WorldWideScience

Sample records for supersaturated ambient air

  1. On the influence of atmospheric super-saturation layer on China's heavy haze-fog events

    Science.gov (United States)

    Wang, Jizhi; Yang, Yuanqin; Zhang, Xiaoye; Liu, Hua; Che, Huizheng; Shen, Xiaojing; Wang, Yaqiang

    2017-12-01

    With the background of global change, the air quality in Earth's atmosphere has significantly decreased. The North China Plain (NCP), Yangtze River Delta (YRD), Pearl River Delta (PRD) and Si-Chuan Basin (SCB) are the major areas suffering the decreasing air quality and frequent pollution events in recent years. Studying the effect of meteorological conditions on the concentration of pollution aerosols in these pollution sensitive regions is a hot focus now. This paper analyses the characteristics of atmospheric super-saturation and the corresponding H_PMLs (height of supersaturated pollution mixing layer), investigating their contribution to the frequently-seen heavy haze-fog weather. The results suggest that: (1) in the above-mentioned pollution sensitive regions in China, super-saturated layers repeatedly appear in the low altitude and the peak value of supersaturation S can reach 6-10%, which makes pollution particles into the wet adiabatic uplift process in the stable-static atmosphere. After low-level atmosphere reaches the super-saturation state below the H_PMLs, meteorological condition contributes to humidification and condensation of pollution particles. (2) Caculation of condensation function Fc, one of PLAM sensetive parameter, indicates that super-saturation state helps promote condensation, beneficial to the formation of Condensational Kink (CK) in the pollution sensitive areas. This favors the formation of new aerosol particles and intensities the cumulative growth of aerosol concentration. (3) By calculating the convective inhibition energy on average │CIN│ > 1.0 × 104 J kg-1, we found the value is about 100 times higher than the stable critical value. The uplifting diffusion of the particles is inhibited by the ambient airflow. So, this is the important reason for the aggravation and persistence of aerosol pollutants in local areas. (4) H_PMLs is negatively correlated to the pollution meteorological condition index PLAM which can describe the

  2. Ambient Air Quality Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Office of Air and Radiation's (OAR) Ambient Air Quality Data (Current) contains ambient air pollution data collected by EPA, other federal agencies, as well as...

  3. 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...

  4. Experimental study on total dissolved gas supersaturation in water

    Directory of Open Access Journals (Sweden)

    Lu Qu

    2011-12-01

    Full Text Available More and more high dams have been constructed and operated in China. The total dissolved gas (TDG supersaturation caused by dam discharge leads to gas bubble disease or even death of fish. Through a series of experiments, the conditions and requirements of supersaturated TDG generation were examined in this study. The results show that pressure (water depth, aeration, and bubble dissolution time are required for supersaturated TDG generation, and the air-water contact area and turbulence intensity are the main factors that affect the generation rate of supersaturated TDG. The TDG supersaturation levels can be reduced by discharging water to shallow shoals downstream of the dam or using negative pressure pipelines. Furthermore, the TDG supersaturation levels in stilling basins have no direct relationship with those in reservoirs. These results are of great importance for further research on the prediction of supersaturated TDG generation caused by dam discharge and aquatic protection.

  5. Hazardous air pollutant handbook: measurements, properties, and fate in ambient air

    Energy Technology Data Exchange (ETDEWEB)

    Spicer, C.W. (ed.); Gordon, S.M.; Kelly, T.J.; Holdren, M.W.; Mukund, R. [Battelle, Columbus, OH (United States)

    2002-07-01

    Focussing on the 188 hazardous air pollutants (HAPs) identified in the Title III of the US Clean Air Act Amendments, this work reviews the methods used to identify, measure, and locate the presence of toxics in ambient air. After a classification and characterization of the HAPs, the current status of ambient measurement methods are surveyed and categorized according to applicable, likely, and potential methods. The results of studies of ambient air concentrations of the HAPs are presented. Methods used to study atmospheric transformations of toxic air pollutants are reviewed and the concept of atmospheric lifetimes of HAPs is discussed.

  6. 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...

  7. 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

  8. 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

  9. 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...

  10. 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.

  11. 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.

  12. 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)

  13. 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...

  14. 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.

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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

  2. Investigation of the effective peak supersaturation for liquid-phase clouds at the high-alpine site Jungfraujoch, Switzerland (3580 m a.s.l.

    Directory of Open Access Journals (Sweden)

    E. Hammer

    2014-01-01

    Full Text Available Aerosols influence the Earth's radiation budget directly through absorption and scattering of solar radiation in the atmosphere but also indirectly by modifying the properties of clouds. However, climate models still suffer from large uncertainties as a result of insufficient understanding of aerosol-cloud interactions. At the high altitude research station Jungfraujoch (JFJ; 3580 m a.s.l., Switzerland cloud condensation nuclei (CCN number concentrations at eight different supersaturations (SS from 0.24% to 1.18% were measured using a CCN counter during Summer 2011. Simultaneously, in-situ aerosol activation properties of the prevailing ambient clouds were investigated by measuring the total and interstitial (non-activated dry particle number size distributions behind two different inlet systems. Combining all experimental data, a new method was developed to retrieve the so-called effective peak supersaturation SSpeak, as a measure of the SS at which ambient clouds are formed. A 17-month CCN climatology was then used to retrieve the SSpeak values also for four earlier summer campaigns (2000, 2002, 2004 and 2010 where no direct CCN data were available. The SSpeak values varied between 0.01% and 2.0% during all campaigns. An overall median SSpeak of 0.35% and dry activation diameter of 87 nm was observed. It was found that the difference in topography between northwest and southeast plays an important role for the effective peak supersaturation in clouds formed in the vicinity of the JFJ, while differences in the number concentration of potential CCN only play a minor role. Results show that air masses coming from the southeast (with the slowly rising terrain of the Aletsch Glacier generally experience lower SSpeak values than air masses coming from the northwest (steep slope. The observed overall median values were 0.41% and 0.22% for northwest and southeast wind conditions, respectively, corresponding to literature values for cumulus clouds and

  3. 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.

  4. Supersaturating drug delivery systems

    DEFF Research Database (Denmark)

    Laitinen, Riikka; Löbmann, Korbinian; Grohganz, Holger

    2017-01-01

    of the bioavailability of poorly water-soluble drugs by increasing the driving force for drug absorption. However, ASDs often require a high weight percentage of carrier (usually a hydrophilic polymer) to ensure molecular mixing of the drug in the carrier and stabilization of the supersaturated state, often leading......Amorphous solid dispersions (ASDs) are probably the most common and important supersaturating drug delivery systems for the formulation of poorly water-soluble compounds. These delivery systems are able to achieve and maintain a sustained drug supersaturation which enables improvement...... strategy for poorly-soluble drugs. While the current research on co-amorphous formulations is focused on preparation and characterization of these systems, more detailed research on their supersaturation and precipitation behavior and the effect of co-formers on nucleation and crystal growth inhibition...

  5. 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.

  6. Structure and Supersaturation of Highly Concentrated Solutions of Buckyball in 1-Butyl-3-Methylimidazolium Tetrafluoroborate

    DEFF Research Database (Denmark)

    Fileti, E. E.; Chaban, V. V.

    2014-01-01

    Solubilization of fullerenes is of high interest because of their wide usage in both fundamental research and numerous applications. This paper reports molecular dynamics (MD) simulations of saturated and supersaturated solutions of C-60 in 1-butyl-3-methylimidazolium tetrafluoroborate, [C4C1IM......-long real-time dynamics. The ion-molecular structure patterns in saturated and supersaturated solutions are distinguished in terms of radial distribution functions and cluster analysis of the solute particles. The cation separated solute pair is found to be a common structure in both saturated......][BF4], room-temperature ionic liquid (RTIL). The simulations cover a wide range of temperatures between 280 and 500 K at ambient pressure. Unlike in simpler solvents, C-60 in [C4C1IM][BF4] forms highly supersaturated solutions, whose internal arrangement remains unaltered during nearly a microsecond...

  7. Air supersaturation, release of wooden fibres and upstream migration of Atlantic salmon at Rygene power plant in the River Nidelva, Aust Agder county

    International Nuclear Information System (INIS)

    Thorstad, Eva B.; Kroglund, Frode; Oekland, Finn; Heggberget, Tor G.

    1997-01-01

    Incidents of dead fish have been reported in connection with a power plant at Rygene on the River Nidelva in the Aust-Agder county, Norway. Air supersaturation has been used in a bypass construction of the power plant tunnel system. In addition, wooden fibres from a fabric have been released into the water of the tunnel. Results from relevant studies concerning air saturation, wooden fibres and upstream migration are summarised in this report. 148 refs., 4 figs., 2 tabs

  8. 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)

  9. 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.

  10. 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.

  11. Studying the propensity of compounds to supersaturate

    DEFF Research Database (Denmark)

    Palmelund, Henrik; Madsen, Cecilie Maria; Christensen, Jakob Plum

    2016-01-01

    Supersaturating drug delivery systems can enhance the oral bioavailability of poorly soluble drug compounds. Supersaturation of such compounds has been studied in many different ways; however, a more standardized method is required. The rationale of choosing suitable concentrations of supersatura......Supersaturating drug delivery systems can enhance the oral bioavailability of poorly soluble drug compounds. Supersaturation of such compounds has been studied in many different ways; however, a more standardized method is required. The rationale of choosing suitable concentrations...... of supersaturation to study has previously been very inconsistent. This makes comparisons between studies and compounds difficult, as the propensity of compounds to supersaturate varies greatly. This study presents a standardized method to study the supersaturation of drug compounds. The method allows, both......, for a ranking of compounds according to their supersaturation propensity and the effectiveness of precipitation inhibitors. The time-concentration profile of supersaturation and precipitation was studied in situ for 4 different concentrations for 6 model compounds (albendazole, aprepitant, danazol, felodipine...

  12. 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...

  13. 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...

  14. 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.

  15. 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.

  16. 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

  17. A case study on the formation and evolution of ice supersaturation in the vicinity of a warm conveyor belt's outflow region

    Directory of Open Access Journals (Sweden)

    P. Spichtinger

    2005-01-01

    Full Text Available A case study is presented on the formation and evolution of an ice-supersaturated region (ISSR that was detected by a radiosonde in NE Germany at 06:00 UTC 29 November 2000. The ISSR was situated in the vicinity of the outflow region of a warm conveyor belt associated with an intense event of cyclogenesis in the eastern North Atlantic. Using ECMWF analyses and trajectory calculations it is determined when the air parcels became supersaturated and later subsaturated again. In the case considered, the state of air parcel supersaturation can last for longer than 24h. The ISSR was unusually thick: while the mean vertical extension of ISSRs in NE Germany is about 500m, the one investigated here reached 3km. The ice-supersaturated region investigated was bordered both vertically and horizontally by strongly subsaturated air. Near the path of the radiosonde the ISSR was probably cloud free, as inferred from METEOSAT infrared images. However, at other locations within the ISSR it is probable that there were cirrus clouds. Relative humidity measurements obtained by the Lindenberg radiosonde are used to correct the negative bias of the ECMWF humidity and to construct two-dimensional maps of ice supersaturation over Europe during the considered period. A systematic backward trajectory analysis for the ISSRs on these maps shows that the ISSR air masses themselves experienced only a moderate upward motion during the previous days, whereas parts of the ISSRs were located just above strongly ascending air masses from the boundary layer. This indicates qualitatively that warm conveyor belts associated with mid-latitude cyclogenesis are disturbances that can induce the formation of ISSRs in the upper troposphere. The ISSR maps also lead us to a new perception of ISSRs as large dynamic regions of supersaturated air where cirrus clouds can be embedded at some locations while there is clear air at others.

  18. 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.

  19. 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...

  20. Ambient air pollution and low birthweight: a European cohort study (ESCAPE)

    NARCIS (Netherlands)

    Pedersen, Marie; Giorgis-Allemand, Lise; Bernard, Claire; Aguilera, Inmaculada; Andersen, Anne-Marie Nybo; Ballester, Ferran; Beelen, Rob M. J.; Chatzi, Leda; Cirach, Marta; Danileviciute, Asta; Dedele, Audrius; Eijsden, Manon van; Estarlich, Marisa; Fernández-Somoano, Ana; Fernández, Mariana F.; Forastiere, Francesco; Gehring, Ulrike; Grazuleviciene, Regina; Gruzieva, Olena; Heude, Barbara; Hoek, Gerard; de Hoogh, Kees; van den Hooven, Edith H.; Håberg, Siri E.; Jaddoe, Vincent W. V.; Klümper, Claudia; Korek, Michal; Krämer, Ursula; Lerchundi, Aitana; Lepeule, Johanna; Nafstad, Per; Nystad, Wenche; Patelarou, Evridiki; Porta, Daniela; Postma, Dirkje; Raaschou-Nielsen, Ole; Rudnai, Peter; Sunyer, Jordi; Stephanou, Euripides; Sørensen, Mette; Thiering, Elisabeth; Tuffnell, Derek; Varró, Mihály J.; Vrijkotte, Tanja G. M.; Wijga, Alet; Wilhelm, Michael; Wright, John; Nieuwenhuijsen, Mark J.; Pershagen, Göran; Brunekreef, Bert; Kogevinas, Manolis; Slama, Rémy

    2013-01-01

    Background Ambient air pollution has been associated with restricted fetal growth, which is linked with adverse respiratory health in childhood. We assessed the effect of maternal exposure to low concentrations of ambient air pollution on birthweight. Methods We pooled data from 14 population-based

  1. 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.

  2. 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.

  3. Methods for estimating on-site ambient air concentrations at disposal sites

    International Nuclear Information System (INIS)

    Hwang, S.T.

    1987-01-01

    Currently, Gaussian type dispersion modeling and point source approximation are combined to estimate the ambient air concentrations of pollutants dispersed downwind of an areawide emission source, using the approach of virtual point source approximation. This Gaussian dispersion modeling becomes less accurate as the receptor comes closer to the source, and becomes inapplicable for the estimation of on-site ambient air concentrations at disposal sites. Partial differential equations are solved with appropriate boundary conditions for use in estimating the on-site concentrations in the ambient air impacted by emissions from an area source such as land disposal sites. Two variations of solution techniques are presented, and their predictions are compared

  4. 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.

  5. 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

  6. 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.

  7. Burden of disease attributed to ambient air pollution in Thailand: A GIS-based approach.

    Directory of Open Access Journals (Sweden)

    Chayut Pinichka

    Full Text Available Growing urbanisation and population requiring enhanced electricity generation as well as the increasing numbers of fossil fuel in Thailand pose important challenges to air quality management which impacts on the health of the population. Mortality attributed to ambient air pollution is one of the sustainable development goals (SDGs. We estimated the spatial pattern of mortality burden attributable to selected ambient air pollution in 2009 based on the empirical evidence in Thailand.We estimated the burden of disease attributable to ambient air pollution based on the comparative risk assessment (CRA framework developed by the World Health Organization (WHO and the Global Burden of Disease study (GBD. We integrated geographical information systems (GIS-based exposure assessments into spatial interpolation models to estimate ambient air pollutant concentrations, the population distribution of exposure and the concentration-response (CR relationship to quantify ambient air pollution exposure and associated mortality. We obtained air quality data from the Pollution Control Department (PCD of Thailand surface air pollution monitoring network sources and estimated the CR relationship between relative risk (RR and concentration of air pollutants from the epidemiological literature.We estimated 650-38,410 ambient air pollution-related fatalities and 160-5,982 fatalities that could have been avoided with a 20 reduction in ambient air pollutant concentrations. The summation of population-attributable fraction (PAF of the disease burden for all-causes mortality in adults due to NO2 and PM2.5 were the highest among all air pollutants at 10% and 7.5%, respectively. The PAF summation of PM2.5 for lung cancer and cardiovascular disease were 16.8% and 14.6% respectively and the PAF summations of mortality attributable to PM10 was 3.4% for all-causes mortality, 1.7% for respiratory and 3.8% for cardiovascular mortality, while the PAF summation of mortality

  8. Burden of disease attributed to ambient air pollution in Thailand: A GIS-based approach.

    Science.gov (United States)

    Pinichka, Chayut; Makka, Nuttapat; Sukkumnoed, Decharut; Chariyalertsak, Suwat; Inchai, Puchong; Bundhamcharoen, Kanitta

    2017-01-01

    Growing urbanisation and population requiring enhanced electricity generation as well as the increasing numbers of fossil fuel in Thailand pose important challenges to air quality management which impacts on the health of the population. Mortality attributed to ambient air pollution is one of the sustainable development goals (SDGs). We estimated the spatial pattern of mortality burden attributable to selected ambient air pollution in 2009 based on the empirical evidence in Thailand. We estimated the burden of disease attributable to ambient air pollution based on the comparative risk assessment (CRA) framework developed by the World Health Organization (WHO) and the Global Burden of Disease study (GBD). We integrated geographical information systems (GIS)-based exposure assessments into spatial interpolation models to estimate ambient air pollutant concentrations, the population distribution of exposure and the concentration-response (CR) relationship to quantify ambient air pollution exposure and associated mortality. We obtained air quality data from the Pollution Control Department (PCD) of Thailand surface air pollution monitoring network sources and estimated the CR relationship between relative risk (RR) and concentration of air pollutants from the epidemiological literature. We estimated 650-38,410 ambient air pollution-related fatalities and 160-5,982 fatalities that could have been avoided with a 20 reduction in ambient air pollutant concentrations. The summation of population-attributable fraction (PAF) of the disease burden for all-causes mortality in adults due to NO2 and PM2.5 were the highest among all air pollutants at 10% and 7.5%, respectively. The PAF summation of PM2.5 for lung cancer and cardiovascular disease were 16.8% and 14.6% respectively and the PAF summations of mortality attributable to PM10 was 3.4% for all-causes mortality, 1.7% for respiratory and 3.8% for cardiovascular mortality, while the PAF summation of mortality attributable to

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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...

  14. 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 ...

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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 ...

  3. 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

  4. 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

  5. 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,

  6. 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.

  7. Phase stability in wear-induced supersaturated Al-Ti solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Y.; Yokoyama, K. [Dept. of Functional Machinery Mechanics Shinshu Univ., Ueda (Japan); Hosoda, H. [Precision and Intelligence Lab., Tokyo Inst. of Tech., Nagatsuta, Midori-ku, Yokohama (Japan)

    2002-07-01

    Al-Ti supersaturated solid solutions were introduced by wear testing and the rapid quenching of an Al/Al{sub 3}Ti composite (part of an Al/Al{sub 3}Ti functionally graded material) that was fabricated using the centrifugal method. The phase stability of the supersaturated solid solution was studied through systematic annealing of the supersaturated solid solution. It was found that the Al-Ti supersaturated solid solution decomposed into Al and Al{sub 3}Ti intermetallic compound phases during the heat treatment. The Al-Ti supersaturated solid solutions fabricated were, therefore, not an equilibrium phase, and thus decomposed into the equilibrium phases during heat treatment. It was also found that heat treatment leads to a significant hardness increase for the Al-Ti supersaturated solid solution. Finally, it was concluded that formation of the wear-induced supersaturated solid solution layer was a result of severe plastic deformation. (orig.)

  8. 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.

  9. 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.

  10. 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.

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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...

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. Photoinduced nucleation: A novel tool for detecting molecules in air at ultra-low concentrations

    International Nuclear Information System (INIS)

    Katz, Joseph L.; Lihavainen, Heikki; Rudek, Markus M.; Salter, Brian C.

    2000-01-01

    This paper describes the development of a novel detection method and the demonstration of its capability to detect substances at concentrations as small as a few parts per trillion. It is shown that photoinduced nucleation is not in itself a nucleation process; rather, supersaturated vapor condenses onto long-lasting clusters formed by chemical reaction of photo-excited molecules. The role of the supersaturated vapor is to increase the size of these photoproducts by condensation to a size readily detectable by light scattering. Furthermore, the measured nucleation rate variation with illumination wavelength exactly matches the substance's vapor-phase UV light absorption wavelength dependence, thus providing species identification. The ability to detect and identify molecules of substances at extremely low concentrations from ambient air is useful for detecting and monitoring pollutants, and for detecting explosives such as TNT. (c) 2000 American Institute of Physics

  9. 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

  10. 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.

  11. 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.

  12. Why the free floating macrophyte Stratiotes aloides mainly grows in highly CO2-supersaturated waters

    DEFF Research Database (Denmark)

    Nielsen, Lasse Tor; Borum, Jens

    2008-01-01

    consistently supersaturated CO2 conditions to grow and complete its life cycle. Submerged rosettes formed from over-wintering turions had typical traits of submerged plants with high specific leaf area and low chlorophyll a concentrations. Emergent leaf parts of mature, floating specimens had typical...... estimated at CO2 concentrations corresponding to air equilibrium were not sufficiently high to support any noticeable growth except for rosettes, in which bicarbonate utilization combined with high CO2 affinity resulted in photosynthetic rates corresponding to almost 34% of maximum rates at high free CO2....... We conclude that S. aloides requires consistently high CO2-supersaturation to support high growth and to complete its life cycle, and we infer that this requirement explains why S. aloides mainly grows in ponds, ditches and reed zones that are characterized by strong CO2-supersaturation....

  13. 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...

  14. 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

  15. 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...

  16. 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.

  17. 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.

  18. 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

  19. Carbon diffusion in carbon-supersaturated ferrite and austenite

    Czech Academy of Sciences Publication Activity Database

    Čermák, Jiří; Král, Lubomír

    2014-01-01

    Roč. 586, FEB (2014), s. 129-135 ISSN 0925-8388 R&D Projects: GA ČR(CZ) GAP108/11/0148; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : carbon diffusion * Carbon supersaturation * Carbon supersaturation * Ferrite * Austenite Subject RIV: BJ - Thermodynamics Impact factor: 2.999, year: 2014

  20. 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.

  1. The use of supersaturation for the vaginal application of microbicides

    DEFF Research Database (Denmark)

    Grammen, Carolien; Plum, Jakob; Van Den Brande, Jeroen

    2014-01-01

    In this study, we investigated the potential of supersaturation for the formulation of the poorly water-soluble microbicide dapivirine (DPV) in an aqueous vaginal gel in order to enhance its vaginal tissue uptake. Different excipients such as hydroxypropylmethylcellulose, polyethylene glycol 1000....... The best performing supersaturated gel containing 500 μM DPV (supersaturation degree of 4) in the presence of sulfobutyl ether-beta-cyclodextrin (2.5%) appeared to be stable for at least 3 months. In addition, the gel generated a significant increase in vaginal drug uptake in rabbits as compared...... with suspension gels. We conclude that supersaturation is a possible strategy to enhance the vaginal concentration of hydrophobic microbicides, thereby increasing permeation into the vaginal submucosa....

  2. 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

  3. 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.)

  4. 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

  5. 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.

  6. 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...

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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...

  12. 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

  13. 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

  14. 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

  15. 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)

  16. 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

  17. 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

  18. 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.

  19. 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...

  20. 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

  1. Cumulative effects of cascade hydropower stations on total dissolved gas supersaturation.

    Science.gov (United States)

    Ma, Qian; Li, Ran; Feng, Jingjie; Lu, Jingying; Zhou, Qin

    2018-03-01

    Elevated levels of total dissolved gas (TDG) may occur downstream of dams during the spill process. These high levels would increase the incidence of gas bubble disease in fish and cause severe environmental impacts. With increasing numbers of cascade hydropower stations being built or planned, the cumulative effects of TDG supersaturation are becoming increasingly prominent. The TDG saturation distribution in the downstream reaches of the Jinsha River was studied to investigate the cumulative effects of TDG supersaturation resulting from the cascade hydropower stations. A comparison of the effects of the joint operation and the single operation of two hydropower stations (XLD and XJB) was performed to analyze the risk degree to fish posed by TDG supersaturation. The results showed that water with supersaturated TDG generated at the upstream cascade can be transported to the downstream power station, leading to cumulative TDG supersaturation effects. Compared with the single operation of XJB, the joint operation of both stations produced a much higher TDG saturation downstream of XJB, especially during the non-flood discharge period. Moreover, the duration of high TDG saturation and the lengths of the lethal and sub-lethal areas were much higher in the joint operation scenario, posing a greater threat to fish and severely damaging the environment. This work provides a scientific basis for strategies to reduce TDG supersaturation to the permissible level and minimize the potential risk of supersaturated TDG.

  2. 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

  3. 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.

  4. 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...

  5. Volatile Organic Compounds (VOCs) in the Ambient Air Of Concentration Unit of Sar-Cheshmeh Copper Complex

    International Nuclear Information System (INIS)

    Faghihi-Zrandi, A.; Akhgar, M. R.

    2016-01-01

    Air pollutants including gases, vapors and particles, are emitted from different sources. Volatile organic compounds are the most important pollutants in the ambient air of industries. The present study was carried out to identify and measurement of volatile organic compounds in concentration unit of Sar-Cheshmeh Copper Complex. In this study, sampling of the volatile organic compounds was done by using activated charcoal tube. To identify and measure these compounds gas chromatography/mass spectroscopy were used. Thirteen volatile organic compounds were identified in the ambient air of concentration unit. Among these compounds, the mean value and maximum concentration of isopropyl alcohol and nonane were 255, 640 μg/m3 and 1577, 14400 μg/m3, respectively. By using SPSS software and independent sample t- test, showed that there were no significant difference between mean value concentration of isopropyl alcohol and nonane in the ambient air and TLV values of these compounds (isopropyl alcohol; 200 ppm and nonane; 200 ppm) (P >0.05).

  6. 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

  7. 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

  8. 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...

  9. Raman spectroscopic studies on single supersaturated droplets of sodium and magnesium acetate.

    Science.gov (United States)

    Wang, Liang-Yu; Zhang, Yun-Hong; Zhao, Li-Jun

    2005-02-03

    Raman spectroscopy was used to study structural changes, in particular, the formation of contact-ion pairs in supersaturated aqueous NaCH(3)COO and Mg(CH(3)COO)(2) droplets at ambient temperatures. The single droplets levitated in an electrodynamic balance (EDB), lost water, and became supersaturated when the relative humidity (RH) decreased. For NaCH(3)COO droplet the water-to-solute molar ratio (WSR) was 3.87 without solidification when water molecules were not enough to fill in the first hydration layer of Na(+), in favor of the formation of contact-ion pairs. However, the symmetric stretching vibration band (nu(3) mode) of free -COO(-) constantly appeared at 1416 cm(-1), and no spectroscopic information related to monodentate, bidentate, or bridge bidentate contact-ion pairs was observed due to the weak interactions between the Na(+) and acetate ion. On the other hand, the band of methyl deformation blue shifted from 1352 to 1370 cm(-1) (at RH = 34.2%, WSR = 2.43), corresponding to the solidification process of a novel metastable phase in the highly supersaturated solutions. With further decreasing RH, a small amount of supersaturated solution still existed and was proposed to be hermetically covered by the metastable phase of the particle. In contrast, the interaction between Mg(2+) and acetate ion is much stronger. When WSR decreased from 21.67 to 2.58 for the Mg(CH(3)COO)(2) droplet, the band of C-C-symmetric stretching (nu(4) mode) had a blue shift from 936 to 947 cm(-1). The intensity of the two new shoulders (approximately 1456 and approximately 1443 cm(-1)) of the nu(3) band of free -COO(-) at 1420 cm(-1) increased with the decrease of WSR. These changes were attributed to the formation of contact-ion pairs with bidentate structures. In particular, the small frequency difference between the shoulder at approximately 1443 cm(-1) and the nu(3) band of the free -COO(-) group (approximately 1420 cm(-1)) was proposed to be related to the formation of a chain

  10. 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.

  11. 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.

  12. 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.

  13. 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)

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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...

  19. 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

  20. 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

  1. 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

  2. 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

  3. Air supersaturation, release of wooden fibres and upstream migration of Atlantic salmon at Rygene power plant in the River Nidelva, Aust Agder county; Vurdering av luftovermetning, trefiberutslipp og oppvandring av laks ved Rygene kraftverk i Nidelva, Aust-Agder

    Energy Technology Data Exchange (ETDEWEB)

    Thorstad, Eva B.; Kroglund, Frode; Oekland, Finn; Heggberget, Tor G.

    1997-12-31

    Incidents of dead fish have been reported in connection with a power plant at Rygene on the River Nidelva in the Aust-Agder county, Norway. Air supersaturation has been used in a bypass construction of the power plant tunnel system. In addition, wooden fibres from a fabric have been released into the water of the tunnel. Results from relevant studies concerning air saturation, wooden fibres and upstream migration are summarised in this report. 148 refs., 4 figs., 2 tabs.

  4. 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

  5. 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...

  6. Indoor and ambient air concentrations of respirable particles between two hospitals in Kashan (2014-2015

    Directory of Open Access Journals (Sweden)

    Mahmoud Mohammadyan

    2017-04-01

    Full Text Available Background: The hospital environment requires special attention to provide healthful indoor air quality for protecting patients and healthcare workers against the occupational diseases. The aim of this study was to determine the concentrations of respirable particles indoor and ambient air of two hospitals in Kashan. Materials and Method: This cross-sectional study was conducted during 3 months (Marth 2014 to May 2015. Indoor and outdoor PM10 and PM2.5 concentrations were measured four times a week in the operating room, pediatric and ICU2 (Intensive Care Unit wards using a real time dust monitor at two hospitals. A total number of 480 samples (80 samples indoors and 40 outdoors from wards were collected. Results: The highest mean PM2.5 and PM10 for indoors were determined 57.61± 68.57 µg m-3 and 212.36±295.49 µg m-3, respectively. The results showed a significant relationship between PM2.5 and PM10 in the indoor and ambient air of two hospitals (P<0.05. PM2.5 and PM10 concentrations were different in all of the selected wards (P<0.05. Conclusion: The respirable particle concentrations in the indoor and ambient air in both hospitals were higher than the 24-hours WHO and US-EPA standards. Thence, utilizing sufficient and efficient air conditioning systems in hospitals can be useful in improving indoor air quality and reducing the respirable particle concentrations.

  7. 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...

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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).

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. THE SEARCH FOR SUPER-SATURATION IN CHROMOSPHERIC EMISSION

    International Nuclear Information System (INIS)

    Christian, Damian J.; Arias, Tersi; Mathioudakis, Mihalis; Jess, David B.; Jardine, Moira

    2011-01-01

    We investigate if the super-saturation phenomenon observed at X-ray wavelengths for the corona exists in the chromosphere for rapidly rotating late-type stars. Moderate resolution optical spectra of fast-rotating EUV- and X-ray-selected late-type stars were obtained. Stars in α Per were observed in the northern hemisphere with the Isaac Newton 2.5 m telescope and Intermediate Dispersion Spectrograph. Selected objects from IC 2391 and IC 2602 were observed in the southern hemisphere with the Blanco 4 m telescope and R-C spectrograph at CTIO. Ca II H and K fluxes were measured for all stars in our sample. We find the saturation level for Ca II K at log (L CaK /L bol ) = -4.08. The Ca II K flux does not show a decrease as a function of increased rotational velocity or smaller Rossby number as observed in the X-ray. This lack of 'super-saturation' supports the idea of coronal stripping as the cause of saturation and super-saturation in stellar chromospheres and coronae, but the detailed underlying mechanism is still under investigation.

  19. 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

  20. 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.

  1. Correlation of Air Quality Data to Ultrafine Particles (UFP Concentration and Size Distribution in Ambient Air

    Directory of Open Access Journals (Sweden)

    Werner Hofmann

    2010-07-01

    Full Text Available This study monitored ultrafine particles (UFP concurrent with environmental air quality data, investigating whether already existing instrumentation used by environmental authorities can provide reference values for estimating UFP concentrations. Of particular interest was the relation of UFP to PM10 (particulate matter and nitrogen oxides (NOx, NO2 in ambient air. Existing PM measurement methods alone did not correspond exactly enough with the actual particle number, but we observed a link between NOx and NO2 to UFP concentration. The combined data could act as proxy-indicator for authorities in estimating particle number concentrations, but cannot replace UFP monitoring.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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 ...

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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 ...

  14. 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

  15. The use of supersaturation for the vaginal application of microbicides: a case study with dapivirine.

    Science.gov (United States)

    Grammen, Carolien; Plum, Jakob; Van Den Brande, Jeroen; Darville, Nicolas; Augustyns, Koen; Augustijns, Patrick; Brouwers, Joachim

    2014-11-01

    In this study, we investigated the potential of supersaturation for the formulation of the poorly water-soluble microbicide dapivirine (DPV) in an aqueous vaginal gel in order to enhance its vaginal tissue uptake. Different excipients such as hydroxypropylmethylcellulose, polyethylene glycol 1000, and cyclodextrins were evaluated for their ability to inhibit precipitation of supersaturated DPV in the formulation vehicle as such as well as in biorelevant media. In vitro permeation assessment across HEC-1A cell layers demonstrated an enhanced DPV flux from supersaturated gels compared with suspension gels. The best performing supersaturated gel containing 500 μM DPV (supersaturation degree of 4) in the presence of sulfobutyl ether-beta-cyclodextrin (2.5%) appeared to be stable for at least 3 months. In addition, the gel generated a significant increase in vaginal drug uptake in rabbits as compared with suspension gels. We conclude that supersaturation is a possible strategy to enhance the vaginal concentration of hydrophobic microbicides, thereby increasing permeation into the vaginal submucosa. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  16. Do lagoons near concentrated animal feeding operations promote nitrous oxide supersaturation?

    International Nuclear Information System (INIS)

    Makris, Konstantinos C.; Sarkar, Dibyendu; Andra, Syam S.; Bach, Stephan B.H.; Datta, Rupali

    2009-01-01

    Animal wastewater lagoons nearby concentrated animal feeding operations (CAFOs) represent the latest tendency in global animal farming, severely impacting the magnitude of greenhouse gas emissions, including nitrous oxide (N 2 O). We hypothesized that lagoon wastewater could be supersaturated with N 2 O as part of incomplete microbial nitrification/denitrification processes, thereby regulating the N 2 O partitioning in the gaseous phase. The objectives of this study were: (i) to investigate the magnitude of dissolved N 2 O concentrations in the lagoon; and (ii) to determine the extent to which supersaturation of N 2 O occurs in wastewater lagoons. Dissolved N 2 O concentrations in the wastewater samples were high, ranging from 0.4 to 40.5 μg N 2 O mL -1 . Calculated dissolved N 2 O concentrations from the experimentally measured partition coefficients were much greater than those typically expected in aquatic systems ( 2 O mL -1 ). Knowledge of the factors controlling the magnitude of N 2 O supersaturation could potentially bridge mass balance differences between in situ measurements and global N 2 O models. - Supersaturation of nitrous oxide may occur in lagoons near concentrated animal feeding operations.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. Effect of biomass open burning on particulate matter and polycyclic aromatic hydrocarbon concentration levels and PAH dry deposition in ambient air.

    Science.gov (United States)

    Chiu, Jui C; Shen, Yun H; Li, Hsing W; Chang, Shun S; Wang, Lin C; Chang-Chien, Guo P

    2011-01-01

    The objectives of the present study were to investigate particulate matter (PM) and polycyclic aromatic hydrocarbon (PAH) concentrations in ambient air during rice straw open burning and non-open burning periods. In the ambient air of a rice field, the mean PM concentration during and after an open burning event were 1828 and 102 μg m⁻³, respectively, which demonstrates that during a rice field open burning event, the PM concentration in the ambient air of rice field is over 17 times higher than that of the non-open burning period. During an open burning event, the mean total PAH and total toxic equivalence (BaP(eq)) concentrations in the ambient air of a rice field were 7206 ng m⁻³ and 10.3 ng m⁻³, respectively, whereas after the open burning event, they were 376 ng m⁻³ and 1.50 ng m⁻³, respectively. Open burning thus increases total PAH and total BaP(eq) concentrations by 19-fold and 6.8-fold, respectively. During a rice straw open burning event, in the ambient air of a rice field, the mean dry deposition fluxes of total PAHs and total BaP(eq) were 1222 μg m⁻² day⁻¹ and 4.80 μg m⁻² day⁻¹, respectively, which are approximately 60- and 3-fold higher than those during the non-open burning period, respectively. During the non-open burning period, particle-bound PAHs contributed 79.2-84.2% of total dry deposition fluxes (gas + particle) of total PAHs. However, an open burning event increases the contribution to total PAH dry deposition by particle-bound PAHs by up to 85.9-95.5%. The results show that due to the increased amount of PM in the ambient air resulting from rice straw open burning, particle-bound PAHs contributed more to dry deposition fluxes of total PAHs than they do during non-open burning periods. The results show that biomass (rice straw) open burning is an important PAH emission source that significantly increases both PM and PAH concentration levels and PAH dry deposition in ambient air.

  2. 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).

  3. 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.

  4. 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.

  5. 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

  6. 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...

  7. 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.

  8. Ambient concentrations and personal exposure to polycyclic aromatic hydrocarbons (PAH) in an urban community with mixed sources of air pollution

    Science.gov (United States)

    ZHU, XIANLEI; FAN, ZHIHUA (TINA); WU, XIANGMEI; JUNG, KYUNG HWA; OHMAN-STRICKLAND, PAMELA; BONANNO, LINDA J.; LIOY, PAUL J.

    2014-01-01

    Assessment of the health risks resulting from exposure to ambient polycyclic aromatic hydrocarbons (PAH) is limited by a lack of environmental exposure data among the general population. This study characterized personal exposure and ambient concentrations of PAH in the Village of Waterfront South (WFS), an urban community with many mixed sources of air toxics in Camden, New Jersey, and CopeWood/Davis Streets (CDS), an urban reference area located ~1 mile east of WFS. A total of 54 and 53 participants were recruited from non-smoking households in WFS and CDS, respectively. In all, 24-h personal and ambient air samples were collected simultaneously in both areas on weekdays and weekends during summer and winter. The ambient PAH concentrations in WFS were either significantly higher than or comparable to those in CDS, indicating the significant impact of local sources on PAH pollution in WFS. Analysis of diagnostic ratios and correlation suggested that diesel truck traffic, municipal waste combustion and industrial combustion were the major sources in WFS. In such an area, ambient air pollution contributed significantly to personal PAH exposure, explaining 44–96% of variability in personal concentrations. This study provides valuable data for examining the impact of local ambient PAH pollution on personal exposure and therefore potential health risks associated with environmental PAH pollution. PMID:21364704

  9. 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...

  10. Experimental Investigation of the Effect of Change in Ambient Air Temperature on Power Consumption of Domestic Refrigerators

    Directory of Open Access Journals (Sweden)

    J. A. Olorunmaiye

    2012-12-01

    Full Text Available One of the manifestations of climate change is increase.in ambient air temperature usually referred to as global warming. For sustainable development in a country, there is need to identify impacts of climate change and the necessary adaptation and mitigation strategies to adopt. To simulate the effect of global warming on the power consumption of refrigerators, a (model No. 150 THERMOCOOL refrigerator filled with twenty-five 750cl packaged water bottleswas run in an air-conditioned room, in a room with the air-conditioner switched off and near an oven in a bakery. The electric power consumption of the refrigerator was measured using "Watts up?.net" Watt meter and the ambient temperature was measured using FLUKE temperature/humidity meter. The average hourly energy consumption of the refrigerator operating at mean ambient temperatures of 25.4°C, 30.7oC, 38.8°C were 93.844 Wh, 100.32 Wh and 105.08 Wh respectively. Some possible ways to reduce the increase in power consumption of refrigerators due to global warming include using compressors of higher efficiency and condensers of greater effectiveness.

  11. Ambient air emissions of polycyclic aromatic hydrocarbons and female breast cancer incidence in US.

    Science.gov (United States)

    Stults, William Parker; Wei, Yudan

    2018-05-05

    To examine ambient air pollutants, specifically polycyclic aromatic hydrocarbons (PAHs), as a factor in the geographic variation of breast cancer incidence seen in the US, we conducted an ecological study involving counties throughout the US to examine breast cancer incidence in relation to PAH emissions in ambient air. Age-adjusted incidence rates of female breast cancer from the surveillance, epidemiology, and end results (SEER) program of the US National Cancer Institute were collected and analyzed using SEER*Stat 8.3.2. PAH emissions data were obtained from the Environmental Protection Agency. Linear regression analysis was performed using SPSS 23 software for Windows to analyze the association between PAH emissions and breast cancer incidence, adjusting for potential confounders. Age-adjusted incidence rates of female breast cancer were found being significantly higher in more industrialized metropolitan SEER regions over the years of 1973-2013 as compared to less industrialized regions. After adjusting for sex, race, education, socioeconomic status, obesity, and smoking prevalence, PAH emission density was found to be significantly associated with female breast cancer incidence, with the adjusted β of 0.424 (95% CI 0.278, 0.570; p < 0.0001) for emissions from all sources and of 0.552 (95% CI 0.278, 0.826; p < 0.0001) for emissions from traffic source. This study suggests that PAH exposure from ambient air could play a role in the increased breast cancer risk among women living in urban areas of the US. Further research could provide insight into breast cancer etiology and prevention.

  12. Chronic effects of ambient air pollution on respiratory morbidities among Chinese children: a cross-sectional study in Hong Kong.

    Science.gov (United States)

    Gao, Yang; Chan, Emily Yy; Li, Liping; Lau, Patrick Wc; Wong, Tze Wai

    2014-02-03

    The chronic health effects from exposure to ambient air pollution are still unclear. This study primarily aims to examine the relationship between long-term exposure to ambient air pollution and respiratory morbidities in Chinese children. A cross-sectional study was conducted among 2,203 school children aged 8-10 in three districts with different air pollution levels in Hong Kong. Annual means for ambient PM10, SO2, NO2 and O3 in each district were used to estimate participants' individual exposure. Two questionnaires were used to collect children's respiratory morbidities and other potential risk factors. Multivariable logistic regression was fitted to estimate the risks of air pollution for respiratory morbidities. Compared to those in the low-pollution district (LPD), girls in the high-pollution district (HPD) were at significantly higher risk for cough at night (ORadj. = 1.81, 95% CI: 1.71-2.78) and phlegm without colds (ORadj. = 3.84, 95% CI: 1.74-8.47). In addition, marginal significance was reached for elevated risks for asthma, wheezing symptoms, and phlegm without colds among boys in HPD (adjusted ORs: 1.71-2.82), as well as chronic cough among girls in HPD (ORadj. = 2.03, 95% CI: 0.88-4.70). Results have confirmed certain adverse effects on children's respiratory health from long-term exposure to ambient air pollution. PM10 may be the most relevant pollutant with adverse effects on wheezing and phlegm in boys. Both PM10 and NO2 may be contributing to cough and phlegm in girls.

  13. Ambient air pollution as a risk factor for lung cancer

    Directory of Open Access Journals (Sweden)

    COHEN AARON J

    1997-01-01

    Full Text Available Epidemiologic studies over the last 40 years have observed that general ambient air pollution, chiefly due to the by- products of the incomplete combustion of fossil fuels, is associated with small relative increases in lung cancer. The evidence derives from studies of lung cancer trends, studies of occupational groups, comparisons of urban and rural populations, and case-control and cohort studies using diverse exposure metrics. Recent prospective cohort studies observed 30-50% increases in the risk of lung cancer in relation to approximately a doubling of respirable particle exposure. While these data reflect the effects of exposures in past decades, and despite some progress in reducing air pollution, large numbers of people in the US continue to be exposed to pollutant mixtures containing known or suspected carcinogens. These observations suggest that the most widely cited estimates of the proportional contribution of air pollution to lung cancer occurrence in the US, based largely on the results of animal experimentation, may be too low. It is important that better epidemiologic research be conducted to allow improved estimates of lung cancer risk from air pollution in the general population. The development and application of new epidemiologic methods, particularly the improved characterization of population-wide exposure to mixtures of air pollutants and the improved design of ecologic studies, could improve our ability to measure accurately the magnitude of excess cancer related to air pollution.

  14. Dynamic air layer on textured superhydrophobic surfaces

    KAUST Repository

    Vakarelski, Ivan Uriev

    2013-09-03

    We provide an experimental demonstration that a novel macroscopic, dynamic continuous air layer or plastron can be sustained indefinitely on textured superhydrophobic surfaces in air-supersaturated water by a natural gas influx mechanism. This type of plastron is an intermediate state between Leidenfrost vapor layers on superheated surfaces and the equilibrium Cassie-Baxter wetting state on textured superhydrophobic surfaces. We show that such a plastron can be sustained on the surface of a centimeter-sized superhydrophobic sphere immersed in heated water and variations of its dynamic behavior with air saturation of the water can be regulated by rapid changes of the water temperature. The simple experimental setup allows for quantification of the air flux into the plastron and identification of the air transport model of the plastron growth. Both the observed growth dynamics of such plastrons and millimeter-sized air bubbles seeded on the hydrophilic surface under identical air-supersaturated solution conditions are consistent with the predictions of a well-mixed gas transport model. © 2013 American Chemical Society.

  15. Ambient air pollution, climate change, and population health in China.

    Science.gov (United States)

    Kan, Haidong; Chen, Renjie; Tong, Shilu

    2012-07-01

    As the largest developing country, China has been changing rapidly over the last three decades and its economic expansion is largely driven by the use of fossil fuels, which leads to a dramatic increase in emissions of both ambient air pollutants and greenhouse gases (GHGs). China is now facing the worst air pollution problem in the world, and is also the largest emitter of carbon dioxide. A number of epidemiological studies on air pollution and population health have been conducted in China, using time-series, case-crossover, cross-sectional, cohort, panel or intervention designs. The increased health risks observed among Chinese population are somewhat lower in magnitude, per amount of pollution, than the risks found in developed countries. However, the importance of these increased health risks is greater than that in North America or Europe, because the levels of air pollution in China are very high in general and Chinese population accounts for more than one fourth of the world's totals. Meanwhile, evidence is mounting that climate change has already affected human health directly and indirectly in China, including mortality from extreme weather events; changes in air and water quality; and changes in the ecology of infectious diseases. If China acts to reduce the combustion of fossil fuels and the resultant air pollution, it will reap not only the health benefits associated with improvement of air quality but also the reduced GHG emissions. Consideration of the health impact of air pollution and climate change can help the Chinese government move forward towards sustainable development with appropriate urgency. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. 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.

  17. 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.

  18. 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

  19. Local emission of primary air pollutants and its contribution to wet deposition and concentrations of aerosols and gases in ambient air in Japan

    Science.gov (United States)

    Aikawa, Masahide; Hiraki, Takatoshi; Tomoyose, Nobutaka; Ohizumi, Tsuyoshi; Noguchi, Izumi; Murano, Kentaro; Mukai, Hitoshi

    2013-11-01

    We studied wet deposition by precipitation and the concentrations of aerosols and gases in ambient air in relation to the primary air pollutants discharged from domestic areas. The concentrations of aerosols and gases were influenced by nearby emissions except for non-sea-salt SO, which is transported long distances. The area facing the Sea of Japan showed much larger wet deposition than other areas, although the domestic emissions of the primary air pollutants there were small and showed a peak in wet deposition from October to March, as distinct from April to September in other areas. We performed the correlation analyses between wet deposition of each component and the product of the concentrations of corresponding aerosols and gases in ambient air and the two-thirds power of the precipitation. From the results, following scavenging processes were suggested. • Sulfate and ammonium were scavenged in precipitation as particulate matter such as (NH4)2SO4 and NH4HSO4. • Nitrate was scavenged mainly in precipitation through gaseous HNO3. • Ammonium was complementarily scavenged in precipitation through aerosols such as (NH4)2SO4 and NH4HSO4 and through gaseous NH3.

  20. Study on the impact of industrial flue gases on the PCDD/Fs congener profile in ambient air.

    Science.gov (United States)

    Węgiel, Małgorzata; Chrząszcz, Ryszard; Maślanka, Anna; Grochowalski, Adam

    2014-11-01

    The aim of this study was to examine the impact of emissions from combustion processes from sinter, medical, waste and sewage waste incineration plants on the PCDD and PCDF congener profile in ambient air in Krakow (city in Poland). The subject matter of the study were air samples from the outskirts and the city center. It was found that in flue gases from industrial sources and in ambient air the share of PCDF congeners in relation to the total content of PCDD/Fs was higher than the share of PCDDs. However, in air samples collected in the city center, this relationship was reversed. The PCDD congener profiles in flue gases and in air samples are comparable. However, in the samples from the city centre, the share of OCDD is significantly higher and amounts to about 80%. The PCDF congener shares show higher spatial diversity, although in all the analyzed air samples, ODCF and 1,2,3,4,6,7,8 HpCDF dominated. Analyzing the share of congeners in regard to the sum of PCDDs/Fs a mutual resemblance of air from the suburbs, exhaust gases from the sinter ore and sewage sludge incinerator plant was observed. The study showed a similarity between the profile of congeners in air from the city centre and exhaust gases from the medical waste incinerator. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Short-term effects of ambient air pollution on emergency room admissions due to cardiovascular causes in Beijing, China

    International Nuclear Information System (INIS)

    Ma, Yuxia; Zhao, Yuxin; Yang, Sixu; Zhou, Jianding; Xin, Jinyuan; Wang, Shigong; Yang, Dandan

    2017-01-01

    Ambient air pollution has been a major global public health issue. A number of studies have shown various adverse effects of ambient air pollution on cardiovascular diseases. In the current study, we investigated the short-term effects of ambient air pollution on emergency room (ER) admissions due to cardiovascular causes in Beijing from 2009 to 2012 using a time-series analysis. A total of 82430 ER cardiovascular admissions were recorded. Different gender (male and female) and age groups (15yrs ≤ age <65 yrs and age ≥ 65 yrs) were also examined by single model and multiple-pollutant model. Three major pollutants (SO 2 , NO 2 and PM 10 ) had lag effects of 0–2 days on cardiovascular ER admissions. The relative risks (95% CI) of per 10 μg/m 3 increase in PM 10 , SO 2 and NO 2 were 1.008 (0.997–1.020), 1.008(0.999–1.018) and 1.014(1.003–1.024), respectively. The effect was more pronounced in age ≥65 and males in Beijing. We also found the stronger acute effects on the elderly and females at lag 0 than on the younger people and males at lag 2. - Highlights: • Significant associations were found between air pollution and emergency admissions of cardiovascular diseases. • Air pollutants had lag effects on age and gender groups. • Stronger effects of air pollutants were observed for age ≥65 yrs and males. • More acute effects of air pollutants were found for age ≥65 yrs and females. - Air pollutants had significant lag effects on different age and gender groups. The effects were more pronounced in age ≥65 and males in Beijing, China.

  2. Biofilm Formation Derived from Ambient Air and the Characteristics of Apparatus

    International Nuclear Information System (INIS)

    Kanematsu, H; Kougo, H; Kuroda, D; Itho, H; Ogino, Y; Yamamoto, Y

    2013-01-01

    Biofilm is a kind of thin film on solidified matters, being derived from bacteria. Generally, planktonic bacteria float in aqueous environments, soil or air, most of which can be regarded as oligotrophic environments. Since they have to survive by instinct, they seek for nutrients that would exist on materials surfaces as organic matters. Therefore, bacteria attach materials surfaces reversibly. The attachment and detachment repeat for a while and finally, they attach on them irreversibly and the number of bacteria on them increases. At a threshold number, bacteria produce polymeric matters at the same time by quorum sensing mechanism and the biofilm produces on material surfaces. The biofilm produced in that way generally contains water (more than 80%), EPS (Exopolymeric Substance) and bacteria themselves. And they might bring about many industrial problems, fouling, corrosion etc. Therefore, it is very important for us to control and prevent the biofilm formation properly. However, it is generally very hard to produce biofilm experimentally and constantly in ambient atmosphere on labo scale. The authors invented an apparatus where biofilm could form on specimen's surfaces from house germs in the ambient air. In this experiment, we investigated the basic characteristics of the apparatus, reproducibility, the change of biofilm with experimental time, the quality change of water for biofilm formation and their significance for biofilm research.

  3. Direct NMR Monitoring of Phase Separation Behavior of Highly Supersaturated Nifedipine Solution Stabilized with Hypromellose Derivatives.

    Science.gov (United States)

    Ueda, Keisuke; Higashi, Kenjirou; Moribe, Kunikazu

    2017-07-03

    We investigated the phase separation behavior and maintenance mechanism of the supersaturated state of poorly water-soluble nifedipine (NIF) in hypromellose (HPMC) derivative solutions. Highly supersaturated NIF formed NIF-rich nanodroplets through phase separation from aqueous solution containing HPMC derivative. Dissolvable NIF concentration in the bulk water phase was limited by the phase separation of NIF from the aqueous solution. HPMC derivatives stabilized the NIF-rich nanodroplets and maintained the NIF supersaturation with phase-separated NIF for several hours. The size of the NIF-rich phase was different depending on the HPMC derivatives dissolved in aqueous solution, although the droplet size had no correlation with the time for which NIF supersaturation was maintained without NIF crystallization. HPMC acetate and HPMC acetate succinate (HPMC-AS) effectively maintained the NIF supersaturation containing phase-separated NIF compared with HPMC. Furthermore, HPMC-AS stabilized NIF supersaturation more effectively in acidic conditions. Solution 1 H NMR measurements of NIF-supersaturated solution revealed that HPMC derivatives distributed into the NIF-rich phase during the phase separation of NIF from the aqueous solution. The hydrophobicity of HPMC derivative strongly affected its distribution into the NIF-rich phase. Moreover, the distribution of HPMC-AS into the NIF-rich phase was promoted at lower pH due to the lower aqueous solubility of HPMC-AS. The distribution of a large amount of HPMC derivatives into NIF-rich phase induced the strong inhibition of NIF crystallization from the NIF-rich phase. Polymer distribution into the drug-rich phase directly monitored by solution NMR technique can be a useful index for the stabilization efficiency of drug-supersaturated solution containing a drug-rich phase.

  4. 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

  5. 75 FR 9894 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

    Science.gov (United States)

    2010-03-04

    ..., Research Triangle Park, North Carolina 27711. Designation of this new equivalent method is intended to... ENVIRONMENTAL PROTECTION AGENCY [FRL-9121-6] Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods: Designation of One New Equivalent Method AGENCY: Environmental...

  6. 76 FR 15974 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

    Science.gov (United States)

    2011-03-22

    ..., Research Triangle Park, North Carolina 27711. Designation of these new equivalent methods is intended to... ENVIRONMENTAL PROTECTION AGENCY [FRL-9285-2] Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods: Designation of Four New Equivalent Methods AGENCY: Environmental...

  7. 75 FR 51039 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

    Science.gov (United States)

    2010-08-18

    ..., Research Triangle Park, North Carolina 27711. Designation of these new equivalent methods is intended to... ENVIRONMENTAL PROTECTION AGENCY [FRL-9190-5] Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods: Designation of Two New Equivalent Methods AGENCY: Environmental...

  8. Vanadium supersaturated silicon system: a theoretical and experimental approach

    Science.gov (United States)

    Garcia-Hemme, Eric; García, Gregorio; Palacios, Pablo; Montero, Daniel; García-Hernansanz, Rodrigo; Gonzalez-Diaz, Germán; Wahnon, Perla

    2017-12-01

    The effect of high dose vanadium ion implantation and pulsed laser annealing on the crystal structure and sub-bandgap optical absorption features of V-supersaturated silicon samples has been studied through the combination of experimental and theoretical approaches. Interest in V-supersaturated Si focusses on its potential as a material having a new band within the Si bandgap. Rutherford backscattering spectrometry measurements and formation energies computed through quantum calculations provide evidence that V atoms are mainly located at interstitial positions. The response of sub-bandgap spectral photoconductance is extended far into the infrared region of the spectrum. Theoretical simulations (based on density functional theory and many-body perturbation in GW approximation) bring to light that, in addition to V atoms at interstitial positions, Si defects should also be taken into account in explaining the experimental profile of the spectral photoconductance. The combination of experimental and theoretical methods provides evidence that the improved spectral photoconductance up to 6.2 µm (0.2 eV) is due to new sub-bandgap transitions, for which the new band due to V atoms within the Si bandgap plays an essential role. This enables the use of V-supersaturated silicon in the third generation of photovoltaic devices.

  9. Perspective for Future Research Direction About Health Impact of Ambient Air Pollution in China.

    Science.gov (United States)

    Dong, Guang-Hui

    2017-01-01

    Air pollution has become one of the major risks to human health because of the progressive increase in the use of vehicles powered by fossil fuels. Although lots of works on the health impact of ambient air pollution have been done in China, the following recommendations for future research were identified in this chapter: (1) the synergistic effect of indoor air pollution with climate change; (2) develop new technologies to improve accurate assessment of air pollution exposure; (3) well-designed cohort study of sensitive populations including children, older people, and people with chronic health problems; (4) multi-omics technologies in the underlying mechanisms study; and (5) benefits evaluation of improvement of air quality. In conclusion, China is becoming a suitable study site, providing an ideal opportunity to evaluate the effects of environmental pollution, including air pollution, on human health, which might serve as an example for developing countries where health impacts of air pollution are as serious as in China.

  10. 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.

  11. Amine-tethered solid adsorbents coupling high adsorption capacity and regenerability for CO2 capture from ambient air.

    Science.gov (United States)

    Choi, Sunho; Gray, McMahan L; Jones, Christopher W

    2011-05-23

    Silica supported poly(ethyleneimine) (PEI) materials are prepared via impregnation and demonstrated to be promising adsorbents for CO(2) capture from ultra-dilute gas streams such as ambient air. A prototypical class 1 adsorbent, containing 45 wt% PEI (PEI/silica), and two new modified PEI-based aminosilica adsorbents, derived from PEI modified with 3-aminopropyltrimethoxysilane (A-PEI/silica) or tetraethyl orthotitanate (T-PEI/silica), are prepared and characterized by using thermogravimetric analysis and FTIR spectroscopy. The modifiers are shown to enhance the thermal stability of the polymer-oxide composites, leading to higher PEI decomposition temperatures. The modified adsorbents present extremely high CO(2) adsorption capacities under conditions simulating ambient air (400 ppm CO(2) in inert gas), exceeding 2 mol(CO (2)) kg(sorbent)(-1), as well as enhanced adsorption kinetics compared to conventional class 1 sorbents. The new adsorbents show excellent stability in cyclic adsorption-desorption operations, even under dry conditions in which aminosilica adsorbents are known to lose capacity due to urea formation. Thus, the adsorbents of this type can be considered promising materials for the direct capture of CO(2) from ultra-dilute gas streams such as ambient air. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. 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.

  13. Energy Levels of Defects Created in Silicon Supersaturated with Transition Metals

    Science.gov (United States)

    García, H.; Castán, H.; Dueñas, S.; García-Hemme, E.; García-Hernansaz, R.; Montero, D.; González-Díaz, G.

    2018-03-01

    Intermediate-band semiconductors have attracted much attention for use in silicon-based solar cells and infrared detectors. In this work, n-Si substrates have been implanted with very high doses (1013 cm-2 and 1014 cm-2) of vanadium, which gives rise to a supersaturated layer inside the semiconductor. However, the Mott limit was not exceeded. The energy levels created in the supersaturated silicon were studied in detail by means of thermal admittance spectroscopy. We found a single deep center at energy near E C - 200 meV. This value agrees with one of the levels found for vanadium in silicon. The capture cross-section values of the deep levels were also calculated, and we found a relationship between the capture cross-section and the energy position of the deep levels which follows the Meyer-Neldel rule. This process usually appears in processes involving multiple excitations. The Meyer-Neldel energy values agree with those previously obtained for silicon supersaturated with titanium and for silicon contaminated with iron.

  14. Short-term effects of ambient air pollution on emergency room admissions due to cardiovascular causes in Beijing, China.

    Science.gov (United States)

    Ma, Yuxia; Zhao, Yuxin; Yang, Sixu; Zhou, Jianding; Xin, Jinyuan; Wang, Shigong; Yang, Dandan

    2017-11-01

    Ambient air pollution has been a major global public health issue. A number of studies have shown various adverse effects of ambient air pollution on cardiovascular diseases. In the current study, we investigated the short-term effects of ambient air pollution on emergency room (ER) admissions due to cardiovascular causes in Beijing from 2009 to 2012 using a time-series analysis. A total of 82430 ER cardiovascular admissions were recorded. Different gender (male and female) and age groups (15yrs ≤ age pollutant model. Three major pollutants (SO 2 , NO 2 and PM 10 ) had lag effects of 0-2 days on cardiovascular ER admissions. The relative risks (95% CI) of per 10 μg/m 3 increase in PM 10 , SO 2 and NO 2 were 1.008 (0.997-1.020), 1.008(0.999-1.018) and 1.014(1.003-1.024), respectively. The effect was more pronounced in age ≥65 and males in Beijing. We also found the stronger acute effects on the elderly and females at lag 0 than on the younger people and males at lag 2. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. 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.

  16. Review of Current Literature and Research on Gas Supersaturation and Gas Bubble Trauma: Special Publication Number 1, 1986.

    Energy Technology Data Exchange (ETDEWEB)

    Colt, John; Bouck, Gerald R.; Fidler, Larry

    1986-12-01

    This report presents recently published information and on-going research on the various areas of gas supersaturation. Growing interest in the effects of chronic gas supersaturation on aquatic animals has been due primarily to heavy mortality of salmonid species under hatchery conditions. Extensive examination of affected animals has failed to consistently identify pathogenic organisms. Water quality sampling has shown that chronic levels of gas supersaturation are commonly present during a significant period of the year. Small marine fish larvae are significantly more sensitive to gas supersaturation than salmonids. Present water quality criteria for gas supersaturation are not adequate for the protection of either salmonids under chronic exposure or marine fish larvae, especially in aquaria or hatcheries. To increase communication between interested parties in the field of gas supersaturation research and control, addresses and telephone numbers of all people responding to the questionnaire are included. 102 refs.

  17. Effect of supersaturation on L-glutamic acid polymorphs under droplet-based microchannels

    Science.gov (United States)

    Jiang, Nan; Wang, Zhanzhong; Dang, Leping; Wei, Hongyuan

    2016-07-01

    Supersaturation is an important controlling factor for crystallization process and polymorphism. Droplet-based microchannels and conventional crystallization were used to investigate polymorphs of L-gluatamic acid in this work. The results illustrate that it is easy to realize the accurate and rapid control of the crystallization temperature in the droplets, which is especially beneficial to heat and mass transfer during crystallization. It is also noted that higher degree of supersaturation favors the nucleation of α crystal form, while lower degree of supersaturation favors the nucleation of β crystal form under droplet-based microchannels for L-gluatamic acid. In addition, there is a different nucleation behavior to be found under droplet-based microchannels both for the β form and α form of L-glutamic acid. This new finding can provide important insight into the development and design of investigation meanings for drug polymorph.

  18. The association between low level exposures to ambient air pollution and term low birth weight: a retrospective cohort study

    Directory of Open Access Journals (Sweden)

    Stieb David

    2006-02-01

    Full Text Available Abstract Background Studies in areas with relatively high levels of air pollution have found some positive associations between exposures to ambient levels of air pollution and several birth outcomes including low birth weight (LBW. The purpose of this study was to examine the association between LBW among term infants and ambient air pollution, by trimester of exposure, in a region of lower level exposures. Methods The relationship between LBW and ambient levels of particulate matter up to 10 um in diameter (PM10, sulfur dioxide (SO2 and ground-level ozone (O3 was evaluated using the Nova Scotia Atlee Perinatal Database and ambient air monitoring data from the Environment Canada National Air Pollution Surveillance Network and the Nova Scotia Department of Environment. The cohort consisted of live singleton births (≥37 weeks of gestation between January1,1988 and December31,2000. Maternal exposures to air pollution were assigned to women living within 25 km of a monitoring station at the time of birth. Air pollution was evaluated as a continuous and categorical variable (using quartile exposures for each trimester and relative risks were estimated from logistic regression, adjusted for confounding variables. Results There were 74,284 women with a term, singleton birth during the study period and with exposure data. In the analyses unadjusted for year of birth, first trimester exposures in the highest quartile for SO2 and PM10suggested an increased risk of delivering a LBW infant (relative risk = 1.36, 95% confidence interval = 1.04 to 1.78 for SO2 exposure and relative risk = 1.33, 95% confidence interval = 1.02 to 1.74 for PM10. After adjustment for birth year, the relative risks were attenuated somewhat and not statistically significant. A dose-response relationship for SO2 was noted with increasing levels of exposure. No statistically significant effects were noted for ozone. Conclusion Our results suggest that exposure during the first

  19. 76 FR 46083 - Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Sulfur

    Science.gov (United States)

    2011-08-01

    ... 2. Linking ANC to Deposition 3. Linking Deposition to Ambient Air Indicators 4. Aquatic... ANC Levels 2. ANC Levels Related to Effects on Aquatic Ecosystems 3. Consideration of Episodic Acidity 4. Consideration of Ecosystem Response Time 5. Prior Examples of Target ANC Levels 6. Consideration...

  20. 75 FR 45627 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

    Science.gov (United States)

    2010-08-03

    ... Research and Development on March 30, 2010. The analytical procedure of this method has been tested in... Protection Agency, Research Triangle Park, North Carolina 27711. Designation of this new equivalent method is... ENVIRONMENTAL PROTECTION AGENCY [FRL-9184-5] Office of Research and Development; Ambient Air...

  1. Applying policy and health effects of air pollution in South Korea: focus on ambient air quality standards

    Science.gov (United States)

    Ha, Jongsik

    2014-01-01

    Objectives South Korea’s air quality standards are insufficient in terms of establishing a procedure for their management. The current system lacks a proper decision-making process and prior evidence is not considered. The purpose of this study is to propose a measure for establishing atmospheric environmental standards in South Korea that will take into consideration the health of its residents. Methods In this paper, the National Ambient Air Quality Standards (NAAQS) of the US was examined in order to suggest ways, which consider health effects, to establish air quality standards in South Korea. Up-to-date research on the health effects of air pollution was then reviewed, and tools were proposed to utilize the key results. This was done in an effort to ensure the reliability of the standards with regard to public health. Results This study showed that scientific research on the health effects of air pollution and the methodology used in the research have contributed significantly to establishing air quality standards. However, as the standards are legally binding, the procedure should take into account the effects on other sectors. Realistically speaking, it is impossible to establish standards that protect an entire population from air pollution. Instead, it is necessary to find a balance between what should be done and what can be done. Conclusions Therefore, establishing air quality standards should be done as part of an evidence-based policy that identifies the health effects of air pollution and takes into consideration political, economic, and social contexts. PMID:25300297

  2. 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.

  3. Environmental resources of selected areas of Hawaii: Climate, ambient air quality, and noise

    Energy Technology Data Exchange (ETDEWEB)

    Lombardi, D.A.; Blasing, T.J.; Easterly, C.E.; Reed, R.M. [Oak Ridge National Lab., TN (United States); Hamilton, C.B. [Univ. of Tennessee, Knoxville, TN (United States)

    1995-03-01

    This report has been prepared to make available and archive background scientific data and related information on climate, ambient air quality, and ambient noise levels collected during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. The US Department of Energy (DOE) published a notice withdrawing its Notice of Intent to prepare the HGP-EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. The report presents a general description of the climate add air quality for the islands of Hawaii (henceforth referred to as Hawaii), Maui and Oahu. It also presents a literature review as baseline information on the health effects of sulfide. The scientific background data and related information is being made available for use by others in conducting future scientific research in these areas. This report describes the environmental resources present in the areas studied (i.e., the affected environment) and does not represent an assessment of environmental impacts.

  4. Role of amine structure on carbon dioxide adsorption from ultradilute gas streams such as ambient air.

    Science.gov (United States)

    Didas, Stephanie A; Kulkarni, Ambarish R; Sholl, David S; Jones, Christopher W

    2012-10-01

    A fundamental study on the adsorption properties of primary, secondary, and tertiary amine materials is used to evaluate what amine type(s) are best suited for ultradilute CO(2) capture applications. A series of comparable materials comprised of primary, secondary, or tertiary amines ligated to a mesoporous silica support via a propyl linker are used to systematically assess the role of amine type. Both CO(2) and water adsorption isotherms are presented for these materials in the range relevant to CO(2) capture from ambient air and it is demonstrated that primary amines are the best candidates for CO(2) capture from air. Primary amines possess both the highest amine efficiency for CO(2) adsorption as well as enhanced water affinity compared to other amine types or the bare silica support. The results suggest that the rational design of amine adsorbents for the extraction of CO(2) from ambient air should focus on adsorbents rich in primary amines. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Exposure to Ambient Fine Particulate Air Pollution in Utero as a Risk Factor for Child Stunting in Bangladesh.

    Science.gov (United States)

    Goyal, Nihit; Canning, David

    2017-12-23

    Pregnant mothers in Bangladesh are exposed to very high and worsening levels of ambient air pollution. Maternal exposure to fine particulate matter has been associated with low birth weight at much lower levels of exposure, leading us to suspect the potentially large effects of air pollution on stunting in children in Bangladesh. We estimate the relationship between exposure to air pollution in utero and child stunting by pooling outcome data from four waves of the nationally representative Bangladesh Demographic and Health Survey conducted between 2004 and 2014, and calculating children's exposure to ambient fine particulate matter in utero using high resolution satellite data. We find significant increases in the relative risk of child stunting, wasting, and underweight with higher levels of in utero exposure to air pollution, after controlling for other factors that have been found to contribute to child anthropometric failure. We estimate the relative risk of stunting in the second, third, and fourth quartiles of exposure as 1.074 (95% confidence interval: 1.014-1.138), 1.150 (95% confidence interval: 1.069-1.237, and 1.132 (95% confidence interval: 1.031-1.243), respectively. Over half of all children in Bangladesh in our sample were exposed to an annual ambient fine particulate matter level in excess of 46 µg/m³; these children had a relative risk of stunting over 1.13 times that of children in the lowest quartile of exposure. Reducing air pollution in Bangladesh could significantly contribute to the Sustainable Development Goal of reducing child stunting.

  6. Hygienic assessment of ambient air quality and health risks to population of Krasnoyarsk region

    Directory of Open Access Journals (Sweden)

    D.V. Goryaev

    2016-06-01

    Full Text Available This study fulfills the hygienic assessment of ambient air quality in the populated areas of the Krasnoyarsk Region. It is shown that the total number of emission sources in the region is more than 23 600 units, what is higher than in previous years. Around 90.7 % out of them correspond to the set standards of permissible emissions. Air monitoring was carried by the establishments of Roshydromet, Rospotrebnadzor and by other organizations at 94 observation posts in eight urban districts and 2 municipal districts of the region. The status of the ambient air in a sequence of the populated areas of Krasnoyarsk region, namely in the cities Achinsk, Kansk, Krasnoyarsk, Lesosibirsk, Minusinsk, Norilsk, is characterized by the presence of certain pollutants, the level of which exceeds the hygienic standards. Prioritized pollutants are benzo(apyrene, suspended solids, nitrogen, and sulfur dioxide, formaldehyde and others. In the settlements the economic entities violate the legal requirements in the field of sanitary and epidemiological welfare of the population. The probability of the population’s health deterioration grows along with the growth of risk factors. The risks of respiratory diseases, immune system, blood and blood-forming organs and the additional mortality are assessed as unacceptable. Ensuring air quality of the urban residential areas and municipal districts of the Krasnoyarsk Territory requires the introducing the complex measures to improve it. The established levels of human health risk associated with exposure to polluted air are an additional criterion for selection of the priority objects when planning the implementation of risk-based model for supervisory activities in the field of sanitary and epidemiological welfare of the population.

  7. Galvanic detection of sulfur dioxide in ambient air at trace levels by anodic oxidation

    NARCIS (Netherlands)

    Lindqvist, F.

    1978-01-01

    A continuous method for the measurement of SO2 in ambient air at trace levels is described. The principle of detection is based on the anodic oxidation of SO2 in a galvanic cell. A differential measuring technique with a cell with two anodes and one cathode is used; background and noise current are

  8. Evaluation and Comparison of Chemiluminescence and UV Photometric Methods for Measuring Ozone Concentrations in Ambient Air

    Science.gov (United States)

    The current Federal Reference Method (FRM) for measuring concentrations of ozone in ambient air is based on the dry, gas-phase, chemiluminescence reaction between ethylene (C2H4) and any ozone (O3) that may be p...

  9. The effect of ambient ozone and humidity on the performance of nylon and Teflon filters used in ambient air monitoring filter-pack systems

    Science.gov (United States)

    PE Padgett

    2010-01-01

    Nylon and Teflon filter media are frequently used for monitoring ambient air pollutants. These media are subject to many environmental factors that may influence adsorption and retention of particulate and gaseous nitrogenous pollutants. This study evaluated the effects of ozone and humidity on the efficacy of nylon and Teflon filters used in the US dry deposition...

  10. A Causal Inference Analysis of the Effect of Wildland Fire Smoke on Ambient Air Pollution Levels and Health Burden

    Science.gov (United States)

    Wildfire smoke is a major contributor to ambient air pollution levels. In this talk, we develop a spatio-temporal model to estimate the contribution of fire smoke to overall air pollution in different regions of the country. We combine numerical model output with observational da...

  11. Occurrence and Concentrations of Toxic VOCs in the Ambient Air of Gumi, an Electronics-Industrial City in Korea

    Directory of Open Access Journals (Sweden)

    Sung-Ok Baek

    2015-08-01

    Full Text Available This study was carried out to characterize the occurrence and concentrations of a variety of volatile organic compounds (VOCs including aliphatic, aromatic, halogenated, nitrogenous, and carbonyl compounds, in the ambient air of Gumi City, where a large number of electronics industries are found. Two field monitoring campaigns were conducted for a one year period in 2003/2004 and 2010/2011 at several sampling sites in the city, representing industrial, residential and commercial areas. More than 80 individual compounds were determined in this study, and important compounds were then identified according to their abundance, ubiquity and toxicity. The monitoring data revealed toluene, trichloroethylene and acetaldehyde to be the most significant air toxics in the city, and their major sources were mainly industrial activities. On the other hand, there was no clear evidence of an industrial impact on the concentrations of benzene and formaldehyde in the ambient air of the city. Overall, seasonal variations were not as distinct as locational variations in the VOCs concentrations, whereas the within-day variations showed a typical pattern of urban air pollution, i.e., increase in the morning, decrease in the afternoon, and an increase again in the evening. Considerable decreases in the concentrations of VOCs from 2003 to 2011 were observed. The reductions in the ambient concentrations were confirmed further by the Korean PRTR data in industrial emissions within the city. Significant decreases in the concentrations of benzene and acetaldehyde were also noted, whereas formaldehyde appeared to be almost constant between the both campaigns. The decreased trends in the ambient levels were attributed not only to the stricter regulations for VOCs in Korea, but also to the voluntary agreement of major companies to reduce the use of organic solvents. In addition, a site planning project for an eco-friendly industrial complex is believed to play a contributory

  12. An experimental verification of the compensation of length change of line scales caused by ambient air pressure

    International Nuclear Information System (INIS)

    Takahashi, Akira; Miwa, Nobuharu

    2010-01-01

    Line scales are used as a working standard of length for the calibration of optical measuring instruments such as profile projectors, measuring microscopes and video measuring systems. The authors have developed a one-dimensional calibration system for line scales to obtain a lower uncertainty of measurement. The scale calibration system, named Standard Scale Calibrator SSC-05, employs a vacuum interferometer system for length measurement, a 633 nm iodine-stabilized He–Ne laser to calibrate the oscillating frequency of the interferometer laser light source and an Abbe's error compensation structure. To reduce the uncertainty of measurement, the uncertainty factors of the line scale and ambient conditions should not be neglected. Using the length calibration system, the expansion and contraction of a line scale due to changes in ambient air pressure were observed and the measured scale length was corrected into the length under standard atmospheric pressure, 1013.25 hPa. Utilizing a natural rapid change in the air pressure caused by a tropical storm (typhoon), we carried out an experiment on the length measurement of a 1000 mm long line scale made of glass ceramic with a low coefficient of thermal expansion. Using a compensation formula for the length change caused by changes in ambient air pressure, the length change of the 1000 mm long line scale was compensated with a standard deviation of less than 1 nm

  13. Maintaining Supersaturation of Nimodipine by PVP with or without the Presence of Sodium Lauryl Sulfate and Sodium Taurocholate.

    Science.gov (United States)

    Pui, Yipshu; Chen, Yuejie; Chen, Huijun; Wang, Shan; Liu, Chengyu; Tonnis, Wouter; Chen, Linc; Serno, Peter; Bracht, Stefan; Qian, Feng

    2018-05-30

    Amorphous solid dispersion (ASD) is one of the most versatile supersaturating drug delivery systems to improve the dissolution rate and oral bioavailability of poorly water-soluble drugs. PVP based ASD formulation of nimodipine (NMD) has been marketed and effectively used in clinic for nearly 30 years, yet the mechanism by which PVP maintains the supersaturation and subsequently improves the bioavailability of NMD was rarely investigated. In this research, we first studied the molecular interactions between NMD and PVP by solution NMR, using CDCl 3 as the solvent, and the drug-polymer Flory-Huggins interaction parameter. No strong specific interaction between PVP and NMD was detected in the nonaqueous state. However, we observed that aqueous supersaturation of NMD could be significantly maintained by PVP, presumably due to the hydrophobic interactions between the hydrophobic moieties of PVP and NMD in aqueous medium. This hypothesis was supported by dynamic light scattering (DLS) and supersaturation experiments in the presence of different surfactants. DLS revealed the formation of NMD/PVP aggregates when NMD was supersaturated, suggesting the formation of hydrophobic interactions between the drug and polymer. The addition of surfactants, sodium lauryl sulfate (SLS) or sodium taurocholate (NaTC), into PVP maintained that NMD supersaturation demonstrated different effects: SLS could only improve NMD supersaturation with concentration above its critical aggregation concentration (CAC) value while not with lower concentration. Nevertheless, NaTC could prolong NMD supersaturation independent of concentration, with lower concentration outperformed higher concentration. We attribute these observations to PVP-surfactant interactions and the formation of PVP/surfactant complexes. In summary, despite the lack of specific interactions in the nonaqueous state, NMD aqueous supersaturation in the presence of PVP was attained by hydrophobic interactions between the hydrophobic

  14. Relationship between ambient air pollution and DNA damage in Polish mothers and newborns

    International Nuclear Information System (INIS)

    Whyatt, R.M.; Santella, R.M.; Jedrychowski, W.; Garte, S.J.; Bell, D.A.; Ottman, R.; Gladek-Yarborough, A.; Cosma, G.; Young, T.L.; Cooper, T.B.; Randall, M.C.; Manchester, D.K.; Perera, F.P.

    1998-01-01

    Industrialized regions in Poland are characterized by high ambient pollution, including polycyclic aromatic hydrocarbons (PAHs) from coal burning for industry and home heating. In experimental bioassays, certain PAHs are transplacental carcinogens and developmental toxicants. The amount of PAHs bound to DNA (PAH-DNA adducts) in maternal and umbilical white blood cells were measured in 70 mothers and newborns from Krakow, Poland. Modulation of adduct levels by genotypes previously linked to risk of lung cancer, specifically glutathione S-transferase M1(GSTM1) and cytochrome P4501A1 (CYP1A1). There was a dose-related increase in maternal and newborn adduct levels with ambient pollution at the women's place of residence among subjects who were not employed away from home (p less than or equal to 0.05). Maternal smoking (active and passive) significantly increased maternal (p less than or equal to 0.01) but not newborn adduct levels. Results indicate that PAH-induced DNA damage in mothers and newborns is increased by ambient air pollution

  15. 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.

  16. Comparitive study of ambient air quality status for big cities of Punjab (Pakistan)

    International Nuclear Information System (INIS)

    Shahid, M.A.K.; Mahmood, A.

    2010-01-01

    This study was undertaken to investigate the quality of air in Lahore and Faisalabad at selected sites. Total eight sampling stations were selected and all the sampling locations fall in different environmental backdrops such as residential, commercial, industrial and rural (control) areas. To study the quality of air, Suspended Particulate Matter (SPM), Nitrogen dioxide (NO/sub 2/) and Sulphur dioxide (SO/sub 2/) were selected In the present study, it was found that the SPM NO/sub 2/ and SO/sub 2/ levels in all the sampling locations are within the permissible limits. However, the raising levels indicated at Residential cum Industrial area (shopping complex along with banks) followed by pure industrial area. The source of these pollutants is primarily transport sector and secondly industries. The ambient air quality reported to be low except 2Kl reported as medium. Sociological survey was conducted to determine the health hazards and the diseases related to air pollution. The results were alarming and found to be compatible with Punjab Public Health and Engineering Department (PPHE). There fore it is suggested that air quality management demands. (author)

  17. Transcriptome Profiling of the Lungs Reveals Molecular Clock Genes Expression Changes after Chronic Exposure to Ambient Air Particles

    Directory of Open Access Journals (Sweden)

    Pengcheng Song

    2017-01-01

    Full Text Available The symptoms of asthma, breathlessness, insomnia, etc. all have relevance to pulmonary rhythmic disturbances. Epidemiology and toxicology studies have demonstrated that exposure to ambient air particles can result in pulmonary dysfunction. However, there are no data directly supporting a link between air pollution and circadian rhythm disorder. In the present study, we found that breathing highly polluted air resulted in changes of the molecular clock genes expression in lung by transcriptome profiling analyses in a rodent model. Compared to those exposed to filtered air, in both pregnant and offspring rats in the unfiltered group, key clock genes (Per1, Per2, Per3, Rev-erbα and Dbp expression level decreased and Bmal1 expression level increased. In both rat dams and their offspring, after continuous exposure to unfiltered air, we observed significant histologic evidence for both perivascular and peribronchial inflammation, increased tissue and systemic oxidative stress in the lungs. Our results suggest that chronic exposure to particulate matter can induce alterations of clock genes expression, which could be another important pathway for explaining the feedbacks of ambient particle exposure in addition to oxidative stress and inflammation.

  18. Supersaturation of zafirlukast in fasted and fed state intestinal media with and without precipitation inhibitors

    DEFF Research Database (Denmark)

    Madsen, Cecilie Maria; Boyd, Ben; Rades, Thomas

    2016-01-01

    by 40%. The aim of this study was to investigate the effect of simulated fasted and fed state intestinal media as well as the effect of HPMC and PVP on the supersaturation and precipitation of ZA in vitro. Supersaturation of aZA was studied in vitro in a small scale setup using the μDiss Profiler......™. Several media were used for this study: One medium simulating the fasted state intestinal fluids and three media simulating different fed state intestinal fluids. Solid state changes of the drug were investigated by small angle x-ray scattering. The duration wherein aZA was maintained at a supersaturated...... simulated intestinal media, but the concentration during supersaturation was higher. It was thus not possible to predict any positive or negative food effects from the dissolution/precipitation curves from different media. Lipolysis products in the fed state simulated media seemed to cause both a negative...

  19. Antioxidants keep the potentially probiotic but highly oxygen-sensitive human gut bacterium Faecalibacterium prausnitzii alive at ambient air.

    Directory of Open Access Journals (Sweden)

    M Tanweer Khan

    Full Text Available The beneficial human gut microbe Faecalibacterium prausnitzii is a 'probiotic of the future' since it produces high amounts of butyrate and anti-inflammatory compounds. However, this bacterium is highly oxygen-senstive, making it notoriously difficult to cultivate and preserve. This has so far precluded its clinical application in the treatment of patients with inflammatory bowel diseases. The present studies were therefore aimed at developing a strategy to keep F. prausnitzii alive at ambient air. Our previous research showed that F. prausnitzii can survive in moderately oxygenized environments like the gut mucosa by transfer of electrons to oxygen. For this purpose, the bacterium exploits extracellular antioxidants, such as riboflavin and cysteine, that are abundantly present in the gut. We therefore tested to what extent these antioxidants can sustain the viability of F. prausnitzii at ambient air. The present results show that cysteine can facilitate the survival of F. prausnitzii upon exposure to air, and that this effect is significantly enhanced the by addition of riboflavin and the cryoprotectant inulin. The highly oxygen-sensitive gut bacterium F. prausnitzii can be kept alive at ambient air for 24 h when formulated with the antioxidants cysteine and riboflavin plus the cryoprotectant inulin. Improved formulations were obtained by addition of the bulking agents corn starch and wheat bran. Our present findings pave the way towards the biomedical exploitation of F. prausnitzii in redox-based therapeutics for treatment of dysbiosis-related inflammatory disorders of the human gut.

  20. Ambient air pollution exposure and respiratory, cardiovascular and cerebrovascular mortality in Cape Town, South Africa: 2001–2006.

    Science.gov (United States)

    Wichmann, Janine; Voyi, Kuku

    2012-11-05

    Little evidence is available on the strength of the association between ambient air pollution exposure and health effects in developing countries such as South Africa. The association between the 24-h average ambient PM(10), SO(2) and NO(2) levels and daily respiratory (RD), cardiovascular (CVD) and cerebrovascular (CBD) mortality in Cape Town (2001-2006) was investigated with a case-crossover design. For models that included entire year data, an inter-quartile range (IQR) increase in PM(10) (12 mg/m3) and NO(2) (12 mg/m3) significantly increased CBD mortality by 4% and 8%, respectively. A significant increase of 3% in CVD mortality was observed per IQR increase in NO(2) and SO(2) (8 mg/m3). In the warm period, PM(10) was significantly associated with RD and CVD mortality. NO(2) had significant associations with CBD, RD and CVD mortality, whilst SO(2) was associated with CVD mortality. None of the pollutants were associated with any of the three outcomes in the cold period. Susceptible groups depended on the cause-specific mortality and air pollutant. There is significant RD, CVD and CBD mortality risk associated with ambient air pollution exposure in South Africa, higher than reported in developed countries.

  1. Ambient Air Pollution Exposure and Respiratory, Cardiovascular and Cerebrovascular Mortality in Cape Town, South Africa: 2001–2006

    Directory of Open Access Journals (Sweden)

    Kuku Voyi

    2012-11-01

    Full Text Available Little evidence is available on the strength of the association between ambient air pollution exposure and health effects in developing countries such as South Africa. The association between the 24-h average ambient PM10, SO2 and NO2 levels and daily respiratory (RD, cardiovascular (CVD and cerebrovascular (CBD mortality in Cape Town (2001–2006 was investigated with a case-crossover design. For models that included entire year data, an inter-quartile range (IQR increase in PM10 (12 mg/m3 and NO2 (12 mg/m3 significantly increased CBD mortality by 4% and 8%, respectively. A significant increase of 3% in CVD mortality was observed per IQR increase in NO2 and SO2 (8 mg/m3. In the warm period, PM10 was significantly associated with RD and CVD mortality. NO2 had significant associations with CBD, RD and CVD mortality, whilst SO2 was associated with CVD mortality. None of the pollutants were associated with any of the three outcomes in the cold period. Susceptible groups depended on the cause-specific mortality and air pollutant. There is significant RD, CVD and CBD mortality risk associated with ambient air pollution exposure in South Africa, higher than reported in developed countries.

  2. Ambient air pollution, traffic noise and adult asthma prevalence: a BioSHaRE approach.

    Science.gov (United States)

    Cai, Yutong; Zijlema, Wilma L; Doiron, Dany; Blangiardo, Marta; Burton, Paul R; Fortier, Isabel; Gaye, Amadou; Gulliver, John; de Hoogh, Kees; Hveem, Kristian; Mbatchou, Stéphane; 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 aerodynamic diameter ≤10 µm (PM 10 ) and nitrogen dioxide (NO 2 )) were estimated by a pan-European Land Use Regression model for 2007. Traffic noise for 2009 was modelled at home addresses by adapting a standardised noise assessment framework (CNOSSOS-EU). A cross-sectional analysis of 646 731 participants aged ≥20 years was undertaken using DataSHIELD to pool data for individual-level analysis via a "compute to the data" approach. Multivariate logistic regression models were fitted to assess the effects of each exposure on lifetime and current asthma prevalence.PM 10 or NO 2 higher by 10 µg·m -3 was associated with 12.8% (95% CI 9.5-16.3%) and 1.9% (95% CI 1.1-2.8%) higher lifetime asthma prevalence, respectively, independent of confounders. Effects were larger in those aged ≥50 years, ever-smokers and less educated. Noise exposure was not significantly associated with asthma prevalence.This study suggests that long-term ambient PM 10 exposure is associated with asthma prevalence in western European adults. Traffic noise is not associated with asthma prevalence, but its potential to impact on asthma exacerbations needs further investigation. Copyright ©ERS 2017.

  3. In-line bulk supersaturation measurement by electrical conductometry in KDP crystal growth from aqueous solution

    Science.gov (United States)

    Bordui, P. F.; Loiacono, G. M.

    1984-07-01

    A method is presented for in-line bulk supersaturation measurement in crystal growth from aqueous solution. The method is based on a computer-controlled concentration measurement exploiting an experimentally predetermined cross-correlation between the concentration, electrical conductivity, and temperature of the growth solution. The method was applied to Holden crystallization of potassium dihydrogen phosphate (KDP). An extensive conductivity-temperature-concentration data base was generated for this system over a temperature range of 31 to 41°C. The method yielded continous, automated bulk supersaturation output accurate to within ±0.05 g KDP100 g water (±0.15% relative supersaturation).

  4. 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.

  5. 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.

  6. 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...

  7. Supersaturation-nucleation behavior of poorly soluble drugs and its impact on the oral absorption of drugs in thermodynamically high-energy forms.

    Science.gov (United States)

    Ozaki, Shunsuke; Minamisono, Takuma; Yamashita, Taro; Kato, Takashi; Kushida, Ikuo

    2012-01-01

    In order to better understand the oral absorption behavior of poorly water-soluble drugs, their supersaturation-nucleation behavior was characterized in fasted state simulated intestinal fluid. The induction time (t(ind)) for nucleation was measured for four model drugs: itraconazole, erlotinib, troglitazone, and PLX4032. Supersaturated solutions were prepared by solvent shift method, and nucleation initiation was monitored by ultraviolet detection. The relationship between t(ind) and degree of supersaturation was analyzed in terms of classical nucleation theory. The defined supersaturation stability proved to be compound specific. Clinical data on oral absorption were investigated for drugs in thermodynamically high-energy forms such as amorphous forms and salts and was compared with in vitro supersaturation-nucleation characteristics. Solubility-limited maximum absorbable dose was proportionate to intestinal effective drug concentrations, which are related to supersaturation stability and thermodynamic solubility. Supersaturation stability was shown to be an important factor in determining the effect of high-energy forms. The characterization of supersaturation-nucleation behavior by the presented method is, therefore, valuable for assessing the potential absorbability of poorly water-soluble drugs. Copyright © 2011 Wiley-Liss, Inc.

  8. Enhanced diffusion of dopants in vacancy supersaturation produced by MeV implantation

    International Nuclear Information System (INIS)

    Venezia, V.C.; Univ. of North Texas, Denton, TX; Haynes, T.E.; Agarwal, A.; Lucent Technologies, Murray Hill, NJ; Gossmann, H.J.; Eaglesham, D.J.

    1997-04-01

    The diffusion of Sb and B markers has been studied in vacancy supersaturations produced by MeV Si implantation in float zone (FZ) silicon and bonded etch-back silicon-on-insulator (BESOI) substrates. MeV Si implantation produces a vacancy supersaturated near-surface region and an interstitial-rich region at the projected ion range. Transient enhanced diffusion (TED) of Sb in the near surface layer was observed as a result of a 2 MeV Si + , 1 x 10 16 /cm 2 , implant. A 4x larger TED of Sb was observed in BESOI than in FZ silicon, demonstrating that the vacancy supersaturation persists longer in BESOI than in FZ. B markers in samples with MeV Si implant showed a factor of 10x smaller diffusion relative to markers without the MeV Si + implant. This data demonstrates that a 2 MeV Si + implant injects vacancies into the near surface region

  9. 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.

  10. 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

  11. Ambient Air Pollution Exposure and Respiratory, Cardiovascular and Cerebrovascular Mortality in Cape Town, South Africa: 2001?2006

    OpenAIRE

    Wichmann, Janine; Voyi, Kuku

    2012-01-01

    Little evidence is available on the strength of the association between ambient air pollution exposure and health effects in developing countries such as South Africa. The association between the 24-h average ambient PM10, SO2 and NO2 levels and daily respiratory (RD), cardiovascular (CVD) and cerebrovascular (CBD) mortality in Cape Town (2001–2006) was investigated with a case-crossover design. For models that included entire year data, an inter-quartile range (IQR) increase in PM1...

  12. Short term respiratory health effects of ambient air pollution: results of the APHEA project in Paris.

    OpenAIRE

    Dab, W; Medina, S; Quénel, P; Le Moullec, Y; Le Tertre, A; Thelot, B; Monteil, C; Lameloise, P; Pirard, P; Momas, I; Ferry, R; Festy, B

    1996-01-01

    STUDY OBJECTIVE: To quantify the short term respiratory health effects of ambient air pollution in the Paris area. DESIGN: Time series analysis of daily pollution levels using Poisson regression. SETTING: Paris, 1987-92. MEASUREMENTS AND MAIN RESULTS: Air pollution was monitored by measurement of black smoke (BS) (15 monitoring stations), sulphur dioxide (SO2), nitrogen dioxide (NO2), particulate matter less than 13 microns in diameter (PM13), and ozone (O3) (4 stations). Daily mortality and ...

  13. Association between ambient air pollution and hospitalization for ischemic and hemorrhagic stroke in China: A multicity case-crossover study.

    Science.gov (United States)

    Liu, Hui; Tian, Yaohua; Xu, Yan; Huang, Zhe; Huang, Chao; Hu, Yonghua; Zhang, Jun

    2017-11-01

    There is growing interest in the association between ambient air pollution and stroke, but few studies have investigated the association in developing countries. The primary objective of this study was to examine the association between levels of ambient air pollutants and hospital admission for stroke in China. A time-stratified case-crossover analysis was conducted between 2014 and 2015 in 14 large Chinese cities among 200,958 ischemic stroke and 41,746 hemorrhagic stroke hospitalizations. We used conditional logistic regression to estimate the percentage changes in stroke admissions in relation to interquartile range increases in air pollutants. Air pollution was positively associated with ischemic stroke. A difference of an interquartile range of the 6-day average for particulate matter less than 10 μm in aerodynamic diameter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone corresponded to 0.7% (95% CI: 0%, 1.4%), 1.6% (95% CI: 1.0%, 2.3%), 2.6% (95% CI: 1.8%, 3.5%), 0.5% (95% CI: -0.2%, 1.1%), and 1.3% (95% CI: 0.3%, 2.3%) increases in ischemic stroke admissions, respectively. For hemorrhagic stroke, we observed the only significant association in relation to nitrogen dioxide on the current day (percentage change: 1.6%; 95% CI: 0.3%, 2.9%). Our findings contribute to the limited scientific literature concerning the effect of ambient air pollution on stroke in developing countries. Our findings may have significant public health implications for primary prevention of stroke in China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. 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...

  15. Removal of polycyclic aromatic hydrocarbons (PAHs) from industrial sludges in the ambient air conditions: automotive industry.

    Science.gov (United States)

    Karaca, Gizem; Tasdemir, Yucel

    2013-01-01

    Removal of polycyclic aromatic hydrocarbons (PAHs) existed in automotive industry treatment sludge was examined by considering the effects of temperature, UV, titanium dioxide (TiO2) and diethyl amine (DEA) in different dosages (i.e., 5% and 20%) in this study. Application of TiO2 and DEA to the sludge samples in ambient environment was studied. Ten PAH (Σ10 PAH) compounds were targeted and their average value in the sludge was found to be 4480 ± 1450 ng/g dry matter (DM). Total PAH content of the sludge was reduced by 25% in the ambient air environment. Meteorological conditions, atmospheric deposition, evaporation and sunlight irradiation played an effective role in the variations in PAH levels during the tests carried out in ambient air environment. Moreover, it was observed that when the ring numbers of PAHs increased, their removal rates also increased. Total PAH level did not change with the addition of 5% DEA and only 10% decreased with 5% TiO2 addition. PAH removal ratios were 8% and 32% when DEA (20%) and TiO2 (20%) were added, respectively. It was concluded that DEA was a weak photo-sensitizer yet TiO2 was effective only at 20% dosage.

  16. Effects of the rate of supersaturation generation on polymorphic crystallization of m-hydroxybenzoic acid and o-aminobenzoic acid

    Science.gov (United States)

    He, Guangwen; Wong, Annie B. H.; Chow, Pui Shan; Tan, Reginald B. H.

    2011-01-01

    Effects of the rate of supersaturation generation on polymorphic crystallization have been investigated through evaporation and cooling crystallization experiments of m-hydroxybenzoic acid (m-HBA) in methanol, acetone and ethyl acetate, and o-aminobenzoic acid (o-ABA) in ethanol. The rate of supersaturation generation has been altered by systematically changing either the cooling rate or the evaporation rate of solvent using a jacketed crystallizer and a microfluidic evaporation device, respectively. The results have revealed that the rate of supersaturation generation and the tendency of the formation of the less stable polymorph are positively correlated. Kinetic effects are dominant when the rate of supersaturation generation is high, thereby producing the metastable polymorphs (orthorhombic m-HBA; Form II of o-ABA); on the contrary, more stable polymorphs (monoclinic m-HBA; Forms III and I of o-ABA) are formed when the rate of supersaturation generation is low and the thermodynamic effects are prevailing.

  17. 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

  18. Tritium concentration in ambient air around Kaiga Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Srinivas S Kamath

    2018-01-01

    Full Text Available Tritium (3H is one of the important long-lived radioisotopes in the gaseous effluent from nuclear power plants. In this article, we present the results of 3H monitoring in ambient air samples around the Kaiga Nuclear Power Plant, on the West Coast of India. Air samples were collected by moisture condensation method and the 3H concentration was determined by liquid scintillation spectrometry. The 3H concentration in the 2.3–15 km zone of the power plant varied in the range of <0.04–6.64 Bq m−3 with a median of 0.67 Bq m−3. The samples collected from the 2.3–5 km zone of the power plant exhibit marginally higher concentration when compared to the 5–10 km and 10–15 km zones, which is as expected. The values observed in the present study for Kaiga region are similar to those reported from other nuclear power plants, both within India and other parts of the world.

  19. 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.

  20. The potential effect of differential ambient and deployment chamber temperatures on PRC derived sampling rates with polyurethane foam (PUF) passive air samplers

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Karen, E-mail: k.kennedy@uq.edu.a [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia); Hawker, Darryl W. [Griffith University, School of Environment, Nathan QLD 4111 (Australia); Bartkow, Michael E. [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia); Carter, Steve [Queensland Health Forensic and Scientific Services, Coopers Plains QLD 4108 (Australia); Ishikawa, Yukari; Mueller, Jochen F. [University of Queensland, EnTox (National Research Centre for Environmental Toxicology), 39 Kessels Rd., Coopers Plains QLD 4108 (Australia)

    2010-01-15

    Performance reference compound (PRC) derived sampling rates were determined for polyurethane foam (PUF) passive air samplers in both sub-tropical and temperate locations across Australia. These estimates were on average a factor of 2.7 times higher in summer than winter. The known effects of wind speed and temperature on mass transfer coefficients could not account for this observation. Sampling rates are often derived using ambient temperatures, not the actual temperatures within deployment chambers. If deployment chamber temperatures are in fact higher than ambient temperatures, estimated sampler-air partition coefficients would be greater than actual partition coefficients resulting in an overestimation of PRC derived sampling rates. Sampling rates determined under measured ambient temperatures and estimated deployment chamber temperatures in summer ranged from 7.1 to 10 m{sup 3} day{sup -1} and 2.2-6.8 m{sup 3} day{sup -1} respectively. These results suggest that potential differences between ambient and deployment chamber temperatures should be considered when deriving PRC-based sampling rates. - Internal deployment chamber temperatures rather than ambient temperatures may be required to accurately estimate PRC-based sampling rates.

  1. Limitations of ambient air quality standards in evaluating indoor environments

    International Nuclear Information System (INIS)

    Peterson, J.E.

    1992-01-01

    Analysis of the kinds of data used for the derivation of ambient air quality standards (AAQSs) for carbon monoxide and ozone shows that these values are based on the toxicology of the materials and thus are suitable for evaluating potential health effects of indoor environments, especially on the very young, the aged, and the infirm. A similar analysis shows that the AAQSs for suspended particulate matter, nitrogen dioxide, and sulfur dioxide are strictly empirical and that they should not be used for any but their first, intended purpose. The AAQSs for non-methane hydrocarbons are based on photochemical smog production, not injury of any kind, and have no utility for indoor environment evaluation

  2. Quantifying regional consumption-based health impacts attributable to ambient air pollution in China.

    Science.gov (United States)

    Zhang, Yanxia; Qu, Shen; Zhao, Jing; Zhu, Ge; Zhang, Yanxu; Lu, Xi; Sabel, Clive E; Wang, Haikun

    2018-03-01

    Serious air pollution has caused about one million premature deaths per year in China recently. Besides cross-border atmospheric transport of air pollution, trade also relocates pollution and related health impacts across China as a result of the spatial separation between consumption and production. This study proposes an approach for calculating the health impacts of emissions due to a region's consumption based on a multidisciplinary methodology coupling economic, atmospheric, and epidemiological models. These analyses were performed for China's Beijing and Hebei provinces. It was found that these provinces' consumption-based premature deaths attributable to ambient PM 2.5 were respectively 22,500 and 49,700, which were 23% higher and 37% lower than the numbers solely within their boundaries in 2007. The difference between the effects of trade and trade-related emissions on premature deaths attributable to air pollution in a region has also been clarified. The results illustrate the large and broad impact of domestic trade on regional air quality and the need for comprehensive consideration of supply chains in designing policy to mitigate the negative health impacts of air pollution across China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. A prospective cohort study on ambient air pollution and respiratory morbidities including childhood asthma in adolescents from the western Cape Province: study protocol.

    Science.gov (United States)

    Olaniyan, Toyib; Jeebhay, Mohamed; Röösli, Martin; Naidoo, Rajen; Baatjies, Roslynn; Künzil, Nino; Tsai, Ming; Davey, Mark; de Hoogh, Kees; Berman, Dilys; Parker, Bhawoodien; Leaner, Joy; Dalvie, Mohamed Aqiel

    2017-09-16

    There is evidence from existing literature that ambient air pollutant exposure in early childhood likely plays an important role in asthma exacerbation and other respiratory symptoms, with greater effect among asthmatic children. However, there is inconclusive evidence on the role of ambient air pollutant exposures in relation to increasing asthma prevalence as well as asthma induction in children. At the population level, little is known about the potential synergistic effects between pollen allergens and air pollutants since this type of association poses challenges in uncontrolled real life settings. In particular, data from sub-Sahara Africa is scarce and virtually absent among populations residing in informal residential settlements. A prospective cohort study of 600 school children residing in four informal settlement areas with varying potential ambient air pollutant exposure levels in the Western Cape in South Africa is carried-out. The study has two follow-up periods of at least six-months apart including an embedded panel study in summer and winter. The exposure assessment component models temporal and spatial variability of air quality in the four study areas over the study duration using land-use regression modelling (LUR). Additionally, daily pollen levels (mould spores, tree, grass and weed pollen) in the study areas are recorded. In the panel study asthma symptoms and serial peak flow measurements is recorded three times daily to determine short-term serial airway changes in relation to varying ambient air quality and pollen over 10-days during winter and summer. The health outcome component of the cohort study include; the presence of asthma using a standardised ISAAC questionnaire, spirometry, fractional exhaled nitric-oxide (FeNO) and the presence of atopy (Phadiatop). This research applies state of the art exposure assessment approaches to characterize the effects of ambient air pollutants on childhood respiratory health, with a specific focus on

  4. A prospective cohort study on ambient air pollution and respiratory morbidities including childhood asthma in adolescents from the western Cape Province: study protocol

    Directory of Open Access Journals (Sweden)

    Toyib Olaniyan

    2017-09-01

    Full Text Available Abstract Background There is evidence from existing literature that ambient air pollutant exposure in early childhood likely plays an important role in asthma exacerbation and other respiratory symptoms, with greater effect among asthmatic children. However, there is inconclusive evidence on the role of ambient air pollutant exposures in relation to increasing asthma prevalence as well as asthma induction in children. At the population level, little is known about the potential synergistic effects between pollen allergens and air pollutants since this type of association poses challenges in uncontrolled real life settings. In particular, data from sub-Sahara Africa is scarce and virtually absent among populations residing in informal residential settlements. Methods/design A prospective cohort study of 600 school children residing in four informal settlement areas with varying potential ambient air pollutant exposure levels in the Western Cape in South Africa is carried-out. The study has two follow-up periods of at least six-months apart including an embedded panel study in summer and winter. The exposure assessment component models temporal and spatial variability of air quality in the four study areas over the study duration using land-use regression modelling (LUR. Additionally, daily pollen levels (mould spores, tree, grass and weed pollen in the study areas are recorded. In the panel study asthma symptoms and serial peak flow measurements is recorded three times daily to determine short-term serial airway changes in relation to varying ambient air quality and pollen over 10-days during winter and summer. The health outcome component of the cohort study include; the presence of asthma using a standardised ISAAC questionnaire, spirometry, fractional exhaled nitric-oxide (FeNO and the presence of atopy (Phadiatop. Discussion This research applies state of the art exposure assessment approaches to characterize the effects of ambient air

  5. 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.

  6. 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.

  7. 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

  8. Impact of curcumin supersaturation in antibacterial photodynamic therapy-effect of cyclodextrin type and amount

    DEFF Research Database (Denmark)

    Hegge, A.B.; Nielsen, T.T.; Larsen, Kim Lambertsen

    2012-01-01

    Curcumin has been investigated as a potential photosensitizer (PS) in antimicrobial photodynamic therapy (aPDT). The phototoxic effect of curcumin is dependent on proper formulations of the compound because of the lipophilic nature of the molecule and the extremely low water solubility...... at physiological conditions. In the present study, the combination of curcumin with either a methylated β-cyclodextrin (CD) or polyethylene glycol-based β-CD or γ-CD polymers was investigated in aPDT using Escherichia coli (E. coli) and Enterococcus faecalis as model bacteria. Solutions with various...... supersaturation ratios of curcumin were prepared with the selected CD or CD polymers. The concept of supersaturation was then investigated as a mean to enhance the phototoxic effect of curcumin, especially toward the gram-negative bacteria E. coli. A high supersaturation ratio corresponded with high phototoxicity...

  9. 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)

  10. Annual report of the ambient air quality measurements in Austria 2000

    International Nuclear Information System (INIS)

    Spangl, W.; Schneider, J.

    2001-01-01

    This report presents the result of the ambient air quality measurements conducted according to the air quality act (Austrian Federal Law Gazette I 115/97) in Austria in 2000. This act defines ambient air quality limit values for sulphur dioxide, nitrogen dioxide, total suspended particulates (TSP), carbon monoxide, benzene, lead in air, deposition (total mass including lead and cadmium) and a target value for ozone. The report also comprises results of explorative measurements of PM10 and PM2,5. Only one exceedance of the limit value for sulphur dioxide (0,20 mg/m 3 as half hour mean value, not to be exceeded more than three times a day; 0,50 mg/m 3 as half hour mean value) was observed. The exceedance was caused by air pollution transport from Slovenia. The limit values for nitrogen dioxide and total suspended particulates were exceeded quite frequently in 2000. For nitrogen dioxide, mainly traffic stations were affected. Exceedances of the limit value (0,20 mg/m 3 as half hour mean value) were observed both during winter episodes with unfavourable conditions for dispersion, as well as in spring/summer at a heavily frequented road during episodes with high ozone levels, causing rapid oxidation of NO to NO 2 . Exceedances of the limit value for total suspended particulates (0,15 mg/m 3 as daily mean value) were predominately recorded in urban areas in the vicinity of heavily frequented streets, especially in southern alpine basins and valleys with unfavourable dispersion conditions. The highest pollution was recorded at a heavily frequented crossroad in Graz. For carbon monoxide (eight hour mean value of 10 mg/m 3 ), benzene ( 10 μg/m 3 as annual mean value) and lead (1 μg/m 3 , as annual mean value), no exceedances were recorded. The pollution levels of sulphur dioxide and carbon monoxide show a strong decrease during the last decade, whereas for nitrogen dioxide and particulate matter no clear trend can be identified. The target value of ozone is exceeded at

  11. Direct atmospheric pressure chemical ionization-tandem mass spectrometry for the continuous real-time trace analysis of benzene, toluene, ethylbenzene, and xylenes in ambient air.

    Science.gov (United States)

    Badjagbo, Koffi; Picard, Pierre; Moore, Serge; Sauvé, Sébastien

    2009-05-01

    Real-time monitoring of benzene, toluene, ethylbenzene, and xylenes (BTEX) in ambient air is essential for the early warning detection associated with the release of these hazardous chemicals and in estimating the potential exposure risks to humans and the environment. We have developed a tandem mass spectrometry (MS/MS) method for continuous real-time determination of ambient trace levels of BTEX. The technique is based on the sampling of air via an atmospheric pressure inlet directly into the atmospheric pressure chemical ionization (APCI) source. The method is linear over four orders of magnitude, with correlation coefficients greater than 0.996. Low limits of detection in the range 1-2 microg/m(3) are achieved for BTEX. The reliability of the method was confirmed through the evaluation of quality parameters such as repeatability and reproducibility (relative standard deviation below 8% and 10%, respectively) and accuracy (over 95%). The applicability of this method to real-world samples was evaluated through measurements of BTEX levels in real ambient air samples and results were compared with a reference GC-FID method. This direct APCI-MS/MS method is suitable for real-time analysis of BTEX in ambient air during regulation surveys as well as for the monitoring of industrial processes or emergency situations.

  12. 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.

  13. Estimates and 25-year trends of the global burden of disease attributable to ambient air pollution : an analysis of data from the Global Burden of Diseases Study 2015

    NARCIS (Netherlands)

    Cohen, Aaron J; Brauer, Michael; Burnett, Richard; Anderson, H Ross; Frostad, Joseph; Estep, Kara; Balakrishnan, Kalpana; Brunekreef, Bert|info:eu-repo/dai/nl/067548180; Dandona, Lalit; Dandona, Rakhi; Feigin, Valery; Freedman, Greg; Hubbell, Bryan; Jobling, Amelia; Kan, Haidong; Knibbs, Luke; Liu, Yang|info:eu-repo/dai/nl/411298119; Martin, Randall; Morawska, Lidia; Pope, C Arden; Shin, Hwashin; Straif, Kurt; Shaddick, Gavin; Thomas, Matthew; van Dingenen, Rita; van Donkelaar, Aaron; Vos, Theo; Murray, Christopher J L; Forouzanfar, Mohammad H

    BACKGROUND: Exposure to ambient air pollution increases morbidity and mortality, and is a leading contributor to global disease burden. We explored spatial and temporal trends in mortality and burden of disease attributable to ambient air pollution from 1990 to 2015 at global, regional, and country

  14. Seasonal Variability of Concentration and Air Quality of Ambient Particulate Matter in Sosnowiec City

    Directory of Open Access Journals (Sweden)

    Jolanta Cembrzyńska

    2015-12-01

    Full Text Available Introduction: Exposing the population to more than standard concentration of particulate matter (PM is a crucial factor shaping the public health on urbanized areas both in Europe and Poland. In most cases, exceeded air quality standards relate to the winter period, in which there has been the greatest amount. Many studies have indicated, that exposure to PM can cause adverse health effects. Human exposure especially to fine particles (with an aerodynamic diameter less than 2.5 µm, causes risk of cardiovascular and respiratory diseases, due to daily mortality and hospital admissions. Various types of epidemiological studies have indicated, that ambient air pollution is responsible for increasing risk of lung cancer. For this reason, in 2013 The International Agency for Research on Cancer (IARC classified outdoor air pollution and particulate matter as carcinogenic to humans (Group 1.

  15. Inhibition of crystal nucleation and growth by water-soluble polymers and its impact on the supersaturation profiles of amorphous drugs.

    Science.gov (United States)

    Ozaki, Shunsuke; Kushida, Ikuo; Yamashita, Taro; Hasebe, Takashi; Shirai, Osamu; Kano, Kenji

    2013-07-01

    The impact of water-soluble polymers on drug supersaturation behavior was investigated to elucidate the role of water-soluble polymers in enhancing the supersaturation levels of amorphous pharmaceuticals. Hydroxypropyl methylcellulose (HPMC), polyvinylpyrrolidone (PVP), and Eudragit L-100 (Eudragit) were used as representative polymers, and griseofulvin and danazol were used as model drugs. Supersaturation profiles of amorphous drugs were measured in biorelevant dissolution tests. Crystal growth rate was measured from the decrease in dissolved drug concentration in the presence of seed crystals. Nucleation kinetics was evaluated by measuring the induction time for nucleation. All experiments were performed in the presence and absence of polymers. The degree of supersaturation of the amorphous model drugs increased with an increase in the inhibitory efficiency of polymers against crystal nucleation and growth (HPMC > PVP > Eudragit). In the presence of HPMC, the addition of seed crystals diminished the supersaturation ratio dramatically for griseofulvin and moderately for danazol. The results demonstrated that the polymers contributed to drug supersaturation by inhibiting both nucleation and growth. The effect of the polymers was drug dependent. The detailed characterization of polymers would allow selection of appropriate crystallization inhibitors and a planned quality control strategy for the development of supersaturable formulations. Copyright © 2013 Wiley Periodicals, Inc.

  16. Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Rooftop Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Bargach, Youssef [Navigant Consulting Inc., Burlington, MA (United States)

    2016-09-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for Low-Global Warming Potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants relative to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in packaged or Rooftop Unit (RTU) air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerants selection process, the test procedures, and the final results.

  17. Multiscale description of carbon-supersaturated ferrite in severely drawn pearlitic wires

    International Nuclear Information System (INIS)

    Nematollahi, Gh. Ali; Grabowski, Blazej; Raabe, Dierk; Neugebauer, Jörg

    2016-01-01

    A multiscale simulation approach based on atomistic calculations and a discrete diffusion model is developed and applied to carbon-supersaturated ferrite, as experimentally observed in severely deformed pearlitic steel. We employ the embedded atom method and the nudged elastic band technique to determine the energetic profile of a carbon atom around a screw dislocation in bcc iron. The results clearly indicate a special region in the proximity of the dislocation core where C atoms are strongly bound, but where they can nevertheless diffuse easily due to low barriers. Our analysis suggests that the previously proposed pipe mechanism for the case of a screw dislocation is unlikely. Instead, our atomistic as well as the diffusion model results support the so-called drag mechanism, by which a mobile screw dislocation is able to transport C atoms along its glide plane. Combining the C-dislocation interaction energies with density-functional-theory calculations of the strain dependent C formation energy allows us to investigate the C supersaturation of the ferrite phase under wire drawing conditions. Corresponding results for local and total C concentrations agree well with previous atom probe tomography measurements indicating that a significant contribution to the supersaturation during wire drawing is due to dislocations.

  18. Valoracion economica ambiental de la calidad del aire por emisiones industriales en la ciudad de quevedo,ecuador

    OpenAIRE

    Espol; Cabrera Casillas, Elvis Antonio; Lozano Mendoza, Pedro Harrys

    2017-01-01

    El objetivo principal del estudio es realizar una valoracion economico ambiental por la mejora de la calidad del aire en quevedo, para esto se elaboro un escenario hipotètico utilizando el metodo de valoracion contingente en su formato dicotomico doble. Guayaquil CAMBIO CLIMATICO

  19. 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

  20. 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.

  1. Risk assessment for nickel and nickel compounds in the ambient air from exposure by inhalation. Review of the European situation

    Energy Technology Data Exchange (ETDEWEB)

    Lepicard, S; Schneider, T [Centre d` Etude sur l` Evaluation de la Protection dans le Domaine Nucleaire, 92 - Fontenay-aux-Roses (France); Fritsch, P; Maximilien, R [Commissariat a l` Energie Atomique, Brussels (Belgium). Dept. des Sciences du Vivant; Deloraine, A [Centre Rhone-Alpes d` Epidemiologie et de Prevention Sanitaire (France)

    1997-12-01

    The objective of this report is to evaluate the risk associated with exposure to nickel in the ambient air, for the general public. The document is divided into three parts, comprising: A review of the regulatory context, a description of the physical and chemical characteristics of nickel and certain nickel compounds, a description of certain industrial processes involving nickel, and the characterization of human exposure (emissions, immissions, transport in the atmosphere); a risk assessment on the basis of human (occupational exposure) and animal data related to the presumed risk of lung cancer; an assessment of the risk associated with exposure to nickel in the ambient air for the general public. (R.P.) 55 refs.

  2. Environmental Resources of Selected Areas of Hawaii: Climate, Ambient Air Quality, and Noise (DRAFT)

    Energy Technology Data Exchange (ETDEWEB)

    Lombardi, D.A.; Blasing, T.J.; Easterly, C.E.; Hamilton, C.B.

    1994-06-01

    This report has been prepared to make available and archive background scientific data and related information on climate, ambient air quality, and ambient noise levels collected during the preparation of the environmental impact statement (EIS) for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of hawaii in its April 1989 proposal to Congress. The US Department of Energy (DOE) published a notice in the Federal Register on May 17, 1994 withdrawing its Notice of Intent of February 14, 1992, to prepare the HGP-EIS. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. The report presents a general description of the climate and air quality for the islands of Hawaii (henceforth referred to as Hawaii), Maui, and Oahu. It also presents a literature review as baseline information on the health effects of hydrogen sulfide. the scientific background data and related information is being made available for use by others in conducting future scientific research in these areas. This report describes the environmental resources present in the areas studied (i.e., the affected environment) and does not represent an assessment of environmental impacts.

  3. Role of oxidative stress in cardiovascular disease outcomes following exposure to ambient air pollution.

    Science.gov (United States)

    Kelly, Frank J; Fussell, Julia C

    2017-09-01

    Exposure to ambient air pollution is associated with adverse cardiovascular outcomes. These are manifested through several, likely overlapping, pathways including at the functional level, endothelial dysfunction, atherosclerosis, pro-coagulation and alterations in autonomic nervous system balance and blood pressure. At numerous points within each of these pathways, there is potential for cellular oxidative imbalances to occur. The current review examines epidemiological, occupational and controlled exposure studies and research employing healthy and diseased animal models, isolated organs and cell cultures in assessing the importance of the pro-oxidant potential of air pollution in the development of cardiovascular disease outcomes. The collective body of data provides evidence that oxidative stress (OS) is not only central to eliciting specific cardiac endpoints, but is also implicated in modulating the risk of succumbing to cardiovascular disease, sensitivity to ischemia/reperfusion injury and the onset and progression of metabolic disease following ambient pollution exposure. To add to this large research effort conducted to date, further work is required to provide greater insight into areas such as (a) whether an oxidative imbalance triggers and/or worsens the effect and/or is representative of the consequence of disease progression, (b) OS pathways and cardiac outcomes caused by individual pollutants within air pollution mixtures, or as a consequence of inter-pollutant interactions and (c) potential protection provided by nutritional supplements and/or pharmacological agents with antioxidant properties, in susceptible populations residing in polluted urban cities. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  4. 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.

  5. Detectors for alpha particles and X-rays operating in ambient air in pulse counting mode and/or with gas amplification

    CERN Document Server

    Charpak, Georges; Breuil, P; Peskov, Vladimir

    2008-01-01

    Ionization chambers working in ambient air in current detection mode are widely used in several applications such as smoke detection, dosimetry, therapeutic beam monitoring and cetera. The aim of this work was to investigate if gaseous detectors can operate in ambient air in pulse counting mode as well as with gas amplification. . To investigate the feasibility of this method two types of open- end gaseous detectors were build and successfully tested. The first one was a single wire or multiwire cylindrical geometry detector operating in pulse mode at a gas gain of 1. The second type alpha detector was an innovative GEM-like detector with resistive electrodes operating in air in avalanche mode at high gas gains (up to 10E4). A detailed comparison between these two detectors is given as well as comparison with the commercially available alpha detectors. The main advantages of gaseous detectors operating in air in a pulse detection mode are their simplicity, low cost and high sensitivity. One of the possible ap...

  6. Design and instrumentation of an automotive heat pump system using ambient air, engine coolant and exhaust gas as a heat source

    International Nuclear Information System (INIS)

    Hosoz, M.; Direk, M.; Yigit, K.S.; Canakci, M.; Alptekin, E.; Turkcan, A.

    2009-01-01

    Because the amount of waste heat used for comfort heating of the passenger compartment in motor vehicles decreases continuously as a result of the increasing engine efficiencies originating from recent developments in internal combustion engine technology, it is estimated that heat requirement of the passenger compartment in vehicles using future generation diesel engines will not be met by the waste heat taken from the engine coolant. The automotive heat pump (AHP) system can heat the passenger compartment individually, or it can support the present heating system of the vehicle. The AHP system can also be employed in electric vehicles, which do not have waste heat, as well as vehicles driven by a fuel cell. The authors of this paper observed that such an AHP system using ambient air as a heat source could not meet the heat requirement of the compartment when ambient temperature was extremely low. The reason is the decrease in the amount of heat taken from the ambient air as a result of low evaporating temperatures. Furthermore, the moisture condensed from air freezed on the evaporator surface, thus blocking the air flow through it. This problem can be solved by using the heat of engine coolant or exhaust gases. In this case, the AHP system can have a higher heating capacity and reuse waste heat. (author)

  7. 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

  8. 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.

  9. 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

  10. Analysis of Volatile Organic Compounds in the Ambient Air of a Paper Mill- A Case Study

    Directory of Open Access Journals (Sweden)

    Xin Tong

    2015-11-01

    Full Text Available In this work, volatile organic compounds (VOCs in the ambient air of a secondary fiber paper mill were analyzed. For the sake of studying pollution comprehensively, four sites in the paper mill were analyzed and active sampling methods were used. Desorption was carried out with two solvents, carbon disulfide and dichloromethane. The compositions of VOCs were determined by gas chromatography-mass spectrometry (GC-MS method. The main identified substances in the four sites were as follows: (1 waste paper sorting room: alkanes, phenols, and esters; (2 papermaking workshop: benzene series, alkanes, ethers, and phenols; (3 vacuum pump outlet: benzene series and phenols; and (4 office area: benzene series and phenols. Two main toxic substances in VOCs, the benzene series and phenols, were detected in the ambient air of the paper mill. The benzene series existed in three places along the main process of the paper mill and even existed in the office area, which was far away from the production line. Additionally, phenols were detected in all sampling locations in the paper mill.

  11. Alternative Refrigerant Evaluation for High-Ambient Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [ORNL; Munk, Jeffrey D [ORNL; Shrestha, Som S [ORNL; Linkous, Randall Lee [ORNL; Goetzler, William [Navigant Consulting Inc.; Guernsey, Matt [Navigant Consulting Inc.; Kassuga, Theo [Navigant Consulting Inc.

    2015-08-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient Temperature Testing Program for Low-GWP Refrigerants aims to develop an understanding of the performance of low-Global Warming Potential (low-GWP) alternatives to Hydrochlorofluorocarbon (HCFC) and Hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high ambient temperature conditions. This interim working paper describes the parties involved, the alternative refrigerants selection process, the test procedures, and the preliminary results.

  12. Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Kassuga, Theo [Navigant Consulting Inc., Burlington, MA (United States)

    2015-10-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for low– global warming potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerant selection process, the test procedures, and the final results.

  13. Supersaturation induced by Itraconazole/Soluplus® micelles provided high GI absorption in vivo

    Directory of Open Access Journals (Sweden)

    Yue Zhong

    2016-04-01

    Full Text Available To investigate the effect of supersaturation induced by micelle formation during dissolution on the bioavailability of itraconazole (ITZ/Soluplus® solid dispersion. Solid dispersions prepared by hot melt extrusion (HME were compressed into tablets directly with other excipients. Dissolution behavior of ITZ tablets was studied by dissolution testing and the morphology of micelles in dissolution media was studied using transmission electron microscopy (TEM. Drug transferring from stomach into intestine was simulated to obtain a supersaturated drug solution. Bioavailability studies were performed on the ITZ tablets and Sporanox® in beagle dogs. The morphology of micelles in the dissolution media was observed to be spherical in shape, with an average size smaller than 100 nm. The supersaturated solutions formed by Soluplus® micelles were stable and no precipitation took place over a period of 180 min. Compared with Sporanox®, ITZ tablets exhibited a 2.50-fold increase in the AUC(0–96 of ITZ and a 1.95-fold increase in its active metabolite hydroxyitraconazole (OH-ITZ in the plasma of beagle dogs. The results obtained provided clear evidence that not only the increase in the dissolution rate in the stomach, but also the supersaturation produced by micelles in the small intestine may be of great assistance in the successful development of poorly water-soluble drugs. The micelles formed by Soluplus® enwrapped the molecular ITZ inside the core which promoted the amount of free drug in the intestinal cavity and carried ITZ through the aqueous boundary layer (ABL, resulting in high absorption by passive transportation across biological membranes. The uptake of intact micelles through pinocytosis together with the inhibition of P-glycoprotein-mediated drug efflux in intestinal epithelia contributed to the absorption of ITZ in the gastrointestinal tract. These results indicate that HME with Soluplus®, which can induce supersaturation by micelle

  14. Análisis de metales en filtros de aire para monitoreo ambiental

    OpenAIRE

    Ballena Salvador, Luis Humberto; Ballena Salvador, Luis Humberto

    2012-01-01

    La mayoría de laboratorios de servicios de análisis para medio ambiente, realizan implementación y/o validación de métodos analíticos normalizados y no normalizados para matrices de aguas, suelos y aire. Al no existir métodos normalizados se hace la validación de un método nuevo, se realizan pruebas a nivel de laboratorio de límites de detección e incertidumbre de los analitos; y finalmente se hace una incertidumbre con parámetros de calidad interlaboratorios. Para el estudio de calidad de...

  15. Association between ambient air pollution and proliferation of umbilical cord blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Novack, L., E-mail: novack@bgu.ac.il [Department of Public Health, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva (Israel); Yitshak-Sade, M. [Clinical Research Center, Soroka University Medical Center, Beer-Sheva (Israel); Landau, D. [Division of Neonatology, University Medical Center, Beer-Sheva (Israel); Kloog, I. [Department of Geography, Ben-Gurion University of the Negev, Beer-Sheva (Israel); Sarov, B. [Department of Public Health, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva (Israel); Karakis, I. [Environmental Epidemiology Department, Ministry of Health, Jerusalem (Israel); Ashkelon Academic College, Ashkelon (Israel)

    2016-11-15

    It has been established as a common knowledge that ambient air pollution (AAP) has an adverse effect on human health. The pathophysiological mechanism of this impact is likely to be related to the oxidative stress. In the current study we estimate the association between AAP and cell proliferation (CP) of umbilical cord blood cells, representing maternal organism most proximal to the fetal body. Blood samples were tested for proliferation in 292 enrolled Arab-Bedouin women at delivery (July 2012–March 2013). The estimates of AAP were defined by a hybrid satellite based model predicting both PM{sub 2.5} (particles<2.5 µm in diameter) and PM{sub 10} (particles<10 µm in diameter) as well as monitoring stations for gaseous air pollutants. Risk estimates of pollution exposure were adjusted to medical history, household risk factors and meteorological factors on the day of delivery or one week prior. Ambient ozone (O{sub 3}) levels on 1, 2, 3and 4 days prior to delivery were associated with lower CP (Prevalence ratio (PR)=0.92, 0.92, 0.93, 0.93, respectively). Increase in inter-quartile range (IOR) of PM{sub 2.5} one day before delivery was associated with 9% increase in CP levels (PR=1.09). The positive direction in association was changed to negative association with CP for PM{sub 2.5} levels measured at more distant time periods (PR=0.90 and 0.93 for lags 5 and 6 days, respectively). Investigation of PM{sub 10} levels indicated a similar pattern (PR=1.05 for pollution values recorded one day before delivery and 0.93 and 0.95 for lags of 5 and 6 days, respectively). Carbon monoxide (CO) levels were associated with lower CP on the day of delivery and 1 day prior (PR=0.92 and PR=0.94). To conclude, the levels of cell proliferation of umbilical cord blood cells appear to be associated with the AAP. More studies are needed to support our findings. - Highlights: • Ambient air pollutants were suggested to have an impact on cell proliferation (CP) of umbilical cord

  16. Association between ambient air pollution and proliferation of umbilical cord blood cells

    International Nuclear Information System (INIS)

    Novack, L.; Yitshak-Sade, M.; Landau, D.; Kloog, I.; Sarov, B.; Karakis, I.

    2016-01-01

    It has been established as a common knowledge that ambient air pollution (AAP) has an adverse effect on human health. The pathophysiological mechanism of this impact is likely to be related to the oxidative stress. In the current study we estimate the association between AAP and cell proliferation (CP) of umbilical cord blood cells, representing maternal organism most proximal to the fetal body. Blood samples were tested for proliferation in 292 enrolled Arab-Bedouin women at delivery (July 2012–March 2013). The estimates of AAP were defined by a hybrid satellite based model predicting both PM 2.5 (particles<2.5 µm in diameter) and PM 10 (particles<10 µm in diameter) as well as monitoring stations for gaseous air pollutants. Risk estimates of pollution exposure were adjusted to medical history, household risk factors and meteorological factors on the day of delivery or one week prior. Ambient ozone (O 3 ) levels on 1, 2, 3and 4 days prior to delivery were associated with lower CP (Prevalence ratio (PR)=0.92, 0.92, 0.93, 0.93, respectively). Increase in inter-quartile range (IOR) of PM 2.5 one day before delivery was associated with 9% increase in CP levels (PR=1.09). The positive direction in association was changed to negative association with CP for PM 2.5 levels measured at more distant time periods (PR=0.90 and 0.93 for lags 5 and 6 days, respectively). Investigation of PM 10 levels indicated a similar pattern (PR=1.05 for pollution values recorded one day before delivery and 0.93 and 0.95 for lags of 5 and 6 days, respectively). Carbon monoxide (CO) levels were associated with lower CP on the day of delivery and 1 day prior (PR=0.92 and PR=0.94). To conclude, the levels of cell proliferation of umbilical cord blood cells appear to be associated with the AAP. More studies are needed to support our findings. - Highlights: • Ambient air pollutants were suggested to have an impact on cell proliferation (CP) of umbilical cord blood. • Ozone (O 3 ) and

  17. 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

  18. Cold Start Emissions of Spark-Ignition Engines at Low Ambient Temperatures as an Air Quality Risk

    Directory of Open Access Journals (Sweden)

    Bielaczyc Piotr

    2014-12-01

    Full Text Available SI engines are highly susceptible to excess emissions when started at low ambient temperatures. This phenomenon has multiple air quality and climate forcing implications. Direct injection petrol engines feature a markedly different fuelling strategy, and so their emissions behaviour is somewhat different from indirect injection petrol engines. The excess emissions of direct injection engines at low ambient temperatures should also differ. Additionally, the direct injection fuel delivery process leads to the formation of PM, and DISI engines should show greater PM emissions at low ambient temperatures. This study reports on laboratory experiments quantifying excess emissions of gaseous and solid pollutants over a legislative driving cycle following cold start at a low ambient temperature for both engine types. Over the legislative cycle for testing at -7°C (the UDC, emissions of HC, CO, NOx and CO2 were higher when tested at -7°C than at 24°C. Massive increases in emissions of HC and CO were observed, together with more modest increases in NOx and CO2 emissions. Results from the entire driving cycle showed excess emissions in both phases (though they were much larger for the UDC. The DISI vehicle showed lower increases in fuel consumption than the port injected vehicles, but greater increases in emission of HC and CO. DISI particle number emissions increased by around 50%; DISI particle mass by over 600%. The observed emissions deteriorations varied somewhat by engine type and from vehicle to vehicle. Excesses were greatest following start-up, but persisted, even after several hundred seconds’ driving. The temperature of the intake air appeared to have a limited but significant effect on emissions after the engine has been running for some time. All vehicles tested here comfortably met the relevant EU limits, providing further evidence that these limits are no longer challenging and need updating.

  19. Mass spectrometry of solid samples in open air using combined laser ionization and ambient metastable ionization

    International Nuclear Information System (INIS)

    He, X.N.; Xie, Z.Q.; Gao, Y.; Hu, W.; Guo, L.B.; Jiang, L.; Lu, Y.F.

    2012-01-01

    Mass spectrometry of solid samples in open air was carried out using combined laser ionization and metastable ionization time-of-flight mass spectrometry (LI-MI-TOFMS) in ambient environment for qualitative and semiquantitative (relative analyte information, not absolute information) analysis. Ambient metastable ionization using a direct analysis in realtime (DART) ion source was combined with laser ionization time-of-flight mass spectrometry (LI-TOFMS) to study the effects of combining metastable and laser ionization. A series of metallic samples from the National Institute of Standards and Technology (NIST 494, 495, 498, 499, and 500) and a pure carbon target were characterized using LI-TOFMS in open air. LI-MI-TOFMS was found to be superior to laser-induced breakdown spectroscopy (LIBS). Laser pulse energies between 10 and 200 mJ at the second harmonic (532 nm) of an Nd:YAG laser were applied in the experiment to obtain a high degree of ionization in plasmas. Higher laser pulse energy improves signal intensities of trace elements (such as Fe, Cr, Mn, Ni, Ca, Al, and Ag). Data were analyzed by numerically calculating relative sensitivity coefficients (RSCs) and limit of detections (LODs) from mass spectrometry (MS) and LIBS spectra. Different parameters, such as boiling point, ionization potential, RSC, LOD, and atomic weight, were shown to analyze the ionization and MS detection processes in open air.

  20. Long-term exposure to ambient air pollution and incidence of brain tumor

    DEFF Research Database (Denmark)

    Andersen, Zorana J.; Pedersen, Marie; Weinmayr, Gudrun

    2018-01-01

    .5 absorbance (Hazard Ratio and 95% Confidence Interval: 1.67; 0.89-3.14 per 10 -5/m 3), and weak positive or null associations with the other pollutants. Hazard ratio for PM2.5 absorbance (1.01; 0.38-2.71 per 10 -5/m 3) and all other pollutants were lower for nonmalignant than for malignant brain tumors......Background: Epidemiological evidence on the association between ambient air pollution and brain tumor risk is sparse and inconsistent. Methods: In 12 cohorts from six European countries, individual estimates of annual mean air pollution levels at the baseline residence were estimated...... by standardized land-use regression models developed within the ESCAPE and TRANSPHORM projects: particulate matter (PM) ≤ 2.5, ≤ 10, and 2.5-10 μm in diameter (PM2.5, PM10, and PMcoarse), PM2.5 absorbance, nitrogen oxides (NO2 and NOx) and elemental composition of PM. We estimated cohort-specific associations...

  1. [Bibliometrics and visualization analysis of land use regression models in ambient air pollution research].

    Science.gov (United States)

    Zhang, Y J; Zhou, D H; Bai, Z P; Xue, F X

    2018-02-10

    Objective: To quantitatively analyze the current status and development trends regarding the land use regression (LUR) models on ambient air pollution studies. Methods: Relevant literature from the PubMed database before June 30, 2017 was analyzed, using the Bibliographic Items Co-occurrence Matrix Builder (BICOMB 2.0). Keywords co-occurrence networks, cluster mapping and timeline mapping were generated, using the CiteSpace 5.1.R5 software. Relevant literature identified in three Chinese databases was also reviewed. Results: Four hundred sixty four relevant papers were retrieved from the PubMed database. The number of papers published showed an annual increase, in line with the growing trend of the index. Most papers were published in the journal of Environmental Health Perspectives . Results from the Co-word cluster analysis identified five clusters: cluster#0 consisted of birth cohort studies related to the health effects of prenatal exposure to air pollution; cluster#1 referred to land use regression modeling and exposure assessment; cluster#2 was related to the epidemiology on traffic exposure; cluster#3 dealt with the exposure to ultrafine particles and related health effects; cluster#4 described the exposure to black carbon and related health effects. Data from Timeline mapping indicated that cluster#0 and#1 were the main research areas while cluster#3 and#4 were the up-coming hot areas of research. Ninety four relevant papers were retrieved from the Chinese databases with most of them related to studies on modeling. Conclusion: In order to better assess the health-related risks of ambient air pollution, and to best inform preventative public health intervention policies, application of LUR models to environmental epidemiology studies in China should be encouraged.

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

    Science.gov (United States)

    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.

  3. 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.

  4. Zn-Ni sulfide selective precipitation: The role of supersaturation

    NARCIS (Netherlands)

    Sampaio, R.M.M.; Timmers, R.A.; Kocks, N.; Andre, V.; Duarte, M.T.; Hullebusch, van E.D.; Farges, F.; Lens, P.N.L.

    2010-01-01

    The selective removal of Zn with Na2S from a mixture of Zn and Ni was studied in a continuously stirred tank reactor. At pH 5 and pS 18 the selectivity was improved from 61% to 99% by reducing the supersaturation at the dosing points by means of the reduction of the influent concentrations. The

  5. Chromatography related performance of the Monitor for Aerosols and Gases in Ambient Air (MARGA): laboratory and field based evaluation

    Science.gov (United States)

    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 measureme...

  6. Geographic variations in female breast cancer incidence in relation to ambient air emissions of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Large, Courtney; Wei, Yudan

    2017-07-01

    A significant geographic variation of breast cancer incidence exists, with incidence rates being much higher in industrialized regions. The objective of the current study was to assess the role of environmental factors such as exposure to ambient air pollution, specifically carcinogenic polycyclic aromatic hydrocarbons (PAHs) that may be playing in the geographic variations in breast cancer incidence. Female breast cancer incidence and ambient air emissions of PAHs were examined in the northeastern and southeastern regions of the USA by analyzing data from the Surveillance, Epidemiology, and End Results (SEER) Program and the State Cancer Profiles of the National Cancer Institute and from the Environmental Protection Agency. Linear regression analysis was conducted to evaluate the association between PAH emissions and breast cancer incidence in unadjusted and adjusted models. Significantly higher age-adjusted incidence rates of female breast cancer were seen in northeastern SEER regions, when compared to southeastern regions, during the years of 2000-2012. After adjusting for potential confounders, emission densities of total PAHs and four carcinogenic individual PAHs (benzo[a]pyrene, dibenz[a,h]anthracene, naphthalene, and benzo[b]fluoranthene) showed a significantly positive association with annual incidence rates of breast cancer, with a β of 0.85 (p = 0.004), 58.37 (p = 0.010), 628.56 (p = 0.002), 0.44 (p = 0.041), and 77.68 (p = 0.002), respectively, among the northeastern and southeastern states. This study suggests a potential relationship between ambient air emissions of carcinogenic PAHs and geographic variations of female breast cancer incidence in the northeastern and southeastern US. Further investigations are needed to explore these interactions and elucidate the role of PAHs in regional variations of breast cancer incidence.

  7. Remote sensing FTIR-system for emission monitoring and ambient air control of atmospheric trace gases and air pollutants; Remote sensing FTIR-System zur Emissions- und Immissionsmessung atmosphaerischer Spurengasse und Luftschadstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmann, T; Mosebach, H; Bittner, H [Kayser-Threde GmbH, Muenchen (Germany)

    1994-01-01

    The Fourier Transform Infrared spectrometer K300, based on the double-pendulum interferometer, is due to its optical design particularly suitable for high resolution remote sensing emission and transmission (long path monitoring) measurements of air pollutants and atmospheric trace gases in the field. The applications encompass direct emission measurements of hot flue gases and aircraft engine exhaust as well as surveillance of industrial complexes and waste disposal sites and ambient air control of e.g. traffic polluted sites. For direct emission measurements the infrared radiation of hot gases is utilized. Monitoring of cold diffuse emissions (e.g. at waste disposal sites) and ambient air control is carried out applying a bistatic transmission configuration with an artificial infrared source (glowbar) facing the instrument from a distance up to several hundred meters (long-path monitoring). Following a short introduction of the measurement technique and system, results from the above mentioned applications, obtained during several field studies are depicted and discussed. 19 refs., 8 figs., 12 tabs.

  8. Setting ambient air quality standards for particulate matter

    International Nuclear Information System (INIS)

    McClellan, Roger O.

    2002-01-01

    Ambient air particulate matter (PM), unspecified as to chemical composition, is of concern because of its health effects. Air quality standards for PM have been established in many countries. The earliest standards were based on threshold models and use of a margin of safety. Initially, standards were based on the mass of total suspended material. In the 1980s a shift to a size-specific standard, PM 10 , began. PM 10 is the fraction of PM captured with 50% efficiency at 10 μm and greater efficiency at smaller sizes. In the late 1990s, standards were proposed for PM 2.5 , which is captured with 50% efficiency at 2.5 μm. The standards for PM are based almost exclusively on human epidemiological data, with laboratory animal and in vitro data used in a supporting role. During the 1990s, new statistical tools began to be used and demonstrated an association between increased PM and an increase in cardiorespiratory morbidity and mortality. The analyses are complicated by the effects of other pollutants such as ozone. Effects have been observed down to 10-20 μg of PM 10 per cubic meter, levels equal to or below background in many parts of the world. In many studies there has been no evidence of a threshold. In the absence of a threshold, a critical issue becomes how to determine how low is low enough? This paper reviews the current literature on PM health effects and suggests research avenues that may yield data which, combined with public policy considerations, may be able to address the issue of 'how low is low enough?'

  9. 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.

  10. Cooling Crystallization of Indomethacin: Effect of Supersaturation, Temperature and Seeding on Polymorphism and Crystal Size Distribution

    DEFF Research Database (Denmark)

    Malwade, Chandrakant Ramkrishna; Qu, Haiyan

    2018-01-01

    In this work, effect of crystallization parameters i.e., supersaturation, seeding, and temperature on polymorphism and crystal size of a non-steroidal anti-inflammatory drug, indomethacin (IMC), was investigated. Firstly, several crystallization solvents (ethanol, methanol, ethyl acetate, acetone...... of IMC from ethanol confirmed that the supersaturation, operating temperature and seeding does affect the polymorphism as well as crystal size distribution of IMC. Fine needle shaped crystals of metastable α-IMC were obtained at 5 °C with high supersaturation even in presence of γ-IMC seeds, while...... rhombic plates like crystals of thermodynamically stable γ-IMC were obtained in remaining experiments. The amount of seed loading only marginally influenced the crystal growth rate and median particle diameter (d50). Particle size analysis of crystals obtained showed bimodal distribution in all...

  11. Impact Analysis of Temperature and Humidity Conditions on Electrochemical Sensor Response in Ambient Air Quality Monitoring.

    Science.gov (United States)

    Wei, Peng; Ning, Zhi; Ye, Sheng; Sun, Li; Yang, Fenhuan; Wong, Ka Chun; Westerdahl, Dane; Louie, Peter K K

    2018-01-23

    The increasing applications of low-cost air sensors promises more convenient and cost-effective systems for air monitoring in many places and under many conditions. However, the data quality from such systems has not been fully characterized and may not meet user expectations in research and regulatory uses, or for use in citizen science. In our study, electrochemical sensors (Alphasense B4 series) for carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO₂), and oxidants (O x ) were evaluated under controlled laboratory conditions to identify the influencing factors and quantify their relation with sensor outputs. Based on the laboratory tests, we developed different correction methods to compensate for the impact of ambient conditions. Further, the sensors were assembled into a monitoring system and tested in ambient conditions in Hong Kong side-by-side with regulatory reference monitors, and data from these tests were used to evaluate the performance of the models, to refine them, and validate their applicability in variable ambient conditions in the field. The more comprehensive correction models demonstrated enhanced performance when compared with uncorrected data. One over-arching observation of this study is that the low-cost sensors may promise excellent sensitivity and performance, but it is essential for users to understand and account for several key factors that may strongly affect the nature of sensor data. In this paper, we also evaluated factors of multi-month stability, temperature, and humidity, and considered the interaction of oxidant gases NO₂ and ozone on a newly introduced oxidant sensor.

  12. Impact Analysis of Temperature and Humidity Conditions on Electrochemical Sensor Response in Ambient Air Quality Monitoring

    Directory of Open Access Journals (Sweden)

    Peng Wei

    2018-01-01

    Full Text Available The increasing applications of low-cost air sensors promises more convenient and cost-effective systems for air monitoring in many places and under many conditions. However, the data quality from such systems has not been fully characterized and may not meet user expectations in research and regulatory uses, or for use in citizen science. In our study, electrochemical sensors (Alphasense B4 series for carbon monoxide (CO, nitric oxide (NO, nitrogen dioxide (NO2, and oxidants (Ox were evaluated under controlled laboratory conditions to identify the influencing factors and quantify their relation with sensor outputs. Based on the laboratory tests, we developed different correction methods to compensate for the impact of ambient conditions. Further, the sensors were assembled into a monitoring system and tested in ambient conditions in Hong Kong side-by-side with regulatory reference monitors, and data from these tests were used to evaluate the performance of the models, to refine them, and validate their applicability in variable ambient conditions in the field. The more comprehensive correction models demonstrated enhanced performance when compared with uncorrected data. One over-arching observation of this study is that the low-cost sensors may promise excellent sensitivity and performance, but it is essential for users to understand and account for several key factors that may strongly affect the nature of sensor data. In this paper, we also evaluated factors of multi-month stability, temperature, and humidity, and considered the interaction of oxidant gases NO2 and ozone on a newly introduced oxidant sensor.

  13. Impact Analysis of Temperature and Humidity Conditions on Electrochemical Sensor Response in Ambient Air Quality Monitoring

    Science.gov (United States)

    Ning, Zhi; Ye, Sheng; Sun, Li; Yang, Fenhuan; Wong, Ka Chun; Westerdahl, Dane; Louie, Peter K. K.

    2018-01-01

    The increasing applications of low-cost air sensors promises more convenient and cost-effective systems for air monitoring in many places and under many conditions. However, the data quality from such systems has not been fully characterized and may not meet user expectations in research and regulatory uses, or for use in citizen science. In our study, electrochemical sensors (Alphasense B4 series) for carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO2), and oxidants (Ox) were evaluated under controlled laboratory conditions to identify the influencing factors and quantify their relation with sensor outputs. Based on the laboratory tests, we developed different correction methods to compensate for the impact of ambient conditions. Further, the sensors were assembled into a monitoring system and tested in ambient conditions in Hong Kong side-by-side with regulatory reference monitors, and data from these tests were used to evaluate the performance of the models, to refine them, and validate their applicability in variable ambient conditions in the field. The more comprehensive correction models demonstrated enhanced performance when compared with uncorrected data. One over-arching observation of this study is that the low-cost sensors may promise excellent sensitivity and performance, but it is essential for users to understand and account for several key factors that may strongly affect the nature of sensor data. In this paper, we also evaluated factors of multi-month stability, temperature, and humidity, and considered the interaction of oxidant gases NO2 and ozone on a newly introduced oxidant sensor. PMID:29360749

  14. Long-Term Exposure to Ambient Air Pollution and Incidence of Postmenopausal Breast Cancer in 15 European Cohorts within the ESCAPE Project

    Science.gov (United States)

    Stafoggia, Massimo; Weinmayr, Gudrun; Pedersen, Marie; Galassi, Claudia; Jørgensen, Jeanette T.; Oudin, Anna; Forsberg, Bertil; Olsson, David; Oftedal, Bente; Marit Aasvang, Gunn; Aamodt, Geir; Pyko, Andrei; Pershagen, Göran; Korek, Michal; De Faire, Ulf; Pedersen, Nancy L.; Östenson, Claes-Göran; Fratiglioni, Laura; Eriksen, Kirsten T.; Tjønneland, Anne; Peeters, Petra H.; Bueno-de-Mesquita, Bas; Plusquin, Michelle; Key, Timothy J.; Jaensch, Andrea; Nagel, Gabriele; Lang, Alois; Wang, Meng; Tsai, Ming-Yi; Fournier, Agnes; Boutron-Ruault, Marie-Christine; Baglietto, Laura; Grioni, Sara; Marcon, Alessandro; Krogh, Vittorio; Ricceri, Fulvio; Sacerdote, Carlotta; Migliore, Enrica; Tamayo-Uria, Ibon; Amiano, Pilar; Dorronsoro, Miren; Vermeulen, Roel; Sokhi, Ranjeet; Keuken, Menno; de Hoogh, Kees; Beelen, Rob; Vineis, Paolo; Cesaroni, Giulia; Brunekreef, Bert; Hoek, Gerard; Raaschou-Nielsen, Ole

    2017-01-01

    Background: Epidemiological evidence on the association between ambient air pollution and breast cancer risk is inconsistent. Objective: We examined the association between long-term exposure to ambient air pollution and incidence of postmenopausal breast cancer in European women. Methods: In 15 cohorts from nine European countries, individual estimates of air pollution levels at the residence were estimated by standardized land-use regression models developed within the European Study of Cohorts for Air Pollution Effects (ESCAPE) and Transport related Air Pollution and Health impacts - Integrated Methodologies for Assessing Particulate Matter (TRANSPHORM) projects: particulate matter (PM) ≤2.5μm, ≤10μm, and 2.5–10μm in diameter (PM2.5, PM10, and PMcoarse, respectively); PM2.5 absorbance; nitrogen oxides (NO2 and NOx); traffic intensity; and elemental composition of PM. We estimated cohort-specific associations between breast cancer and air pollutants using Cox regression models, adjusting for major lifestyle risk factors, and pooled cohort-specific estimates using random-effects meta-analyses. Results: Of 74,750 postmenopausal women included in the study, 3,612 developed breast cancer during 991,353 person-years of follow-up. We found positive and statistically insignificant associations between breast cancer and PM2.5 {hazard ratio (HR)=1.08 [95% confidence interval (CI): 0.77, 1.51] per 5 μg/m3}, PM10 [1.07 (95% CI: 0.89, 1.30) per 10 μg/m3], PMcoarse [1.20 (95% CI: 0.96, 1.49 per 5 μg/m3], and NO2 [1.02 (95% CI: 0.98, 1.07 per 10 μg/m3], and a statistically significant association with NOx [1.04 (95% CI: 1.00, 1.08) per 20 μg/m3, p=0.04]. Conclusions: We found suggestive evidence of an association between ambient air pollution and incidence of postmenopausal breast cancer in European women. https://doi.org/10.1289/EHP1742 PMID:29033383

  15. Proposed Pathophysiologic Framework to Explain Some Excess Cardiovascular Death Associated with Ambient Air Particle Pollution: Insights for Public Health Translation

    Science.gov (United States)

    The paper proposes a pathophysiologic framework to explain the well-established epidemiological association between exposure to ambient air particle pollution and premature cardiovascular mortality, and offers insights into public health solutions that extend beyond regularory en...

  16. Unrestricted release measurements with ambient air ionization monitors

    International Nuclear Information System (INIS)

    MacArthur, D.; Gunn, R.; Dockray, T.; Luff, C.

    1999-01-01

    Radiation monitoring systems based on the long-range alpha detection (LRAD) technique, such as the BNFL Instruments IonSens trademark, provide a single contamination measurement for an entire object rather than the more familiar individual readings for smaller surface areas. The LRAD technique relies on the ionization of ambient air molecules by alpha particles, and the subsequent detection of these ions, rather than direct detection of the alpha particles themselves. A single monitor can detect all of the ions produced over a large object and report a total contamination level for the entire surface of that object. However, both the unrestricted release limits specified in USDOE Order 5400.5 (and similar documents in other countries), and the definitions of radioactive waste categories, are stated in terms of contamination per area. Thus, conversion is required between the total effective contamination as measured by the LRAD-based detector and the allowable release limits. In addition, since the release limits were not written assuming an averaging detector system, the method chosen to average the assumed contamination over the object can have a significant impact on the effective sensitivity of the detector

  17. 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)

  18. A Review of Epidemiological Research on Adverse Neurological Effects of Exposure to Ambient Air Pollution

    Science.gov (United States)

    Xu, Xiaohui; Ha, Sandie Uyen; Basnet, Rakshya

    2016-01-01

    There is a growing body of epidemiological research reporting the neurological effects of ambient air pollution. We examined current evidence, identified the strengths and weaknesses of published epidemiological studies, and suggest future directions for research in this area. Studies were identified through a systematic search of online scientific databases, in addition to a manual search of the reference lists from the identified papers. Despite being a relatively new area of investigation, overall, there is mounting evidence implicating adverse effects of air pollution on neurobehavioral function in both adults and children. Further research is needed to expand our understanding of these relationships, including improvement in the accuracy of exposure assessments; focusing on specific toxicants and their relationships to specific health endpoints, such as neurodevelopmental disorders and neurodegenerative diseases; investigating the combined neurological effects of multiple air pollutants; and further exploration of genetic susceptibility for neurotoxicity of air pollution. In order to achieve these goals collaborative efforts are needed from multidisciplinary teams, including experts in toxicology, biostatistics, geographical science, epidemiology, and neurology. PMID:27547751

  19. Ambient air pollution exposure and the incidence of related health effects among racial/ethnic minorities

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A.; Wernette, D.R.

    1997-02-01

    Differences among racial and ethnic groups in morbidity and mortality rates for diseases, including diseases with environmental causes, have been extensively documented. However, documenting the linkages between environmental contaminants, individual exposures, and disease incidence has been hindered by difficulties in measuring exposure for the population in general and for minority populations in particular. After briefly discussing research findings on associations of common air pollutants with disease incidence, the authors summarize recent studies of radial/ethnic subgroup differences in incidence of these diseases in the US. They then present evidence of both historic and current patterns of disproportionate minority group exposure to air pollution as measured by residence in areas where ambient air quality standards are violated. The current indications of disproportionate potential exposures of minority and low-income populations to air pollutants represent the continuation of a historical trend. The evidence of linkage between disproportionate exposure to air pollution of racial/ethnic minorities and low-income groups and their higher rates of some air pollution-related diseases is largely circumstantial. Differences in disease incidence and mortality rates among racial/ethnic groups are discussed for respiratory diseases, cancers, and lead poisoning. Pollutants of concern include CO, Pb, SO{sub 2}, O{sub 3}, and particulates.

  20. Cost-effective alternative to nano-encapsulation: Amorphous curcumin-chitosan nanoparticle complex exhibiting high payload and supersaturation generation.

    Science.gov (United States)

    Nguyen, Minh Hiep; Yu, Hong; Kiew, Tie Yi; Hadinoto, Kunn

    2015-10-01

    While the wide-ranging therapeutic activities of curcumin have been well established, its successful delivery to realize its true therapeutic potentials faces a major challenge due to its low oral bioavailability. Even though nano-encapsulation has been widely demonstrated to be effective in enhancing the bioavailability of curcumin, it is not without drawbacks (i.e. low payload and costly preparation). Herein we present a cost-effective bioavailability enhancement strategy of curcumin in the form of amorphous curcumin-chitosan nanoparticle complex (or curcumin nanoplex in short) exhibiting a high payload (>80%). The curcumin nanoplex was prepared by a simple yet highly efficient drug-polysaccharide complexation method that required only mixing of the curcumin and chitosan solutions under ambient condition. The effects of (1) pH and (2) charge ratio of chitosan to curcumin on the (i) physical characteristics of the nanoplex (i.e. size, colloidal stability and payload), (ii) complexation efficiency, and (iii) production yield were investigated from which the optimal preparation condition was determined. The nanoplex formation was found to favor low acidic pH and charge ratio below unity. At the optimal condition (i.e. pH 4.4. and charge ratio=0.8), stable curcumin nanoplex (≈260nm) was prepared at >90% complexation efficiency and ≈50% production yield. The amorphous state stability, colloidal stability, and in vitro non-cytotoxicity of the nanoplex were successfully established. The curcumin nanoplex produced prolonged supersaturation (3h) in the presence of hydroxypropyl methylcellulose (HPMC) at five times of the saturation solubility of curcumin. In addition, curcumin released from the nanoplex exhibited improved chemical stability owed to the presence of chitosan. Both results (i.e. high supersaturation and improved chemical stability) bode well for the ability of the curcumin nanoplex to enhance the bioavailability of curcumin clinically. Copyright © 2015

  1. Codissolution of calcium hydrogenphosphate and sodium hydrogencitrate in water. Spontaneous supersaturation of calcium citrate increasing calcium bioavailability

    DEFF Research Database (Denmark)

    Hedegaard, Martina Vavrusova; Danielsen, Bente Pia; Garcia, André Castilho

    2018-01-01

    The sparingly soluble calcium hydrogenphosphate dihydrate, co-dissolving in water during dissolution of freely soluble sodium hydrogencitrate sesquihydrate as caused by proton transfer from hydrogencitrate to hydrogenphosphate, was found to form homogenous solutions supersaturated by a factor up...... to 8 in calcium citrate tetrahydrate. A critical hydrogencitrate concentration for formation of homogeneous solutions was found to depend linearly on dissolved calcium hydrogenphosphate: [HCitr2-] = 14[CaHPO4] - 0.05 at 25 °C. The lag phase for precipitation of calcium citrate tetrahydrate......, as identified from FT-IR spectra, from these spontaneously formed supersaturated solutions was several hours, and the time to reach solubility equilibrium was several days. Initial calcium ion activity was found to be almost independent of the degree of supersaturation as determined electrochemically...

  2. 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.

  3. Investigation of the Intra- and Interlaboratory Reproducibility of a Small Scale Standardized Supersaturation and Precipitation Method

    DEFF Research Database (Denmark)

    Plum, Jakob; Madsen, Cecilie M; Teleki, Alexandra

    2017-01-01

    order for the three model compounds using the SSPM (aprepitant > felodipine ≈ fenofibrate). The α-value is dependent on the experimental setup and can be used as a parameter to evaluate the uniformity of the data set. This study indicated that the SSPM was able to obtain the same rank order of the β...... compound available for absorption. However, due to the stochastic nature of nucleation, supersaturating drug delivery systems may lead to inter- and intrapersonal variability. The ability to define a feasible range with respect to the supersaturation level is a crucial factor for a successful formulation...... reproducibility study of felodipine was conducted, after which seven partners contributed with data for three model compounds; aprepitant, felodipine, and fenofibrate, to determine the interlaboratory reproducibility of the SSPM. The first part of the SSPM determines the apparent degrees of supersaturation (a...

  4. 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

  5. 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.

  6. Combined Effects of Supersaturation Rates and Doses on the Kinetic-Solubility Profiles of Amorphous Solid Dispersions Based on Water-Insoluble Poly(2-hydroxyethyl methacrylate) Hydrogels.

    Science.gov (United States)

    Schver, Giovanna C R M; Lee, Ping I

    2018-05-07

    Under nonsink dissolution conditions, the kinetic-solubility profiles of amorphous solid dispersions (ASDs) based on soluble carriers typically exhibit so-called "spring-and-parachute" concentration-time behaviors. However, the kinetic-solubility profiles of ASDs based on insoluble carriers (including hydrogels) are known to show sustained supersaturation during nonsink dissolution through a matrix-regulated diffusion mechanism by which the supersaturation of the drug is built up gradually and sustained over an extended period without any dissolved polymers acting as crystallization inhibitors. Despite previous findings demonstrating the interplay between supersaturation rates and total doses on the kinetic-solubility profiles of soluble amorphous systems (including ASDs based on dissolution-regulated releases from soluble polymer carriers), the combined effects of supersaturation rates and doses on the kinetic-solubility profiles of ASDs based on diffusion-regulated releases from water-insoluble carriers have not been investigated previously. Thus, the objective of this study is to examine the impacts of total doses and supersaturation-generation rates on the resulting kinetic-solubility profiles of ASDs based on insoluble hydrogel carriers. We employed a previously established ASD-carrier system based on water-insoluble-cross-linked-poly(2-hydroxyethyl methacrylate) (PHEMA)-hydrogel beads and two poorly water soluble model drugs: the weakly acidic indomethacin (IND) and the weakly basic posaconazole (PCZ). Our results show clearly for the first time that by using the smallest-particle-size fraction and a high dose (i.e., above the critical dose), it is indeed possible to significantly shorten the duration of sustained supersaturation in the kinetic-solubility profile of an ASD based on a water-insoluble hydrogel carrier, such that it resembles the spring-and-parachute dissolution profiles normally associated with ASDs based on soluble carriers. This generates

  7. 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.

  8. Nucleation and droplet growth from supersaturated vapor at temperatures below the triple point temperature

    DEFF Research Database (Denmark)

    Toxværd, Søren

    2016-01-01

    temperature Ttr.p. crystallizes via a liquid droplet is an example of Ostwald's step rule. The homogeneous nucleation in the supersaturated gas is not to a crystal, but to a liquid-like critical nucleus. We have for the first time performed constant energy (NVE) Molecular Dynamics (MD) of homogeneous...... nucleation without the use of a thermostat. The simulations of homogeneous nucleation in a Lennard-Jones system from supersaturated vapor at temperatures below Ttr.p. reveals that the nucleation to a liquid-like critical nucleus is initiated by a small cold cluster [S. Toxvaerd, J. Chem. Phys. \\textbf{143...

  9. 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

  10. Decomposition features of a supersaturated solid solution in the Mg-3.3 wt. % Yb alloy

    International Nuclear Information System (INIS)

    Dobromyslov, A.V.; Kajgorodova, L.I.; Sukhanov, V.D.; Dobatkina, T.V.

    2007-01-01

    Methods of electron microscopy, hardness measuring and X-ray diffraction analysis are applied to study decomposition kinetics for a supersaturated solid solution in a Mg-3.3 mas. % alloy on aging within a temperature range of 150-225 deg C. The mechanism of supersaturation solid solution decomposition is revealed along with the nature of phases precipitated at various stages of aging: on incomplete and extended aging as well as at maximum hardness. The types of structural constituents responsible for changes of hardness on aging are determined [ru

  11. Effect of surfactants, gastric emptying, and dosage form on supersaturation of dipyridamole in an in vitro model simulating the stomach and duodenum.

    Science.gov (United States)

    Mitra, A; Fadda, H M

    2014-08-04

    The purpose of this study was to investigate the influence of gastric emptying patterns, surfactants, and dosage form on the supersaturation of a poorly soluble weakly basic drug, dipyridamole, using an in vitro model mimicking the dynamic environment of the upper gastrointestinal tract, and, furthermore, to evaluate the usefulness of this model in establishing correlations to in vivo bioavailability for drugs with solubility/dissolution limited absorption. A simulated stomach duodenum model comprising four compartments was used to assess supersaturation and precipitation kinetics as a function of time. It integrates physiologically relevant fluid volumes, fluid transfer rates, and pH changes of the upper GI tract. Monoexponential gastric emptying patterns simulating the fasted state were compared to linear gastric emptying patterns simulating the fed state. The effect of different surfactants commonly used in oral preparations, specifically, sodium lauryl sulfate (SLS), poloxamer-188, and polysorbate-80, on dipyridamole supersaturation was investigated while maintaining surface tension of the simulated gastric fluids at physiological levels and without obtaining artificial micellar solubilization of the drug. The supersaturation behavior of different dose strengths of dipyridamole was explored. Significant levels of dipyridamole supersaturation were observed in the duodenal compartment under all the different in vivo relevant conditions explored. Dipyridamole supersaturation ratios of up to 11-fold have been observed, and supersaturation has been maintained for up to 120 min. Lower duodenal concentrations of dipyridamole were observed under linear gastric emptying patterns compared to mononexponential gastric emptying. The mean duodenal area under concentration-time curves (AUC60min) for the dipyridamole concentration profile in the duodenal compartment is significantly different for all the surfactants explored (P stomach duodenum model can provide a reliable and

  12. Study of supersaturation of defects under neutron irradiation by Zener relaxation

    International Nuclear Information System (INIS)

    Gonzalez, Hector C.; Justus, Francisco J.W.

    2004-01-01

    Vacancy supersaturation in dynamic equilibrium under fast neutron irradiation could be determined by anelastic relaxation. This phenomenon is particularly noticeable in some substitutional binary alloys. Relaxation is due to the reordering of atoms pairs under a stress, being a local reordering at the atomic scale. Relaxation time (τ) is inversely proportional to the vacancy concentration (Cv) and decreases under irradiation because a dynamical equilibrium of vacancy concentration, higher than thermodynamic equilibrium, is established. Theoretical models allow estimating the magnitude of that supersaturation. Determinations of τ at different temperatures, with and without fast neutron irradiations, were made with an 'in situ' device placed in the high temperature loop in the RA1 CAC-CNEA reactor. An alloy Au-30% Ni was used, since it presents an appreciable Zener effect. The measurements were performed in a spring-shaped specimen in order to minimize temperature and flux gradients. An Arrhenius plot of τ was obtained, and it was observed that for temperatures lower than 220 C degrees a vacancy supersaturation exists. The lowest temperature of our experiments was 190 C degrees. A value of τ at this temperature was three times lower under irradiations. A plot of τ vs. fast neutron fluence (φ f t) at the irradiation temperature T= 203 C degrees was obtained. An increase of τ was observed. After an annealing at T = 280 C degrees, the value of τ recovers the value corresponding to the unirradiated case. This fact suggests that the loops produced by irradiation act as defect sinks. (author) [es

  13. Technology review: prototyping platforms for monitoring ambient conditions.

    Science.gov (United States)

    Afolaranmi, Samuel Olaiya; Ramis Ferrer, Borja; Martinez Lastra, Jose Luis

    2018-05-08

    The monitoring of ambient conditions in indoor spaces is very essential owing to the amount of time spent indoors. Specifically, the monitoring of air quality is significant because contaminated air affects the health, comfort and productivity of occupants. This research work presents a technology review of prototyping platforms for monitoring ambient conditions in indoor spaces. It involves the research on sensors (for CO 2 , air quality and ambient conditions), IoT platforms, and novel and commercial prototyping platforms. The ultimate objective of this review is to enable the easy identification, selection and utilisation of the technologies best suited for monitoring ambient conditions in indoor spaces. Following the review, it is recommended to use metal oxide sensors, optical sensors and electrochemical sensors for IAQ monitoring (including NDIR sensors for CO 2 monitoring), Raspberry Pi for data processing, ZigBee and Wi-Fi for data communication, and ThingSpeak IoT platform for data storage, analysis and visualisation.

  14. 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

  15. 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...

  16. Quantitative and enantioselective analysis of monoterpenes from plant chambers and in ambient air using SPME

    Directory of Open Access Journals (Sweden)

    N. Yassaa

    2010-11-01

    Full Text Available A headspace solid-phase microextraction (HS-SPME and gas chromatography/mass spectrometry (GC/MS system has been developed for quantifying enantiomeric and nonenantiomeric monoterpenes in plant chamber studies and ambient air. Performance of this system was checked using a capillary diffusion system to produce monoterpene standards. The adsorption efficiency, competitive adsorption and chromatographic peak resolution of monoterpene enantiomer pairs were compared for three SPME fibre coatings: 75 μm Carboxen-PDMS (CAR-PDMS, 50/30 μm divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS and 65 μm divinylbenzene-polydimethylsiloxane (DVB-PDMS. Key parameters such as the linearity and reproducibility of the SPME system have been investigated in this work. The best compromise between the enantiomeric separation of monoterpenes and competitive adsorption of the isoprenoids on the solid SPME fibre coating was found for DVB-PDMS fibres. The optimum conditions using DVB-PDMS fibres were applied to measure the exchange rates of monoterpenes in the emission of Quercus ilex using a laboratory whole plant enclosure under light and dark conditions, as well as in ambient air. With 592 and 223 ng m−2 s−1 respectively, β-myrcene and limonene were the predominant monoterpenes in the emission of Q. ilex. These values were closely comparable to those obtained using a zNose and cartridge GC-FID systems.

  17. Quantitative and enantioselective analysis of monoterpenes from plant chambers and in ambient air using SPME

    Science.gov (United States)

    Yassaa, N.; Custer, T.; Song, W.; Pech, F.; Kesselmeier, J.; Williams, J.

    2010-11-01

    A headspace solid-phase microextraction (HS-SPME) and gas chromatography/mass spectrometry (GC/MS) system has been developed for quantifying enantiomeric and nonenantiomeric monoterpenes in plant chamber studies and ambient air. Performance of this system was checked using a capillary diffusion system to produce monoterpene standards. The adsorption efficiency, competitive adsorption and chromatographic peak resolution of monoterpene enantiomer pairs were compared for three SPME fibre coatings: 75 μm Carboxen-PDMS (CAR-PDMS), 50/30 μm divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) and 65 μm divinylbenzene-polydimethylsiloxane (DVB-PDMS). Key parameters such as the linearity and reproducibility of the SPME system have been investigated in this work. The best compromise between the enantiomeric separation of monoterpenes and competitive adsorption of the isoprenoids on the solid SPME fibre coating was found for DVB-PDMS fibres. The optimum conditions using DVB-PDMS fibres were applied to measure the exchange rates of monoterpenes in the emission of Quercus ilex using a laboratory whole plant enclosure under light and dark conditions, as well as in ambient air. With 592 and 223 ng m-2 s-1 respectively, β-myrcene and limonene were the predominant monoterpenes in the emission of Q. ilex. These values were closely comparable to those obtained using a zNose and cartridge GC-FID systems.

  18. 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

  19. Water uptake by biomass burning aerosol at sub- and supersaturated conditions: closure studies and implications for the role of organics

    Directory of Open Access Journals (Sweden)

    U. Dusek

    2011-09-01

    Full Text Available We investigate the CCN activity of freshly emitted biomass burning particles and their hygroscopic growth at a relative humidity (RH of 85%. The particles were produced in the Mainz combustion laboratory by controlled burning of various wood types. The water uptake at sub- and supersaturations is parameterized by the hygroscopicity parameter, κ (c.f. Petters and Kreidenweis, 2007. For the wood burns, κ is low, generally around 0.06. The main emphasis of this study is a comparison of κ derived from measurements at sub- and supersaturated conditions (κG and κCCN, in order to see whether the water uptake at 85% RH can predict the CCN properties of the biomass burning particles. Differences in κGand κCCN can arise through solution non-idealities, the presence of slightly soluble or surface active compounds, or non-spherical particle shape. We find that κG and κCCN agree within experimental uncertainties (of around 30% for particle sizes of 100 and 150 nm; only for 50 nm particles is κCCN larger than κG by a factor of 2. The magnitude of this difference and its dependence on particle size is consistent with the presence of surface active organic compounds. These compounds mainly facilitate the CCN activation of small particles, which form the most concentrated solution droplets at the point of activation. The 50 nm particles, however, are only activated at supersaturations higher than 1% and are therefore of minor importance as CCN in ambient clouds. By comparison with the actual chemical composition of the biomass burning particles, we estimate that the hygroscopicity of the water-soluble organic carbon (WSOC fraction can be represented by a κWSOC value of approximately 0.2. The effective hygroscopicity of a typical wood burning particle can therefore be represented by a linear mixture of an inorganic component with κ ≅ 0.6, a WSOC

  20. Short-Term Exposure to Ambient Air Pollution and Biomarkers of Systemic Inflammation: The Framingham Heart Study.

    Science.gov (United States)

    Li, Wenyuan; Dorans, Kirsten S; Wilker, Elissa H; Rice, Mary B; Ljungman, Petter L; Schwartz, Joel D; Coull, Brent A; Koutrakis, Petros; Gold, Diane R; Keaney, John F; Vasan, Ramachandran S; Benjamin, Emelia J; Mittleman, Murray A

    2017-09-01

    The objective of this study is to examine associations between short-term exposure to ambient air pollution and circulating biomarkers of systemic inflammation in participants from the Framingham Offspring and Third Generation cohorts in the greater Boston area. We included 3996 noncurrent smoking participants (mean age, 53.6 years; 54% women) who lived within 50 km from a central air pollution monitoring site in Boston, MA, and calculated the 1- to 7-day moving averages of fine particulate matter (diameterpollution was associated with higher levels of C-reactive protein, interleukin-6, and tumor necrosis factor receptor 2 but not fibrinogen or tumor necrosis factor α in individuals residing in the greater Boston area. © 2017 American Heart Association, Inc.

  1. 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.

  2. Modeling the effects of reformulated gasoline usages on ambient concentrations of ozone and five air toxics

    International Nuclear Information System (INIS)

    Ligocki, M.P.; Schulhof, R.R.; Jackson, R.E.; Jimenez, M.M.; Atkinson, D.

    1993-01-01

    The use of reformulated gasolines to reduce motor-vehicle-related hydrocarbon emissions has been mandated by the 1990 Clean Air Act Amendments for nine severely polluted urban areas. Using a version of the Urban Airshed Model that includes explicit representation of five motor-vehicle-related air toxics, the effects of reformulated gasoline usage on ambient ozone and toxics concentrations were simulated. Simulations were conducted for two urban areas. Baltimore-Washington and Houston, for the year 1995. Additional simulation were conducted for Baltimore-Washington including winter and 1999 scenarios. In the Baltimore-Washington areas, the 1995 Federal reformulated gasoline scenario produce reductions of 1.1 percent in simulated peak ozone and 2.7 percent in the areal extent of simulated ozone exceedances. Simulated ozone reductions were much smaller in Houston. In the reformulated gasoline simulations, secondary formulation of formaldehyde and acetaldehyde was reduced, and decreases in ambient benzene and polycyclic organic matter (POM) concentrations were simulated. Larger reductions in ozone and toxics concentrations were simulated for reformulated gasolines meeting California Phase II standards than for those meeting Federal standards. The effects of reductions in motor-vehicle-related nitrogen oxides (NO x ) emissions, alone and in combination with hydrocarbon reductions, were also examined

  3. Methane flux across the air-water interface - Air velocity effects

    Science.gov (United States)

    Sebacher, D. I.; Harriss, R. C.; Bartlett, K. B.

    1983-01-01

    Methane loss to the atmosphere from flooded wetlands is influenced by the degree of supersaturation and wind stress at the water surface. Measurements in freshwater ponds in the St. Marks Wildlife Refuge, Florida, demonstrated that for the combined variability of CH4 concentrations in surface water and air velocity over the water surface, CH4 flux varied from 0.01 to 1.22 g/sq m/day. The liquid exchange coefficient for a two-layer model of the gas-liquid interface was calculated as 1.7 cm/h for CH4 at air velocity of zero and as 1.1 + 1.2 v to the 1.96th power cm/h for air velocities from 1.4 to 3.5 m/s and water temperatures of 20 C.

  4. Assessing environmental inequalities in ambient air pollution across urban Australia.

    Science.gov (United States)

    Knibbs, Luke D; Barnett, Adrian G

    2015-04-01

    Identifying inequalities in air pollution levels across population groups can help address environmental justice concerns. We were interested in assessing these inequalities across major urban areas in Australia. We used a land-use regression model to predict ambient nitrogen dioxide (NO2) levels and sought the best socio-economic and population predictor variables. We used a generalised least squares model that accounted for spatial correlation in NO2 levels to examine the associations between the variables. We found that the best model included the index of economic resources (IER) score as a non-linear variable and the percentage of non-Indigenous persons as a linear variable. NO2 levels decreased with increasing IER scores (higher scores indicate less disadvantage) in almost all major urban areas, and NO2 also decreased slightly as the percentage of non-Indigenous persons increased. However, the magnitude of differences in NO2 levels was small and may not translate into substantive differences in health. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. 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.

  6. Real-time monitoring of BTEX in air via ambient-pressure MPI

    Science.gov (United States)

    Swenson, Orven F.; Carriere, Josef P.; Isensee, Harlan; Gillispie, Gregory D.; Cooper, William F.; Dvorak, Michael A.

    1998-05-01

    We have developed and begun to field test a very sensitive method for real-time measurements of single-ring aromatic hydrocarbons in ambient air. In this study, we focus on the efficient 1 + 1 resonance enhanced multiphoton ionization (REMPI) of the BTEX species in the narrow region between 266 and 267 nm. We particularly emphasize 266.7 nm, a wavelength at which both benzene and toluene exhibit a sharp absorbance feature and benzene and its alkylated derivatives all absorb. An optical parametric oscillator system generating 266.7 nm, a REMPI cell, and digital oscilloscope detector are mounted on a breadboard attached to a small cart. In the first field test, the cart was wheeled through the various rooms of a chemistry research complex. Leakage of fuel through the gas caps of cars and light trucks in a parking lot was the subject of the second field test. The same apparatus was also used for a study in which the performance of the REMPI detector and a conventional photoionization detector were compared as a BTEX mixture was eluted by gas chromatography. Among the potential applications of the methodology are on-site analysis of combustion and manufacturing processes, soil gas and water headspace monitoring, space cabin and building air quality, and fuel leak detection.

  7. pH-Induced precipitation behavior of weakly basic compounds: determination of extent and duration of supersaturation using potentiometric titration and correlation to solid state properties.

    Science.gov (United States)

    Hsieh, Yi-Ling; Ilevbare, Grace A; Van Eerdenbrugh, Bernard; Box, Karl J; Sanchez-Felix, Manuel Vincente; Taylor, Lynne S

    2012-10-01

    To examine the precipitation and supersaturation behavior of ten weak bases in terms of the relationship between pH-concentration-time profiles and the solid state properties of the precipitated material. Initially the compound was dissolved at low pH, followed by titration with base to induce precipitation. Upon precipitation, small aliquots of acid or base were added to induce slight subsaturation and supersaturation respectively and the resultant pH gradient was determined. The concentration of the unionized species was calculated as a function of time and pH using mass and charge balance equations. Two patterns of behavior were observed in terms of the extent and duration of supersaturation arising following an increase in pH and this behavior could be rationalized based on the crystallization tendency of the compound. For compounds that did not readily crystallize, an amorphous precipitate was formed and a prolonged duration of supersaturation was observed. For compounds that precipitated to crystalline forms, the observed supersaturation was short-lived. This study showed that supersaturation behavior has significant correlation with the solid-state properties of the precipitate and that pH-metric titration methods can be utilized to evaluate the supersaturation behavior.

  8. Positive association between short-term ambient air pollution exposure and children blood pressure in China-Result from the Seven Northeast Cities (SNEC) study.

    Science.gov (United States)

    Zeng, Xiao-Wen; Qian, Zhengmin Min; Vaughn, Michael G; Nelson, Erik J; Dharmage, Shyamali C; Bowatte, Gayan; Perret, Jennifer; Chen, Duo-Hong; Ma, Huimin; Lin, Shao; de Foy, Benjamin; Hu, Li-Wen; Yang, Bo-Yi; Xu, Shu-Li; Zhang, Chuan; Tian, Yan-Peng; Nian, Min; Wang, Jia; Xiao, Xiang; Bao, Wen-Wen; Zhang, Ya-Zhi; Dong, Guang-Hui

    2017-05-01

    The impact of ambient air pollution on health causes concerns in China. However, little is known about the association of short-term air pollution exposure with blood pressure (BP) in children. The goal of present study was to assess the association between short-term air pollution and BP in children from a highly polluted area in China. This study enrolled 9354 children in 24 elementary and middle schools (aged 5-17 years) from the Seven Northeast Cities (SNEC) study, respectively, during the period of 2012-2013. Ambient air pollutants, including particulate matter with an aerodynamic diameter of ≤10 μm (PM 10 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ) and ozone (O 3 ) on the days (1-5 days) preceding BP examination were collected from local air monitoring stations. Generalized additive models and two-level regression analyses were used to evaluate the relationship between air pollution and BP after adjusting for other covariates. Results showed that with an interquartile range (IQR) increase in PM 10 (50.0 μg/m 3 ) and O 3 (53.0 μg/m 3 ) level during the 5-day mean exposure, positive associations with elevated BP were observed, with an odds ratio of 2.17 (95% CI, 1.61-2.93) for PM 10 and 2.77 (95% CI, 1.94-3.95) for O 3 . Both systolic BP and diastolic BP levels were positively associated with an IQR increase of four air pollutants at different lag times. Specifically, an IQR increase in the 5-day mean of PM 10 and O 3 was associated with elevation of 2.07 mmHg (95% CI, 1.71-2.44) and 3.29 mmHg (95% CI, 2.86-3.72) in systolic BP, respectively. When stratified by sex, positive relationships were observed for elevated BP with NO 2 exposure only in males. This is the first report on the relationship between ambient short-term air pollution exposure and children BP in China. Findings indicate a need to control air pollutants and protect children from heavy air pollution exposure in China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. 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.

  10. 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

  11. 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

  12. 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

  13. Extremely slow carbon diffusion in carbon-supersaturated surface of ferrite

    Czech Academy of Sciences Publication Activity Database

    Čermák, Jiří; Král, Lubomír

    2014-01-01

    Roč. 52, č. 3 (2014), s. 125-133 ISSN 0023-432X R&D Projects: GA ČR(CZ) GAP108/11/0148; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : carbon diffusion * carbon supersaturation * diffusion barrier * ferrite * P91 Subject RIV: BJ - Thermodynamics Impact factor: 0.406, year: 2014

  14. 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.

  15. Re-establishment of the air kerma and ambient dose equivalent standards for the BIPM protection-level 60Co beam

    International Nuclear Information System (INIS)

    Kessler, C.; Roger, P.

    2005-07-01

    The air kerma and ambient dose equivalent standards for the protection-level 60 Co beam have been re-established following the repositioning of the irradiator and modifications to the beam. Details concerning the standards and the new uncertainty budgets are described in this report with their implications for dosimetry comparisons and calibrations. (authors)

  16. Laboratory Studies of the Effects of Pressure and Dissolved Gas Supersaturation on Turbine-Passed Fish

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, Duane A.

    2009-09-14

    Migratory and resident fish in the Columbia River Basin are exposed to stresses associated with hydroelectric power production, including changes in pressure as they pass through turbines and dissolved gas supersaturation (resulting from the release of water from the spillway). To examine pressure changes as a source of turbine-passage injury and mortality, Pacific Northwest National Laboratory scientists conducted specific tests using a hyperbaric chamber. Tests were designed to simulate Kaplan turbine passage conditions and to quantify the response of fish to rapid pressure changes, with and without the complication of fish being acclimated to gas-supersaturated water.

  17. 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.

  18. 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

  19. 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

  20. Long-term exposure to ambient air pollution (including PM1) and metabolic syndrome: The 33 Communities Chinese Health Study (33CCHS).

    Science.gov (United States)

    Yang, Bo-Yi; Qian, Zhengmin Min; Li, Shanshan; Fan, Shujun; Chen, Gongbo; Syberg, Kevin M; Xian, Hong; Wang, Si-Quan; Ma, Huimin; Chen, Duo-Hong; Yang, Mo; Liu, Kang-Kang; Zeng, Xiao-Wen; Hu, Li-Wen; Guo, Yuming; Dong, Guang-Hui

    2018-07-01

    Little evidence exists about the effects of long-term exposure to ambient air pollution on metabolic syndrome (MetS). This study aimed to determine the association between long-term ambient air pollution and MetS in China. A total of 15,477 adults who participated in the 33 Communities Chinese Health Study (33CCHS) in 2009 were evaluated. MetS was defined based on the recommendation by the Joint Interim Societies. Exposure to air pollutants was assessed using data from monitoring stations and a spatial statistical model (including particles with diameters ≤ 1.0 µm (PM 1 ), ≤ 2.5 µm (PM 2.5 ), and ≤ 10 µm (PM 10 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), and ozone (O 3 )). Two-level logistic regression analyses were utilized to assess the associations between air pollutants and MetS. The prevalence of MetS was 30.37%. The adjusted odds ratio of MetS per 10 µg/m 3 increase in PM 1 , PM 2.5 , PM 10 , SO 2 , NO 2 , and O 3 were 1.12 (95% CI = 1.00-1.24), 1.09 (95% CI = 1.00-1.18), 1.13 (95% CI = 1.08-1.19), 1.10 (95% CI = 1.02-1.18), 1.33 (95% CI = 1.12-1.57), and 1.10 (95% CI = 1.01-1.18), respectively. Stratified analyses indicated that the above associations were stronger in participants with the demographic variables of males, < 50 years of age, and higher income, as well as with the behavioral characteristics of smoking, drinking, and consuming sugar-sweetened soft drinks frequently. This study indicates that long-term exposure to ambient air pollutants may increase the risk of MetS, especially among males, the young to middle aged, those of low income, and those with unhealthy lifestyles. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Laboratory and field based evaluation of chromatography related performance of the Monitor for AeRosols and Gases in ambient Air (MARGA)

    Science.gov (United States)

    The semi-continuous Monitor for AeRosols and Gases in Ambient air (MARGA) was evaluated using laboratory and field data with a focus on chromatography. The performance and accuracy assessment revealed various errors and uncertainties resulting from mis-identification and mis-int...

  2. 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.)

  3. 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.

  4. Environmental impact of the programs of substitution of room type air conditioning equipment; Impacto ambiental de los programas de sustitucion de equipos de aire tipo cuarto

    Energy Technology Data Exchange (ETDEWEB)

    Alarcon Aleman, Jose Mauricio [OLADE, Quito (Ecuador)

    2002-09-01

    The present article approaches in a general way the relation that exists between the environment and the saving of electrical energy, especially in the Programs of Demand Side Management (DSM). In particular form the potential environmental impacts are described, derived of the use and the discard of the room type air conditioning equipment, goes deep into the characteristics of their cooling fluids, as well as in the relation that these keep with the protocols of Montreal and Kyoto. Finally, this article comments the incidence which have, the manufacturers as the institutions that implement DSM programs, on the environmental part of the programs of substitution of room type air conditioning equipment. In addition it is briefly described, the pilot program developed by Fideicomiso para el Ahorro de Energia Electrica (FIDE) as a successful case. [Spanish] En forma general, el presente articulo aborda la relacion que existe entre el medio ambiente y el ahorro de energia electrica, especialmente en los Programas de Administracion por el Lado de la Demanda (ALD). En forma particular se describen los impactos ambientales potenciales, derivados del uso y desecho de los equipos de aire acondicionado tipo cuarto, se ahonda en las caracteristicas de sus refrigerantes, asi como en la relacion que estos guardan con los protocolos de Montreal y Kioto. Finalmente, se comenta la incidencia que tienen, tanto los fabricantes como las instituciones que implementan programas de ALD, sobre la parte ambiental de los programas de sustitucion de equipos de aire acondicionado tipo cuarto. Ademas se describe brevemente, el programa piloto desarrollado por el Fideicomiso para el Ahorro de Energia Electrica (FIDE) como un caso exitoso.

  5. Decomposition of supersaturated solid solutions Mg-Ho and Mg-Gd

    International Nuclear Information System (INIS)

    Sukhanov, V.D.; Dobromyslov, A.V.; Rokhlin, L.L.; Dobatkina, T.V.

    2002-01-01

    Methods of electron microscopy and X-ray diffraction analysis are applied to study ageing magnesium base alloys with holmium and gadolinium. It is shown that the precipitation of supersaturated Mg base solid solutions goes through several subsequent stages and is accompanied by a considerable precipitation hardening effect at the stage of metastable phase precipitation. The influence of aging time and temperature on precipitation kinetics is established [ru

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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

  13. Decoupling of bilayer leaflets under gas supersaturation: nitrogen nanobubbles in a membrane and their implication in decompression sickness

    Science.gov (United States)

    Li, Jing; Zhang, Xianren; Cao, Dapeng

    2018-05-01

    Decompression sickness (also known as diver’s sickness) is a disease that arises from the formation of a bubble inside the body caused by rapid decompression from high atmospheric pressures. However, the nature of pre-existing micronuclei that are proposed for interpreting the formation and growth of the bubble, as well as their very existence, is still highly controversial. In this work, atomistic molecular dynamics simulations are employed to investigate the nucleation of gas bubbles under the condition of nitrogen supersaturation, in the presence of a lipid bilayer and lipid micelle representing other macromolecules with a smaller hydrophobic region. Our simulation results demonstrate that by crossing a small energy barrier, excess nitrogen molecules can enter the lipid bilayer nearly spontaneously, for which the hydrophobic core serves as a potential well for gas enrichment. At a rather low nitrogen supersaturation, gas molecules in the membrane are dispersed in the hydrophobic region of the bilayer, with a slight increase in membrane thickness. But as the level of gas supersaturation reaches a threshold, the accumulation of N2 molecules in the bilayer center causes the two leaflets to be decoupled and the formation of nanobubbles. Therefore, we propose a nucleation mechanism for bubble formation in a supersaturated solution of inert gas: a cell membrane acts as a potential well for gas enrichment, being an ideal location for forming nanobubbles that induce membrane damage at a high level of gas supersaturation. As opposed to previous models, the new mechanism involves forming gas nuclei in a very low-tension hydrophobic environment, and thus a rather low energy barrier is required and pre-existing bubble micronuclei are not needed.

  14. Air Gaps, Size Effect, and Corner-Turning in Ambient LX-17

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P C; Hernandez, A; Cabacungan, C; Fried, L; Garza, R; Glaesemann, K; Lauderbach, L; Liao, S; Vitello, P

    2008-02-05

    Various ambient measurements are presented for LX-17. The size (diameter) effect has been measured with copper and Lucite confinement, where the failure radii are 4.0 and 6.5 mm, respectively. The air well corner-turn has been measured with an LX-07 booster, and the dead-zone results are comparable to the previous TATB-boosted work. Four double cylinders have been fired, and dead zones appear in all cases. The steel-backed samples are faster than the Lucite-backed samples by 0.6 {micro}s. Bare LX-07 and LX-17 of 12.7 mm-radius were fired with air gaps. Long acceptor regions were used to truly determine if detonation occurred or not. The LX-07 crossed at 10 mm with a slight time delay. Steady state LX-17 crossed at 3.5 mm gap but failed to cross at 4.0 mm. LX-17 with a 12.7 mm run after the booster crossed a 1.5 mm gap but failed to cross 2.5 mm. Timing delays were measured where the detonation crossed the gaps. The Tarantula model is introduced as embedded in 0 reactive flow JWL++ and Linked Cheetah V4, mostly at 4 zones/mm. Tarantula has four pressure regions: off, initiation, failure and detonation. The physical basis of the input parameters is considered.

  15. Design Strategy for CO2 Adsorption from Ambient Air Using a Supported Amine Based Sorbent in a Fixed Bed Reactor

    NARCIS (Netherlands)

    Yu, Qian; Brilman, D. W.F.

    In this work, a fixed bed reactor is evaluated for CO2 capture from ambient air using an amine based ion exchange resin. Using adsorption experiments, the effect of superficial velocity and bed length on process economics is investigated. It is shown that the optimal conditions are found at an

  16. Filtered air plastic chamber as an experimental facility to prove visible damage of crops due to air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Y; Yoda, H; Omichi, S; Shiratori, K

    1975-01-01

    An experimental filtered air chamber was constructed to prove the visible damage of crops due to air pollution. The chamber was provided with another room into which non-filtered ambient air was introduced. The purified air was prepared by filtering ambient air with activated carbon. The average content of air pollutants in the purified air chamber was less than 10 to 20% of the ozone and 20% of the sulfur oxides in the ambient air. However, cultivated vegetables such as tobacco and spinach, which are susceptible to oxidant, showed no visible damage in the filtered air chamber, and showed the same damage in the nonfiltered air chamber as was seen in fields at the same time.

  17. Ten years measuring PCDDs/PCDFs in ambient air in Catalonia (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Lluis, G; Gomez, R; Guinart, X; Hernandez, I [Dept. de Medi Ambient de la Generalitat de Catalunya (Spain); Esteban, A; Caixach, J; Manich, A; Rivera, J [Mass Spectrometry Lab., Dept. of Ecotechnologies, IIQAB-CSIC (Spain)

    2004-09-15

    PCDDs and PCDFs can be formed as unwanted by-products in many anthropogenic processes and their presence in the atmosphere comes mainly from several industrial activities which include, for instance, a variety of thermal processes such as waste management plants, cement kiln plants, sintering plants and other diffuse sources. Furthermore, once released into the atmosphere, these toxicants can be transported far from their original sources and as a result their presence can be determined in remote areas. In this sense, great efforts have been made to increase the knowledge about these pollutants and stringent regulations aiming to protect public health have already been established. Monitoring programs play an important role in public and sanitary decisions. In particular, the presence and trend of this pollutants in the atmosphere have been subject of many environmental studies performed all over the world. In 1994, the Environmental Department (Departament de Medi Ambient) of the Catalonian Government (Generalitat de Catalunya) in collaboration with the Dioxin Laboratory /Mass Spectrometry Laboratory (Dept.of Ecotechnologies) of the Spanish Council for Scientific Research (CSIC) started a surveillance programme on PCDDs/PCDFs in ambient air. The aim of the study was to determine dioxin levels and to assess temporal trends of the atmospheric content of these pollutants in major industrial sites all over Catalonia. Moreover, samples from urban and rural areas as well as other supposedly non-affected sites were also considered. Furthermore, in accordance with the new regulatory framework, a comparison of two different sampling devices, TSP and PM10, has also been performed during the study.

  18. Evaluation of the causal framework used for setting national ambient air quality standards.

    Science.gov (United States)

    Goodman, Julie E; Prueitt, Robyn L; Sax, Sonja N; Bailey, Lisa A; Rhomberg, Lorenz R

    2013-11-01

    Abstract A scientifically sound assessment of the potential hazards associated with a substance requires a systematic, objective and transparent evaluation of the weight of evidence (WoE) for causality of health effects. We critically evaluated the current WoE framework for causal determination used in the United States Environmental Protection Agency's (EPA's) assessments of the scientific data on air pollutants for the National Ambient Air Quality Standards (NAAQS) review process, including its methods for literature searches; study selection, evaluation and integration; and causal judgments. The causal framework used in recent NAAQS evaluations has many valuable features, but it could be more explicit in some cases, and some features are missing that should be included in every WoE evaluation. Because of this, it has not always been applied consistently in evaluations of causality, leading to conclusions that are not always supported by the overall WoE, as we demonstrate using EPA's ozone Integrated Science Assessment as a case study. We propose additions to the NAAQS causal framework based on best practices gleaned from a previously conducted survey of available WoE frameworks. A revision of the NAAQS causal framework so that it more closely aligns with these best practices and the full and consistent application of the framework will improve future assessments of the potential health effects of criteria air pollutants by making the assessments more thorough, transparent, and scientifically sound.

  19. Mortality, hospital days and expenditures attributable to ambient air pollution from particulate matter in Israel.

    Science.gov (United States)

    Ginsberg, Gary M; Kaliner, Ehud; Grotto, Itamar

    2016-01-01

    Worldwide, ambient air pollution accounts for around 3.7 million deaths annually. Measuring the burden of disease is important not just for advocacy but also is a first step towards carrying out a full cost-utility analysis in order to prioritise technological interventions that are available to reduce air pollution (and subsequent morbidity and mortality) from industrial, power generating and vehicular sources. We calculated the average national exposure to particulate matter particles less than 2.5 μm (PM2.5) in diameter by weighting readings from 52 (non-roadside) monitoring stations by the population of the catchment area around the station. The PM2.5 exposure level was then multiplied by the gender and cause specific (Acute Lower Respiratory Infections, Asthma, Circulatory Diseases, Coronary Heart Failure, Chronic Obstructive Pulmonary Disease, Diabetes, Ischemic Heart Disease, Lung Cancer, Low Birth Weight, Respiratory Diseases and Stroke) relative risks and the national age, cause and gender specific mortality (and hospital utilisation which included neuro-degenerative disorders) rates to arrive at the estimated mortality and hospital days attributable to ambient PM2.5 pollution in Israel in 2015. We utilised a WHO spread-sheet model, which was expanded to include relative risks (based on more recent meta-analyses) of sub-sets of other diagnoses in two additional models. Mortality estimates from the three models were 1609, 1908 and 2253 respectively in addition to 184,000, 348,000 and 542,000 days hospitalisation in general hospitals. Total costs from PM2.5 pollution (including premature burial costs) amounted to $544 million, $1030 million and $1749 million respectively (or 0.18 %, 0.35 % and 0.59 % of GNP). Subject to the caveat that our estimates were based on a limited number of non-randomly sited stations exposure data. The mortality, morbidity and monetary burden of disease attributable to air pollution from particulate matter in Israel is of

  20. Improved arterial blood oxygenation following intravenous infusion of cold supersaturated dissolved oxygen solution.

    Science.gov (United States)

    Grady, Daniel J; Gentile, Michael A; Riggs, John H; Cheifetz, Ira M

    2014-01-01

    One of the primary goals of critical care medicine is to support adequate gas exchange without iatrogenic sequelae. An emerging method of delivering supplemental oxygen is intravenously rather than via the traditional inhalation route. The objective of this study was to evaluate the gas-exchange effects of infusing cold intravenous (IV) fluids containing very high partial pressures of dissolved oxygen (>760 mm Hg) in a porcine model. Juvenile swines were anesthetized and mechanically ventilated. Each animal received an infusion of cold (13 °C) Ringer's lactate solution (30 mL/kg/hour), which had been supersaturated with dissolved oxygen gas (39.7 mg/L dissolved oxygen, 992 mm Hg, 30.5 mL/L). Arterial blood gases and physiologic measurements were repeated at 15-minute intervals during a 60-minute IV infusion of the supersaturated dissolved oxygen solution. Each animal served as its own control. Five swines (12.9 ± 0.9 kg) were studied. Following the 60-minute infusion, there were significant increases in PaO2 and SaO2 (P < 0.05) and a significant decrease in PaCO2 (P < 0.05), with a corresponding normalization in arterial blood pH. Additionally, there was a significant decrease in core body temperature (P < 0.05) when compared to the baseline preinfusion state. A cold, supersaturated dissolved oxygen solution may be intravenously administered to improve arterial blood oxygenation and ventilation parameters and induce a mild therapeutic hypothermia in a porcine model.

  1. Effectiveness of supersaturation promoting excipients on albendazole concentrations in upper gastrointestinal lumen of fasted healthy adults.

    Science.gov (United States)

    Kourentas, Alexandros; Vertzoni, Maria; Symillides, Mira; Goumas, Konstantinos; Gibbon, Robert; Butler, James; Reppas, Christos

    2016-08-25

    To evaluate the impact of dosage form relevant levels of a polymeric precipitation inhibitor and of lipid excipients on supersaturation of upper gastrointestinal contents with albendazole, a lipophilic weak base. Albendazole concentrations in stomach and in duodenum were evaluated after administration of 1) a suspension in water (Susp-Control), 2) a suspension in water in which hydroxyprolylmethylcellulose E5 (HPMC E5) had been pre-dissolved (Susp-HPMC), and 3) and 4) two contrasting designs of lipid based suspensions dispersed in water (Susp-IIIA and Susp-IV), on a cross-over basis to fasted healthy adults. Limited, but statistically significant supersaturation of duodenal contents was observed after Susp-HPMC, Susp-IIIA, and Susp-IV; supersaturation was more consistent after Susp-HPMC administration. Based on total albendazole amount per volume, gastric secretions did not significantly alter volumes of bulk gastric contents during the first 40min post administration of a glass of non-caloric water-based fluid. Αlbendazole gastric concentrations were higher than in the administered suspensions, but similar for all four formulations. Gastric emptying of albendazole after administration of Susp-Control or Susp-HPMC was slower than after administration of Susp-IIIA or Susp-IV. Small amounts of HPMC E5 were as effective as lipid excipients in achieving supersaturation of duodenal contents with albendazole, a fast precipitating weak base, in fasted adults. However, compared with the effect of HPMC E5 the effect of lipid excipients was delayed and variable. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. 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)

  3. Air pollution and lung cancer incidence in 17 European cohorts

    DEFF Research Database (Denmark)

    Raaschou-Nielsen, Ole; Andersen, Zorana Jovanovic; Beelen, Rob

    2013-01-01

    Ambient air pollution is suspected to cause lung cancer. We aimed to assess the association between long-term exposure to ambient air pollution and lung cancer incidence in European populations.......Ambient air pollution is suspected to cause lung cancer. We aimed to assess the association between long-term exposure to ambient air pollution and lung cancer incidence in European populations....

  4. Nutrient digestibility and growth in rainbow trout (Oncorhynchus mykiss) are impaired by short term exposure to moderate supersaturation in total gas pressure

    DEFF Research Database (Denmark)

    Skov, Peter Vilhelm; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2013-01-01

    Excess levels of dissolved nitrogen gas (N2) may occur in recirculating aquaculture systems, as a result of aeration efforts, localized occurrences of denitrification, or from insufficient degassing of makeup water. If levels of dissolved N2 are sufficiently high, or if oxygen (O2) is also...... maintained at or above saturation, this leads to a supersaturation in total gas pressure (TGP). Depending on severity, total gas pressures above saturation may lead to gas bubble trauma, evident by visual inspection of the fish. Physiological effects of subclinical levels of TGP are not well known and have...... not been investigated for rainbow trout. The present study examined the effects of N2 supersaturation, with or without simultaneous excess TGP. Supersaturation with N2 (ΔP 22mmHg) without total gas supersaturation (ΔTGP −6mmHg) did not have any significant effects on feed intake, feed conversion or growth...

  5. Application of computational fluid dynamics and pedestrian-behavior simulations to the design of task-ambient air-conditioning systems of a subway station

    Energy Technology Data Exchange (ETDEWEB)

    Fukuyo, Kazuhiro [Graduate School of Innovation and Technology Management, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611 (Japan)

    2006-04-15

    The effects of task-ambient (TA) air-conditioning systems on the air-conditioning loads in a subway station and the thermal comfort of passengers were studied using computational fluid dynamics (CFD) and pedestrian-behavior simulations. The pedestrian-behavior model was applied to a standard subway station. Task areas were set up to match with crowdedness as predicted by the pedestrian-behavior simulations. Subsequently, a variety of TA air-conditioning systems were designed to selectively control the microclimate of the task areas. Their effects on the thermal environment in the station in winter were predicted by CFD. The results were compared with those of a conventional air-conditioning system and evaluated in relation to the thermal comfort of subway users and the air-conditioning loads. The comparison showed that TA air-conditioning systems improved thermal comfort and decreased air-conditioning loads. (author)

  6. In Silico Modeling Approach for the Evaluation of Gastrointestinal Dissolution, Supersaturation, and Precipitation of Posaconazole.

    Science.gov (United States)

    Hens, Bart; Pathak, Shriram M; Mitra, Amitava; Patel, Nikunjkumar; Liu, Bo; Patel, Sanjaykumar; Jamei, Masoud; Brouwers, Joachim; Augustijns, Patrick; Turner, David B

    2017-12-04

    The aim of this study was to evaluate gastrointestinal (GI) dissolution, supersaturation, and precipitation of posaconazole, formulated as an acidified (pH 1.6) and neutral (pH 7.1) suspension. A physiologically based pharmacokinetic (PBPK) modeling and simulation tool was applied to simulate GI and systemic concentration-time profiles of posaconazole, which were directly compared with intraluminal and systemic data measured in humans. The Advanced Dissolution Absorption and Metabolism (ADAM) model of the Simcyp Simulator correctly simulated incomplete gastric dissolution and saturated duodenal concentrations of posaconazole in the duodenal fluids following administration of the neutral suspension. In contrast, gastric dissolution was approximately 2-fold higher after administration of the acidified suspension, which resulted in supersaturated concentrations of posaconazole upon transfer to the upper small intestine. The precipitation kinetics of posaconazole were described by two precipitation rate constants, extracted by semimechanistic modeling of a two-stage medium change in vitro dissolution test. The 2-fold difference in exposure in the duodenal compartment for the two formulations corresponded with a 2-fold difference in systemic exposure. This study demonstrated for the first time predictive in silico simulations of GI dissolution, supersaturation, and precipitation for a weakly basic compound in part informed by modeling of in vitro dissolution experiments and validated via clinical measurements in both GI fluids and plasma. Sensitivity analysis with the PBPK model indicated that the critical supersaturation ratio (CSR) and second precipitation rate constant (sPRC) are important parameters of the model. Due to the limitations of the two-stage medium change experiment the CSR was extracted directly from the clinical data. However, in vitro experiments with the BioGIT transfer system performed after completion of the in silico modeling provided an almost

  7. 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)

  8. 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).

  9. Standard audit procedure for continuous emission monitors and ambient air monitoring instruments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-06-15

    The instruments were published in an operational policy manual in 2009. This policy aims to introduce standard audit criteria that can be used to determine if continuous emission monitors and ambient air monitoring devices are operating within acceptable parameters. Before delivering upscale points of the instrument to be audited, each one of the audit equipment used in the field is required to be at normal operating conditions. Before the beginning of the audit, each one of the meteorological and flow measurement equipment is required to be conditioned to current conditions. If the audit fails, the instrument will have to be audited quarterly. The establishment of specific procedures based on instrument manufacturer or certifying body operational standards is required in the case of non-continuous monitoring instruments presenting operational principles outside of the audit procedures listed in the document.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. Short-term exposure to high ambient air pollution increases airway inflammation and respiratory symptoms in chronic obstructive pulmonary disease patients in Beijing, China.

    Science.gov (United States)

    Wu, Shaowei; Ni, Yang; Li, Hongyu; Pan, Lu; Yang, Di; Baccarelli, Andrea A; Deng, Furong; Chen, Yahong; Shima, Masayuki; Guo, Xinbiao

    2016-09-01

    Few studies have investigated the short-term respiratory effects of ambient air pollution in chronic obstructive pulmonary disease (COPD) patients in the context of high pollution levels in Asian cities. A panel of 23 stable COPD patients was repeatedly measured for biomarkers of airway inflammation including exhaled nitric oxide (FeNO) and exhaled hydrogen sulfide (FeH2S) (215 measurements) and recorded for daily respiratory symptoms (794person-days) in two study periods in Beijing, China in January-September 2014. Daily ambient air pollution data were obtained from nearby central air-monitoring stations. Mixed-effects models were used to estimate the associations between exposures and health measurements with adjustment for potential confounders including temperature and relative humidity. Increasing levels of air pollutants were associated with significant increases in both FeNO and FeH2S. Interquartile range (IQR) increases in PM2.5 (76.5μg/m(3), 5-day), PM10 (75.0μg/m(3), 5-day) and SO2 (45.7μg/m(3), 6-day) were associated with maximum increases in FeNO of 13.6% (95% CI: 4.8%, 23.2%), 9.2% (95% CI: 2.1%, 16.8%) and 34.2% (95% CI: 17.3%, 53.4%), respectively; and the same IQR increases in PM2.5 (6-day), PM10 (6-day) and SO2 (7-day) were associated with maximum increases in FeH2S of 11.4% (95% CI: 4.6%, 18.6%), 7.8% (95% CI: 2.3%, 13.7%) and 18.1% (95% CI: 5.5%, 32.2%), respectively. Increasing levels of air pollutants were also associated with increased odds ratios of sore throat, cough, sputum, wheeze and dyspnea. FeH2S may serve as a novel biomarker to detect adverse respiratory effects of air pollution. Our results provide potential important public health implications that ambient air pollution may pose risk to respiratory health in the context of high pollution levels in densely-populated cities in the developing world. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. 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.

  14. 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.

  15. 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.

  16. Satellite-based Estimates of Ambient Air Pollution and Global Variations in Childhood Asthma Prevalence

    Science.gov (United States)

    Anderson, H. Ross; Butland, Barbara K.; Donkelaar, Aaron Matthew Van; Brauer, Michael; Strachan, David P.; Clayton, Tadd; van Dingenen, Rita; Amann, Marcus; Brunekreef, Bert; Cohen, Aaron; hide

    2012-01-01

    Background: The effect of ambient air pollution on global variations and trends in asthma prevalence is unclear. Objectives: Our goal was to investigate community-level associations between asthma prevalence data from the International Study of Asthma and Allergies in Childhood (ISAAC) and satellite-based estimates of particulate matter with aerodynamic diameter < 2.5 microm (PM2.5) and nitrogen dioxide (NO2), and modelled estimates of ozone. Methods: We assigned satellite-based estimates of PM2.5 and NO2 at a spatial resolution of 0.1deg × 0.1deg and modeled estimates of ozone at a resolution of 1deg × 1deg to 183 ISAAC centers. We used center-level prevalence of severe asthma as the outcome and multilevel models to adjust for gross national income (GNI) and center- and country-level sex, climate, and population density. We examined associations (adjusting for GNI) between air pollution and asthma prevalence over time in centers with data from ISAAC Phase One (mid-1900s) and Phase Three (2001-2003). Results: For the 13- to 14-year age group (128 centers in 28 countries), the estimated average within-country change in center-level asthma prevalence per 100 children per 10% increase in center-level PM2.5 and NO2 was -0.043 [95% confidence interval (CI): -0.139, 0.053] and 0.017 (95% CI: -0.030, 0.064) respectively. For ozone the estimated change in prevalence per parts per billion by volume was -0.116 (95% CI: -0.234, 0.001). Equivalent results for the 6- to 7-year age group (83 centers in 20 countries), though slightly different, were not significantly positive. For the 13- to 14-year age group, change in center-level asthma prevalence over time per 100 children per 10% increase in PM2.5 from Phase One to Phase Three was -0.139 (95% CI: -0.347, 0.068). The corresponding association with ozone (per ppbV) was -0.171 (95% CI: -0.275, -0.067). Conclusion: In contrast to reports from within-community studies of individuals exposed to traffic pollution, we did not find

  17. 76 FR 58509 - Release of Risk and Exposure Assessment Planning Document for the Review of the National Ambient...

    Science.gov (United States)

    2011-09-21

    ... Assessment Planning Document for the Review of the National Ambient Air Quality Standards for Lead AGENCY... available for public review the Review of the National Ambient Air Quality Standards for Lead: Risk and... and/or welfare effects in this review of the national ambient air quality standards (NAAQS) for lead...

  18. Constraining the supersaturation density equation of state from core-collapse supernova simulations? Excluded volume extension of the baryons

    International Nuclear Information System (INIS)

    Fischer, Tobias

    2016-01-01

    In this article the role of the supersaturation density equation of state (EOS) is explored in simulations of failed core-collapse supernova explosions. Therefore the nuclear EOS is extended via a one-parameter excluded-volume description for baryons, taking into account their finite and increasing volume with increasing density in excess of saturation density. Parameters are selected such that the resulting supernova EOS represent extreme cases, with high pressure variations at supersaturation density which feature extreme stiff and soft EOS variants of the reference case, i.e. without excluded-volume corrections. Unlike in the interior of neutron stars with central densities in excess of several times saturation density, central densities of core-collapse supernovae reach only slightly above saturation density. Hence, the impact of the supersaturation density EOS on the supernova dynamics as well as the neutrino signal is found to be negligible. It is mainly determined from the low- and intermediate-density domain, which is left unmodified within this generalized excluded volume approach. (orig.)

  19. 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.

  20. Effects of ambient conditions on fuel cell vehicle performance

    Science.gov (United States)

    Haraldsson, K.; Alvfors, P.

    Ambient conditions have considerable impact on the performance of fuel cell hybrid vehicles. Here, the vehicle fuel consumption, the air compressor power demand, the water management system and the heat loads of a fuel cell hybrid sport utility vehicle (SUV) were studied. The simulation results show that the vehicle fuel consumption increases with 10% when the altitude increases from 0 m up to 3000 m to 4.1 L gasoline equivalents/100 km over the New European Drive Cycle (NEDC). The increase is 19% on the more power demanding highway US06 cycle. The air compressor is the major contributor to this fuel consumption increase. Its load-following strategy makes its power demand increase with increasing altitude. Almost 40% of the net power output of the fuel cell system is consumed by the air compressor at the altitude of 3000 m with this load-following strategy and is thus more apparent in the high-power US06 cycle. Changes in ambient air temperature and relative humidity effect on the fuel cell system performance in terms of the water management rather in vehicle fuel consumption. Ambient air temperature and relative humidity have some impact on the vehicle performance mostly seen in the heat and water management of the fuel cell system. While the heat loads of the fuel cell system components vary significantly with increasing ambient temperature, the relative humidity did not have a great impact on the water balance. Overall, dimensioning the compressor and other system components to meet the fuel cell system requirements at the minimum and maximum expected ambient temperatures, in this case 5 and 40 °C, and high altitude, while simultaneously choosing a correct control strategy are important parameters for efficient vehicle power train management.

  1. Baseline repeated measures from controlled human exposure studies: associations between ambient air pollution exposure and the systemic inflammatory biomarkers IL-6 and fibrinogen.

    Science.gov (United States)

    Thompson, Aaron M S; Zanobetti, Antonella; Silverman, Frances; Schwartz, Joel; Coull, Brent; Urch, Bruce; Speck, Mary; Brook, Jeffrey R; Manno, Michael; Gold, Diane R

    2010-01-01

    Systemic inflammation may be one of the mechanisms mediating the association between ambient air pollution and cardiovascular morbidity and mortality. Interleukin-6 (IL-6) and fibrinogen are biomarkers of systemic inflammation that are independent risk factors for cardio-vascular disease. We investigated the association between ambient air pollution and systemic inflammation using baseline measurements of IL-6 and fibrinogen from controlled human exposure studies. In this retrospective analysis we used repeated-measures data in 45 nonsmoking subjects. Hourly and daily moving averages were calculated for ozone, nitrogen dioxide, sulfur dioxide, and particulate matter pollutants on systemic IL-6 and fibrinogen. Effect modification by season was considered. We observed a positive association between IL-6 and O3 [0.31 SD per O3 interquartile range (IQR); 95% confidence interval (CI), 0.080.54] and between IL-6 and SO2 (0.25 SD per SO2 IQR; 95% CI, 0.060.43). We observed the strongest effects using 4-day moving averages. Responses to pollutants varied by season and tended to be higher in the summer, particularly for O3 and PM2.5. Fibrinogen was not associated with pollution. This study demonstrates a significant association between ambient pollutant levels and baseline levels of systemic IL-6. These findings have potential implications for controlled human exposure studies. Future research should consider whether ambient pollution exposure before chamber exposure modifies IL-6 response.

  2. Supersaturated calcium carbonate solutions are classical

    Energy Technology Data Exchange (ETDEWEB)

    Henzler, Katja; Fetisov, Evgenii O.; Galib, Mirza; Baer, Marcel D.; Legg, Benjamin A.; Borca, Camelia; Xto, Jacinta M.; Pin, Sonia; Fulton, John L.; Schenter, Gregory K.; Govind, Niranjan; Siepmann, J. Ilja; Mundy, Christopher J.; Huthwelker, Thomas; De Yoreo, James J.

    2018-01-01

    We will present a description of nucleation phenomena in the condensed phase that takes into account non-ideal solution effects associated with cluster-cluster interaction. To do this we employ aggregation-volume bias Monte Carlo simulation, making the estimation of free-energy of large pre-critical clusters of sizes 10-20 tractable. We will compare and contrast empirical potential and electronic structure (e.g. Density functional theory) based descriptions of molecular interaction associated with the nucleation of CaCO3, highlighting free-energy trends and qualitative differences in populations of pre-critical clusters as a function of supersaturation. The influence of how the precise local interaction influences the non-ideal solution behavior on the nucleation and growth processes will be highlighted. This research was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences.

  3. Calidad ambiental interior: bienestar, confort y salud

    Directory of Open Access Journals (Sweden)

    Francisco Vargas Marcos

    2005-01-01

    Full Text Available Distintas formas de interpretar las condiciones ambientales han llevado al desarrollo de conceptos tales como edificio enfermo, calidad del aire o calidad ambiental interior, todos ellos encaminados a entender la complejidad de los contaminantes en los ambientes cerrados y las implicaciones sobre la salud de la población. La propuesta de "Calidad ambiental interior" es un avance conceptual y operativo que supera ampliamente a los anteriores, puesto que orienta las acciones hacia ambientes saludables sin limitar al aire la idea de contaminación. El objetivo del trabajo es identificar las competencias y el marco legislativo que permiten actuar en la prevención de riesgos asociados a la exposición de contaminantes en ambientes interiores. Óptimas condiciones en los ambientes interiores deben redundar en salud, bienestar y confort, tanto en lo que respecta a la vida laboral como a los ámbitos donde se desarrollan las actividades cotidianas extralaborales, escolares, de descanso y de ocio. La sociedad actual exige lugares seguros, limpios y bien climatizados, para lo que es necesario integrar percepciones y exigencias de los habitantes y alcanzar un óptimo equilibrio entre estándares sociales, uso de la energía y desarrollo sostenible, buscando confort sin contaminar y sin aumentar el consumo de fuentes energéticas que degraden el medio ambiente. El desarrollo legislativo se orienta a la seguridad y la salud en los lugares de trabajo y la regulación de las sustancias químicas. La Sanidad Ambiental lleva a cabo tareas de prevención y control, participa en la ejecución de convenios internacionales de reducción de contaminantes y desechos y promueve acciones para el desarrollo de la Estrategia Europea de Salud y Medio Ambiente.

  4. Important Roles of Enthalpic and Entropic Contributions to CO 2 Capture from Simulated Flue Gas and Ambient Air Using Mesoporous Silica Grafted Amines

    KAUST Repository

    Alkhabbaz, Mustafa A.; Bollini, Praveen; Foo, Guo Shiou; Sievers, Carsten; Jones, Christopher W.

    2014-01-01

    © 2014 American Chemical Society. The measurement of isosteric heats of adsorption of silica supported amine materials in the low pressure range (0- 0.1 bar) is critical for understanding the interactions between CO2 and amine sites at low coverage and hence to the development of efficient amine adsorbents for CO2 capture from flue gas and ambient air. Heats of adsorption for an array of silica-supported amine materials are experimentally measured at low coverage using a Calvet calorimeter equipped with a customized dosing manifold. In a series of 3-aminopropylfunctionalized silica materials, higher amine densities resulted in higher isosteric heats of adsorption, clearly showing that the density/proximity of amine sites can influence the amine efficiency of adsorbents. In a series of materials with fixed amine loading but different amine types, strongly basic primary and secondary amine materials are shown to have essentially identical heats of adsorption near 90 kJ/mol. However, the adsorption uptakes vary substantially as a function of CO2 partial pressure for different primary and secondary amines, demonstrating that entropic contributions to adsorption may play a key role in adsorption at secondary amine sites, making adsorption at these sites less effi cient at the low coverages that are important to the direct capture of CO2 from ambient air. Thus, while primary amines are confirmed to be the most effective amine types for CO2 capture from ambient air, this is not due to enhanced enthalpic contributions associated with primary amines over secondary amines, but may be due to unfavorable entropic factors associated with organization of the second alkyl chain on the secondary amine during CO2 adsorption. Given this hypothesis, favorable entropic factors may be the main reason primary amine based adsorbents are more effective under air capture conditions.

  5. Important Roles of Enthalpic and Entropic Contributions to CO 2 Capture from Simulated Flue Gas and Ambient Air Using Mesoporous Silica Grafted Amines

    KAUST Repository

    Alkhabbaz, Mustafa A.

    2014-09-24

    © 2014 American Chemical Society. The measurement of isosteric heats of adsorption of silica supported amine materials in the low pressure range (0- 0.1 bar) is critical for understanding the interactions between CO2 and amine sites at low coverage and hence to the development of efficient amine adsorbents for CO2 capture from flue gas and ambient air. Heats of adsorption for an array of silica-supported amine materials are experimentally measured at low coverage using a Calvet calorimeter equipped with a customized dosing manifold. In a series of 3-aminopropylfunctionalized silica materials, higher amine densities resulted in higher isosteric heats of adsorption, clearly showing that the density/proximity of amine sites can influence the amine efficiency of adsorbents. In a series of materials with fixed amine loading but different amine types, strongly basic primary and secondary amine materials are shown to have essentially identical heats of adsorption near 90 kJ/mol. However, the adsorption uptakes vary substantially as a function of CO2 partial pressure for different primary and secondary amines, demonstrating that entropic contributions to adsorption may play a key role in adsorption at secondary amine sites, making adsorption at these sites less effi cient at the low coverages that are important to the direct capture of CO2 from ambient air. Thus, while primary amines are confirmed to be the most effective amine types for CO2 capture from ambient air, this is not due to enhanced enthalpic contributions associated with primary amines over secondary amines, but may be due to unfavorable entropic factors associated with organization of the second alkyl chain on the secondary amine during CO2 adsorption. Given this hypothesis, favorable entropic factors may be the main reason primary amine based adsorbents are more effective under air capture conditions.

  6. 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.

  7. Important roles of enthalpic and entropic contributions to CO2 capture from simulated flue gas and ambient air using mesoporous silica grafted amines.

    Science.gov (United States)

    Alkhabbaz, Mustafa A; Bollini, Praveen; Foo, Guo Shiou; Sievers, Carsten; Jones, Christopher W

    2014-09-24

    The measurement of isosteric heats of adsorption of silica supported amine materials in the low pressure range (0-0.1 bar) is critical for understanding the interactions between CO2 and amine sites at low coverage and hence to the development of efficient amine adsorbents for CO2 capture from flue gas and ambient air. Heats of adsorption for an array of silica-supported amine materials are experimentally measured at low coverage using a Calvet calorimeter equipped with a customized dosing manifold. In a series of 3-aminopropyl-functionalized silica materials, higher amine densities resulted in higher isosteric heats of adsorption, clearly showing that the density/proximity of amine sites can influence the amine efficiency of adsorbents. In a series of materials with fixed amine loading but different amine types, strongly basic primary and secondary amine materials are shown to have essentially identical heats of adsorption near 90 kJ/mol. However, the adsorption uptakes vary substantially as a function of CO2 partial pressure for different primary and secondary amines, demonstrating that entropic contributions to adsorption may play a key role in adsorption at secondary amine sites, making adsorption at these sites less efficient at the low coverages that are important to the direct capture of CO2 from ambient air. Thus, while primary amines are confirmed to be the most effective amine types for CO2 capture from ambient air, this is not due to enhanced enthalpic contributions associated with primary amines over secondary amines, but may be due to unfavorable entropic factors associated with organization of the second alkyl chain on the secondary amine during CO2 adsorption. Given this hypothesis, favorable entropic factors may be the main reason primary amine based adsorbents are more effective under air capture conditions.

  8. Use of a screening method to determine excipients which optimize the extent and stability of supersaturated drug solutions and application of this system to solid formulation design.

    Science.gov (United States)

    Vandecruys, Roger; Peeters, Jef; Verreck, Geert; Brewster, Marcus E

    2007-09-05

    Assessing the effect of excipients on the ability to attain and maintain supersaturation of drug-based solution may provide useful information for the design of solid formulations. Judicious selection of materials that affect either the extent or stability of supersaturating drug delivery systems may be enabling for poorly soluble drug candidates or other difficult-to-formulate compounds. The technique suggested herein is aimed at providing a screening protocol to allow preliminary assessment of these factors based on small to moderate amounts of drug substance. A series of excipients were selected that may, by various mechanisms, affect supersaturation including pharmaceutical polymers such as HMPC and PVP, surfactants such as Polysorbate 20, Cremophor RH40 and TPGS and hydrophilic cyclodextrins such as HPbetaCD. Using a co-solvent based method and 25 drug candidates, the data suggested, on the whole, that the surfactants and the selected cyclodextrin seemed to best augment the extent of supersaturation but had variable benefits as stabilizers, while the pharmaceutical polymers had useful effect on supersaturation stability but were less helpful in increasing the extent of supersaturation. Using these data, a group of simple solid dosage forms were prepared and tested in the dog for one of the drug candidates. Excipients that gave the best extent and stability for the formed supersaturated solution in the screening assay also gave the highest oral bioavailability in the dog.

  9. Ambient Air Pollution and Hypertensive Disorders of Pregnancy: A Systematic Review and Meta-analysis

    Science.gov (United States)

    Hu, Hui; Ha, Sandie; Roth, Jeffrey; Kearney, Greg; Talbott, Evelyn O.; Xu, Xiaohui

    2014-01-01

    Hypertensive disorders of pregnancy (HDP, including gestational hypertension, preeclampsia, and eclampsia) have a substantial public health impact. Maternal exposure to high levels of air pollution may trigger HDP, but this association remains unclear. The objective of our report is to assess and quantify the association between maternal exposures to criteria air pollutants (ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter ≤ 10, 2.5 μm) on HDP risk. PubMed, EMBASE, MEDLINE, Current Contents, Global Health, and Cochrane were searched (last search: September, 2013). After a detailed screening of 270 studies, 10 studies were extracted. We conducted meta-analyses if a pollutant in a specific exposure window was reported by at least four studies. Using fixed- and random-effects models, odds ratios (ORs) and 95% CIs were calculated for each pollutant with specific increment of concentration. Increases in risks of HDP (OR per 10 ppb = 1.16; 95% CI, 1.03-1.30) and preeclampsia (OR per 10 ppb = 1.10; 95% CI, 1.03-1.17) were observed to be associated with exposure to NO2 during the entire pregnancy, and significant associations between HDP and exposure to CO (OR per 1 ppm = 1.79; 95% CI, 1.31-2.45) and O3 (OR per 10 ppb = 1.09; 95% CI, 1.05-1.13) during the first trimester were also observed. Our review suggests an association between ambient air pollution and HDP risk. Although the ORs were relatively low, the population-attributable fractions were not negligible given the ubiquitous nature of air pollution. PMID:25242883

  10. 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.

  11. 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

  12. Air pollution in the Slovak Republic, 2001

    International Nuclear Information System (INIS)

    Mitosinkova, M.; Kozakovic, L.; Zavodsky, D.; Sajtakova, E.; Mareckova, K.; Pukancikova, K.

    2003-01-01

    A report on air quality and contribution of individual sources on its pollution in the Slovak Republic in 2001 is presented. This report consists of two parts: (1) Ambient air and (2) Emission. Ambient air part is divided into the following chapters: Regional air pollution and quality of precipitation; Local air pollution; Atmospheric ozone. Emission part is divided into the following chapters: Emission and air pollution source inventory, Greenhouse gas emissions

  13. One year of operation of Mammoth Pacific`s MP1-100 turbine with metastable, supersaturated expansions

    Energy Technology Data Exchange (ETDEWEB)

    Mines, G.L. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-12-31

    The Idaho National Engineering and Environmental Laboratory`s Heat Cycle Research project is developing a technology base that will increase the use of moderate-temperature hydrothermal resources to generate electrical power. One of the concepts under investigation is the use of a metastable, supersaturated turbine expansion. This expansion process supports a supersaturated vapor. If brought to equilibrium conditions, liquid condensate would be present in the expanding vapor. Analytical studies show that a plant designed to operate with this expansion will have an improvement in the brine effectiveness of up to 8% provided there is no adverse impact on turbine performance. Determining the impact of this expansion on turbine performance is focus of the project investigations being reported.

  14. 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.

  15. 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.

  16. Copper(I)/TEMPO Catalyzed Aerobic Oxidation of Primary Alcohols to Aldehydes with Ambient Air

    Science.gov (United States)

    Hoover, Jessica M.; Steves, Janelle E.; Stahl, Shannon S.

    2012-01-01

    This protocol describes a practical laboratory-scale method for aerobic oxidation of primary alcohols to aldehydes, using a chemoselective CuI/TEMPO catalyst system. The catalyst is prepared in situ from commercially available reagents, and the reactions are performed in a common organic solvent (acetonitrile) with ambient air as the oxidant. Three different reaction conditions and three procedures for the isolation and purification of the aldehyde product are presented. The oxidations of eight different alcohols, described here, include representative examples of each reaction condition and purification method. Reaction times vary from 20 min to 24 h, depending on the alcohol, while the purification methods each take about 2 h. The total time necessary for the complete protocol ranges from 3 – 26 h. PMID:22635108

  17. 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.

  18. Air Gaps, Size Effect, and Corner-Turning in Ambient LX-17

    Energy Technology Data Exchange (ETDEWEB)

    Souers, P C; Hernandez, A; Cabacungen, C; Fried, L; Garza, R; Glaesemann, K; Lauderbach, L; Liao, S; Vitello, P

    2007-05-30

    Various ambient measurements are presented for LX-17. The size (diameter) effect has been measured with copper and Lucite confinement, where the failure radii are 4.0 and 6.5 mm, respectively. The air well corner-turn has been measured with an LX-07 booster, and the dead-zone results are comparable to the previous TATB-boosted work. Four double cylinders have been fired, and dead zones appear in all cases. The steel-backed samples are faster than the Lucite-backed samples by 0.6 {micro}s. Bare LX-07 and LX-17 of 12.7 mm-radius were fired with air gaps. Long acceptor regions were used to truly determine if detonation occurred or not. The LX-07 crossed at 10 mm with a slight time delay. Steady state LX-17 crossed at 3.5 mm gap but failed to cross at 4.0 mm. LX-17 with a 12.7 mm run after the booster crossed a 1.5 mm gap but failed to cross 2.5 mm. Timing delays were measured where the detonation crossed the gaps. The Tarantula model is introduced as embedded in the Linked Cheetah V4.0 reactive flow code at 4 zones/mm. Tarantula has four pressure regions: off, initiation, failure and detonation. A report card of 25 tests run with the same settings on LX-17 is shown, possibly the most extensive simultaneous calibration yet tried with an explosive. The physical basis of some of the input parameters is considered.

  19. "Supersaturated" self-assembled charge-selective interfacial layers for organic solar cells.

    Science.gov (United States)

    Song, Charles Kiseok; Luck, Kyle A; Zhou, Nanjia; Zeng, Li; Heitzer, Henry M; Manley, Eric F; Goldman, Samuel; Chen, Lin X; Ratner, Mark A; Bedzyk, Michael J; Chang, Robert P H; Hersam, Mark C; Marks, Tobin J

    2014-12-24

    To achieve densely packed charge-selective organosilane-based interfacial layers (IFLs) on the tin-doped indium oxide (ITO) anodes of organic photovoltaic (OPV) cells, a series of Ar2N-(CH2)n-SiCl3 precursors with Ar = 3,4-difluorophenyl, n = 3, 6, 10, and 18, was synthesized, characterized, and chemisorbed on OPV anodes to serve as IFLs. To minimize lateral nonbonded -NAr2···Ar2N- repulsions which likely limit IFL packing densities in the resulting self-assembled monolayers (SAMs), precursor mixtures having both small and large n values are simultaneously deposited. These "heterogeneous" SAMs are characterized by a battery of techniques: contact angle measurements, X-ray reflectivity, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy (UPS), cyclic voltammetry, and DFT computation. It is found that the headgroup densities of these "supersaturated" heterogeneous SAMs (SHSAMs) are enhanced by as much as 17% versus their homogeneous counterparts. Supersaturation significantly modifies the IFL properties including the work function (as much as 16%) and areal dipole moment (as much as 49%). Bulk-heterojunction OPV devices are fabricated with these SHSAMs: ITO/IFL/poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][2-[[(2-ethylhexyl)oxy]carbonyl]-3-fluorothieno[3,4-b]thiophenediyl

  20. Detection of Coxiella burnetii in Ambient Air after a Large Q Fever Outbreak.

    Directory of Open Access Journals (Sweden)

    Myrna M T de Rooij

    Full Text Available One of the largest Q fever outbreaks ever occurred in the Netherlands from 2007-2010, with 25 fatalities among 4,026 notified cases. Airborne dispersion of Coxiella burnetii was suspected but not studied extensively at the time. We investigated temporal and spatial variation of Coxiella burnetii in ambient air at residential locations in the most affected area in the Netherlands (the South-East, in the year immediately following the outbreak. One-week average ambient particulate matter < 10 μm samples were collected at eight locations from March till September 2011. Presence of Coxiella burnetii DNA was determined by quantitative polymerase chain reaction. Associations with various spatial and temporal characteristics were analyzed by mixed logistic regression. Coxiella burnetii DNA was detected in 56 out of 202 samples (28%. Airborne Coxiella burnetii presence showed a clear seasonal pattern coinciding with goat kidding. The spatial variation was significantly associated with number of goats on the nearest goat farm weighted by the distance to the farm (OR per IQR: 1.89, CI: 1.31-2.76. We conclude that in the year after a large Q fever outbreak, temporal variation of airborne Coxiella burnetii is suggestive to be associated with goat kidding, and spatial variation with distance to and size of goat farms. Aerosol measurements show to have potential for source identification and attribution of an airborne pathogen, which may also be applicable in early stages of an outbreak.

  1. Nanosuspensions of 10-hydroxycamptothecin that can maintain high and extended supersaturation to enhance oral absorption: preparation, characterization and in vitro/in vivo evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Pu, Xiaohui; Sun, Jin, E-mail: sunjin66@21cn.com [Shenyang Pharmaceutical University, Department of Biopharmaceutics, School of Pharmacy (China); Han, Jihong [Keele University, School of Pharmacy and Institute for Science and Technology in Medicine (United Kingdom); Lian, He; Zhang, Peng [Shenyang Pharmaceutical University, Department of Biopharmaceutics, School of Pharmacy (China); Yan, Zhongtian [Nantion Institutes for Food and Drug Control (China); He, Zhonggui, E-mail: hezhgui_student@yahoo.com.cn [Shenyang Pharmaceutical University, Department of Biopharmaceutics, School of Pharmacy (China)

    2013-11-15

    The purpose of the study was to prepare and characterize nanosuspensions that can maintain high and extended supersaturation to improve the dissolution and absorption of poorly soluble 10-hydroxycamptothecin (10-HCPT). 10-HCPT oral nanosuspensions (HCPT-Nanosuspensions) were produced on a laboratory-scale by microprecipitation- high pressure homogenization method. The particle morphology and the physical state were studied using transmission electron microscopy, X-ray powder diffraction (XRPD), and differential scanning calorimetry (DSC). Supersaturated dissolution tests were carried out with the paddle method. Caco-2 cell experiments were performed to imitate the oral absorption. The in vivo pharmacokinetics studies were undertaken in rats following oral administration. The 10-HCPT nanoparticles were 135 nm in dimension before lyophilization and were claviform or lump in shape. XRPD and DSC both confirmed that a portion of 10-HCPT was present in a crystalline state in nanosuspension. Supersaturated dissolution tests showed HCPT-Nanosuspensions could maintain high supersaturated level for an extended period time. The cell experiment on HCPT-Nanosuspensions showed a significantly higher uptake and greater membrane permeability compared with the other formulations. The pharmacokinetic test exhibited HCPT-Nanosuspensions had a similar pharmacokinetic performance with 10-HCPT solution. In conclusion, highly and extendedly supersaturated HCPT-Nanosuspensions have been prepared which could result in high peak concentration (C{sub max}) and great exposure (AUC) after oral administration.

  2. Impact of ambient air pollution on gestational age is modified by season in Sydney, Australia

    Directory of Open Access Journals (Sweden)

    Lincoln Doug

    2007-06-01

    Full Text Available Abstract Background The effect of individual pollutants and the period(s during pregnancy when pollutant levels are likely to have most impact on preterm birth is not clear. We evaluated the effect of prenatal exposure to six common urban air pollutants in the Sydney metropolitan area on preterm birth. Methods We obtained information on all births in metropolitan Sydney between January 1, 1998 and December 31, 2000. For each birth, exposure to each air pollutant was estimated for the first trimester, the three months preceding birth, the first month after the estimated date of conception and the month prior to delivery. Gestational age was analysed as a categorical variable in logistic regression models. Results There were 123 840 singleton births in Sydney in 1998–2000 and 4.9% were preterm. Preterm birth was significantly associated with maternal age, maternal smoking, male infant, indigenous status and first pregnancy. Air pollutant levels in the month and three months preceding birth had no significant effect on preterm birth after adjusting for maternal and infant covariates. Ozone levels in the first trimester of pregnancy and spring months of conception and sulphur dioxide were associated with increased risks for preterm births. Nitrogen dioxide was associated with a decreased risk of preterm births. Conclusion We found more protective than harmful associations between ambient air pollutants and preterm births with most associations non-significant. In view of these inconsistent associations, it is important to interpret the harmful effects with caution. If our results are confirmed by future studies then it will be imperative to reduce Sydney's already low air pollution levels even further.

  3. Controlled environment laboratory for the energy certification of refrigeration and air conditioning systems; Laboratorio de ambiente controlado para la certificacion energetica de sistemas de refrigeracion y aire acondicionado

    Energy Technology Data Exchange (ETDEWEB)

    Ambriz, Juan Jose; Romero Paredes, Hernando; Dorantes, Ruben [Universidad Autonoma Metropolitana, Mexico, D.F. (Mexico)

    1999-07-01

    In this paper the general characteristics of the Controlled Environment Laboratory (CELAB) are described and some of the possible tests that could be performed in this device to evaluate the energy efficiency in air conditioning systems, domestic refrigeration and industrial refrigeration, as well as tests to evaluate the hydrothermal comfort in national populations, are presented. [Spanish] En este trabajo se describen las caracteristicas generales del Laboratorio de Ambiente Controlado (LAB), y se presentan algunas de las posibles pruebas que podran ser desarrolladas en este dispositivo para evaluar la eficiencia energetica en sistemas de aire acondicionado, refrigeracion domestica y refrigeracion industrial, asi como para pruebas para evaluar el confort hidrotermico en poblaciones nacionales.

  4. 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

  5. Nanomaterials vs Ambient Ultrafine Particles

    DEFF Research Database (Denmark)

    Stone, Vicki; Miller, Mark R.; Clift, Martin J. D.

    2017-01-01

    BACKGROUND: A rich body of literature exists that has demonstrated adverse human health effects following exposure to ambient air particulate matter (PM), and there is strong support for an important role of ultrafine (nanosized) particles. At present, relatively few human health or epidemiology ...

  6. RadNet (Environmental Radiation Ambient Monitoring System)

    Data.gov (United States)

    U.S. Environmental Protection Agency — RadNet, formerly Environmental Radiation Ambient Monitoring System (ERAMS), is a national network of monitoring stations that regularly collect air, precipitation,...

  7. Determination of Glycol Ethers in Ambient Air by Adsorption Sampling and Thermal Desorption with GC/MS Analysis: Performance Evaluation and Field Application

    Directory of Open Access Journals (Sweden)

    Young-Kyo Seo

    2012-01-01

    Full Text Available Some of glycol ethers, such as 2-methoxyethanol (2-ME and 2-ethoxyethanol (2-EE are known to be toxic and classified as hazardous air pollutants in USA, Japan and Germany. In Korea, however, there has been no study conducted so far for these compounds in ambient air. In addition, no clear methodologies for the measurement of glycol ethers have been yet established. We carried out this study to evaluate a sampling and analytical method for the determination of glycol ethers, in ambient air samples collected in specific industrial areas of South Korea. To measure glycol ethers, adsorption sampling and thermal desorption with GC/MS analysis were used in this study. The analytical method showed good repeatability, linearity and sensitivity. The lower detection limits were estimated to be approximately 0.3∼0.5 ppb. Based on storage tests, it was suggested that samples should be analyzed within two weeks. It was also demonstrated that this method can be used for the simultaneous measurement of glycol ethers and other aromatic VOCs such as benzene, toluene, and xylenes. Field sampling campaign was carried out at 2 sites, located in a large industrial area, from October 2006 to June 2007, and a total of 480 samples were collected seasonally. Among them, 2-ME was not detected from any samples, while 2-EE and 2-Ethyloxyethylacetate (2-EEA were found in 7 and 70 samples, respectively. The measured concentrations of 2-EE and 2-EEA for samples were ranged from 0.7-2.5 ppb and from 0.5-10.5 ppb, respectively. To our knowledge, this is the first measurement report for glycol ethers in the ambient atmosphere not only in Korea but also the rest of the world.

  8. Future research needs associated with the assessment of potential human health risks from exposure to toxic ambient air pollutants

    DEFF Research Database (Denmark)

    Möller, Lennart; Schuetzle, Dennis; Autrup, Herman

    1994-01-01

    of identification and quantification of toxics in source emissions and ambient air, atmospheric transport and chemistry, exposure level assessment, the development of improved in vitro bioassays, biomarker development, the development of more accurate epidemiological methodologies, and risk quantification......This paper presents key conclusions and future research needs from a Workshop on the Risk Assessment of Urban Air, Emissions, Exposure, Risk Identification, and Quantification, which was held in Stockholm during June 1992 by 41 participants from 13 countries. Research is recommended in the areas...... techniques. Studies are described that will be necessary to assess and reduce the level of uncertainties associated with each step of the risk assessment process. International collaborative research efforts between industry and government organizations are recommended as the most effective way to carry out...

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

    NARCIS (Netherlands)

    Heeres, P.; Setiawan, R.; Krol, M.C.; Adema, E.H.

    2009-01-01

    This paper describes two new methods for the determination of NO2 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 NO2. With standard colorimetrical analysis, the amount of

  10. Synthesis of ammonia directly from air and water at ambient temperature and pressure

    Science.gov (United States)

    Lan, Rong; Irvine, John T. S.; Tao, Shanwen

    2013-01-01

    The N≡N bond (225 kcal mol−1) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N2 separation and H2 production stages. A maximum ammonia production rate of 1.14 × 10−5 mol m−2 s−1 has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future. PMID:23362454

  11. Synthesis of ammonia directly from air and water at ambient temperature and pressure.

    Science.gov (United States)

    Lan, Rong; Irvine, John T S; Tao, Shanwen

    2013-01-01

    The N≡N bond (225 kcal mol⁻¹) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N₂ separation and H₂ production stages. A maximum ammonia production rate of 1.14 × 10⁻⁵ mol m⁻² s⁻¹ has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future.

  12. 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

  13. 2011 NATA - Risks and Annual Ambient Concentrations

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes the modeled annual ambient concentrations and risks at the census tract level for the 2011 National Air Toxics Assessment. All concentrations...

  14. Concentration and Size Distribution of Particulate Matter in a Broiler House Ambient Air

    Directory of Open Access Journals (Sweden)

    Ismael Rodrigues Amador

    2016-07-01

    Full Text Available Atmospheric particulate matter (PM is an important constituent of ambient air. The determination of its concentration and size distribution in different environments is essential because of its ability to penetrate deeply into animal and human respiratory tract. In this study, air sampling was performed in a broiler house to estimate the concentration and size distribution of PM emitted along with its activities. Low-vol impactor (< 10 mm, cyclones (< 2.5 e < 1.0 mm, and Sioutas cascade impactor (> 2.5; 1.0 – 2.5; 0.50 – 1.0; 0.25 – 0.50; < 0.25 mm connected with membrane pumps were used. PM10 showed high concentration (209 - 533 mg m-3. PM2.5 and PM1.0 initially showed relatively low concentration (20.8 and 16.0 mg m-3 respectively with significantly increasing levels (412.9 and 344.8 mg m-3 respectively during the samplings. It was also possible to observe the contribution of fine particles. This was evidenced by the high correlation between PM2.5 and PM1.0 and by the profile of particle distribution in the Sioutas sampler. PM concentration levels are considered excessively high, with great potential to affect animal and human health. DOI: http://dx.doi.org/10.17807/orbital.v8i3.847 

  15. The filamentous ascomycete Sordaria macrospora can survive in ambient air without carbonic anhydrases.

    Science.gov (United States)

    Lehneck, Ronny; Elleuche, Skander; Pöggeler, Stefanie

    2014-06-01

    The rapid interconversion of carbon dioxide and bicarbonate (hydrogen carbonate) is catalysed by metalloenzymes termed carbonic anhydrases (CAs). CAs have been identified in all three domains of life and can be divided into five evolutionarily unrelated classes (α, β, γ, δ and ζ) that do not share significant sequence similarities. The function of the mammalian, prokaryotic and plant α-CAs has been intensively studied but the function of CAs in filamentous ascomycetes is mostly unknown. The filamentous ascomycete Sordaria macrospora codes for four CAs, three of the β-class and one of the α-class. Here, we present a functional analysis of CAS4, the S. macrospora α-class CA. The CAS4 protein was post-translationally glycosylated and secreted. The knockout strain Δcas4 had a significantly reduced rate of ascospore germination. To determine the cas genes required for S. macrospora growth under ambient air conditions, we constructed double and triple mutations of the four cas genes in all possible combinations and a quadruple mutant. Vegetative growth rate of the quadruple mutant lacking all cas genes was drastically reduced compared to the wild type and invaded the agar under normal air conditions. Likewise the fruiting bodies were embedded in the agar and completely devoid of mature ascospores. © 2014 John Wiley & Sons Ltd.

  16. Riverine CO2 supersaturation and outgassing in a subtropical monsoonal mountainous area (Three Gorges Reservoir Region) of China

    Science.gov (United States)

    Li, Siyue; Ni, Maofei; Mao, Rong; Bush, Richard T.

    2018-03-01

    Rivers are an important source of CO2 to the atmosphere, however, mountainous rivers and streams with high emission rates are not well studied particularly in China. We report the first detailed investigation on monsoonal mountainous rivers in the Three Gorges Reservoir (TGR) region, with a focus on the riverine CO2 partial pressure (pCO2), CO2 degassing and their potential controls. The pCO2 levels ranged from 50 to 6019 μatm with averages of 1573 (SD. ±1060) in dry Autumn and 1276 (SD. ±1166) μatm in wet Summer seasons. 94% of samples were supersaturated with CO2 with respect to the atmospheric equilibrium (410 μatm). Monsoonal precipitation controlled pCO2 seasonality, with both the maximal and minimal levels occurring in the wet season, and showing the overall effects of dilution. Riverine pCO2 could be predicted better in the dry season using pH, DO% and DTP, whereas pH and DOC were better predictors in the wet season. We conclude that in-situ respiration of allochthonous organic carbon, rather than photosynthesis, resulted in negative relationships between pCO2 and DO and pH, and thus CO2 supersaturation. Photosynthetic primary production was effectively limited by rapid flow velocity and short residence time. The estimated water-to-air CO2 emission rate in the TGR rivers was 350 ± 319 in the Autumn and lower, yet more variable at 326 ± 439 mmol/m2/d in Summer. Our calculated CO2 areal fluxes were in the upper-level magnitude of published data, demonstrating the importance of mountainous rivers and streams as a global greenhouse gas source, and urgency for more detailed studies on CO2 degassing, to address a global data gap for these environments.

  17. Air Sparging Versus Gas Saturated Water Injection for Remediation of Volatile LNAPL in the Borden Aquifer

    Science.gov (United States)

    Barker, J.; Nelson, L.; Doughty, C.; Thomson, N.; Lambert, J.

    2009-05-01

    In the shallow, rather homogeneous, unconfined Borden sand aquifer, field trials of air sparging (Tomlinson et al., 2003) and pulsed air sparging (Lambert et al., 2009) have been conducted, the latter to remediate a residual gasoline source emplaced below the water table. As well, a supersaturated (with CO2) water injection (SWI) technology, using the inVentures inFusion system, has been trialed in two phases: 1. in the uncontaminated sand aquifer to evaluate the radius of influence, extent of lateral gas movement and gas saturation below the water table, and 2. in a sheet pile cell in the Borden aquifer to evaluate the recovery of volatile hydrocarbon components (pentane and hexane) of an LNAPL emplaced below the water table (Nelson et al., 2008). The SWI injects water supersaturated with CO2. The supersaturated injected water moves laterally away from the sparge point, releasing CO2 over a wider area than does gas sparging from a single well screen. This presentation compares these two techniques in terms of their potential for remediating volatile NAPL components occurring below the water table in a rather homogeneous sand aquifer. Air sparging created a significantly greater air saturation in the vicinity of the sparge well than did the CO2 system (60 percent versus 16 percent) in the uncontaminated Borden aquifer. However, SWI pushed water, still supersaturated with CO2, up to about 2.5 m from the injection well. This would seem to provide a considerable advantage over air sparging from a point, in that gas bubbles are generated at a much larger radius from the point of injection with SWI and so should involve additional gas pathways through a residual NAPL. Overall, air sparging created a greater area of influence, defined by measurable air saturation in the aquifer, but air sparging also injected about 12 times more gas than was injected in the SWI trials. The pulsed air sparging at Borden (Lambert et al.) removed about 20 percent (4.6 kg) of gasoline

  18. 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.

  19. 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.

  20. The impact of supersaturation level for oral absorption of BCS class IIb drugs, dipyridamole and ketoconazole, using in vivo predictive dissolution system: Gastrointestinal Simulator (GIS).

    Science.gov (United States)

    Tsume, Yasuhiro; Matsui, Kazuki; Searls, Amanda L; Takeuchi, Susumu; Amidon, Gregory E; Sun, Duxin; Amidon, Gordon L

    2017-05-01

    The development of formulations and the assessment of oral drug absorption for Biopharmaceutical Classification System (BCS) class IIb drugs is often a difficult issue due to the potential for supersaturation and precipitation in the gastrointestinal (GI) tract. The physiological environment in the GI tract largely influences in vivo drug dissolution rates of those drugs. Thus, those physiological factors should be incorporated into the in vitro system to better assess in vivo performance of BCS class IIb drugs. In order to predict oral bioperformance, an in vitro dissolution system with multiple compartments incorporating physiologically relevant factors would be expected to more accurately predict in vivo phenomena than a one-compartment dissolution system like USP Apparatus 2 because, for example, the pH change occurring in the human GI tract can be better replicated in a multi-compartmental platform. The Gastrointestinal Simulator (GIS) consists of three compartments, the gastric, duodenal and jejunal chambers, and is a practical in vitro dissolution apparatus to predict in vivo dissolution for oral dosage forms. This system can demonstrate supersaturation and precipitation and, therefore, has the potential to predict in vivo bioperformance of oral dosage forms where this phenomenon may occur. In this report, in vitro studies were performed with dipyridamole and ketoconazole to evaluate the precipitation rates and the relationship between the supersaturation levels and oral absorption of BCS class II weak base drugs. To evaluate the impact of observed supersaturation levels on oral absorption, a study utilizing the GIS in combination with mouse intestinal infusion was conducted. Supersaturation levels observed in the GIS enhanced dipyridamole and ketoconazole absorption in mouse, and a good correlation between their supersaturation levels and their concentration in plasma was observed. The GIS, therefore, appears to represent in vivo dissolution phenomena and

  1. Resonance-enhanced laser-induced plasma spectroscopy: ambient gas effects

    International Nuclear Information System (INIS)

    Lui, S.L.; Cheung, N.H.

    2003-01-01

    When performing laser-induced plasma spectroscopy for elemental analysis, the sensitivity could be significantly enhanced if the plume was resonantly rekindled by a dye laser pulse. The extent of the enhancement was found to depend on the ambient gas. Air, nitrogen, helium, argon and xenon at pressures ranging from vacuum to 1 bar were investigated. In vacuum, the analyte signal was boosted because of reduced cooling, but it soon decayed as the plume freely expanded. By choosing the right ambient gas at the right pressure, the expanding plume could be confined as well as thermally insulated to maximize the analyte signal. For instance, an ambient of 13 mbar xenon yielded a signal-to-noise ratio of 110. That ratio was 53 when the pellet was ablated in air, and decreased further to 5 if the dye laser was tuned off resonance

  2. Secondary organic aerosol formation from in situ OH, O3, and NO3 oxidation of ambient forest air in an oxidation flow reactor

    Science.gov (United States)

    Palm, Brett B.; Campuzano-Jost, Pedro; Day, Douglas A.; Ortega, Amber M.; Fry, Juliane L.; Brown, Steven S.; Zarzana, Kyle J.; Dube, William; Wagner, Nicholas L.; Draper, Danielle C.; Kaser, Lisa; Jud, Werner; Karl, Thomas; Hansel, Armin; Gutiérrez-Montes, Cándido; Jimenez, Jose L.

    2017-04-01

    Ambient pine forest air was oxidized by OH, O3, or NO3 radicals using an oxidation flow reactor (OFR) during the BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen - Rocky Mountain Biogenic Aerosol Study) campaign to study biogenic secondary organic aerosol (SOA) formation and organic aerosol (OA) aging. A wide range of equivalent atmospheric photochemical ages was sampled, from hours up to days (for O3 and NO3) or weeks (for OH). Ambient air processed by the OFR was typically sampled every 20-30 min, in order to determine how the availability of SOA precursor gases in ambient air changed with diurnal and synoptic conditions, for each of the three oxidants. More SOA was formed during nighttime than daytime for all three oxidants, indicating that SOA precursor concentrations were higher at night. At all times of day, OH oxidation led to approximately 4 times more SOA formation than either O3 or NO3 oxidation. This is likely because O3 and NO3 will only react with gases containing C = C bonds (e.g., terpenes) to form SOA but will not react appreciably with many of their oxidation products or any species in the gas phase that lacks a C = C bond (e.g., pinonic acid, alkanes). In contrast, OH can continue to react with compounds that lack C = C bonds to produce SOA. Closure was achieved between the amount of SOA formed from O3 and NO3 oxidation in the OFR and the SOA predicted to form from measured concentrations of ambient monoterpenes and sesquiterpenes using published chamber yields. This is in contrast to previous work at this site (Palm et al., 2016), which has shown that a source of SOA from semi- and intermediate-volatility organic compounds (S/IVOCs) 3.4 times larger than the source from measured VOCs is needed to explain the measured SOA formation from OH oxidation. This work suggests that those S/IVOCs typically do not contain C = C bonds. O3 and NO3 oxidation produced SOA with elemental O : C and H : C

  3. Enhancement of the EUV emission of a metallic capillary discharge operated with argon ambient gas

    Energy Technology Data Exchange (ETDEWEB)

    Chan, L. S., E-mail: lschan1982@yahoo.com; Tan, D., E-mail: lschan1982@yahoo.com; Saboohi, S., E-mail: lschan1982@yahoo.com; Yap, S. L., E-mail: lschan1982@yahoo.com; Wong, C. S., E-mail: lschan1982@yahoo.com [Plasma Technology Research Centre, Physics Department, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-03-05

    In this work, the metallic capillary discharge is operated with two different ambients: air and argon. In the experiments reported here, the chamber is first evacuated to 10{sup −5} mbar. The discharge is initiated by the transient hollow cathode effect generated electron beam, with either air ambient or argon ambient at 10{sup −4} mbar. The bombardment of electron beam at the tip of the stainless steel anode gives rise to a metallic vapor, which is injected into the capillary and initiates the main discharge through the capillary. The EUV emission is measured for different discharge voltages for both conditions and compared. It is found that the metallic capillary discharge with argon ambientis able to produce higher EUV energy compared to that with air ambient.

  4. Future research needs associated with the assessment of potential human health risks from exposure to toxic ambient air pollutants

    DEFF Research Database (Denmark)

    Möller, Lennart; Schuetzle, Dennis; Autrup, Herman

    1994-01-01

    of identification and quantification of toxics in source emissions and ambient air, atmospheric transport and chemistry, exposure level assessment, the development of improved in vitro bioassays, biomarker development, the development of more accurate epidemiological methodologies, and risk quantification...... techniques. Studies are described that will be necessary to assess and reduce the level of uncertainties associated with each step of the risk assessment process. International collaborative research efforts between industry and government organizations are recommended as the most effective way to carry out...

  5. Performance improvement of air-cooled refrigeration system by using evaporatively cooled air condenser

    Energy Technology Data Exchange (ETDEWEB)

    Hajidavalloo, E.; Eghtedari, H. [Mechanical Engineering Department, Shahid Chamran University, Golestan St., Ahvaz (Iran)

    2010-08-15

    Increasing the coefficient of performance of air conditioner with air-cooled condenser is a challenging problem especially in area with very hot weather conditions. Application of evaporatively cooled air condenser instead of air-cooled condenser is proposed in this paper as an efficient way to solve the problem. An evaporative cooler was built and coupled to the existing air-cooled condenser of a split-air-conditioner in order to measure its effect on the cycle performance under various ambient air temperatures up to 49 C. Experimental results show that application of evaporatively cooled air condenser has significant effect on the performance improvement of the cycle and the rate of improvement is increased as ambient air temperature increases. It is also found that by using evaporatively cooled air condenser in hot weather conditions, the power consumption can be reduced up to 20% and the coefficient of performance can be improved around 50%. More improvements can be expected if a more efficient evaporative cooler is used. (author)

  6. 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.

  7. Evaluation of an Absorption Heat Pump to Mitigate Plant Capacity Reduction Due to Ambient Temperature Rise for an Air-Cooled Ammonia and Water Cycle: Preprint

    International Nuclear Information System (INIS)

    Bharathan, D.; Nix, G.

    2001-01-01

    Air-cooled geothermal plants suffer substantial decreases in generating capacity at increased ambient temperatures. As the ambient temperature rises by 50 F above a design value of 50 F, at low brine-resource temperatures, the decrease in generating capacity can be more than 50%. This decrease is caused primarily by increased condenser pressure. Using mixed-working fluids has recently drawn considerable attention for use in power cycles. Such cycles are more readily amenable to use of absorption ''heat pumps.'' For a system that uses ammonia and water as the mixed-working fluid, this paper evaluates using an absorption heat pump to reduce condenser backpressure. At high ambient temperatures, part of the turbine exhaust vapor is absorbed into a circulating mixed stream in an absorber in series with the main condenser. This steam is pumped up to a higher pressure and heated to strip the excess vapor, which is recondensed using an additional air-cooled condenser. The operating conditions are chosen to reconstitute this condensate back to the same concentration as drawn from the original system. We analyzed two power plants of nominal 1-megawatt capacity. The design resource temperatures were 250 F and 300 F. Ambient temperature was allowed to rise from a design value of 50 F to 100 F. The analyses indicate that using an absorption heat pump is feasible. For the 300 F resource, an increased brine flow of 30% resulted in a net power increase of 21%. For the 250 F resource, the increase was smaller. However, these results are highly plant- and equipment-specific because evaluations must be carried out at off-design conditions for the condenser. Such studies should be carried out for specific power plants that suffer most from increased ambient temperatures

  8. 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)

  9. Ambient Air Pollution and Risk for Ischemic Stroke: A Short-Term Exposure Assessment in South China

    Directory of Open Access Journals (Sweden)

    Pi Guo

    2017-09-01

    Full Text Available Data on the association between air pollution and risk of ischemic stroke in China are still limited. This study aimed to investigate the association between short-term exposure to ambient air pollution and risk of ischemic strokes in Guangzhou, the most densely-populated city in south China, using a large-scale multicenter database of stroke hospital admissions. Daily counts of ischemic stroke admissions over the study years 2013–2015 were obtained from the Guangzhou Cardiovascular and Cerebrovascular Disease Event Surveillance System. Daily particulate matter <2.5 μm in diameter (PM2.5, sulfur dioxide (SO2, nitrogen dioxide (NO2, ozone (O3, and meteorological data were collected. The associations between air pollutants and hospital admissions for stroke were examined using relative risks (RRs and their corresponding 95% confidence intervals (CIs based on time-series Poisson regression models, adjusting for temperature, public holiday, day of week, and temporal trends in stroke. Ischemic stroke admissions increased from 27,532 to 35,279 through 2013 to 2015, increasing by 28.14%. Parameter estimates for NO2 exposure were robust regardless of the model used. The association between same-day NO2 (RR = 1.0509, 95% CI: 1.0353–1.0668 exposure and stroke risk was significant when accounting for other air pollutants, day of the week, public holidays, temperature, and temporal trends in stroke events. Overall, we observed a borderline significant association between NO2 exposure modeled as an averaged lag effect and ischemic stroke risk. This study provides data on air pollution exposures and stroke risk, and contributes to better planning of clinical services and emergency contingency response for stroke.

  10. AMBIENT CONDITIONS EFFECTS ON PERFORMANCE OF GAS TURBINE COGENERATION POWER PLANTS

    OpenAIRE

    Necmi Ozdemir*

    2016-01-01

    In this study, the performances of a simple and an air preheated cogeneration cycles in ambient conditions are compared with each other. A computer program written by the author in FORTRAN codes is used for the calculation of the enthalpy and entropy values of the streams, Exergy analysis is done and compared for the simple and the air preheated cogeneration cycles for different ambient conditions. The two cogeneration cycles are evaluated in terms of heat powers and electric, electrical to h...

  11. Wear Behavior of Selected Nuclear Grade Graphites at Room Temperature in Ambient Air Environment

    International Nuclear Information System (INIS)

    Kim, Eung-Seon; Park, Kwang-Seok; Kim, Yong-Wan

    2008-01-01

    In a very high temperature reactor (VHTR), graphite will be used not only for as a moderator and reflector but also as a major structural component due to its excellent neutronic, thermal and mechanical properties. In the VHTR, wear of graphite components is inevitable due to a neutron irradiation-induced dimensional change, thermal gradient, relative motions of graphite components and a shock load such as an earthquake. Large wear particles accumulated at the bottom of a reactor can influence the cooling of the lower part and small wear particles accumulated on the primary circuit and heat exchanger tube can make it difficult to inspect the equipment, and also decrease the heat exchange rate. In the present work, preliminary wear tests were performed at room temperature in ambient air environment to understand the basic wear characteristics of selected nuclear grade graphites for the VHTR

  12. Air-cooled LiBr-water absorption chillers for solar air conditioning in extremely hot weathers

    International Nuclear Information System (INIS)

    Kim, D.S.; Infante Ferreira, C.A.

    2009-01-01

    A low temperature-driven absorption cycle is theoretically investigated for the development of an air-cooled LiBr-water absorption chiller to be combined with low-cost flat solar collectors for solar air conditioning in hot and dry regions. The cycle works with dilute LiBr-water solutions so that risk of LiBr crystallization is less than for commercially available water-cooled LiBr-water absorption chillers even in extremely hot ambient conditions. Two-phase heat exchangers in the system were modelled taking account of the heat and mass transfer resistances in falling film flows by applying the film theory in thermal and concentration boundary layers. Both directly and indirectly air-cooled chillers were modelled by properly combining component models and boundary conditions in a matrix system and solved with an algebraic equation solver. Simulation results predict that the chillers would deliver chilled water around 7.0 deg. C with a COP of 0.37 from 90 deg. C hot water under 35 deg. C ambient condition. At 50 deg. C ambient temperature, the chillers retained about 36% of their cooling power at 35 deg. C ambient. Compared with the directly air-cooled chiller, the indirectly air-cooled chiller presented a cooling power performance reduction of about 30%

  13. Integrating air-related health surveillance into air quality management: perceptions and practicalities

    CSIR Research Space (South Africa)

    Wright, C

    2012-06-01

    Full Text Available Health surveillance is presently not an integral part of air quality management in South Africa, although ambient air pollution standards are derived from health effects of personal exposure. In a survey to air quality officials and environmental...

  14. Short-term association between ambient air pollution and pneumonia in children: A systematic review and meta-analysis of time-series and case-crossover studies.

    Science.gov (United States)

    Nhung, Nguyen Thi Trang; Amini, Heresh; Schindler, Christian; Kutlar Joss, Meltem; Dien, Tran Minh; Probst-Hensch, Nicole; Perez, Laura; Künzli, Nino

    2017-11-01

    Ambient air pollution has been associated with respiratory diseases in children. However, its effects on pediatric pneumonia have not been meta-analyzed. We conducted a systematic review and meta-analysis of the short-term association between ambient air pollution and hospitalization of children due to pneumonia. We searched the Web of Science and PubMed for indexed publications up to January 2017. Pollutant-specific excess risk percentage (ER%) and confidence intervals (CI) were estimated using random effect models for particulate matter (PM) with diameter ≤ 10 (PM 10 ) and ≤2.5 μm (PM 2.5 ), sulfur dioxide (SO 2 ), ozone (O 3 ), nitrogen dioxide (NO 2 ), and carbon monoxide (CO). Results were further stratified by subgroups (children under five, emergency visits versus hospital admissions, income level of study location, and exposure period). Seventeen studies were included in the meta-analysis. The ER% per 10 μg/m 3 increase of pollutants was 1.5% (95% CI: 0.6%-2.4%) for PM 10 and 1.8% (95% CI: 0.5%-3.1%) for PM 2.5 . The corresponding values per 10 ppb increment of gaseous pollutants were 2.9% (95% CI: 0.4%-5.3%) for SO 2 , 1.7% (95% CI: 0.5%-2.8%) for O 3 , and 1.4% (95% CI: 0.4%-2.4%) for NO 2 . ER% per 1000 ppb increment of CO was 0.9% (95% CI: 0.0%-1.9%). Associations were not substantially different between subgroups. This meta-analysis shows a positive association between daily levels of ambient air pollution markers and hospitalization of children due to pneumonia. However, lack of studies from low-and middle-income countries limits the quantitative generalizability given that susceptibilities to the adverse effects of air pollution may be different in those populations. The meta-regression in our analysis further demonstrated a strong effect of country income level on heterogeneity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Annual report on the ambient air quality measurement in Austria 2004

    International Nuclear Information System (INIS)

    Spangl, W.; Nagl, C.; Schneider, J.

    2006-01-01

    A summary of the ambient air quality situation (measurements) conducted according to the Air Quality Act and the Ozone Act in Austria during 2004 is presented. The situation was assessed mainly in relation to Austrian limit and target values of sulfur dioxide, nitrogen oxides, particulate matter (this is measured using two different indicators: total suspended particulates (TSP) and PM10), carbon monoxide, benzene and lead. The PM10 limit value - 35 days with average concentrations above 50 μg/m 3 - was exceeded at 27 sites. The highest exceedances were measured at traffic related sites in large cities, in particular the city of Graz, in Vienna, at industrial sites (e.g. Linz). Main sources for primary particulate matter are road traffic, domestic heating (in particular wood burning), industrial emissions, construction activities and off-road sources. For nitrogen dioxide, the short term limit value was exceeded at few traffic related sites, mainly - but not only - in larger towns. The limit value for the protection of vegetation of 30 μg/m 3 NO x was exceeded at one site in Tyrol (Kramsach). Limit values for sulfur dioxide were exceeded at three sites. Neither the limit values for carbon monoxide, lead and benzene nor the alert thresholds for nitrogen dioxide or sulfur dioxide were exceeded in this year. Deposition of total particulates limit value was exceeded at a few sites, lead and cadmium in two industrial sites. Low ozone levels were measured at most monitoring sites, the information threshold of 180 μg/m 3 ozone as one hour mean was exceeded at 21 sites on all together 9 days and the alert threshold of 240 μg/m 3 as one hour mean was not exceeded. 45 figs., 57 tabs. (nevyjel)

  16. A proposed methodology for the assessment of arsenic, nickel, cadmium and lead levels in ambient air

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Germán, E-mail: santosg@unican.es; Fernández-Olmo, Ignacio

    2016-06-01

    Air quality assessment, required by the European Union (EU) Air Quality Directive, Directive 2008/50/EC, is part of the functions attributed to Environmental Management authorities. Based on the cost and time consumption associated with the experimental works required for the air quality assessment in relation to the EU-regulated metal and metalloids, other methods such as modelling or objective estimation arise as competitive alternatives when, in accordance with the Air Quality Directive, the levels of pollutants permit their use at a specific location. This work investigates the possibility of using statistical models based on Partial Least Squares Regression (PLSR) and Artificial Neural Networks (ANNs) to estimate the levels of arsenic (As), cadmium (Cd), nickel (Ni) and lead (Pb) in ambient air and their application for policy purposes. A methodology comprising the main steps that should be taken into consideration to prepare the input database, develop the model and evaluate their performance is proposed and applied to a case of study in Santander (Spain). It was observed that even though these approaches present some difficulties in estimating the individual sample concentrations, having an equivalent performance they can be considered valid for the estimation of the mean values – those to be compared with the limit/target values – fulfilling the uncertainty requirements in the context of the Air Quality Directive. Additionally, the influence of the consideration of input variables related to atmospheric stability on the performance of the studied statistical models has been determined. Although the consideration of these variables as additional inputs had no effect on As and Cd models, they did yield an improvement for Pb and Ni, especially with regard to ANN models. - Highlights: • EU encourages modelling techniques over measurements for air quality assessment. • A methodology for minor pollutants assessment by statistical modelling is presented.

  17. A proposed methodology for the assessment of arsenic, nickel, cadmium and lead levels in ambient air

    International Nuclear Information System (INIS)

    Santos, Germán; Fernández-Olmo, Ignacio

    2016-01-01

    Air quality assessment, required by the European Union (EU) Air Quality Directive, Directive 2008/50/EC, is part of the functions attributed to Environmental Management authorities. Based on the cost and time consumption associated with the experimental works required for the air quality assessment in relation to the EU-regulated metal and metalloids, other methods such as modelling or objective estimation arise as competitive alternatives when, in accordance with the Air Quality Directive, the levels of pollutants permit their use at a specific location. This work investigates the possibility of using statistical models based on Partial Least Squares Regression (PLSR) and Artificial Neural Networks (ANNs) to estimate the levels of arsenic (As), cadmium (Cd), nickel (Ni) and lead (Pb) in ambient air and their application for policy purposes. A methodology comprising the main steps that should be taken into consideration to prepare the input database, develop the model and evaluate their performance is proposed and applied to a case of study in Santander (Spain). It was observed that even though these approaches present some difficulties in estimating the individual sample concentrations, having an equivalent performance they can be considered valid for the estimation of the mean values – those to be compared with the limit/target values – fulfilling the uncertainty requirements in the context of the Air Quality Directive. Additionally, the influence of the consideration of input variables related to atmospheric stability on the performance of the studied statistical models has been determined. Although the consideration of these variables as additional inputs had no effect on As and Cd models, they did yield an improvement for Pb and Ni, especially with regard to ANN models. - Highlights: • EU encourages modelling techniques over measurements for air quality assessment. • A methodology for minor pollutants assessment by statistical modelling is presented.

  18. EVAPORATION FORM OF ICE CRYSTALS IN SUBSATURATED AIR AND THEIR EVAPORATION MECHANISM

    OpenAIRE

    ゴンダ, タケヒコ; セイ, タダノリ; Takehiko, GONDA; Tadanori, SEI

    1987-01-01

    The evaporation form and the evaporation mechanism of dendritic ice crystals grown in air of 1.0×(10)^5 Pa and at water saturation and polyhedral ice crystals grown in air of 4.0×10 Pa and at relatively low supersaturation are studied. In the case of dendritic ice crystals, the evaporation preferentially occurs in the convex parts of the crystal surfaces and in minute secondary branches. On the other hand, in the case of polyhedral ice crystals, the evaporation preferentially occurs in the pa...

  19. Assessment of Ambient Air Quality and Air Quality Index in Golden Corridor of Gujarat, India: A Case Study of Dahej Port

    Directory of Open Access Journals (Sweden)

    Hiren B. Soni

    2018-01-01

    Full Text Available Clean air is the basic requirement of all living organisms. In recent times, due to population growth, urban sprawl, industrial development, and vehicular boom, the quality of air is deteriorating and being polluted. Pollutants of major public health concerns include particulate matter, carbon monoxide, ozone, nitrogen dioxide, and sulfur dioxide, which pose serious threats to human health and hygiene. In the present study, prime particulate pollutants (PM10, PM2.5, and gaseous pollutants (SO2, and NO2 were estimated at seven stations in and around Dahej Port, Gujarat, India. The obtained values of PM10, PM2.5, SO2, and NO2 in all the studied stations (seven ranged from 67.39 to 98.75, 29.57 to 45.79, 17.76 to 22.29 and 28.29 to 32.42 mg/m3, respectively. The level of PM10 at all sampling locations, and that of PM2.5 at Station A3 (Lakhigam were found little higher than prescribed permissible limits of CPCB standards, while SO2 and NO2levels were within the acceptable range. The Air Quality Index (AQI score was found to be ranged from 76.50 to 97.75, which is at satisfactory level as per CPCB standards. Further, precautionary measures and management strategies to minimize the effect of particulate as well as gaseous pollutants have also been suggested for achieving its ambient levels in and around Dahej Port, Gujarat, India.International Journal of EnvironmentVolume-6, Issue-4, Sep-Nov 2017, page: 28-41

  20. 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

  1. 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.

  2. 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

  3. Air Quality and Indoor Environmental Exposures: Clinical ...

    Science.gov (United States)

    Indoor air quality (IAQ) is a term which refers to the air quality within and around buildings and homes as it relates to the health and comfort of the occupants. Many ambient (outdoor) air pollutants readily permeate indoor spaces. Because indoor air can be considerably more polluted than ambient air, the USEPA lists poor IAQ as a major environmental concern. In the sections that follow, health effects associated with commonly encountered ambient air pollutants and indoor contaminants will be broken down by agent class. In some cases, exposure may be acute, with one or more pets (and owners) experiencing signs within a relatively short period. However, most exposures are episodic or chronic, making it difficult to definitively link poor IAQ to respiratory or other adverse health outcomes. Age or underlying immunologic, cardiac, or respiratory disease may further complicate the clinical picture, as those patients may be more sensitive to (and affected by) lower concentrations than prove problematic for healthy housemates. Because pets, like their owners, spend most of their lives indoors, we will discuss how certain home conditions can worsen indoor air quality and will briefly discuss measures to improve IAQ for owners and their pets. In this overview presentation, health effects associated with commonly encountered ambient air pollutants and indoor contaminants will be broken down by agent class. Because pets, like their owners, spend most of their lives indoo

  4. Chemical constituents and sources of ambient particulate air pollution and biomarkers of endothelial function in a panel of healthy adults in Beijing, China

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shaowei; Yang, Di; Pan, Lu; Shan, Jiao; Li, Hongyu; Wei, Hongying [Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, Beijing (China); Wang, Bin [Institute of Reproductive & Child Health, Peking University School of Public Health, Beijing (China); Huang, Jing [Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, Beijing (China); Baccarelli, Andrea A. [Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA (United States); Shima, Masayuki [Department of Public Health, Hyogo College of Medicine, Hyogo (Japan); Deng, Furong, E-mail: lotus321321@126.com [Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, Beijing (China); Guo, Xinbiao, E-mail: guoxb@bjmu.edu.cn [Department of Occupational and Environmental Health Sciences, Peking University School of Public Health, Beijing (China)

    2016-08-01

    Background: Exposure to ambient air pollution has been associated with endothelial dysfunction as reflected by short-term alterations in circulating biomarkers, but the chemical constituents and pollution sources behind the association has been unclear. Methods: We investigated the associations between various ambient air pollutants including gases and 31 chemical constituents and seven sources of fine particles (PM{sub 2.5}) and biomarkers of endothelial function, including endothelin-1 (ET-1), E-selectin, soluble intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), based on 462 repeated measurements in a panel of 40 college students who were followed for three study periods before and after relocating from a suburban area to an urban area in Beijing, China in 2010–2011. Air pollution data were obtained from central air-monitoring stations. Linear mixed-effects models were used to estimate the changes in biomarkers associated with exposures. Results: Total PM{sub 2.5} mass showed few appreciable associations with examined biomarkers. However, several PM{sub 2.5} constituents and related sources showed significant associations with examined biomarkers. PM{sub 2.5} from dust/soil and several crustal and transition metals, including strontium, iron, titanium, cobalt and magnesium, were significantly associated with increases in ET-1 at 1-day average; manganese and potassium were significantly associated with increases in ICAM-1 at 2-day average; and PM{sub 2.5} from industry and metal cadmium were significantly associated with decreases in VCAM-1 at 1-day average. In addition, carbon monoxide was significantly associated with increasing ICAM-1 at 1-day and 2-day averages, whereas nitric oxide was significantly associated with decreasing ICAM-1 at 1-day and 3-day averages. Conclusions: Our results suggest that certain PM{sub 2.5} metal constituents were more closely associated with circulating biomarkers of endothelial function

  5. Effect of isobaric breathing gas shifts from air to heliox mixtures on resolution of air bubbles in lipid and aqueous tissues of recompressed rats

    DEFF Research Database (Denmark)

    Hyldegaard, Ole; Kerem, Dikla; Melamed, Y

    2011-01-01

    Deep tissue isobaric counterdiffusion that may cause unwanted bubble formation or transient bubble growth has been referred to in theoretical models and demonstrated by intravascular gas formation in animals, when changing inert breathing gas from nitrogen to helium after hyperbaric air breathing....... We visually followed the in vivo resolution of extravascular air bubbles injected at 101 kPa into nitrogen supersaturated rat tissues: adipose, spinal white matter, skeletal muscle or tail tendon. Bubbles were observed during isobaric breathing-gas shifts from air to normoxic (80:20) heliox mixture...... breathing. No such bubble growth was observed in spinal white matter, skeletal muscle or tendon. In spinal white matter, an immediate breathing gas shift after the hyperbaric air exposure from air to both (80:20) and (50:50) heliox, coincident with recompression to either 285 or 405 kPa, caused consistent...

  6. Experimental Precipitation of Carbonate Minerals: Effect of pH, Supersaturation and Substrate

    OpenAIRE

    Tetteh, Abednego

    2012-01-01

    Understanding the controlling factors and elucidating the requirements and conditions necessary for carbon dioxide (CO2) storage by mineral trapping (or carbonation) is of paramount interest for any technical application as a means for carbon dioxide capture and storage (CCS). The effect of pH, supersaturation and substrate has been studied using non-stirred batch reactors at initial constant temperature of 150 oC. These conditions are relevant for mineral trapping. A set of experiments was c...

  7. Addition of PM2.5 into the National Ambient Air Quality Standards of China and the Contribution to Air Pollution Control: The Case Study of Wuhan, China

    Science.gov (United States)

    You, Mingqing

    2014-01-01

    PM2.5 has gradually become a major environmental problem of China with its rapid economic development, urbanization, and increasing of motor vehicles. Findings and awareness of serious PM2.5 pollution make the PM2.5 a new criterion pollutant of the Chinese National Ambient Air Quality Standard (NAAQS) revised in 2012. The 2012 NAAQS sets the PM2.5 concentrate limitation with the 24-hour average value and the annual mean value. Wuhan is quite typical among central and southern China in climate, economy, development level, and energy consumption. The data are cited from the official website of Wuhan Environmental Protection Bureau and cover the period from 1 January to 30 June 2013. The data definitely confirm the existence of serious PM2.5 pollution in Wuhan and indicate that the addition of PM2.5 as a criterion pollutant significantly brings down the attainment rate of air quality. The example of Wuhan reveals that local governments should take measures to reduce the emission of PM2.5 if it affects the attainment rate and the performance evaluation value of air quality. The main contribution of 2012 NAAQS is that it brings down the attainment rate of the air quality and forces local governmental officials to take the measures accordingly. PMID:24982994

  8. Addition of PM 2.5 into the national ambient air quality standards of China and the contribution to air pollution control: the case study of Wuhan, China.

    Science.gov (United States)

    You, Mingqing

    2014-01-01

    PM2.5 has gradually become a major environmental problem of China with its rapid economic development, urbanization, and increasing of motor vehicles. Findings and awareness of serious PM2.5 pollution make the PM2.5 a new criterion pollutant of the Chinese National Ambient Air Quality Standard (NAAQS) revised in 2012. The 2012 NAAQS sets the PM2.5 concentrate limitation with the 24-hour average value and the annual mean value. Wuhan is quite typical among central and southern China in climate, economy, development level, and energy consumption. The data are cited from the official website of Wuhan Environmental Protection Bureau and cover the period from 1 January to 30 June 2013. The data definitely confirm the existence of serious PM2.5 pollution in Wuhan and indicate that the addition of PM2.5 as a criterion pollutant significantly brings down the attainment rate of air quality. The example of Wuhan reveals that local governments should take measures to reduce the emission of PM2.5 if it affects the attainment rate and the performance evaluation value of air quality. The main contribution of 2012 NAAQS is that it brings down the attainment rate of the air quality and forces local governmental officials to take the measures accordingly.

  9. Addition of PM2.5 into the National Ambient Air Quality Standards of China and the Contribution to Air Pollution Control: The Case Study of Wuhan, China

    Directory of Open Access Journals (Sweden)

    Mingqing You

    2014-01-01

    Full Text Available PM2.5 has gradually become a major environmental problem of China with its rapid economic development, urbanization, and increasing of motor vehicles. Findings and awareness of serious PM2.5 pollution make the PM2.5 a new criterion pollutant of the Chinese National Ambient Air Quality Standard (NAAQS revised in 2012. The 2012 NAAQS sets the PM2.5 concentrate limitation with the 24-hour average value and the annual mean value. Wuhan is quite typical among central and southern China in climate, economy, development level, and energy consumption. The data are cited from the official website of Wuhan Environmental Protection Bureau and cover the period from 1 January to 30 June 2013. The data definitely confirm the existence of serious PM2.5 pollution in Wuhan and indicate that the addition of PM2.5 as a criterion pollutant significantly brings down the attainment rate of air quality. The example of Wuhan reveals that local governments should take measures to reduce the emission of PM2.5 if it affects the attainment rate and the performance evaluation value of air quality. The main contribution of 2012 NAAQS is that it brings down the attainment rate of the air quality and forces local governmental officials to take the measures accordingly.

  10. Detectors for alpha particles and X-rays operating in ambient air in pulse counting mode or/and with gas amplification

    International Nuclear Information System (INIS)

    Charpak, G; Benaben, P; Breuil, P; Peskov, V

    2008-01-01

    Ionization chambers working in ambient air in current detection mode are attractive due to their simplicity and low cost and are widely used in several applications such as smoke detection, dosimetry, therapeutic beam monitoring and so on. The aim of this work was to investigate if gaseous detectors can operate in ambient air in pulse counting mode as well as with gas amplification which potentially offers the highest possible sensitivity in applications like alpha particle detection or high energy X-ray photon or electron detection. To investigate the feasibility of this method two types of open- end gaseous detectors were build and successfully tested. The first one was a single wire or multiwire cylindrical geometry detector operating in pulse mode at a gas gain of one (pulse ionization chamber). This detector was readout by a custom made wide -band charge sensitive amplifier able to deal with slow induced signals generated by slow motion of negative and positive ions. The multiwire detector was able to detect alpha particles with an efficiency close to 22%. The second type of an alpha detector was an innovative GEM-like detector with resistive electrodes operating in air in avalanche mode at high gas gains (up to 10 4 ). This detector can also operate in a cascaded mode or being combined with other detectors, for example with MICROMEGAS. This detector was readout by a conventional charge -sensitive amplifier and was able to detect alpha particles with 100% efficiency. This detector could also detect X-ray photons or fast electrons. A detailed comparison between these two detectors is given as well as a comparison with commercially available alpha detectors. The main advantages of gaseous detectors operating in air in a pulse detection mode are their simplicity, low cost and high sensitivity. One of the possible applications of these new detectors is alpha particle background monitors which, due to their low cost can find wide application not only in houses, but

  11. A conversion method of air-kerma from the primary, scatter and leakage radiations to ambient dose equivalent for calculating the mamography x-ray shielding barrier

    International Nuclear Information System (INIS)

    Kharrati, H.

    2005-01-01

    The primary, scatter, and leakage doses(in Gy), which constitute the data base for calculating shielding requirements for x-ray facilities, are often converted to the equivalent dose (in sievert) by using a constant of conversion of 1.145Sv/Gy. This constant is used for diagnostic radiology as well as for mammography spectra, and is derived by considering an exposure of 1 R corresponds to an air kerma of 8.73 m Gy, which renders by tradition an equivalent dose of 10 mSv. However, this conversion does not take into account the energy dependence of the conversion coefficients relating air kerma to the equivalent dose as described in ICRU report. Moreover, current radiation protection standards propose the use of the quantity ambient dose equivalent in order to qualify the efficiently of given radiation shielding. Therefore, in this study, a new approach has been introduced for derivation ambient dose equivalent from air kerma to calculate shielding requirements in mammography facilities. This new approach has been used to compute the conversion coefficients relating air kerma to ambient dose equivalent for mammography reference beam series of the Netherlands Metrology Institute Van Swinden Laboratorium (NMi), National Institute of Standards and Technology (NIST), and International Atomic Energy Agency (AIEA) laboratories. The calculation has been performed by the means of two methods which show a maximum deviation less than 10%2 for the primary, scatter, and leakage radiations. The results show that the conversion coefficients vary from 0.242 Sv/ Gy to 0.692 Sv/Gy with an average value of 0.436 Sv/Gy for the primary and the scatter radiations, and form 0.156 Sv/Gy to 1.329 Sv/Gy with an average value of 0.98 Sv/Gy for the leakage radiation. Simpkin et al. using an empirical approach propose a conversion value of 0.50 Sv/Gy for the mammography x-ray spectra. This value approximately coincides with the average conversion value of 0.436 Sv/Gy obtained in this work for

  12. Association between long-term exposure to ambient air pollution and diabetes mortality in the US.

    Science.gov (United States)

    Lim, Chris C; Hayes, Richard B; Ahn, Jiyoung; Shao, Yongzhao; Silverman, Debra T; Jones, Rena R; Garcia, Cynthia; Thurston, George D

    2018-05-17

    Recent mechanistic and epidemiological evidence implicates air pollution as a potential risk factor for diabetes; however, mortality risks have not been evaluated in a large US cohort assessing exposures to multiple pollutants with detailed consideration of personal risk factors for diabetes. We assessed the effects of long-term ambient air pollution exposures on diabetes mortality in the NIH-AARP Diet and Health Study, a cohort of approximately a half million subjects across the contiguous U.S. The cohort, with a follow-up period between 1995 and 2011, was linked to residential census tract estimates for annual mean concentration levels of PM 2.5 , NO 2 , and O 3 . Associations between the air pollutants and the risk of diabetes mortality (N = 3598) were evaluated using multivariate Cox proportional hazards models adjusted for both individual-level and census-level contextual covariates. Diabetes mortality was significantly associated with increasing levels of both PM 2.5 (HR = 1.19; 95% CI: 1.03-1.39 per 10 μg/m 3 ) and NO 2 (HR = 1.09; 95% CI: 1.01-1.18 per 10 ppb). The strength of the relationship was robust to alternate exposure assessments and model specifications. We also observed significant effect modification, with elevated mortality risks observed among those with higher BMI and lower levels of fruit consumption. We found that long-term exposure to PM 2.5 and NO 2 , but not O 3 , is related to increased risk of diabetes mortality in the U.S, with attenuation of adverse effects by lower BMI and higher fruit consumption, suggesting that air pollution is involved in the etiology and/or control of diabetes. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Long-term exposure to road traffic noise, ambient air pollution, and cardiovascular risk factors in the HUNT and lifelines cohorts.

    Science.gov (United States)

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

    2017-08-01

    Blood biochemistry may provide information on associations between road traffic noise, air pollution, and cardiovascular disease risk. We evaluated this in two large European cohorts (HUNT3, Lifelines). Road traffic noise exposure was modelled for 2009 using a simplified version of the Common Noise Assessment Methods in Europe (CNOSSOS-EU). Annual ambient air pollution (PM10, NO2) at residence was estimated for 2007 using a Land Use Regression model. The statistical platform DataSHIELD was used to pool data from 144 082 participants aged ≥20 years to enable individual-level analysis. Generalized linear models were fitted to assess cross-sectional associations between pollutants and high-sensitivity C-reactive protein (hsCRP), blood lipids and for (Lifelines only) fasting blood glucose, for samples taken during recruitment in 2006-2013. Pooling both cohorts, an inter-quartile range (IQR) higher day-time noise (5.1 dB(A)) was associated with 1.1% [95% confidence interval (95% CI: 0.02-2.2%)] higher hsCRP, 0.7% (95% CI: 0.3-1.1%) higher triglycerides, and 0.5% (95% CI: 0.3-0.7%) higher high-density lipoprotein (HDL); only the association with HDL was robust to adjustment for air pollution. An IQR higher PM10 (2.0 µg/m3) or NO2 (7.4 µg/m3) was associated with higher triglycerides (1.9%, 95% CI: 1.5-2.4% and 2.2%, 95% CI: 1.6-2.7%), independent of adjustment for noise. Additionally for NO2, a significant association with hsCRP (1.9%, 95% CI: 0.5-3.3%) was seen. In Lifelines, an IQR higher noise (4.2 dB(A)) and PM10 (2.4 µg/m3) was associated with 0.2% (95% CI: 0.1-0.3%) and 0.6% (95% CI: 0.4-0.7%) higher fasting glucose respectively, with both remaining robust to adjustment for air/noise pollution. Long-term exposures to road traffic noise and ambient air pollution were associated with blood biochemistry, providing a possible link between road traffic noise/air pollution and cardio-metabolic disease risk. Published on behalf of the European Society of

  14. Do US Ambient Air Lead Levels Have a Significant Impact on Childhood Blood Lead Levels: Results of a National Study

    Directory of Open Access Journals (Sweden)

    LuAnn L. Brink

    2013-01-01

    Full Text Available Introduction. Although lead paint and leaded gasoline have not been used in the US for thirty years, thousands of US children continue to have blood lead levels (BLLs of concern. Methods. We investigated the potential association of modeled air lead levels and BLLs ≥ 10 μg/dL using a large CDC database with BLLs on children aged 0–3 years. Percent of children with BLLs ≥ 10 μg/dL (2000–2007 by county and proportion of pre-50 housing and SES variables were merged with the US EPA's National Air Toxics Assessment (NATA modeled air lead data. Results. The proportion with BLL ≥ 10 μg/dL was 1.24% in the highest air lead counties, and the proportion with BLL ≥ 10 μg/dL was 0.36% in the lowest air lead counties, resulting in a crude prevalence ratio of 3.4. Further analysis using multivariate negative binomial regression revealed that NATA lead was a significant predictor of % BLL ≥ 10 μg/dL after controlling for percent pre-l950 housing, percent rural, and percent black. A geospatial regression revealed that air lead, percent older housing, and poverty were all significant predictors of % BLL ≥ 10 μg/dL. Conclusions. More emphasis should be given to potential sources of ambient air lead near residential areas.

  15. Developing a source-receptor methodology for the characterization of VOC sources in ambient air

    International Nuclear Information System (INIS)

    Borbon, A.; Badol, C.; Locoge, N.

    2005-01-01

    Since 2001, in France, a continuous monitoring of about thirty ozone precursor non-methane hydrocarbons (NMHC) is led in some urban areas. The automated system for NMHC monitoring consists of sub-ambient preconcentration on a cooled multi-sorbent trap followed by thermal desorption and bidimensional Gas Chromatography/Flame Ionisation Detection analysis.The great number of data collected and their exploitation should provide a qualitative and quantitative assessment of hydrocarbon sources. This should help in the definition of relevant strategies of emission regulation as stated by the European Directive relative to ozone in ambient air (2002/3/EC). The purpose of this work is to present the bases and the contributions of an original methodology known as source-receptor in the characterization of NMHC sources. It is a statistical and diagnostic approach, adaptable and transposable in all urban sites, which integrates the spatial and temporal dynamics of the emissions. The methods for source identification combine descriptive or more complex complementary approaches: 1) univariate approach through the analysis of NMHC time series and concentration roses, 2) bivariate approach through a Graphical Ratio Analysis and a characterization of scatterplot distributions of hydrocarbon pairs, 3) multivariate approach with Principal Component Analyses on various time basis. A linear regression model is finally developed to estimate the spatial and temporal source contributions. Apart from vehicle exhaust emissions, sources of interest are: combustion and fossil fuel-related activities, petrol and/or solvent evaporation, the double anthropogenic and biogenic origin of isoprene and other industrial activities depending on local parameters. (author)

  16. Length-dependent thermoelectric characteristics of silicon nanowires on plastics in a relatively low temperature regime in ambient air

    International Nuclear Information System (INIS)

    Choi, Jinyong; Cho, Kyoungah; Kim, Sangsig

    2013-01-01

    We report on the thermoelectric characteristics of p-type silicon nanowires (NWs) on plastics in the relatively low temperature regime below 47 ° C, and for temperature differences of less than 10 K in ambient air. Thermal profile images are utilized to directly determine the temperature difference in the NWs generated by Joule heating in air. The Seebeck coefficient of the NWs increases from 294 to 414 μV K −1 as the NW length varies from 40 to 280 μm. For a temperature difference of 7 K, the maximal Seebeck voltage can be estimated to be 2.7 mV for NWs with a length of 280 μm. In contrast, the output power is maximized for NWs length of 240 μm. The maximized output power obtained experimentally in this study is 2.1 pW at a temperature difference of 6 K. The thermoelectric characteristics are analyzed and discussed. (paper)

  17. Investigating air quality and air-related complaints in the City of Tshwane, South Africa

    CSIR Research Space (South Africa)

    Wright, C

    2011-12-01

    Full Text Available To determine the impact of implemented air quality interventions beyond ambient air pollution reductions, indicators need to be identified and appropriate health data need to be routinely collected to track air-related health. Presently, the only...

  18. 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

  19. 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.

  20. Ambient particulate air pollution induces oxidative stress and alterations of mitochondria and gene expression in brown and white adipose tissues

    Directory of Open Access Journals (Sweden)

    Harkema Jack R

    2011-07-01

    Full Text Available Abstract Background Prior studies have demonstrated a link between air pollution and metabolic diseases such as type II diabetes. Changes in adipose tissue and its mitochondrial content/function are closely associated with the development of insulin resistance and attendant metabolic complications. We investigated changes in adipose tissue structure and function in brown and white adipose depots in response to chronic ambient air pollutant exposure in a rodent model. Methods Male ApoE knockout (ApoE-/- mice inhaled concentrated fine ambient PM (PM 2.5 or filtered air (FA for 6 hours/day, 5 days/week, for 2 months. We examined superoxide production by dihydroethidium staining; inflammatory responses by immunohistochemistry; and changes in white and brown adipocyte-specific gene profiles by real-time PCR and mitochondria by transmission electron microscopy in response to PM2.5 exposure in different adipose depots of ApoE-/- mice to understand responses to chronic inhalational stimuli. Results Exposure to PM2.5 induced an increase in the production of reactive oxygen species (ROS in brown adipose depots. Additionally, exposure to PM2.5 decreased expression of uncoupling protein 1 in brown adipose tissue as measured by immunohistochemistry and Western blot. Mitochondrial number was significantly reduced in white (WAT and brown adipose tissues (BAT, while mitochondrial size was also reduced in BAT. In BAT, PM2.5 exposure down-regulated brown adipocyte-specific genes, while white adipocyte-specific genes were differentially up-regulated. Conclusions PM2.5 exposure triggers oxidative stress in BAT, and results in key alterations in mitochondrial gene expression and mitochondrial alterations that are pronounced in BAT. We postulate that exposure to PM2.5 may induce imbalance between white and brown adipose tissue functionality and thereby predispose to metabolic dysfunction.

  1. 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)

  2. Voltage and Thermally Driven Roll-to-Roll Organic Printed Transistor Made in Ambient Air Conditions

    DEFF Research Database (Denmark)

    Pastorelli, Francesco

    of the organic semiconductor poly3hexylthiophene and the dielectric material polyvinylphenol before the gate was applied by screen printing. All the processing was realized in ambient air on a PET flexible substrate. We explore the footprint and the practically accessible geometry of such devices with a special......Resume: Organic thin film transistors offer great potential for use in flexible electronics. Much of this potential lies in the solution processability of the organic polymers enabling both roll coating and printing on flexible substrates and thus greatly reducing the material and fabrication costs....... We present flexible organic power transistors prepared by fast (20 m min−1) roll-to-roll flexographic printing of the drain and source electrode structures, with an interspace below 50 um, directly on polyester foil[1]. The devices have top gate architecture and were completed by slotdie coating...

  3. Ocean Ambient Noise Measurement and Theory

    CERN Document Server

    Carey, William M

    2011-01-01

    This book develops the theory of ocean ambient noise mechanisms and measurements, and also describes general noise characteristics and computational methods.  It concisely summarizes the vast ambient noise literature using theory combined with key representative results.  The air-sea boundary interaction zone is described in terms of non-dimensional variables requisite for future experiments.  Noise field coherency, rare directional measurements, and unique basin scale computations and methods are presented.  The use of satellite measurements in these basin scale models is demonstrated.  Finally, this book provides a series of appendices giving in-depth mathematical treatments.  With its complete and careful discussions of both theory and experimental results, this book will be of the greatest interest to graduate students and active researchers working in fields related to ambient noise in the ocean.

  4. Identification of the Products of Oxidation of Quercetin by Air Oxygenat Ambient Temperature

    Directory of Open Access Journals (Sweden)

    Viktor A Utsal

    2007-03-01

    Full Text Available Oxidation of quercetin by air oxygen takes place in water and aqueous ethanol solutions under mild conditions, namely in moderately-basic media (pH ∼ 8-10 at ambient temperature and in the absence of any radical initiators, without enzymatic catalysis or irradiation of the reaction media by light. The principal reaction products are typical of other oxidative degradation processes of quercetin, namely 3,4-dihydroxy-benzoic (proto-catechuic and 2,4,6-trihydroxybenzoic (phloroglucinic acids, as well as the decarboxylation product of the latter – 1,3,5-trihydroxybenzene (phloroglucinol. In accordance with the literature data, this process involves the cleavage of the γ-pyrone fragment (ring C of the quercetin molecule by oxygen, with primary formation of 4,6-dihydroxy-2-(3,4-dihydroxybenzoyloxybenzoic acid (depside. However under such mild conditions the accepted mechanism of this reaction (oxidative decarbonylation with formation of carbon monoxide, CO should be reconsidered as preferably an oxidative decarboxylation with formation of carbon dioxide, CO2. Direct head-space analysis of the gaseous components formed during quercetin oxidation in aqueous solution at ambient temperature indicates that the ratio of carbon dioxide/carbon monoxide in the gas phase after acidification of the reaction media is ca. 96:4 %. Oxidation under these mild conditions is typical for other flavonols having OH groups at C3 (e.g., kaempferol, but it is completely suppressed if this hydroxyl group is substituted by a glycoside fragment (as in rutin, or a methyl substituent. An alternative oxidation mechanism involving the direct cleavage of the C2-C3 bond in the diketo-tautomer of quercetin is proposed.

  5. Enhanced oral bioavailability of valsartan using a polymer-based supersaturable self-microemulsifying drug delivery system

    Directory of Open Access Journals (Sweden)

    Yeom DW

    2017-05-01

    Full Text Available Dong Woo Yeom,1,* Bo Ram Chae,2,* Ho Yong Son,1 Jin Han Kim,1 Jun Soo Chae,1 Seh Hyon Song,2 Dongho Oh,2 Young Wook Choi1 1College of Pharmacy, Chung-Ang University, Seoul, 2Daewon Pharm. Co., Ltd, Seoul, Republic of Korea *These authors contributed equally to this work Abstract: A novel, supersaturable self-microemulsifying drug delivery system (S-SMEDDS was successfully formulated to enhance the dissolution and oral absorption of valsartan (VST, a poorly water-soluble drug, while reducing the total quantity for administration. Poloxamer 407 is a selectable, supersaturating agent for VST-containing SMEDDS composed of 10% Capmul® MCM, 45% Tween® 20, and 45% Transcutol® P. The amounts of SMEDDS and Poloxamer 407 were chosen as formulation variables for a 3-level factorial design. Further optimization was established by weighting different levels of importance on response variables for dissolution and total quantity, resulting in an optimal S-SMEDDS in large quantity (S-SMEDDS_LQ; 352 mg in total and S-SMEDDS in reduced quantity (S-SMEDDS_RQ; 144.6 mg in total. Good agreement was observed between predicted and experimental values for response variables. Consequently, compared with VST powder or suspension and SMEDDS, both S-SMEDDS_LQ and S-SMEDDS_RQ showed excellent in vitro dissolution and in vivo oral bioavailability in rats. The magnitude of dissolution and absorption-enhancing capacities using quantity-based comparisons was in the order S-SMEDDS_RQ > S-SMEDDS_LQ > SMEDDS > VST powder or suspension. Thus, we concluded that, in terms of developing an effective SMEDDS preparation with minimal total quantity, S-SMEDDS_RQ is a promising candidate. Keywords: valsartan, SMEDDS, supersaturation, factorial design, optimization, bio­availability 

  6. Vacancies supersaturation induced by fast neutron irradiation in FeNi alloys

    International Nuclear Information System (INIS)

    Lucki, G.; Chambron, W.; Watanabe, S.; Verdone, J.

    1975-01-01

    The void formation in metals and alloys during irradiation with high-energy particles is a problem of interest in physics and of paramount importance in nuclear technology. Voids are formed as a consequence of vacancy supersaturation and result in swelling as well as in changes of mechanical, electrical and magnetic properties of materials used in power reactors. Isothermal annealings were performed between 400 and 500 0 C with and without fast-neutron (1 MeV) irradiation. Pure Fe--Ni (50--50 at. percent) was irradiated in the Melousine reactor in Grenoble, and Fe--Ni(Mo) (50--50 at. percent + 50 ppM), in the IEAR-1 reactor at the Instituto de Energia Atomica in Sao Paulo. The toroidal-shaped specimens were fabricated from Johnson Mathey zone-refined ingots, and were initially annealed at 800 0 C during 1 h in hydrogen atmosphere and then slowly cooled (4 h) inside the furnace. Magnetic After Effect measurements (MAE) permitted the evaluation of activation energies during fast-neutron irradiation (1.54 eV) and without irradiation (3.14 eV) for pure Fe--Ni and respectively (1.36 eV) and (2.32 eV) for Fe--Ni(Mo). Since the time constants of the relaxation process are inversely proportional to the vacancy concentration, a quantitative evaluation of vacancy supersaturation was made; it decreases from the value 700 at 410 0 C to the value 40 at 490 0 C for pure Fe--Ni and from 765 to 121 for Fe--Ni(Mo) in the same temperature range. 3 figures, 5 tables

  7. Meteorology drives ambient air quality in a valley: a case of Sukinda chromite mine, one among the ten most polluted areas in the world.

    Science.gov (United States)

    Mishra, Soumya Ranjan; Pradhan, Rudra Pratap; Prusty, B Anjan Kumar; Sahu, Sanjat Kumar

    2016-07-01

    The ambient air quality (AAQ) assessment was undertaken in Sukinda Valley, the chromite hub of India. The possible correlations of meteorological variables with different air quality parameters (PM10, PM2.5, SO2, NO2 and CO) were examined. Being the fourth most polluted area in the globe, Sukinda Valley has always been under attention of researchers, for hexavalent chromium contamination of water. The monitoring was carried out from December 2013 through May 2014 at six strategic locations in the residential and commercial areas around the mining cluster of Sukinda Valley considering the guidelines of Central Pollution Control Board (CPCB). In addition, meteorological parameters viz., temperature, relative humidity, wind speed, wind direction and rainfall, were also monitored. The air quality data were subjected to a general linear model (GLM) coupled with one-way analysis of variance (ANOVA) test for testing the significant difference in the concentration of various parameters among seasons and stations. Further, a two-tailed Pearson's correlation test helped in understanding the influence of meteorological parameters on dispersion of pollutants in the area. All the monitored air quality parameters varied significantly among the monitoring stations suggesting (i) the distance of sampling location to the mine site and other allied activities, (ii) landscape features and topography and (iii) meteorological parameters to be the forcing functions. The area was highly polluted with particulate matters, and in most of the cases, the PM level exceeded the National Ambient Air Quality Standards (NAAQS). The meteorological parameters seemed to play a major role in the dispersion of pollutants around the mine clusters. The role of wind direction, wind speed and temperature was apparent in dispersion of the particulate matters from their source of generation to the surrounding residential and commercial areas of the mine.

  8. Kinetics and mechanism of the oxidation of cerium in air at ambient temperature

    International Nuclear Information System (INIS)

    Wheeler, D.W.

    2016-01-01

    Highlights: • XRD and transverse sections suggest Ce_2O_3 forms on Ce before being overlaid by CeO_2. • XRD and oxide thickness measurements both indicate linear oxidation. • Extensive cracking on oxide surface which sustains continuing oxidation. • Electron microscopy has shown features indicative of nodular oxidation. • Oxide growth rate determined to be 0.1 μm day"−"1 under the conditions in this study. - Abstract: This paper describes a study of the oxidation of cerium in air at ambient temperature. Specimens were exposed for up to 60 days, during which they were analysed by X-ray diffraction (XRD) at regular intervals. Both XRD and oxide thickness measurements indicate linear oxidation over the duration of this study. Under the conditions employed in this study, the rate of oxide growth has been determined to be 0.1 μm day"−"1. The oxidation process appears to be assisted by extensive cracking in the oxide layer which acts as a non-protective film for the underlying metal.

  9. Territorios vulnerables e injusticia ambiental en Argentina

    OpenAIRE

    Miguel Lacabana; Clara Bressano

    2016-01-01

    Justicia ambiental es un concepto fructífero en tanto modificó la perspectiva clásica de análisis sobre el problema de la degradación ambiental al establecer como principal interrogante no tanto las "causas" que producen tal degradación sino que interroga el proceso político, económico y social que consolida la desigual distribución social de las cargas nocivas de la contaminación. El conurbano sur de Buenos Aires y dentro de este el Municipio de Quilmes condensan distintas situaciones se vul...

  10. 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.

  11. 78 FR 10589 - Revision of Air Quality Implementation Plan; California; Sacramento Metropolitan Air Quality...

    Science.gov (United States)

    2013-02-14

    ... Quality Implementation Plan; California; Sacramento Metropolitan Air Quality Management District... Sacramento Metropolitan Air Quality Management District (SMAQMD or District) portion of the California State... sources within the areas covered by the plan as necessary to assure that the National Ambient Air Quality...

  12. Propagation of atmospheric pressure helium plasma jet into ambient air at laminar gas flow

    Science.gov (United States)

    Pinchuk, M.; Stepanova, O.; Kurakina, N.; Spodobin, V.

    2017-05-01

    The formation of an atmospheric pressure plasma jet (APPJ) in a gas flow passing through the discharge gap depends on both gas-dynamic properties and electrophysical parameters of the plasma jet generator. The paper presents the results of experimental and numerical study of the propagation of the APPJ in a laminar flow of helium. A dielectric-barrier discharge (DBD) generated inside a quartz tube equipped with a coaxial electrode system, which provided gas passing through it, served as a plasma source. The transition of the laminar regime of gas flow into turbulent one was controlled by the photography of a formed plasma jet. The corresponding gas outlet velocity and Reynolds numbers were revealed experimentally and were used to simulate gas dynamics with OpenFOAM software. The data of the numerical simulation suggest that the length of plasma jet at the unvarying electrophysical parameters of DBD strongly depends on the mole fraction of ambient air in a helium flow, which is established along the direction of gas flow.

  13. Benefits of mitigated ambient air quality due to transportation control on childhood asthma hospitalization during the 2002 summer Asian games in Busan, Korea.

    Science.gov (United States)

    Lee, Jong-Tae; Son, Ji-Young; Cho, Yong-Sung

    2007-08-01

    The objective of this study is to see whether there were any health benefits of mitigated air pollution concentration due to reduced traffic flow during a citywide intervention for the 2002 Summer Asian Games. Relative risks of hospitalization for childhood asthma during the post-Asian Game period compared with the baseline period were estimated using a time-series analysis of the generalized additive Poisson model. Fourteen consecutive days of traffic volume control in Busan during the Games reduced all regulated air pollutant levels by 1-25%. The estimated relative risk of hospitalization during the post-Games period over the baseline period was 0.73 (95% confidence interval [CI] = 0.49, 1.11). We observed that this reduced air pollution was unique in 2002 when the traffic volume reduction program was applied during the Games period. This empirical data provides epidemiologic evidence of the health benefits resulting from environmental interventions to reduce ambient air pollution.

  14. A Comparison of the Health Effects of Ambient Particulate Matter Air Pollution from Five Emission Sources

    Directory of Open Access Journals (Sweden)

    Neil J. Hime

    2018-06-01

    Full Text Available This article briefly reviews evidence of health effects associated with exposure to particulate matter (PM air pollution from five common outdoor emission sources: traffic, coal-fired power stations, diesel exhaust, domestic wood combustion heaters, and crustal dust. The principal purpose of this review is to compare the evidence of health effects associated with these different sources with a view to answering the question: Is exposure to PM from some emission sources associated with worse health outcomes than exposure to PM from other sources? Answering this question will help inform development of air pollution regulations and environmental policy that maximises health benefits. Understanding the health effects of exposure to components of PM and source-specific PM are active fields of investigation. However, the different methods that have been used in epidemiological studies, along with the differences in populations, emission sources, and ambient air pollution mixtures between studies, make the comparison of results between studies problematic. While there is some evidence that PM from traffic and coal-fired power station emissions may elicit greater health effects compared to PM from other sources, overall the evidence to date does not indicate a clear ‘hierarchy’ of harmfulness for PM from different emission sources. Further investigations of the health effects of source-specific PM with more advanced approaches to exposure modeling, measurement, and statistics, are required before changing the current public health protection approach of minimising exposure to total PM mass.

  15. EXPERIENCIA INTEGRADORA PARA EDUCACIÓN AMBIENTAL

    Directory of Open Access Journals (Sweden)

    Jorge F. Coronel

    2015-01-01

    Full Text Available En este trabajo se relacionó la práctica experimental de laboratorio co n el análisis de problemas ambientales. El objetivo de este trabajo es analizar una propuesta que vinculó el trabajo experimental con la situación del ambiente local para promover el cuidado de la naturaleza y su uso con sostenibilidad . Esta estrategia brindó un enfoque integrador aportando a los alumnos de profesorado una alternativa de aprendizaje con exper iencias sencillas para el estudio cualitativo de l ambiente local y motivar a l análisis de problemas asociad o s. Las experiencias permitieron caracterizar las muestras de suelo, agua y aire del lugar de residencia de los alumnos. La información experimental obtenida potenció la discusión de la situación ambiental actual. E l enfoque de enseñanza basado en problemas socio - científicos posibilit ó la visión interdisciplinar del tema , redimensionando valores y acciones para el cuidado ambiental y el desarrollo sustentable.

  16. 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.

  17. The use of cryogenic air sampling in the spectroscopy of airborne gamma-ray emitters

    International Nuclear Information System (INIS)

    Perdue, P.T.; Haywood, F.F.

    1982-01-01

    Wet air can be sampled over a period of four to twelve hours and, with a transfer into a special Marinelli-dewar, can be counted in a spectrometer for several hours. The present minimum detectable amount is about 4 Bq/m 3 for 222 Rn and 220 Rn with liquid air in the counting dewar equivalent to one cubic meter of ambient air. The amount of ambient air sampled can be determined from ambient pressure, temperature, and absolute humidity determinations. Standard meteorological tables are used to determine the weight of ambient air in grams/litre. This quantity divided into the net weight of liquid yields the total litres of ambient air sampled. Tests run so far with 85 Kr indicate that the noble fission gases behave in a manner similar to radon, allowing measurements of stack gases, reactor plumes, etc. The minimum detectable quantity of 85 Kr appears to be about 300 Bq/m 3 , depending upon the 222 Rn and 220 Rn content of the air

  18. Ambient air quality in Lower Town Quebec

    International Nuclear Information System (INIS)

    Sebez, S.

    2007-01-01

    A municipal waste incinerator near Lower Town Quebec has been identified as a major source of air pollution, notably emissions of dioxins, furans, nitrogen oxides (NOx), volatile organic matter (VOC) and polycyclic aromatic hydrocarbons (PAH). Combustion fumes contain gases such as carbon monoxide (CO), carbon dioxide (CO 2 ) and sulphur dioxide (SO 2 ), as well as dusts, fly ash and particulate matter that is easily airborne. The risks associated with poor air quality have been evaluated along with the effects of pollutants on young children, pregnant women, senior citizens and those with cardiac problems. Some studies have reported that exposure to NOx may cause lung cancer and certain VOCs can irritate the respiratory tract system. Air quality tests have also revealed the presence of mercury. In combination, all these pollutants create smog. The concrete actions that have been taken to address smog issues were discussed. The distance between the incinerator and different residential areas within Lower Town Quebec have been measured along with air quality. Health risks were found to be higher in areas closer to the incinerator. Major modifications have been recommended in order to reduce pollution emissions from the incinerator. These include modernizing the equipment, installing proper scrubbers, and to ultimately the close the incinerator if it continues to underperform. refs., tabs., figs

  19. Revealing source signatures in ambient BTEX concentrations

    International Nuclear Information System (INIS)

    Zalel, Amir; Yuval; Broday, David M.

    2008-01-01

    Management of ambient concentrations of Volatile Organic Compounds (VOCs) is essential for maintaining low ozone levels in urban areas where its formation is under a VOC-limited regime. The significant decrease in traffic-induced VOC emissions in many developed countries resulted in relatively comparable shares of traffic and non-traffic VOC emissions in urban airsheds. A key step for urban air quality management is allocating ambient VOC concentrations to their pertinent sources. This study presents an approach that can aid in identifying sources that contribute to observed BTEX concentrations in areas characterized by low BTEX concentrations, where traditional source apportionment techniques are not useful. Analysis of seasonal and diurnal variations of ambient BTEX concentrations from two monitoring stations located in distinct areas reveal the possibility to identify source categories. Specifically, the varying oxidation rates of airborne BTEX compounds are used to allocate contributions of traffic emissions and evaporative sources to observed BTEX concentrations. - BTEX sources are identified from temporal variations of ambient concentration

  20. 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