adjusting for individual characteristics. We tested the robustness of the result using generalised linear mixed model, accounting for within-woman correlation. Mean age of the women was 35 years. Average BMI was 20.9 kg/m2 and the study population underwent 1.4 IVF cycles on average. Cumulative pregnancy rate in multiple IVF cycles was 51.3% per person. Survival analysis showed that air pollution during periods 1 and 3 was generally associated with IVF outcomes. Increased NO2 (adjusted HR = 0.93, 95% CI

77 FR 12524 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Lead Ambient Air Quality...

Science.gov (United States)

2012-03-01

... Promulgation of Air Quality Implementation Plans; Indiana; Lead Ambient Air Quality Standards AGENCY... Indiana State Implementation Plan (SIP) for lead (Pb) under the Clean Air Act (CAA). This submittal incorporates the National Ambient Air Quality Standards (NAAQS) for Pb promulgated by EPA in 2008. DATES...

75 FR 65594 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Ohio Ambient Air Quality...

Science.gov (United States)

2010-10-26

... Promulgation of Air Quality Implementation Plans; Ohio; Ohio Ambient Air Quality Standards AGENCY... the Ohio Administrative Code (OAC) relating to the consolidation of Ohio's Ambient Air Quality Standards (AAQS) into Ohio's State Implementation Plan (SIP) under the Clean Air Act. On April 8, 2009, and...

76 FR 72097 - Air Quality Designations for the 2008 Lead (Pb) National Ambient Air Quality Standards

Science.gov (United States)

2011-11-22

... Air Quality Designations for the 2008 Lead (Pb) National Ambient Air Quality Standards AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: This rule establishes air quality designations for most areas in the United States for the 2008 lead (Pb) National Ambient Air Quality Standards...

Volatile organic compounds in urban atmospheres: Long-term measurements of ambient air concentrations in differently loaded regions of Leipzig

Energy Technology Data Exchange (ETDEWEB)

Knobloch, T.; Asperger, A.; Engewald, W. [University of Leipzig, Institute of Analytical Chemistry, Leipzig (Germany)

1997-09-01

For the comprehensive characterization of ambient air concentrations of a broad spectrum of volatile organic compounds (VOCs) an analytical method is described, consisting of adsorptive enrichment, thermal desorption without cryofocusing, and capillary gas chromatographic separation. The method was applied during two-week measuring campaigns in winter and summer 1995, and in the winter of 1996. Long-term sampling was carried out at sampling points in residential areas in the suburbs and near the city center of Leipzig. About 70 VOCs - mainly hydrocarbons from propene to hexadecane - were identified both by GC-MS and chromatographic retention data and quantified after external calibration. Mean values of VOC concentrations obtained during the sampling periods are reported and discussed with regard to the topographical location of the sampling points in the Leipzig area, seasonal variations, and possible emission sources. (orig.) With 7 figs., 3 tabs., 18 refs.

Ambient air quality observations in the Athabasca oil sands region

International Nuclear Information System (INIS)

1996-01-01

Both Syncrude and Suncor have plans to develop new oil sands leases and to increase crude oil and bitumen recovery in the Athabasca oil sands region. In recognition of the effects that this will have on the environment, Suncor has proposed modifications to reduce SO 2 emissions to the atmosphere, while Syncrude plans to develop additional ambient air quality, sulphur deposition and biomonitoring programs. This report discussed the ambient air quality monitoring that was undertaken in the Fort McMurray-Fort McKay airshed. Twelve continuous ambient air quality stations and 76 passive monitoring stations are maintained in the region. Environment Canada maintains eight precipitation monitoring stations in northern Alberta and Saskatchewan. Source characterization, ambient air quality and meteorology observations, air quality monitoring, and air quality data from continuous sulphur dioxide, hydrogen sulphide, nitrogen oxides, ozone, carbon monoxide, hydrocarbon, acid rain and particulates analyzers were reviewed. The documentation of all computer files used for the analysis of the air quality data is discussed in the Appendix. 47 refs., 39 tabs., 53 figs

Ambient Air Pollutants Have Adverse Effects on Insulin and Glucose Homeostasis in Mexican Americans

Science.gov (United States)

Chen, Zhanghua; Salam, Muhammad T.; Toledo-Corral, Claudia; Watanabe, Richard M.; Xiang, Anny H.; Buchanan, Thomas A.; Habre, Rima; Bastain, Theresa M.; Lurmann, Fred; Wilson, John P.; Trigo, Enrique

2016-01-01

OBJECTIVE Recent studies suggest that air pollution plays a role in type 2 diabetes (T2D) incidence and mortality. The underlying physiological mechanisms have yet to be established. We hypothesized that air pollution adversely affects insulin sensitivity and secretion and serum lipid levels. RESEARCH DESIGN AND METHODS Participants were selected from BetaGene (n = 1,023), a study of insulin resistance and pancreatic β-cell function in Mexican Americans. All participants underwent DXA and oral and intravenous glucose tolerance tests and completed dietary and physical activity questionnaires. Ambient air pollutant concentrations (NO2, O3, and PM2.5) for short- and long-term periods were assigned by spatial interpolation (maximum interpolation radius of 50 km) of data from air quality monitors. Traffic-related air pollution from freeways (TRAP) was estimated using the dispersion model as NOx. Variance component models were used to analyze individual and multiple air pollutant associations with metabolic traits. RESULTS Short-term (up to 58 days cumulative lagged averages) exposure to PM2.5 was associated with lower insulin sensitivity and HDL-to-LDL cholesterol ratio and higher fasting glucose and insulin, HOMA-IR, total cholesterol, and LDL cholesterol (LDL-C) (all P ≤ 0.036). Annual average PM2.5 was associated with higher fasting glucose, HOMA-IR, and LDL-C (P ≤ 0.043). The effects of short-term PM2.5 exposure on insulin sensitivity were largest among obese participants. No statistically significant associations were found between TRAP and metabolic outcomes. CONCLUSIONS Exposure to ambient air pollutants adversely affects glucose tolerance, insulin sensitivity, and blood lipid concentrations. Our findings suggest that ambient air pollutants may contribute to the pathophysiology in the development of T2D and related sequelae. PMID:26868440

Numerical Analysis of Exergy for Air-Conditioning Influenced by Ambient Temperature

Directory of Open Access Journals (Sweden)

Jing-Nang Lee

2014-07-01

Full Text Available The article presents numerical analysis of exergy for air-conditioning influenced by ambient temperature. The model of numerical simulation uses an integrated air conditioning system exposed in varied ambient temperature to observe change of the four main devices, the compressor, the condenser, the capillary, and the evaporator in correspondence to ambient temperature. The analysis devices of the four devices’s exergy influenced by the varied ambient temperature and found that the capillary has unusual increasing exergy loss vs. increasing ambient temperature in comparison to the other devices. The result shows that reducing exergy loss of the capillary influenced by the ambient temperature is the key for improving working efficiency of an air-conditioning system when influence of the ambient temperature is considered. The higher ambient temperature causes the larger pressure drop of capillary and more exergy loss.

The concentrations of ambient Burkholderia pseudomallei during typhoon season in endemic area of melioidosis in Taiwan.

Directory of Open Access Journals (Sweden)

Ya-Lei Chen

Full Text Available BACKGROUND: Melioidosis is a severe bacterial infection caused by Burkholderia pseudomallei with a high case-fatality rate. Epidemiological and animal studies show the possibility of inhalation transmission. However, no B. pseudomallei concentrations in ambient air have been researched. Here, we developed a method to quantify ambient B. pseudomallei and then measured concentrations of ambient B. pseudomallei during the typhoon season and the non-typhoon season to determine the factors influencing ambient B. pseudomallei levels. METHODS: We quantified ambient B. pseudomallei by using a filter/real-time qPCR method in the Zoynan Region in Kaohsiung, southern Taiwan. Twenty-four hour samples were collected at a sampling rate of 20 L/min every day from June 11 to December 21, 2012 including during the typhoon season (June to September and reference season (October to December. RESULTS: We successfully developed a filtration/real-time qPCR method to quantify ambient B. pseudomallei. To our knowledge, this is the first report describing concentrations of ambient B. pseudomallei. Ambient B. pseudomallei were only detected during the typhoon season when compared to the reference season. For the typhoons affecting the Zoynan Region, the positive rates of ambient B. pseudomallei were very high at 80% to 100%. During June to December, rainfall was positively correlated with ambient B. pseudomallei with a statistical significance. Sediment at a nearby pond significantly influenced the concentration of ambient B. pseudomallei. During the typhoon month, the typhoon was positively correlated with ambient B. pseudomallei whereas wind speed was reversely correlated with ambient B. pseudomallei. CONCLUSIONS: Our data suggest the possibility of transmission of B. pseudomallei via inhalation during the typhoon season.

The concentrations of ambient Burkholderia pseudomallei during typhoon season in endemic area of melioidosis in Taiwan.

Science.gov (United States)

Chen, Ya-Lei; Yen, Yu-Chuan; Yang, Chun-Yuh; Lee, Min Sheng; Ho, Chi-Kung; Mena, Kristina D; Wang, Peng-Yau; Chen, Pei-Shih

2014-01-01

Melioidosis is a severe bacterial infection caused by Burkholderia pseudomallei with a high case-fatality rate. Epidemiological and animal studies show the possibility of inhalation transmission. However, no B. pseudomallei concentrations in ambient air have been researched. Here, we developed a method to quantify ambient B. pseudomallei and then measured concentrations of ambient B. pseudomallei during the typhoon season and the non-typhoon season to determine the factors influencing ambient B. pseudomallei levels. We quantified ambient B. pseudomallei by using a filter/real-time qPCR method in the Zoynan Region in Kaohsiung, southern Taiwan. Twenty-four hour samples were collected at a sampling rate of 20 L/min every day from June 11 to December 21, 2012 including during the typhoon season (June to September) and reference season (October to December). We successfully developed a filtration/real-time qPCR method to quantify ambient B. pseudomallei. To our knowledge, this is the first report describing concentrations of ambient B. pseudomallei. Ambient B. pseudomallei were only detected during the typhoon season when compared to the reference season. For the typhoons affecting the Zoynan Region, the positive rates of ambient B. pseudomallei were very high at 80% to 100%. During June to December, rainfall was positively correlated with ambient B. pseudomallei with a statistical significance. Sediment at a nearby pond significantly influenced the concentration of ambient B. pseudomallei. During the typhoon month, the typhoon was positively correlated with ambient B. pseudomallei whereas wind speed was reversely correlated with ambient B. pseudomallei. Our data suggest the possibility of transmission of B. pseudomallei via inhalation during the typhoon season.

Air Quality of Beijing and Impacts of the New Ambient Air Quality Standard

Directory of Open Access Journals (Sweden)

Wei Chen

2015-08-01

Full Text Available Beijing has been publishing daily reports on its air quality since 2000, and while the air pollution index (API shows that the air quality has improved greatly since 2000, this is not the perception of Beijing’s residents. The new national ambient air quality standard (NAAQS-2012, which includes the monitoring of PM2.5, has posed stricter standards for evaluating air quality. With the new national standard, the air quality in Beijing is calculated using both NAAQS-2012 and the previous standard. The annual attainment rate has dropped from 75.5% to 50.7%. The spatial analysis of air quality shows that only a background station could attain the national standard, while urban and suburban stations exceed the national standard. Among the six pollutants included in the NAAQS-2012, PM2.5 is the major contributor to the air quality index (AQI comparing with the five other pollutants. The results indicate that under previous NAAQS without PM2.5 monitoring, the air quality has improved greatly in the past decade.  By considering PM2.5, the air quality attainment has dropped greatly. Furthermore, a great effort is needed for local government to bring down the PM2.5 concentration.

Secondary organic aerosol formation from ambient air in an oxidation flow reactor in central Amazonia

Directory of Open Access Journals (Sweden)

B. B. Palm

2018-01-01

Full Text Available Secondary organic aerosol (SOA formation from ambient air was studied using an oxidation flow reactor (OFR coupled to an aerosol mass spectrometer (AMS during both the wet and dry seasons at the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5 field campaign. Measurements were made at two sites downwind of the city of Manaus, Brazil. Ambient air was oxidized in the OFR using variable concentrations of either OH or O3, over ranges from hours to days (O3 or weeks (OH of equivalent atmospheric aging. The amount of SOA formed in the OFR ranged from 0 to as much as 10 µg m−3, depending on the amount of SOA precursor gases in ambient air. Typically, more SOA was formed during nighttime than daytime, and more from OH than from O3 oxidation. SOA yields of individual organic precursors under OFR conditions were measured by standard addition into ambient air and were confirmed to be consistent with published environmental chamber-derived SOA yields. Positive matrix factorization of organic aerosol (OA after OH oxidation showed formation of typical oxidized OA factors and a loss of primary OA factors as OH aging increased. After OH oxidation in the OFR, the hygroscopicity of the OA increased with increasing elemental O : C up to O : C ∼ 1.0, and then decreased as O : C increased further. Possible reasons for this decrease are discussed. The measured SOA formation was compared to the amount predicted from the concentrations of measured ambient SOA precursors and their SOA yields. While measured ambient precursors were sufficient to explain the amount of SOA formed from O3, they could only explain 10–50 % of the SOA formed from OH. This is consistent with previous OFR studies, which showed that typically unmeasured semivolatile and intermediate volatility gases (that tend to lack C = C bonds are present in ambient air and can explain such additional SOA formation. To investigate the sources of the

77 FR 60985 - Ambient Air Monitoring Reference and Equivalent Methods: Designation of Three New Equivalent Methods

Science.gov (United States)

2012-10-05

... Methods: Designation of Three New Equivalent Methods AGENCY: Environmental Protection Agency. ACTION: Notice of the designation of three new equivalent methods for monitoring ambient air quality. SUMMARY... equivalent methods, one for measuring concentrations of PM 2.5 , one for measuring concentrations of PM 10...

Concentrations, sources and human health risk of inhalation exposure to air toxics in Edmonton, Canada.

Science.gov (United States)

Bari, Md Aynul; Kindzierski, Warren B

2017-04-01

With concern about levels of air pollutants in recent years in the Capital Region of Alberta, an investigation of ambient concentrations, sources and potential human health risk of hazardous air pollutants (HAPs) or air toxics was undertaken in the City of Edmonton over a 5-year period (2009-2013). Mean concentrations of individual HAPs in ambient air including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs) and trace metals ranged from 0.04 to 1.73 μg/m 3 , 0.01-0.54 ng/m 3 , and 0.05-3.58 ng/m 3 , respectively. Concentrations of benzene, naphthalene, benzo(a)pyrene (BaP), arsenic, manganese and nickel were far below respective annual Alberta Ambient Air Quality Objectives. Carcinogenic and non-carcinogenic risk of air toxics were also compared with risk levels recommended by regulatory agencies. Positive matrix factorization identified six air toxics sources with traffic as the dominant contributor to total HAPs (4.33 μg/m 3 , 42%), followed by background/secondary organic aerosol (SOA) (1.92 μg/m 3 , 25%), fossil fuel combustion (0.92 μg/m 3 , 11%). On high particulate air pollution event days, local traffic was identified as the major contributor to total HAPs compared to background/SOA and fossil fuel combustion. Carcinogenic risk values of traffic, background/SOA and metals industry emissions were above the USEPA acceptable level (1 × 10 -6 ), but below a tolerable risk (1 × 10 -4 ) and Alberta benchmark (1 × 10 -5 ). These findings offer useful preliminary information about current ambient air toxics levels, dominant sources and their potential risk to public health; and this information can support policy makers in the development of appropriate control strategies if required. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ambient air contamination: Characterization and detection techniques

Science.gov (United States)

Nulton, C. P.; Silvus, H. S.

1985-01-01

Techniques to characterize and detect sources of ambient air contamination are described. Chemical techniques to identify indoor contaminants are outlined, they include gas chromatography, or colorimetric detection. Organics generated from indoor materials at ambient conditions and upon combustion are characterized. Piezoelectric quartz crystals are used as precision frequency determining elements in electronic oscillators.

Ambient air sampling of organic pollutants and heavy metals within the EU/93/AIR/22 PHARE Project

International Nuclear Information System (INIS)

Kocan, A.

1997-01-01

Within the framework of the project the concentrations of eight heavy metals, vapour mercury, seven polychlorinated dibenzo-p-dioxin's, ten polychlordibenzofuran congeners, eighteen polychlorinated biphenyls, two chlorinated pesticides (hexachlorobenzene, p,p'-DDE and p,p'-DDT), fourteen polycyclic aromatic hydrocarbons, forty-two volatile organic compounds, total suspended particles were analysed. The morphology characterization of collected airborne particles and bioassays aimed at the evaluation of the mutagenic potency of pollutants present in collected air were also performed. Ambient air heavy metals were caught on cellulose filters using the same type of the sampler used for semi-volatile compounds sampling and analysed by atomic spectrometry. Vapour mercury was trapped on gold sand packed in a tube through which about 280 L of ambient air during 24 hours were drawn. On-site analysis was performed by an atomic fluorescence analyzer. Inhalable air particles, i.e particles less than 10 μm in diameter were collected by a sampler equipped with a cascade impactor fractionating into five size fractions involving respirable (<3 μm) fractions. The morphology and composition of the respirable fractions was investigated by scanning electron microscopy and X-ray microanalysis

Rainwater capacities for BTEX scavenging from ambient air

Science.gov (United States)

Šoštarić, A.; Stanišić Stojić, S.; Vuković, G.; Mijić, Z.; Stojić, A.; Gržetić, I.

2017-11-01

The contribution of atmospheric precipitation to volatile organic compound (VOC) removal from the atmosphere remains a matter of scientific debate. The aim of this study was to examine the potential of rainwater for benzene, toluene, ethylbenzene and xylene (BTEX) scavenging from ambient air. To that end, air and rainwater samples were collected simultaneously during several rain events that occurred over two distinct time periods in the summer and autumn of 2015. BTEX concentrations in the gaseous and aqueous phases were determined using proton transfer reaction mass spectrometry. The results reveal that the registered amounts of BTEX in rainwater samples were higher than those predicted by Henry's law. Additional analysis, including physico-chemical characterization and source apportionment, was performed and a possible mechanism underlying the BTEX adsorption to the aqueous phase was considered and discussed herein. Finally, regression multivariate methods (MVA) were successfully applied (with relative errors from 20%) to examine the functional dependency of BTEX enrichment factor on gaseous concentrations, physico-chemical properties of rainwater and meteorological parameters.

The State of Ambient Air Quality of Jeddah, Saudi Arabia

Science.gov (United States)

Hussain, M. M.; Aburizaiza, O. S.; Khwaja, H. A.; Siddique, A.; Nayebare, S. R.; Zeb, J.; Blake, D. R.

2014-12-01

Ambient air pollution in major cities of Saudi Arabia is a substantial environmental and health concern. A study was undertaken to assess the air quality of Jeddah, Saudi Arabia by the analysis of respirable particulate matter (PM2.5), black carbon (BC), trace metals (Na, Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Sr, Cd, Sb, and Pb), and water-soluble ions (F-, Cl-, NO3-, SO42-, C2O42-, and NH42+). Sulfur and BC mass concentration ranged 0.99 - 7.39 μg/m3 and 0.70 - 3.09 μg/m3, respectively, while the PM2.5 mass concentration ranged 23 - 186 μg/m3. Maximum BC contribution to PM2.5 was 5.6%. Atmospheric PM2.5 concentrations were well above the 24 h WHO guideline of 20 μg/m3. Air Quality Index (AQI) indicates that there were 8% days of moderate air quality, 28% days of unhealthy air quality for sensitive groups, 55% days of unhealthy air quality, and 9% days of very unhealthy air quality during the study period. Sulfate SO42- dominated the identifiable components. The major contributors to PM2.5 were soil and crustal material; vehicle emissions (black carbon factor); and fuel oil combustion in industries (sulfur factor), according to the Positive Matrix Factorization (PMF). This study highlights the importance of focusing control strategies not only on reducing PM concentration, but also on the reduction of toxic components of the PM, to most effectively protect human health and the environment.

Some measurements of ambient air pollution

International Nuclear Information System (INIS)

Memon, H.R.; Memon, A.A.; Behan, M.Y.

1999-01-01

Ambient air pollution arising from different sources in Karachi and its surroundings has been studied. The urban centres like Karachi are mostly confronted with eye-irritation, reduce visibility, heart-diseases, nervous disorder, smog and other unpleasant experiences. In this paper quantitative estimations of some air-pollutants such as sulphur dioxide, carbon monoxide, oxides of nitrogen, chlorine and particular matters are presented with their hazardous effects. The remedial measures for the control of major air emissions are also discussed. (author)

Air quality more extensive monitoring of particulates pollution but concentrations must be reduced by 2005

International Nuclear Information System (INIS)

Ba, M.; Colosio, J.

2000-09-01

Most epidemiological data point to a link between the concentrations of particles measured in the ambient air and the effects of air pollution on human health. Particulates emitted by road traffic and industry are among the most harmful; they carry serious risks. The particulate monitoring network and legislation on the issue are constantly changing. In France, the number of monitoring stations has more than doubled in recent years. EC Directive 1999/30/EC of 22 April 1999 sets limit values for concentrations of particulates in ambient air to be complied with at certain given dates. In France, while the concentrations measured in urban areas with over 100 000 inhabitants are below the limit values set by the Directive for today, they are significantly higher than those to be complied with by 1 January 2005. (author)

Pure air-plasma bullets propagating inside microcapillaries and in ambient air

KAUST Repository

Lacoste, Deanna; Bourdon, Anne; Kuribara, Koichi; Urabe, Keiichiro; Stauss, Sven; Terashima, Kazuo

2014-01-01

This paper reports on the characterization of air-plasma bullets in microcapillary tubes and in ambient air, obtained without the use of inert or noble gases. The bullets were produced by nanosecond repetitively pulsed discharges, applied in a dielectric barrier discharge configuration. The anode was a tungsten wire with a diameter of 50 μm, centered in the microcapillary, while the cathode was a silver ring, fixed on the outer surface of the fused silica tube. The effects of the applied voltage and the inner diameter of the microcapillary tube on the plasma behavior were investigated. Inside the tubes, while the topology of the bullets seems to be strongly dependent on the diameter, their velocity is only a function of the amplitude of the applied voltage. In ambient air, the propagation of air bullets with a velocity of about 1.25 ×105 m s-1 is observed.

Pure air-plasma bullets propagating inside microcapillaries and in ambient air

KAUST Repository

Lacoste, Deanna

2014-11-04

This paper reports on the characterization of air-plasma bullets in microcapillary tubes and in ambient air, obtained without the use of inert or noble gases. The bullets were produced by nanosecond repetitively pulsed discharges, applied in a dielectric barrier discharge configuration. The anode was a tungsten wire with a diameter of 50 μm, centered in the microcapillary, while the cathode was a silver ring, fixed on the outer surface of the fused silica tube. The effects of the applied voltage and the inner diameter of the microcapillary tube on the plasma behavior were investigated. Inside the tubes, while the topology of the bullets seems to be strongly dependent on the diameter, their velocity is only a function of the amplitude of the applied voltage. In ambient air, the propagation of air bullets with a velocity of about 1.25 ×105 m s-1 is observed.

75 FR 81126 - Revisions to Lead Ambient Air Monitoring Requirements

Science.gov (United States)

2010-12-27

... tons per year of lead is necessary to provide sufficient information about airborne lead levels near... Revisions to Lead Ambient Air Monitoring Requirements AGENCY: Environmental Protection Agency (EPA). ACTION...) that revised the primary and secondary National Ambient Air Quality Standards (NAAQS) for lead and...

The use of passive samplers for monitoring polycyclic aromatic hydrocarbons in ambient air

International Nuclear Information System (INIS)

Jacob, J.; Grimmer, G.; Hildebrandt, A.

1993-01-01

In this study polycyclic aromatic hydrocarbon (PAH) concentrations of ambient air are compared to those present in leaves, spruce sprouts and in the corresponding soil used as passive samplers. Marked profile alterations were detected in various soil horizons with increasing relative concentrations of higher boiling and decreasing relative concentrations of lower boiling PAH with depth. There is no direct correlation between the absolute PAH masses found in air samples and those collected by passive samplers or detected in corresponding soil samples. Even the PAH profiles differ significantly: they can, however, be correlated by introducing PAH - and sampler-specific factors. The PAH profiles appear to indicate that coal combustion mostly contributes to the PAH air pollution in the FRG. The time course of the concentration of benzo(a)pyrene and benzo(e)pyrene during the past seven years as measured with spruce sprouts as biological passive sampler indicate a significant decrease of the PAH concentration (by a factor of two) in the FRG. First measurements in a clean air area of the Eastern part of the FRG exhibited up to ten times higher PAH concentrations than found in comparable areas of the western part of the country

A direct sensitivity approach to predict hourly ozone resulting from compliance with the National Ambient Air Quality Standard.

Science.gov (United States)

Simon, Heather; Baker, Kirk R; Akhtar, Farhan; Napelenok, Sergey L; Possiel, Norm; Wells, Benjamin; Timin, Brian

2013-03-05

In setting primary ambient air quality standards, the EPA's responsibility under the law is to establish standards that protect public health. As part of the current review of the ozone National Ambient Air Quality Standard (NAAQS), the US EPA evaluated the health exposure and risks associated with ambient ozone pollution using a statistical approach to adjust recent air quality to simulate just meeting the current standard level, without specifying emission control strategies. One drawback of this purely statistical concentration rollback approach is that it does not take into account spatial and temporal heterogeneity of ozone response to emissions changes. The application of the higher-order decoupled direct method (HDDM) in the community multiscale air quality (CMAQ) model is discussed here to provide an example of a methodology that could incorporate this variability into the risk assessment analyses. Because this approach includes a full representation of the chemical production and physical transport of ozone in the atmosphere, it does not require assumed background concentrations, which have been applied to constrain estimates from past statistical techniques. The CMAQ-HDDM adjustment approach is extended to measured ozone concentrations by determining typical sensitivities at each monitor location and hour of the day based on a linear relationship between first-order sensitivities and hourly ozone values. This approach is demonstrated by modeling ozone responses for monitor locations in Detroit and Charlotte to domain-wide reductions in anthropogenic NOx and VOCs emissions. As seen in previous studies, ozone response calculated using HDDM compared well to brute-force emissions changes up to approximately a 50% reduction in emissions. A new stepwise approach is developed here to apply this method to emissions reductions beyond 50% allowing for the simulation of more stringent reductions in ozone concentrations. Compared to previous rollback methods, this

YOGYAKARTA AIR BORNE QUALITY BASED ON THE LEAD PARTICULATE CONCENTRATION

Directory of Open Access Journals (Sweden)

Zaenal Abidin

2010-06-01

Full Text Available Analysis of Yogyakarta air quality based on concentration of lead particulate using Fast Neutron Activation Analysis (FNAA method has been done. The sample was taken 3 times in 16 strategic locations of Yogyakarta city using Hi-Vol air sampler that equipped with cellulose filter TFA 2133. The sample irradiated for 30 min with 14 MeV fast neutron and then counted using gamma spectroscopy (AccuSpec. The result indicated that concentration of Pb-208 along Diponegoro street up to Janti street respectively are minimally (0.689 - 0.775 mg/m3, and maximally:  (1.598 - 1.785 mg/m3. According to DIY governor decree No. 153/2002 about the limited toxicity ambient on Yogyakarta area it is concentration that Pb. The concentration of Pb-208 are still below the permitted value of 2 mg/m3, but in certain areas, the Pb concentration is almost equal to upper limit of permitted concentration of Pb.   Keywords: air borne, neutron generator, FNAA

Influence of the ambient humidity on the concentration of natural deposition-mode ice-nucleating particles

Directory of Open Access Journals (Sweden)

M. L. López

2016-01-01

Full Text Available This study reports measurements of deposition-mode ice-nucleating particle (INP concentrations at ground level during the period July–December 2014 in Córdoba, Argentina. Ambient air was sampled into a cloud chamber where the INP concentration was measured at a temperature of −25 °C and a 15 % supersaturation over ice. Measurements were performed on days with different thermodynamic conditions, including rainy days. The effect of the relative humidity at ground level (RHamb on the INP concentration was analyzed. The number of INPs activated varied from 1 L−1 at RHamb of 25 % to 30 L−1 at RHamb of 90 %. In general, a linear trend between the INP concentration and the RHamb was found, suggesting that this variability must be related to the effectiveness of the aerosols acting as INPs. From the backward trajectories analysis, it was found that the link between INP concentration and RHamb is independent of the origin of the air masses. The role of biological INPs and nucleation occurring in pores and cavities was discussed as a possible mechanism to explain the increase of the INP concentration during high ambient relative humidity events. This work provides valuable measurements of deposition-mode INP concentrations from the Southern Hemisphere where INP data are sparse so far.

Simple and accurate quantification of BTEX in ambient air by SPME and GC-MS.

Science.gov (United States)

Baimatova, Nassiba; Kenessov, Bulat; Koziel, Jacek A; Carlsen, Lars; Bektassov, Marat; Demyanenko, Olga P

2016-07-01

Benzene, toluene, ethylbenzene and xylenes (BTEX) comprise one of the most ubiquitous and hazardous groups of ambient air pollutants of concern. Application of standard analytical methods for quantification of BTEX is limited by the complexity of sampling and sample preparation equipment, and budget requirements. Methods based on SPME represent simpler alternative, but still require complex calibration procedures. The objective of this research was to develop a simpler, low-budget, and accurate method for quantification of BTEX in ambient air based on SPME and GC-MS. Standard 20-mL headspace vials were used for field air sampling and calibration. To avoid challenges with obtaining and working with 'zero' air, slope factors of external standard calibration were determined using standard addition and inherently polluted lab air. For polydimethylsiloxane (PDMS) fiber, differences between the slope factors of calibration plots obtained using lab and outdoor air were below 14%. PDMS fiber provided higher precision during calibration while the use of Carboxen/PDMS fiber resulted in lower detection limits for benzene and toluene. To provide sufficient accuracy, the use of 20mL vials requires triplicate sampling and analysis. The method was successfully applied for analysis of 108 ambient air samples from Almaty, Kazakhstan. Average concentrations of benzene, toluene, ethylbenzene and o-xylene were 53, 57, 11 and 14µgm(-3), respectively. The developed method can be modified for further quantification of a wider range of volatile organic compounds in air. In addition, the new method is amenable to automation. Copyright © 2016 Elsevier B.V. All rights reserved.

78 FR 47191 - Air Quality Designations for the 2010 Sulfur Dioxide (SO2) Primary National Ambient Air Quality...

Science.gov (United States)

2013-08-05

... Air Quality Designations for the 2010 Sulfur Dioxide (SO[bdi2]) Primary National Ambient Air Quality... air quality designations for certain areas in the United States for the 2010 primary Sulfur Dioxide (SO 2 ) National Ambient Air Quality Standard (NAAQS). The EPA is issuing this rule to identify areas...

Monitoring the levels of toxic air pollutants in the ambient air of ...

African Journals Online (AJOL)

user

The ambient air quality in Freetown, Sierra Leone was investigated for the first time for toxic air pollutants. ..... 215 Switzerland), in a water bath at temperature of 55°C and pressure of ..... scraps. Furthermore, the prolonged use of generators.

Measurement of volatile plant compounds in field ambient air by thermal desorption-gas chromatography-mass spectrometry.

Science.gov (United States)

Cai, Xiao-Ming; Xu, Xiu-Xiu; Bian, Lei; Luo, Zong-Xiu; Chen, Zong-Mao

2015-12-01

Determination of volatile plant compounds in field ambient air is important to understand chemical communication between plants and insects and will aid the development of semiochemicals from plants for pest control. In this study, a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method was developed to measure ultra-trace levels of volatile plant compounds in field ambient air. The desorption parameters of TD, including sorbent tube material, tube desorption temperature, desorption time, and cold trap temperature, were selected and optimized. In GC-MS analysis, the selected ion monitoring mode was used for enhanced sensitivity and selectivity. This method was sufficiently sensitive to detect part-per-trillion levels of volatile plant compounds in field ambient air. Laboratory and field evaluation revealed that the method presented high precision and accuracy. Field studies indicated that the background odor of tea plantations contained some common volatile plant compounds, such as (Z)-3-hexenol, methyl salicylate, and (E)-ocimene, at concentrations ranging from 1 to 3400 ng m(-3). In addition, the background odor in summer was more abundant in quality and quantity than in autumn. Relative to previous methods, the TD-GC-MS method is more sensitive, permitting accurate qualitative and quantitative measurements of volatile plant compounds in field ambient air.

Technical comments on EPA`s proposed revisions to the National Ambient Air Quality Standard for particulate matter

Energy Technology Data Exchange (ETDEWEB)

Lipfert, F.W.

1997-03-01

The US Environmental Protection Agency (EPA) has proposed new ambient air quality standards specifically for fine particulate matter, regulating concentrations of particles with median aerodynamic diameters less than 2.5 {mu}m (PM{sub 2.5}). Two new standards have been proposed: a maximum 24-hr concentration that is intended to protect against acute health effects, and an annual concentration limit that is intended to protect against longer-term health effects. EPA has also proposed a slight relaxation of the 24-hr standard for inhalable particles (PM{sub 10}), by allowing additional exceedances each year. Fine particles are currently being indirectly controlled by means of regulations for PM{sub 10} and TSP, under the Clean Air Act of 1970 and subsequent amendments. Although routine monitoring of PM{sub 2.5} is rare and data are sparse, the available data indicate that ambient concentrations have been declining at about 6% per year under existing regulations.

Cooling system with compressor bleed and ambient air for gas turbine engine

Science.gov (United States)

Marsh, Jan H.; Marra, John J.

2017-11-21

A cooling system for a turbine engine for directing cooling fluids from a compressor to a turbine blade cooling fluid supply and from an ambient air source to the turbine blade cooling fluid supply to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The cooling system may include a compressor bleed conduit extending from a compressor to the turbine blade cooling fluid supply that provides cooling fluid to at least one turbine blade. The compressor bleed conduit may include an upstream section and a downstream section whereby the upstream section exhausts compressed bleed air through an outlet into the downstream section through which ambient air passes. The outlet of the upstream section may be generally aligned with a flow of ambient air flowing in the downstream section. As such, the compressed air increases the flow of ambient air to the turbine blade cooling fluid supply.

Ambient air pollution and low birth weight - are some women more vulnerable than others?

Science.gov (United States)

Westergaard, Nadja; Gehring, Ulrike; Slama, Rémy; Pedersen, Marie

2017-07-01

Ambient air pollution is controllable, and it is one of the greatest environmental threats to human health. Studies conducted worldwide have provided evidence that maternal exposure to ambient air pollution during pregnancy enhances the risk of low birth weight at term (TLBW, air pollution. The aim of this commentary is to review the published literature on the association between ambient air pollution and TLBW regarding increased vulnerability for the above-mentioned subgroups. Although more than fifty epidemiological studies have examined the associations between ambient air pollution and TLBW to date, we only identified six studies that examined the potential effect modification of the association between ambient air pollution and TLBW by the above listed maternal risk factors. Two studies assessed effect modification caused by smoking on the association between ambient air pollution and TLBW. The adjusted odds ratio (OR) for TLBW associated with exposure to ambient air pollution were in one study higher among women who smoked during pregnancy, as compared to the OR of non-smoking women, while in the other study the association was in the opposite direction. The association of ambient air pollution and TLBW were higher among women characterized by extreme BMI (two studies) and low SES compared to non-obese women or women of higher SES (four studies), respectively. Only one study reported the estimated effects among asthmatic and non-asthmatic women and no statistically significant effect modification was evident for the risk of TLBW associated with ambient air pollution. The current epidemiologic evidence is scarce, but suggests that pregnant women who are smoking, being underweight, overweight/obese or having lower SES are a vulnerable subpopulation when exposed to ambient air pollution, with and increased risk of having a child with TLBW. The limited evidence precludes for definitive conclusions and further studies are recommended. Copyright © 2017. Published

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

Organochlorine pesticides in the ambient air of Chiapas, Mexico.

Science.gov (United States)

Alegria, Henry; Bidleman, Terry F; Figueroa, Miguel Salvador

2006-04-01

Organochlorine (OC) pesticides were measured in the ambient air of Chiapas, Mexico during 2000-2001. Concentrations of some OC pesticides (DDTs, chlordanes, toxaphene) were elevated compared with levels in the Great Lakes region, while those of other pesticides were not (hexachlorocyclohexanes, dieldrin). While this suggests southern Mexico as a source region for the former group of chemicals, comparably high levels have also been reported in parts of the southern United States, where their suspected sources are soil emissions (DDTs, toxaphene) and termiticide usage (chlordane). Ratios of p,p'-DDT/p,p'-DDE and trans-chlordane/cis-chlordane/trans-nonachlor (TC/CC/TN) in Chiapas suggest a mixture of fresh and weathered sources, while congener profiles of toxaphene suggest emission of old residues from soils. This is supported by air parcel back trajectory analysis, which indicated that air masses over Chiapas at the time of sampling had previously passed over areas of continuing or recent use of some OC pesticides as well as areas of past use.

Alfalfa nutritive quality for ruminant livestock as influenced by ambient air quality in west-central Alberta

International Nuclear Information System (INIS)

Lin, J.C.; Nosal, M.; Muntifering, R.B.; Krupa, S.V.

2007-01-01

Alfalfa (Medicago sativa) nutritive quality response to ambient ozone (O 3 ), sulfur dioxide (SO 2 ) and oxides of nitrogen (NO x ) were assessed at three locations in west-central Alberta, Canada (1998-2002). Yield data were segregated into high and low relative to overall median yield. Ozone concentrations (hourly median and 95th-percentile) and precipitation (P) contributed 69 and 29%, respectively, to the variability in crude protein (CP) concentration in low-yielding alfalfa, whereas mean temperature (T) and relative humidity (RH) collectively influenced 98% of the variation in CP in high-yielding alfalfa. Three-fourths of the accounted variation in relative feed value (RFV) of low-yielding alfalfa was attributable to P, T and RH, whereas median and 95th-percentile hourly O 3 concentrations and SO 2 and NO x exposure integrals contributed 25%. In contrast, air quality, (mainly O 3 ) influenced 86% of the accounted variation in RFV of high-yielding alfalfa, and T and P collectively contributed 14%. - Exposure to ambient concentrations of phytotoxic air pollutants affected nutritive quality of alfalfa for ruminant livestock in a yield-dependent manner

A Long-Life Lithium-Air Battery in Ambient Air with a Polymer Electrolyte Containing a Redox Mediator.

Science.gov (United States)

Guo, Ziyang; Li, Chao; Liu, Jingyuan; Wang, Yonggang; Xia, Yongyao

2017-06-19

Lithium-air batteries when operated in ambient air generally exhibit poor reversibility and cyclability, because of the Li passivation and Li 2 O 2 /LiOH/Li 2 CO 3 accumulation in the air electrode. Herein, we present a Li-air battery supported by a polymer electrolyte containing 0.05 m LiI, in which the polymer electrolyte efficiently alleviates the Li passivation induced by attacking air. Furthermore, it is demonstrated that I - /I 2 conversion in polymer electrolyte acts as a redox mediator that facilitates electrochemical decomposition of the discharge products during recharge process. As a result, the Li-air battery can be stably cycled 400 times in ambient air (relative humidity of 15 %), which is much better than previous reports. The achievement offers a hope to develop the Li-air battery that can be operated in ambient air. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ambient air pollution and pregnancy-induced hypertensive disorders

DEFF Research Database (Denmark)

Pedersen, Marie; Stayner, Leslie; Slama, Rémy

2014-01-01

to ambient air pollution and pregnancy-induced hypertensive disorders including gestational hypertension and preeclampsia. We searched electronic databases for English language studies reporting associations between ambient air pollution and pregnancy-induced hypertensive disorders published between December.......5), carbon monoxide (CO), ozone (O3), proximity to major roads, and traffic density met our inclusion criteria. Most studies reported that air pollution increased risk for pregnancy-induced hypertensive disorders. There was significant heterogeneity in meta-analysis, which included 16 studies reporting...... on gestational hypertension and preeclampsia as separate or combined outcomes; there was less heterogeneity in findings of the 10 studies reporting solely on preeclampsia. Meta-analyses showed increased risks of hypertensive disorders in pregnancy for all pollutants except CO. Random-effect meta...

Monitoring of total suspended air particulate in the ambient air of ...

African Journals Online (AJOL)

Monitoring of total suspended air particulate in the ambient air of welding, car painting and. V. C. IKAMAISE, I. B. OBIOH, I. E. OFOZIE, F. A. AKEREDOLU. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/gjpas.v7i4.16316.

The association between ambient fine particulate air pollution and physical activity: a cohort study of university students living in Beijing.

Science.gov (United States)

Yu, Hongjun; Yu, Miao; Gordon, Shelby Paige; Zhang, Ruiling

2017-10-05

Air pollution has become a substantial environmental issue affecting human health and health-related behavior in China. Physical activity is widely accepted as a method to promote health and well-being and is potentially influenced by air pollution. Previous population-based studies have focused on the impact of air pollution on physical activity in the U.S. using a cross-sectional survey method; however, few have examined the impact on middle income countries such as China using follow-up data. The purpose of this study is to examine the impact of ambient fine particulate matter (PM 2.5 ) air pollution on physical activity among freshmen students living in Beijing by use of follow-up data. We conducted 4 follow-up health surveys on 3445 freshmen students from Tsinghua University from 2012 to 2013 and 2480 freshmen completed all 4 surveys. Linear individual fixed-effect regressions were performed based on repeated-measure physical activity-related health behaviors and ambient PM 2.5 concentrations among the follow-up participants. An increase in ambient PM 2.5 concentration by one standard deviation (44.72 μg/m 3 ) was associated with a reduction in 22.32 weekly minutes of vigorous physical activity (95% confidence interval [CI] = 24.88-19.77), a reduction in 10.63 weekly minutes of moderate physical activity (95% CI = 14.61-6.64), a reduction in 32.45 weekly minutes of moderate to vigorous physical activity (MVPA) (95% CI = 37.63-27.28), and a reduction in 226.14 weekly physical activity MET-minute scores (95% CI = 256.06-196.21). The impact of ambient PM 2.5 concentration on weekly total minutes of moderate physical activity tended to be greater among males than among females. Ambient PM 2.5 air pollution significantly discouraged physical activity among Chinese freshmen students living in Beijing. Future studies are warranted to replicate study findings in other Chinese cities and universities, and policy interventions are urgently needed to reduce air

Passive radiative cooling below ambient air temperature under direct sunlight.

Science.gov (United States)

Raman, Aaswath P; Anoma, Marc Abou; Zhu, Linxiao; Rephaeli, Eden; Fan, Shanhui

2014-11-27

Cooling is a significant end-use of energy globally and a major driver of peak electricity demand. Air conditioning, for example, accounts for nearly fifteen per cent of the primary energy used by buildings in the United States. A passive cooling strategy that cools without any electricity input could therefore have a significant impact on global energy consumption. To achieve cooling one needs to be able to reach and maintain a temperature below that of the ambient air. At night, passive cooling below ambient air temperature has been demonstrated using a technique known as radiative cooling, in which a device exposed to the sky is used to radiate heat to outer space through a transparency window in the atmosphere between 8 and 13 micrometres. Peak cooling demand, however, occurs during the daytime. Daytime radiative cooling to a temperature below ambient of a surface under direct sunlight has not been achieved because sky access during the day results in heating of the radiative cooler by the Sun. Here, we experimentally demonstrate radiative cooling to nearly 5 degrees Celsius below the ambient air temperature under direct sunlight. Using a thermal photonic approach, we introduce an integrated photonic solar reflector and thermal emitter consisting of seven layers of HfO2 and SiO2 that reflects 97 per cent of incident sunlight while emitting strongly and selectively in the atmospheric transparency window. When exposed to direct sunlight exceeding 850 watts per square metre on a rooftop, the photonic radiative cooler cools to 4.9 degrees Celsius below ambient air temperature, and has a cooling power of 40.1 watts per square metre at ambient air temperature. These results demonstrate that a tailored, photonic approach can fundamentally enable new technological possibilities for energy efficiency. Further, the cold darkness of the Universe can be used as a renewable thermodynamic resource, even during the hottest hours of the day.

Ambient concentrations of aldehydes in relation to Beijing Olympic air pollution control measures

Science.gov (United States)

Gong, J. C.; Zhu, T.; Hu, M.; Zhang, L. W.; Cheng, H.; Zhang, L.; Tong, J.; Zhang, J.

2010-08-01

Aldehydes are ubiquitous constituents of the atmosphere. Their concentrations are elevated in polluted urban atmospheres. The present study was carried out to characterize three aldehydes of most health concern (formaldehyde, acetaldehyde, and acrolein) in a central Beijing site in the summer and early fall of 2008 (from June to October). Measurements were made before, during, and after the Beijing Olympics to examine whether the air pollution control measures implemented to improve Beijing's air quality during the Olympics had any impact on concentrations of the three aldehydes. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.34 ± 15.12 μg/m3, 27.09 ± 15.74 μg/m3 and 2.32 ± 0.95 μg/m3, respectively, for the entire period of measurements, all being the highest among the levels measured in cities around the world in photochemical smog seasons. Among the three measured aldehydes, only acetaldehyde had a substantially reduced mean concentration during the Olympic air pollution control period compared to the pre-Olympic period. Formaldehyde and acrolein followed the changing pattern of temperature and were each significantly correlated with ozone (a secondary product of photochemical reactions). In contrast, acetaldehyde was significantly correlated with several pollutants emitted mainly from local emission sources (e.g., NO2, CO, and PM2.5). These findings suggest that local direct emissions had a larger impact on acetaldehyde than formaldehyde and acrolein.

Measurement of Ambient Air Motion of D. I. Gasoline Spray by LIF-PIV

Science.gov (United States)

Yamakawa, Masahisa; Isshiki, Seiji; Yoshizaki, Takuo; Nishida, Keiya

Ambient air velocity distributions in and around a D. I. gasoline spray were measured using a combination of LIF and PIV techniques. A rhodamine and water solution was injected into ambient air to disperse the fine fluorescent liquid particles used as tracers. A fuel spray was injected into the fluorescent tracer cloud and was illuminated by an Nd: YAG laser light sheet (532nm). The scattered light from the spray droplets and tracers was cut off by a high-pass filter (>560nm). As the fluorescence (>600nm) was transmitted through the high-pass filter, the tracer images were captured using a CCD camera and the ambient air velocity distribution could be obtained by PIV based on the images. This technique was applied to a D. I. gasoline spray. The ambient air flowed up around the spray and entered into the tail of the spray. Furthermore, the relative velocity between the spray and ambient air was investigated.

Impact of ambient fine particulate matter air pollution on health behaviors: a longitudinal study of university students in Beijing, China.

Science.gov (United States)

An, R; Yu, H

2018-03-19

Poor air quality has become a national public health concern in China. This study examines the impact of ambient fine particulate matter (PM 2.5 ) air pollution on health behaviors among college students in Beijing, China. Prospective cohort study. Health surveys were repeatedly administered among 12,000 newly admitted students at Tsinghua University during 2012-2015 over their freshman year. Linear individual fixed-effect regressions were performed to estimate the impacts of ambient PM 2.5 concentration on health behaviors among survey participants, adjusting for various time-variant individual characteristics and environmental measures. Ambient PM 2.5 concentration was found to be negatively associated with time spent on walking, vigorous physical activity and sedentary behavior in the last week, but positively associated with time spent on nighttime/daytime sleep among survey participants. An increase in the ambient PM 2.5 concentration by one standard deviation (36.5 μg/m³) was associated with a reduction in weekly total minutes of walking by 7.3 (95% confidence interval [CI] = 5.3-9.4), a reduction in weekly total minutes of vigorous physical activity by 10.1 (95% CI = 8.5-11.7), a reduction in daily average hours of sedentary behavior by 0.06 (95% CI = 0.02-0.10) but an increase in daily average hours of nighttime/daytime sleep by 1.07 (95% CI = 1.04-1.11). Ambient PM 2.5 air pollution was inversely associated with physical activity level but positively associated with sleep duration among college students. Future studies are warranted to replicate study findings in other Chinese cities and universities, and policy interventions are urgently called to reduce air pollution level in China's urban areas. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Ambient fine particulate matter air pollution and leisure-time physical inactivity among US adults.

Science.gov (United States)

An, R; Xiang, X

2015-12-01

There is mounting evidence documenting the adverse health effects of short- and long-term exposure to ambient fine particulate matter (PM2.5) air pollution, but population-based evidence linking PM2.5 and health behaviour remains lacking. This study examined the relationship between ambient PM2.5 air pollution and leisure-time physical inactivity among US adults 18 years of age and above. Retrospective data analysis. Participant-level data (n = 2,381,292) from the Behavioral Risk Factor Surveillance System 2003-2011 surveys were linked with Wide-ranging Online Data for Epidemiologic Research air quality data by participants' residential county and interview month/year. Multilevel logistic regressions were performed to examine the effect of ambient PM2.5 air pollution on participants' leisure-time physical inactivity, accounting for various individual and county-level characteristics. Regressions were estimated on the overall sample and subsamples stratified by sex, age cohort, race/ethnicity and body weight status. One unit (μg/m(3)) increase in county monthly average PM2.5 concentration was found to be associated with an increase in the odds of physical inactivity by 0.46% (95% confidence interval = 0.34%-0.59%). The effect was similar between the sexes but to some extent (although not always statistically significant) larger for younger adults, Hispanics, and overweight/obese individuals compared with older adults, non-Hispanic whites or African Americans, and normal weight individuals, respectively. Ambient PM2.5 air pollution is found to be associated with a modest but measurable increase in individuals' leisure-time physical inactivity, and the relationship tends to differ across population subgroups. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Assessing plant response to ambient ozone: growth of young apple trees in open-top chambers and corresponding ambient air plots

International Nuclear Information System (INIS)

Manning, W.J.; Cooley, D.R.; Tuttle, A.F.; Frenkel, M.A.; Bergweiler, C.J.

2004-01-01

Open-top chambers (OTCs) and corresponding ambient air plots (AA) were used to assess the impact of ambient ozone on growth of newly planted apple trees at the Montague Field research center in Amherst, MA. Two-year-old apple trees (Malus domestica Borkh 'Rogers Red McIntosh') were planted in the ground in circular plots. Four of the plots were enclosed with OTCs where incoming air was charcoal-filtered (CF); four were enclosed with OTCs where incoming air was not charcoal-filtered (NF) and four were not enclosed, allowing access to ambient air conditions (AA). Conditions in both CF and NF OTCs resulted in increased tree growth and changed incidence of disease and arthropod pests, compared to trees in AA. As a result, we were not able to use the OTC method to assess the impact of ambient ozone on growth of young apple trees in Amherst, MA. - Capsule: Conditions in charcoal-filtered and non-filtered open-top chambers affected apple tree growth equally and prevented assessment of ambient ozone effects

Kriged and modeled ambient air levels of benzene in an urban environment: an exposure assessment study

Directory of Open Access Journals (Sweden)

Lai Dejian

2011-03-01

Full Text Available Abstract Background There is increasing concern regarding the potential adverse health effects of air pollution, particularly hazardous air pollutants (HAPs. However, quantifying exposure to these pollutants is problematic. Objective Our goal was to explore the utility of kriging, a spatial interpolation method, for exposure assessment in epidemiologic studies of HAPs. We used benzene as an example and compared census tract-level kriged predictions to estimates obtained from the 1999 U.S. EPA National Air Toxics Assessment (NATA, Assessment System for Population Exposure Nationwide (ASPEN model. Methods Kriged predictions were generated for 649 census tracts in Harris County, Texas using estimates of annual benzene air concentrations from 17 monitoring sites operating in Harris and surrounding counties from 1998 to 2000. Year 1999 ASPEN modeled estimates were also obtained for each census tract. Spearman rank correlation analyses were performed on the modeled and kriged benzene levels. Weighted kappa statistics were computed to assess agreement between discretized kriged and modeled estimates of ambient air levels of benzene. Results There was modest correlation between the predicted and modeled values across census tracts. Overall, 56.2%, 40.7%, 31.5% and 28.2% of census tracts were classified as having 'low', 'medium-low', 'medium-high' and 'high' ambient air levels of benzene, respectively, comparing predicted and modeled benzene levels. The weighted kappa statistic was 0.26 (95% confidence interval (CI = 0.20, 0.31, indicating poor agreement between the two methods. Conclusions There was a lack of concordance between predicted and modeled ambient air levels of benzene. Applying methods of spatial interpolation for assessing exposure to ambient air pollutants in health effect studies is hindered by the placement and number of existing stationary monitors collecting HAP data. Routine monitoring needs to be expanded if we are to use these data

Alfalfa nutritive quality for ruminant livestock as influenced by ambient air quality in west-central Alberta

Energy Technology Data Exchange (ETDEWEB)

Lin, J.C. [Department of Animal Sciences, Auburn University, Auburn, AL 36849 (United States); Nosal, M. [Department of Mathematics and Statistics, University of Calgary, Calgary, AB T2N 1N4 (Canada); Muntifering, R.B. [Department of Animal Sciences, Auburn University, Auburn, AL 36849 (United States)]. E-mail: muntirb@auburn.edu; Krupa, S.V. [Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108 (United States)

2007-09-15

Alfalfa (Medicago sativa) nutritive quality response to ambient ozone (O{sub 3}), sulfur dioxide (SO{sub 2}) and oxides of nitrogen (NO {sub x} ) were assessed at three locations in west-central Alberta, Canada (1998-2002). Yield data were segregated into high and low relative to overall median yield. Ozone concentrations (hourly median and 95th-percentile) and precipitation (P) contributed 69 and 29%, respectively, to the variability in crude protein (CP) concentration in low-yielding alfalfa, whereas mean temperature (T) and relative humidity (RH) collectively influenced 98% of the variation in CP in high-yielding alfalfa. Three-fourths of the accounted variation in relative feed value (RFV) of low-yielding alfalfa was attributable to P, T and RH, whereas median and 95th-percentile hourly O{sub 3} concentrations and SO{sub 2} and NO {sub x} exposure integrals contributed 25%. In contrast, air quality, (mainly O{sub 3}) influenced 86% of the accounted variation in RFV of high-yielding alfalfa, and T and P collectively contributed 14%. - Exposure to ambient concentrations of phytotoxic air pollutants affected nutritive quality of alfalfa for ruminant livestock in a yield-dependent manner.

Ambient air cooling arrangement having a pre-swirler for gas turbine engine blade cooling

Science.gov (United States)

Lee, Ching-Pang; Tham, Kok-Mun; Schroeder, Eric; Meeroff, Jamie; Miller, Jr., Samuel R; Marra, John J

2015-01-06

A gas turbine engine including: an ambient-air cooling circuit (10) having a cooling channel (26) disposed in a turbine blade (22) and in fluid communication with a source (12) of ambient air: and an pre-swirler (18), the pre-swirler having: an inner shroud (38); an outer shroud (56); and a plurality of guide vanes (42), each spanning from the inner shroud to the outer shroud. Circumferentially adjacent guide vanes (46, 48) define respective nozzles (44) there between. Forces created by a rotation of the turbine blade motivate ambient air through the cooling circuit. The pre-swirler is configured to impart swirl to ambient air drawn through the nozzles and to direct the swirled ambient air toward a base of the turbine blade. The end walls (50, 54) of the pre-swirler may be contoured.

Wintertime Ambient Ammonia Concentrations in Northern Utah's Urban Valleys

Science.gov (United States)

Hammond, I. A.; Martin, R. S.; Silva, P.; Baasandorj, M.

2017-12-01

Many of the population centers in northern Utah are currently classified as non-attainment or serious non-attainment, Wasatch Front, for PM2.5 and previous studies have shown ammonium nitrate to often be the largest contributor to the particulate mass. Furthermore, measurements have shown several of the Wasatch Front cities and Cache Valley (UT/ID) consistently recorded some of the highest ambient ammonia (NH3) concentrations in the continental United States. As a part of the multi-organization 2017 Utah Winter Fine Particulate Study real-time NH3 concentrations were monitored in the Cache Valley at the Logan, UT site, collocated at an EPA sampling trailer near the Utah State University (USU) campus. A Picarro model G2508 was to used collect 5-sec averaged concentrations of NH3, carbon dioxide (CO2), and methane (CH4) from January 16th to February 14th, 2017. Parts of three inversion events, wherein the PM2.5 concentrations approached or exceeded the National Ambient Air Quality Standards, were captured during the sampling period, including a 10-day event from January 25th to February 4th. Concentrations of all three of the observed species showed significant accumulation during the events, with NH3 concentrations ranging from below the detection limit (70 ppb. Preliminary analysis suggested the temporal NH3 changes tracked the increase in PM2.5 throughout the inversion events; however, a one-day period of NH3 depletion during the main inversion event was observed while PM2.5 continued to increase. Additionally, a network of passive NH3 samplers (Ogawa Model 3300) were arrayed at 25 sites throughout the Cache Valley and at 11 sites located along the Wasatch Front. These networks sampled for three 7-day periods, during the same study time frame. Ion chromatographic (IC) analyses of the sample pads are not yet finalized; however, preliminary results show concentrations in the tens of ppb and seemingly spatially correlate with previous studies showing elevated

A GIS-based spatial correlation analysis for ambient air pollution and AECOPD hospitalizations in Jinan, China.

Science.gov (United States)

Wang, Wenqiao; Ying, Yangyang; Wu, Quanyuan; Zhang, Haiping; Ma, Dedong; Xiao, Wei

2015-03-01

Acute exacerbations of COPD (AECOPD) are important events during disease procedure. AECOPD have negative effect on patients' quality of life, symptoms and lung function, and result in high socioeconomic costs. Though previous studies have demonstrated the significant association between outdoor air pollution and AECOPD hospitalizations, little is known about the spatial relationship utilized a spatial analyzing technique- Geographical Information System (GIS). Using GIS to investigate the spatial association between ambient air pollution and AECOPD hospitalizations in Jinan City, 2009. 414 AECOPD hospitalization cases in Jinan, 2009 were enrolled in our analysis. Monthly concentrations of five monitored air pollutants (NO2, SO2, PM10, O3, CO) during January 2009-December 2009 were provided by Environmental Protection Agency of Shandong Province. Each individual was geocoded in ArcGIS10.0 software. The spatial distribution of five pollutants and the temporal-spatial specific air pollutants exposure level for each individual was estimated by ordinary Kriging model. Spatial autocorrelation (Global Moran's I) was employed to explore the spatial association between ambient air pollutants and AECOPD hospitalizations. A generalized linear model (GLM) using a Poisson distribution with log-link function was used to construct a core model. At residence, concentrations of SO2, PM10, NO2, CO, O3 and AECOPD hospitalization cases showed statistical significant spatially clustered. The Z-score of SO2, PM10, CO, O3, NO2 at residence is 15.88, 13.93, 12.60, 4.02, 2.44 respectively, while at workplace, concentrations of PM10, SO2, O3, CO and AECOPD hospitalization cases showed statistical significant spatially clustered. The Z-score of PM10, SO2, O3, CO at workplace is 11.39, 8.07, 6.10, and 5.08 respectively. After adjusting for potential confounders in the model, only the PM10 concentrations at workplace showed statistical significance, with a 10 μg/m(3) increase of PM10 at

Development and Application of an Oxidation Flow Reactor to Study Secondary Organic Aerosol Formation from Ambient Air

Science.gov (United States)

Palm, Brett Brian

Secondary organic aerosols (SOA) in the atmosphere play an important role in air quality, human health, and climate. However, the sources, formation pathways, and fate of SOA are poorly constrained. In this dissertation, I present development and application of the oxidation flow reactor (OFR) technique for studying SOA formation from OH, O3, and NO3 oxidation of ambient air. With a several-minute residence time and a portable design with no inlet, OFRs are particularly well-suited for this purpose. I first introduce the OFR concept, and discuss several advances I have made in performing and interpreting OFR experiments. This includes estimating oxidant exposures, modeling the fate of low-volatility gases in the OFR (wall loss, condensation, and oxidation), and comparing SOA yields of single precursors in the OFR with yields measured in environmental chambers. When these experimental details are carefully considered, SOA formation in an OFR can be more reliably compared with ambient SOA formation processes. I then present an overview of what OFR measurements have taught us about SOA formation in the atmosphere. I provide a comparison of SOA formation from OH, O3, and NO3 oxidation of ambient air in a wide variety of environments, from rural forests to urban air. In a rural forest, the SOA formation correlated with biogenic precursors (e.g., monoterpenes). In urban air, it correlated instead with reactive anthropogenic tracers (e.g., trimethylbenzene). In mixed-source regions, the SOA formation did not correlate well with any single precursor, but could be predicted by multilinear regression from several precursors. Despite these correlations, the concentrations of speciated ambient VOCs could only explain approximately 10-50% of the total SOA formed from OH oxidation. In contrast, ambient VOCs could explain all of the SOA formation observed from O3 and NO3 oxidation. Evidence suggests that lower-volatility gases (semivolatile and intermediate-volatility organic

AGE AND STRAIN INFLUENCES ON LUNG RESPONSES TO CONCENTRATED AIR PARTICULATES (CAPS) IN RODENTS

Science.gov (United States)

Asthma, an inflammatory airways disease, is an urgent health problem. Recent epidemiologic studies have demonstrated positive associations between ambient air particulate matter concentrations and daily respiratory morbidity ? including exacerbations of asthma. Of note, elderly i...

Respiratory diseases in preschool children in the city of Niš exposed to suspended particulates and carbon monoxide from ambient air

Directory of Open Access Journals (Sweden)

Đorđević Amelija

2016-01-01

Full Text Available Background/Aim. Analysis of air quality in Serbia indicates that the city of Niš belongs to a group of cities characterized by the third category of air quality (excessive air pollution. The aim of the study was to analyze the degree of causality between ambient air quality affected by particulate matter of 10 μm (PM10 and carbon monoxide (CO and the incidence of respiratory diseases in preschool children in the city of Niš. Methods. We quantified the influence of higher PM10 concentrations and carbon monoxide comprising motor vehicle exhausts in the city of Niš on the occurrence of unwanted health effects in preschool children by means of the hazard quotient (HQ, individual health risk (Ri, and the probability of cancer (ICR. The methodology used was according to the US Environmental Protection Agency (EPA, and it included basic scientific statistical methods, compilation methods, and the relevant mathematical methods for assessing air pollution health risk, based on the use of attribute equations. Results. Measurement of ambient air pollutant concentrations in the analyzed territory for the entire monitoring duration revealed that PM10 concentrations were significantly above the allowed limits during 80% of the days. The maximum measured PM10 concentration was 191.6 μg/m3, and carbon monoxide 5.415 mg/m3. The incidence of respiratory diseases in the experimental group, with a prominent impact of polluted air was 57.17%, whereas the incidence in the control group was considerably lower, 41.10 %. There were also significant differences in the distribution of certain respiratory diseases. Conclusion. In order to perform good causal analysis of air quality and health risk, it is very important to establish and develop a system for long-term monitoring, control, assessment, and prediction of air pollution. We identified the suspended PM10 and CO as ambient air pollutants causing negative health effects in the exposed preschool children

Review of Portable and Low-Cost Sensors for the Ambient Air Monitoring of Benzene and Other Volatile Organic Compounds.

Science.gov (United States)

Spinelle, Laurent; Gerboles, Michel; Kok, Gertjan; Persijn, Stefan; Sauerwald, Tilman

2017-06-28

This article presents a literature review of sensors for the monitoring of benzene in ambient air and other volatile organic compounds. Combined with information provided by stakeholders, manufacturers and literature, the review considers commercially available sensors, including PID-based sensors, semiconductor (resistive gas sensors) and portable on-line measuring devices as for example sensor arrays. The bibliographic collection includes the following topics: sensor description, field of application at fixed sites, indoor and ambient air monitoring, range of concentration levels and limit of detection in air, model descriptions of the phenomena involved in the sensor detection process, gaseous interference selectivity of sensors in complex VOC matrix, validation data in lab experiments and under field conditions.

Preliminary assessment of BTEX concentrations in indoor air of residential buildings and atmospheric ambient air in Ardabil, Iran

Science.gov (United States)

Hazrati, Sadegh; Rostami, Roohollah; Farjaminezhad, Manoochehr; Fazlzadeh, Mehdi

2016-05-01

BTEX concentrations in indoor and outdoor air of 50 homes were studied in Ardabil city and their influencing parameters including; heating system, using gas stove and samovar, tobacco smoking, the floors in which the monitored homes were located, and kitchen plan were considered in the study. Risk assessment analysis was carried out with the obtained concentrations based on EPA IRIS reference doses. BTEX compounds were sampled by charcoal tubes and the samples were analyzed by a GC-FID. Concentrations of benzene (15.18 μg/m3 vs. 8.65 μg/m3), toluene (69.70 μg/m3 vs. 40.56 μg/m3), ethylbenzene (12.07 μg/m3 vs. 4.92 μg/m3) and xylene (48.08 μg/m3 vs. 7.44 μg/m3) in indoor air were significantly (p < 0.05) higher than the levels quantified for outdoor air. The obtained concentrations of benzene were considerably higher than the recommended value of 5 μg/m3 established by Iran environmental protection organization. Among the BTEX compounds, benzene (HQ = 0.51) and xylene (HQ = 0.47) had notable hazard quotient and were the main pollutants responsible for high hazard index in the monitored homes (HI = 1.003). The results showed considerably high cancer risk for lifetime exposure to the indoor (125 × 10-6) and outdoor (71 × 10-6) benzene. Indoor benzene concentrations in homes were significantly influenced by type of heating system, story, and natural gas appliances.

Analysis of ambient SO2 concentrations and winds in the complex surrounding of a thermal power plant

International Nuclear Information System (INIS)

Mlakar, P.

2004-01-01

SO 2 pollution is still a significant problem in Slovenia, especially around large thermal power plants (TPPs), like the one at Sostanj. The Sostanj TPP is the exclusive source of SO 2 in the area and is therefore a perfect example for air pollution studies. In order to understand air pollution around the Sostanj TPP in detail, some analyses of emissions and ambient concentrations of SO 2 at six automated monitoring stations in the surrounding of the TPP were made. The data base from 1991 to 1993 was used when there were no desulfurization plants in operations. Statistical analyses of the influence of the emissions from the three TPP stacks at different measuring points were made. The analyses prove that the smallest stack (100 m) mainly pollutes villages and towns near the TPP within a radius of a few kilometers. The medium stack's (150 m) influence is noticed at shorter as well as at longer distances up to more than ten kilometers. The highest stack (230 m) pollutes mainly at longer distances, where the plume reaches the higher hills. Detailed analyses of ambient SO 2 concentrations were made. They show the temporal and spatial distribution of different classes of SO 2 concentrations from very low to alarming values. These analyses show that pollution patterns at a particular station remain the same if observed on a yearly basis, but can vary very much if observed on a monthly basis, mainly because of different weather patterns. Therefore the winds in the basin (as the most important feature influencing air pollution dispersion) were further analysed in detail to find clusters of similar patterns. For cluster analysis of ground-level winds patterns in the basin around the Sostanj Thermal Power Plant, the Kohonen neural network and Leaders' method were used. Furthermore the dependence of ambient SO 2 concentrations on the clusters obtained was analysed. The results proved that effective cluster analysis can be a useful tool for compressing a huge wind data base in

Analysis of ambient SO 2 concentrations and winds in the complex surroundings of a thermal power plant

Science.gov (United States)

Mlakar, P.

2004-11-01

SO2 pollution is still a significant problem in Slovenia, especially around large thermal power plants (TPPs), like the one at Šoštanj. The Šoštanj TPP is the exclusive source of SO2 in the area and is therefore a perfect example for air pollution studies. In order to understand air pollution around the Šoštanj TPP in detail, some analyses of emissions and ambient concentrations of SO2 at six automated monitoring stations in the surroundings of the TPP were made. The data base from 1991 to 1993 was used when there were no desulfurisation plants in operation. Statistical analyses of the influence of the emissions from the three TPP stacks at different measuring points were made. The analyses prove that the smallest stack (100 m) mainly pollutes villages and towns near the TPP within a radius of a few kilometres. The medium stack's (150 m) influence is noticed at shorter as well as at longer distances up to more than ten kilometres. The highest stack (230 m) pollutes mainly at longer distances, where the plume reaches the higher hills. Detailed analyses of ambient SO2 concentrations were made. They show the temporal and spatial distribution of different classes of SO2 concentrations from very low to alarming values. These analyses show that pollution patterns at a particular station remain the same if observed on a yearly basis, but can vary very much if observed on a monthly basis, mainly because of different weather patterns. Therefore the winds in the basin (as the most important feature influencing air pollution dispersion) were further analysed in detail to find clusters of similar patterns. For cluster analysis of ground-level winds patterns in the basin around the Šoštanj Thermal Power Plant, the Kohonen neural network and Leaders' method were used. Furthermore, the dependence of ambient SO2 concentrations on the clusters obtained was analysed. The results proved that effective cluster analysis can be a useful tool for compressing a huge wind data base

Effects of Ambient Air Pollution Exposure on Olfaction: A Review.

Science.gov (United States)

Ajmani, Gaurav S; Suh, Helen H; Pinto, Jayant M

2016-11-01

Olfactory dysfunction affects millions of people worldwide. This sensory impairment is associated with neurodegenerative disease and significantly decreased quality of life. Exposure to airborne pollutants has been implicated in olfactory decline, likely due to the anatomic susceptibility of the olfactory nerve to the environment. Historically, studies have focused on occupational exposures, but more recent studies have considered effects from exposure to ambient air pollutants. To examine all relevant human data evaluating a link between ambient pollution exposure and olfaction and to review supporting animal data in order to examine potential mechanisms for pollution-associated olfactory loss. We identified and reviewed relevant articles from 1950 to 2015 using PubMed and Web of Science and focusing on human epidemiologic and pathophysiologic studies. Animal studies were included only to support pertinent data on humans. We reviewed findings from these studies evaluating a relationship between environmental pollutant exposure and olfactory function. We identified and reviewed 17 articles, with 1 additional article added from a bibliography search, for a total of 18 human studies. There is evidence in human epidemiologic and pathologic studies that increased exposure to ambient air pollutants is associated with olfactory dysfunction. However, most studies have used proxies for pollution exposure in small samples of convenience. Human pathologic studies, with supporting animal work, have also shown that air pollution can contact the olfactory epithelium, translocate to the olfactory bulb, and migrate to the olfactory cortex. Pollutants can deposit at each location, causing direct damage and disruption of tissue morphology or inducing local inflammation and cellular stress responses. Ambient air pollution may impact human olfactory function. Additional studies are needed to examine air pollution-related olfactory impacts on the general population using measured

Determination of volatile organic compounds (VOCs) using tedlar bag/solid-phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) in ambient and workplace air

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Hwan; Lee, Dai Woon [Yonsei Univ., Seoul (Korea, Republic of); Hwang, Seung Man; Heo, Gwi Suk [Korea Research Institute of Standards and Science, Taejon (Korea, Republic of)

2002-03-01

SPME techniques have proven to be very useful tools in the analysis of wide VOCs in the air. In this study, we estimated VOCs in ambient and workplace air using a Tedlar ba/SPME/GC/MS system. The calibration curve was set to be linear over the range of 1-30 ppbv. The detection limits ranged from 10 pptv 0.93 ppbv for all VOCs. Reproducibility of TO-14 target gas mixtures by SPME/GC/MS averaged at 8.8 R.S.D (%). Air toxic VOCs (hazardous air pollutants, HAPs) containing a total of forty halohydrocarbons, aromatics, and haloaro-matic carbons could be analyzed with significant accuracy, detection limit and linearity at low ppbv level. Only reactive VOCs with low molecular weight, such as chloromethane, vinylchloride, ethylchloride and 1,2-dichloro-ethane, yielded relatively poor results using this technique. In ambient air samples, ten VOCs were identified and quantified after external calibration. VOC concentration in ambient and workplace air ranged from 0.04 to 1.85 ppbv. The overall process was successfully applied to identify and quantify VOCs in ambient/workplace air.

Determination of volatile organic compounds (VOCs) using tedlar bag/solid-phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) in ambient and workplace air

International Nuclear Information System (INIS)

Lee, Jae Hwan; Lee, Dai Woon; Hwang, Seung Man; Heo, Gwi Suk

2002-01-01

SPME techniques have proven to be very useful tools in the analysis of wide VOCs in the air. In this study, we estimated VOCs in ambient and workplace air using a Tedlar ba/SPME/GC/MS system. The calibration curve was set to be linear over the range of 1-30 ppbv. The detection limits ranged from 10 pptv 0.93 ppbv for all VOCs. Reproducibility of TO-14 target gas mixtures by SPME/GC/MS averaged at 8.8 R.S.D (%). Air toxic VOCs (hazardous air pollutants, HAPs) containing a total of forty halohydrocarbons, aromatics, and haloaro-matic carbons could be analyzed with significant accuracy, detection limit and linearity at low ppbv level. Only reactive VOCs with low molecular weight, such as chloromethane, vinylchloride, ethylchloride and 1,2-dichloro-ethane, yielded relatively poor results using this technique. In ambient air samples, ten VOCs were identified and quantified after external calibration. VOC concentration in ambient and workplace air ranged from 0.04 to 1.85 ppbv. The overall process was successfully applied to identify and quantify VOCs in ambient/workplace air

Impact of a new gasoline benzene regulation on ambient air pollutants in Anchorage, Alaska

Science.gov (United States)

Yano, Yuriko; Morris, Stephen S.; Salerno, Christopher; Schlapia, Anne M.; Stichick, Mathew

2016-05-01

The purpose of this study was to quantify the impact of a new U.S. Environmental Protection Agency (EPA) standard that limits the amount of benzene allowed in gasoline on ambient benzene concentrations. This new standard, together with two companion regulations that limit cold-temperature automotive emissions and the permeability of portable fuel containers, was expected to lower the levels of ambient benzene and other volatile organic compounds (VOCs) nationwide. In this study the impact of the gasoline benzene standard was evaluated in Anchorage, Alaska in a two-phase ambient air monitoring study conducted before and after the new gasoline standard was implemented. Gasoline sold by Anchorage retailers was also evaluated in each phase to determine the content of benzene and other gasoline components. The average benzene content in Anchorage gasoline was reduced by 70%, from 5.05% (w/w) to 1.53% (w/w) following the implementation of the standard. The annual mean ambient benzene concentration fell by 51%, from 0.99 ppbv in Phase 1 to 0.49 ppbv in Phase 2. Analysis suggests the change in gasoline benzene content alone reduced benzene emissions by 46%. The changes in toluene, ethylbenzene, and xylene content in gasoline between Phase 1 and 2 were relatively small and the differences in the mean ambient concentrations of these compounds between phases were modest. Our results suggest that cold winter communities in high latitude and mountainous regions may benefit more from the gasoline benzene standard because of high benzene emissions resulting from vehicle cold start and a tendency to develop atmospheric stagnation conditions in the winter.

Carbonyl atmospheric reaction products of aromatic hydrocarbons in ambient air

Science.gov (United States)

Obermeyer, Genevieve; Aschmann, Sara M.; Atkinson, Roger; Arey, Janet

To convert gaseous carbonyls to oximes during sampling, an XAD-4 resin denuder system pre-coated with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine and followed by analysis with methane positive chemical ionization gas chromatography/mass spectrometry was used to measure carbonyls in ambient air samples in Riverside, CA. In conjunction with similar analyses of environmental chamber OH radical-initiated reactions of o- and p-xylene, 1,2,4-trimethylbenzene, ethylbenzene, 4-hydroxy-2-butanone and 1,4-butanediol, we identified benzaldehyde, o-, m- and p-tolualdehyde and acetophenone and the dicarbonyls glyoxal, methylglyoxal, biacetyl, ethylglyoxal, 1,4-butenedial, 3-hexene-2,5-dione, 3-oxo-butanal, 1,4-butanedial and malonaldehyde in the ambient air samples. As discussed, these carbonyls and dicarbonyls can be formed from the OH radical-initiated reactions of aromatic hydrocarbons and other volatile organic compounds emitted into the atmosphere, and we conclude that in situ atmospheric formation is a major source of these carbonyls in our Riverside, CA, ambient air samples.

Ambient air pollution, temperature and out-of-hospital coronary deaths in Shanghai, China

International Nuclear Information System (INIS)

Dai, Jinping; Chen, Renjie; Meng, Xia; Yang, Changyuan; Zhao, Zhuohui; Kan, Haidong

2015-01-01

Few studies have evaluated the effects of ambient air pollution and temperature in triggering out-of-hospital coronary deaths (OHCDs) in China. We evaluated the associations of air pollution and temperature with daily OHCDs in Shanghai, China from 2006 to 2011. We applied an over-dispersed generalized additive model and a distributed lag nonlinear model to analyze the effects of air pollution and temperature, respectively. A 10 μg/m 3 increase in the present-day PM 10 , PM 2.5 , SO 2 , NO 2 and CO were associated with increases in OHCD mortality of 0.49%, 0.68%, 0.88%, 1.60% and 0.08%, respectively. A 1 °C decrease below the minimum-mortality temperature corresponded to a 3.81% increase in OHCD mortality on lags days 0–21, and a 1 °C increase above minimum-mortality temperature corresponded to a 4.61% increase over lag days 0–3. No effects were found for in-hospital coronary deaths. This analysis suggests that air pollution, low temperature and high temperature may increase the risk of OHCDs. - Highlights: • Few studies have evaluated the effects of air pollution and temperature on OHCDs in China. • The present-day concentrations of air pollution were associated with OHCDs. • The effect of high temperatures on OHCDs was more immediate than low temperatures. • No significant effects were found for in-hospital coronary deaths. - Ambient air pollution and temperature may trigger out-of-hospital coronary deaths but not in-hospital coronary deaths

Concentrations in ambient air and emissions of cyclic volatile methylsiloxanes in Zurich, Switzerland.

Science.gov (United States)

Buser, Andreas M; Kierkegaard, Amelie; Bogdal, Christian; MacLeod, Matthew; Scheringer, Martin; Hungerbühler, Konrad

2013-07-02

Tens of thousands of tonnes of cyclic volatile methylsiloxanes (cVMS) are used each year globally, which leads to high and continuous cVMS emissions to air. However, field measurements of cVMS in air and empirical information about emission rates to air are still limited. Here we present measurements of decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) in air for Zurich, Switzerland. The measurements were performed in January and February 2011 over a period of eight days and at two sites (city center and background) with a temporal resolution of 6-12 h. Concentrations of D5 and D6 are higher in the center of Zurich and range from 100 to 650 ng m(-3) and from 10 to 79 ng m(-3), respectively. These values are among the highest levels of D5 and D6 reported in the literature. In a second step, we used a multimedia environmental fate model parametrized for the region of Zurich to interpret the levels and time trends in the cVMS concentrations and to back-calculate the emission rates of D5 and D6 from the city of Zurich. The average emission rates obtained for D5 and D6 are 120 kg d(-1) and 14 kg d(-1), respectively, which corresponds to per-capita emissions of 310 mg capita(-1) d(-1) for D5 and 36 mg capita(-1) d(-1) for D6.

Ambient air pollution the risk of stillbirth: A prospective birth cohort study in Wuhan, China.

Science.gov (United States)

Yang, Shaoping; Tan, Yafei; Mei, Hui; Wang, Fang; Li, Na; Zhao, Jinzhu; Zhang, Yiming; Qian, Zhengmin; Chang, Jen Jen; Syberg, Kevin M; Peng, Anna; Mei, Hong; Zhang, Dan; Zhang, Yan; Xu, Shunqing; Li, Yuanyuan; Zheng, Tongzhang; Zhang, Bin

2018-04-01

Recent studies suggest that ambient air pollution exposure during pregnancy is associated with stillbirth occurrence. However, the results on the associations between ambient air pollutants and stillbirths are inconsistent and little is known about the gestational timing of sensitive periods for the effects of ambient air pollutants exposure on stillbirth. This study aimed to examine whether exposure to high levels of ambient air pollutants in a Chinese population is associated with an increased risk of stillbirth, and determine the gestational period when the fetus is most susceptible. We conducted a population-based cohort study in Wuhan, China, involving 95,354 births between June 10, 2011 and June 9, 2013. The exposure assessments were based on the daily mean concentrations of air pollutants obtained from the exposure monitor nearest to the pregnant women's residence. Logistic regression analyses were performed to determine the associations between stillbirths and exposure to each of the air pollutants at different pregnancy periods with adjustment for confounding factors. Stillbirth increased with a 10 μg/m 3 increase in particulate matter 2.5 (PM 2.5 ) in each stage of pregnancy, and a significant association between carbon monoxide (CO) exposure and stillbirth was found during the third trimester (adjusted odds ratio (aOR): 1.01, 95% confidence interval (CI): 1.00-1.01) and in the entire pregnancy (aOR: 1.18, 95% CI: 1.04-1.34). Furthermore, an increased risk of stillbirth in the third trimester was associated with a 10 μg/m 3 increase in PM 10 (aOR: 1.08, 95% CI: 1.04-1.11), nitrogen dioxide (NO 2 ) (aOR: 1.13, 95% CI: 1.07-1.21) and sulfur dioxide (SO 2 ) (aOR: 1.26, 95% CI: 1.16-1.35). However, no positive association was observed between ozone exposure and stillbirth. In the two-pollutant models, PM 2.5 and CO exposures were found to be consistently associated with stillbirth. Our study revealed that exposure to high levels of PM 2.5 , PM 10 , SO 2

78 FR 19990 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Ohio Ambient Air Quality...

Science.gov (United States)

2013-04-03

... Promulgation of Air Quality Implementation Plans; Ohio; Ohio Ambient Air Quality Standards; Correction AGENCY... approved revisions to Ohio regulations that consolidated air quality standards in a new chapter of rules... State's air quality standards into Ohio Administrative Code (OAC) 3745-25 and modifying an assortment of...

Impact of ambient air pollution on physical activity among adults: a systematic review and meta-analysis.

Science.gov (United States)

An, Ruopeng; Zhang, Sheng; Ji, Mengmeng; Guan, Chenghua

2018-03-01

This study systematically reviewed literature regarding the impact of ambient air pollution on physical activity among children and adults. Keyword and reference search was conducted in PubMed and Web of Science to systematically identify articles meeting all of the following criteria - study designs: interventions or experiments, retrospective or prospective cohort studies, cross-sectional studies, and case-control studies; subjects: adults; exposures: specific air pollutants and overall air quality; outcomes: physical activity and sedentary behaviour; article types: peer-reviewed publications; and language: articles written in English. Meta-analysis was performed to estimate the pooled effect size of ambient PM 2.5 air pollution on physical inactivity. Seven studies met the inclusion criteria. Among them, six were conducted in the United States, and one was conducted in the United Kingdom. Six adopted a cross-sectional study design, and one used a prospective cohort design. Six had a sample size larger than 10,000. Specific air pollutants assessed included PM 2.5 , PM 10 , O 3 , and NO x , whereas two studies focused on overall air quality. All studies found air pollution level to be negatively associated with physical activity and positively associated with leisure-time physical inactivity. Study participants, and particularly those with respiratory disease, self-reported a reduction in outdoor activities to mitigate the detrimental impact of air pollution. Meta-analysis revealed a one unit (μg/m 3 ) increase in ambient PM 2.5 concentration to be associated with an increase in the odds of physical inactivity by 1.1% (odds ratio = 1.011; 95% confidence interval = 1.001, 1.021; p-value air pollution discouraged physical activity. Current literature predominantly adopted a cross-sectional design and focused on the United States. Future studies are warranted to implement a longitudinal study design and evaluate the impact of air pollution on physical

The Burden of COPD Morbidity Attributable to the Interaction between Ambient Air Pollution and Temperature in Chengdu, China

Directory of Open Access Journals (Sweden)

Hang Qiu

2018-03-01

Full Text Available Evidence on the burden of chronic obstructive pulmonary disease (COPD morbidity attributable to the interaction between ambient air pollution and temperature has been limited. This study aimed to examine the modification effect of temperature on the association of ambient air pollutants (including particulate matter (PM with aerodynamic diameter <10 μm (PM10 and <2.5 μm (PM2.5, nitrogen dioxide (NO2, sulfur dioxide (SO2, carbon monoxide (CO and ozone (O3 with risk of hospital admissions (HAs for COPD, as well as the associated morbidity burden in urban areas of Chengdu, China, from 2015 to 2016. Based on the generalized additive model (GAM with quasi-Poisson link, bivariate response surface model and stratification parametric model were developed to investigate the potential interactions between ambient air pollution and temperature on COPD HAs. We found consistent interactions between ambient air pollutants (PM2.5, PM10 and SO2 and low temperature on COPD HAs, demonstrated by the stronger associations between ambient air pollutants and COPD HAs at low temperatures than at moderate temperatures. Subgroup analyses showed that the elderly (≥80 years and males were more vulnerable to this interaction. The joint effect of PM and low temperature had the greatest impact on COPD morbidity burden. Using WHO air quality guidelines as reference concentration, about 17.30% (95% CI: 12.39%, 22.19% and 14.72% (95% CI: 10.38%, 19.06% of COPD HAs were attributable to PM2.5 and PM10 exposures on low temperature days, respectively. Our findings suggested that low temperature significantly enhanced the effects of PM and SO2 on COPD HAs in urban Chengdu, resulting in increased morbidity burden. This evidence has important implications for developing interventions to reduce the risk effect of COPD morbidity.

PCDD/F and PCB multi-media ambient concentrations, congener patterns and occurrence in a Mediterranean coastal lagoon (Etang de Thau, France)

Energy Technology Data Exchange (ETDEWEB)

Castro-Jimenez, J. [European Commission-DG Joint Research Centre, Institute for Environment and Sustainability(IES), TP 290, Via Enrico Fermi, 1. 21020 Ispra (Vatican City State, Holy See,) (Italy)], E-mail: javier.castro-jimenez@jrc.it; Deviller, G.; Ghiani, M.; Loos, R.; Mariani, G.; Skejo, H.; Umlauf, G.; Wollgast, J. [European Commission-DG Joint Research Centre, Institute for Environment and Sustainability(IES), TP 290, Via Enrico Fermi, 1. 21020 Ispra (Vatican City State, Holy See,) (Italy); Laugier, T. [Ifremer, Laboratory of Environmental Resources, Bd Jean Monnet, BP 171, 34203 Sete Cedex (France); Heas-Moisan, K.; Leaute, F.; Munschy, C.; Tixier, C.; Tronczynski, J. [Ifremer, Laboratory of Biogeochemistry of Organic Contaminants, BP 21105, 44311 Nantes Cedex 3 (France)

2008-11-15

Ambient concentrations, congener patterns and multi-media distribution of PCDD/Fs and PCBs were determined in air, water, sediment and mussels in a semi-enclosed marine ecosystem (Thau lagoon, France). {sigma}2,3,7,8-PCDD/F and {sigma}7ICES PCB air concentrations (0.2-1.4 and 31-57 pg m{sup -3}, respectively) were typical of rural areas. Concentrations in the water column were very low for PCDD/Fs (163-476 fg L{sup -1}) and low for PCBs (138-708 pg L{sup -1}). PCDD/F and PCB concentrations found in surface sediment (0.15-1.6 and 2.5-33 ng g{sup -1} d.w., respectively) and mussel (13-21 pg g{sup -1} d.w. and 10-39 ng g{sup -1} d.w., respectively) were medium levels. PCDD/F congener patterns observed in air, water particulate phase and sediments were similar suggesting direct coupling among these compartments and atmospheric inputs of PCDD/Fs into the lagoon. Conversely, for the same set of samples, similar patterns were not observed for PCBs in the mentioned compartments. - Multi-media ambient concentrations and distribution of PCDD/Fs and PCBs in Thau Lagoon provide insight into the POPs behavior in semi-enclosed marine ecosystems.

THE GENOTOXICITY OF AMBIENT OUTDOOR AIR, A REVIEW: SALMONELLA MUTAGENICITY

Science.gov (United States)

The genotoxicity of ambient outdoor air, a review: Salmonella mutagenicityAbstractMutagens in urban air pollution come from anthropogenic sources (especially combustion sources) and are products of airborne chemical reactions. Bacterial mutation tests have been used ...

Effects of ambient oxygen concentration on soot temperature and concentration for biodiesel and diesel spray combustion

KAUST Repository

Zhang, Ji

2015-06-01

Ambient oxygen concentration, a key variable directly related to exhaust gas recirculation (EGR) levels in diesel engines, plays a significant role in particulate matter (PM) and nitrogen oxides (NOx) emissions. The utilization of biodiesel in diesel engines has been investigated over the last decades for its renewable characteristics and lower emissions compared to diesel. In an earlier work, we demonstrated that the soot temperature and concentration of biodiesel were lower than diesel under regular diesel engine conditions without EGR. Soot concentration was quantified by a parameter called KL factor. As a continuous effort, this paper presents an experimental investigation of the ambient oxygen concentration on soot temperature and KL factor during biodiesel and diesel spray combustion. The experiment was implemented in a constant volume chamber system, where the ambient oxygen concentration varied from 21 to 10% and the ambient temperature was kept to 1,000 K. A high speed two-color pyrometry technique was used to measure transient soot temperature and the KL factor of the spray flame. The soot temperature of biodiesel is found to be lower than that of diesel under the same conditions, which follows the same trend from our previous results found when the ambient temperature changes to 21% oxygen conditions. A reduction in ambient oxygen concentration generally reduces the soot temperature for both fuels. However, this is a complicated effect on soot processes as the change of oxygen concentration greatly affects the balance between soot formation and oxidation. The KL factor is observed to be the highest at 12% O2 for diesel and 18% O2 for biodiesel, respectively. On the other hand, the 10% O2 condition shows the lowest KL factor for both fuels. These results can provide quantitative experimental evidences to optimize the ambient oxygen concentration for diesel engines using different fuels for better emissions characteristics. © 2014 American Society of

Is There an Association Between Ambient Air Pollution and Bladder Cancer Incidence? Analysis of 15 European Cohorts

DEFF Research Database (Denmark)

Pedersen, Marie; Stafoggia, Massimo; Weinmayr, Gudrun

2016-01-01

Background: Ambient air pollution contains low concentrations of carcinogens implicated in the etiology of urinary bladder cancer (BC). Little is known about whether exposure to air pollution influences BC in the general population. Objective: To evaluate the association between long-term exposure......) with diameter Pollution Effects project...... of information about lifetime exposure. Conclusions: There was no evidence of an association between exposure to outdoor air pollution levels at place of residence and risk of BC. Patient summary: We assessed the link between outdoor air pollution at place of residence and bladder cancer using the largest study...

Low temperature and moisture swing sorption of CO2 from ambient air using a Na-based adsorbent

NARCIS (Netherlands)

Rodriguez Mosqueda, Rafael; Brem, Gerrit; Bramer, Eduard A.

2017-01-01

The continuous increase of the carbon dioxide concentration in the atmosphere is a recognized problem that will lead the humanity to catastrophic scenarios unless it is drastically reduced. One option to tackle this issue is to retrieve CO2 directly from ambient air, which has the advantage that it

An enzymatic-fluorimetric method for monitoring of ethanol in ambient air

Energy Technology Data Exchange (ETDEWEB)

Schilling, M.; Voigt, G.; Klockow, D. [Institut fuer Spektrochemie und Angewandte Spektroskopie (ISAS), Dortmund (Germany); Tavares, T. [Instituto de Quimica, Universidade Federal da Bahia (UFBa), Rua Augusto Viana, s/n - Canela, 40110-010 Salvador/Bahia (Brazil)

1999-05-01

A method is described for the continuous monitoring of ethanol in ambient air. The system consists of a scrubber coil for enrichment of the analyte from air in an aqueous solution and a directly connected fluorescence detector. Because of using a reagent solution containing alcohol dehydrogenase (ADH) and nicotinamide adenine dinucleotide (NAD{sup +}) for absorption, ethanol can react directly with ADH and NAD{sup +} during air sampling, producing NADH, which can be measured by fluorescence detection. The influence of reagent concentrations, gas flow rate and scrubber solution flow rate on the performance of the instrument was tested. Possible ozone interferences can be avoided by placing a KI coated filter in front of the scrubber inlet. The response time of the system was found to be 2.3 min and the detection limit about 1 ppb{sub V}. The applicability of the developed method was demonstrated during a field campaign in Brazil. (orig.) With 7 figs., 35 refs.

Ambient air pollution exposure and full-term birth weight in California

Directory of Open Access Journals (Sweden)

Sadd James L

2010-07-01

Full Text Available Abstract Background Studies have identified relationships between air pollution and birth weight, but have been inconsistent in identifying individual pollutants inversely associated with birth weight or elucidating susceptibility of the fetus by trimester of exposure. We examined effects of prenatal ambient pollution exposure on average birth weight and risk of low birth weight in full-term births. Methods We estimated average ambient air pollutant concentrations throughout pregnancy in the neighborhoods of women who delivered term singleton live births between 1996 and 2006 in California. We adjusted effect estimates of air pollutants on birth weight for infant characteristics, maternal characteristics, neighborhood socioeconomic factors, and year and season of birth. Results 3,545,177 singleton births had monitoring for at least one air pollutant within a 10 km radius of the tract or ZIP Code of the mother's residence. In multivariate models, pollutants were associated with decreased birth weight; -5.4 grams (95% confidence interval -6.8 g, -4.1 g per ppm carbon monoxide, -9.0 g (-9.6 g, -8.4 g per pphm nitrogen dioxide, -5.7 g (-6.6 g, -4.9 g per pphm ozone, -7.7 g (-7.9 g, -6.6 g per 10 μg/m3 particulate matter under 10 μm, -12.8 g (-14.3 g, -11.3 g per 10 μg/m3 particulate matter under 2.5 μm, and -9.3 g (-10.7 g, -7.9 g per 10 μg/m3 of coarse particulate matter. With the exception of carbon monoxide, estimates were largely unchanged after controlling for co-pollutants. Effect estimates for the third trimester largely reflect the results seen from full pregnancy exposure estimates; greater variation in results is seen in effect estimates specific to the first and second trimesters. Conclusions This study indicates that maternal exposure to ambient air pollution results in modestly lower infant birth weight. A small decline in birth weight is unlikely to have clinical relevance for individual infants, and there is debate about whether

A realistic in vitro exposure revealed seasonal differences in (pro-)inflammatory effects from ambient air in Fribourg, Switzerland.

Science.gov (United States)

Bisig, Christoph; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

2018-01-01

Ambient air pollutant levels vary widely in space and time, therefore thorough local evaluation of possible effects is needed. In vitro approaches using lung cell cultures grown at the air-liquid interface and directly exposed to ambient air can offer a reliable addition to animal experimentations and epidemiological studies. To evaluate the adverse effects of ambient air in summer and winter a multi-cellular lung model (16HBE14o-, macrophages, and dendritic cells) was exposed in a mobile cell exposure system. Cells were exposed on up to three consecutive days each 12 h to ambient air from Fribourg, Switzerland, during summer and winter seasons. Higher particle number, particulate matter mass, and nitrogen oxide levels were observed in winter ambient air compared to summer. Good cell viability was seen in cells exposed to summer air and short-term winter air, but cells exposed three days to winter air were compromised. Exposure of summer ambient air revealed no significant upregulation of oxidative stress or pro-inflammatory genes. On the opposite, the winter ambient air exposure led to an increased oxidative stress after two exposure days, and an increase in three assessed pro-inflammatory genes already after 12 h of exposure. We found that even with a short exposure time of 12 h adverse effects in vitro were observed only during exposure to winter but not summer ambient air. With this work we have demonstrated that our simple, fast, and cost-effective approach can be used to assess (adverse) effects of ambient air.

Ambient Air Pollution Monitoring Network Over Alexandria City And The Nile DELTA, Egypt

International Nuclear Information System (INIS)

El Raey, M.; Shalaby, E.; Guirguis, S.; Ghatass, Z.; Said, H.H.; Zahran, A.; Rashad, M.; Sivertsen, B.

2007-01-01

The Egyptian Environmental Affairs Agency (EEAA) has established a National Air Pollution Network for Egypt. A part of this network covers Alexandria and the Nile delta region and is being operated by the Institute of Graduate Studies and Research (IGSR), University of Alexandria. This paper presents a description of the network, the QA/QC program as well as results from automatic monitors and manually operated instruments . . Preliminary interpretations and implications of air pollution levels have also been discussed. The network monitors ambient air quality indicators including SO 2 , NO 2 , CO, O 3 and PM 10 . The sites for measurements were selected to represent industrial, traffic and domestic sources. Eight stations are established over Alexandria City and seven stations are distributed over Nile delta major cities Damanhur, Kafr EI-Dawwar, Kafr EI-Zayat, Mahala, Tanta, Damietta and Mansoura. The results represent the first long term air quality data for the southern Mediterranean region, which have been properly quality assured and quality controlled. The main results indicate that measured NO 2 concentrations have not exceeded the national air quality limit (AQL) values given for Egypt. The same occurred for SO 2 except at one site located in Kafr Elzayat in the Delta, where large emissions from brick factories impact the site. The 8-hour average CO concentrations were exceeded at a few occasions. PM 10 concentrations have been identified as the major air pollution problem. Concentrations exceeding 70 μm 3 (AQL) have been observed over many sites most of the time. It is suggested that a strong program for tree cultivation on the western desert may be essential for protection

The deployment of carbon monoxide wireless sensor network (CO-WSN) for ambient air monitoring.

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Chaiwatpongsakorn, Chaichana; Lu, Mingming; Keener, Tim C; Khang, Soon-Jai

2014-06-16

Wireless sensor networks are becoming increasingly important as an alternative solution for environment monitoring because they can reduce cost and complexity. Also, they can improve reliability and data availability in places where traditional monitoring methods are difficult to site. In this study, a carbon monoxide wireless sensor network (CO-WSN) was developed to measure carbon monoxide concentrations at a major traffic intersection near the University of Cincinnati main campus. The system has been deployed over two weeks during Fall 2010, and Summer 2011-2012, traffic data was also recorded by using a manual traffic counter and a video camcorder to characterize vehicles at the intersection 24 h, particularly, during the morning and evening peak hour periods. According to the field test results, the 1 hr-average CO concentrations were found to range from 0.1-1.0 ppm which is lower than the National Ambient Air Quality Standards (NAAQS) 35 ppm on a one-hour averaging period. During rush hour periods, the traffic volume at the intersection varied from 2,067 to 3,076 vehicles per hour with 97% being passenger vehicles. Furthermore, the traffic volume based on a 1-h average showed good correlation (R2 = 0.87) with the 1-h average CO-WSN concentrations for morning and evening peak time periods whereas CO-WSN results provided a moderate correlation (R2 = 0.42) with 24 hours traffic volume due to fluctuated changes of meteorological conditions. It is concluded that the performance and the reliability of wireless ambient air monitoring networks can be used as an alternative method for real time air monitoring.

Exposure to ambient air pollution--does it affect semen quality and the level of reproductive hormones?

Science.gov (United States)

Radwan, Michał; Jurewicz, Joanna; Polańska, Kinga; Sobala, Wojciech; Radwan, Paweł; Bochenek, Michał; Hanke, Wojciech

2016-01-01

Ambient air pollution has been associated with a variety of reproductive disorders. However, a limited amount of research has been conducted to examine the association between air pollution and male reproductive outcomes, specifically semen quality. The present study was designed to address the hypothesis that exposure to fluctuating levels of specific air pollutants adversely affects sperm parameters and the level of reproductive hormones. The study population consisted of 327 men who were attending an infertility clinic in Łodź, Poland for diagnostic purposes and who had normal semen concentration of 15-300 mln/ml. All participants were interviewed and provided a semen sample. Air quality data were obtained from AirBase database. The statistically significant association was observed between abnormalities in sperm morphology and exposure to all examined air pollutants (PM10, PM2.5, SO2, NOX, CO). Exposure to air pollutants (PM10, PM2.5, CO, NOx) was also negatively associated with the level of testosterone. Additional exposure to PM2.5, PM10 increase the percentage of cells with immature chromatin (HDS). The present study provides suggestive evidence of an association between ambient air pollution and sperm quality. Further research is needed to explore this association in more detail. Individual precise exposure assessment would be needed for more detailed risk characterization.

Ambient Air Pollution and Biomarkers of Health Effect.

Science.gov (United States)

Yang, Di; Yang, Xuan; Deng, Furong; Guo, Xinbiao

2017-01-01

Recently, the air pollution situation of our country is very serious along with the development of urbanization and industrialization. Studies indicate that the exposure of air pollution can cause a rise of incidence and mortality of many diseases, such as chronic obstructive pulmonary disease (COPD), asthma, myocardial infarction, and so on. However, there is now growing evidence showing that significant air pollution exposures are associated with early biomarkers in various systems of the body. In order to better prevent and control the damage effect of air pollution, this article summarizes comprehensively epidemiological studies about the bad effects on the biomarkers of respiratory system, cardiovascular system, and genetic and epigenetic system exposure to ambient air pollution.

An Evaluation of Uncertainty Associated to Analytical Measurements of Selected Polycyclic Aromatic Compounds in Ambient Air; Estudio sobre las Incertidumbres Asociadas al Metodo de Determinacion de PAC's Seleccionados en Muestras de Aire Ambiente

Energy Technology Data Exchange (ETDEWEB)

Barrado, A. I.; Garcia, S.; Perez, R. M.

2013-06-01

This paper presents an evaluation of uncertainty associated to analytical measurement of eighteen polycyclic aromatic compounds (PACs) in ambient air by liquid chromatography with fluorescence detection (HPLC/FD). The study was focused on analyses of PM{sub 1}0, PM{sub 2}.5 and gas phase fractions. Main analytical uncertainty was estimated for eleven polycyclic aromatic hydrocarbons (PAHs), four nitro polycyclic aromatic hydrocarbons (nitro-PAHs) and two hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) based on the analytical determination, reference material analysis and extraction step. Main contributions reached 15-30% and came from extraction process of real ambient samples, being those for nitro- PAHs the highest (20-30%). Range and mean concentration of PAC mass concentrations measured in gas phase and PM{sub 1}0/PM{sub 2}.5 particle fractions during a full year are also presented. Concentrations of OH-PAHs were about 2-4 orders of magnitude lower than their parent PAHs and comparable to those sparsely reported in literature. (Author) 7 refs.

Effect of the Agricultural Biomass Burning on the Ambient Air Quality of Lumbini

Science.gov (United States)

Mehra, M.; Panday, A. K.; Praveen, P. S.; Bhujel, A.; Pokhrel, S.; Ram, K.

2017-12-01

The emissions from increasing anthropogenic activities has led to degradation in ambient air quality of Lumbini (UNESCO world heritage site) and its surrounding environments. The presence of high concentrations of air pollutants is of concern because of its implications for public health, atmospheric visibility, chemistry, crop yield, weather and climate on a local to regional scale. The study region experiences wide-spread on-field agricultural residue burning, particularly in the months of November (paddy residue burning) and April (wheat residue burning). In an attempt to study the impact of emissions from post-harvest burning of paddy and wheat residue in Nepal, the International Centre for Integrated Mountain Development, in collaboration with the Government of Nepal's Department of Environment and the Lumbini International Research Institute, established the Lumbini Air Quality Observatory (LAQO) in May 2016 for continuous measurement of Black carbon (BC), particulate matter (PM10, PM2.5 & PM1), as well as concentration of gaseous pollutant and meteorological parameters. Here we present results of the surface observations from LAQO for the months with intensified paddy and wheat open biomass burning during November 2016 and April 2017, respectively. The average concentrations of BC, PM2.5 and PM10 were 11.3±6.2 µg m-3, 96.7±48.9 µg m-3 and 132.3±59.1 µg m-3 respectively during the month of November 2016. On the other hand, the surface concentrations of BC, PM2.5 and PM10 were found to be 11.0±8.3 µg m-3, 45.0±35.0 µg m-3 and 114.0±96.1 µg m-3 during April 2017. A significant increase in the primary pollutant concentration was observed during both types of open agricultural burning periods. However, BC/PM2.5 ratio was almost higher by factor of two during paddy burning as compared to wheat residue burning. Source characteristics and the relative contribution of agricultural burning to PM concentrations at Lumbini are being computed based on

Gas-phase naphthalene concentration data recovery in ambient air and its relevance as a tracer of sources of volatile organic compounds

Science.gov (United States)

Uria-Tellaetxe, Iratxe; Navazo, Marino; de Blas, Maite; Durana, Nieves; Alonso, Lucio; Iza, Jon

2016-04-01

Despite the toxicity of naphthalene and the fact that it is a precursor of atmospheric photooxidants and secondary aerosol, studies on ambient gas-phase naphthalene are generally scarce. Moreover, as far as we are concerned, this is the first published one using long-term hourly ambient gas-phase naphthalene concentrations. In this work, it has been also demonstrated the usefulness of ambient gas-phase naphthalene to identify major sources of volatile organic compounds (VOC) in complex scenarios. Initially, in order to identify main benzene emission sources, hourly ambient measurements of 60 VOC were taken during a complete year together with meteorological data in an urban/industrial area. Later, due to the observed co-linearity of some of the emissions, a procedure was developed to recover naphthalene concentration data from recorded chromatograms to use it as a tracer of the combustion and distillation of petroleum products. The characteristic retention time of this compound was determined comparing previous GC-MS and GC-FID simultaneous analysis by means of relative retention times, and its concentration was calculated by using relative response factors. The obtained naphthalene concentrations correlated fairly well with ethene (r = 0.86) and benzene (r = 0.92). Besides, the analysis of daily time series showed that these compounds followed a similar pattern, very different from that of other VOC, with minimum concentrations at day-time. This, together with the results from the assessment of the meteorological dependence pointed out a coke oven as the major naphthalene and benzene emitting sources in the study area.

Artificial intelligence modeling to evaluate field performance of photocatalytic asphalt pavement for ambient air purification.

Science.gov (United States)

Asadi, Somayeh; Hassan, Marwa; Nadiri, Ataallah; Dylla, Heather

2014-01-01

In recent years, the application of titanium dioxide (TiO₂) as a photocatalyst in asphalt pavement has received considerable attention for purifying ambient air from traffic-emitted pollutants via photocatalytic processes. In order to control the increasing deterioration of ambient air quality, urgent and proper risk assessment tools are deemed necessary. However, in practice, monitoring all process parameters for various operating conditions is difficult due to the complex and non-linear nature of air pollution-based problems. Therefore, the development of models to predict air pollutant concentrations is very useful because it can provide early warnings to the population and also reduce the number of measuring sites. This study used artificial neural network (ANN) and neuro-fuzzy (NF) models to predict NOx concentration in the air as a function of traffic count (Tr) and climatic conditions including humidity (H), temperature (T), solar radiation (S), and wind speed (W) before and after the application of TiO₂ on the pavement surface. These models are useful for modeling because of their ability to be trained using historical data and because of their capability for modeling highly non-linear relationships. To build these models, data were collected from a field study where an aqueous nano TiO₂ solution was sprayed on a 0.2-mile of asphalt pavement in Baton Rouge, LA. Results of this study showed that the NF model provided a better fitting to NOx measurements than the ANN model in the training, validation, and test steps. Results of a parametric study indicated that traffic level, relative humidity, and solar radiation had the most influence on photocatalytic efficiency.

Air quality in Europe - 2012 report

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-09-15

This report presents an overview and analysis of the status and trends of air quality in Europe based on concentration measurements in ambient air and data on anthropogenic emissions and trends from 2001 - when mandatory monitoring of ambient air concentrations of selected pollutants first produced reliable air quality information - to 2010. (Author)

Ambient air pollution, traffic noise and adult asthma prevalence : A BioSHaRE approach

NARCIS (Netherlands)

Cai, Yutong; Zijlema, Wilma L.; Doiron, Dany; Blangiardo, Marta; Burton, Paul R.; Fortier, Isabel; Gaye, Amadou; Gulliver, John; de Hoogh, Kees; Hveem, Kristian; Mbatchou, Stephane; Morley, David W; Stolk, Ronald P.; Elliott, Paul; Hansell, Anna L.; Hodgson, Susan

2017-01-01

We investigated the effects of both ambient air pollution and traffic noise on adult asthma prevalence, using harmonised data from three European cohort studies established in 2006-2013 (HUNT3, Lifelines and UK Biobank). Residential exposures to ambient air pollution (particulate matter with

Anthropogenic Vanadium emissions to air and ambient air concentrations in North-West Europe

Directory of Open Access Journals (Sweden)

Visschedijk A. H. J.

2013-04-01

Full Text Available An inventory of Vanadium emissions for North-West Europe for the year 2005 was made based on an identification of the major sources. The inventory covers Belgium, Germany, Denmark, France, United Kingdom, Luxembourg, Netherlands and the OSPAR region of the North Sea. Vanadium emission were calculated bottom-up using energy use activity data and collected fuel and sector-specific emissions factors, taking into account various emission control measures. The NW European emissions were dominated by combustion of heavy fuel oil and petroleum cokes. Total emissions for 2005 amounted to 1569 tons/yr. The major sources are sea going ships (39%, petroleum refineries (35% and industry (19%. Emission is strongly concentrated at the densely populated cities with major sea ports. The location of sources at or near the major port cities was confirmed by observational data, as was the downward trend in emissions due to emission control, fuel switches in industry and fuel quality improvement. The results show the positive impact of lower sulphur fuels on other possible health relevant air pollutants such as particle bound Vanadium. The emission inventory can be expanded to the full European domain and can be used to for air quality modeling and particularly for the tracing of source contributions from certain types of fossil fuels (petroleum coke and residual fuel oil. Moreover, it will allow the monitoring of changes in fuel use over time.

Single and double long pulse laser ablation of aluminum induced in air and water ambient

International Nuclear Information System (INIS)

Akbari Jafarabadi, Marzieh; Mahdieh, Mohammad Hossein

2017-01-01

Highlights: • Laser ablation of aluminum target by single and double pulse (∼ 5 ns delay) in ambient air and distilled water • Comparing with air, in ambient water, plasma confinement results in higher crater depth. • In comparison with single pulse laser ablation, the absorption of the laser pulse energy is higher for double pulse regime. • As a result of ablated material expansion, the crater depth is decreased if the target is placed at lower depth. - Abstract: In this paper, single pulse and double pulse laser ablation of an aluminum target in two interaction ambient was investigated experimentally. The interaction was performed by nanosecond Nd:YAG laser beam in air and four depths (i.e. 9, 13, 17, and 21 mm) of distilled water ambient. The irradiation was carried out in single and collinear double pulse configurations in both air and liquid ambient. Crater geometry (depth and diameter) was measured by an optical microscope. The results indicated that the crater geometry strongly depends on both single pulse and double pulse configurations and interaction ambient. In single pulse regime, the crater diameter is higher for all water depths compared to that of air. However, the crater depth, depend on water depth, is higher or lower than the crater depth in air. In double pulse laser ablation, there are greater values for both crater diameters and crater depths in the water.

Low concentrations of persistent organic pollutants (POPs) in air at Cape Verde.

Science.gov (United States)

Nøst, Therese Haugdahl; Halse, Anne Karine; Schlabach, Martin; Bäcklund, Are; Eckhardt, Sabine; Breivik, Knut

2018-01-15

Ambient air is a core medium for monitoring of persistent organic pollutants (POPs) under the Stockholm Convention and is used in studies of global transports of POPs and their atmospheric sources and source regions. Still, data based on active air sampling remain scarce in many regions. The primary objectives of this study were to (i) monitor concentrations of selected POPs in air outside West Africa, and (ii) to evaluate potential atmospheric processes and source regions affecting measured concentrations. For this purpose, an active high-volume air sampler was installed on the Cape Verde Atmospheric Observatory at Cape Verde outside the coast of West Africa. Sampling commenced in May 2012 and 43 samples (24h sampling) were collected until June 2013. The samples were analyzed for selected polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB) and chlordanes. The concentrations of these POPs at Cape Verde were generally low and comparable to remote sites in the Arctic for several compounds. Seasonal trends varied between compounds and concentrations exhibited strong temperature dependence for chlordanes. Our results indicate net volatilization from the Atlantic Ocean north of Cape Verde as sources of these POPs. Air mass back trajectories demonstrated that air masses measured at Cape Verde were generally transported from the Atlantic Ocean or the North African continent. Overall, the low concentrations in air at Cape Verde were likely explained by absence of major emissions in areas from which the air masses originated combined with depletion during long-range atmospheric transport due to enhanced degradation under tropical conditions (high temperatures and concentrations of hydroxyl radicals). Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Ambient air pollution and low birth weight - are some women more vulnerable than others?

NARCIS (Netherlands)

Westergaard, Nadja; Gehring, Ulrike|info:eu-repo/dai/nl/304831344; Slama, Rémy; Pedersen, Marie

BACKGROUND AND OBJECTIVES: Ambient air pollution is controllable, and it is one of the greatest environmental threats to human health. Studies conducted worldwide have provided evidence that maternal exposure to ambient air pollution during pregnancy enhances the risk of low birth weight at term

Landfills as sources of polyfluorinated compounds, polybrominated diphenyl ethers and musk fragrances to ambient air

Science.gov (United States)

Weinberg, Ingo; Dreyer, Annekatrin; Ebinghaus, Ralf

2011-02-01

In order to investigate landfills as sources of polyfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs) and synthetic musk fragrances to the atmosphere, air samples were simultaneously taken at two landfills (one active and one closed) and two reference sites using high volume air samplers. Contaminants were accumulated on glass fiber filters (particle phase) and PUF/XAD-2/PUF cartridges (gas phase), extracted by methyl-tert butyl ether/acetone (neutral PFCs), methanol (ionic PFCs) or hexane/acetone (PBDEs, musk fragrances), and detected by GC-MS (neutral PFCs, PBDEs, musk fragrances) or HPLC-MS/MS (ionic PFCs). Total concentrations ranged from 84 to 706 pg m -3 (volatile PFCs, gas phase), from fragrances, gas + particle phase) and from 1 to 11 pg m -3 (PBDEs, gas + particle phase). Observed sum concentrations of PFCs and synthetic musk fragrances and partly PBDE concentrations were elevated at landfill sites compared to corresponding reference sites. Concentrations determined at the active landfill were higher than those of the inactive landfill. Overall, landfills can be regarded as a source of synthetic musk fragrances, several PFCs and potentially of PBDEs to ambient air.

Acute effects of urban ambient air pollution on respiratory symptoms, asthma medication use, and doctor visits for asthma in a cohort of Australian children

International Nuclear Information System (INIS)

Jalaludin, Bin B.; O'Toole, Brian I.; Leeder, Stephen R.

2004-01-01

We enrolled a cohort of primary school children with a history of wheeze (n=148) in an 11-month longitudinal study to examine the relationship between ambient air pollution and respiratory morbidity. We obtained daily air pollution (ozone, particulate matter less than 10 μm, and nitrogen dioxide), meteorological, and pollen data. One hundred twenty-five children remained in the final analysis. We used logistic regression models to determine associations between air pollution and respiratory symptoms, asthma medication use, and doctor visits for asthma. There were no associations between ambient ozone concentrations and respiratory symptoms, asthma medication use, and doctor visits for asthma. There was, however, an association between PM 10 concentrations and doctor visits for asthma (RR=1.11, 95% CI=1.04-1.19) and between NO 2 concentration and wet cough (RR=1.05, 95% CI=1.003-1.10) in single-pollutant models. The associations remained significant in multipollutant models. There was no consistent evidence that children with wheeze, positive histamine challenge, and doctor diagnosis of asthma reacted differently to air pollution from children with wheeze and doctor diagnosis of asthma and children with wheeze only. There were significant associations between PM 10 levels and doctor visits for asthma and an association between NO 2 levels and the prevalence of wet cough. We were, however, unable to demonstrate that current levels of ambient air pollution in western Sydney have a coherent range of adverse health effects on children with a history of wheezing

Fish oil and olive oil supplements attenuate the adverse cardiovascular effects of concentrated ambient air pollution particles exposure in healthy middle-aged adult human volunteers

Science.gov (United States)

Exposure to ambient levels of air pollution increases cardiovascular morbidity and mortality. Advanced age is among the factors associated with susceptibility to the adverse effects of air pollution. Dietary fatty acid supplementation has been shown to decrease cardiovascular ris...

A class of non-linear exposure-response models suitable for health impact assessment applicable to large cohort studies of ambient air pollution.

Science.gov (United States)

Nasari, Masoud M; Szyszkowicz, Mieczysław; Chen, Hong; Crouse, Daniel; Turner, Michelle C; Jerrett, Michael; Pope, C Arden; Hubbell, Bryan; Fann, Neal; Cohen, Aaron; Gapstur, Susan M; Diver, W Ryan; Stieb, David; Forouzanfar, Mohammad H; Kim, Sun-Young; Olives, Casey; Krewski, Daniel; Burnett, Richard T

2016-01-01

The effectiveness of regulatory actions designed to improve air quality is often assessed by predicting changes in public health resulting from their implementation. Risk of premature mortality from long-term exposure to ambient air pollution is the single most important contributor to such assessments and is estimated from observational studies generally assuming a log-linear, no-threshold association between ambient concentrations and death. There has been only limited assessment of this assumption in part because of a lack of methods to estimate the shape of the exposure-response function in very large study populations. In this paper, we propose a new class of variable coefficient risk functions capable of capturing a variety of potentially non-linear associations which are suitable for health impact assessment. We construct the class by defining transformations of concentration as the product of either a linear or log-linear function of concentration multiplied by a logistic weighting function. These risk functions can be estimated using hazard regression survival models with currently available computer software and can accommodate large population-based cohorts which are increasingly being used for this purpose. We illustrate our modeling approach with two large cohort studies of long-term concentrations of ambient air pollution and mortality: the American Cancer Society Cancer Prevention Study II (CPS II) cohort and the Canadian Census Health and Environment Cohort (CanCHEC). We then estimate the number of deaths attributable to changes in fine particulate matter concentrations over the 2000 to 2010 time period in both Canada and the USA using both linear and non-linear hazard function models.

Electric scooters : Batteries in the battle against ambient air pollution?

NARCIS (Netherlands)

van Boven, Job FM; An, Pham Le; Kirenga, Bruce J; Chavannes, Niels H.

2017-01-01

Ambient air pollution is a major global health threat, responsible for an estimated loss of 103 million disability-adjusted life-years in 2015,1,2 and a main contributor to numerous health problems, such as cardiovascular and respiratory diseases.3,4 Within the traffic domain of air pollution, cars,

COMPARISON OF INDOOR AIR QUALITY IN RESTAURANT KITCHENS IN TEHRAN WITH AMBIENT AIR QUALITY

Directory of Open Access Journals (Sweden)

M. Ghasemkhani, F. Naseri

2008-01-01

Full Text Available The indoor air quality of 131 restaurant kitchens in Tehran was investigated from May to September 2006. Gas stoves use in restaurant kitchens is a major source of indoor combustion, product carbon monoxide and nitrogen dioxide. The study focused on one of the busy zones located in the southwest and central part of the city. Measurements were done for indoor and outdoor air pollutants, carbon monoxide and nitrogen dioxide; ambient temperature and relative humidity were also measured. Result indicated that the mean levels of CO and NO2 in restaurant kitchens were below the recommended limit of 25 and 3ppm, respectively. Correlations between indoor and outdoor air quality were performed consequently. Results of the mean ambient temperature and relative humidity were above the guideline. In this study the mean levels of CO and NO2 gas cooking in restaurant kitchens were found to be lower compared with the similar studies.

Contribution of the in-vehicle microenvironment to individual ambient-source nitrogen dioxide exposure: the Multi-Ethnic Study of Atherosclerosis and Air Pollution.

Science.gov (United States)

Hazlehurst, Marnie F; Spalt, Elizabeth W; Nicholas, Tyler P; Curl, Cynthia L; Davey, Mark E; Burke, Gregory L; Watson, Karol E; Vedal, Sverre; Kaufman, Joel D

2018-03-06

Exposure estimates that do not account for time in-transit may underestimate exposure to traffic-related air pollution, but exact contributions have not been studied directly. We conducted a 2-week monitoring, including novel in-vehicle sampling, in a subset of the Multi-Ethnic Study of Atherosclerosis and Air Pollution cohort in two cities. Participants spent the majority of their time indoors and only 4.4% of their time (63 min/day) in-vehicle, on average. The mean ambient-source NO 2 concentration was 5.1 ppb indoors and 32.3 ppb in-vehicle during drives. On average, indoor exposure contributed 69% and in-vehicle exposure contributed 24% of participants' ambient-source NO 2 exposure. For participants in the highest quartile of time in-vehicle (≥1.3 h/day), indoor and in-vehicle contributions were 60 and 31%, respectively. Incorporating infiltrated indoor and measured in-vehicle NO 2 produced exposure estimates 5.6 ppb lower, on average, than using only outdoor concentrations. The indoor microenvironment accounted for the largest proportion of ambient-source exposure in this older population, despite higher concentrations of NO 2 outdoors and in vehicles than indoors. In-vehicle exposure was more influential among participants who drove the most and for participants residing in areas with lower outdoor air pollution. Failure to characterize exposures in these microenvironments may contribute to exposure misclassification in epidemiologic studies.

PM4 crystalline silica emission factors and ambient concentrations at aggregate-producing sources in California.

Science.gov (United States)

Richards, John R; Brozell, Todd T; Rea, Charles; Boraston, Geoff; Hayden, John

2009-11-01

The California Construction and Industrial Minerals Association and the National Stone, Sand, & Gravel Association have sponsored tests at three sand and gravel plants in California to compile crystalline silica emission factors for particulate matter (PM) of aerodynamic diameter of 4 microm or less (PM4) and ambient concentration data. This information is needed by industrial facilities to evaluate compliance with the Chronic Reference Exposure Level (REL) for ambient crystalline silica adopted in 2005 by the California Office of Environmental Health Hazard Assessment. The REL applies to PM4 respirable PM. Air Control Techniques, P.C. sampled for PM4 crystalline silica using a conventional sampler for PM of aerodynamic diameter of 2.5 microm or less (PM2.5), which met the requirements of 40 Code of Federal Regulations Part 50, Appendix L. The sample flow rate was adjusted to modify the 50% cut size to 4 microm instead of 2.5 microm. The filter was also changed to allow for crystalline silica analyses using National Institute for Occupational Safety and Health (NIOSH) Method 7500. The particle size-capture efficiency curve for the modified Appendix L instrument closely matched the performance curve of NIOSH Method 0600 for PM4 crystalline silica and provided a minimum detection limit well below the levels attainable with NIOSH Method 0600. The results of the tests indicate that PM4 crystalline silica emissions range from 0.000006 to 0.000110 lb/t for screening operations, tertiary crushers, and conveyor transfer points. The PM4 crystalline silica emission factors were proportional to the crystalline silica content of the material handled in the process equipment. Measured ambient concentrations ranged from 0 (below detectable limit) to 2.8 microg/m3. All values measured above 2 microg/m3 were at locations upwind of the facilities being tested. The ambient PM4 crystalline silica concentrations measured during this study were below the California REL of 3 microg/m3

Impacts of rural worker migration on ambient air quality and health in China: From the perspective of upgrading residential energy consumption.

Science.gov (United States)

Shen, Huizhong; Chen, Yilin; Russell, Armistead G; Hu, Yongtao; Shen, Guofeng; Yu, Haofei; Henneman, Lucas R F; Ru, Muye; Huang, Ye; Zhong, Qirui; Chen, Yuanchen; Li, Yufei; Zou, Yufei; Zeng, Eddy Y; Fan, Ruifang; Tao, Shu

2018-04-01

In China, rural migrant workers (RMWs) are employed in urban workplaces but receive minimal resources and welfare. Their residential energy use mix (REM) and pollutant emission profiles are different from those of traditional urban (URs) and rural residents (RRs). Their migration towards urban areas plays an important role in shaping the magnitudes and spatial patterns of pollutant emissions, ambient PM 2.5 (fine particulate matter with a diameter smaller than 2.5 μm) concentrations, and associated health impacts in both urban and rural areas. Here we evaluate the impacts of RMW migration on REM pollutant emissions, ambient PM 2.5 , and subsequent premature deaths across China. At the national scale, RMW migration benefits ambient air quality because RMWs tend to transition to a cleaner REM upon arrival at urban areas-though not as clean as urban residents'. In 2010, RMW migration led to a decrease of 1.5 μg/m 3 in ambient PM 2.5 exposure concentrations (C ex ) averaged across China and a subsequent decrease of 12,200 (5700 to 16,300, as 90% confidence interval) in premature deaths from exposure to ambient PM 2.5 . Despite the overall health benefit, large-scale cross-province migration increased megacities' PM 2.5 levels by as much as 10 μg/m 3 due to massive RMW inflows. Model simulations show that upgrading within-city RMWs' REMs can effectively offset the RMW-induced PM 2.5 increase in megacities, and that policies that properly navigate migration directions may have potential for balancing the economic growth against ambient air quality deterioration. Our study indicates the urgency of considering air pollution impacts into migration-related policy formation in the context of rapid urbanization in China. Copyright © 2018 Elsevier Ltd. All rights reserved.

An Evaluation of Uncertainty Associated to Analytical Measurements of Selected Polycyclic Aromatic Compounds in Ambient Air

International Nuclear Information System (INIS)

Barrado, A. I.; Garcia, S.; Perez, R. M.

2013-01-01

This paper presents an evaluation of uncertainty associated to analytical measurement of eighteen polycyclic aromatic compounds (PACs) in ambient air by liquid chromatography with fluorescence detection (HPLC/FD). The study was focused on analyses of PM 1 0, PM 2 .5 and gas phase fractions. Main analytical uncertainty was estimated for eleven polycyclic aromatic hydrocarbons (PAHs), four nitro polycyclic aromatic hydrocarbons (nitro-PAHs) and two hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) based on the analytical determination, reference material analysis and extraction step. Main contributions reached 15-30% and came from extraction process of real ambient samples, being those for nitro- PAHs the highest (20-30%). Range and mean concentration of PAC mass concentrations measured in gas phase and PM 1 0/PM 2 .5 particle fractions during a full year are also presented. Concentrations of OH-PAHs were about 2-4 orders of magnitude lower than their parent PAHs and comparable to those sparsely reported in literature. (Author)

Energy and material balance of CO2 capture from ambient air.

Science.gov (United States)

Zeman, Frank

2007-11-01

Current Carbon Capture and Storage (CCS) technologies focus on large, stationary sources that produce approximately 50% of global CO2 emissions. We propose an industrial technology that captures CO2 directly from ambient air to target the remaining emissions. First, a wet scrubbing technique absorbs CO2 into a sodium hydroxide solution. The resultant carbonate is transferred from sodium ions to calcium ions via causticization. The captured CO2 is released from the calcium carbonate through thermal calcination in a modified kiln. The energy consumption is calculated as 350 kJ/mol of CO2 captured. It is dominated by the thermal energy demand of the kiln and the mechanical power required for air movement. The low concentration of CO2 in air requires a throughput of 3 million cubic meters of air per ton of CO2 removed, which could result in significant water losses. Electricity consumption in the process results in CO2 emissions and the use of coal power would significantly reduce to net amount captured. The thermodynamic efficiency of this process is low but comparable to other "end of pipe" capture technologies. As another carbon mitigation technology, air capture could allow for the continued use of liquid hydrocarbon fuels in the transportation sector.

Environmentally Persistent Free Radical (EPFRs) - Ambient Air Particulates, Soils and Fate of Some Pollutants

Science.gov (United States)

Lomnicki, S. M.

2017-12-01

Environmentally Persistent Free Radicals (EPFRs) are relatively recently discovered species that are present on ambient air particulates. Their origin is typically associated with the combustion borne PM, where in the cool zone of the combustion process aromatic precursors react with the metal centers of particulates forming surface-organic complex with radical characteristics. EPFRs have been found to be sufficiently resistant to be emitted from the combustion sources and persist in the ambient air on particulates. Their inhalation has been associated with severe health effects, and potentially are one of the major agents contributing the epidemiological risks of PM exposure. Interestingly, EPFRs can be formed not only at the elevated temperatures but also in ambient conditions, where the contact of precursor molecules with transition metal (but not only) domains can result in adsorbate complexes. In fact, EPFRs have been detected in the contaminated soils, or during the oil spill incidents. It is very likely, that the interaction of some molecules released to the air can result in the formation of EPFRs on the ambient air particulates in atmospheric conditions. These species can be a natural degradation by-products that lead to the formation of oxygenated organics in ambient atmosphere.

Association between Ambient Air Pollution and Hospital Emergency Admissions for Respiratory and Cardiovascular Diseases in Beijing: a Time Series Study.

Science.gov (United States)

Zhang, Ying; Wang, Shi Gong; Ma, Yu Xia; Shang, Ke Zheng; Cheng, Yi Fan; Li, Xu; Ning, Gui Cai; Zhao, Wen Jing; Li, Nai Rong

2015-05-01

To investigate the association between ambient air pollution and hospital emergency admissions in Beijing. In this study, a semi-parametric generalized additive model (GAM) was used to evaluate the specific influences of air pollutants (PM10, SO2, and NO2) on hospital emergency admissions with different lag structures from 2009 to 2011, the sex and age specific influences of air pollution and the modifying effect of seasons on air pollution to analyze the possible interaction. It was found that a 10 μg/m3 increase in concentration of PM10 at lag 03 day, SO2 and NO2 at lag 0 day were associated with an increase of 0.88%, 0.76%, and 1.82% respectively in overall emergency admissions. A 10 μg/m3 increase in concentration of PM10, SO2 and NO2 at lag 5 day were associated with an increase of 1.39%, 1.56%, and 1.18% respectively in cardiovascular disease emergency admissions. For lag 02, a 10 μg/m3 increase in concentration of PM10, SO2 and NO2 were associated with 1.72%, 1.34%, and 2.57% increases respectively in respiratory disease emergency admissions. This study further confirmed that short-term exposure to ambient air pollution was associated with increased risk of hospital emergency admissions in Beijing. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Twenty years of measurement of polycyclic aromatic hydrocarbons (PAHs) in UK ambient air by nationwide air quality networks.

Science.gov (United States)

Brown, Andrew S; Brown, Richard J C; Coleman, Peter J; Conolly, Christopher; Sweetman, Andrew J; Jones, Kevin C; Butterfield, David M; Sarantaridis, Dimitris; Donovan, Brian J; Roberts, Ian

2013-06-01

The impact of human activities on the health of the population and of the wider environment has prompted action to monitor the presence of toxic compounds in the atmosphere. Toxic organic micropollutants (TOMPs) are some of the most insidious and persistent of these pollutants. Since 1991 the United Kingdom has operated nationwide air quality networks to assess the presence of TOMPs, including polycyclic aromatic hydrocarbons (PAHs), in ambient air. The data produced in 2010 marked 20 years of nationwide PAH monitoring. This paper marks this milestone by providing a novel and critical review of the data produced since nationwide monitoring began up to the end of 2011 (the latest year for which published data is available), discussing how the networks performing this monitoring has evolved, and elucidating trends in the concentrations of the PAHs measured. The current challenges in the area and a forward look to the future of air quality monitoring for PAHs are also discussed briefly.

GIS-based assessment of cancer risk due to benzene in Tehran ambient air.

Science.gov (United States)

Atabi, Farideh; Mirzahosseini, Seyed Alireza Hajiseyed

2013-10-01

The present study aimed to assess the risk of cancer due to benzene in the ambient air of gas stations and traffic zones in the north of Tehran. The cancer risk was estimated using the population distribution data for benzene levels and the unit risk for benzene proposed by the United States Environmental Protection Agency (US EPA). Sixteen sampling locations were monitored, once every week, during 5 April 2010 to 25 March 2011. The results showed that the mean annual benzene concentration was 14.51±3.17 parts per billion (ppb) for traffic zones and 29.01±1.32 ppb for outside gas stations. The risk calculated was 1026×10(-6) for gas station 27 and 955×10(-6) for gas station 139. According to our results, the annual benzene level in Tehran ambient air is 2 to 20 times higher than the respective value specified in International Standard (1.56 ppb). Moreover, the results showed a notable increase of cancer risks, ranging from 10% to 56%, for the vicinity population close to the gas stations in comparison to the vicinity population in the traffic zones.

Long-term exposure to ambient air pollution and mortality due to cardiovascular disease and cerebrovascular disease in Shenyang, China.

Directory of Open Access Journals (Sweden)

Pengfei Zhang

Full Text Available BACKGROUND: The relationship between ambient air pollution exposure and mortality of cardiovascular and cerebrovascular diseases in human is controversial, and there is little information about how exposures to ambient air pollution contribution to the mortality of cardiovascular and cerebrovascular diseases among Chinese. The aim of the present study was to examine whether exposure to ambient-air pollution increases the risk for cardiovascular and cerebrovascular disease. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a retrospective cohort study among humans to examine the association between compound-air pollutants [particulate matter <10 µm in aerodynamic diameter (PM(10, sulfur dioxide (SO(2 and nitrogen dioxide (NO(2] and mortality in Shenyang, China, using 12 years of data (1998-2009. Also, stratified analysis by sex, age, education, and income was conducted for cardiovascular and cerebrovascular mortality. The results showed that an increase of 10 µg/m(3 in a year average concentration of PM(10 corresponds to 55% increase in the risk of a death cardiovascular disease (hazard ratio [HR], 1.55; 95% confidence interval [CI], 1.51 to 1.60 and 49% increase in cerebrovascular disease (HR, 1.49; 95% CI, 1.45 to 1.53, respectively. The corresponding figures of adjusted HR (95%CI for a 10 µg/m(3 increase in NO(2 was 2.46 (2.31 to 2.63 for cardiovascular mortality and 2.44 (2.27 to 2.62 for cerebrovascular mortality, respectively. The effects of air pollution were more evident in female that in male, and nonsmokers and residents with BMI<18.5 were more vulnerable to outdoor air pollution. CONCLUSION/SIGNIFICANCE: Long-term exposure to ambient air pollution is associated with the death of cardiovascular and cerebrovascular diseases among Chinese populations.

Temporal Variation of Ambient PM10 Concentration within an Urban-Industrial Environment

Science.gov (United States)

Wong, Yoon-Keaw; Noor, Norazian Mohamed; Izzah Mohamad Hashim, Nur

2018-03-01

PM10 concentration in the ambient air has been reported to be the main pollutant affecting human health, particularly in the urban areas. This research is conducted to study the variation of PM10 concentration at the three urban-industrial areas in Malaysia, namely Shah Alam, Kuala Terengganu and Melaka. In addition, the association and correlation between PM10 concentration and other air pollutants will be distinguished. Five years interval dataset (2008-2012) consisting of PM10, SOX, NOX and O3 concentrations and other weather parameters such as wind speed, humidity and temperature were obtained from Department of Environment, Malaysia. Shah Alam shows the highest average of PM10 concentration with the value of 62.76 μg/m3 in June, whereas for Kuala Terengganu was 59.29 μg/m3 in February and 46.61 μg/m3 in August for Melaka. Two peaks were observed from the time series plot using the averaged monthly PM10 concentration. First peak occurs when PM10 concentration rises from January to February and the second peak is reached in June and remain high for the next two consecutive months for Shah Alam and Kuala Terengganu. Meanwhile the second peak for Melaka is only achieved in August as a result of the transboundary of smoke from forest fires in the Sumatra region during dry season from May to September. Both of the pollutants can be sourced from rapid industrial activities at Shah Alam. PM10 concentration is strongly correlated with carbon monoxide concentration in Kuala Terengganu and Melaka with value of r2 = 0.1725 and 0.2744 respectively. High carbon monoxide and PM10 concentration are associated with burning of fossil fuel from increased number of vehicles at these areas.

Effects of Ambient Temperature and Forced-air Warming on Intraoperative Core Temperature: A Factorial Randomized Trial.

Science.gov (United States)

Pei, Lijian; Huang, Yuguang; Xu, Yiyao; Zheng, Yongchang; Sang, Xinting; Zhou, Xiaoyun; Li, Shanqing; Mao, Guangmei; Mascha, Edward J; Sessler, Daniel I

2018-05-01

The effect of ambient temperature, with and without active warming, on intraoperative core temperature remains poorly characterized. The authors determined the effect of ambient temperature on core temperature changes with and without forced-air warming. In this unblinded three-by-two factorial trial, 292 adults were randomized to ambient temperatures 19°, 21°, or 23°C, and to passive insulation or forced-air warming. The primary outcome was core temperature change between 1 and 3 h after induction. Linear mixed-effects models assessed the effects of ambient temperature, warming method, and their interaction. A 1°C increase in ambient temperature attenuated the negative slope of core temperature change 1 to 3 h after anesthesia induction by 0.03 (98.3% CI, 0.01 to 0.06) °Ccore/(h°Cambient) (P ambient temperature with passive insulation, but was unaffected by ambient temperature during forced-air warming (0.02 [98.3% CI, -0.04 to 0.09] °Ccore/°Cambient; P = 0.40). After an average of 3.4 h of surgery, core temperature was 36.3° ± 0.5°C in each of the forced-air groups, and ranged from 35.6° to 36.1°C in passively insulated patients. Ambient intraoperative temperature has a negligible effect on core temperature when patients are warmed with forced air. The effect is larger when patients are passively insulated, but the magnitude remains small. Ambient temperature can thus be set to comfortable levels for staff in patients who are actively warmed.

A measurement of summertime dry deposition of ambient air particulates and associated metallic pollutants in Central Taiwan.

Science.gov (United States)

Fang, Guor-Cheng; Chiang, Hung-Che; Chen, Yu-Cheng; Xiao, You-Fu; Wu, Chia-Ming; Kuo, Yu-Chen

2015-04-01

The purpose of this study is to characterize metallic elements associated with atmospheric particulate matter in the dry deposition plate, total suspended particulate, fine particles, and coarse particles at Taichung Harbor and Gong Ming Junior High School (airport) in central Taiwan at a sampling site from June 2013 to August 2013. The results indicated that: (1) the average concentrations of the metallic elements Cr and Cd were highest at the Gong Ming Junior High School (airport), and the average concentrations of the metallic elements Ni, Cu, and Pb were highest at the Taichung Harbor sampling site. (2) The high smelting industry density and export/import rate of heavily loaded cargos were the main reasons leading to these findings. (3) The average metallic element dry deposition and metallic element PM(2.5-10) all followed the order of Pb > Cr > Cu > Ni > Cd at the two sampling sites. However, the average metallic elements Cu and Pb were found to have the highest dry deposition velocities and concentrations in PM(2.5) for the two sampling sites in this study. (4) The correlation coefficients of ambient air particle dry deposition and concentration with wind speed at the airport were higher than those from the harbor sampling site. The wind and broad open spaces at Taichung Airport were the possible reasons for the increasing correlation coefficients for ambient air particle concentration and dry deposition with wind speed at the Taichung Airport sampling site.

75 FR 22126 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

Science.gov (United States)

2010-04-27

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9142-1] Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods: Designation of One New Equivalent Method AGENCY: Environmental Protection Agency. ACTION: Notice of the designation of one new equivalent method for monitoring ambient air...

76 FR 62402 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

Science.gov (United States)

2011-10-07

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9476-7] Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods; Designation of One New Equivalent Method AGENCY: Environmental Protection Agency. ACTION: Notice of the designation of one new equivalent method for monitoring ambient air...

75 FR 30022 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

Science.gov (United States)

2010-05-28

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9156-1] Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods: Designation of One New Equivalent Method AGENCY: Environmental Protection Agency. ACTION: Notice of the designation of one new equivalent method for monitoring ambient air...

Biomarkers of ambient air pollution and lung cancer

DEFF Research Database (Denmark)

Demetriou, Christiana A; Raaschou-Nielsen, Ole; Loft, Steffen

2012-01-01

The association between ambient air pollution exposure and lung cancer risk has been investigated in prospective studies and the results are generally consistent, indicating that long-term exposure to air pollution may cause lung cancer. Despite the prospective nature and consistent findings...... and progression from external exposure to tumour formation and some have also been suggested as risk predictors of future cancer, reinforcing causal reasoning. However, methodological issues such as confounding, publication bias and use of surrogate tissues instead of target tissues in studies on these markers...

Short-term Effects of Ambient Air Pollution on Emergency Department Visits for Asthma: An Assessment of Effect Modification by Prior Allergic Disease History

Directory of Open Access Journals (Sweden)

Juhwan Noh

2016-09-01

Full Text Available Objectives The goal of this study was to investigate the short-term effect of ambient air pollution on emergency department (ED visits in Seoul for asthma according to patients’ prior history of allergic diseases. Methods Data on ED visits from 2005 to 2009 were obtained from the Health Insurance Review and Assessment Service. To evaluate the risk of ED visits for asthma related to ambient air pollutants (carbon monoxide [CO], nitrogen dioxide [NO2], ozone [O3], sulfur dioxide [SO2], and particulate matter with an aerodynamic diameter <10 μm [PM10], a generalized additive model with a Poisson distribution was used; a single-lag model and a cumulative-effect model (average concentration over the previous 1-7 days were also explored. The percent increase and 95% confidence interval (CI were calculated for each interquartile range (IQR increment in the concentration of each air pollutant. Subgroup analyses were done by age, gender, the presence of allergic disease, and season. Results A total of 33 751 asthma attack cases were observed during the study period. The strongest association was a 9.6% increase (95% CI, 6.9% to 12.3% in the risk of ED visits for asthma per IQR increase in O3 concentration. IQR changes in NO2 and PM10 concentrations were also significantly associated with ED visits in the cumulative lag 7 model. Among patients with a prior history of allergic rhinitis or atopic dermatitis, the risk of ED visits for asthma per IQR increase in PM10 concentration was higher (3.9%; 95% CI, 1.2% to 6.7% than in patients with no such history. Conclusions Ambient air pollutants were positively associated with ED visits for asthma, especially among subjects with a prior history of allergic rhinitis or atopic dermatitis.

Ambient air quality of karachi city as reflected by atmospheric particulate matter (PM/sub 10/) concentrations

International Nuclear Information System (INIS)

Hashmi, D.R.; Shareef, A.

2016-01-01

The present study examines the variation of ambient aerosol (PM/sub 10/) concentrations in Karachi, city. Samples were collected from ten different locations, representative of urban background, residential, traffic and industrial areas from 2007 to 2011. At each location, PM/sub 10/) was measured continuously from 08:00 am to 06:00 pm at local time. The maximum 10 h average particulate matter (PM/sub 10/) mass concentrations were found at Tibet Centre (440.1 mg/m/sup 3/) and minimum at PCSIR Campus (21.7 mg/m/sup 3/) during 2008. A rising trend during 2008 may be due to the civil works for bridges and extension of roads at different locations in Karachi. The results also suggest that urban traffic and industrial areas appeared to have higher PM/sub 10/) concentration than residential and background areas. (author)

Quality assurance and quality control for Hydro-Quebec's ambient air monitoring networks

International Nuclear Information System (INIS)

Lambert, M.; Varfalvy, L.

1993-01-01

Hydro Quebec has three ambient air monitoring networks to determine the contribution of some of its thermal plants to ambient air quality. They are located in Becancour (gas turbines), Iles-de-la-Madeleine (diesel), and Tracy (conventional oil-fired). To ensure good quality results and consistency between networks, a quality assurance/quality control program was set up. A description is presented of the ambient air quality monitoring network and the quality assurance/quality control program. A guide has been created for use by the network operators, discussing objectives of the individual network, a complete description of each network, field operation for each model of instrument in use, treatment of data for each data logger in use, global considerations regarding quality assurance and control, and reports. A brief overview is presented of the guide's purpose and contents, focusing on the field operation section and the sulfur dioxide and nitrogen oxide monitors. 6 figs., 1 tab

Evaluation of methods for monitoring air concentrations of hydrogen sulfide

Directory of Open Access Journals (Sweden)

Katarzyna Janoszka

2013-06-01

Full Text Available The development of different branches of industry and a growing fossil fuels mining results in a considerable emission of by-products. Major air pollutants are: CO, CO₂, SO₂, SO₃, H₂S, nitrogen oxides, as well as compounds of an organic origin. The main aspects of this paper is to review and evaluate methods used for monitoring of hydrogen sulfide in the air. Different instrumental techniques were discussed, electrochemical, chromatographic and spectrophotometric (wet and dry, to select the method most suitable for monitoring low levels of hydrogen sulfide, close to its odor threshold. Based on the literature review the method for H₂S determination in the air, involving absorption in aqueous zinc acetate and reaction with N,N-dimethylo-p-phenylodiamine and FeCl₃, has been selected and preliminary verified. The adopted method allows for routine measurements of low concentration of hydrogen sulfide, close to its odor threshold in workplaces and ambient air. Med Pr 2013;64(3:449–454

Time-series analysis for ambient concentrations

Energy Technology Data Exchange (ETDEWEB)

Gonzalez-Manteiga, W.; Prada-Sanchez, J.M.; Cao, R.; Garcia-Jurado, I.; Febrero-Bande, M.; Lucas-Dominguez, T. (Santiago de Compostela University, Santiago de Compostela (Spain). Dept. of Statistics and Operations Research)

1993-02-01

In this paper a dynamic system is presented which has been implemented to predict, every 5 min, the ambient concentrations of SO[sub 2] in the neighbourhood of a power station run by ENDESA, the National Electricity Company of Spain, in As Pontes. This prediction task is very important in order to prevent a high ground-level of concentration of SO[sub 2]. For forecasting a mixed model is used which has a parametric component and a nonparametric one. Confidence intervals are also constructed for future observations using bootstrap and classical techniques. 4 refs., 5 figs., 3 tabs.

Benzene levels in ambient air and breath of smokers and nonsmokers in urban and pristine environments

Energy Technology Data Exchange (ETDEWEB)

Wester, R.C.; Maibach, H.I.; Gruenke, L.D.; Craig, J.C.

1986-01-01

Benzene levels in human breath and in ambient air were compared in the urban area of San Francisco (SF) and in a more remote coastal pristine setting of Stinson Beach, Calif. (SB). Benzene analysis was done by gas chromatography-mass spectroscopy (GC-MS). Ambient benzene levels were sevenfold higher in SF (2.6 +/- 1.3 ppb, n = 25) than SB (0.38 +/- 0.39 ppb, n = 21). In SF, benzene in smokers' breath (6.8 +/- 3.0 ppb) was greater than in nonsmokers' breath (2.5 +/- 0.8 ppb) and smokers' ambient air (3.3 +/- 0.8 ppb). In SB the same pattern was observed: benzene in smokers' breath was higher than in nonsmokers' breath and ambient air. Benzene in SF nonsmokers' breath was greater than in SB nonsmokers' breath. Marijuana-only smokers had benzene breath levels between those of smokers and nonsmokers. There was little correlation between benzene in breath and number of cigarettes smoked, or with other benzene exposures such as diet. Of special interest was the finding that benzene in breath of SF nonsmokers (2.5 +/- 0.8 ppb) was greater than that in nonsmokers ambient air (1.4 +/- 0.1 ppb). The same was true in SB, where benzene in nonsmokers breath was greater than ambient air (1.8 +/- 0.2 ppb versus 1.0 +/- 0.1 ppb on d 1 and 1.3 +/- 0.3 ppb versus 0.23 +/- 0.18 ppb on d 2). This suggests an additional source of benzene other than outdoor ambient air.

Three Mile Island ambient-air-temperature sensor measurements

International Nuclear Information System (INIS)

Fryer, M.O.

1983-01-01

Data from the ambient-air-temperature sensors in Three Mile Island-Unit 2 (TMI-2) reactor containment building are analyzed. The data were for the period of the hydrogen burn that was part of the TMI-2 accident. From the temperature data, limits are placed on the duration of the hydrogen burn

Effects of ambient oxygen concentration on soot temperature and concentration for biodiesel and diesel spray combustion

KAUST Repository

Zhang, Ji; Jing, Wei; Roberts, William L.; Fang, Tiegang

2015-01-01

during biodiesel and diesel spray combustion. The experiment was implemented in a constant volume chamber system, where the ambient oxygen concentration varied from 21 to 10% and the ambient temperature was kept to 1,000 K. A high speed two-color

Assessment of ambient air quality in Chidambaram a south Indian town

Directory of Open Access Journals (Sweden)

P. Balashanmugam

2012-06-01

Full Text Available Worldwide preliminary studies in large number are advocated to create data base, to identify potential cities / towns that warrant “continuous ambient air quality monitoring and control mechanism” and to evolve priorities for clean air target. The results reported pertain to an eight hour random preliminary air sampling exercise carried out at each of the eight select locations in Chidambaram, a southern semi urban settlement in India. Criteria pollutants SPM, CO, SO2 and NO2 measured are found to have either crossed or on the verge of crossing the limits, necessitating the immediate installation of a continuous monitoring and control mechanism. While transport related emissions are the major sources of air contamination, increasing civil construction activities also contribute to particulates. The exponential rise in volume of vehicles, disadvantageous traffic flow pattern, differing driving cycle pattern and human interceptions deserve due attention. It is concluded that Chidambaram town is a strong case for continuous monitoring of ambient air quality due to alarming and increasing level of pollutants.

Projecting future summer mortality due to ambient ozone concentration and temperature changes

Science.gov (United States)

Lee, Jae Young; Lee, Soo Hyun; Hong, Sung-Chul; Kim, Ho

2017-05-01

Climate change is known to affect the human health both directly by increased heat stress and indirectly by altering environments, particularly by altering the rate of ambient ozone formation in the atmosphere. Thus, the risks of climate change may be underestimated if the effects of both future temperature and ambient ozone concentrations are not considered. This study presents a projection of future summer non-accidental mortality in seven major cities of South Korea during the 2020s (2016-2025) and 2050s (2046-2055) considering changes in temperature and ozone concentration, which were predicted by using the HadGEM3-RA model and Integrated Climate and Air Quality Modeling System, respectively. Four Representative Concentration Pathway (RCP) scenarios (RCP 2.6, 4.5, 6.0, and 8.5) were considered. The result shows that non-accidental summer mortality will increase by 0.5%, 0.0%, 0.4%, and 0.4% in the 2020s, 1.9%, 1.5%, 1.2%, and 4.4% in the 2050s due to temperature change compared to the baseline mortality during 2001-2010, under RCP 2.6, 4.5, 6.0, and 8.5, respectively, whereas the mortality will increase by 0.0%, 0.5%, 0.0%, and 0.5% in the 2020s, and 0.2%, 0.2%, 0.4%, and 0.6% in the 2050s due to ozone concentration change. The projection result shows that the future summer morality in South Korea is increased due to changes in both temperature and ozone, and the magnitude of ozone-related increase is much smaller than that of temperature-related increase, especially in the 2050s.

Effects of the precursor concentration and different annealing ambients on the structural, optical, and electrical properties of nanostructured V2O5 thin films deposited by spray pyrolysis technique

Science.gov (United States)

Irani, Rowshanak; Rozati, Seyed Mohammad; Beke, Szabolcs

2018-04-01

V2O5 thin films were deposited with different precursor concentrations of 0.01, 0.05, and 0.1 M on glass substrates by spray pyrolysis technique, then the optimized films were annealed in different ambients (air, oxygen, and vacuum). The results showed that by increasing the concentration, the films grew along the (001) direction with an orthorhombic structure. Field emission scanning electron microscopy showed that nanorods were formed when depositing 0.05 molar of VCl3. We conclude that with the precursor concentration, the surface nanostructure can be well-controlled. Annealing improved the crystallinity under all ambients, but the best crystallinity was achieved in vacuum. It was revealed that the as-deposited films had the highest transmission, whereas the films annealed in air had the lowest. When annealed in air, the optical band gap decreased from 2.45 to 2.32 eV. The sheet resistance, resistivity, mobility, conductivity, and carrier concentration were measured for all the prepared V2O5 films.

76 FR 76048 - Air Quality Designations for the 2008 Lead (Pb) National Ambient Air Quality Standards

Science.gov (United States)

2011-12-06

... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 81 [EPA-HQ-OAR-2009-0443; FRL-9492-3] RIN 2060-AR17 Air Quality Designations for the 2008 Lead (Pb) National Ambient Air Quality Standards Correction In rule document 2011-29460 appearing on pages 72097-72120 in the issues of Tuesday, November 22, 2011...

Establishment of ambient air quality trends using historical monitoring data from Edmonton and Fort McKay, Alberta

International Nuclear Information System (INIS)

Faisal, K.; Gamal El-Din, M.

2006-01-01

Ambient air trends were assessed using data collected over an 8 year period from monitoring stations in Edmonton and Fort McKay, Alberta. In particular, the study evaluated the short term trends in the concentration of carbon monoxide (CO), nitrogen dioxide (NO 2 ), ozone (O 3 ), and particulate matter (PM 2.5 ) in Edmonton, as well as the NO 2 , O 3 , PM 2.5 , and total hydrocarbons in Fort McKay. In order to evaluate the ambient air trends, this study examined the changes in concentrations of these pollutants between the 50 - 90 percentiles of concentration distributions for a calendar year. These statistics were assumed to be linear over the period of study and fitted using simple linear regression. Hypothesis tests were performed to determine if the slopes of the best-fit lines were greater or less than zero. There was no indication of a statistically significant short-term trend for NO 2 and O 3 for the city of Edmonton. However, statistically pronounced decreasing trends were noted for CO and PM 2.5 . There was no indication of statistically significant trend for any of the pollutants examined at Fort McKay over the study period. It was cautioned that since the period of study over which trends were examined was short, the changes or lack of changes observed do not necessarily indicate long term trends. However, the results suggest that air quality has remained unchanged during the last 6 to 8 years, despite increased economic development in Edmonton and continued oil sands development in Fort McKay

The impact of ambient air pollution on the human blood metabolome.

Science.gov (United States)

Vlaanderen, J J; Janssen, N A; Hoek, G; Keski-Rahkonen, P; Barupal, D K; Cassee, F R; Gosens, I; Strak, M; Steenhof, M; Lan, Q; Brunekreef, B; Scalbert, A; Vermeulen, R C H

2017-07-01

Biological perturbations caused by air pollution might be reflected in the compounds present in blood originating from air pollutants and endogenous metabolites influenced by air pollution (defined here as part of the blood metabolome). We aimed to assess the perturbation of the blood metabolome in response to short term exposure to air pollution. We exposed 31 healthy volunteers to ambient air pollution for 5h. We measured exposure to particulate matter, particle number concentrations, absorbance, elemental/organic carbon, trace metals, secondary inorganic components, endotoxin content, gaseous pollutants, and particulate matter oxidative potential. We collected blood from the participants 2h before and 2 and 18h after exposure. We employed untargeted metabolite profiling to monitor 3873 metabolic features in 493 blood samples from these volunteers. We assessed lung function using spirometry and six acute phase proteins in peripheral blood. We assessed the association of the metabolic features with the measured air pollutants and with health markers that we previously observed to be associated with air pollution in this study. We observed 89 robust associations between air pollutants and metabolic features two hours after exposure and 118 robust associations 18h after exposure. Some of the metabolic features that were associated with air pollutants were also associated with acute health effects, especially changes in forced expiratory volume in 1s. We successfully identified tyrosine, guanosine, and hypoxanthine among the associated features. Bioinformatics approach Mummichog predicted enriched pathway activity in eight pathways, among which tyrosine metabolism. This study demonstrates for the first time the application of untargeted metabolite profiling to assess the impact of air pollution on the blood metabolome. Copyright © 2017 Elsevier Inc. All rights reserved.

In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor

Science.gov (United States)

Palm, Brett B.; Campuzano-Jost, Pedro; Ortega, Amber M.; Day, Douglas A.; Kaser, Lisa; Jud, Werner; Karl, Thomas; Hansel, Armin; Hunter, James F.; Cross, Eben S.; Kroll, Jesse H.; Peng, Zhe; Brune, William H.; Jimenez, Jose L.

2016-03-01

An oxidation flow reactor (OFR) is a vessel inside which the concentration of a chosen oxidant can be increased for the purpose of studying SOA formation and aging by that oxidant. During the BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen-Rocky Mountain Biogenic Aerosol Study) field campaign, ambient pine forest air was oxidized by OH radicals in an OFR to measure the amount of SOA that could be formed from the real mix of ambient SOA precursor gases, and how that amount changed with time as precursors changed. High OH concentrations and short residence times allowed for semicontinuous cycling through a large range of OH exposures ranging from hours to weeks of equivalent (eq.) atmospheric aging. A simple model is derived and used to account for the relative timescales of condensation of low-volatility organic compounds (LVOCs) onto particles; condensational loss to the walls; and further reaction to produce volatile, non-condensing fragmentation products. More SOA production was observed in the OFR at nighttime (average 3 µg m-3 when LVOC fate corrected) compared to daytime (average 0.9 µg m-3 when LVOC fate corrected), with maximum formation observed at 0.4-1.5 eq. days of photochemical aging. SOA formation followed a similar diurnal pattern to monoterpenes, sesquiterpenes, and toluene+p-cymene concentrations, including a substantial increase just after sunrise at 07:00 local time. Higher photochemical aging (> 10 eq. days) led to a decrease in new SOA formation and a loss of preexisting OA due to heterogeneous oxidation followed by fragmentation and volatilization. When comparing two different commonly used methods of OH production in OFRs (OFR185 and OFR254-70), similar amounts of SOA formation were observed. We recommend the OFR185 mode for future forest studies. Concurrent gas-phase measurements of air after OH oxidation illustrate the decay of primary VOCs, production of small oxidized organic

In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor

Directory of Open Access Journals (Sweden)

B. B. Palm

2016-03-01

Full Text Available An oxidation flow reactor (OFR is a vessel inside which the concentration of a chosen oxidant can be increased for the purpose of studying SOA formation and aging by that oxidant. During the BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen–Rocky Mountain Biogenic Aerosol Study field campaign, ambient pine forest air was oxidized by OH radicals in an OFR to measure the amount of SOA that could be formed from the real mix of ambient SOA precursor gases, and how that amount changed with time as precursors changed. High OH concentrations and short residence times allowed for semicontinuous cycling through a large range of OH exposures ranging from hours to weeks of equivalent (eq. atmospheric aging. A simple model is derived and used to account for the relative timescales of condensation of low-volatility organic compounds (LVOCs onto particles; condensational loss to the walls; and further reaction to produce volatile, non-condensing fragmentation products. More SOA production was observed in the OFR at nighttime (average 3 µg m−3 when LVOC fate corrected compared to daytime (average 0.9 µg m−3 when LVOC fate corrected, with maximum formation observed at 0.4–1.5 eq. days of photochemical aging. SOA formation followed a similar diurnal pattern to monoterpenes, sesquiterpenes, and toluene+p-cymene concentrations, including a substantial increase just after sunrise at 07:00 local time. Higher photochemical aging (> 10 eq. days led to a decrease in new SOA formation and a loss of preexisting OA due to heterogeneous oxidation followed by fragmentation and volatilization. When comparing two different commonly used methods of OH production in OFRs (OFR185 and OFR254-70, similar amounts of SOA formation were observed. We recommend the OFR185 mode for future forest studies. Concurrent gas-phase measurements of air after OH oxidation illustrate the decay of primary VOCs, production

Modeling the dependency of radon concentration levels inside ancient Egyptian tombs on the ambient temperature variations

International Nuclear Information System (INIS)

Metwally, S.M.; Abo-Elmagdb, M.; Salamaa, E.

2007-01-01

Radon concentration inside partially closed places like dwellings, caves and tombs, depends on many parameters. Some parameters are known quantitatively as radon exhalation rate for walls, decay constant, surface to volume ratio and outdoor concentration while other parameters as ventilation rate is in common known qualitatively due to useless of traditional methods (tracer gases) in many places as ancient Egyptian tombs. This work introduces a derived mathematical model to evaluate the sensitivity of radon concentration levels inside single sided opening places as ancient Egyptian tombs on the ambient temperature differences. The obtained formula for the natural ventilation rate depends on the indoor and outdoor temperature difference and the geometrical dimensions of the doorway. The effects of in and out flow mixing, air viscosity, streamline contraction, swirling flow and turbulence, were taken into consideration in terms of an empirical correction factor. According UNSCEAR reports, the exhalation rate Φ=C ra λ rn fρ s (1-ε)L; C ra the effective radium content, λ rn decay constant, f emanation fraction, ρ s soil grain density, ε porosity and L diffusion length, these are approximately static parameters but the variability of ambient temperature introduces a source of energy of fluctuating strength to radon atoms in rocks which controls the flow rate and the ambient content of radon. Therefore, the change of outdoor and indoor temperature difference causes fluctuation of value and direction of volume flow rate in such places consequently causes the daily variation and on average the seasonal variation of radon concentration. Therefore according to the present model, the daily accurate expectation of radon concentrations inside ancient Egyptian tombs, require precise measurements of indoor and outdoor temperatures

Impact of National Ambient Air Quality Standards Nonattainment Designations on Particulate Pollution and Health.

Science.gov (United States)

Zigler, Corwin M; Choirat, Christine; Dominici, Francesca

2018-03-01

Despite dramatic air quality improvement in the United States over the past decades, recent years have brought renewed scrutiny and uncertainty surrounding the effectiveness of specific regulatory programs for continuing to improve air quality and public health outcomes. We employ causal inference methods and a spatial hierarchical regression model to characterize the extent to which a designation of "nonattainment" with the 1997 National Ambient Air Quality Standard for ambient fine particulate matter (PM2.5) in 2005 causally affected ambient PM2.5 and health outcomes among over 10 million Medicare beneficiaries in the Eastern United States in 2009-2012. We found that, on average across all retained study locations, reductions in ambient PM2.5 and Medicare health outcomes could not be conclusively attributed to the nonattainment designations against the backdrop of other regional strategies that impacted the entire Eastern United States. A more targeted principal stratification analysis indicates substantial health impacts of the nonattainment designations among the subset of areas where the designations are estimated to have actually reduced ambient PM2.5 beyond levels achieved by regional measures, with noteworthy reductions in all-cause mortality, chronic obstructive pulmonary disorder, heart failure, ischemic heart disease, and respiratory tract infections. These findings provide targeted evidence of the effectiveness of local control measures after nonattainment designations for the 1997 PM2.5 air quality standard.

The relationships between ambient air pollutants and childhood asthma and eczema are modified by emotion and conduct problems.

Science.gov (United States)

Zhou, Cailiang; Baïz, Nour; Banerjee, Soutrik; Charpin, Denis André; Caillaud, Denis; de Blay, Fréderic; Raherison, Chantal; Lavaud, François; Annesi-Maesano, Isabella

2013-12-01

This study examined the hypothesis that emotion and conduct problems (ECPs) may modify the relationships between ambient air pollutants and childhood asthma and eczema. In the cross-sectional study, 4209 French schoolchildren (aged 10e12 years) were investigated between March 1999 and October 2000. Ambient air pollutants exposures were estimated with dispersion modeling. Health outcomes and ECPs were evaluated by validated questionnaires, completed by the parents. Marginal models were used to analyze the relationships of exposures to ambient air pollutants and/or ECPs to asthma phenotypes and current eczema, adjusting for potential confounders. In our population, interactions were found between ECPs and exposures to ambient air pollutants (benzene, carbon monoxide, nitrogen dioxide, nitrogen oxides, particulate matter with an aerodynamic diameter below 10 mm, volatile organic compounds) (P eczema (aOR, 2.21; 95% CI, 1.61e3.02). Children with ECPs had 1.17e1.51 times higher aORs for the associations between ambient air pollutants and asthma phenotypes and current eczema than those without ECPs. ECPs may modify the relationships between ambient air pollutants and childhood asthma and eczema. 2013 Elsevier Inc. All rights reserved.

Ambient air pollution and thrombosis.

Science.gov (United States)

Robertson, Sarah; Miller, Mark R

2018-01-03

Air pollution is a growing public health concern of global significance. Acute and chronic exposure is known to impair cardiovascular function, exacerbate disease and increase cardiovascular mortality. Several plausible biological mechanisms have been proposed for these associations, however, at present, the pathways are incomplete. A seminal review by the American Heart Association (2010) concluded that the thrombotic effects of particulate air pollution likely contributed to their effects on cardiovascular mortality and morbidity. The aim of the current review is to appraise the newly accumulated scientific evidence (2009-2016) on contribution of haemostasis and thrombosis towards cardiovascular disease induced by exposure to both particulate and gaseous pollutants.Seventy four publications were reviewed in-depth. The weight of evidence suggests that acute exposure to fine particulate matter (PM 2.5 ) induces a shift in the haemostatic balance towards a pro-thrombotic/pro-coagulative state. Insufficient data was available to ascertain if a similar relationship exists for gaseous pollutants, and very few studies have addressed long-term exposure to ambient air pollution. Platelet activation, oxidative stress, interplay between interleukin-6 and tissue factor, all appear to be potentially important mechanisms in pollution-mediated thrombosis, together with an emerging role for circulating microvesicles and epigenetic changes.Overall, the recent literature supports, and arguably strengthens, the contention that air pollution contributes to cardiovascular morbidity by promoting haemostasis. The volume and diversity of the evidence highlights the complexity of the pathophysiologic mechanisms by which air pollution promotes thrombosis; multiple pathways are plausible and it is most likely they act in concert. Future research should address the role gaseous pollutants play in the cardiovascular effects of air pollution mixture and direct comparison of potentially

A Gas Chromatographic System for the Detection of Ethylene Gas Using Ambient Air as a Carrier Gas.

Science.gov (United States)

Zaidi, Nayyer Abbas; Tahir, Muhammad Waseem; Vellekoop, Michael J; Lang, Walter

2017-10-07

Ethylene gas is a naturally occurring gas that has an influence on the shelf life of fruit during their transportation in cargo ships. An unintentional exposure of ethylene gas during transportation results in a loss of fruit. A gas chromatographic system is presented here for the detection of ethylene gas. The gas chromatographic system was assembled using a preconcentrator, a printed 3D printed gas chromatographic column, a humidity sensor, solenoid valves, and an electrochemical ethylene gas sensor. Ambient air was used as a carrier gas in the gas chromatographic system. The flow rate was fixed to 10 sccm. It was generated through a mini-pump connected in series with a mass flow controller. The metal oxide gas sensor is discussed with its limitation in ambient air. The results show the chromatogram obtained from metal oxide gas sensor has low stability, drifts, and has uncertain peaks, while the chromatogram from the electrochemical sensor is stable and precise. Furthermore, ethylene gas measurements at higher ppb concentration and at lower ppb concentration were demonstrated with the electrochemical ethylene gas sensor. The system separates ethylene gas and humidity. The chromatograms obtained from the system are stable, and the results are 1.2% repeatable in five similar measurements. The statistical calculation of the gas chromatographic system shows that a concentration of 2.3 ppb of ethylene gas can be detected through this system.

Ambient air sampling for radioactive air contaminants at Los Alamos National Laboratory: A large research and development facility

International Nuclear Information System (INIS)

Eberhart, C.F.

1998-01-01

This paper describes the ambient air sampling program for collection, analysis, and reporting of radioactive air contaminants in and around Los Alamos National Laboratory (LANL). Particulate matter and water vapor are sampled continuously at more than 50 sites. These samples are collected every two weeks and then analyzed for tritium, and gross alpha, gross beta, and gamma ray radiation. The alpha, beta, and gamma measurements are used to detect unexpected radionuclide releases. Quarterly composites are analyzed for isotopes of uranium ( 234 U, 235 U, 238 U), plutonium ( 238 Pu, 239/249 Pu), and americium ( 241 Am). All of the data is stored in a relational database with hard copies as the official records. Data used to determine environmental concentrations are validated and verified before being used in any calculations. This evaluation demonstrates that the sampling and analysis process can detect tritium, uranium, plutonium, and americium at levels much less than one percent of the public dose limit of 10 millirems. The isotopic results also indicate that, except for tritium, off-site concentrations of radionuclides potentially released from LANL are similar to typical background measurements

Correlation between meteorological conditions and the concentration of radionuclides in the ground layer of atmospheric air

International Nuclear Information System (INIS)

Krajny, E.; Osrodka, L.; Wojtylak, M.; Michalik, B.; Skowronek, J.

2001-01-01

The main goal of this work was to find correlation between the concentrations of radionuclides in outdoor air and the meteorological conditions like: atmospheric pressure, wind velocity and amount of precipitation. Because the sampling period of radionuclides concentrations in air was relatively long (7 days), the average levels of meteorological parameters have been calculated within the same time. Data of radionuclide concentrations and meteorological data have been analyzed in order to find statistical correlation. The regression analysis and one of AI methods, known as neural network, were applied. In general, analysis of the gathered data does not show any strong correlation between the meteorological conditions and the concentrations of the radionuclides in air. A slightly stronger correlation we found for radionuclides with relatively short half-lives. The only positive correlation has been found between the 7 Be concentration and air temperature (at the significance level α = 0.05). In our opinion, the lack of correlation was caused by a too long sampling time in measurements of radionuclides in outdoor air (a whole week). Results of analysis received by means of the artificial neuron network are better. We were able to find certain groups of meteorological conditions, related with the corresponding concentrations of particular radionuclides in air. Preliminary measurements of radon progeny concentration support the thesis that the link between changes of meteorological parameters and concentrations of radionuclides in ambient air must exist. (author)

Assessment of suspended particulate matters and their heavy metal content in the ambient air of Mobarakeh city, Isfahan, Iran

Directory of Open Access Journals (Sweden)

Avazali Saririan Mobarakeh

2014-01-01

Conclusion: This study showed that ambient air of Mobarakeh city is polluted by TSP. The high concentration of Fe and Ni in this area may be attributed to the nearby industrial emissions. Therefore, in industrial areas, efforts should be taken to control the atmospheric pollution in order to protect humans from hazardous health effects of these potentially toxic pollutants.

Low-carbon energy policy and ambient air pollution in Shanghai, China: a health-based economic assessment.

Science.gov (United States)

Chen, Changhong; Chen, Bingheng; Wang, Bingyan; Huang, Cheng; Zhao, Jing; Dai, Yi; Kan, Haidong

2007-02-01

Energy and related health issues are of growing concern worldwide today. To investigate the potential public health and economic impact of ambient air pollution under various low-carbon energy scenarios in Shanghai, we estimated the exposure level of Shanghai residents to air pollution under various planned scenarios, and assessed the public health impact using concentration-response functions derived from available epidemiologic studies. We then estimated the corresponding economic values of the health effects based on unit values for each health outcome. Our results show that ambient air pollution in relation to low-carbon energy scenarios could have a significant impact on the future health status of Shanghai residents, both in physical and monetary terms. Compared with the base case scenario, implementation of various low-carbon energy scenarios could prevent 2804-8249 and 9870-23,100 PM10-related avoidable deaths (mid-value) in 2010 and 2020, respectively. It could also decrease incidence of several relevant diseases. The corresponding economic benefits could reach 507.31-1492.33 and 2642.45-6192.11 million U.S. dollars (mid-value) in 2010 and 2020, respectively. These findings illustrate that a low-carbon energy policy will not only decrease the emission of greenhouse gases, but also play an active role in the reduction of air pollutant emissions, improvement of air quality, and promotion of public health. Our estimates can provide useful information to local decision-makers for further cost-benefit analysis.

Low-carbon energy policy and ambient air pollution in Shanghai, China: A health-based economic assessment

International Nuclear Information System (INIS)

Chen Changhong; Chen Bingheng; Wang Bingyan; Huang Cheng; Zhao Jing; Dai Yi; Kan Haidong

2007-01-01

Energy and related health issues are of growing concern worldwide today. To investigate the potential public health and economic impact of ambient air pollution under various low-carbon energy scenarios in Shanghai, we estimated the exposure level of Shanghai residents to air pollution under various planned scenarios, and assessed the public health impact using concentration-response functions derived from available epidemiologic studies. We then estimated the corresponding economic values of the health effects based on unit values for each health outcome. Our results show that ambient air pollution in relation to low-carbon energy scenarios could have a significant impact on the future health status of Shanghai residents, both in physical and monetary terms. Compared with the base case scenario, implementation of various low-carbon energy scenarios could prevent 2804-8249 and 9870-23,100 PM 10 -related avoidable deaths (mid-value) in 2010 and 2020, respectively. It could also decrease incidence of several relevant diseases. The corresponding economic benefits could reach 507.31-1492.33 and 2642.45-6192.11 million U.S. dollars (mid-value) in 2010 and 2020, respectively. These findings illustrate that a low-carbon energy policy will not only decrease the emission of greenhouse gases, but also play an active role in the reduction of air pollutant emissions, improvement of air quality, and promotion of public health. Our estimates can provide useful information to local decision-makers for further cost-benefit analysis

Estimating cancer risk from outdoor concentrations of hazardous air pollutants in 1990

Energy Technology Data Exchange (ETDEWEB)

Woodruff, T.J.; Caldwell, J.; Cogliano, V.J.; Axelrad, D.A.

2000-03-01

A public health concern regarding hazardous air pollutants (HAPs) is their potential to cause cancer. It has been difficult to assess potential cancer risks from HAPs, due primarily to lack of ambient concentration data for the general population. The Environmental Protection Agency's Cumulative Exposure Project modeled 1990 outdoor concentrations of HAPs across the United States, which were combined with inhalation unit risk estimates to estimate the potential increase in excess cancer risk for individual carcinogenic HAPs. These were summed3d to provide an estimate of cancer risk from multiple HAPs. The analysis estimates a median excess cancer risk of 18 lifetime cancer cases per 100,000 people for all HAP concentrations. About 75% of estimated cancer risk was attributable to exposure to polycyclic organic matter, 1,3-butadiene, formaldehyde, benzene, and chromium. Consideration of some specific uncertainties, including underestimation of ambient concentrations, combining upper 95% confidence bound potency estimates, and changes to potency estimates, found that cancer risk may be underestimated by 15% or overestimated by 40--50%. Other unanalyzed uncertainties could make these under- or overestimates larger. This analysis used 1990 estimates of concentrations and can be used to track progress toward reducing cancer risk to the general population.

Energy saving potential of natural ventilation in China: The impact of ambient air pollution

International Nuclear Information System (INIS)

Tong, Zheming; Chen, Yujiao; Malkawi, Ali; Liu, Zhu; Freeman, Richard B.

2016-01-01

Highlights: • Natural ventilation potential is affected largely by ambient air pollution in China. • NV hours of 76 Chinese cities based on weather and ambient air quality are estimated. • Cooling energy savings and carbon reductions of 35 major Chinese cities are estimated. • 8–78% of the cooling energy usage can be potentially reduced by NV. • Our findings provide guidelines to improve energy policies in China. - Abstract: Natural ventilation (NV) is a key sustainable solution for reducing the energy use in buildings, improving thermal comfort, and maintaining a healthy indoor environment. However, the energy savings and environmental benefits are affected greatly by ambient air pollution in China. Here we estimate the NV potential of all major Chinese cities based on weather, ambient air quality, building configuration, and newly constructed square footage of office buildings in the year of 2015. In general, little NV potential is observed in northern China during the winter and southern China during the summer. Kunming located in the Southwest China is the most weather-favorable city for natural ventilation, and reveals almost no loss due to air pollution. Building Energy Simulation (BES) is conducted to estimate the energy savings of natural ventilation in which ambient air pollution and total square footage at each city must be taken into account. Beijing, the capital city, displays limited per-square-meter saving potential due to the unfavorable weather and air quality for natural ventilation, but its largest total square footage of office buildings makes it become the city with the greatest energy saving opportunity in China. Our analysis shows that the aggregated energy savings potential of office buildings at 35 major Chinese cities is 112 GWh in 2015, even after allowing for a 43 GWh loss due to China’s serious air pollution issue especially in North China. 8–78% of the cooling energy consumption can be potentially reduced by natural

Study on element concentrations in aerosol in ambient air from Phnom Penh, Cambodia

International Nuclear Information System (INIS)

Kashima, Yuji; Sakai, Haruya; Matsui, Mitsuaki

2004-01-01

In order to accumulate basic information necessary for reduction of suspended particle materials (SPM) in Phnom Penh, various element concentrations were measured with ICP-mass spectrometry and neutron activation analysis, and some their sources were estimated. SPM were collected at a roadside area in the middle of the City (1 point, 11 samples of 24 hours and 14 samples of 7 ∼ 16 hours) and two residence areas (2 points, 13 samples of 24 hours and 1 sample of 16 hours) with membrane filters of air samplers set at the level of 8∼9 m height. For research SPM sources, two kinds of comparative samples were also collected from roadside dust and soil (2 points, 9 samples) and from exhaust deposit of vehicles (bicycle 11, gasoline automobile 7, diesel car 10 samples) and electric generator (6 samples). SPM concentrations measured were 67∼1,000 μg/m 3 (average 410 μg/m 3 ). The concentrations in the roadside area were several times higher than in the residence area. Toxic element concentrations were all higher in roadside with an exception of Cd. The concentrations of Pb was 44 ng/m 3 on the average, amounting to 1/10 of WHO Guidelines. Comparing element concentrations of SPM with those of the soils and deposits, factor analysis using 18 elements including Ba, V, Pb suggests three major sources of soil, vehicle exhaust, and oil burning. (H. Yokoo)

Pilot study investigating ambient air toxics emissions near a Canadian kraft pulp and paper facility in Pictou County, Nova Scotia.

Science.gov (United States)

Hoffman, Emma; Guernsey, Judith R; Walker, Tony R; Kim, Jong Sung; Sherren, Kate; Andreou, Pantelis

2017-09-01

Air toxics are airborne pollutants known or suspected to cause cancer or other serious health effects, including certain volatile organic compounds (VOCs), prioritized by the US Environmental Protection Agency (EPA). While several EPA-designated air toxics are monitored at a subset of Canadian National Air Pollution Surveillance (NAPS) sites, Canada has no specific "air toxics" control priorities. Although pulp and paper (P&P) mills are major industrial emitters of air pollutants, few studies quantified the spectrum of air quality exposures. Moreover, most NAPS monitoring sites are in urban centers; in contrast, rural NAPS sites are sparse with few exposure risk records. The objective of this pilot study was to investigate prioritized air toxic ambient VOC concentrations using NAPS hourly emissions data from a rural Pictou, Nova Scotia Kraft P&P town to document concentration levels, and to determine whether these concentrations correlated with wind direction at the NAPS site (located southwest of the mill). Publicly accessible Environment and Climate Change Canada data (VOC concentrations [Granton NAPS ID: 31201] and local meteorological conditions [Caribou Point]) were examined using temporal (2006-2013) and spatial analytic methods. Results revealed several VOCs (1,3-butadiene, benzene, and carbon tetrachloride) routinely exceeded EPA air toxics-associated cancer risk thresholds. 1,3-Butadiene and tetrachloroethylene were significantly higher (p towns and contribute to poor health in nearby communities.

Ambient particulate air pollution from vehicles promotes lipid peroxidation and inflammatory responses in rat lung.

Science.gov (United States)

Pereira, C E L; Heck, T G; Saldiva, P H N; Rhoden, C R

2007-10-01

Oxidative stress plays a major role in the pathogenesis of particle-dependent lung injury. Ambient particle levels from vehicles have not been previously shown to cause oxidative stress to the lungs. The present study was conducted to a) determine whether short-term exposure to ambient levels of particulate air pollution from vehicles elicits inflammatory responses and lipid peroxidation in rat lungs, and b) determine if intermittent short-term exposures (every 4 days) induce some degree of tolerance. Three-month-old male Wistar rats were exposed to ambient particulate matter (PM) from vehicles (N = 30) for 6 or 20 continuous hours, or for intermittent (5 h) periods during 20 h for 4 consecutive days or to filtered air (PM polluted air for 20 h (P-20) showed a significant increase in the total number of leukocytes in bronchoalveolar lavage compared to control (C-20: 2.61 x 105 +/- 0.51;P-20: 5.01 x 105 +/- 0.81; P air pollution did not cause a significant increase in lung water content. These data suggest oxidative stress as one of the mechanisms responsible for the acute adverse respiratory effects of particles, and suggest that short-term inhalation of ambient particulate air pollution from street with high automobile traffic represents a biological hazard.

40 CFR Appendix S to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Nitrogen...

Science.gov (United States)

2010-07-01

... Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) S Appendix S to Part 50 Protection... National Ambient Air Quality Standards for Oxides of Nitrogen (Nitrogen Dioxide) 1. General (a) This... national ambient air quality standards for oxides of nitrogen as measured by nitrogen dioxide (“NO2 NAAQS...

Modeling the dependency of radon concentration levels inside ancient Egyptian tombs on the ambient temperature variations

Energy Technology Data Exchange (ETDEWEB)

Metwally, S M; Abo-Elmagdb, M [Faculty of Science, Department of Physics, Ain Shams University, P. O. Box 11566, Cairo (Egypt); Salamaa, E [National Institute for Standard, Radiation Measurements Department, Cairo (Egypt)

2007-06-15

Radon concentration inside partially closed places like dwellings, caves and tombs, depends on many parameters. Some parameters are known quantitatively as radon exhalation rate for walls, decay constant, surface to volume ratio and outdoor concentration while other parameters as ventilation rate is in common known qualitatively due to useless of traditional methods (tracer gases) in many places as ancient Egyptian tombs. This work introduces a derived mathematical model to evaluate the sensitivity of radon concentration levels inside single sided opening places as ancient Egyptian tombs on the ambient temperature differences. The obtained formula for the natural ventilation rate depends on the indoor and outdoor temperature difference and the geometrical dimensions of the doorway. The effects of in and out flow mixing, air viscosity, streamline contraction, swirling flow and turbulence, were taken into consideration in terms of an empirical correction factor. According UNSCEAR reports, the exhalation rate {phi}=C{sub ra}{lambda}{sub rn} f{rho}{sub s}(1-{epsilon})L; C{sub ra} the effective radium content, {lambda}{sub rn} decay constant, f emanation fraction, {rho}{sub s} soil grain density, {epsilon} porosity and L diffusion length, these are approximately static parameters but the variability of ambient temperature introduces a source of energy of fluctuating strength to radon atoms in rocks which controls the flow rate and the ambient content of radon. Therefore, the change of outdoor and indoor temperature difference causes fluctuation of value and direction of volume flow rate in such places consequently causes the daily variation and on average the seasonal variation of radon concentration. Therefore according to the present model, the daily accurate expectation of radon concentrations inside ancient Egyptian tombs, require precise measurements of indoor and outdoor temperatures.

Pollution characteristic of VOCs of ambient air in winter and spring in Shijiazhuang City

Directory of Open Access Journals (Sweden)

Qing CHANG

2015-06-01

Full Text Available In order to further explore the pollution characteristics of volatile organic compounds in ambient air in winter and spring in Shijiazhuang City, the pollution characteristics of 62 volatile organic compounds (VOCs, monthly and quarterly variation, the correlation between VOCs and PM2.5, and the main sources of VOCs are investigated by using EPA TO-15 method. It shows that 40 organic compounds of the 64 VOCs have been quantitatively determined in winter and spring in the city, which are mainly acetone, benzene, carbon tetrachloride, dichloromethane, toluene, ethyl acetate, etc.. In the no-quantitatively determined components, higher ethanol, butyl acetate, butane etc. are detected. The VOCs concentration has positive correlation with the PM2.5 concentration during haze days.

Long-term trends in California mobile source emissions and ambient concentrations of black carbon and organic aerosol.

Science.gov (United States)

McDonald, Brian C; Goldstein, Allen H; Harley, Robert A

2015-04-21

A fuel-based approach is used to assess long-term trends (1970-2010) in mobile source emissions of black carbon (BC) and organic aerosol (OA, including both primary emissions and secondary formation). The main focus of this analysis is the Los Angeles Basin, where a long record of measurements is available to infer trends in ambient concentrations of BC and organic carbon (OC), with OC used here as a proxy for OA. Mobile source emissions and ambient concentrations have decreased similarly, reflecting the importance of on- and off-road engines as sources of BC and OA in urban areas. In 1970, the on-road sector accounted for ∼90% of total mobile source emissions of BC and OA (primary + secondary). Over time, as on-road engine emissions have been controlled, the relative importance of off-road sources has grown. By 2010, off-road engines were estimated to account for 37 ± 20% and 45 ± 16% of total mobile source contributions to BC and OA, respectively, in the Los Angeles area. This study highlights both the success of efforts to control on-road emission sources, and the importance of considering off-road engine and other VOC source contributions when assessing long-term emission and ambient air quality trends.

Modification of the effect of ambient air pollution on pediatric asthma emergency visits: susceptible subpopulations

Science.gov (United States)

Strickland, Matthew J; Klein, Mitchel; Flanders, W Dana; Chang, Howard H; Mulholland, James A; Tolbert, Paige E; Darrow, Lyndsey A

2016-01-01

Background Children may have differing susceptibility to ambient air pollution concentrations depending on various background characteristics of the children. Methods Using emergency department (ED) data linked with birth records from Atlanta, Georgia, we identified ED visits for asthma or wheeze among children aged 2–16 years from 1 January 2002 through 30 June 2010 (n=109,758). We stratified by preterm delivery, term low birth weight, maternal race, Medicaid status, maternal education, maternal smoking, delivery method, and history of a bronchiolitis ED visit. Population-weighted daily average concentrations were calculated for 1-hour maximum carbon monoxide and nitrogen dioxide; 8-hour maximum ozone; and 24-hour average particulate matter less than 10 microns in diameter, particulate matter less than 2.5 microns in diameter (PM2.5), and the PM2.5 components sulfate, nitrate, ammonium, elemental carbon, and organic carbon, using measurements from stationary monitors. Poisson time-series models were used to estimate rate ratios for associations between three-day moving average pollutant concentrations and daily ED visit counts and to investigate effect-measure modification by the stratification factors. Results Associations between pollutant concentrations and asthma exacerbations were larger among children born preterm and among children born to African American mothers. Stratification by race and preterm status together suggested that both factors affected susceptibility. The largest estimated effect size (for an interquartile-range increase in pollution) was observed for ozone among preterm births to African American mothers: rate ratio=1.138 (95% confidence interval=1.077–1.203). In contrast, the rate ration for the ozone association among full-term births to mothers of other races was 1.025 (0.970–1.083). Conclusions Results support the hypothesis that children vary in their susceptibility to ambient air pollutants. PMID:25192402

Particle-bound Dechlorane Plus and polybrominated diphenyl ethers in ambient air around Shanghai, China

Energy Technology Data Exchange (ETDEWEB)

Yu Zhiqiang [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Liao Ru' e [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Li Huiru, E-mail: huiruli@gig.ac.cn [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Mo Ligui [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Zeng Xiangying; Sheng Guoying; Fu Jiamo [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

2011-10-15

In present study, atmospheric particles from Shanghai, the biggest city and the most important industrial base in China, were analyzed for polybrominated diphenyl ethers (PBDEs) and Dechlorane Plus (DP). Concentrations of {Sigma}{sub 20}PBDEs and DP both exhibited the changing trend of industrial area > urban areas. Jiading District had the highest levels of particulate PBDEs and DP with values of 744 {+-} 152 pg/m{sup 3} and 5.48 {+-} 1.28 pg/m{sup 3}, respectively. Compared with similar data in other areas of the world, PBDEs in Shanghai were at medium pollution level, while DP was at lower level, which reflected their different production and use in Shanghai. The results from multiple linear regression analysis suggested that deca-BDE mixture was the most important contributor of particulate PBDEs in Shanghai. The fractions of anti-DP showed no significant differences to those of the technical mixtures (p > 0.05), which suggested that no obviously stereoselective process occurred in ambient air around Shanghai. - Highlights: > Atmospheric PBDEs of Shanghai were at moderate levels and dominated by BDE-209. > Particulate DP was low even Shanghai is not far from the DP manufacturing factory. > DP showed no obviously stereoselective process in air particles from Shanghai. > Significant positive correlation was found between particulate PBDEs and PBDD/Fs. - The moderate PBDEs levels with deca-BDE being the most important contributor and low DP levels in ambient air around Shanghai reflected their different usage in this area.

Particle-bound Dechlorane Plus and polybrominated diphenyl ethers in ambient air around Shanghai, China

International Nuclear Information System (INIS)

Yu Zhiqiang; Liao Ru'e; Li Huiru; Mo Ligui; Zeng Xiangying; Sheng Guoying; Fu Jiamo

2011-01-01

In present study, atmospheric particles from Shanghai, the biggest city and the most important industrial base in China, were analyzed for polybrominated diphenyl ethers (PBDEs) and Dechlorane Plus (DP). Concentrations of Σ 20 PBDEs and DP both exhibited the changing trend of industrial area > urban areas. Jiading District had the highest levels of particulate PBDEs and DP with values of 744 ± 152 pg/m 3 and 5.48 ± 1.28 pg/m 3 , respectively. Compared with similar data in other areas of the world, PBDEs in Shanghai were at medium pollution level, while DP was at lower level, which reflected their different production and use in Shanghai. The results from multiple linear regression analysis suggested that deca-BDE mixture was the most important contributor of particulate PBDEs in Shanghai. The fractions of anti-DP showed no significant differences to those of the technical mixtures (p > 0.05), which suggested that no obviously stereoselective process occurred in ambient air around Shanghai. - Highlights: → Atmospheric PBDEs of Shanghai were at moderate levels and dominated by BDE-209. → Particulate DP was low even Shanghai is not far from the DP manufacturing factory. → DP showed no obviously stereoselective process in air particles from Shanghai. → Significant positive correlation was found between particulate PBDEs and PBDD/Fs. - The moderate PBDEs levels with deca-BDE being the most important contributor and low DP levels in ambient air around Shanghai reflected their different usage in this area.

Ambient air quality at the wider area of an industrial mining facility at Stratoni, Chalkidiki, Greece.

Science.gov (United States)

Gaidajis, Georgios; Angelakoglou, Komninos; Gazea, Emmy

2012-01-01

To assess ambient air quality at the wider area of a mining-industrial facility in Chalkidiki, Greece, the particulate matter with an aerodynamic diameter of 10 μm (PM(10)) and its content in characteristic elements, i.e., As, Cd, Cu, Fe, Mn, Pb, Zn were monitored for a period of three years (2008-2010). Gravimetric air samplers were employed for the particulate matter sampling at three sampling stations located in the immediate vicinity of the industrial facility and at a neighbouring residential site. Monitoring data indicated that the 3-year median PM(10) concentrations were 23.3 μg/m(3) at the residential site close to the facility and 28.7 μg/m(3) at the site within the facility indicating a minimal influence from the industrial activities to the air quality of the neighbouring residential area. Both annual average and median PM(10) concentration levels were below the indicative European standards, whereas similar spatial and temporal variation was observed for the PM(10) constituents. The average Pb concentrations measured for the three sampling sites were 0.2, 0.146 and 0.174 μg/m(3) respectively, well below the indicative limit of 0.5 μg/m(3). The quantitative and qualitative comparison of PM(10) concentrations and its elemental constituent for the three sampling stations did not indicate any direct influence of the mining-industrial activities to the air quality of the Stratoni residential area.

Acute effects of ambient air pollution on lower respiratory infections in Hanoi children: An eight-year time series study.

Science.gov (United States)

Nhung, Nguyen Thi Trang; Schindler, Christian; Dien, Tran Minh; Probst-Hensch, Nicole; Perez, Laura; Künzli, Nino

2018-01-01

Lower respiratory diseases are the most frequent causes of hospital admission in children worldwide, particularly in developing countries. Daily levels of air pollution are associated with lower respiratory diseases, as documented in many time-series studies. However, investigations in low-and-middle-income countries, such as Vietnam, remain sparse. This study investigated the short-term association of ambient air pollution with daily counts of hospital admissions due to pneumonia, bronchitis and asthma among children aged 0-17 in Hanoi, Vietnam. We explored the impact of age, gender and season on these associations. Daily ambient air pollution concentrations and hospital admission counts were extracted from electronic databases received from authorities in Hanoi for the years 2007-2014. The associations between outdoor air pollution levels and hospital admissions were estimated for time lags of zero up to seven days using Quasi-Poisson regression models, adjusted for seasonal variations, meteorological variables, holidays, influenza epidemics and day of week. All ambient air pollutants were positively associated with pneumonia hospitalizations. Significant associations were found for most pollutants except for ozone and sulfur dioxide in children aged 0-17. Increments of an interquartile range (21.9μg/m 3 ) in the 7-day-average level of NO 2 were associated with a 6.1% (95%CI 2.5% to 9.8%) increase in pneumonia hospitalizations. These associations remained stable in two-pollutant models. All pollutants other than CO were positively associated with hospitalizations for bronchitis and asthma. Associations were stronger in infants than in children aged 1-5. Strong associations between hospital admissions for lower respiratory infections and daily levels of air pollution confirm the need to adopt sustainable clean air policies in Vietnam to protect children's health. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Assessment of ambient air quality in Chidambaram a south Indian town

OpenAIRE

P. Balashanmugam; A.R. Ramanathan; V. Nehrukumar

2012-01-01

Worldwide preliminary studies in large number are advocated to create data base, to identify potential cities / towns that warrant “continuous ambient air quality monitoring and control mechanism” and to evolve priorities for clean air target. The results reported pertain to an eight hour random preliminary air sampling exercise carried out at each of the eight select locations in Chidambaram, a southern semi urban settlement in India. Criteria pollutants SPM, CO, SO2 and NO2 measured are fou...

Contamination of Ambient Air with Acinetobacter baumannii on Consecutive Inpatient Days.

Science.gov (United States)

Shimose, Luis A; Doi, Yohei; Bonomo, Robert A; De Pascale, Dennise; Viau, Roberto A; Cleary, Timothy; Namias, Nicholas; Kett, Daniel H; Munoz-Price, L Silvia

2015-07-01

Acinetobacter-positive patients had their ambient air tested for up to 10 consecutive days. The air was Acinetobacter positive for an average of 21% of the days; the rate of contamination was higher among patients colonized in the rectum than in the airways (relative risk [RR], 2.35; P = 0.006). Of the 6 air/clinical isolate pairs available, 4 pairs were closely related according to rep-PCR results. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Health effects associated with exposure to ambient air pollution.

Science.gov (United States)

Samet, Jonathan; Krewski, Daniel

2007-02-01

The World Health Organization has identified ambient air pollution as a high public health priority, based on estimates of air pollution related death and disability-adjusted life years derived in its Global Burden of Disease initiative. The NERAM Colloquium Series on Health and Air Quality was initiated to strengthen the linkage between scientists, policymakers, and other stakeholders by reviewing the current state of science, identifying policy-relevant gaps and uncertainties in the scientific evidence, and proposing a path forward for research and policy to improve air quality and public health. The objective of this paper is to review the current state of science addressing the impacts of air pollution on human health. The paper is one of four background papers prepared for the 2003 NERAM/AirNet Conference on Strategies for Clean Air and Health, the third meeting in the international Colloquium Series. The review is based on the framework and findings of the U.S. National Research Committee (NRC) on Research Priorities for Airborne Particulate Matter and addresses key questions underlying air quality risk management policy decisions.

Automatic system for ecological monitoring of ambient air in the region of energy complex 'Maritsa-Iztok'

International Nuclear Information System (INIS)

Vasilev, V.; Videnova, I.; Nedyalkov, N.

2000-01-01

This report presents the automatic system for ecological monitoring of ambient air in the region of the energy complex 'Maritza-Iztok', developed by CCS-Bulgaria, Bulgarian Academy of Sciences, Institute of Control and System Research. The automatic station takes the concentration of nitric oxides, sulfuric dioxide and dust, as well as the meteorological indicators: temperature and humidity, atmospheric pressure, wind direction and speed, sun heat and radiation. The data appears on a information board and is kept in a database

Short-term effects of ambient air pollution on pediatric outpatient visits for respiratory diseases in Yichang city, China.

Science.gov (United States)

Liu, Yuewei; Xie, Shuguang; Yu, Qing; Huo, Xixiang; Ming, Xiaoyan; Wang, Jing; Zhou, Yun; Peng, Zhe; Zhang, Hai; Cui, Xiuqing; Xiang, Hua; Huang, Xiji; Zhou, Ting; Chen, Weihong; Shi, Tingming

2017-08-01

Previous studies have suggested that short-term exposure to ambient air pollution was associated with pediatric hospital admissions and emergency room visits for certain respiratory diseases; however, there is limited evidence on the association between short-term air pollution exposure and pediatric outpatient visits. Our aim was to quantitatively assess the short-term effects of ambient air pollution on pediatric outpatient visits for respiratory diseases. We conducted a time-series study in Yichang city, China between Jan 1, 2014 and Dec 31, 2015. Daily counts of pediatric respiratory outpatient visits were collected from 3 large hospitals, and then linked with air pollution data from 5 air quality monitoring stations by date. We used generalized additive Poisson models to conduct linear and nonlinear exposure-response analyses between air pollutant exposures and pediatric respiratory outpatient visits, adjusting for seasonality, day of week, public holiday, temperature, and relative humidity. Each interquartile range (IQR) increase in PM 2.5 (lag 0), PM 10 (lag 0), NO 2 (lag 0), CO (lag 0), and O 3 (lag 4) concentrations was significantly associated with a 1.91% (95% CI: 0.60%, 3.23%), 2.46% (1.09%, 3.85%), 1.88% (0.49%, 3.29%), 2.00% (0.43%, 3.59%), and 1.91% (0.45%, 3.39%) increase of pediatric respiratory outpatient visits, respectively. Similarly, the nonlinear exposure-response analyses showed monotonic increases of pediatric respiratory outpatient visits by increasing air pollutant exposures, though the associations for NO 2 and CO attenuated at higher concentrations. These associations were unlikely modified by season. We did not observe significant association for SO 2 exposure. Our results suggest that short-term exposures to PM 2.5 , PM 10 , NO 2 , CO, and O 3 may account for increased risk of pediatric outpatient visits for respiratory diseases, and emphasize the needs for reduction of air pollutant exposures for children. Copyright © 2017

Evaluation of a low-cost optical particle counter (Alphasense OPC-N2) for ambient air monitoring

Science.gov (United States)

Crilley, Leigh R.; Shaw, Marvin; Pound, Ryan; Kramer, Louisa J.; Price, Robin; Young, Stuart; Lewis, Alastair C.; Pope, Francis D.

2018-02-01

A fast-growing area of research is the development of low-cost sensors for measuring air pollutants. The affordability and size of low-cost particle sensors makes them an attractive option for use in experiments requiring a number of instruments such as high-density spatial mapping. However, for these low-cost sensors to be useful for these types of studies their accuracy and precision need to be quantified. We evaluated the Alphasense OPC-N2, a promising low-cost miniature optical particle counter, for monitoring ambient airborne particles at typical urban background sites in the UK. The precision of the OPC-N2 was assessed by co-locating 14 instruments at a site to investigate the variation in measured concentrations. Comparison to two different reference optical particle counters as well as a TEOM-FDMS enabled the accuracy of the OPC-N2 to be evaluated. Comparison of the OPC-N2 to the reference optical instruments shows some limitations for measuring mass concentrations of PM1, PM2.5 and PM10. The OPC-N2 demonstrated a significant positive artefact in measured particle mass during times of high ambient RH (> 85 %) and a calibration factor was developed based upon κ-Köhler theory, using average bulk particle aerosol hygroscopicity. Application of this RH correction factor resulted in the OPC-N2 measurements being within 33 % of the TEOM-FDMS, comparable to the agreement between a reference optical particle counter and the TEOM-FDMS (20 %). Inter-unit precision for the 14 OPC-N2 sensors of 22 ± 13 % for PM10 mass concentrations was observed. Overall, the OPC-N2 was found to accurately measure ambient airborne particle mass concentration provided they are (i) correctly calibrated and (ii) corrected for ambient RH. The level of precision demonstrated between multiple OPC-N2s suggests that they would be suitable devices for applications where the spatial variability in particle concentration was to be determined.

Ambient concentrations of total suspended particulate matter and its elemental constituents at the wider area of the mining facilities of TVX Hellas in Chalkidiki, Greece.

Science.gov (United States)

Gaidajis, George

2003-01-01

To assess ambient air quality at the wider area of TVX Hellas mining facilities, the Total Suspended Particulate matter (TSP) and its content in characteristic elements, i.e., As, Cd, Cu, Fe, Mn, Pb, Zn are being monitored for more than thirty months as part of the established Environmental Monitoring Program. High Volume air samplers equipped with Tissue Quartz filters were employed for the collection of TSP. Analyses were effected after digestion of the suspended particulate with an HNO3-HCl solution and determination of elemental concentrations with an Atomic Absorption Spectroscopy equipped with graphite furnace. The sampling stations were selected to record representatively the existing ambient air quality in the vicinity of the facilities and at remote sites not affected from industrial activities. Monitoring data indicated that the background TSP concentrations ranged from 5-60 microg/m3. Recorded TSP concentrations at the residential sites close to the facilities ranged between 20-100 microg/m3, indicating only a minimal influence from the mining and milling activities. Similar spatial variation was observed for the TSP constituents and specifically for Pb and Zn. To validate the monitoring procedures, a parallel sampling campaign took place with different High Volume samplers at days where low TSP concentrations were expected. The satisfactory agreement (+/- 11%) at low concentrations (50-100 microg/m3) clearly supported the reproducibility of the techniques employed specifically at the critical range of lower concentrations.

Ambient air pollution associated to domestic wood burning heating systems

International Nuclear Information System (INIS)

Friboulet, I.; Durif, M.; Malherbe, L.

2009-01-01

Main publications are considering effects of wood burning appliances on indoor air quality, which is a major issue in some countries. But impacts on ambient air, close environment and human exposure are rather poorly characterised so far. Besides, woods burning for domestic purpose may develop in the next years while promoting bio fuels. The aim of the ongoing study is to assess in which conditions associated air pollution and population exposure could be significant, this poster shows preliminary results of the impact of a village of 98 houses equipped with a wood burning heating system. (N.C.)

Highly sensitive determination of polycyclic aromatic hydrocarbons in ambient air dust by gas chromatography-mass spectrometry after molecularly imprinted polymer extraction

Energy Technology Data Exchange (ETDEWEB)

Krupadam, Reddithota J.; Bhagat, Bhagyashree; Khan, Muntazir S. [National Environmental Engineering Research Institute, Nagpur (India)

2010-08-15

A method based on solid-phase extraction with a molecularly imprinted polymer (MIP) has been developed to determine five probable human carcinogenic polycyclic aromatic hydrocarbons (PAHs) in ambient air dust by gas chromatography-mass spectrometry (GC-MS). Molecularly imprinted poly(vinylpyridine-co-ethylene glycol dimethacrylate) was chosen as solid-phase extraction (SPE) material for PAHs. The conditions affecting extraction efficiency, for example surface properties, concentration of PAHs, and equilibration times were evaluated and optimized. Under optimum conditions, pre-concentration factors for MIP-SPE ranged between 80 and 93 for 10 mL ambient air dust leachate. PAHs recoveries from MIP-SPE after extraction from air dust were between 85% and 97% and calibration graphs of the PAHs showed a good linearity between 10 and 1000 ng L{sup -1} (r=0.99). The extraction efficiency of MIP for PAHs was compared with that of commercially available SPE materials - powdered activated carbon (PAC) and polystyrene-divinylbenzene resin (XAD) - and it was shown that the extraction capacity of the MIP was better than that of the other two SPE materials. Organic matter in air dust had no effect on MIP extraction, which produced a clean extract for GC-MS analysis. The detection limit of the method proposed in this article is 0.15 ng L{sup -1} for benzo[a]pyrene, which is a marker molecule of air pollution. The method has been applied to the determination of probable carcinogenic PAHs in air dust of industrial zones and satisfactory results were obtained. (orig.)

Highly sensitive determination of polycyclic aromatic hydrocarbons in ambient air dust by gas chromatography-mass spectrometry after molecularly imprinted polymer extraction.

Science.gov (United States)

Krupadam, Reddithota J; Bhagat, Bhagyashree; Khan, Muntazir S

2010-08-01

A method based on solid--phase extraction with a molecularly imprinted polymer (MIP) has been developed to determine five probable human carcinogenic polycyclic aromatic hydrocarbons (PAHs) in ambient air dust by gas chromatography-mass spectrometry (GC-MS). Molecularly imprinted poly(vinylpyridine-co-ethylene glycol dimethacrylate) was chosen as solid-phase extraction (SPE) material for PAHs. The conditions affecting extraction efficiency, for example surface properties, concentration of PAHs, and equilibration times were evaluated and optimized. Under optimum conditions, pre-concentration factors for MIP-SPE ranged between 80 and 93 for 10 mL ambient air dust leachate. PAHs recoveries from MIP-SPE after extraction from air dust were between 85% and 97% and calibration graphs of the PAHs showed a good linearity between 10 and 1000 ng L(-1) (r = 0.99). The extraction efficiency of MIP for PAHs was compared with that of commercially available SPE materials--powdered activated carbon (PAC) and polystyrene-divinylbenzene resin (XAD)--and it was shown that the extraction capacity of the MIP was better than that of the other two SPE materials. Organic matter in air dust had no effect on MIP extraction, which produced a clean extract for GC-MS analysis. The detection limit of the method proposed in this article is 0.15 ng L(-1) for benzo[a]pyrene, which is a marker molecule of air pollution. The method has been applied to the determination of probable carcinogenic PAHs in air dust of industrial zones and satisfactory results were obtained.

MODELING THE AMBIENT CONDITION EFFECTS OF AN AIR-COOLED NATURAL CIRCULATION SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Hu, Rui; Lisowski, Darius D.; Bucknor, Matthew; Kraus, Adam R.; Lv, Qiuping

2017-07-02

The Reactor Cavity Cooling System (RCCS) is a passive safety concept under consideration for the overall safety strategy of advanced reactors such as the High Temperature Gas-Cooled Reactor (HTGR). One such variant, air-cooled RCCS, uses natural convection to drive the flow of air from outside the reactor building to remove decay heat during normal operation and accident scenarios. The Natural convection Shutdown heat removal Test Facility (NSTF) at Argonne National Laboratory (“Argonne”) is a half-scale model of the primary features of one conceptual air-cooled RCCS design. The facility was constructed to carry out highly instrumented experiments to study the performance of the RCCS concept for reactor decay heat removal that relies on natural convection cooling. Parallel modeling and simulation efforts were performed to support the design, operation, and analysis of the natural convection system. Throughout the testing program, strong influences of ambient conditions were observed in the experimental data when baseline tests were repeated under the same test procedures. Thus, significant analysis efforts were devoted to gaining a better understanding of these influences and the subsequent response of the NSTF to ambient conditions. It was determined that air humidity had negligible impacts on NSTF system performance and therefore did not warrant consideration in the models. However, temperature differences between the building exterior and interior air, along with the outside wind speed, were shown to be dominant factors. Combining the stack and wind effects together, an empirical model was developed based on theoretical considerations and using experimental data to correlate zero-power system flow rates with ambient meteorological conditions. Some coefficients in the model were obtained based on best fitting the experimental data. The predictive capability of the empirical model was demonstrated by applying it to the new set of experimental data. The

Inhaled concentrated ambient particles are associated with hematologic and bronchoalveolar lavage changes in canines.

Science.gov (United States)

Clarke, R W; Coull, B; Reinisch, U; Catalano, P; Killingsworth, C R; Koutrakis, P; Kavouras, I; Murthy, G G; Lawrence, J; Lovett, E; Wolfson, J M; Verrier, R L; Godleski, J J

2000-01-01

Pulmonary inflammatory and hematologic responses of canines were studied after exposure to concentrated ambient particles (CAPs) using the Harvard ambient particle concentrator (HAPC). For pulmonary inflammatory studies, normal dogs were exposed in pairs to either CAPs or filtered air (paired studies) for 6 hr/day on 3 consecutive days. For hematologic studies, dogs were exposed for 6 hr/day for 3 consecutive days with one receiving CAPs while the other was simultaneously exposed to filtered air; crossover of exposure took place the following week (crossover studies). Physicochemical characterization of CAPs exposure samples included measurements of particle mass, size distribution, and composition. No statistical differences in biologic responses were found when all CAPs and all sham exposures were compared. However, the variability in biologic response was considerably higher with CAPs exposure. Subsequent exploratory graphical analyses and mixed linear regression analyses suggested associations between CAPs constituents and biologic responses. Factor analysis was applied to the compositional data from paired and crossover experiments to determine elements consistently associated with each other in CAPs samples. In paired experiments, four factors were identified; in crossover studies, a total of six factors were observed. Bronchoalveolar lavage (BAL) and hematologic data were regressed on the factor scores. Increased BAL neutrophil percentage, total peripheral white blood cell (WBC) counts, circulating neutrophils, and circulating lymphocytes were associated with increases in the aluminum/silicon factor. Increased circulating neutrophils and increased BAL macrophages were associated with the vanadium/nickel factor. Increased BAL neutrophils were associated with the bromine/lead factor when only the compositional data from the third day of CAPs exposure were used. Significant decreases in red blood cell counts and hemoglobin levels were correlated with the sulfur

Ambient particulate matter air pollution and cardiopulmonary diseases.

Science.gov (United States)

Thurston, George; Lippmann, Morton

2015-06-01

Population exposures to ambient outdoor particulate matter (PM) air pollution have been assessed to represent a major burden on global health. Ambient PM is a diverse class of air pollution, with characteristics and health implications that can vary depending on a host of factors, including a particle's original source of emission or formation. The penetration of inhaled particles into the thorax is dependent on their deposition in the upper respiratory tract during inspiration, which varies with particle size, flow rate and tidal volume, and in vivo airway dimensions. All of these factors can be quite variable from person to person, depending on age, transient illness, cigarette smoke and other short-term toxicant exposures that cause transient bronchoconstriction, and occupational history associated with loss of lung function or cumulative injury. The adverse effects of inhaled PM can result from both short-term (acute) and long-term (chronic) exposures to PM, and can range from relatively minor, such as increased symptoms, to very severe effects, including increased risk of premature mortality and decreased life expectancy from long-term exposure. Control of the most toxic PM components can therefore provide major health benefits, and can help guide the selection of the most human health optimal air quality control and climate change mitigation policy measures. As such, a continued improvement in our understanding of the nature and types of PM that are most dangerous to health, and the mechanism(s) of their respective health effects, is an important public health goal. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

76 FR 22665 - Release of Final Document Related to the Review of the National Ambient Air Quality Standards for...

Science.gov (United States)

2011-04-22

... criteria. The revised air quality criteria reflect advances in scientific knowledge on the effects of the... National Ambient Air Quality Standards, contains staff analyses of the scientific bases for alternative... Document Related to the Review of the National Ambient Air Quality Standards for Particulate Matter AGENCY...

Ambient air monitoring to support HLW repository site characterization

International Nuclear Information System (INIS)

Fransioli, P.M.; Dixon, W.R.

1993-01-01

Site characterization at the Yucca Mountain site includes an ambient air quality and meteorological monitoring program to provide information for environmental and site characterization issues. The program is designed to provide data for four basic purposes: Atmospheric dispersion calculations to estimate impacts of possible airborne releases of radiological material; Engineering design and extreme weather event characterization; Local climate studies for environmental impact analyses and climate characterization; and, Air quality permits required for site characterization work. The program is compiling a database that will provide the basis for analyses and reporting related to the purposes of the program. Except for reporting particulate matter and limited meteorological data to the State of Nevada for an air quality permit condition, the data have yet to be formally analyzed and reported

ISS Ambient Air Quality: Updated Inventory of Known Aerosol Sources

Science.gov (United States)

Meyer, Marit

2014-01-01

Spacecraft cabin air quality is of fundamental importance to crew health, with concerns encompassing both gaseous contaminants and particulate matter. Little opportunity exists for direct measurement of aerosol concentrations on the International Space Station (ISS), however, an aerosol source model was developed for the purpose of filtration and ventilation systems design. This model has successfully been applied, however, since the initial effort, an increase in the number of crewmembers from 3 to 6 and new processes on board the ISS necessitate an updated aerosol inventory to accurately reflect the current ambient aerosol conditions. Results from recent analyses of dust samples from ISS, combined with a literature review provide new predicted aerosol emission rates in terms of size-segregated mass and number concentration. Some new aerosol sources have been considered and added to the existing array of materials. The goal of this work is to provide updated filtration model inputs which can verify that the current ISS filtration system is adequate and filter lifetime targets are met. This inventory of aerosol sources is applicable to other spacecraft, and becomes more important as NASA considers future long term exploration missions, which will preclude the opportunity for resupply of filtration products.

Impact of ambient air temperature and heat load variation on the performance of air-cooled heat exchangers in propane cycles in LNG plants – Analytical approach

International Nuclear Information System (INIS)

Fahmy, M.F.M.; Nabih, H.I.

2016-01-01

Highlights: • An analytical method regulated the air flow rate in an air-cooled heat exchanger. • Performance of an ACHE in a propane cycle in an LNG plant was evaluated. • Summer inlet air temperature had higher impact on ACHE air flow rate requirement. - Abstract: An analytical method is presented to evaluate the air flow rate required in an air-cooled heat exchanger used in a propane pre-cooling cycle operating in an LNG (liquefied natural gas) plant. With variable ambient air inlet temperature, the air flow rate is to be increased or decreased so as to assure and maintain good performance of the operating air-cooled heat exchanger at the designed parameters and specifications. This analytical approach accounts for the variations in both heat load and ambient air inlet temperature. The ambient air inlet temperature is modeled analytically by simplified periodic relations. Thus, a complete analytical method is described so as to manage the problem of determining and accordingly regulate, either manually or automatically, the flow rate of air across the finned tubes of the air-cooled heat exchanger and thus, controls the process fluid outlet temperature required for the air-cooled heat exchangers for both cases of constant and varying heat loads and ambient air inlet temperatures. Numerical results are obtained showing the performance of the air-cooled heat exchanger of a propane cycle which cools both NG (natural gas) and MR (mixed refrigerant) streams in the LNG plant located at Damietta, Egypt. The inlet air temperature variation in the summer time has a considerable effect on the required air mass flow rate, while its influence becomes relatively less pronounced in winter.

Assessment and remediation of odor emissions from a complex industrial facility (Ambient air odor regulations in Canada and the United States)

International Nuclear Information System (INIS)

Boose, T.; Reusing, G.

2002-01-01

This paper describes the findings of a review and presents examples of ambient air odor regulations in Canada and the United States. State and provincial odor regulations were reviewed and other metropolitan cities or counties (regions) that have separate odor regulations were also included. The key topics addressed in this paper include an assessment of the methods used for odor regulation and the methods used to evaluate the odor impact to determine compliance with the regulation. Three types of ambient air odor regulations were identified: 1. 28 States, Provinces and regions (jurisdictions) have specific odor regulations. These regulations generally define what constitutes an odor impact and typically provide requirements for remedial measures; 2. 25 jurisdictions regulate odors by a general prohibition regulation. These regulations define odor in ambient air as a condition of air pollution, nuisance or objectionable odor that would typically prevent persons from the enjoyment of life and property; and 3. 13 jurisdictions do not have specific or general prohibition regulations regarding odors. For the jurisdictions that have specific or general prohibition odor regulations, there are a number of different techniques used to define what constitutes an odor impact. Odor impacts are typically defined in a regulation by one (or more) of the following techniques: dilution to threshold, or odor unit limit; determination of odor emission rates; odor concentration limits for selected chemicals (ppm); comparison with the n-butanol intensity scale (1 to 8); and investigation by an agency investigator. Compliance with odor regulations is typically determined using one (or more) of the following field methods: odor stack testing and dispersion modelling; odor panel analysis of stack or ambient air samples; chemical monitoring (ppm); odor school certified / agency investigator; and scentometer. (author)

40 CFR Appendix R to Part 50 - Interpretation of the National Ambient Air Quality Standards for Lead

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Interpretation of the National Ambient Air Quality Standards for Lead R Appendix R to Part 50 Protection of Environment ENVIRONMENTAL.... 50, App. R Appendix R to Part 50—Interpretation of the National Ambient Air Quality Standards for...

Experimental Assessment of residential split type air-conditioning systems using alternative refrigerants to R-22 at high ambient temperatures

International Nuclear Information System (INIS)

Joudi, Khalid A.; Al-Amir, Qusay R.

2014-01-01

Highlights: • R290, R407C and R410A in residential split A/C units at high ambient. • 1 and 2 TR residential air conditioners with R22 alternatives at high ambient. • Residential split unit performance at ambients up to 55 °C with R22 alternatives. - Abstract: Steady state performance of residential air conditioning systems using R22 and alternatives R290, R407C, R410A, at high ambient temperatures, have been investigated experimentally. System performance parameters such as optimum refrigerant charge, coefficient of performance, cooling capacity, power consumption, pressure ratio, power per ton of refrigeration and TEWI environmental factor have been determined. All refrigerants were tested in the cooling mode operation under high ambient air temperatures, up to 55 °C, to determine their suitability. Two split type air conditioner of 1 and 2 TR capacities were used. A psychrometric test facility was constructed consisting of a conditioned cool compartment and an environmental duct serving the condenser. Air inside the conditioned compartment was maintained at 25 °C dry bulb and 19 °C wet bulb for all tests. In the environmental duct, the ambient air temperature was varied from 35 °C to 55 °C in 5 °C increments. The study showed that R290 is the better candidate to replace R22 under high ambient air temperatures. It has lower TEWI values and a better coefficient of performance than the other refrigerants tested. It is suitable as a drop-in refrigerant. R407C has the closest performance to R22, followed by R410A

Real-time measurements of secondary organic aerosol formation and aging from ambient air in an oxidation flow reactor in the Los Angeles area

Science.gov (United States)

Ortega, Amber M.; Hayes, Patrick L.; Peng, Zhe; Palm, Brett B.; Hu, Weiwei; Day, Douglas A.; Li, Rui; Cubison, Michael J.; Brune, William H.; Graus, Martin; Warneke, Carsten; Gilman, Jessica B.; Kuster, William C.; de Gouw, Joost; Gutiérrez-Montes, Cándido; Jimenez, Jose L.

2016-06-01

Field studies in polluted areas over the last decade have observed large formation of secondary organic aerosol (SOA) that is often poorly captured by models. The study of SOA formation using ambient data is often confounded by the effects of advection, vertical mixing, emissions, and variable degrees of photochemical aging. An oxidation flow reactor (OFR) was deployed to study SOA formation in real-time during the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign in Pasadena, CA, in 2010. A high-resolution aerosol mass spectrometer (AMS) and a scanning mobility particle sizer (SMPS) alternated sampling ambient and reactor-aged air. The reactor produced OH concentrations up to 4 orders of magnitude higher than in ambient air. OH radical concentration was continuously stepped, achieving equivalent atmospheric aging of 0.8 days-6.4 weeks in 3 min of processing every 2 h. Enhancement of organic aerosol (OA) from aging showed a maximum net SOA production between 0.8-6 days of aging with net OA mass loss beyond 2 weeks. Reactor SOA mass peaked at night, in the absence of ambient photochemistry and correlated with trimethylbenzene concentrations. Reactor SOA formation was inversely correlated with ambient SOA and Ox, which along with the short-lived volatile organic compound correlation, indicates the importance of very reactive (τOH ˜ 0.3 day) SOA precursors (most likely semivolatile and intermediate volatility species, S/IVOCs) in the Greater Los Angeles Area. Evolution of the elemental composition in the reactor was similar to trends observed in the atmosphere (O : C vs. H : C slope ˜ -0.65). Oxidation state of carbon (OSc) in reactor SOA increased steeply with age and remained elevated (OSC ˜ 2) at the highest photochemical ages probed. The ratio of OA in the reactor output to excess CO (ΔCO, ambient CO above regional background) vs. photochemical age is similar to previous studies at low to moderate ages and also extends to

Real-time measurements of secondary organic aerosol formation and aging from ambient air in an oxidation flow reactor in the Los Angeles area

Directory of Open Access Journals (Sweden)

A. M. Ortega

2016-06-01

Full Text Available Field studies in polluted areas over the last decade have observed large formation of secondary organic aerosol (SOA that is often poorly captured by models. The study of SOA formation using ambient data is often confounded by the effects of advection, vertical mixing, emissions, and variable degrees of photochemical aging. An oxidation flow reactor (OFR was deployed to study SOA formation in real-time during the California Research at the Nexus of Air Quality and Climate Change (CalNex campaign in Pasadena, CA, in 2010. A high-resolution aerosol mass spectrometer (AMS and a scanning mobility particle sizer (SMPS alternated sampling ambient and reactor-aged air. The reactor produced OH concentrations up to 4 orders of magnitude higher than in ambient air. OH radical concentration was continuously stepped, achieving equivalent atmospheric aging of 0.8 days–6.4 weeks in 3 min of processing every 2 h. Enhancement of organic aerosol (OA from aging showed a maximum net SOA production between 0.8–6 days of aging with net OA mass loss beyond 2 weeks. Reactor SOA mass peaked at night, in the absence of ambient photochemistry and correlated with trimethylbenzene concentrations. Reactor SOA formation was inversely correlated with ambient SOA and Ox, which along with the short-lived volatile organic compound correlation, indicates the importance of very reactive (τOH  ∼  0.3 day SOA precursors (most likely semivolatile and intermediate volatility species, S/IVOCs in the Greater Los Angeles Area. Evolution of the elemental composition in the reactor was similar to trends observed in the atmosphere (O : C vs. H : C slope  ∼  −0.65. Oxidation state of carbon (OSc in reactor SOA increased steeply with age and remained elevated (OSC  ∼  2 at the highest photochemical ages probed. The ratio of OA in the reactor output to excess CO (ΔCO, ambient CO above regional background vs. photochemical age is similar to

Measuring concentrations of selected air pollutants inside California vehicles. Final report

International Nuclear Information System (INIS)

Rodes, C.; Sheldon, L.; Whitaker, D.; Clayton, A.; Fitzgerald, K.

1999-01-01

This project measured 2-hour integrated concentrations of PM10, PM2.5, metals and a number of organic chemicals including benzene and MTBE inside vehicles on California roadways. Using continuous samplers, particle counts, black carbon, and CO were also measured. In addition to measuring in-vehicle levels, the investigators measured pollutant levels just outside the vehicle, at roadside stations, and ambient air monitoring stations. Different driving scenarios were designed to assess the effects of a number of factors on in-vehicle pollutant levels. These factors included roadway type, carpool lanes, traffic conditions, geographical locations, vehicle type, and vehicle ventilation conditions. The statewide average in-vehicle concentrations of benzene, MTBE, and formaldehyde ranged from 3--22 microg/m 3 , 3--90 microg/m 3 , and 0---22 microg/m 3 , respectively. The ranges of mean PM10 and PM2.5 in-vehicle levels in Sacramento were 20--40 microg/m 3 and 6--22 microg/m 3 , respectively. In general, pollutant levels inside or just outside the vehicles were higher than those measured at the roadside stations or the ambient air stations. In-vehicle pollutant levels were consistently higher in Los Angeles than Sacramento. Pollutant levels measured inside vehicles traveling in a carpool lane were much lower than those in the right-hand, slower lanes. Under the study conditions, factors such as vehicle type and ventilation and little effect on in-vehicle pollutant levels. Other factors, such as roadway type, freeway congestion level, and time-of-day had some influence on in-vehicle pollution levels

Relation of whole blood carboxyhemoglobin concentration to ambient carbon monoxide exposure estimated using regression.

Science.gov (United States)

Rudra, Carole B; Williams, Michelle A; Sheppard, Lianne; Koenig, Jane Q; Schiff, Melissa A; Frederick, Ihunnaya O; Dills, Russell

2010-04-15

Exposure to carbon monoxide (CO) and other ambient air pollutants is associated with adverse pregnancy outcomes. While there are several methods of estimating CO exposure, few have been evaluated against exposure biomarkers. The authors examined the relation between estimated CO exposure and blood carboxyhemoglobin concentration in 708 pregnant western Washington State women (1996-2004). Carboxyhemoglobin was measured in whole blood drawn around 13 weeks' gestation. CO exposure during the month of blood draw was estimated using a regression model containing predictor terms for year, month, street and population densities, and distance to the nearest major road. Year and month were the strongest predictors. Carboxyhemoglobin level was correlated with estimated CO exposure (rho = 0.22, 95% confidence interval (CI): 0.15, 0.29). After adjustment for covariates, each 10% increase in estimated exposure was associated with a 1.12% increase in median carboxyhemoglobin level (95% CI: 0.54, 1.69). This association remained after exclusion of 286 women who reported smoking or being exposed to secondhand smoke (rho = 0.24). In this subgroup, the median carboxyhemoglobin concentration increased 1.29% (95% CI: 0.67, 1.91) for each 10% increase in CO exposure. Monthly estimated CO exposure was moderately correlated with an exposure biomarker. These results support the validity of this regression model for estimating ambient CO exposures in this population and geographic setting.

Seasonal and temporal variations of criteria air pollutants and the influence of meteorological parameters on the concentration of pollutants in ambient air in lahore, pakistan

International Nuclear Information System (INIS)

Tabinda, A.B.; Munir, S.; Yasir, A.; Ilyas, A.

2016-01-01

Criteria air pollutants have their significance for causing health threats and damage to the environment. The study was conducted to assess the seasonal and temporal variations of criteria air pollutants and evaluating the correlations of criteria air pollutants with meteorological parameters in the city of Lahore, Pakistan for a period of one year from April 2010 to March 2011. The concentrations of criteria air pollutants were determined at fixed monitoring stations equipped with HORIBA analyzers. The annual average concentrations (μ/m/super 3/) of PM /sub 2.5/, O/sub 3/, SO/sub 2/, CO and NO/sub x/ (NO+NO/sub 2/) for this study period were 118.94±57.46, 46.0±24.2, 39.9±8.9, 1940±1300 and 130.9±81.0 (61.8±46.2+57.3±22.19), respectively. PM/sub 2.5/, SO/sub 2/, CO and NO/sub x/ had maximum concentrations during winter whereas O/sub 3/ had maximum concentration during summer. Minimum concentrations of PM/sub 2.5/, SO/sub 2/ and NO/sub x/ were found during monsoon as compared to other seasons due to rainfall which scavenged these pollutants. The O/sub 3/ showed positive correlation with temperature and solar radiation but negative correlation with wind speed. All other criteria air pollutants showed negative correlation with wind speed, temperature and solar radiation. A significant (P<0.01) correlation was found between NO/sub x/ and CO (r = 0.779) which showed that NO/sub x/ and CO arise from common source that could be the vehicular emission. PM/sub 2.5/ was significantly correlated (P<0.01) with NO/sub x/ (r = 0.524) and CO (r = 0.519), respectively. High traffic intensity and traffic jams were responsible for increased air pollutants level especially the PM/sub 2.5/, NO/sub x/ and CO. (author)

Pressure drop in packed beds of spherical particles at ambient and elevated air temperatures

Directory of Open Access Journals (Sweden)

Pešić Radojica

2015-01-01

Full Text Available The aim of this work was the experimental investigation of the particle friction factor for air flow through packed bed of particles at ambient and elevated temperatures. The experiments were performed by measuring the pressure drop across the packed bed, heated to the desired temperature by hot air. Glass spherical particles of seven different diameters were used. The temperature range of the air flowing through the packed bed was from 20ºC to 350ºC and the bed voidages were from 0.3574 to 0.4303. The obtained results were correlated using a number of available literature correlations. The overall best fit of all of the experimental data was obtained using Ergun [1] equation, with mean absolute deviation of 10.90%. Ergun`s equation gave somewhat better results in correlating the data at ambient temperature with mean absolute deviation of 9.77%, while correlation of the data at elevated temperatures gave mean absolute deviation of 12.38%. The vast majority of the correlations used gave better results when applied to ambient temperature data than to the data at elevated temperatures. Based on the results obtained, Ergun [1] equation is proposed for friction factor calculation both at ambient and at elevated temperatures. [Projekat Ministarstva nauke Republike Srbije, br. ON172022

Neurobehavioral effects of ambient air pollution on cognitive performance in US adults.

Science.gov (United States)

Chen, Jiu-Chiuan; Schwartz, Joel

2009-03-01

In vivo animal experiments demonstrate neurotoxicity of exposures to particulate matter (PM) and ozone, but only one small epidemiological study had linked ambient air pollution with central nervous system (CNS) functions in children. To examine the neurobehavioral effects associated with long-term exposure to ambient PM and ozone in adults. We conducted a secondary analysis of the Neurobehavioral Evaluation System-2 (NES2) data (including a simple reaction time test [SRTT] measuring motor response speed to a visual stimulus; a symbol-digit substitution test [SDST] for coding ability; and a serial-digit learning test [SDLT] for attention and short-term memory) from 1764 adult participants (aged 37.5+/-10.9 years) of the Third National Health and Nutrition Examination Survey in 1988-1991. Based on ambient PM(10) (PM with aerodynamic diameter SDLT, but not in SRTT. Each 10-ppb increase in annual ozone was associated with increased SDST and SDLT scores by 0.16 (95%CI: 0.01, 0.23) and 0.56 (95%CI: 0.07, 1.05), equivalent to 3.5 and 5.3 years of aging-related decline in cognitive performance. Our study provides the first epidemiological data supporting the adverse neurobehavioral effects of ambient air pollutants in adults.

40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

Science.gov (United States)

2010-07-01

... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data.... Primary and Secondary Ambient Air Quality Standards for Ozone. 2.1 Data Reporting and Handling Conventions... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of...

Low-level NOx removal in ambient air by pulsed corona technology

International Nuclear Information System (INIS)

Beckers, F J C M; Hoeben, W F L M; Pemen, A J M; Van Heesch, E J M

2013-01-01

Although removal of NO x by (pulsed) corona discharges has been thoroughly investigated for high concentrations of NO x in flue gas, removal of low levels in ambient air proves to be a difficult task. (Sub) ppm NO x levels exist in traffic tunnels due to accumulation of exhaust gases. The application of pulsed corona technology for purification of traffic tunnel air is studied during a series of lab and field experiments. An industrial pilot scale wire-cylinder type corona reactor has been utilized. Lab tests have been carried out using a diesel generator as NO x source. NO x conversion levels have been determined by applying two Recordum Airpointers (chemiluminescence-based detection). The detector appeared to be cross-sensitive for HNO 3 and high levels of O 3 . NO x removal rates of 60–80% were obtained for inlet levels of 2–10 ppm. The SIE value of 10 ppm NO x removal is 7 J l −1 . The corona discharges produce ppm level NO x at high energy densities. This intrinsic NO x production limits removal of inlet levels due to equilibrium between production and oxidation. (paper)

Meso-scale wrinkled coatings to improve heat transfers of surfaces facing ambient air

International Nuclear Information System (INIS)

Kakiuchida, Hiroshi; Tajiri, Koji; Tazawa, Masato; Yoshimura, Kazuki; Shimono, Kazuaki; Nakagawa, Yukio; Takahashi, Kazuhiro; Fujita, Keisuke; Myoko, Masumi

2015-01-01

Meso-scale (micrometer-to submillimeter-scale) wrinkled surfaces coated on steel sheets used in outdoor storage and transport facilities for industrial low-temperature liquids were discovered to efficiently increase convective heat transfer between ambient air and the surface. The radiative and convective heat transfer coefficients of various wrinkled surfaces, which were formed by coating steel sheets with several types of shrinkable paints, were examined. The convective heat transfer coefficient of a surface colder than ambient air monotonically changed with average height difference and interval distance of the wrinkle undulation, where the proportions were 0.0254 and 0.0054 W/m 2 /K/μm, respectively. With this wrinkled coating, users can lower the possibility of condensation and reduce rust and maintenance cost of facilities for industrial low-temperature liquids. From the point of view of manufacturers, this coating method can be easily adapted to conventional manufacturing processes. - Highlights: • Various wrinkled surfaces were fabricated by a practical process. • Topographical effect on convection was parameterized separately from radiation. • Meso-scale wrinkled coatings increased convective heat transfer with ambient air. • Maintenance cost of outdoor steel sheets due to condensation can be reduced

The Effect of Future Ambient Air Pollution on Human Premature Mortality to 2100 Using Output from the ACCMIP Model Ensemble

Science.gov (United States)

Silva, Raquel A.; West, J. Jason; Lamarque, Jean-Francois; Shindell, Drew T.; Collins, William J.; Dalsoren, Stig; Faluvegi, Greg; Folberth, Gerd; Horowitz, Larry W.; Nagashima, Tatsuya;

The effect of future ambient air pollution on human premature mortality to 2100 using output from the ACCMIP model ensemble

Directory of Open Access Journals (Sweden)

R. A. Silva

2016-08-01

Full Text Available Ambient air pollution from ground-level ozone and fine particulate matter (PM2.5 is associated with premature mortality. Future concentrations of these air pollutants will be driven by natural and anthropogenic emissions and by climate change. Using anthropogenic and biomass burning emissions projected in the four Representative Concentration Pathway scenarios (RCPs, the ACCMIP ensemble of chemistry–climate models simulated future concentrations of ozone and PM2.5 at selected decades between 2000 and 2100. We use output from the ACCMIP ensemble, together with projections of future population and baseline mortality rates, to quantify the human premature mortality impacts of future ambient air pollution. Future air-pollution-related premature mortality in 2030, 2050 and 2100 is estimated for each scenario and for each model using a health impact function based on changes in concentrations of ozone and PM2.5 relative to 2000 and projected future population and baseline mortality rates. Additionally, the global mortality burden of ozone and PM2.5 in 2000 and each future period is estimated relative to 1850 concentrations, using present-day and future population and baseline mortality rates. The change in future ozone concentrations relative to 2000 is associated with excess global premature mortality in some scenarios/periods, particularly in RCP8.5 in 2100 (316 thousand deaths year−1, likely driven by the large increase in methane emissions and by the net effect of climate change projected in this scenario, but it leads to considerable avoided premature mortality for the three other RCPs. However, the global mortality burden of ozone markedly increases from 382 000 (121 000 to 728 000 deaths year−1 in 2000 to between 1.09 and 2.36 million deaths year−1 in 2100, across RCPs, mostly due to the effect of increases in population and baseline mortality rates. PM2.5 concentrations decrease relative to 2000 in all scenarios

Seasonal variations of ambient air mercury species nearby an airport

Science.gov (United States)

Fang, Guor-Cheng; Tsai, Kai-Hsiang; Huang, Chao-Yang; Yang, Kuang-Pu Ou; Xiao, You-Fu; Huang, Wen-Chuan; Zhuang, Yuan-Jie

2018-04-01

This study focuses on the collection of ambient air mercury species (total gaseous mercury (TGM), reactive gaseous mercury (RGM), gaseous element mercury (GEM) and particulate bound mercury (PBM) pollutants at airport nearby sampling site during the year of Apr. 2016 to Mar. 2017 by using Four-stage gold amalgamation and denuder. The results indicated that the average TGM, RGM and GEM concentrations were 5.04 ± 2.43 ng/m3, 29.58 ± 80.54 pg/m3, 4.70 ± 2.63 ng/m3, respectively during the year of Apr. 2016 to Mar. 2017 (n = 49) period at this airport sampling site nearby. In addition, the results also indicated that the average PBM concentrations in TSP and PM2.5 were 0.35 ± 0.08 ng/m3 and 0.09 ± 0.03 ng/m3, respectively. And the average PBM in TSP concentrations order follows as summer > autumn > spring > winter, while the average PBM in PM2.5 concentrations order follows as spring > summer > winter > autumn. Moreover, the average TGM, RGM and GEM concentrations order follow as spring > summer > autumn > winter. Finally, the Asian continent has the highest average mercury species concentrations (TGM, RGM, GEM and PBM) when compared with the American and European continents, and the average mercury species concentrations (TGM, RGM, GEM and PBM) displayed declined trends for North America (United States and Canada) and Europe (Spain, Sweden and Southern Baltic) during the years of 2004-2014. Also noteworthy is that the average mercury species concentrations (TGM, RGM, GEM) displayed increasing trends in China and Taiwan during the years of 2008-2016. Japan and Korea are the only two exceptions. Those above two countries mercury species concentrations displayed decreasing trends during years of 2008-2015.

Ambient air pollution, lung function, and airway responsiveness in asthmatic children

NARCIS (Netherlands)

Ierodiakonou, Despo; Zanobetti, Antonella; Coull, Brent A.; Melly, Steve; Postma, Dirkje S.; Boezen, H. Marike; Vonk, Judith M.; Williams, Paul V.; Shapiro, Gail G.; McKone, Edward F.; Hallstrand, Teal S.; Koenig, Jane Q.; Schildcrout, Jonathan S.; Lumley, Thomas; Fuhlbrigge, Anne N.; Koutrakis, Petros; Schwartz, Joel; Weiss, Scott T.; Gold, Diane R.

BACKGROUND: Although ambient air pollution has been linked to reduced lung function in healthy children, longitudinal analyses of pollution effects in asthmatic patients are lacking. OBJECTIVE: We sought to investigate pollution effects in a longitudinal asthma study and effect modification by

Experimental analysis of the thermal entrainment factor of air curtains in vertical open display cabinets for different ambient air conditions

International Nuclear Information System (INIS)

Gaspar, Pedro Dinis; Carrilho Goncalves, L.C.; Pitarma, R.A.

2011-01-01

The vertical open refrigerated display cabinets suffer alterations of their thermal performance and energy efficiency due to variations of ambient air conditions. The air curtain provides an aerothermodynamics insulation effect that can be evaluated by the thermal entrainment factor calculation as an engineering approximation or by the calculus of all sensible and latent thermal loads. This study presents the variation of heat transfer rate and thermal entrainment factor obtained through experimental tests carried out for different ambient air conditions, varying air temperature, relative humidity, velocity and its direction relatively to the display cabinet frontal opening. The thermal entrainment factor are analysed and compared with the total sensible and latent heats results for the experimental tests. From an engineering point of view, it is concluded that thermal entrainment factor cannot be used indiscriminately, although its use is suitable to design better cabinet under the same climate class condition.

75 FR 81477 - Approval and Promulgation of Air Quality Implementation Plans; Virginia; Amendments to Ambient...

Science.gov (United States)

2010-12-28

... Abatement of Air Pollution: 9VAC5 Chapter 30--Ambient Air Quality Standards incorporates the annual and 24... Commonwealth and takes prompt and appropriate measures to remedy the violations. Virginia's Voluntary... CFR Part 52 Environmental protection, Air pollution control, Incorporation by reference, Nitrogen...

The Effects of Urban Form on Ambient Air Pollution and Public Health Risk: A Case Study in Raleigh, North Carolina

Science.gov (United States)

Rodriguez, Daniel A.; Huegy, Joseph; Gibson, Jacqueline MacDonald

2014-01-01

Since motor vehicles are a major air pollution source, urban designs that decrease private automobile use could improve air quality and decrease air pollution health risks. Yet, the relationships among urban form, air quality, and health are complex and not fully understood. To explore these relationships, we model the effects of three alternative development scenarios on annual average fine particulate matter (PM2.5) concentrations in ambient air and associated health risks from PM2.5 exposure in North Carolina’s Raleigh-Durham-Chapel Hill area. We integrate transportation demand, land-use regression, and health risk assessment models to predict air quality and health impacts for three development scenarios: current conditions, compact development, and sprawling development. Compact development slightly decreases (−0.2%) point estimates of regional annual average PM2.5 concentrations, while sprawling development slightly increases (+1%) concentrations. However, point estimates of health impacts are in opposite directions: compact development increases (+39%) and sprawling development decreases (−33%) PM2.5-attributable mortality. Further, compactness increases local variation in PM2.5 concentrations and increases the severity of local air pollution hotspots. Hence, this research suggests that while compact development may improve air quality from a regional perspective, it may also increase the concentration of PM2.5 in local hotspots and increase population exposure to PM2.5. Health effects may be magnified if compact neighborhoods and PM2.5 hotspots are spatially co-located. We conclude that compactness alone is an insufficient means of reducing the public health impacts of transportation emissions in automobile-dependent regions. Rather, additional measures are needed to decrease automobile dependence and the health risks of transportation emissions. PMID:25490890

Ambient air monitoring for organic compounds, acids, and metals at Los Alamos National Laboratory, January 1991

International Nuclear Information System (INIS)

Williams, C.H.; Eberhart, C.F.

1992-01-01

Los Alamos National Laboratory (LANL) contracted Radian Corporation (Radian) to conduct a short-term, intensive air monitoring program whose goal was to estimate the impact of chemical emissions from LANL on the ambient air environment. A comprehensive emission inventory had identified more than 600 potential air contaminants in LANL's emissions. A subset of specific target chemicals was selected for monitoring: 20 organic vapors, 6 metals and 5 inorganic acid vapors. These were measured at 5 ground level sampling sites around LANL over seven consecutive days in January 1991. The sampling and analytical strategy used a combination of EPA and NIOSH methods modified for ambient air applications

System for measuring of air concentration in air-steam mixture during the transients

International Nuclear Information System (INIS)

Gorbenko, Gennady A.; Gakal, Pavlo G.; Epifanov, Konstantin S.; Osokin, Gennady V.; Smirnov, Sergey V.

2006-01-01

Description of system for air concentration measuring in air-steam mixture during the transients is represented. Air concentration measuring is based on discrete sampling method. The measuring system consists of sampler, transport pipeline, distributor and six measuring vessels. From the sampler air-steam mixture comes to distributor through transport pipeline and fills consecutively the measuring vessels. The true air concentration in place of measurement was defined based on measured air concentration in samples taken from measuring vessels. For this purpose, the mathematical model of transients in measuring system was developed. Air concentration transient in air-steam mixture in place of measurement was described in mathematical model by air concentration time-dependent function. The function parameters were defined based on air concentration measured in samples taken from measuring vessels. Estimated error of air concentration identification was about 10%. Measuring system was used in experiments on EREC BKV-213 test facility intended for testing of VVER-440/V-213 reactor barbotage-vacuum system

Impact of emissions from natural gas production facilities on ambient air quality in the Barnett Shale area: a pilot study.

Science.gov (United States)

Zielinska, Barbara; Campbell, Dave; Samburova, Vera

2014-12-01

Rapid and extensive development of shale gas resources in the Barnett Shale region of Texas in recent years has created concerns about potential environmental impacts on water and air quality. The purpose of this study was to provide a better understanding of the potential contributions of emissions from gas production operations to population exposure to air toxics in the Barnett Shale region. This goal was approached using a combination of chemical characterization of the volatile organic compound (VOC) emissions from active wells, saturation monitoring for gaseous and particulate pollutants in a residential community located near active gas/oil extraction and processing facilities, source apportionment of VOCs measured in the community using the Chemical Mass Balance (CMB) receptor model, and direct measurements of the pollutant gradient downwind of a gas well with high VOC emissions. Overall, the study results indicate that air quality impacts due to individual gas wells and compressor stations are not likely to be discernible beyond a distance of approximately 100 m in the downwind direction. However, source apportionment results indicate a significant contribution to regional VOCs from gas production sources, particularly for lower-molecular-weight alkanes (gas production. Implications: Rapid and extensive development of shale gas resources in recent years has created concerns about potential environmental impacts on water and air quality. This study focused on directly measuring the ambient air pollutant levels occurring at residential properties located near natural gas extraction and processing facilities, and estimating the relative contributions from gas production and motor vehicle emissions to ambient VOC concentrations. Although only a small-scale case study, the results may be useful for guidance in planning future ambient air quality studies and human exposure estimates in areas of intensive shale gas production.

Ambient carbon monoxide and daily mortality in three Chinese cities: the China Air Pollution and Health Effects Study (CAPES).

Science.gov (United States)

Chen, Renjie; Pan, Guowei; Zhang, Yanping; Xu, Qun; Zeng, Guang; Xu, Xiaohui; Chen, Bingheng; Kan, Haidong

2011-11-01

Ambient carbon monoxide (CO) is an air pollutant primarily generated by traffic. CO has been associated with increased mortality and morbidity in developed countries, but few studies have been conducted in Asian developing countries. In the China Air Pollution and Health Effects Study (CAPES), the short-term associations between ambient CO and daily mortality were examined in three Chinese cities: Shanghai, Anshan and Taiyuan. Poisson regression models incorporating natural spline smoothing functions were used to adjust for long-term and seasonal trend of mortality, as well as other time-varying covariates. Effect estimates were obtained for each city and then for the cities combined. In both individual-city and combined analysis, significant associations of CO with both total non-accidental and cardiovascular mortality were observed. In the combined analysis, a 1 mg/m(3) increase of 2-day moving average concentrations of CO corresponded to 2.89% (95%CI: 1.68, 4.11) and 4.17% (95%CI: 2.66, 5.68) increase of total and cardiovascular mortality, respectively. CO was not significantly associated with respiratory mortality. Sensitivity analyses showed that our findings were generally insensitive to alternative model specifications. In conclusion, ambient CO was associated with increased risk of daily mortality in these three cities. Our findings suggest that the role of exposure to CO and other traffic-related air pollutants should be further investigated in China. Copyright © 2011 Elsevier B.V. All rights reserved.

Time series analysis of ambient air concentrations in Alexandria and Nile delta region, Egypt

International Nuclear Information System (INIS)

EI Raev, M.; Shalaby, E.A.; Ghatass, Z.F.; Marey, H.S.

2007-01-01

Data collected from the Air Monitoring Network of Alexandria and Delta (EEAA/EIMP-program), were analyzed. Emphasis is given to indicator pollutants PM 10 , NO 2 , SO 2 , O 3 and CO. Two sites have been selected in Alexandria (IGSR and Shohada) and three sites in Delta region (Kafr Elzyat, Mansoura and Mahalla) for analysis of three years from 2000-2002. Box -Jenkins modeling has been used mainly for forecasting and assessing relative importance of various parameters or pollutants. Results showed that, the autoregressive (AR) order for all series ranged from 0-2 except NO 2 at Mansoura site. Also the moving average order ranged from 0-2 except CO at IGSR site. Nitrogen dioxide and Ozone at IGSR site have the same ARIMA model which is (0, 1, and 2). Cross correlation analysis has revealed important information on the dynamics, chemistry and interpretation of ambient pollution. Cross-correlation functions of SO 2 and PM 10 at IGSR sites suggest that, sulfur dioxide has been adsorbed on the surface of particulates which has an alkaline nature. This enhances the oxidation of sulfur dioxide to sulfate, which results in low levels of SO 2 in spite of the presence of sources

40 CFR Appendix P to Part 50 - Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone

Science.gov (United States)

2010-07-01

... the data handling procedures for the reported data). 2.3Comparisons with the Primary and Secondary... Secondary National Ambient Air Quality Standards for Ozone P Appendix P to Part 50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY...

Changes in gene expression in chronic allergy mouse model exposed to natural environmental PM2.5-rich ambient air pollution.

Science.gov (United States)

Ouyang, Yuhui; Xu, Zhaojun; Fan, Erzhong; Li, Ying; Miyake, Kunio; Xu, Xianyan; Zhang, Luo

2018-04-20

Particulate matter (PM) air pollution has been associated with an increase in the incidence of chronic allergic diseases; however, the mechanisms underlying the effect of exposure to natural ambient air pollution in chronic allergic diseases have not been fully elucidated. In the present study, we aimed to investigate the cellular responses induced by exposure to natural ambient air pollution, employing a mouse model of chronic allergy. The results indicated that exposure to ambient air pollution significantly increased the number of eosinophils in the nasal mucosa. The modulation of gene expression profile identified a set of regulated genes, and the Triggering Receptor Expressed on Myeloid cells1(TREM1) signaling canonical pathway was increased after exposure to ambient air pollution. In vitro, PM2.5 increased Nucleotide-binding oligomerization domain-containing protein 1 (Nod1) and nuclear factor (NF)-κB signaling pathway activation in A549 and HEK293 cell cultures. These results suggest a novel mechanism by which, PM2.5 in ambient air pollution may stimulate the innate immune system through the PM2.5-Nod1-NF-κB axis in chronic allergic disease.

Occurrence of currently used pesticides in ambient air of Centre Region (France)

Science.gov (United States)

Coscollà, Clara; Colin, Patrice; Yahyaoui, Abderrazak; Petrique, Olivier; Yusà, Vicent; Mellouki, Abdelwahid; Pastor, Agustin

2010-10-01

Ambient air samples were collected, from 2006 to 2008 at three rural and two urban sites in Centre Region (France) and analyzed for 56 currently used pesticides (CUPs), of which 41 were detected. The four CUPs most frequently detected were the herbicides trifluralin, acetochlor and pendimethalin and the fungicide chlorothalonil, which were found with frequencies ranging between 52 and 78%, and with average concentrations of 1.93, 1.32, 1.84 and 12.15 ng m -3, respectively. Among the detected pesticides, concentrations of eight fungicides (spiroxamine, fenpropimorph, cyprodinil, tolyfluanid, epoxiconazole, vinchlozolin, fluazinam, fludioxinil), two insecticides (propargite, ethoprophos), and one herbicide (oxyfluorfen) are, to our knowledge, reported for the first time in the literature. The majority of the CUPs showed a seasonal trend, with most of the detections and the highest concentrations occurring during the spring and early summer. The most important pesticides detected were related to arable crops and fruit orchards, the main cultures in this region, highlighting the fact that the main sources come from local applications. Minor differences were found in the profiles of pesticides within rural areas and between rural and urban areas.

The determination of nitrogen dioxide in ambient air with free hanging filters as passive samplers, and a new calibration method using fritted bubblers.

Science.gov (United States)

Heeres, Paul; Setiawan, Rineksa; Krol, Maarten Cornelis; Adema, Eduard Hilbrand

2009-12-01

This paper describes two new methods for the determination of NO(2) in the ambient air. The first method consists of free hanging filters with a diameter of 2.5 cm as passive samplers. The filters are impregnated with triethanolamine to bind NO(2). With standard colorimetrical analysis, the amount of NO(2) on the filters is determined. The second method is performed with fritted bubblers filled with Saltzman reagent, where, with a special procedure the absorption efficiencies of the bubblers are determined using ambient air, without the use of standard gases and electronic analytical instruments. The results of the bubblers are used to calibrate the free hanging filters. The two methods were applied simultaneously in the city of Yogyakarta, Indonesia. The methods are inexpensive and very well suited for use in low-budget situations. A characteristic of the free filter is the Sampling Volume, SV. This is the ratio of the amount of NO(2) on the filter and the ambient concentration. With the filter used in this study, the amount of triethanolamine and exposure time, the SV is 0.0166 m(3). The sampling rate (SR) of the filter, 4.6 cm(3)/s, is high. Hourly averaged measurements are performed for 15 hours per day in four busy streets. The measured amounts of NO(2) on the filters varied between 0.57 and 2.02 microg NO(2), at ambient air concentrations of 32 to 141 microg/m(3) NO(2). During the experiments the wind velocity was between 0.2 and 2.0 m/s, the relative humidity between 24 and 83 % and the temperature between 295 K and 311 K. These variations in weather conditions have no influence on the uptake of NO(2).

Short-term effects of ambient air pollution on pediatric outpatient visits for respiratory diseases in Yichang city, China

International Nuclear Information System (INIS)

Liu, Yuewei; Xie, Shuguang; Yu, Qing; Huo, Xixiang; Ming, Xiaoyan; Wang, Jing; Zhou, Yun; Peng, Zhe; Zhang, Hai; Cui, Xiuqing; Xiang, Hua; Huang, Xiji; Zhou, Ting; Chen, Weihong; Shi, Tingming

2017-01-01

Previous studies have suggested that short-term exposure to ambient air pollution was associated with pediatric hospital admissions and emergency room visits for certain respiratory diseases; however, there is limited evidence on the association between short-term air pollution exposure and pediatric outpatient visits. Our aim was to quantitatively assess the short-term effects of ambient air pollution on pediatric outpatient visits for respiratory diseases. We conducted a time-series study in Yichang city, China between Jan 1, 2014 and Dec 31, 2015. Daily counts of pediatric respiratory outpatient visits were collected from 3 large hospitals, and then linked with air pollution data from 5 air quality monitoring stations by date. We used generalized additive Poisson models to conduct linear and nonlinear exposure-response analyses between air pollutant exposures and pediatric respiratory outpatient visits, adjusting for seasonality, day of week, public holiday, temperature, and relative humidity. Each interquartile range (IQR) increase in PM 2.5 (lag 0), PM 10 (lag 0), NO 2 (lag 0), CO (lag 0), and O 3 (lag 4) concentrations was significantly associated with a 1.91% (95% CI: 0.60%, 3.23%), 2.46% (1.09%, 3.85%), 1.88% (0.49%, 3.29%), 2.00% (0.43%, 3.59%), and 1.91% (0.45%, 3.39%) increase of pediatric respiratory outpatient visits, respectively. Similarly, the nonlinear exposure-response analyses showed monotonic increases of pediatric respiratory outpatient visits by increasing air pollutant exposures, though the associations for NO 2 and CO attenuated at higher concentrations. These associations were unlikely modified by season. We did not observe significant association for SO 2 exposure. Our results suggest that short-term exposures to PM 2.5 , PM 10 , NO 2 , CO, and O 3 may account for increased risk of pediatric outpatient visits for respiratory diseases, and emphasize the needs for reduction of air pollutant exposures for children. - Highlights: • PM 2

Unexpected O and O3 production in the effluent of He/O2 microplasma jets emanating into ambient air

International Nuclear Information System (INIS)

Ellerweg, D; Von Keudell, A; Benedikt, J

2012-01-01

Microplasma jets are commonly used to treat samples in ambient air. The effect of admixing air into the effluent may severely affect the composition of the emerging species. Here, the effluent of a He/O 2 microplasma jet has been analyzed in a helium and in an air atmosphere by molecular beam mass spectrometry. First, the composition of the effluent in air was recorded as a function of the distance to determine how fast air admixes into the effluent. Then, the spatial distribution of atomic oxygen and ozone in the effluent was recorded in ambient air and compared with measurements in a helium atmosphere. Additionally, a fluid model of the gas flow with reaction kinetics of reactive oxygen species in the effluent was constructed. In ambient air, the O density declines only slightly faster with distance compared with a helium atmosphere. In contrast, the O 3 density in ambient air increases significantly faster with distance compared with a helium atmosphere. This unexpected behavior cannot be explained by simple recombination reactions of O atoms with O 2 molecules. A reaction scheme involving the reaction of plasma-produced excited O 2 * species of unknown identity with ground state O 2 molecules is proposed as a possible explanation for these observations. (paper)

Programming of mouse obesity by maternal exposure to concentrated ambient fine particles.

Science.gov (United States)

Chen, Minjie; Wang, Xiaoke; Hu, Ziying; Zhou, Huifen; Xu, Yanyi; Qiu, Lianglin; Qin, Xiaobo; Zhang, Yuhao; Ying, Zhekang

2017-06-23

Many diseases including obesity may originate through alterations in the early-life environment that interrupts fetal development. Increasing evidence has shown that exposure to ambient fine particles (PM 2.5 ) is associated with abnormal fetal development. However, its long-term metabolic effects on offspring have not been systematically investigated. To determine if maternal exposure to PM 2.5 programs offspring obesity, female C57Bl/6j mice were exposed to filtered air (FA) or concentrated ambient PM 2.5 (CAP) during pre-conception, pregnancy, and lactation, and the developmental and metabolic responses of offspring were assessed. The growth trajectory of offspring revealed that maternal exposure to CAP significantly decreased offspring birth weight but increased body weight of adult male but not female offspring, and the latter was expressed as increased adiposity. These adult male offspring had increased food intake, but were sensitive to exogenous leptin. Their hypothalamic expression of Socs3 and Pomc, two target genes of leptin, was not changed, and the hypothalamic expression of NPY, an orexigenic peptide that is inhibited by leptin, was significantly increased. These decreases in central anorexigenic signaling were accompanied by reduced plasma leptin and its expression in adipose tissues, the primary source of circulating leptin. In contrast, maternal exposure did not significantly change any of these indexes in adult female offspring. Pyrosequencing demonstrated that the leptin promoter methylation of adipocytes was significantly increased in CAP-exposed male but not female offspring. Our data indicate that maternal exposure to ambient PM 2.5 programs obesity in male offspring probably through alterations in the methylation of the promoter region of the leptin gene.

Effects of ambient oxygen concentration on biodiesel and diesel spray combustion under simulated engine conditions

KAUST Repository

Zhang, Ji

2013-08-01

This study investigates the effect of ambient oxygen concentration on biodiesel and diesel spray combustion under simulated compression-ignition engine conditions in a constant-volume chamber. The apparent heat release rate (AHRR) is calculated based on the measured pressure. High-speed imaging of OH* chemiluminescence and natural luminosity (NL) is employed to visualize the combustion process. Temporally and spatially resolved NL and OH* contour plots are obtained. The result indicates that AHRR depends monotonically on the ambient oxygen concentration for both fuels. A lower oxygen concentration yields a slower AHRR increase rate, a lower peak AHRR value, but a higher AHRR value during the burn-out stage when compared with higher ambient oxygen concentration conditions. OH* chemiluminescence and NL contours indicate that biodiesel may experience a longer premixed-combustion duration. The 18% ambient O2 condition works better for biodiesel than diesel in reducing soot luminosity. With 12% O2, diesel combustion is significantly degraded. However, both fuels experience low temperature combustion at 10% O2. These results may imply that biodiesel is able to achieve the desired lower soot production under a moderate oxygen level with higher combustion efficiency, while diesel needs to be burned under very low ambient oxygen concentration for low soot production. © 2013 Elsevier Ltd.

Effects of ambient oxygen concentration on biodiesel and diesel spray combustion under simulated engine conditions

KAUST Repository

Zhang, Ji; Jing, Wei; Roberts, William L.; Fang, Tiegang

2013-01-01

This study investigates the effect of ambient oxygen concentration on biodiesel and diesel spray combustion under simulated compression-ignition engine conditions in a constant-volume chamber. The apparent heat release rate (AHRR) is calculated based on the measured pressure. High-speed imaging of OH* chemiluminescence and natural luminosity (NL) is employed to visualize the combustion process. Temporally and spatially resolved NL and OH* contour plots are obtained. The result indicates that AHRR depends monotonically on the ambient oxygen concentration for both fuels. A lower oxygen concentration yields a slower AHRR increase rate, a lower peak AHRR value, but a higher AHRR value during the burn-out stage when compared with higher ambient oxygen concentration conditions. OH* chemiluminescence and NL contours indicate that biodiesel may experience a longer premixed-combustion duration. The 18% ambient O2 condition works better for biodiesel than diesel in reducing soot luminosity. With 12% O2, diesel combustion is significantly degraded. However, both fuels experience low temperature combustion at 10% O2. These results may imply that biodiesel is able to achieve the desired lower soot production under a moderate oxygen level with higher combustion efficiency, while diesel needs to be burned under very low ambient oxygen concentration for low soot production. © 2013 Elsevier Ltd.

A Narrative Review on the Human Health Effects of Ambient Air Pollution in Sub-Saharan Africa: An Urgent Need for Health Effects Studies

Science.gov (United States)

Coker, Eric; Kizito, Samuel

2018-01-01

An important aspect of the new sustainable development goals (SDGs) is a greater emphasis on reducing the health impacts from ambient air pollution in developing countries. Meanwhile, the burden of human disease attributable to ambient air pollution in sub-Saharan Africa is growing, yet estimates of its impact on the region are possibly underestimated due to a lack of air quality monitoring, a paucity of air pollution epidemiological studies, and important population vulnerabilities in the region. The lack of ambient air pollution epidemiologic data in sub-Saharan Africa is also an important global health disparity. Thousands of air pollution health effects studies have been conducted in Europe and North America, rather than in urban areas that have some of the highest measured air pollution levels in world, including urban areas in sub-Saharan Africa. In this paper, we provide a systematic and narrative review of the literature on ambient air pollution epidemiological studies that have been conducted in the region to date. Our review of the literature focuses on epidemiologic studies that measure air pollutants and relate air pollution measurements with various health outcomes. We highlight the gaps in ambient air pollution epidemiological studies conducted in different sub-regions of sub-Saharan Africa and provide methodological recommendations for future environmental epidemiology studies addressing ambient air pollution in the region. PMID:29494501

A Narrative Review on the Human Health Effects of Ambient Air Pollution in Sub-Saharan Africa: An Urgent Need for Health Effects Studies.

Science.gov (United States)

Coker, Eric; Kizito, Samuel

2018-03-01

An important aspect of the new sustainable development goals (SDGs) is a greater emphasis on reducing the health impacts from ambient air pollution in developing countries. Meanwhile, the burden of human disease attributable to ambient air pollution in sub-Saharan Africa is growing, yet estimates of its impact on the region are possibly underestimated due to a lack of air quality monitoring, a paucity of air pollution epidemiological studies, and important population vulnerabilities in the region. The lack of ambient air pollution epidemiologic data in sub-Saharan Africa is also an important global health disparity. Thousands of air pollution health effects studies have been conducted in Europe and North America, rather than in urban areas that have some of the highest measured air pollution levels in world, including urban areas in sub-Saharan Africa. In this paper, we provide a systematic and narrative review of the literature on ambient air pollution epidemiological studies that have been conducted in the region to date. Our review of the literature focuses on epidemiologic studies that measure air pollutants and relate air pollution measurements with various health outcomes. We highlight the gaps in ambient air pollution epidemiological studies conducted in different sub-regions of sub-Saharan Africa and provide methodological recommendations for future environmental epidemiology studies addressing ambient air pollution in the region.

A Narrative Review on the Human Health Effects of Ambient Air Pollution in Sub-Saharan Africa: An Urgent Need for Health Effects Studies

Directory of Open Access Journals (Sweden)

Eric Coker

2018-03-01

Full Text Available An important aspect of the new sustainable development goals (SDGs is a greater emphasis on reducing the health impacts from ambient air pollution in developing countries. Meanwhile, the burden of human disease attributable to ambient air pollution in sub-Saharan Africa is growing, yet estimates of its impact on the region are possibly underestimated due to a lack of air quality monitoring, a paucity of air pollution epidemiological studies, and important population vulnerabilities in the region. The lack of ambient air pollution epidemiologic data in sub-Saharan Africa is also an important global health disparity. Thousands of air pollution health effects studies have been conducted in Europe and North America, rather than in urban areas that have some of the highest measured air pollution levels in world, including urban areas in sub-Saharan Africa. In this paper, we provide a systematic and narrative review of the literature on ambient air pollution epidemiological studies that have been conducted in the region to date. Our review of the literature focuses on epidemiologic studies that measure air pollutants and relate air pollution measurements with various health outcomes. We highlight the gaps in ambient air pollution epidemiological studies conducted in different sub-regions of sub-Saharan Africa and provide methodological recommendations for future environmental epidemiology studies addressing ambient air pollution in the region.

Time-varying cycle average and daily variation in ambient air pollution and fecundability.

Science.gov (United States)

Nobles, Carrie J; Schisterman, Enrique F; Ha, Sandie; Buck Louis, Germaine M; Sherman, Seth; Mendola, Pauline

2018-01-01

Does ambient air pollution affect fecundability? While cycle-average air pollution exposure was not associated with fecundability, we observed some associations for acute exposure around ovulation and implantation with fecundability. Ambient air pollution exposure has been associated with adverse pregnancy outcomes and decrements in semen quality. The LIFE study (2005-2009), a prospective time-to-pregnancy study, enrolled 501 couples who were followed for up to one year of attempting pregnancy. Average air pollutant exposure was assessed for the menstrual cycle before and during the proliferative phase of each observed cycle (n = 500 couples; n = 2360 cycles) and daily acute exposure was assessed for sensitive windows of each observed cycle (n = 440 couples; n = 1897 cycles). Discrete-time survival analysis modeled the association between fecundability and an interquartile range increase in each pollutant, adjusting for co-pollutants, site, age, race/ethnicity, parity, body mass index, smoking, income and education. Cycle-average air pollutant exposure was not associated with fecundability. In acute models, fecundability was diminished with exposure to ozone the day before ovulation and nitrogen oxides 8 days post ovulation (fecundability odds ratio [FOR] 0.83, 95% confidence interval [CI]: 0.72, 0.96 and FOR 0.84, 95% CI: 0.71, 0.99, respectively). However, particulate matter ≤10 microns 6 days post ovulation was associated with greater fecundability (FOR 1.25, 95% CI: 1.01, 1.54). Although our study was unlikely to be biased due to confounding, misclassification of air pollution exposure and the moderate study size may have limited our ability to detect an association between ambient air pollution and fecundability. While no associations were observed for cycle-average ambient air pollution exposure, consistent with past research in the United States, exposure during critical windows of hormonal variability was associated with prospectively measured couple

Comparison of background levels of culturable fungal spore concentrations in indoor and outdoor air in southeastern Austria

Science.gov (United States)

Haas, D.; Habib, J.; Luxner, J.; Galler, H.; Zarfel, G.; Schlacher, R.; Friedl, H.; Reinthaler, F. F.

2014-12-01

Background concentrations of airborne fungi are indispensable criteria for an assessment of fungal concentrations indoors and in the ambient air. The goal of this study was to define the natural background values of culturable fungal spore concentrations as reference values for the assessment of moldy buildings. The concentrations of culturable fungi were determined outdoors as well as indoors in 185 dwellings without visible mold, obvious moisture problems or musty odor. Samples were collected using the MAS-100® microbiological air sampler. The study shows a characteristic seasonal influence on the background levels of Cladosporium, Penicillium and Aspergillus. Cladosporium sp. had a strong outdoor presence, whereas Aspergillus sp. and Penicillium sp. were typical indoor fungi. For the region of Styria, the median outdoor concentrations are between 100 and 940 cfu/m³ for culturable xerophilic fungi in the course of the year. Indoors, median background levels are between 180 and 420 cfu/m³ for xerophilic fungi. The I/O ratios of the airborne fungal spore concentrations were between 0.2 and 2.0. For the assessment of indoor and outdoor air samples the dominant genera Cladosporium, Penicillium and Aspergillus should receive special consideration.

Maternal exposure to ambient air pollution and fetal growth in North-East Scotland: A population-based study using routine ultrasound scans.

Science.gov (United States)

Clemens, Tom; Turner, Steve; Dibben, Chris

2017-10-01

Maternal ambient air pollution exposure is associated with reduced birthweight. Few studies have examined the effect on growth in utero and none have examined the effect of exposure to particulates less than 2.5µm (PM 2.5 ) and possible effect modification by smoking status. Examine the effect of maternal exposure to ambient concentrations of PM 10 , PM 2.5 and nitrogen dioxide (NO 2 ) for in utero fetal growth, size at birth and effect modification by smoking status. Administratively acquired second and third trimester fetal measurements (bi-parietal diameter, femur length and abdominal circumference), birth outcomes (weight, crown heel length and occipito-frontal circumference) and maternal details were obtained from routine fetal ultrasound scans and maternity records (period 1994-2009). These were modelled against residential annual pollution concentrations (calendar year mean) adjusting for covariates and stratifying by smoking status. In the whole sample (n=13,775 pregnancies), exposure to PM 10 , PM 2.5 and NO 2 was associated with reductions in measurements at birth and biparietal diameter from late second trimester onwards. Among mothers who did not smoke at all during pregnancy (n=11,075), associations between biparietal diameter and pollution exposure remained significant but were insignificant among those who did smoke (n=2700). Femur length and abdominal circumference were not significantly associated with pollution exposure. Fetal growth is strongly associated with particulates exposure from later in second trimester onwards but the effect appears to be subsumed by smoking. Typical ambient exposures in this study were relatively low compared to other studies and given these results, it may be necessary to consider reducing recommended "safe" ambient air exposures. Copyright © 2017. Published by Elsevier Ltd.

Using National Ambient Air Quality Standards for fine particulate matter to assess regional wildland fire smoke and air quality management.

Science.gov (United States)

Schweizer, Don; Cisneros, Ricardo; Traina, Samuel; Ghezzehei, Teamrat A; Shaw, Glenn

2017-10-01

Wildland fire is an important ecological process in the California Sierra Nevada. Personal accounts from pre-20th century describe a much smokier environment than present day. The policy of suppression beginning in the early 20th century and climate change are contributing to increased megafires. We use a single particulate monitoring site at the wildland urban interface to explore impacts from prescribed, managed, and full suppression wildland fires from 2006 to 2015 producing a contextual assessment of smoke impacts over time at the landscape level. Prescribed fire had little effect on local fine particulate matter (PM 2.5 ) air quality with readings typical of similar non-fire times; hourly and daily good to moderate Air Quality Index (AQI) for PM 2.5 , maximum hourly concentrations 21-103 μg m -3 , and mean concentrations between 7.7 and 13.2 μg m -3 . Hourly and daily AQI was typically good or moderate during managed fires with 3 h and one day reaching unhealthy while the site remained below National Ambient Air Quality Standards (NAAQS), with maximum hourly concentrations 27-244 μg m -3 , and mean concentrations 6.7-11.7 μg m -3 . The large high intensity fire in this area created the highest short term impacts (AQI unhealthy for 4 h and very unhealthy for 1 h), 11 unhealthy for sensitive days, and produced the only annual value (43.9 μg m -3 ) over the NAAQS 98th percentile for PM 2.5 (35 μg m -3 ). Pinehurst remained below the federal standards for PM 2.5 when wildland fire in the local area was managed to 7800 ha (8-22% of the historic burn area). Considering air quality impacts from smoke using the NAAQS at a landscape level over time can give land and air managers a metric for broader evaluation of smoke impacts particularly when assessing ecologically beneficial fire. Allowing managers to control the amount and timing of individual wildland fire emissions can help lessen large smoke impacts to public health from a megafire

Estimation of air quality by air pollution indices

International Nuclear Information System (INIS)

Liblik, Valdo; Kundel, Helmut

1999-01-01

A novel system for estimating the quality of atmospheric air in the over-ground air layer with the help of air pollution indices was developed. The method is based on a comparison of measured or calculated maximum short-term concentrations and average annual concentrations of pollutants with maximum permissible concentrations (with regard to human beings and vegetation). Special air quality estimation scales for residential areas and natural systems are presented. On the basis of the concentration of the substance under study zones of very high, high, rather high, moderate, low and very low air pollution were distinguished in the over-ground layer of the atmosphere. These are projected to land surface for landscape zonation. The application of the system of indices is demonstrated in the analysis of air quality for the towns of Kohtla-Jarve, Johvi and Kivioli (in 1997-1998). A comparative analysis of the air pollution zones distinguished on the basis of emissions and data from bio monitoring yielded satisfactory results. The system of air pollution indices developed enables to process the results of air monitoring in case of pollution fields of complicated composition so that the result for estimating the quality of ambient air in a residential area is easily understood by inhabitants and interpretable with the help of a special scale; analyse temporal changes in the quality of the air in towns, villages and other residential areas and use the results as basis for developing measures for reducing the pollution of ambient air; carry out zonation of large territories on the basis of air pollution levels (spatial air pollution zones are projected on the ground surface) and estimate air quality in places where air monitoring is lacking to forecast the possible effect of air pollution on natural systems (author)

Cardiopulmonary Toxicity Induced by Ambient Particulate Matter (BI City Concentrated Ambient Particle Study)

Energy Technology Data Exchange (ETDEWEB)

Annette Rohr; James Wagner Masako Morishita; Gerald Keeler; Jack Harkema

2010-06-30

Alterations in heart rate variability (HRV) have been reported in rodents exposed to concentrated ambient particles (CAPs) from different regions of the United States. The goal of this study was to compare alterations in cardiac function induced by CAPs in two distinct regional atmospheres. AirCARE 1, a mobile laboratory with an EPA/Harvard fine particle (particulate matter <2.5 {micro}m; PM{sub 2.5}) concentrator was located in urban Detroit, MI, where the PM mixture is heavily influenced by motor vehicles, and in Steubenville, OH, where PM is derived primarily from long-range transport and transformation of power plant emissions, as well as from local industrial operations. Each city was studied during both winter and summer months, for a total of four sampling periods. Spontaneously hypertensive rats instrumented for electrocardiogram (ECG) telemetry were exposed to CAPs 8 h/day for 13 consecutive days during each sampling period. Heart rate (HR), and indices of HRV (standard deviation of the average normal-to-normal intervals [SDNN]; square root of the mean squared difference of successive normal-to-normal intervals [rMSSD]), were calculated for 30-minute intervals during exposures. A large suite of PM components, including nitrate, sulfate, elemental and organic carbon, and trace elements, were monitored in CAPs and ambient air. In addition, a unique sampler, the Semi-Continuous Elements in Air Sampler (SEAS) was employed to obtain every-30-minute measurements of trace elements. Positive matrix factorization (PMF) methods were applied to estimate source contributions to PM{sub 2.5}. Mixed modeling techniques were employed to determine associations between pollutants/CAPs components and HR and HRV metrics. Mean CAPs concentrations in Detroit were 518 and 357 {micro}g/m{sup 3} (summer and winter, respectively) and 487 and 252 {micro}g/m{sup 3} in Steubenville. In Detroit, significant reductions in SDNN were observed in the summer in association with cement

Effect of Ambient Air Pollution on Hospitalization for Heart Failure in 26 of China's Largest Cities.

Science.gov (United States)

Liu, Hui; Tian, Yaohua; Song, Jing; Cao, Yaying; Xiang, Xiao; Huang, Chao; Li, Man; Hu, Yonghua

2018-03-01

There is growing interest in the association between ambient air pollution and congestive heart failure (CHF), but research data from developing countries are very limited. The primary aim of this study was to examine the association between short-term exposure to air pollution and hospital admission for CHF in China. A time-stratified case-crossover study was conducted between 2014 and 2015 in 26 large Chinese cities among 105,501 CHF hospitalizations. Conditional logistic regression models were applied to estimate the percentage changes in CHF admissions in relation to per interquartile range increases in air pollutant concentrations. Air pollution was positively associated with CHF hospitalizations. An interquartile range increase in fine particulate, particulate matter less than 10 µm in aerodynamic diameter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone concentrations on the current day corresponded to 1.2% (95% confidence interval [CI] 0.5%, 1.8%), 1.3% (95% CI 0.5%, 2.0%), 1.0% (95% CI 0.2%, 1.7%), 1.6% (95% CI 0.6%, 2.5%), 1.2% (95% CI 0.5%, 1.9%), and 0.4% (95% CI -0.9%, 1.7%) increases in CHF admissions, respectively. In conclusion, our findings contribute to the limited scientific literature concerning the effects of air pollution on CHF risk for high-exposure settings typical in developing countries, which may have significant public health implications for prevention of CHF in China. Copyright © 2017 Elsevier Inc. All rights reserved.

Development, enhancement, and evaluation of aircraft measurement techniques for national ambient air quality standard criteria pollutants

Science.gov (United States)

Brent, Lacey Cluff

The atmospheric contaminants most harmful to human health are designated Criteria Pollutants. To help Maryland attain the national ambient air quality standards (NAAQS) for Criteria Pollutants, and to improve our fundamental understanding of atmospheric chemistry, I conducted aircraft measurements in the Regional Atmospheric Measurement Modeling Prediction Program (RAMMPP). These data are used to evaluate model simulations and satellite observations. I developed techniques for improving airborne observation of two NAAQS pollutants, particulate matter (PM) and nitrogen dioxide (NO2). While structure and composition of organic aerosol are important for understanding PM formation, the molecular speciation of organic ambient aerosol remains largely unknown. The spatial distribution of reactive nitrogen is likewise poorly constrained. To examine water-soluble organic aerosol (WSOA) during an air pollution episode, I designed and implemented a shrouded aerosol inlet system to collect PM onto quartz fiber filters from a Cessna 402 research aircraft. Inlet evaluation conducted during a side-by-side flight with the NASA P3 demonstrated agreement to within 30%. An ion chromatographic mass spectrometric method developed using the NIST Standard Reference Material (SRM) 1649b Urban Dust, as a surrogate material resulted in acidic class separation and resolution of at least 34 organic acids; detection limits approach pg/g concentrations. Analysis of aircraft filter samples resulted in detection of 8 inorganic species and 16 organic acids of which 12 were quantified. Aged, re-circulated metropolitan air showed a greater number of dicarboxylic acids compared to air recently transported from the west. While the NAAQS for NO2 is rarely exceeded, it is a precursor molecule for ozone, America's most recalcitrant pollutant. Using cavity ringdown spectroscopy employing a light emitting diode (LED), I measured vertical profiles of NO2 (surface to 2.5 km) west (upwind) of the Baltimore

How private vehicle use increases ambient air pollution concentrations at schools during the morning drop-off of children

Science.gov (United States)

Adams, Matthew D.; Requia, Weeberb J.

2017-09-01

A child's exposure to environmental pollutants can have life-long health effects. Thus it is critical to understand the potential exposure pathways. In this paper, we examine the increase in ambient PM2.5 concentrations at schools from private vehicle use for dropping children off at school. In North America, students are commonly driven to school in a private vehicle. Additionally, students walk or cycle, or take a school bus. Our vehicle surveys recorded between 23 and 116 personal vehicles at 25 schools, where enrolment ranged from 160 to 765 students. We fit a linear regression model to predict the number of vehicles at schools we did not observe within our study area, which explained 57% of the variation in our surveys. A microsimulation traffic model was created for each of the 86 schools we studied. Outputs from the traffic model were used to determine the emissions generated at each school. PM2.5 emissions varied from 0.14 to 6.38 g. Lastly, we dispersed the emissions produced by private vehicles dropping off students, which are emissions generated by unnecessary trips because students further than walking distance are provided transportation by the school board. At the drop-off location in front of the school, we found ambient concentration increases of at least 5 μg/m3, 10 μg/m3, 25 μg/m3 and 50 μg/m3 during 16.8%, 7.6%, 2.0% and 0.5% of the mornings, respectively. This research was conducted in a medium-sized North American city and should allow transferability to similar cities. We conclude that the use of private vehicles can significantly increase local concentrations, regardless of background conditions.

Incorporating environmental constraints to electricity generation in the city of Buenos Aires; Despacho economico-ambiental de la oferta de generacion de energia electrica en la ciudad de Buenos Aires

Energy Technology Data Exchange (ETDEWEB)

Dawidowski, Laura E; Gomez, Dario R; Bajano, Hector [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Quimica; Anbinder, Gustavo D; Rey, Francisco C [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Reactores y Centrales Nucleares

1999-07-01

A prototype for an integrated system that includes air quality constraints to the procedure that is presently in use to determine the daily economic dispatch of power plants in Argentina is proposed. The recent incorporation of new machines to the installed capacity of the three power plants located in the densely populated metropolitan area of Buenos Aires, the thermal-based future expansion of the power sector and the relatively high nitrogen oxides concentrations that can be associated to electricity generation in the city of Buenos Aires, served to motivate this work. The prototype attempts to generate a dispatch that is compatible with the environment taking into account the present economic dispatch, weather forecast and dispersion models to evaluate ambient air concentrations of nitrogen oxides (NO{sub x}) caused by the combined operation of the thermal power plants. Although the prototype deals exclusively with NO{sub x}, since these are the pollutants of primary concern considering the fuel consumption pattern of argentinean power plants, its structure is general enough to take into account other pollutants such as sulfur dioxide and particulate matter. (author)

Effect of environmental dust particles on laser textured yttria-stabilized zirconia surface in humid air ambient

Science.gov (United States)

Yilbas, B. S.; Ali, H.; Al-Sharafi, A.; Al-Sulaiman, F.; Karatas, C.

2018-05-01

Zirconium nitride is used as a selective surface for concentrated solar heating applications and one of the methods to form a zirconium nitride is texturing of zirconia surface by a high intensity laser beam under high pressure nitrogen gas environment. Laser texturing also provides hydrophobic surface characteristics via forming micro/nano pillars at the surface; however, environmental dust settlement on textured surface influences the surface characteristics significantly. In the present study, laser texturing of zirconia surface and effects of the dust particles on the textured surface in a humid air ambient are investigated. Analytical tools are used to assess the morphological changes on the laser textured surface prior and after the dust settlement in the humid air ambient. It is found that laser textured surface has hydrophobic characteristics. The mud formed during condensate of water on the dust particles alters the characteristics of the laser textured surface. The tangential force required to remove the dry mud from the textured surface remains high; in which case, the dried liquid solution at the mud-textured surface interface is responsible for the strong adhesion of the dry mud on the textured surface. The textured surface becomes hydrophilic after the dry mud was removed from the surface by a desalinated water jet.

Association of Geography and Ambient Air Pollution with Urine Metal Concentrations in Six US Cities: The Multi-Ethnic Study of Atherosclerosis

Directory of Open Access Journals (Sweden)

Yuanjie Pang

2016-03-01

Full Text Available We investigated the associations of urinary concentrations of antimony, cadmium, tungsten and uranium with geographic locations and with ambient air pollution in 304 adults in the Multi-Ethnic Study of Atherosclerosis from six US cities. After adjustment for sociodemographics, body mass index, and smoking status, urinary cadmium was the highest in Winston-Salem among all study sites (the geometric mean [GM] in Winston-Salem was 0.84 µg/L [95% confidence interval (CI 0.57–1.22]. The adjusted GMs of urinary tungsten and uranium were highest in Los Angeles (0.11 µg/L [95% CI 0.08–0.16] and 0.019 µg/L [95% CI 0.016–0.023], respectively. The adjusted GM ratio comparing fine particulate matter (PM2.5 tertiles 2 and 3 with the lowest tertile were 1.64 (95% CI 1.05–2.56 and 3.55 (95% CI 2.24–5.63 for tungsten, and 1.18 (95% CI 0.94–1.48 and 1.70 (95% CI 1.34–2.14 for uranium. The results for tungsten remained similar after adjustment for study site. Urinary cadmium, tungsten and uranium concentrations differed by geographic locations in MESA (Multi-Ethnic Study of Atherosclerosis communities. PM2.5 levels could contribute to geographic differences in tungsten exposure. These findings highlight the need to implement preventive strategies to decrease toxic metal exposure and to evaluate the health effects of chronic exposure to those metals.

Speciated mercury measurements in ambient air from 2009 to 2011 at a Central European rural background monitoring site

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Weigelt A.

2013-04-01

Full Text Available Since January 2009 highly time-resolved mercury speciation measurements in ambient air are carried out at the Central European German EMEP monitoring station and measurement site of the German Federal Environment Agency “Waldhof“, providing the longest Central European dataset for mercury species. First statistical analyses do not indicate long term trends for the concentrations of gaseous elemental mercury (GEM and particle bound mercury (TPM. A potential increasing trend for reactive gaseous mercury (RGM will have to be verified in the coming years and should be regarded as indicative only at present. A seasonal cycle for TPM could be observed with higher concentrations during winter time. Furthermore a diurnal cycle for RGM is apparent with highest concentrations in the early afternoon.

Ambient and household air pollution: complex triggers of disease

Science.gov (United States)

Farmer, Stephen A.; Nelin, Timothy D.; Falvo, Michael J.

2014-01-01

Concentrations of outdoor air pollution are on the rise, particularly due to rapid urbanization worldwide. Alternatively, poor ventilation, cigarette smoke, and other toxic chemicals contribute to rising concentrations of indoor air pollution. The World Health Organization recently reported that deaths attributable to indoor and outdoor air pollutant exposure are more than double what was originally documented. Epidemiological, clinical, and animal data have demonstrated a clear connection between rising concentrations of air pollution (both indoor and outdoor) and a host of adverse health effects. During the past five years, animal, clinical, and epidemiological studies have explored the adverse health effects associated with exposure to both indoor and outdoor air pollutants throughout the various stages of life. This review provides a summary of the detrimental effects of air pollution through examination of current animal, clinical, and epidemiological studies and exposure during three different periods: maternal (in utero), early life, and adulthood. Additionally, we recommend future lines of research while suggesting conceivable strategies to curb exposure to indoor and outdoor air pollutants. PMID:24929855

Ambient and household air pollution: complex triggers of disease.

Science.gov (United States)

Farmer, Stephen A; Nelin, Timothy D; Falvo, Michael J; Wold, Loren E

2014-08-15

Concentrations of outdoor air pollution are on the rise, particularly due to rapid urbanization worldwide. Alternatively, poor ventilation, cigarette smoke, and other toxic chemicals contribute to rising concentrations of indoor air pollution. The World Health Organization recently reported that deaths attributable to indoor and outdoor air pollutant exposure are more than double what was originally documented. Epidemiological, clinical, and animal data have demonstrated a clear connection between rising concentrations of air pollution (both indoor and outdoor) and a host of adverse health effects. During the past five years, animal, clinical, and epidemiological studies have explored the adverse health effects associated with exposure to both indoor and outdoor air pollutants throughout the various stages of life. This review provides a summary of the detrimental effects of air pollution through examination of current animal, clinical, and epidemiological studies and exposure during three different periods: maternal (in utero), early life, and adulthood. Additionally, we recommend future lines of research while suggesting conceivable strategies to curb exposure to indoor and outdoor air pollutants.

77 FR 39205 - Public Hearings for Proposed Rules-National Ambient Air Quality Standards for Particulate Matter

Science.gov (United States)

2012-07-02

..., respectively, and to make corresponding revisions to the data handling conventions for PM and ambient air.... Environmental Protection Agency, Office of Air Quality Planning and Standards, Ariel Rios Building, 1200...

Long-term exposure to ambient air pollution and mortality in a Chinese tuberculosis cohort.

Science.gov (United States)

Peng, Zhuoxin; Liu, Cong; Xu, Biao; Kan, Haidong; Wang, Weibing

2017-02-15

Evidence for the relationship between exposure to ambient air pollution and the mortality of tuberculosis (TB) patients is limited. We analyzed the association between long-term exposure to particulate matter mortality in a Chinese TB patients cohort from 2003 to 2013. Data from the Global Burden of Disease 2013 estimate were used to assess yearly average concentrations of PM 2.5 and ozone at the household addresses of participants. Cox regression was used to calculate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for cause-specific mortality, controlling for demographic and other TB-related factors. There were 4444 eligible subjects, including 891 deaths, over a median follow-up of 2464days. Per an interquartile range increase (2.06μg/m 3 ), multivariable analysis indicated that exposure to PM 2.5 was significantly associated with overall mortality (aHR=1.30, 95% CI: 1.19, 1.42), mortality from TB (aHR=1.46, 95% CI: 1.15, 1.85), respiratory cancers (aHR=1.72, 95% CI: 1.36, 2.19), other respiratory diseases (aHR=1.19, 95% CI: 1.02, 1.38), and other cancers (aHR=1.76, 95% CI: 1.33, 2.32). Long-term exposure to PM 2.5 increases the risk of death from TB and other diseases among TB patients. It suggests that the control of ambient air pollution may help decreasing the mortality caused by TB. Copyright © 2016 Elsevier B.V. All rights reserved.

Intracerebral haemorrhage associated with hourly concentration of ambient particulate matter: case-crossover analysis.

Science.gov (United States)

Yamazaki, S; Nitta, H; Ono, M; Green, J; Fukuhara, S

2007-01-01

To examine the association of hourly time lagged concentration of ambient particulate matter and death due to stroke. Mortality data for five years (January 1990 to December 1994) were obtained from the Ministry of Health, Labour, and Welfare of Japan. Data were used only if the deceased was 65 years old or older at the time of death, if death was attributed to intracerebral haemorrhage or ischaemic stroke, and if the deceased lived in one of 13 major urban areas. Hourly mean concentrations of PM7, NO2, and photochemical oxidants were measured at monitoring stations in the 13 areas. Time stratified case-crossover analysis was used to examine the data for evidence of triggering stroke mortality. The 1-hour mean concentration of PM7 measured about 2 hours before death was associated with the risk of death due to intracerebral haemorrhage from April to September (odds ratio = 2.40, 95% CI 1.48 to 3.89, for exposure to PM7 of more than 200 microg/m3 (threshold)). The higher risk was independent of the 24-hour mean concentration of PM7. PM7 was not associated with death due to ischaemic stroke. Transiently high concentrations of PM7 are associated with death due to intracerebral haemorrhage. Air quality standards or guidelines for particulate matter should be based not only on 24-hour mean concentrations, but also on hourly data.

Intracerebral haemorrhage associated with hourly concentration of ambient particulate matter: case‐crossover analysis

Science.gov (United States)

Yamazaki, S; Nitta, H; Ono, M; Green, J; Fukuhara, S

2007-01-01

Aims To examine the association of hourly time lagged concentration of ambient particulate matter and death due to stroke. Methods Mortality data for five years (January 1990 to December 1994) were obtained from the Ministry of Health, Labour, and Welfare of Japan. Data were used only if the deceased was 65 years old or older at the time of death, if death was attributed to intracerebral haemorrhage or ischaemic stroke, and if the deceased lived in one of 13 major urban areas. Hourly mean concentrations of PM7, NO2, and photochemical oxidants were measured at monitoring stations in the 13 areas. Time stratified case‐crossover analysis was used to examine the data for evidence of triggering stroke mortality. Results The 1‐hour mean concentration of PM7 measured about 2 hours before death was associated with the risk of death due to intracerebral haemorrhage from April to September (odds ratio = 2.40, 95% CI 1.48 to 3.89, for exposure to PM7 of more than 200 μg/m3 (threshold)). The higher risk was independent of the 24‐hour mean concentration of PM7. PM7 was not associated with death due to ischaemic stroke. Conclusions Transiently high concentrations of PM7 are associated with death due to intracerebral haemorrhage. Air quality standards or guidelines for particulate matter should be based not only on 24‐hour mean concentrations, but also on hourly data. PMID:16847037

Automatic colorimetric determination of low concentrations of sulphate for measuring sulphur dioxide in ambient air

Energy Technology Data Exchange (ETDEWEB)

Persson, G A

1966-01-01

An automatic colorimetric method for the determination of low concentrations of sulphate (0-10 microgram/ml) using the thoron indicator is described. Total amounts of sulphate as small as 0.3 micrograms can be determined. The sulphate is precipitated with barium perchlorate and the excess of barium is indicated with 1-(o-arsenophenylazo)-2-naphthol-3-6-disulfonic acid(thoron). The procedure is worked out primarily for the determination of sulphur dioxide in air after absorption in diluted hydrogen peroxide.

A study of bacteria, fungi and biomass in particulate matter in ambient air of Khorramabad during summer and autumn 2012

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hatam Godini

2015-05-01

Full Text Available Introduction: Particulate matter refers to the combination of atmospheric pollutants that a portion of this particulate is bioaerosol. The aim of this study was the evaluation of bacteria, fungi and biomass in particulate matter in ambient air of Khorramabad during summer and autumn 2012. Materials and Methods: This study was a cross sectional study that conducted in Khorramabad city during summer and fall 2012. Sampling has been done via high-volume sampler. The special cultures were used for cultivation and determination of fungal and Heterotrophic Plate Count (HPC (and Bradford method were used to determine bacteria and protein as biomass indicator, respectively. Relationship between these variables with metrological parameters was evaluated too. Results: The highest PM10 in July (257.18 µg/m3 and lowest in September (92.45 µg/m3 had been recorded. The highest amount of bacteria and fungi were measured as monthly in November (605 No/m3 and December (120 No/m3, respectively. The highest of protein concentration was measured in August, September and December (27-30 µg/m3. With the increase in PM10, biomass concentration in the air showed a meaningful increase. Conclusion: Biomass concentration in the air increased with increasing PM10 but it had no significant effect on the concentration of bacteria and fungi in the air. Meteorological factors such as temperature, humidity, wind speed, solar radiation and the amount of exposure time had a significant impact on bioaerosol concentrations in the air.

Ambient krypton-85 air sampling at Hanford

International Nuclear Information System (INIS)

Trevathan, M.S.; Price, K.R.

1985-01-01

In the fall of 1982, the Environmental Evaluations Section of Pacific Northwest Laboratory (PNL) initiated a network of continuous 85 Kr air samplers located on and around the Hanford Site. This effort was in response to the resumption of operations at a nuclear fuel reprocessing plant located onsite where 85 Kr was to be released during fuel dissolution. Preoperational data were collected using noble gas samplers designed by the Environmental Protection Agency-Las Vegas (EPA-LV). The samplers functioned erratically resulting in excessive maintenance costs and prompted a search for a new sampling system. State-of-the-art 85 Dr sampling methods were reviewed and found to be too costly, too complex and inappropriate for field application, so a simple bag collection system was designed and field tested. The system is composed of a reinforced, heavy plastic bag, connected to a variable flow pump and housed in a weatherproof enclosure. At the end of the four week sampling period the air in the bag is transferred by a compressor into a pressure tank for easy transport to the laboratory for analysis. After several months of operation, the air sampling system has proven its reliability and sensitivity to ambient levels of 85 Kr

Ambient krypton-85 air sampling at Hanford

International Nuclear Information System (INIS)

Trevathan, M.S.; Price, K.R.

1984-10-01

In the fall of 1982, the Environmental Evaluations Section of Pacific Northwest Laboratory (PNL) initiated a network of continuous krypton-85 air samplers located on and around the Hanford Site. This effort was in response to the resumption of operations at a nuclear fuel reprocessing plant located onsite where krypton-85 was to be released during fuel dissolution. Preoperational data were collected using noble gas samplers designed by the Environmental Protection Agency-Las Vegas (EPA-LV). The samplers functioned erratically resulting in excessive maintenance costs and prompted a search for a new sampling system. State of the art krypton-85 sampling methods were reviewed and found to be too costly, too complex and inappropriate for field application, so a simple bag collection system was designed and field tested. The system is composed of a reinforced, heavy plastic bag, connected to a variable flow pump and housed in a weatherproof enclosure. At the end of the four week sampling period the air in the bag is transferred by a compressor into a pressure tank for easy transport to the laboratory for analysis. After several months of operation, the air sampling system has proven its reliability and sensitivity to ambient levels of krypton-85. 3 references, 3 figures, 1 table

Growth Responses of Wheat (Triticum aestivumL. var. HD 2329 Exposed to Ambient Air Pollution under Varying Fertility Regimes

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Anoop Singh

2003-01-01

Full Text Available The problem of urban air pollution has attracted special attention in India due to a tremendous increase in the urban population; motor vehicles vis a vis the extent of energy utilization. Field studies were conducted on wheat crops (Triticum aestivum L. var. HD 2329 by keeping the pot-grown plants in similar edaphic conditions at nine different sites in Allahabad City to quantify the effects of ambient air pollution levels on selected growth and yield parameters. Air quality monitoring was done at all the sites for gaseous pollutants viz. SO2, NO2, and O3. Various growth parameters (plant height, biomass, leaf area, NPP, etc. showed adverse effects at sites receiving higher pollution load. Reduction in test weight and harvest index was found to be directly correlated with the levels of pollutant concentrations. The study clearly showed the negative impact of air pollution on periurban agriculture.

Declining ambient air pollution and lung function improvement in Austrian children

Science.gov (United States)

Neuberger, Manfred; Moshammer, Hanns; Kundi, Michael

Three thousand four hundred fifty-one Austrian elementary school children were examined (between 2 and 8 times) by spirometry by standardized methods, over a 5 yr period. The districts where they lived were grouped into those where NO 2 declined during this period (by at least 30 μg/m 3 measured as half year means) and those with less or no decline in ambient NO 2. In both groups of districts, SO 2 and TSP fell by similar amounts over this period. A continuous improvement of MEF25 (maximum exspiratory flow rate at 25% vital capacity) was found in districts with declining ambient NO 2. Populations did not differ in respect of anthropometric factors, passive smoking or socioeconomic status. A birth cohort from this study population which was followed up to age 18 confirmed the improved growth of MEF25 with decline in NO 2, while the improved growth of forced vital capacity was more related to decline in SO 2. This study provides the first evidence that improvements in the outdoor air quality during the 1980s are correlated with health benefits, and suggest that adverse effects on lung function related to ambient air pollution are reversible before adulthood. Improvement of small airway functions appeared to be more dependent on reductions of NO 2 than reduction in SO 2 and TSP.

Radial diffusive sampler for the determination of 8-h ambient ozone concentrations

International Nuclear Information System (INIS)

Plaisance, H.; Gerboles, M.; Piechocki, A.; Detimmerman, F.; Saeger, E. de

2007-01-01

The 8-h ozone radial diffusive sampler was evaluated according to the CEN protocol for the validation of diffusive samplers. All the parameters regarding the sampler characteristics were found to be consistent with the requirements of this protocol apart from the blank value, which must be evaluated and subtracted at each sampling. The nominal uptake rate was determined in laboratory conditions. However, the uptake rate depends on the mass uptake, temperature, humidity and on the combination of temperature and humidity. Based on laboratory experiments, an empirical model has been established which improved the agreement between the radial sampler and the reference method. This improvement was observed under several different meteorological and emission conditions of sampling. By using the model equation of uptake rate, the data quality objective of 30% for the expanded uncertainty included in the O 3 European Directive, is easily attained. Therefore, the sampler represents an appropriate indicative method. - A passive sampler has been fully validated for monitoring 8-h ozone concentrations in ambient air

Household Cooking with Solid Fuels Contributes to Ambient PM2.5 Air Pollution and the Burden of Disease

Science.gov (United States)

Chafe, Zoë A.; Brauer, Michael; Klimont, Zbigniew; Van Dingenen, Rita; Mehta, Sumi; Rao, Shilpa; Riahi, Keywan; Dentener, Frank

2014-01-01

Background: Approximately 2.8 billion people cook with solid fuels. Research has focused on the health impacts of indoor exposure to fine particulate pollution. Here, for the 2010 Global Burden of Disease project (GBD 2010), we evaluated the impact of household cooking with solid fuels on regional population-weighted ambient PM2.5 (particulate matter ≤ 2.5 μm) pollution (APM2.5). Objectives: We estimated the proportion and concentrations of APM2.5 attributable to household cooking with solid fuels (PM2.5-cook) for the years 1990, 2005, and 2010 in 170 countries, and associated ill health. Methods: We used an energy supply–driven emissions model (GAINS; Greenhouse Gas and Air Pollution Interactions and Synergies) and source-receptor model (TM5-FASST) to estimate the proportion of APM2.5 produced by households and the proportion of household PM2.5 emissions from cooking with solid fuels. We estimated health effects using GBD 2010 data on ill health from APM2.5 exposure. Results: In 2010, household cooking with solid fuels accounted for 12% of APM2.5 globally, varying from 0% of APM2.5 in five higher-income regions to 37% (2.8 μg/m3 of 6.9 μg/m3 total) in southern sub-Saharan Africa. PM2.5-cook constituted > 10% of APM2.5 in seven regions housing 4.4 billion people. South Asia showed the highest regional concentration of APM2.5 from household cooking (8.6 μg/m3). On the basis of GBD 2010, we estimate that exposure to APM2.5 from cooking with solid fuels caused the loss of 370,000 lives and 9.9 million disability-adjusted life years globally in 2010. Conclusions: PM2.5 emissions from household cooking constitute an important portion of APM2.5 concentrations in many places, including India and China. Efforts to improve ambient air quality will be hindered if household cooking conditions are not addressed. Citation: Chafe ZA, Brauer M, Klimont Z, Van Dingenen R, Mehta S, Rao S, Riahi K, Dentener F, Smith KR. 2014. Household cooking with solid fuels contributes to

A simple method to determine Tr concentrations in the moisture of the exhaust air of nuclear facilities and in the ambient air

International Nuclear Information System (INIS)

Weber, H.W.; Schuettelkopf, H.

1983-04-01

In the course of nuclear power plant operation radioactive tritium is generated which is released to the environment as HTO via the exhaust air and the liquid effluents. Measurement and balancing of the tritium emissions are required in order to be able to evaluate the resulting radiation exposure of the population. For determination of the HTO emission the humidity of the measured air is absorbed at a rod shaped molecular sieve of 1/16'' mesh size. The desiccant is contacted with T-free water and the T activity concentration of the water is determined after 3 H/ 1 H isotope exchange. The rod shaped molecular sieves are suited for use under this method on account of their drying capacity largely independent of temperature and air humidity and the good handling capability. The detection limit is at 19 Bq HTO/m 3 air. The exhaust air from several 3 H-emitters of the Karlsruhe Nuclear Research Center was monitored by this method for its HTO content and the results were compared with the values measured at existing points of measurement. The good results have been the reason for the application of such collectors in the routine T-measurement performed within the framework of exhaust air monitoring on the site of the Karlsruhe Nuclear Research Center. (orig./HP) [de

Ambient Air Ammonia (NH3) Concentration in Two Solid Waste ...

African Journals Online (AJOL)

MBI

2017-05-22

May 22, 2017 ... and thereby adds significantly to the external costs related to air pollution in ... condensation nuclei and indirectly increase cloud life time (Myhre et al., 2009). ..... Cost Effective Strategy for Reducing. Atmospheric Particulate ...

Apparatus and method for maintaining an article at a temperature that is less than the temperature of the ambient air

Science.gov (United States)

Klett, James; Klett, Lynn

2018-04-03

An apparatus for maintaining the temperature of an article at a temperature that is below the ambient air temperature includes an enclosure having an outer wall that defines an interior chamber for holding a volume of sealed air. An insert is disposed inside of the chamber and has a body that is made of a porous graphite foam material. A vacuum pump penetrates the outer wall and fluidly connects the sealed air in the interior chamber with the ambient air outside of the enclosure. The temperatures of the insert and article is maintained at temperatures that are below the ambient air temperature when a volume of a liquid is wicked into the pores of the porous insert and the vacuum pump is activated to reduce the pressure of a volume of sealed air within the interior chamber to a pressure that is below the vapor pressure of the liquid.

The Cardiopulmonary Effects of Ambient Air Pollution and Mechanistic Pathways: A Comparative Hierarchical Pathway Analysis

Science.gov (United States)

Thomas, Duncan C.; Zhang, Junfeng; Kipen, Howard M.; Rich, David Q.; Zhu, Tong; Huang, Wei; Hu, Min; Wang, Guangfa; Wang, Yuedan; Zhu, Ping; Lu, Shou-En; Ohman-Strickland, Pamela; Diehl, Scott R.; Eckel, Sandrah P.

2014-01-01

Previous studies have investigated the associations between exposure to ambient air pollution and biomarkers of physiological pathways, yet little has been done on the comparison across biomarkers of different pathways to establish the temporal pattern of biological response. In the current study, we aim to compare the relative temporal patterns in responses of candidate pathways to different pollutants. Four biomarkers of pulmonary inflammation and oxidative stress, five biomarkers of systemic inflammation and oxidative stress, ten parameters of autonomic function, and three biomarkers of hemostasis were repeatedly measured in 125 young adults, along with daily concentrations of ambient CO, PM2.5, NO2, SO2, EC, OC, and sulfate, before, during, and after the Beijing Olympics. We used a two-stage modeling approach, including Stage I models to estimate the association between each biomarker and pollutant over each of 7 lags, and Stage II mixed-effect models to describe temporal patterns in the associations when grouping the biomarkers into the four physiological pathways. Our results show that candidate pathway groupings of biomarkers explained a significant amount of variation in the associations for each pollutant, and the temporal patterns of the biomarker-pollutant-lag associations varied across candidate pathways (p<0.0001) and were not linear (from lag 0 to lag 3: p = 0.0629, from lag 3 to lag 6: p = 0.0005). These findings suggest that, among this healthy young adult population, the pulmonary inflammation and oxidative stress pathway is the first to respond to ambient air pollution exposure (within 24 hours) and the hemostasis pathway responds gradually over a 2–3 day period. The initial pulmonary response may contribute to the more gradual systemic changes that likely ultimately involve the cardiovascular system. PMID:25502951

The cardiopulmonary effects of ambient air pollution and mechanistic pathways: a comparative hierarchical pathway analysis.

Directory of Open Access Journals (Sweden)

Ananya Roy

Full Text Available Previous studies have investigated the associations between exposure to ambient air pollution and biomarkers of physiological pathways, yet little has been done on the comparison across biomarkers of different pathways to establish the temporal pattern of biological response. In the current study, we aim to compare the relative temporal patterns in responses of candidate pathways to different pollutants. Four biomarkers of pulmonary inflammation and oxidative stress, five biomarkers of systemic inflammation and oxidative stress, ten parameters of autonomic function, and three biomarkers of hemostasis were repeatedly measured in 125 young adults, along with daily concentrations of ambient CO, PM2.5, NO2, SO2, EC, OC, and sulfate, before, during, and after the Beijing Olympics. We used a two-stage modeling approach, including Stage I models to estimate the association between each biomarker and pollutant over each of 7 lags, and Stage II mixed-effect models to describe temporal patterns in the associations when grouping the biomarkers into the four physiological pathways. Our results show that candidate pathway groupings of biomarkers explained a significant amount of variation in the associations for each pollutant, and the temporal patterns of the biomarker-pollutant-lag associations varied across candidate pathways (p<0.0001 and were not linear (from lag 0 to lag 3: p = 0.0629, from lag 3 to lag 6: p = 0.0005. These findings suggest that, among this healthy young adult population, the pulmonary inflammation and oxidative stress pathway is the first to respond to ambient air pollution exposure (within 24 hours and the hemostasis pathway responds gradually over a 2-3 day period. The initial pulmonary response may contribute to the more gradual systemic changes that likely ultimately involve the cardiovascular system.

Variation of indoor radon concentration and ambient dose equivalent rate in different outdoor and indoor environments

Energy Technology Data Exchange (ETDEWEB)

Stojanovska, Zdenka; Janevik, Emilija; Taleski, Vaso [Goce Delcev University, Faculty of Medical Sciences, Stip (Macedonia, The Former Yugoslav Republic of); Boev, Blazo [Goce Delcev University, Faculty of Natural and Technical Sciences, Stip (Macedonia, The Former Yugoslav Republic of); Zunic, Zora S. [University of Belgrade, Institute of Nuclear Sciences ' ' Vinca' ' , Belgrade (Serbia); Ivanova, Kremena; Tsenova, Martina [National Center of Radiobiology and Radiation Protection, Sofia (Bulgaria); Ristova, Mimoza [University in Ss. Cyril and Methodius, Faculty of Natural Sciences and Mathematic, Institute of Physics, Skopje (Macedonia, The Former Yugoslav Republic of); Ajka, Sorsa [Croatian Geological Survey, Zagreb (Croatia); Bossew, Peter [German Federal Office for Radiation Protection, Berlin (Germany)

2016-05-15

Subject of this study is an investigation of the variations of indoor radon concentration and ambient dose equivalent rate in outdoor and indoor environments of 40 dwellings, 31 elementary schools and five kindergartens. The buildings are located in three municipalities of two, geologically different, areas of the Republic of Macedonia. Indoor radon concentrations were measured by nuclear track detectors, deployed in the most occupied room of the building, between June 2013 and May 2014. During the deploying campaign, indoor and outdoor ambient dose equivalent rates were measured simultaneously at the same location. It appeared that the measured values varied from 22 to 990 Bq/m{sup 3} for indoor radon concentrations, from 50 to 195 nSv/h for outdoor ambient dose equivalent rates, and from 38 to 184 nSv/h for indoor ambient dose equivalent rates. The geometric mean value of indoor to outdoor ambient dose equivalent rates was found to be 0.88, i.e. the outdoor ambient dose equivalent rates were on average higher than the indoor ambient dose equivalent rates. All measured can reasonably well be described by log-normal distributions. A detailed statistical analysis of factors which influence the measured quantities is reported. (orig.)

GIS-based models for ambient PM exposure and health impact assessment for the UK

International Nuclear Information System (INIS)

Stedman, John R; Grice, Susannah; Kent, Andrew; Cooke, Sally

2009-01-01

GIS-based models have been developed to map ambient PM 10 and PM 25 mass concentrations across the UK. The resulting maps are used for the assessments of air quality required by the EU ambient air quality directives, health impact assessment and the development of UK air quality policy. Maps are presented for 2006 along with projections to 2020. The largest single contribution to the UK population-weighted mean annual mean background concentrations of PM 10 in 2006 is estimated to be from secondary PM (43%), followed by the contribution from primary PM (24%). Concentrations are predicted to decline by 15% for PM 10 and 13% for PM 25 over the period from 2006 to 2020. The extent of exceedence of the 24-hour limit value is predicted to decline from 1.9% to 0.1% of urban major roads over the same period. The potential health benefits of reductions in ambient PM are large. A reduction in concentration of 0.93 μg m -3 as a result of a possible package of measures has been estimated within the UK Air Quality Strategy to result in a reduction in life years lost of approximately 2 - 4 million over a period of 100 years.

Will the circle be unbroken: a history of the U.S. National Ambient Air Quality Standards.

Science.gov (United States)

Bachmann, John

2007-06-01

In celebration of the 100th anniversary of the Air & Waste Management Association, this review examines the history of air quality management (AQM) in the United States over the last century, with an emphasis on the ambient standards programs established by the landmark 1970 Clean Air Act (CAA) Amendments. The current CAA system is a hybrid of several distinct air pollution control philosophies, including the recursive or circular system driven by ambient standards. Although this evolving system has resulted in tremendous improvements in air quality, it has been far from perfect in terms of timeliness and effectiveness. The paper looks at several periods in the history of the U.S. program, including: (1) 1900-1970, spanning the early smoke abatement and smog control programs, the first federal involvement, and the development of a hybrid AQM approach in the 1970 CAA; (2) 1971-1976, when the first National Ambient Air Quality Standards (NAAQS) were set and implemented; (3) 1977-1993, a period of the first revisions to the standards, new CAA Amendments, delays in implementation and decision-making, and key science/policy/legislative developments that would alter both the focus and scale of air pollution programs and how they are implemented; and (4) 1993-2006, the second and third wave of NAAQS revisions and their implementation in the context of the 1990 CAA. This discussion examines where NAAQS have helped drive implementation programs and how improvements in both effects and air quality/control sciences influenced policy and legislation to enhance the effectiveness of the system over time. The review concludes with a look toward the future of AQM, emphasizing challenges and ways to meet them. The most significant of these is the need to make more efficient progress toward air quality goals, while adjusting the system to address the growing intersections between air quality management and climate change.

Ambient air pollution, smog episodes and mortality in Jinan, China.

Science.gov (United States)

Zhang, Jun; Liu, Yao; Cui, Liang-Liang; Liu, Shou-Qin; Yin, Xi-Xiang; Li, Huai-Chen

2017-09-11

We aimed to assess the acute effects of ambient air pollution and weather conditions on mortality in the context of Chinese smog episodes. A total of 209,321 deaths were recorded in Jinan, a large city in eastern China, during 2011-15. The mean concentrations of daily particulate matter ≤10 μm (PM 10 ), fine particulate matter (PM 2.5 ), sulfur dioxide (SO 2 ) and nitrogen dioxide (NO 2 ) were 169 μg/m 3 , 100 μg/m 3 , 77 μg/m 3 , and 54 μg/m 3 , respectively. Increases of 10 μg/m 3 in PM 10 , PM 2.5 , SO 2 and NO 2 were associated with 1.11% (95% CI 0.96-1.26%), 0.71% (95% CI 0.60-0.82%), 1.69% (95% CI 1.56-1.83%), and 3.12% (95% CI 2.72-3.53%) increases in daily non-accidental mortality rates, respectively. Moreover, the risk estimates for these 4 pollutants were higher in association with respiratory and cardiovascular mortality. The effects of all the evaluated pollutants on mortality were greater in winter than in summer. Smog episodes were associated with a 5.87% (95% CI 0.16-11.58%) increase in the rate of overall mortality. This study highlights the effect of exposure to air pollution on the rate of mortality in China.

Real-time ambient air monitoring adjacent to the Houston ship channel for volatile organic compounds associated with the refinery operations using the trace atmospheric gas analyzer (TAGA)

International Nuclear Information System (INIS)

Mickunas, D.B.

2009-01-01

An Urban Air Toxic Monitoring Program was developed by the United States Environmental Protection Agency (US EPA) to help evaluate the potential toxic air pollution in urban areas. The Trace Atmospheric Gas Analyzer (TAGA) was used to monitor the ambient air for target compounds associated with industrial, motor vehicle, and natural emissions sources in areas adjacent to the Houston Ship Channel in Texas. In this study, the TAGA used triple quadrupole technology to perform qualitative and quantitative analyses for benzene, toluene, xylenes, styrene, 1,3-butadiene, methyl tert-butyl ether, and 1,2,3-trichloropropane. The concentrations for the various ion pairs of the target compounds were updated approximately every 2 seconds. The information was incorporated into the geographic information system (GIS) along with the global positioning system (GPS) information for the TAGA location, aerial views of the monitoring area, and meteorological data for the associated region. The information is used to isolate the emission sources and help reduce air pollution. The GPS output helps determine a path-averaged concentration along various routes. Combined with meteorological data, this information can be used in risk assessment to calculate downwind impacts associated with the target compounds under other meteorological conditions and to determine health impacts. It was concluded that the TAGA can provide rapid, accurate and reliable analytical information for monitoring ambient air. 2 refs., 1 tab., 9 figs

Real-time ambient air monitoring adjacent to the Houston ship channel for volatile organic compounds associated with the refinery operations using the trace atmospheric gas analyzer (TAGA)

Energy Technology Data Exchange (ETDEWEB)

Mickunas, D.B. [United States Environmental Protection Agency, Research Triangle Park, NC (United States). Environmental Response Team; Wood, J.; Weeks, W. [Lockheed Martin Response Engineering and Analytical Contract, Edison, NJ (Canada)

2009-07-01

An Urban Air Toxic Monitoring Program was developed by the United States Environmental Protection Agency (US EPA) to help evaluate the potential toxic air pollution in urban areas. The Trace Atmospheric Gas Analyzer (TAGA) was used to monitor the ambient air for target compounds associated with industrial, motor vehicle, and natural emissions sources in areas adjacent to the Houston Ship Channel in Texas. In this study, the TAGA used triple quadrupole technology to perform qualitative and quantitative analyses for benzene, toluene, xylenes, styrene, 1,3-butadiene, methyl tert-butyl ether, and 1,2,3-trichloropropane. The concentrations for the various ion pairs of the target compounds were updated approximately every 2 seconds. The information was incorporated into the geographic information system (GIS) along with the global positioning system (GPS) information for the TAGA location, aerial views of the monitoring area, and meteorological data for the associated region. The information is used to isolate the emission sources and help reduce air pollution. The GPS output helps determine a path-averaged concentration along various routes. Combined with meteorological data, this information can be used in risk assessment to calculate downwind impacts associated with the target compounds under other meteorological conditions and to determine health impacts. It was concluded that the TAGA can provide rapid, accurate and reliable analytical information for monitoring ambient air. 2 refs., 1 tab., 9 figs.

High Concentrations of Organic Contaminants in Air from Ship Breaking Activities in Chittagong, Bangladesh.

Science.gov (United States)

Nøst, Therese H; Halse, Anne K; Randall, Scott; Borgen, Anders R; Schlabach, Martin; Paul, Alak; Rahman, Atiqur; Breivik, Knut

2015-10-06

The beaches on the coast of Chittagong in Bangladesh are one of the most intense ship breaking areas in the world. The aim of the study was to measure the concentrations of organic contaminants in the air in the city of Chittagong, including the surrounding ship breaking areas using passive air samplers (N = 25). The compounds detected in the highest amounts were the polycyclic aromatic hydrocarbons (PAHs) and short-chain chlorinated paraffins (SCCPs), whereas dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB), and polychlorinated biphenyls (PCBs) were several orders of magnitude lower in comparison. PCBs, PAHs, and HCB were highest at sites near the ship breaking activities, whereas DDTs and SCCPs were higher in the urban areas. Ship breaking activities likely act as atmospheric emission sources of PCBs, PAHs, and HCB, thus adding to the international emphasis on responsible recycling of ships. Concentrations of PAHs, PCBs, DDTs, HCB, and SCCPs in ambient air in Chittagong are high in comparison to those found in similar studies performed in other parts of Asia. Estimated toxic equivalent quotients indicate elevated human health risks caused by inhalation of PAHs at most sites.

Ambient Ozone Concentrations and the Risk of Perforated and Nonperforated Appendicitis: A Multicity Case-Crossover Study

Science.gov (United States)

Tanyingoh, Divine; Dixon, Elijah; Johnson, Markey; Wheeler, Amanda J.; Myers, Robert P.; Bertazzon, Stefania; Saini, Vineet; Madsen, Karen; Ghosh, Subrata; Villeneuve, Paul J.

2013-01-01

Background: Environmental determinants of appendicitis are poorly understood. Past work suggests that air pollution may increase the risk of appendicitis. Objectives: We investigated whether ambient ground-level ozone (O3) concentrations were associated with appendicitis and whether these associations varied between perforated and nonperforated appendicitis. Methods: We based this time-stratified case-crossover study on 35,811 patients hospitalized with appendicitis from 2004 to 2008 in 12 Canadian cities. Data from a national network of fixed-site monitors were used to calculate daily maximum O3 concentrations for each city. Conditional logistic regression was used to estimate city-specific odds ratios (ORs) relative to an interquartile range (IQR) increase in O3 adjusted for temperature and relative humidity. A random-effects meta-analysis was used to derive a pooled risk estimate. Stratified analyses were used to estimate associations separately for perforated and nonperforated appendicitis. Results: Overall, a 16-ppb increase in the 7-day cumulative average daily maximum O3 concentration was associated with all appendicitis cases across the 12 cities (pooled OR = 1.07; 95% CI: 1.02, 1.13). The association was stronger among patients presenting with perforated appendicitis for the 7-day average (pooled OR = 1.22; 95% CI: 1.09, 1.36) when compared with the corresponding estimate for nonperforated appendicitis [7-day average (pooled OR = 1.02, 95% CI: 0.95, 1.09)]. Heterogeneity was not statistically significant across cities for either perforated or nonperforated appendicitis (p > 0.20). Conclusions: Higher levels of ambient O3 exposure may increase the risk of perforated appendicitis. PMID:23842601

Modeling Study of the Contribution of Wildfires to Ambient Black Carbon Concentrations

Science.gov (United States)

Chung, S. H.; Gonzalez-Abraham, R.; Lamb, B. K.; Larkin, N. K.; Strand, T.; O'Neill, S.

2013-12-01

Wildland fires are a major source of particulate emissions, including black carbon (BC). In combination with other emissions, these BC and particulate emissions can directly lead to air quality degradation, both locally and more regionally. BC and other particulate matter (PM) can also affect climate in various ways, including by scattering and absorbing radiation, modifying cloud formation and properties, and changing snow albedo. BC emissions reduction is a potential strategy for mitigating global warming because it is emitted in large quantities and has a relatively short lifetime in the atmosphere in comparison to long-live greenhouse gases. Due to the highly variable nature of wildland fires, both in terms of fire occurrences on the landscape and the high spatial and temporal variability of fuels, consumption, and emissions, the impact of wildfire emissions varies significantly over the period of the wildfire season as well as inter-annually. In the U.S., while anthropogenic emissions are projected to decrease, as the climate warms wildfire activity is predicted to increase along with the contribution of fire emissions. Thus, a robust analysis of the effects of BC from fire emissions on air quality and climate necessitates a comprehensive, multi-scale study of all fire-related pollutants and other emission sources spanning multiple years of fire data and weather conditions. In this study we apply the WRF-BlueSky-SMOKE-CMAQ regional air-quality modeling system for multi-year (1997-2005) summertime simulations to evaluate the contribution of fire emissions to atmospheric BC and total PM2.5 concentrations. Historical fire records from the Bureau of Land Management are used by the BlueSky framework to calculate fire emissions. Plume rise is calculated by the SMOKE emission processor, taking into account meteorology from the WRF model. These emissions are combined with anthropogenic emissions from the NEI 2002 and biogenic emissions from the MEGAN model. CMAQ is

Trends in on-road vehicle emissions and ambient air quality in Atlanta, Georgia, USA, from the late 1990s through 2009.

Science.gov (United States)

Vijayaraghavan, Krish; DenBleyker, Allison; Ma, Lan; Lindhjem, Chris; Yarwood, Greg

2014-07-01

On-road vehicle emissions of carbon monoxide (CO), nitrogen oxides (NO(x)), and volatile organic compounds (VOCs) during 1995-2009 in the Atlanta Metropolitan Statistical Area were estimated using the Motor Vehicle Emission Simulator (MOVES) model and data from the National Emissions Inventories and the State of Georgia. Statistically significant downward trends (computed using the nonparametric Theil-Sen method) in annual on-road CO, NO(x), and VOC emissions of 6.1%, 3.3%, and 6.0% per year, respectively, are noted during the 1995-2009 period despite an increase in total vehicle distance traveled. The CO and NO(x) emission trends are correlated with statistically significant downward trends in ambient air concentrations of CO and NO(x) in Atlanta ranging from 8.0% to 11.8% per year and from 5.8% to 8.7% per year, respectively, during similar time periods. Weather-adjusted summertime ozone concentrations in Atlanta exhibited a statistically significant declining trend of 2.3% per year during 2001-2009. Although this trend coexists with the declining trends in on-road NO(x), VOC, and CO emissions, identifying the cause of the downward trend in ozone is complicated by reductions in multiple precursors from different source sectors. Implications: Large reductions in on-road vehicle emissions of CO and NO(x) in Atlanta from the late 1990s to 2009, despite an increase in total vehicle distance traveled, contributed to a significant improvement in air quality through decreases in ambient air concentrations of CO and NO(x) during this time period. Emissions reductions in motor vehicles and other source sectors resulted in these improvements and the observed declining trend in ozone concentrations over the past decade. Although these historical trends cannot be extrapolated to the future because pollutant concentration contributions due to on-road vehicle emissions will likely become an increasingly smaller fraction of the atmospheric total, they provide an indication of

Personal exposures of preschool children to carbon monoxide: roles of ambient air quality and gas stoves

Energy Technology Data Exchange (ETDEWEB)

Alm, S.; Reponen, A.; Mukala, K.; Pasanen, P.; Tuomisto, J.; Jantunen, M.J. (National Public Health Institute, Kuopio (Finland). Division of Environmental Health)

1994-12-01

Personal 1 h mean CO exposures of preschool children in two day care centers (Toolo and Vallila) in Helsinki were measured with continuously recording personal exposure monitors. In Vallila, the median CO exposure of children from homes with gas stoves was 2.0 mgm[sup -3], and with electric stoves, 0.9 mgm[sup -3]. In Tooloo, the corresponding values were 1.9 and 1.0 mgm[sup -3], respectively. The national ambient air quality guidelines for CO in Finland were exceeded in a few percent of the exposure measurements. The results were compared to fixed-site ambient air monitoring data and related to the presence of town-gas fired stoves in the children's homes. The results show that fixed-site ambient air monitors are of little value in predicting personal exposures of children or even their relative differences between areas. They also show that town-gas fired stoves may have a profound effect on the CO exposures of the children. 8 refs., 4 figs., 3 tabs.

Combined cadmium and elevated ozone affect concentrations of cadmium and antioxidant systems in wheat under fully open-air conditions

International Nuclear Information System (INIS)

Guo, Hongyan; Tian, Ran; Zhu, Jianguo; Zhou, Hui; Pei, Daping; Wang, Xiaorong

2012-01-01

Highlights: ► Combined effect of elevated O 3 and Cd levels on wheat was studied using the free-air concentration enrichment system. ► Elevated O 3 levels result in an increased concentration of Cd in wheat plants grown on Cd-contaminated soils. ► Combined cadmium and elevated O 3 have a significantly synergic effect on oxidative stress in wheat shoots. - Abstract: Pollution of the environment with both ozone (O 3 ) and heavy metals has been steadily increasing. An understanding of their combined effects on plants, especially crops, is limited. Here we studied the effects of elevated O 3 on oxidative stress and bioaccumulation of cadmium (Cd) in wheat under Cd stress using a free-air concentration enrichment (FACE) system. In this field experiment in Jiangdu (Jiangsu Province, China), wheat plants were grown in pots containing soil with various concentrations of cadmium (0, 2, and 10 mg kg −1 Cd was added to the soil) under ambient conditions and under elevated O 3 levels (50% higher than the ambient O 3 ). Present results showed that elevated O 3 led to higher concentrations of Cd in wheat tissues (shoots, husk and grains) with respect to contaminated soil. Combined exposure to Cd and elevated O 3 levels strongly affected the antioxidant isoenzymes POD, APX and CAT and accelerated oxidative stress in wheat leaves. Our results suggest that elevated O 3 levels cause a reduction in food quality and safety.

Public health implications of urban air pollution in developing countries

Energy Technology Data Exchange (ETDEWEB)

Schwela, D.H. [World Health Organisation, Geneva (Switzerland)

1995-12-31

Exposure to air pollution is an almost inescapable part of urban life throughout the world. Ambient air pollutant levels in urban areas are generally a reflection of emissions. For sulphur dioxide, total suspended particulate matter and lead, ambient concentrations are declining in the industrialized western countries. For nitrogen dioxide, ambient levels in cities are generally constant, or slightly increasing. For carbon dioxide, they are variable, declining where controls are being applied. In a substantial number of cities, particularly in developing countries, WHO guidelines are being often exceeded for the compounds mentioned. Given the rate at which these cities are growing, the air pollution situation will probably worsen if environmental control measures are not implemented. As a consequence, the health and well-being of urban residents will further deteriorate with high ambient air pollutant concentrations causing increased mortality, morbidity, deficits on pulmonary functions and cardiovascular and neurobehavioural effects. (author)

Public health implications of urban air pollution in developing countries

Energy Technology Data Exchange (ETDEWEB)

Schwela, D H [World Health Organisation, Geneva (Switzerland)

1996-12-31

Exposure to air pollution is an almost inescapable part of urban life throughout the world. Ambient air pollutant levels in urban areas are generally a reflection of emissions. For sulphur dioxide, total suspended particulate matter and lead, ambient concentrations are declining in the industrialized western countries. For nitrogen dioxide, ambient levels in cities are generally constant, or slightly increasing. For carbon dioxide, they are variable, declining where controls are being applied. In a substantial number of cities, particularly in developing countries, WHO guidelines are being often exceeded for the compounds mentioned. Given the rate at which these cities are growing, the air pollution situation will probably worsen if environmental control measures are not implemented. As a consequence, the health and well-being of urban residents will further deteriorate with high ambient air pollutant concentrations causing increased mortality, morbidity, deficits on pulmonary functions and cardiovascular and neurobehavioural effects. (author)

Photocatalytic removal of nitrogen oxides from ambient air using solar energy; Taiyo energy wo riyoshita taikichu no NOx no hikari shokubai jokyo

Energy Technology Data Exchange (ETDEWEB)

Fukaya, M; Taoda, H; Watanabe, E; Nonami, T; Iseda, K; Kato, K [National Industrial Research Institute of Nagoya, Nagoya (Japan); Kunieda, S [NGK Insulators, Ltd., Nagoya (Japan); Kato, S

1997-11-25

Experiment was made on removal of NOx from ambient air using ceramic blocks coated with a newly developed easy-to- handle TiO2 film photocatalyst. After TiO2 sol was prepared by hydrolyzing titanium tetraisopropoxide, the photocatalytic blocks were prepared through drying and sintering after immersing the blocks in TiO2 sol. The effect of the number of coating on catalytic performance was studied using the single-coated and triple-coated blocks. Artificial solar light of 1mW/cm{sup 2} was used as light source for flowing reaction experiment of air (containing NOx) in a laboratory. NOx concentration rapidly decreased with irradiation, and 94% and 98% of NOx were removed by the single- and triple-coated blocks, respectively. NOx was completely oxidized to HNO3 through NO2 by triple-coated blocks. The demonstration test of removal of NOx from ambient air in Okazaki city showed a removal rate of nearly 90% in noonday and 40% or more in average, while not 0% but 5-20% even in the nighttime. The latter is probably derived from adsorption by the porous photocatalytic blocks. 2 figs., 4 tabs.

Ambient air pollution and primary liver cancer incidence in four European cohorts within the ESCAPE project

NARCIS (Netherlands)

Pedersen, Marie; Andersen, Zorana J; Stafoggia, Massimo; Weinmayr, Gudrun; Galassi, Claudia; Sørensen, Mette; Eriksen, Kirsten T; Tjønneland, Anne; Loft, Steffen; Jaensch, Andrea; Nagel, Gabriele; Concin, Hans; Tsai, Ming-Yi; Grioni, Sara; Marcon, Alessandro; Krogh, Vittorio; Ricceri, Fulvio; Sacerdote, Carlotta; Ranzi, Andrea; Sokhi, Ranjeet; Vermeulen, Roel|info:eu-repo/dai/nl/216532620; Hoogh, Kees de; Wang, Meng; Beelen, Rob|info:eu-repo/dai/nl/30483100X; Vineis, Paolo; Brunekreef, Bert|info:eu-repo/dai/nl/067548180; Hoek, Gerard|info:eu-repo/dai/nl/069553475; Raaschou-Nielsen, Ole

2017-01-01

BACKGROUND: Tobacco smoke exposure increases the risk of cancer in the liver, but little is known about the possible risk associated with exposure to ambient air pollution. OBJECTIVES: We evaluated the association between residential exposure to air pollution and primary liver cancer incidence.

Intraurban Spatiotemporal Variability of Ambient Air Pollutants across Metropolitan St. Louis

Science.gov (United States)

Du, Li

Ambient air monitoring networks have been established in the United States since the 1970s to comply with the Clean Air Act. The monitoring networks are primarily used to determine compliance but also provide substantive support to air quality management and air quality research including studies on health effects of air pollutants. The Roxana Air Quality Study (RAQS) was conducted at the fenceline of a petroleum refinery in Roxana, Illinois. In addition to providing insights into air pollutant impacts from the refinery, these measurements increased the St. Louis area monitoring network density for gaseous air toxics and fine particulate matter (PM2.5) speciation and thus provided an opportunity to examine intraurban spatiotemporal variability for these air quality parameters. This dissertation focused on exploring and assessing aspects of ambient air pollutant spatiotemporal variability in the St. Louis area from three progressively expanded spatial scales using a suite of methods and metrics. RAQS data were used to characterize air quality conditions in the immediate vicinity of the petroleum refinery. For example, PM2.5 lanthanoids were used to track impacts from refinery fluidized bed catalytic cracker emissions. RAQS air toxics data were interpreted by comparing to network data from the Blair Street station in the City of St. Louis which is a National Air Toxics Trends Station. Species were classified as being spatially homogeneous (similar between sites) or heterogeneous (different between sites) and in the latter case these differences were interpreted using surface winds data. For PM 2.5 species, there were five concurrently operating sites in the St. Louis area - including the site in Roxana - which are either formally part of the national Chemical Speciation Network (CSN) or rigorously follow the CSN sampling and analytical protocols. This unusually large number of speciation sites for a region the size of St. Louis motivated a detailed examination of

Determination of sulfur dioxide in ambient air and in industrial stack using X-ray fluorescence technique

International Nuclear Information System (INIS)

Sumitra, T.; Chankow, N.; Punnachaiya, S.; Laopaibul, R.

1988-01-01

Sulfur dioxide is a major air pollutant of concern. The gas has to be monitored both in ambient air and in industrial stacks. There are several methods of measuring sulfur dioxide. Standard methods adopted for Thailand are based on chemical methods. These are normally sensitive to light and temperature changes. Therefore a method of collecting air sample and determination of SO 2 by X-ray fluorescence technique was developed. Air sampling was done by an in-house low cost air sampler using automobile battery, dependency on a.c. source was thus avoided. The air pump has a flow rate between 0.2-1.5 liters/minute and draw about 0.6 A from a 12 V battery. SO 2 was collected on 37 mm filters impregnated with 5% sodium carbonate. This method could detect SO 2 from 10 μg up. The method has been checked by interlaboratory comparison. Field test has also been performed at some tobacco curing plants in Amphoe Sansai, Changwat Chiengmai, both in ambient air and in stacks. The results were found to be satisfactory and comparable with the standard methods

The effect of the lead from the ambient air and health evaluation of the school children population

International Nuclear Information System (INIS)

Kochubovski, Mihail Vasil

2003-01-01

Veles with its geographic position, atmospheric specifics, urban and industrial concentration with wrong location of the Lead and Zink Smelter-opposite to the Wind Rose, multiplied by inconvenient power plants is analysedhydro-topographic factors has all predispositions for huge and continuous air pollution (3 decades) with specific agent-lead. There is statistically high significant difference by Student t-test (t = 15.14; p 3 ), related to the control area-v.lvankovci (x = 0.03 μg/m 3 ) . Registered average annual concentration of lead in the ambient air is 89% higher than the recommended value from WHO and EU (0.5 μg/m 3 ). Increased concentration of lead in the ambient air, represent high risk factor for the health of the exposed children population in the city of Veles. There has been registered statistically significant difference (t = 3.96; p 20 μg/dl). Pearson test of correlation between registered values of EEG and the intelligence quotient, has shown negative moderate correlation (r = -0.31; p < 0.05). With Pearson test of correlation between registered values of EEG and blood-lead levels, has been got low correlation (r = 0.12; p < 0.05). It can be concluded that all registered outputs in the examined children can be reversible, and still they are in compensatory phase without clear clinical sign of disease. Electromyography has not shown any disorder in neuromuscular conductivity in selected children. Pearson test of correlation between registered values of SEMG and blood-lead levels, has shown negative correlation (r = -0.07; p < 0.05). Results shows that selected children are with normal activity of the autonomous nervous system and they adequately respond to the stress situation. It can be concluded that there is an obvious environmental-health risk in Veles, with enough evidences for the pollution of the environment in Veles, as well the impact of higher blood-lead levels to NAG, IQ, graphomotoric ability in the examined children, as well to EEG

Seasonal variation, risk assessment and source estimation of PM 10 and PM10-bound PAHs in the ambient air of Chiang Mai and Lamphun, Thailand.

Science.gov (United States)

Pengchai, Petch; Chantara, Somporn; Sopajaree, Khajornsak; Wangkarn, Sunanta; Tengcharoenkul, Urai; Rayanakorn, Mongkon

2009-07-01

Daily PM10 concentrations were measured at four sampling stations located in Chiang Mai and Lamphun provinces, Thailand. The sampling scheme was conducted during June 2005 to June 2006; every 3 days for 24 h in each sampling period. The result revealed that all stations shared the same pattern, in which the PM10 (particulate matters with diameter of less than 10 microm) concentration increased at the beginning of dry season (December) and reached its peak in March before decreasing by the end of April. The maximum PM10 concentration for each sampling station was in the range of 140-182 microg/m(3) which was 1.1-1.5 times higher than the Thai ambient air quality standard of 120 microg/m(3). This distinctly high concentration of PM10 in the dry season (Dec. 05-Mar. 06) was recognized as a unique seasonal pattern for the northern part of Thailand. PM10 concentration had a medium level of negative correlation (r = -0.696 to -0.635) with the visibility data. Comparing the maximum PM10 concentration detected at each sampling station to the permitted PM10 level of the national air quality standard, the warning visibility values for the PM10 pollution-watch system were determined as 10 km for Chiang Mai Province and 5 km for Lamphun Province. From the analysis of PM10 constituents, no component exceeded the national air quality standard. The total concentrations of PM10-bond polycyclic aromatic hydrocarbons (PAHs) are calculated in terms of total toxicity equivalent concentrations (TTECs) using the toxicity equivalent factors (TEFs) method. TTECs in Chiang Mai and Lamphun ambient air was found at a level comparable to those observed in Nagasaki, Bangkok and Rome and at a lower level than those reported at Copenhagen. The annual number of lung cancer cases for Chiang Mai and Lamphun Provinces was estimated at two cases/year which was lower than the number of cases in Bangkok (27 cases/year). The principal component analysis/absolute principal component scores (PCA

Design and laboratory testing of a new flow-through directional passive air sampler for ambient particulate matter.

Science.gov (United States)

Lin, Chun; Solera Garcia, Maria Angeles; Timmis, Roger; Jones, Kevin C

2011-03-01

A new type of directional passive air sampler (DPAS) is described for collecting particulate matter (PM) in ambient air. The prototype sampler has a non-rotating circular sampling tray that is divided into covered angular channels, whose ends are open to winds from sectors covering the surrounding 360°. Wind-blown PM from different directions enters relevant wind-facing channels, and is retained there in collecting pools containing various sampling media. Information on source direction and type can be obtained by examining the distribution of PM between channels. Wind tunnel tests show that external wind velocities are at least halved over an extended area of the collecting pools, encouraging PM to settle from the air stream. Internal and external wind velocities are well-correlated over an external velocity range of 2.0-10.0 m s⁻¹, which suggests it may be possible to relate collected amounts of PM simply to ambient concentrations and wind velocities. Measurements of internal wind velocities in different channels show that velocities decrease from the upwind channel round to the downwind channel, so that the sampler effectively resolves wind directions. Computational fluid dynamics (CFD) analyses were performed on a computer-generated model of the sampler for a range of external wind velocities; the results of these analyses were consistent with those from the wind tunnel. Further wind tunnel tests were undertaken using different artificial particulates in order to assess the collection performance of the sampler in practice. These tests confirmed that the sampler can resolve the directions of sources, by collecting particulates preferentially in source-facing channels.

Femtosecond laser ablation of polytetrafluoroethylene (Teflon) in ambient air

International Nuclear Information System (INIS)

Wang, Z.B.; Hong, M.H.; Lu, Y.F.; Wu, D.J.; Lan, B.; Chong, T.C.

2003-01-01

Teflon, polytetrafluorethylene (PTFE), is an important material in bioscience and medical application due to its special characteristics (bio-compatible, nonflammable, antiadhesive, and heat resistant). The advantages of ultrashort laser processing of Teflon include a minimal thermal penetration region and low processing temperatures, precision removal of material, and good-quality feature definition. In this paper, laser processing of PTFE in ambient air by a Ti:sapphire femtosecond laser (780 nm, 110 fs) is investigated. It is found that the pulse number on each irradiated surface area must be large enough for a clear edge definition and the ablated depth increases with the pulse number. The air ionization effect at high laser fluences not only degrades the ablated structures quality but also reduces the ablation efficiency. High quality microstructures are demonstrated with controlling laser fluence below a critical fluence to exclude the air ionization effect. The ablated microstructures show strong adhesion property to liquids and clear edges that are suitable for bio-implantation applications. Theoretical calculation is used to analyze the evolution of the ablated width and depth at various laser fluences

Assessing the effects of oil sands related ozone precursor emissions on ambient ozone levels in the Alberta oil sands region, Canada

Science.gov (United States)

Cho, Sunny; Vijayaraghavan, Krish; Spink, David; Cosic, Biljana; Davies, Mervyn; Jung, Jaegun

2017-11-01

A study was undertaken to determine whether, and the extent to which, increased ground-level ozone (O3) precursor emissions from oil sands development have impacted ambient air quality in the north-eastern Alberta, Canada, over the period 1998 to 2012. Temporal trends in emissions of O3 precursors (NOx and VOC) and ambient air concentrations of O3 precursors, and O3 were examined using the Theil-Sen statistical analysis method. Statistically significant correlations between NOx emissions and ambient NOx concentrations were found mainly near surface (open-pit) mining areas where mine fleets are a large source of NOx emissions. No statistically significant trends in the 4th highest daily maximum 8-hr average O3 at any of the continuous and passive ambient air monitoring stations were found. A significant long-term decrease in monthly averaged O3 is observed at some ambient monitoring sites in summer. A visual examination of long-term variations in annual NOx and VOC emissions and annual 4th highest daily maximum 8-hr O3 concentrations does not reveal any indication of a correlation between O3 concentrations and O3 precursor emissions or ambient levels in the study area. Despite a significant increase in oil sands NOx emissions (8%/yr), there is no statistically significant increase in long-term O3 concentrations at any of monitoring stations considered. This suggests that there is surplus NOx available in the environment which results in a titration of ambient O3 in the areas that have ambient monitoring. The limited ambient O3 monitoring data distant from NOx emission sources makes it impossible to assess the impact of these increased O3 precursor levels on O3 levels on a regional scale. As a precautionary measure, the increasing oil sands development O3 precursor emissions would require that priority be given to the management of these emissions to prevent possible future O3 ambient air quality issues.

Health risk assessment on human exposed to heavy metals in the ambient air PM10 in Ahvaz, southwest Iran

Science.gov (United States)

Goudarzi, Gholamreza; Alavi, Nadali; Geravandi, Sahar; Idani, Esmaeil; Behrooz, Hamid Reza Adeli; Babaei, Ali Akbar; Alamdari, Farzaneh Aslanpour; Dobaradaran, Sina; Farhadi, Majid; Mohammadi, Mohammad Javad

2018-02-01

Heavy metals (HM) are one of the main components of urban air pollution. Today, megacities and industrial regions in southwest of Iran are frequently suffering from severe haze episodes, which essentially caused by PM10-bound heavy metals. The purpose of this study was to evaluate the health risk assessment on human exposed to heavy metals (Cr, Ni, Pb, and Zn) in the ambient air PM10 in Ahvaz, southwest Iran. In this study, we estimated healthy people from the following scenarios: (S3) residential site; (S2) high-traffic site; (S1) industrial site in Ahvaz metropolitan during autumn and winter. In the current study, high-volume air samplers equipped with quartz fiber filters were used to sampling and measurements of heavy metal concentration. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was utilized for detection of heavy metal concentration (ng m-3). Also, an estimate of the amount of health risk assessment (hazard index) of Cr, Ni, Pb, and Zn of heavy metal exposure to participants was used. Result of this study showed that the residential and industrial areas had the lowest and the highest level of heavy metal. Based on the result of this study, average levels of heavy metal in industrial, high-traffic, and residential areas in autumn and winter were 31.48, 30.89, and 23.21 μg m-3 and 42.60, 37.70, and 40.07 μg m-3, respectively. Based on the result of this study, the highest and the lowest concentration of heavy metal had in the industrial and residential areas. Zn and Pb were the most abundant elements among the studied PM10-bound heavy metals, followed by Cr and Ni. The carcinogenic risks of Cr, Pb, and the integral HQ of metals in PM10 for children and adults via inhalation and dermal exposures exceeded 1 × 10-4 in three areas. Also, based on the result of this study, the values of hazard index (HI) of HM exposure in different areas were significantly higher than standard. The health risks attributed to HM should be further

Sensor-less control of the methanol concentration of direct methanol fuel cells at varying ambient temperatures

International Nuclear Information System (INIS)

An, Myung-Gi; Mehmood, Asad; Ha, Heung Yong

2014-01-01

Highlights: • A new algorithm is proposed for the sensor-less control of methanol concentration. • Two different strategies are used depending on the ambient temperatures. • Energy efficiency of the DMFC system has been improved by using the new algorithm. - Abstract: A new version of an algorithm is used to control the methanol concentration in the feed of DMFC systems without using methanol sensors under varying ambient temperatures. The methanol concentration is controlled indirectly by controlling the temperature of the DMFC stack, which correlates well with the methanol concentration. Depending on the ambient temperature relative to a preset reference temperature, two different strategies are used to control the stack temperature: either reducing the cooling rate of the methanol solution passing through an anode-side heat exchanger; or, lowering the pumping rate of the pure methanol to the depleted feed solution. The feasibility of the algorithm is evaluated using a DMFC system that consists of a 200 W stack and the balance of plant (BOP). The DMFC system includes a sensor-less methanol controller that is operated using a LabView system as the central processing unit. The algorithm is experimentally confirmed to precisely control the methanol concentration and the stack temperature at target values under an environment of varying ambient temperatures

Chromatography related performance of the Monitor for AeRosols and GAses in ambient air (MARGA: laboratory and field-based evaluation

Directory of Open Access Journals (Sweden)

X. Chen

2017-10-01

Full Text Available Evaluation of the semi-continuous Monitor for AeRosols and GAses in ambient air (MARGA, Metrohm Applikon B.V. was conducted with an emphasis on examination of accuracy and precision associated with processing of chromatograms. Using laboratory standards and atmospheric measurements, analytical accuracy, precision and method detection limits derived using the commercial MARGA software were compared to an alternative chromatography procedure consisting of a custom Java script to reformat raw MARGA conductivity data and Chromeleon (Thermo Scientific Dionex software for peak integration. Our analysis revealed issues with accuracy and precision resulting from misidentification and misintegration of chromatograph peaks by the MARGA automated software as well as a systematic bias at low concentrations for anions. Reprocessing and calibration of raw MARGA data using the alternative chromatography method lowered method detection limits and reduced variability (precision between parallel sampler boxes. Instrument performance was further evaluated during a 1-month intensive field campaign in the fall of 2014, including analysis of diurnal patterns of gaseous and particulate water-soluble species (NH3, SO2, HNO3, NH4+, SO42− and NO3−, gas-to-particle partitioning and particle neutralization state. At ambient concentrations below  ∼  1 µg m−3, concentrations determined using the MARGA software are biased +30 and +10 % for NO3− and SO42−, respectively, compared to concentrations determined using the alternative chromatography procedure. Differences between the two methods increase at lower concentrations. We demonstrate that positively biased NO3− and SO42− measurements result in overestimation of aerosol acidity and introduce nontrivial errors to ion balances of inorganic aerosol. Though the source of the bias is uncertain, it is not corrected by the MARGA online single-point internal LiBr standard. Our results show that

Chromatography related performance of the Monitor for AeRosols and GAses in ambient air (MARGA): laboratory and field-based evaluation

Science.gov (United States)

Chen, Xi; Walker, John T.; Geron, Chris

2017-10-01

Evaluation of the semi-continuous Monitor for AeRosols and GAses in ambient air (MARGA, Metrohm Applikon B.V.) was conducted with an emphasis on examination of accuracy and precision associated with processing of chromatograms. Using laboratory standards and atmospheric measurements, analytical accuracy, precision and method detection limits derived using the commercial MARGA software were compared to an alternative chromatography procedure consisting of a custom Java script to reformat raw MARGA conductivity data and Chromeleon (Thermo Scientific Dionex) software for peak integration. Our analysis revealed issues with accuracy and precision resulting from misidentification and misintegration of chromatograph peaks by the MARGA automated software as well as a systematic bias at low concentrations for anions. Reprocessing and calibration of raw MARGA data using the alternative chromatography method lowered method detection limits and reduced variability (precision) between parallel sampler boxes. Instrument performance was further evaluated during a 1-month intensive field campaign in the fall of 2014, including analysis of diurnal patterns of gaseous and particulate water-soluble species (NH3, SO2, HNO3, NH4+, SO42- and NO3-), gas-to-particle partitioning and particle neutralization state. At ambient concentrations below ˜ 1 µg m-3, concentrations determined using the MARGA software are biased +30 and +10 % for NO3- and SO42-, respectively, compared to concentrations determined using the alternative chromatography procedure. Differences between the two methods increase at lower concentrations. We demonstrate that positively biased NO3- and SO42- measurements result in overestimation of aerosol acidity and introduce nontrivial errors to ion balances of inorganic aerosol. Though the source of the bias is uncertain, it is not corrected by the MARGA online single-point internal LiBr standard. Our results show that calibration and verification of instrument accuracy

Turbine airfoil with ambient cooling system

Science.gov (United States)

Campbell, Jr, Christian X.; Marra, John J.; Marsh, Jan H.

2016-06-07

A turbine airfoil usable in a turbine engine and having at least one ambient air cooling system is disclosed. At least a portion of the cooling system may include one or more cooling channels configured to receive ambient air at about atmospheric pressure. The ambient air cooling system may have a tip static pressure to ambient pressure ratio of at least 0.5, and in at least one embodiment, may include a tip static pressure to ambient pressure ratio of between about 0.5 and about 3.0. The cooling system may also be configured such that an under root slot chamber in the root is large to minimize supply air velocity. One or more cooling channels of the ambient air cooling system may terminate at an outlet at the tip such that the outlet is aligned with inner surfaces forming the at least one cooling channel in the airfoil to facilitate high mass flow.

Effects of ambient temperature and oxygen concentration on diesel spray combustion using a single-nozzle injector in a constant volume combustion chamber

KAUST Repository

Jing, Wei

2013-09-02

concentrations while the area of OH* emission is larger than the area of Band A and Band B emissions at higher O2 concentrations, for a given ambient temperature. Moreover, the mixture stoichiometry was analyzed using a reformulated definition of excess air ratio for diluted combustion, and this shows that more mixing is required to achieve complete combustion for low ambient oxygen concentration conditions where longer and wider flames are observed. This observation is also verified by the flame length estimated from the NL images. © 2013 Copyright Taylor and Francis Group, LLC.

Effects of ambient temperature and oxygen concentration on diesel spray combustion using a single-nozzle injector in a constant volume combustion chamber

KAUST Repository

Jing, Wei; Roberts, William L.; Fang, Tiegang

2013-01-01

concentrations while the area of OH* emission is larger than the area of Band A and Band B emissions at higher O2 concentrations, for a given ambient temperature. Moreover, the mixture stoichiometry was analyzed using a reformulated definition of excess air ratio for diluted combustion, and this shows that more mixing is required to achieve complete combustion for low ambient oxygen concentration conditions where longer and wider flames are observed. This observation is also verified by the flame length estimated from the NL images. © 2013 Copyright Taylor and Francis Group, LLC.

OZONE AMBIENT AIR QUALITY STANDARD HAS BENEFICIAL EFFECT ON PONDEROSA PINE IN CALIFORNIA

Science.gov (United States)

Ambient air quality standards and control strategies are implemented to protect humans and vegetation from adverse effects. However, to date there has not been a simple and objective method to determine if the standards and resultant control strategies have reduced O3 impacts on ...

Air Pollution Modelling to Predict Maximum Ground Level Concentration for Dust from a Palm Oil Mill Stack

Directory of Open Access Journals (Sweden)

Regina A. A.

2010-12-01

Full Text Available The study is to model emission from a stack to estimate ground level concentration from a palm oil mill. The case study is a mill located in Kuala Langat, Selangor. Emission source is from boilers stacks. The exercise determines the estimate the ground level concentrations for dust to the surrounding areas through the utilization of modelling software. The surround area is relatively flat, an industrial area surrounded by factories and with palm oil plantations in the outskirts. The model utilized in the study was to gauge the worst-case scenario. Ambient air concentrations were garnered calculate the increase to localized conditions. Keywords: emission, modelling, palm oil mill, particulate, POME

The Association between Ambient Air Pollution and Allergic Rhinitis: Further Epidemiological Evidence from Changchun, Northeastern China

Science.gov (United States)

Teng, Bo; Zhang, Xuelei; Yi, Chunhui; Zhang, Yan; Ye, Shufeng; Wang, Yafang; Tong, Daniel Q.; Lu, Binfeng

2017-01-01

With the continuous rapid urbanization process over the last three decades, outdoors air pollution has become a progressively more serious public health hazard in China. To investigate the possible associations, lag effects and seasonal differences of urban air quality on respiratory health (allergic rhinitis) in Changchun, a city in Northeastern China, we carried out a time-series analysis of the incidents of allergic rhinitis (AR) from 2013 to 2015. Environmental monitoring showed that PM2.5 and PM10 were the major air pollutants in Changchun, followed by SO2, NO2 and O3. The results also demonstrated that the daily concentrations of air pollutants had obvious seasonal differences. PM10 had higher daily mean concentrations in spring (May, dust storms), autumn (October, straw burning) and winter (November to April, coal burning). The mean daily number of outpatient AR visits in the warm season was higher than in the cold season. The prevalence of allergic rhinitis was significantly associated with PM2.5, PM10, SO2 and NO2, and the increased mobility was 10.2% (95% CI, 5.5%–15.1%), 4.9% (95% CI, 0.8%–9.2%), 8.5% (95% CI, −1.8%–19.8%) and 11.1% (95% CI, 5.8%–16.5%) for exposure to each 1-Standard Deviation (1-SD) increase of pollutant, respectively. Weakly or no significant associations were observed for CO and O3. As for lag effects, the highest Relative Risks (RRs) of AR from SO2, NO2, PM10 and PM2.5 were on the same day, and the highest RR from CO was on day 4 (L4). The results also indicated that the concentration of air pollutants might contribute to the development of AR. To summarize, this study provides further evidence of the significant association between ambient particulate pollutants (PM2.5 and PM10, which are usually present in high concentrations) and the prevalence of respiratory effects (allergic rhinitis) in the city of Changchun, located in Northeastern China. Environmental control and public health strategies should be enforced to

The Association between Ambient Air Pollution and Allergic Rhinitis: Further Epidemiological Evidence from Changchun, Northeastern China

Directory of Open Access Journals (Sweden)

Bo Teng

2017-02-01

Full Text Available With the continuous rapid urbanization process over the last three decades, outdoors air pollution has become a progressively more serious public health hazard in China. To investigate the possible associations, lag effects and seasonal differences of urban air quality on respiratory health (allergic rhinitis in Changchun, a city in Northeastern China, we carried out a time-series analysis of the incidents of allergic rhinitis (AR from 2013 to 2015. Environmental monitoring showed that PM2.5 and PM10 were the major air pollutants in Changchun, followed by SO2, NO2 and O3. The results also demonstrated that the daily concentrations of air pollutants had obvious seasonal differences. PM10 had higher daily mean concentrations in spring (May, dust storms, autumn (October, straw burning and winter (November to April, coal burning. The mean daily number of outpatient AR visits in the warm season was higher than in the cold season. The prevalence of allergic rhinitis was significantly associated with PM2.5, PM10, SO2 and NO2, and the increased mobility was 10.2% (95% CI, 5.5%–15.1%, 4.9% (95% CI, 0.8%–9.2%, 8.5% (95% CI, −1.8%–19.8% and 11.1% (95% CI, 5.8%–16.5% for exposure to each 1-Standard Deviation (1-SD increase of pollutant, respectively. Weakly or no significant associations were observed for CO and O3. As for lag effects, the highest Relative Risks (RRs of AR from SO2, NO2, PM10 and PM2.5 were on the same day, and the highest RR from CO was on day 4 (L4. The results also indicated that the concentration of air pollutants might contribute to the development of AR. To summarize, this study provides further evidence of the significant association between ambient particulate pollutants (PM2.5 and PM10, which are usually present in high concentrations and the prevalence of respiratory effects (allergic rhinitis in the city of Changchun, located in Northeastern China. Environmental control and public health strategies should be enforced to

Influence of sample temperature and environmental humidity on measurements of benzene in ambient air by transportable GC-PID

Directory of Open Access Journals (Sweden)

C. Romero-Trigueros

2017-10-01

Full Text Available Calibration of in situ analysers of air pollutants is usually done with dry standards. In this paper, the influence of sample temperature and environmental humidity on benzene measurements by gas chromatography coupled with a photoionisation detector (GC-PID is studied. Two reference gas mixtures (40 and 5 µg m−3 nominal concentration benzene in air were subjected to two temperature cycles (20/5/20 °C and 20/35/20 °C and measured with two identical GC-PIDs. The change in sample temperature did not produce any significant change in readings. Regarding ambient humidity, the chromatographs were calibrated for benzene with dry gases and subjected to measure reference standards with humidity (20 and 80 % at 20 °C. When measuring a concentration of 0.5 µg m−3 benzene in air, the levels of humidity tested did not produce any significant interference in measurements taken with any of the analysers. However, when measuring a concentration of 40 µg m−3, biases in measurements of 18 and 21 % for each respective analyser were obtained when the relative humidity of the sample was 80 % at 20 °C. Further tests were carried out to study the nature of this interference. Results show that humidity interference depends on both the amount fractions of water vapour and benzene. If benzene concentrations in an area are close to its annual limit value (5 µg m−3, biases of 2.2 % can be expected when the absolute humidity is 8.6 g cm−3 – corresponding to a relative humidity of 50 % at 20 °C. This can be accounted for in the uncertainty budget of measurements with no need for corrections. If benzene concentrations are above the annual limit value, biases become higher. Thus, in these cases, actions should be taken to reduce the humidity interference, as an underestimation of benzene concentrations may cause a mismanagement of air quality in these situations.

Ambient air pollution, lung function, and airway responsiveness in asthmatic children.

Science.gov (United States)

Ierodiakonou, Despo; Zanobetti, Antonella; Coull, Brent A; Melly, Steve; Postma, Dirkje S; Boezen, H Marike; Vonk, Judith M; Williams, Paul V; Shapiro, Gail G; McKone, Edward F; Hallstrand, Teal S; Koenig, Jane Q; Schildcrout, Jonathan S; Lumley, Thomas; Fuhlbrigge, Anne N; Koutrakis, Petros; Schwartz, Joel; Weiss, Scott T; Gold, Diane R

2016-02-01

Although ambient air pollution has been linked to reduced lung function in healthy children, longitudinal analyses of pollution effects in asthmatic patients are lacking. We sought to investigate pollution effects in a longitudinal asthma study and effect modification by controller medications. We examined associations of lung function and methacholine responsiveness (PC20) with ozone, carbon monoxide (CO), nitrogen dioxide, and sulfur dioxide concentrations in 1003 asthmatic children participating in a 4-year clinical trial. We further investigated whether budesonide and nedocromil modified pollution effects. Daily pollutant concentrations were linked to ZIP/postal code of residence. Linear mixed models tested associations of within-subject pollutant concentrations with FEV1 and forced vital capacity (FVC) percent predicted, FEV1/FVC ratio, and PC20, adjusting for seasonality and confounders. Same-day and 1-week average CO concentrations were negatively associated with postbronchodilator percent predicted FEV1 (change per interquartile range, -0.33 [95% CI, -0.49 to -0.16] and -0.41 [95% CI, -0.62 to -0.21], respectively) and FVC (-0.19 [95% CI, -0.25 to -0.07] and -0.25 [95% CI, -0.43 to -0.07], respectively). Longer-term 4-month CO averages were negatively associated with prebronchodilator percent predicted FEV1 and FVC (-0.36 [95% CI, -0.62 to -0.10] and -0.21 [95% CI, -0.42 to -0.01], respectively). Four-month averaged CO and ozone concentrations were negatively associated with FEV1/FVC ratio (P pollution adversely influences lung function and PC20 in asthmatic children. Treatment with controller medications might not protect but rather worsens the effects of CO on PC20. This clinical trial design evaluates modification of pollution effects by treatment without confounding by indication. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

The range of ambient air pollution by effluents arising by coal combustion in different types of furnaces

International Nuclear Information System (INIS)

Konieczynski, J.; Pason, A.; Zelinski, J.

1994-01-01

The range of ambient air contamination caused by coal incineration in different furnace types was analysed. Application of the integrated emission coefficient enabled to determine domestic stoves as the main source of air pollutants in Gliwice. (Author). 7 refs, 2 tabs

Air pollution exposure modeling of individuals

Science.gov (United States)

Air pollution epidemiology studies of ambient fine particulate matter (PM2.5) often use outdoor concentrations as exposure surrogates. These surrogates can induce exposure error since they do not account for (1) time spent indoors with ambient PM2.5 levels attenuated from outdoor...

The Impact of Future Emissions Changes on Air Pollution Concentrations and Related Human Health Effects

Science.gov (United States)

Mikolajczyk, U.; Suppan, P.; Williams, M.

2015-12-01

Quantification of potential health benefits of reductions in air pollution on the local scale is becoming increasingly important. The aim of this study is to conduct health impact assessment (HIA) by utilizing regionally and spatially specific data in order to assess the influence of future emission scenarios on human health. In the first stage of this investigation, a modeling study was carried out using the Weather Research and Forecasting (WRF) model coupled with Chemistry to estimate ambient concentrations of air pollutants for the baseline year 2009, and for the future emission scenarios in southern Germany. Anthropogenic emissions for the baseline year 2009 are derived from the emission inventory provided by the Netherlands Organization of Applied Scientific Research (TNO) (Denier van der Gon et al., 2010). For Germany, the TNO emissions were replaced by gridded emission data with a high spatial resolution of 1/64 x 1/64 degrees. Future air quality simulations are carried out under different emission scenarios, which reflect possible energy and climate measures in year 2030. The model set-up included a nesting approach, where three domains with horizontal resolution of 18 km, 6 km and 2 km were defined. The simulation results for the baseline year 2009 are used to quantify present-day health burdens. Concentration-response functions (CRFs) for PM2.5 and NO2 from the WHO Health risks of air Pollution in Europe (HRAPIE) project were applied to population-weighted mean concentrations to estimate relative risks and hence to determine numbers of attributable deaths and associated life-years lost. In the next step, future health impacts of projected concentrations were calculated taking into account different emissions scenarios. The health benefits that we assume with air pollution reductions can be used to provide options for future policy decisions to protect public health.

Representativeness of air quality monitoring networks

NARCIS (Netherlands)

Duyzer, J.; Hout, D. van den; Zandveld, P.; Ratingen, S. van

2015-01-01

The suitability of European networks to check compliance with air quality standards and to assess exposure of the population was investigated. An air quality model (URBIS) was applied to estimate and compare the spatial distribution of the concentration of nitrogen dioxide (NO2) in ambient air in

Efficient and stable CH3NH3PbI3-x(SCN)x planar perovskite solar cells fabricated in ambient air with low-temperature process

Science.gov (United States)

Zhang, Zongbao; Zhou, Yang; Cai, Yangyang; Liu, Hui; Qin, Qiqi; Lu, Xubing; Gao, Xingsen; Shui, Lingling; Wu, Sujuan; Liu, Jun-Ming

2018-02-01

Planar perovskite solar cells (PSCs) based on CH3NH3PbI3-x(SCN)x (SCN: thiocyanate) active layer and low-temperature processed TiO2 films are fabricated by a sequential two-step method in ambient air. Here, alkali thiocyanates (NaSCN, KSCN) are added into Pb(SCN)2 precursor to improve the microstructure of CH3NH3PbI3-x(SCN)x perovskite layers and performance of the as-prepared PSCs. At the optimum concentrations of alkali thiocyanates as additives, the as-prepared NaSCN-modified and KSCN-modified PSCs demonstrate the efficiencies of 16.59% and 15.63% respectively, being much higher than 12.73% of the reference PSCs without additives. This improvement is primarily ascribed to the enhanced electron transport, reduced recombination rates and much improved microstructures with large grain size and low defect density at grain boundaries. Importantly, it is revealed that the modified PSCs at the optimized concentrations of alkali thiocyanates additives exhibit remarkably improved stability than the reference PSCs against humid circumstance, and a continuous exposure to humid air without encapsulation over 45 days only records about 5% degradation of the efficiency. These findings provide a facile approach to fabricate efficient and stable PSCs by low processing temperature in ambient air, both of which are highly preferred for future practical applications of PSCs.

EMRP JRP MetNH3: Towards a Consistent Metrological Infrastructure for Ammonia Measurements in Ambient Air

Science.gov (United States)

Leuenberger, Daiana; Balslev-Harder, David; Braban, Christine F.; Ebert, Volker; Ferracci, Valerio; Gieseking, Bjoern; Hieta, Tuomas; Martin, Nicholas A.; Pascale, Céline; Pogány, Andrea; Tiebe, Carlo; Twigg, Marsailidh M.; Vaittinen, Olavi; van Wijk, Janneke; Wirtz, Klaus; Niederhauser, Bernhard

2016-04-01

Measuring ammonia in ambient air is a sensitive and priority issue due to its harmful effects on human health and ecosystems. In addition to its acidifying effect on natural waters and soils and to the additional nitrogen input to ecosystems, ammonia is an important precursor for secondary aerosol formation in the atmosphere. The European Directive 2001/81/EC on "National Emission Ceilings for Certain Atmospheric Pollutants (NEC)" regulates ammonia emissions in the member states. However, there is a lack of regulation regarding certified reference material (CRM), applicable analytical methods, measurement uncertainty, quality assurance and quality control (QC/QA) procedures as well as in the infrastructure to attain metrological traceability. As shown in a key comparison in 2007, there are even discrepancies between reference materials provided by European National Metrology Institutes (NMIs) at amount fraction levels up to three orders of magnitude higher than ambient air levels. MetNH3 (Metrology for ammonia in ambient air), a three-year project that started in June 2014 in the framework of the European Metrology Research Programme (EMRP), aims to reduce the gap between requirements set by the European emission regulations and state-of-the-art of analytical methods and reference materials. The overarching objective of the JRP is to achieve metrological traceability for ammonia measurements in ambient air from primary certified reference material CRM and instrumental standards to the field level. This requires the successful completion of the three main goals, which have been assigned to three technical work packages: To develop improved reference gas mixtures by static and dynamic gravimetric generation methods Realisation and characterisation of traceable preparative calibration standards (in pressurised cylinders as well as mobile generators) of ammonia amount fractions similar to those in ambient air based on existing methods for other reactive analytes. The

Associations between ambient air pollution and daily mortality among persons with congestive heart failure

International Nuclear Information System (INIS)

Goldberg, Mark S.; Burnett, Richard T.; Valois, M.-F.; Flegel, Kenneth; Bailar III, John C.; Brook, Jeffrey; Vincent Renaud; Radon, Katja

2003-01-01

We conducted a mortality time series study to investigate the association between daily mortality for congestive heart failure (CHF), and dail concentrations of particles and gaseous pollutants in the ambient air o Montreal, Quebec, during the period 1984-1993. In addition, using data fro the universal Quebec Health Insurance Plan, we identified individuals ≥6 years of age who, one year before death, had a diagnosis of CHF. Fixed-sit air pollution monitors in Montreal provided daily mean levels of pollutants We regressed the logarithm of daily counts of mortality on the daily mean levels of each pollutant, after accounting for seasonal and subseasonal fluctuations in the mortality time series, non-Poisson dispersion, weather variables, and other gaseous and particle pollutants. Using cause of deat information, we did not find any associations between daily mortality for CH and any air pollutants. The analyses of CHF defined from the medical record showed positive associations with coefficient of haze, the extinction coefficient, SO 2 , and NO 2 . For example, the mean percent increase in dail mortality for an increase in the coefficient of haze across the interquartile range was 4.32% (95% CI: 0.95-7.80%) and for NO 2 it was 4.08% (95% CI 0.59-7.68%). These effects were generally higher in the warm season

Baseline ambient gaseous ammonia concentrations in the Four Corners area and eastern Oklahoma, USA.

Science.gov (United States)

Sather, Mark E; Mathew, Johnson; Nguyen, Nghia; Lay, John; Golod, George; Vet, Robert; Cotie, Joseph; Hertel, Terry; Aaboe, Erik; Callison, Ryan; Adam, Jacque; Keese, Danielle; Freise, Jeremy; Hathcoat, April; Sakizzie, Brenda; King, Michael; Lee, Chris; Oliva, Sylvia; San Miguel, George; Crow, Leon; Geasland, Frank

2008-11-01

Ambient ammonia monitoring using Ogawa passive samplers was conducted in the Four Corners area and eastern Oklahoma, USA during 2007. The resulting data will be useful in the multipollutant management of ozone, nitrogen oxides, and visibility (atmospheric regional haze) in the Four Corners area, an area with growing oil/gas production and increasing coal-based power plant construction. The passive monitoring data also add new ambient ammonia concentration information for the U.S. and will be useful to scientists involved in present and future visibility modeling exercises. Three week integrated passive ammonia samples were taken at five sites in the Four Corners area and two sites in eastern Oklahoma from December, 2006 through December, 2007 (January, 2008 for two sites). Results show significantly higher regional background ammonia concentrations in eastern Oklahoma (1.8 parts per billion (ppb) arithmetic mean) compared to the Four Corners area (0.2 ppb arithmetic mean). Annual mean ammonia concentrations for all Four Corners area sites for the 2007 study ranged from 0.2 ppb to 1.5 ppb. Peak ambient ammonia concentrations occurred in the spring and summer in both areas. The passive samplers deployed at the Stilwell, Oklahoma site compared favorably with other passive samplers and a continuous ammonia monitoring instrument.

Thermogravimetric analysis of silicon carbide-silicon nitride fibers at ambient to 1000 C in air

Science.gov (United States)

Daniels, J. G.; Ledbetter, F. E., III; Clemons, J. M.; Penn, B. G.

1984-01-01

Thermogravimetric analysis of silicon carbide-silicon nitride fibers was carried out at ambient to 1000 C in air. The weight loss over this temperature range was negligible. In addition, the oxidative stability at high temperature for a short period of time was determined. Fibers heated at 1000 C in air for fifteen minutes showed negligible weight loss (i.e., less than 1 percent).

Health and air quality 2005 : phase 2 : valuation of health impacts from air quality in the Lower Fraser Valley airshed

Energy Technology Data Exchange (ETDEWEB)

Furberg, M.; Preston, K. [RWDI West Inc., Vancouver, BC (Canada); Sawyer, D. [Marbek Resource Consultants Ltd., Ottawa, ON (Canada); Brauer, M. [British Columbia Univ., Vancouver, BC (Canada). School of Occupational and Environmental Hygiene; Hanvelt, R. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Health Care and Epidemiology

2005-07-15

This study provided estimates the health benefits and costs associated with specified changes in ambient air concentrations of particulate matter (PM) and ozone in the Lower Fraser Valley (LFV). Estimates were developed on a regional level. The study focused on PM and ozone, as current air quality monitoring data and scientific findings have indicated that these are the air contaminants of greatest concern in the region. Known air quality health outcome relationships were applied in a spreadsheet model to predict changes in health outcomes associated with 6 ambient air quality scenarios for 3 sub-regions within the LFV airshed. Concentration response functions based on epidemiological studies were used to estimate the number of health events associated with changes in air quality. For each scenario, the model calculated the expected number of the following health outcomes: mortality; chronic bronchitis; respiratory hospital admissions; cardiac hospital admissions; emergency room visits; child acute bronchitis; restricted activity days; asthma symptom days; minor restricted activity days and acute respiratory symptom days. The model also produced the dollar value of the health outcomes. A dollar metric was used so that the health outcomes could be aggregated and compared with other air quality management actions such the costs of improving ambient air quality. Results indicated that improving ambient air quality in the LFV will produce valued and socially desirable benefits, including reduced mortality and morbidity. The measures contemplated by decision-makers to maintain and improve air quality in the LFV will trigger benefits that are likely to be significant. 101 refs., 7 tabs., 7 figs.

Reduced Ultrafine Particle Concentration in Urban Air: Changes in Nucleation and Anthropogenic Emissions.

Science.gov (United States)

Saha, Provat K; Robinson, Ellis S; Shah, Rishabh U; Zimmerman, Naomi; Apte, Joshua S; Robinson, Allen L; Presto, Albert A

2018-06-19

Nucleation is an important source of ambient ultrafine particles (UFP). We present observational evidence of the changes in the frequency and intensity of nucleation events in urban air by analyzing long-term particle size distribution measurements at an urban background site in Pittsburgh, Pennsylvania during 2001-2002 and 2016-2017. We find that both frequency and intensity of nucleation events have been reduced by 40-50% over the past 15 years, resulting in a 70% reduction in UFP concentrations from nucleation. On average, the particle growth rates are 30% slower than 15 years ago. We attribute these changes to dramatic reductions in SO 2 (more than 90%) and other pollutant concentrations. Overall, UFP concentrations in Pittsburgh have been reduced by ∼48% in the past 15 years, with a ∼70% reduction in nucleation, ∼27% in weekday local sources (e.g., weekday traffic), and 49% in the regional background. Our results highlight that a reduction in anthropogenic emissions can considerably reduce nucleation events and UFP concentrations in a polluted urban environment.

Emissions from residential energy use dominate exposure to ambient fine particulate matter in India

Science.gov (United States)

Conibear, L.; Butt, E. W.; Knote, C. J.; Arnold, S.; Spracklen, D. V.

2017-12-01

Exposure to ambient particulate matter of less than 2.5 µm in diameter (PM2.5) is a leading cause of disease burden in India. Information on the source contributions to the burden of disease attributable to ambient PM2.5 exposure is critical to support the national and sub-national control of air pollution. Previous studies analysing the contributions of different emission sectors to disease burden in India have been limited by coarse model resolutions and a lack of extensive PM2.5 observations before 2016. We use a regional numerical weather prediction model online-coupled with chemistry, evaluated against extensive surface observations, to make the first high resolution study of the contributions of seven emission sectors to the disease burden associated with ambient PM2.5 exposure in India. We find that residential energy use is the dominant contributing emission sector. Removing air pollution emissions from residential energy use would reduce population-weighted annual mean ambient PM2.5 concentrations by 52%, reducing the number of premature mortalities caused by exposure to ambient PM2.5 by 26%, equivalent to 268,000 (95% uncertainty interval (95UI): 167,000-360,000) lives every year. The smaller fractional reduction in mortality burden is due to the non-linear exposure-response relationship at the high PM2.5 concentrations observed across India and consequently large reductions in emissions are required to reduce the health burden from ambient PM2.5 exposure in India. Keywords: ambient air quality, India, residential energy use, health impact, particulate matter, WRF-Chem

40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 2 2010-07-01 2010-07-01 false National primary and secondary ambient air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section 50.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS NATIONAL...

Characteristics and determinants of ambient fungal spores in Hualien, Taiwan

Science.gov (United States)

Ho, Hsiao-Man; Rao, Carol Y.; Hsu, Hsiao-Hsien; Chiu, Yueh-Hsiu; Liu, Chi-Ming; Chao, H. Jasmine

Characteristics and determinants of ambient aeroallergens are of much concern in recent years because of the apparent health impacts of allergens. Yet relatively little is known about the complex behaviors of ambient aeroallergens. To address this issue, we monitored ambient fungal spores in Hualien, Taiwan from 1993-1996 to examine the compositions and temporal variations of fungi, and to evaluate possible determinants. We used a Burkard seven-day volumetric spore trap to collect daily fungal spores. Air pollutants, meteorological factors, and Asian dust events were included in the statistical analyses to predict fungal levels. We found that the most dominant fungal categories were ascospores, followed by Cladosporium and Aspergillus/Penicillium. The majority of the fungal categories had significant diurnal and seasonal variations. Total fungi, Cladosporium, Ganoderma, Arthrinium/Papularia, Cercospora, Periconia, Alternaria, Botrytis, and PM 10 had significantly higher concentrations ( p<0.05) during the period affected by Asian dust events. In multiple regression models, we found that temperature was consistently and positively associated with fungal concentrations. Other factors correlated with fungal concentrations included ozone, particulate matters with an aerodynamic diameter less than 10 μm (PM 10), relative humidity, rainfall, atmospheric pressure, total hydrocarbons, carbon monoxide, nitrogen dioxide, and sulfur dioxide. Most of the fungal categories had higher levels in 1994 than in 1995-96, probably due to urbanization of the study area. In this study, we demonstrated complicated interrelationships between fungi and air pollution/meteorological factors. In addition, long-range transport of air pollutants contributed significantly to local aeroallergen levels. Future studies should examine the health impacts of aeroallergens, as well as the synergistic/antagonistic effects of weather, and local and global-scale air pollutions.

Decarburization and hardness changes of Fe-C-Cr-Mn-Si steels caused by high temperature oxidation in ambient air

Energy Technology Data Exchange (ETDEWEB)

Kucera, J; Broz, P [Academy of Sciences, Brno (Czech Republic); Hajduga, M; Glowacki, J [Tech. Univ., Lodz (Poland). Dept. of Mater. Sci.

1999-07-01

In the present paper the investigation of carbon diffusion and hardness changes in Fe-C-Cr-Mn-Si steels initiated by surface oxidation are reported. The oxidation anneals were carried out in ambient air. The measurements of carbon concentration and the metallographic investigation have shown that the steels decarburize expressively in the course of the oxidation process. The evaluation of the carbon concentration curves N{sub C}(x, t) yielded diffusion coefficients D{sub C} of carbon in the given steels. The dependence of D{sub C} on the concentration N{sub i} of alloying elements i is expressed by the use of diffusion interaction coefficients {beta}{sub C}{sup i}. The decrease of carbon concentration caused the increase of grain size in subsurface layers and the decrease of hardness HV. The dependence of HV(x, t) on N{sub C}(x, t) is expressed by the general parabolic relationship y(t) = k t{sup m}. (orig.) 24 refs.

Air quality in low-ventilated museum storage buildings

DEFF Research Database (Denmark)

Ryhl-Svendsen, Morten; Aasbjerg Jensen, Lars; Klenz Larsen, Poul

2014-01-01

Modern low-energy museum storage buildings are often designed for a low air exchange rate, on the order of less than 1 exchange per day. We investigated how this affected the indoor air quality in six Danish museum storage buildings. The infiltration of ambient pollutants, and the level to which...... internally-generated pollutants accumulate, were measured by passive sampling of ozone, nitrogen dioxide, and organic acids. The air exchange rates and the interchange of air between storage rooms were measured by the per-fluorocarbon tracer gas method. Ambient pollutants were reduced in concentration...

[Concentrations of mercury in ambient air in wastewater irrigated area of Tianjin City and its accumulation in leafy vegetables].

Science.gov (United States)

Zheng, Shun-An; Han, Yun-Lei; Zheng, Xiang-Qun

2014-11-01

limit of mercury in food. Spinach appeared to accumulate more mercury than the other four vegetables, in which the median and mean mercury content were both higher than 20 μg x kg(-1). The mercury concentrations in rape, lettuce and allium tuberosum were lower than the standard. Moreover, test results indicated that the Hg content in leafy vegetables was mainly the gaseous mercury through leaf adsorption but not the Hg particulates. This study clearly manifested that there should be a great concern on the pollution risk of both air-and soil borne mercury when cultivating leafy vegetables in long-term wastewater-irrigated area.

A Narrative Review on the Human Health Effects of Ambient Air Pollution in Sub-Saharan Africa: An Urgent Need for Health Effects Studies

OpenAIRE

Eric Coker; Samuel Kizito

2018-01-01

An important aspect of the new sustainable development goals (SDGs) is a greater emphasis on reducing the health impacts from ambient air pollution in developing countries. Meanwhile, the burden of human disease attributable to ambient air pollution in sub-Saharan Africa is growing, yet estimates of its impact on the region are possibly underestimated due to a lack of air quality monitoring, a paucity of air pollution epidemiological studies, and important population vulnerabilities in the re...