Science.gov

Sample records for air change effectiveness

  1. Effect of climate change on air quality

    NASA Astrophysics Data System (ADS)

    Jacob, Daniel J.; Winner, Darrell A.

    Air quality is strongly dependent on weather and is therefore sensitive to climate change. Recent studies have provided estimates of this climate effect through correlations of air quality with meteorological variables, perturbation analyses in chemical transport models (CTMs), and CTM simulations driven by general circulation model (GCM) simulations of 21st-century climate change. We review these different approaches and their results. The future climate is expected to be more stagnant, due to a weaker global circulation and a decreasing frequency of mid-latitude cyclones. The observed correlation between surface ozone and temperature in polluted regions points to a detrimental effect of warming. Coupled GCM-CTM studies find that climate change alone will increase summertime surface ozone in polluted regions by 1-10 ppb over the coming decades, with the largest effects in urban areas and during pollution episodes. This climate penalty means that stronger emission controls will be needed to meet a given air quality standard. Higher water vapor in the future climate is expected to decrease the ozone background, so that pollution and background ozone have opposite sensitivities to climate change. The effect of climate change on particulate matter (PM) is more complicated and uncertain than for ozone. Precipitation frequency and mixing depth are important driving factors but projections for these variables are often unreliable. GCM-CTM studies find that climate change will affect PM concentrations in polluted environments by ±0.1-1 μg m -3 over the coming decades. Wildfires fueled by climate change could become an increasingly important PM source. Major issues that should be addressed in future research include the ability of GCMs to simulate regional air pollution meteorology and its sensitivity to climate change, the response of natural emissions to climate change, and the atmospheric chemistry of isoprene. Research needs to be undertaken on the effect of climate

  2. Effect of Dynamic Sector Boundary Changes on Air Traffic Controllers

    NASA Technical Reports Server (NTRS)

    Jung, Jaewoo; Lee, Paul; Kessell, Angela; Homola, Jeff; Zelinski, Shannon

    2010-01-01

    The effect of dynamic sector boundary changes on air traffic controller workload was investigated with data from a human-in-the-loop simulation. Multiple boundary changes were made during simulated operations, and controller rating of workload was recorded. Analysis of these data showed an increase of 16.9% in controller workload due to boundary changes. This increased workload was correlated with the number of aircraft handoffs and change in sector volume. There was also a 12.7% increase in average workload due to the changed sector design after boundary changes. This increase was correlated to traffic flow crossing points getting closer to sector boundaries and an increase in the number of flights with short dwell time in a sector. This study has identified some of the factors that affect controller workload when sector boundaries are changed, but more research is needed to better understand their relationships.

  3. Climate Change and Air Pollution: Effects on Respiratory Allergy.

    PubMed

    D'Amato, Gennaro; Pawankar, Ruby; Vitale, Carolina; Lanza, Maurizia; Molino, Antonio; Stanziola, Anna; Sanduzzi, Alessandro; Vatrella, Alessandro; D'Amato, Maria

    2016-09-01

    A body of evidence suggests that major changes involving the atmosphere and the climate, including global warming induced by anthropogenic factors, have impact on the biosphere and human environment. Studies on the effects of climate change on respiratory allergy are still lacking and current knowledge is provided by epidemiological and experimental studies on the relationship between allergic respiratory diseases, asthma and environmental factors, such as meteorological variables, airborne allergens, and air pollution. Urbanization with its high levels of vehicle emissions, and a westernized lifestyle are linked to the rising frequency of respiratory allergic diseases and bronchial asthma observed over recent decades in most industrialized countries. However, it is not easy to evaluate the impact of climate changes and air pollution on the prevalence of asthma in the general population and on the timing of asthma exacerbations, although the global rise in asthma prevalence and severity could also be an effect of air pollution and climate change. Since airborne allergens and air pollutants are frequently increased contemporaneously in the atmosphere, an enhanced IgE-mediated response to aeroallergens and enhanced airway inflammation could account for the increasing frequency of respiratory allergy and asthma in atopic subjects in the last 5 decades. Pollen allergy is frequently used to study the relationship between air pollution and respiratory allergic diseases, such as rhinitis and bronchial asthma. Epidemiologic studies have demonstrated that urbanization, high levels of vehicle emissions, and westernized lifestyle are correlated with an increased frequency of respiratory allergy prevalently in people who live in urban areas in comparison with people living in rural areas. Climatic factors (temperature, wind speed, humidity, thunderstorms, etc.) can affect both components (biological and chemical) of this interaction.

  4. Climate Change and Air Pollution: Effects on Respiratory Allergy.

    PubMed

    D'Amato, Gennaro; Pawankar, Ruby; Vitale, Carolina; Lanza, Maurizia; Molino, Antonio; Stanziola, Anna; Sanduzzi, Alessandro; Vatrella, Alessandro; D'Amato, Maria

    2016-09-01

    A body of evidence suggests that major changes involving the atmosphere and the climate, including global warming induced by anthropogenic factors, have impact on the biosphere and human environment. Studies on the effects of climate change on respiratory allergy are still lacking and current knowledge is provided by epidemiological and experimental studies on the relationship between allergic respiratory diseases, asthma and environmental factors, such as meteorological variables, airborne allergens, and air pollution. Urbanization with its high levels of vehicle emissions, and a westernized lifestyle are linked to the rising frequency of respiratory allergic diseases and bronchial asthma observed over recent decades in most industrialized countries. However, it is not easy to evaluate the impact of climate changes and air pollution on the prevalence of asthma in the general population and on the timing of asthma exacerbations, although the global rise in asthma prevalence and severity could also be an effect of air pollution and climate change. Since airborne allergens and air pollutants are frequently increased contemporaneously in the atmosphere, an enhanced IgE-mediated response to aeroallergens and enhanced airway inflammation could account for the increasing frequency of respiratory allergy and asthma in atopic subjects in the last 5 decades. Pollen allergy is frequently used to study the relationship between air pollution and respiratory allergic diseases, such as rhinitis and bronchial asthma. Epidemiologic studies have demonstrated that urbanization, high levels of vehicle emissions, and westernized lifestyle are correlated with an increased frequency of respiratory allergy prevalently in people who live in urban areas in comparison with people living in rural areas. Climatic factors (temperature, wind speed, humidity, thunderstorms, etc.) can affect both components (biological and chemical) of this interaction. PMID:27334776

  5. Climate Change and Air Pollution: Effects on Respiratory Allergy

    PubMed Central

    Pawankar, Ruby; Vitale, Carolina; Lanza, Maurizia; Molino, Antonio; Stanziola, Anna; Sanduzzi, Alessandro; Vatrella, Alessandro; D'Amato, Maria

    2016-01-01

    A body of evidence suggests that major changes involving the atmosphere and the climate, including global warming induced by anthropogenic factors, have impact on the biosphere and human environment. Studies on the effects of climate change on respiratory allergy are still lacking and current knowledge is provided by epidemiological and experimental studies on the relationship between allergic respiratory diseases, asthma and environmental factors, such as meteorological variables, airborne allergens, and air pollution. Urbanization with its high levels of vehicle emissions, and a westernized lifestyle are linked to the rising frequency of respiratory allergic diseases and bronchial asthma observed over recent decades in most industrialized countries. However, it is not easy to evaluate the impact of climate changes and air pollution on the prevalence of asthma in the general population and on the timing of asthma exacerbations, although the global rise in asthma prevalence and severity could also be an effect of air pollution and climate change. Since airborne allergens and air pollutants are frequently increased contemporaneously in the atmosphere, an enhanced IgE-mediated response to aeroallergens and enhanced airway inflammation could account for the increasing frequency of respiratory allergy and asthma in atopic subjects in the last 5 decades. Pollen allergy is frequently used to study the relationship between air pollution and respiratory allergic diseases, such as rhinitis and bronchial asthma. Epidemiologic studies have demonstrated that urbanization, high levels of vehicle emissions, and westernized lifestyle are correlated with an increased frequency of respiratory allergy prevalently in people who live in urban areas in comparison with people living in rural areas. Climatic factors (temperature, wind speed, humidity, thunderstorms, etc.) can affect both components (biological and chemical) of this interaction. PMID:27334776

  6. The effects of global change upon United States air quality

    NASA Astrophysics Data System (ADS)

    Gonzalez-Abraham, R.; Avise, J.; Chung, S. H.; Lamb, B.; Salathé, E. P., Jr.; Nolte, C. G.; Loughlin, D.; Guenther, A.; Wiedinmyer, C.; Duhl, T.; Zhang, Y.; Streets, D. G.

    2014-12-01

    To understand more fully the effects of global changes on ambient concentrations of ozone and particulate matter with aerodynamic diameter smaller than 2.5 μm (PM2.5) in the US, we conducted a comprehensive modeling effort to evaluate explicitly the effects of changes in climate, biogenic emissions, land use, and global/regional anthropogenic emissions on ozone and PM2.5 concentrations and composition. Results from the ECHAM5 global climate model driven with the A1B emission scenario from the Intergovernmental Panel on Climate Change (IPCC) were downscaled using the Weather Research and Forecasting (WRF) model to provide regional meteorological fields. We developed air quality simulations using the Community Multiscale Air Quality Model (CMAQ) chemical transport model for two nested domains with 220 and 36 km horizontal grid cell resolution for a semi-hemispheric domain and a continental United States (US) domain, respectively. The semi-hemispheric domain was used to evaluate the impact of projected Asian emissions changes on US air quality. WRF meteorological fields were used to calculate current (2000s) and future (2050s) biogenic emissions using the Model of Emissions of Gases and Aerosols from Nature (MEGAN). For the semi-hemispheric domain CMAQ simulations, present-day global emissions inventories were used and projected to the 2050s based on the IPCC A1B scenario. Regional anthropogenic emissions were obtained from the US Environmental Protection Agency National Emission Inventory 2002 (EPA NEI2002) and projected to the future using the MARKet ALlocation (MARKAL) energy system model assuming a business as usual scenario that extends current decade emission regulations through 2050. Our results suggest that daily maximum 8 h average ozone (DM8O) concentrations will increase in a range between 2 to 12 ppb across most of the continental US, with the highest increase in the South, Central, and Midwest regions of the US, due to increases in temperature, enhanced

  7. The effects of global change upon United States air quality

    NASA Astrophysics Data System (ADS)

    Gonzalez-Abraham, R.; Chung, S. H.; Avise, J.; Lamb, B.; Salathé, E. P., Jr.; Nolte, C. G.; Loughlin, D.; Guenther, A.; Wiedinmyer, C.; Duhl, T.; Zhang, Y.; Streets, D. G.

    2015-11-01

    To understand more fully the effects of global changes on ambient concentrations of ozone and particulate matter with aerodynamic diameter smaller than 2.5 μm (PM2.5) in the United States (US), we conducted a comprehensive modeling effort to evaluate explicitly the effects of changes in climate, biogenic emissions, land use and global/regional anthropogenic emissions on ozone and PM2.5 concentrations and composition. Results from the ECHAM5 global climate model driven with the A1B emission scenario from the Intergovernmental Panel on Climate Change (IPCC) were downscaled using the Weather Research and Forecasting (WRF) model to provide regional meteorological fields. We developed air quality simulations using the Community Multiscale Air Quality Model (CMAQ) chemical transport model for two nested domains with 220 and 36 km horizontal grid cell resolution for a semi-hemispheric domain and a continental United States (US) domain, respectively. The semi-hemispheric domain was used to evaluate the impact of projected global emissions changes on US air quality. WRF meteorological fields were used to calculate current (2000s) and future (2050s) biogenic emissions using the Model of Emissions of Gases and Aerosols from Nature (MEGAN). For the semi-hemispheric domain CMAQ simulations, present-day global emissions inventories were used and projected to the 2050s based on the IPCC A1B scenario. Regional anthropogenic emissions were obtained from the US Environmental Protection Agency National Emission Inventory 2002 (EPA NEI2002) and projected to the future using the MARKet ALlocation (MARKAL) energy system model assuming a business as usual scenario that extends current decade emission regulations through 2050. Our results suggest that daily maximum 8 h average ozone (DM8O) concentrations will increase in a range between 2 to 12 parts per billion (ppb) across most of the continental US. The highest increase occurs in the South, Central and Midwest regions of the US due to

  8. The Effects of Global Change upon United States Air Quality

    EPA Science Inventory

    To understand more fully the effects of global changes on ambient concentrations of ozone and particulate matter with aerodynamic diameter smaller than 2.5 μm (PM2.5) in the US, we conducted a comprehensive modeling effort to evaluate explicitly the effects of change...

  9. Acute effects of air pollution changes in schoolchildren: the Gardanne coal basin study

    NASA Astrophysics Data System (ADS)

    Charpin, D.; Kleisbauer, J. P.; Fondarai, A.; Francheterre, A.; Fondarai, J.; Graland, B.; Viala, A.

    1988-12-01

    In the literature, studies devoted to shortterm effects of air pollution episodes in children have provided controversial results. To evaluate if acute air pollution changes in the Gardanne coal basin (France) could have deleterious effects on children's pulmonary function, we studied 160 children on two different days. Each in-school examination consisted of a short questionnaire and a spirometric assessment. The area included districts of high and low pollution levels. In the former, the two examinations took place at different air pollution levels whereas, in the latter, the air pollution levels were comparable. We obtained higher spirometric values during the second examination, regardless of air pollution changes and suggesting a learning effect, which vanished when we used FEV1/FVC ratio. The difference in FEV1/FVC between days of low and high pollution was significant but merely equal to 2%. There was no change of clinical symptom score.

  10. The effect of future outdoor air pollution on human health and the contribution of climate change

    NASA Astrophysics Data System (ADS)

    Silva, R.; West, J. J.; Lamarque, J.; Shindell, D.; Collins, W.; Dalsoren, S. B.; Faluvegi, G. S.; Folberth, G.; Horowitz, L. W.; Nagashima, T.; Naik, V.; Rumbold, S.; Skeie, R.; Sudo, K.; Takemura, T.; Bergmann, D. J.; Cameron-Smith, P. J.; Cionni, I.; Doherty, R. M.; Eyring, V.; Josse, B.; MacKenzie, I. A.; Plummer, D.; Righi, M.; Stevenson, D. S.; Strode, S. A.; Szopa, S.; Zeng, G.

    2013-12-01

    At present, exposure to outdoor air pollution from ozone and fine particulate matter (PM2.5) causes over 2 million deaths per year, due to respiratory and cardiovascular diseases and lung cancer. Future ambient concentrations of ozone and PM2.5 will be affected by both air pollutant emissions and climate change. Here we estimate the potential impact of future outdoor air pollution on premature human mortality, and isolate the contribution of future climate change due to its effect on air quality. We use modeled present-day (2000) and future global ozone and PM2.5 concentrations from simulations with an ensemble of chemistry-climate models from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). Future air pollution was modeled for global greenhouse gas and air pollutant emissions in the four IPCC AR5 Representative Concentration Pathway (RCP) scenarios, for 2030, 2050 and 2100. All model outputs are regridded to a common 0.5°x0.5° horizontal resolution. Future premature mortality is estimated for each RCP scenario and year based on changes in concentrations of ozone and PM2.5 relative to 2000. Using a health impact function, changes in concentrations for each RCP scenario are combined with future population and cause-specific baseline mortality rates as projected by a single independent scenario in which the global incidence of cardiopulmonary diseases is expected to increase. The effect of climate change is isolated by considering the difference between air pollutant concentrations from simulations with 2000 emissions and a future year climate and simulations with 2000 emissions and climate. Uncertainties in the results reflect the uncertainty in the concentration-response function and that associated with variability among models. Few previous studies have quantified the effects of future climate change on global human health via changes in air quality, and this is the first such study to use an ensemble of global models.

  11. A new procedure to analyze the effect of air changes in building energy consumption

    PubMed Central

    2014-01-01

    Background Today, the International Energy Agency is working under good practice guides that integrate appropriate and cost effective technologies. In this paper a new procedure to define building energy consumption in accordance with the ISO 13790 standard was performed and tested based on real data from a Spanish region. Results Results showed that the effect of air changes on building energy consumption can be defined using the Weibull peak function model. Furthermore, the effect of climate change on building energy consumption under several different air changes was nearly nil during the summer season. Conclusions The procedure obtained could be the much sought-after solution to the problem stated by researchers in the past and future research works relating to this new methodology could help us define the optimal improvement in real buildings to reduce energy consumption, and its related carbon dioxide emissions, at minimal economical cost. PMID:24456655

  12. Effects on asthma and respiratory allergy of Climate change and air pollution.

    PubMed

    D'Amato, Gennaro; Vitale, Carolina; De Martino, Annamaria; Viegi, Giovanni; Lanza, Maurizia; Molino, Antonio; Sanduzzi, Alessandro; Vatrella, Alessandro; Annesi-Maesano, Isabella; D'Amato, Maria

    2015-01-01

    The major changes to our world are those involving the atmosphere and the climate, including global warming induced by anthropogenic factors, with impact on the biosphere and human environment. Studies on the effects of climate changes on respiratory allergy are still lacking and current knowledge is provided by epidemiological and experimental studies on the relationship between allergic respiratory diseases, asthma and environmental factors, like meteorological variables, airborne allergens and air pollution. Epidemiologic studies have demonstrated that urbanization, high levels of vehicle emissions and westernized lifestyle are correlated with an increased frequency of respiratory allergy, mainly in people who live in urban areas in comparison with people living in rural areas. However, it is not easy to evaluate the impact of climate changes and air pollution on the prevalence of asthma in general and on the timing of asthma exacerbations, although the global rise in asthma prevalence and severity could be also considered an effect of air pollution and climate changes. Since airborne allergens and air pollutants are frequently increased contemporaneously in the atmosphere, enhanced IgE-mediated response to aeroallergens and enhanced airway inflammation could account for the increasing frequency of respiratory allergy and asthma in atopic subjects in the last five decades. Pollen allergy is frequently used to study the interrelationship between air pollution and respiratory allergic diseases such as rhinitis and bronchial asthma. Climatic factors (temperature, wind speed, humidity, thunderstorms, etc) can affect both components (biological and chemical) of this interaction. Scientific societies should be involved in advocacy activities, such as those realized by the Global Alliance against chronic Respiratory Diseases (GARD). PMID:26697186

  13. Effects on asthma and respiratory allergy of Climate change and air pollution.

    PubMed

    D'Amato, Gennaro; Vitale, Carolina; De Martino, Annamaria; Viegi, Giovanni; Lanza, Maurizia; Molino, Antonio; Sanduzzi, Alessandro; Vatrella, Alessandro; Annesi-Maesano, Isabella; D'Amato, Maria

    2015-01-01

    The major changes to our world are those involving the atmosphere and the climate, including global warming induced by anthropogenic factors, with impact on the biosphere and human environment. Studies on the effects of climate changes on respiratory allergy are still lacking and current knowledge is provided by epidemiological and experimental studies on the relationship between allergic respiratory diseases, asthma and environmental factors, like meteorological variables, airborne allergens and air pollution. Epidemiologic studies have demonstrated that urbanization, high levels of vehicle emissions and westernized lifestyle are correlated with an increased frequency of respiratory allergy, mainly in people who live in urban areas in comparison with people living in rural areas. However, it is not easy to evaluate the impact of climate changes and air pollution on the prevalence of asthma in general and on the timing of asthma exacerbations, although the global rise in asthma prevalence and severity could be also considered an effect of air pollution and climate changes. Since airborne allergens and air pollutants are frequently increased contemporaneously in the atmosphere, enhanced IgE-mediated response to aeroallergens and enhanced airway inflammation could account for the increasing frequency of respiratory allergy and asthma in atopic subjects in the last five decades. Pollen allergy is frequently used to study the interrelationship between air pollution and respiratory allergic diseases such as rhinitis and bronchial asthma. Climatic factors (temperature, wind speed, humidity, thunderstorms, etc) can affect both components (biological and chemical) of this interaction. Scientific societies should be involved in advocacy activities, such as those realized by the Global Alliance against chronic Respiratory Diseases (GARD).

  14. [The effects of air pollution and climate change on pulmonary diseases].

    PubMed

    Rohde, G

    2008-04-01

    From as early as 1930 there has been evidence for effects on health of air pollution. Ozone, particulates and nitrogen dioxide are the most important pollutants today. The acute increase in air pollution leads to a significant raise in morbidity and mortality. Hospital admissions of patients with chronic obstructive pulmonary disease (COPD) or asthma are more frequent during these periods. Chronic exposure to pollution causes bronchitis, accelerated decline of lung function and impaired maturing of the lungs. Ozone and a residence in proximity to major roads seem to play a role in the development of asthma. A further important environmental factor is climate change, which has an impact on air pollution but also on distribution and quality of aero-allergens and the dissemination and transmission of respiratory pathogens.

  15. An analysis of air-turborocket engine performance including effects of component changes

    NASA Technical Reports Server (NTRS)

    Luidens, Roger W; Weber, Richard J

    1956-01-01

    An analytical study of the air-turborocket engine is presented, showing both full-power operation over a range of flight speeds and part-power operation at several supersonic speeds. Engine weight, drag, and area variations are calculated in addition to the internal thrust coefficient and specific impulse. Tehe effects of changes in the component designs and efficiencies are indicated. Maximum specific impulse (including nacelle drag and using gasoline - nitric acid propellants) at Mach 2.3 is 1500 lb/(lb/sec). The performance is compared with that of a typical turbojet engine.

  16. Incinerator performance: effects of changes in waste input and furnace operation on air emissions and residues.

    PubMed

    Astrup, Thomas; Riber, Christian; Pedersen, Anne Juul

    2011-10-01

    Waste incineration can be considered a robust technology for energy recovery from mixed waste. Modern incinerators are generally able to maintain relatively stable performance, but changes in waste input and furnace operation may affect emissions. This study investigated how inorganic air emissions and residue composition at a full-scale incinerator were affected by known additions of specific waste materials to the normal municipal solid waste (MSW) input. Six individual experiments were carried out (% ww of total waste input): NaCl (0.5%), shoes (1.6%), automobile shredder waste (14%), batteries (0.5%), poly(vinyl chloride) (5.5%) and chromate-cupper-arsenate impregnated wood (11%). Materials were selected based on chemical composition and potential for being included or excluded from the waste mix. Critical elements in the waste materials were identified based on comparison with six experiments including 'as-large-as-possible' changes in furnace operation (oxygen levels, air supply and burnout level) only using normal MSW as input. The experiments showed that effects from the added waste materials were significant in relation to: air emissions (in particular As, Cd, Cr, Hg, Sb), element transfer coefficients, and residue composition (As, Cd, Cl, Cr, Cu, Hg, Mo, Ni, Pb, S, Sb, Zn). Changes in furnace operation could not be directly linked to changes in emissions and residues. The results outlined important elements in waste which should be addressed in relation to waste incinerator performance. Likely ranges of element transfer coefficients were provided as the basis for sensitivity analysis of life-cycle assessment (LCA) results involving waste incinerator technologies.

  17. Incinerator performance: effects of changes in waste input and furnace operation on air emissions and residues.

    PubMed

    Astrup, Thomas; Riber, Christian; Pedersen, Anne Juul

    2011-10-01

    Waste incineration can be considered a robust technology for energy recovery from mixed waste. Modern incinerators are generally able to maintain relatively stable performance, but changes in waste input and furnace operation may affect emissions. This study investigated how inorganic air emissions and residue composition at a full-scale incinerator were affected by known additions of specific waste materials to the normal municipal solid waste (MSW) input. Six individual experiments were carried out (% ww of total waste input): NaCl (0.5%), shoes (1.6%), automobile shredder waste (14%), batteries (0.5%), poly(vinyl chloride) (5.5%) and chromate-cupper-arsenate impregnated wood (11%). Materials were selected based on chemical composition and potential for being included or excluded from the waste mix. Critical elements in the waste materials were identified based on comparison with six experiments including 'as-large-as-possible' changes in furnace operation (oxygen levels, air supply and burnout level) only using normal MSW as input. The experiments showed that effects from the added waste materials were significant in relation to: air emissions (in particular As, Cd, Cr, Hg, Sb), element transfer coefficients, and residue composition (As, Cd, Cl, Cr, Cu, Hg, Mo, Ni, Pb, S, Sb, Zn). Changes in furnace operation could not be directly linked to changes in emissions and residues. The results outlined important elements in waste which should be addressed in relation to waste incinerator performance. Likely ranges of element transfer coefficients were provided as the basis for sensitivity analysis of life-cycle assessment (LCA) results involving waste incinerator technologies. PMID:21930520

  18. EFFECTS OF CHANGING COALS ON THE EMISSIONS OF METAL HAZARDOUS AIR POLLUTANTS FROM THE COMBUSTION OF PULVERIZED COAL

    EPA Science Inventory

    The report discusses tests conducted at EPA's Air Pollution Prevention and Control Division to evaluate the effects of changing coals on emissions of metal hazardous air pollutants from coal-fired boilers. Six coals were burned in a 29 kW (100,000 Btu/hr) down-fired combustor und...

  19. The potential impacts of climate variability and change on air pollution-related health effects in the United States.

    PubMed Central

    Bernard, S M; Samet, J M; Grambsch, A; Ebi, K L; Romieu, I

    2001-01-01

    Climate change may affect exposures to air pollutants by affecting weather, anthropogenic emissions, and biogenic emissions and by changing the distribution and types of airborne allergens. Local temperature, precipitation, clouds, atmospheric water vapor, wind speed, and wind direction influence atmospheric chemical processes, and interactions occur between local and global-scale environments. If the climate becomes warmer and more variable, air quality is likely to be affected. However, the specific types of change (i.e., local, regional, or global), the direction of change in a particular location (i.e., positive or negative), and the magnitude of change in air quality that may be attributable to climate change are a matter of speculation, based on extrapolating present understanding to future scenarios. There is already extensive evidence on the health effects of air pollution. Ground-level ozone can exacerbate chronic respiratory diseases and cause short-term reductions in lung function. Exposure to particulate matter can aggravate chronic respiratory and cardiovascular diseases, alter host defenses, damage lung tissue, lead to premature death, and possibly contribute to cancer. Health effects of exposures to carbon monoxide, sulfur dioxide, and nitrogen dioxide can include reduced work capacity, aggravation of existing cardiovascular diseases, effects on pulmonary function, respiratory illnesses, lung irritation, and alterations in the lung's defense systems. Adaptations to climate change should include ensuring responsiveness of air quality protection programs to changing pollution levels. Research needs include basic atmospheric science work on the association between weather and air pollutants; improving air pollution models and their linkage with climate change scenarios; and closing gaps in the understanding of exposure patterns and health effects. PMID:11359687

  20. The potential impacts of climate variability and change on air pollution-related health effects in the United States.

    PubMed

    Bernard, S M; Samet, J M; Grambsch, A; Ebi, K L; Romieu, I

    2001-05-01

    Climate change may affect exposures to air pollutants by affecting weather, anthropogenic emissions, and biogenic emissions and by changing the distribution and types of airborne allergens. Local temperature, precipitation, clouds, atmospheric water vapor, wind speed, and wind direction influence atmospheric chemical processes, and interactions occur between local and global-scale environments. If the climate becomes warmer and more variable, air quality is likely to be affected. However, the specific types of change (i.e., local, regional, or global), the direction of change in a particular location (i.e., positive or negative), and the magnitude of change in air quality that may be attributable to climate change are a matter of speculation, based on extrapolating present understanding to future scenarios. There is already extensive evidence on the health effects of air pollution. Ground-level ozone can exacerbate chronic respiratory diseases and cause short-term reductions in lung function. Exposure to particulate matter can aggravate chronic respiratory and cardiovascular diseases, alter host defenses, damage lung tissue, lead to premature death, and possibly contribute to cancer. Health effects of exposures to carbon monoxide, sulfur dioxide, and nitrogen dioxide can include reduced work capacity, aggravation of existing cardiovascular diseases, effects on pulmonary function, respiratory illnesses, lung irritation, and alterations in the lung's defense systems. Adaptations to climate change should include ensuring responsiveness of air quality protection programs to changing pollution levels. Research needs include basic atmospheric science work on the association between weather and air pollutants; improving air pollution models and their linkage with climate change scenarios; and closing gaps in the understanding of exposure patterns and health effects.

  1. The potential impacts of climate variability and change on air pollution-related health effects in the United States.

    PubMed

    Bernard, S M; Samet, J M; Grambsch, A; Ebi, K L; Romieu, I

    2001-05-01

    Climate change may affect exposures to air pollutants by affecting weather, anthropogenic emissions, and biogenic emissions and by changing the distribution and types of airborne allergens. Local temperature, precipitation, clouds, atmospheric water vapor, wind speed, and wind direction influence atmospheric chemical processes, and interactions occur between local and global-scale environments. If the climate becomes warmer and more variable, air quality is likely to be affected. However, the specific types of change (i.e., local, regional, or global), the direction of change in a particular location (i.e., positive or negative), and the magnitude of change in air quality that may be attributable to climate change are a matter of speculation, based on extrapolating present understanding to future scenarios. There is already extensive evidence on the health effects of air pollution. Ground-level ozone can exacerbate chronic respiratory diseases and cause short-term reductions in lung function. Exposure to particulate matter can aggravate chronic respiratory and cardiovascular diseases, alter host defenses, damage lung tissue, lead to premature death, and possibly contribute to cancer. Health effects of exposures to carbon monoxide, sulfur dioxide, and nitrogen dioxide can include reduced work capacity, aggravation of existing cardiovascular diseases, effects on pulmonary function, respiratory illnesses, lung irritation, and alterations in the lung's defense systems. Adaptations to climate change should include ensuring responsiveness of air quality protection programs to changing pollution levels. Research needs include basic atmospheric science work on the association between weather and air pollutants; improving air pollution models and their linkage with climate change scenarios; and closing gaps in the understanding of exposure patterns and health effects. PMID:11359687

  2. THE EFFECT OF OPENING WINDOWS ON AIR CHANGE RATES IN TWO HOMES

    EPA Science Inventory

    Over 300 air change rate experiments were completed in two occupied residences: a two-story detached house in Redwood City, CA and a three-story townhouse in Reston, VA. A continuous monitor was used to measure the decay of sulfur hexafluoride tracer gas over periods of 1 to 1...

  3. Effects of Climate Change on residential indoor-outdoor Air Exchange

    EPA Science Inventory

    INTRODUCTION: Climate change is expected to increase the mean and peak ambient temperatures, and perhaps wind patterns and intensity, while indoor environments will remain within the range of human thermal comfort. As passive air exchange through infiltration is partly driven by ...

  4. The Effect of Conceptual Change Approach to Eliminate 9th Grade High School Students' Misconceptions about Air Pressure

    ERIC Educational Resources Information Center

    Akbas, Yavuz; Gencturk, Ebru

    2011-01-01

    The aim of this study was to determine the effectiveness of teaching based on conceptual change overcome misconceptions of 9th grade high school students about the subject of air pressure. The sampling of the study was formed with two classes of 9th grade students from a general high school in the city-center of Trabzon. A quasi-experimental…

  5. Effects of future climate and land cover changes on biogenic emissions and air quality in the US

    NASA Astrophysics Data System (ADS)

    Chung, S. H.; Gonzalez Abraham, R.; Arroyo, A.; Lamb, B. K.; Duhl, T.; Wiedinmyer, C.; Guenther, A. B.; Zhang, Y.; Salathe, E. P.

    2009-12-01

    Biogenic volatile organic compounds (BVOCs) emitted from vegetations are highly reactive in the atmosphere and contribute to ozone and secondary organic aerosol formation. Climate change influences vegetation distributions and emissions of BVOCs and thereby affects air quality. As part of a comprehensive investigation of the effects of global change on regional air quality in the US, this study examines the effects of future climate and land cover changes on emissions of BVOCs into the atmosphere and air quality in the US. The mesoscale WRF (Weather Research and Forecasting) model is applied at hemispheric (220 km grid cells) and continental US (36 km grid cells) scales for current (1995-2004) and future (2045-2054) decades to downscale climate results from the ECHAM5 global climate model for IPCC SRES scenario A1B. The MEGAN (Model of Emissions of Gases and Aerosols from Nature) model is driven by WRF meteorological results to predict biogenic emissions of VOCs and NOx. MEGAN accounts for vegetation species distributions and environmental factors such as temperature and light. Current decade vegetation distributions are derived from satellite observations. Future vegetation distributions are predicted from MAPSS (Mapped Atmosphere-Plant-Soil System) and the land cover model of IMAGE 2.0 (Integrated Model to Assess the Global Environment). Future land cover changes include the expansion of croplands so that land management changes can also be examined. The CMAQ (Community Multiscale Air Quality Modeling) chemical transport model is used to simulate O3 and aerosol concentrations using current- and future-decade biogenic emissions but with anthropogenic emissions held constant at current-decade levels. Results showing the changes in US air quality due to climate- and landuse-driven changes in biogenic emissions will be presented. These results are compared to previous simulations derived from the IPCC SRES scenario A1 scenario with the PCM (Parallel Climate Model

  6. Effects of climatic changes and urban air pollution on the rising trends of respiratory allergy and asthma

    PubMed Central

    2011-01-01

    Over the past two decades there has been increasing interest in studies regarding effects on human health of climate changes and urban air pollution. Climate change induced by anthropogenic warming of the earth's atmosphere is a daunting problem and there are several observations about the role of urbanization, with its high levels of vehicle emissions and other pollutants, and westernized lifestyle with respect to the rising frequency of respiratory allergic diseases observed in most industrialized countries. There is also evidence that asthmatic subjects are at increased risk of developing exacerbations of bronchial obstruction with exposure to gaseous (ozone, nitrogen dioxide, sulfur dioxide) and particulate inhalable components of air pollution. A change in the genetic predisposition is an unlikely cause of the increasing frequency in allergic diseases because genetic changes in a population require several generations. Consequently, environmental factors such as climate change and indoor and outdoor air pollution may contribute to explain the increasing frequency of respiratory allergy and asthma. Since concentrations of airborne allergens and air pollutants are frequently increased contemporaneously, an enhanced IgE-mediated response to aeroallergens and enhanced airway inflammation could account for the increasing frequency of allergic respiratory diseases and bronchial asthma. Scientific societies such as the European Academy of Allergy and Clinical Immunology, European Respiratory Society and the World Allergy Organization have set up committees and task forces to produce documents to focalize attention on this topic, calling for prevention measures. PMID:22958620

  7. The air quality and regional climate effects of widespread solar power generation under a changing regulatory environment

    NASA Astrophysics Data System (ADS)

    Millstein, D.; Zhai, P.; Menon, S.

    2011-12-01

    Over the past decade significant reductions of NOx and SOx emissions from coal burning power plants in the U.S. have been achieved due to regulatory action and substitution of new generation towards natural gas and wind power. Low natural gas prices, ever decreasing solar generation costs, and proposed regulatory changes, such as to the Cross State Air Pollution Rule, promise further long-run coal power plant emission reductions. Reduced power plant emissions have the potential to affect ozone and particulate air quality and influence regional climate through aerosol cloud interactions and visibility effects. Here we investigate, on a national scale, the effects on future (~2030) air quality and regional climate of power plant emission regulations in contrast to and combination with policies designed to aggressively promote solar electricity generation. A sophisticated, economic and engineering based, hourly power generation dispatch model is developed to explore the integration of significant solar generation resources (>10% on an energy basis) at various regions across the county, providing detailed estimates of substitution of solar generation for fossil fuel generation resources. Future air pollutant emissions from all sectors of the economy are scaled based on the U.S. Environmental Protection Agency's National Emission Inventory to account for activity changes based on population and economic projections derived from county level U.S. Census data and the Energy Information Administration's Annual Energy Outlook. Further adjustments are made for technological and regulatory changes applicable within various sectors, for example, emission intensity adjustments to on-road diesel trucking due to exhaust treatment and improved engine design. The future year 2030 is selected for the emissions scenarios to allow for the development of significant solar generation resources. A regional climate and air quality model (Weather Research and Forecasting, WRF model) is

  8. Air pollution-caused changes in photosynthesis: Effects on plant growth and rhizosphere functions

    SciTech Connect

    Winner, W.E. . Dept. of General Science); Antibus, R.K.; Linkins, A.E. . Dept. of Biology)

    1990-02-01

    The relationships between plants, soil nutrient status, and rhizosphere symbionts were probed using ozone (O{sub 3}), a commonly occurring air pollutant, as an above-ground stress to alter carbon gain. Laboratory experiments were designed to examine O{sub 3} effects on: (1) tree species grown at varying nutrient levels, (2) plants in symbiosis with a dinitrogen-fixing symbiont, (3) plants in symbiosis with mycorrhizal fungi, and (4) plants having both a dinitrogen-fixing symbiont and mycorrhizae. Photosynthesis measurements and growth analysis were applied to detect O{sub 3} effects on plant carbon gain and allocation, respectively. Stable carbon isotope ratios were analyzed as a means of integrating effects of O{sub 3} on gas exchange of leaves over the life of the plant. Transmission electron microscopy detected alterations in plant root cells symbiotic with dinitrogen-fixing bacteria caused by ozone. To better understand the relationship between host plant and mycorrhizal fungi, studies were conducted on utilization of carbohydrate by ectomycorrhizal fungi and metabolism of ectomycorrhizal fungi and roots. Taken together, these studies provide new information on metabolic relationships of plants and symbionts and the effect of O{sub 3} on these relationships.

  9. Projections of mid-century summer air-quality for North America: effects of changes in climate and precursor emissions

    NASA Astrophysics Data System (ADS)

    Kelly, J.; Makar, P. A.; Plummer, D. A.

    2012-06-01

    Ten year simulations of North American current and future air-quality were carried out using a regional air-quality model driven by a regional climate model, in turn driven by a general circulation model. Three separate summer scenarios were performed: a scenario representing the years 1997 to 2006, and two SRES A2 climate scenarios for the years 2041 to 2050. The first future climate scenario makes use of 2002 anthropogenic precursor emissions, and the second applied emissions scaling factors derived from the IPCC Representative Concentration Pathway 6 (RCP 6) scenario to estimate emissions for 2050 from existing 2020 projections. Ten-year averages of ozone and PM2.5 at North American monitoring network stations were used to evaluate the model's current chemical climatology. The model was found to have a similar performance for ozone as when driven by an operational weather forecast model. The PM2.5 predictions had larger negative biases, likely resulting from the absence of rainwater evaporation, and from sub-regional negative biases in the surface temperature fields, in the version of the climate model used here. The differences between the two future climate simulations and the current climate simulation were used to predict the changes to air-quality that might be expected in a future warmer climate, if anthropogenic precursor emissions remain constant at their current levels, versus if the RCP 6 emissions controls were adopted. Metrics of concentration, human health, and ecosystem damage were compared for the simulations. The scenario with future climate and current anthropogenic emissions resulted in worse air-quality than for current conditions - that is, the effect of climate-change alone, all other factors being similar, would be a worsening of air-quality. These effects are spatially inhomogeneous, with the magnitude and sign of the changes varying with region. The scenario with future climate and RCP 6 emissions for 2050 resulted in an improved air

  10. Projections of mid-century summer air-quality for North America: effects of changes in climate and precursor emissions

    NASA Astrophysics Data System (ADS)

    Kelly, J.; Makar, P. A.; Plummer, D. A.

    2012-02-01

    Ten year simulations of North American current and future air-quality were carried out using a regional air-quality model driven by a regional climate model, in turn driven by a general circulation model. Three separate summer scenarios were performed: a scenario representing the years 1997 to 2006, and two SRES A2 climate scenarios for the years 2041 to 2050. The first future climate scenario makes use of 2002 anthropogenic precursor emissions, and the second applied emissions scaling factors derived from the IPCC Representative Concentration Pathway 6 (RCP 6) scenario to estimate emissions for 2050 from existing 2020 projections. Ten-year averages of ozone and PM2.5 at North American monitoring network stations were used to evaluate the model's current chemical climatology. The model was found to have a similar performance for ozone as when driven by an operational weather forecast model. The PM2.5 predictions had larger negative biases, likely resulting from the absence of rainwater evaporation, and from sub-regional negative biases in the surface temperature fields, in the version of the climate model used here. The differences between the two future climate simulations and the current climate simulation were used to predict the changes to air-quality that might be expected in a future warmer climate, if anthropogenic precursor emissions remain constant at their current levels, versus if the RCP 6 emissions controls were adopted. Metrics of concentration, human health, and ecosystem damage were compared for the simulations. The scenario with future climate and current anthropogenic emissions resulted in worse air-quality than for current conditions - that is, the effect of climate-change alone, all other factors being similar, would be a worsening of air-quality. These effects are spatially inhomogeneous, with the magnitude and sign of the changes varying with region. The scenario with future climate and RCP 6 emissions for 2050 resulted in an improved air

  11. Effects of sudden air pressure changes on hospital admissions for cardiovascular diseases in Prague

    NASA Astrophysics Data System (ADS)

    Kysely, Jan; Plavcova, Eva

    2013-04-01

    Sudden weather changes have long been supposed to be associated with negative impacts on human health. However, relatively few studies attempted to quantify these relationships. In this study, we use large 6-hour changes of atmospheric sea level pressure as proxy for sudden weather changes, and evaluate their association with hospital admissions for cardiovascular diseases. Winter and summer seasons and positive and negative pressure changes are analyzed separately, using data for the city of Prague (population of 1.2 million) over 16-year period (1994-2009). We find that sudden pressure drops in winter are associated with significant increases in the number of hospital admissions. Increases in morbidity are not observed for pressure drops in summer, nor pressure increases in any season. Analysis of synoptic weather maps shows that the large pressure drops in winter are associated with strong zonal (westerly) flow and rapidly moving low pressure systems with centres over Northern Europe and atmospheric fronts affecting the area of Western and Central Europe. Several of the largest pressure decreases were associated with infamous winter storms (such as Lothar on December 25, 1999 and Kyrill on January 18, 2007). Analysis of links between passages of strong atmospheric fronts and hospital admissions shows that the links are much weaker if weather changes are characterized by frontal passages. Since climate models project strengthening of the zonal circulation in winter and increased frequency of winter storms, the negative effects of such weather phenomena and their possible changes in a warmer climate of the 21st century need to be better understood, particularly as their importance in inducing excess morbidity and mortality in winter may increase compared to cold spells.

  12. Strategic effects of future environmental policy commitments: climate change, solar radiation management and correlated air pollutants.

    PubMed

    Qu, Jingwen; Silva, Emilson Caputo Delfino

    2015-03-15

    We study the effects of environmental policy commitments in a futuristic world in which solar radiation management (SRM) can be utilized to reduce climate change damages. Carbon and sulfur dioxide emissions (correlated pollutants) can be reduced through tradable permits. We show that if nations simultaneously commit to carbon permit policies, national SRM levels rise with carbon quotas. Alternatively, if they simultaneously commit to SRM policies, the global temperature falls with each unit increase in the global SRM level. A nation always wishes to be a leader in policymaking, but prefers carbon to SRM policymaking. The globe prefers SRM policy commitments.

  13. Health Effects of Air Pollution

    MedlinePlus

    ... Health effects of air pollution Health effects of air pollution Breathing air that is not clean can hurt ... important to know about the health effects that air pollution can have on you and others. Once you ...

  14. The Impact of Future Emissions Changes on Air Pollution Concentrations and Related Human Health Effects

    NASA Astrophysics Data System (ADS)

    Mikolajczyk, U.; Suppan, P.; Williams, M.

    2015-12-01

    Quantification of potential health benefits of reductions in air pollution on the local scale is becoming increasingly important. The aim of this study is to conduct health impact assessment (HIA) by utilizing regionally and spatially specific data in order to assess the influence of future emission scenarios on human health. In the first stage of this investigation, a modeling study was carried out using the Weather Research and Forecasting (WRF) model coupled with Chemistry to estimate ambient concentrations of air pollutants for the baseline year 2009, and for the future emission scenarios in southern Germany. Anthropogenic emissions for the baseline year 2009 are derived from the emission inventory provided by the Netherlands Organization of Applied Scientific Research (TNO) (Denier van der Gon et al., 2010). For Germany, the TNO emissions were replaced by gridded emission data with a high spatial resolution of 1/64 x 1/64 degrees. Future air quality simulations are carried out under different emission scenarios, which reflect possible energy and climate measures in year 2030. The model set-up included a nesting approach, where three domains with horizontal resolution of 18 km, 6 km and 2 km were defined. The simulation results for the baseline year 2009 are used to quantify present-day health burdens. Concentration-response functions (CRFs) for PM2.5 and NO2 from the WHO Health risks of air Pollution in Europe (HRAPIE) project were applied to population-weighted mean concentrations to estimate relative risks and hence to determine numbers of attributable deaths and associated life-years lost. In the next step, future health impacts of projected concentrations were calculated taking into account different emissions scenarios. The health benefits that we assume with air pollution reductions can be used to provide options for future policy decisions to protect public health.

  15. Tree-Ring Nitrogen Isotopes As Environmental Monitoring Tools - Inferring Air Quality Changes And Climate Effects

    NASA Astrophysics Data System (ADS)

    Savard, M. M.; Begin, C.; Smirnoff, A.; Marion, J.

    2008-12-01

    Anthropogenic emissions of atmospheric nitrogen greatly increased over the last 150 years, however the monitoring of nitrous oxide concentration in North America started only recently, generally during the last 30 years. Could the geochemical characteristics of tree rings be used to infer past changes in nitrogen cycles of temperate regions? To address this question we use long-term series (125 years) of nitrogen stable isotopes (δ15N) obtained from rings of pine (Pinus strobus) and beech (Fagus grandifolia) trees in the Montreal region (western Quebec), and of beech specimens in the Georgian Bay Islands National Park (central Ontario). Reliability tests of N concentrations in wood treated for removal of soluble materials reveal that the reproducibility from tree to tree is poor, and that the concentrations in both Pine and Beech trees change in the heartwood-sapwood transition zones. We therefore reject N concentration as environmental indicator. Alternatively, the N stable isotopes pass all reliability tests. In Montreal, short-term δ15N fluctuations correlate directly with precipitation and inversely with temperature. A long-term decreasing isotope trend suggests progressive changes in soil chemistry after 1951. A pedochemical change is also inferred for the Georgian Bay site on the basis of a positive δ15N trend initiated after 1971. At both sites, the long-term δ15N series correlate with a proxy for NOx emissions, and the δ13C values of the same ring series suggest that all studied trees have been stressed by phytotoxic pollutants. We propose that the contrasted long-term δ15N changes of Montreal and Georgian Bay reflect deposition of NOx emissions from cars and coal-power plants, with higher proportions from coal burning in Georgian Bay. This interpretation is conceivable because recent monitoring indicates that coal-power plant NOx emissions play an important role in the annual N budget in Ontario, but they seem negligible on the Quebec side. This

  16. The effect of processing and compositional changes on the tribology of PM212 in air

    NASA Technical Reports Server (NTRS)

    Bogdanski, Michael S.; Sliney, Harold E.; Dellacorte, Christopher

    1993-01-01

    The effects of processing and compositional variations on the tribological performance of PM212 were studied. PM212 is a self lubricating powder metallurgy composite, comprised of a wear resistant metal bonded chromium carbide matrix, containing the solid lubricants barium fluoride/calcium fluoride eutectic and silver. Several composites were formulated which had lubricant, matrix, and processing variations. Processing variations included sintering and hot isostatic pressing. Pins fabricated from the composites were slid against superalloys disks in a pin-on-disk tribometer to study the tribological properties. Several composites exhibited low friction and wear in sliding against a nickel based superalloy. The tribological performance by several different composites showed that the composition of PM212 can be altered without dramatically affecting performance.

  17. The effect of processing and compositional changes on the tribology of PM212 in air

    SciTech Connect

    Bogdanski, M.S.; Sliney, H.E.; DellaCorte, C.

    1993-04-01

    The effects of processing and compositional variations on the tribological performance of PM212 were investigated. PM212 is a self-lubricating powder metallurgy composite, comprised of a wear-resistant metal bonded chromium carbide matrix, containing the solid lubricants barium fluoride/calcium fluoride eutectic and silver. Several composites were formulated which had lubricant, matrix, and processing variations. Processing variations included sintering and hot isostatic pressing. Pins fabricated from the composites were slid against superalloy disks in a pinon-disk tribometer to study the tribological properties. Several composites exhibited low friction and wear in sliding against a nickel-based superalloy. The good tribological performance by several different composites showed that the composition of PM212 can be altered without dramatically affecting performance.

  18. Have the short-term mortality effects of particulate matter air pollution changed in Australia over the period 1993-2007?

    PubMed

    Roberts, Steven

    2013-11-01

    The author investigates whether the mortality effect of particulate matter air pollution (PM10) has changed in Australia over the period 1993-2007. This period corresponds to an era of increasing Government intervention aimed at improving air quality and, as a result, a potential decrease in the toxicity of PM10. Evidence is found that the mortality effect of PM10 has declined in both Brisbane and Sydney. For Sydney we estimate that the effects of PM10 on total and cardiovascular mortality are, respectively, decreasing at the rate of 10% and 13% annually. We speculate that one possible reason for this decline could be a reduction in the toxicity of PM10. A difference between this study and a similar United States study is that PM10 concentrations have not been declining in Australia. This means that the observed decline in the mortality effect of PM10 is not an artefact of a declining PM10 concentration.

  19. The changing paradigm of air pollution monitoring.

    PubMed

    Snyder, Emily G; Watkins, Timothy H; Solomon, Paul A; Thoma, Eben D; Williams, Ronald W; Hagler, Gayle S W; Shelow, David; Hindin, David A; Kilaru, Vasu J; Preuss, Peter W

    2013-10-15

    The air pollution monitoring paradigm is rapidly changing due to recent advances in (1) the development of portable, lower-cost air pollution sensors reporting data in near-real time at a high-time resolution, (2) increased computational and visualization capabilities, and (3) wireless communication/infrastructure. It is possible that these advances can support traditional air quality monitoring by supplementing ambient air monitoring and enhancing compliance monitoring. Sensors are beginning to provide individuals and communities the tools needed to understand their environmental exposures with these data individual and community-based strategies can be developed to reduce pollution exposure as well as understand linkages to health indicators. Each of these areas as well as corresponding challenges (e.g., quality of data) and potential opportunities associated with development and implementation of air pollution sensors are discussed.

  20. Simulations and projections of major air pollutants over the United States and uncertainty analyses, effects of natural change and human activities

    NASA Astrophysics Data System (ADS)

    Lei, Hang

    Changes in global climate and pollutant emissions are very likely to continue in the coming decades driven by the human-related activities and natural fluctuations in the Earth climate system. These potential changes would have very important consequences on regional air quality over the contiguous United States due to their effects on atmospheric chemical and physical processes. To understand these effects, the present studies use the global climate chemistry model, CAM-Chem version 3, to systematically assess potential changes in major air pollutants including surface ozone, particulate matter and mercury from the present (1998--2002) to the 2050 (2048--2052). The projections of future air quality consider changes in global climate, precursor emissions from anthropogenic and biogenic sources, and pollutant transport. Moreover, to evaluate the projection uncertainties resulting from different plausible trends of climate and emissions as a result of unknown human-related activities and climate variations, three IPCC SRES scenarios, A1FI, A1B and B1, are considered and compared to evaluate the resulting uncertainty in projecting future pollutant concentrations. To achieve a better understanding on the effect of mineral dust emissions on changes in future air quality especially the PM concentrations, a physical dust aerosol module is developed and incorporated into the CAM-Chem model. A mercury module is developed for the CAM-Chem model to simulate the atmospheric cycle of mercury and its consequences on the toxicity of U.S. air quality. For the study of ozone air quality, we focus on the risk of high ozone episodes and the relative contributions from changes in local anthropogenic emissions (LE) versus changes in intercontinental transport (ICT) on 2050 U.S. surface ozone air quality. It is found that the projected changes in air temperature, precipitation, lighting, planetary boundary layer height and cyclone activities tend to intensify the associated extreme

  1. Exploring the consequences of climate change for indoor air quality

    NASA Astrophysics Data System (ADS)

    Nazaroff, William W.

    2013-03-01

    Climate change will affect the concentrations of air pollutants in buildings. The resulting shifts in human exposure may influence public health. Changes can be anticipated because of altered outdoor pollution and also owing to changes in buildings effected in response to changing climate. Three classes of factors govern indoor pollutant levels in occupied spaces: (a) properties of pollutants; (b) building factors, such as the ventilation rate; and (c) occupant behavior. Diversity of indoor conditions influences the public health significance of climate change. Potentially vulnerable subpopulations include not only the young and the infirm but also those who lack resources to respond effectively to changing conditions. Indoor air pollutant levels reflect the sum of contributions from indoor sources and from outdoor pollutants that enter with ventilation air. Pollutant classes with important indoor sources include the byproducts of combustion, radon, and volatile and semivolatile organic compounds. Outdoor pollutants of special concern include particulate matter and ozone. To ensure good indoor air quality it is important first to avoid high indoor emission rates for all pollutants and second to ensure adequate ventilation. A third factor is the use of air filtration or air cleaning to achieve further improvements where warranted. Reprinted with permission from Climate Change, the Indoor Environment, and Health (2011) by the National Academy of Sciences, Courtesy of the National Academies Press, Washington, DC.

  2. Voice Change Due to Paratracheal Air Cysts

    PubMed Central

    Rhee, Youn Ju; Han, Sung Joon; Chong, Yoo Young; Cho, Hyun Jin; Kang, Shin Kwang; Lee, Choong-Sik; Kang, Min-Woong

    2016-01-01

    Paratracheal air cysts are a rare entity in which cystic formation occurs adjacent to the trachea. Most patients with paratracheal air cysts are asymptomatic, and the cysts are detected incidentally on chest radiograph or computed tomography (CT) scan. Most symptomatic patients complain of pulmonary symptoms or repeated respiratory infection. Rarely, the air cysts can lead to paralysis of the recurrent laryngeal nerve as a result of direct compression. We report a case of a 59-year-old male patient who presented with voice change, and the cause was identified as paratracheal air cysts on a chest CT scan. Surgical resection via video-assisted mediastinoscopy was performed, and the voice recovered immediately after the operation. PMID:27525245

  3. Effects of sudden air pressure changes on hospital admissions for cardiovascular diseases in Prague, 1994-2009.

    PubMed

    Plavcová, Eva; Kyselý, Jan

    2014-08-01

    Sudden weather changes have long been thought to be associated with negative impacts on human health, but relatively few studies have attempted to quantify these relationships. We use large 6-h changes in atmospheric pressure as a proxy for sudden weather changes and evaluate their association with hospital admissions for cardiovascular diseases (CVD). Winter and summer seasons and positive and negative pressure changes are analysed separately, using data for the city of Prague (population 1.2 million) over a 16-year period (1994-2009). We found that sudden pressure drops in winter are associated with significant rise in hospital admissions. Increased CVD morbidity was observed neither for pressure drops in summer nor pressure increases in any season. Analysis of synoptic weather maps shows that large pressure drops in winter are associated with strong zonal flow and rapidly moving low-pressure systems with centres over northern Europe and atmospheric fronts affecting western and central Europe. Analysis of links between passages of strong atmospheric fronts and hospital admissions, however, shows that the links disappear if weather changes are characterised by frontal passages. Sudden pressure drops in winter are associated also with significant excess CVD mortality. As climate models project strengthening of zonal circulation in winter and increased frequency of windstorms, the negative effects of such weather phenomena and their possible changes in a warmer climate of the twenty-first century need to be better understood, particularly as their importance in inducing excess morbidity and mortality in winter may increase compared to cold spells.

  4. Effects of sudden air pressure changes on hospital admissions for cardiovascular diseases in Prague, 1994-2009

    NASA Astrophysics Data System (ADS)

    Plavcová, Eva; Kyselý, Jan

    2014-08-01

    Sudden weather changes have long been thought to be associated with negative impacts on human health, but relatively few studies have attempted to quantify these relationships. We use large 6-h changes in atmospheric pressure as a proxy for sudden weather changes and evaluate their association with hospital admissions for cardiovascular diseases (CVD). Winter and summer seasons and positive and negative pressure changes are analysed separately, using data for the city of Prague (population 1.2 million) over a 16-year period (1994-2009). We found that sudden pressure drops in winter are associated with significant rise in hospital admissions. Increased CVD morbidity was observed neither for pressure drops in summer nor pressure increases in any season. Analysis of synoptic weather maps shows that large pressure drops in winter are associated with strong zonal flow and rapidly moving low-pressure systems with centres over northern Europe and atmospheric fronts affecting western and central Europe. Analysis of links between passages of strong atmospheric fronts and hospital admissions, however, shows that the links disappear if weather changes are characterised by frontal passages. Sudden pressure drops in winter are associated also with significant excess CVD mortality. As climate models project strengthening of zonal circulation in winter and increased frequency of windstorms, the negative effects of such weather phenomena and their possible changes in a warmer climate of the twenty-first century need to be better understood, particularly as their importance in inducing excess morbidity and mortality in winter may increase compared to cold spells.

  5. Climate change and air quality: international perspectives and policy implications

    SciTech Connect

    Ronald Prinn; Stephen Dorling

    2005-10-01

    Three major air quality relevant atmospheric constituents that also influence the climate are methane, ozone, and aerosols. Their respective atmospheric lifetimes are roughly 10 years, several days (near surface) to a month (in the free troposphere), and a week. Both O{sub 3} and aerosols are important regional air pollutants in the troposphere. All three constituents also influence the radiative budget of the atmosphere. With the exception of black carbon (BC) aerosols reflect radiation and have a net cooling effect. BC, absorbs solar radiation and warms the atmosphere locally, setting off a readjustment of heat, momentum, clouds, and precipitation patterns that are at least regional in scale. They all have clear international relevance. Interactions between air quality and climate change are highly complex. The Prinn 7 calculations suggest that air pollution policies may have only a small influence, either positive or negative, on global-scale climate change. However, even small militations of climate change can be disproportionately important in economic terms. This occurs because the highest cost climate change mitigation measures, those occurring at the margin, may be avoided. More policy-relevant research needs to be undertaken. This research should include studies of (1) the effects of air pollution policy on overall demand for fossil fuels and individual demands for coal, oil, and gas; (2) the effects of caps on BC (as a regulated air pollutant) on climate; and (3) the effects on ecosystems of changes in deposition rates of acids, nitrates, and sulfates and levels of exposure to SO{sub 2} and NO{sub 2} resulting from air pollution reductions. This article is one of a set of six in this issue of EM devoted to understanding the interactions between climate change and air quality. 12 refs., 1 fig.

  6. Omega-3 Fatty Acid Supplementation Appears to Attenuate Particulate Air Pollution-induced Cardiac Effects and Lipid Changes in Healthy Middle-aged Adults.

    EPA Science Inventory

    Context: Air pollution exposure has been associated with adverse cardiovascular effects. A recent epidemiologic study reported that omega-3 fatty acid (fish oil) supplementation blunted the cardiac responses to air pollution exposure. Objective: To evaluate in a randomized contro...

  7. Changing the Paradigm of Air Pollution Monitoring

    EPA Science Inventory

    Historically, approaches for monitoring air pollution generally use expensive, complex, stationary equipment,1,2 which limits who collects data, why data are collected, and how data are accessed. This paradigm is changing with the materialization of lower-cost, easy-to...

  8. Influence of temperature changes on ambient air NOx chemiluminescence measurements.

    PubMed

    Miñarro, Marta Doval; Ferradás, Enrique González; Martínez, Francisco J Marzal

    2012-09-01

    Users of automatic air pollution monitors are largely unaware of how certain parameters, like temperature, can affect readings. The present work examines the influence of temperature changes on chemiluminescence NO(x) measurements made with a Thermo Scientific 42i analyzer, a model widely used in air monitoring networks and air pollution studies. These changes are grouped into two categories according to European Standard EN 14211: (1) changes in the air surrounding the analyzers and (2) changes in the sampled air. First, the sensitivity tests described in Standard EN 14211 were performed to determine whether the analyzer performance was adapted to the requirements of the standard. The analyzer met the performance criteria of both tests; however, some differences were detected in readings with temperature changes even though the temperature compensator was on. Sample temperature changes were studied more deeply as they were the most critical (they cannot be controlled and differences of several tens of degrees can be present in a single day). Significant differences in readings were obtained when changing sample temperature; however, maximum deviations were around 3% for temperature ranges of 15°C. If other possible uncertainty contributions are controlled and temperature variations with respect to the calibration temperature are not higher than 15°C, the effect of temperature changes could be acceptable and no data correction should have to be applied. PMID:21964932

  9. [Temporal change in annual air temperature and heat island effect in a coastal city and an inland city at mid-latitude in China during 1956-1998].

    PubMed

    Chao, Lu-men; Sun, Jian-xin

    2009-12-01

    Temporal changes in air temperature and urban heat island (UHI) effects during 1956-1998 were compared between a coastal city, Ji' nan, and an inland city, Xi' an, which were similar in latitude, size and development. During 1956-1978, except that the annual mean minimum temperature in Ji' nan increased by 0.37 degrees C x 10 a(-1), the temperature variables in the two cities did not display any apparent trend. During 1979-1998, all temperature variables of the two cities showed an increasing trend. Comparing with that in Ji' nan, the increasing rate of annual mean maximum temperature and annual mean temperature in Xi' an was greater, but that of annual mean minimum temperature was smaller. In the two cities, heat island effect occurred during 1956-1978 but without any apparent trend, whereas during 1979-1998, this effect increased with time, especially in Xi' an where the annual mean minimum temperature and annual mean temperature increased by 0.22 degrees C x 10 a(-1) and 0.32 degrees C x 10 a(-1), respectively. Both the level and the inter-annual variation of the heat island effect were much greater in Ji' nan than in Xi' an, but the increasing rate of this effect was greater in Xi' an than in Ji' nan. Obvious differences were observed in the increasing rate of annual mean maximum air temperature, annual mean air temperature, and annual mean minimum temperature as well as the heat island effect in Ji' nan, whereas negligible differences were found in Xi' an. Among the three temperature variables, annual mean minimum temperature displayed the most obvious increasing trend and was most affected by heat island effect, while annual mean maximum temperature was most variable inter-annually. Geographical location not only affected the magnitude of urban warming, but also affected the mode of urban warming and the strength of heat island effect.

  10. How emissions, climate, and land use change will impact mid-century air quality over the United States: a focus on effects at national parks

    NASA Astrophysics Data System (ADS)

    Martin, M. Val; Heald, C. L.; Lamarque, J.-F.; Tilmes, S.; Emmons, L. K.; Schichtel, B. A.

    2015-03-01

    We use a global coupled chemistry-climate-land model (CESM) to assess the integrated effect of climate, emissions and land use changes on annual surface O3 and PM2.5 in the United States with a focus on national parks (NPs) and wilderness areas, using the RCP4.5 and RCP8.5 projections. We show that, when stringent domestic emission controls are applied, air quality is predicted to improve across the US, except surface O3 over the western and central US under RCP8.5 conditions, where rising background ozone counteracts domestic emission reductions. Under the RCP4.5 scenario, surface O3 is substantially reduced (about 5 ppb), with daily maximum 8 h averages below the primary US Environmental Protection Agency (EPA) National Ambient Air Quality Standards (NAAQS) of 75 ppb (and even 65 ppb) in all the NPs. PM2.5 is significantly reduced in both scenarios (4 μg m-3; ~50%), with levels below the annual US EPA NAAQS of 12 μg m-3 across all the NPs; visibility is also improved (10-15 dv; >75 km in visibility range), although some western US parks with Class I status (40-74 % of total sites in the US) are still above the 2050 planned target level to reach the goal of natural visibility conditions by 2064. We estimate that climate-driven increases in fire activity may dominate summertime PM2.5 over the western US, potentially offsetting the large PM2.5 reductions from domestic emission controls, and keeping visibility at present-day levels in many parks. Our study indicates that anthropogenic emission patterns will be important for air quality in 2050. However, climate and land use changes alone may lead to a substantial increase in surface O3 (2-3 ppb) with important consequences for O3 air quality and ecosystem degradation at the US NPs. Our study illustrates the need to consider the effects of changes in climate, vegetation, and fires in future air quality management and planning and emission policy making.

  11. Toxic effects of air freshener emissions.

    PubMed

    Anderson, R C; Anderson, J H

    1997-01-01

    To evaluate whether emissions of a commercial air freshener produced acute toxic effects in a mammalian species, the authors allowed male Swiss-Webster mice to breathe the emissions of one commercial-brand solid air freshener for 1 h. Sensory irritation and pulmonary irritation were evaluated with the ASTM-E-981 test. A computerized version of this test measured the duration of the break at the end of inspiration and the duration of the pause at the end of expiration--two parameters subject to alteration via respiratory effects of airborne toxins. Measurements of expiratory flow velocity indicated changes in airflow limitation. The authors then subjected mice to a functional observational battery, the purpose of which was to probe for changes in nervous system function. Emissions of this air freshener at several concentrations (including concentrations to which many individuals are actually exposed) caused increases in sensory and pulmonary irritation, decreases in airflow velocity, and abnormalities of behavior measured by the functional observational battery score. The test atmosphere was subjected to gas chromatography/mass spectroscopy, and the authors noted the presence of chemicals with known irritant and neurotoxic properties. The Material Safety Data Sheet for the air freshener indicated that there was a potential for toxic effects in humans. The air freshener used in the study did not diminish the effect of other pollutants tested in combination. The results demonstrated that the air freshener may have actually exacerbated indoor air pollution via addition of toxic chemicals to the atmosphere.

  12. Climate Change, Air Pollution, and the Economics of Health Impacts

    NASA Astrophysics Data System (ADS)

    Reilly, J.; Yang, T.; Paltsev, S.; Wang, C.; Prinn, R.; Sarofim, M.

    2003-12-01

    Climate change and air pollution are intricately linked. The distinction between greenhouse substances and other air pollutants is resolved at least for the time being in the context of international negotiations on climate policy through the identification of CO2, CH4, N2O, SF6 and the per- and hydro- fluorocarbons as substances targeted for control. Many of the traditional air pollutant emissions including for example CO, NMVOCs, NOx, SO2, aerosols, and NH3 also directly or indirectly affect the radiative balance of the atmosphere. Among both sets of gases are precursors of and contributors to pollutants such as tropopospheric ozone, itself a strong greenhouse gas, particulate matter, and other pollutants that affect human health. Fossil fuel combustion, production, or transportation is a significant source for many of these substances. Climate policy can thus affect traditional air pollution or air pollution policy can affect climate. Health effects of acute or chronic exposure to air pollution include increased asthma, lung cancer, heart disease and bronchitis among others. These, in turn, redirect resources in the economy toward medical expenditures or result in lost labor or non-labor time with consequent effects on economic activity, itself producing a potential feedback on emissions levels. Study of these effects ultimately requires a fully coupled earth system model. Toward that end we develop an approach for introducing air pollution health impacts into the Emissions Prediction and Policy Analysis (EPPA) model, a component of the MIT Integrated Global Systems Model (IGSM) a coupled economics-chemistry-atmosphere-ocean-terrestrial biosphere model of earth systems including an air pollution model resolving the urban scale. This preliminary examination allows us to consider how climate policy affects air pollution and consequent health effects, and to study the potential impacts of air pollution policy on climate. The novel contribution is the effort to

  13. Air flow paths and porosity/permeability change in a saturated zone during in situ air sparging.

    PubMed

    Tsai, Yih-Jin

    2007-04-01

    This study develops methods to estimate the change in soil characteristics and associated air flow paths in a saturated zone during in situ air sparging. These objectives were achieved by performing combined in situ air sparging and tracer testing, and comparing the breakthrough curves obtained from the tracer gas with those obtained by a numerical simulation model that incorporates a predicted change in porosity that is proportional to the air saturation. The results reveal that revising the porosity and permeability according to the distribution of gas saturation is helpful in breakthrough curve fitting, however, these changes are unable to account for the effects of preferential air flow paths, especially in the zone closest to the points of air injection. It is not known the extent to which these preferential air flow paths were already present versus created, increased, or reduced as a result of the air sparging experiment. The transport of particles from around the sparging well could account for the overall increase in porosity and permeability observed in the study. Collection of soil particles in a monitoring well within 2m of the sparging well provided further evidence of the transport of particles. Transport of particles from near the sparging well also appeared to decrease the radius of influence (ROI). Methods for predicting the effects of pressurized air injection and water flow on the creation or modification of preferential air flow paths are still needed to provide a full description of the change in soil conditions that accompany air sparging.

  14. Composition changes in refrigerant blends for automotive air conditioning

    SciTech Connect

    Jetter, J.J.; Delafield, F.R.; Ng, A.S.; Ratanaphruks, K.; Tufts, M.W.

    1999-07-01

    Three refrigerant blends used to replace the chlorofluorocarbon R-12 in automotive air conditioners were evaluated for composition changes due to typical servicing and leakage. When recommended service procedures were followed, changes in blend compositions were relatively small. Small changes in blend compositions caused no significant changes in refrigeration capacities. However, when recommended procedures were not followed, changes in compositions were relatively large. The amount of change in composition and the resulting effect on performance varied among the three refrigerant blends that were tested. Of the three blends, a quaternary blend containing hydrochlorofluorocarbon R-22 had the greatest changes in composition, while a binary blend containing hydrofluorocarbon R-134a had the smallest changes in composition.

  15. Changing perspectives on air-pollution stress

    SciTech Connect

    Bormann, F.H.; Likens, G.E.

    1987-06-01

    As more has been learned about the nature of air pollution and more sophisticated techniques have been developed for measurement, it has become apparent that acid rain is only one of an interrelated array of airshed-watershed problems. Despite important reductions in some pollutant emissions, the authors believe the situation today is worse than it appeared to be 15 years ago. Recently scientists have reported data showing that in some locations dry deposition of hydrogen ion, sulfur, and nitrogen in coarse and fine particles and vapors may exceed the same substances measured in bulk precipitation. As scientists learned about acid rain, they also became more aware of photochemical oxidant pollution. Symptoms of ozone damage on crops and natural vegetation have been found in a majority of states. As understanding and measurement ability have increased, estimates of the magnitude of the air pollution problem have grown. The recent measurements of dry deposition, cloud-water deposition, and photochemical oxidant concentrations have greatly increased estimates of airborne pollutants reaching ecosystems. They have shown that the photochemical oxidant problem cannot be separated from the acid-rain problem and that the combined effects may be both episodic and long-term. These findings indicate that regional air pollution is more severe than it was perceived to be 15 years ago. Solving the problem will be extremely difficult and expensive both in terms of monitoring and assessing effects on ecosystems under realistic conditions. The longer the delays in setting an official policy of comprehensive correctional measures, the more environmental damage may occur. Extensive damage, in turn, would increase the cost of measures for protection and recovery.

  16. Ventilating-air change rate versus particulate contaminant spread

    SciTech Connect

    Langer, G.; Deitesfeld, C.A.

    1987-11-13

    This study provides information on the spread of particulate contamination from glovebox leaks in plutonium manufacturing facilities, with emphasis on the effect of ventilating-air change rate on contaminated spread. A new, very sensitive aerosol tracer technique was developed to simulate plutonium aerosol leaks and its dispersion in a room. The tracer, a submicron aerosol of phloroglucinol, does not interfere with work activity and is detected by its ability to form ice crystals in a supercooled cloud. This technique was applied in Buildings 371 and 707 plutonium production areas. The tracer spread throughout the rooms in a few minutes and reached its equilibrium concentration in 10 to 25 min. Also, to clear the room of all tracer took about the same time. In one room, tracer concentration decreased proportionally to the air change rate, while in the second one, air change rate had no effect. This points out the need for air velocity data. Also, future work must include simultaneous particle concentration measurements at several points. 4 refs., 9 figs., 2 tabs.

  17. Health Effects of Air Pollution.

    ERIC Educational Resources Information Center

    Environmental Education Report and Newsletter, 1985

    1985-01-01

    Summarizes health hazards associated with air pollution, highlighting the difficulty in establishing acceptable thresholds of exposure. Respiratory disease, asthma, cancer, cardiovascular disease, and other problems are addressed. Indicates that a wide range of effects from any one chemical exists and that there are differences in sensitivity to…

  18. Mobile Air Monitoring: Measuring Change in Air Quality in the City of Hamilton, 2005-2010

    ERIC Educational Resources Information Center

    Adams, Matthew D.; DeLuca, Patrick F.; Corr, Denis; Kanaroglou, Pavlos S.

    2012-01-01

    This paper examines the change in air pollutant concentrations between 2005 and 2010 occurring in the City of Hamilton, Ontario, Canada. After analysis of stationary air pollutant concentration data, we analyze mobile air pollutant concentration data. Air pollutants included in the analysis are CO, PM[subscript 2.5], SO[subscript 2], NO,…

  19. Evaluation of the impact of transportation changes on air quality

    NASA Astrophysics Data System (ADS)

    Titos, G.; Lyamani, H.; Drinovec, L.; Olmo, F. J.; Močnik, G.; Alados-Arboledas, L.

    2015-08-01

    Transport regulation at local level for the abatement of air pollution has gained significant traction in the EU. In this work, we analyze the effect of different transportation changes on air quality in two similarly sized cities: Granada (Spain) and Ljubljana (Slovenia). Several air pollutants were measured at both sites before and after the implementation of the changes. In Ljubljana, a 72% reduction of local black carbon (BC), from 5.6 to 1.6 μg/m3, was observed after the restriction was implemented. In Granada, statistically significant reductions of 1.3 μg/m3 (37%) in BC and of 15 μg/m3 (33%) in PM10 concentrations were observed after the public transportation re-organization. However, the improvement observed in air quality was very local since other areas of the cities did not improve significantly. We show that closing streets to private traffic, renewal of the bus fleet and re-organization of the public transportation significantly benefit air quality.

  20. Ground cloud air quality effects

    NASA Technical Reports Server (NTRS)

    Brubaker, K. L.

    1980-01-01

    The effects of the ground cloud associated with launching of a large rocket on air quality are discussed. The ground cloud consists of the exhaust emitted by the rocket during the first 15 to 25 seconds following ignition and liftoff, together with a large quantity of entrained air, cooling water, dust and other debris. Immediately after formation, the ground cloud rises in the air due to the buoyant effect of its high thermal energy content. Eventually, at an altitude typically between 0.7 and 3 km, the cloud stabilizes and is carried along by the prevailing wind at that altitude. For the use of heavy lift launch vehicles small quantities of nitrogen oxides, primarily nitric oxide and nitrogen dioxide, are expected to be produced from a molecular nitrogen impurity in the fuel or liquid oxygen, or from entrainment and heating of ambient air in the hot rocket exhaust. In addition, possible impurities such as sulfur in the fuel would give rise to a corresponding amount of oxidation products such as sulfur dioxide.

  1. Increases in ambient particulate matter air pollution, acute changes in platelet function, and effect modification by aspirin and omega-3 fatty acids: A panel study.

    PubMed

    Becerra, Adan Z; Georas, Steve; Brenna, J Thomas; Hopke, Philip K; Kane, Cathleen; Chalupa, David; Frampton, Mark W; Block, Robert; Rich, David Q

    2016-01-01

    Increased particulate matter (PM) air pollutant concentrations have been associated with platelet activation. It was postulated that elevated air pollutant concentrations would be associated with increases in measures of platelet function and that responses would be blunted when taking aspirin and/or fish oil. Data from a sequential therapy trial (30 subjects with type 2 diabetes mellitus), with 4 clinic visits (first: no supplements, second: aspirin, third: omega-3 fatty acid supplements, fourth: aspirin and omega-3 fatty acids) per subject, were utilized. Using linear mixed models, adjusted for relative humidity, temperature, visit number, and season, changes in three platelet function measures including (1) aggregation induced by adenosine diphosphate (ADP), (2) aggregation induced by collagen, and (3) thromboxane B2 production were associated with interquartile range (IQR) increases in mean concentrations of ambient PM2.5, black carbon, ultrafine particles (UFP; 10-100 nm), and accumulation mode particles (AMP; 100-500 nm) in the previous 1-96 h. IQR increases in mean UFP and AMP concentrations were associated with significant decreases in platelet response, with the largest being a -0.43 log(pg/ml) decrease in log(thromboxane B2) (95% CI = -0.8, -0.1) associated with each 582-particles/cm(3) increase in AMP, and a -1.7 ohm reduction in collagen-induced aggregation (95% CI = -3.1, -0.3) associated with each 2097-particles/cm(3) increase in UFP in the previous 72 h. This UFP effect on thromboxane B2 was significantly muted in diabetic subjects taking aspirin (-0.01 log[pg/ml]; 95% CI = -0.4, 0.3). The reason for this finding remains unknown, and needs to be investigated in future studies. PMID:27029326

  2. Increases in ambient particulate matter air pollution, acute changes in platelet function, and effect modification by aspirin and omega-3 fatty acids: A panel study.

    PubMed

    Becerra, Adan Z; Georas, Steve; Brenna, J Thomas; Hopke, Philip K; Kane, Cathleen; Chalupa, David; Frampton, Mark W; Block, Robert; Rich, David Q

    2016-01-01

    Increased particulate matter (PM) air pollutant concentrations have been associated with platelet activation. It was postulated that elevated air pollutant concentrations would be associated with increases in measures of platelet function and that responses would be blunted when taking aspirin and/or fish oil. Data from a sequential therapy trial (30 subjects with type 2 diabetes mellitus), with 4 clinic visits (first: no supplements, second: aspirin, third: omega-3 fatty acid supplements, fourth: aspirin and omega-3 fatty acids) per subject, were utilized. Using linear mixed models, adjusted for relative humidity, temperature, visit number, and season, changes in three platelet function measures including (1) aggregation induced by adenosine diphosphate (ADP), (2) aggregation induced by collagen, and (3) thromboxane B2 production were associated with interquartile range (IQR) increases in mean concentrations of ambient PM2.5, black carbon, ultrafine particles (UFP; 10-100 nm), and accumulation mode particles (AMP; 100-500 nm) in the previous 1-96 h. IQR increases in mean UFP and AMP concentrations were associated with significant decreases in platelet response, with the largest being a -0.43 log(pg/ml) decrease in log(thromboxane B2) (95% CI = -0.8, -0.1) associated with each 582-particles/cm(3) increase in AMP, and a -1.7 ohm reduction in collagen-induced aggregation (95% CI = -3.1, -0.3) associated with each 2097-particles/cm(3) increase in UFP in the previous 72 h. This UFP effect on thromboxane B2 was significantly muted in diabetic subjects taking aspirin (-0.01 log[pg/ml]; 95% CI = -0.4, 0.3). The reason for this finding remains unknown, and needs to be investigated in future studies.

  3. COMPOSITION CHANGES IN REFRIGERANT BLENDS FOR AUTOMOTIVE AIR CONDITIONING

    EPA Science Inventory

    Three refrigerant blends used to replace CFC-12 in automotive air conditioners were evaluated for composition changes due to typical servicing and leakage. When recommended service procedures were followed, changes in blend compositions were relatively small. Small changes in b...

  4. Model-based estimation of changes in air temperature seasonality

    NASA Astrophysics Data System (ADS)

    Barbosa, Susana; Trigo, Ricardo

    2010-05-01

    Seasonality is a ubiquitous feature in climate time series. Climate change is expected to involve not only changes in the mean of climate parameters but also changes in the characteristics of the corresponding seasonal cycle. Therefore the identification and quantification of changes in seasonality is a highly relevant topic in climate analysis, particularly in a global warming context. However, the analysis of seasonality is far from a trivial task. A key challenge is the discrimination between long-term changes in the mean and long-term changes in the seasonal pattern itself, which requires the use of appropriate statistical approaches in order to be able to distinguish between overall trends in the mean and trends in the seasons. Model based approaches are particularly suitable for the analysis of seasonality, enabling to assess uncertainties in the amplitude and phase of seasonal patterns within a well defined statistical framework. This work addresses the changes in the seasonality of air temperature over the 20th century. The analysed data are global air temperature values close to surface (2m above ground) and mid-troposphere (500 hPa geopotential height) from the recently developed 20th century reanalysis. This new 3-D Reanalysis dataset is available since 1891, considerably extending all other Reanalyses currently in use (e.g. NCAR, ECWMF), and was obtained with the Ensemble Filter (Compo et al., 2006) by assimilation of pressure observations into a state-of-the-art atmospheric general circulation model that includes the radiative effects of historical time-varying CO2 concentrations, volcanic aerosol emissions and solar output variations. A modeling approach based on autoregression (Barbosa et al, 2008; Barbosa, 2009) is applied within a Bayesian framework for the estimation of a time varying seasonal pattern and further quantification of changes in the amplitude and phase of air temperature over the 20th century. Barbosa, SM, Silva, ME, Fernandes, MJ

  5. Modeling of an air-backed diaphragm in dynamic pressure sensors: Effects of the air cavity

    NASA Astrophysics Data System (ADS)

    Liu, Haijun; Olson, Douglas A.; Yu, Miao

    2014-12-01

    As the key structure of most dynamic pressure sensors, a diaphragm backed by an air cavity plays a critical role in the determination of sensor performance metrics. In this paper, we investigate the influence of air cavity length on the sensitivity and bandwidth. A continuum mechanics model neglecting the air viscous effect is first developed to capture the structural-acoustic coupling between a clamped circular diaphragm and a cylindrical backing air cavity. To facilitate sensor design, close-form approximations are obtained to calculate the static sensitivity and the fundamental natural frequency of the air-backed diaphragm. Parametric studies based on this analytical model show that the air cavity can change both the effective mass and the effective stiffness of the diaphragm. One new finding is that the natural frequency of the air-backed diaphragm behaves differently in three different cavity length ranges. In particular, due to the mass effect of the air cavity being dominant, it is shown for the first time that the natural frequency decreases when the cavity length decreases below a critical value in the short cavity range. Furthermore, a finite element method (FEM) model is developed to validate the continuum mechanics model and to study the damping effect of the air cavity. These results provide important design guidelines for dynamic pressure sensors with air-backed diaphragms.

  6. ASSESSMENT OF THE IMPACTS OF GLOBAL CHANGE ON REGIONAL U.S. AIR QUALITY: A SYNTHESIS OF CLIMATE CHANGE IMPACTS ON GROUND-LEVEL OZONE (AN INTERIM REPORT OF THE U.S. EPA GLOBAL CHANGE RESEARCH PROGRAM)

    EPA Science Inventory

    The Air Quality Assessment Final Report is intended for managers and scientists working on air quality to provide them with information on the potential effects of climate change on regional air quality in the United States.

  7. Changes in air flow patterns using surfactants and thickeners during air sparging: bench-scale experiments.

    PubMed

    Kim, Juyoung; Kim, Heonki; Annable, Michael D

    2015-01-01

    Air injected into an aquifer during air sparging normally flows upward according to the pressure gradients and buoyancy, and the direction of air flow depends on the natural hydrogeologic setting. In this study, a new method for controlling air flow paths in the saturated zone during air sparging processes is presented. Two hydrodynamic parameters, viscosity and surface tension of the aqueous phase in the aquifer, were altered using appropriate water-soluble reagents distributed before initiating air sparging. Increased viscosity retarded the travel velocity of the air front during air sparging by modifying the viscosity ratio. Using a one-dimensional column packed with water-saturated sand, the velocity of air intrusion into the saturated region under a constant pressure gradient was inversely proportional to the viscosity of the aqueous solution. The air flow direction, and thus the air flux distribution was measured using gaseous flux meters placed at the sand surface during air sparging experiments using both two-, and three-dimensional physical models. Air flow was found to be influenced by the presence of an aqueous patch of high viscosity or suppressed surface tension in the aquifer. Air flow was selective through the low-surface tension (46.5 dyn/cm) region, whereas an aqueous patch of high viscosity (2.77 cP) was as an effective air flow barrier. Formation of a low-surface tension region in the target contaminated zone in the aquifer, before the air sparging process is inaugurated, may induce air flow through the target zone maximizing the contaminant removal efficiency of the injected air. In contrast, a region with high viscosity in the air sparging influence zone may minimize air flow through the region prohibiting the region from de-saturating.

  8. Changes in air flow patterns using surfactants and thickeners during air sparging: bench-scale experiments.

    PubMed

    Kim, Juyoung; Kim, Heonki; Annable, Michael D

    2015-01-01

    Air injected into an aquifer during air sparging normally flows upward according to the pressure gradients and buoyancy, and the direction of air flow depends on the natural hydrogeologic setting. In this study, a new method for controlling air flow paths in the saturated zone during air sparging processes is presented. Two hydrodynamic parameters, viscosity and surface tension of the aqueous phase in the aquifer, were altered using appropriate water-soluble reagents distributed before initiating air sparging. Increased viscosity retarded the travel velocity of the air front during air sparging by modifying the viscosity ratio. Using a one-dimensional column packed with water-saturated sand, the velocity of air intrusion into the saturated region under a constant pressure gradient was inversely proportional to the viscosity of the aqueous solution. The air flow direction, and thus the air flux distribution was measured using gaseous flux meters placed at the sand surface during air sparging experiments using both two-, and three-dimensional physical models. Air flow was found to be influenced by the presence of an aqueous patch of high viscosity or suppressed surface tension in the aquifer. Air flow was selective through the low-surface tension (46.5 dyn/cm) region, whereas an aqueous patch of high viscosity (2.77 cP) was as an effective air flow barrier. Formation of a low-surface tension region in the target contaminated zone in the aquifer, before the air sparging process is inaugurated, may induce air flow through the target zone maximizing the contaminant removal efficiency of the injected air. In contrast, a region with high viscosity in the air sparging influence zone may minimize air flow through the region prohibiting the region from de-saturating. PMID:25462638

  9. Changes in air flow patterns using surfactants and thickeners during air sparging: Bench-scale experiments

    NASA Astrophysics Data System (ADS)

    Kim, Juyoung; Kim, Heonki; Annable, Michael D.

    2015-01-01

    Air injected into an aquifer during air sparging normally flows upward according to the pressure gradients and buoyancy, and the direction of air flow depends on the natural hydrogeologic setting. In this study, a new method for controlling air flow paths in the saturated zone during air sparging processes is presented. Two hydrodynamic parameters, viscosity and surface tension of the aqueous phase in the aquifer, were altered using appropriate water-soluble reagents distributed before initiating air sparging. Increased viscosity retarded the travel velocity of the air front during air sparging by modifying the viscosity ratio. Using a one-dimensional column packed with water-saturated sand, the velocity of air intrusion into the saturated region under a constant pressure gradient was inversely proportional to the viscosity of the aqueous solution. The air flow direction, and thus the air flux distribution was measured using gaseous flux meters placed at the sand surface during air sparging experiments using both two-, and three-dimensional physical models. Air flow was found to be influenced by the presence of an aqueous patch of high viscosity or suppressed surface tension in the aquifer. Air flow was selective through the low-surface tension (46.5 dyn/cm) region, whereas an aqueous patch of high viscosity (2.77 cP) was as an effective air flow barrier. Formation of a low-surface tension region in the target contaminated zone in the aquifer, before the air sparging process is inaugurated, may induce air flow through the target zone maximizing the contaminant removal efficiency of the injected air. In contrast, a region with high viscosity in the air sparging influence zone may minimize air flow through the region prohibiting the region from de-saturating.

  10. The effectiveness of a heated air curtain

    NASA Astrophysics Data System (ADS)

    Frank, Daria

    2014-11-01

    Air curtains are high-velocity plane turbulent jets which are installed in the doorway in order to reduce the heat and the mass exchange between two environments. The air curtain effectiveness E is defined as the fraction of the exchange flow prevented by the air curtain compared to the open-door situation. In the present study, we investigate the effects of an opposing buoyancy force on the air curtain effectiveness. Such an opposing buoyancy force arises for example if a downwards blowing air curtain is heated. We conducted small-scale experiments using water as the working fluid with density differences created by salt and sugar. The effectiveness of a downwards blowing air curtain was measured for situations in which the initial density of the air curtain was less than both the indoor and the outdoor fluid density, which corresponds to the case of a heated air curtain. We compare the effectiveness of the heated air curtain to the case of the neutrally buoyant air curtain. It is found that the effectiveness starts to decrease if the air curtain is heated beyond a critical temperature. Furthermore, we propose a theoretical model to describe the dynamics of the buoyant air curtain. Numerical results obtained from solving this model corroborate our experimental findings.

  11. IMPACTS OF AIR POLLUTION AND CLIMATE CHANGE ON FOREST ECOSYSTEMS - EMERGING RESEARCH NEEDS

    EPA Science Inventory

    Outcomes from the 22nd meeting for Specialists in Air Pollution Effects on Forest Ecosystems "Forests under Anthropogenic Pressure - Effects of Air Pollution, Climate Change and Urban Development", September 10-16, 2006, Riverside, CA, USA are summarized. Tropospheric ozone is st...

  12. Human health effects of air pollution.

    PubMed

    Kampa, Marilena; Castanas, Elias

    2008-01-01

    Hazardous chemicals escape to the environment by a number of natural and/or anthropogenic activities and may cause adverse effects on human health and the environment. Increased combustion of fossil fuels in the last century is responsible for the progressive change in the atmospheric composition. Air pollutants, such as carbon monoxide (CO), sulfur dioxide (SO(2)), nitrogen oxides (NOx), volatile organic compounds (VOCs), ozone (O(3)), heavy metals, and respirable particulate matter (PM2.5 and PM10), differ in their chemical composition, reaction properties, emission, time of disintegration and ability to diffuse in long or short distances. Air pollution has both acute and chronic effects on human health, affecting a number of different systems and organs. It ranges from minor upper respiratory irritation to chronic respiratory and heart disease, lung cancer, acute respiratory infections in children and chronic bronchitis in adults, aggravating pre-existing heart and lung disease, or asthmatic attacks. In addition, short- and long-term exposures have also been linked with premature mortality and reduced life expectancy. These effects of air pollutants on human health and their mechanism of action are briefly discussed.

  13. Characterizing climate change impacts on human exposures to air pollutants

    EPA Science Inventory

    Human exposures to air pollutants such as ozone (O3) have the potential to be altered by changes in climate through multiple factors that drive population exposures, including: ambient pollutant concentrations, human activity patterns, population sizes and distributions, and hous...

  14. Impact of Climate Change on Air Quality and Public Health in Urban Areas.

    PubMed

    Hassan, Noor Artika; Hashim, Zailina; Hashim, Jamal Hisham

    2016-03-01

    This review discusses how climate undergo changes and the effect of climate change on air quality as well as public health. It also covers the inter relationship between climate and air quality. The air quality discussed here are in relation to the 5 criteria pollutants; ozone (O3), carbon dioxide (CO2), nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter (PM). Urban air pollution is the main concern due to higher anthropogenic activities in urban areas. The implications on health are also discussed. Mitigating measures are presented with the final conclusion.

  15. Impact of Climate Change on Air Quality and Public Health in Urban Areas.

    PubMed

    Hassan, Noor Artika; Hashim, Zailina; Hashim, Jamal Hisham

    2016-03-01

    This review discusses how climate undergo changes and the effect of climate change on air quality as well as public health. It also covers the inter relationship between climate and air quality. The air quality discussed here are in relation to the 5 criteria pollutants; ozone (O3), carbon dioxide (CO2), nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter (PM). Urban air pollution is the main concern due to higher anthropogenic activities in urban areas. The implications on health are also discussed. Mitigating measures are presented with the final conclusion. PMID:26141092

  16. Committee on air pollution effects research: 40 years of UK air pollution.

    PubMed

    Fowler, David; Dise, Nancy; Sheppard, Lucy

    2016-01-01

    The UK Committee on Air Pollution Effects Research (CAPER) was established 40 years ago. This special section was compiled to mark this anniversary. During this time there have been dramatic changes in the composition of the air over the UK. The four papers in this special section of Environmental Pollution represent the current air pollution effects research focus on ozone and nitrogen deposition, two related issues and are proving from a policy perspective to be quite intractable issues. The UK CAPER research community continues to advance the underpinning science and engages closely with the user community in government departments.

  17. Motor Vehicles, Air Pollution, and Climate Change

    NASA Astrophysics Data System (ADS)

    Mark, Jason

    2000-04-01

    Despite years of technical progress, motor vehicles continue to be a leading cause of environmental damage in the United States. For example, today's cars and trucks are the largest source of air pollution in many urban areas. US motor vehicles also account for 25 percent of the nation's carbon emissions, more than most countries emit from all sources combined. Fortunately, a host of technical improvements are emerging that could go a long ways towards taking vehicles out of the pollution picture. In the near-term, improving on the century-old internal combustion engine can deliver much-needed incremental gains. But electric drive vehicles--whether powered by batteries, small engines in hybrid configuration, or fuel cells--ultimately offer the greatest promise. Such technologies could dramatically reduce energy use, greenhouse gas emissions, and key air pollutants. The bulk of technical attention in recent years has been focused on improving the passenger vehicle, which will be the dominant energy consumer in the transportation sector for years to come. But freight trucks are also of growing concern, both because their contribution to global warming is on the rise and because serious questions are being raised about the public health impact of diesel technology. As a result, heavy trucks are emerging as a priority issue. Capitalizing on the opportunity presented by new technologies will not only require continued technical innovation but also policy action. As research into improved engines, fuels, and drive systems bears fruit over the coming years, aggressive and prudent policies will ensure that these new options make it onto the road and deliver on their environmental promise.

  18. Air-temperature variations and ENSO effects in Indonesia, the Philippines and El Salvador. ENSO patterns and changes from 1866-1993

    NASA Astrophysics Data System (ADS)

    Harger, J. R. E.

    industrial development in infrastructure for Jakarta has been significant only since 1980 or so and was not apparent before 1970 when the city had the aspect of an extended village with few large buildings (greater than 3-4 stories) and no extensive highways. The 1.65° difference between 1866 and 1991 can presumably by partitioned into: (1) urban heat-island effect, (2) effect of deforestation, (3) effect of secular micro-climate shift, (4) influence of general global warming with particular reference to the tropics. When the blocks of non-ENSO years in themselves are considered, the deviations from the secular trend for warmest month mean temperatures in successive years are correlated with that of the next immediate year deviation so that either continual warming or cooling appears to take place from the termination of one ENSO to the initiation of the next. When the deviations around the secular trend shown by the warmest month average temperatures are summed for the inter-ENSO intervals (the separate non-ENSO years) the resultant "heat-loading" index is positively correlated with the following (initial) ENSO warmest month deviation from the overall ENSO warmest month secular trend. This provides an immediate predictive mechanism for the likely strength of an ENSO, in terms of the dry season impact to the Island of Java, should one occur in the next year to break a non-ENSO sequence. The length of the build-up and the build-up achieved seems not to be related. The relationship does not in itself however, predict the occurrence of the "next" ENSO. The data show that a consistent structure underlies ENSO events for the last century and a quarter. However, as a process monitored by mean monthly air-temperature measurements at Jakarta-Semarang, the system is changing in character with time in association with an overall atmospheric temperature increase in a way that involves increased intra-annual temperature fluctuations. In general ENSO years are associated with higher

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

    PubMed

    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.

  20. Air distribution and size changes in the remediated zone after air sparging for soil particle movement.

    PubMed

    Tsai, Yih-Jin

    2008-10-30

    In an unconsolidated porous medium, soil particles can be mobilized by physical perturbation. In model systems of fluids flowing over spherical particles attached to flat surfaces, the hydrodynamic shear force depends on the fluid viscosity, particle radius, and flow velocity. Soil particles can be reasonably expected to be transported by flowing water during air sparging when the particle-size distribution does not fit the densest possible particle arrangement. If soil particles are transported during air sparging, then the distribution of the porosity and reservoir permeability will change. The remediated zone changes because of the changes in soil characteristics. This study applied some mathematical models to elucidate the mobilization process of soil particles during in situ air sparging. The changes in the characteristics of the soil and the swept volume of injected air during air sparging were also investigated. The results demonstrated that particle movement reduced the radius of influence (ROI) and the swept volume of injected air. In this case study, the maximum reducing rates in ROI and the swept volume were 24% and 26% for the zone where the gas saturation exceeded 10%.

  1. Climate Change and Agriculture: Effects and Adaptation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This document is a synthesis of science literature on the effects of climate change on agriculture and issues associated with agricultural adaptation to climate change. Information is presented on how long-term changes in air temperatures, precipitation, and atmospheric levels of carbon dioxide wi...

  2. Changes in tropospheric composition and air quality.

    PubMed

    Tang, X; Madronich, S; Wallington, T; Calamari, D

    1998-10-01

    Reductions in stratospheric ozone (O3) cause increased penetration of ultraviolet-B (UV-B) radiation to the troposphere, and therefore increases in the chemical activity in the lower atmosphere (the troposphere). Tropospheric ozone levels are sensitive to local concentrations of nitrogen oxides (NOx) and hydrocarbons. Model studies suggest that additional UV-B radiation reduces tropospheric ozone in clean environments (low NOx), and increases tropospheric ozone in polluted areas (high NOx). Assuming other factors remain constant, additional UV-B will increase the rate at which primary pollutants are removed from the troposphere. Increased UV-B is expected to increase the concentration of hydroxyl radicals (OH) and result in faster removal of pollutants such as carbon monoxide (CO), methane (CH4), non-methane hydrocarbons (NMHCs), sulfur and nitrogen oxides, hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs). Concentrations of peroxy radicals (both inorganic and organic) are expected to increase, leading to higher atmospheric levels of hydrogen peroxide (H2O2) and organic peroxides. The effects of UV-B increases on tropospheric O3, OH, methane, CO, and possibly other tropospheric constituents, while not negligible, will be difficult to detect because the concentrations of these species are also influenced by many other variable factors (e.g., emissions). Trifluoroacetic acid (TFA, CF3COOH) is produced in the atmosphere by the degradation of HCFC-123 (CF3CHCl2), HCFC-124 (CF3CHFCl), and HFC-134a (CF3CH2F), which are used as substitutes for ozone-depleting substances. The atmospheric oxidation mechanisms of these replacement compounds are well established. Reported measurements of TFA in rain, rivers, lakes, and oceans show it to be a ubiquitous component of the hydrosphere, present at levels much higher than can be explained by reported sources. The levels of TFA produced by the atmospheric degradation of HFCs and HCFCs emitted up to the year 2020 are

  3. Effect of Initial Mixture Temperature on Flame Speed of Methane-Air, Propane-Air, and Ethylene-Air Mixtures

    NASA Technical Reports Server (NTRS)

    Dugger, Gordon L

    1952-01-01

    Flame speeds based on the outer edge of the shadow cast by the laminar Bunsen cone were determined as functions of composition for methane-air mixtures at initial mixture temperatures ranging from -132 degrees to 342 degrees c and for propane-air and ethylene-air mixtures at initial mixture temperatures ranging from -73 degrees to 344 degrees c. The data showed that maximum flame speed increased with temperature at an increasing rate. The percentage change in flame speed with change in initial temperature for the three fuels followed the decreasing order, methane, propane, and ethylene. Empirical equations were determined for maximum flame speed as a function of initial temperature over the temperature range covered for each fuel. The observed effect of temperature on flame speed for each of the fuels was reasonably well predicted by either the thermal theory as presented by Semenov or the square-root law of Tanford and Pease.

  4. Co-benefits of air quality and climate change policies on air quality of the Mediterranean

    NASA Astrophysics Data System (ADS)

    Pozzoli, Luca; Mert Gokturk, Ozan; Unal, Alper; Kindap, Tayfun; Janssens-Maenhout, Greet

    2015-04-01

    The Mediterranean basin is one of the regions of the world where significant impacts due to climate changes are predicted to occur in the future. Observations and model simulations are used to provide to the policy makers scientifically based estimates of the necessity to adjust national emission reductions needed to achieve air quality objectives in the context of a changing climate, which is not only driven by GHGs, but also by short lived climate pollutants, such as tropospheric ozone and aerosols. There is an increasing interest and need to design cost-benefit emission reduction strategies, which could improve both regional air quality and global climate change. In this study we used the WRF-CMAQ air quality modelling system to quantify the contribution of anthropogenic emissions to ozone and particulate matter concentrations in Europe and the Eastern Mediterranean and to understand how this contribution could change in different future scenarios. We have investigated four different future scenarios for year 2050 defined during the European Project CIRCE: a "business as usual" scenario (BAU) where no or just actual measures are taken into account; an "air quality" scenario (BAP) which implements the National Emission Ceiling directive 2001/81/EC member states of the European Union (EU-27); a "climate change" scenario (CC) which implements global climate policies decoupled from air pollution policies; and an "integrated air quality and climate policy" scenario (CAP) which explores the co-benefit of global climate and EU-27 air pollution policies. The BAP scenario largely decreases summer ozone concentrations over almost the entire continent, while the CC and CAP scenarios similarly determine lower decreases in summer ozone but extending all over the Mediterranean, the Middle East countries and Russia. Similar patterns are found for winter PM concentrations; BAP scenario improves pollution levels only in the Western EU countries, and the CAP scenario determines

  5. Air bubble bursting effect of lotus leaf.

    PubMed

    Wang, Jingming; Zheng, Yongmei; Nie, Fu-Qiang; Zhai, Jin; Jiang, Lei

    2009-12-15

    In this paper, a phenomenon of air bubbles quickly bursting within several milliseconds on a "self-cleaning" lotus leaf was described. This observation prompted the synthesis of artificial surfaces similar to that of the lotus leaf. The artificial leaf surfaces, prepared by photolithography and wet etching, showed a similar air bubble bursting effect. Smooth and rough silicon surfaces with an ordered nanostructure or patterned microstructure were utilized to study the contribution of the micro/nano hierarchical structures to this phenomenon of air bubble bursting. Air bubbles were found to burst on some superhydrophobic surfaces with microstructure (within 220 ms). However, air bubbles burst much more rapidly (within 13 ms) on similar surfaces with micro/nanostructure. The height, width, and spacing of hierarchical structures could also affect air bubble bursting, and the effect of the height was more obvious. When the height of hierarchical structures was around the height found in natural lotus papillae, the width and spacing were significant for air bubble bursting. An original model was proposed to further evaluate the reason why the micro/nano hierarchical rough structures had an excellent air bubble bursting effect, and the validity of the model was theoretically demonstrated.

  6. The Altitude Effect on Air Speed Indicators

    NASA Technical Reports Server (NTRS)

    Hersey, M D; Hunt, F L; Eaton, H N

    1921-01-01

    The object of this report is to present the results of a theoretical and experimental study of the effect, on the performance of air speed indicators, of the different atmospheric conditions experienced at various altitudes.

  7. Adverse health effects of outdoor air pollutants.

    PubMed

    Curtis, Luke; Rea, William; Smith-Willis, Patricia; Fenyves, Ervin; Pan, Yaqin

    2006-08-01

    Much research on the health effects of outdoor air pollution has been published in the last decade. The goal of this review is to concisely summarize a wide range of the recent research on health effects of many types of outdoor air pollution. A review of the health effects of major outdoor air pollutants including particulates, carbon monoxide, sulfur and nitrogen oxides, acid gases, metals, volatile organics, solvents, pesticides, radiation and bioaerosols is presented. Numerous studies have linked atmospheric pollutants to many types of health problems of many body systems including the respiratory, cardiovascular, immunological, hematological, neurological and reproductive/ developmental systems. Some studies have found increases in respiratory and cardiovascular problems at outdoor pollutant levels well below standards set by such agencies as the US EPA and WHO. Air pollution is associated with large increases in medical expenses, morbidity and is estimated to cause about 800,000 annual premature deaths worldwide [Cohen, A.J., Ross Alexander, H., Ostro, B., Pandey, K.D., Kryzanowski, M., Kunzail, N., et al., 2005. The global burden of disease due to outdoor air pollution. J Toxicol Environ Health A. 68: 1-7.]. Further research on the health effects of air pollution and air pollutant abatement methods should be very helpful to physicians, public health officials, industrialists, politicians and the general public. PMID:16730796

  8. Air pollution effects on ventricular repolarization.

    PubMed

    Lux, Robert L; Pope, C Arden

    2009-05-01

    We conducted a retrospective study of a set of previously published electrocardiographic data to investigate the possible direct association between levels of particulate air pollution and changes in ventricular repolarization -- the cardiac electrophysiologic process that manifests itself as the T wave* of the electrocardiogram (ECG) and that is definitively linked to and responsible for increased arrhythmogenesis. The published findings from this data set demonstrated a clear cardiac effect, namely, a reduction in heart rate variability (HRV) parameter values with increased levels of particulate air pollution (Pope et al. 2004), suggesting possible arrhythmogenic effects. Given this positive finding and the well-established sensitivity of cardiac repolarization to physiologic, pharmacologic, and neurologic interventions, and in light of emerging novel tools for assessing repolarization, we hypothesized that high levels of particulate air pollution would alter repolarization independent of changes in heart rate and, consequently, would increase arrhythmogenic risk. The likely mechanism of any deleterious effects on repolarization would be alteration of sodium, calcium, and potassium channels. The channel's structure, function, and kinetics are responsible for generating the cellular action potentials, which, when summed over the entire heart, result in the waves recorded by the ECG. A positive finding would provide evidence that increased levels of air pollution may be directly linked to increases in arrhythmogenic risk and, potentially, sudden cardiac death. The study population consisted of 88 nonsmoking, elderly subjects in whom multiple, continuous, 24-hour, 2-channel ECG recordings were collected, along with blood samples to evaluate inflammatory mechanisms (not pursued in the current study). The concentration of fine particulate matter (PM2.5, particulate matter with an aerodynamic diameter < or = 2.5 microm) in daily samples was measured or estimated and

  9. European Air Quality and Climate Change: a numerical modeling study

    NASA Astrophysics Data System (ADS)

    Lacressonniere, G.

    2011-12-01

    In the context of climate change, the evolution of air quality in Europe is a challenging scientific question, despite the political measures taken to limit and reduce anthropogenic emissions. Heat waves, changes in transport pathways or synoptic patterns, increase of emissions in other areas in the world, or for instance possible increase of biogenic emissions or changes in deposition and land use may affect adversely future Air Quality levels in Europe. In the context of a project co-funded by the French environment agency ADEME, a numerical modeling study has begun relying on the tools used by Météo-France for its contribution to the 5th IPCC assessment report, to GMES atmospheric services (MACC FP7 project) and to the French national operational Air Quality platform Prév'Air (http://www.prevair.org). In particular, the MOCAGE 3-D chemical transport model (CTM) is used with a configuration comprising a global (2°) and a European domain (0.2°), allowing representation of both long-range transport of pollutants and European Air Quality at relevant resolutions and with a two-ways coupling. MOCAGE includes 47 layers from the surface to 5hPa. The first step of this project was to assess the impact of meteorological forcings, either analyses ("best" meteorology available for the recent past) or climate runs for the current atmosphere, on air quality hindcasts with MOCAGE over Europe. For these climate runs, we rely on Météo-France Earth-System model CNRM-CM, and particularly the ARPEGE-climate general circulation model for the atmosphere. By studying several key variables for Air Quality (surface and low troposphere concentrations of ozone, nitrogen oxides, volatile organic compounds, radicals, PM,...), we investigated the indicators that are robust, through averages over several years, (monthly averages, frequency of exceedances, AOTs, ...) for a given climate when using climatological forcings instead of analyses, which constitutes the reference. Both

  10. Bringing air pollution into the climate change equation.

    PubMed

    Pettersen, Marit Viktoria; Fleck, Fiona

    2014-08-01

    As countries gear up for a major round of international climate talks next year in Paris, the growing problem of air pollution is fast becoming a vital part of the climate change and health debate. Fiona Fleck talks to Marit Viktoria Pettersen. PMID:25177069

  11. Change point analysis of mean annual air temperature in Iran

    NASA Astrophysics Data System (ADS)

    Shirvani, A.

    2015-06-01

    The existence of change point in the mean of air temperature is an important indicator of climate change. In this study, Student's t parametric and Mann-Whitney nonparametric Change Point Models (CPMs) were applied to test whether a change point has occurred in the mean of annual Air Temperature Anomalies Time Series (ATATS) of 27 synoptic stations in different regions of Iran for the period 1956-2010. The Likelihood Ratio Test (LRT) was also applied to evaluate the detected change points. The ATATS of all stations except Bandar Anzali and Gorgan stations, which were serially correlated, were transformed to produce an uncorrelated pre-whitened time series as an input file for the CPMs and LRT. Both the Student's t and Mann-Whitney CPMs detected the change point in the ATATS of (a) Tehran Mehrabad, Abadan, Kermanshah, Khoramabad and Yazd in 1992, (b) Mashhad and Tabriz in 1993, (c) Bandar Anzali, Babolsar and Ramsar in 1994, (d) Kerman and Zahedan in 1996 at 5% significance level. The likelihood ratio test shows that the ATATS before and after detected change points in these 12 stations are normally distributed with different means. The Student's t and Mann-Whitney CPMs suggested different change points for individual stations in Bushehr, Bam, Shahroud, and Gorgan. However, the LRT confirmed the change points in these four stations as 1997, 1996, 1993, and 1996, respectively. No change points were detected in the remaining 11 stations.

  12. "Air pollution in Delhi: Its Magnitude and Effects on Health".

    PubMed

    Rizwan, Sa; Nongkynrih, Baridalyne; Gupta, Sanjeev Kumar

    2013-01-01

    Air pollution is responsible for many health problems in the urban areas. Of late, the air pollution status in Delhi has undergone many changes in terms of the levels of pollutants and the control measures taken to reduce them. This paper provides an evidence-based insight into the status of air pollution in Delhi and its effects on health and control measures instituted. The urban air database released by the World Health Organization in September 2011 reported that Delhi has exceeded the maximum PM10 limit by almost 10-times at 198 μg/m3. Vehicular emissions and industrial activities were found to be associated with indoor as well as outdoor air pollution in Delhi. Studies on air pollution and mortality from Delhi found that all-natural-cause mortality and morbidity increased with increased air pollution. Delhi has taken several steps to reduce the level of air pollution in the city during the last 10 years. However, more still needs to be done to further reduce the levels of air pollution.

  13. Health effects of outdoor air pollution

    PubMed Central

    Abelsohn, Alan; Stieb, Dave M.

    2011-01-01

    Abstract Objective To inform family physicians about the health effects of air pollution and to provide an approach to counseling vulnerable patients in order to reduce exposure. Sources of information MEDLINE was searched using terms relevant to air pollution and its adverse effects. We reviewed English-language articles published from January 2008 to December 2009. Most studies provided level II evidence. Main message Outdoor air pollution causes substantial morbidity and mortality in Canada. It can affect both the respiratory system (exacerbating asthma and chronic obstructive pulmonary disease) and the cardiovascular system (triggering arrhythmias, cardiac failure, and stroke). The Air Quality Health Index (AQHI) is a new communication tool developed by Health Canada and Environment Canada that indicates the level of health risk from air pollution on a scale of 1 to 10. The AQHI is widely reported in the media, and the tool might be of use to family physicians in counseling high-risk patients (such as those with asthma, chronic obstructive pulmonary disease, or cardiac failure) to reduce exposure to outdoor air pollution. Conclusion Family physicians can use the AQHI and its health messages to teach patients with asthma and other high-risk patients how to reduce health risks from air pollution. PMID:21841106

  14. Air pollution holiday effect in metropolitan Kaohsiung

    NASA Astrophysics Data System (ADS)

    Tan, P.; Chen, P. Y.

    2014-12-01

    Different from Taipei, the metropolitan Kaohsiung which is a coastal and industrial city has the major pollution sources from stationary sources such as coal-fired power plants, petrochemical facilities and steel plants, rather than mobile sources. This study was an attempt to conduct a comprehensive and systematical examination of the holiday effect, defined as the difference in air pollutant concentrations between holiday and non-holiday periods, over the Kaohsiung metropolitan area. We documented evidence of a "holiday effect", where concentrations of NOx, CO, NMHC, SO2 and PM10 were significantly different between holidays and non-holidays, in the Kaohsiung metropolitan area from daily surface measurements of seven air quality monitoring stations of the Taiwan Environmental Protection Administration during the Chinese New Year (CNY) and non-Chinese New Year (NCNY) periods of 1994-2010. Concentrations of the five pollutants were lower in the CNY than in the NCNY period, however, that of O3 was higher in the CNY than in the NCNY period and had no holiday effect. The exclusion of the bad air quality day (PSI > 100) and the Lantern Festival Day showed no significant effects on the holiday effects of air pollutants. Ship transportation data of Kaohsiung Harbor Bureau showed a statistically significant difference in the CNY and NCNY period. This difference was consistent with those found in air pollutant concentrations of some industrial and general stations in coastal areas, implying the possible impact of traffic activity on the air quality of coastal areas. Holiday effects of air pollutants over the Taipei metropolitan area by Tan et al. (2009) are also compared.

  15. Changes in airborne fungi from the outdoors to indoor air; large HVAC systems in nonproblem buildings in two different climates.

    PubMed

    Kemp, P C; Neumeister-Kemp, H G; Esposito, B; Lysek, G; Murray, F

    2003-01-01

    Little is known about the changes in occurrence and distribution of airborne fungi as they are transported in the airstream from the outdoor air through the heating, ventilation, and air conditioning (HVAC) system to the indoor air. To better understand this, airborne fungi were analyzed in the HVAC systems of two large office buildings in different climate zones. Fungal samples were taken in each of the walk-in chambers of the HVAC systems using a six-stage Andersen Sampler with malt extract agar. Results showed that fungal species changed with different locations in the HVAC systems. The outdoor air intake produced the greatest filtration effect for both the counts and species of outdoor air fungi. The colony forming unit (CFU) counts and species diversity was further reduced in the air directly after the filters. The cooling coils also had a substantial filtration effect. However, in room air the CFU counts were double and the mixture of fungal species was different from the air leaving the HVAC system at the supply air outlet in most locations. Diffusion of outdoor air fungi to the indoors did not explain the changes in the mixture of airborne fungi from the outdoor air to the indoor air, and some of the fungi present in the indoor air did not appear to be transported indoors by the HVAC systems.

  16. U.S. Air Quality and Health Benefits from Avoided Climate Change under Greenhouse Gas Mitigation.

    PubMed

    Garcia-Menendez, Fernando; Saari, Rebecca K; Monier, Erwan; Selin, Noelle E

    2015-07-01

    We evaluate the impact of climate change on U.S. air quality and health in 2050 and 2100 using a global modeling framework and integrated economic, climate, and air pollution projections. Three internally consistent socioeconomic scenarios are used to value health benefits of greenhouse gas mitigation policies specifically derived from slowing climate change. Our projections suggest that climate change, exclusive of changes in air pollutant emissions, can significantly impact ozone (O3) and fine particulate matter (PM2.5) pollution across the U.S. and increase associated health effects. Climate policy can substantially reduce these impacts, and climate-related air pollution health benefits alone can offset a significant fraction of mitigation costs. We find that in contrast to cobenefits from reductions to coemitted pollutants, the climate-induced air quality benefits of policy increase with time and are largest between 2050 and 2100. Our projections also suggest that increasing climate policy stringency beyond a certain degree may lead to diminishing returns relative to its cost. However, our results indicate that the air quality impacts of climate change are substantial and should be considered by cost-benefit climate policy analyses.

  17. U.S. Air Quality and Health Benefits from Avoided Climate Change under Greenhouse Gas Mitigation.

    PubMed

    Garcia-Menendez, Fernando; Saari, Rebecca K; Monier, Erwan; Selin, Noelle E

    2015-07-01

    We evaluate the impact of climate change on U.S. air quality and health in 2050 and 2100 using a global modeling framework and integrated economic, climate, and air pollution projections. Three internally consistent socioeconomic scenarios are used to value health benefits of greenhouse gas mitigation policies specifically derived from slowing climate change. Our projections suggest that climate change, exclusive of changes in air pollutant emissions, can significantly impact ozone (O3) and fine particulate matter (PM2.5) pollution across the U.S. and increase associated health effects. Climate policy can substantially reduce these impacts, and climate-related air pollution health benefits alone can offset a significant fraction of mitigation costs. We find that in contrast to cobenefits from reductions to coemitted pollutants, the climate-induced air quality benefits of policy increase with time and are largest between 2050 and 2100. Our projections also suggest that increasing climate policy stringency beyond a certain degree may lead to diminishing returns relative to its cost. However, our results indicate that the air quality impacts of climate change are substantial and should be considered by cost-benefit climate policy analyses. PMID:26053628

  18. Air-driven Brazil nut effect

    NASA Astrophysics Data System (ADS)

    Naylor, M.; Swift, Michael; King, P.

    2003-07-01

    A large heavy object may rise to the top of a bed of smaller particles under the influence of vertical vibration, the “Brazil nut effect.” Recently it has been noted that interstitial air can influence the Brazil nut rise time. Here we report that the air movement induced by vertical vibration produces a very strong Brazil nut effect for fine granular beds. We use a porous-bottomed box to investigate the mechanism responsible for this effect and to demonstrate that it is related to the piling of fine beds, first reported by Chladni and studied by Faraday. Both effects are due to the strong interaction of the fine particles with the air, as it is forced through the bed by the vibration.

  19. Estimation of potential evapotranspiration from extraterrestrial radiation, air temperature and humidity to assess future climate change effects on the vegetation of the Northern Great Plains, USA

    USGS Publications Warehouse

    King, David A.; Bachelet, Dominique M.; Symstad, Amy J.; Ferschweiler, Ken; Hobbins, Michael

    2014-01-01

    The potential evapotranspiration (PET) that would occur with unlimited plant access to water is a central driver of simulated plant growth in many ecological models. PET is influenced by solar and longwave radiation, temperature, wind speed, and humidity, but it is often modeled as a function of temperature alone. This approach can cause biases in projections of future climate impacts in part because it confounds the effects of warming due to increased greenhouse gases with that which would be caused by increased radiation from the sun. We developed an algorithm for linking PET to extraterrestrial solar radiation (incoming top-of atmosphere solar radiation), as well as temperature and atmospheric water vapor pressure, and incorporated this algorithm into the dynamic global vegetation model MC1. We tested the new algorithm for the Northern Great Plains, USA, whose remaining grasslands are threatened by continuing woody encroachment. Both the new and the standard temperature-dependent MC1 algorithm adequately simulated current PET, as compared to the more rigorous PenPan model of Rotstayn et al. (2006). However, compared to the standard algorithm, the new algorithm projected a much more gradual increase in PET over the 21st century for three contrasting future climates. This difference led to lower simulated drought effects and hence greater woody encroachment with the new algorithm, illustrating the importance of more rigorous calculations of PET in ecological models dealing with climate change.

  20. Climate change, extreme weather events, air pollution and respiratory health in Europe.

    PubMed

    De Sario, M; Katsouyanni, K; Michelozzi, P

    2013-09-01

    Due to climate change and other factors, air pollution patterns are changing in several urbanised areas of the world, with a significant effect on respiratory health both independently and synergistically with weather conditions; climate scenarios show Europe as one of the most vulnerable regions. European studies on heatwave episodes have consistently shown a synergistic effect of air pollution and high temperatures, while the potential weather-air pollution interaction during wildfires and dust storms is unknown. Allergen patterns are also changing in response to climate change, and air pollution can modify the allergenic potential of pollens, especially in the presence of specific weather conditions. The underlying mechanisms of all these interactions are not well known; the health consequences vary from decreases in lung function to allergic diseases, new onset of diseases, exacerbation of chronic respiratory diseases, and premature death. These multidimensional climate-pollution-allergen effects need to be taken into account in estimating both climate and air pollution-related respiratory effects, in order to set up adequate policy and public health actions to face both the current and future climate and pollution challenges.

  1. Air monitoring of aromatic hydrocarbons during automobile spray painting for developing change schedule of respirator cartridges

    PubMed Central

    2014-01-01

    In the absence of End of Service Life Indicator (ESLI), a cartridge change schedule should be established for ensuring that cartridges are changed before their end of service life. Factors effecting service life of cartridges were evaluated, including the amount of atmospheric contamination with aromatic hydrocarbon vapors in the workplace, temperature, and relative humidity of the air. A new change schedule was established based on comparing the results of air monitoring and workplace conditions, laboratory experiment, and the NIOSH MultiVapor software. Spray painters were being exposed to aromatic hydrocarbons in a range exceeding occupational exposure limits. The cartridge change schedule was not effective and could no longer provide adequate protection against organic contaminants for sprayers. Change schedules for respirator cartridges should be reduced from 16–24 hours to 4 hours. NIOSH’s service life software program could be applied to developing cartridge change schedules. PMID:24468234

  2. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    SciTech Connect

    Rudd, Armin; Bergey, Daniel

    2014-02-01

    In this project, Building America research team Building Science Corporation tested the effectiveness of ventilation systems at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. This was because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four system factor categories: balance, distribution, outside air source, and recirculation filtration. Recommended system factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  3. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    SciTech Connect

    Rudd, A.; Bergey, D.

    2014-02-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. It was inferior because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four System Factor Categories: Balance, Distribution, Outside Air Source, and Recirculation Filtration. Recommended System Factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  4. MODELING THE IMPACT OF AIR POLLUTION ON GLOBAL CLIMATE CHANGE

    EPA Science Inventory

    Tropospheric ozone (O3) and aerosols have major effects on climate and are the two air pollutants of most concern in the developed world. O3 is a major greenhouse gas (GHG) and light-absorbing aerosols such as black carbon (BC) also contribute to global warm...

  5. Air pollutants effects on forest ecosystems

    SciTech Connect

    Not Available

    1985-01-01

    This book presents the papers given at a conference on the effects of acid rain on forests. The conference was sponsored by the National Acid Precipitation Assessment Program (NAPAP). Topics considered at the conference included the status of US research on acid deposition and its effects contributing factors to the decline of forests, evidence for effects on ecosystems, the effects of air pollutants on forest ecosystems in North America and Europe, forest management, and future scientific research programs and management approaches.

  6. Development of Refrigerant Change Indicator and Dirty Air Filter Sensor

    SciTech Connect

    Mei, V.

    2003-06-24

    The most common problems affecting residential and light commercial heating, ventilation, and air-conditioning (HVAC) systems are slow refrigerant leaks and dirty air filters. Equipment users are usually not aware of a problem until most of the refrigerant has escaped or the air filter is clogged with dirt. While a dirty air filter can be detected with a technology based on the air pressure differential across the filter, such as a ''whistling'' indicator, it is not easy to incorporate this technology into existing HVAC diagnostic equipment. Oak Ridge National Laboratory is developing a low-cost, nonintrusive refrigerant charge indicator and dirty air filter detection sensor. The sensors, based on temperature measurements, will be inexpensive and easy to incorporate into existing heat pumps and air conditioners. The refrigerant charge indicator is based on the fact that when refrigerant starts to leak, the evaporator coil temperature starts to drop and the level of liquid subcooling drops. When the coil temperature or liquid subcooling drops below a preset reading, a signal, such as a yellow warning light, can be activated to warn the equipment user that the system is undercharged. A further drop of coil temperature or liquid subcooling below another preset reading would trigger a second warning signal, such as a red warning light, to warn the equipment user that the unit now detects a leak and immediate action should be taken. The warning light cannot be turned off until it is re-set by a refrigeration repairman. To detect clogged air filters, two additional temperature sensors can be applied, one each across the evaporator. When the air filter is accumulating buildup, the temperature differential across the evaporator will increase because of the reduced airflow. When the temperature differential reaches a pre-set reading, a signal will be sent to the equipment user that the air filter needs to be changed. A traditional refrigerant charge indicator requires

  7. The effects of air leaks on solar air heating systems

    NASA Technical Reports Server (NTRS)

    Elkin, R.; Cash, M.

    1979-01-01

    This paper presents the results of an investigation to determine the effects of leakages in collector and duct work on the system performance of a typical single-family residence solar air heating system. Positive (leakage out) and negative (leakage in) pressure systems were examined. Collector and duct leakage rates were varied from 10 to 30 percent of the system flow rate. Within the range of leakage rates investigated, solar contribution to heated space and domestic hot water loads was found to be reduced up to 30 percent from the no-leak system contribution with duct leakage equally divided between supply and return duct; with supply duct leakage greater than return leakage a reduction of up to 35 percent was noted. The negative pressure system exhibited a reduction in solar contribution somewhat larger than the positive pressure system for the same leakage rates.

  8. Extracting changes in air temperature using acoustic coda phase delays.

    PubMed

    Marcillo, Omar; Arrowsmith, Stephen; Whitaker, Rod; Morton, Emily; Scott Phillips, W

    2014-10-01

    Blast waves produced by 60 high-explosive detonations were recorded at short distances (few hundreds of meters); the corresponding waveforms show charge-configuration independent coda-like features (i.e., similar shapes, amplitudes, and phases) lasting several seconds. These features are modeled as reflected and/or scattered waves by acoustic reflectors/scatters surrounding the explosions. Using explosion pairs, relative coda phase delays are extracted and modeled as changes in sound speed due to changes in air temperature. Measurements from nearby weather towers are used for validation. PMID:25324115

  9. Effects of air emissions on wildlife resources. Air pollution and acid rain report No. 1

    SciTech Connect

    Newman, J.R.

    1980-05-01

    This publication describes in general the pathways of contamination, direct and indirect effects of air emissions on wildlife resources, and the potential use of wildlife as biological indicators of air quality degradation. Also included in the report are summaries of air pollution incidents involving wildlife, responses of wildlife to air pollution, major target systems of selected air pollutants, and information on the capacity of some air pollutants to accumulate in body tissues.

  10. Effect of road blockages on local air pollution during the Hong Kong protests and its implications for air quality management.

    PubMed

    Brimblecombe, Peter; Ning, Zhi

    2015-12-01

    Roadside air quality in urban areas is largely affected by the traffic emissions. Changes in emissions and transport control policy are often assumed to yield benefits in air quality, but have often not always been effective in producing perceptible improvements due to the complexity of meteorological conditions. This study evaluates the air quality before, during and after a temporary roadway blockage event in Hong Kong that took place during Hong Kong protests from late September to mid-December, 2014. The local regulatory air quality monitoring data from both roadside and general ambient stations were used to assess the impact of roadway blockages on the air quality. There was a public perception of improved air quality, but analysis of the data shows the changes can be difficult to discern. This study showed some benefits deriving from road blockages on the local air quality, but the impact was not always apparent because of seasonal variation in meteorological conditions and synoptic transport of pollutants. The finding suggests care is required before making policy changes based on claimed benefits of shifting transport routes. The study highlights the needs to remove seasonal and meteorological change when examining air pollution data to develop strategies to improve air quality.

  11. Effect of road blockages on local air pollution during the Hong Kong protests and its implications for air quality management.

    PubMed

    Brimblecombe, Peter; Ning, Zhi

    2015-12-01

    Roadside air quality in urban areas is largely affected by the traffic emissions. Changes in emissions and transport control policy are often assumed to yield benefits in air quality, but have often not always been effective in producing perceptible improvements due to the complexity of meteorological conditions. This study evaluates the air quality before, during and after a temporary roadway blockage event in Hong Kong that took place during Hong Kong protests from late September to mid-December, 2014. The local regulatory air quality monitoring data from both roadside and general ambient stations were used to assess the impact of roadway blockages on the air quality. There was a public perception of improved air quality, but analysis of the data shows the changes can be difficult to discern. This study showed some benefits deriving from road blockages on the local air quality, but the impact was not always apparent because of seasonal variation in meteorological conditions and synoptic transport of pollutants. The finding suggests care is required before making policy changes based on claimed benefits of shifting transport routes. The study highlights the needs to remove seasonal and meteorological change when examining air pollution data to develop strategies to improve air quality. PMID:26245533

  12. Summary Report for the Workshop on Integrating Climate Change Adaption into Air Quality Decision Making

    EPA Science Inventory

    Over the past few decades, air quality planners have forecasted future air pollution levels based on information about changing emissions from stationary and mobile sources, population trends, transportation demand, natural sources of emissions, and other pressures on air quality...

  13. [Airport related air pollution and health effects].

    PubMed

    Iavicoli, Ivo; Fontana, Luca; Ancona, Carla; Forastiere, Francesco

    2014-01-01

    Airport is an extremely complex emission source of airborne pollutants that can have a significant impact on the environment. Indeed, several airborne chemicals emitted during airport activities may significantly get worse air quality and increase exposure level of both airport workers and general population living nearby the airports. In recent years airport traffic has increased and consequently several studies investigated the association between airport-related air pollution and occurrence of adverse health effects, particularly on respiratory system, in exposed workers and general population resident nearby. In this context, we carried out a critical evaluation of the studies that investigated this correlation in order to obtain a deeper knowledge of this issue and to identify the future research needs. Results show that the evidence of association between airport-related air pollution and health effects on workers and residents is still limited. PMID:25115476

  14. [Airport related air pollution and health effects].

    PubMed

    Iavicoli, Ivo; Fontana, Luca; Ancona, Carla; Forastiere, Francesco

    2014-01-01

    Airport is an extremely complex emission source of airborne pollutants that can have a significant impact on the environment. Indeed, several airborne chemicals emitted during airport activities may significantly get worse air quality and increase exposure level of both airport workers and general population living nearby the airports. In recent years airport traffic has increased and consequently several studies investigated the association between airport-related air pollution and occurrence of adverse health effects, particularly on respiratory system, in exposed workers and general population resident nearby. In this context, we carried out a critical evaluation of the studies that investigated this correlation in order to obtain a deeper knowledge of this issue and to identify the future research needs. Results show that the evidence of association between airport-related air pollution and health effects on workers and residents is still limited.

  15. Earth Under Siege: From Air Pollution to Global Change

    NASA Astrophysics Data System (ADS)

    Friend, James P.

    Lucky indeed are the students taking Richard Turco's course and using his book, Earth Under Siege: From Air Pollution to Global Change. They have an enthusiastic and communicative lecturer who is a true authority in his field and who passionately devotes his efforts to enlightening his students.The passion is evident in the text, but it never interferes with the rigor of the material presented.Earth Under Siege is based on lectures given by Turco in a popular course for undergraduate students of all stripes at the University of California at Los Angeles. Student knowledge that is provided by a high school college preparatory curriculum is assumed.The style is engagingly informal and the book is a delight to read. Sprinkled throughout are pithy comments, many humorous, that are designed to heighten student understanding and interest. They also reveal Turco's personal opinions about issues of air pollution. However, despite the title, it is clear that Turco is not an environmental zealot. He is scientifically accurate and thorough in presenting vital information about air pollution on all scales, local through global. He is also clear-eyed and nondoctrinaire in presenting social, political, and economic aspects of air pollution. His devotion is to the education of individuals who can become informed members of an environmentally aware society.

  16. Effecting dietary change.

    PubMed

    Adamson, Ashley J; Mathers, John C

    2004-11-01

    A world epidemic of diet-related chronic disease is currently being faced. In the UK incidence of obesity alone has tripled in the last 20 years and this trend is predicted to continue. Consensus exists for the urgent need for a change in diet and other lifestyle factors and for the direction and targets for this change. The evidence for how this change can be achieved is less certain. It has been established that disease processes begin in childhood. Recent evidence indicates that dietary habits too are established in childhood but that these habits are amenable to change. While establishing a healthy lifestyle in childhood is paramount, interventions have the potential to promote positive change throughout the life course. Success in reversing current trends in diet-related disease will depend on commitment from legislators, health professionals, industry and individuals, and this collaboration must seek to address not only the food choices of the individual but also the environment that influences such choices. Recent public health policy development in England, if fully supported and implemented, is a positive move towards this goal. Evidence for effective strategies to promote dietary change at the individual level is emerging and three reviews of this evidence are discussed. In addition, three recent dietary intervention studies, in three different settings and with different methods and aims, are presented to illustrate methods of effecting dietary change. Further work is required on what factors influence the eating behaviour and physical activity of individuals. There is a need for further theory-based research on which to develop more effective strategies to enable individuals to adopt healthier lifestyles.

  17. Health Impacts of Air Pollution Under a Changing Climate

    NASA Astrophysics Data System (ADS)

    Kinney, P. L.; Knowlton, K.; Rosenthal, J.; Hogrefe, C.; Rosenzweig, C.; Solecki, W.

    2003-12-01

    Outdoor air pollution remains a serious public health problem in cities throughout the world. In the US, despite considerable progress in reducing emissions over the past 30 years, as many as 50,000 premature deaths each year have been attributed to airborne particulate matter alone. Tropospheric ozone has been associated with increased daily mortality and hospitalization rates, and with a variety of related respiratory problems. Weather plays an important role in the transport and transformation of air pollution. In particular, a warming climate is likely to promote the atmospheric reactions that are responsible for ozone and secondary aerosol production, as well as increasing emissions of many of their volatile precursors. Increasingly, efforts to address urban air pollution problems throughout the world will be complicated by trends and variability in climate. The New York Climate and Health Project (NYCHP) is developing and applying tools for integrated assessment of health impacts from air pollution and heat associated with climate and land-use changes in the New York City metropolitan region. Global climate change is modeled over the 21st century based on the Intergovernmental Panel on Climate Change (IPCC) A2 greenhouse gas emissions scenario using the Goddard Institute for Space Studies (GISS) Global Atmosphere-Ocean Model (GCM). Meteorological fields are downscaled to a 36 km grid over the eastern US using the Penn State/NCAR MM5 mesoscale meteorological model. MM5 results are then used as input to the Community Multiscale Air Quality (CMAQ) model for simulating air quality, with emissions based on the Sparse Matrix Operator Kernel Emissions Modeling System (SMOKE). To date, simulations have been performed for five summer seasons each during the 1990s and the 2050s. An evaluation of the present-day climate and air quality predictions indicates that the modeling system largely captures the observed climate-ozone system. Analysis of future-year predictions

  18. Climate change and air pollution jointly creating nightmare for tourism industry.

    PubMed

    Sajjad, Faiza; Noreen, Umara; Zaman, Khalid

    2014-11-01

    The objective of the study is to examine the long-run and causal relationship between climate change (i.e., greenhouse gas emissions, hydrofluorocarbons, per fluorocarbons, and sulfur hexafluoride), air pollution (i.e., methane emissions, nitrous oxide emissions, and carbon dioxide emissions), and tourism development indicators (i.e., international tourism receipts, international tourism expenditures, natural resource depletion, and net forest depletion) in the World's largest regions. The aggregate data is used for robust analysis in the South Asia, the Middle East and North Africa, sub-Saharan Africa, and East Asia and the Pacific regions, over a period of 1975-2012. The results show that climatic factors and air pollution have a negative impact on tourism indicators in the form of deforestation and natural resource depletion. The impact is evident, as we have seen the systematic eroding of tourism industry, due to severe changes in climate and increasing strain of air pollution. There are several channels of cause-effect relationship between the climatic factors, air pollution, and tourism indicators in the World's region. The study confirms the unidirectional, bidirectional, and causality independent relationship between climatic factors, air pollution, and tourism indicators in the World. It is conclusive that tourism industry is facing all time bigger challenges of reduce investment, less resources, and minor importance from the government agencies because of the two broad challenges, i.e., climate change and air pollution, putting them in a dismal state.

  19. Climate change, air pollution and extreme events leading to increasing prevalence of allergic respiratory diseases.

    PubMed

    D'Amato, Gennaro; Baena-Cagnani, Carlos E; Cecchi, Lorenzo; Annesi-Maesano, Isabella; Nunes, Carlos; Ansotegui, Ignacio; D'Amato, Maria; Liccardi, Gennaro; Sofia, Matteo; Canonica, Walter G

    2013-01-01

    The prevalence of asthma and allergic diseases has increased dramatically during the past few decades not only in industrialized countries. Urban air pollution from motor vehicles has been indicated as one of the major risk factors responsible for this increase.Although genetic factors are important in the development of asthma and allergic diseases, the rising trend can be explained only in changes occurred in the environment. Despite some differences in the air pollution profile and decreasing trends of some key air pollutants, air quality is an important concern for public health in the cities throughout the world.Due to climate change, air pollution patterns are changing in several urbanized areas of the world, with a significant effect on respiratory health.The observational evidence indicates that recent regional changes in climate, particularly temperature increases, have already affected a diverse set of physical and biological systems in many parts of the world. Associations between thunderstorms and asthma morbidity in pollinosis subjects have been also identified in multiple locations around the world.Allergens patterns are also changing in response to climate change and air pollution can modify the allergenic potential of pollens especially in presence of specific weather conditions.The underlying mechanisms of all these interactions are not well known yet. The consequences on health vary from decreases in lung function to allergic diseases, new onset of diseases, and exacerbation of chronic respiratory diseases.Factor clouding the issue is that laboratory evaluations do not reflect what happens during natural exposition, when atmospheric pollution mixtures in polluted cities are inhaled. In addition, it is important to recall that an individual's response to pollution exposure depends on the source and components of air pollution, as well as meteorological conditions. Indeed, some air pollution-related incidents with asthma aggravation do not depend

  20. Climate change, air pollution and extreme events leading to increasing prevalence of allergic respiratory diseases

    PubMed Central

    2013-01-01

    The prevalence of asthma and allergic diseases has increased dramatically during the past few decades not only in industrialized countries. Urban air pollution from motor vehicles has been indicated as one of the major risk factors responsible for this increase. Although genetic factors are important in the development of asthma and allergic diseases, the rising trend can be explained only in changes occurred in the environment. Despite some differences in the air pollution profile and decreasing trends of some key air pollutants, air quality is an important concern for public health in the cities throughout the world. Due to climate change, air pollution patterns are changing in several urbanized areas of the world, with a significant effect on respiratory health. The observational evidence indicates that recent regional changes in climate, particularly temperature increases, have already affected a diverse set of physical and biological systems in many parts of the world. Associations between thunderstorms and asthma morbidity in pollinosis subjects have been also identified in multiple locations around the world. Allergens patterns are also changing in response to climate change and air pollution can modify the allergenic potential of pollens especially in presence of specific weather conditions. The underlying mechanisms of all these interactions are not well known yet. The consequences on health vary from decreases in lung function to allergic diseases, new onset of diseases, and exacerbation of chronic respiratory diseases. Factor clouding the issue is that laboratory evaluations do not reflect what happens during natural exposition, when atmospheric pollution mixtures in polluted cities are inhaled. In addition, it is important to recall that an individual’s response to pollution exposure depends on the source and components of air pollution, as well as meteorological conditions. Indeed, some air pollution-related incidents with asthma aggravation do not

  1. Climate change, air pollution and extreme events leading to increasing prevalence of allergic respiratory diseases.

    PubMed

    D'Amato, Gennaro; Baena-Cagnani, Carlos E; Cecchi, Lorenzo; Annesi-Maesano, Isabella; Nunes, Carlos; Ansotegui, Ignacio; D'Amato, Maria; Liccardi, Gennaro; Sofia, Matteo; Canonica, Walter G

    2013-02-11

    The prevalence of asthma and allergic diseases has increased dramatically during the past few decades not only in industrialized countries. Urban air pollution from motor vehicles has been indicated as one of the major risk factors responsible for this increase.Although genetic factors are important in the development of asthma and allergic diseases, the rising trend can be explained only in changes occurred in the environment. Despite some differences in the air pollution profile and decreasing trends of some key air pollutants, air quality is an important concern for public health in the cities throughout the world.Due to climate change, air pollution patterns are changing in several urbanized areas of the world, with a significant effect on respiratory health.The observational evidence indicates that recent regional changes in climate, particularly temperature increases, have already affected a diverse set of physical and biological systems in many parts of the world. Associations between thunderstorms and asthma morbidity in pollinosis subjects have been also identified in multiple locations around the world.Allergens patterns are also changing in response to climate change and air pollution can modify the allergenic potential of pollens especially in presence of specific weather conditions.The underlying mechanisms of all these interactions are not well known yet. The consequences on health vary from decreases in lung function to allergic diseases, new onset of diseases, and exacerbation of chronic respiratory diseases.Factor clouding the issue is that laboratory evaluations do not reflect what happens during natural exposition, when atmospheric pollution mixtures in polluted cities are inhaled. In addition, it is important to recall that an individual's response to pollution exposure depends on the source and components of air pollution, as well as meteorological conditions. Indeed, some air pollution-related incidents with asthma aggravation do not depend

  2. Respiratory effects of indoor air pollution

    SciTech Connect

    Samet, J.M.; Marbury, M.C.; Spengler, J.D.

    1987-05-01

    Since the early 1970s, the health effects of indoor air pollution have been investigated with increasing intensity. A large body of literature is now available on diverse aspects of indoor air pollution: sources, concentrations, health effects, engineering, and policy. This article provides a selective summary of this new information with an emphasis on health effects relevant to health care practitioners concerned primarily with immunologically mediated respiratory diseases. We address exposures associated with acute and chronic respiratory effects: tobacco smoke, nitrogen dioxide, wood smoke, and formaldehyde. The article also describes the diverse health problems experienced by workers in newer sealed office buildings. The importance of indoor concentrations in determining personal exposures to pollutants is emphasized.

  3. Impacts of Regional Climate Change on Biogenic Emissions and Air Quality

    SciTech Connect

    Zhang, Yang; Hu, X.-M.; Leung, Lai R.; Gustafson, William I.

    2008-09-25

    Regional air quality simulations are conducted for four summers (2001, 2002, 2051, and 2052) to examine the sensitivity of air quality to potential regional climate change in the U.S. In response to the predicted warmer climate in 2051/2052, emissions of isoprene and terpene increase by 20-92.1% and 20-56%, respectively, over most of the domain. Surface O3, which is sensitive to changes in temperature and solar radiation but relatively insensitive to changes in PBL height and cloud fraction, increase by up to 19-20%. PM2.5, its compositions, and visibility exhibit an overall negative sensitivity (decrease by up to 40%), resulting from the competition of the negative temperature effect and positive emission/temperature effects. While the response of dry deposition is governed by the negative sensitivity of surface resistances, that of wet deposition is either positive or negative, depending on the relative dominancy of changes in PM2.5 and precipitation. Overall the net climatic effect dominates changes in O3, PM2.5, wet and total deposition, and the net biogenic emission effect is important for isoprene, organic matter, visibility, and dry deposition over several regions. Models that do not include secondary organic aerosol formation from isoprene photooxidation may underestimate by at least 20% the air quality responses to future climate changes over many areas of the modeling domain. Both regional climate and air quality exhibit interannual variability, particularly in temperature, isoprene emissions, and PM2.5 concentrations, indicating a need for long-term simulations to predict future air quality.

  4. Physical effects of negative air ions in a wet sauna

    NASA Astrophysics Data System (ADS)

    Watanabe, I.; Noro, Hiroshi; Ohtsuka, Yoshinori; Mano, Yukio; Agishi, Yuko

    The physical effects of negative air ions on humans were determined in an experimental sauna room equipped with an ionizer. Thirteen healthy persons took a wet sauna bath (dry bulb temperature 42° C, relative humidity 100%, 10 min exposure) with or without negative air ions. The subjects were not told when they were being exposed to negative air ions. There were no differences in the moods of these persons or changes in their blood pressures between the two saunas. The surface temperatures of the foreheads, hands, and legs in the sauna with negative ions were significantly higher than those in the sauna without ions. The pulse rates and sweat produced in the sauna with ions were singificantly higher than those in the sauna without ions. The results suggest that negative ions may amplify the effects on humans of the sauna.

  5. Regional volume changes in canine lungs suspended in air

    NASA Technical Reports Server (NTRS)

    Abbrecht, Peter H.; Kyle, Richard R.; Bryant, Howard J.; Feuerstein, Irwin

    1995-01-01

    The purpose of this study was to determine the effect of the absence of a pleural pressure gradient (simulating the presumed condition found in microgravity) upon regional expansion of the lung. We attempted to produce a uniform pressure over the surface of the lung by suspending excised lungs in air. Such studies should help determine whether or not the absence of a pleural pressure gradient leads to uniform ventilation. A preparation in which there is no pleural pressure gradient should also be useful in studying non-gravitational effects on ventilation distribution.

  6. Cardiovascular Effects of Nickel in Ambient Air

    PubMed Central

    Lippmann, Morton; Ito, Kazuhiko; Hwang, Jing-Shiang; Maciejczyk, Polina; Chen, Lung-Chi

    2006-01-01

    Background Fine particulate matter (FPM) in ambient air causes premature mortality due to cardiac disease in susceptible populations. Objective Our objective in this study was to determine the most influential FPM components. Methods A mouse model of atherosclerosis (ApoE−/−) was exposed to either filtered air or concentrated FPM (CAPs) in Tuxedo, New York (85 μg/m3 average, 6 hr/day, 5 days/week, for 6 months), and the FPM elemental composition was determined for each day. We also examined associations between PM components and mortality for two population studies: National Mortality and Morbidity Air Pollution Study (NMMAPS) and Hong Kong. Results For the CAPs-exposed mice, the average of nickel was 43 ng/m3, but on 14 days, there were Ni peaks at ~ 175 ng/m3 and unusually low FPM and vanadium. For those days, back-trajectory analyses identified a remote Ni point source. Electrocardiographic measurements on CAPs-exposed and sham-exposed mice showed Ni to be significantly associated with acute changes in heart rate and its variability. In NMMAPS, daily mortality rates in the 60 cities with recent speciation data were significantly associated with average Ni and V, but not with other measured species. Also, the Hong Kong sulfur intervention produced sharp drops in sulfur dioxide, Ni, and V, but not other components, corresponding to the intervention-related reduction in cardiovascular and pulmonary mortality. Conclusions Known biological mechanisms cannot account for the significant associations between Ni with the acute cardiac function changes in the mice or with cardiovascular mortality in people at low ambient air concentrations; therefore, further research is needed. PMID:17107850

  7. Changes in the frequency of extreme air pollution events over the Eastern United States and Europe

    NASA Astrophysics Data System (ADS)

    Rieder, H. E.; Fiore, A. M.; Polvani, L. M.; Lamarque, J.-F.; Fang, Y.; Staehelin, J.

    2012-04-01

    Over the past few decades, thresholds for national air quality standards, intended to protect public health and welfare, have been lowered repeatedly. At the same time observations, over Europe and the Eastern U.S., demonstrate that extreme air pollution events (high O3 and PM2.5) are typically associated with stagnation events. Recent work showed that in a changing climate high air pollution events are likely to increase in frequency and duration. Within this work we examine meteorological and surface ozone observations from CASTNet over the U.S. and EMEP over Europe. With innovative statistical tools - i.e., statistics of extremes (EVT) - we analyze the frequency distribution of extreme air pollution events over the Eastern United States and Europe. The upper tail of observed values at individual stations (e.g., within the CASTNet), i.e., the extremes (maximum daily 8-hour average (MDA8) O3>60ppb) are poorly described by a Gaussian distribution. However, further analysis showed that applying Peak-Over-Threshold-models, better capture the extremes and allows us to estimate return levels of pollution events above certain threshold values of interest. The results show that changes in national ambient air quality standards had significant effect on the occurrence frequency of high air pollution episodes.

  8. Climate change and the meteorological drivers of PM air pollution: Understanding U.S. particulate matter concentrations in a changing climate

    EPA Science Inventory

    Particulate matter (PM) air pollution is a serious public health issue for the United States. While there is a growing body of evidence that climate change will partially counter the effectiveness of future precursor emission reductions to reduce ozone (O3) air pollution, the lin...

  9. The Air Toxics Health Effects Database (ATHED)

    SciTech Connect

    Woodall, George M. Smith, Roy L.

    2008-11-15

    The Air Toxics Health Effects Database (ATHED) is currently used by the EPA's Office of Air Quality Planning and Standards (OAQPS) to support risk assessments for the Residual Risk Program. An assessment of the residual risk is required to be performed at a specified time (typically 8years) following the promulgation of a technology-based Maximum Achievable Control Technologies (MACT) standard. The goal of the Residual Risk Program is to assure that the risk that remains after MACT standards are implemented (i.e., the 'residual risk') is acceptable, and if not, to propose additional regulations to mitigate those risks. ATHED maintains all available reference values for each chemical as separate data records, and includes values for all exposure durations (acute, short-term, subchronic and chronic). These values are used as benchmarks to determine acceptable exposure levels to the hazardous air pollutants (HAPs) listed in Section 112 of the Clean Air Act. ATHED also provides useful background information on the uncertainty and/or modifying factors that were applied in the derivation of each reference value, as well as the point of departure and the critical study/studies. To facilitate comparisons across durations for a specific chemical, ATHED data can be graphically presented.

  10. Health Effects of Climate Change

    MedlinePlus

    ... For example, existing investments in research on air pollution and respiratory disease; characteristics of vector range; and effects of acute and chronic exposure to agricultural chemicals are yielding important research advances that may ...

  11. Considering Climate Change in U.S. Air Quality Management

    SciTech Connect

    Hogrefe, C.; Leung, Lai R.; Mickley, L. J.; Hunt, Sherri W.; Winner, D. A.

    2005-10-01

    Despite the challenges in linking global and regional processes, evidence from recent studies suggests that the effects of a changing climate should not be neglected when planning for the future attainment of regional-scale ozone standards such as the U.S. NAAQS. Research underway should provide insight regarding the impact of climate change on Ozone and PM2.5 and of the complex interaction of climate, land-use, and technology change.

  12. The Effects of Air Pollution and Temperature on COPD

    PubMed Central

    Hansel, Nadia N.; McCormack, Meredith C.; Kim, Victor

    2016-01-01

    Chronic Obstructive Pulmonary Disease (COPD) affects 12–16 million people in the United States and is the third-leading cause of death. In developed countries, smoking is the greatest risk factor for the development of COPD, but other exposures also contribute to the development and progression of the disease. Several studies suggest, though are not definitive, that outdoor air pollution exposure is linked to the prevalence and incidence of COPD. Among individuals with COPD, outdoor air pollutants are associated with loss of lung function and increased respiratory symptoms. In addition, outdoor air pollutants are also associated with COPD exacerbations and mortality. There is much less evidence for the impact of indoor air on COPD, especially in developed countries in residences without biomass exposure. The limited existing data suggests that indoor particulate matter and nitrogen dioxide concentrations are linked to increased respiratory symptoms among patients with COPD. In addition, with the projected increases in temperature and extreme weather events in the context of climate change there has been increased attention to the effects of heat exposure. Extremes of temperature—both heat and cold—have been associated with increased respiratory morbidity in COPD. Some studies also suggest that temperature may modify the effect of pollution exposure and though results are not conclusive, understanding factors that may modify susceptibility to air pollution in patients with COPD is of utmost importance. PMID:26683097

  13. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  14. Effects of particulate air pollution on asthmatics

    SciTech Connect

    Perry, G.B.; Chai, H.; Dickey, D.W.; Jones, R.H.; Kinsman, R.A.; Morrill, C.G.; Spector, S.L.; Weiser, P.C.

    1983-01-01

    Twenty-four asthmatic subjects in Denver were followed from January through March 1979, a three-month period in which Denver air pollution levels are generally high and variable. Dichotomous, virtual impactor samplers provided daily measurements (micrograms/m3) of inhaled particulate matter (total mass, sulfates, and nitrates) for coarse (2.5--15 micrograms in aerodynamic diameter) and fine fractions (less than 2.5 micrometers). Carbon monoxide, sulfur dioxide, ozone, temperature, and barometric pressure were also measured. Twice daily measurements of each subject's peak expiratory flow rates, use of as-needed aerosolized bronchodilators, and report of airways obstruction symptoms characteristic of asthma were tested for relationships to air pollutants using a random effects model across subjects. During the time actually observed, there were very few days in which high levels of suspended particulates were recorded. Of the environmental variables studied, only fine nitrates were associated with increased symptom reports and increased aerosolized bronchodilator usage.

  15. Chronic Effects of Air Pollution are Probably Overestimated.

    PubMed

    Boffetta, Paolo; La Vecchia, Carlo; Moolgavkar, Suresh

    2015-05-01

    Inappropriate measures of exposure, including inadequate consideration of latency in the analysis of chronic effects of air pollution, may lead to overestimation of the impact of air pollution on health effects. A relatively simple way to check the plausibility of results on chronic effects of air pollution would be to report in parallel the smoking-associated risks.

  16. Regional change in snow water equivalent-surface air temperature relationship over Eurasia during boreal spring

    NASA Astrophysics Data System (ADS)

    Wu, Renguang; Chen, Shangfeng

    2016-10-01

    Present study investigates local relationship between surface air temperature and snow water equivalent (SWE) change over mid- and high-latitudes of Eurasia during boreal spring. Positive correlation is generally observed around the periphery of snow covered region, indicative of an effect of snow on surface temperature change. In contrast, negative correlation is usually found over large snow amount area, implying a response of snow change to wind-induced surface temperature anomalies. With the seasonal retreat of snow covered region, region of positive correlation between SWE and surface air temperature shifts northeastward from March to May. A diagnosis of surface heat flux anomalies in April suggests that the snow impact on surface air temperature is dominant in east Europe and west Siberia through modulating surface shortwave radiation. In contrast, atmospheric effect on SWE is important in Siberia and Russia Far East through wind-induced surface sensible heat flux change. Further analysis reveals that atmospheric circulation anomalies in association with snowmelt over east Siberia may be partly attributed to sea surface temperature anomalies in the North Atlantic and the atmospheric circulation anomaly pattern associated with snowmelt over Russia Far East has a close association with the Arctic Oscillation.

  17. Global topics and novel approaches in the study of air pollution, climate change and forest ecosystems.

    PubMed

    Sicard, Pierre; Augustaitis, Algirdas; Belyazid, Salim; Calfapietra, Carlo; de Marco, Alessandra; Fenn, Mark; Bytnerowicz, Andrzej; Grulke, Nancy; He, Shang; Matyssek, Rainer; Serengil, Yusuf; Wieser, Gerhard; Paoletti, Elena

    2016-06-01

    Research directions from the 27th conference for Specialists in Air Pollution and Climate Change Effects on Forest Ecosystems (2015) reflect knowledge advancements about (i) Mechanistic bases of tree responses to multiple climate and pollution stressors, in particular the interaction of ozone (O3) with nitrogen (N) deposition and drought; (ii) Linking genetic control with physiological whole-tree activity; (iii) Epigenetic responses to climate change and air pollution; (iv) Embedding individual tree performance into the multi-factorial stand-level interaction network; (v) Interactions of biogenic and anthropogenic volatile compounds (molecular, functional and ecological bases); (vi) Estimating the potential for carbon/pollution mitigation and cost effectiveness of urban and peri-urban forests; (vii) Selection of trees adapted to the urban environment; (viii) Trophic, competitive and host/parasite relationships under changing pollution and climate; (ix) Atmosphere-biosphere-pedosphere interactions as affected by anthropospheric changes; (x) Statistical analyses for epidemiological investigations; (xi) Use of monitoring for the validation of models; (xii) Holistic view for linking the climate, carbon, N and O3 modelling; (xiii) Inclusion of multiple environmental stresses (biotic and abiotic) in critical load determinations; (xiv) Ecological impacts of N deposition in the under-investigated areas; (xv) Empirical models for mechanistic effects at the local scale; (xvi) Broad-scale N and sulphur deposition input and their effects on forest ecosystem services; (xvii) Measurements of dry deposition of N; (xviii) Assessment of evapotranspiration; (xix) Remote sensing assessment of hydrological parameters; and (xx) Forest management for maximizing water provision and overall forest ecosystem services. Ground-level O3 is still the phytotoxic air pollutant of major concern to forest health. Specific issues about O3 are: (xxi) Developing dose-response relationships and

  18. Isotope effect of mercury diffusion in air

    PubMed Central

    Koster van Groos, Paul G.; Esser, Bradley K.; Williams, Ross W.; Hunt, James R.

    2014-01-01

    Identifying and reducing impacts from mercury sources in the environment remains a considerable challenge and requires process based models to quantify mercury stocks and flows. The stable isotope composition of mercury in environmental samples can help address this challenge by serving as a tracer of specific sources and processes. Mercury isotope variations are small and result only from isotope fractionation during transport, equilibrium, and transformation processes. Because these processes occur in both industrial and environmental settings, knowledge of their associated isotope effects is required to interpret mercury isotope data. To improve the mechanistic modeling of mercury isotope effects during gas phase diffusion, an experimental program tested the applicability of kinetic gas theory. Gas-phase elemental mercury diffusion through small bore needles from finite sources demonstrated mass dependent diffusivities leading to isotope fractionation described by a Rayleigh distillation model. The measured relative atomic diffusivities among mercury isotopes in air are large and in agreement with kinetic gas theory. Mercury diffusion in air offers a reasonable explanation of recent field results reported in the literature. PMID:24364380

  19. Cost analysis of impacts of climate change on regional air quality.

    PubMed

    Liao, Kuo-Jen; Tagaris, Efthimios; Russell, Armistead G; Amar, Praveen; He, Shan; Manomaiphiboon, Kasemsan; Woo, Jung-Hun

    2010-02-01

    Climate change has been predicted to adversely impact regional air quality with resulting health effects. Here a regional air quality model and a technology analysis tool are used to assess the additional emission reductions required and associated costs to offset impacts of climate change on air quality. Analysis is done for six regions and five major cities in the continental United States. Future climate is taken from a global climate model simulation for 2049-2051 using the Intergovernmental Panel on Climate Change (IPCC) A1B emission scenario, and emission inventories are the same as current ones to assess impacts of climate change alone on air quality and control expenses. On the basis of the IPCC A1B emission scenario and current control technologies, least-cost sets of emission reductions for simultaneously offsetting impacts of climate change on regionally averaged 4th highest daily maximum 8-hr average ozone and yearly averaged PM2.5 (particulate matter [PM] with an aerodynamic diameter less than 2.5 microm) for the six regions examined are predicted to range from $36 million (1999$) yr(-1) in the Southeast to $5.5 billion yr(-1) in the Northeast. However, control costs to offset climate-related pollutant increases in urban areas can be greater than the regional costs because of the locally exacerbated ozone levels. An annual cost of $4.1 billion is required for offsetting climate-induced air quality impairment in 2049-2051 in the five cities alone. Overall, an annual cost of $9.3 billion is estimated for offsetting climate change impacts on air quality for the six regions and five cities examined. Much of the additional expense is to reduce increased levels of ozone. Additional control costs for offsetting the impacts everywhere in the United States could be larger than the estimates in this study. This study shows that additional emission controls and associated costs for offsetting climate impacts could significantly increase currently estimated

  20. Social Justice Is in the Air: Teaching Climate Change and Air Pollution with Scientific and Social Inquiry

    NASA Astrophysics Data System (ADS)

    Hahnenberger, M.

    2014-12-01

    The intersection of environmental with social problems is a growing area of concern for scientists, policy makers, and citizens. Climate change and air pollution are two current environmental issues holding the public's attention which require collaboration of all stakeholders to create meaningful solutions. General education science courses are critical venues to engage students in the intersection of science with society. Effective teaching methods for these intersections include case studies, gallery walks, and town hall meetings. A case study from California explores how air quality has greatly improved in Los Angeles in the past 20 years, however residents of neighborhoods with lower socioeconomic status are still exposed to high levels of air pollutants. Students analyze scientific and health data to develop understanding and expertise in the problem, and are then tasked with developing a cost-benefit analysis of solutions. Gallery walks can be used to connect natural phenomena, such as hurricanes and severe weather, with their human impacts. Students bring their personal experiences with disasters and recovery to analyze how societies should deal with the changing climate and weather risks in their region, the country, or across the world. Town hall meetings allow students to gain expertise and perspective while embodying a role as a particular stakeholder in a climate mitigation or adaptation issue. A successful application of this method is a discussion of whether a resort community should be rebuilt on a barrier island after being destroyed in a category 3 hurricane. Stakeholders which students take on as roles have included climate scientists, homeowners, emergency managers, meteorologists, and others. Including distinct connections to social issues in introductory science courses helps students to not only engage with the material in a deeper way, but also helps to create critical thinkers who will become better citizens for tomorrow.

  1. Indoor air pollution: Acute adverse health effects and host susceptibility

    SciTech Connect

    Zummo, S.M.; Karol, M.H.

    1996-01-01

    Increased awareness of the poor quality of indoor air compared with outdoor air has resulted in a significant amount of research on the adverse health effects and mechanisms of action of indoor air pollutants. Common indoor air agents are identified, along with resultant adverse health effects, mechanisms of action, and likely susceptible populations. Indoor air pollutants range from biological agents (such as dust mites) to chemical irritants (such as nitrogen dioxide, carbon monoxide, sulfur dioxide, formaldehyde, and isocyanates). These agents may exert their effects through allergic as well as nonallergic mechanisms. While the public does not generally perceive poor indoor air quality as a significant health risk, increasing reports of illness related to indoor air and an expanding base of knowledge on the health effects of indoor air pollution are likely to continue pushing the issue to the forefront.

  2. Estimating the change of porosity in the saturated zone during air sparging.

    PubMed

    Tsai, Yih-jin; Kuo, Yu-chia; Chen, Tsu-chi; Chou, Feng-chih

    2006-01-01

    Air sparging is a remedial method for groundwater. The remedial region is similar to the air flow region in the saturated zone. If soil particles are transported during air sparging, the porosity distributions in the saturated zone change, which may alter the flow path of the air. To understand better the particle movement, this study performed a sandbox test to estimate the soil porosity change during air sparging. A clear fracture was formed and the phenomenon of particle movement was observed when the air injection was started. The moved sand filled the porous around the fracture and the reparked sand filled the fracture, reducing the porosity around the fracture. The results obtained from the photographs of the sandbox, the current measurements and the direct sand sample measurements were close to each other and are credible. Therefore, air injection during air sparging causes sand particle movement of sand, altering the characteristic of the sand matrix and the air distribution.

  3. Air pollution effects due to deregulation of the electric industry

    NASA Astrophysics Data System (ADS)

    Davoodi, Khojasteh Riaz

    The Energy Policy Act of 1992 introduced the concept of open-access into the electric utility industry which allows privately-owned utilities to transmit power produced by non-utility generators and independent power producers (IPPs). In April 1996, the Federal Energy Regulatory Commission (FERC) laid down the final rules (Orders No. 888 & No. 889), which required utilities to open their transmission lines to any power producer and charge them no more than what they pay for the use of their own lines. These rules set the stage for the retail sale of electricity to industrial, commercial and residential utility customers; non-utility generators (Nugs); and power marketers. These statutory, regulatory and administrative changes create for the electric utility industry two different forces that contradict each other. The first is the concept of competition among utility companies; this places a greater emphasis on electric power generation cost control and affects generation/fuel mix selection and demand side management (DSM) activities. The second force, which is converse to the first, is that utilities are major contributors to the air pollution burden in the United States and environmental concerns are forcing them to reduce emissions of air pollutants by using more environmentally friendly fuels and implementing energy saving programs. This study evaluates the impact of deregulation within the investor owned electric utilities and how this deregulation effects air quality by investigating the trend in demand side management programs and generation/fuel mix. A survey was conducted of investor owned utilities and independent power producers. The results of the survey were analyzed by analysis of variance and regression analysis to determine the impact to Air Pollution. An air Quality Impact model was also developed in this study. This model consists of six modules: (1) demand side management and (2) consumption of coal, (3) gas, (4) renewable, (5) oil and (6

  4. Clearing the air: a review of the effects of particulate matter air pollution on human health.

    PubMed

    Anderson, Jonathan O; Thundiyil, Josef G; Stolbach, Andrew

    2012-06-01

    -dependent relationship between PM and human disease, and that removal from a PM-rich environment decreases the prevalence of these diseases. While further study is needed to elucidate the effects of composition, chemistry, and the PM effect on susceptible populations, the preponderance of data shows that PM exposure causes a small but significant increase in human morbidity and mortality. Most sources agree on certain "common sense" recommendations, although there are lonely limited data to support them. Indoor PM exposure can be reduced by the usage of air conditioning and particulate filters, decreasing indoor combustion for heating and cooking, and smoking cessation. Susceptible populations, such as the elderly or asthmatics, may benefit from limiting their outdoor activity during peak traffic periods or poor air quality days. These simple changes may benefit individual patients in both short-term symptomatic control and long-term cardiovascular and respiratory complications.

  5. Retinal Microvascular Responses to Short-Term Changes in Particulate Air Pollution in Healthy Adults

    PubMed Central

    Louwies, Tijs; Kicinski, Michal; De Boever, Patrick; Nawrot, Tim S.

    2013-01-01

    Background: Microcirculation plays an important role in the physiology of cardiovascular health. Air pollution is an independent risk factor for the development and progression of cardiovascular diseases, but the number of studies on the relation between air pollution and the microcirculation is limited. Objectives: We examined the relationship between short-term changes in air pollution and microvascular changes. Methods: We measured retinal microvasculature using fundus image analysis in a panel of 84 healthy adults (52% female), 22–63 years of age, during January–May 2012. Blood vessels were measured as central retinal arteriolar/venular equivalent (CRAE/CRVE), with a median of 2 measurements (range, 1–3). We used monitoring data on particulate air pollution (PM10) and black carbon (BC). Mixed-effect models were used to estimate associations between CRAE/CRVE and exposure to PM10 and BC using various exposure windows. Results: CRAE and CRVE were associated with PM10 and BC concentrations, averaged over the 24 hr before the retinal examinations. Each 10-µg/m3 increase in PM10 was associated with a 0.93-µm decrease (95% CI: –1.42, –0.45; p = 0.0003) in CRAE and a 0.86-µm decrease (95% CI: –1.42, –0.30; p = 0.004) in CRVE after adjusting for individual characteristics and time varying conditions such as ambient temperature. Each 1-µg/m3 increase in BC was associated with a 1.84-µm decrease (95% CI: –3.18, –0.51; p < 0.001) in CRAE. Conclusions: Our findings suggest that the retinal microvasculature responds to short-term changes in air pollution levels. These results support a mechanistic pathway through which air pollution can act as a trigger of cardiovascular events at least in part through effects on the microvasculature. Citation: Louwies T, Int Panis L, Kicinski M, De Boever P, Nawrot TS. 2013. Retinal microvascular responses to short-term changes in particulate air pollution in healthy adults. Environ Health Perspect 121:1011–1016;

  6. The Impact of Saharan Air Layer Dust on the Intensity and Intensity Change of Hurricane Earl

    NASA Astrophysics Data System (ADS)

    Bucher, G.; Boybeyi, Z.

    2012-12-01

    The study of tropical cyclone (TC) intensity and intensity change has become an increasingly important research topic, as the storms pose a significant threat to the lives and property along coastal regions, and maritime interests. The Saharan Air Layer (SAL) is an elevated layer of warm, dry, and dusty air that is formed by intense heating and strong winds over the Sahara desert. This dust, and hot and dry air moves across the Atlantic over the maritime layer. An emerging area of research is the role that the SAL has on the development and intensity of TCs in the North Atlantic tropical basin. In 2010, Hurricane Earl gave us a unique opportunity to study the effects of the SAL during the formative stages of the storm. Using the Weather and Forecasting Model with chemistry (WRF-Chem), this study investigated what the effect of SAL characteristics (thermodynamic and aerosol) had on Earl's intensity and intensity change. We concentrated on the direct and indirect radiative effects of the SAL aerosols, by utilizing the dust-only module in WRF-Chem and comparing results to observations, reanalysis, and a dust-free run. The results show that Earl did not appreciably intensify until it moved out from beneath the influence of the SAL, after which it evolved into a CAT 4 hurricane. This was due mainly to the shear associated with the SAL, but the dust radiative effects also contributed to the slow growth.

  7. Ambient air quality and the effects of air pollutants on otolaryngology in Beijing.

    PubMed

    Zhang, Fengying; Xu, Jin; Zhang, Ziying; Meng, Haiying; Wang, Li; Lu, Jinmei; Wang, Wuyi; Krafft, Thomas

    2015-08-01

    To investigate temporal patterns, pollution concentrations and the health effects of air pollutants in Beijing we carried out time-series analyses on daily concentrations of ambient air pollutants and daily numbers of outpatient visits for otolaryngology over 2 years (2011-2012) to identify possible health effects of air pollutants. The results showed that PM10 was the major air pollutant in Beijing and that air quality was slightly better in 2012 than in 2011. Seasonal differences were apparent for SO2 and NO2. Both the background and urban areas of Beijing experienced particulate matter pollution in 2011. In addition to local air pollution, Beijing was also affected by pollutants transported from other regions, especially during heavy air pollution episodes. PM10, NO2, and SO2 concentrations showed positive associations with numbers of outpatient visits for otolaryngology during winter. NO2 and SO2 also had adverse ear, nose, and throat health effects outside of winter. The ear, nose, and throat health risks caused by air pollutants were higher during the winter than during the summer. NO2 had stronger influence on increased the likelihood of outpatient visits than SO2. The findings provide additional information about air quality and health effects of air pollution in Beijing.

  8. The Effects of Air Pollution on Ischemic Stroke Admission Rate

    PubMed Central

    Alimohammadi, Hossein; Fakhri, Sara; Derakhshanfar, Hojjat; Hosseini-Zijoud, Seyed-Mostafa; Safari, Saeed

    2016-01-01

    The present study aimed to determine the relationship between the level of air pollutants and the rate of ischemic stroke (IS) admissions to hospitals. In this retrospective cross-sectional study, stroke admissions (January-March 2012 and 2013) to an emergency department and air pollution and meteorological data were gathered. The relationship between air pollutant levels and hospital admission rates were evaluated using the generalize additive model. In all 379 patients with IS were referred to the hospital (52.5% male; mean age 68.2±13.3 years). Both transient (p<0.001) and long-term (p<0.001) rises in CO level increases the risk of IS. Increased weekly (p<0.001) and monthly (p<0.001) average O3 levels amplifies this risk, while a transient increase in NO2 (p<0.001) and SO2 (p<0.001) levels has the same effect. Long-term changes in PM10 (p<0.001) and PM2.5 (p<0.001) also increase the risk of IS. The findings showed that the level of air pollutants directly correlates with the number of stroke admissions to the emergency department. PMID:26866000

  9. Long-term Changes in Extreme Air Pollution Meteorology and the Implications for Air Quality.

    PubMed

    Hou, Pei; Wu, Shiliang

    2016-01-01

    Extreme air pollution meteorological events, such as heat waves, temperature inversions and atmospheric stagnation episodes, can significantly affect air quality. Based on observational data, we have analyzed the long-term evolution of extreme air pollution meteorology on the global scale and their potential impacts on air quality, especially the high pollution episodes. We have identified significant increasing trends for the occurrences of extreme air pollution meteorological events in the past six decades, especially over the continental regions. Statistical analysis combining air quality data and meteorological data further indicates strong sensitivities of air quality (including both average air pollutant concentrations and high pollution episodes) to extreme meteorological events. For example, we find that in the United States the probability of severe ozone pollution when there are heat waves could be up to seven times of the average probability during summertime, while temperature inversions in wintertime could enhance the probability of severe particulate matter pollution by more than a factor of two. We have also identified significant seasonal and spatial variations in the sensitivity of air quality to extreme air pollution meteorology. PMID:27029386

  10. Long-term Changes in Extreme Air Pollution Meteorology and the Implications for Air Quality.

    PubMed

    Hou, Pei; Wu, Shiliang

    2016-03-31

    Extreme air pollution meteorological events, such as heat waves, temperature inversions and atmospheric stagnation episodes, can significantly affect air quality. Based on observational data, we have analyzed the long-term evolution of extreme air pollution meteorology on the global scale and their potential impacts on air quality, especially the high pollution episodes. We have identified significant increasing trends for the occurrences of extreme air pollution meteorological events in the past six decades, especially over the continental regions. Statistical analysis combining air quality data and meteorological data further indicates strong sensitivities of air quality (including both average air pollutant concentrations and high pollution episodes) to extreme meteorological events. For example, we find that in the United States the probability of severe ozone pollution when there are heat waves could be up to seven times of the average probability during summertime, while temperature inversions in wintertime could enhance the probability of severe particulate matter pollution by more than a factor of two. We have also identified significant seasonal and spatial variations in the sensitivity of air quality to extreme air pollution meteorology.

  11. Long-term Changes in Extreme Air Pollution Meteorology and the Implications for Air Quality

    PubMed Central

    Hou, Pei; Wu, Shiliang

    2016-01-01

    Extreme air pollution meteorological events, such as heat waves, temperature inversions and atmospheric stagnation episodes, can significantly affect air quality. Based on observational data, we have analyzed the long-term evolution of extreme air pollution meteorology on the global scale and their potential impacts on air quality, especially the high pollution episodes. We have identified significant increasing trends for the occurrences of extreme air pollution meteorological events in the past six decades, especially over the continental regions. Statistical analysis combining air quality data and meteorological data further indicates strong sensitivities of air quality (including both average air pollutant concentrations and high pollution episodes) to extreme meteorological events. For example, we find that in the United States the probability of severe ozone pollution when there are heat waves could be up to seven times of the average probability during summertime, while temperature inversions in wintertime could enhance the probability of severe particulate matter pollution by more than a factor of two. We have also identified significant seasonal and spatial variations in the sensitivity of air quality to extreme air pollution meteorology. PMID:27029386

  12. Long-term Changes in Extreme Air Pollution Meteorology and the Implications for Air Quality

    NASA Astrophysics Data System (ADS)

    Hou, Pei; Wu, Shiliang

    2016-03-01

    Extreme air pollution meteorological events, such as heat waves, temperature inversions and atmospheric stagnation episodes, can significantly affect air quality. Based on observational data, we have analyzed the long-term evolution of extreme air pollution meteorology on the global scale and their potential impacts on air quality, especially the high pollution episodes. We have identified significant increasing trends for the occurrences of extreme air pollution meteorological events in the past six decades, especially over the continental regions. Statistical analysis combining air quality data and meteorological data further indicates strong sensitivities of air quality (including both average air pollutant concentrations and high pollution episodes) to extreme meteorological events. For example, we find that in the United States the probability of severe ozone pollution when there are heat waves could be up to seven times of the average probability during summertime, while temperature inversions in wintertime could enhance the probability of severe particulate matter pollution by more than a factor of two. We have also identified significant seasonal and spatial variations in the sensitivity of air quality to extreme air pollution meteorology.

  13. Air quality in postunification Erfurt, East Germany: associating changes in pollutant concentrations with changes in emissions.

    PubMed Central

    Ebelt, S; Brauer, M; Cyrys, J; Tuch, T; Kreyling, W G; Wichmann, H E; Heinrich, J

    2001-01-01

    The unification of East and West Germany in 1990 resulted in sharp decreases in emissions of major air pollutants. This change in air quality has provided an opportunity for a natural experiment to evaluate the health impacts of air pollution. We evaluated airborne particle size distribution and gaseous co-pollutant data collected in Erfurt, Germany, throughout the 1990s and assessed the extent to which the observed changes are associated with changes in the two major emission sources: coal burning for power production and residential heating, and motor vehicles. Continuous data for sulfur dioxide, total suspended particulates (TSP), nitric oxide, carbon monoxide, and meteorologic parameters were available for 1990-1999, and size-selective particle number and mass concentration measurements were made during winters of 1991 and 1998. We used hourly profiles of pollutants and linear regression analyses, stratified by year, weekday/weekend, and hour, using NO and SO(2) as markers of traffic- and heating-related combustion sources, respectively, to study the patterns of various particle size fractions. Supplementary data on traffic and heating-related sources were gathered to support hypotheses linking these sources with observed changes in ambient air pollution levels. Substantially decreased (19-91%) concentrations were observed for all pollutants, with the exception of particles in the 0.01-0.03 microm size range (representing the smallest ultrafine particles that were measured). The number concentration for these particles increased by 115% between 1991 and 1998. The ratio of these ultrafine particles to TSP also increased by more than 500%, indicating a dramatic change in the size distribution of airborne particles. Analysis of hourly concentration patterns indicated that in 1991, concentrations of SO(2) and larger particle sizes were related to residential heating with coal. These peaks were no longer evident in 1998 due to decreases in coal consumption and

  14. Air pollution response to changing weather and power plant emissions in the eastern United States

    NASA Astrophysics Data System (ADS)

    Bloomer, Bryan Jaye

    Air pollution in the eastern United States causes human sickness and death as well as damage to crops and materials. NOX emission reduction is observed to improve air quality. Effectively reducing pollution in the future requires understanding the connections between smog, precursor emissions, weather, and climate change. Numerical models predict global warming will exacerbate smog over the next 50 years. My analysis of 21 years of CASTNET observations quantifies a climate change penalty. I calculate, for data collected prior to 2002, a climate penalty factor of ˜3.3 ppb O3/°C across the power plant dominated receptor regions in the rural, eastern U.S. Recent reductions in NOX emissions decreased the climate penalty factor to ˜2.2 ppb O3/°C. Prior to 1995, power plant emissions of CO2, SO2, and NOX were estimated with fuel sampling and analysis methods. Currently, emissions are measured with continuous monitoring equipment (CEMS) installed directly in stacks. My comparison of the two methods show CO 2 and SO2 emissions are ˜5% lower when inferred from fuel sampling; greater differences are found for NOX emissions. CEMS are the method of choice for emission inventories and commodity trading and should be the standard against which other methods are evaluated for global greenhouse gas trading policies. I used CEMS data and applied chemistry transport modeling to evaluate improvements in air quality observed by aircraft during the North American electrical blackout of 2003. An air quality model produced substantial reductions in O3, but not as much as observed. The study highlights weaknesses in the model as commonly used for evaluating a single day event and suggests areas for further investigation. A new analysis and visualization method quantifies local-daily to hemispheric-seasonal scale relationships between weather and air pollution, confirming improved air quality despite increasing temperatures across the eastern U.S. Climate penalty factors indicate

  15. Effects of air pollution on the upper aerodigestive tract.

    PubMed

    Holt, G R

    1996-02-01

    The main route of contamination of the human body with airborne pollutants is through the upper air and food passages. Because of the delicate balance of the mucous membranes and special sensory organs of these passages with respect to mucociliary activity, local and recruited immune responses, rapid uptake of chemicals, and carcinogenic potential, the ingestion or inhalation of pollutants in the air can be harmful to these internal body barriers. The particular target organs for air pollution effects on the upper aerodigestive tract include the mucosa, olfactory epithelium, auditory receptor cells, glottic epithelium, and adjacent neural and muscular tissues. Hearing loss caused by noise exposure may be aggravated by the concomitant inhalation of solvents. The strongest evidence for the carcinogenic effect of occupational inhalants in the nasal cavity and paranasal sinuses is seen with exposure to hardwood dust, tobacco smoke, furniture making, and leather tanning. With the exception of tobacco smoke, which produces squamous cell carcinomas, the majority of the occupationally related cancers are adenocarcinomas, usually of the intestinal variety. Tobacco smoke, passive or active, may lead to end-artery obliteration at the level of the otic end organ, causing a progressive sensorineural hearing loss. Further environmental research in the upper aerodigestive tract should aim at developing biologic markers to determine early, premalignant tissue changes; identifying the effects of chronic, low-dose toxic exposure on mucous membranes and neurosensory organs; providing field-tested tools for the standardized screening of large at-risk populations.

  16. Effects of data selection on the assimilation of AIRS data

    NASA Technical Reports Server (NTRS)

    Joiner, Joanna; Brin, E.; Treadon, R.; Derber, J.; VanDelst, P.; DeSilva, A.; Marshall, J. Le; Poli, P.; Atlas, R.; Cruz, C.; Bungato, D.

    2006-01-01

    The Atmospheric InfraRed Sounder (AIRS), flying aboard NASA's Earth Observing System (EOS) Aqua satellite with the Advanced Microwave Sounding Unit-A (AMSU-A), has been providing data for use in numerical weather prediction (NWP) and data assimilation systems (DAS) for over three years. The full AIRS data set is currently not transmitted in near-real-time (NRT) to the NWP centers. Instead, data sets with reduced spatial and spectral information are produced and made available in NRT. In this paper, we evaluate the use of different channel selections and error specifications. We achieved significant positive impact from the Aqua AIRS/AMSU-A combination in both hemispheres during our experimental time period of January 2003. The best results were obtained using a set of 156 channels that did not include any in the 6.7micron water vapor band. The latter have a large influence on both temperature and humidity analyses. If observation and background errors are not properly specified, the partitioning of temperature and humidity information from these channels will not be correct, and this can lead to a degradation in forecast skill. We found that changing the specified channel errors had a significant effect on the amount of data that entered into the analysis as a result of quality control thresholds that are related to the errors. However, changing the channel errors within a relatively small window did not significantly impact forecast skill with the 155 channel set. We also examined the effects of different types of spatial data reduction on assimilated data sets and NWP forecast skill. Whether we picked the center or the warmest AIRS pixel in a 3x3 array affected the amount of data ingested by the analysis but had a negligible impact on the forecast skill.

  17. Changes in the planetary heat balance with chemical changes in air

    NASA Technical Reports Server (NTRS)

    Chamberlain, J. W.

    1980-01-01

    The concept of an 'equivalent radiative atmosphere', a simplified model of the atmospheric radiative aspects, is used to explore changes in the greenhouse effect, caused by changes in the atmospheric composition, and changes in the incident solar flux. By extending this model to the zonal energy-balance type, it is shown that global heating has the more profound effect at higher latitudes. It is also shown that the positive feedback in H2O opacity is comparable to the initial change in opacity due, for example, to a change in CO2 content.

  18. Effect of Intake Air Filter Condition on Vehicle Fuel Economy

    SciTech Connect

    Norman, Kevin M; Huff, Shean P; West, Brian H

    2009-02-01

    The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy and the U.S. Environmental Protection Agency (EPA) jointly maintain a fuel economy website (www.fueleconomy.gov), which helps fulfill their responsibility under the Energy Policy Act of 1992 to provide accurate fuel economy information [in miles per gallon (mpg)] to consumers. The site provides information on EPA fuel economy ratings for passenger cars and light trucks from 1985 to the present and other relevant information related to energy use such as alternative fuels and driving and vehicle maintenance tips. In recent years, fluctuations in the price of crude oil and corresponding fluctuations in the price of gasoline and diesel fuels have renewed interest in vehicle fuel economy in the United States. (User sessions on the fuel economy website exceeded 20 million in 2008 compared to less than 5 million in 2004 and less than 1 million in 2001.) As a result of this renewed interest and the age of some of the references cited in the tips section of the website, DOE authorized the Oak Ridge National Laboratory (ORNL) Fuels, Engines, and Emissions Research Center (FEERC) to initiate studies to validate and improve these tips. This report documents a study aimed specifically at the effect of engine air filter condition on fuel economy. The goal of this study was to explore the effects of a clogged air filter on the fuel economy of vehicles operating over prescribed test cycles. Three newer vehicles (a 2007 Buick Lucerne, a 2006 Dodge Charger, and a 2003 Toyota Camry) and an older carbureted vehicle were tested. Results show that clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS). The engine control systems were able to maintain the desired AFR regardless of intake restrictions, and therefore fuel consumption was not increased. The carbureted engine did show a decrease in

  19. Effects on health of air pollution: a narrative review.

    PubMed

    Mannucci, Pier Mannuccio; Harari, Sergio; Martinelli, Ida; Franchini, Massimo

    2015-09-01

    Air pollution is a complex and ubiquitous mixture of pollutants including particulate matter, chemical substances and biological materials. There is growing awareness of the adverse effects on health of air pollution following both acute and chronic exposure, with a rapidly expanding body of evidence linking air pollution with an increased risk of respiratory (e.g., asthma, chronic obstructive pulmonary disease, lung cancer) and cardiovascular disease (e.g., myocardial infarction, heart failure, cerebrovascular accidents). Elderly subjects, pregnant women, infants and people with prior diseases appear especially susceptible to the deleterious effects of ambient air pollution. The main diseases associated with exposure to air pollutants will be summarized in this narrative review.

  20. The effects of fabric air permeability and moisture absorption on clothing microclimate and subjective sensation in sedentary women at cyclic changes of ambient temperatures from 27 degrees C to 33 degrees C.

    PubMed

    Ha, M; Tokura, H; Yanai, Y; Moriyama, T; Tsuchiya, N

    1999-12-01

    The present paper aimed at learning the effects of two different levels of air permeability and moisture absorption on clothing microclimate and subjective sensation in sedentary women. Three kinds of clothing ensemble were investigated: 1) polyester clothing with low moisture absorption and low air permeability (A clothing); 2) polyester clothing with low moisture absorption and high air permeability (B clothing); and 3) cotton clothing with high moisture absorption and high air permeability (C clothing). After 20 min of dressing time, the room temperature and humidity began to rise from 27 degrees C and 50% rh to 33 degrees C and 70% rh over 20 min, and it was maintained for 30 min (Section I); it then began to fall to 27 degrees C and 50% rh over 20 min, and it was maintained there for 20 min (Section II). The subject sat quietly on a chair for 110 min. The main findings are summarized as follows: 1) The clothing surface temperature was significantly higher in C clothing than in B clothing during section I, but it was significantly higher in B clothing than in C clothing during section II. 2) Although the positive relationship between the microclimate humidity and forearm sweat rate was significantly confirmed in all three kinds of clothing, the microclimate humidity at the chest for the same sweat rate was lower in C clothing than in A and B clothing. These results were discussed in terms of thermal physiology.

  1. Air damping effect on the air-based CMUT operation

    NASA Astrophysics Data System (ADS)

    Cha, Bu-Sang; Kanashima, Takeshi; Lee, Seung-Mok; Okuyama, Masanori

    2015-08-01

    The vibration amplitude, damping ratio and viscous damping force in capacitive micromachinedultrasonic transducers (CMUTs) with a perforated membrane have been calculated theoretically and compared with the experimental data on its vibration behavior. The electrical bias of the DC and the AC voltages and the operation frequency conditions influence the damping effect because leads to variations in the gap height and the vibration velocity of the membrane. We propose a new estimation method to determine the damping ratio by the decay rate of the vibration amplitudes of the perforated membrane plate are measured using a laser vibrometer at each frequency, and the damping ratios were calculated from those results. The influences of the vibration frequency and the electrostatic force on the damping effect under the various operation conditions have been studied.

  2. Technology Solutions Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    SciTech Connect

    A. Rudd and D. Bergey

    2015-08-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs.

  3. Effect of Ambient Design Temperature on Air-Cooled Binary Plant Output

    SciTech Connect

    Dan Wendt; Greg Mines

    2011-10-01

    Air-cooled binary plants are designed to provide a specified level of power production at a particular air temperature. Nominally this air temperature is the annual mean or average air temperature for the plant location. This study investigates the effect that changing the design air temperature has on power generation for an air-cooled binary plant producing power from a resource with a declining production fluid temperature and fluctuating ambient temperatures. This analysis was performed for plants operating both with and without a geothermal fluid outlet temperature limit. Aspen Plus process simulation software was used to develop optimal air-cooled binary plant designs for specific ambient temperatures as well as to rate the performance of the plant designs at off-design operating conditions. Results include calculation of annual and plant lifetime power generation as well as evaluation of plant operating characteristics, such as improved power generation capabilities during summer months when electric power prices are at peak levels.

  4. Air plasma effect on dental disinfection

    SciTech Connect

    Duarte, S.; Murata, R. M.; Saxena, D.; Kuo, S. P.; Chen, C. Y.; Huang, K. J.; Popovic, S.

    2011-07-15

    A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formation was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.

  5. Air plasma effect on dental disinfection

    NASA Astrophysics Data System (ADS)

    Duarte, S.; Kuo, S. P.; Murata, R. M.; Chen, C. Y.; Saxena, D.; Huang, K. J.; Popovic, S.

    2011-07-01

    A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formation was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.

  6. Quantifying the health impacts of air pollution under a changing climate—a review of approaches and methodology

    NASA Astrophysics Data System (ADS)

    Sujaritpong, Sarunya; Dear, Keith; Cope, Martin; Walsh, Sean; Kjellstrom, Tord

    2014-03-01

    Climate change has been predicted to affect future air quality, with inevitable consequences for health. Quantifying the health effects of air pollution under a changing climate is crucial to provide evidence for actions to safeguard future populations. In this paper, we review published methods for quantifying health impacts to identify optimal approaches and ways in which existing challenges facing this line of research can be addressed. Most studies have employed a simplified methodology, while only a few have reported sensitivity analyses to assess sources of uncertainty. The limited investigations that do exist suggest that examining the health risk estimates should particularly take into account the uncertainty associated with future air pollution emissions scenarios, concentration-response functions, and future population growth and age structures. Knowledge gaps identified for future research include future health impacts from extreme air pollution events, interactions between temperature and air pollution effects on public health under a changing climate, and how population adaptation and behavioural changes in a warmer climate may modify exposure to air pollution and health consequences.

  7. Implications of incorporating air-quality co-benefits into climate change policymaking

    NASA Astrophysics Data System (ADS)

    Nemet, G. F.; Holloway, T.; Meier, P.

    2010-01-01

    We present an analysis of the barriers and opportunities for incorporating air quality co-benefits into climate policy assessments. It is well known that many strategies for reducing greenhouse gas emissions also decrease emissions of health-damaging air pollutants and precursor species, including particulate matter, nitrogen oxides, and sulfur dioxide. In a survey of previous studies we found a range of estimates for the air quality co-benefits of climate change mitigation of 2- 196/tCO2 with a mean of 49/tCO2, and the highest co-benefits found in developing countries. These values, although of a similar order of magnitude to abatement cost estimates, are only rarely included in integrated assessments of climate policy. Full inclusion of these co-benefits would have pervasive implications for climate policy in areas including: optimal policy stringency, overall costs, distributional effects, robustness to discount rates, incentives for international cooperation, and the value of adaptation, forests, and climate engineering relative to mitigation. Under-valuation results in part from uncertainty in climatic damages, valuation inconsistency, and institutional barriers. Because policy debates are framed in terms of cost minimization, policy makers are unlikely to fully value air quality co-benefits unless they can be compared on an equivalent basis with the benefits of avoided climatic damages. While air quality co-benefits have been prominently portrayed as a hedge against uncertainty in the benefits of climate change abatement, this assessment finds that full inclusion of co-benefits depends on—rather than substitutes for—better valuation of climate damages.

  8. Health effects of particulate air pollution: time for reassessment?

    PubMed Central

    Pope, C A; Bates, D V; Raizenne, M E

    1995-01-01

    Numerous studies have observed health effects of particulate air pollution. Compared to early studies that focused on severe air pollution episodes, recent studies are more relevant to understanding health effects of pollution at levels common to contemporary cities in the developed world. We review recent epidemiologic studies that evaluated health effects of particulate air pollution and conclude that respirable particulate air pollution is likely an important contributing factor to respiratory disease. Observed health effects include increased respiratory symptoms, decreased lung function, increased hospitalizations and other health care visits for respiratory and cardiovascular disease, increased respiratory morbidity as measured by absenteeism from work or school or other restrictions in activity, and increased cardiopulmonary disease mortality. These health effects are observed at levels common to many U.S. cities including levels below current U.S. National Ambient Air Quality Standards for particulate air pollution. Images Figure 1. PMID:7656877

  9. Health effects of particulate air pollution: time for reassessment?

    PubMed

    Pope, C A; Bates, D V; Raizenne, M E

    1995-05-01

    Numerous studies have observed health effects of particulate air pollution. Compared to early studies that focused on severe air pollution episodes, recent studies are more relevant to understanding health effects of pollution at levels common to contemporary cities in the developed world. We review recent epidemiologic studies that evaluated health effects of particulate air pollution and conclude that respirable particulate air pollution is likely an important contributing factor to respiratory disease. Observed health effects include increased respiratory symptoms, decreased lung function, increased hospitalizations and other health care visits for respiratory and cardiovascular disease, increased respiratory morbidity as measured by absenteeism from work or school or other restrictions in activity, and increased cardiopulmonary disease mortality. These health effects are observed at levels common to many U.S. cities including levels below current U.S. National Ambient Air Quality Standards for particulate air pollution.

  10. Examining Projected Changes in Weather & Air Quality Extremes Between 2000 & 2030 using Dynamical Downscaling

    EPA Science Inventory

    Climate change may alter regional weather extremes resulting in a range of environmental impacts including changes in air quality, water quality and availability, energy demands, agriculture, and ecology. Dynamical downscaling simulations were conducted with the Weather Research...

  11. Threat to future global food security from climate change and ozone air pollution

    NASA Astrophysics Data System (ADS)

    Tai, Amos P. K.; Martin, Maria Val; Heald, Colette L.

    2014-09-01

    Future food production is highly vulnerable to both climate change and air pollution with implications for global food security. Climate change adaptation and ozone regulation have been identified as important strategies to safeguard food production, but little is known about how climate and ozone pollution interact to affect agriculture, nor the relative effectiveness of these two strategies for different crops and regions. Here we present an integrated analysis of the individual and combined effects of 2000-2050 climate change and ozone trends on the production of four major crops (wheat, rice, maize and soybean) worldwide based on historical observations and model projections, specifically accounting for ozone-temperature co-variation. The projections exclude the effect of rising CO2, which has complex and potentially offsetting impacts on global food supply. We show that warming reduces global crop production by >10% by 2050 with a potential to substantially worsen global malnutrition in all scenarios considered. Ozone trends either exacerbate or offset a substantial fraction of climate impacts depending on the scenario, suggesting the importance of air quality management in agricultural planning. Furthermore, we find that depending on region some crops are primarily sensitive to either ozone (for example, wheat) or heat (for example, maize) alone, providing a measure of relative benefits of climate adaptation versus ozone regulation for food security in different regions.

  12. Changes in lung function after working with the shotcrete lining method under compressed air conditions.

    PubMed Central

    Kessel, R; Redl, M; Mauermayer, R; Praml, G J

    1989-01-01

    Shotcrete techniques under compressed air are increasingly applied in the construction of tunnels. Up to now little is known about the influence of shotcrete dusts on the function of the lung. The lung function of 30 miners working with shotcrete under compressed air (before and after one shift) was measured. They carried personal air samplers to assess the total dust exposure. Long term effects were studied on a second group of 29 individuals exposed to shotcrete dusts and compressed air for two years. A significant increase of airway resistance and a significant decrease of some flow-volume parameters were found after one workshift. These changes partially correlate close to the dust exposure. After two years exposure a significant decrease of mean expiratory flow (MEF)50 and MEF25 was found. These results point to damage in the small airways and emphasise the major role of the lung function test--including the flow-volume manoeuvre for the medical examination of the workers. Additionally, they should carry filter masks. Images PMID:2923823

  13. Evaluation of co-benefits from combined climate change and air pollution reduction strategies

    NASA Astrophysics Data System (ADS)

    Leitao, Joana; Van Dingenen, Rita; Dentener, Frank; Rao, Shilpa

    2014-05-01

    climate and air pollution strategies assessed. The TM5-FASST tool allows for a fast screening of emission scenario variants and the resulting impacts can be investigated by source country, source sector level or by precursor. Developed at JRC, this model is a linearized version derived from the full chemical transport model TM5-CTM, taking as input pollutants emissions from 56 source regions with global coverage. The resulting pollutant concentrations are determined and their associated effect on human health (from PM2.5 and O3), the yield loss of damaged crops (from O3), and CO2eq of short lived climate forcers are quantified. The analysis of the LIMITS scenarios allows for impact assessment of alternate air pollution control assumptions on pollutant emission trajectories out to 2030 and 2050. The results show that stringent climate policies provide a significant air quality benefit compared to current legislation air quality policy. The identified benefits and trade-offs provide a strong incentive for the implementation of combined national policy focusing both on climate change and air pollution.

  14. Rapid urban growth, land-use changes and air pollution in Santiago, Chile

    NASA Astrophysics Data System (ADS)

    Romero, H.; Ihl, M.; Rivera, A.; Zalazar, P.; Azocar, P.

    This paper is a contribution to the understanding of the topoclimatic and environmental geography of the basin where Santiago — one of the most polluted Latin American city - is located. In the first part, land-use change is analysed looking at the climatic transformation caused by the rapid transit from natural semiarid surface to urban areas. In the second part, seasonal weather and daily cycles of slope winds and the available ventilation are described trying to relate those patterns with the spatial distribution of air pollution. A combination of meteorological, geographical and cultural factors explain extreme air pollution events: meteorologically, Santiago is under permanent subsidence inversion layers. Geographically, the city is located in a closed basin surrounded by mountains. Culturally, the urban area has the highest population concentration (40% of the national total), industries (near 70% of the total) and vehicles, which are the main sources of smog. The urban and suburban transport system is based on a large number of buses (diesel) and private cars, both experiencing a rapid growth from the past few years. The city and specially the transport system generates high emissions of pollutant, but the natural semiarid deforested soils and slopes are also important sources. The local wind system can explain the differential spatial distribution on the concentration of air pollutants in the city and its periphery. In winter (rain season) concentrations of particulate matter are higher at the centre and the SW part of the city. The andean piedmont area (E part of the city) shows minimum values, suggesting major ventilation effects of slope and valley winds. Ozone exceeds air quality standards in summer (dry season) at all sites in the centre and periphery. However, the O 3-concentrations are higher on preferred residential areas located at the piedmont area (E part of the city), suggesting air pollution transport effects. Currently, there is no

  15. Modeling exposure close to air pollution sources in naturally ventilated residences: association of turbulent diffusion coefficient with air change rate.

    PubMed

    Cheng, Kai-Chung; Acevedo-Bolton, Viviana; Jiang, Ruo-Ting; Klepeis, Neil E; Ott, Wayne R; Fringer, Oliver B; Hildemann, Lynn M

    2011-05-01

    For modeling exposure close to an indoor air pollution source, an isotropic turbulent diffusion coefficient is used to represent the average spread of emissions. However, its magnitude indoors has been difficult to assess experimentally due to limitations in the number of monitors available. We used 30-37 real-time monitors to simultaneously measure CO at different angles and distances from a continuous indoor point source. For 11 experiments involving two houses, with natural ventilation conditions ranging from <0.2 to >5 air changes per h, an eddy diffusion model was used to estimate the turbulent diffusion coefficients, which ranged from 0.001 to 0.013 m² s⁻¹. The model reproduced observed concentrations with reasonable accuracy over radial distances of 0.25-5.0 m. The air change rate, as measured using a SF₆ tracer gas release, showed a significant positive linear correlation with the air mixing rate, defined as the turbulent diffusion coefficient divided by a squared length scale representing the room size. The ability to estimate the indoor turbulent diffusion coefficient using two readily measurable parameters (air change rate and room dimensions) is useful for accurately modeling exposures in close proximity to an indoor pollution source.

  16. Climate change and air pollution in megacities: A challenge for interdisciplinary research

    NASA Astrophysics Data System (ADS)

    Suppan, Peter; Gurjar, B. R.

    2010-05-01

    The impact of climate change on Megacities as well as feedback mechanisms from urban conglomerations to climate change are issues which will have major consequences to the urban life quality. One of such issues is the impact of climate change on air quality in Megacities and its future development as well as the contribution of green house gases (GHG) from urban emissions to climate change. Based on a survey of more than 500 stakeholders from 25 cites it was expressed, that air pollution is the most significant environmental challenge followed by traffic congestion issues. This statement enforces the scientific work on air quality in which vehicular emissions play a major role for the air pollution in urban conglomerations and further - interdisciplinary - investigations on air pollution have to be done. In view of the ongoing climate change - which will amplify environmental problems - it is important that the scientific community of climate change, air pollution, health and social science experts convene with regional and local stakeholders in order to introduce suitable measures and to reduce and minimize air pollution levels and health impacts. Results of the assessment of the air quality, the impact of global climate change and its consequences on human health in large urban agglomerations will be discussed and presented.

  17. Characterization of air freshener emission: the potential health effects.

    PubMed

    Kim, Sanghwa; Hong, Seong-Ho; Bong, Choon-Keun; Cho, Myung-Haing

    2015-01-01

    Air freshener could be one of the multiple sources that release volatile organic compounds (VOCs) into the indoor environment. The use of these products may be associated with an increase in the measured level of terpene, such as xylene and other volatile air freshener components, including aldehydes, and esters. Air freshener is usually used indoors, and thus some compounds emitted from air freshener may have potentially harmful health impacts, including sensory irritation, respiratory symptoms, and dysfunction of the lungs. The constituents of air fresheners can react with ozone to produce secondary pollutants such as formaldehyde, secondary organic aerosol (SOA), oxidative product, and ultrafine particles. These pollutants then adversely affect human health, in many ways such as damage to the central nervous system, alteration of hormone levels, etc. In particular, the ultrafine particles may induce severe adverse effects on diverse organs, including the pulmonary and cardiovascular systems. Although the indoor use of air freshener is increasing, deleterious effects do not manifest for many years, making it difficult to identify air freshener-associated symptoms. In addition, risk assessment recognizes the association between air fresheners and adverse health effects, but the distinct causal relationship remains unclear. In this review, the emitted components of air freshener, including benzene, phthalate, and limonene, were described. Moreover, we focused on the health effects of these chemicals and secondary pollutants formed by the reaction with ozone. In conclusion, scientific guidelines on emission and exposure as well as risk characterization of air freshener need to be established. PMID:26354370

  18. Ambient air pollution, weather changes, and outpatient visits for allergic conjunctivitis: A retrospective registry study.

    PubMed

    Hong, Jiaxu; Zhong, Taoling; Li, Huili; Xu, Jianming; Ye, Xiaofang; Mu, Zhe; Lu, Yi; Mashaghi, Alireza; Zhou, Ying; Tan, Mengxi; Li, Qiyuan; Sun, Xinghuai; Liu, Zuguo; Xu, Jianjiang

    2016-01-01

    Allergic conjunctivitis is a common problem that significantly impairs patients' quality of life. Whether air pollution serves as a risk factor for the development of allergic conjunctivitis remains elusive. In this paper, we assess the relationship between air pollutants and weather conditions with outpatient visits for allergic conjunctivitis. By using a time-series analysis based on the largest dataset ever assembled to date, we found that the number of outpatient visits for allergic conjunctivitis was significantly correlated with the levels of NO2, O3, and temperature, while its association with humidity was statistically marginal. No associations between PM10, PM2.5, SO2, or wind velocity and outpatient visits were seen. Subgroup analyses showed that sex seemed to modify the effects of humidity on outpatient visits for allergic conjunctivitis, but not for NO2, O3, or temperature. People younger than 40 were found to be susceptible to changes of all four parameters, while those older than 40 were only consistently affected by NO2 levels. Our findings revealed that higher levels of ambient NO2, O3, and temperature increase the chances of outpatient visits for allergic conjunctivitis. Ambient air pollution and weather changes may contribute to the worsening of allergic conjunctivitis. PMID:27033635

  19. Ambient air pollution, weather changes, and outpatient visits for allergic conjunctivitis: A retrospective registry study

    NASA Astrophysics Data System (ADS)

    Hong, Jiaxu; Zhong, Taoling; Li, Huili; Xu, Jianming; Ye, Xiaofang; Mu, Zhe; Lu, Yi; Mashaghi, Alireza; Zhou, Ying; Tan, Mengxi; Li, Qiyuan; Sun, Xinghuai; Liu, Zuguo; Xu, Jianjiang

    2016-04-01

    Allergic conjunctivitis is a common problem that significantly impairs patients’ quality of life. Whether air pollution serves as a risk factor for the development of allergic conjunctivitis remains elusive. In this paper, we assess the relationship between air pollutants and weather conditions with outpatient visits for allergic conjunctivitis. By using a time-series analysis based on the largest dataset ever assembled to date, we found that the number of outpatient visits for allergic conjunctivitis was significantly correlated with the levels of NO2, O3, and temperature, while its association with humidity was statistically marginal. No associations between PM10, PM2.5, SO2, or wind velocity and outpatient visits were seen. Subgroup analyses showed that sex seemed to modify the effects of humidity on outpatient visits for allergic conjunctivitis, but not for NO2, O3, or temperature. People younger than 40 were found to be susceptible to changes of all four parameters, while those older than 40 were only consistently affected by NO2 levels. Our findings revealed that higher levels of ambient NO2, O3, and temperature increase the chances of outpatient visits for allergic conjunctivitis. Ambient air pollution and weather changes may contribute to the worsening of allergic conjunctivitis.

  20. Ambient air pollution, weather changes, and outpatient visits for allergic conjunctivitis: A retrospective registry study

    PubMed Central

    Hong, Jiaxu; Zhong, Taoling; Li, Huili; Xu, Jianming; Ye, Xiaofang; Mu, Zhe; Lu, Yi; Mashaghi, Alireza; Zhou, Ying; Tan, Mengxi; Li, Qiyuan; Sun, Xinghuai; Liu, Zuguo; Xu, Jianjiang

    2016-01-01

    Allergic conjunctivitis is a common problem that significantly impairs patients’ quality of life. Whether air pollution serves as a risk factor for the development of allergic conjunctivitis remains elusive. In this paper, we assess the relationship between air pollutants and weather conditions with outpatient visits for allergic conjunctivitis. By using a time-series analysis based on the largest dataset ever assembled to date, we found that the number of outpatient visits for allergic conjunctivitis was significantly correlated with the levels of NO2, O3, and temperature, while its association with humidity was statistically marginal. No associations between PM10, PM2.5, SO2, or wind velocity and outpatient visits were seen. Subgroup analyses showed that sex seemed to modify the effects of humidity on outpatient visits for allergic conjunctivitis, but not for NO2, O3, or temperature. People younger than 40 were found to be susceptible to changes of all four parameters, while those older than 40 were only consistently affected by NO2 levels. Our findings revealed that higher levels of ambient NO2, O3, and temperature increase the chances of outpatient visits for allergic conjunctivitis. Ambient air pollution and weather changes may contribute to the worsening of allergic conjunctivitis. PMID:27033635

  1. Ambient air pollution, weather changes, and outpatient visits for allergic conjunctivitis: A retrospective registry study.

    PubMed

    Hong, Jiaxu; Zhong, Taoling; Li, Huili; Xu, Jianming; Ye, Xiaofang; Mu, Zhe; Lu, Yi; Mashaghi, Alireza; Zhou, Ying; Tan, Mengxi; Li, Qiyuan; Sun, Xinghuai; Liu, Zuguo; Xu, Jianjiang

    2016-04-01

    Allergic conjunctivitis is a common problem that significantly impairs patients' quality of life. Whether air pollution serves as a risk factor for the development of allergic conjunctivitis remains elusive. In this paper, we assess the relationship between air pollutants and weather conditions with outpatient visits for allergic conjunctivitis. By using a time-series analysis based on the largest dataset ever assembled to date, we found that the number of outpatient visits for allergic conjunctivitis was significantly correlated with the levels of NO2, O3, and temperature, while its association with humidity was statistically marginal. No associations between PM10, PM2.5, SO2, or wind velocity and outpatient visits were seen. Subgroup analyses showed that sex seemed to modify the effects of humidity on outpatient visits for allergic conjunctivitis, but not for NO2, O3, or temperature. People younger than 40 were found to be susceptible to changes of all four parameters, while those older than 40 were only consistently affected by NO2 levels. Our findings revealed that higher levels of ambient NO2, O3, and temperature increase the chances of outpatient visits for allergic conjunctivitis. Ambient air pollution and weather changes may contribute to the worsening of allergic conjunctivitis.

  2. Cookstoves Research: Improving Air Quality and Slowing Climate Change

    EPA Science Inventory

    Household air pollution, mainly from solid-fuel cookstoves in the developing world, is estimated to cause approximately 4 million premature deaths per year, and emissions of black carbon and other pollutants from cookstoves affect regional and global climate. The Global Alliance...

  3. Global topics and novel approaches in the study of air pollution, climate change and forest ecosystems.

    PubMed

    Sicard, Pierre; Augustaitis, Algirdas; Belyazid, Salim; Calfapietra, Carlo; de Marco, Alessandra; Fenn, Mark; Bytnerowicz, Andrzej; Grulke, Nancy; He, Shang; Matyssek, Rainer; Serengil, Yusuf; Wieser, Gerhard; Paoletti, Elena

    2016-06-01

    Research directions from the 27th conference for Specialists in Air Pollution and Climate Change Effects on Forest Ecosystems (2015) reflect knowledge advancements about (i) Mechanistic bases of tree responses to multiple climate and pollution stressors, in particular the interaction of ozone (O3) with nitrogen (N) deposition and drought; (ii) Linking genetic control with physiological whole-tree activity; (iii) Epigenetic responses to climate change and air pollution; (iv) Embedding individual tree performance into the multi-factorial stand-level interaction network; (v) Interactions of biogenic and anthropogenic volatile compounds (molecular, functional and ecological bases); (vi) Estimating the potential for carbon/pollution mitigation and cost effectiveness of urban and peri-urban forests; (vii) Selection of trees adapted to the urban environment; (viii) Trophic, competitive and host/parasite relationships under changing pollution and climate; (ix) Atmosphere-biosphere-pedosphere interactions as affected by anthropospheric changes; (x) Statistical analyses for epidemiological investigations; (xi) Use of monitoring for the validation of models; (xii) Holistic view for linking the climate, carbon, N and O3 modelling; (xiii) Inclusion of multiple environmental stresses (biotic and abiotic) in critical load determinations; (xiv) Ecological impacts of N deposition in the under-investigated areas; (xv) Empirical models for mechanistic effects at the local scale; (xvi) Broad-scale N and sulphur deposition input and their effects on forest ecosystem services; (xvii) Measurements of dry deposition of N; (xviii) Assessment of evapotranspiration; (xix) Remote sensing assessment of hydrological parameters; and (xx) Forest management for maximizing water provision and overall forest ecosystem services. Ground-level O3 is still the phytotoxic air pollutant of major concern to forest health. Specific issues about O3 are: (xxi) Developing dose-response relationships and

  4. Comparative microarray analysis and pulmonary changes in Brown Norway rats exposed to ovalbumin and concentrated air particulates.

    PubMed

    Heidenfelder, Brooke L; Reif, David M; Harkema, Jack R; Cohen Hubal, Elaine A; Hudgens, Edward E; Bramble, Lori A; Wagner, James G; Morishita, Masako; Keeler, Gerald J; Edwards, Stephen W; Gallagher, Jane E

    2009-03-01

    The interaction between air particulates and genetic susceptibility has been implicated in the pathogenesis of asthma. The overall objective of this study was to determine the effects of inhalation exposure to environmentally relevant concentrated air particulates (CAPs) on the lungs of ovalbumin (ova) sensitized and challenged Brown Norway rats. Changes in gene expression were compared with lung tissue histopathology, morphometry, and biochemical and cellular parameters in bronchoalveolar lavage fluid (BALF). Ova challenge was responsible for the preponderance of gene expression changes, related largely to inflammation. CAPs exposure alone resulted in no significant gene expression changes, but CAPs and ova-exposed rodents exhibited an enhanced effect relative to ova alone with differentially expressed genes primarily related to inflammation and airway remodeling. Gene expression data was consistent with the biochemical and cellular analyses of the BALF, the pulmonary pathology, and morphometric changes when comparing the CAPs-ova group to the air-saline or CAPs-saline group. However, the gene expression data were more sensitive than the BALF cell type and number for assessing the effects of CAPs and ova versus the ova challenge alone. In addition, the gene expression results provided some additional insight into the TGF-beta-mediated molecular processes underlying these changes. The broad-based histopathology and functional genomic analyses demonstrate that exposure to CAPs exacerbates rodents with allergic inflammation induced by an allergen and suggests that asthmatics may be at increased risk for air pollution effects. PMID:19176365

  5. Air sparging effectiveness: laboratory characterization of air-channel mass transfer zone for VOC volatilization.

    PubMed

    Braida, W J; Ong, S K

    2001-10-12

    Air sparging in conjunction with soil vapor extraction is one of many technologies currently being applied for the remediation of groundwater contaminated with volatile organic compounds (VOCs). Mass transfer at the air-water interface during air sparging is affected by various soil and VOC properties. In this study with a single air-channel apparatus, mass transfer of VOCs was shown to occur within a thin layer of saturated porous media next to the air channel. In this zone, the VOCs were found to rapidly deplete during air sparging resulting in a steep concentration gradient while the VOC concentration outside the zone remained fairly constant. The sizes of the mass transfer zone were found to range from 17 to 41 mm or 70d(50) and 215d(50) (d(50)=mean particle size) for low organic carbon content media (<0.01% OC). The size of the mass transfer zone was found to be proportional to the square root of the aqueous diffusivity of the VOC, and was affected by the mean particle size, and the uniformity coefficient. Effects of the volatility of the VOCs as represented by the Henry's law constants and the airflow rates on the mass transfer zone were found to be negligible but VOC mass transfer from air-water interface to bulk air phase seems to play a role. A general correlation for predicting the size of the mass transfer zone was developed. The model was developed using data from nine different VOCs and verified by two other VOCs. The existence of the mass transfer zone provides an explanation for the tailing effect of the air phase concentration under prolonged air sparging and the rebound in the VOC air phase concentration after the sparging system is turned off.

  6. UNDERSTANDING THE EFFECTS OF AIR POLLUTION ON HUMAN HEALTH

    EPA Science Inventory

    Modern air pollution regulation is first and foremost motivated by concerns about the effects of air pollutants on human health and secondarily by concerns about its effects on ecosystems, cultural artifacts, and quality of life values such as visibility. This order of priority ...

  7. [Air contamination in the Autonomous City of Buenos Aires: the current risk or future climate change, a false option].

    PubMed

    Abrutzky, Rosana; Dawidowski, Laura; Murgida, Ana; Natenzon, Claudia Eleonor

    2014-09-01

    Based on the theoretical framework of environmental risk, this article discusses the management of air quality in the Autonomous City of Buenos Aires in relation to current and potential impacts of toxic gases and global climate change on the health of the population. Information on historical and current management of the air was linked to the results of the South American Emissions, Megacities and Climate research project to assess danger, exposure, vulnerability and uncertainty as the dimensions of risk. By contextualizing public policies developed in recent decades on this subject, it was possible to identify emerging configurations of risk and uncertainties as accelerators of social vulnerability. On the one hand, the fact that there is a positive correlation between mortality, changes in temperature and air pollution was confirmed. On the other hand, it became clear that there is a disconnect between air quality management and health care management, while limitations were found in the proposed mitigation measures relating to emissions of greenhouse gases produced by fuel, revealing uncertainties regarding their efficacy.

  8. The impact of changing technology on the demand for air transportation

    NASA Technical Reports Server (NTRS)

    Kneafsey, J. T.; Taneja, N. K.

    1978-01-01

    Demand models for air transportation that are sensitive to the impact of changing technology were developed. The models are responsive to potential changes in technology, and to changing economic, social, and political factors as well. In addition to anticipating the wide differences in the factors influencing the demand for long haul and short haul air travel, the models were designed to clearly distinguish among the unique features of these markets.

  9. Measurements of CFC Isotope Changes in Firn, Stratospheric and Tropospheric Air

    NASA Astrophysics Data System (ADS)

    Allin, S.; Laube, J.; Witrant, E.; Kaiser, J.; McKenna, E.; Dennis, P.; Mulvaney, R.; Capron, E.; Martinerie, P.; Blunier, T.; Schwander, J.; Fraser, P. J.; Sturges, W. T.

    2014-12-01

    The degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone. Recent studies of CFC-12 (CCl2F2) have reported strong chlorine and carbon isotope fractionations in stratospheric and tropospheric samples, respectively. The δ(37Cl) variations were attributed to isotope dependent sink reactions, similar to effects seen in nitrous oxide (N2O), whereas adjustments to manufacturing processes were used to explain the δ(13C) changes. Using air archives to measure chlorine and carbon isotope ratios in CFCs could help to identify and quantify their sources and sinks. We analyse the three most abundant CFCs and show that CFC-11 (CCl3F) and CFC-113 (CClF2CCl2F) exhibit significant chlorine isotope fractionation in the stratosphere, in common with CFC-12. We then use a 2-box model to estimate the expected tropospheric isotope signature of these gases, based on their emissions and transport history, as well as their measured stratospheric isotope fractionation constants (ɛapp). We also present long-term δ(37Cl) and δ(13C) trends of all three CFCs, determined from background tropospheric samples from the Cape Grim air archive (1978 - 2010) and firn air samples from the Arctic (NEEM, Greenland) and Antarctica (Fletcher Promontory). These measurements are compared to our model trends, leading to an evaluation of long-term chlorine and carbon isotope changes. This study also extends the novel approach to measuring trace gas isotope ratios in small air volumes, using a single-detector gas chromatography-mass spectrometry system.

  10. Satellite Remote Sensing of Ozone Change, Air Quality and Climate

    NASA Technical Reports Server (NTRS)

    Hilsenrath, Ernest; Bhartia, Pawan K. (Technical Monitor)

    2001-01-01

    To date satellite remote sensing of ozone depletion has been very successful. Data sets have been validated and measured trends are in agreement with model calculations. Technology developed for sensing the stratosphere is now being employed to study air quality and climate with promising results. These new data show that air quality is a transcontinental issue, but that better instrumentation is needed. Recent data show a connection between the stratosphere, troposphere and climate, which will require new technology to quantify these relationships. NASA and NOAA (National Oceanic and Atmospheric Administration) are planning and developing new missions. Recent results from TOMS (Total Ozone Mapping Spectrometer), SeaWiffs, and Terra will be discussed and upcoming missions to study atmospheric chemistry will be discussed.

  11. Technological change and productivity growth in the air transport industry

    NASA Technical Reports Server (NTRS)

    Rosenberg, N.; Thompson, A.; Belsley, S. E.

    1978-01-01

    The progress of the civil air transport industry in the United States was examined in the light of a proposal of Enos who, after examining the growth of the petroleum industry, divided that phenomenon into two phases, the alpha and the beta; that is, the invention, first development and production, and the improvement phase. The civil air transport industry developed along similar lines with the technological progress coming in waves; each wave encompassing several new technological advances while retaining the best of the old ones. At the same time the productivity of the transport aircraft as expressed by the product of the aircraft velocity and the passenger capacity increased sufficiently to allow the direct operating cost in cents per passenger mile to continually decrease with each successive aircraft development.

  12. Respiratory effects of air pollution on children.

    PubMed

    Goldizen, Fiona C; Sly, Peter D; Knibbs, Luke D

    2016-01-01

    A substantial proportion of the global burden of disease is directly or indirectly attributable to exposure to air pollution. Exposures occurring during the periods of organogenesis and rapid lung growth during fetal development and early post-natal life are especially damaging. In this State of the Art review, we discuss air toxicants impacting on children's respiratory health, routes of exposure with an emphasis on unique pathways relevant to young children, methods of exposure assessment and their limitations and the adverse health consequences of exposures. Finally, we point out gaps in knowledge and research needs in this area. A greater understanding of the adverse health consequences of exposure to air pollution in early life is required to encourage policy makers to reduce such exposures and improve human health.

  13. Comprehensive national database of tree effects on air quality and human health in the United States.

    PubMed

    Hirabayashi, Satoshi; Nowak, David J

    2016-08-01

    Trees remove air pollutants through dry deposition processes depending upon forest structure, meteorology, and air quality that vary across space and time. Employing nationally available forest, weather, air pollution and human population data for 2010, computer simulations were performed for deciduous and evergreen trees with varying leaf area index for rural and urban areas in every county in the conterminous United States. The results populated a national database of annual air pollutant removal, concentration changes, and reductions in adverse health incidences and costs for NO2, O3, PM2.5 and SO2. The developed database enabled a first order approximation of air quality and associated human health benefits provided by trees with any forest configurations anywhere in the conterminous United States over time. Comprehensive national database of tree effects on air quality and human health in the United States was developed.

  14. Comprehensive national database of tree effects on air quality and human health in the United States.

    PubMed

    Hirabayashi, Satoshi; Nowak, David J

    2016-08-01

    Trees remove air pollutants through dry deposition processes depending upon forest structure, meteorology, and air quality that vary across space and time. Employing nationally available forest, weather, air pollution and human population data for 2010, computer simulations were performed for deciduous and evergreen trees with varying leaf area index for rural and urban areas in every county in the conterminous United States. The results populated a national database of annual air pollutant removal, concentration changes, and reductions in adverse health incidences and costs for NO2, O3, PM2.5 and SO2. The developed database enabled a first order approximation of air quality and associated human health benefits provided by trees with any forest configurations anywhere in the conterminous United States over time. Comprehensive national database of tree effects on air quality and human health in the United States was developed. PMID:27176764

  15. Changing air mass frequencies in Canada: potential links and implications for human health.

    PubMed

    Vanos, J K; Cakmak, S

    2014-03-01

    Many individual variables have been studied to understand climate change, yet an overall weather situation involves the consideration of many meteorological variables simultaneously at various times diurnally, seasonally, and yearly. The current study identifies a full weather situation as an air mass type using synoptic scale classification, in 30 population centres throughout Canada. Investigative analysis of long-term air mass frequency trends was completed, drawing comparisons between seasons and climate zones. We find that the changing air mass trends are highly dependent on the season and climate zone being studied, with an overall increase of moderate ('warm') air masses and decrease of polar ('cold') air masses. In the summertime, general increased moisture content is present throughout Canada, consistent with the warming air masses. The moist tropical air mass, containing the most hot and humid air, is found to increase in a statistically significant fashion in the summertime in 46% of the areas studied, which encompass six of Canada's ten largest population centres. This emphasises the need for heat adaptation and acclimatisation for a large proportion of the Canadian population. In addition, strong and significant decreases of transition/frontal passage days were found throughout Canada. This result is one of the most remarkable transition frequency results published to date due to its consistency in identifying declining trends, coinciding with research completed in the United States (US). We discuss relative results and implications to similar US air mass trend analyses, and draw upon research studies involving large-scale upper-level air flow and vortex connections to air mass changes, to small-scale meteorological and air pollution interactions. Further research is warranted to better understand such connections, and how these air masses relate to the overall and city-specific health of Canadians.

  16. The health effects of exercising in air pollution.

    PubMed

    Giles, Luisa V; Koehle, Michael S

    2014-02-01

    The health benefits of exercise are well known. Many of the most accessible forms of exercise, such as walking, cycling, and running often occur outdoors. This means that exercising outdoors may increase exposure to urban air pollution. Regular exercise plays a key role in improving some of the physiologic mechanisms and health outcomes that air pollution exposure may exacerbate. This problem presents an interesting challenge of balancing the beneficial effects of exercise along with the detrimental effects of air pollution upon health. This article summarizes the pulmonary, cardiovascular, cognitive, and systemic health effects of exposure to particulate matter, ozone, and carbon monoxide during exercise. It also summarizes how air pollution exposure affects maximal oxygen consumption and exercise performance. This article highlights ways in which exercisers could mitigate the adverse health effects of air pollution exposure during exercise and draws attention to the potential importance of land use planning in selecting exercise facilities.

  17. Health effects of air pollution and the Japanese compensation law

    SciTech Connect

    Namekata, T.; Duv Florey, C.

    1987-01-01

    The contents of this book are: Part 1. Individual Presentations: I. Gas Cooking and Respiratory Disease in Children, II. Health Effects of Fossil Fuel Combustion Compared With Effects of Energy Shortages, III. Daily Symptoms of Lung Function in Relation to Air Pollution: A Study in West Berlin 1982/83, IV. Studies of the Acute Effects of London Smog, and Their Relevance to Present-Day Conditions, V. Epidemiological Issues on Air Pollution in the Japanese Pollution-Related Health Damage Compensation Law. Part 2. Panel Discussion: Epidemiological Issues on Air Pollution in the Japanese Pollution-Related Health Damage Compensation Law; Problems in Air Pollution Epidemiology; Exposure Criteria for Compensation; Problems in the Use of Respiratory Symptoms Questionnaires; Legal and Policy Issues in the Japanes Compensation Law. Part 3. Background Information: I. Legal and Policy Issues in the Japanese Compensation Law. II. Reappraisal of Air Pollution/Health Effects Studies in Japan.

  18. Cooling of Gas Turbines I - Effects of Addition of Fins to Blade Tips and Rotor, Admission of Cooling Air Through Part of Nozzles, and Change in Thermal Conductivity of Turbine Components

    NASA Technical Reports Server (NTRS)

    Brown, Byron

    1947-01-01

    An analysis was developed for calculating the radial temperature distribution in a gas turbine with only the temperatures of the gas and the cooling air and the surface heat-transfer coefficient known. This analysis was applied to determine the temperatures of a complete wheel of a conventional single-stage impulse exhaust-gas turbine. The temperatures were first calculated for the case of the turbine operating at design conditions of speed, gas flow, etc. and with only the customary cooling arising from exposure of the outer blade flange and one face of the rotor to the air. Calculations were next made for the case of fins applied to the outer blade flange and the rotor. Finally the effects of using part of the nozzles (from 0 to 40 percent) for supplying cooling air and the effects of varying the metal thermal conductivity from 12 to 260 Btu per hour per foot per degree Farenheit on the wheel temperatures were determined. The gas temperatures at the nozzle box used in the calculations ranged from 1600F to 2000F. The results showed that if more than a few hundred degrees of cooling of turbine blades are required other means than indirect cooling with fins on the rotor and outer blade flange would be necessary. The amount of cooling indicated for the type of finning used could produce some improvement in efficiency and a large increase in durability of the wheel. The results also showed that if a large difference is to exist between the effective temperature of the exhaust gas and that of the blade material, as must be the case with present turbine materials and the high exhaust-gas temperatures desired (2000F and above), two alternatives are suggested: (a) If metal with a thermal conductivity comparable with copper is used, then the blade temperature can be reduced by strong cooling at both the blade tip and root. The center of the blade will be less than 2000F hotter than the ends; (b) With low conductivity materials some method of direct cooling other than

  19. Impact of Aerosol Direct Effect on East Asian Air Quality During the EAST-AIRE Campaign

    NASA Astrophysics Data System (ADS)

    Wang, J.; Allen, D. J.; Pickering, K. E.; Li, Z.

    2015-12-01

    Three WRF-Chem simulations were conducted for East Asia region during March 2005 East Asian Studies of Tropospheric Aerosols: an International Regional Experiment (EAST-AIRE) Intensive Observation Campaign (IOC) period to investigate the direct effects of aerosols on surface radiation and air quality. WRF-Chem captured the temporal and spatial variations of meteorological fields, trace gases, and aerosol loadings. Surface shortwave radiation changes due to the aerosol direct effect (ADE) were calculated and compared with data from six World Radiation Data Center (WRDC) stations. The comparison indicated that WRF-Chem can simulate the surface short wave radiation moderately well, with temporal correlations between 0.4 and 0.7, and high biases between 9 to 120 W/m2. Domain-wide, WRF-Chem showed a decrease of 22 W/m2 in surface SW radiation due to the aerosol direct effect, consistent with observational studies. The ADE demonstrates diverse influences on air quality in East Asian. For example, the surface concentration of PM2.5 increases in eastern China (~11.1%) due to ADE, but decreases in central China (-7.3%), western China (-8.8%), and Sichuan Basin (-4%). Surface 1-hour maximum ozone is reduced by 2.3%, owing to less radiation reaching the surface due to the ADE. Since PM2.5 pollution raises serious public concern in China, regulations that control the emissions of PM2.5 and its precursors have been implemented. We investigate the impact of reducing two different types of aerosols, sulfate (scattering) and black carbon (absorbing), by cutting 80% of SO2 and black carbon (BC) emissions in two sensitivity simulations. We found that reducing SO2 emissions results in the decline of PM2.5 as much as 16mg/m3 in eastern China, and 20mg/m3 in the Sichuan Basin. Reducing the BC emissions by the same percentage causes the PM2.5 to decrease as much as 40mg/m3 in eastern China, and 25mg/m3 in the Sichuan Basin. The monthly averaged surface 1-hour maximum ozone increases 3

  20. A turbulence-driven air fumigation facility for studying air pollution effects on vegetation

    SciTech Connect

    Lipfert, F.; Lewin, K.; Hendrey, G.; Nagy, J. ); Alexander, Y. . Applied Mathematics Dept.)

    1990-10-01

    Studying the effects of atmospheric perturbations on plant growth has usually involved compromises between realism and convenience. Isolating the effects of specific parameters, such as air pollution, elevated CO{sub 2} concentration, or water stress, requires a manipulated rather than a completely natural environment. Attempts to develop large free-air controlled exposure systems date back several years, primarily for experimental exposures to elevated levels of air pollutants such as SO{sub 2} or ozone. These early systems suffered from two types of problems: imprecise control of the exposure gas concentrations; substantial spatial variability within the exposed plots. The Free-Air CO{sub 2} Enrichment (FACE) open-air fumigation system, developed at Brookhaven National Laboratory (BNL), has addressed both of these problem areas. This system differs from other free-air exposure systems in that the injection gas is pre-diluted in ambient air to an average 3--4% by volume, and the injection gas mass flow is adjusted each second by the micoprocessor-driven controller. This document discusses the design and performance of this facility. 3 refs., 4 figs., 1 tab.

  1. Footprints of air pollution and changing environment on the sustainability of built infrastructure.

    PubMed

    Kumar, Prashant; Imam, Boulent

    2013-02-01

    Over 150 research articles relating three multi-disciplinary topics (air pollution, climate change and civil engineering structures) are reviewed to examine the footprints of air pollution and changing environment on the sustainability of building and transport structures (referred as built infrastructure). The aim of this review is to synthesize the existing knowledge on this topic, highlight recent advances in our understanding and discuss research priorities. The article begins with the background information on sources and emission trends of global warming (CO(2), CH(4), N(2)O, CFCs, SF(6)) and corrosive (SO(2), O(3), NO(X)) gases and their role in deterioration of building materials (e.g. steel, stone, concrete, brick and wood) exposed in outdoor environments. Further section covers the impacts of climate- and pollution-derived chemical pathways, generally represented by dose-response functions (DRFs), and changing environmental conditions on built infrastructure. The article concludes with the discussions on the topic areas covered and research challenges. A comprehensive inventory of DRFs is compiled. The case study carried out for analysing the inter-comparability of various DRFs on four different materials (carbon steel, limestone, zinc and copper) produced comparable results. Results of another case study revealed that future projected changes in temperature and/or relatively humidity are expected to have a modest effect on the material deterioration rate whereas changes in precipitation were found to show a more dominant impact. Evidences suggest that both changing and extreme environmental conditions are expected to affect the integrity of built infrastructure both in terms of direct structural damage and indirect losses of transport network functionality. Unlike stone and metals, substantially limited information is available on the deterioration of brick, concrete and wooden structures. Further research is warranted to develop more robust and

  2. AIR POLLUTION EFFECTS ON SEMEN QUALITY

    EPA Science Inventory

    The potential impact of exposure to periods of high air pollution on male reproductive health was examined within the framework of an international project conducted in the Czech Republic. Semen quality was evaluated in young men (age 18) living in the Teplice District who are ex...

  3. Effects of air temperature, humidity, and air movement on thermal comfort under hot and humid conditions

    SciTech Connect

    Tanabe, Shinichi; Kimura, Kenichi

    1994-12-31

    The purpose of this paper is to review and summarize the effects of air temperature, humidity, and air movement on thermal comfort under hot and humid conditions with a view toward energy conservation. Recently, ASHRAE published a new comfort envelope in Standard 55-1992. In that standard, the upper limit of relative humidity (RH) was wet at 60%. In hot and humid regions, humidity levels higher than 60% may often be observed. This upper limit of humidity is discussed based on their subjective data. In addition, the results show that under hot and humid conditions, air movement may be one of the least expensive methods of providing thermal comfort. The effect of air movement is also described in this paper.

  4. Coal mining activities change plant community structure due to air pollution and soil degradation.

    PubMed

    Pandey, Bhanu; Agrawal, Madhoolika; Singh, Siddharth

    2014-10-01

    The aim of this study was to investigate the effects of coal mining activities on the community structures of woody and herbaceous plants. The response of individual plants of community to defilement caused by coal mining was also assessed. Air monitoring, soil physico-chemical and phytosociological analyses were carried around Jharia coalfield (JCF) and Raniganj coalfield. The importance value index of sensitive species minified and those of tolerant species enhanced with increasing pollution load and altered soil quality around coal mining areas. Although the species richness of woody and herbaceous plants decreased with higher pollution load, a large number of species acclimatized to the stress caused by the coal mining activities. Woody plant community at JCF was more affected by coal mining than herbaceous community. Canonical correspondence analysis revealed that structure of herbaceous community was mainly driven by soil total organic carbon, soil nitrogen, whereas woody layer community was influenced by sulphur dioxide in ambient air, soil sulphate and soil phosphorus. The changes in species diversity observed at mining areas indicated an increase in the proportion of resistant herbs and grasses showing a tendency towards a definite selection strategy of ecosystem in response to air pollution and altered soil characteristics.

  5. Impacts of future climate and emission changes on U.S. air quality

    NASA Astrophysics Data System (ADS)

    Penrod, Ashley; Zhang, Yang; Wang, Kai; Wu, Shiang-Yuh; Leung, L. Ruby

    2014-06-01

    Changes in climate and emissions will affect future air quality. In this work, simulations of regional air quality during current (2001-2005) and future (2026-2030) winter and summer are conducted with the newly released CMAQ version 5.0 to examine the impacts of simulated future climate and anthropogenic emission projections on air quality over the U.S. Current meteorological and chemical predictions are evaluated against observations to assess the model's capability in reproducing the seasonal differences. WRF and CMAQ capture the overall observational spatial patterns and seasonal differences. Biases in model predictions are attributed to uncertainties in emissions, boundary conditions, and limitations in model physical and chemical treatments as well as the use of a coarse grid resolution. Increased temperatures (up to 3.18 °C) and decreased ventilation (up to 157 m in planetary boundary layer height) are found in both future winter and summer, with more prominent changes in winter. Increases in future temperatures result in increased isoprene and terpene emissions in winter and summer, driving the increase in maximum 8-h average O3 (up to 5.0 ppb) over the eastern U.S. in winter while decreases in NOx emissions drive the decrease in O3 over most of the U.S. in summer. Future PM2.5 concentrations in winter and summer and many of its components decrease due to decreases in primary anthropogenic emissions and the concentrations of secondary anthropogenic pollutants as well as increased precipitation in winter. Future winter and summer dry and wet deposition fluxes are spatially variable and increase with decreasing surface resistance and precipitation, respectively. They decrease with a decrease in ambient particulate concentrations. Anthropogenic emissions play a more important role in summer than in winter for future O3 and PM2.5 levels, with a dominance of the effects of significant emission reductions over those of climate change on future PM2.5 levels.

  6. Ecological effects of environmental change.

    PubMed

    Luque, Gloria M; Hochberg, Michael E; Holyoak, Marcel; Hossaert, Martine; Gaill, Françoise; Courchamp, Franck

    2013-05-01

    This Special Issue of Ecology Letters presents contributions from an international meeting organised by Centre National de la Recherche Scientifique (CNRS) and Ecology Letters on the broad theme of ecological effects of global environmental change. The objectives of these articles are to synthesise, hypothesise and illustrate the ecological effects of environmental change drivers and their interactions, including habitat loss and fragmentation, pollution, invasive species and climate change. A range of disciplines is represented, including stoichiometry, cell biology, genetics, evolution and biodiversity conservation. The authors emphasise the need to account for several key ecological factors and different spatial and temporal scales in global change research. They also stress the importance of ecosystem complexity through approaches such as functional group and network analyses, and of mechanisms and predictive models with respect to environmental responses to global change across an ecological continuum: population, communities and ecosystems. Lastly, these articles provide important insights and recommendations for environmental conservation and management, as well as highlighting future research priorities.

  7. Modelling of air pressure effects in casting moulds

    NASA Astrophysics Data System (ADS)

    Attar, E.; Homayonifar, P.; Babaei, R.; Asgari, K.; Davami, P.

    2005-09-01

    In the casting process, as a mould is filled with molten metal, air escapes through the vents. Air pressure in the mould cavity has serious effects upon the filling behaviour such as surface profile of the molten metal and filling time. In this project a computational model was developed for calculation of air pressure during the mould filling. A 3D single phase code based on the SOLA-VOF algorithm was used for the prediction of the fluid flow. The ideal gas assumption, conservation of mass equation and Bernoulli law were used for the calculation of air pressure. A new algorithm was developed to interpolate air pressure on the surface cells. The creation of air pressure was correlated with the sizes of the vents and their locations. An experimental test was designed to verify the modelling results. Comparison between the experimental data and simulation results has shown a good agreement.

  8. Air exchange effectiveness in office buildings: Measurement techniques and results

    SciTech Connect

    Fisk, W.J.; Faulkner, D.

    1992-07-01

    We define two air exchange effectiveness parameters which indicate the extent of short circuiting, mixing, or displacement air flow in an entire building, the air diffusion effectiveness which indicates the air flow pattern locally, and the normalized local age of air. After describing two tracer gas procedures for measuring these parameters, we discuss assumptions inherent in the data analysis that are often violated in large office buildings. To obtain valuable data, careful selection of buildings for measurements and assessments to determine if operating conditions are reasonably consistent with the assumptions are necessary. Multiple factors, in addition to the air flow pattern in the occupied space, can affect measurement results, consequently, the interpretation of measurements is not straightforward. We summarize the results of measurements in several office buildings and in a research laboratory. Almost all measurements indicate that the extent of both short circuiting and displacement flow is small. A moderate amount of short circuiting is evident from a few measurements in rooms with heated supply air. Ages of air and their reciprocals (local ventilation rates) often vary substantially between rooms, probably because of room-to-room variation in the rate of air supply. For future research, we suggest assessments of measurement accuracy, development of measurement approaches that may be practically applied for a broader range of buildings, and a greater focus on pollutant removal efficiencies.

  9. [Aerodynamics study on pressure changes inside pressure-type whole-body plethysmograph produced by flowing air].

    PubMed

    Xu, Wei-Hua; Shen, Hua-Hao

    2010-02-25

    When using pressure-type plethysmography to test lung function of rodents, calculation of lung volume is always based on Boyle's law. The precondition of Boyle's law is that perfect air is static. However, air in the chamber is flowing continuously when a rodent breathes inside the chamber. Therefore, Boyle's law, a principle of air statics, may not be appropriate for measuring pressure changes of flowing air. In this study, we deduced equations for pressure changes inside pressure-type plethysmograph and then designed three experiments to testify the theoretic deduction. The results of theoretic deduction indicated that increased pressure was generated from two sources: one was based on Boyle's law, and the other was based on the law of conservation of momentum. In the first experiment, after injecting 0.1 mL, 0.2 mL, 0.4 mL of air into the plethysmograph, the pressure inside the chamber increased sharply to a peak value, then promptly decreased to horizontal pressure. Peak values were significantly higher than the horizontal values (P<0.001). This observation revealed that flowing air made an extra effect on air pressure in the plethysmograph. In the second experiment, the same volume of air was injected into the plethysmograph at different frequencies (0, 0.5, 1, 2, 3 Hz) and pressure changes inside were measured. The results showed that, with increasing frequencies, the pressure changes in the chamber became significantly higher (P<0.001). In the third experiment, small animal ventilator and pipette were used to make two types of airflow with different functions of time. The pressure changes produced by the ventilator were significantly greater than those produced by the pipette (P<0.001). Based on the data obtained, we draw the conclusion that, the flow of air plays a role in pressure changes inside the plethysmograph, and the faster the airflow is, the higher the pressure changes reach. Furthermore, the type of airflow also influences the pressure changes

  10. [Aerodynamics study on pressure changes inside pressure-type whole-body plethysmograph produced by flowing air].

    PubMed

    Xu, Wei-Hua; Shen, Hua-Hao

    2010-02-25

    When using pressure-type plethysmography to test lung function of rodents, calculation of lung volume is always based on Boyle's law. The precondition of Boyle's law is that perfect air is static. However, air in the chamber is flowing continuously when a rodent breathes inside the chamber. Therefore, Boyle's law, a principle of air statics, may not be appropriate for measuring pressure changes of flowing air. In this study, we deduced equations for pressure changes inside pressure-type plethysmograph and then designed three experiments to testify the theoretic deduction. The results of theoretic deduction indicated that increased pressure was generated from two sources: one was based on Boyle's law, and the other was based on the law of conservation of momentum. In the first experiment, after injecting 0.1 mL, 0.2 mL, 0.4 mL of air into the plethysmograph, the pressure inside the chamber increased sharply to a peak value, then promptly decreased to horizontal pressure. Peak values were significantly higher than the horizontal values (P<0.001). This observation revealed that flowing air made an extra effect on air pressure in the plethysmograph. In the second experiment, the same volume of air was injected into the plethysmograph at different frequencies (0, 0.5, 1, 2, 3 Hz) and pressure changes inside were measured. The results showed that, with increasing frequencies, the pressure changes in the chamber became significantly higher (P<0.001). In the third experiment, small animal ventilator and pipette were used to make two types of airflow with different functions of time. The pressure changes produced by the ventilator were significantly greater than those produced by the pipette (P<0.001). Based on the data obtained, we draw the conclusion that, the flow of air plays a role in pressure changes inside the plethysmograph, and the faster the airflow is, the higher the pressure changes reach. Furthermore, the type of airflow also influences the pressure changes.

  11. Behavioural change, indoor air pollution and child respiratory health in developing countries: a review.

    PubMed

    Barnes, Brendon R

    2014-04-25

    Indoor air pollution caused by the indoor burning of solid biomass fuels has been associated with Acute Respiratory Infections such as pneumonia amongst children of less than five years of age. Behavioural change interventions have been identified as a potential strategy to reduce child indoor air pollution exposure, yet very little is known about the impact of behavioural change interventions to reduce indoor air pollution. Even less is known about how behaviour change theory has been incorporated into indoor air pollution behaviour change interventions. A review of published studies spanning 1983-2013 suggests that behavioural change strategies have the potential to reduce indoor air pollution exposure by 20%-98% in laboratory settings and 31%-94% in field settings. However, the evidence is: (1) based on studies that are methodologically weak; and (2) have little or no underlying theory. The paper concludes with a call for more rigorous studies to evaluate the role of behavioural change strategies (with or without improved technologies) to reduce indoor air pollution exposure in developing countries as well as interventions that draw more strongly on existing behavioural change theory and practice.

  12. Behavioural change, indoor air pollution and child respiratory health in developing countries: a review.

    PubMed

    Barnes, Brendon R

    2014-05-01

    Indoor air pollution caused by the indoor burning of solid biomass fuels has been associated with Acute Respiratory Infections such as pneumonia amongst children of less than five years of age. Behavioural change interventions have been identified as a potential strategy to reduce child indoor air pollution exposure, yet very little is known about the impact of behavioural change interventions to reduce indoor air pollution. Even less is known about how behaviour change theory has been incorporated into indoor air pollution behaviour change interventions. A review of published studies spanning 1983-2013 suggests that behavioural change strategies have the potential to reduce indoor air pollution exposure by 20%-98% in laboratory settings and 31%-94% in field settings. However, the evidence is: (1) based on studies that are methodologically weak; and (2) have little or no underlying theory. The paper concludes with a call for more rigorous studies to evaluate the role of behavioural change strategies (with or without improved technologies) to reduce indoor air pollution exposure in developing countries as well as interventions that draw more strongly on existing behavioural change theory and practice. PMID:24776723

  13. Behavioural Change, Indoor Air Pollution and Child Respiratory Health in Developing Countries: A Review

    PubMed Central

    Barnes, Brendon R.

    2014-01-01

    Indoor air pollution caused by the indoor burning of solid biomass fuels has been associated with Acute Respiratory Infections such as pneumonia amongst children of less than five years of age. Behavioural change interventions have been identified as a potential strategy to reduce child indoor air pollution exposure, yet very little is known about the impact of behavioural change interventions to reduce indoor air pollution. Even less is known about how behaviour change theory has been incorporated into indoor air pollution behaviour change interventions. A review of published studies spanning 1983–2013 suggests that behavioural change strategies have the potential to reduce indoor air pollution exposure by 20%–98% in laboratory settings and 31%–94% in field settings. However, the evidence is: (1) based on studies that are methodologically weak; and (2) have little or no underlying theory. The paper concludes with a call for more rigorous studies to evaluate the role of behavioural change strategies (with or without improved technologies) to reduce indoor air pollution exposure in developing countries as well as interventions that draw more strongly on existing behavioural change theory and practice. PMID:24776723

  14. Rapid microRNA changes in airways of human volunteers after controlled exposure to air pollutants

    EPA Science Inventory

    Introduction/Rationale: Exposure to air pollutants, including ozone and diesel exhaust (DE) are known to cause acute cardiopulmonary dysfunction; however, the molecular mechanisms underlying these changes remain elusive. One mechanism for rapid regulation of multiple genes is a...

  15. EXAMINING THE IMPACT OF CLIMATE CHANGE ON REGIONAL AIR QUALITY OVER THE UNITED STATES

    EPA Science Inventory

    This presentation summarizes recent results produced in support of the assessment of climate change impacts on ozone and particulate matter over the continental United States. Preliminary findings of climate scenario, meteorologically-drive emissions and air quality simulation a...

  16. Membrane air-stripping: Effects of pretreatment

    SciTech Connect

    Castro, K. ); Zander, A.K. . Dept. of Civil and Environmental Engineering)

    1995-03-01

    As a result of the Safe Drinking Water Act and its 1986 amendments, the number of regulated volatile organic chemicals (VOCs) has increased substantially. The discovery of drinking water supply sources contaminated by VOCs is also increasing. These factors have led to the development of alternative treatment methods for control of VOCs. Microporous polypropylene hollow-fiber membranes offer significant advantages over packed-tower aeration for removing volatile organic chemicals. A laboratory study assessed the performance of membrane air-stripping in continuous operation, while exposed to various pretreatments. Results indicate that membrane air-stripping is compatible with low-pH or low-chlorine waters but not with waters of high pH or high-chlorine concentration or those that are ozonated.

  17. Contribution of ecosystem services to air quality and climate change mitigation policies: the case of urban forests in Barcelona, Spain.

    PubMed

    Baró, Francesc; Chaparro, Lydia; Gómez-Baggethun, Erik; Langemeyer, Johannes; Nowak, David J; Terradas, Jaume

    2014-05-01

    Mounting research highlights the contribution of ecosystem services provided by urban forests to quality of life in cities, yet these services are rarely explicitly considered in environmental policy targets. We quantify regulating services provided by urban forests and evaluate their contribution to comply with policy targets of air quality and climate change mitigation in the municipality of Barcelona, Spain. We apply the i-Tree Eco model to quantify in biophysical and monetary terms the ecosystem services "air purification," "global climate regulation," and the ecosystem disservice "air pollution" associated with biogenic emissions. Our results show that the contribution of urban forests regulating services to abate pollution is substantial in absolute terms, yet modest when compared to overall city levels of air pollution and GHG emissions. We conclude that in order to be effective, green infrastructure-based efforts to offset urban pollution at the municipal level have to be coordinated with territorial policies at broader spatial scales.

  18. Effect of ionizing radiation on moist air systems

    SciTech Connect

    Reed, D.T.; Van Konynenburg, R.A.

    1987-12-31

    The radiation chemistry of nitrogen/oxygen/water systems is reviewed. General radiolytic effects in dry nitrogen/oxygen systems are relatively well characterized. Irradiation results in the formation of steady state concentrations of ozone, nitrous oxide and nitrogen dioxide. In closed systems, the concentration observed depends on the total dose, temperature and initial gas composition. Only three studies have been published that focus on the radiation chemistry of nitrogen/oxygen/water homogeneous gas systems. Mixed phase work that is relevant to the gaseous system is also summarized. The presence of water vapor results in the formation of nitric acid and significantly changes the chemistry observed in dry air systems. Mechanistic evidence from the studies reviewed are summarized and discussed in relation to characterizing the gas phase during the containment period of a repository in tuff.

  19. Tackling air pollution and extreme climate changes in China: Implementing the Paris climate change agreement.

    PubMed

    Tambo, Ernest; Duo-Quan, Wang; Zhou, Xiao-Nong

    2016-10-01

    China still depends on coal for more than 60% of its power despite big investments in the process of shifting to nuclear, solar and wind power renewable energy resources alignment with Paris climate change agreement (Paris CCA). Chinese government through the Communist Party Central Committee (CPCC) ascribes great importance and commitment to Paris CCA legacy and history landmark implementation at all levels. As the world's biggest carbon dioxide emitter, China has embarked on "SMART" pollution and climate changes programs and measures to reduce coal-fired power plants to less than 50% in the next five years include: new China model of energy policies commitment on CO2 and greenhouse gas emissions reductions to less than 20% non-fossil energy use by 2030 without undermining their economic growth, newly introduced electric vehicles transportation benefits, interactive and sustained air quality index (AQI) monitoring systems, decreasing reliance on fossil fuel economic activities, revision of energy price reforms and renewable energy to less energy efficient technologies development. Furthermore, ongoing CPCC improved environmental initiatives, implemented strict regulations and penalties on local companies and firms' pollution production management, massive infrastructures such as highways to reduce CO2 expansion of seven regional emissions trading markets and programs for CO2 emissions and other pollutants are being documented. Maximizing on the centralized nature of the China's government, implemented Chinese pollution, climate changes mitigation and adaptation initiatives, "SMART" strategies and credible measures are promising. A good and practical example is the interactive and dynamic website and database covering 367 Chinese cities and providing real time information on environmental and pollution emissions AQI. Also, water quality index (WQI), radiation and nuclear safety monitoring and management systems over time and space. These are ongoing Chinese

  20. Tackling air pollution and extreme climate changes in China: Implementing the Paris climate change agreement.

    PubMed

    Tambo, Ernest; Duo-Quan, Wang; Zhou, Xiao-Nong

    2016-10-01

    China still depends on coal for more than 60% of its power despite big investments in the process of shifting to nuclear, solar and wind power renewable energy resources alignment with Paris climate change agreement (Paris CCA). Chinese government through the Communist Party Central Committee (CPCC) ascribes great importance and commitment to Paris CCA legacy and history landmark implementation at all levels. As the world's biggest carbon dioxide emitter, China has embarked on "SMART" pollution and climate changes programs and measures to reduce coal-fired power plants to less than 50% in the next five years include: new China model of energy policies commitment on CO2 and greenhouse gas emissions reductions to less than 20% non-fossil energy use by 2030 without undermining their economic growth, newly introduced electric vehicles transportation benefits, interactive and sustained air quality index (AQI) monitoring systems, decreasing reliance on fossil fuel economic activities, revision of energy price reforms and renewable energy to less energy efficient technologies development. Furthermore, ongoing CPCC improved environmental initiatives, implemented strict regulations and penalties on local companies and firms' pollution production management, massive infrastructures such as highways to reduce CO2 expansion of seven regional emissions trading markets and programs for CO2 emissions and other pollutants are being documented. Maximizing on the centralized nature of the China's government, implemented Chinese pollution, climate changes mitigation and adaptation initiatives, "SMART" strategies and credible measures are promising. A good and practical example is the interactive and dynamic website and database covering 367 Chinese cities and providing real time information on environmental and pollution emissions AQI. Also, water quality index (WQI), radiation and nuclear safety monitoring and management systems over time and space. These are ongoing Chinese

  1. Changes in tropospheric composition and air quality due to stratospheric ozone depletion and climate change.

    PubMed

    Wilson, S R; Solomon, K R; Tang, X

    2007-03-01

    It is well-understood that reductions in air quality play a significant role in both environmental and human health. Interactions between ozone depletion and global climate change will significantly alter atmospheric chemistry which, in turn, will cause changes in concentrations of natural and human-made gases and aerosols. Models predict that tropospheric ozone near the surface will increase globally by up to 10 to 30 ppbv (33 to 100% increase) during the period 2000 to 2100. With the increase in the amount of the stratospheric ozone, increased transport from the stratosphere to the troposphere will result in different responses in polluted and unpolluted areas. In contrast, global changes in tropospheric hydroxyl radical (OH) are not predicted to be large, except where influenced by the presence of oxidizable organic matter, such as from large-scale forest fires. Recent measurements in a relatively clean location over 5 years showed that OH concentrations can be predicted by the intensity of solar ultraviolet radiation. If this relationship is confirmed by further observations, this approach could be used to simplify assessments of air quality. Analysis of surface-level ozone observations in Antarctica suggests that there has been a significant change in the chemistry of the boundary layer of the atmosphere in this region as a result of stratospheric ozone depletion. The oxidation potential of the Antarctic boundary layer is estimated to be greater now than before the development of the ozone hole. Recent modeling studies have suggested that iodine and iodine-containing substances from natural sources, such as the ocean, may increase stratospheric ozone depletion significantly in polar regions during spring. Given the uncertainty of the fate of iodine in the stratosphere, the results may also be relevant for stratospheric ozone depletion and measurements of the influence of these substances on ozone depletion should be considered in the future. In agreement with

  2. Changes in tropospheric composition and air quality due to stratospheric ozone depletion and climate change.

    PubMed

    Wilson, S R; Solomon, K R; Tang, X

    2007-03-01

    It is well-understood that reductions in air quality play a significant role in both environmental and human health. Interactions between ozone depletion and global climate change will significantly alter atmospheric chemistry which, in turn, will cause changes in concentrations of natural and human-made gases and aerosols. Models predict that tropospheric ozone near the surface will increase globally by up to 10 to 30 ppbv (33 to 100% increase) during the period 2000 to 2100. With the increase in the amount of the stratospheric ozone, increased transport from the stratosphere to the troposphere will result in different responses in polluted and unpolluted areas. In contrast, global changes in tropospheric hydroxyl radical (OH) are not predicted to be large, except where influenced by the presence of oxidizable organic matter, such as from large-scale forest fires. Recent measurements in a relatively clean location over 5 years showed that OH concentrations can be predicted by the intensity of solar ultraviolet radiation. If this relationship is confirmed by further observations, this approach could be used to simplify assessments of air quality. Analysis of surface-level ozone observations in Antarctica suggests that there has been a significant change in the chemistry of the boundary layer of the atmosphere in this region as a result of stratospheric ozone depletion. The oxidation potential of the Antarctic boundary layer is estimated to be greater now than before the development of the ozone hole. Recent modeling studies have suggested that iodine and iodine-containing substances from natural sources, such as the ocean, may increase stratospheric ozone depletion significantly in polar regions during spring. Given the uncertainty of the fate of iodine in the stratosphere, the results may also be relevant for stratospheric ozone depletion and measurements of the influence of these substances on ozone depletion should be considered in the future. In agreement with

  3. Changes in tropospheric composition and air quality due to stratospheric ozone depletion.

    PubMed

    Solomon, Keith R; Tang, Xiaoyan; Wilson, Stephen R; Zanis, Prodromos; Bais, Alkiviadis F

    2003-01-01

    Increased UV-B through stratospheric ozone depletion leads to an increased chemical activity in the lower atmosphere (the troposphere). The effect of stratospheric ozone depletion on tropospheric ozone is small (though significant) compared to the ozone generated anthropogenically in areas already experiencing air pollution. Modeling and experimental studies suggest that the impacts of stratospheric ozone depletion on tropospheric ozone are different at different altitudes and for different chemical regimes. As a result the increase in ozone due to stratospheric ozone depletion may be greater in polluted regions. Attributable effects on concentrations are expected only in regions where local emissions make minor contributions. The vertical distribution of NOx (NO + NO2), the emission of volatile organic compounds and the abundance of water vapor, are important influencing factors. The long-term nature of stratospheric ozone depletion means that even a small increase in tropospheric ozone concentration can have a significant impact on human health and the environment. Trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CDFA) are produced by the atmospheric degradation of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs). TFA has been measured in rain, rivers, lakes, and oceans, the ultimate sink for these and related compounds. Significant anthropogenic sources of TFA other than degradation HCFCs and HFCs have been identified. Toxicity tests under field conditions indicate that the concentrations of TFA and CDFA currently produced by the atmospheric degradation of HFCs and HCFCs do not present a risk to human health and the environment. The impact of the interaction between ozone depletion and future climate change is complex and a significant area of current research. For air quality and tropospheric composition, a range of physical parameters such as temperature, cloudiness and atmospheric transport will modify the impact of UV-B. Changes in the

  4. The application of remote sensing techniques for air pollution analysis and climate change on Indian subcontinent

    NASA Astrophysics Data System (ADS)

    Palve, S. N.; Nemade, P. D., Dr.; Ghude, S. D., Dr.

    2016-06-01

    India is home to an extraordinary variety of climatic regions, ranging from tropical in the south to temperate and alpine in the Himalayan north, where elevated regions receive sustained winter snowfall. The subcontinent is characterized by high levels of air pollution due to intensively developing industries and mass fuel consumption for domestic purposes. The main tropospheric pollutants (O3, NO2, CO, formaldehyde (HCHO) and SO2) and two major greenhouse gases (tropospheric O3 and methane (CH4)) and important parameters of aerosols, which play a key role in climate change and affecting on the overall well-being of subcontinent residents. In light of considering these facts this paper aims to investigate possible impact of air pollutants over the climate change on Indian subcontinent. Satellite derived column aerosol optical depth (AOD) is a cost effective way to monitor and study aerosols distribution and effects over a long time period. AOD is found to be increasing rapidly since 2000 in summer season that may cause adverse effect to the agricultural crops and also to the human health. Increased aerosol loading may likely affect the rainfall which is responsible for the observed drought conditions over the Indian subcontinent. Carbon monoxide is emitted into the atmosphere by biomass burning activities and India is the second largest contributor of CO emissions in Asia. The MOPITT CO retrievals at 850 hPa show large CO emission from the IG region. The development of convective activity associated with the ASM leads to large scale vertical transport of the boundary layer CO from the Indian region into the upper troposphere. TCO over the Indian subcontinent during 2007 has a systematic and gradual variation, spatial as well as temporal. Higher amount of TCO in the northern latitudes and simultaneous lower TCO at near equatorial latitudes indicates depletion of ozone near the equator and accumulation at higher latitudes within the subcontinent. In addition, changes

  5. The effect of undissolved air on isochoric freezing.

    PubMed

    Perez, Pedro A; Preciado, Jessica; Carlson, Gary; DeLonzor, Russ; Rubinsky, Boris

    2016-06-01

    This study evaluates the effect of undissolved air on isochoric freezing of aqueous solutions. Isochoric freezing is concerned with freezing in a constant volume thermodynamic system. A possible advantage of the process is that it substantially reduces the percentage of ice in the system at every subzero temperature, relative to atmospheric freezing. At the pressures generated by isochoric freezing, or high pressure isobaric freezing, air cannot be considered an incompressible substance and the presence of undissolved air substantially increases the amount of ice that forms at any subfreezing temperature. This effect is measurable at air volumes as low as 1%. Therefore eliminating the undissolved air, or any separate gaseous phase, from the system is essential for retaining the properties of isochoric freezing. PMID:27074589

  6. Which ornamental plant species effectively remove benzene from indoor air?

    NASA Astrophysics Data System (ADS)

    Liu, Yan-Ju; Mu, Yu-Jing; Zhu, Yong-Guan; Ding, Hui; Crystal Arens, Nan

    Phytoremediation—using plants to remove toxins—is an attractive and cost effective way to improve indoor air quality. This study screened ornamental plants for their ability to remove volatile organic compounds from air by fumigating 73 plant species with 150 ppb benzene, an important indoor air pollutant that poses a risk to human health. The 10 species found to be most effective at removing benzene from air were fumigated for two more days (8 h per day) to quantify their benzene removal capacity. Crassula portulacea, Hydrangea macrophylla, Cymbidium Golden Elf., Ficus microcarpa var. fuyuensis, Dendranthema morifolium, Citrus medica var. sarcodactylis, Dieffenbachia amoena cv. Tropic Snow; Spathiphyllum Supreme; Nephrolepis exaltata cv. Bostoniensis; Dracaena deremensis cv. Variegata emerged as the species with the greatest capacity to remove benzene from indoor air.

  7. The effect of undissolved air on isochoric freezing.

    PubMed

    Perez, Pedro A; Preciado, Jessica; Carlson, Gary; DeLonzor, Russ; Rubinsky, Boris

    2016-06-01

    This study evaluates the effect of undissolved air on isochoric freezing of aqueous solutions. Isochoric freezing is concerned with freezing in a constant volume thermodynamic system. A possible advantage of the process is that it substantially reduces the percentage of ice in the system at every subzero temperature, relative to atmospheric freezing. At the pressures generated by isochoric freezing, or high pressure isobaric freezing, air cannot be considered an incompressible substance and the presence of undissolved air substantially increases the amount of ice that forms at any subfreezing temperature. This effect is measurable at air volumes as low as 1%. Therefore eliminating the undissolved air, or any separate gaseous phase, from the system is essential for retaining the properties of isochoric freezing.

  8. Air quality and temperature effects on exercise-induced bronchoconstriction.

    PubMed

    Rundell, Kenneth W; Anderson, Sandra D; Sue-Chu, Malcolm; Bougault, Valerie; Boulet, Louis-Philippe

    2015-04-01

    Exercise-induced bronchoconstriction (EIB) is exaggerated constriction of the airways usually soon after cessation of exercise. This is most often a response to airway dehydration in the presence of airway inflammation in a person with a responsive bronchial smooth muscle. Severity is related to water content of inspired air and level of ventilation achieved and sustained. Repetitive hyperpnea of dry air during training is associated with airway inflammatory changes and remodeling. A response during exercise that is related to pollution or allergen is considered EIB. Ozone and particulate matter are the most widespread pollutants of concern for the exercising population; chronic exposure can lead to new-onset asthma and EIB. Freshly generated emissions particulate matter less than 100 nm is most harmful. Evidence for acute and long-term effects from exercise while inhaling high levels of ozone and/or particulate matter exists. Much evidence supports a relationship between development of airway disorders and exercise in the chlorinated pool. Swimmers typically do not respond in the pool; however, a large percentage responds to a dry air exercise challenge. Studies support oxidative stress mediated pathology for pollutants and a more severe acute response occurs in the asthmatic. Winter sport athletes and swimmers have a higher prevalence of EIB, asthma and airway remodeling than other athletes and the general population. Because of fossil fuel powered ice resurfacers in ice rinks, ice rink athletes have shown high rates of EIB and asthma. For the athlete training in the urban environment, training during low traffic hours and in low traffic areas is suggested. PMID:25880506

  9. Air quality and temperature effects on exercise-induced bronchoconstriction.

    PubMed

    Rundell, Kenneth W; Anderson, Sandra D; Sue-Chu, Malcolm; Bougault, Valerie; Boulet, Louis-Philippe

    2015-04-01

    Exercise-induced bronchoconstriction (EIB) is exaggerated constriction of the airways usually soon after cessation of exercise. This is most often a response to airway dehydration in the presence of airway inflammation in a person with a responsive bronchial smooth muscle. Severity is related to water content of inspired air and level of ventilation achieved and sustained. Repetitive hyperpnea of dry air during training is associated with airway inflammatory changes and remodeling. A response during exercise that is related to pollution or allergen is considered EIB. Ozone and particulate matter are the most widespread pollutants of concern for the exercising population; chronic exposure can lead to new-onset asthma and EIB. Freshly generated emissions particulate matter less than 100 nm is most harmful. Evidence for acute and long-term effects from exercise while inhaling high levels of ozone and/or particulate matter exists. Much evidence supports a relationship between development of airway disorders and exercise in the chlorinated pool. Swimmers typically do not respond in the pool; however, a large percentage responds to a dry air exercise challenge. Studies support oxidative stress mediated pathology for pollutants and a more severe acute response occurs in the asthmatic. Winter sport athletes and swimmers have a higher prevalence of EIB, asthma and airway remodeling than other athletes and the general population. Because of fossil fuel powered ice resurfacers in ice rinks, ice rink athletes have shown high rates of EIB and asthma. For the athlete training in the urban environment, training during low traffic hours and in low traffic areas is suggested.

  10. Extreme weather and air pollution effects on cardiovascular and respiratory hospital admissions in Cyprus.

    PubMed

    Tsangari, H; Paschalidou, A K; Kassomenos, A P; Vardoulakis, S; Heaviside, C; Georgiou, K E; Yamasaki, E N

    2016-01-15

    In many regions of the world, climatic change is associated with increased extreme temperatures, which can have severe effects on mortality and morbidity. In this study, we examine the effect of extreme weather on hospital admissions in Cyprus, for inland and coastal areas, through the use of synoptic weather classifications (air mass types). In addition, the effect of particulate air pollution (PM10) on morbidity is examined. Our results show that two air mass types, namely (a) warm, rainy days with increased levels of water vapour in the atmosphere and (b) cold, cloudy days with increased levels of precipitation, were associated with increased morbidity in the form of hospital admissions. This was true both for cardiovascular and respiratory conditions, for all age groups, but particularly for the elderly, aged over 65. Particulate air pollution was also associated with increased morbidity in Cyprus, where the effect was more pronounced for cardiovascular diseases. PMID:26519584

  11. Extreme weather and air pollution effects on cardiovascular and respiratory hospital admissions in Cyprus.

    PubMed

    Tsangari, H; Paschalidou, A K; Kassomenos, A P; Vardoulakis, S; Heaviside, C; Georgiou, K E; Yamasaki, E N

    2016-01-15

    In many regions of the world, climatic change is associated with increased extreme temperatures, which can have severe effects on mortality and morbidity. In this study, we examine the effect of extreme weather on hospital admissions in Cyprus, for inland and coastal areas, through the use of synoptic weather classifications (air mass types). In addition, the effect of particulate air pollution (PM10) on morbidity is examined. Our results show that two air mass types, namely (a) warm, rainy days with increased levels of water vapour in the atmosphere and (b) cold, cloudy days with increased levels of precipitation, were associated with increased morbidity in the form of hospital admissions. This was true both for cardiovascular and respiratory conditions, for all age groups, but particularly for the elderly, aged over 65. Particulate air pollution was also associated with increased morbidity in Cyprus, where the effect was more pronounced for cardiovascular diseases.

  12. Relationships between Changes in Urban Characteristics and Air Quality in East Asia from 2000 to 2010.

    PubMed

    Larkin, Andrew; van Donkelaar, Aaron; Geddes, Jeffrey A; Martin, Randall V; Hystad, Perry

    2016-09-01

    Characteristics of urban areas, such as density and compactness, are associated with local air pollution concentrations. The potential for altering air pollution through changing urban characteristics, however, is less certain, especially for expanding cities within the developing world. We examined changes in urban characteristics from 2000 to 2010 for 830 cities in East Asia to evaluate associations with changes in nitrogen dioxide (NO2) and fine particulate matter (PM2.5) air pollution. Urban areas were stratified by population size into small (100 000-250 000), medium, (250 000-1 000 000), and large (>1 000 000). Multivariate regression models including urban baseline characteristics, meteorological variables, and change in urban characteristics explained 37%, 49%, and 54% of the change in NO2 and 29%, 34%, and 37% of the change in PM2.5 for small, medium and large cities, respectively. Change in lights at night strongly predicted change in NO2 and PM2.5, while urban area expansion was strongly associated with NO2 but not PM2.5. Important differences between changes in urban characteristics and pollutant levels were observed by city size, especially NO2. Overall, changes in urban characteristics had a greater impact on NO2 and PM2.5 change than baseline characteristics, suggesting urban design and land use policies can have substantial impacts on local air pollution levels.

  13. Relationships between Changes in Urban Characteristics and Air Quality in East Asia from 2000 to 2010.

    PubMed

    Larkin, Andrew; van Donkelaar, Aaron; Geddes, Jeffrey A; Martin, Randall V; Hystad, Perry

    2016-09-01

    Characteristics of urban areas, such as density and compactness, are associated with local air pollution concentrations. The potential for altering air pollution through changing urban characteristics, however, is less certain, especially for expanding cities within the developing world. We examined changes in urban characteristics from 2000 to 2010 for 830 cities in East Asia to evaluate associations with changes in nitrogen dioxide (NO2) and fine particulate matter (PM2.5) air pollution. Urban areas were stratified by population size into small (100 000-250 000), medium, (250 000-1 000 000), and large (>1 000 000). Multivariate regression models including urban baseline characteristics, meteorological variables, and change in urban characteristics explained 37%, 49%, and 54% of the change in NO2 and 29%, 34%, and 37% of the change in PM2.5 for small, medium and large cities, respectively. Change in lights at night strongly predicted change in NO2 and PM2.5, while urban area expansion was strongly associated with NO2 but not PM2.5. Important differences between changes in urban characteristics and pollutant levels were observed by city size, especially NO2. Overall, changes in urban characteristics had a greater impact on NO2 and PM2.5 change than baseline characteristics, suggesting urban design and land use policies can have substantial impacts on local air pollution levels. PMID:27442110

  14. Insect hygroreceptor responses to continuous changes in humidity and air pressure.

    PubMed

    Tichy, H; Kallina, W

    2010-06-01

    The most favored model of humidity transduction views the cuticular wall of insect hygroreceptive sensilla as a hygromechanical transducer. Hygroscopic swelling or shrinking alters the geometry of the wall, deforming the dendritic membranes of the moist and dry cells. The small size the sensilla and their position surrounded by elevated structures creates technical difficulties to mechanically stimulate them by direct contact. The present study investigated hygroreceptors on the antennae of the cockroach and the stick insect. Accurately controlled, homogeneous mechanical input was delivered by modulating air pressure. Both the moist and dry cells responded not only to changes in air pressure but also in the opposite direction, as observed during changes in air humidity. The moist cell's excitatory response to increasing humidity and increasing air pressure implies that swelling of the hygroscopic cuticle compresses the dendrites, and the dry cell's excitatory response to decreasing humidity and decreasing air pressure implies that shrinking of the hygroscopic cuticle expands the dendrites. The moist and dry cells of the stick insect are more sensitive to pressure changes than those of the cockroach, but the responses to air pressure are generally weaker than to humidity. Therefore the hygroreceptive sensilla differ in their physical properties and constitutions. Furthermore, the mechanical parameters associated with homogeneous changes in air pressure on the sensillum surface can only partially account for the responses of the moist and dry cells of both species to humidity stimulation. PMID:20375249

  15. Insect hygroreceptor responses to continuous changes in humidity and air pressure

    PubMed Central

    Tichy, H.; Kallina, W.

    2011-01-01

    The most favored model of humidity transduction views the cuticular wall of insect hygroreceptive sensilla as a hygromechanical transducer. Hygroscopic swelling or shrinking alters the geometry of the wall, deforming the dendritic membranes of the moist and dry cells. The small size the sensilla and their position surrounded by elevated structures creates technical difficulties to mechanically stimulate them by direct contact. The present study investigated hygroreceptors on the antennae of the cockroach and the stick insect. Accurately controlled, homogeneous mechanical input was delivered by modulating air pressure. Both the moist and dry cells responded not only to changes in air pressure, but also in the opposite direction, as observed during changes in air humidity. The moist-cell’s excitatory response to increasing humidity and increasing air pressure implies that swelling of the hygroscopic cuticle compresses the dendrites, and the dry-cell’s excitatory response to decreasing humidity and decreasing air pressure implies that shrinking of the hygroscopic cuticle expands the dendrites. The moist and dry cells of the stick insect are more sensitive to pressure changes than those of the cockroach, but the responses to air pressure are generally weaker than to humidity. Therefore, the hygroreceptive sensilla differ in their physical properties and constitutions. Furthermore, the mechanical parameters associated with homogeneous changes in air pressure on the sensillum surface can only partially account for the responses of the moist and dry cells of both species to humidity stimulation. PMID:20375249

  16. Adverse respiratory effects of outdoor air pollution in the elderly.

    PubMed

    Bentayeb, M; Simoni, M; Baiz, N; Norback, D; Baldacci, S; Maio, S; Viegi, G; Annesi-Maesano, I

    2012-09-01

    Compared to the rest of the population, the elderly are potentially highly susceptible to the effects of outdoor air pollution due to normal and pathological ageing. The purpose of the present review was to gather data on the effects on respiratory health of outdoor air pollution in the elderly, on whom data are scarce. These show statistically significant short-term and chronic adverse effects of various outdoor air pollutants on cardiopulmonary morbidity and mortality in the elderly. When exposed to air pollution, the elderly experience more hospital admissions for asthma and chronic obstructive pulmonary disease (COPD) and higher COPD mortality than others. Previous studies also indicate that research on the health effects of air pollution in the elderly has been affected by methodological problems in terms of exposure and health effect assessments. Few pollutants have been considered, and exposure assessment has been based mostly on background air pollution and more rarely on objective measurements and modelling. Significant progress needs to be made through the development of 'hybrid' models utilising the strengths of information on exposure in various environments to several air pollutants, coupled with daily activity exposure patterns. Investigations of chronic effects of air pollution and of multi-pollutant mixtures are needed to better understand the role of air pollution in the elderly. Lastly, smoking, occupation, comorbidities, treatment and the neighbourhood context should be considered as confounders or modifiers of such a role. In this context, the underlying biological, physiological and toxicological mechanisms need to be explored to better understand the phenomenon through a multidisciplinary approach. PMID:22871325

  17. Effects of Aspect Ratio on Air Flow at High Subsonic Mach Numbers

    NASA Technical Reports Server (NTRS)

    Lindsey, W F; Humphreys, Milton D

    1952-01-01

    Schlieren photographs were used in an investigation to determine the effects of changing the aspect ratio from infinity to 2 on the air flow past a wing at high subsonic Mach numbers. The results indicated that the decreased effects of compressibility on drag coefficients for the finite wing are produced by a reduction in the compression shock and flow separation.

  18. Investigating the Effects of Traffic on Air Pollution.

    ERIC Educational Resources Information Center

    Taylor, Sharon

    2001-01-01

    Discusses the benefits of bringing scientists into the classroom to collaborate with children on environmental research projects. Describes one collaborative project that focused on the effects of traffic on air pollution. (DDR)

  19. Effective strategies for behavior change.

    PubMed

    Coleman, Mary Thoesen; Pasternak, Ryan H

    2012-06-01

    Strategies that are most effective in both prevention and management of chronic disease consider factors such as age, ethnicity, community, and technology. Most behavioral change strategies derive their components from application of the health belief model, the theory of reasoned action/theory of planned behavior, transtheoretical model, and social cognitive theory. Many tools such as the readiness ruler and personalized action plan form are available to assist health care teams to facilitate healthy behavior change. Primary care providers can support behavior changes by providing venues for peer interventions and family meetings and by making new partnerships with community organizations.

  20. Effective strategies for behavior change.

    PubMed

    Coleman, Mary Thoesen; Pasternak, Ryan H

    2012-06-01

    Strategies that are most effective in both prevention and management of chronic disease consider factors such as age, ethnicity, community, and technology. Most behavioral change strategies derive their components from application of the health belief model, the theory of reasoned action/theory of planned behavior, transtheoretical model, and social cognitive theory. Many tools such as the readiness ruler and personalized action plan form are available to assist health care teams to facilitate healthy behavior change. Primary care providers can support behavior changes by providing venues for peer interventions and family meetings and by making new partnerships with community organizations. PMID:22608867

  1. Satellite Models for Global Environmental Change in the NASA Health and Air Quality Programs

    NASA Astrophysics Data System (ADS)

    Haynes, J.; Estes, S. M.

    2015-12-01

    Satellite remote sensing of the environment offers a unique vantage point that can fill in the gaps of environmental, spatial, and temporal data for tracking disease. Health and Air Quality providers and researchers are effective by the global environmental changes that are occurring and they need environmental data to study and understand the geographic, environmental, and meteorological differences in disease. This presentation maintains a diverse constellation of Earth observing research satellites and sponsors research in developing satellite data applications across a wide spectrum of areas including environmental health; infectious disease; air quality standards, policies, and regulations; and the impact of climate change on health and air quality. Successfully providing predictions with the accuracy and specificity required by decision makers will require advancements over current capabilities in a number of interrelated areas. These areas include observations, modeling systems, forecast development, application integration, and the research to operations transition process. This presentation will highlight many projects on which NASA satellites have been a primary partner with local, state, Federal, and international operational agencies over the past twelve years in these areas. Domestic and International officials have increasingly recognized links between environment and health. Health providers and researchers need environmental data to study and understand the geographic, environmental, and meteorological differences in disease. The presentation is directly related to Earth Observing systems and Global Health Surveillance and will present research results of the remote sensing environmental observations of earth and health applications, which can contribute to the health research. As part of NASA approach and methodology they have used Earth Observation Systems and Applications for Health Models to provide a method for bridging gaps of environmental

  2. Numerical simulation of changes in tropical cyclone intensity using a coupled air-sea model

    NASA Astrophysics Data System (ADS)

    Duan, Yihong; Wu, Rongsheng; Yu, Runling; Liang, Xudong

    2013-10-01

    A coupled air-sea model for tropical cyclones (TCs) is constructed by coupling the Pennsylvania State University/National Center for Atmospheric Research mesoscale model (MM5) with the Princeton Ocean Model. Four numerical simulations of tropical cyclone development have been conducted using different configurations of the coupled model on the f-plane. When coupled processes are excluded, a weak initial vortex spins up into a mature symmetric TC that strongly resembles those observed and simulated in prior research. The coupled model reproduces the reduction in sea temperature induced by the TC reasonably well, as well as changes in the minimum central pressure of the TC that result from negative atmosphere-ocean feedbacks. Asymmetric structures are successfully simulated under conditions of uniform environmental flow. The coupled ocean-atmosphere model is suitable for simulating air-sea interactions under TC conditions. The effects of the ocean on the track of the TC and changes in its intensity under uniform environmental flow are also investigated. TC intensity responds nonlinearly to sea surface temperature (SST). The TC intensification rate becomes smaller once the SST exceeds a certain threshold. Oceanic stratification also influences TC intensity, with stronger stratification responsible for a larger decrease in intensity. The value of oceanic enthalpy is small when the ocean is weakly stratified and large when the ocean is strongly stratified, demonstrating that the oceanic influence on TC intensity results not only from SST distributions but also from stratification. Air-sea interaction has only a slight influence on TC movement in this model.

  3. Air Change Rates and Interzonal Flows in Residences, and the Need for Multi-Zone Models for Exposure and Health Analysis

    EPA Science Inventory

    Air change rates (ACRs) and interzonal flows are key determinants of indoor air quality (IAQ) and building energy use. This paper characterizes ACRs and interzonal flows in 126 houses, and evaluates effects of these parameters on IAQ. ACRs measured using weeklong tracer measureme...

  4. An Air Quality Data Analysis System for Interrelating Effects, Standards and Needed Source Reductions

    ERIC Educational Resources Information Center

    Larsen, Ralph I.

    1973-01-01

    Makes recommendations for a single air quality data system (using average time) for interrelating air pollution effects, air quality standards, air quality monitoring, diffusion calculations, source-reduction calculations, and emission standards. (JR)

  5. Simulation of climate change impacts on grain sorghum production grown under free air CO2 enrichment

    NASA Astrophysics Data System (ADS)

    Fu, Tongcheng; Ko, Jonghan; Wall, Gerard W.; Pinter, Paul J.; Kimball, Bruce A.; Ottman, Michael J.; Kim, Han-Yong

    2016-07-01

    Potential impacts of climate change on grain sorghum (Sorghum bicolor) productivity were investigated using the CERES-sorghum model in the Decision Support System for Agrotechnology Transfer v4.5. The model was first calibrated for a sorghum cultivar grown in a free air CO2 enrichment experiment at the University of Arizona, Maricopa, Arizona, USA in 1998. The model was then validated with an independent dataset collected in 1999. The simulated grain yield, growth, and soil water of sorghum for the both years were in statistical agreement with the corresponding measurements, respectively. Neither simulated nor measured yields responded to elevated CO2, but both were sensitive to water supply. The validated model was then applied to simulate possible effects of climate change on sorghum grain yield and water use efficiency in western North America for the years 2080-2100. The projected CO2 fertilizer effect on grain yield was dominated by the adverse effect of projected temperature increases. Therefore, temperature appears to be a dominant driver of the global climate change influencing future sorghum productivity. These results suggest that an increase in water demand for sorghum production should be anticipated in a future high-CO2 world.

  6. Marketing Higher Education Means Organizational Change. AIR Forum 1981 Paper.

    ERIC Educational Resources Information Center

    Miklich, Beverly

    The issues, organizational changes, and institutional reactions that colleges and universities perceive as associated with implementation of new marketing practices were identified in a review of the literature and interviews with officials from 25 institutions primarily in or near Los Angeles, California. Several trends were revealed: successful…

  7. Potential impact of a US climate policy and air quality regulations on future air quality and climate change

    NASA Astrophysics Data System (ADS)

    Lee, Y. H.; Shindell, D. T.; Faluvegi, G.; Pinder, R. W.

    2015-11-01

    We have investigated how future air quality and climate change are influenced by the US air quality regulations that existed or were proposed in 2013 and a hypothetical climate mitigation policy that reduces 2050 CO2 emissions to be 50 % below 2005 emissions. Using NASA GISS ModelE2, we look at the impacts in year 2030 and 2055. The US energy-sector emissions are from the GLIMPSE project (GEOS-Chem LIDORT Integrated with MARKAL for the Purpose of Scenario Exploration), and other US emissions and the rest of the world emissions are based on the RCP4.5 scenario. The US air quality regulations are projected to have a strong beneficial impact on US air quality and public health in the future but result in positive radiative forcing. Surface PM2.5 is reduced by ~ 2 μg m-3 on average over the US, and surface ozone by ~ 8 ppbv. The improved air quality prevents about 91 400 premature deaths in the US, mainly due to the PM2.5 reduction (~ 74 200 lives saved). The air quality regulations reduces the light-reflecting aerosols (i.e., sulfate and organic matter) more than the light-absorbing species (i.e., black carbon and ozone), leading a strong positive radiative forcing (RF) by both aerosols direct and indirect forcing: total RF is ~ 0.04 W m-2 over the globe; ~ 0.8 W m-2 over the US. Under the hypothetical climate policy, future US energy relies less on coal and thus SO2 emissions are noticeably reduced. This provides air quality co-benefits, but it leads to climate dis-benefits over the US. In 2055, the US mean total RF is +0.22 W m-2 due to positive aerosol direct and indirect forcing, while the global mean total RF is -0.06 W m-2 due to the dominant negative CO2 RF (instantaneous RF). To achieve a regional-scale climate benefit via a climate policy, it is critical (1) to have multi-national efforts to reduce GHGs emissions and (2) to target emission reduction of light-absorbing species (e.g., BC and O3) on top of long-lived species. The latter is very desirable as the

  8. Air pollution in Delhi: Its Magnitude and Effects on Health”

    PubMed Central

    Rizwan, SA; Nongkynrih, Baridalyne; Gupta, Sanjeev Kumar

    2013-01-01

    Air pollution is responsible for many health problems in the urban areas. Of late, the air pollution status in Delhi has undergone many changes in terms of the levels of pollutants and the control measures taken to reduce them. This paper provides an evidence-based insight into the status of air pollution in Delhi and its effects on health and control measures instituted. The urban air database released by the World Health Organization in September 2011 reported that Delhi has exceeded the maximum PM10 limit by almost 10-times at 198 μg/m3. Vehicular emissions and industrial activities were found to be associated with indoor as well as outdoor air pollution in Delhi. Studies on air pollution and mortality from Delhi found that all-natural-cause mortality and morbidity increased with increased air pollution. Delhi has taken several steps to reduce the level of air pollution in the city during the last 10 years. However, more still needs to be done to further reduce the levels of air pollution. PMID:23559696

  9. Effects of air pollution on ecosystems and biological diversity in the eastern United States.

    PubMed

    Lovett, Gary M; Tear, Timothy H; Evers, David C; Findlay, Stuart E G; Cosby, B Jack; Dunscomb, Judy K; Driscoll, Charles T; Weathers, Kathleen C

    2009-04-01

    Conservation organizations have most often focused on land-use change, climate change, and invasive species as prime threats to biodiversity conservation. Although air pollution is an acknowledged widespread problem, it is rarely considered in conservation planning or management. In this synthesis, the state of scientific knowledge on the effects of air pollution on plants and animals in the Northeastern and Mid-Atlantic regions of the United States is summarized. Four air pollutants (sulfur, nitrogen, ozone, and mercury) and eight ecosystem types ranging from estuaries to alpine tundra are considered. Effects of air pollution were identified, with varying levels of certainty, in all the ecosystem types examined. None of these ecosystem types is free of the impacts of air pollution, and most are affected by multiple pollutants. In aquatic ecosystems, effects of acidity, nitrogen, and mercury on organisms and biogeochemical processes are well documented. Air pollution causes or contributes to acidification of lakes, eutrophication of estuaries and coastal waters, and mercury bioaccumulation in aquatic food webs. In terrestrial ecosystems, the effects of air pollution on biogeochemical cycling are also very well documented, but the effects on most organisms and the interaction of air pollution with other stressors are less well understood. Nevertheless, there is strong evidence for effects of nitrogen deposition on plants in grasslands, alpine areas, and bogs, and for nitrogen effects on forest mycorrhizae. Soil acidification is widespread in forest ecosystems across the eastern United States and is likely to affect the composition and function of forests in acid-sensitive areas over the long term. Ozone is known to cause reductions in photosynthesis in many terrestrial plant species. For the most part, the effects of these pollutants are chronic, not acute, at the exposure levels common in the eastern United States. Mortality is often observed only at experimentally

  10. The Adverse Effects of Air Pollution on the Nervous System

    PubMed Central

    Genc, Sermin; Zadeoglulari, Zeynep; Fuss, Stefan H.; Genc, Kursad

    2012-01-01

    Exposure to ambient air pollution is a serious and common public health concern associated with growing morbidity and mortality worldwide. In the last decades, the adverse effects of air pollution on the pulmonary and cardiovascular systems have been well established in a series of major epidemiological and observational studies. In the recent past, air pollution has also been associated with diseases of the central nervous system (CNS), including stroke, Alzheimer's disease, Parkinson's disease, and neurodevelopmental disorders. It has been demonstrated that various components of air pollution, such as nanosized particles, can easily translocate to the CNS where they can activate innate immune responses. Furthermore, systemic inflammation arising from the pulmonary or cardiovascular system can affect CNS health. Despite intense studies on the health effects of ambient air pollution, the underlying molecular mechanisms of susceptibility and disease remain largely elusive. However, emerging evidence suggests that air pollution-induced neuroinflammation, oxidative stress, microglial activation, cerebrovascular dysfunction, and alterations in the blood-brain barrier contribute to CNS pathology. A better understanding of the mediators and mechanisms will enable the development of new strategies to protect individuals at risk and to reduce detrimental effects of air pollution on the nervous system and mental health. PMID:22523490

  11. Land use changes and its impacts on air quality and atmospheric patterns

    NASA Astrophysics Data System (ADS)

    Freitas, E. D.; Mazzoli, C. R.; Martins, L. D.; Martins, J. A.; Carvalho, V.; Andrade, M.

    2013-05-01

    Possible modifications on atmospheric patterns and air quality caused by land use changes are discussed in this work. With the increasing interest in alternative energy sources, mainly due to the replacement of fossil fuels, large part of the Brazilian territory is being used for sugar cane cultivation. The resultant modifications in land use and some activities associated to this crop are studied with some detail through numerical modeling of the atmosphere. The same tool was applied to study the effect of surface type and emission sources over urban areas in the neighborhoods of the cultivated areas, in particular those located in the Metropolitan Area of Campinas, inside the state of São Paulo, Brazil. The main focus of this work was to identify some relationship between these two types of land use modification and its influence on the regional atmospheric circulation patterns and air quality over agricultural and urban areas affected by biomass burning and the traditional sources of pollutants, such as industries and vehicles. First, the effect of urban areas was analyzed and it was possible to identify typical patterns associated with urban heat islands, especially over the city of Campinas. In this region, air temperature differences up to 3 K were detected during night time. During the day, due to the atmospheric conditions of the studied period, this effect was not significant. Afterwards, the effect of sugar cane cultivated regions was discussed. The results show that the regions of sugar cane grow can significantly modify the surface energy fluxes, with direct consequences to the standards of local temperature and humidity and over nearby regions. Sensitivity tests were carried out during part of September, 2007, through the substitution of the sugar cane by a generic crop in the model, and show that during the day the cultivated areas can present temperatures up to 0,65 k higher than those in the case of the generic one. Throughout the dispersion module

  12. Register Closing Effects on Forced Air Heating System Performance

    SciTech Connect

    Walker, Iain S.

    2003-11-01

    Closing registers in forced air heating systems and leaving some rooms in a house unconditioned has been suggested as a method of quickly saving energy for California consumers. This study combined laboratory measurements of the changes in duct leakage as registers are closed together with modeling techniques to estimate the changes in energy use attributed to closing registers. The results of this study showed that register closing led to increased energy use for a typical California house over a wide combination of climate, duct leakage and number of closed registers. The reduction in building thermal loads due to conditioning only a part of the house was offset by increased duct system losses; mostly due to increased duct leakage. Therefore, the register closing technique is not recommended as a viable energy saving strategy for California houses with ducts located outside conditioned space. The energy penalty associated with the register closing technique was found to be minimized if registers furthest from the air handler are closed first because this tends to only affect the pressures and air leakage for the closed off branch. Closing registers nearer the air handler tends to increase the pressures and air leakage for the whole system. Closing too many registers (more than 60%) is not recommended because the added flow resistance severely restricts the air flow though the system leading to safety concerns. For example, furnaces may operate on the high-limit switch and cooling systems may suffer from frozen coils.

  13. Groundwater air stripping: Effect on water toxicity

    SciTech Connect

    Eldridge, R.B.; Simpson, C.W.; Elliott, D.J.

    1995-02-01

    An air stripping unit was designed to reduce groundwater hydrocarbon content and biotoxicity to acceptable levels. A pilot plant study was conducted to determine the water treatability and to optimize the commercial unit design conditions. A measurement of the pilot plant effluent toxicity was obtained from {open_quotes}Microtox{close_quotes} analysis and rigorous bio-assays. These results indicated that reduction of the water hydrocarbon content to permitted discharge limits was accompanied by the elimination of water toxicity. The Onda mass transfer model was used to prepare the commercial unit design. A post-installation evaluation indicated that the model gave a good representation of the commercial unit performance. Toxicity reductions observed in the pilot plant were also observed in the commercial unit. 3 refs., 5 figs., 3 tabs.

  14. Air pollution effects on the structure of Citrus aurantium leaves

    SciTech Connect

    Psaras, G.K.; Christodoulakis, N.S.

    1987-09-01

    Individual air pollutants cause acute and chronic plant injury, act on stomata and affect carbon dioxide exchange as well as plant growth and development. Inhibition of photosynthesis by several air pollutants has been reported repeatedly. Besides, structural modifications of cell organelles have been reported after fumigation by SO/sub 2/. Although chlorosis and subsequent necrosis are common phenomena caused by artificial treatment with pollutants, fine structural leaf characteristics of plants exposed to long-term air pollution in natural conditions are little explored. Light microscope examination of air pollution affected leaves of plants common in natural ecosystems of Athens' metropolitan area revealed chlorosis phenomena. Electron microscope examination of the leaves of a common subshrub of greek phryganic formations grown in a heavily air polluted natural ecosystem of Athens metropolitan area revealed pronounced ultrastructural anomalies of chloroplasts, mitochondria and microbodies of the mesophyll cells. This organelle destruction of the photosynthesizing tissue as well as the minimization of the ecosystem primary productivity are attributed to the compound action of several toxic air pollutants of the photochemical smog of Athens. This work describes the long-term air pollution effects on the structural features of the leaves of Citrus aurantium, a decorative species planted throughout the heavily air polluted city of Athens.

  15. 78 FR 77106 - U.S. Air Force Reminder Re: United Launch Alliance (ULA) Consent Order and Recent Change in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... Department of the Air Force U.S. Air Force Reminder Re: United Launch Alliance (ULA) Consent Order and Recent Change in Department of Defense (DOD) Compliance Officer AGENCY: Headquarters Air Force, Deputy Under Secretary of the Air Force (Space). ACTION: Publicize Consent Order, Notify Public of New DOD...

  16. Bring Me Men and Women. Mandated Change at the U.S. Air Force Academy.

    ERIC Educational Resources Information Center

    Stiehm, Judith Hicks

    The planning and problems associated with the 1975 Congressional mandate calling for the integration of women into the U.S. Air Force Academy are described. The book examines how Air Force planners made decisions and whether their decisions were effective. Beliefs that were previously held inviolable--that upper body strength is important, that…

  17. A new model for investigating the mortality effects of multiple air pollutants in air pollution mortality time-series studies.

    PubMed

    Roberts, Steven

    2006-03-01

    Because the U.S. Environmental Protection Agency regulates air pollutants independently, the majority of time-series studies on air pollution and mortality have focused on estimating the adverse health effects of a single pollutant. However, due to the sometimes high correlation between air pollutants, the results from studies that focus on a single air pollutant can be difficult to interpret. In addition, the high correlation between air pollutants can produce problems of interpretation for the standard method of investigating the adverse health effects due to multiple air pollutants. The standard method involves simultaneously including the multiple air pollutants in a single statistical model. Because of this, the development of new models to concurrently estimate the adverse health effects of multiple air pollutants has recently been identified as an important area of future research. In this article, a new model for disentangling the joint effects of multiple air pollutants in air pollution mortality time-series studies is introduced. This new model uses the time-series data to assign each air pollutant a weight that indicates the pollutant's contribution to the air pollution mixture that affects mortality and to estimate the effect of this air pollution mixture on mortality. This model offers an improvement in statistical estimation precision over the standard method. It also avoids problems of interpretation that can occur if the standard method is used. This new model is then illustrated by applying it to time-series data from two U.S. counties.

  18. Air Quality from Early Pittsburgh to the Present: The Science of Change

    NASA Astrophysics Data System (ADS)

    Davidson, Cliff

    2009-03-01

    Throughout Pittsburgh's history over the past 250 years, coal reserves in the city and nearby have influenced its economy, demographics, and environmental quality. They have also played a major role in determining air quality in the region. For example, Pittsburgh became famous for its high particle loadings as early as the beginning of the nineteenth century, when the first complaints about air quality in the city were recorded. Nevertheless, residents tolerated the high coal smoke levels since jobs depended on the iron works, steel mills, and other industries. When natural gas was discovered just east of the city in the 1870's and replaced coal for some applications, particle concentrations decreased. But the local supplies of natural gas ran short several years later, and as industry continued to expand in the 1890's the city went back to the use of coal as its primary fuel. The return to smoky air was met with resistance that marked the beginning of sustained public outcry and initiation of several air pollution studies. The next half century was marked by periods of occasional high and low concentration, the latter due to events such as the financial panic of 1907 and the depression of the 1930's. It was not until the 1940's that effective regulations were passed to reduce smoky conditions. Particle levels fell throughout the 1950's and 1960's, and eventually the decline of heavy industry in Pittsburgh led to relatively clean air in many parts of the city. Over the past few decades, airborne particle concentrations averaged across the Pittsburgh region have remained below their earlier levels. However, there are still ``hot spots'' of high concentration resulting from regional background coming from upwind areas and emissions of some large sources that have continued to operate in the Pittsburgh region. Furthermore, the composition of airborne particles in the city has changed from earlier times. Such particles are now the result of emissions from sources in

  19. Forests under climate change and air pollution: gaps in understanding and future directions for research.

    PubMed

    Matyssek, R; Wieser, G; Calfapietra, C; de Vries, W; Dizengremel, P; Ernst, D; Jolivet, Y; Mikkelsen, T N; Mohren, G M J; Le Thiec, D; Tuovinen, J-P; Weatherall, A; Paoletti, E

    2012-01-01

    Forests in Europe face significant changes in climate, which in interaction with air quality changes, may significantly affect forest productivity, stand composition and carbon sequestration in both vegetation and soils. Identified knowledge gaps and research needs include: (i) interaction between changes in air quality (trace gas concentrations), climate and other site factors on forest ecosystem response, (ii) significance of biotic processes in system response, (iii) tools for mechanistic and diagnostic understanding and upscaling, and (iv) the need for unifying modelling and empirical research for synthesis. This position paper highlights the above focuses, including the global dimension of air pollution as part of climate change and the need for knowledge transfer to enable reliable risk assessment. A new type of research site in forest ecosystems ("supersites") will be conducive to addressing these gaps by enabling integration of experimentation and modelling within the soil-plant-atmosphere interface, as well as further model development.

  20. Ocular surface adverse effects of ambient levels of air pollution.

    PubMed

    Torricelli, André Augusto Miranda; Novaes, Priscila; Matsuda, Monique; Alves, Milton Ruiz; Monteiro, Mário Luiz Ribeiro

    2011-01-01

    It is widely recognized today that outdoor air pollution can affect human health. Various chemical components that are present in ambient pollution may have an irritant effect on the mucous membranes of the body, particularly those of the respiratory tract. Much less attention has been focused on the adverse effect on the ocular surface, despite the fact that this structure is even more exposed to air pollution than the respiratory mucosa since only a very thin tear film separates the corneal and conjunctival epithelia from the air pollutants. So far, clinical data are the more widespread tools used by ophthalmologists for assessing possible aggression to the ocular surface; however, clinical findings alone appears not to correlate properly with the complaints presented by the patients pointing out the need for further clinical and laboratory studies on the subject. The purpose of this study is to review signs and symptoms associated with chronic long-term exposure to environmental air pollutants on the ocular structures currently defined as the ocular surface and to review clinical and laboratory tests used to investigate the adverse effects of air pollutants on such structures. We also review previous studies that investigated the adverse effects of air pollution on the ocular surface and discuss the need for further investigation on the subject.

  1. Health effects of air quality regulations in Delhi, India

    NASA Astrophysics Data System (ADS)

    Foster, Andrew; Kumar, Naresh

    2011-03-01

    This, the first systematic study, quantifies the health effects of air quality regulations in Delhi, which adopted radical measures to improve air quality, including, for example, the conversion of all commercial vehicles to compressed natural gas (CNG), and the closure of polluting industries in residential areas from 2000 to 2002. Air pollution data, collected at 113 sites (spread across Delhi and its neighboring areas) from July-December 2003, were used to compute exposure at the place of residence of 3989 subjects. A socio-economic and respiratory health survey was administered in 1576 households. This survey collected time-use, residence histories, demographic information, and direct measurements of lung function with subjects. The optimal interpolation methods were used to link air pollution and respiratory health data at the place of their residence. Resident histories, in combination with secondary data, were used to impute cumulative exposure prior to the air-quality interventions, and the effects of recent air quality measures on lung function were then evaluated. Three important findings emerge from the analysis. First, the interventions were associated with a significant improvement in respiratory health. Second, the effect of these interventions varied significantly by gender and income. Third, consistent with a causal interpretation of these results, effects were the strongest among those individuals who spend a disproportionate share of their time out-of-doors.

  2. Health Effects of Air Quality Regulations in Delhi, India

    PubMed Central

    Foster, Andrew; Kumar, Naresh

    2011-01-01

    This, the first systematic study, quantifies the health effects of air quality regulations in Delhi, which adopted radical measures to improve air quality, including, for example, the conversion of all commercial vehicles to compressed natural gas (CNG), and the closure of polluting industries in residential areas from 2000 to 2002. Air pollution data, collected at 113 sites (spread across Delhi and its neighboring areas) from July-December 2003, were used to compute exposure at the place of residence of 3,989 subjects. A socio-economic and respiratory health survey was administered in 1,576 households. This survey collected time-use, residence histories, demographic information, and direct measurements of lung function with subjects. The optimal interpolation methods were used to link air pollution and respiratory health data at the place of their residence. Resident histories, in combination with secondary data, were used to impute cumulative exposure prior to the air-quality interventions, and the effects of recent air quality measures on lung function were then evaluated. Three important findings emerge from the analysis. First, the interventions were associated with a significant improvement in respiratory health. Second, the effect of these interventions varied significantly by gender and income. Third, consistent with a causal interpretation of these results, effects were the strongest among those individuals who spend a disproportionate share of their time out-of-doors. PMID:21461142

  3. Downscaling a Global Climate Model to Simulate Climate Change Impacts on U.S. Regional and Urban Air Quality

    NASA Technical Reports Server (NTRS)

    Trail, M.; Tsimpidi, A. P.; Liu, P.; Tsigaridis, K.; Hu, Y.; Nenes, A.; Russell, A. G.

    2013-01-01

    Climate change can exacerbate future regional air pollution events by making conditions more favorable to form high levels of ozone. In this study, we use spectral nudging with WRF to downscale NASA earth system GISS modelE2 results during the years 2006 to 2010 and 2048 to 2052 over the continental United States in order to compare the resulting meteorological fields from the air quality perspective during the four seasons of five-year historic and future climatological periods. GISS results are used as initial and boundary conditions by the WRF RCM to produce hourly meteorological fields. The downscaling technique and choice of physics parameterizations used are evaluated by comparing them with in situ observations. This study investigates changes of similar regional climate conditions down to a 12km by 12km resolution, as well as the effect of evolving climate conditions on the air quality at major U.S. cities. The high resolution simulations produce somewhat different results than the coarse resolution simulations in some regions. Also, through the analysis of the meteorological variables that most strongly influence air quality, we find consistent changes in regional climate that would enhance ozone levels in four regions of the U.S. during fall (Western U.S., Texas, Northeastern, and Southeastern U.S), one region during summer (Texas), and one region where changes potentially would lead to better air quality during spring (Northeast). We also find that daily peak temperatures tend to increase in most major cities in the U.S. which would increase the risk of health problems associated with heat stress. Future work will address a more comprehensive assessment of emissions and chemistry involved in the formation and removal of air pollutants.

  4. Impact of 2050 climate change on North American wildfire: consequences for ozone air quality

    NASA Astrophysics Data System (ADS)

    Yue, X.; Mickley, L. J.; Logan, J. A.; Hudman, R. C.; Martin, M. V.; Yantosca, R. M.

    2015-09-01

    We estimate future area burned in the Alaskan and Canadian forest by the mid-century (2046-2065) based on the simulated meteorology from 13 climate models under the A1B scenario. We develop ecoregion-dependent regressions using observed relationships between annual total area burned and a suite of meteorological variables and fire weather indices, and apply these regressions to the simulated meteorology. We find that for Alaska and western Canada, almost all models predict significant (p < 0.05) increases in area burned at the mid-century, with median values ranging from 150 to 390 %, depending on the ecoregion. Such changes are attributed to the higher surface air temperatures and 500 hPa geopotential heights relative to present day, which together lead to favorable conditions for wildfire spread. Elsewhere the model predictions are not as robust. For the central and southern Canadian ecoregions, the models predict increases in area burned of 45-90 %. Except for the Taiga Plain, where area burned decreases by 50 %, no robust trends are found in northern Canada, due to the competing effects of hotter weather and wetter conditions there. Using the GEOS-Chem chemical transport model, we find that changes in wildfire emissions alone increase mean summertime surface ozone levels by 5 ppbv for Alaska, 3 ppbv for Canada, and 1 ppbv for the western US by the mid-century. In the northwestern US states, local wildfire emissions at the mid-century enhance surface ozone by an average of 1 ppbv, while transport of boreal fire pollution further degrades ozone air quality by an additional 0.5 ppbv. The projected changes in wildfire activity increase daily summertime surface ozone above the 95th percentile by 1 ppbv in the northwestern US, 5 ppbv in the high latitudes of Canada, and 15 ppbv in Alaska, suggesting a greater frequency of pollution episodes in the future atmosphere.

  5. Potential Impact of a US Climate Policy and Air Quality Regulations on Future Air Quality and Climate Change

    NASA Technical Reports Server (NTRS)

    Lee, Y. H.; Faluvegi, Gregory S.

    2016-01-01

    We have investigated how future air quality and climate change are influenced by the US air quality regulations that existed or were proposed in 2013 and a hypothetical climate mitigation policy that aims to reduce 2050 CO2 emissions to be 50% below 2005 emissions. Using the NASA GISS ModelE2 general circulation model, we look at the impacts for year 2030 and 2055. The US energy-sector emissions are from the GLIMPSE project (GEOS-Chem LIDORT Integrated with MARKAL (MARKet ALlocation) for the Purpose of Scenario Exploration), and other US emissions data sets and the rest of the world emissions data sets are based on the RCP4.5 scenario. The US air quality regulations are projected to have a strong beneficial impact on US air quality and public health in year 2030 and 2055 but result in positive radiative forcing. Under this scenario, no more emission constraints are added after 2020, and the impacts on air quality and climate change are similar between year 2030 and 2055. Surface particulate matter with a diameter smaller than 2.5 micron PM(sub 2:5) is reduced by 2 approximately µg/m(sup -3) on average over the USA, and surface ozone by approximately 8 ppbv. The improved air quality prevents about 91 400 premature deaths in the USA, mainly due to the PM(sub 2:5) reduction approximately (74 200 lives saved). The air quality regulations reduce the light-reflecting aerosols (i.e., sulfate and organic matter) more than the light-absorbing species (i.e., black carbon and ozone), leading to a strong positive radiative forcing (RF) over the USA by both aerosols' direct and indirect forcing: the total RF is approximately 0.04 W m(sup -2) over the globe, and approximately 0.8 W m(sup -2) over the USA. Under the hypothetical climate policy, a future CO2 emissions cut is achieved in part by relying less on coal, and thus SO2 emissions are noticeably reduced. This provides air quality co-benefits, but it could lead to potential climate disbenefits over the USA. In 2055, the US

  6. Potential impact of a US climate policy and air quality regulations on future air quality and climate change

    NASA Astrophysics Data System (ADS)

    Lee, Yunha; Shindell, Drew T.; Faluvegi, Greg; Pinder, Rob W.

    2016-04-01

    We have investigated how future air quality and climate change are influenced by the US air quality regulations that existed or were proposed in 2013 and a hypothetical climate mitigation policy that aims to reduce 2050 CO2 emissions to be 50 % below 2005 emissions. Using the NASA GISS ModelE2 general circulation model, we look at the impacts for year 2030 and 2055. The US energy-sector emissions are from the GLIMPSE project (GEOS-Chem LIDORT Integrated with MARKAL (MARKet ALlocation) for the Purpose of Scenario Exploration), and other US emissions data sets and the rest of the world emissions data sets are based on the RCP4.5 scenario. The US air quality regulations are projected to have a strong beneficial impact on US air quality and public health in year 2030 and 2055 but result in positive radiative forcing. Under this scenario, no more emission constraints are added after 2020, and the impacts on air quality and climate change are similar between year 2030 and 2055. Surface particulate matter with a diameter smaller than 2.5 µm (PM2.5) is reduced by ˜ 2 µg m-3 on average over the USA, and surface ozone by ˜ 8 ppbv. The improved air quality prevents about 91 400 premature deaths in the USA, mainly due to the PM2.5 reduction (˜ 74 200 lives saved). The air quality regulations reduce the light-reflecting aerosols (i.e., sulfate and organic matter) more than the light-absorbing species (i.e., black carbon and ozone), leading to a strong positive radiative forcing (RF) over the USA by both aerosols' direct and indirect forcing: the total RF is ˜ 0.04 W m-2 over the globe, and ˜ 0.8 W m-2 over the USA. Under the hypothetical climate policy, a future CO2 emissions cut is achieved in part by relying less on coal, and thus SO2 emissions are noticeably reduced. This provides air quality co-benefits, but it could lead to potential climate disbenefits over the USA. In 2055, the US mean total RF is +0.22 W m-2 due to positive aerosol direct and indirect forcing

  7. On the impact of entrapped air in infiltration under ponding conditions. Part a: Preferential air flow path effects on infiltration

    NASA Astrophysics Data System (ADS)

    Mizrahi, Guy; Weisbrod, Noam; Furman, Alex

    2015-04-01

    Entrapped air effects on infiltration under ponding conditions could be important for massive infiltration of managed aquifer recharge (MAR) or soil aquifer treatment (SAT) of treated wastewater. Earlier studies found that under ponding conditions, air is being entrapped and compressed until it reaches a pressure which will enable the air to escape (unstable air flow). They also found that entrapped air could reduce infiltration by 70-90%. Most studies have dealt with entrapped air effects when soil surface topography is flat. The objective of this study is to investigate, under ponding conditions, the effects of: (1) irregular surface topography on preferential air flow path development (stable air flow); (2) preferential air flow path on infiltration; and (3) hydraulic head on infiltration when air is trapped. Column experiments were used to investigate these particular effects. A 140 cm deep and 30 cm wide column packed with silica sand was used under two boundary conditions: in the first, air can only escape vertically upward through the soil surface; in the second, air is free to escape through 20 ports installed along the column perimeter. The surface was flooded with 13 liters of water, with ponding depth decreasing with time. Two soil surface conditions were tested: flat surface and irregular surface (high and low surface zones). Additionally, Helle-show experiments were conducted in order to obtain a visual observation of preferential air flow path development. The measurements were carried out using a tension meter, air pressure transducers, TDR and video cameras. It was found that in irregular surfaces, stable air flow through preferential paths was developed in the high altitude zones. Flat surface topography caused unstable air flow through random paths. Comparison between irregular and flat surface topography showed that the entrapped air pressure was lower and the infiltration rate was about 40% higher in the irregular surface topography than in the

  8. Biofuels that cause land-use change may have much larger non-GHG air quality emissions than fossil fuels.

    PubMed

    Tsao, C-C; Campbell, J E; Mena-Carrasco, M; Spak, S N; Carmichael, G R; Chen, Y

    2012-10-01

    Although biofuels present an opportunity for renewable energy production, significant land-use change resulting from biofuels may contribute to negative environmental, economic, and social impacts. Here we examined non-GHG air pollution impacts from both indirect and direct land-use change caused by the anticipated expansion of Brazilian biofuels production. We synthesized information on fuel loading, combustion completeness, and emission factors, and developed a spatially explicit approach with uncertainty and sensitivity analyses to estimate air pollution emissions. The land-use change emissions, ranging from 6.7 to 26.4 Tg PM(2.5), were dominated by deforestation burning practices associated with indirect land-use change. We also found Brazilian sugar cane ethanol and soybean biodiesel including direct and indirect land-use change effects have much larger life-cycle emissions than conventional fossil fuels for six regulated air pollutants. The emissions magnitude and uncertainty decrease with longer life-cycle integration periods. Results are conditional to the single LUC scenario employed here. After LUC uncertainty, the largest source of uncertainty in LUC emissions stems from the combustion completeness during deforestation. While current biofuels cropland burning policies in Brazil seek to reduce life-cycle emissions, these policies do not address the large emissions caused by indirect land-use change.

  9. Biofuels that cause land-use change may have much larger non-GHG air quality emissions than fossil fuels.

    PubMed

    Tsao, C-C; Campbell, J E; Mena-Carrasco, M; Spak, S N; Carmichael, G R; Chen, Y

    2012-10-01

    Although biofuels present an opportunity for renewable energy production, significant land-use change resulting from biofuels may contribute to negative environmental, economic, and social impacts. Here we examined non-GHG air pollution impacts from both indirect and direct land-use change caused by the anticipated expansion of Brazilian biofuels production. We synthesized information on fuel loading, combustion completeness, and emission factors, and developed a spatially explicit approach with uncertainty and sensitivity analyses to estimate air pollution emissions. The land-use change emissions, ranging from 6.7 to 26.4 Tg PM(2.5), were dominated by deforestation burning practices associated with indirect land-use change. We also found Brazilian sugar cane ethanol and soybean biodiesel including direct and indirect land-use change effects have much larger life-cycle emissions than conventional fossil fuels for six regulated air pollutants. The emissions magnitude and uncertainty decrease with longer life-cycle integration periods. Results are conditional to the single LUC scenario employed here. After LUC uncertainty, the largest source of uncertainty in LUC emissions stems from the combustion completeness during deforestation. While current biofuels cropland burning policies in Brazil seek to reduce life-cycle emissions, these policies do not address the large emissions caused by indirect land-use change. PMID:22924498

  10. Hematological and hemorheological effects of air pollution

    SciTech Connect

    Baskurt, O.K.; Levi, E.; Caglayan, S.; Dikmenoglu, N.; Kutman, M.N. )

    1990-07-01

    Selected hematological parameters and erythrocyte deformability indexes for 16 young male military students were compared before and after a period of exposure to heavy pollution. These students lived in Ankara, which has a serious air pollution problem. The mean sulfur dioxide levels measured at a station proximal to the campus where the students lived were 188 micrograms/m3 and 201 micrograms/m3 during first and second measurements, respectively. During the period between the two measurements, the mean sulfur dioxide level was 292 micrograms/m3. Significant erythropoiesis was indicated by increased erythrocyte counts and hemoglobin and hematocrit levels. Methemoglobin percentage was increased to 2.37 +/- 0.49% (mean +/- standard error) from 0.51 +/- 0.23%. Sulfhemoglobinemia was present in six subjects after the period of pollution, but it was not present in any student prior to this period. Significant increases in erythrocyte deformability indexes were observed after the period of pollution, i.e., from 1.13 +/- 0.01 to 1.21 +/0 0.02, implying that erythrocytes were less flexible, which might impair tissue perfusion.

  11. Changes in Ultrastructure and Sensory Characteristics on Electro-magnetic and Air Blast Freezing of Beef during Frozen Storage.

    PubMed

    Choi, Yun-Sang; Ku, Su-Kyung; Jeong, Ji-Yun; Jeon, Ki-Hong; Kim, Young-Boong

    2015-01-01

    The ultrastructure in the beef muscle of the electro-magnetic resonance and air blast freezing during the frozen storage, and the changes in the quality characteristics after thawing were evaluated. The size of ice crystal was small and evenly formed in the initial freezing period, and it showed that the size was increased as the storage period was elapsed (p<0.05). The beef stored by the electro-magnetic resonance freezing showed the size of ice crystal with a lower rate of increase than the air blast freezing during the frozen storage. The thawing loss of beef stored by the electro-magnetic resonance freezing was significantly lower than the air blast freezing during frozen storage (p<0.05), and it showed that the thawing loss of the round was higher than the loin. Water holding capacity decreased as the storage period became longer while the electro-magnetic resonance freezing was higher than the air blast on 8 month (p<0.05). As a result of sensory evaluation, the beef stored by the electro-magnetic resonance freezing did not show the difference until 4 months, and it showed higher acceptability in comparison with the beef stored by the air blast freezing. Thus, it is considered that the freezing method has an effect on the change in the ultrastructure and quality characteristics of the beef.

  12. The Effects of Very Light Jet Air Taxi Operations on Commercial Air Traffic

    NASA Technical Reports Server (NTRS)

    Smith, Jeremy C.; Dollyhigh, Samuel M.

    2006-01-01

    This study investigates the potential effects of Very Light Jet (VLJ) air taxi operations adding to delays experienced by commercial passenger air transportation in the year 2025. The affordable cost relative to existing business jets and ability to use many of the existing small, minimally equipped, but conveniently located airports is projected to stimulate a large demand for the aircraft. The resulting increase in air traffic operations will mainly be at smaller airports, but this study indicates that VLJs have the potential to increase further the pressure of demand at some medium and large airports, some of which are already operating at or near capacity at peak times. The additional delays to commercial passenger air transportation due to VLJ air taxi operations are obtained from simulation results using the Airspace Concepts Evaluation System (ACES) simulator. The direct increase in operating cost due to additional delays is estimated. VLJs will also cause an increase in traffic density, and this study shows increased potential for conflicts due to VLJ operations.

  13. Air pollution may alter efforts to mitigate climate change

    NASA Astrophysics Data System (ADS)

    Yassaa, Noureddine

    2016-02-01

    Renewable energy, considered in the past as a mitigation option to climate change by reducing carbon emission, is now becoming a source of energy security and competing fossil fuels in many areas of the world. According to recent reports (e.g., IEA, IRENA, REN21), renewable energy has reached in 2014 a historical record of power generation capacity. With 1712 GW installed capacity in 2014, renewable energy represents 27.7% of the world's power generating capacity. Solar photovoltaic (PV) energy, conversion of solar light to electricity through solar panels, has increased to reach 177 GW mostly due to the political engagement for the deployment of renewable through targeted programs and the decrease of PV panels prize in the market (roughly 80% decrease since 2008 according to IRENA's report). Concentrated Solar Power (CSP), reaching a total capacity of 4.4 GW in 2014 (REN21 Report), is also demonstrating a clear growth and progresses have been made with regards to the efficiency, the storage capacity and the cost. In order to reduce the energy consumption and carbon emissions, water solar heaters are being installed in the rooftop of households and a total capacity of 406 GW thermal was recorded in 2014 (REN21 Report).

  14. Assessing changes in stratospheric mean age of air and fractional release using historical trace gas observations

    NASA Astrophysics Data System (ADS)

    Laube, Johannes; Bönisch, Harald; Engel, Andreas; Röckmann, Thomas; Sturges, William

    2014-05-01

    Large-scale stratospheric transport is pre-dominantly governed by the Brewer-Dobson circulation. Due to climatic change a long-term acceleration of this residual stratospheric circulation has been proposed (e.g. Austin et al.,2006). Observational evidence has revealed indications for temporary changes (e.g. Bönisch et al., 2011) but a confirmation of a significant long-term trend is missing so far (e.g. Engel et al., 2009). A different aspect is a possible long-term change in the break-down of chemically important species such as chlorofluorocarbons as proposed by Butchart et al. 2001. Recent studies show significant differences adding up to more than 20 % in the chlorine released from such compounds (Newman et al., 2007; Laube et al., 2013). We here use a data set of three long-lived trace gases, namely SF6, CF2Cl2, and N2O, as measured in whole-air samples collected during balloon and aircraft flights between 1975 and 2011, to assess changes in stratospheric transport and chemistry. For this purpose we utilise the mean stratospheric transit times (or mean ages of air) in combination with a measure of the chemical decomposition (i.e. fractional release factors). We also evaluate the influence of different trend correction methods on these quantities and explore their variability with latitude, altitude, and season. References Austin, J. & Li, F.: On the relationship between the strength of the Brewer-Dobson circulation and the age of stratospheric air, Geophys. Res. Lett., 33, L17807, 2006. Bönisch, H., Engel, A., Birner, Th., Hoor, P., Tarasick, D. W., and Ray, E. A.: On the structural changes in the Brewer-Dobson circulation after 2000, Atmos. Chem. Phys., 11, 3937-3948, 2011. Butchart, N. & Scaife, A. A. Removal of chlorofluorocarbons by increased mass exchange between the stratosphere and troposphere in a changing climate. Nature, 410, 799-802, 2001. Engel, A., Möbius, T., Bönisch, H., Schmidt, U., Heinz, R., Levin, I., Atlas, E., Aoki, S., Nakazawa, T

  15. Detailed Comparison of Blast Effects in Air and Vacuum

    SciTech Connect

    Tringe, J W; Molitoris, J D; Garza, R G; Andreski, H G; Batteux, J D; Lauderbach, L M; Vincent, E R; Wong, B M

    2007-07-26

    Although blast mitigation is most often achieved with solid shielding, ambient gas pressure can also affect the coupling of shock waves to solid targets. In this work the role of air as an energy transfer medium was examined experimentally by subjecting identical large-area rectangular witness plates to short-range blast effects in air and vacuum ({approx}50 mtorr) at 25 C. The expanding reactant front of 3 kg C4 charges was observed by fast camera to be cylindrically symmetric in both air and vacuum. The horizontal component of the reactant cloud velocity (perpendicular to the witness plates) was constant in both cases, with values of 3.0 and 5.9 km/s for air and vacuum, respectively. As a result of the blast, witness plates were plastically deformed into a shallow dish geometry, with local maxima 30 and 20 mm deep for air and vacuum, respectively. The average plate deflection from the air blast was 11 mm, {approx}10% deeper than the average vacuum plate deflection. Shock pressure estimates were made with a simple impedance-matching model, and indicate peak values in the 30-50 MPa range are consistent with the reactant cloud density and velocity. However, more detailed analysis is necessary to definitely establish the mechanisms by which air couples shock energy to the plates.

  16. Effective Stack Design in Air Pollution Control.

    ERIC Educational Resources Information Center

    Clarke, John H.

    1968-01-01

    Stack design problems fall into two general caterories--(1) those of building re-entry, and (2) those of general area pollution. Extensive research has developed adequate information, available in the literature, to permit effective stack design. A major roadblock to effective design has been the strong belief by architects and engineers that high…

  17. Building America Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts, Tyler, Texas

    SciTech Connect

    2015-08-01

    ?Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four System Factor Categories: Balance, Distribution, Outside Air Source, and Recirculation Filtration. Recommended System Factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy.

  18. Changes in air quality and tropospheric composition due to depletion of stratospheric ozone and interactions with changing climate: implications for human and environmental health.

    PubMed

    Madronich, S; Shao, M; Wilson, S R; Solomon, K R; Longstreth, J D; Tang, X Y

    2015-01-01

    UV radiation is an essential driver for the formation of photochemical smog, which includes ground-level ozone and particulate matter (PM). Recent analyses support earlier work showing that poor outdoor air quality is a major environmental hazard as well as quantifying health effects on regional and global scales more accurately. Greater exposure to these pollutants has been linked to increased risks of cardiovascular and respiratory diseases in humans and is associated globally with several million premature deaths per year. Ozone also has adverse effects on yields of crops, leading to loss of billions of US dollars each year. These detrimental effects also may alter biological diversity and affect the function of natural ecosystems. Future air quality will depend mostly on changes in emission of pollutants and their precursors, but changes in UV radiation and climate will contribute as well. Significant reductions in emissions, mainly from the energy and transportation sectors, have already led to improved air quality in many locations. Air quality will continue to improve in those cities/states that can afford controls, and worsen where the regulatory infrastructure is not available. Future changes in UV radiation and climate will alter the rates of formation of ground-level ozone and photochemically-generated particulate matter and must be considered in predictions of air quality. The decrease in UV radiation associated with recovery of stratospheric ozone will, according to recent global atmospheric model simulations, lead to increases in ground-level ozone at most locations. If correct, this will add significantly to future ground-level ozone trends. However, the spatial resolution of these global models is insufficient to inform policy at this time, especially for urban areas. UV radiation affects the atmospheric concentration of hydroxyl radicals, ˙OH, which are responsible for the self-cleaning of the atmosphere. Recent measurements confirm that, on a

  19. The Air Force Academy Instructor Workstation (IWS): II. Effectiveness.

    ERIC Educational Resources Information Center

    Gist, Thomas E.; And Others

    1989-01-01

    Discusses the results of measuring the in-class effectiveness of a computer-controlled instructor workstation (IWS) that was developed at the Air Force Academy. Treatments for the experimental and control groups in an introductory physics course are described, and effects on student performance, student attitudes, and instructor attitudes are…

  20. Modification by antioxidant supplementation of changes in human lung function associated with air pollutant exposure: A systematic review

    PubMed Central

    2011-01-01

    negative effects of urban air pollution on lung function. Conclusions The data evaluating modification of changes in lung function associated with air pollutant exposure by antioxidant supplementation, in intact humans, is limited. Of 13 studies dedicated to this concern, ten demonstrated an attenuation of pollution-associated decrements. There is growing evidence for the benefit of anti-oxidant supplementation in moderating the effects of air pollution on lung function, but more research on human participants is needed to inform this topic. PMID:21729301

  1. Impacts of grassland types and vegetation cover changes on surface air temperature in the regions of temperate grassland of China

    NASA Astrophysics Data System (ADS)

    Shen, Xiangjin; Liu, Binhui; Li, Guangdi; Yu, Pujia; Zhou, Daowei

    2016-10-01

    The sensitivity of surface air temperature response to different grassland types and vegetation cover changes in the regions of temperate grassland of China was analyzed by observation minus reanalysis (OMR) method. The basis of the OMR approach is that reanalysis data are insensitive to local surface properties, so the temperature differences between surface observations and reanalysis can be attributed to land effects. Results showed that growing-season air temperature increased by 0.592 °C/decade in the regions of temperate grassland of China, with about 31 % of observed warming associated with the effects of grassland types and vegetation cover changes. For different grassland types, the growing-season OMR trend was the strongest for temperate desert steppe (0.259 °C/decade) and the weakest for temperate meadow (0.114 °C/decade). Our results suggest that the stronger intraseasonal changes of grassland vegetation are present, the more sensitive the OMR trend responds to the intraseasonal vegetation cover changes. In August and September, the OMR of temperate meadow showed a weak cooling trend. For temperate meadow, about 72.2 and 72.6 % of surface cooling were explained by both grassland type and increase of vegetation cover for August and September, respectively. For temperate steppe and temperate desert steppe, due to the limited soil moisture and little evaporative cooling feedback, the vegetation changes have no significant effect on the surface air temperature. These results indicate that the impact of grassland types and vegetation cover changes should be considered when projecting further climate change in the temperate grassland region of China.

  2. SEM study of the effects of crude oil on the gills and air breathing organs of climbing perch, Anabas testudineus

    SciTech Connect

    Prasad, M.S. )

    1991-12-01

    Ultrastructural studies on the effects of crude oil on the gills are scanty. Recently, researchers studied the effect of crude oil on the air breathing organs of striped gourami using scanning electron microscope and observed mucous cell hyperplasia coupled with telangiectasis in the epithelia of air breathing organs. The present investigation has been undertaken to study crude oil toxicity by observing the morphological changes occurring in the epithelia of gills and air breathing organs of climbing perch, Anabas testudineus at SEM level. Since the epithelia of gills and air breathing organs function in two different media, a comparative account for their sensitivity to crude oil solutions would be informative.

  3. Solar Eclipse Effect on Shelter Air Temperature

    NASA Technical Reports Server (NTRS)

    Segal, M.; Turner, R. W.; Prusa, J.; Bitzer, R. J.; Finley, S. V.

    1996-01-01

    Decreases in shelter temperature during eclipse events were quantified on the basis of observations, numerical model simulations, and complementary conceptual evaluations. Observations for the annular eclipse on 10 May 1994 over the United States are presented, and these provide insights into the temporal and spatial changes in the shelter temperature. The observations indicated near-surface temperature drops of as much as 6 C. Numerical model simulations for this eclipse event, which provide a complementary evaluation of the spatial and temporal patterns of the temperature drops, predict similar decreases. Interrelationships between the temperature drop, degree of solar irradiance reduction, and timing of the peak eclipse are also evaluated for late spring, summer, and winter sun conditions. These simulations suggest that for total eclipses the drops in shelter temperature in midlatitudes can be as high as 7 C for a spring morning eclipse.

  4. Climate change and air quality - measures with co-benefits in China

    SciTech Connect

    Kristin Aunan; Jinghua Fang; Tao Hu; Hans Martin Seip; Haakon Vennemo

    2006-08-15

    Several studies carried out in China over the past 5-10 years, including the authors own work, have found that many measures aimed primarily at reducing local air pollution decrease GHG emissions as a co-benefit. Conversely, a range of CO{sub 2} mitigation policies entail reductions in air pollution as a co-benefit. This implies that the real costs of climate policies in China may be lower than anticipated by the government. This article describes the links between climate change and air quality issues as well as the health and environmental benefits accruing from alterative measures and policies for CO{sub 2} mitigation in China where coal is expected to remain a main energy source for many years to come. The tremendous potential to cut GHG emissions while simultaneously reducing air pollution should make cooperation on climate control strategies more attractive to China and other countries in a similar position. 43 refs., 3 figs., 1 tab.

  5. Respiratory effects of air pollution on allergic disease

    SciTech Connect

    Pierson, W.E.; Koenig, J.Q. )

    1992-10-01

    Allergic patients have an increased susceptibility to the adverse effects of both natural and man-made air pollutants. This goes for both indoor and outdoor air pollutants and manifests itself with biochemical, cellular, and pathophysiologic expressions of adverse health effects in allergic individuals. Also occupationally induced allergic diseases will remain very important. This area has been reviewed recently by Cullen et al. Since allergic patients comprise somewhere between 15% and 20% of the population, this increased susceptibility is of crucial importance not only for medical care and research but for legislative and regulatory consideration to protect these vulnerable individuals.108 references.

  6. Auditory Effects of Multiple Impulses from a Seismic Air Gun on Bottlenose Dolphins (Tursiops truncatus).

    PubMed

    Schlundt, Carolyn E; Finneran, James J; Branstetter, Brian K; Trickey, Jennifer S; Bowman, Victoria; Jenkins, Keith

    2016-01-01

    Auditory thresholds were measured in three bottlenose dolphins before and after exposure to ten impulses from a seismic air gun. Thresholds were measured using behavioral and electrophysiological methods to determine the amount of temporary threshold shift induced. The results suggest that the potential for seismic surveys using air guns to cause auditory effects on dolphins may be lower than previously predicted; however, two of the three dolphins exhibited "anticipatory" behavioral changes at the highest exposure condition that suggested they were attempting to mitigate the effects of the exposures.

  7. Detailed Comparison of Blast Effects in Air and Vacuum

    NASA Astrophysics Data System (ADS)

    Tringe, J. W.; Molitoris, J. D.; Garza, R. G.; Andreski, H. G.; Batteux, J. D.; Lauderbach, L. M.; Vincent, E. R.; Wong, B. M.

    2007-12-01

    The role of air as an energy transfer medium was examined experimentally by subjecting identical large-area rectangular witness plates to short-range blast effects in air and vacuum (˜50 mtorr) at 25 °C. The expanding reactant front of 3 kg C4 charges was observed by fast camera to be cylindrically symmetric in both air and vacuum. The horizontal component of the reactant cloud velocity (perpendicular to the witness plates) was constant in both cases, with values of 3.0 and 5.9 km/s for air and vacuum, respectively. As a result of the blast, witness plates were plastically deformed into a shallow dish geometry, with local maxima 30 and 20 mm deep for air and vacuum, respectively. The average plate deflection from the air blast was 11 mm, ˜10% deeper than the average vacuum plate deflection. Shock pressure estimates were made with a simple impedance-matching model, and indicate peak values in the 30-50 MPa range are consistent with the reactant cloud density and velocity. However, more detailed analysis is necessary to better understand the time-dependent coupling of shock energy that plastically deforms the plates.

  8. Characteristics of DNA methylation changes induced by traffic-related air pollution.

    PubMed

    Ding, Rui; Jin, Yongtang; Liu, Xinneng; Zhu, Ziyi; Zhang, Yuan; Wang, Ting; Xu, Yinchun

    2016-01-15

    Traffic-related air pollution (TRAP) is a potential risk factor for numerous respiratory disorders, including lung cancer, while alteration of DNA methylation may be one of the underlying mechanisms. However, the effects of TRAP mixtures on DNA methylation have not been investigated. We have studied the effects of brief or prolonged TRAP exposures on DNA methylation in the rat. The exposures were performed in spring and autumn, with identical study procedures. In each season, healthy Wistar rats were exposed to TRAP at for 4 h, 7 d, 14 d, or 28 d. Global DNA methylation (LINE-1 and Alu) and specific gene methylation (p16(CDKN2A), APC, and iNOS) in the DNA from blood and lung tissues were quantified by pyrosequencing. Multiple linear regression was applied to assess the influence of air pollutants on DNA methylation levels. The levels of PM2.5, PM10, and NO2 in the high and moderate groups were significantly higher than in the control group. The DNA methylation levels were not significantly different between spring and autumn. When spring and autumn data were analyzed together, PM2.5, PM10, and NO2 exposures were associated with changes in%5mC (95% CI) in LINE-1, iNOS, p16(CDKN2A), and APC ranging from -0.088 (-0.150, -0.026) to 0.102 (0.049, 0.154) per 1 μg/m(3) increase in the pollutant concentration. Prolonged exposure to a high level of TRAP was negatively associated with LINE-1 and iNOS methylation, and positively associated with APC methylations in the DNA from lung tissues but not blood. These findings show that TRAP exposure is associated with decreased methylation of LINE-1 and iNOS, and increased methylation of p16(CDKN2A) and APC.

  9. Managing Chemotherapy Side Effects: Memory Changes

    MedlinePlus

    ... C ancer I nstitute Managing Chemotherapy Side Effects Memory Changes What is causing these changes? Your doctor ... thinking or remembering things Managing Chemotherapy Side Effects: Memory Changes Get help to remember things. Write down ...

  10. Effects of successive air and nitrox dives on human vascular function.

    PubMed

    Marinovic, Jasna; Ljubkovic, Marko; Breskovic, Toni; Gunjaca, Grgo; Obad, Ante; Modun, Darko; Bilopavlovic, Nada; Tsikas, Dimitrios; Dujic, Zeljko

    2012-06-01

    SCUBA diving is regularly associated with asymptomatic changes in cardiac, pulmonary and vascular function. The aim of this study was to evaluate the changes in vascular/endothelial function following SCUBA diving and to assess the potential difference between two breathing gases: air and nitrox 36 (36% oxygen and 64% nitrogen). Ten divers performed two 3-day diving series (no-decompression dive to 18 m with 47 min bottom time with air and nitrox, respectively), with 2 weeks pause in between. Arterial/endothelial function was assessed using SphygmoCor and flow-mediated dilation measurements, and concentration of nitrite before and after diving was determined in venous blood. Production of nitrogen bubbles post-dive was assessed by ultrasonic determination of venous gas bubble grade. Significantly higher bubbling was found after all air dives as compared to nitrox dives. Pulse wave velocity increased slightly (~6%), significantly after both air and nitrox diving, indicating an increase in arterial stiffness. However, augmentation index became significantly more negative after diving indicating smaller wave reflection. There was a trend for post-dive reduction of FMD after air dives; however, only nitrox diving significantly reduced FMD. No significant differences in blood nitrite before and after the dives were found. We found that nitrox diving affects systemic/vascular function more profoundly than air diving by reducing FMD response, most likely due to higher oxygen load. Both air and nitrox dives increased arterial stiffness, but decreased wave reflection suggesting a decrease in peripheral resistance due to exercise during diving. These effects of nitrox and air diving were not followed by changes in plasma nitrite.

  11. Evaluation of AIRS, MODIS, and HIRS 11 Micron Brightness Temperature Difference Changes from 2002 through 2006

    NASA Technical Reports Server (NTRS)

    Broberg, Steven E.; Aumann, Hartmut H.; Gregorich, David T.; Xiong, X.

    2006-01-01

    In an effort to validate the accuracy and stability of AIRS data at low scene temperatures (200-250 K range), we evaluated brightness temperatures at 11 microns with Aqua MODIS band 31 and HIRS/3 channel 8 for Antarctic granules between September 2002 and May 2006. We found excellent agreement with MODIS (at the 0.2 K level) over the full emperature range in data from early in the Aqua mission. However, in more recent data, starting in April 2005, we found a scene temperature dependence in MODIS-AIRS brightness temperature differences, with a discrepancy of 1- 1.5 K at 200 K. The comparison between AIRS and HIRS/3 (channel 8) on NOAA 16 for the same time period yields excellent agreement. The cause and time dependence of the disagreement with MODIS is under evaluation, but the change was coincident with a change in the MODIS production software from collection 4 to 5.

  12. The effects of negative air ions on various physiological functions during work in a hot environment

    NASA Astrophysics Data System (ADS)

    Inbar, O.; Rotstein, A.; Dlin, R.; Dotan, R.; Sulman, F. G.

    1982-06-01

    The effects of negative air-ions on human physical performance has been investigated. Twenty-one healthy males, 20 25 years old (X=23.6±2.6) were exposed to two 180-min rest and exercise sessions two weeks apart. The subjects were randomly assigned into either an experimental group (n=12) or to a control group (n=9). The experimental group performed the first session in neutral air conditions and the second one in air containing 1.36 to 1.90×105 negative air ions and 1.40 to 1.66×102 positive air ions/ml. The control group performed both sessions under neutral air conditions. All sessions were held at Ta=40±1‡C and 25±5% RH. Each session included one hour of resting under the respective ionization conditions, followed by 3 30-min cycle ergometer work bouts, separated by 7-min rest periods. The mechanical work-load during the bicycle exercise was 1.64±0.6 W/kg BW. The experimental group showed a significant reduction with negative air-ions in heart rate (HR), in rectal temperature, and in the rating of perceived exertion (RPE), all when compared with their own neutral session. The control group showed no significant changes between the first and the second exposure. Although not statistically significant, being exposed to negative air-ions seems also to reduce total sweat rate and minute ventilation (VE), and to increase O2 pulse. It is suggested that under the conditions of this study negative air ions can improve various cardiovascular and thermoregulatory functions as well as subjective feelings during physical effort. It is felt that such positive influences may be augmented by increasing the exposure time to negative ionized air and/or prolonging the stressful conditions.

  13. Effect of glow discharge air plasma on grain crops seed

    SciTech Connect

    Dubinov, A.E.; Lazarenko, E.M.; Selemir, V.D.

    2000-02-01

    Oat and barley seeds have been exposed to both continuous and pulsed glow discharge plasmas in air to investigate the effects on germination and sprout growth. Statistical analysis was used to evaluate the effect of plasma exposure on the percentage germination and length of sprout growth. A stimulating effect of plasma exposure was found together with a strong dependence on whether continuous or pulsed discharges were used.

  14. Historical changes in air temperature are evident in temperature fluxes measured in the sub-soil.

    NASA Astrophysics Data System (ADS)

    Fraser, Fiona; McCormick, Benjamin; Hallett, Paul; Wookey, Philip; Hopkins, David

    2013-04-01

    Warming trends in soil temperature have implications for a plethora of soil processes, including exacerbated climate change through the net release of greenhouse gases. Whereas long-term datasets of air temperature changes are abundant, a search of scientific literature reveals a lack of information on soil temperature changes and their specific consequences. We analysed five long-term data series collected in the UK (Dundee and Armagh) and Canada (Charlottetown, Ottawa and Swift Current). They show that the temperatures of soils at 5 - 20 cm depth, and sub-soils at 30 - 150 cm depth, increased in line with air temperature changes over the period 1958 - 2003. Differences were found, however, between soil and air temperatures when data were sub-divided into seasons. In spring, soil temperature warming ranged from 0.19°C at 30 cm in Armagh to 4.30°C at 50 cm in Charlottetown. In summer, however, the difference was smaller and ranged from 0.21°C at 10 cm in Ottawa to 3.70°C at 50 cm in Charlottetown. Winter temperatures were warmer in soil and ranged from 0.45°C at 5 cm in Charlottetown to 3.76°C at 150 cm in Charlottetown. There were significant trends in changes to soil temperature over time, whereas air temperature trends tended only to be significant in winter (changes range from 1.27°C in Armagh to 3.35°C in Swift Current). Differences in the seasonal warming patterns between air and soil temperatures have potential implications for the parameterization of models of biogeochemical cycling.

  15. Influence of policy and climate change on air quality within the UK West Midlands plume

    NASA Astrophysics Data System (ADS)

    Walker, H. L.; Baker, J.

    2009-04-01

    The photochemical trajectory model (PTM), coupled with the Master Chemical Mechanism (MCM v3.1), was used to assess the contribution of locally emitted anthropogenic and biogenic emissions to ambient secondary pollutant levels recorded in Birmingham, UK during the summer Pollution in the Urban Midlands Atmosphere (PUMA) campaign (9 June - 12 July 1999). The contribution to ozone (and particulate matter) formation were found to be small, 0.0 to 3.2 ppb (0 to 11 %), with an overall average contribution of about 0.35 ppb or 1.0 % of the total ozone during the period. Subsequently, a stationary or slowly advecting boundary layer scenario was used to assess the timescales for which the local emissions within the West Midlands react and impact on secondary pollutant levels within or downwind of the region. Considering averaged biogenic and anthropogenic emissions across the region as representative of the West Midlands plume, the formation of ozone was found to be VOC-limited, and increased emissions of BVOCs were found to overall increase the reactivity of the plume. Future emissions scenarios were then modelled for 2010, 2015 and 2020 taking into account implementation of European legislation and possible climate change. This work reports on the predicted effects of these policy implementations and possible climate changes have on air quality within and downwind of the West Midlands connurbation.

  16. Climate change and pollutant emissions impacts on air quality in 2050 over Portugal

    NASA Astrophysics Data System (ADS)

    Sá, E.; Martins, H.; Ferreira, J.; Marta-Almeida, M.; Rocha, A.; Carvalho, A.; Freitas, S.; Borrego, C.

    2016-04-01

    Changes in climate and air pollutant emissions will affect future air quality from global to urban scale. In this study, regional air quality simulations for historical and future periods are conducted, with CAMx version 6.0, to investigate the impacts of future climate and anthropogenic emission projections on air quality over Portugal and the Porto metropolitan area in 2050. The climate and the emission projections were derived from the Representative Concentrations Pathways (RCP8.5) scenario. Modelling results show that climate change will impact NO2, PM10 and O3 concentrations over Portugal. The NO2 and PM10 annual means will increase in Portugal and in the Porto municipality, and the maximum 8-hr daily O3 value will increase in the Porto suburban areas (approximately 5%) and decrease in the urban area (approximately 2%). When considering climate change and projected anthropogenic emissions, the NO2 annual mean decreases (approximately 50%); PM10 annual mean will increase in Portugal and decrease in Porto municipality (approximately 13%); however PM10 and O3 levels increase and extremes occur more often, surpassing the currently legislated annual limits and displaying a higher frequency of daily exceedances. This air quality degradation is likely to be related with the trends found for the 2046-2065 climate, which implies warmer and dryer conditions, and with the increase of background concentrations of ozone and particulate matter. The results demonstrate the need for Portuguese authorities and policy-makers to design and implement air quality management strategies that take climate change impacts into account.

  17. Effect of atomization air on droplet dynamics of spray flames

    SciTech Connect

    Presser, C.; Semerjian, H.G. . Center for Chemical Technology); Gupta, A.K. . Dept. of Mechanical Engineering)

    1988-01-01

    Fuel spray combustions is an important part of a wide variety of propulsion and power systems such as furnaces and gas turbine combustors, afterburners, fuel-injection internal combustion engines, liquid rocket engines, etc. Recent studies using air-assist nozzles have shown that the design and fabrication of these nozzles can directly influence spray circumferential uniformity, i.e., the presence of asymmetrical fuel flux profiles in combustors. The practical implications of these fuel flux nonuniformities are that they seriously alter the spray structure, which subsequently affects droplet/air interactions, local fuel/air mixing, overall flame characteristics and combustor performance, and pollutant emission levels. In addition, the effect of aerodynamic factors on spray characteristics has been investigated. This paper discusses the effect of atomization air on the droplet dynamics of spray flames formed by an air-assist nozzle. Presented are spatial distributions of mean droplet velocity and their probability distributions, which provide quantitative information for examination of the observed spray flame features.

  18. Evolving Best Practice in Learning About Air Quality and Climate Change Science in ACCENT

    NASA Astrophysics Data System (ADS)

    Schuepbach, E.

    2008-12-01

    Learning about air quality and climate change science has developed into a transdisciplinary impact generator, moulded by academic-stakeholder partnerships, where complementary skills and competences lead to a culture of dialogue, mutual learning and decision-making. These sweeping changes are mirrored in the evolving best practice within the European Network of Excellence on Atmospheric Composition Change (ACCENT). The Training and Education Programme in ACCENT pursues an integrated approach and innovative avenues to sharing knowledge and communicating air quality and climate change science to various end-user groups, including teachers, policy makers, stakeholders, and the general public. Early career scientists are involved in the process, and are trained to acquire new knowledge in a variety of learning communities and environments. Here, examples of both the open system of teaching within ACCENT training workshops for early career scientists, and the engagement of non-academic audiences in the joint learning process are presented.

  19. Effect of body repositioning after venous air embolism. An echocardiographic study

    NASA Technical Reports Server (NTRS)

    Geissler, H. J.; Allen, S. J.; Mehlhorn, U.; Davis, K. L.; Morris, W. P.; Butler, B. D.

    1997-01-01

    BACKGROUND: Current therapy for massive venous air embolism (VAE) may include the use of the left lateral recumbent (LLR) position, although its effectiveness has been questioned. This study used transesophageal echocardiography to evaluate the effect of body repositioning on intracardiac air and acute cardiac dimension changes. METHODS: Eighteen anesthetized dogs in the supine position received a venous air injection of 2.5 ml/kg at a rate of 5 ml/ s. After 1 min the dogs were repositioned into either the LLR, LLR 10 degrees head down (LLR-10 degrees), right lateral recumbence, or remained in the supine position. RESULTS: Repositioning after VAE resulted in relocation of intracardiac air to nondependent areas of the right heart. Peak right ventricular (RV) diameter increase and mean arterial pressure decrease were greater in the repositioned animals compared with those in the supine position (P < 0.05). Right ventricular diameter and mean arterial pressure showed an inverse correlation (r = 0.81). Peak left atrial diameter decrease was greater in the LLR and LLR-10 degrees positions compared with the supine position (P < 0.05). Repositioning did not influence peak pulmonary artery pressure increase, and no correlation was found between RV diameter and pulmonary artery pressure. All animals showed electrocardiogram and echocardiographic changes reconcilable with myocardial ischemia. CONCLUSIONS: In dogs, body repositioning after VAE provided no benefit in hemodynamic performance or cardiac dimension changes, although relocation of intracardiac air was demonstrated. Right ventricular air did not appear to result in significant RV outflow obstruction, as pulmonary artery pressure increased uniformly in all groups and was not influenced by the relocation of intracardiac air. The combination of increased RV afterload and arterial hypotension, possibly with subsequent RV ischemia rather than RV outflow obstruction by an airlock appeared to be the primary mechanism for

  20. Feasibility of cooling emplacement drifts by ventilation air and effects of pre-cooling intake air by refrigeration

    SciTech Connect

    Yang, Hang; Bhattacharyya, K.K.

    1995-12-01

    This study evaluates effects of applying refrigerated air to cool emplacement drifts and provides a preliminary basis for future design analyses. Evaluations include impacts of airflow rates, intake air temperature, ventilation systems capability, and effectiveness of pre-cooling. Representative results provided from this study include the heat removal capability of ventilation air, effects of refrigerating intake air on continuous cooling, and effects of refrigerating intake air on rapid (blast cooling). It is possible to cool emplacement drifts within a reasonable time period, using airflow at ambient temperature is reasonable quantity. Refrigerating intake air can significantly reduce required cooling time or airflow rate, but it is inefficient as far as power consumption is concerned.

  1. A Study of the Effects of Air Pollution on Children

    ERIC Educational Resources Information Center

    Bury, Irene B.

    1970-01-01

    An investigation of the possible effects of air pollution on the absenteeism of elementary school children showed that a greater percent of absences occurred in the test group than in a comparable group. There is little question as to the importance that such information should have for educators, informed parents, and other adults in community…

  2. The Effects of a Blizzard on Urban Air Pollution.

    ERIC Educational Resources Information Center

    da Silva, Armando; Bein, Frederick L.

    1981-01-01

    The chronology and effects of a 1978 blizzard on Indianapolis' air pollution levels (ozone, sulfur dioxide, carbon monoxide) are used as a case study for geography classes. Photographs, graphs, and maps are provided as examples of meteorological data collection and interpretation. (AM)

  3. Effects of air velocity on laying hen production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal conditions play a major role in production efficiency in commercial poultry production. Mitigation of thermal stress can improve productivity, but must be achieved economically. Weather and system design can limit effectiveness of evaporative cooling and increased air movement has been sho...

  4. CARDIAC MOLECULAR EFFECTS INDUCED BY AIR POLLUTION PARTICLES

    EPA Science Inventory

    Abstract Submitted to the American Thoracic Society 98th International Conference, May 17 - 22, 2002, Atlanta, GA

    CARDIAC MOLECULAR EFFECTS INDUCED BY AIR POLLUTION PARTICLES
    K. Dreher1, R. Jaskot1, J. Richards1, and T. Knuckles2. 1U. S. Environmental Protection Agency,...

  5. Attribution of precipitation changes on ground-air temperature offset: Granger causality analysis

    NASA Astrophysics Data System (ADS)

    Cermak, Vladimir; Bodri, Louise

    2016-06-01

    This work examines the causal relationship between the value of the ground-air temperature offset and the precipitation changes for monitored 5-min data series together with their hourly and daily averages obtained at the Sporilov Geophysical Observatory (Prague). Shallow subsurface soil temperatures were monitored under four different land cover types (bare soil, sand, short-cut grass and asphalt). The ground surface temperature (GST) and surface air temperature (SAT) offset, ΔT(GST-SAT), is defined as the difference between the temperature measured at the depth of 2 cm below the surface and the air temperature measured at 5 cm above the surface. The results of the Granger causality test did not reveal any evidence of Granger causality for precipitation to ground-air temperature offsets on the daily scale of aggregation except for the asphalt pavement. On the contrary, a strong evidence of Granger causality for precipitation to the ground-air temperature offsets was found on the hourly scale of aggregation for all land cover types except for the sand surface cover. All results are sensitive to the lag choice of the autoregressive model. On the whole, obtained results contain valuable information on the delay time of ΔT(GST-SAT) caused by the rainfall events and confirmed the importance of using autoregressive models to understand the ground-air temperature relationship.

  6. Economic assessment of crop damages due to air pollution: the role of quality effects.

    PubMed

    Shortle, J S; Phillips, M; Dunn, J W

    1988-01-01

    Biological research has established that air pollution can affect the yield and quality of agricultural crops. Economic assessments of crop exposure to air pollution have focused on the yield effect. This study illustrates the implications of considering crop quality effects in addition to crop yield changes for the case of O3 impacts on soybeans. An economic model of US soybean, soybean oil, and soybean meal markets is used to simulate the impacts of increased soybean yields due to reduced O3 concentrations with and without changes in soybean quality. The simulations with quality effects are richer in their distributional implications and show larger increases in economic surplus than the simulations with yield effects only.

  7. The Potential Impacts of Climate Change on Air Quality in the Upper Northern Thailand

    NASA Astrophysics Data System (ADS)

    Chotamonsak, Chakrit; Salathé, Eric P.; Kreasuwun, Jiemjai

    2016-04-01

    In this study, the Weather Research and Forecasting (WRF) model were used as regional climate model to dynamically downscale the ECHAM5 Global Climate Model projection for the regional climate change impact on air quality-related meteorological conditions in the upper northern Thailand. The analyses were focused on meteorological variables that potentially impact on the regional air quality such as sea level pressure, planetary boundary layer height (PBLH), surface temperature, wind speed and ventilation. Comparisons were made between the present (1990-2009) and future (2045-2064) climate downscaling results during majority air pollution season (dry season, January-April). Analyses showed that the sea level pressure will be stronger in the future, suggesting more stable atmosphere. Increases in temperature were obvious observed throughout the region. Decreases in the surface wind and PBLH were predicted during air pollution season, indicating weaker ventilation rate in this region. Consequently, air quality-related meteorological variables were predicted to change in almost part of the upper northern Thailand, yielding a favorable meteorological condition for pollutant accumulation in the future.

  8. Air pollution "holiday effect" resulting from the Chinese New Year

    NASA Astrophysics Data System (ADS)

    Tan, Pei-Hua; Chou, Chia; Liang, Jing-Yi; Chou, Charles C.-K.; Shiu, Chein-Jung

    Our study was an attempt to conduct a comprehensive and systematical examination of the holiday effect, defined as the difference in air pollutant concentrations between holiday and non-holiday periods. This holiday effect can be applied to other countries with similar national or cultural holidays. Hourly and daily surface measurements of six major air pollutants from thirteen air quality monitoring stations of the Taiwan Environmental Protection Administration during the Chinese New Year (CNY) and non-Chinese New Year (NCNY) periods were used. We documented evidence of a "holiday effect", where air pollutant concentrations were significantly different between holidays (CNY) and non-holidays (NCNY), in the Taipei metropolitan area over the past thirteen years (1994-2006). The concentrations of NO x, CO, NMHC, SO 2 and PM 10 were lower in the CNY than in the NCNY period, while the variation in the concentration of O 3 was reversed, which was mainly due to the NO titration effect. Similar differences in these six air pollutants between the CNY and NCNY periods were also found in the diurnal cycle and in the interannual variation. For the diurnal cycle, a common traffic-related double-peak variation was observed in the NCNY period, but not in the CNY period. Impacts of dust storms were also observed, especially on SO 2 and PM 10 in the CNY period. In the 13-year period of 1994-2006, decreasing trends of NO x and CO in the NCNY period implied a possible reduction of local emissions. Increasing trends of SO 2 and PM 10 in the CNY period, on the other hand, indicated a possible enhancement of long-range transport. These two mechanisms weakened the holiday effect.

  9. Climate Change and Health Risks from Extreme Heat and Air Pollution in the Eastern United States

    NASA Astrophysics Data System (ADS)

    Limaye, V.; Vargo, J.; Harkey, M.; Holloway, T.; Meier, P.; Patz, J.

    2013-12-01

    Climate change is expected to exacerbate health risks from exposure to extreme heat and air pollution through both direct and indirect mechanisms. Directly, warmer ambient temperatures promote biogenic emissions of ozone precursors and favor the formation of ground-level ozone, while an anticipated increase in the frequency of stagnant air masses will allow fine particulates to accumulate. Indirectly, warmer summertime temperatures stimulate energy demand and exacerbate polluting emissions from the electricity sector. Thus, while technological adaptations such as air conditioning can reduce risks from exposures to extreme heat, they can trigger downstream damage to air quality and public health. Through an interdisciplinary modeling effort, we quantify the impacts of climate change on ambient temperatures, summer energy demand, air quality, and public health. The first phase of this work explores how climate change will directly impact the burden of heat-related mortality. Climatic patterns, demographic trends, and epidemiologic risk models suggest that populations in the eastern United States are likely to experience an increasing heat stress mortality burden in response to rising summertime air temperatures. We use North American Regional Climate Change Assessment Program modeling data to estimate mid-century 2-meter air temperatures and humidity across the eastern US from June-August, and quantify how long-term changes in actual and apparent temperatures from present-day will affect the annual burden of heat-related mortality across this region. With the US Environmental Protection Agency's Environmental Benefits Mapping and Analysis Program, we estimate health risks using concentration-response functions, which relate temperature increases to changes in annual mortality rates. We compare mid-century summertime temperature data, downscaled using the Weather Research and Forecasting model, to 2007 baseline temperatures at a 12 km resolution in order to estimate

  10. Effect of Air Ions on Submicron T1 Bacteriophage Aerosols

    PubMed Central

    Happ, John W.; Harstad, J. Bruce; Buchanan, Lee M.

    1966-01-01

    The effect of a high concentration of ionized air molecules on sampling T1 phage aerosols of submicron particle size was evaluated by comparing the phage recoveries of all-glass impingers (AGI-4) and type 6 filter papers. Sampler recoveries of all ionized aerosols were less than the recoveries of nonionized control aerosols. These reductions in recovery were greater with positive ions than with negative ions or ions of mixed polarity. The AGI-4 allowed considerable slippage, which was not affected by the air ions. Type 6 filter paper recoveries were less than AGI-4 recoveries. The air ions did not appear to affect the aerosol particle size as determined by an electron microscope. Images Fig. 1 Fig. 3 PMID:16349691

  11. On the impact of entrapped air in infiltration under ponding conditions: Part a: Preferential air flow path effects on infiltration

    NASA Astrophysics Data System (ADS)

    Weisbord, N.; Mizrahi, G.; Furman, A.

    2015-12-01

    Entrapped air effects on infiltration under ponding conditions could be important for massive infiltration of managed aquifer recharge or soil aquifer treatment. Earlier studies found that under ponding conditions air could reduce infiltration by 70-90%. Most studies have dealt with entrapped air effects when soil surface topography is flat. The objective of this study is to investigate the effects of: (1) irregular surface topography on preferential air flow path development; (2) preferential air flow path on infiltration; and (3) hydraulic head on infiltration when air is trapped. Column experiments were used to investigate these particular effects. A 140 cm deep and 30 cm wide column packed with silica sand was used under two boundary conditions: in the first, air can only escape vertically upward through the soil surface; in the second, air is free to escape. The surface was flooded with 13 liters of water, with ponding depth decreasing with time. Two soil surface conditions were tested: flat surface and irregular. It was found that in irregular surfaces, stable air flow through preferential paths was developed in the high altitude zones. Flat surface topography caused unstable air flow through random paths. Comparison between irregular and flat surface topography showed that the entrapped air pressure was lower and the infiltration rate was about 40% higher in the irregular surface topography than in the flat surface topography. No difference of infiltration rate between flat and irregular surface topography was observed when air was free to escape along the infiltration path. It was also found that at the first stage of infiltration, higher hydraulic heads caused higher entrapped air pressures and lower infiltration rates. In contrast, higher hydraulic head results in higher infiltration rate, when air was free to escape. Our results suggest that during ponding conditions: (1) preferential air flow paths develop at high surface zones of irregular topography

  12. Temperature changes in rheumatoid hand treated with nitrogen vapors and cold air.

    PubMed

    Korman, Paweł; Straburzyńska-Lupa, Anna; Romanowski, Wojciech; Trafarski, Andrzej

    2012-10-01

    The aim of the study was the thermovisual comparison of mean temperature of hand surface changes after local cryotherapy with vapors of nitrogen (-160°C) and cold air (-30°C). Forty-seven patients with rheumatoid arthritis (39 women and 8 men; average age 56.2 ± 10.5 years) were included in the study. They had the application of topic cryotherapy using nitrogen vapors or cold air on one hand. Main outcome measure was surface temperature of dorsal sides of the cooled and contralateral hands. Thermal images of both hands were taken before and up to 3 h after the treatment. One minute after application, nitrogen vapors induced decrease in surface skin temperature of the cooled hand from 28.9 ± 1.8°C to 17.9 ± 2.2°C, P < 0.05, whereas cold air from 29.4 ± 2.4°C to 23.1 ± 2.2°C, P < 0.05. However, significantly lower temperature was obtained with vapors of nitrogen (P < 0.05). Just after the treatment, a rapid rewarming occurred and hands reached baseline temperature in 15 min in both applications and they did not differ till the end of the procedure. Both nitrogen vapors and cold air induce similar temperature changes in hands with the exclusion of temperature obtained 1 min after the treatment. Changes in non-cooled hands indicate contralateral reaction.

  13. Oil Palm expansion over Southeast Asia: land use change and air quality

    NASA Astrophysics Data System (ADS)

    Silva, S. J.; Heald, C. L.; Geddes, J.; Marlier, M. E.; Austin, K.; Kasibhatla, P. S.

    2015-12-01

    Over recent decades oil palm plantations have rapidly expanded across Southeast Asia (SEA). Much of this expansion has come at the expense of natural forests and grasslands. Aircraft measurements from a 2008 campaign, OP3, found that oil palm plantations emit as much as 7 times more isoprene than nearby natural forests. Furthermore, SEA is a rapidly developing region, with increasing urban population, and growing air quality concerns. Thus, SEA represents an ideal case study to examine the impacts of land use change on air quality in the region, and whether those changes can be detected from satellite observations of atmospheric composition. We investigate the impacts of historical and future oil palm expansion in SEA using satellite data, high-resolution land maps, and the chemical transport model GEOS-Chem. We examine the impact of palm plantations on surface-atmosphere processes (dry deposition, biogenic emissions). We show the sensitivity of air quality to current and future oil palm expansion scenarios, and discuss the limitations of current satellite measurements in capturing these changes. Our results indicate that while the impact of oil palm expansion on air quality can be significant, the retrieval error and sensitivity of the satellite measurements limit our ability to observe these impacts from space.

  14. The effect of inlet air vitiation on combustion efficiency

    SciTech Connect

    Zuomin, F.; Yijun, J.

    1985-01-01

    Experimental results of the effect of inlet air vitiation produced by a vitiating preheater on combustion efficiency of a turbojet combustor and a model ramjet combustor are presented in this paper. An empirical correlation and a calculation method based on stirred reactor theory are derived to correct the vitiation effect. Results obtained by means of these two methods are in good agreement with test data.

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

    PubMed Central

    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

  16. Effects of warm air-drying and spreading on resin bonding.

    PubMed

    Galan, D; Williams, P T; Kasloff, Z

    1991-12-01

    The purpose of this study was to compare the effect on resin-to-enamel bonding produced by warm air from a hair dryer, and to correlate changes in resin bond strength with resin tag structure. Herculite-XR resin composite and Bondlite bonding resin were used. The three technique variables were the type of air used for drying, air dryer distance, and drying and spreading time. Control samples were dried and the bonding resin spread with a dental air syringe, whereas warm air from a hair dryer was used on the experimental samples. The bond strength (MPa) was determined in shear at a crosshead speed of 1 mm/min. Following bond strength evaluation, the teeth were immersed in 10% HCl for enamel dissolution and the resin tag structure was examined with the SEM. ANOVA analyses of shear bond strengths were performed. Warm air-drying and spreading for 15 seconds at 6 cm and 5 seconds at 6 cm respectively, produced statistically greater shear bond strengths (x = 20.4 +/- 4.4 MPa, P less than 0.05). The other drying time/distance combinations, including the control (x = 14.4 +/- 3.3 MPa), were not statistically different. Differences in resin tag structure were qualitatively evident under the SEM, with sharp tags produced by the warm air-drying and spreading techniques, compared to the blunt tags created by syringe air-drying and spreading. Warm air-drying and spreading significantly improved the bond strength. No apparent correlation exists between bond strength and tag length.

  17. Effects of China's Energy Policy on Future Air Quality in China and the U.S.

    NASA Astrophysics Data System (ADS)

    Li, M.; Selin, N. E.; Karplus, V. J.; Li, C. T.; Zhang, D.; Luo, X.; Zhang, X.

    2014-12-01

    We examine the effects of recently announced energy policies in mainland China on air quality in both China and the U.S. in 2030. China is the largest contributor to global anthropogenic emissions of air pollutants, especially the precursors to ozone and fine particulate matter (PM2.5) such as nitrogen oxides (NOx) and sulfur dioxide (SO2). Efforts to limit coal use in China under the country's National Air Pollution Action Plan will reduce these air pollutants. Control efforts are expected to not only decrease the concentration of ozone and PM2.5 locally in China, but also reduce the trans-Pacific transport of air pollutants to the U.S. We couple an energy-economic model with sub-national detail for China (the China Regional Energy Model, or C-REM) to a global atmospheric chemistry model (GEOS-Chem) to assess air pollution reductions under an energy policy scenario relative to a no policy baseline scenario. Future Chinese anthropogenic emissions are predicted by C-REM under a national energy policy scenario which achieves a 20% reduction in energy intensity from 2012 to 2017 by targeting fossil fuel use nationwide as specified in the National Air Pollution Action Plan and also meets the Plan's sub-national constraint that coal use must not increase above present levels in three largest urban regions (the Beijing-Tianjin-Hebei Area, Yangtze River Delta, and Pearl River Delta) through 2030. Using GEOS-Chem, we project changes in the surface concentration of ozone and PM2.5 over China and the U.S. in 2030. We find that air pollutants decrease substantially over both China and the U.S. under the national targets set by the Air Pollution Action Plan.

  18. The 2010 California Research at the Nexus of Air Quality and Climate Change (CalNex) field study

    NASA Astrophysics Data System (ADS)

    Ryerson, T. B.; Andrews, A. E.; Angevine, W. M.; Bates, T. S.; Brock, C. A.; Cairns, B.; Cohen, R. C.; Cooper, O. R.; Gouw, J. A.; Fehsenfeld, F. C.; Ferrare, R. A.; Fischer, M. L.; Flagan, R. C.; Goldstein, A. H.; Hair, J. W.; Hardesty, R. M.; Hostetler, C. A.; Jimenez, J. L.; Langford, A. O.; McCauley, E.; McKeen, S. A.; Molina, L. T.; Nenes, A.; Oltmans, S. J.; Parrish, D. D.; Pederson, J. R.; Pierce, R. B.; Prather, K.; Quinn, P. K.; Seinfeld, J. H.; Senff, C. J.; Sorooshian, A.; Stutz, J.; Surratt, J. D.; Trainer, M.; Volkamer, R.; Williams, E. J.; Wofsy, S. C.

    2013-06-01

    The California Research at the Nexus of Air Quality and Climate Change (CalNex) field study was conducted throughout California in May, June, and July of 2010. The study was organized to address issues simultaneously relevant to atmospheric pollution and climate change, including (1) emission inventory assessment, (2) atmospheric transport and dispersion, (3) atmospheric chemical processing, and (4) cloud-aerosol interactions and aerosol radiative effects. Measurements from networks of ground sites, a research ship, tall towers, balloon-borne ozonesondes, multiple aircraft, and satellites provided in situ and remotely sensed data on trace pollutant and greenhouse gas concentrations, aerosol chemical composition and microphysical properties, cloud microphysics, and meteorological parameters. This overview report provides operational information for the variety of sites, platforms, and measurements, their joint deployment strategy, and summarizes findings that have resulted from the collaborative analyses of the CalNex field study. Climate-relevant findings from CalNex include that leakage from natural gas infrastructure may account for the excess of observed methane over emission estimates in Los Angeles. Air-quality relevant findings include the following: mobile fleet VOC significantly declines, and NOx emissions continue to have an impact on ozone in the Los Angeles basin; the relative contributions of diesel and gasoline emission to secondary organic aerosol are not fully understood; and nighttime NO3 chemistry contributes significantly to secondary organic aerosol mass in the San Joaquin Valley. Findings simultaneously relevant to climate and air quality include the following: marine vessel emissions changes due to fuel sulfur and speed controls result in a net warming effect but have substantial positive impacts on local air quality.

  19. Mortality from asthma and chronic bronchitis associated with changes in sulfur oxides air pollution

    SciTech Connect

    Imai, M.; Yoshida, K.; Kitabatake, M.

    1986-01-01

    Death certificates issued in Yokkaichi, Japan, during the 21 yr from 1963 until 1983 were surveyed to determine the relationship between changes in air pollution and mortality due to bronchial asthma and chronic bronchitis. The following results were obtained. In response to worsening air pollution, mortality for bronchial asthma and chronic bronchitis began to increase. Mortality due to bronchial asthma decreased immediately in response to improvement of pollution, whereas mortality due to chronic bronchitis decreased to the level in the control area 4 to 5 yr after the concentration of sulfur dioxide (SO/sub 2/) began to satisfy the ambient air quality standard. In the polluted area, mortality due to bronchial asthma in subjects who were 20 yr of age was higher during the period in which higher concentrations of sulfur oxides were prevalent.

  20. European Air Quality and Climate Change: first steps of a numerical modeling study

    NASA Astrophysics Data System (ADS)

    Lacressonnière, Gwendoline; Peuch, Vincent-Henri; Josse, Béatrice; Joly, Mathieu; Martet, Maud

    2010-05-01

    In the context of climate change, the evolution of air quality in Europe is a challenging scientific question, despite the political measures taken to limit and reduce anthropogenic emissions. Heat waves, changes in transport pathways or synoptic patterns, increase of emissions in other areas in the world (in particular in Asia), or for instance possible increase of biogenic emissions may affect adversely future Air Quality levels in Europe. In the context of a project co-funded by the French environment agency ADEME, a numerical modeling study has begun relying on the tools used by Météo-France for its contribution to the 5th IPCC assessment report, to GMES atmospheric services (MACC FP7 project) and to the French national operational Air Quality platform Prév'Air (http://www.prevair.org). In particular, the MOCAGE 3-D chemical transport model (CTM) is used with a configuration comprising a global (2°) and a European domain (0.2°), allowing representation of both long-range transport of pollutants and European Air Quality at relevant resolutions and with a two-ways coupling. MOCAGE includes 47 layers from the surface to 5hPa. The first step of this project is to assess the impact of meteorological forcings, either analyses ("best" meteorology available for the recent past) or climate runs for the current atmosphere (interpolated on the same high resolution grid), on air quality hindcasts with MOCAGE over Europe. For these climate runs, we rely on Météo-France Earth-System model CNRM-CM, and particularly the ARPEGE-climate general circulation model for the atmosphere. By studying several key variables for Air Quality (surface and low troposphere concentrations of ozone, nitrogen oxides, volatile organic compounds, radicals, PM,…) we aim at investigating the indicators that are robust or not (monthly averages, frequency of exceedances, AOTs,…) for a given climate when using climatological forcings instead of analyses (reference), all the rest in the CTM

  1. Health effects of SRS non-radiological air emissions

    SciTech Connect

    Stewart, J.

    1997-06-16

    This report examines the potential health effects of non radiological emissions to the air resulting from operations at the Savannah River Site (SRS). The scope of this study was limited to the 55 air contaminants for which the US Environmental Protection Agency (EPA) has quantified risk by determining unit risk factors (excess cancer risks) and/or reference concentrations (deleterious non cancer risks). Potential health impacts have been assessed in relation to the maximally exposed individual. This is a hypothetical person who resides for a lifetime at the SRS boundary. The most recent (1994) quality assured SRS emissions data available were used. Estimated maximum site boundary concentrations of the air contaminants were calculated using air dispersion modeling and 24-hour and annual averaging times. For the emissions studied, the excess cancer risk was found to be less than the generally accepted risk level of 1 in 100,000 and, in most cases, was less than 1 in 1,000,000. Deleterious non cancer effects were also found to be very unlikely.

  2. Air pollutant effects on fetal and early postnatal development.

    PubMed

    Wang, Lei; Pinkerton, Kent E

    2007-09-01

    Numerical research on the health effects of air pollution has been published in the last decade. Epidemiological studies have shown that children's exposure to air pollutants during fetal development and early postnatal life is associated with many types of health problems including abnormal development (low birth weight [LBW], very low birth weight [VLBW], preterm birth [PTB], intrauterine growth restriction [IUGR], congenital defects, and intrauterine and infant mortality), decreased lung growth, increased rates of respiratory tract infections, childhood asthma, behavioral problems, and neurocognitive decrements. This review focuses on the health effects of major outdoor air pollutants including particulates, carbon monoxide (CO), sulfur and nitrogen oxides (SO(2), NOx), ozone, and one common indoor air pollutant, environmental tobacco smoke (ETS). Animal data is presented that demonstrate perinatal windows of susceptibility to sidestream smoke, a surrogate for ETS, resulting in altered airway sensitivity and cell type frequency. A study of neonatal monkeys exposed to sidestream smoke during the perinatal period and/or early postnatal period that resulted in an altered balance of Th1-/Th2-cytokine secretion, skewing the immune response toward the allergy-associated Th2 cytokine phenotype, is also discussed. PMID:17963272

  3. Measured Air Distribution Effectiveness for Residential Mechanical Ventilation Systems

    SciTech Connect

    Sherman, Max; Sherman, Max H.; Walker, Iain S.

    2008-05-01

    The purpose of ventilation is dilute or remove indoor contaminants that an occupant is exposed to. In a multi-zone environment such as a house, there will be different dilution rates and different source strengths in every zone. Most US homes have central HVAC systems, which tend to mix the air thus the indoor conditions between zones. Different types of ventilation systems will provide different amounts of exposure depending on the effectiveness of their air distribution systems and the location of sources and occupants. This paper will report on field measurements using a unique multi-tracer measurement system that has the capacity to measure not only the flow of outdoor air to each zone, but zone-to-zone transport. The paper will derive seven different metrics for the evaluation of air distribution. Measured data from two homes with different levels of natural infiltration will be used to evaluate these metrics for three different ASHRAE Standard 62.2 compliant ventilation systems. Such information can be used to determine the effectiveness of different systems so that appropriate adjustments can be made in residential ventilation standards such as ASHRAE Standard 62.2.

  4. Upper-air temperature change trends above arid region of Northwest China during 1960-2009

    NASA Astrophysics Data System (ADS)

    Chen, Zhongsheng; Chen, Yaning; Xu, Jianhua; Bai, Ling

    2015-04-01

    This study summarized upper-air temperature change trends based on the monthly datasets of 14 sounding stations in the arid region of Northwest China during 1960-2009. Over the investigated period, the change in upper-air temperature measured at eight standard pressure levels shows that an obvious warming at 850-400 hPa, which decreases with altitude, changes to an apparent cooling at 300-50 hPa. There is a positive correlation between the surface and 850-300-hPa temperatures, but a negative correlation between the surface and 200-50-hPa temperatures. Over the full 1960-2009 record, patterns of statistically significant mid-lower tropospheric warming and upper tropospheric and mid-lower stratospheric cooling are clearly evident. Also, the annual temperature cycle indicates that the peak temperature shifts from July in the troposphere to February in the mid-lower stratosphere, suggesting the importance of seasonal trend analysis. We found that the warming in the mid-lower troposphere is more pronounced during the summer, autumn, and winter, whereas the cooling in the upper troposphere and mid-lower stratosphere is larger during the summer and autumn. Furthermore, there are also many regional differences in the upper-air temperature change, regardless of both season and layer.

  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.

    PubMed

    Hyldegaard, O; Kerem, D; Melamed, Y

    2011-09-01

    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 while at 285 kPa or following immediate recompression to either 285 or 405 kPa, breathing 80:20 and 50:50 heliox mixtures. During the isobaric shifts, some bubbles in adipose tissue grew marginally for 10-30 min, subsequently they shrank and disappeared at a rate similar to or faster than during air 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 shrinkage of all air bubbles, until they disappeared from view. Deep tissue isobaric counterdiffusion may cause some air bubbles to grow transiently in adipose tissue. The effect is marginal and of no clinical consequence. Bubble disappearance rate is faster with heliox breathing mixtures as compared to air. We see no reason for reservations in the use of heliox breathing during treatment of air-diving-induced decompression sickness.

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

    PubMed

    Hyldegaard, O; Kerem, D; Melamed, Y

    2011-09-01

    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 while at 285 kPa or following immediate recompression to either 285 or 405 kPa, breathing 80:20 and 50:50 heliox mixtures. During the isobaric shifts, some bubbles in adipose tissue grew marginally for 10-30 min, subsequently they shrank and disappeared at a rate similar to or faster than during air 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 shrinkage of all air bubbles, until they disappeared from view. Deep tissue isobaric counterdiffusion may cause some air bubbles to grow transiently in adipose tissue. The effect is marginal and of no clinical consequence. Bubble disappearance rate is faster with heliox breathing mixtures as compared to air. We see no reason for reservations in the use of heliox breathing during treatment of air-diving-induced decompression sickness. PMID:21318313

  7. The effect of body postures on the distribution of air gap thickness and contact area

    NASA Astrophysics Data System (ADS)

    Mert, Emel; Psikuta, Agnes; Bueno, Marie-Ange; Rossi, René M.

    2016-08-01

    The heat and mass transfer in clothing is predominantly dependent on the thickness of air layer and the magnitude of contact area between the body and the garment. The air gap thickness and magnitude of the contact area can be affected by the posture of the human body. Therefore, in this study, the distribution of the air gap and the contact area were investigated for different body postures of a flexible manikin. In addition, the effect of the garment fit (regular and loose) and style (t-shirts, sweatpants, jacket and trousers) were analysed for the interaction between the body postures and the garment properties. A flexible manikin was scanned using a three-dimensional (3D) body scanning technique, and the scans were post-processed in dedicated software. The body posture had a strong effect on the air gap thickness and the contact area for regions where the garment had a certain distance from the body. Furthermore, a mathematical model was proposed to estimate the possible heat transfer coefficient for the observed air layers and their change with posture. The outcome of this study can be used to improve the design of the protective and functional garments and predict their effect on the human body.

  8. The Process of Effecting Change.

    ERIC Educational Resources Information Center

    McClelland, William A.

    Characteristics of the change process are described and the importance of improving understanding of the process of change is indicated. A summary of some relevant literature on the diffusion of innovation draws from studies in rural sociology, cultural anthropology, industry, education, and psychology. In addition, two premodels of change are…

  9. Daily changes in oxygen saturation and pulse rate associated with particulate air pollution and barometric pressure.

    PubMed

    Dockery, D W; Pope, C A; Kanner, R E; Martin Villegas, G; Schwartz, J

    1999-01-01

    Epidemiologic studies have linked fine particulate air pollution with increases in morbidity and mortality rates from cardiopulmonary complications. Although the underlying biologic mechanisms responsible for this increase remain largely unknown, potential pathways include transient declines in blood oxygenation and changes in pulse rate following exposures to particulate air pollution episodes. This study evaluated potential associations between daily measures of respirable particulate matter (PM) with pulse rate and oxygen saturation of the blood. Pulse rate and oxygen saturation (Spo2) using pulse oximetry were measured daily in 90 elderly subjects living near air pollution monitors during the winter of 1995-96 in Utah Valley. We also evaluated potential associations of oxygen saturation and pulse rate with barometric pressure. Small but statistically significant positive associations between day-to-day changes in Spo2 and barometric pressure were observed. Pulse rate was inversely associated with barometric pressure. Exposure to particulate pollution was not significantly associated with Spo2 except in male participants 80 years of age or older. Increased daily pulse rate, as well as the odds of having a pulse rate 5 or 10 beats per minute (bpm) above normal (normal is defined as the individual's mean pulse rate throughout the study period), were significantly associated with exposure to particulate pollution on the previous 1 to 5 days. The medical or biologic relevance of these increases in pulse rate following exposure to particulate air pollution requires further study.

  10. Air quality impacts of European wildfire emissions in a changing climate

    NASA Astrophysics Data System (ADS)

    Knorr, Wolfgang; Dentener, Frank; Hantson, Stijn; Jiang, Leiwen; Klimont, Zbigniew; Arneth, Almut

    2016-05-01

    Wildfires are not only a threat to human property and a vital element of many ecosystems, but also an important source of air pollution. In this study, we first review the available evidence for a past or possible future climate-driven increase in wildfire emissions in Europe. We then introduce an ensemble of model simulations with a coupled wildfire-dynamic-ecosystem model, which we combine with published spatial maps of both wildfire and anthropogenic emissions of several major air pollutants to arrive at air pollutant emission projections for several time slices during the 21st century. The results indicate moderate wildfire-driven emission increases until 2050, but there is a possibility of large increases until the last decades of this century at high levels of climate change. We identify southern and north-eastern Europe as potential areas where wildfires may surpass anthropogenic pollution sources during the summer months. Under a scenario of high levels of climate change (Representative Concentration Pathway, RCP, 8.5), emissions from wildfires in central and northern Portugal and possibly southern Italy and along the west coast of the Balkan peninsula are projected to reach levels that could affect annual mean particulate matter concentrations enough to be relevant for meeting WHO air quality targets.

  11. Daily changes in oxygen saturation and pulse rate associated with particulate air pollution and barometric pressure.

    PubMed

    Dockery, D W; Pope, C A; Kanner, R E; Martin Villegas, G; Schwartz, J

    1999-01-01

    Epidemiologic studies have linked fine particulate air pollution with increases in morbidity and mortality rates from cardiopulmonary complications. Although the underlying biologic mechanisms responsible for this increase remain largely unknown, potential pathways include transient declines in blood oxygenation and changes in pulse rate following exposures to particulate air pollution episodes. This study evaluated potential associations between daily measures of respirable particulate matter (PM) with pulse rate and oxygen saturation of the blood. Pulse rate and oxygen saturation (Spo2) using pulse oximetry were measured daily in 90 elderly subjects living near air pollution monitors during the winter of 1995-96 in Utah Valley. We also evaluated potential associations of oxygen saturation and pulse rate with barometric pressure. Small but statistically significant positive associations between day-to-day changes in Spo2 and barometric pressure were observed. Pulse rate was inversely associated with barometric pressure. Exposure to particulate pollution was not significantly associated with Spo2 except in male participants 80 years of age or older. Increased daily pulse rate, as well as the odds of having a pulse rate 5 or 10 beats per minute (bpm) above normal (normal is defined as the individual's mean pulse rate throughout the study period), were significantly associated with exposure to particulate pollution on the previous 1 to 5 days. The medical or biologic relevance of these increases in pulse rate following exposure to particulate air pollution requires further study. PMID:10192116

  12. Effects of air and water temperatures on resting metabolism of auklets and other diving birds.

    PubMed

    Richman, Samantha E; Lovvorn, James R

    2011-01-01

    For small aquatic endotherms, heat loss while floating on water can be a dominant energy cost, and requires accurate estimation in energetics models for different species. We measured resting metabolic rate (RMR) in air and on water for a small diving bird, the Cassin's auklet (Ptychoramphus aleuticus), and compared these results to published data for other diving birds of diverse taxa and sizes. For 8 Cassin's auklets (~165 g), the lower critical temperature was higher on water (21 °C) than in air (16 °C). Lowest values of RMR (W kg⁻¹) averaged 19% higher on water (12.14 ± 3.14 SD) than in air (10.22 ± 1.43). At lower temperatures, RMR averaged 25% higher on water than in air, increasing with similar slope. RMR was higher on water than in air for alcids, cormorants, and small penguins but not for diving ducks, which appear exceptionally resistant to heat loss in water. Changes in RMR (W) with body mass either in air or on water were mostly linear over the 5- to 20-fold body mass ranges of alcids, diving ducks, and penguins, while cormorants showed no relationship of RMR with mass. The often large energetic effects of time spent floating on water can differ substantially among major taxa of diving birds, so that relevant estimates are critical to understanding their patterns of daily energy use. PMID:21527823

  13. Effects of air and water temperatures on resting metabolism of auklets and other diving birds.

    PubMed

    Richman, Samantha E; Lovvorn, James R

    2011-01-01

    For small aquatic endotherms, heat loss while floating on water can be a dominant energy cost, and requires accurate estimation in energetics models for different species. We measured resting metabolic rate (RMR) in air and on water for a small diving bird, the Cassin's auklet (Ptychoramphus aleuticus), and compared these results to published data for other diving birds of diverse taxa and sizes. For 8 Cassin's auklets (~165 g), the lower critical temperature was higher on water (21 °C) than in air (16 °C). Lowest values of RMR (W kg⁻¹) averaged 19% higher on water (12.14 ± 3.14 SD) than in air (10.22 ± 1.43). At lower temperatures, RMR averaged 25% higher on water than in air, increasing with similar slope. RMR was higher on water than in air for alcids, cormorants, and small penguins but not for diving ducks, which appear exceptionally resistant to heat loss in water. Changes in RMR (W) with body mass either in air or on water were mostly linear over the 5- to 20-fold body mass ranges of alcids, diving ducks, and penguins, while cormorants showed no relationship of RMR with mass. The often large energetic effects of time spent floating on water can differ substantially among major taxa of diving birds, so that relevant estimates are critical to understanding their patterns of daily energy use.

  14. Respiratory health effects of air pollution: update on biomass smoke and traffic pollution.

    PubMed

    Laumbach, Robert J; Kipen, Howard M

    2012-01-01

    Mounting evidence suggests that air pollution contributes to the large global burden of respiratory and allergic diseases, including asthma, chronic obstructive pulmonary disease, pneumonia, and possibly tuberculosis. Although associations between air pollution and respiratory disease are complex, recent epidemiologic studies have led to an increased recognition of the emerging importance of traffic-related air pollution in both developed and less-developed countries, as well as the continued importance of emissions from domestic fires burning biomass fuels, primarily in the less-developed world. Emissions from these sources lead to personal exposures to complex mixtures of air pollutants that change rapidly in space and time because of varying emission rates, distances from source, ventilation rates, and other factors. Although the high degree of variability in personal exposure to pollutants from these sources remains a challenge, newer methods for measuring and modeling these exposures are beginning to unravel complex associations with asthma and other respiratory tract diseases. These studies indicate that air pollution from these sources is a major preventable cause of increased incidence and exacerbation of respiratory disease. Physicians can help to reduce the risk of adverse respiratory effects of exposure to biomass and traffic air pollutants by promoting awareness and supporting individual and community-level interventions.

  15. Respiratory Health Effects of Air Pollution: Update on Biomass Smoke and Traffic Pollution

    PubMed Central

    Laumbach, Robert J.; Kipen, Howard M.

    2012-01-01

    Mounting evidence suggests that air pollution contributes to the large global burden of respiratory and allergic diseases including asthma, chronic obstructive pulmonary disease, pneumonia and possibly tuberculosis. Although associations between air pollution and respiratory disease are complex, recent epidemiologic studies have led to an increased recognition of the emerging importance of traffic-related air pollution in both developed and less-developed countries, as well as the continued importance of emissions from domestic fires burning biomass fuels primarily in the less-developed world. Emissions from these sources lead to personal exposures to complex mixtures of air pollutants that change rapidly in space and time due to varying emission rates, distances from source, ventilation rates, and other factors. Although the high degree of variability in personal exposure to pollutants from these sources remains a challenge, newer methods for measuring and modeling these exposures are beginning to unravel complex associations with asthma and other respiratory disease. These studies indicate that air pollution from these sources is a major preventable cause of increased incidence and exacerbation of respiratory disease. Physicians can help to reduce the risk of adverse respiratory effects of exposure to biomass and traffic air pollutants by promoting awareness and supporting individual and community-level interventions. PMID:22196520

  16. Effect of air pollution on athlete health and performance.

    PubMed

    Rundell, Kenneth William

    2012-05-01

    Unfavourable effects on the respiratory and the cardiovascular systems from short-term and long-term inhalation of air pollution are well documented. Exposure to freshly generated mixed combustion emissions such as those observed in proximity to roadways with high volumes of traffic and those from ice-resurfacing equipment are of particular concern. This is because there is a greater toxicity from freshly generated whole exhaust than from its component parts. The particles released from emissions are considered to cause oxidative damage and inflammation in the airways and the vascular system, and may be related to decreased exercise performance. However, few studies have examined this aspect. Several papers describe deleterious effects on health from chronic and acute air pollution exposure. However, there has been no research into the effects of long-term exposure to air pollution on athletic performance and a paucity of studies that describe the effects of acute exposure on exercise performance. The current knowledge of exercising in the high-pollution environment and the consequences that it may have on athlete performance are reviewed.

  17. Effectiveness of national air pollution control policies on the air quality in metropolitan areas of China.

    PubMed

    Wang, Shuxiao; Xing, Jia; Zhao, Bin; Jang, Carey; Hao, Jiming

    2014-01-01

    Understanding the effectiveness of national air pollution controls is important for control policy design to improve the future air quality in China. This study evaluated the effectiveness of major national control policies implemented recently in China through a modeling analysis. The sulfur dioxide (SO2) control policy during the 11th Five Year Plan period (2006-2010) had succeeded in reducing the national SO2 emission in 2010 by 14% from its 2005 level, which correspondingly reduced ambient SO2 and sulfate (SO4(2-)) concentrations by 13%-15% and 8%-10% respectively over east China. The nitrogen oxides (NO(x)) control policy during the 12th Five Year Plan period (2011-2015) targets the reduction of the national NO(x) emission in 2015 by 10% on the basis of 2010. The simulation results suggest that such a reduction in NO(x) emission will reduce the ambient nitrogen dioxide (NO2), nitrate (NO3(-)), 1-hr maxima ozone (O3) concentrations and total nitrogen deposition by 8%, 3%-14%, 2% and 2%-4%, respectively over east China. The application of new emission standards for power plants will further reduce the NO2, NO3(-), 1-hr maxima O(3 concentrations and total nitrogen deposition by 2%-4%, 1%-6%, 0-2% and 1%-2%, respectively. Sensitivity analysis was conducted to evaluate the inter-provincial impacts of emission reduction in Beijing-Tianjin-Hebei and the Yangtze River Delta, which indicated the need to implement joint regional air pollution control.

  18. Effectiveness of national air pollution control policies on the air quality in metropolitan areas of China.

    PubMed

    Wang, Shuxiao; Xing, Jia; Zhao, Bin; Jang, Carey; Hao, Jiming

    2014-01-01

    Understanding the effectiveness of national air pollution controls is important for control policy design to improve the future air quality in China. This study evaluated the effectiveness of major national control policies implemented recently in China through a modeling analysis. The sulfur dioxide (SO2) control policy during the 11th Five Year Plan period (2006-2010) had succeeded in reducing the national SO2 emission in 2010 by 14% from its 2005 level, which correspondingly reduced ambient SO2 and sulfate (SO4(2-)) concentrations by 13%-15% and 8%-10% respectively over east China. The nitrogen oxides (NO(x)) control policy during the 12th Five Year Plan period (2011-2015) targets the reduction of the national NO(x) emission in 2015 by 10% on the basis of 2010. The simulation results suggest that such a reduction in NO(x) emission will reduce the ambient nitrogen dioxide (NO2), nitrate (NO3(-)), 1-hr maxima ozone (O3) concentrations and total nitrogen deposition by 8%, 3%-14%, 2% and 2%-4%, respectively over east China. The application of new emission standards for power plants will further reduce the NO2, NO3(-), 1-hr maxima O(3 concentrations and total nitrogen deposition by 2%-4%, 1%-6%, 0-2% and 1%-2%, respectively. Sensitivity analysis was conducted to evaluate the inter-provincial impacts of emission reduction in Beijing-Tianjin-Hebei and the Yangtze River Delta, which indicated the need to implement joint regional air pollution control. PMID:24649687

  19. Effect of low emission sources on air quality in Cracow

    SciTech Connect

    Nedoma, J.

    1995-12-31

    The paper presents calculation of power engineering low emission and results of stimulation of the effect of this emission on air quality in Cracow, Poland. It has been stated that the segment of low emission in central areas of the town makes up ca. 40% of the observed concentration of sulfur dioxide. Furthermore it has been stated that the capital investment must be concentrated in the central part of the town in order to reach noticeable improvement of air quality in Cracow. Neither the output of a separate power source nor the emission level and its individual harmful effect, but the location of the source and especially packing density of the sources must decide the priority of upgrading actions.

  20. A proxy analysis of urban air quality hazards in Bergen, Norway under a changing climate.

    NASA Astrophysics Data System (ADS)

    Wolf, Tobias; Esau, Igor; Reuder, Joachim

    2014-05-01

    The urban air quality in Bergen, Norway is characterized by clean air throughout most of the year interrupted by short episodes of hazardous pollution levels especially in close proximity to major road-emission sources. These pollution episodes are linked to winter time anti-cyclonic weather conditions with persistent stable temperature stratification (inversions) in the Atmospheric Boundary Layer. Although the pollution episodes are local events, the high pollution episodes are linked to large-scale persistent blockings in the atmospheric circulation. Here we present an atmospheric circulation proxy for the pollution episodes based on the ECMWF ERA-Interim reanalysis. The proxy is based on local 3-hourly instantaneous wind-speeds and directions at the 1000 hPa pressure level, and 1-day running mean temperature deviations at 2 m above ground from the 1-day running mean temperatures averaged over the full ERA-Interim record length. We tuned the thresholds for each quantity to the occurrence of events with an hourly mean NO2 concentration > 150 μg/m3 at a high pollution reference station. A condition on cloud cover had only little effect, sea-level pressure was not applicable. High pollution episodes predicted during typical low traffic days (Sundays, Christmas, New Year) were removed. The final proxy had a detection rate of 82 %, a false alarm rate of 77 % and a correct null prediction rate of 96 %. The high false alarm rate was expected because of the relaxed thresholds chosen in order to include a large fraction of possible states of atmospheric circulation that lead to hazardous air quality. Additionally, the false alarm rate was high because no constraint on the persistence of adverse meteorological conditions was set and because of the high variability of traffic, not always leading to hazardous pollution levels, even if the atmospheric circulation would allow for it. The Scandinavian index, an often used proxy for the occurrence of atmospheric circulation

  1. Assessing the changes in the biomechanical properties of the crystalline lens induced by cold cataract with air-pulse OCE

    NASA Astrophysics Data System (ADS)

    Wu, C.; Singh, M.; Liu, C.-H.; Han, Z.; Li, J.; Raghunathan, R.; Larin, K. V.

    2015-11-01

    A cataract is the increase in opacity of the crystalline lens that can pathologically degrade visual acuity. In this study, we utilized a phase-sensitive optical coherence elastography (OCE) system to study the effects of a cold cataract on the biomechanical properties of the porcine crystalline lens in vitro. The cold cataract was induced by placing the whole lens in a low temperature environment until the lens was obviously clouded. Air-pulse OCE measurements were conducted on 6 lenses before and after cold cataract induction. A low amplitude displacement (≤ 10 µm) was induced by a focused air-pulse and the temporal deformation profiles from the surface and within the lenses were analyzed. The results demonstrated that the stiffness of the porcine lens increased after induction of the cold cataract, and it demonstrated the feasibility of OCE to assess the biomechanical changes in the lens due to cataract.

  2. Effect of air pollutants on the pulmonary surfactant system.

    PubMed

    Müller, B; Seifart, C; Barth, P J

    1998-09-01

    Air pollutants have been recognized to influence the structure and function of the surfactant system. Agents that have received the most attention include ozone, nitrogen dioxide, hyperoxia, diesel exhaust, tobacco smoke, silica and fibrous materials such as asbestos. The deleterious effects of air pollutants on the surfactant system depend on the size of the agent, on its solubility in aqueous solutions and chemical reactivity and on its concentration and the duration of exposure. Hereby the following general rules apply: the smaller the agent's size and the less water soluble the pollutant is, the greater the tendency to reach the alveoli during breathing. In addition, the reactivity also determines the depth of penetration into alveoli. Compounds with high reactivity such as O3, which also fulfil the earlier rules, will react with the upper respiratory tract compared with compounds with slightly reduced reactivity, such as NO2, which will penetrate the alveoli. The common consequence of exposure to air pollutants is an accumulation of surfactant phospholipids and surfactant-specific proteins in the bronchoalveolar lavage fluid. These components also are structurally altered, mainly by oxidant gases, resulting in impairment of their biological activity. Thus, for surfactant phospholipids, there is impaired adsorption to the air-liquid interface due to oxidation of their fatty acids. Also, surfactant protein A, regarded as a modulator of the surfactant system, shows impaired functions after exposure to oxidants. It is likely that in addition to the effects described in this review not all effects are known because the molecular effects of several key components (e.g. SP-B and C) have not been well studied.

  3. Extended effects of air pollution on cardiopulmonary mortality in Vienna

    NASA Astrophysics Data System (ADS)

    Neuberger, Manfred; Rabczenko, Daniel; Moshammer, Hanns

    BackgroundCurrent standards for fine particulates and nitrogen dioxide are under revision. Patients with cardiovascular disease have been identified as the largest group which need to be protected from effects of urban air pollution. MethodsWe sought to estimate associations between indicators of urban air pollution and daily mortality using time series of daily TSP, PM 10, PM 2.5, NO 2, SO 2, O 3 and nontrauma deaths in Vienna (Austria) 2000-2004. We used polynomial distributed lag analysis adjusted for seasonality, daily temperature, relative humidity, atmospheric pressure and incidence of influenza as registered by sentinels. ResultsAll three particulate measures and NO 2 were associated with mortality from all causes and from ischemic heart disease and COPD at all ages and in the elderly. The magnitude of the effect was largest for PM 2.5 and NO 2. Best predictor of mortality increase lagged 0-7 days was PM 2.5 (for ischemic heart disease and COPD) and NO 2 (for other heart disease and all causes). Total mortality increase, lagged 0-14 days, per 10 μg m -3 was 2.6% for PM 2.5 and 2.9% for NO 2, mainly due to cardiopulmonary and cerebrovascular causes. ConclusionAcute and subacute lethal effects of urban air pollution are predicted by PM 2.5 and NO 2 increase even at relatively low levels of these pollutants. This is consistent with results on hospital admissions and the lack of a threshold. While harvesting (reduction of mortality after short increase due to premature deaths of most sensitive persons) seems to be of minor importance, deaths accumulate during 14 days after an increase of air pollutants. The limit values for PM 2.5 and NO 2 proposed for 2010 in the European Union are unable to prevent serious health effects.

  4. New Directions: Understanding Interactions of Air Quality and Climate Change at Regional Scales

    EPA Science Inventory

    The estimates of the short-lived climate forcers’ (SLCFs) impacts and mitigation effects on the radiation balance have large uncertainty because the current global model set-ups and simulations contain simplified parameterizations and do not completely cover the full range of air...

  5. An assessment of California wildfire effects on air quality

    NASA Astrophysics Data System (ADS)

    Sermondadaz, S. M.; Jin, L.; Brown, N. J.

    2009-12-01

    Wildfires are a seasonal and recurrent problem in California. In addition to the damage caused each year and their heavy societal cost, wildfires may also have non-negligible effects on air quality. Most current studies usually focus on anthropogenic emissions impacts. Improved knowledge of the fires’ effect on various pollutant species -such as ozone, and ozone precursors, i.e. carbon monoxide, nitrogen oxides and volatile organic compounds - might be useful and relevant for control strategies and environmental policies. For this purpose, this model study uses the Community Multiscale Air Quality Model (CMAQ) to assess the effects of fire emissions as a perturbation, through the comparison of simulations performed with and without fire emissions. Emissions, boundaries and meteorological data used in this study are extracted from a severe fire episode in summer 2000. We assess the spread of ozone and its precursor pollutants (CO, NOX, VOC) around specifically chosen fire perimeters. Distribution of air pollutants in both horizontal and vertical dimensions is considered to achieve a better understanding of the pollutant formation and transport along the fire plumes. We assess how far fire emissions influence pollutant concentrations at surface and aloft. The impact of fire emissions depends on the fire size, its location and the meteorology associated with it. Our study provides information on ozone formation and transport caused by fire events, which may have implications for ozone violations in affected regions.

  6. The effects of air pollution regulations on the US refining industry. Task 3

    SciTech Connect

    Not Available

    1989-06-01

    Numerous air pollution regulations affecting petroleum refineries recently have been promulgated, have been proposed, or are under consideration at the federal, state, and local level. As shown in Figure ES-1, all of these environmental regulations are intended to take effect over the relatively short time period from 1989 through 1995. In the aggregate these regulatory activities have significant implications for the US refining industry and the Nation, including: Major investment requirements; changes in industry profitability; potential closure of some refineries; and potential changes in crude oil or product import dependence. At issue is whether the cumulative effect of these regulations could so adversely affect the US refining industry that US national security would be affected. In addition to the regulations outlined in Figure ES-1, President Bush recently presented a major new plan to improve the nation`s air quality. The aspects of the President`s plan that could strongly affect US refineries are summarized below.

  7. Changes in large-scale air circulation and connection with climate variables in Romania

    NASA Astrophysics Data System (ADS)

    Stefan, Sabina; Barbu, Nicu

    2016-04-01

    The aim of this paper is the analysis of the relationship between climate variables (seasonal mean air temperature - T2m, and seasonal amount of precipitation - PP) and large-scale air circulation. In order to achieve this, the air circulation types were derived from GrossWetterTypen (GWT) and WetterLagenKlassifikation (WLK) Catalogues developed within COST733 framework. Daily air circulation types are divided into 18 groups according to the GWT Catalogue and in 40 groups according to the WLK Catalogue and for each type winter (DJF) and summer (JJA) occurrence frequency were calculated. To this end the Pearson correlation coefficient between climate variables and circulation type's frequency were computed. The results reveals that in wintertime the GWT circulation types captures better than WLK circulation types the T2m variability in time that for summer the WLK circulation types captures better than GWT circulation types. This is due to the seasonal variability of the horizontal extension of air masses. We found that the T2m is positive correlated to anticyclonic circulation types and negative correlated with cyclonic types and the PP is correlated to the cyclonic circulation and negative correlated to anticyclonic ones. Additionally, the trend significance of the climate variables as well as air circulation types have been analysed with the non-parametric Mann-Kendall test. The changes of the trends were detected by employing the non-parametric Pettit test. From the trend analysis we can state that some of the anticyclonic circulation types presents upward tendency and some of the cyclonic circulation presents downward tendency. This is an important results because explain the upward trend of the T2m and the downward trend of the PP.

  8. Perspective: ambient air pollution: inflammatory response and effects on the lung's vasculature.

    PubMed

    Grunig, Gabriele; Marsh, Leigh M; Esmaeil, Nafiseh; Jackson, Katelin; Gordon, Terry; Reibman, Joan; Kwapiszewska, Grazyna; Park, Sung-Hyun

    2014-03-01

    Particulates from air pollution are implicated in causing or exacerbating respiratory and systemic cardiovascular diseases and are thought to be among the leading causes of morbidity and mortality. However, the contribution of ambient particulate matter to diseases affecting the pulmonary circulation, the right heart, and especially pulmonary hypertension is much less documented. Our own work and that of other groups has demonstrated that prolonged exposure to antigens via the airways can cause severe pulmonary arterial remodeling. In addition, vascular changes have been well documented in a typical disease of the airways, asthma. These experimental and clinical findings link responses in the airways with responses in the lung's vasculature. It follows that particulate air pollution could cause, or exacerbate, diseases in the pulmonary circulation and associated pulmonary hypertension. This perspective details the literature for support of this concept. Data regarding the health effects of particulate matter from air pollution on the lung's vasculature, with emphasis on the lung's inflammatory responses to particulate matter deposition and pulmonary hypertension, are discussed. A deeper understanding of the health implications of exposure to ambient particulate matter will improve our knowledge of how to improve the management of lung diseases, including diseases of the pulmonary circulation. As man-made ambient particulate air pollution is typically linked to economic growth, a better understanding of the health effects of exposure to particulate air pollution is expected to integrate the global goal of achieving healthy living for all.

  9. Perspective: ambient air pollution: inflammatory response and effects on the lung’s vasculature

    PubMed Central

    Esmaeil, Nafiseh; Reibman, Joan

    2014-01-01

    Abstract Particulates from air pollution are implicated in causing or exacerbating respiratory and systemic cardiovascular diseases and are thought to be among the leading causes of morbidity and mortality. However, the contribution of ambient particulate matter to diseases affecting the pulmonary circulation, the right heart, and especially pulmonary hypertension is much less documented. Our own work and that of other groups has demonstrated that prolonged exposure to antigens via the airways can cause severe pulmonary arterial remodeling. In addition, vascular changes have been well documented in a typical disease of the airways, asthma. These experimental and clinical findings link responses in the airways with responses in the lung’s vasculature. It follows that particulate air pollution could cause, or exacerbate, diseases in the pulmonary circulation and associated pulmonary hypertension. This perspective details the literature for support of this concept. Data regarding the health effects of particulate matter from air pollution on the lung’s vasculature, with emphasis on the lung’s inflammatory responses to particulate matter deposition and pulmonary hypertension, are discussed. A deeper understanding of the health implications of exposure to ambient particulate matter will improve our knowledge of how to improve the management of lung diseases, including diseases of the pulmonary circulation. As man-made ambient particulate air pollution is typically linked to economic growth, a better understanding of the health effects of exposure to particulate air pollution is expected to integrate the global goal of achieving healthy living for all. PMID:25006418

  10. Ecological effects of global change

    NASA Astrophysics Data System (ADS)

    Menzel, A.

    2010-03-01

    Mankind actually puts manifolds loads on our earth including stratospheric ozone depletion, rising freshwater use, changes of land cover and land use. For several of these threats, critical loads and thresholds may be already exceeded, e.g. nitrogen input, climate change and biodiversity loss (Röckström et al. 2009). The working group on Impacts, Adaptation and Vulnerability of the last IPCC report (AR4, 2007) concluded that anthropogenic warming over the last three decades has had a discernible influence on many physical and biological systems, thus global fingerprint of anthropogenic climate change was detectable on all continents and almost all ocean areas (Rosenzweig et al. 2007, 2008). 90% of the significant temperature related changes in 29000 records analysed were consistent with climate warming, e.g. in warming climates earlier spring events, distributional shifts pole wards and to higher altitudes, or community changes with reduced cold adapted species were observed. These impacts, already visible and only related to less than 1°C global warming, allow a limited glance at future changes and pressures on our ecosystems, as the rate of warming may accelerate and will be linked to stronger and more frequent extreme events. Vegetation is an important component of the climate system, part of biogeochemical cycles and the lower boundary of GCMs characterised by certain albedo and roughness. Thus, climate change impacts on vegetation exert feedbacks. The most striking and challenging problems in analysing climate change impacts on ecosystems are related to cases where one would expect major changes due to warming however there is reduced, limited or no reaction in the observed systems. This feature is known as divergence problem in tree ring research, called resilience in ecosystem dynamics or might be simply a time-lag or environmental monitoring problem. However, there are various other pressures by global change, e.g. land use change or pollution, leading

  11. Air quality effects of alternative fuels. Final report

    SciTech Connect

    Guthrie, P.; Ligocki, M.; Looker, R.; Cohen, J.

    1997-11-01

    To support the Alternative Fuels Utilization Program, a comparison of potential air quality effects of alternative transportation fuels is being performed. This report presents the results of Phase 1 of this program, focusing on reformulated gasoline (RFG), methanol blended with 15 percent gasoline (M85), and compressed natural gas (CNG). The fuels are compared in terms of effects on simulated future concentrations of ozone and mobile source air toxics in a photochemical grid model. The fuel comparisons were carried out for the future year 2020 and assumed complete replacement of gasoline in the projected light-duty gasoline fleet by each of the candidate fuels. The model simulations were carried out for the areas surrounding Los Angeles and Baltimore/DC, and other (non-mobile) sources of atmospheric emissions were projected according to published estimates of economic and population growth, and planned emission control measures specific to each modeling domain. The future-year results are compared to a future-year run with all gasoline vehicle emissions removed. The results of the comparison indicate that the use of M85 is likely to produce similar ozone and air toxics levels as those projected from the use of RFG. Substitution of CNG is projected to produce significantly lower levels of ozone and the mobile source air toxics than those projected for RFG or M85. The relative benefits of CNG substitution are consistent in both modeling domains. The projection methodologies used for the comparison are subject to a large uncertainty, and modeled concentration distributions depend on meteorological conditions. The quantitative comparison of fuel effects is thus likely to be sensitive to alternative assumptions. The consistency of the results for two very different modeling domains, using very different base assumptions, lends credibility to the qualitative differentiation among these fuels. 32 refs., 42 figs., 47 tabs.

  12. Changes in maximum air temperatures over the Ukraine territory under modern climate changes

    NASA Astrophysics Data System (ADS)

    Khomenko, Inna

    2015-04-01

    For nine stations of the Ukraine (Kyiv, Lviv, Odesa, Poltava, Simferopol, Uzhgorod, Uman, Kharkiv, Chernivtsi), the series of average daily maximum temperature for periods of 41 to 112 years are analyzed during the warm season (May, 1 to September, 30). In the contribution the statistical theory of extreme values changes, so called "block maximum" method, and "peaks-over-threshold" method are used to represent changes in the temporal series of maximum temperature under modern climate change. For four sites in the Ukraine - Poltava, Simferopol, Uzhgorod, Uman - received a positive trend (changes in temperature are from 1.0 to 3,40C), in Kharkiv, Odesa and Chernivtsi a decrease in temperature with time are observed and for two stations - Kyiv and Lviv - changes are barely noticeable. It should be noted that negative trend corresponds to the regions, where low absolute maximum temperatures are observed, and positive trends fit regions with high values of observed absolute maximum. The research shows shift in the generalized extreme value distributions of average maximum temperatures for the first and last year of record. The results showed shift of modal values, lower and upper boundary of distributions to higher temperatures for all sites in the Ukraine, Uzhhorod and Kharkiv excepted. For all nine sites the return levels of highest temperatures are calculated. Indices for the selection of heat waves (90th percentile, 95th percentile and heat wave criterion proposed by WMO) were calculated for each days of the period under study for all nine sites. For 15th day of each month of the period concerned the maps of extreme indices were created. These maps can be used to output more suitable and accurate heat wave indices for the territory of Ukraine. For Odesa heat waves were selected by means of the different extreme criteria. All criteria don't show increase of heat wave number with time in Odesa. The obtained results show that maximum number of heat waves were observed

  13. Metropolitan New York in the greenhouse: Air quality and health effects

    SciTech Connect

    Kleinman, L.I.; Lipfert, F.

    1996-01-01

    A variety of potential effects on human health resulting from climate change have been identified in several assessments. According to an international panel{sup 1} they include direct effects of extreme temperatures on cardiovascular deaths, secondary effects due to vector-borne diseases or crop yields, and tertiary effects such as those that might arise from conflicts over freshwater supplies. To this fist we add the secondary effects of increased air pollution, which may result either directly from climate change or indirectly from increased air conditioning loads and the corresponding pollutant emissions from electric utilities. Higher ozone concentrations have been linked to increased ambient temperatures by both theory and observations of monitoring data. A similar association with particulate matter has been limited to observations, thus far. The pollution-heat linkage has been recognized before` but health effects have not been evaluated in terms of predictions of the joint effects of both agents. This paper has been prepared in two sections. First, we discuss the ozone situation with special reference to the Northeast Corridor and New York. In the second section, we present estimates of the health effects of climate change on New York and discuss some mitigation options.

  14. The effect of the solar eclipse on the air temperature near the ground

    NASA Astrophysics Data System (ADS)

    Szalowski, Karol

    2002-10-01

    This paper describes the effect of the air temperature decrease in low boundary layer during the solar eclipse with special regard to influence on convectional events. The phenomenon progress was modelled to predict solar radiation flux changes. Then the basic model of local ground and air temperature changes was constructed. The qualitative features of air temperature-time curve during the eclipse were explained. The effect was investigated experimentally on the example of the partial eclipse observed from Szczawnica, Poland on 11th August, 1999. The results of the precise air temperature measurements were presented. The general shape of temperature curve was confirmed. The problem of convection intensity and temporal scales of convectional events was examined. It was observed that the temperature variance decreased over a factor of 2 in the maximum eclipse- centred, 50min long time interval which depicts the reduced convection regime. In addition, the temperature spectrum for long periods obtained for this time range seem to differ significantly from one registered before and after. The convection near the maximum eclipse is characterised by a dominant temporal scale of 22min, while before and after 11-13min scale is the most important.

  15. An effective silencer design for artificially air conditioned environment.

    PubMed

    Fujiwara, Kyoji; Pang, Li Feng

    2004-11-01

    An effective silencer for an air conditioning duct is studied. A duct with an acoustically soft boundary is employed as an effective silencer. On the acoustically soft boundary the sound pressure is zero and it is impossible to realize such boundary in the air-borne sound field, because of the non-existence of a much lighter medium than the air. In this study, the arrangement of one-quarter wave-length acoustic tubes is employed as a soft boundary. This acoustic tube has frequency dependence, but the sound pressure becomes nearly zero at the tube mouth around the odd resonance frequency. The relation between the noise reduction efficiency and this acoustically soft boundary is examined experimentally and more than 40 dB noise reduction is obtained in a one-half octave band around the first resonance frequency. It is also made clear that more than one wave length of soft boundary is required to get enough reduction compared with the reduction obtained in the case of quite a long soft boundary.

  16. Mobile Air Monitoring Data Processing Strategies and Effects on Spatial Air Pollution Trends

    EPA Science Inventory

    The collection of real-time air quality measurements while in motion (i.e., mobile monitoring) is currently conducted worldwide to evaluate in situ emissions, local air quality trends, and air pollutant exposure. This measurement strategy pushes the limits of traditional data an...

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

    PubMed Central

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

    2016-01-01

    Background: 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. Objectives: 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. Methods: 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. Results: 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. Conclusions: Ambient air pollution may impact human olfactory function. Additional studies are needed to examine air pollution

  18. The Effect of Computers on School Air-Conditioning.

    ERIC Educational Resources Information Center

    Fickes, Michael

    2000-01-01

    Discusses the issue of increased air-conditioning demand when schools equip their classrooms with computers that require enhanced and costlier air-conditioning systems. Air-conditioning costs are analyzed in two elementary schools and a middle school. (GR)

  19. Product lifetime, energy efficiency and climate change: A case study of air conditioners in Japan.

    PubMed

    Nishijima, Daisuke

    2016-10-01

    This study proposed a modelling technique for estimating life-cycle CO2 emissions of durable goods by considering changes in product lifetime and energy efficiency. The stock and flow of durable goods was modelled by Weibull lifetime distributions and the trend in annual energy efficiency (i.e., annual electricity consumption) of an "average" durable good was formulated as a reverse logistic curve including a technologically critical value (i.e., limit energy efficiency) with respect to time. I found that when the average product lifetime is reduced, there is a trade-off between the reduction in emissions during product use (use phase), due to the additional purchases of new, more energy-efficient air conditioners, and the increase in emissions arising from the additional production of new air conditioners stimulated by the reduction of the average product lifetime. A scenario analysis focused on residential air conditioners in Japan during 1972-2013 showed that for a reduction of average lifetime of 1 year, if the air conditioner energy efficiency limit can be improved by 1.4% from the estimated current efficiency level, then CO2 emissions can be reduced by approximately the same amount as for an extension of average product lifetime of 1 year. PMID:27423771

  20. Product lifetime, energy efficiency and climate change: A case study of air conditioners in Japan.

    PubMed

    Nishijima, Daisuke

    2016-10-01

    This study proposed a modelling technique for estimating life-cycle CO2 emissions of durable goods by considering changes in product lifetime and energy efficiency. The stock and flow of durable goods was modelled by Weibull lifetime distributions and the trend in annual energy efficiency (i.e., annual electricity consumption) of an "average" durable good was formulated as a reverse logistic curve including a technologically critical value (i.e., limit energy efficiency) with respect to time. I found that when the average product lifetime is reduced, there is a trade-off between the reduction in emissions during product use (use phase), due to the additional purchases of new, more energy-efficient air conditioners, and the increase in emissions arising from the additional production of new air conditioners stimulated by the reduction of the average product lifetime. A scenario analysis focused on residential air conditioners in Japan during 1972-2013 showed that for a reduction of average lifetime of 1 year, if the air conditioner energy efficiency limit can be improved by 1.4% from the estimated current efficiency level, then CO2 emissions can be reduced by approximately the same amount as for an extension of average product lifetime of 1 year.

  1. Characterizing air temperature changes in the Tarim Basin over 1960-2012.

    PubMed

    Peng, Dongmei; Wang, Xiujun; Zhao, Chenyi; Wu, Xingren; Jiang, Fengqing; Chen, Pengxiang

    2014-01-01

    There has been evidence of warming rate varying largely over space and between seasons. However, little has been done to evaluate the spatial and temporal variability of air temperature in the Tarim Basin, northwest China. In this study, we collected daily air temperature from 19 meteorological stations for the period of 1960-2012, and analyzed annual mean temperature (AMT), the annual minimum (T min) and maximum temperature (Tmax), and mean temperatures of all twelve months and four seasons and their anomalies. Trend analyses, standard deviation of the detrended anomaly (SDDA) and correlations were carried out to characterize the spatial and temporal variability of various mean air temperatures. Our data showed that increasing trend was much greater in the T min (0.55°C/10a) than in the AMT (0.25°C/10a) and Tmax (0.12°C/10a), and the fluctuation followed the same order. There were large spatial variations in the increasing trends of both AMT (from -0.09 to 0.43 °C/10a) and T min (from 0.15 to 1.12°C/10a). Correlation analyses indicated that AMT had a significantly linear relationship with T min and the mean temperatures of four seasons. There were also pronounced changes in the monthly air temperature from November to March at decadal time scale. The seasonality (i.e., summer and winter difference) of air temperature was stronger during the period of 1960-1979 than over the recent three decades. Our preliminary analyses indicated that local environmental conditions (such as elevation) might be partly responsible for the spatial variability, and large scale climate phenomena might have influences on the temporal variability of air temperature in the Tarim Basin. In particular, there was a significant correlation between index of El Niño-Southern Oscillation (ENSO) and air temperature of May (P = 0.004), and between the index of Pacific Decadal Oscillation (PDO) and air temperature of July (P = 0.026) over the interannual to decadal time scales. PMID:25375648

  2. Characterizing air temperature changes in the Tarim Basin over 1960-2012.

    PubMed

    Peng, Dongmei; Wang, Xiujun; Zhao, Chenyi; Wu, Xingren; Jiang, Fengqing; Chen, Pengxiang

    2014-01-01

    There has been evidence of warming rate varying largely over space and between seasons. However, little has been done to evaluate the spatial and temporal variability of air temperature in the Tarim Basin, northwest China. In this study, we collected daily air temperature from 19 meteorological stations for the period of 1960-2012, and analyzed annual mean temperature (AMT), the annual minimum (T min) and maximum temperature (Tmax), and mean temperatures of all twelve months and four seasons and their anomalies. Trend analyses, standard deviation of the detrended anomaly (SDDA) and correlations were carried out to characterize the spatial and temporal variability of various mean air temperatures. Our data showed that increasing trend was much greater in the T min (0.55°C/10a) than in the AMT (0.25°C/10a) and Tmax (0.12°C/10a), and the fluctuation followed the same order. There were large spatial variations in the increasing trends of both AMT (from -0.09 to 0.43 °C/10a) and T min (from 0.15 to 1.12°C/10a). Correlation analyses indicated that AMT had a significantly linear relationship with T min and the mean temperatures of four seasons. There were also pronounced changes in the monthly air temperature from November to March at decadal time scale. The seasonality (i.e., summer and winter difference) of air temperature was stronger during the period of 1960-1979 than over the recent three decades. Our preliminary analyses indicated that local environmental conditions (such as elevation) might be partly responsible for the spatial variability, and large scale climate phenomena might have influences on the temporal variability of air temperature in the Tarim Basin. In particular, there was a significant correlation between index of El Niño-Southern Oscillation (ENSO) and air temperature of May (P = 0.004), and between the index of Pacific Decadal Oscillation (PDO) and air temperature of July (P = 0.026) over the interannual to decadal time scales.

  3. Characterizing Air Temperature Changes in the Tarim Basin over 1960–2012

    PubMed Central

    Peng, Dongmei; Wang, Xiujun; Zhao, Chenyi; Wu, Xingren; Jiang, Fengqing; Chen, Pengxiang

    2014-01-01

    There has been evidence of warming rate varying largely over space and between seasons. However, little has been done to evaluate the spatial and temporal variability of air temperature in the Tarim Basin, northwest China. In this study, we collected daily air temperature from 19 meteorological stations for the period of 1960–2012, and analyzed annual mean temperature (AMT), the annual minimum (Tmin) and maximum temperature (Tmax), and mean temperatures of all twelve months and four seasons and their anomalies. Trend analyses, standard deviation of the detrended anomaly (SDDA) and correlations were carried out to characterize the spatial and temporal variability of various mean air temperatures. Our data showed that increasing trend was much greater in the Tmin (0.55°C/10a) than in the AMT (0.25°C/10a) and Tmax (0.12°C/10a), and the fluctuation followed the same order. There were large spatial variations in the increasing trends of both AMT (from −0.09 to 0.43 °C/10a) and Tmin (from 0.15 to 1.12°C/10a). Correlation analyses indicated that AMT had a significantly linear relationship with Tmin and the mean temperatures of four seasons. There were also pronounced changes in the monthly air temperature from November to March at decadal time scale. The seasonality (i.e., summer and winter difference) of air temperature was stronger during the period of 1960–1979 than over the recent three decades. Our preliminary analyses indicated that local environmental conditions (such as elevation) might be partly responsible for the spatial variability, and large scale climate phenomena might have influences on the temporal variability of air temperature in the Tarim Basin. In particular, there was a significant correlation between index of El Niño-Southern Oscillation (ENSO) and air temperature of May (P = 0.004), and between the index of Pacific Decadal Oscillation (PDO) and air temperature of July (P = 0.026) over the interannual to decadal time scales. PMID

  4. Encapsulated graphene field-effect transistors for air stable operation

    SciTech Connect

    Alexandrou, Konstantinos Kymissis, Ioannis; Petrone, Nicholas; Hone, James

    2015-03-16

    In this work, we report the fabrication of encapsulated graphene field effects transistors (GFETs) with excellent air stability operation in ambient environment. Graphene's 2D nature makes its electronics properties very sensitive to the surrounding environment, and thus, non-encapsulated graphene devices show extensive vulnerability due to unintentional hole doping from the presence of water molecules and oxygen limiting their performance and use in real world applications. Encapsulating GFETs with a thin layer of parylene-C and aluminum deposited on top of the exposed graphene channel area resulted in devices with excellent electrical performance stability for an extended period of time. Moisture penetration is reduced significantly and carrier mobility degraded substantially less when compared to non-encapsulated control devices. Our CMOS compatible encapsulation method minimizes the problems of environmental doping and lifetime performance degradation, enabling the operation of air stable devices for next generation graphene-based electronics.

  5. Power Reduction of the Air-Breathing Hall-Effect Thruster

    NASA Astrophysics Data System (ADS)

    Kim, Sungrae

    Electric propulsion system is spotlighted as the next generation space propulsion system due to its benefits; one of them is specific impulse. While there are a lot of types in electric propulsion system, Hall-Effect Thruster, one of electric propulsion system, has higher thrust-to-power ratio and requires fewer power supplies for operation in comparison to other electric propulsion systems, which means it is optimal for long space voyage. The usual propellant for Hall-Effect Thruster is Xenon and it is used to be stored in the tank, which may increase the weight of the thruster. Therefore, one theory that uses the ambient air as a propellant has been proposed and it is introduced as Air-Breathing Hall-Effect Thruster. Referring to the analysis on Air-Breathing Hall-Effect Thruster, the goal of this paper is to reduce the power of the thruster so that it can be applied to real mission such as satellite orbit adjustment. To reduce the power of the thruster, two assumptions are considered. First one is changing the altitude for the operation, while another one is assuming the alpha value that is electron density to ambient air density. With assumptions above, the analysis was done and the results are represented. The power could be decreased to 10s˜1000s with the assumptions. However, some parameters that do not satisfy the expectation, which would be the question for future work, and it will be introduced at the end of the thesis.

  6. Ozone changes under solar geoengineering: implications for UV exposure and air quality

    NASA Astrophysics Data System (ADS)

    Nowack, P. J.; Abraham, N. L.; Braesicke, P.; Pyle, J. A.

    2015-11-01

    Various forms of geoengineering have been proposed to counter anthropogenic climate change. Methods which aim to modify the Earth's energy balance by reducing insolation are often subsumed under the term Solar Radiation Management (SRM). Here, we present results of a standard SRM modelling experiment in which the incoming solar irradiance is reduced to offset the global mean warming induced by a quadrupling of atmospheric carbon dioxide. For the first time in an atmosphere-ocean coupled climate model, we include atmospheric composition feedbacks such as ozone changes under this scenario. Including the composition changes, we find large reductions in surface UV-B irradiance, with implications for vitamin D production, and increases in surface ozone concentrations, both of which could be important for human health. We highlight that both tropospheric and stratospheric ozone changes should be considered in the assessment of any SRM scheme, due to their important roles in regulating UV exposure and air quality.

  7. Response of air-sea carbon fluxes and climate to orbital forcing changes in the Community Climate System Model

    NASA Astrophysics Data System (ADS)

    Jochum, M.; Peacock, S.; Moore, K.; Lindsay, K.

    2010-07-01

    A global general circulation model coupled to an ocean ecosystem model is used to quantify the response of carbon fluxes and climate to changes in orbital forcing. Compared to the present-day simulation, the simulation with the Earth's orbital parameters from 115,000 years ago features significantly cooler northern high latitudes but only moderately cooler southern high latitudes. This asymmetry is explained by a 30% reduction of the strength of the Atlantic Meridional Overturning Circulation that is caused by an increased Arctic sea ice export and a resulting freshening of the North Atlantic. The strong northern high-latitude cooling and the direct insolation induced tropical warming lead to global shifts in precipitation and winds to the order of 10%-20%. These climate shifts lead to regional differences in air-sea carbon fluxes of the same order. However, the differences in global net air-sea carbon fluxes are small, which is due to several effects, two of which stand out: first, colder sea surface temperature leads to a more effective solubility pump but also to increased sea ice concentration which blocks air-sea exchange, and second, the weakening of Southern Ocean winds that is predicted by some idealized studies occurs only in part of the basin, and is compensated by stronger winds in other parts.

  8. Thermal effects on bacterial bioaerosols in continuous air flow.

    PubMed

    Jung, Jae Hee; Lee, Jung Eun; Kim, Sang Soo

    2009-08-01

    Exposure to bacterial bioaerosols can have adverse effects on health, such as infectious diseases, acute toxic effects, and allergies. The search for ways of preventing and curing the harmful effects of bacterial bioaerosols has created a strong demand for the study and development of an efficient method of controlling bioaerosols. We investigated the thermal effects on bacterial bioaerosols of Escherichia coli and Bacillus subtilis by using a thermal electric heating system in continuous air flow. The bacterial bioaerosols were exposed to a surrounding temperature that ranged from 20 degrees C to 700 degrees C for about 0.3 s. Both E. coli and B. subtilis vegetative cells were rendered more than 99.9% inactive at 160 degrees C and 350 degrees C of wall temperature of the quartz tube, respectively. Although the data on bacterial injury showed that the bacteria tended to sustain greater damage as the surrounding temperature increased, Gram-negative E. coli was highly sensitive to structural injury but Gram-positive B. subtilis was slightly more sensitive to metabolic injury. In addition, the inactivation of E. coli endotoxins was found to range from 9.2% (at 200 degrees C) to 82.0% (at 700 degrees C). However, the particle size distribution and morphology of both bacterial bioaerosols were maintained, despite exposure to a surrounding temperature of 700 degrees C. Our results show that thermal heating in a continuous air flow can be used with short exposure time to control bacterial bioaerosols by rendering the bacteria and endotoxins to a large extent inactive. This result could also be useful for developing more effective thermal treatment strategies for use in air purification or sterilization systems to control bioaerosols.

  9. Seasonal pattern of the acute mortality effects of air pollution.

    PubMed

    Qian, Zhengmin; Lin, Hung-Mo; Stewart, Walter F; Kong, Linli; Xu, Fen; Zhou, Denjin; Zhu, Zhicao; Liang, Shengwen; Chen, Weiqing; Shah, Nirav; Stetter, Christy; He, Qingci

    2010-04-01

    Evidence of seasonal variation of acute mortality effects of air pollution is inconsistent. The seasonal patterns of associations between daily mortality and daily mean concentrations of particulate matter 10 microm or less in aerodynamic diameter (PM10), sulfur dioxide (SO2), and nitrogen dioxide (NO2) were examined using 4 yr of data (2001-2004) in Wuhan, China. Four distinct seasons occur in Wuhan, where approximately 4.5 million residents live in the city core area of 201 km2. Air pollution levels are higher and pollution ranges are wider in Wuhan than in most cities. Quasi-likelihood estimation within the context of the generalized additive models (natural spline [NS] models in R) was used to model the natural logarithm of the expected daily death counts as a function of the predictor variables. The estimates of the interaction between seasons and pollution were obtained from the main effects and pollutant season interaction models. It was found that the interactions between three pollutants and cause-specific mortality were statistically significant (P < 0.05). The strongest effects occurred consistently in winter for all-natural, cardiovascular, stroke, and respiratory mortality. Every 10-microg/m3 increase in PM10 daily concentration at lag 0-1 days was associated with an increase in all-natural mortality of 0.69% (95% confidence interval [CI]: 0.44-0.94%) for winter, 0.34% (95% CI: 0.00-0.69%) for spring, 0.45% (95% CI: -0.13 to 1.04%) for summer, and -0.21% (95% CI: -0.54 to 0.12%) for fall. The results show a clear seasonal pattern of acute mortality effects of ambient air pollution and the strongest effects occurred during winter in the study city.

  10. Air pollution induced changes in the photosynthetic pigments of selected plant species.

    PubMed

    Joshi, P C; Swami, Abhishek

    2009-03-01

    Changes in the concentration of different photosynthetic pigments (Chlorophyll and carotenoids) were determined in the leaves of six tree species exposed to air pollution due to vehicular emissions. The six tree species, which are all economically important because of their being fruit bearers, used for timber fodder and as road side trees on the basis of their air pollution tolerance index. These included Mangifera indica L., Tectona grandis Linn.f , Shorea robusta Gaertn.f., Holoptelea integrifolia (Roxb.) Planch, Eucalyptus citridora Hook. Syn. and Mallotus philippinensis Muell-Arg. Reduction in chlorophyll 'a', 'b' and carotenoid was recorded in the leaf samples collected from polluted areas when compared with samples from control areas. The highest reduction in total chlorophyll was observed in Holoptelea integrifolia (Roxb.) (48.73%) Planch whereas, the lowest reduction (17.84 %) was recorded in Mallotus philippinensis Muell-Arg. Similarly in case of carotenoid contents, highest reduction (43.02%) was observed in Eucalyptus citridora, and lowest in Mallotus philippinensis Muell-Arg (19.31%). The data obtained were further analyzed using one-way ANOVA and a significant change was recorded in the studied parameters. These studies clearly indicate that the vehicular induced air pollution reduces the concentration of photosynthetic pigments in the trees exposed to road side pollution.

  11. Impacts of Future Climate and Emission Changes on U.S. Air Quality

    SciTech Connect

    Penrod, Ashley; Zhang, Yang; Wang, K.; Wu, Shiang Yuh; Leung, Lai-Yung R.

    2014-06-01

    Changes in climate and emissions will affect future air quality. In this work, simulations of present (2001-2005) and future (2026-2030) regional air quality are conducted with the newly released CMAQ version 5.0 to examine the individual and combined impacts of simulated future climate and anthropogenic emission projections on air quality over the U.S. Current (2001-2005) meteorological and chemical predictions are evaluated against observational data to assess the model’s capability in reproducing the seasonal differences. Overall, WRF and CMAQ perform reasonably well. Increased temperatures (up to 3.18 °C) and decreased ventilation (up to 157 m in planetary boundary layer height) are found in both future winter and summer, with more prominent changes in winter. Increases in future temperatures result in increased isoprene and terpene emissions in winter and summer, driving the increase in maximum 8-h average O3 (up to 5.0 ppb) over the eastern U.S. in winter while decreases in NOx emissions drive the decrease in O3 over most of the U.S. in summer. Future concentrations of PM2.5 in winter and summer and many of its components including organic matter in winter, ammonium and nitrate in summer, and sulfate in winter and summer, decrease due to decreases in primary anthropogenic emissions and the concentrations of secondary anthropogenic pollutants and increased precipitation in winter. Future winter and summer dry and wet deposition fluxes are spatially variable and increase with increasing surface resistance and precipitation (e.g., NH4+ and NO3- dry and wet deposition fluxes increase in winter over much of the U.S.), respectively, and decrease with a decrease in ambient particulate concentrations (e.g., SO42- dry and wet deposition fluxes decrease over the eastern U.S. in summer and winter). Sensitivity simulations show that anthropogenic emission projections dominate over changes in climate in their impacts on the U.S. air quality in the near future. Changes

  12. Changes in the frequency of extreme air pollution events over the Eastern United States and Europe

    NASA Astrophysics Data System (ADS)

    Rieder, H. E.; Fiore, A. M.; Fang, Y.; Staehelin, J.

    2011-12-01

    Over the past few decades, thresholds for national air quality standards, intended to protect public health and welfare, have been lowered repeatedly. At the same time observations, over Europe and the Eastern U.S., demonstrate that extreme air pollution events (high O3 and PM2.5) are typically associated with stagnation events. Recent work showed that in a changing climate high air pollution events are likely to increase in frequency and duration. Within this work we examine meteorological and surface ozone observations from CASTNet over the U.S. and EMEP over Europe and "idealized" simulations with the GFDL AM3 chemistry-climate model, which isolate the role of climate change on air quality. Specifically, we examine an "idealized 1990s" simulation, forced with 20-year mean monthly climatologies for sea surface temperatures and sea ice from observations for 1981-2000, and an "idealized 2090s" simulation forced by the observed climatologies plus the multi-model mean changes in sea surface temperature and sea ice simulated by 19 IPCC AR-4 models under the A1B scenario for 2081-2100. With innovative statistical tools (empirical orthogonal functions (EOFs) and statistics of extremes (EVT)), we analyze the frequency distribution of past, present and future extreme air pollution events over the Eastern United States and Europe. The upper tail of observed values at individual stations (e.g., within the CASTNet), i.e., the extremes (maximum daily 8-hour average (MDA8) O3>60ppb) are poorly described by a Gaussian distribution. However, further analysis showed that applying Peak-Over-Threshold-models, better capture the extremes and allows us to estimate return levels of pollution events above certain threshold values of interest. We next apply EOF analysis to identify regions that vary coherently within the ground-based monitoring networks. Over the United States, the first EOF obtained from the model in both the 1990s and 2090s idealized simulations identifies the

  13. Impact of aerosol direct effect on East Asian air quality during the EAST-AIRE campaign

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Allen, Dale J.; Pickering, Kenneth E.; Li, Zhanqing; He, Hao

    2016-06-01

    WRF-Chem simulations were performed for the March 2005 East Asian Studies of Tropospheric Aerosols: an International Regional Experiment (EAST-AIRE) Intensive Observation Campaign (IOC) to investigate the direct effects of aerosols on surface radiation and air quality. Domain-wide, WRF-Chem showed a decrease of 20 W/m2 in surface shortwave (SW) radiation due to the aerosol direct effect (ADE), consistent with observational studies. The ADE caused 24 h surface PM2.5 (particulate matter with diameter < 2.5 µm) concentrations to increase in eastern China (4.4%), southern China (10%), western China (2.3%), and the Sichuan Basin (9.6%), due to different aerosol compositions in these four regions. Conversely, surface 1 h maximum ozone was reduced by 2.3% domain-wide and up to 12% in eastern China because less radiation reached the surface. We also investigated the impact of reducing SO2 and black carbon (BC) emissions by 80% on aerosol amounts via two sensitivity simulations. Reducing SO2 decreased surface PM2.5 concentrations in the Sichuan Basin and southern China by 5.4% and decreased ozone by up to 6 ppbv in the Sichuan Basin and Southern China. Reducing BC emissions decreased PM2.5 by 3% in eastern China and the Sichuan Basin but increased surface ozone by up to 3.6 ppbv in eastern China and the Sichuan Basin. This study indicates that the benefits of reducing PM2.5 associated with reducing absorbing aerosols may be partially offset by increases in ozone at least for a scenario when NOx and VOC emissions are unchanged.

  14. Macrolichens as biomonitors of air-quality change in western Pennsylvania

    SciTech Connect

    McClenahen, J.R.; Davis, D.D.; Hutnik, R.J.

    2007-07-01

    Species richness of corticolous macrolichens was monitored at one- or two-year intervals on a total of 63 plots from 1997-2003 in a region of west-central Pennsylvania that included four coal-fired power generating stations and an industrial city. Lichen richness significantly increased from an average of 5.7 species/plot in 1997 to 9.3 species/plot in 2003. A linear mean rate of gain in species on regional monitoring plots was 0.56 species/yr. Plots along a major ridge top had a slower but significant gain in richness, and a localized area flanked by the city and two generating stations exhibited less lichen recolonization. Our results confirm the value of macrolichens as indicators of air quality and the importance of examining temporal as well as spatial changes in lichen richness to ascertain air-quality status.

  15. Mathematical Modeling of Radiocesium Migration and Air Dose Rate Changes in Eastern Fukushima Prefecture

    NASA Astrophysics Data System (ADS)

    Kitamura, A.; Sakuma, K.; Kurikami, H.; Malins, A.; Okumura, M.; Itakura, M.; Yamada, S.; Machida, M.

    2015-12-01

    Radioactive cesium that was deposited over Fukushima Prefecture after the accident at the Fukushima Daiichi nuclear power plant station is one of the major concerns regarding health physics today. Its migration is primarily by soil erosion and sediment transport within surface water during times of heavy rainfall and flooding. In order to predict the future distribution of radioactive cesium and resulting air dose rate at any location in Fukushima, we have integrated a number of mathematical models covering different time and spatial scales. In this presentation we report our overall scheme of prediction starting from sediment and radioactive cesium movement and resulting long term air dose rate changes. Specifically, we present simulation results of sediment movement and radioactive cesium migration using semi-empirical and physics based watershed models, and that of sediment and radioactive cesium behavior in a dam reservoir using one and two dimensional river simulation models. The model's results are compared with ongoing field monitoring.

  16. Dosimetric effects of an air cavity for the SAVI partial breast irradiation applicator

    SciTech Connect

    Richardson, Susan L.; Pino, Ramiro

    2010-08-15

    Purpose: To investigate the dosimetric effect of the air inside the SAVI partial breast irradiation device. Methods: The authors have investigated how the air inside the SAVI partial breast irradiation device changes the delivered dose from the homogeneously calculated dose. Measurements were made with the device filled with air and water to allow comparison to a homogenous dose calculation done by the treatment planning system. Measurements were made with an ion chamber, TLDs, and film. Monte Carlo (MC) simulations of the experiment were done using the EGSnrc suite. The MC model was validated by comparing the water-filled calculations to those from a commercial treatment planning system. Results: The magnitude of the dosimetric effect depends on the size of the cavity, the arrangement of sources, and the relative dwell times. For a simple case using only the central catheter of the largest device, MC results indicate that the dose at the prescription point 1 cm away from the air-water boundary is about 9% higher than the homogeneous calculation. Independent measurements in a water phantom with a similar air cavity gave comparable results. MC simulation of a realistic multidwell position plan showed discrepancies of about 5% on average at the prescription point for the largest device. Conclusions: The dosimetric effect of the air cavity is in the range of 3%-9%. Unless a heterogeneous dose calculation algorithm is used, users should be aware of the possibility of small treatment planning dose errors for this device and make modifications to the treatment delivery, if necessary.

  17. Air pathway effects of nuclear materials production at the Hanford Site, 1983 to 1992

    SciTech Connect

    Patton, G.W.; Cooper, A.T.

    1993-10-01

    This report describes the air pathway effects of Hanford Site operations from 1983 to 1992 on the local environment by summarizing the air concentrations of selected radionuclides at both onsite and offsite locations, comparing trends in environment concentrations to changing facility emissions, and briefly describing trends in the radiological dose to the hypothetical maximally exposed member of the public. The years 1983 to 1992 represent the last Hanford Site plutonium production campaign, and this report deals mainly with the air pathway effects from the 200 Areas, in which the major contributors to radiological emissions were located. An additional purpose for report was to review the environmental data for a long period of time to provide insight not available in an annual report format. The sampling and analytical systems used by the Surface Environmental Surveillance Project (SESP) to collect air samples during the period of this report were sufficiently sensitive to observe locally elevated concentrations of selected radionuclides near onsite source of emission as well as observing elevated levels, compared to distant locations, of some radionuclides at the down wind perimeter. The US DOE Derived Concentration Guides (DCGs) for airborne radionuclides were not exceeded for any air sample collected during 1983 to 1992, with annual average concentrations of all radionuclides at the downwind perimeter being considerably below the DCG values. Air emissions at the Hanford Site during the period of this report were dominated by releases from the PUREX Plant, with {sup 85}Kr being the major release on a curie basis and {sup 129}I being the major release on a radiological dose basis. The estimated potential radiological dose from Hanford Site point source emissions to the hypothetical maximally exposed individual (MEI) ranged from 0. 02 to 0.22 mrem/yr (effective dose equivalent), which is well below the DOE radiation limit to the public of 100 mrem/yr.

  18. Epidemiological studies of the respiratory effects of air pollution.

    PubMed

    Lebowitz, M D

    1996-05-01

    Environmental epidemiological studies of the health effects of air pollution have been major contributors to the understanding of such effects. The chronic effects of atmospheric pollutants have been studied, but, except for the known respiratory effects of particulate matter (PM), they have not been studied conclusively. There are ongoing studies of the chronic effects of certain pollutant classes, such as ozone, acid rain, airborne toxics, and the chemical form of PM (including diesel exhaust). Acute effects on humans due to outdoor and indoor exposures to several gases/fumes and PM have been demonstrated in epidemiological studies. However, the effects of these environmental factors on susceptible individuals are not known conclusively. These acute effects are especially important because they increase the human burden of minor illnesses, increase disability, and are thought to decrease productivity. They may be related to the increased likelihood of chronic disease as well. Further research is needed in this latter area, to determine the contributions of the time-related activities of individuals in different microenvironments (outdoors, in homes, in transit). Key elements of further studies are the assessment of total exposure to the different pollutants (occurring from indoor and outdoor source) and the interactive effects of pollutants. Major research areas include determination of the contributions of indoor sources and of vehicle emissions to total exposure, how to measure such exposures, and how to measure human susceptibility and responses (including those at the cellular and molecular level). Biomarkers of exposures, doses and responses, including immunochemicals, biochemicals and deoxyribonucleic acid (DNA) adducts, are beginning to promote some basic knowledge of exposure-response, especially the mechanisms. These will be extremely useful additions to standard physiological, immunological, and clinical instruments, and the understanding of biological

  19. The Dynamic Characteristic and Hysteresis Effect of an Air Spring

    NASA Astrophysics Data System (ADS)

    Löcken, F.; Welsch, M.

    2015-02-01

    In many applications of vibration technology, especially in chassis, air springs present a common alternative to steel spring concepts. A design-independent and therefore universal approach is presented to describe the dynamic characteristic of such springs. Differential and constitutive equations based on energy balances of the enclosed volume and the mountings are given to describe the nonlinear and dynamic characteristics. Therefore all parameters can be estimated directly from physical and geometrical properties, without parameter fitting. The numerically solved equations fit very well to measurements of a passenger car air spring. In a second step a simplification of this model leads to a pure mechanical equation. While in principle the same parameters are used, just an empirical correction of the effective heat transfer coefficient is needed to handle some simplification on this topic. Finally, a linearization of this equation leads to an analogous mechanical model that can be assembled from two common spring- and one dashpot elements in a specific arrangement. This transfer into "mechanical language" enables a system description with a simple force-displacement law and a consideration of the nonobvious hysteresis and stiffness increase of an air spring from a mechanical point of view.

  20. Can air temperature be used to project influences of climate change on stream temperature?

    USGS Publications Warehouse

    Arismendi, Ivan; Safeeq, Mohammad; Dunham, Jason B.; Johnson, Sherri L.

    2014-01-01

    Worldwide, lack of data on stream temperature has motivated the use of regression-based statistical models to predict stream temperatures based on more widely available data on air temperatures. Such models have been widely applied to project responses of stream temperatures under climate change, but the performance of these models has not been fully evaluated. To address this knowledge gap, we examined the performance of two widely used linear and nonlinear regression models that predict stream temperatures based on air temperatures. We evaluated model performance and temporal stability of model parameters in a suite of regulated and unregulated streams with 11–44 years of stream temperature data. Although such models may have validity when predicting stream temperatures within the span of time that corresponds to the data used to develop them, model predictions did not transfer well to other time periods. Validation of model predictions of most recent stream temperatures, based on air temperature–stream temperature relationships from previous time periods often showed poor performance when compared with observed stream temperatures. Overall, model predictions were less robust in regulated streams and they frequently failed in detecting the coldest and warmest temperatures within all sites. In many cases, the magnitude of errors in these predictions falls within a range that equals or exceeds the magnitude of future projections of climate-related changes in stream temperatures reported for the region we studied (between 0.5 and 3.0 °C by 2080). The limited ability of regression-based statistical models to accurately project stream temperatures over time likely stems from the fact that underlying processes at play, namely the heat budgets of air and water, are distinctive in each medium and vary among localities and through time.

  1. Clinical leadership effectiveness, change and complexity.

    PubMed

    McKimm, Judy; Till, Alex

    2015-04-01

    This article explores how an understanding of approaches to leading and managing change and complexity science can help clinical leaders engage with and manage change in complex environments and systems more effectively.

  2. Response of ozone to changes in hydrocarbon and nitrogen oxide concentrations in outdoor smog chambers filled with Los Angeles air

    NASA Astrophysics Data System (ADS)

    Kelly, Nelson A.; Gunst, Richard F.

    During the summer portion of the 1987 Southern California Air Quality Study (SCAQS), outdoor smog chamber experiments were performed on Los Angeles air to determine the response of maximum ozone levels, O 3(max), to changes in the initial concentrations of hydrocarbons, HC, and nitrogen oxides, NO x. These captive-air experiments were conducted in downtown Los Angeles and in the downwind suburb of Claremont. Typically, eight chambers were filled with LA air in the morning. In some chambers the initial HC and/or NO x concentrations were changed by 25% to 50% by adding various combinations of a mixture of HC, clean air, or NO x. The O 3 concentration in each chamber was monitored throughout the day to determine O 3(max). An empirical mathematical model for O 3(max) was developed from regression fits to the initial HC and NO x concentrations and to the average daily temperature at both sites. This is the first time that a mathematical expression for the O 3-precursor relationship and the positive effect of temperature on O 3(max) have been quantified using captive-air experiments. An ozone isopleth diagram prepared from the empirical model was qualitatively similar to those prepared from photochemical mechanisms. This constitutes the first solely empirical corroboration of the O 3 contour shape for Los Angeles. To comply with the Federal Ozone Standard in LA, O 3(max) must be reduced by approximately 50%. Several strategies for reducing O 3(max) by 50% were evaluated using the empirical model. For the average initial conditions that we measured in LA, the most efficient strategy is one that reduces HC by 55-75%, depending on the ambient HC/NO x ratio. Any accompanying reduction in NO x would be counter-productive to the benefits of HC reductions. In fact, reducing HC and NO x simultaneously requires larger percentage reductions for both than the reduction required when HC alone is reduced. The HC-reduction strategy is the most efficient on average, but no single

  3. Effects of air pollution on children’s pulmonary health

    NASA Astrophysics Data System (ADS)

    Tabaku, Afrim; Bejtja, Gazmend; Bala, Silvana; Toci, Ervin; Resuli, Jerina

    2011-12-01

    IntroductionMany reports regarding the effects of air pollution on children's respiratory health have appeared in the scientific literature. Some investigators found increases in persistent cough and phlegm, bronchitis, and early respiratory infections in communities with poor air quality. The purpose of this survey was to compare the pulmonary function of children living in urban area of Tirana city with children living in suburban area of the city. Material and methodsThis survey is carried out during 2004-2005 period on 238 children living in urban area and in 72 children living in suburban area, measuring dynamic pulmonary function. A questionnaire was used to collect data on sex, current respiratory symptoms, allergy diagnosed by the physician, parent education and smoking habit of parents, presence of animals, synthetic carpets and moulds in their houses. The selection of schools, and children included in this survey was done by randomized method. Also, we have measured and classic air pollutants. ResultsComparing the results of values of pulmonary function of two groups of children, we have shown that differences were significant ( p 0.001), whereas comparing symptoms were for cough ( p 0.011) and for phlegm ( p 0.032). The level of particulate matter (PM10) and total suspended matter (TSP) were over the recommended limit values, whereas the levels of other pollutants have resulted within recommended levels of World Health Organization (WHO) ConclusionsThe results of this survey suggest that air pollution is associated with respiratory health of children causing a slight decrease in values of pulmonary function in children of urban area compared with those of suburban area.

  4. Evaluating the Contribution of Natural Variability and Climate Model Response to Uncertainty in Projections of Climate Change Impacts on U.S. Air Quality

    EPA Science Inventory

    We examine the effects of internal variability and model response in projections of climate impacts on U.S. ground-level ozone across the 21st century using integrated global system modeling and global atmospheric chemistry simulations. The impact of climate change on air polluti...

  5. Changing the role of the air traffic controller: how will free flight affect memory for spatial events?

    PubMed

    Nicholls, Alastair P; Melia, Anne; Farmer, Eric W; Shaw, Gareth; Milne, Tracey; Stedmon, Alex; Sharples, Sarah; Cox, Gemma

    2007-07-01

    At present, air traffic controllers (ATCOs) exercise strict control over routing authority for aircraft movement in airspace. The onset of a free flight environment, however, may well result in a dramatic change to airspace jurisdictions, with aircraft movements for the large part being governed by aircrew, not ATCOs. The present study examined the impact of such changes on spatial memory for recent and non-recent locations of aircraft represented on a visual display. The experiment contrasted present conditions, in which permission for manoeuvres is granted by ATCOs, with potential free flight conditions, in which aircrew undertake deviations without explicit approval from ATCOs. Results indicated that the ATCO role adopted by participants impacted differently on short-term and long-term spatial representations of aircraft manoeuvres. Although informing participants of impending deviations has beneficial effects on spatial representations in the short term, long-term representations of spatial events are affected deleteriously by the presentation of subsequent information pertaining to other aircraft. This study suggests strongly that recognition of the perceptual and cognitive consequences of changing to a free flight environment is crucial if air safety is not to be jeopardized. PMID:17451635

  6. CONCRETE BLOCKS' ADVERSE EFFECTS ON INDOOR AIR AND RECOMMENDED SOLUTIONS

    EPA Science Inventory

    Air infiltration through highly permeable concrete blocks can allow entry of various serious indoor air pollutants. An easy approach to avoiding these pollutants is to select a less–air-permeable concrete block. Tests show that air permeability of concrete blocks can vary by a fa...

  7. Effects of Seismic Air Guns on Pallid Sturgeon and Paddlefish.

    PubMed

    Popper, Arthur N; Carlson, Thomas J; Gross, Jackson A; Hawkins, Anthony D; Zeddies, David; Powell, Lynwood; Young, John

    2016-01-01

    Pallid sturgeon and paddlefish were placed at different distances from a seismic air gun array to determine the potential effects on mortality and nonauditory body tissues from the sound from a single shot. Fish were held 7 days postexposure and then necropsied. No fish died immediately after sound exposure or over the postexposure period. Statistical analysis of injuries showed no differences between the experimental and control animals in either type or severity of injuries. There was also no difference in injuries between fish exposed closest to the source compared with those exposed furthest from the source. PMID:26611044

  8. Effects of Seismic Air Guns on Pallid Sturgeon and Paddlefish.

    PubMed

    Popper, Arthur N; Carlson, Thomas J; Gross, Jackson A; Hawkins, Anthony D; Zeddies, David; Powell, Lynwood; Young, John

    2016-01-01

    Pallid sturgeon and paddlefish were placed at different distances from a seismic air gun array to determine the potential effects on mortality and nonauditory body tissues from the sound from a single shot. Fish were held 7 days postexposure and then necropsied. No fish died immediately after sound exposure or over the postexposure period. Statistical analysis of injuries showed no differences between the experimental and control animals in either type or severity of injuries. There was also no difference in injuries between fish exposed closest to the source compared with those exposed furthest from the source.

  9. Anger superiority effect for change detection and change blindness.

    PubMed

    Lyyra, Pessi; Hietanen, Jari K; Astikainen, Piia

    2014-11-01

    In visual search, an angry face in a crowd "pops out" unlike a happy or a neutral face. This "anger superiority effect" conflicts with views of visual perception holding that complex stimulus contents cannot be detected without focused top-down attention. Implicit visual processing of threatening changes was studied by recording event-related potentials (ERPs) using facial stimuli using the change blindness paradigm, in which conscious change detection is eliminated by presenting a blank screen before the changes. Already before their conscious detection, angry faces modulated relatively early emotion sensitive ERPs when appearing among happy and neutral faces, but happy faces only among neutral, not angry faces. Conscious change detection was more efficient for angry than happy faces regardless of background. These findings indicate that the brain can implicitly extract complex emotional information from facial stimuli, and the biological relevance of threatening contents can speed up their break up into visual consciousness.

  10. Aerosol Absorption by Black Carbon and Dust: Implications of Climate Change and Air Quality in Asia

    NASA Technical Reports Server (NTRS)

    Chin, Mian

    2010-01-01

    Atmospheric aerosol distributions from 2000 to 2007 are simulated with the global model GOCART to attribute light absorption by aerosol to its composition and sources. We show the seasonal and interannual variations of absorbing aerosols in the atmosphere over Asia, mainly black carbon and dust. and their linkage to the changes of anthropogenic and dust emissions in the region. We compare our results with observations from satellite and ground-based networks, and estimate the importance of black carbon and dust on regional climate forcing and air quality.

  11. Effects of air current speed, light intensity and co2 concentration on photosynthesis and transpiration of plant leaves

    NASA Astrophysics Data System (ADS)

    Kitaya, Y.; Tsuruyama, J.; Shibuya, T.; Kiyota, M.

    To obtain basic data for adequate air circulation to promote gas exchange and growth of plants in closed plant culture modules in bioregenerative life support systems in space, the effects of air current speeds less than 0.8 m s-1 on transpiration (Tr) and net photosynthetic rates (Pn) of sweetpotato and barley leaves were determined using a leaf chamber method under different photosynthetic photon flux densities (PPFDs) and CO_2 concentrations. The air current speed inside the leaf chamber was controlled by controlling the input voltages for an air circulation fan. The leaf surface boundary layer resistance was determined by the evaporation rate of wet paper and the water vapor pressure difference between the paper and surrounding air in the leaf chamber. The Tr and Pn of leaves rapidly increased as the air current speed increased from 0.01 to 0.1 m s-1 and gradually increased from 0.1 to 0.8 m s-1. These changes are correspondent to the change of the leaf surface boundary layer resistance. The depression of Tr by low air current speeds was greater than that of Pn. Tr and Pn decreased by 0.5 and 0.7 times, respectively, as the air current speed decreased from 0.8 to 0.01 m s-1. The depressions of Tr and Pn by low air current speeds were most notable at PPFDs of 500 and 250 μmol m-2 s-1, respectively. The air current speeds affected Tr and Pn at a CO_2 concentration of 700 μmol mol-1 as well as at 400 μmol mol-1. The results confirmed the importance of controlling air movement for enhancing Tr and Pn under the relatively high PPFD and elevated CO_2 levels likely in plant culture systems in space.

  12. Joint Effects of Ambient Air Pollutants on Pediatric Asthma Emergency Department Visits in Atlanta, 1998–2004

    EPA Science Inventory

    Background: Because ambient air pollution exposure occurs in the form of mixtures, consideration of joint effects of multiple pollutants may advance our understanding of air pollution health effects. Methods: We assessed the joint effect of selected ambient air pollutant com...

  13. Effects of air resistance on AT-cut quartz thickness-shear resonators.

    PubMed

    Chen, Yangyang; Wang, Ji; Du, Jianke; Zhang, Weiping; Yang, Jiashi

    2013-02-01

    We study theoretically the effects of air resistance on an AT-cut quartz plate thickness-shear mode resonator. Mindlin's two-dimensional equations for coupled thickness-shear and flexural motions of piezoelectric plates are employed for the crystal resonator. The equations of a Newtonian fluid and the equations of linear acoustics are used for the shear and compressive waves in the air surrounding the resonator, respectively. Solutions for free and electrically forced vibrations are obtained. The impedance of the resonator is calculated. The effects of air resistance are examined. It is found that air viscosity causes a relative frequency shift of the order of ppm. When the material quality factor of quartz Q = 10(5), the air viscosity and compressibility both have significant effects on resonator impedance. For resonators with larger aspect ratios the effects of air resistance are weaker, and the effect of air compressibility is weaker than air viscosity.

  14. Research on inert gas narcosis and air velocity effects on metabolic performance

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The effects of air velocity on metabolic performance are studied by using high forced airflow in a closed environment as a mechanism to control the concentration of volatile animal wastes. Air velocities between 100 and 200 ft/min are without significant effects on the metabolism of rats. At velocities of 200 ft/min and above, oxygen consumption and CO2 production as well as food consumption increase. In most instances, the changes are on the order of 5-10%. At the same time, the RQ for the animals increases slightly and generally correlates well with oxygen consumption and CO2 production. Experiments on the nature of inert gas narcosis show that halothane and methoxyflurane are rather potent inhibitors of the NADH:O2 oxidoreductase system in rats. These experiments suggest that the mechanism of inert gas narcosis is not mandatorily related to a membrane surface phenomenon.

  15. Air mass distribution and the heterogeneity of the climate change signal in the Hudson Bay/Foxe Basin region, Canada

    NASA Astrophysics Data System (ADS)

    Leung, Andrew; Gough, William

    2016-08-01

    The linkage between changes in air mass distribution and temperature trends from 1971 to 2010 is explored in the Hudson Bay/Foxe Basin region. Statistically significant temperature increases were found of varying spatial and temporal magnitude. Concurrent statistically significant changes in air mass frequency at the same locations were also detected, particularly in the declining frequency of dry polar (DP) air. These two sets of changes were found to be linked, and we thus conclude that the heterogeneity of the climatic warming signal in the region is at least partially the result of a fundamental shift in the concurrent air mass frequency in addition to global and regional changes in radiative forcing due to increases in long-lived greenhouse gases.

  16. Quantifying the effects of mixing and residual circulation on trends of stratospheric mean age of air

    NASA Astrophysics Data System (ADS)

    Ploeger, Felix; Abalos, Marta; Birner, Thomas; Konopka, Paul; Legras, Bernard; Müller, Rolf; Riese, Martin

    2015-04-01

    Trends in stratospheric mean age of air are driven both by changes in the (slow, large scale) residual mean mass circulation and by changes in (fast, locally acting) eddy mixing. However, to what degree both effects affect mean age trends is an open question. Here, we present a method that allows the effects of mixing and residual circulation on trends of mean age of air to be quantified. This method is based on mean age simulations with the Lagrangian chemistry transport model CLaMS driven by ERA-Interim reanalysis, and on the mean age tracer continuity equation integrated along the residual circulation. CLaMS simulated climatological mean age in the lower stratosphere shows reliable agreement with balloon borne in-situ obsevations and with satellite observations by MIPAS (Michelson Interferometer for Passive Atmospheric Sounding). During 1990--2013, CLaMS simulated mean age decreases throughout most of the stratosphere, qualitatively consistent with results based on climate model simulations (e.g., Butchart et al., 2010). Remarkably, in the Northern hemisphere subtropics and mid-latitudes above about 24km CLaMS mean age trends are insignificant, consistent with published mean age trends from in-situ observations (Engel et al., 2009). Furthermore, during 2002--2012 CLaMS mean age changes show a clear hemispheric asymmetry in agreement with MIPAS satellite observations (Stiller et al., 2012; Ploeger et al., 2014) and HCl decadal changes (Mahieu et al., 2014). We find that changes in the transit time along the residual circulation alone cannot explain the mean age trends, and including the effect of mixing integrated along the air parcel history is essential. Therefore, differences in mean age trends between models or between models and observations are likely related to differences in the integrated effect of mixing on mean age of air. Above about 550K, trends in the integrated mixing effect appear to be likely coupled to residual circulation changes. References

  17. Evaluation of Impacts of Landuse Changes on Air Quality in Hyderabad Metropolis Using Remote Sensing and GIS - A Case Study from Indian Sub-Continent

    NASA Astrophysics Data System (ADS)

    Vuppala, P.; S. S, A.; Mareddy, A.

    2004-12-01

    Around the world cities in developing countries are rapidly growing as more and more people become urban dwellers resulting in increased level of air pollution caused by changes in transportation, energy production and industrial activities. Air quality is an issue of critical importance in view of the accumulating evidence showing the adverse effects of pollution on human health, agricultural crops, manmade environments and ecosystems. An integrated study for identification of appropriate sites for representative evaluation of air pollution, novel means of monitoring air quality, identifying the predominant sources of pollution, effective assessment of air quality and evaluation of different management strategies essential for the development of a healthy and livable region is carried out for Hyderabad metropolis in India using Remote sensing and Geographical Information System (GIS) based assessment tools. Correlation studies between the concentration level of pollutants in urban air and urban land use are also dealt with. Municipal Corporation of Hyderabad (MCH) is divided into eleven planning zones out of which the present study area i.e. Zone I & IIA comprises of industrial, highly commercial and densely populated areas, apart from medium and sparse residential areas making it environmentally sensitive. Sampling locations were identified based on the land use/ land cover of the region and air samples were collected from areas having varying land use patterns using a high volume air sampler. The samples were then analyzed for the presence of Sulphur oxides(SO--x), Oxides of Nitrogen(NO--x), Total Suspended Particulate Matter(TSPM) and Respirable Suspended Particulate Matter(RSPM) using standard protocols and maps showing spatial distribution of SOx, NO--x, TSPM & RSPM were prepared using curve fitting technique of Arc/Info & ArcView GIS software. Air Quality Index (AQI), indicating the overall quality of air and extent of pollution is also calculated, based on

  18. Effects of gamma-irradiation and air annealing on Yb-doped Y3Al5O12 single crystal.

    PubMed

    Zeng, Xionghui; Xu, Xiaodong; Wang, Xiaodan; Zhao, Zhiwei; Zhao, Guangjun; Xu, Jun

    2008-03-01

    The effects of gamma-irradiation on the air-annealed 10at.% Yb:Y(3)Al(5)O(12) (YAG) and air annealing on the gamma-irradiated 10at.% Yb:YAG have been studied by the difference absorption spectra before and after treatment. The gamma-irradiation and air annealing led to opposite changes of the absorption properties of the Yb:YAG crystal. After air annealing, the gamma-irradiation induced centers were totally removed and the concentration of Fe(3+) and Yb(3+) were lightly increased. For the first time, the gamma-irradiation induced valence changes between Yb(3+) and Yb(2+) ions in Yb:YAG crystals have been observed.

  19. Project ATLANTA (Atlanta Land use Analysis: Temperature and Air Quality): Use of Remote Sensing and Modeling to Analyze How Urban Land Use Change Affects Meteorology and Air Quality Through Time

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale A.; Luvall, Jeffrey C.; Estes, Maurice G., Jr.

    1999-01-01

    This paper presents an overview of Project ATLANTA (ATlanta Land use ANalysis: Temperature and Air-quality) which is an investigation that seeks to observe, measure, model, and analyze how the rapid growth of the Atlanta, Georgia metropolitan area since the early 1970's has impacted the region's climate and air quality. The primary objectives for this research effort are: (1) To investigate and model the relationships between land cover change in the Atlanta metropolitan, and the development of the urban heat island phenomenon through time; (2) To investigate and model the temporal relationships between Atlanta urban growth and land cover change on air quality; and (3) To model the overall effects of urban development on surface energy budget characteristics across the Atlanta urban landscape through time. Our key goal is to derive a better scientific understanding of how land cover changes associated with urbanization in the Atlanta area, principally in transforming forest lands to urban land covers through time, has, and will, effect local and regional climate, surface energy flux, and air quality characteristics. Allied with this goal is the prospect that the results from this research can be applied by urban planners, environmental managers and other decision-makers, for determining how urbanization has impacted the climate and overall environment of the Atlanta area. Multiscaled remote sensing data, particularly high resolution thermal infrared data, are integral to this study for the analysis of thermal energy fluxes across the Atlanta urban landscape.

  20. Changes to indoor air quality as a result of relocating families from slums to public housing

    NASA Astrophysics Data System (ADS)

    Burgos, Soledad; Ruiz, Pablo; Koifman, Rosalina

    2013-05-01

    One largely unstudied benefit of relocating families from slums to public housing is the potential improvement in indoor air quality (IAQ). We compared families that moved from slums to public housing with those that remained living in slums in Santiago, Chile in terms of fine particulate matter (PM2.5) as main indicator of change. A cross-sectional study of 98 relocated families and 71 still living in slums was carried out, obtaining indoor and outdoor samples by a Personal Environmental Monitor. Home characteristics, including indoor air pollution sources were collected through questionnaires. Multivariate regression models included the intervention (public housing or slum), indoor pollution sources, outdoor PM2.5 and family characteristics as predictors. Indoor PM2.5 concentrations were higher in slums (77.8 μg m-3 [SD = 35.7 μg m-3]) than in public housing (55.7 μg m-3 [SD = 34.6 μg m-3], p < 0.001). Differences between indoor and outdoor PM2.5 were significant only in the slum houses. The multivariate analysis showed that housing intervention significantly decreased indoor PM2.5 (10.4 μg m-3) after adjusting by the other predictors. Outdoor PM2.5 was the main predictor of indoor PM2.5. Other significant factors were water heating fuels and indoor smoking. Having infants 1-23 months was associated with a lowering of indoor PM2.5. Our results suggest that a public housing program that moves families from slums to public housing improves indoor air quality directly and also indirectly through air pollution sources.

  1. Air pollution and associated human mortality: The role of air pollutant emissions, climate change and methane concentration increases during the industrial period

    NASA Astrophysics Data System (ADS)

    Fang, Y.; Naik, V.; Horowitz, L. W.; Mauzerall, D. L.

    2012-12-01

    Increases in surface ozone (O3) and fine particulate matter (≤ 2.5μm aerodynamic diameter, PM2.5) are associated with excess premature human mortalities. Here we estimate changes in surface O3 and PM2.5 since preindustrial (1860) times and the global present-day (2000) premature human mortalities associated with these changes. We go beyond previous work to analyze and differentiate the contribution of three factors: changes in emissions of short-lived air pollutants, climate change, and increased methane (CH4) concentrations, to air pollution levels and the associated premature mortalities. We use a coupled chemistry-climate model in conjunction with global population distributions in 2000 to estimate exposure attributable to concentration changes since 1860 from each factor. Attributable mortalities are estimated using health impact functions of long-term relative risk estimates for O3 and PM2.5 from the epidemiology literature. We find global mean surface PM2.5 and health-relevant O3 (defined as the maximum 6-month mean of 1-hour daily maximum O3 in a year) have increased by 8±0.16 μg/m3 and 30±0.16 ppbv, respectively, over this industrial period as a result of combined changes in emissions of air pollutants (EMIS), climate (CLIM) and CH4 concentrations (TCH4). EMIS, CLIM and TCH4 cause global average PM2.5 (O3) to change by +7.5±0.19 μg/m3 (+25±0.30 ppbv), +0.4±0.17 μg/m3 (+0.5±0.28 ppbv), and -0.02±0.01 μg/m3 (+4.3±0.33 ppbv), respectively. Total changes in PM2.5 are associated with 1.5 (95% confidence interval, CI, 1.0-2.5) million all-cause mortalities annually and in O3 are associated with 375 (95% CI, 129-592) thousand respiratory mortalities annually. Most air pollution mortality is driven by changes in emissions of short-lived air pollutants and their precursors (95% and 85% of mortalities from PM2.5 and O3 respectively). However, changing climate and increasing CH4 concentrations also increased premature mortality associated with air

  2. Air pollution and associated human mortality: the role of air pollutant emissions, climate change and methane concentration increases during the industrial period

    NASA Astrophysics Data System (ADS)

    Fang, Y.; Naik, V.; Horowitz, L. W.; Mauzerall, D. L.

    2012-09-01

    Increases in surface ozone (O3) and fine particulate matter (≤2.5 μm} aerodynamic diameter, PM2.5) are associated with excess premature human mortalities. Here we estimate changes in surface O3 and PM2.5 since preindustrial (1860) times and the global present-day (2000) premature human mortalities associated with these changes. We go beyond previous work to analyze and differentiate the contribution of three factors: changes in emissions of short-lived air pollutants, climate change, and increased methane (CH4) concentrations, to air pollution levels and the associated premature mortalities. We use a coupled chemistry-climate model in conjunction with global population distributions in 2000 to estimate exposure attributable to concentration changes since 1860 from each factor. Attributable mortalities are estimated using health impact functions of long-term relative risk estimates for O3 and PM2.5 from the epidemiology literature. We find global mean surface PM2.5 and health-relevant O3 (defined as the maximum 6-month mean of 1-h daily maximum O3 in a year) have increased by 8 ± 0.16 μg m-3 and 30 ± 0.16 ppbv, respectively, over this industrial period as a result of combined changes in emissions of air pollutants (EMIS), climate (CLIM) and CH4 concentrations (TCH4). EMIS, CLIM and TCH4 cause global average PM2.5(O3) to change by +7.5 ± 0.19 μg m-3 (+25 ± 0.30 ppbv), +0.4 ± 0.17 μg m-3 (+0.5 ± 0.28 ppbv), and -0.02 ± 0.01 μg m-3 (+4.3 ± 0.33 ppbv), respectively. Total changes in PM2.5 are associated with 1.5 (95% confidence interval, CI, 1.0-2.5) million all-cause mortalities annually and in O3 are associated with 375 (95% CI, 129-592) thousand respiratory mortalities annually. Most air pollution mortality is driven by changes in emissions of short-lived air pollutants and their precursors (95% and 85% of mortalities from PM2.5 and O3, respectively). However, changing climate and increasing CH4 concentrations also increased premature mortality

  3. The effects of air gap reflections during air-coupled leaky Lamb wave inspection of thin plates.

    PubMed

    Fan, Zichuan; Jiang, Wentao; Cai, Maolin; Wright, William M D

    2016-02-01

    Air-coupled ultrasonic inspection using leaky Lamb waves offers attractive possibilities for non-contact testing of plate materials and structures. A common method uses an air-coupled pitch-catch configuration, which comprises a transmitter and a receiver positioned at oblique angles to a thin plate. It is well known that the angle of incidence of the ultrasonic bulk wave in the air can be used to preferentially generate specific Lamb wave modes in the plate in a non-contact manner, depending on the plate dimensions and material properties. Multiple reflections of the ultrasonic waves in the air gap between the transmitter and the plate can produce additional delayed waves entering the plate at angles of incidence that are different to those of the original bulk wave source. Similarly, multiple reflections of the leaky Lamb waves in the air gap between the plate and an inclined receiver may then have different angles of incidence and propagation delays when arriving at the receiver and hence the signal analysis may become complex, potentially leading to confusion in the identification of the wave modes. To obtain a better understanding of the generation, propagation and detection of leaky Lamb waves and the effects of reflected waves within the air gaps, a multiphysics model using finite element methods was established. This model facilitated the visualisation of the propagation of the reflected waves between the transducers and the plate, the subsequent generation of additional Lamb wave signals within the plate itself, their leakage into the adjacent air, and the reflections of the leaky waves in the air gap between the plate and receiver. Multiple simulations were performed to evaluate the propagation and reflection of signals produced at different transducer incidence angles. Experimental measurements in air were in good agreement with simulation, which verified that the multiphysics model can provide a convenient and accurate way to interpret the signals in

  4. Studies with the USF/NASA toxicity screening test method - Effect of air flow and effect of fabric dye

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Lopez, M. T.

    1976-01-01

    One sample each of commercial polyurethane and polychloroprene flexible foams were evaluated using the USF/NASA toxicity screening test method. Air flow rates of 0, 0.16, 16, and 48 ml/sec were used to determine the effect of air flow on relative toxicity. Time to first sign of incapacitation and time to death were substantially reduced with both polyurethane and polychloroprene flexible foams by the introduction of 16 to 48 ml/sec air flow. The relative toxicity rankings of these materials were not altered by changes in air flow. Under these test conditions, the polyurethane foam consistently appeared more toxic than the polychloroprene foam. Samples of six different colors from the same fabric were evaluated separately, using the USF/NASA toxicity screening test method, to determine the effect of fabric dye, if any. The material was an upholstery fabric, consisting of 46 percent cotton, 33 percent wool, and 21 percent nylon. There appeared to be no significant effect of fabric dye on relative toxicity, for this material under these test conditions.

  5. The Effect of the Saharan Air Layer on the Formation of Hurricane Isabel (2003) Simulated with AIRS Data

    NASA Technical Reports Server (NTRS)

    Wu, iguang; Braun, Scott A.; Qu, John J.

    2006-01-01

    The crucial physics of how the atmosphere really accomplishes the tropical cyclogenesis process is still poorly understood. The presence of the Saharan Air Layer (SAL), an elevated mixed layer of warm and dry air that extends from Africa to the tropical Atlantic and contains a substantial amount of mineral dust, adds more complexity to the tropical cyclogenesis process in the Atlantic basin. The impact of the SAL on tropical cyclogenesis is still uncertain. Karyampudi and Carlson (1988) conclude that a strong SAL can potentially aid tropical cyclone development while Dunion and Velden (2004) argue that the SAL generally inhibits tropical cyclogenesis and intensification. Advancing our understanding of the physical mechanisms of tropical cyclogenesis and the associated roles of the SAL strongly depends on the improvement in the observations over the data-sparse ocean areas. After the Atmospheric Infrared Sounder (AIRS), the Advanced Microwave Sounding Unit (AMSU), and the microwave Humidity Sounder of Brazil (HSB) were launched with the NASA Aqua satellite in 2002, new data products retrieved from the AIRS suite became available for studying the effect of the warm, dry air mass associated with the SAL (referred to as the thermodynamic effect). The vertical profiles of the AIRS retrieved temperature and humidity provide an unprecedented opportunity to examine the thermodynamic effect of the SAL. The observational data can be analyzed and assimilated into numerical models, in which the model thermodynamic state is allowed to relax to the observed state from AIRS data. The objective of this study is to numerically demonstrate that the thermodynamic effect of the SAL on the formation of Hurricane Isabel (2003) can be largely simulated through nudging of the AIRS data.

  6. Direct effects of energy-related air pollutants on plant sexual reproduction

    SciTech Connect

    Ragsdale, H.L.; Murdy, W.H.

    1987-12-08

    Our completed research program concentrated on the direct in vivo effects of energy-related air pollutants on plant sexual reproduction. Direct air pollution effects on plant sexual reproduction have been studied for SO{sub 2} and NO{sub 2}, two of the three major air pollutants.

  7. Can changing the timing of outdoor air intake reduce indoor concentrations of traffic-related pollutants in schools?

    PubMed

    MacNeill, M; Dobbin, N; St-Jean, M; Wallace, L; Marro, L; Shin, T; You, H; Kulka, R; Allen, R W; Wheeler, A J

    2016-10-01

    Traffic emissions have been associated with a wide range of adverse health effects. Many schools are situated close to major roads, and as children spend much of their day in school, methods to reduce traffic-related air pollutant concentrations in the school environment are warranted. One promising method to reduce pollutant concentrations in schools is to alter the timing of the ventilation so that high ventilation time periods do not correspond to rush hour traffic. Health Canada, in collaboration with the Ottawa-Carleton District School Board, tested the effect of this action by collecting traffic-related air pollution data from four schools in Ottawa, Canada, during October and November 2013. A baseline and intervention period was assessed in each school. There were statistically significant (P < 0.05) reductions in concentrations of most of the pollutants measured at the two late-start (9 AM start) schools, after adjusting for outdoor concentrations and the absolute indoor-outdoor temperature difference. The intervention at the early-start (8 AM start) schools did not have significant reductions in pollutant concentrations. Based on these findings, changing the timing of the ventilation may be a cost-effective mechanism of reducing traffic-related pollutants in late-start schools located near major roads.

  8. Who benefits from environmental policy? An environmental justice analysis of air quality change in Britain, 2001-2011

    NASA Astrophysics Data System (ADS)

    Mitchell, Gordon; Norman, Paul; Mullin, Karen

    2015-10-01

    Air quality in Great Britain has improved in recent years, but not enough to prevent the European Commission (EC) taking legal action for non-compliance with limit values. Air quality is a national public health concern, with disease burden associated with current air quality estimated at 29 000 premature deaths per year due to fine particulates, with a further burden due to NO2. National small-area analyses showed that in 2001 poor air quality was much more prevalent in socio-economically deprived areas. We extend this social distribution of air quality analysis to consider how the distribution changed over the following decade (2001-2011), a period when significant efforts to meet EC air quality directive limits have been made, and air quality has improved. We find air quality improvement is greatest in the least deprived areas, whilst the most deprived areas bear a disproportionate and rising share of declining air quality including non-compliance with air quality standards. We discuss the implications for health inequalities, progress towards environmental justice, and compatibility of social justice and environmental sustainability objectives.

  9. Changes in future air quality, deposition, and aerosol-cloud interactions under future climate and emission scenarios

    NASA Astrophysics Data System (ADS)

    Glotfelty, Timothy; Zhang, Yang; Karamchandani, Prakash; Streets, David G.

    2016-08-01

    The prospect of global climate change will have wide scale impacts, such as ecological stress and human health hazards. One aspect of concern is future changes in air quality that will result from changes in both meteorological forcing and air pollutant emissions. In this study, the GU-WRF/Chem model is employed to simulate the impact of changing climate and emissions following the IPCC AR4 SRES A1B scenario. An average of 4 future years (2020, 2030, 2040, and 2050) is compared against an average of 2 current years (2001 and 2010). Under this scenario, by the Mid-21st century global air quality is projected to degrade with a global average increase of 2.5 ppb in the maximum 8-hr O3 level and of 0.3 μg m-3 in 24-hr average PM2.5. However, PM2.5 changes are more regional due to regional variations in primary aerosol emissions and emissions of gaseous precursor for secondary PM2.5. Increasing NOx emissions in this scenario combines with a wetter climate elevating levels of OH, HO2, H2O2, and the nitrate radical and increasing the atmosphere's near surface oxidation state. This differs from findings under the RCP scenarios that experience declines in OH from reduced NOx emissions, stratospheric recovery of O3, and increases in CH4 and VOCs. Increasing NOx and O3 levels enhances the nitrogen and O3 deposition, indicating potentially enhanced crop damage and ecosystem stress under this scenario. The enhanced global aerosol level results in enhancements in aerosol optical depth, cloud droplet number concentration, and cloud optical thickness. This leads to dimming at the Earth's surface with a global average reduction in shortwave radiation of 1.2 W m-2. This enhanced dimming leads to a more moderate warming trend and different trends in radiation than those found in NCAR's CCSM simulation, which does not include the advanced chemistry and aerosol treatment of GU-WRF/Chem and cannot simulate the impacts of changing climate and emissions with the same level of detailed

  10. Acute Effects of Fine Particulate Air Pollution on ST Segment Height: A Longitudinal Study

    EPA Science Inventory

    Background: The mechanisms for the relationship between particulate air pollution and cardiac disease are not fully understood. Air pollution-induced myocardial ischemia is one of the potentially important mechanisms. Methods: We investigate the acute effects and the time cours...

  11. The possible role of local air pollution in climate change in West Africa

    NASA Astrophysics Data System (ADS)

    Knippertz, Peter; Evans, Mat J.; Field, Paul R.; Fink, Andreas H.; Liousse, Catherine; Marsham, John H.

    2015-09-01

    The climate of West Africa is characterized by a sensitive monsoon system that is associated with marked natural precipitation variability. This region has been and is projected to be subject to substantial global and regional-scale changes including greenhouse-gas-induced warming and sea-level rise, land-use and land-cover change, and substantial biomass burning. We argue that more attention should be paid to rapidly increasing air pollution over the explosively growing cities of West Africa, as experiences from other regions suggest that this can alter regional climate through the influences of aerosols on clouds and radiation, and will also affect human health and food security. We need better observations and models to quantify the magnitude and characteristics of these impacts.

  12. Conformational changes of a calix[8]arene derivative at the air-water interface.

    PubMed

    de Miguel, Gustavo; Pedrosa, José M; Martín-Romero, María T; Muñoz, Eulogia; Richardson, Tim H; Camacho, Luis

    2005-03-10

    The particular behavior of a p-tert-butyl calix[8]arene derivative (C8A) has been studied at the air-water interface using surface pressure-area isotherms, surface potential-area isotherms, film relaxation measurements, Brewster angle microscopy (BAM), and infrared spectroscopy for Langmuir-Blodgett films. Thus, it is observed that the properties of the film, for example, isotherms, domain formation, and FTIR spectra, recorded during the first compression cycle differ appreciably from those during the second compression and following cycles. The results obtained are interpreted on the basis of the conformational changes of the C8A molecules by surface pressure, allowing us to inquire into the inter- and intramolecular interactions (hydrogen bonds) of those molecules. Thus, the compression induces changes in the kind of hydrogen bonds from intra- and intermolecular with other C8A molecules to hydrogen bonds with water molecules. PMID:16851456

  13. Conformational changes of a calix[8]arene derivative at the air-water interface.

    PubMed

    de Miguel, Gustavo; Pedrosa, José M; Martín-Romero, María T; Muñoz, Eulogia; Richardson, Tim H; Camacho, Luis

    2005-03-10

    The particular behavior of a p-tert-butyl calix[8]arene derivative (C8A) has been studied at the air-water interface using surface pressure-area isotherms, surface potential-area isotherms, film relaxation measurements, Brewster angle microscopy (BAM), and infrared spectroscopy for Langmuir-Blodgett films. Thus, it is observed that the properties of the film, for example, isotherms, domain formation, and FTIR spectra, recorded during the first compression cycle differ appreciably from those during the second compression and following cycles. The results obtained are interpreted on the basis of the conformational changes of the C8A molecules by surface pressure, allowing us to inquire into the inter- and intramolecular interactions (hydrogen bonds) of those molecules. Thus, the compression induces changes in the kind of hydrogen bonds from intra- and intermolecular with other C8A molecules to hydrogen bonds with water molecules.

  14. Advances of air pollution science: from forest decline to multiple-stress effects on forest ecosystem services.

    PubMed

    Paoletti, E; Schaub, M; Matyssek, R; Wieser, G; Augustaitis, A; Bastrup-Birk, A M; Bytnerowicz, A; Günthardt-Goerg, M S; Müller-Starck, G; Serengil, Y

    2010-06-01

    Over the past 20 years, the focus of forest science on air pollution has moved from forest decline to a holistic framework of forest health, and from the effects on forest production to the ecosystem services provided by forest ecosystems. Hence, future research should focus on the interacting factorial impacts and resulting antagonistic and synergistic responses of forest trees and ecosystems. The synergistic effects of air pollution and climatic changes, in particular elevated ozone, altered nitrogen, carbon and water availability, must be key issues for research. Present evidence suggests air pollution will become increasingly harmful to forests under climate change, which requires integration amongst various stressors (abiotic and biotic factors, including competition, parasites and fire), effects on forest services (production, biodiversity protection, soil protection, sustained water balance, socio-economical relevance) and assessment approaches (research, monitoring, modeling) to be fostered.

  15. Advances of air pollution science: from forest decline to multiple-stress effects on forest ecosystem services.

    PubMed

    Paoletti, E; Schaub, M; Matyssek, R; Wieser, G; Augustaitis, A; Bastrup-Birk, A M; Bytnerowicz, A; Günthardt-Goerg, M S; Müller-Starck, G; Serengil, Y

    2010-06-01

    Over the past 20 years, the focus of forest science on air pollution has moved from forest decline to a holistic framework of forest health, and from the effects on forest production to the ecosystem services provided by forest ecosystems. Hence, future research should focus on the interacting factorial impacts and resulting antagonistic and synergistic responses of forest trees and ecosystems. The synergistic effects of air pollution and climatic changes, in particular elevated ozone, altered nitrogen, carbon and water availability, must be key issues for research. Present evidence suggests air pollution will become increasingly harmful to forests under climate change, which requires integration amongst various stressors (abiotic and biotic factors, including competition, parasites and fire), effects on forest services (production, biodiversity protection, soil protection, sustained water balance, socio-economical relevance) and assessment approaches (research, monitoring, modeling) to be fostered. PMID:20036449

  16. Laser response of a quartz crystal microbalance: frequency changes induced by light irradiation in the air phase.

    PubMed

    Kawasaki, Takayoshi; Mochida, Tetsuhiro; Katada, Jun-ichi; Okahata, Yoshio

    2009-09-01

    A weak laser irradiation (523-785 nm, 5-60 mW) onto an Au electrode surface of a 27-MHz quartz crystal microbalance (QCM) caused a frequency increase (a mass decrease) in the air phase. These frequency changes depended on the wavelength of the irradiated laser in the order of 523 nm > 636 nm > 785 nm, which corresponds to the light absorbance of the Au electrode of the QCM. The laser response increased linearly with increasing laser power (5-60 mW). In addition, the laser response showed a maximum at the incidence angle of 72 degrees when the P-polarized 636 nm laser was irradiated on the Au surface, due to the evanescent effect. These laser responses were also observed in the humid air of H2O, D2O, and in the vapors of various alcohols. Based on these findings, the observed frequency increase (mass decrease) can be explained by the photo-induced reversible desorption of water molecules from the Au electrode surface of the QCM due to the interfacial property changes.

  17. Bias stress effect in "air-gap" organic field-effect transistors.

    PubMed

    Chen, Y; Podzorov, V

    2012-05-22

    The origin of the bias stress effect related only to semiconductor properties is investigated in "air-gap" organic field-effect transistors (OFETs) in the absence of a material gate dielectric. The effect becomes stronger as the density of trap states in the semiconductor increases. A theoretical model based on carrier trapping and relaxation in localized tail states is formulated. Polar molecular vapors in the gap of "air-gap" OFETs also have a significant impact on the bias stress effect via the formation of bound states between the charge carriers and molecular dipoles at the semiconductor surface. PMID:22499410

  18. Impact of climate and land cover changes on tropospheric ozone air quality and public health in East Asia between 1980 and 2010

    NASA Astrophysics Data System (ADS)

    Fu, Y.; Tai, A. P. K.

    2015-09-01

    Understanding how historical climate and land cover changes have affected tropospheric ozone in East Asia would help constrain the large uncertainties associated with future East Asian air quality projections. We perform a series of simulations using a global chemical transport model driven by assimilated meteorological data and a suite of land cover and land use data to examine the public health effects associated with changes in climate, land cover, land use, and anthropogenic emissions between the 5-year periods 1981-1985 and 2007-2011 in East Asia. We find that between these two periods land cover change alone could lead to a decrease in summertime surface ozone by up to 4 ppbv in East Asia and ~ 2000 fewer ozone-related premature deaths per year, driven mostly by enhanced dry deposition resulting from climate- and CO2-induced increase in vegetation density, which more than offsets the effect of reduced isoprene emission arising from cropland expansion. Climate change alone could lead to an increase in summertime ozone by 2-10 ppbv in most regions of East Asia and ~ 6000 more premature deaths annually, mostly attributable to warming. The combined impacts (-2 to +12 ppbv) show that while the effect of climate change is more pronounced, land cover change could offset part of the climate effect and lead to a previously unknown public health benefit. While the changes in anthropogenic emissions remain the largest contributor to deteriorating ozone air quality in East Asia over the past 30 years, we show that climate change and land cover changes could lead to a substantial modification of ozone levels, and thus should come into consideration when formulating future air quality management strategies. We also show that the sensitivity of surface ozone to land cover change is more dependent on dry deposition than on isoprene emission in most of East Asia, leading to ozone responses that are quite distinct from that in North America, where most ozone

  19. The Effective Mass of a Ball in the Air

    ERIC Educational Resources Information Center

    Messer, J.; Pantaleone, J.

    2010-01-01

    The air surrounding a projectile affects the projectile's motion in three very different ways: the drag force, the buoyant force, and the added mass. The added mass is an increase in the projectile's inertia from the motion of the air around it. Here we experimentally measure the added mass of a spherical projectile in air. The results agree well…

  20. Health effects of particulate air pollution and airborne desert dust

    NASA Astrophysics Data System (ADS)

    Lelieveld, J.; Pozzer, A.; Giannadaki, D.; Fnais, M.

    2013-12-01

    Air pollution by fine particulate matter (PM2.5) has increased strongly with industrialization and urbanization. In the past decades this increase has taken place at a particularly high pace in South and East Asia. We estimate the premature mortality and the years of human life lost (YLL) caused by anthropogenic PM2.5 and airborne desert dust (DU2.5) on regional and national scales (Giannadaki et al., 2013; Lelieveld et al., 2013). This is based on high-resolution global model calculations that resolve urban and industrial regions in relatively great detail. We apply an epidemiological health impact function and find that especially in large countries with extensive suburban and rural populations, air pollution-induced mortality rates have been underestimated given that previous studies largely focused on the urban environment. We calculate a global premature mortality by anthropogenic aerosols of 2.2 million/year (YLL ≈ 16 million/year) due to lung cancer and cardiopulmonary disease. High mortality rates by PM2.5 are found in China, India, Bangladesh, Pakistan and Indonesia. Desert dust DU2.5 aerosols add about 0.4 million/year (YLL ≈ 3.6 million/year). Particularly significant mortality rates by DU2.5 occur in Pakistan, China and India. The estimated global mean per capita mortality caused by airborne particulates is about 0.1%/year (about two thirds of that caused by tobacco smoking). We show that the highest premature mortality rates are found in the Southeast Asia and Western Pacific regions (about 25% and 46% of the global rate, respectively) where more than a dozen of the most highly polluted megacities are located. References: Giannadaki, D., A. Pozzer, and J. Lelieveld, Modeled global effects of airborne desert dust on air quality and premature mortality, Atmos. Chem. Phys. Discuss. (submitted), 2013. Lelieveld, J., C. Barlas, D. Giannadaki, and A. Pozzer, Model calculated global, regional and megacity premature mortality due to air pollution by ozone

  1. The effects of bedroom air quality on sleep and next-day performance.

    PubMed

    Strøm-Tejsen, P; Zukowska, D; Wargocki, P; Wyon, D P

    2016-10-01

    The effects of bedroom air quality on sleep and next-day performance were examined in two field-intervention experiments in single-occupancy student dormitory rooms. The occupants, half of them women, could adjust an electric heater to maintain thermal comfort but they experienced two bedroom ventilation conditions, each maintained for 1 week, in balanced order. In the initial pilot experiment (N = 14), bedroom ventilation was changed by opening a window (the resulting average CO2 level was 2585 or 660 ppm). In the second experiment (N = 16), an inaudible fan in the air intake vent was either disabled or operated whenever CO2 levels exceeded 900 ppm (the resulting average CO2 level was 2395 or 835 ppm). Bedroom air temperatures varied over a wide range but did not differ between ventilation conditions. Sleep was assessed from movement data recorded on wristwatch-type actigraphs and subjects reported their perceptions and their well-being each morning using online questionnaires. Two tests of next-day mental performance were applied. Objectively measured sleep quality and the perceived freshness of bedroom air improved significantly when the CO2 level was lower, as did next-day reported sleepiness and ability to concentrate and the subjects' performance of a test of logical thinking.

  2. Air Distribution Effectiveness for Residential Mechanical Ventilation: Simulation and Comparison of Normalized Exposures

    SciTech Connect

    Petithuguenin, T.D.P.; Sherman, M.H.

    2009-05-01

    The purpose of ventilation is to dilute indoor contaminants that an occupant is exposed to. Even when providing the same nominal rate of outdoor air, different ventilation systems may distribute air in different ways, affecting occupants' exposure to household contaminants. Exposure ultimately depends on the home being considered, on source disposition and strength, on occupants' behavior, on the ventilation strategy, and on operation of forced air heating and cooling systems. In any multi-zone environment dilution rates and source strengths may be different in every zone and change in time, resulting in exposure being tied to occupancy patterns.This paper will report on simulations that compare ventilation systems by assessing their impact on exposure by examining common house geometries, contaminant generation profiles, and occupancy scenarios. These simulations take into account the unsteady, occupancy-tied aspect of ventilation such as bathroom and kitchen exhaust fans. As most US homes have central HVAC systems, the simulation results will be used to make appropriate recommendations and adjustments for distribution and mixing to residential ventilation standards such as ASHRAE Standard 62.2.This paper will report on work being done to model multizone airflow systems that are unsteady and elaborate the concept of distribution matrix. It will examine several metrics for evaluating the effect of air distribution on exposure to pollutants, based on previous work by Sherman et al. (2006).

  3. Effects of ultraviolet (UV) irradiation in air and under vacuum on low-k dielectrics

    NASA Astrophysics Data System (ADS)

    Choudhury, F. A.; Ryan, E. T.; Nguyen, H. M.; Nishi, Y.; Shohet, J. L.

    2016-07-01

    This work addresses the effect of ultraviolet radiation of wavelengths longer than 250 nm on Si-CH3 bonds in porous low-k dielectrics. Porous low-k films (k = 2.3) were exposed to 4.9 eV (254 nm) ultraviolet (UV) radiation in both air and vacuum for one hour. Using Fourier Transform Infrared (FTIR) spectroscopy, the chemical structures of the dielectric films were analyzed before and after the UV exposure. UV irradiation in air led to Si-CH3 bond depletion in the low-k material and made the films hydrophilic. However, no change in Si-CH3 bond concentration was observed when the same samples were exposed to UV under vacuum with a similar fluence. These results indicate that UV exposures in vacuum with wavelengths longer than ˜250 nm do not result in Si-CH3 depletion in low-k films. However, if the irradiation takes place in air, the UV irradiation removes Si-CH3 although direct photolysis of air species does not occur above ˜242nm. We propose that photons along with molecular oxygen and, water, synergistically demethylate the low-k films.

  4. Effect of green roofs on air temperature; measurement study of well-watered and dry conditions

    NASA Astrophysics Data System (ADS)

    Solcerova, Anna; van de Ven, Frans; Wang, Mengyu; van de Giesen, Nick

    2016-04-01

    Rapid urbanization and increasing number and duration of heat waves poses a need for understanding urban climate and ways to mitigate extremely high temperatures. One of repeatedly suggested and often investigated methods to moderate the so called urban heat island are green roofs. This study investigates several extensive green roofs in Utrecht (NL) and their effect on air temperature right above the roof surface. Air temperature was measured 15 and 30 cm above the roof surface and also in the substrate. We show that under normal condition is air above green roof, compared to white gravel roof, colder at night and warmer during day. This suggest that green roofs might help decrease air temperatures at night, when the urban heat island is strongest, but possibly contribute to high temperatures during daytime. We also measured situation when the green roofs wilted and dried out. Under such conditions green roof exhibits more similar behavior to conventional white gravel roof. Interestingly, pattern of soil temperature remains almost the same for both dry and well-prospering green roof, colder during day and warmer at night. As such, green roof works as a buffer of diurnal temperature changes.

  5. Blood volume changes. [weightlessness effects

    NASA Technical Reports Server (NTRS)

    Johnson, P. C.; Driscoll, T. B.; Leblance, A. D.

    1974-01-01

    Analysis of radionuclide volume determinations made for the crewmembers of selected Gemini and Apollo missions showed that orbital spaceflight has an effect on red cell mass. Because the methods and the protocol developed for earlier flights were used for the crews of the three Skylab missions, direct comparisons are possible. After each Skylab mission, decreases were found in crewmembers' red cell masses. The mean red cell mass decrease of 11 percent or 232 milliliters was approximately equal to the 10 percent mean red cell mass decrease of the Apollo 14 to 17 crewmembers. The red cell mass drop was greatest and the postrecovery reticulocyte response least for crewmembers of the 28-day Skylab 2 mission. Analyses of data from the red cell mass determinations indicate that the red cell mass drops occurred in the first 30 days of flight and that a gradual recovery of the red cell mass deficits began approximately 60 days after launch. The beginning of red cell mass regeneration during the Skylab 4 flight may explain the higher postmission reticulocyte counts.

  6. Changes in air quality and tropospheric composition due to depletion of stratospheric ozone and interactions with climate.

    PubMed

    Tang, X; Wilson, S R; Solomon, K R; Shao, M; Madronich, S

    2011-02-01

    Air pollution will be directly influenced by future changes in emissions of pollutants, climate, and stratospheric ozone, and will have significant consequences for human health and the environment. UV radiation is one of the controlling factors for the formation of photochemical smog, which includes tropospheric ozone (O(3)) and aerosols; it also initiates the production of hydroxyl radicals (˙OH), which control the amount of many climate- and ozone-relevant gases (e.g., methane and HCFCs) in the atmosphere. Numerical models predict that future changes in UV radiation and climate will modify the trends and geographic distribution of ˙OH, thus affecting the formation of photochemical smog in many urban and regional areas. Concentrations of ˙OH are predicted to decrease globally by an average of 20% by 2100, with local concentrations varying by as much as a factor of two above and below current values. However, significant differences between modelled and measured values in a limited number of case studies show that chemistry of hydroxyl radicals in the atmosphere is not fully understood. Photochemically produced tropospheric ozone is projected to increase. If emissions of anthropogenic air pollutants from combustion of fossil fuels, burning of biomass, and agricultural activities continue to increase, concentrations of tropospheric O(3) will tend to increase over the next 20-40 years in certain regions of low and middle latitudes because of interactions of emissions, chemical processes, and climate change. Climate-driven increases in temperature and humidity will also increase production of tropospheric O(3) in polluted regions, but reduce it in more pristine regions. Higher temperatures tend to increase emissions of nitrogen oxides (NO(x)) from some soils and release of biogenic volatile organic compounds (VOCs) from vegetation, leading to greater background concentrations of ozone in the troposphere. The net effects of future changes in UV radiation

  7. Future Tree Effects on Air Quality and Human Health in the United States

    NASA Astrophysics Data System (ADS)

    Hirabayashi, S.; Nowak, D.

    2014-12-01

    Trees are critical green infrastructure for mitigating adverse effects associated with human population, land use, and climate change (e.g. urban heat island, greenhouse gasses, air pollution, and floods). i-Tree (www.itreetools.org) is a suite of software tools developed by the USDA Forest Service and The Davey Institute that allows users to assess urban forest structure and the ecosystem services provided. Using i-Tree, the annual effects of trees on air quality and human health in urban and rural areas of counties across the conterminous United States have been quantified for 2010 (Nowak et al. 2014). Here, we extended the study to incorporate future forest structure scenarios using a model that accounts for tree growth, mortality and new plantings. Computer simulations using local environmental data and the possible leaf area index (LAI) for deciduous or evergreen tree covers were performed in urban and rural areas of counties across the conterminous United States. The result is a tree effects database on air pollutant removal (CO, NO2, O3, PM10, PM2.5 and SO2), biogenic emission of volatile organic compounds (VOCs), and monetary values associated with human health quantified per unit tree cover area with deciduous or evergreen trees and LAI ranging from 0 to 18 within each modeling domain. With these data, the potential annual effects that trees have on air quality and human health under future scenarios of urban forest extent can be readily derived for anywhere in the conterminous United States. The developed database will be integrated into i-Tree's suite in 2015 to enhance its functionality in estimating tree effects under the future scenarios.

  8. Thresholds in conservation effectiveness under climate change

    NASA Astrophysics Data System (ADS)

    Hansen, A.; Phillips, L.

    2007-12-01

    We describe a new approach to conservation that derives from the effect of energy on ecosystem properties and then evaluate potential threshold responses of conservation effectiveness under climate change. Many tests of species energy theory provide evidence that species richness varies with measures of energy such as net primary productivity (NPP). Across continents, this relationship is most often unimodal, with species richness peaking in intermediate energy places and decreasing at higher NPP levels. NPP also influences ecosystem response to habitat fragmentation, recovery after disturbance, and trophic relationships. We have developed a topology for conservation whereby conservation priorities and management effectiveness differ among low, intermediate, and high energy ecosystems. We evaluated the projected change in NPP and conservation topology of ecoregions under future climate change scenarios. We found that projected NPP under climate change caused a subset of ecoregions to shift across the peak of the unimodal species energy curve, suggesting dramatic changes in conservation effectiveness are possible.

  9. Stratospheric ozone changes under solar geoengineering: implications for UV exposure and air quality

    NASA Astrophysics Data System (ADS)

    Nowack, Peer Johannes; Abraham, Nathan Luke; Braesicke, Peter; Pyle, John Adrian

    2016-03-01

    Various forms of geoengineering have been proposed to counter anthropogenic climate change. Methods which aim to modify the Earth's energy balance by reducing insolation are often subsumed under the term solar radiation management (SRM). Here, we present results of a standard SRM modelling experiment in which the incoming solar irradiance is reduced to offset the global mean warming induced by a quadrupling of atmospheric carbon dioxide. For the first time in an atmosphere-ocean coupled climate model, we include atmospheric composition feedbacks for this experiment. While the SRM scheme considered here could offset greenhouse gas induced global mean surface warming, it leads to important changes in atmospheric composition. We find large stratospheric ozone increases that induce significant reductions in surface UV-B irradiance, which would have implications for vitamin D production. In addition, the higher stratospheric ozone levels lead to decreased ozone photolysis in the troposphere. In combination with lower atmospheric specific humidity under SRM, this results in overall surface ozone concentration increases in the idealized G1 experiment. Both UV-B and surface ozone changes are important for human health. We therefore highlight that both stratospheric and tropospheric ozone changes must be considered in the assessment of any SRM scheme, due to their important roles in regulating UV exposure and air quality.

  10. Statistical Variability and Persistence Change in Daily Air Temperature Time Series from High Latitude Arctic Stations

    NASA Astrophysics Data System (ADS)

    Suteanu, Cristian

    2015-07-01

    In the last decades, Arctic communities have been reporting that weather conditions are becoming less predictable. Most scientific studies have not been able to consistently confirm such a trend. The question regarding the possible increase in weather variability was addressed here based on daily minimum and maximum surface air temperature time series from 15 high latitude Arctic stations from Canada, Norway, and the Russian Federation. A range of analysis methods were applied, distinguished mainly by the way in which they treat time scale. Statistical L-moments were determined for temporal windows of different lengths. While the picture provided by L-scale and L-kurtosis is not consistent with an increasing variability, L-skewness was found to change towards more positive values, reflecting an enhancement of warm spells. Haar wavelet analysis was applied both to the entire time series and to running windows. Persistence diagrams were generated based on running windows advancing through time and on local slopes of Haar analysis graphs; they offer a more nuanced view on variability by reflecting its change over time on a range of temporal scales. Local increases in variability could be identified in some cases, but no consistent change was detected in any of the stations over the studied temporal scales. The possibility for other intervals of temporal scale (e.g., days, hours, minutes) to potentially reveal a different situation cannot be ruled out. However, in the light of the results presented here, explanations for the discrepancy between variability perception and results of pattern analysis might have to be explored using an integrative approach to weather variables such as air temperature, cloud cover, precipitation, wind, etc.

  11. Passenger aircraft cabin air quality: trends, effects, societal costs, proposals.

    PubMed

    Hocking, M B

    2000-08-01

    As aircraft operators have sought to substantially reduce propulsion fuel cost by flying at higher altitudes, the energy cost of providing adequate outside air for ventilation has increased. This has lead to a significant decrease in the amount of outside air provided to the passenger cabin, partly compensated for by recirculation of filtered cabin air. The purpose of this review paper is to assemble the available measured air quality data and some calculated estimates of the air quality for aircraft passenger cabins to highlight the trend of the last 25 years. The influence of filter efficiencies on air quality, and a few medically documented and anecdotal cases of illness transmission aboard aircraft are discussed. Cost information has been collected from the perspective of both the airlines and passengers. Suggestions for air quality improvement are given which should help to result in a net, multistakeholder savings and improved passenger comfort.

  12. Some Effects of Air Flow on the Penetration and Distribution of Oil Sprays

    NASA Technical Reports Server (NTRS)

    Rothrock, A M; Beardsley, E G

    1929-01-01

    Tests were made to determine the effects of air flow on the characteristics of fuel sprays from fuel injection valves. Curves and photographs are presented showing the airflow throughout the chamber and the effects of the air flow on the fuel spray characteristics. It was found that the moving air had little effect on the spray penetration except with the 0.006 inch orifice. The moving air did, however, affect the oil particles on the outside of the spray cone. After spray cut-off, the air flow rapidly distributed the atomized fuel throughout the spray chamber.

  13. Cold air performance of a 12.766-centimeter-tip-diameter axial-flow cooled turbine. 2: Effect of air ejection on turbine performance

    NASA Technical Reports Server (NTRS)

    Haas, J. E.; Kofskey, M. G.

    1977-01-01

    An air cooled version of a single-stage, axial-flow turbine was investigated to determine aerodynamic performance with and without air ejection from the stator and rotor blades surfaces to simulate the effect of cooling air discharge. Air ejection rate was varied from 0 to 10 percent of turbine mass flow for both the stator and the rotor. A primary-to-air ejection temperature ratio of about 1 was maintained.

  14. Volcanic gas emissions and their effect on ambient air character

    SciTech Connect

    Sutton, A.J.; Elias, T.

    1994-01-01

    This bibliography was assembled to service an agreement between Department of Energy and the USGS to provide a body of references and useful annotations for understanding background gas emissions from Kilauea volcano. The current East Rift Zone (ERZ) eruption of Kilauea releases as much as 500,000 metric tonnes of SO{sub 2} annually, along with lesser amounts of other chemically and radiatively active species including H{sub 2}S, HCl, and HF. Primary degassing locations on Kilauea are located in the summit caldera and along the middle ERZ. The effects of these emissions on ambient air character are a complex function of chemical reactivity, source geometry and effusivity, and local meteorology. Because of this complexity, we organized the bibliography into three main sections: (1) characterizing gases as they leave the edifice; (2) characterizing gases and chemical reaction products away from degassing sources; and (3) Hawaii Island meteorology.

  15. Short-term effects of daily air pollution on mortality

    NASA Astrophysics Data System (ADS)

    Wan Mahiyuddin, Wan Rozita; Sahani, Mazrura; Aripin, Rasimah; Latif, Mohd Talib; Thach, Thuan-Quoc; Wong, Chit-Ming

    2013-02-01

    The daily variations of air pollutants in the Klang Valley, Malaysia, which includes Kuala Lumpur were investigated for its association with mortality counts using time series analysis. This study located in the tropic with much less seasonal variation than typically seen in more temperate climates. Data on daily mortality for the Klang Valley (2000-2006), daily mean concentrations of air pollutants of PM10, SO2, CO, NO2, O3, daily maximum O3 and meteorological conditions were obtained from Malaysian Department of Environment. We examined the association between pollutants and daily mortality using Poisson regression while controlling for time trends and meteorological factors. Effects of the pollutants (Relative Risk, RR) on current-day (lag 0) mortality to seven previous days (lag 7) and the effects of the pollutants from the first two days (lag 01) to the first eight days (lag 07) were determined. We found significant associations in the single-pollutant model for PM10 and the daily mean O3 with natural mortality. For the daily mean O3, the highest association was at lag 05 (RR = 1.0215, 95% CI = 1.0013-1.0202). CO was found not significantly associated with natural mortality, however the RR's of CO were found to be consistently higher than PM10. In spite of significant results of PM10, the magnitude of RR's of PM10 was not important for natural mortality in comparison with either daily mean O3 or CO. There is an association between daily mean O3 and natural mortality in a two-pollutants model after adjusting for PM10. Most pollutants except SO2, were significantly associated with respiratory mortality in a single pollutant model. Daily mean O3 is also important for respiratory mortality, with over 10% of mortality associated with every IQR increased. These findings are noteworthy because seasonal confounding is unlikely in this relatively stable climate, by contrast with more temperate regions.

  16. Energy and air emission effects of water supply.

    PubMed

    Stokes, Jennifer R; Horvath, Arpad

    2009-04-15

    Life-cycle air emission effects of supplying water are explored using a hybrid life-cycle assessment For the typically sized U.S. utility analyzed, recycled water is preferable to desalination and comparable to importation. Seawater desalination has an energy and air emission footprint that is 1.5-2.4 times larger than that of imported water. However, some desalination modes fare better; brackish groundwater is 53-66% as environmentally intensive as seawater desalination. The annual water needs (326 m3) of a typical Californian that is met with imported water requires 5.8 GJ of energy and creates 360 kg of CO2 equivalent emissions. With seawater desalination, energy use would increase to 14 GJ and 800 kg of CO2 equivalent emissions. Meeting the water demand of California with desalination would consume 52% of the state's electricity. Supply options were reassessed using alternative electricity mixes, including the average mix of the United States and several renewable sources. Desalination using solar thermal energy has lower greenhouse gas emissions than that of imported and recycled water (using California's electricity mix), but using the U.S. mix increases the environmental footprint by 1.5 times. A comparison with a more energy-intensive international scenario shows that CO2 equivalent emissions for desalination in Dubai are 1.6 times larger than in California. The methods, decision support tool (WEST), and results of this study should persuade decision makers to make informed water policy choices by including energy consumption and material use effects in the decision-making process.

  17. A numerical investigation of the effects of dry air aloft on deep convection

    NASA Astrophysics Data System (ADS)

    James, Richard P.

    A high-resolution numerical model was used to investigate the direct effects of dry air above cloud base in the environment of convective storms. Simulations of both quasi-linear convective systems and supercells were performed in which the relative humidity in a midlevel dry layer was varied while preserving the buoyancy profile and CAPE. The presence of dry air caused a reduction in overall storm intensity, as measured by updraft mass flux, total condensation and total rainfall; the reduction was more dramatic at lower values of CAPE. In high-CAPE line-type simulations, the downdraft mass flux and cold pool strength were enhanced at the rear of the trailing stratiform region in a drier environment. However, the downdraft and cold pool strengths were unchanged in the convective region, and were also unchanged or reduced in simulations of supercells and of line-type systems at lower CAPE. The effects of dry air aloft are interpreted in terms of the reduction in the rate of updraft entrainment when dry air is present, leading to decreased mass flux and a lower rate of condensate production. Smaller hydrometeor mixing ratios then exert a negative influence on the latent cooling rates associated with phase changes in the downdraft formation regions. This effect offsets the enhancement of rain evaporation that is expected to occur in a drier environment and thereby prevents the strengthening of downdrafts and low-level outflow. The modeling results reported here are inconsistent with the widespread notion that dry air aloft is favorable for stronger downdrafts and greater low-level outflow intensity. A review of the literature is presented in which it is shown that observational evidence does not unambiguously support the necessity of dry air aloft for strong downdrafts and outflow. The relative importance of environmental humidity, temperature and stability are examined, and it is shown that some observational studies may have overemphasized the role of environmental

  18. Ancillary human health benefits of improved air quality resulting from climate change mitigation

    PubMed Central

    Bell, Michelle L; Davis, Devra L; Cifuentes, Luis A; Krupnick, Alan J; Morgenstern, Richard D; Thurston, George D

    2008-01-01

    Background Greenhouse gas (GHG) mitigation policies can provide ancillary benefits in terms of short-term improvements in air quality and associated health benefits. Several studies have analyzed the ancillary impacts of GHG policies for a variety of locations, pollutants, and policies. In this paper we review the existing evidence on ancillary health benefits relating to air pollution from various GHG strategies and provide a framework for such analysis. Methods We evaluate techniques used in different stages of such research for estimation of: (1) changes in air pollutant concentrations; (2) avoided adverse health endpoints; and (3) economic valuation of health consequences. The limitations and merits of various methods are examined. Finally, we conclude with recommendations for ancillary benefits analysis and related research gaps in the relevant disciplines. Results We found that to date most assessments have focused their analysis more heavily on one aspect of the framework (e.g., economic analysis). While a wide range of methods was applied to various policies and regions, results from multiple studies provide strong evidence that the short-term public health and economic benefits of ancillary benefits related to GHG mitigation strategies are substantial. Further, results of these analyses are likely to be underestimates because there are a number of important unquantified health and economic endpoints. Conclusion Remaining challenges include integrating the understanding of the relative toxicity of particulate matter by components or sources, developing better estimates of public health and environmental impacts on selected sub-populations, and devising new methods for evaluating heretofore unquantified and non-monetized benefits. PMID:18671873

  19. Effects of business-as-usual anthropogenic emissions on air quality

    NASA Astrophysics Data System (ADS)

    Pozzer, A.; Zimmermann, P.; Doering, U. M.; van Aardenne, J.; Tost, H.; Dentener, F.; Janssens-Maenhout, G.; Lelieveld, J.

    2012-08-01

    The atmospheric chemistry general circulation model EMAC has been used to estimate the impact of anthropogenic emission changes on global and regional air quality in recent and future years (2005, 2010, 2025 and 2050). The emission scenario assumes that population and economic growth largely determine energy and food consumption and consequent pollution sources with the current technologies ("business as usual"). This scenario is chosen to show the effects of not implementing legislation to prevent additional climate change and growing air pollution, other than what is in place for the base year 2005, representing a pessimistic (but plausible) future. By comparing with recent observations, it is shown that the model reproduces the main features of regional air pollution distributions though with some imprecisions inherent to the coarse horizontal resolution (~100 km) and simplified bottom-up emission input. To identify possible future hot spots of poor air quality, a multi pollutant index (MPI), suited for global model output, has been applied. It appears that East and South Asia and the Middle East represent such hotspots due to very high pollutant concentrations, while a general increase of MPIs is observed in all populated regions in the Northern Hemisphere. In East Asia a range of pollutant gases and fine particulate matter (PM2.5) is projected to reach very high levels from 2005 onward, while in South Asia air pollution, including ozone, will grow rapidly towards the middle of the century. Around the Persian Gulf, where natural PM2.5 concentrations are already high (desert dust), ozone levels are expected to increase strongly. The population weighted MPI (PW-MPI), which combines demographic and pollutant concentration projections, shows that a rapidly increasing number of people worldwide will experience reduced air quality during the first half of the 21st century. Following this business as usual scenario, it is projected that air quality for the global

  20. Effects of business-as-usual anthropogenic emissions on air quality

    NASA Astrophysics Data System (ADS)

    Pozzer, A.; Zimmermann, P.; Doering, U. M.; van Aardenne, J.; Tost, H.; Dentener, F.; Janssens-Maenhout, G.; Lelieveld, J.

    2012-04-01

    The atmospheric chemistry general circulation model EMAC has been used to estimate the impact of anthropogenic emission changes on global and regional air quality in recent and future years (2005, 2010, 2025 and 2050). The emission scenario assumes that population and economic growth largely determine energy and food consumption and consequent pollution sources with the current technologies ("business as usual"). This scenario is chosen to show the effects of not implementing legislation to prevent additional climate change and growing air pollution, other than what is in place for the base year 2005, representing a pessimistic (but feasible) future. By comparing with recent observations, it is shown that the model reproduces the main features of regional air pollution distributions though with some imprecisions inherent to the coarse horizontal resolution (~100 km) and simplified bottom-up emission input. To identify possible future hot spots of poor air quality, a multi pollutant index (MPI), suited for global model output, has been applied. It appears that East and South Asia and the Middle East represent such hotspots due to very high pollutant concentrations, although a general increase of MPIs is observed in all populated regions in the Northern Hemisphere. In East Asia a range of pollutant gases and fine particulate matter (PM2.5) is projected to reach very high levels from 2005 onward, while in South Asia air pollution, including ozone, will grow rapidly towards the middle of the century. Around the Arabian Gulf, where natural PM2.5 concentrations are already high (desert dust), ozone levels are expected to increase strongly. The per capita MPI (PCMPI), which combines demographic and pollutants concentrations projections, shows that a rapidly increasing number of people worldwide will experience reduced air quality during the first half of the 21st century. Following the business as usual scenario, it is projected that air quality for the global average

  1. FT-IR remote sensing of atmospheric species: Application to global change and air pollution

    SciTech Connect

    Vazquez, G.J.

    1995-12-31

    In this contribution, the author describes two applications of Fourier Transform Infrared Spectroscopy to the monitoring of atmospheric compounds. Firstly, the author reports FTIR solar spectroscopy measurements carried out at ground level at NCAR and on airplanes employing a spectrometer of 0.06 cm{sup -1} resolution. Sample atmospheric spectra and fitting examples are presented for key species relevant to stratospheric chemistry and global change: ozone (O{sub 3}), a chlorofluorocarbon (CF{sub 2}Cl{sub 2}), a greenhouse gas (N{sub 2}O), HCl, NO and HNO{sub 3}. Secondly, the author briefly describes urban air pollution measurements at an intersection with heavy traffic in Tucson, AZ. Two FTIR spectrometers of 1 cm{sup -1} resolution were employed to carry out long-path open-path measurements of the CO/CO{sub 2} ratio and SF{sub 6}. Two FEAT and two LPUV instruments were employed for ancillary measurements of CO, CO{sub 2}, NO, and aromatic hydrocarbons. Measurements of CO at two heights and a comparison of CO/CO{sub 2} ratios obtained by FEAT exhaust emission and FTIR ambient air measurements are reported.

  2. Effect of wind tunnel air velocity on VOC flux rates from CAFO manure and wastewater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind tunnels and flux chambers are often used to estimate volatile organic compound (VOC) emissions from animal feeding operations (AFOs) without regard to air velocity or sweep air flow rates. Laboratory experiments were conducted to evaluate the effect of wind tunnel air velocity on VOC emission ...

  3. Air Pollution and Its Effects on an Individual's Health and Exercise Performance.

    ERIC Educational Resources Information Center

    Singh, A. I. Clifford

    1988-01-01

    Air Pollution is a common environmental stressor affecting the training and competitive performance of athletes, commonly irritating the eyes, nose, and throat. The health and exercise effects of such primary and secondary air pollutants as carbon monoxide, sulfur dioxide, air particulates, ozone, and nitrogen dioxide are discussed. (CB)

  4. THE EFFECTS OF BUILDING FEATURES ON INDOOR AIR AND POLLUTANT MOVEMENTS

    EPA Science Inventory

    The paper discusses full-scale residential building tests to determine the effects of building features on indoor air and pollutant movement. It was found that the activated heating and air-conditioning (HAC) system served as a conductor that enhanced the indoor air movement and ...

  5. Effect of air on energy and rise-time spectra measured by proportional gas counter

    SciTech Connect

    Kawano, T.; Tanaka, M.; Isozumi, S.; Isozumi, Y.; Tosaki, M.; Sugiyama, T.

    2015-03-15

    Air exerts a negative effect on radiation detection using a gas counter because oxygen contained in air has a high electron attachment coefficient and can trap electrons from electron-ion pairs created by ionization from incident radiation in counting gas. This reduces radiation counts. The present study examined the influence of air on energy and rise-time spectra measurements using a proportional gas counter. In addition, a decompression procedure method was proposed to reduce the influence of air and its effectiveness was investigated. For the decompression procedure, the counting gas inside the gas counter was decompressed below atmospheric pressure before radiation detection. For the spectrum measurement, methane as well as various methane and air mixtures were used as the counting gas to determine the effect of air on energy and rise-time spectra. Results showed that the decompression procedure was effective for reducing or eliminating the influence of air on spectra measurement using a proportional gas counter. (authors)

  6. Change of 180 degrees in the direction of a uniform current of air

    NASA Technical Reports Server (NTRS)

    Witoszynski, C

    1926-01-01

    In the construction of aerodynamic tunnels, it is a very important matter to obtain a uniform current of air in the sections where measurements are to be made. The straight type ordinarily used for attaining a uniform current and generally recommended for use, has great defects. If we desire to avoid these defects, it is well to give the canals of the tunnel such a form that the current, after the change of direction of its asymptotes, approximates a uniform and rectilinear movement. But for this, the condition must be met that at no place does the flow exceed the maximum velocity assumed, equal to the velocity in the straight parts of the canal.

  7. Effect of High Air Velocities on the Distribution and Penetration of a Fuel Spray

    NASA Technical Reports Server (NTRS)

    Rothrock, A M

    1931-01-01

    By means of the NACA Spray Photography Equipment high speed moving pictures were taken of the formation and development of fuel sprays from an automatic injection valve. The sprays were injected normal to and counter to air at velocities from 0 to 800 feet per second. The air was at atmosphere temperature and pressure. The results show that high air velocities are an effective means of mixing the fuel spray with the air during injection.

  8. Collaborative Leadership for Promoting Effective School Change.

    ERIC Educational Resources Information Center

    Mullen, Bennat; And Others

    1994-01-01

    When initiating major structural change in schools, collaboration among educators, community members, and business persons is vital. This publication describes the efforts of the Ysleta (Texas) Independent School District, which successfully used collaboration to promote effective school change. Within the district, the Del Valle High School has…

  9. Effects of climate change on croplands

    EPA Science Inventory

    This talk will describe likely changes in temperature and precipitation expected in the northwestern US with global climate change, and their potential impacts on Oregon croplands. The focus will be on the effects of temperature and carbon dioxide on crop productivity, weed cont...

  10. Cardiorespiratory biomarker responses in healthy young adults to drastic air quality changes surrounding the 2008 Beijing Olympics.

    PubMed

    Zhang, Junfeng; Zhu, Tong; Kipen, Howard; Wang, Guangfa; Huang, Wei; Rich, David; Zhu, Ping; Wang, Yuedan; Lu, Shou-En; Ohman-Strickland, Pamela; Diehl, Scott; Hu, Min; Tong, Jian; Gong, Jicheng; Thomas, Duncan

    2013-02-01

    Associations between air pollution and cardiorespiratory mortality and morbidity have been well established, but data to support biologic mechanisms underlying these associations are limited. We designed this study to examine several prominently hypothesized mechanisms by assessing Beijing residents' biologic responses, at the biomarker level, to drastic changes in air quality brought about by unprecedented air pollution control measures implemented during the 2008 Beijing Olympics. To test the hypothesis that changes in air pollution levels are associated with changes in biomarker levels reflecting inflammation, hemostasis, oxidative stress, and autonomic tone, we recruited and retained 125 nonsmoking adults (19 to 33 years old) free of cardiorespiratory and other chronic diseases. Using the combination of a quasi-experimental design and a panel-study approach, we measured biomarkers of autonomic dysfunction (heart rate [HR*] and heart rate variability [HRV]), of systemic inflammation and oxidative stress (plasma C-reactive protein [CRP], fibrinogen, blood cell counts and differentials, and urinary 8-hydroxy-2'-deoxyguanosine [8-OHdG]), of pulmonary inflammation and oxidative stress (fractional exhaled nitric oxide [FeNO], exhaled breath condensate [EBC] pH, EBC nitrate, EBC nitrite, EBC nitrite+nitrate [sum of the concentrations of nitrite and nitrate], and EBC 8-isoprostane), of hemostasis (platelet activation [plasma sCD62P and sCD40L], platelet aggregation, and von Willebrand factor [vWF]), and of blood pressure (systolic blood pressure [SBP] and diastolic blood pressure [DBP]). These biomarkers were measured on each subject twice before, twice during, and twice after the Beijing Olympics. For each subject, repeated measurements were separated by at least one week to avoid potential residual effects from a prior measurement. We measured a large suite of air pollutants (PM2.5 [particulate matter < or = 2.5 microm in aerodynamic diameter] and constituents

  11. Cardiorespiratory biomarker responses in healthy young adults to drastic air quality changes surrounding the 2008 Beijing Olympics.

    PubMed

    Zhang, Junfeng; Zhu, Tong; Kipen, Howard; Wang, Guangfa; Huang, Wei; Rich, David; Zhu, Ping; Wang, Yuedan; Lu, Shou-En; Ohman-Strickland, Pamela; Diehl, Scott; Hu, Min; Tong, Jian; Gong, Jicheng; Thomas, Duncan

    2013-02-01

    Associations between air pollution and cardiorespiratory mortality and morbidity have been well established, but data to support biologic mechanisms underlying these associations are limited. We designed this study to examine several prominently hypothesized mechanisms by assessing Beijing residents' biologic responses, at the biomarker level, to drastic changes in air quality brought about by unprecedented air pollution control measures implemented during the 2008 Beijing Olympics. To test the hypothesis that changes in air pollution levels are associated with changes in biomarker levels reflecting inflammation, hemostasis, oxidative stress, and autonomic tone, we recruited and retained 125 nonsmoking adults (19 to 33 years old) free of cardiorespiratory and other chronic diseases. Using the combination of a quasi-experimental design and a panel-study approach, we measured biomarkers of autonomic dysfunction (heart rate [HR*] and heart rate variability [HRV]), of systemic inflammation and oxidative stress (plasma C-reactive protein [CRP], fibrinogen, blood cell counts and differentials, and urinary 8-hydroxy-2'-deoxyguanosine [8-OHdG]), of pulmonary inflammation and oxidative stress (fractional exhaled nitric oxide [FeNO], exhaled breath condensate [EBC] pH, EBC nitrate, EBC nitrite, EBC nitrite+nitrate [sum of the concentrations of nitrite and nitrate], and EBC 8-isoprostane), of hemostasis (platelet activation [plasma sCD62P and sCD40L], platelet aggregation, and von Willebrand factor [vWF]), and of blood pressure (systolic blood pressure [SBP] and diastolic blood pressure [DBP]). These biomarkers were measured on each subject twice before, twice during, and twice after the Beijing Olympics. For each subject, repeated measurements were separated by at least one week to avoid potential residual effects from a prior measurement. We measured a large suite of air pollutants (PM2.5 [particulate matter < or = 2.5 microm in aerodynamic diameter] and constituents

  12. Cardiorespiratory Biomarker Responses in Healthy Young Adults to Drastic Air Quality Changes Surrounding the 2008 Beijing Olympics

    PubMed Central

    Zhang, Junfeng; Zhu, Tong; Kipen, Howard; Wang, Guangfa; Huang, Wei; Rich, David; Zhu, Ping; Wang, Yuedan; Lu, Shou-En; Ohman-Strickland, Pamela; Diehl, Scott; Hu, Min; Tong, Jian; Gong, Jicheng; Thomas, Duncan

    2014-01-01

    Associations between air pollution and cardiorespiratory mortality and morbidity have been well established, but data to support biologic mechanisms underlying these associations are limited. We designed this study to examine several prominently hypothesized mechanisms by assessing Beijing residents’ biologic responses, at the biomarker level, to drastic changes in air quality brought about by unprecedented air pollution control measures implemented during the 2008 Beijing Olympics. To test the hypothesis that changes in air pollution levels are associated with changes in biomarker levels reflecting inflammation, hemostasis, oxidative stress, and autonomic tone, we recruited and retained 125 nonsmoking adults (19 to 33 years old) free of cardiorespiratory and other chronic diseases. Using the combination of a quasi-experimental design and a panel-study approach, we measured biomarkers of autonomic dysfunction (heart rate [HR*] and heart rate variability [HRV]), of systemic inflammation and oxidative stress (plasma C-reactive protein [CRP], fibrinogen, blood cell counts and differentials, and urinary 8-hydroxy-2′-deoxyguanosine [8-OHdG]), of pulmonary inflammation and oxidative stress (fractional exhaled nitric oxide [FeNO], exhaled breath condensate [EBC] pH, EBC nitrate, EBC nitrite, EBC nitrite+nitrate [sum of the concentrations of nitrite and nitrate], and EBC 8-isoprostane), of hemostasis (platelet activation [plasma sCD62P and sCD40L], platelet aggregation, and von Willebrand factor [vWF]), and of blood pressure (systolic blood pressure [SBP] and diastolic blood pressure [DBP]). These biomarkers were measured on each subject twice before, twice during, and twice after the Beijing Olympics. For each subject, repeated measurements were separated by at least one week to avoid potential residual effects from a prior measurement. We measured a large suite of air pollutants (PM2.5 [particulate matter ≤ 2.5 μm in aerodynamic diameter] and constituents, sulfur

  13. Association between media alerts of air quality index and change of outdoor activity among adult asthma in six states, BRFSS, 2005.

    PubMed

    Wen, Xiao-Jun; Balluz, Lina; Mokdad, Ali

    2009-02-01

    Media alerts of air quality index (AQI) were designed to inform the public the need to avoid harmful air pollution by changing their outdoor activities. The relationship between AQI media alerts and change in outdoor activities among people with asthma is unknown. Our objective is to examine this relationship. Data were analyzed in a cross-sectional study from 33,888 adults, in six states, who responded to the questions in the 2005 Behavioral Risk Factor Surveillance System (BRFSS) about reductions/changes in outdoor activity. The prevalence of change in outdoor activity due to media alerts was 31% among adults with lifetime asthma and 16% without asthma. The prevalence of outdoor activity change increased to 75% among those with lifetime asthma and to 68% without asthma, when the combined the effects of media alerts and individual perception were examined. The odds of activity change based on the media alerts was 2.30 (Adjusted odds ratio [aOR] = 2.16, 95% Confidence interval [CI]: 1.61, 2.90) among those with lifetime asthma and 1.72 (aO R = 1.72, 95% CI: 1.50, 1.98) without asthma, compared to those unaware of media alerts, after adjustment for demographic variables and covariates. This study shows that awareness of media alerts as well as health professional advice may be associated with reported changes in outdoor activities. Therefore, along with consistent efforts to improve the air quality, government agencies, health professionals, and community leaders should implement measures to effectively inform the public about air quality and educate them to take appropriate actions accordingly.

  14. UNINTENDED BENEFITS: LEADERSHIP SKILLS AND BEHAVIORAL CHANGE AMONG GUATEMALAN FIELDWORKERS EMPLOYED IN A LONGITUDINAL HOUSEHOLD AIR POLLUTION STUDY*

    PubMed Central

    KUO, DEVINA; THOMPSON, LISA M.; LEE, AMY; ROMERO, CAROLINA; SMITH, KIRK R.

    2015-01-01

    The RESPIRE and CRECER studies measured the effects of reduced household air pollution (HAP) from wood-fired cookstoves on respiratory health in rural highland Guatemala. This article examines behavior change and leadership skill development in local community members who were hired as fieldworkers to assist with research. Fieldworkers administered household questionnaires, shared functions similar to community health workers, and bridged health resources to communities. A mixed-methods design for data collection (in-depth interviews, focus groups, impact drawings, knowledge questionnaire, and retrospective pre-test) was used. Purposive sampling included 10 fieldworkers and 13 local service providers. Fieldworkers showed an increase in knowledge, positive attitudes, and practices around HAP. They developed new technical, interpersonal, and leadership skills. Fieldworkers played a crucial role in building confianza (trust) with the community, bridging resources, and improving outside researchers’ relationships with locals. Recommendations for future researchers include inclusion of additional training courses and adoption of community participatory approaches. PMID:22192940

  15. Unintended benefits: leadership skills and behavioral change among Guatemalan fieldworkers employed in a longitudinal household air pollution study.

    PubMed

    Kuo, Devina; Thompson, Lisa M; Lee, Amy; Romero, Carolina; Smith, Kirk R

    2010-01-01

    The RESPIRE and CRECER studies measured the effects of reduced household air pollution (HAP) from wood-fired cookstoves on respiratory health in rural highland Guatemala. This article examines behavior change and leadership skill development in local community members who were hired as fieldworkers to assist with research. Fieldworkers administered household questionnaires, shared functions similar to community health workers, and bridged health resources to communities. A mixed-methods design for data collection (in-depth interviews, focus groups, impact drawings, knowledge questionnaire, and retrospective pre-test) was used. Purposive sampling included 10 fieldworkers and 13 local service providers. Fieldworkers showed an increase in knowledge, positive attitudes, and practices around HAP. They developed new technical, interpersonal, and leadership skills. Fieldworkers played a crucial role in building confianza (trust) with the community, bridging resources, and improving outside researchers' relationships with locals. Recommendations for future researchers include inclusion of additional training courses and adoption of community participatory approaches.

  16. ASSESSING HIPPOCAMPAL CHANGES INDICATIVE OF NEUROTOXIC EFFECTS.

    EPA Science Inventory

    Subtle changes in cognitive function are often the earliest indication of neurotoxic effects in humans. The hippocampus is a large forebrain structure subserving specific kinds of information encoding and consolidation in humans and other animals. Because of it laminar structur...

  17. Measuring the impact of energy consumption and air quality indicators on climate change: evidence from the panel of UNFCC classified countries.

    PubMed

    Ozturk, Ilhan

    2015-10-01

    This study examines the relationship between energy consumption, air pollution, and climate change in the panel of six economically diversified countries classified by the United Nations Framework Convention on Climate Change (UNFCC) as industrialized countries and economies in transition nations by using the panel econometric techniques for the period of 1990-2012. The results of pooled least square regression show that both the energy consumption and air quality indicators have a positive and significant relationship with the climate change, i.e., 1 % increase in energy consumption increases greenhouse gas emissions by 0.124 %, carbon dioxide emissions increase by 0.652 %, methane emissions increase by 0.123 %, and nitrous oxide emissions increase greenhouse gas emissions by 0.105 % age points. The results of fixed-effect regression and random-effect regression confirmed the deteriorating impact of air quality indicators on climate change; however, the results failed to show any significant association between energy consumption and climate change when absorbing country-specific shocks and time-variant shocks during the study time period.

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

    NASA Technical Reports Server (NTRS)

    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.

  19. Effect of fireworks on ambient air quality in Malta

    NASA Astrophysics Data System (ADS)

    Camilleri, Renato; Vella, Alfred J.

    2010-11-01

    Religious festivals ( festas) in the densely populated Maltese archipelago (Central Mediterranean) are ubiquitous during summer when 86 of them are celebrated between June and October, each involving the burning of fireworks both in ground and aerial displays over a period of 3 days or longer per festival. We assessed the effect of fireworks on the air quality by comparing PM 10 and its content of Al, Ba, Cu, Sr and Sb which materials are used in pyrotechnic compositions. PM 10 was collected mainly from two sites, one in Malta (an urban background site) and the other in Gozo (a rural site) during July-August 2005 when 59 feasts were celebrated and September-October 2005 when only 11 feasts occurred. For both Malta and Gozo, PM 10 and metal concentration levels measured as weekly means were significantly higher during July-August compared to September-October and there exist strong correlations between PM 10 and total metal content. Additionally, for Malta dust, Al, Ba, Cu and Sr correlated strongly with each other and also with total concentration of all five metals. The same parameters measured in April 2006 in Malta were at levels similar to those found in the previous October. Ba and Sb in dust from the urban background site in Malta during July-August were at comparable or higher concentration than recently reported values in PM 10 from a heavily-trafficked London road and this suggests that these metals are locally not dominated by sources from roadside materials such as break liner wear but more likely by particulate waste from fireworks. Our findings point to the fact that festa firework displays contribute significantly and for a prolonged period every year to airborne dust in Malta where PM 10 is an intractable air quality concern. The presence in this dust of elevated levels of Ba and especially Sb, a possible carcinogen, is of concern to health.

  20. Effectiveness of in situ air sparging for removing NAPL gasoline from a sandy aquifer near Perth, Western Australia.

    PubMed

    Johnston, C D; Rayner, J L; Briegel, D

    2002-11-01

    . Inclusion of air sparging increased the mass extracted by a factor of 1.9 (more for individual petroleum hydrocarbons) over and above that for soil vapour extraction alone for the 30 days of sparging. Air sparging was also effective in removing residual NAPL from below the water table. The mass of petroleum hydrocarbons removed from the site was not reflected in changes to the mass of NAPL in the aquifer. This result is apparently due to lateral inflow of NAPL to the site although evidence of a depleted source of volatilised hydrocarbons suggests the possible development of mass transfer limitations.

  1. Change in strategy of solving psychological tests: evidence of nitrogen narcosis in shallow air-diving.

    PubMed

    Petri, N M

    2003-01-01

    The depths from 10 to 30 m are usually not considered narcotic in scuba air-diving, and evidence of psychomotor disturbances attributable to nitrogen narcosis at these depths is weak and contradictory. 15 experienced male divers were tested in a chamber at 1, 2, 3, and 4 bars over five consecutive days using a battery of computer generated psychological tests-Computerized Reactionmeter Drenovac (CRD-series). Total test solving time, minimal single task solving time, total "ballast" time, and total number of errors were recorded. Nitrogen narcosis effects were evident at all hyperbaric pressures with marked performance differences among subjects. MANOVA revealed significant effects of nitrogen partial pressure for groups of the same variables as follows: total test solving time (p < 0.001), total "ballast" time (p < 0.001), and total number of errors (p = 0.038), but not for minimal single task solving time. ANOVA showed significant effects of pressure only on tests of visual discrimination of signal location (total test solving time: p = 0.012, total "ballast" time: p < 0.001), simple convergent visual orientation (total test solving time: p = 0.012), and convergent thinking (total test solving time: p = 0.002, total number of errors: p = 0.049). The order of the pressure exposures had no influence on subject performance. Impaired psychomotor processing found during air exposures from 2 to 4 bars suggests that nitrogen narcosis at depths usually considered safe from its effects might be a problem in underwater operations that require accuracy, speed, limited time of performance, and complex psychomotor skills.

  2. Strain-induced extinction of hydrogen-air counterflow diffusion flames - Effects of steam, CO2, N2, and O2 additives to air

    NASA Technical Reports Server (NTRS)

    Pellett, G. L.; Northam, G. B.; Wilson, L. G.

    1992-01-01

    A fundamental study was performed using axisymmetric nozzle and tubular opposed jet burners to measure the effects of laminar plug flow and parabolic input velocity profiles on the extinction limits of H2-air counterflow diffusion flames. Extinction limits were quantified by 'flame strength', (average axial air jet velocity) at blowoff of the central flame. The effects of key air contaminants, on the extinction limits, are characterized and analyzed relative to utilization of combustion contaminated vitiated air in high enthalpy supersonic test facilities.

  3. Assessing Resistance to Change During Shifting from Legacy to Open Web-Based Systems in the Air Transport Industry

    NASA Astrophysics Data System (ADS)

    Brewer, Denise

    The air transport industry (ATI) is a dynamic, communal, international, and intercultural environment in which the daily operations of airlines, airports, and service providers are dependent on information technology (IT). Many of the IT legacy systems are more than 30 years old, and current regulations and the globally distributed workplace have brought profound changes to the way the ATI community interacts. The purpose of the study was to identify the areas of resistance to change in the ATI community and the corresponding factors in change management requirements that minimize product development delays and lead to a successful and timely shift from legacy to open web-based systems in upgrading ATI operations. The research questions centered on product development team processes as well as the members' perceived need for acceptance of change. A qualitative case study approach rooted in complexity theory was employed using a single case of an intercultural product development team dispersed globally. Qualitative data gathered from questionnaires were organized using Nvivo software, which coded the words and themes. Once coded, themes emerged identifying the areas of resistance within the product development team. Results of follow-up interviews with team members suggests that intercultural relationship building prior to and during project execution; focus on common team goals; and, development of relationships to enhance interpersonal respect, understanding and overall communication help overcome resistance to change. Positive social change in the form of intercultural group effectiveness evidenced in increased team functioning during major project transitions is likely to result when global managers devote time to cultural understanding.

  4. The effect of pretreatments on air drying characteristics of persimmons

    NASA Astrophysics Data System (ADS)

    Demiray, Engin; Tulek, Yahya

    2016-03-01

    In this study, whole and peeled persimmons were dried in the ranges of 55-75 °C of drying temperature in a hot air dryer. The effect of drying temperature and pretreatments on the drying characteristics was determined. Immersing in a solution of 20 % sucrose resulted in an increase in the drying rate of persimmons. A non-linear regression procedure was used to fit five thin-layer drying models available in the literature to the experimental moisture loss data. The Page and Modified Page models have shown a better fit to the experimental drying data as compared to other models. The effective diffusivity was determined to be 9.237 × 10-10-10.395 × 10-10 m2 s-1 for the blanched persimmons and 7.755 × 10-10-9.631 × 10-10 m2 s-1 for immersed sucrose solution persimmons. The activation energies for diffusion were calculated to be 56.09 kJ mol-1 (for blanched) and 10.28 kJ mol-1 (for immersed sucrose solution).

  5. Air Pollution in Megacities: Sources and Regional/Global Effects

    NASA Astrophysics Data System (ADS)

    Artaxo, P.

    2007-12-01

    Air Pollution in Megacities is increasing significantly in all continents. The socio-economic and health problems are escalating, especially in developing countries. In terms of sources, urban transportation is relevant in most cities, as well as industrial pollution. In Latin American Cities such as Sao Paulo, Mexico City and Santiago, serious governmental efforts are being doing to reduce emissions and effects. Latin America has about 300 cities with population above 300.000 people. In Sao Paulo, the significant increase in the use of ethanol as fuel brings important increase in aldehyde concentrations. In all 3 Megacities, high aerosol concentrations are observed, with clear effects on population health. Large studies on aerosol source apportionment were done in these 3 cities, and detailed results will be presented. Quantification of aerosol sources is a problem, especially in the organic aerosol component that is high in most of Megacities. In Asia and Africa, the problems are similar as in Latin America, and the large emissions from these urban centers are relevant and needs to be taken into account in policies to reduce carbon dioxide emissions.

  6. Urban Climate Effects on Air Pollution and Atmospheric Chemistry

    NASA Astrophysics Data System (ADS)

    Rasoul, Tara; Bloss, William; Pope, Francis

    2016-04-01

    Tropospheric ozone, adversely affects the environment and human health. The presence of chlorine nitrate (ClNO2) in the troposphere can enhance ozone (O3) formation as it undergoes photolysis, releasing chlorine reactive atoms (Cl) and nitrogen dioxide (NO2), both of which enhance tropospheric ozone formation. The importance of new sources of tropospheric ClNO2 via heterogeneous processes has recently been highlighted. This study employed a box model, using the Master Chemical Mechanism (MCM version 3.2) to assess the effect of ClNO2 on air quality in urban areas within the UK. The model updated to include ClNO2 production, photolysis, a comprehensive parameterisation of dinitrogen pentoxide (N2O5) uptake, and ClNO2 production calculated from bulk aerosol composition. The model simulation revealed the presence of ClNO2 enhances the formation of NO2, organic peroxy radical (CH3O2), O3, and hydroxyl radicals (OH) when compared with simulations excluding ClNO2. In addition, the study examined the effect of temperature variation upon ClNO2 formation. The response of ClNO2 to temperature was analysed to identify the underlying drivers, of particular importance when assessing the response of atmospheric chemistry processes under potential future climates.

  7. Effect of VOC emissions from vegetation on urban air quality during hot periods

    NASA Astrophysics Data System (ADS)

    Churkina, Galina; Kuik, Friderike; Bonn, Boris; Lauer, Axel; Grote, Ruediger; Butler, Tim

    2016-04-01

    Programs to plant millions of trees in cities around the world aim at the reduction of summer temperatures, increase of carbon storage, storm water control, and recreational space, as well as at poverty alleviation. These urban greening programs, however, do not take into account how closely human and natural systems are coupled in urban areas. Compared with the surroundings of cities, elevated temperatures together with high anthropogenic emissions of air and water pollutants are quite typical in urban systems. Urban and sub-urban vegetation respond to changes in meteorology and air quality and can react to pollutants. Neglecting this coupling may lead to unforeseen negative effects on air quality resulting from urban greening programs. The potential of emissions of volatile organic compounds (VOC) from vegetation combined with anthropogenic emissions of air pollutants to produce ozone has long been recognized. This ozone formation potential increases under rising temperatures. Here we investigate how emissions of VOC from urban vegetation affect corresponding ground-level ozone and PM10 concentrations in summer and especially during heat wave periods. We use the Weather Research and Forecasting Model with coupled atmospheric chemistry (WRF-CHEM) to quantify these feedbacks in the Berlin-Brandenburg region, Germany during the two summers of 2006 (heat wave) and 2014 (reference period). VOC emissions from vegetation are calculated by MEGAN 2.0 coupled online with WRF-CHEM. Our preliminary results indicate that the contribution of VOCs from vegetation to ozone formation may increase by more than twofold during heat wave periods. We highlight the importance of the vegetation for urban areas in the context of a changing climate and discuss potential tradeoffs of urban greening programs.

  8. Preliminary Evaluation of the Effectiveness of Air Force Advertising.

    ERIC Educational Resources Information Center

    Vitola, Bart M.

    The Airman Enlistment Questionnaire was administered to a sample of non prior service enlistees, 1,667 males and 300 females. Analysis of the responses shows (1)educational opportunity is the strongest motivator for enlisting in the Air Force; (2) there is an indication that Air Force advertising should make different appeals to men and women; and…

  9. Linking Air, Land, and Water Pollution for Effective Environmental Management

    EPA Science Inventory

    Since the passage of the National Environmental Policy Act in 1970, the U.S. Environmental Protection Agency, other federal agencies, and the states have made substantial progress in improving the Nation’s air and water quality. Traditionally, the air, land, and water pollution ...

  10. The effects of air pollution on the health of children

    PubMed Central

    Buka, Irena; Koranteng, Samuel; Osornio-Vargas, Alvaro R

    2006-01-01

    The present article is intended to inform paediatricians about the associations between ambient air pollution and adverse health outcomes in children within the context of current epidemiological evidence. The majority of the current literature pertains to adverse respiratory health outcomes, including asthma, other respiratory symptoms, and deficits in lung function and growth, as well as exposure to ambient levels of criteria air pollutants. In addition to the above, the present article highlights mortality, pregnancy outcomes, vitamin D deficiency and alteration in the immune system of children. Some of the data on the impact of improved air quality on children’s health are provided, including the reduction of air pollution in former East Germany following the reunification of Germany, as well as the reduction in the rates of childhood asthma events during the 1996 Summer Olympics in Atlanta, Georgia, due to a reduction in local motor vehicle traffic. However, there are many other toxic air pollutants that are regularly released into the air. These pollutants, which are not regularly monitored and have not been adequately researched, are also potentially harmful to children. Significant morbidity and mortality is attributed to ambient air pollution, resulting in a significant economic cost to society. As Canada’s cities grow, air pollution issues need to be a priority in order to protect the health of children and support sustainable development for future generations. PMID:19030320

  11. The effects of air pollution on the health of children.

    PubMed

    Buka, Irena; Koranteng, Samuel; Osornio-Vargas, Alvaro R

    2006-10-01

    The present article is intended to inform paediatricians about the associations between ambient air pollution and adverse health outcomes in children within the context of current epidemiological evidence.The majority of the current literature pertains to adverse respiratory health outcomes, including asthma, other respiratory symptoms, and deficits in lung function and growth, as well as exposure to ambient levels of criteria air pollutants. In addition to the above, the present article highlights mortality, pregnancy outcomes, vitamin D deficiency and alteration in the immune system of children.Some of the data on the impact of improved air quality on children's health are provided, including the reduction of air pollution in former East Germany following the reunification of Germany, as well as the reduction in the rates of childhood asthma events during the 1996 Summer Olympics in Atlanta, Georgia, due to a reduction in local motor vehicle traffic. However, there are many other toxic air pollutants that are regularly released into the air. These pollutants, which are not regularly monitored and have not been adequately researched, are also potentially harmful to children.Significant morbidity and mortality is attributed to ambient air pollution, resulting in a significant economic cost to society. As Canada's cities grow, air pollution issues need to be a priority in order to protect the health of children and support sustainable development for future generations. PMID:19030320

  12. Air pollution and blood lipid markers levels: Estimating short and long-term effects on elderly hypertension inpatients complicated with or without type 2 diabetes.

    PubMed

    Xiao, Sanhua; Liu, Ranran; Wei, Youxiu; Feng, Lin; Lv, Xuemin; Tang, Fei

    2016-08-01

    With the development of society and the economy, many Chinese cities are shrouded in pollution haze for much of the year. Scientific studies have