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Sample records for effective urban air

  1. Investigating the urban heat island effect on air quality

    NASA Astrophysics Data System (ADS)

    Loughner, C. P.; Allen, D. J.; Dickerson, R. R.; Pickering, K. E.; Shou, Y.; Zhang, D.

    2009-12-01

    Urbanization impacts meteorology and air quality in and downwind of cities. An urban heat island can increase the temperature in and downwind of cities. An increase in temperature may worsen air quality by increasing the amount of photochemically produced ozone. During an air pollution episode on July 9, 2007, in which 8-hour maximum ozone and 24-hour average PM2.5 concentrations reached 125ppb and 40μg/m3 respectively, the Washington, DC urban heat island propagated downwind over Columbia, MD and then Baltimore, MD further amplifying the temperature in and downwind of Baltimore. With the use of the Weather Research and Forecasting model coupled with an urban canopy model (WRF/UCM) and EPA’s Community Multi-scale Air Quality (CMAQ) model, the air quality is analyzed within the urban heat island. In addition, the interactions between the Chesapeake Bay breeze, the urban heat island, and the air chemistry are analyzed.

  2. Urban air quality

    NASA Astrophysics Data System (ADS)

    Fenger, Jes

    Since 1950 the world population has more than doubled, and the global number of cars has increased by a factor of 10. In the same period the fraction of people living in urban areas has increased by a factor of 4. In year 2000 this will amount to nearly half of the world population. About 20 urban regions will each have populations above 10 million people. Seen over longer periods, pollution in major cities tends to increase during the built up phase, they pass through a maximum and are then again reduced, as abatement strategies are developed. In the industrialised western world urban air pollution is in some respects in the last stage with effectively reduced levels of sulphur dioxide and soot. In recent decades however, the increasing traffic has switched the attention to nitrogen oxides, organic compounds and small particles. In some cities photochemical air pollution is an important urban problem, but in the northern part of Europe it is a large-scale phenomenon, with ozone levels in urban streets being normally lower than in rural areas. Cities in Eastern Europe have been (and in many cases still are) heavily polluted. After the recent political upheaval, followed by a temporary recession and a subsequent introduction of new technologies, the situation appears to improve. However, the rising number of private cars is an emerging problem. In most developing countries the rapid urbanisation has so far resulted in uncontrolled growth and deteriorating environment. Air pollution levels are here still rising on many fronts. Apart from being sources of local air pollution, urban activities are significant contributors to transboundary pollution and to the rising global concentrations of greenhouse gasses. Attempts to solve urban problems by introducing cleaner, more energy-efficient technologies will generally have a beneficial impact on these large-scale problems. Attempts based on city planning with a spreading of the activities, on the other hand, may generate

  3. 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.

  4. Urban air carcinogens and their effects on health

    SciTech Connect

    Lechner, J.F.

    1994-11-01

    Airborne carcinogens may be relevant especially in metropolitan regions with extreme smog as a primary cause of lung cancer. Lung cancer is most common in urban environs and the incidence directly correlates with the size of the city. In addition, several, but not all formal epidemiological studies also suggest a positive correlation between lung cancer incidence and the intensity of air pollution exposure. There is further support for a role of air pollution; as of 1993, 4.4% of all of the bronchogenic adenocarcinoma cancer cases among Mexicans living in industrialized cities are under 40 years of age. It is plausible that chronic inhalation of automobile combustion products, factory emissions, and/or radon is at least partially responsible for the higher incidence of lung cancer exemplified by the never-smoking urban residents. The exceptionally high incidence of lung cancer cases among never-smokers living in highly industrialized Mexican cities offers a unique opportunity to use molecular epidemiology to test whether chronic inhalation of atmospheric pollutants increases the risk for this disease. Overall, the analysis of the genetic alterations in two cancer genes, and possibly the hprt locus should give new insight as to whether the urban never-smokers developed their cancers because of exposure to environmental pollutants.

  5. Effects of air pollution on thermal structure and dispersion in an urban planetary boundary layer

    NASA Technical Reports Server (NTRS)

    Viskanta, R.; Johnson, R. O.; Bergstrom, R. W.

    1977-01-01

    The short-term effects of urbanization and air pollution on the transport processes in the urban planetary boundary layer (PBL) are studied. The investigation makes use of an unsteady two-dimensional transport model which has been developed by Viskanta et al., (1976). The model predicts pollutant concentrations and temperature in the PBL. The potential effects of urbanization and air pollution on the thermal structure in the urban PBL are considered, taking into account the results of numerical simulations modeling the St. Louis, Missouri metropolitan area.

  6. 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)

  7. Secondary effects of urban heat island mitigation measures on air quality

    NASA Astrophysics Data System (ADS)

    Fallmann, Joachim; Forkel, Renate; Emeis, Stefan

    2016-01-01

    This study presents numerical simulations analysing the effect of urban heat island (UHI) mitigation measures on the chemical composition of the urban atmosphere. The mesoscale chemical transport model WRF-Chem is used to investigate the impact of urban greening and highly reflective surfaces on the concentrations of primary (CO, NO) as well as secondary pollutants (O3) inside the urban canopy. In order to account for the sub-grid scale heterogeneity of urban areas, a multi-layer urban canopy model is coupled to WRF-Chem. Using this canopy model at its full extend requires the introduction of several urban land use classes in WRF-Chem. The urban area of Stuttgart serves as a test bed for the modelling of a case scenario of the 2003 European Heat Wave. The selected mitigation measures are able to reduce the urban temperature by about 1 K and the mean ozone concentration by 5-8%. Model results however document also negative secondary effects on urban air quality, which are closely related to a decrease of vertical mixing in the urban boundary layer. An increase of primary pollutants NO and CO by 5-25% can be observed. In addition, highly reflective surfaces can increase peak ozone concentration by up to 12% due to a high intensity of reflected shortwave radiation accelerating photochemical reactions.

  8. 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.

  9. Analysis of surface air temperature variations and local urbanization effects on central Yunnan Plateau, SW China

    NASA Astrophysics Data System (ADS)

    He, Yunling; Wu, Zhijie; Liu, Xuelian; Deng, Fuying

    2016-10-01

    With the surface air temperature (SAT) data at 37 stations on Central Yunnan Plateau (CYP) for 1961-2010 and the Defense Meteorological Satellite Program/Operational Linescan System (DMSP/OLS) nighttime light data, the temporal-spatial patterns of the SAT trends are detected using Sen's Nonparametric Estimator of Slope approach and MK test, and the impact of urbanization on surface warming is analyzed by comparing the differences between the air temperature change trends of urban stations and their corresponding rural stations. Results indicated that annual mean air temperature showed a significant warming trend, which is equivalent to a rate of 0.17 °C/decade during the past 50 years. Seasonal mean air temperature presents a rising trend, and the trend was more significant in winter (0.31 °C/decade) than in other seasons. Annual/seasonal mean air temperature tends to increase in most areas, and higher warming trend appeared in urban areas, notably in Kunming city. The regional mean air temperature series was significantly impacted by urban warming, and the urbanization-induced warming contributed to approximately 32.3-62.9 % of the total regional warming during the past 50 years. Meantime, the urbanization-induced warming trend in winter and spring was more significant than that in summer and autumn. Since 1985, the urban heat island (UHI) intensity has gradually increased. And the urban temperatures always rise faster than rural temperatures on the CYP.

  10. The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS): Study Design and Methods

    EPA Science Inventory

    The Near-road EXposures and effects of urban air pollutants Study (NEXUS) was designed to examine the relationship between near-roadway exposures to air pollutants and respiratory outcomes in a cohort of asthmatic children who live close to major roadways in Detroit, Michigan USA...

  11. Systemic effects of urban form on air pollution and environmental quality

    SciTech Connect

    Okamoto, P.C.

    1997-12-31

    The form and design of cities and towns have a direct impact on the quality of the natural environment, particularly air and water quality. This paper illustrates some of the dynamic relationships between the form of urban environments and air and water pollution. Recent research suggests how urban form affects environmental quality in at least three ways: (a) how suburban development and its dependency on the private motor vehicle increases air pollution, (b) how exterior building materials help to generate urban heat islands and ozone precursors, and (c) how conventional stormwater drainage systems transport polluted urban runoff into waterways. Today`s aging urban infrastructure provides an important and timely opportunity to re-examine the design of cities and towns with a goal of enhancing overall environmental quality. Many miles of roads, freeways, bridges, and stormwater culverts and pipes are in poor condition and need to be repaired or replaced, while many cities are now failing to meet air and water quality standards designed to protect human and environmental health. This paper also explores seven urban planning and design concepts that could reduce the magnitude of air and water pollution in urban environments and help to improve the health of both cities and their residents.

  12. Effects of prenatal community violence and ambient air pollution on childhood wheeze in an urban population

    PubMed Central

    Mathilda Chiu, Yueh-Hsiu; Coull, Brent A.; Sternthal, Michelle J.; Kloog, Itai; Schwartz, Joel; Cohen, Sheldon; Wright, Rosalind J.

    2013-01-01

    Background: Prenatal exposures to stress and physical toxins influence children’s respiratory health, albeit few studies consider these factors together. Objectives: To concurrently examine effects of prenatal community-level psychosocial (exposure to community violence, ECV) and physical (air pollution) stressors on repeated wheeze in 708 urban children followed to age 2 years. Methods: Multi-item ECV reported by mothers in pregnancy was summarized into a continuous score using Rasch modeling. Prenatal black carbon (BC) exposure was estimated using land-use regression (LUR) modeling; particulate matter (PM2.5) was estimated using LUR incorporating satellite data. Mothers reported child’s wheeze every 3 months. Effects of ECV and air pollutants on repeated wheeze (≥2 episodes) were examined using logistic regression. Interactions between ECV and pollutants were examined. Results: Mothers were primarily Black (29%) and Hispanic (55%) with lower education (62% with ≤12 years); 87 children (12%) wheezed repeatedly. In models examining concurrent exposures, ECV [OR=1.95 (95% CI: 1.13-3.36), highest vs. lowest tertile] and BC [OR=1.84 (95% CI: 1.08-3.12), ≥median vs. air pollution levels was suggested. Conclusions: These findings suggest that both prenatal community violence and air pollution may contribute to respiratory health in these urban children. Moreover, place-based psychosocial stressors may impact host resistance such that physical pollutants may have adverse effects, even at relatively lower levels. PMID:24200349

  13. Biomonitoring of genotoxic effects and elemental accumulation derived from air pollution in community urban gardens.

    PubMed

    Amato-Lourenco, Luís Fernando; Lobo, Debora Jã A; Guimarães, Eliane T; Moreira, Tiana Carla Lopes; Carvalho-Oliveira, Regiani; Saiki, Mitiko; Saldiva, Paulo Hilário Nascimento; Mauad, Thais

    2017-01-01

    Urban gardening is a growing global phenomenon with a positive impact on society. Despite several associated benefits, growing vegetables in urban gardens that are localized in highly polluted areas poses questions about the safety of the produced food. Therefore, the identification of risk factors that result in possible deleterious effects to human health is important for realizing all of the benefits to society. We evaluated the use of two biomonitoring methods in ten urban gardens of Sao Paulo city and one control site: the micronuclei frequencies for early tetrads of Tradescantia pallida (Rose) Hunt. cv. "Purpurea" Boom (hereafter, Trad-MCN) as a short-term indicator of genotoxic response and tree barks to quantify the accumulation of traffic-related chemical elements as a long-term biomarker of air pollution in urban gardens. Mature plants of Tradescantia pallida were exposed in each garden, and their inflorescences were sampled over three months. A random set of 300 early tetrads in 13 to 21 slides per garden were evaluated for micronuclei frequencies. Elemental concentrations in 428 tree barks samples from 107 different trees in the areas surrounding urban gardens were quantified using an energy dispersive X-ray fluorescence spectrometer. The frequency of Trad-MCN has a significant correlation with traffic variables and chemical elements related to road dust and tailpipe emissions deposited in tree barks. Negative associations between Trad-MCN and both the distance through traffic and the presence of vertical obstacles were observed in the community gardens. The Mn/Zn concentrations in tree barks were associated with increased Trad-MCN.

  14. CFD modelling of the aerodynamic effect of trees on urban air pollution dispersion.

    PubMed

    Amorim, J H; Rodrigues, V; Tavares, R; Valente, J; Borrego, C

    2013-09-01

    The current work evaluates the impact of urban trees over the dispersion of carbon monoxide (CO) emitted by road traffic, due to the induced modification of the wind flow characteristics. With this purpose, the standard flow equations with a kε closure for turbulence were extended with the capability to account for the aerodynamic effect of trees over the wind field. Two CFD models were used for testing this numerical approach. Air quality simulations were conducted for two periods of 31h in selected areas of Lisbon and Aveiro, in Portugal, for distinct relative wind directions: approximately 45° and nearly parallel to the main avenue, respectively. The statistical evaluation of modelling performance and uncertainty revealed a significant improvement of results with trees, as shown by the reduction of the NMSE from 0.14 to 0.10 in Lisbon, and from 0.14 to 0.04 in Aveiro, which is independent from the CFD model applied. The consideration of the plant canopy allowed to fulfil the data quality objectives for ambient air quality modelling established by the Directive 2008/50/EC, with an important decrease of the maximum deviation between site measurements and CFD results. In the non-aligned wind situation an average 12% increase of the CO concentrations in the domain was observed as a response to the aerodynamic action of trees over the vertical exchange rates of polluted air with the above roof-level atmosphere; while for the aligned configuration an average 16% decrease was registered due to the enhanced ventilation of the street canyon. These results show that urban air quality can be optimised based on knowledge-based planning of green spaces.

  15. Air Quality Modeling in Support of the Near-road EXposures and effects of Urban air pollutants Study (NEXUS)

    EPA Science Inventory

    The paper presents the results of the model applications to estimate exposure metrics in support of an epidemiologic study in Detroit, Michigan. The Near-road Exposures to Urban air pollutant Study (NEXUS) design includes determining if children in Detroit, MI with asthma living ...

  16. Urban Air Pollution: State of the Science.

    ERIC Educational Resources Information Center

    Seinfeld, John H.

    1989-01-01

    Describes the highly complex mixture of gaseous and particulate matter found in urban air. Explains progress made in the understanding of the physics and chemistry of air pollution, the effects of precursors on ozone, the role of biogenic hydrocarbons, and the principal benefit of methanol-fueled vehicles. (RT)

  17. Minimizing human health effects of urban air pollution through quantification and control of motor vehicular carbon monoxide (CO) in Lahore.

    PubMed

    Aziz, Amer; Bajwa, Ihsan Ullah

    2007-12-01

    Impact of urban air pollution has variety of focuses such as urban ecology, human health, economy, etc. But human health is always given priority. Air pollution is threat to the lives of people living in big cities of Pakistan. In Lahore only there die 1,250 people annually because of air pollution. A strong correlation exists between urban air pollution and human health in Lahore. Growth of COPD is highest among other air pollution borne diseases. Existing mass transit system (one of driving forces behind motor vehicular emission) in Lahore due to frequent stoppages, entering and exit in flow of traffic causes excess discharge of motor vehicular carbon monoxide (CO) which is a hazardous to human health. Quantification and enumeration of this discharge is essential for environmental management. The paper is an attempt to highlight human health effects of urban air pollution through correlation and regression analysis. Further it is focused upon quantifying excess motor vehicular carbon monoxide through application of simplified mobile emission model. In light of results emission control measures are recommended.

  18. Effect of heat waves on VOC emissions from vegetation and urban air quality

    NASA Astrophysics Data System (ADS)

    Churkina, G.; Kuik, F.; Lauer, A.; Bonn, B.; Butler, T. M.

    2015-12-01

    Programs to plant millions of trees in cities around the world aim at the reduction of summer temperatures, increase carbon storage, storm water control, provision of space for recreation, as well as poverty alleviation. Although these multiple benefits speak positively for urban greening programs, the programs do not take into account how close human and natural systems are coupled in urban areas. Elevated temperatures together with anthropogenic emissions of air and water pollutants distinguish the urban system. Urban and sub-urban vegetation responds to ambient changes and reacts with pollutants. Neglecting this coupling may lead to unforeseen drawbacks of urban greening programs. The potential for emissions of volatile organic compounds (VOC) from vegetation combined with anthropogenic emissions to produce ozone has long been recognized. This potential increases under rising temperatures. Here we investigate how heat waves affect emissions of VOC from urban vegetation and corresponding ground-level ozone. In this study we use Weather Research and Forecasting Model with coupled atmospheric chemistry (WRF-CHEM) to quantify these feedbacks in Berlin, Germany during the 2006 heat wave. VOC emissions from vegetation are simulated with MEGAN 2.0 coupled with WRF-CHEM. Our preliminary results indicate that contribution of VOCs from vegetation to ozone formation may increase by more than twofold during the heat wave period. We highlight the importance of the vegetation for urban areas under changing climate and discuss associated tradeoffs.

  19. Effects of Air Pollution on Hospital Emergency Room Visits for Respiratory Diseases: Urban-Suburban Differences in Eastern China.

    PubMed

    Liu, Peng; Wang, Xining; Fan, Jiayin; Xiao, Wenxin; Wang, Yan

    2016-03-19

    A study on the relationships between ambient air pollutants (PM2.5, SO₂ and NO₂) and hospital emergency room visits (ERVs) for respiratory diseases from 2013 to 2014 was performed in both urban and suburban areas of Jinan, a heavily air-polluted city in Eastern China. This research was analyzed using generalized additive models (GAM) with Poisson regression, which controls for long-time trends, the "day of the week" effect and meteorological parameters. An increase of 10 μg/m³ in PM2.5, SO₂ and NO₂ corresponded to a 1.4% (95% confidence interval (CI): 0.7%, 2.1%), 1.2% (95% CI: 0.5%, 1.9%), and 2.5% (95%: 0.8%, 4.2%) growth in ERVs for the urban population, respectively, and a 1.5% (95%: 0.4%, 2.6%), 0.8% (95%: -0.7%, 2.3%), and 3.1% (95%: 0.5%, 5.7%) rise in ERVs for the suburban population, respectively. It was found that females were more susceptible than males to air pollution in the urban area when the analysis was stratified by gender, and the reverse result was seen in the suburban area. Our results suggest that the increase in ERVs for respiratory illnesses is linked to the levels of air pollutants in Jinan, and there may be some urban-suburban discrepancies in health outcomes from air pollutant exposure.

  20. Mechanisms of Air Pollution Transport in Urban Valleys as a Result of the Interplay Between the Temperature Inversion and the Urban Heat Island Effect

    NASA Astrophysics Data System (ADS)

    Rendón, A.; Wirth, V.; Salazar, J. F.; Palacio, C. A.; Brötz, B.

    2014-12-01

    Urban valleys can experience serious air pollution problems of concern for public health. The venting of pollution out of an urban valley is limited by the topography and can be further restricted by low-level temperature inversions and/or local circulations such as those induced by the Urban Heat Island (UHI) effect. The combined effects of a temperature inversion and a UHI on the dynamics of the atmospheric boundary layer and the associated mechanisms of air pollution transport in urban valleys were studied through idealized simulations performed with the EULAG model. Three different aspects were considered: the expansion of the urban area, variations in surface heating owing to topographic shading, and variations of the topography. The results show that different mechanisms of air pollution transport may arise in urban valleys as a result of the interplay between the temperature inversion, the slope flows, and the UHI. Three types of interrelated mechanisms of air pollution transport were identified. Type A describes the transport of pollutants by the slope winds, which can reduce pollution in the lower levels or reinforce the trapping of pollutants below the inversion layer depending on the UHI effect on weakening or reversing the upslope winds. Type B describes closed slope-flow circulations that are likely to occur below an inversion layer near the base of the sidewalls of valleys where an urban area is concentrated on the valley floor. These circulations can develop when upslope winds are detrained toward the center due to the inversion layer, or when the UHI forces downslope winds linked to ascending flows that are also restricted by the inversion layer. Pollutants can remain trapped within these circulation cells that have been termed smog traps. Type C describes a low-level UHI-induced circulation that tends to concentrate pollutants in the valley center and may cause the development of elevated polluted layers below the inversion layer. The persistence

  1. Assessing the environmental effects of urban transit systems: The analysis of air quality effects of selected urban transit systems. Report for July 1993-October 1994

    SciTech Connect

    Dzurik, A.; Husain, D.; Barker, M.; Bryant, B.

    1994-12-01

    The emission rates of air pollutants associated with automobiles, buses, and urban rail mass transit systems were determined in units of grams per passenger mile of travel for the four major urban areas in Florida: Jacksonville, Miami, Tampa, and Orlando. The five criteria pollutants evaluated are: volatile organic compounds (VOCs), particulate matter (PM), carbon monoxide (CO), sulphur oxides (SO2), and nitrogen oxides (NOx).

  2. Effect of increasing urban albedo on meteorology and air quality of Montreal (Canada) - Episodic simulation of heat wave in 2005

    NASA Astrophysics Data System (ADS)

    Touchaei, Ali G.; Akbari, Hashem; Tessum, Christopher W.

    2016-05-01

    Increasing albedo is an effective strategy to mitigate urban air temperature in different climates. Using reflective urban surfaces decreases the air temperature, which potentially reduces the rate of generation of smog. However, for implementing the albedo enhancement, complicated interactions between air, moisture, aerosols, and other gaseous contaminant in the atmosphere should be considered. We used WRF-CHEM to investigate the effect of increasing albedo in Montreal, Canada, during a heat wave period (July 10th through July 12th, 2005) on air quality and urban climate. The reflectivity of roofs, walls, and roads are increased from 0.2 to 0.65, 0.6, and 0.45, respectively. Air temperature at 2-m elevation is decreased during all hours in the simulation period and the maximum reduction is about 1 °C on each day (Tmax is reduced by about 0.7 °C) The concentration of two regulated pollutants -ozone (O3) and fine particulate matters (PM2.5) - is calculated at a height of 5-m above the ground. The maximum decrease in 8-h averaged ozone concentration is about 3% (∼0.2 ppbv). 24-h averaged PM2.5 concentration decreases by 1.8 μg/m3. This relatively small change in concentration of pollutants is related to the decrease in planetary boundary layer height caused by increasing the albedo. Additionally, the combined effect of decreased solar heat gain by building surfaces and decreased air temperature reduces the energy consumption of HVAC systems by 2% (∼0.1 W/m2), which exacerbates the positive effect of the albedo enhancement on the air quality.

  3. Effect of Air Pollution and Rural-Urban Difference on Mental Health of the Elderly in China

    PubMed Central

    TIAN, Tao; CHEN, Yuhuai; ZHU, Jing; LIU, Pengling

    2015-01-01

    Background: China has become an aging society, and the mental health problem of the elderly is increasingly becoming prominent. This paper aimed to analyze the effect of air pollution and rural-urban difference on mental health of the elderly in China. Methods: Using the data from the China Health and Retirement Longitudinal Survey (CHARLS, 2013), after controlling the social demography variable via Tobit and Probit, a regression analysis of the effect of air pollution and rural-urban difference on mental health and psychological disorder was conducted on 6,630 old people (≧60 yr old) of China from February to April 2015. Mental health and psychological disorder of the elderly were measured by the CES-D score of respondents. Air pollution degree of counties and cities (n=123) were measured by SO2 emission. Results: 27.8% of old people had psychological disorders. Air pollution significantly influenced the mental health of the elderly, showing a positive “U-shaped” curve (P<0.001). In China, the urban elderly had better psychological status than the rural elderly had. The female elderly had more serious mental health problems. Marriage, education, and social activities had positive effects on the mental health of the elderly. Conclusion: China’s local governments should consider the influence of air pollution on the mental health of the elderly during economic development. This paper recommends paying attention to the difference in mental health between the urban and rural elderly when making public health policies. Governments could improve the mental health of the elderly by enriching social activities and increasing employment opportunities of the elderly. PMID:26587472

  4. Urban air quality estimation study, phase 1

    NASA Technical Reports Server (NTRS)

    Diamante, J. M.; Englar, T. S., Jr.; Jazwinski, A. H.

    1976-01-01

    Possibilities are explored for applying estimation theory to the analysis, interpretation, and use of air quality measurements in conjunction with simulation models to provide a cost effective method of obtaining reliable air quality estimates for wide urban areas. The physical phenomenology of real atmospheric plumes from elevated localized sources is discussed. A fluctuating plume dispersion model is derived. Individual plume parameter formulations are developed along with associated a priori information. Individual measurement models are developed.

  5. Effects of Air Pollution on Hospital Emergency Room Visits for Respiratory Diseases: Urban-Suburban Differences in Eastern China

    PubMed Central

    Liu, Peng; Wang, Xining; Fan, Jiayin; Xiao, Wenxin; Wang, Yan

    2016-01-01

    A study on the relationships between ambient air pollutants (PM2.5, SO2 and NO2) and hospital emergency room visits (ERVs) for respiratory diseases from 2013 to 2014 was performed in both urban and suburban areas of Jinan, a heavily air-polluted city in Eastern China. This research was analyzed using generalized additive models (GAM) with Poisson regression, which controls for long-time trends, the “day of the week” effect and meteorological parameters. An increase of 10 μg/m3 in PM2.5, SO2 and NO2 corresponded to a 1.4% (95% confidence interval (CI): 0.7%, 2.1%), 1.2% (95% CI: 0.5%, 1.9%), and 2.5% (95%: 0.8%, 4.2%) growth in ERVs for the urban population, respectively, and a 1.5% (95%: 0.4%, 2.6%), 0.8% (95%: −0.7%, 2.3%), and 3.1% (95%: 0.5%, 5.7%) rise in ERVs for the suburban population, respectively. It was found that females were more susceptible than males to air pollution in the urban area when the analysis was stratified by gender, and the reverse result was seen in the suburban area. Our results suggest that the increase in ERVs for respiratory illnesses is linked to the levels of air pollutants in Jinan, and there may be some urban-suburban discrepancies in health outcomes from air pollutant exposure. PMID:27007384

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

    Mansfield, Theodore J; Rodriguez, Daniel A; Huegy, Joseph; Gibson, Jacqueline MacDonald

    2015-05-01

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

  8. Responses of herbaceous plants to urban air pollution: effects on growth, phenology and leaf surface characteristics.

    PubMed

    Honour, Sarah L; Bell, J Nigel B; Ashenden, Trevor W; Cape, J Neil; Power, Sally A

    2009-04-01

    Vehicle exhaust emissions are a dominant feature of urban environments and are widely believed to have detrimental effects on plants. The effects of diesel exhaust emissions on 12 herbaceous species were studied with respect to growth, flower development, leaf senescence and leaf surface wax characteristics. A diesel generator was used to produce concentrations of nitrogen oxides (NO(x)) representative of urban conditions, in solardome chambers. Annual mean NO(x) concentrations ranged from 77 nl l(-l) to 98 nl l(-1), with NO:NO(2) ratios of 1.4-2.2, providing a good experimental simulation of polluted roadside environments. Pollutant exposure resulted in species-specific changes in growth and phenology, with a consistent trend for accelerated senescence and delayed flowering. Leaf surface characteristics were also affected; contact angle measurements indicated changes in surface wax structure following pollutant exposure. The study demonstrated clearly the potential for realistic levels of vehicle exhaust pollution to have direct adverse effects on urban vegetation.

  9. Acute and subacute effects of urban air pollution on cardiopulmonary emergencies and mortality: time series studies in Austrian cities.

    PubMed

    Neuberger, Manfred; Moshammer, Hanns; Rabczenko, Daniel

    2013-10-02

    Daily pollution data (collected in Graz over 16 years and in the Linz over 18 years) were used for time series studies (GAM and case-crossover) on the relationship with daily mortality (overall and specific causes of death). Diagnoses of patients who had been transported to hospitals in Linz were also available on a daily basis from eight years for time series analyses of cardiopulmonary emergencies. Increases in air pollutant levels over several days were followed by increases in mortality and the observed effects increased with the length of the exposure window considered, up to a maximum of 15 days. These mortality changes in Graz and Linz showed similar patterns like the ones found before in Vienna. A significant association of mortality could be demonstrated with NO2, PM2.5 and PM10 even in summer, when concentrations are lower and mainly related to motor traffic. Cardiorespiratory ambulance transports increased with NO2/PM2.5/PM10 by 2.0/6.1/1.7% per 10 µg/m³ on the same day. Monitoring of NO2 (related to motor traffic) and fine particulates at urban background stations predicts acute effects on cardiopulmonary emergencies and extended effects on cardiopulmonary mortality. Both components of urban air pollution are indicators of acute cardiopulmonary health risks, which need to be monitored and reduced, even below current standards.

  10. Acute and Subacute Effects of Urban Air Pollution on Cardiopulmonary Emergencies and Mortality: Time Series Studies in Austrian Cities

    PubMed Central

    Neuberger, Manfred; Moshammer, Hanns; Rabczenko, Daniel

    2013-01-01

    Daily pollution data (collected in Graz over 16 years and in the Linz over 18 years) were used for time series studies (GAM and case-crossover) on the relationship with daily mortality (overall and specific causes of death). Diagnoses of patients who had been transported to hospitals in Linz were also available on a daily basis from eight years for time series analyses of cardiopulmonary emergencies. Increases in air pollutant levels over several days were followed by increases in mortality and the observed effects increased with the length of the exposure window considered, up to a maximum of 15 days. These mortality changes in Graz and Linz showed similar patterns like the ones found before in Vienna. A significant association of mortality could be demonstrated with NO2, PM2.5 and PM10 even in summer, when concentrations are lower and mainly related to motor traffic. Cardiorespiratory ambulance transports increased with NO2/PM2.5/PM10 by 2.0/6.1/1.7% per 10 µg/m3 on the same day. Monitoring of NO2 (related to motor traffic) and fine particulates at urban background stations predicts acute effects on cardiopulmonary emergencies and extended effects on cardiopulmonary mortality. Both components of urban air pollution are indicators of acute cardiopulmonary health risks, which need to be monitored and reduced, even below current standards. PMID:24157504

  11. Urban air pollution and solar energy

    NASA Technical Reports Server (NTRS)

    Gammon, R. B.; Huning, J. R.; Reid, M. S.; Smith, J. H.

    1981-01-01

    The design and performance of solar energy systems for many potential applications (industrial/residential heat, electricity generation by solar concentration and photovoltaics) will be critically affected by local insolation conditions. The effects of urban air pollution are considered and reviewed. A study of insolation data for Alhambra, California (9 km south of Pasadena) shows that, during a recent second-stage photochemical smog alert (greater than or equal to 0.35 ppm ozone), the direct-beam insolation at solar noon was reduced by 40%, and the total global by 15%, from clean air values. Similar effects have been observed in Pasadena, and are attributable primarily to air pollution. Effects due to advecting smog have been detected 200 km away, in the Mojave Desert. Preliminary performance and economic simulations of solar thermal and photovoltaic power systems indicate increasing nonlinear sensitivity of life cycle plant cost to reductions in insolation levels due to pollution.

  12. A modeling study on the effect of urban land surface forcing to regional meteorology and air quality over South China

    NASA Astrophysics Data System (ADS)

    Zhu, Kuanguang; Xie, Min; Wang, Tijian; Cai, Junxiong; Li, Songbing; Feng, Wen

    2017-03-01

    The change of land-use from natural to artificial surface induced by urban expansion can deeply impact the city environment. In this paper, the model WRF/Chem is applied to explore the effect of this change on regional meteorology and air quality over South China, where people have witnessed a rapid rate of urbanization. Two sets of urban maps are adopted to stand for the pre-urbanization and the present urban land-use distributions. Month-long simulations are conducted for January and July, 2014. The results show that urban expansion can obviously change the weather conditions around the big cities of South China. Especially in the Pearl River Delta region (PRD), the urban land-use change can increase the sensible heat flux by 40 W/m2 in January and 80 W/m2 in July, while decrease the latent heat flux about -50 W/m2 in January and -120 W/m2 in July. In the consequent, 2-m air temperature (T2) increases as much as 1 °C and 2 °C (respective to January and July), planetary boundary layer height (PBLH) rises up by 100-150 m and 300 m, 10-m wind speed (WS10) decreases by -1.2 m/s and -0.3 m/s, and 2-m specific humidity is reduced by -0.8 g/kg and -1.5 g/kg. Also, the precipitation in July can be increased as much as 120 mm, with more heavy rains and rainstorms. These variations of meteorological factors can significantly impact the spatial and vertical distribution of air pollutants as well. In PRD, the enhanced updraft can reduce the surface concentrations of PM10 by -40 μg/m3 (30%) in January and -80 μg/m3 (50%) in July, but produce a correlating increase in the concentrations at higher atmospheric layers. However, according to the increase in T2 and the decrease in surface NO, the surface concentrations of O3 in PRD can increase by 2-6 ppb in January and 8-12 ppb in July. Meanwhile, there is a significant increase in the O3 concentrations at upper layers above PRD, which should be attributed to the increase in air temperature and the enhanced upward transport of

  13. Climatic Effects of Urbanization

    NASA Astrophysics Data System (ADS)

    Barzyk, T. M.; Frederick, J. E.

    2005-12-01

    Urban areas around the world have been increasing in size and population density in recent decades. The United Nations reports that in 1900, urbanites comprised 14% of the world's population. This value has increased to 47% in the year 2000, and is expected to grow to 60% by 2030. The goal of this study is to isolate the effects of urbanization on surface radiation balance components and meteorology. Data are recorded from urban and rural locations with a net radiometer and weather station. Instruments record incoming and outgoing solar and thermal radiation, and meteorological variables such as air temperature and pressure, relative humidity and wind speed. Data are incorporated into an energy balance model for urban and natural surfaces to compute heat fluxes due to solar and thermal infrared (longwave) radiation (QSOL and QLW); sensible heat transport (QSENS); evaporation (QEVAP); and conduction (QCONDUC). These fluxes comprise the heating and cooling elements for the different sites. After sunset, the urban surface to air temperature differential (TS - TA) is lower than that in the rural area, and wind speed is decreased due to increased surface roughness, so QSENS is lower. This value decreases even more in an urban canyon environment. Wind speeds in urban canyons are recorded to be up to 15 mph less than regional ones. Urban heat islands are generally assumed to be constant phenomena, existing as much during daytime as at night, but this is not always the case. Rural air temperatures can be greater than or equal to urban ones during the day, which is a reflection of the low specific heats of rural surfaces, but cooling rates are lower in urban areas after sunset, due to their surfaces' high heat capacities, causing these areas to be warmer at night, resulting in the formation of an urban heat island (UHI). UHIs in this respect are cyclical phenomena that occur diurnally. Results show that urban cooling rates can be half as much as rural ones, resulting in

  14. Air Quality Modeling in Support of the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS)

    EPA Science Inventory

    A major challenge in traffic-related air pollution exposure studies is the lack of information regarding pollutant exposure characterization. Air quality modeling can provide spatially and temporally varying exposure estimates for examining relationships between traffic-related a...

  15. The air quality in Danish urban areas.

    PubMed Central

    Jensen, F P; Fenger, J

    1994-01-01

    The Danish air pollution abatement is based by and large on emission control. Since the ratification of the international sulfur protocol of 1985, there has been a continuous tightening of the permissible sulfur content in fuels and of the maximum emissions from power plants. As a consequence, the total annual emission of sulfur dioxide (SO2) has been reduced from 450,000 tons in the seventies to 180,000 tons in 1990. This has had a pronounced effect on the SO2 levels in Danish urban areas. Thus, in Copenhagen, the yearly averages have fallen to about 25%. For nitrogen oxides emitted from the power plants, similar regulations are in force. With this legislation, the most important and crucial source of air pollution in Danish urban areas is road traffic. The contribution of nitrogen oxides from national traffic accounts for nearly half the total Danish emission and is increasing steadily; this is consistent with an observed increase of nitrogen oxides in ambient air. The permissible levels of lead in petrol has been reduced drastically. After an introduction of reduced tax on lead-free petrol, it now accounts for more than two-thirds of the total consumption. As a result, the concentration of lead in urban ambient air has been reduced to less than one-sixth. The introduction of 3-way catalytic converters from October 1990 will result in reductions in the emission of a series of pollutants, e.g., lead, volatile organic compounds, carbon monoxide, and nitrogen oxides. In 1980, a Danish air quality monitoring program was established as a cooperative effort between the authorities, the Government, the countries, the municipalities, and the Greater Copenhagen Council.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7821296

  16. Transport and urban air pollution in India.

    PubMed

    Badami, Madhav G

    2005-08-01

    The rapid growth in motor vehicle activity in India and other rapidly industrializing low-income countries is contributing to high levels of urban air pollution, among other adverse socioeconomic, environmental, health, and welfare impacts. This paper first discusses the local, regional, and global impacts associated with air pollutant emissions resulting from motor vehicle activity, and the technological, behavioral, and institutional factors that have contributed to these emissions, in India. The paper then discusses some implementation issues related to various policy measures that have been undertaken, and the challenges of the policy context. Finally, the paper presents insights and lessons based on the recent Indian experience, for better understanding and more effectively addressing the transport air pollution problem in India and similar countries, in a way that is sensitive to their needs, capabilities, and constraints.

  17. Estimation of the effects of ambient air pollution on life expectancy of urban residents in China

    NASA Astrophysics Data System (ADS)

    Wang, Cuicui; Zhou, Xiaodan; Chen, Renjie; Duan, Xiaoli; Kuang, Xingya; Kan, Haidong

    2013-12-01

    The air quality in China's cities has improved in recent years, but its impact on public health has rarely been investigated. This study was aimed at estimating the potential effects of air quality on life expectancy between 2003 and 2010 in China. We collected annual average concentrations of particulate matter less than 10 microns in aerodynamic diameter (PM10) in 113 key cities, covering all provinces in China, along with the national average age-specific mortality from 2003 to 2010. We constructed a cause-eliminated life table after excluding premature deaths attributable to PM10. The annual average PM10 levels in these cities decreased from 125.3 μg m-3 in 2003 to 88.3 μg m-3 in 2010. As the result, life expectancy loss due to PM10 decreased from 2.13 years in 2003 to 1.30 years in 2010. The estimated life expectancy increase due to PM10 mitigation accounted for 34% of the total increase in life expectancy in the same period. Our results suggested that air quality might have contributed substantially to life expectancy in China.

  18. The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS): study design and methods.

    PubMed

    Vette, Alan; Burke, Janet; Norris, Gary; Landis, Matthew; Batterman, Stuart; Breen, Michael; Isakov, Vlad; Lewis, Toby; Gilmour, M Ian; Kamal, Ali; Hammond, Davyda; Vedantham, Ram; Bereznicki, Sarah; Tian, Nancy; Croghan, Carry

    2013-03-15

    The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) was designed to examine the relationship between near-roadway exposures to air pollutants and respiratory outcomes in a cohort of asthmatic children who live close to major roadways in Detroit, Michigan USA. From September 2010 to December 2012 a total of 139 children with asthma, ages 6-14, were enrolled in the study on the basis of the proximity of their home to major roadways that carried different amounts of diesel traffic. The goal of the study was to investigate the effects of traffic-associated exposures on adverse respiratory outcomes, biomolecular markers of inflammatory and oxidative stress, and how these exposures affect the frequency and severity of respiratory viral infections in a cohort of children with asthma. An integrated measurement and modeling approach was used to quantitatively estimate the contribution of traffic sources to near-roadway air pollution and evaluate predictive models for assessing the impact of near-roadway pollution on children's exposures. Two intensive field campaigns were conducted in Fall 2010 and Spring 2011 to measure a suite of air pollutants including PM2.5 mass and composition, oxides of nitrogen (NO and NO2), carbon monoxide, and black carbon indoors and outdoors of 25 participants' homes, at two area schools, and along a spatial transect adjacent to I-96, a major highway in Detroit. These data were used to evaluate and refine models to estimate air quality and exposures for each child on a daily basis for the health analyses. The study design and methods are described, and selected measurement results from the Fall 2010 field intensive are presented to illustrate the design and successful implementation of the study. These data provide evidence of roadway impacts and exposure variability between study participants that will be further explored for associations with the health measures.

  19. Modeling Spatial and Temporal Variability of Residential Air Exchange Rates for the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS)

    PubMed Central

    Breen, Michael S.; Burke, Janet M.; Batterman, Stuart A.; Vette, Alan F.; Godwin, Christopher; Croghan, Carry W.; Schultz, Bradley D.; Long, Thomas C.

    2014-01-01

    Air pollution health studies often use outdoor concentrations as exposure surrogates. Failure to account for variability of residential infiltration of outdoor pollutants can induce exposure errors and lead to bias and incorrect confidence intervals in health effect estimates. The residential air exchange rate (AER), which is the rate of exchange of indoor air with outdoor air, is an important determinant for house-to-house (spatial) and temporal variations of air pollution infiltration. Our goal was to evaluate and apply mechanistic models to predict AERs for 213 homes in the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS), a cohort study of traffic-related air pollution exposures and respiratory effects in asthmatic children living near major roads in Detroit, Michigan. We used a previously developed model (LBL), which predicts AER from meteorology and questionnaire data on building characteristics related to air leakage, and an extended version of this model (LBLX) that includes natural ventilation from open windows. As a critical and novel aspect of our AER modeling approach, we performed a cross validation, which included both parameter estimation (i.e., model calibration) and model evaluation, based on daily AER measurements from a subset of 24 study homes on five consecutive days during two seasons. The measured AER varied between 0.09 and 3.48 h−1 with a median of 0.64 h−1. For the individual model-predicted and measured AER, the median absolute difference was 29% (0.19 h‑1) for both the LBL and LBLX models. The LBL and LBLX models predicted 59% and 61% of the variance in the AER, respectively. Daily AER predictions for all 213 homes during the three year study (2010–2012) showed considerable house-to-house variations from building leakage differences, and temporal variations from outdoor temperature and wind speed fluctuations. Using this novel approach, NEXUS will be one of the first epidemiology studies to apply calibrated

  20. Modeling spatial and temporal variability of residential air exchange rates for the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS).

    PubMed

    Breen, Michael S; Burke, Janet M; Batterman, Stuart A; Vette, Alan F; Godwin, Christopher; Croghan, Carry W; Schultz, Bradley D; Long, Thomas C

    2014-11-07

    Air pollution health studies often use outdoor concentrations as exposure surrogates. Failure to account for variability of residential infiltration of outdoor pollutants can induce exposure errors and lead to bias and incorrect confidence intervals in health effect estimates. The residential air exchange rate (AER), which is the rate of exchange of indoor air with outdoor air, is an important determinant for house-to-house (spatial) and temporal variations of air pollution infiltration. Our goal was to evaluate and apply mechanistic models to predict AERs for 213 homes in the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS), a cohort study of traffic-related air pollution exposures and respiratory effects in asthmatic children living near major roads in Detroit, Michigan. We used a previously developed model (LBL), which predicts AER from meteorology and questionnaire data on building characteristics related to air leakage, and an extended version of this model (LBLX) that includes natural ventilation from open windows. As a critical and novel aspect of our AER modeling approach, we performed a cross validation, which included both parameter estimation (i.e., model calibration) and model evaluation, based on daily AER measurements from a subset of 24 study homes on five consecutive days during two seasons. The measured AER varied between 0.09 and 3.48 h(-1) with a median of 0.64 h(-1). For the individual model-predicted and measured AER, the median absolute difference was 29% (0.19 h‑1) for both the LBL and LBLX models. The LBL and LBLX models predicted 59% and 61% of the variance in the AER, respectively. Daily AER predictions for all 213 homes during the three year study (2010-2012) showed considerable house-to-house variations from building leakage differences, and temporal variations from outdoor temperature and wind speed fluctuations. Using this novel approach, NEXUS will be one of the first epidemiology studies to apply calibrated and

  1. Divergent effects of urban particulate air pollution on allergic airway responses in experimental asthma: a comparison of field exposure studies

    PubMed Central

    2012-01-01

    Background Increases in ambient particulate matter of aerodynamic diameter of 2.5 μm (PM2.5) are associated with asthma morbidity and mortality. The overall objective of this study was to test the hypothesis that PM2.5 derived from two distinct urban U.S. communities would induce variable responses to aggravate airway symptoms during experimental asthma. Methods We used a mobile laboratory to conduct community-based inhalation exposures to laboratory rats with ovalbumin-induced allergic airways disease. In Grand Rapids exposures were conducted within 60 m of a major roadway, whereas the Detroit was located in an industrial area more than 400 m from roadways. Immediately after nasal allergen challenge, Brown Norway rats were exposed by whole body inhalation to either concentrated air particles (CAPs) or filtered air for 8 h (7:00 AM - 3:00 PM). Both ambient and concentrated PM2.5 was assessed for mass, size fractionation, and major component analyses, and trace element content. Sixteen hours after exposures, bronchoalveolar lavage fluid (BALF) and lung lobes were collected and evaluated for airway inflammatory and mucus responses. Results Similar CAPs mass concentrations were generated in Detroit (542 μg/m3) and Grand Rapids (519 μg/m3). Exposure to CAPs at either site had no effects in lungs of non-allergic rats. In contrast, asthmatic rats had 200% increases in airway mucus and had more BALF neutrophils (250% increase), eosinophils (90%), and total protein (300%) compared to controls. Exposure to Detroit CAPs enhanced all allergic inflammatory endpoints by 30-100%, whereas inhalation of Grand Rapids CAPs suppressed all allergic responses by 50%. Detroit CAPs were characterized by high sulfate, smaller sized particles and were derived from local combustion sources. Conversely Grand Rapids CAPs were derived primarily from motor vehicle sources. Conclusions Despite inhalation exposure to the same mass concentration of urban PM2.5, disparate health

  2. Accounting for spatial effects in land use regression for urban air pollution modeling.

    PubMed

    Bertazzon, Stefania; Johnson, Markey; Eccles, Kristin; Kaplan, Gilaad G

    2015-01-01

    In order to accurately assess air pollution risks, health studies require spatially resolved pollution concentrations. Land-use regression (LUR) models estimate ambient concentrations at a fine spatial scale. However, spatial effects such as spatial non-stationarity and spatial autocorrelation can reduce the accuracy of LUR estimates by increasing regression errors and uncertainty; and statistical methods for resolving these effects--e.g., spatially autoregressive (SAR) and geographically weighted regression (GWR) models--may be difficult to apply simultaneously. We used an alternate approach to address spatial non-stationarity and spatial autocorrelation in LUR models for nitrogen dioxide. Traditional models were re-specified to include a variable capturing wind speed and direction, and re-fit as GWR models. Mean R(2) values for the resulting GWR-wind models (summer: 0.86, winter: 0.73) showed a 10-20% improvement over traditional LUR models. GWR-wind models effectively addressed both spatial effects and produced meaningful predictive models. These results suggest a useful method for improving spatially explicit models.

  3. Effects of air pollution on children's pulmonary function in urban and suburban areas of Wuhan, People's Republic of China

    SciTech Connect

    He, Q.C.; Lioy, P.J.; Wilson, W.E.; Chapman, R.S. )

    1993-11-01

    In May and June of 1988, the spirometric lung function of 604 children, who were aged 7-13 y and who were free of chronic respiratory conditions, was measured in the urban core and a suburb of Wuhan, China. During 1981-1988, ambient total suspended particulate (TSP) levels averaged 481 micrograms/m3 in the urban core and 167 micrograms/m3 in the suburb. In 1988, TSP levels, measured within 500 m of the children's homes, averaged 251 micrograms/m3 in the urban core and 110 micrograms/m3 in the suburb. Levels of sulfur dioxide and nitrogen oxides were also higher in the urban core. Proportions of families who burned coal and gas domestically were similar in both areas. In linear and logarithmic regression models, height was a stronger determinant of forced vital capacity and forced expiratory volume in 1 s than was age or weight. In linear models, the proportion of variance explained by height (R-squared) ranged from 0.54 for urban females' forced expiratory volume in 1 s to 0.77 for suburban males and females. Both forced vital capacity and forced expiratory volume in 1 s were consistently lower in urban than suburban children. The average forced vital capacity and forced expiratory volume in 1 s in children 132-144 cm tall were 6.7% and 3.8% lower, respectively, in the urban core than the suburb; suburban-urban differences increased with height. Suburban-urban differences in slopes of lung function growth curves were statistically significant for forced vital capacity but not for forced expiratory volume in 1 s. Rates of clinical upper respiratory irritation were also generally elevated in urban children. These results strongly suggest that urban ambient air pollution exposure in China contributes to retardation in the growth of children's lung function. Confirmatory longitudinal studies are in progress in Wuhan and three other Chinese cities.

  4. Potential effects of using biodiesel in road-traffic on air quality over the Porto urban area, Portugal

    NASA Astrophysics Data System (ADS)

    Ribeiro, Isabel; Monteiro, Alexandra; Lopes, Myriam

    2016-01-01

    This work aims to assess the impacts of biodiesel blends use in road-traffic on air quality. In this frame, the air quality numerical modelling system WRF-EURAD was applied over Portugal and the Porto urban area, forced by two emission scenarios (including CO, NOx, PM10, PM2.5, NMVOC, formaldehyde, acetaldehyde, acrolein and benzene): a reference scenario, without biofuels, and a scenario where a B20 fuel (20% biodiesel/80% diesel, v/v) is used by the diesel vehicle fleet. Regarding carbonyl compounds, emission scenarios pointed out that B20 fuel can promote an increase of 20% on formaldehyde, acetaldehyde and acrolein emissions, leading to increments on equivalent ozone production. On the other hand, through the air quality modelling exercise, it was verified that the use of B20 helps in controlling air pollution, improving CO and NO2 concentrations in urban airshed in about 20% and 10%, respectively, taking into account a regional simulation grid. However, according to the urban scale simulation, NO2 levels can increase in about 1%, due to the use of B20, over the Porto urban area. For the remaining studied pollutants, namely PM10 and PM2.5, mean concentrations will be reduced all over the territory, however in a negligible amount of <1%.

  5. A principal components analysis of the factors effecting personal exposure to air pollution in urban commuters in Dublin, Ireland.

    PubMed

    McNabola, Aonghus; Broderick, Brian M; Gill, Laurence W

    2009-10-01

    Principal component analysis was used to examine air pollution personal exposure data of four urban commuter transport modes for their interrelationships between pollutants and relationships with traffic and meteorological data. Air quality samples of PM2.5 and VOCs were recorded during peak traffic congestion for the car, bus, cyclist and pedestrian between January 2005 and June 2006 on a busy route in Dublin, Ireland. In total, 200 personal exposure samples were recorded each comprising 17 variables describing the personal exposure concentrations, meteorological conditions and traffic conditions. The data reduction technique, principal component analysis (PCA), was used to create weighted linear combinations of the data and these were subsequently examined for interrelationships between the many variables recorded. The results of the PCA found that personal exposure concentrations in non-motorised forms of transport were influenced to a higher degree by wind speed, whereas personal exposure concentrations in motorised forms of transport were influenced to a higher degree by traffic congestion. The findings of the investigation show that the most effective mechanisms of personal exposure reduction differ between motorised and non-motorised modes of commuter transport.

  6. Endotoxins in urban air in Stockholm, Sweden

    NASA Astrophysics Data System (ADS)

    Nilsson, S.; Merritt, A. S.; Bellander, T.

    2011-01-01

    Endotoxins, i.e. components originating from the outer membrane in the cell wall of Gram-negative bacteria, activate the human immune system, which may result in airway symptoms such as shortness of breath and airway inflammation. Endotoxins are present in the environment, both outdoors and indoors, and stay airborne for a long time. In order to investigate the levels of endotoxins in urban air and the influence of traffic and meteorological factors, particles (PM 10 and PM 2.5) were collected at five sites in Stockholm, Sweden on four occasions per site between May and September 2009. Endotoxins were extracted from the filters and analysis was conducted with the Limulus Amebocyte Lysate (LAL)-assay. Endotoxins were present in urban air in Stockholm, albeit in low levels, and were similar to levels found in urban areas outside Sweden. To our knowledge, this is the northernmost location where endotoxins have been measured. The endotoxin levels found in PM 10 ranged from 0.020 to 0.107 EU m -3 with a geometric mean of 0.050 EU m -3 and the levels found in PM 2.5 ranged from 0.005 to 0.064 EU m -3 with a geometric mean of 0.015 EU m -3. No obvious effects of traffic or meteorological factors on endotoxin levels were observed, although a moderate correlation could be seen with soot. The small number of sampling sites is however a shortcoming of the present study. In future studies, more sites and sampling during all seasons would be preferable in order to get a better picture of the influence of different sources on endotoxin levels.

  7. Heat Waves, Urban Vegetation, and Air Pollution

    NASA Astrophysics Data System (ADS)

    Churkina, G.; Grote, R.; Butler, T. M.

    2014-12-01

    Fast-track programs to plant millions of trees in cities around the world aim at the reduction of summer temperatures, increase carbon storage, storm water control, provision of space for recreation, as well as poverty alleviation. Although these multiple benefits speak positively for urban greening programs, the programs do not take into account how close human and natural systems are coupled in urban areas. Elevated temperatures together with anthropogenic emissions of air and water pollutants distinguish the urban system. Urban and sub-urban vegetation responds to ambient changes and reacts with pollutants. Neglecting the existence of this coupling may lead to unforeseen drawbacks of urban greening programs. The potential for emissions from urban vegetation combined with anthropogenic emissions to produce ozone has long been recognized. This potential increases under rising temperatures. Here we investigate how global change induced heat waves affect emissions of volatile organic compounds (VOC) from urban vegetation and corresponding ground-level ozone levels. We also quantify other ecosystem services provided by urban vegetation (e.g., cooling and carbon storage) and their sensitivity to climate change. In this study we use Weather Research and Forecasting Model with coupled atmospheric chemistry (WRF-CHEM) to quantify these feedbacks in Berlin, Germany during the heat waves in 2003 and 2006. We highlight the importance of the vegetation for urban areas under changing climate and discuss associated tradeoffs.

  8. Air pollution dispersion within urban street canyons

    NASA Astrophysics Data System (ADS)

    Taseiko, Olga V.; Mikhailuta, Sergey V.; Pitt, Anne; Lezhenin, Anatoly A.; Zakharov, Yuri V.

    A semi-empirical mathematical model, Urban Street Model (USM), is proposed to efficiently estimate the dispersion of vehicular air pollution in cities. This model describes urban building arrangements by combining building density, building heights and the permeability of building arrangements relative to wind flow. To estimate the level of air pollution in the city of Krasnoyarsk (in Eastern Siberia), the spatial distribution of pollutant concentrations off roadways is calculated using Markov's processes in USM. The USM-predicted numerical results were compared with field measurements and with results obtained from other frequently used models, CALINE-4 and OSPM. USM consistently yielded the best results. OSPM usually overestimated pollutant concentration values. CALINE-4 consistently underestimated these values. For OSPM, the maximum differences were 160% and for CALINE-4 about 400%. Permeability and building density are necessary parameters for accurately modeling urban air pollution and influencing regulatory requirements for building planning.

  9. Meteorological Conditions Favouring Development of Urban Air Pollution Episodes

    NASA Astrophysics Data System (ADS)

    Baklanov, Alexander; Kukkonen, Jaakko; Finardi, Sandro; Beekmann, Matthias; Sokhi, Ranjeet; Mahura, Alexander; Ginsburg, Alexander; Mažeikis, Adomas

    2013-04-01

    The causes of urban air pollution episodes are complex and depend on various factors including emissions, meteorological parameters, topography, atmospheric chemical processes and solar radiation. The relative importance of such factors is dependent on the geographical region, its surrounding emission source areas and the related climatic characteristics, as well as the season of the year. The key pollutants are PM10, PM2.5, O3 and NO2, as these cause the worst air quality problems in European cities. The main aim of this study realised within the MEGAPOLI project was to describe and quantify the influence of meteorological patterns on urban air pollution especially high-level concentrations air pollution episodes in megacities. Several European urban agglomerations and megacities, including the Po Valley, Helsinki, London, Paris, Moscow, Vilnius, were considered in the study. The study also carried out analysis of meteorological patterns leading to urban air pollution episodes considered by the development of suitable indicators linking particular meteorological conditions/ parameters to increased air pollution levels in the urban areas. These indicators constitute a useful tool for regulators in suggesting effective policies and mitigation measures. Finally, a combination of modelling and analysis of observations data can allow both the quality assurance of the new parameterisations as well as the verification of input emissions.

  10. Crowdsourcing urban air temperatures from smartphone battery temperatures

    NASA Astrophysics Data System (ADS)

    Overeem, A.; Robinson, J. C. R.; Leijnse, H.; Steeneveld, G. J.; Horn, B. K. P.; Uijlenhoet, R.

    2013-08-01

    Accurate air temperature observations in urban areas are important for meteorology and energy demand planning. They are indispensable to study the urban heat island effect and the adverse effects of high temperatures on human health. However, the availability of temperature observations in cities is often limited. Here we show that relatively accurate air temperature information for the urban canopy layer can be obtained from an alternative, nowadays omnipresent source: smartphones. In this study, battery temperatures were collected by an Android application for smartphones. A straightforward heat transfer model is employed to estimate daily mean air temperatures from smartphone battery temperatures for eight major cities around the world. The results demonstrate the enormous potential of this crowdsourcing application for real-time temperature monitoring in densely populated areas.

  11. Urban Air Quality Forecasting in Canada

    NASA Astrophysics Data System (ADS)

    Pavlovic, Radenko; Menard, Sylvain; Cousineau, Sophie; Stroud, Craig; Moran, Michael

    2016-04-01

    Environment and Climate Change Canada has been providing air quality (AQ) forecasts for major Canadian urban centers since 2001. Over this period, the Canadian AQ Forecast Program has expanded and evolved. It currently uses the Regional Air Quality Deterministic Prediction System (RAQDPS) modelling framework. At the heart of the RAQDPS is the GEM-MACH model, an on-line coupled meteorology‒chemistry model configured for a North American domain with 10 km horizontal grid spacing and 80 vertical levels. A statistical post-processing model (UMOS-AQ) is then applied to the RAQDPS hourly forecasts for locations with AQ monitors to reduce point forecast bias and error. These outputs provide the primary guidance from which operational meteorologists disseminate Air Quality Health Index (AQHI) forecasts to the public for major urban centres across Canada. During the 2015 summer Pan Am and Parapan Am Games, which were held in Ontario, Canada, an experimental version of the RAQDPS at 2.5 km horizontal grid spacing was run for a domain over the greater Toronto area. Currently, there is ongoing research to develop and assess AQ systems run at 1 km resolution. This presentation will show analyses of operational AQ forecast performance for several pollutants over the last few years in major Canadian urban centres such as Toronto, Montreal, Vancouver, Ottawa, and Calgary. Trends in observed pollution along with short- and long-term development plans for urban AQ forecasting will also be presented.

  12. Biofuels, vehicle emissions, and urban air quality.

    PubMed

    Wallington, Timothy J; Anderson, James E; Kurtz, Eric M; Tennison, Paul J

    2016-07-18

    Increased biofuel content in automotive fuels impacts vehicle tailpipe emissions via two mechanisms: fuel chemistry and engine calibration. Fuel chemistry effects are generally well recognized, while engine calibration effects are not. It is important that investigations of the impact of biofuels on vehicle emissions consider the impact of engine calibration effects and are conducted using vehicles designed to operate using such fuels. We report the results of emission measurements from a Ford F-350 fueled with either fossil diesel or a biodiesel surrogate (butyl nonanoate) and demonstrate the critical influence of engine calibration on NOx emissions. Using the production calibration the emissions of NOx were higher with the biodiesel fuel. Using an adjusted calibration (maintaining equivalent exhaust oxygen concentration to that of the fossil diesel at the same conditions by adjusting injected fuel quantities) the emissions of NOx were unchanged, or lower, with biodiesel fuel. For ethanol, a review of the literature data addressing the impact of ethanol blend levels (E0-E85) on emissions from gasoline light-duty vehicles in the U.S. is presented. The available data suggest that emissions of NOx, non-methane hydrocarbons, particulate matter (PM), and mobile source air toxics (compounds known, or suspected, to cause serious health impacts) from modern gasoline and diesel vehicles are not adversely affected by increased biofuel content over the range for which the vehicles are designed to operate. Future increases in biofuel content when accomplished in concert with changes in engine design and calibration for new vehicles should not result in problematic increases in emissions impacting urban air quality and may in fact facilitate future required emissions reductions. A systems perspective (fuel and vehicle) is needed to fully understand, and optimize, the benefits of biofuels when blended into gasoline and diesel.

  13. Modeling Spatial and Temporal Variability of Residential Air Exchange Rates for the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS)

    EPA Science Inventory

    Air pollution health studies often use outdoor concentrations as exposure surrogates. Failure to account for variability of residential infiltration of outdoor pollutants can induce exposure errors and lead to bias and incorrect confidence intervals in health effect estimates. Th...

  14. Evaluation of surface air temperature and urban effects in Japan simulated by non-hydrostatic regional climate model

    NASA Astrophysics Data System (ADS)

    Murata, A.; Sasaki, H.; Hanafusa, M.; Kurihara, K.

    2012-12-01

    We evaluated the performance of a well-developed nonhydrostatic regional climate model (NHRCM) with a spatial resolution of 5 km with respect to temperature in the present-day climate of Japan, and estimated urban heat island (UHI) intensity by comparing the model results and observations. The magnitudes of root mean square error (RMSE) and systematic error (bias) for the annual average of daily mean (Ta), maximum (Tx), and minimum (Tn) temperatures are within 1.5 K, demonstrating that the temperatures of the present-day climate are reproduced well by NHRCM. These small errors indicate that temperature variability produced by local-scale phenomena is represented well by the model with a higher spatial resolution. It is also found that the magnitudes of RMSE and bias in the annually-average Tx are relatively large compared with those in Ta and Tn. The horizontal distributions of the error, defined as the difference between simulated and observed temperatures (simulated minus observed), illustrate negative errors in the annually-averaged Tn in three major metropolitan areas: Tokyo, Osaka, and Nagoya. These negative errors in urban areas affect the cold bias in the annually-averaged Tx. The relation between the underestimation of temperature and degree of urbanization is therefore examined quantitatively using National Land Numerical Information provided by the Ministry of Land, Infrastructure, Transport, and Tourism. The annually-averaged Ta, Tx, and Tn are all underestimated in the areas where the degree of urbanization is relatively high. The underestimations in these areas are attributed to the treatment of urban areas in NHRCM, where the effects of urbanization, such as waste heat and artificial structures, are not included. In contrast, in rural areas, the simulated Tx is underestimated and Tn is overestimated although the errors in Ta are small. This indicates that the simulated diurnal temperature range is underestimated. The reason for the relatively large

  15. Isotopic composition of formaldehyde in urban air.

    PubMed

    Rice, Andrew L; Quay, Paul

    2009-12-01

    The isotopic composition of atmospheric formaldehyde was measured in air samples collected in urban Seattle, Washington. A recently developed gas chromatography-isotope ratio mass spectrometry analytical technique was used to extract formaldehyde directly from whole air, separate it from other volatile organic compounds, and measure its (13)C/(12)C and D/H ratio. Measurements of formaldehyde concentration were also made concomitant with isotope ratio. Results of the analysis of nine discrete air samples for delta(13)C-HCHO have a relatively small range in isotopic composition (-31 to -25 per thousand versus VPDB [+/-1.3 per thousand]) over a considerable concentration range (0.8-4.4 ppb [+/-15%]). In contrast, analyses of 17 air samples for deltaD-HCHO show a large range (-296 to +210 per thousand versus VSMOW [+/-50 per thousand]) over the concentrations measured (0.5-2.9 ppb). Observations of deltaD are weakly anticorrelated with concentration. Isotopic data are interpreted using both source- and sink-based approaches. Results of delta(13)C-HCHO are similar to those observed previously for a number of nonmethane hydrocarbons in urban environments and variability can be reconciled with a simple sink-based model. The large variability observed in deltaD-HCHO favors a source-based interpretation with HCHO depleted in deuterium from primary sources of HCHO (i.e., combustion) and HCHO enriched in deuterium from secondary photochemical sources (i.e., hydrocarbon oxidation).

  16. Urban air pollution and health inequities: a workshop report.

    PubMed Central

    2001-01-01

    Over the past three decades, an array of legislation with attendant regulations has been implemented to enhance the quality of the environment and thereby improve the public's health. Despite the many beneficial changes that have followed, there remains a disproportionately higher prevalence of harmful environmental exposures, particularly air pollution, for certain populations. These populations most often reside in urban settings, have low socioeconomic status, and include a large proportion of ethnic minorities. The disparities between racial/ethnic minority and/or low-income populations in cities and the general population in terms of environmental exposures and related health risks have prompted the "environmental justice" or "environmental equity" movement, which strives to create cleaner environments for the most polluted communities. Achieving cleaner environments will require interventions based on scientific data specific to the populations at risk; however, research in this area has been relatively limited. To assess the current scientific information on urban air pollution and its health impacts and to help set the agenda for immediate intervention and future research, the American Lung Association organized an invited workshop on Urban Air Pollution and Health Inequities held 22-24 October 1999 in Washington, DC. This report builds on literature reviews and summarizes the discussions of working groups charged with addressing key areas relevant to air pollution and health effects in urban environments. An overview was provided of the state of the science for health impacts of air pollution and technologies available for air quality monitoring and exposure assessment. The working groups then prioritized research needs to address the knowledge gaps and developed recommendations for community interventions and public policy to begin to remedy the exposure and health inequities. PMID:11427385

  17. A Study of the Combined Effects of Physical Activity and Air Pollution on Mortality in Elderly Urban Residents: The Danish Diet, Cancer, and Health Cohort

    PubMed Central

    de Nazelle, Audrey; Mendez, Michelle Ann; Garcia-Aymerich, Judith; Hertel, Ole; Tjønneland, Anne; Overvad, Kim; Raaschou-Nielsen, Ole; Nieuwenhuijsen, Mark J.

    2015-01-01

    Background Physical activity reduces, whereas exposure to air pollution increases, the risk of premature mortality. Physical activity amplifies respiratory uptake and deposition of air pollutants in the lung, which may augment acute harmful effects of air pollution during exercise. Objectives We aimed to examine whether benefits of physical activity on mortality are moderated by long-term exposure to high air pollution levels in an urban setting. Methods A total of 52,061 subjects (50–65 years of age) from the Danish Diet, Cancer, and Health cohort, living in Aarhus and Copenhagen, reported data on physical activity in 1993–1997 and were followed until 2010. High exposure to air pollution was defined as the upper 25th percentile of modeled nitrogen dioxide (NO2) levels at residential addresses. We associated participation in sports, cycling, gardening, and walking with total and cause-specific mortality by Cox regression, and introduced NO2 as an interaction term. Results In total, 5,534 subjects died: 2,864 from cancer, 1,285 from cardiovascular disease, 354 from respiratory disease, and 122 from diabetes. Significant inverse associations of participation in sports, cycling, and gardening with total, cardiovascular, and diabetes mortality were not modified by NO2. Reductions in respiratory mortality associated with cycling and gardening were more pronounced among participants with moderate/low NO2 [hazard ratio (HR) = 0.55; 95% CI: 0.42, 0.72 and 0.55; 95% CI: 0.41, 0.73, respectively] than with high NO2 exposure (HR = 0.77; 95% CI: 0.54, 1.11 and HR = 0.81; 95% CI: 0.55, 1.18, p-interaction = 0.09 and 0.02, respectively). Conclusions In general, exposure to high levels of traffic-related air pollution did not modify associations, indicating beneficial effects of physical activity on mortality. These novel findings require replication in other study populations. Citation Andersen ZJ, de Nazelle A, Mendez MA, Garcia-Aymerich J, Hertel O, Tjønneland A, Overvad

  18. Evaluating strategies to reduce urban air pollution

    NASA Astrophysics Data System (ADS)

    Duque, L.; Relvas, H.; Silveira, C.; Ferreira, J.; Monteiro, A.; Gama, C.; Rafael, S.; Freitas, S.; Borrego, C.; Miranda, A. I.

    2016-02-01

    During the last years, specific air quality problems have been detected in the urban area of Porto (Portugal). Both PM10 and NO2 limit values have been surpassed in several air quality monitoring stations and, following the European legislation requirements, Air Quality Plans were designed and implemented to reduce those levels. In this sense, measures to decrease PM10 and NO2 emissions have been selected, these mainly related to the traffic sector, but also regarding the industrial and residential combustion sectors. The main objective of this study is to investigate the efficiency of these reduction measures with regard to the improvement of PM10 and NO2 concentration levels over the Porto urban region using a numerical modelling tool - The Air Pollution Model (TAPM). TAPM was applied over the study region, for a simulation domain of 80 × 80 km2 with a spatial resolution of 1 × 1 km2. The entire year of 2012 was simulated and set as the base year for the analysis of the impacts of the selected measures. Taking into account the main activity sectors, four main scenarios have been defined and simulated, with focus on: (1) hybrid cars; (2) a Low Emission Zone (LEZ); (3) fireplaces and (4) industry. The modelling results indicate that measures to reduce PM10 should be focused on residential combustion (fireplaces) and industrial activity and for NO2 the strategy should be based on the traffic sector. The implementation of all the defined scenarios will allow a total maximum reduction of 4.5% on the levels of both pollutants.

  19. Crowdsourcing urban air temperatures from smartphone battery temperatures

    NASA Astrophysics Data System (ADS)

    Overeem, Aart; Robinson, James C. R.; Leijnse, Hidde; Steeneveld, Gert-Jan; Horn, Berthold K. P.; Uijlenhoet, Remko

    2014-05-01

    Accurate air temperature observations in urban areas are important for meteorology and energy demand planning. They are indispensable to study the urban heat island effect and the adverse effects of high temperatures on human health. However, the availability of temperature observations in cities is often limited. Here we show that relatively accurate air temperature information for the urban canopy layer can be obtained from an alternative, nowadays omnipresent source: smartphones. In this study, battery temperatures were collected by an Android application for smartphones. It has been shown that a straightforward heat transfer model can be employed to estimate daily mean air temperatures from smartphone battery temperatures for eight major cities around the world. The results demonstrate the enormous potential of this crowdsourcing application for real-time temperature monitoring in densely populated areas. Battery temperature data were collected by users of an Android application for cell phones (opensignal.com). The application automatically sends battery temperature data to a server for storage. In this study, battery temperatures are averaged in space and time to obtain daily averaged battery temperatures for each city separately. A regression model, which can be related to a physical model, is employed to retrieve daily air temperatures from battery temperatures. The model is calibrated with observed air temperatures from a meteorological station of an airport located in or near the city. Time series of air temperatures are obtained for each city for a period of several months, where 50% of the data is for independent verification. The methodology has been applied to Buenos Aires, London, Los Angeles, Paris, Mexico City, Moscow, Rome, and Sao Paulo. The evolution of the retrieved air temperatures often correspond well with the observed ones. The mean absolute error of daily air temperatures is less than 2 degrees Celsius, and the bias is within 1 degree

  20. Winter urban air particles from Rome (Italy): effects on the monocytic-macrophagic RAW 264.7 cell line.

    PubMed

    Pozzi, Roberta; De Berardis, Barbara; Paoletti, Luigi; Guastadisegni, Cecilia

    2005-11-01

    Epidemiological data show an association between exposure to elevated levels of particulate matter (PM), in particular the fine fraction (<2.5 microm in diameter), and an increase in cardiovascular mortality and respiratory symptoms. The aim of this study was to compare the in vitro toxicity of coarse and fine particulate matter collected with a cascade impactor during winter in an urban area of Rome in relation to their physicochemical characterization (size distribution and chemical composition) as assessed by analytical electron microscopy (SEM/EDX). The X-ray microanalysis data of single particles of coarse and fine matter were analyzed by hierarchical cluster analysis to determine the principal component of the two granulometric fractions. The main chemical difference between the two fractions was the greater abundance of carbonaceous particles in the fine fraction. We compared the ability of coarse and fine fractions, carbon black (CB), and residual oil fly ash (ROFA) to induce arachidonic acid release and tumor necrosis factor-alpha (TNF-alpha) production in the monocytic-macrophagic RAW 264.7 cell line at concentrations of 30 and 120 microg/mL. Our results showed that CB and ROFA were consistently less effective than both fractions of urban particles at inducing an inflammatory reaction in RAW 264.7 cells. Both PM fractions dose-dependently increased TNF-alpha production in RAW 264.7 cells after 5 and 24h of incubation, and only the TNF-alpha production induced by coarse particles at 30 microg/mL decreased significantly (P<0.01) after 24h of treatment. In our in vitro model the winter fine fraction was more reactive than the winter coarse fraction, in contrast to a previously examined summer sample. In the summer sample, coarse particles produced higher levels of inflammatory mediators than fine particles and the CB was consistently less effective than the urban particles. The different behaviors between summer and winter urban fractions may be due to their

  1. Human exposure to urban air pollution.

    PubMed Central

    Boström, C E; Almén, J; Steen, B; Westerholm, R

    1994-01-01

    This study deals with some methods of making human exposure estimates, aimed at describing the human exposure for selected air pollutants in Sweden that are suspected carcinogens. Nitrogen oxides (NOx) have been chosen as an indicator substance for estimating the concentration of the urban plume. Earlier investigations have shown that the traffic in Swedish cities contributes around 85% to the measured NOx concentrations, and that most of the mutagenicity in urban air originates from traffic. The first section of this paper describes measurements in Stockholm of some unregulated light hydrocarbons, such as ethene, ethyne, propane, propene, butane, and isobutane. In addition, measurements of some volatile aromatic hydrocarbons are presented. Simultaneous measurements of carbon monoxide (CO) were made. The ratios between CO and the individual specific compounds were determined by linear regression analysis. By analysis of relationships between CO and NOx, NOx concentrations can be used as a tracer to describe the exposure for these specific compounds. NOx are considered to be a better tracer than CO, because NOx or NO2 values exist for many places over a long time, while CO is measured mostly in streets with high concentrations. At low concentrations, instruments that measure normal CO levels give no detectable signals. Through use of atmospheric dispersion models and models that describe how people live and work in urban areas it has been possible to describe the average exposure to NOx in cities of different sizes. The exposure to NOx for people living in the countryside has also been estimated. In this way, it has been possible to calculate the average exposure dose for NOx for the Swedish population. This figure is 23 micrograms/m3. By use of the relationships between NOx and specific compounds the average dose has been calculated for the following compounds: polyaromatic compounds (PAH); ethene, propene, and butadiene; benzene, toluene, and xylene; formaldehyde

  2. Air pollution and health in urban areas.

    PubMed

    Schwela, D

    2000-01-01

    In this paper, recent reviews of the World Health Organization, other review papers, and more recent literature on the human health effects of current air pollution trends in urban areas are reviewed and summarized as follows: Sulphur dioxide. Some studies, but not others, found associations between sulphur dioxide (SO2) exposure and daily mortality and morbidity. Single-pollutant correlations sometimes disappeared when other pollutants, especially suspended particulate matter (SPM), were included. Cross-sectional studies with asthmatics revealed significant, non-threshold relations between SO2 and decrements of the forced expiratory volume in 1 second (FEV1). Nitrogen dioxide. Weak associations between short-term nitrogen dioxide (NO2) exposure from gas cooking and respiratory symptoms and a decrement in lung function parameters were found in children, but not consistently in exposed women. With long-term exposure, children, but not adults, exhibit increased respiratory symptoms, decreased lung function, and increased incidences of chronic cough, bronchitis, and conjunctivitis. A causal relationship between NO2 exposure and adverse health effects has not yet been established. Carbon monoxide. Binding of CO in the lungs with hemoglobin in the blood forms carboxyhemoglobin (COHb), which impairs the transport of oxygen. The health effects of CO include hypoxia, neurological deficits and neurobehavioral changes, and increases in daily mortality and hospital admissions for cardiovascular diseases. The latter persists even at very low CO levels, indicating no threshold for the onset of these effects. Whether the relation between daily mortality and exposure to CO are causal or whether CO might act as a proxy for SPM is still an open question. Ambient CO may have even more serious health consequences than does COHb formation and at lower levels than that mediated through elevated COHb levels. Ozone. Short-term acute effects of O3 include pulmonary function decrements

  3. Mapping air quality zones for coastal urban centers.

    PubMed

    Freeman, Brian; Gharabaghi, Bahram; Thé, Jesse; Munshed, Mohammad; Faisal, Shah; Abdullah, Meshal; Al Aseed, Athari

    2017-05-01

    This study presents a new method that incorporates modern air dispersion models allowing local terrain and land-sea breeze effects to be considered along with political and natural boundaries for more accurate mapping of air quality zones (AQZs) for coastal urban centers. This method uses local coastal wind patterns and key urban air pollution sources in each zone to more accurately calculate air pollutant concentration statistics. The new approach distributes virtual air pollution sources within each small grid cell of an area of interest and analyzes a puff dispersion model for a full year's worth of 1-hr prognostic weather data. The difference of wind patterns in coastal and inland areas creates significantly different skewness (S) and kurtosis (K) statistics for the annually averaged pollutant concentrations at ground level receptor points for each grid cell. Plotting the S-K data highlights grouping of sources predominantly impacted by coastal winds versus inland winds. The application of the new method is demonstrated through a case study for the nation of Kuwait by developing new AQZs to support local air management programs. The zone boundaries established by the S-K method were validated by comparing MM5 and WRF prognostic meteorological weather data used in the air dispersion modeling, a support vector machine classifier was trained to compare results with the graphical classification method, and final zones were compared with data collected from Earth observation satellites to confirm locations of high-exposure-risk areas. The resulting AQZs are more accurate and support efficient management strategies for air quality compliance targets effected by local coastal microclimates.

  4. The impact of meteorological parameters on urban air quality

    NASA Astrophysics Data System (ADS)

    Ramsey, Nicole R.; Klein, Petra M.; Moore, Berrien

    2014-04-01

    Previous studies have shown that global climate change will have a significant impact on both regional and urban air quality. As air temperatures continue to rise and mid-latitude cyclone frequencies decrease, the overall air quality is expected to degrade. Climate models are currently predicting an increased frequency of record setting heat and drought for Oklahoma during the summer months. A statistical analysis was thus performed on ozone and meteorological data to evaluate the potential effect of increasing surface temperatures and stagnation patterns on urban air quality in the Oklahoma City Metropolitan area. Compared to the climatological normal, the years 2011 and 2012 were exceptionally warm and dry, and were therefore used as case study years for determining the impact of hot, dry conditions on air quality. These results were then compared to cooler, wetter summers to show how urban air quality is affected by a change in meteorological parameters. It was found that an increase in summertime heat and a decrease in summertime precipitation will lead to a substantial increase in both the minimum and maximum ozone concentrations as well as an increase in the total number of exceedance days. During the hotter, drier years, the number of days with ozone concentrations above the legal regulatory limit increased nearly threefold. The length of time in which humans and crops are exposed to these unsafe levels was also doubled. Furthermore, a significant increase was noted in the overnight minimum ozone concentrations. This in turn can lead to significant, adverse affects on both health and agriculture statewide.

  5. Variation in the urban vegetation, surface temperature, air temperature nexus.

    PubMed

    Shiflett, Sheri A; Liang, Liyin L; Crum, Steven M; Feyisa, Gudina L; Wang, Jun; Jenerette, G Darrel

    2017-02-01

    Our study examines the urban vegetation - air temperature (Ta) - land surface temperature (LST) nexus at micro- and regional-scales to better understand urban climate dynamics and the uncertainty in using satellite-based LST for characterizing Ta. While vegetated cooling has been repeatedly linked to reductions in urban LST, the effects of vegetation on Ta, the quantity often used to characterize urban heat islands and global warming, and on the interactions between LST and Ta are less well characterized. To address this need we quantified summer temporal and spatial variation in Ta through a network of 300 air temperature sensors in three sub-regions of greater Los Angeles, CA, which spans a coastal to desert climate gradient. Additional sensors were placed within the inland sub-region at two heights (0.1m and 2m) within three groundcover types: bare soil, irrigated grass, and underneath citrus canopy. For the entire study region, we acquired new imagery data, which allowed calculation of the normalized difference vegetation index (NDVI) and LST. At the microscale, daytime Ta measured along a vertical gradient, ranged from 6 to 3°C cooler at 0.1 and 2m, underneath tall canopy compared to bare ground respectively. At the regional scale NDVI and LST were negatively correlated (p<0.001). Relationships between diel variation in Ta and daytime LST at the regional scale were progressively weaker moving away from the coast and were generally limited to evening and nighttime hours. Relationships between NDVI and Ta were stronger during nighttime hours, yet effectiveness of mid-day vegetated cooling increased substantially at the most arid region. The effectiveness of vegetated Ta cooling increased during heat waves throughout the region. Our findings suggest an important but complex role of vegetation on LST and Ta and that vegetation may provide a negative feedback to urban climate warming.

  6. Effect of atmospheric mixing layer depth variations on urban air quality and daily mortality during Saharan dust outbreaks.

    PubMed

    Pandolfi, M; Tobias, A; Alastuey, A; Sunyer, J; Schwartz, J; Lorente, J; Pey, J; Querol, X

    2014-10-01

    Several epidemiological studies have shown that the outbreaks of Saharan dust over southern European countries can cause negative health effects. The reasons for the increased toxicity of airborne particles during dust storms remain to be understood although the presence of biogenic factors carried by dust particles and the interaction between dust and man-made air pollution have been hypothesized as possible causes. Intriguingly, recent findings have also demonstrated that during Saharan dust outbreaks the local man-made particulates can have stronger effects on health than during days without outbreaks. We show that the thinning of the mixing layer (ML) during Saharan dust outbreaks, systematically described here for the first time, can trigger the observed higher toxicity of ambient local air. The mixing layer height (MLH) progressively reduced with increasing intensity of dust outbreaks thus causing a progressive accumulation of anthropogenic pollutants and favouring the formation of new fine particles or specific relevant species likely from condensation of accumulated gaseous precursors on dust particles surface. Overall, statistically significant associations of MLH with all-cause daily mortality were observed. Moreover, as the MLH reduced, the risk of mortality associated with the same concentration of particulate matter increased due to the observed pollutant accumulation. The association of MLH with daily mortality and the effect of ML thinning on particle toxicity exacerbated when Saharan dust outbreaks occurred suggesting a synergic effect of atmospheric pollutants on health which was amplified during dust outbreaks. Moreover, the results may reflect higher toxicity of primary particles which predominate on low MLH days.

  7. Effect of atmospheric mixing layer depth variations on urban air quality and daily mortality during Saharan dust outbreaks

    PubMed Central

    Pandolfi, M.; Tobias, A.; Alastuey, A.; Sunyer, J.; Schwartz, J.; Lorente, J.; Pey, J.; Querol, X.

    2016-01-01

    Several epidemiological studies have shown that the outbreaks of Saharan dust over southern European countries can cause negative health effects. The reasons for the increased toxicity of airborne particles during dust storms remain to be understood although the presence of biogenic factors carried by dust particles or the interaction between dust and man-made air pollution have been hypothesized as possible causes. Intriguingly, recent findings have also demonstrated that during Saharan dust outbreaks the local man-made particulates can have stronger effects on health than during days without outbreaks. We show that the thinning of the mixing layer (ML) during Saharan dust outbreaks, systematically described here for the first time, can trigger the observed higher toxicity of ambient local air. The mixing layer height (MLH) progressively reduced with increasing intensity of dust outbreaks thus causing a progressive accumulation of anthropogenic pollutants and favouring the formation of new fine particles or specific relevant species likely from condensation of accumulated gaseous precursors on dust particles surface. Overall, statistically significant associations of MLH with all-cause daily mortality were observed. Moreover, as the MLH reduced, the risk of mortality associated with the same concentration of particulate matter increased due to the observed pollutants accumulation. The association of MLH with daily mortality and the effect of ML thinning on particle toxicity exacerbated when Saharan dust outbreaks occurred suggesting a synergic effect of atmospheric pollutants on health which was amplified during dust outbreaks. Moreover, the results may reflect higher toxicity of primary particles which predominate on low MLH days. PMID:25051327

  8. Nonpoint sources of volatile organic compounds in urban areas - Relative importance of land surfaces and air

    USGS Publications Warehouse

    Lopes, T.J.; Bender, D.A.

    1998-01-01

    Volatile organic compounds (VOCs) commonly detected in urban waters across the United States include gasoline-related compounds (e.g. toluene, xylene) and chlorinated compounds (e.g. chloroform, tetrachloroethane [PCE], trichloroethene [TCE]). Statistical analysis of observational data and results of modeling the partitioning of VOCs between air and water suggest that urban land surfaces are the primary nonpoint source of most VOCs. Urban air is a secondary nonpoint source, but could be an important source of the gasoline oxygenate methyl-tert butyl ether (MTBE). Surface waters in urban areas would most effectively be protected by controlling land-surface sources.

  9. Meteorological and air pollution modeling for an urban airport

    NASA Technical Reports Server (NTRS)

    Swan, P. R.; Lee, I. Y.

    1980-01-01

    Results are presented of numerical experiments modeling meteorology, multiple pollutant sources, and nonlinear photochemical reactions for the case of an airport in a large urban area with complex terrain. A planetary boundary-layer model which predicts the mixing depth and generates wind, moisture, and temperature fields was used; it utilizes only surface and synoptic boundary conditions as input data. A version of the Hecht-Seinfeld-Dodge chemical kinetics model is integrated with a new, rapid numerical technique; both the San Francisco Bay Area Air Quality Management District source inventory and the San Jose Airport aircraft inventory are utilized. The air quality model results are presented in contour plots; the combined results illustrate that the highly nonlinear interactions which are present require that the chemistry and meteorology be considered simultaneously to make a valid assessment of the effects of individual sources on regional air quality.

  10. High resolution modeling of the effects of alternative fuels use on urban air quality: introduction of natural gas vehicles in Barcelona and Madrid Greater Areas (Spain).

    PubMed

    Gonçalves, María; Jiménez-Guerrero, Pedro; Baldasano, José M

    2009-01-01

    The mitigation of the effects of on-road traffic emissions on urban air pollution is currently an environmental challenge. Air quality modeling has become a powerful tool to design environment-related strategies. A wide range of options is being proposed; such as the introduction of natural gas vehicles (NGV), biofuels or hydrogen vehicles. The impacts on air quality of introducing specific NGV fleets in Barcelona and Madrid (Spain) are assessed by means of the WRF-ARW/HERMES/CMAQ modeling system with high spatial-temporal resolution (1 km(2), 1 h). Seven emissions scenarios are defined taking into account the year 2004 vehicle fleet composition of the study areas and groups of vehicles susceptible of change under a realistic perspective. O(3) average concentration rises up to 1.3% in Barcelona and up to 2.5% in Madrid when introducing the emissions scenarios, due to the NO(x) reduction in VOC-controlled areas. Nevertheless, NO(2), PM10 and SO(2) average concentrations decrease, up to 6.1%, 1.5% and 6.6% in Barcelona and up to 20.6%, 8.7% and 14.9% in Madrid, respectively. Concerning SO(2) and PM10 reductions the most effective single scenario is the introduction of 50% of NGV instead of the oldest commercial vehicles; it also reduces NO(2) concentrations in Barcelona, however in Madrid lower levels are attained when substituting 10% of the private cars. This work introduces the WRF-ARW/HERMES/CMAQ modeling system as a useful management tool and proves that the air quality improvement plans must be designed considering the local characteristics.

  11. Assessment of urban air pollution and it's probable health impact.

    PubMed

    Barman, S C; Kumar, N; Singh, R; Kisku, G C; Khan, A H; Kidwai, M M; Murthy, R C; Negi, M P S; Pandey, P; Verma, A K; Jain, G; Bhargava, S K

    2010-11-01

    The present study deals with the quantitative effect of vehicular emission on ambient air quality during May 2006 in urban area of Lucknow city. In this study SPM, RSPM, SO2, NOx and 7 trace metals associated with RSPM were estimated at 10 representative locations in urban area and one village area for control. Beside this, air quality index (AQI), health effects of different metals and mortality were assessed. The 24 hr average concentration of SPM, RSPM, SO2 and NOx was found to be 382.3, 171.5, 24.3 and 33.8 microg m(-3) respectively in urban area and these concentrations were found to be significantly (p < 0.01) higher by 94.8, 134.8, 107.4 and 129.6% than control site respectively The 24 hr mean of SPM and RSPM at each location of urban area were found to be higher than prescribed limit of National Ambient Air Quality Standard (NAAQS) except SPM for industrial area. The 24 hr mean concentration of metals associated with RSPM was found to be higher than the control site by 52.3, 271.8, 408.9, 75.81, 62.7, 487.54 and 189.5% for Fe, Cu, Pb, Zn, Ni, Mn and Cr respectively. The inter correlation of metals Pb with Mn, Fe and Cr; Zn with Ni and Cr; Ni with Cr; Mn with Fe and Cu with Cr showed significant positive relation either at p < 0.05 or p < 0.01 level. Metals Pb, Mn and Cr (p < 0.01) and Cu (p < 0.05) showed significant positive correlation with RSPM. These results indicate that ambient air quality in the urban area is affected adversely due to emission and accumulation of SPM, RSPM, SO2, NOx and trace metals. These pollutants may pose detrimental effect on human health, as exposure of these are associated with cardiovascular and respiratory diseases, neurological impairments, increased risk of preterm birth and even mortality and morbidity.

  12. Satellite Monitoring of Urban Air Pollution using MODIS and VIIRS

    NASA Astrophysics Data System (ADS)

    Hsu, N. C.; Bettenhausen, C.; Sayer, A. M.

    2013-05-01

    Due to rapid economical growth in many developing countries, the problem of deteriorating air quality is becoming an important societal issue of public health over mega cities around the world. Although there are many networks of surface PM2.5 and PM10 measurements in place to monitor the level of air pollutant over these urban sites, satellite data are still required to provide comprehensive information on the overall big picture regarding the spatial distribution of aerosols and their transport paths into the surrounding regions. In this paper, we will demonstrate the capability of a new satellite algorithm to retrieve aerosol optical thickness and single scattering albedo over bright-reflecting surfaces such as urban areas. Such retrievals have been difficult to perform using previously available algorithms that use wavelengths from the mid-visible to the near IR because they have trouble separating the aerosol signal from the contribution due to the bright surface reflectance. The new algorithm, called Deep Blue, utilizes blue-wavelength measurements from instruments such as MODIS and VIIRS to infer the properties of aerosols, since the surface reflectance over land in the blue part of the spectrum is much lower than for longer wavelength channels. We have validated the satellite retrieved aerosol optical thickness from both MODIS Collection 6 and new VIIRS Deep Blue products with data from AERONET sunphotometers over urban sites. The comparisons show reasonable agreements between these two. These new satellite products will allow scientists to determine quantitatively the aerosol properties near sources using high spatial resolution measurements from MODIS and VIIRS instruments. The multiyear satellite measurements since 2000 from MODIS will be utilized to investigate the interannual variability of source, pathway, and aerosol loading associated with these urban pollutions. The quantitative effects of direct radiative forcing of these air borne aerosol

  13. Does urban vegetation mitigate air pollution in northern conditions?

    PubMed

    Setälä, Heikki; Viippola, Viljami; Rantalainen, Anna-Lea; Pennanen, Arto; Yli-Pelkonen, Vesa

    2013-12-01

    It is generally accepted that urban vegetation improves air quality and thereby enhances the well-being of citizens. However, empirical evidence on the potential of urban trees to mitigate air pollution is meager, particularly in northern climates with a short growing season. We studied the ability of urban park/forest vegetation to remove air pollutants (NO2, anthropogenic VOCs and particle deposition) using passive samplers in two Finnish cities. Concentrations of each pollutant in August (summer; leaf-period) and March (winter, leaf-free period) were slightly but often insignificantly lower under tree canopies than in adjacent open areas, suggesting that the role of foliage in removing air pollutants is insignificant. Furthermore, vegetation-related environmental variables (canopy closure, number and size of trees, density of understorey vegetation) did not explain the variation in pollution concentrations. Our results suggest that the ability of urban vegetation to remove air pollutants is minor in northern climates.

  14. Controlling Urban Air Pollution: A Benefit-Cost Assessment.

    ERIC Educational Resources Information Center

    Krupnick, Alan J.; Portney, Paul R.

    1991-01-01

    The pros and cons of air pollution control efforts are discussed. Both national and regional air pollution control plans are described. Topics of discussion include benefit-cost analysis, air quality regulation, reducing ozone in the urban areas, the Los Angeles plan, uncertainties, and policy implications. (KR)

  15. Effects of solubility of urban air fine and coarse particles on cytotoxic and inflammatory responses in RAW 264.7 macrophage cell line

    SciTech Connect

    Jalava, Pasi I. Salonen, Raimo O.; Pennanen, Arto S.; Happo, Mikko S.; Penttinen, Piia; Haelinen, Arja I.; Sillanpaeae, Markus; Hillamo, Risto; Hirvonen, Maija-Riitta

    2008-06-01

    We investigated the inflammatory and cytotoxic activities of the water-soluble and -insoluble as well as organic-solvent-soluble and -insoluble fractions of urban air fine (PM{sub 2.5-0.2}) and coarse (PM{sub 10-2.5}) particulate samples. The samples were collected with a high volume cascade impactor (HVCI) in 7-week sampling campaigns of selected seasons in six European cities. Mouse macrophage cells (RAW 264.7) were exposed to the samples for 24 h. The production of nitric oxide (NO) and proinflammatory cytokines (TNF{alpha}, IL-6), and cytotoxicity (MTT-test, apoptosis, cell cycle) were measured. The inflammatory and cytotoxic responses in both size ranges were mostly associated with the insoluble particulate fractions. However, both the water- and organic-solvent-soluble particulate fractions induced TNF{alpha} production and apoptosis and had some other cytotoxic effects. Soil-derived water-soluble and -insoluble components of the chemical PM{sub 2.5-0.2} mass closure had consistent positive correlations with the responses, while the correlations were negative with the secondary inorganic anions (NO{sub 3}{sup -}, NH{sub 4}{sup +}, non-sea-salt SO{sub 4}{sup 2-}) and particulate organic matter (POM). With the PM{sub 10-2.5} samples, sea salt and soluble soil components correlated positively with the induced toxic responses. In this size range, a possible underestimation of the insoluble, soil-related compounds containing Si and Ca, and biological components of POM, increased uncertainties in the evaluation of associations of the mass closure components with the responses. It is concluded that insoluble components of the complex urban air particulate mixture exert the highest inflammatory and cytotoxic activities in the macrophage cell line but, at the same time, they may operate as carriers for active water- and lipid-soluble components.

  16. Air toxics regulatory issues facing urban settings

    SciTech Connect

    Olden, K.; Guthrie, J.

    1996-10-01

    Biomarker research does not exist in isolation. Its usefulness can only be realized when it is translated into prevention strategies to protect public health. In the context of air toxics, these prevention strategies begin with the development of regulatory standards derived from risk assessment schemes. The Clean Air Act Amendments of 1990 list 189 air toxics, including many volatile organics, metals, and pesticides. The National Institute of Environmental Health Sciences (NIEHS), through its affiliation with the National Toxicology Program, has generated toxicity and carcinogenicity data on more than 100 of these air toxics. The NIEHS extramural and intramural research portfolios support a variety of projects that develop and validate biomarkers for use in environmental health science and risk assessment. Biomarkers have a tremendous potential in the areas of regulating air toxics and protecting public health. Risk assessors need data provided by biomarkers of exposure, biomarkers of close/pharmacokinetics, biomarkers of susceptibility or individual variability, and biomarkers of effects. The greatest benefit would be realized if biomarkers could be employed in four areas of primary and secondary prevention. The first is the use of biomarkers to enhance extrapolation of animal data to human exposure situations in establishing risk standards. The second is the use of biomarkers that assess noncancer, as well as cancer, end points. Important health end points include pulmonary dysfunction, immunotoxicity, and neurotoxicity. Third, biomarkers that serve as early warning signs to detect intermediate effects would enhance our ability to design timely and cost-effective intervention strategies. Finally, biomarkers used to evaluate the effectiveness of intervention strategies both in clinical and regulatory settings, would enable us to ensure that programs designed to protect public health do, in fact, achieve the desired outcome. 9 refs., 2 tabs.

  17. Urban compaction or dispersion? An air quality modelling study

    NASA Astrophysics Data System (ADS)

    Martins, Helena

    2012-07-01

    Urban sprawl is altering the landscape, with current trends pointing to further changes in land use that will, in turn, lead to changes in population, energy consumption, atmospheric emissions and air quality. Urban planners have debated on the most sustainable urban structure, with arguments in favour and against urban compaction and dispersion. However, it is clear that other areas of expertise have to be involved. Urban air quality and human exposure to atmospheric pollutants as indicators of urban sustainability can contribute to the discussion, namely through the study of the relation between urban structure and air quality. This paper addresses the issue by analysing the impacts of alternative urban growth patterns on the air quality of Porto urban region in Portugal, through a 1-year simulation with the MM5-CAMx modelling system. This region has been experiencing one of the highest European rates of urban sprawl, and at the same time presents a poor air quality. As part of the modelling system setup, a sensitivity study was conducted regarding different land use datasets and spatial distribution of emissions. Two urban development scenarios were defined, SPRAWL and COMPACT, together with their new land use and emission datasets; then meteorological and air quality simulations were performed. Results reveal that SPRAWL land use changes resulted in an average temperature increase of 0.4 °C, with local increases reaching as high as 1.5 °C. SPRAWL results also show an aggravation of PM10 annual average values and an increase in the exceedances to the daily limit value. For ozone, differences between scenarios were smaller, with SPRAWL presenting larger concentration differences than COMPACT. Finally, despite the higher concentrations found in SPRAWL, population exposure to the pollutants is higher for COMPACT because more inhabitants are found in areas of highest concentration levels.

  18. A FEDERATED PARTNERSHIP FOR URBAN METEOROLOGICAL AND AIR QUALITY MODELING

    EPA Science Inventory

    Recently, applications of urban meteorological and air quality models have been performed at resolutions on the order of km grid sizes. This necessitated development and incorporation of high resolution landcover data and additional boundary layer parameters that serve to descri...

  19. [Spatiotemporal distribution of negative air ion concentration in urban area and related affecting factors: a review].

    PubMed

    Huang, Xiang-Hua; Wang, Jian; Zeng, Hong-Da; Chen, Guang-Shui; Zhong, Xian-Fang

    2013-06-01

    Negative air ion (NAI) concentration is an important indicator comprehensively reflecting air quality, and has significance to human beings living environment. This paper summarized the spatiotemporal distribution features of urban NAI concentration, and discussed the causes of these features based on the characteristics of the environmental factors in urban area and their effects on the physical and chemical processes of NAI. The temporal distribution of NAI concentration is mainly controlled by the periodic variation of solar radiation, while the spatial distribution of NAI concentration along the urban-rural gradient is mainly affected by the urban aerosol distribution, underlying surface characters, and urban heat island effect. The high NAI concentration in urban green area is related to the vegetation life activities and soil radiation, while the higher NAI concentration near the water environment is attributed to the water molecules that participate in the generation of NAI through a variety of ways. The other environmental factors can also affect the generation, life span, component, translocation, and distribution of NAI to some extent. To increase the urban green space and atmospheric humidity and to maintain the soil natural attributes of underlying surface could be the effective ways to increase the urban NAI concentration and improve the urban air quality.

  20. 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.

  1. Linking Urban Air Pollution to Global Tropospheric Chemistry and Climate

    NASA Technical Reports Server (NTRS)

    Wang, Chien

    2005-01-01

    The two major tasks of this project are to study: (a) the impact of urban nonlinear chemistry on chemical budgets of key pollutants in non-urban areas; and (b) the influence of air pollution control strategies in selected metropolitan areas, particularly of emerging economies in East and South Asia, on tropospheric chemistry and hence on regional and global climate.

  2. Nitrated polycyclic aromatic hydrocarbons in urban air particles

    SciTech Connect

    Ramdahl, T.; Becher, G.; Bjorseth, A.

    1982-12-01

    The organic extract of urban air particles from St. Louis, MO, was fractionated by high-performance liquid chromatography. The moderately polar fraction was characterized by gas chromatography-electron impact and methane negative ion chemical ionization mass spectrometry. The compounds identified in the sample included nitronaphthalene, 9-nitroanthracene, 3-nitrofluoranthene, 1-nitropyrene, arenecarbonitriles, and several polycyclic ketones, quinones, and anhydrides. These studies represent the first mass spectrometric evidence of nitroaromatics in urban air particles.

  3. Urban sprawl and air quality in large US cities.

    PubMed

    Stone, Brian

    2008-03-01

    This study presents the results of a paper of urban spatial structure and exceedances of the 8-h national ambient air quality standard for ozone in 45 large US metropolitan regions. Through the integration of a published index of sprawl with metropolitan level data on annual ozone exceedances, precursor emissions, and regional climate over a 13-year period, the association between the extent of urban decentralization and the average number of ozone exceedances per year, while controlling for precursor emissions and temperature, is measured. The results of this analysis support the hypothesis that large metropolitan regions ranking highly on a quantitative index of sprawl experience a greater number of ozone exceedances than more spatially compact metropolitan regions. Importantly, this relationship was found to hold when controlling for population size, average ozone season temperatures, and regional emissions of nitrogen oxides and volatile organic compounds, suggesting that urban spatial structure may have effects on ozone formation that are independent of its effects on precursor emissions from transportation, industry, and power generation facilities.

  4. The effect of long-range air mass transport pathways on PM10 and NO2 concentrations at urban and rural background sites in Ireland: Quantification using clustering techniques.

    PubMed

    Donnelly, Aoife A; Broderick, Brian M; Misstear, Bruce D

    2015-01-01

    The specific aims of this paper are to: (i) quantify the effects of various long range transport pathways nitrogen dioxide (NO2) and particulate matter with diameter less than 10μm (PM10) concentrations in Ireland and identify air mass movement corridors which may lead to incidences poor air quality for application in forecasting; (ii) compare the effects of such pathways at various sites; (iii) assess pathways associated with a period of decreased air quality in Ireland. The origin of and the regions traversed by an air mass 96h prior to reaching a receptor is modelled and k-means clustering is applied to create air-mass groups. Significant differences in air pollution levels were found between air mass cluster types at urban and rural sites. It was found that easterly or recirculated air masses lead to higher NO2 and PM10 levels with average NO2 levels varying between 124% and 239% of the seasonal mean and average PM10 levels varying between 103% and 199% of the seasonal mean at urban and rural sites. Easterly air masses are more frequent during winter months leading to higher overall concentrations. The span in relative concentrations between air mass clusters is highest at the rural site indicating that regional factors are controlling concentration levels. The methods used in this paper could be applied to assist in modelling and forecasting air quality based on long range transport pathways and forecast meteorology without the requirement for detailed emissions data over a large regional domain or the use of computationally demanding modelling techniques.

  5. Effect of air pollution and racism on ethnic differences in respiratory health among adolescents living in an urban environment.

    PubMed

    Astell-Burt, Thomas; Maynard, Maria J; Lenguerrand, Erik; Whitrow, Melissa J; Molaodi, Oarabile R; Harding, Seeromanie

    2013-09-01

    Recent studies suggest that stress can amplify the harm of air pollution. We examined whether experience of racism and exposure to particulate matter with an aerodynamic diameter of less than 2.5 µm and 10 µm (PM2.5 and PM10) had a synergistic influence on ethnic differences in asthma and lung function across adolescence. Analyses using multilevel models showed lower forced expiratory volume (FEV1), forced vital capacity (FVC) and lower rates of asthma among some ethnic minorities compared to Whites, but higher exposure to PM2.5, PM10 and racism. Racism appeared to amplify the relationship between asthma and air pollution for all ethnic groups, but did not explain ethnic differences in respiratory health.

  6. Development of Gridded Fields of Urban Canopy Parameters for Advanced Urban Meteorological and Air Quality Models

    EPA Science Inventory

    Urban dispersion and air quality simulation models applied at various horizontal scales require different levels of fidelity for specifying the characteristics of the underlying surfaces. As the modeling scales approach the neighborhood level (~1 km horizontal grid spacing), the...

  7. Urban air quality of Kathmandu valley

    SciTech Connect

    Sharma, C.K.

    1996-12-31

    The oval shaped tectonic basin of Kathmandu valley occupying about 600 sq. km. of area is situated in the middle sector of Himalayan range. There are three districts in the alley, i.e. Kathmandu, Litilpur, and Bhaktapur. Out of the three the most populated is the Kathmandu city (the capital of Kingdom of Nepal) which has 668,000 population in an area of approximately 50 sq. km. The city population consumes energy about 1/3 of total imports of Nepal in the form of gasoline, diesel, kerosene, furnace oil and cooking gas. This has resulted heavy pollution of air in the city leading bronchitis, and throat and chest diseases. Vehicle has increased several fold leading in recent months to 100,000 in number in a road of about 900 kms., out of which 25% is only metalled. Most of two and three wheelers are polluting the air by emission gases as well as dust particulate. SO{sub 2} has been found to go as high as 202 micro grams per cubic meter and NO{sub 2} to 126 micro gram particularly in winter months when a thick layer of fog covers the valley up to 10:00 AM in the morning. All the gases are mixed within the limited air below the fog and the ground. This creates the problem. Furthermore, municipal waste of 500 m{sup 3} a day and also liquid waste directly dumping in Bagmati river to the tune of 500,000 liters per day makes city ugly and filthy. Unless pollution of air, water, and land are controlled in time, Nepal will lose much of its foreign exchange earnings from tourist industry. It is found that tourist arrivals are considerably reduced in recent years and most of hotels occupancy is 50 to 60% in peak time. Nepal is trying to introduce legal frame work for pollution control but it will take time to be effective like in other developing countries unless government is strong.

  8. Simulating urban-scale air pollutants and their predicting capabilities over the Seoul metropolitan area.

    PubMed

    Park, Il-Soo; Lee, Suk-Jo; Kim, Cheol-Hee; Yoo, Chul; Lee, Yong-Hee

    2004-06-01

    Urban-scale air pollutants for sulfur dioxide, nitrogen dioxide, particulate matter with aerodynamic diameter > or = 10 microm, and ozone (O3) were simulated over the Seoul metropolitan area, Korea, during the period of July 2-11, 2002, and their predicting capabilities were discussed. The Air Pollution Model (TAPM) and the highly disaggregated anthropogenic and the biogenic gridded emissions (1 km x 1 km) recently prepared by the Korean Ministry of Environment were applied. Wind fields with observational nudging in the prognostic meteorological model TAPM are optionally adopted to comparatively examine the meteorological impact on the prediction capabilities of urban-scale air pollutants. The result shows that the simulated concentrations of secondary air pollutant largely agree with observed levels with an index of agreement (IOA) of >0.6, whereas IOAs of approximately 0.4 are found for most primary pollutants in the major cities, reflecting the quality of emission data in the urban area. The observationally nudged wind fields with higher IOAs have little effect on the prediction for both primary and secondary air pollutants, implying that the detailed wind field does not consistently improve the urban air pollution model performance if emissions are not well specified. However, the robust highest concentrations are better described toward observations by imposing observational nudging, suggesting the importance of wind fields for the predictions of extreme concentrations such as robust highest concentrations, maximum levels, and >90th percentiles of concentrations for both primary and secondary urban-scale air pollutants.

  9. Monitoring human exposure to urban air pollutants

    SciTech Connect

    Barale, R.; Barrai, I.; Marrazzini, A.

    1993-10-01

    A multidisciplinary study on a general population exposed to vehicle exhaust was undertaken in Pisa in 1991. Environmental factors such as air pollution and those associated with lifestyle were studied. Meanwhile, biological and medical indicators of health condition were investigated. Chromosomal aberrations, sister chromatid exchanges (SCEs), and micronuclei in lymphocytes were included for the assessment of the genotoxic risk. Because of the large number (3800) of subjects being investigated, standardization of protocols was compulsory. The results on data reproducibility are reported. To assess the reliability of the protocol on a large scale, the population of Porto Tolle, a village located in northeast Italy, was studied and compared to a subset of the Pisa population. Preliminary results showed that probable differences between the two populations and individuals were present in terms of SCE frequencies. The study was potentially able to detect the effects of several factors such as age, smoking, genetics, and environment. The in vitro treatment of lymphocytes with diepoxybutane confirmed the presence of more responsive individuals and permitted us to investigate the genetic predisposition to genetic damage. The possible influence of environmental factors was studied by correlation analyses with external exposure to air pollutants as well as with several lifestyle factors. 10 refs., 5 figs., 1 tab.

  10. Contribution of Urban Heat Island Effect to Urban Warming

    NASA Astrophysics Data System (ADS)

    Ma, Y.

    2013-12-01

    Urban heat island effect of Lanzhou city in china is analyzed using the average temperature, the maximum temperature and the minimum temperature during 1971-2008. Then the heat island intensity trends and contribution rates are calculated using the linear trends of three temperatures of Lanzhou city and the suburb. Results show that the differences of three temperatures between Lanzhou city and the suburb are all taking on increasing trends. The linear trends of average temperature, the maximum temperature and the minimum temperature are 0.3730C /10a,0.1870C /10a and 0.5200C /10a,respectively. The minimum temperature increases most obviously. In recent 38 years,temperatures increase mainly in the latter 19 years (1990-2008), and the linear trends of average temperature, maximum temperature and the minimum temperature of Lanzhou city are 0.6700C/10a,0.1180C/10a and 1.0320C/10a, respectively while those of the suburb are 0.6220C/10a, 0.0710C/10a and 1.130C/10a. The heat island contribution rates of three temperatures are 57.0%, 45.3% and 63.1%, respectively. The linear trends of average temperature and the minimum temperature in winter are the most in both city and the suburb, but the heat island contribution rate of the winter temperatures are not the largest, this possibly related with the severe air pollution in winter in Lanzhou city, because it can hold back urban heat island in some extent. In the latter 19 year,urban heat island effect of Lanzhou city was becoming stronger, but the contribution rates of average temperature and the maximum temperature are declining. This study is important to city planning and studying urbanization and the effect of environmental change on urban temperature.

  11. CFD Modeling For Urban Air Quality Studies

    SciTech Connect

    Lee, R L; Lucas, L J; Humphreys, T D; Chan, S T

    2003-10-27

    The computational fluid dynamics (CFD) approach has been increasingly applied to many atmospheric applications, including flow over buildings and complex terrain, and dispersion of hazardous releases. However there has been much less activity on the coupling of CFD with atmospheric chemistry. Most of the atmospheric chemistry applications have been focused on the modeling of chemistry on larger spatial scales, such as global or urban airshed scale. However, the increased attentions to terrorism threats have stimulated the need of much more detailed simulations involving chemical releases within urban areas. This motivated us to develop a new CFD/coupled-chemistry capability as part of our modeling effort.

  12. SIMULATING URBAN AIR TOXICS OVER CONTINENTAL AND URBAN SCALES

    EPA Science Inventory

    The US EPA is evaluating a version of the CMAQ model to support risk assessment for the exposure to Hazardous Air Pollutants (HAPs). The model uses a variant of the CB4 chemical mechanism to simulate ambient concentrations of twenty HAPs that exist primarily as gaseous compounds...

  13. Urban Heat Island Versus Air Quality - a Numerical Modelling Study for a European City

    NASA Astrophysics Data System (ADS)

    Fallmann, J.; Forkel, R.; Emeis, S.

    2014-12-01

    In 2050 70% of the global population is expected to live in urban areas. Climate change will render these areas more vulnerable to heat waves, which often are accompanied by severe air pollution problems. The Urban Heat Island (UHI) is a feature that adds to the general temperature increase that is expected. Decreasing the UHI can impact air quality as well, because heat influences atmospheric dynamics and accelerates air chemical processes and often also increases the emission of primary pollutants due to increased demand of energy. The goal of this study is to investigate the effect of, e.g., high reflective surfaces and urban greening on mitigating the UHI and the related impact on air quality. A multi-layer urban canopy model is coupled to the mesoscale model WRF-Chem and the urban area of Stuttgart (South-West Germany) is taken as one example. Different scenario runs are executed for short time periods and are compared to a control run. The results show that the UHI effect can be substantially reduced when changing the albedo of roof surfaces, whereas the effect of urban greening is minor. Both scenarios have in common, that they evoke changes in secondary circulation patterns. The effects of these mitigation strategies on chemical composition of the urban atmosphere are complex, attributed to both chemical and dynamical features. Increasing the reflectivity of roof surfaces in the model results in a net decrease of the surface ozone concentration, because ozone formation is highly correlated to temperature. With regard to primary pollutants, e.g. NO, CO and PM10 concentrations are increased when increasing reflectivity. This effect primarily can be ascribed to a reduction of turbulent motion, convection and a decrease of the boundary layer height, coming along with lower temperatures in the urban canopy layer due to increased reflectivity. The table below shows the effect on grid cell mean concentrations for different chemical species and scenarios.

  14. Energy Saving Potentials and Air Quality Benefits of Urban Heat Island Mitigation

    SciTech Connect

    Akbari, Hashem

    2005-08-23

    Urban areas tend to have higher air temperatures than their rural surroundings as a result of gradual surface modifications that include replacing the natural vegetation with buildings and roads. The term ''Urban Heat Island'' describes this phenomenon. The surfaces of buildings and pavements absorb solar radiation and become extremely hot, which in turn warm the surrounding air. Cities that have been ''paved over'' do not receive the benefit of the natural cooling effect of vegetation. As the air temperature rises, so does the demand for air-conditioning (a/c). This leads to higher emissions from power plants, as well as increased smog formation as a result of warmer temperatures. In the United States, we have found that this increase in air temperature is responsible for 5-10% of urban peak electric demand for a/c use, and as much as 20% of population-weighted smog concentrations in urban areas. Simple ways to cool the cities are the use of reflective surfaces (rooftops and pavements) and planting of urban vegetation. On a large scale, the evapotranspiration from vegetation and increased reflection of incoming solar radiation by reflective surfaces will cool a community a few degrees in the summer. As an example, computer simulations for Los Angeles, CA show that resurfacing about two-third of the pavements and rooftops with reflective surfaces and planting three trees per house can cool down LA by an average of 2-3K. This reduction in air temperature will reduce urban smog exposure in the LA basin by roughly the same amount as removing the basin entire onroad vehicle exhaust. Heat island mitigation is an effective air pollution control strategy, more than paying for itself in cooling energy cost savings. We estimate that the cooling energy savings in U.S. from cool surfaces and shade trees, when fully implemented, is about $5 billion per year (about $100 per air-conditioned house).

  15. Role of Surface Characteristics in Urban Meteorology and Air Quality

    NASA Astrophysics Data System (ADS)

    Sailor, David Jean

    Urbanization results in a landscape with significantly modified surface characteristics. The lower values of reflectivity to solar radiation, surface moisture availability, and vegetative cover, along with the higher values of anthropogenic heat release and surface roughness combine to result in higher air temperatures in urban areas relative to their rural counterparts. Through their role in the surface energy balance and surface exchange processes, these surface characteristics are capable of modifying the local meteorology. The impacts on wind speeds, air temperatures, and mixing heights are of particular importance, as they have significant implications in terms of urban energy use and air quality. This research presents several major improvements to the meteorological modeling methodology for highly heterogeneous terrain. A land-use data base is implemented to provide accurate specification of surface characteristic variability in simulations of the Los Angeles Basin. Several vegetation parameterizations are developed and implemented, and a method for including anthropogenic heat release into the model physics is presented. These modeling advancements are then used in a series of three-dimensional simulations which were developed to investigate the potential meteorological impact of several mitigation strategies. Results indicate that application of moderate tree-planting and urban-lightening programs in Los Angeles may produce summertime air temperature reductions on the order of 4^circ C with a concomitant reduction in air pollution. The analysis also reveals several mechanisms whereby the application of these mitigation strategies may potentially increase pollutant concentrations. The pollution and energy use consequences are discussed in detail.

  16. Role of surface characteristics in urban meteorology and air quality

    SciTech Connect

    Sailor, David Jean

    1993-08-01

    Urbanization results in a landscape with significantly modified surface characteristics. The lower values of reflectivity to solar radiation, surface moisture availability, and vegetative cover, along with the higher values of anthropogenic heat release and surface roughness combine to result higher air temperatures in urban areas relative to their rural counterparts. Through their role in the surface energy balance and surface exchange processes, these surface characteristics are capable of modifying the local meteorology. The impacts on wind speeds, air temperatures, and mixing heights are of particular importance, as they have significant implications in terms of urban energy use and air quality. This research presents several major improvements to the meteorological modeling methodology for highly heterogeneous terrain. A land-use data-base is implemented to provide accurate specification of surface characteristic variability in simulations of the Los Angeles Basin. Several vegetation parameterizations are developed and implemented, and a method for including anthropogenic heat release into the model physics is presented. These modeling advancements are then used in a series of three-dimensional simulations which were developed to investigate the potential meteorological impact of several mitigation strategies. Results indicate that application of moderate tree-planting and urban-lightening programs in Los Angeles may produce summertime air temperature reductions on the order of 4°C with a concomitant reduction in air pollution. The analysis also reveals several mechanisms whereby the application of these mitigation strategies may potentially increase pollutant concentrations. The pollution and energy use consequences are discussed in detail.

  17. Urban Air Quality Modelling with AURORA: Prague and Bratislava

    NASA Astrophysics Data System (ADS)

    Veldeman, N.; Viaene, P.; De Ridder, K.; Peelaerts, W.; Lauwaet, D.; Muhammad, N.; Blyth, L.

    2012-04-01

    The European Commission, in its strategy to protect the health of the European citizens, states that in order to assess the impact of air pollution on public health, information on long-term exposure to air pollution should be available. Currently, indicators of air quality are often being generated using measured pollutant concentrations. While air quality monitoring stations data provide accurate time series information at specific locations, air quality models have the advantage of being able to assess the spatial variability of air quality (for different resolutions) and predict air quality in the future based on different scenarios. When running such air quality models at a high spatial and temporal resolution, one can simulate the actual situation as closely as possible, allowing for a detailed assessment of the risk of exposure to citizens from different pollutants. AURORA (Air quality modelling in Urban Regions using an Optimal Resolution Approach), a prognostic 3-dimensional Eulerian chemistry-transport model, is designed to simulate urban- to regional-scale atmospheric pollutant concentration and exposure fields. The AURORA model also allows to calculate the impact of changes in land use (e.g. planting of trees) or of emission reduction scenario's on air quality. AURORA is currently being applied within the ESA atmospheric GMES service, PASODOBLE (http://www.myair-eu.org), that delivers information on air quality, greenhouse gases, stratospheric ozone, … At present there are two operational AURORA services within PASODOBLE. Within the "Air quality forecast service" VITO delivers daily air quality forecasts for Belgium at a resolution of 5 km and for the major Belgian cities: Brussels, Ghent, Antwerp, Liege and Charleroi. Furthermore forecast services are provided for Prague, Czech Republic and Bratislava, Slovakia, both at a resolution of 1 km. The "Urban/regional air quality assessment service" provides urban- and regional-scale maps (hourly resolution

  18. 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 ...

  19. Spatial connectivity of urban clusters and regional climate effects

    NASA Astrophysics Data System (ADS)

    Jia, G.; Hu, Y.; Xu, R.

    2015-12-01

    Rapid urbanization in East Asia in past three decades is considered as a remarkable process that featured with expansion of urban clusters and tightened linkages within and among clusters. Such process could lead to much larger scale climate effects, and could even contribute to sub-regional and regional climate change. In large area of urban clusters with significant expansion of built-up in relatively short period, local urban heat islands could contribute to sub-regional climate forcing. Here we use visible/near infrared and thermal infrared satellite data to estimate multiple scale structure of urban clusters, and to assess effects of urban heat islands at local and regional scales in East Asia. Our estimates of urban extent were greater than previously reported in most global datasets. Strong spatial connection and internal expansion were found in major urban clusters in past 30 years, and was accelerated in past 10 years. Many city clusters were merging into each other, with gradual blurring boundaries and disappearing of gaps among member cities. Cities and towns were more connected with roads and commercial corridors, while wildland and urban greens became more isolated as patches among built-up areas. We would argue that in many cases in this region, urban clusters are no longer "islands", they are now "seas" in term of climate related urban canopy. Urban greens such as parks and plantation were long recognized for their cooling effects that buffer the urban heat island effect, however, such cooling effects tend to be weakened as their patches became smaller and isolated, and over dominated by urban surfaces. There were significant positive relations between urban fraction and urban heat island effects as demonstrated by VNIR and TIR data from multiple satellites. Those new estimates are expected to effectively improve climate simulation for better understanding the impacts of inter-connected urban clusters on air temperature, precipitation, wind speed

  20. Quantifying air pollution attenuation within urban parks: an experimental approach in Shanghai, China.

    PubMed

    Yin, Shan; Shen, Zhemin; Zhou, Pisheng; Zou, Xiaodong; Che, Shengquan; Wang, Wenhua

    2011-01-01

    Parks with various types of vegetations played an important role in ameliorating air quality in urban areas. However, the attenuation effect of urban vegetation on levels of air pollution was rarely been experimentally estimated. This study, using seasonal monitoring data of total suspended particles (TSP), sulfur dioxide (SO(2)) and nitrogen dioxide (NO(2)) from six parks in Pudong District, Shanghai, China, demonstrated vegetations in parks can remove large amount of airborne pollutants. In addition, crown volume coverage (CVC) was introduced to characterize vegetation conditions in parks and a mixed-effects model indicated that CVC and the pollution diffusion distance were key predictors influencing pollutants removal rate. Therefore, it could be estimated by regression analysis that in summer, urban vegetations in Pudong District could contribute to 9.1% of TSP removal, 5.3% of SO(2) and 2.6% of NO(2). The results could be considered for a better park planning and improving air quality.

  1. 3-D simulation of urban warming in Tokyo and proposal of air-cooled city project

    SciTech Connect

    Saitoh, T.S.; Yamada, Noboru

    1999-07-01

    Recent computer projection of the urban warming in Tokyo metropolitan area around the year 2030 showed the authors that the urban temperature near Otemachi, heart of Tokyo, will exceed 43{+-}2 degree Celsius (110 degree Fahrenheit) at 6 p.m. in the summer. In the present paper, modeling and 3-D simulation results of urban warming in the Tokyo metropolitan area were presented and discussed. Furthermore, the effect of the reduction of carbon dioxide (CO{sub 2}) emissions was discussed by using a newly developed 3-D simulation code. Finally, the authors proposed a new concept; cool-air ventilated city project, which alleviates the urban warming, air pollution, and urban discomfort. In this project, the urban outdoor and indoor spaces are ventilated by clean cooled-air, which is produced in the rural or mountainous regions located far away from the urban area. Water of a huge reservoir is cooled below 4 degree Celsius in winter by utilizing sky radiation cooling and will be kept until the summer for indoor and outdoor space cooling. In this study, the feasibility of this system was discussed.

  2. Impact of local urban design and traffic restrictions on air quality in a medium-sized town.

    PubMed

    Acero, J A; Simon, A; Padro, A; Santa Coloma, O

    2012-01-01

    Traffic is the major air pollution source in most urban areas. Nowadays, most of the strategies carried out to improve urban air quality are focused on reducing traffic emissions. Nevertheless, acting locally on urban design can also reduce levels of air pollutants. In this paper, both strategies are studied in several scenarios for a medium-sized town of the Basque Country (Spain). Two main actions are analysed in order to reduce traffic emissions: (1) minor extension ofa pre-existing low emission zone (LEZ); (2) substitution of 10% of passenger cars that are older than 5 years by hybrid and electric vehicles. Regarding local urban design, three alternatives for the development of one side of a street canyon are considered: (1) a park with trees; (2) an open space without obstacles; (3) a building. Two different urban traffic dispersion models are used to calculate the air quality scenarios: PROKAS (Gaussian&box) to analyse the reduction of traffic emissions in the whole urban area and WinMISKAM (CFD) to evaluate specific urban designs. The results show the effectiveness of the analysed actions. On one hand, the definition of a small LEZ, as well as the introduction in 2015 of vehicles with new technology (hybrid and electric), results in minor impacts on PM10 and NO2 ambient concentrations. On the other hand, local urban design can cause significant variation in spatial distribution ofpollutant concentrations emitted inside street canyons. Consequently, urban planners should consider all these aspects when dealing with urban air pollution control.

  3. Improving urban air quality in China: Beijing case study.

    PubMed

    Hao, Jiming; Wang, Litao

    2005-09-01

    China is undergoing rapid urbanization because of unprecedented economic growth. As a result, many cities suffer from air pollution. Two-thirds of China's cities have not attained the ambient air quality standards applicable to urban residential areas (Grade II). Particulate matter (PM), rather than sulfur dioxide (SO2), is the major pollutant reflecting the shift from coal burning to mixed source pollution. In 2002, 63.2 and 22.4% of the monitored cities have PM and SO2 concentrations exceeding the Grade II standard, respectively. Nitrogen oxides (NOx) concentration kept a relatively stable level near the Grade II standard in the last decade and had an increasing potential in recent years because of the rapid motorization. In general, the air pollutants emission did not increase as quickly as the economic growth and energy consumption, and air quality in Chinese cities has improved to some extent. Beijing, a typical representative of rapidly developing cities, is an example to illustrate the possible options for urban air pollution control. Beijing's case provides hope that the challenges associated with improving air quality can be met during a period of explosive development and motorization.

  4. Improving urban air quality in China: Beijing case study

    SciTech Connect

    Jiming Hao; Litao Wang

    2005-09-01

    China is undergoing rapid urbanization because of unprecedented economic growth. As a result, many cities suffer from air pollution. Two-thirds of China's cities have not attained the ambient air quality standards applicable to urban residential areas (Grade II). Particulate matter (PM), rather than sulfur dioxide (SO{sub 2}), is the major pollutant reflecting the shift from coal burning to mixed source pollution. In 2002, 63.2 and 22.4% of the monitored cities have PM and SO{sub 2} concentrations exceeding the Grade II standard, respectively. Nitrogen oxides (NOx) concentration kept a relatively stable level near the Grade II standard in the last decade and had an increasing potential in recent years because of the rapid motorization. In general, the air pollutants emission did not increase as quickly as the economic growth and energy consumption, and air quality in Chinese cities has improved to some extent. Beijing, a typical representative of rapidly developing cities, is an example to illustrate the possible options for urban air pollution control. Beijing's case provides hope that the challenges associated with improving air quality can be met during a period of explosive development and motorization. 21 refs., 19 figs., 6 tabs.

  5. Public's Health Risk Awareness on Urban Air Pollution in Chinese Megacities: The Cases of Shanghai, Wuhan and Nanchang.

    PubMed

    Liu, Xiaojun; Zhu, Hui; Hu, Yongxin; Feng, Sha; Chu, Yuanyuan; Wu, Yanyan; Wang, Chiyu; Zhang, Yuxuan; Yuan, Zhaokang; Lu, Yuanan

    2016-08-25

    This study assessed the public's health risk awareness of urban air pollution triggered by three megacities in China, and the data are the responses from a sample size of 3868 megacity inhabitants from Shanghai, Nanchang and Wuhan. Descriptive analyses were used to summarize the respondents' demographics, perceived health risks from air pollution and sources of health-related knowledge on urban air pollution. Chi-square tests were used to examine if participants' demographics were associated with participant's general attitudes towards current air quality and the three perceived highest health risks due to urban air pollution. We found low rate of satisfaction of current urban air quality as well as poor knowledge of air pollution related indicator. Participants' gender, age and travel experience were found to be associated with the satisfaction of current air quality. The knowledge of air pollution related indicator was significantly affected by respondents' education, monthly income, health status, and sites of study. As many as 46.23% of the participants expressed their feelings of anxiety when exposed to polluted air, especially females, older adults and those with poor health conditions. Most participants believed that coughs/colds, eye problems and skin allergies were the three highest health risks due to urban air pollution based on public education through television/radio, internet and newspaper/magazine. Further public health education is needed to improve public awareness of air pollution and its effects.

  6. Public’s Health Risk Awareness on Urban Air Pollution in Chinese Megacities: The Cases of Shanghai, Wuhan and Nanchang

    PubMed Central

    Liu, Xiaojun; Zhu, Hui; Hu, Yongxin; Feng, Sha; Chu, Yuanyuan; Wu, Yanyan; Wang, Chiyu; Zhang, Yuxuan; Yuan, Zhaokang; Lu, Yuanan

    2016-01-01

    This study assessed the public’s health risk awareness of urban air pollution triggered by three megacities in China, and the data are the responses from a sample size of 3868 megacity inhabitants from Shanghai, Nanchang and Wuhan. Descriptive analyses were used to summarize the respondents’ demographics, perceived health risks from air pollution and sources of health-related knowledge on urban air pollution. Chi-square tests were used to examine if participants’ demographics were associated with participant’s general attitudes towards current air quality and the three perceived highest health risks due to urban air pollution. We found low rate of satisfaction of current urban air quality as well as poor knowledge of air pollution related indicator. Participants’ gender, age and travel experience were found to be associated with the satisfaction of current air quality. The knowledge of air pollution related indicator was significantly affected by respondents’ education, monthly income, health status, and sites of study. As many as 46.23% of the participants expressed their feelings of anxiety when exposed to polluted air, especially females, older adults and those with poor health conditions. Most participants believed that coughs/colds, eye problems and skin allergies were the three highest health risks due to urban air pollution based on public education through television/radio, internet and newspaper/magazine. Further public health education is needed to improve public awareness of air pollution and its effects. PMID:27571088

  7. A theoretical framework for the episodic-urban air quality management plan ( e-UAQMP)

    NASA Astrophysics Data System (ADS)

    Gokhale, Sharad; Khare, Mukesh

    The present research proposes the local urban air quality management plan which combines two different modelling approaches (hybrid model) and possesses an improved predictive ability including the 'probabilistic exceedances over norms' and their 'frequency of occurrences' and so termed, herein, as episodic-urban air quality management plan ( e-UAQMP). The e-UAQMP deals with the consequences of 'extreme' concentrations of pollutant, mainly occurring at urban 'hotspots' e.g. traffic junctions, intersections and signalized roadways and are also influenced by complexities of traffic generated 'wake' effects. The e-UAQMP (based on probabilistic approach), also acts as an efficient preventive measure to predict the 'probability of exceedances' so as to prepare a successful policy responses in relation to the protection of urban environment as well as disseminating information to its sensitive 'receptors'. The e-UAQMP may be tailored to the requirements of the local area for the policy implementation programmes. The importance of such policy-making framework in the context of current air pollution 'episodes' in urban environments is discussed. The hybrid model that is based on both deterministic and stochastic based approaches predicting the 'average' as well as 'extreme' concentration distribution of air pollutants together in form of probability has been used at two air quality control regions (AQCRs) in the Delhi city, India, in formulating and executing the e-UAQMP— first, the income tax office (ITO), one of the busiest signalized traffic intersection and second, the Sirifort, one of the busiest signalized roadways.

  8. Application of 3-D Urbanization Index to Assess Impact of Urbanization on Air Temperature

    PubMed Central

    Wu, Chih-Da; Lung, Shih-Chun Candice

    2016-01-01

    The lack of appropriate methodologies and indicators to quantify three-dimensional (3-D) building constructions poses challenges to authorities and urban planners when formulating polices to reduce health risks due to heat stress. This study evaluated the applicability of an innovative three-dimensional Urbanization Index (3DUI), based on remote sensing database, with a 5 m spatial resolution of 3-D man-made constructions to representing intra-urban variability of air temperature by assessing correlation of 3DUI with air temperature from a 3-D perspective. The results showed robust high correlation coefficients, ranging from 0.83 to 0.85, obtained within the 1,000 m circular buffer around weather stations regardless of season, year, or spatial location. Our findings demonstrated not only the strength of 3DUI in representing intra-urban air-temperature variability, but also its great potential for heat stress assessment within cities. In view of the maximum correlation between building volumes within the 1,000 m circular buffer and ambient air temperature, urban planning should consider setting ceilings for man-made construction volume in each 2 × 2 km2 residential community for thermal environment regulation, especially in Asian metropolis with high population density in city centers. PMID:27079537

  9. Application of 3-D Urbanization Index to Assess Impact of Urbanization on Air Temperature

    NASA Astrophysics Data System (ADS)

    Wu, Chih-Da; Lung, Shih-Chun Candice

    2016-04-01

    The lack of appropriate methodologies and indicators to quantify three-dimensional (3-D) building constructions poses challenges to authorities and urban planners when formulating polices to reduce health risks due to heat stress. This study evaluated the applicability of an innovative three-dimensional Urbanization Index (3DUI), based on remote sensing database, with a 5 m spatial resolution of 3-D man-made constructions to representing intra-urban variability of air temperature by assessing correlation of 3DUI with air temperature from a 3-D perspective. The results showed robust high correlation coefficients, ranging from 0.83 to 0.85, obtained within the 1,000 m circular buffer around weather stations regardless of season, year, or spatial location. Our findings demonstrated not only the strength of 3DUI in representing intra-urban air-temperature variability, but also its great potential for heat stress assessment within cities. In view of the maximum correlation between building volumes within the 1,000 m circular buffer and ambient air temperature, urban planning should consider setting ceilings for man-made construction volume in each 2 × 2 km2 residential community for thermal environment regulation, especially in Asian metropolis with high population density in city centers.

  10. OVERVIEW OF THE MUTAGENICITY OF URBAN AIR

    EPA Science Inventory

    For the past 25 years, there has been great interest in the mutagenicity and carcinogenicity of ambient air and in the sources of those genotoxicants. Prior to the 1980's, the evaluation of airborne toxicants was done on a pollutant-by-pollutant basis. However, the assessment of ...

  11. Urban air pollution, poverty, violence and health--Neurological and immunological aspects as mediating factors.

    PubMed

    Kristiansson, Marianne; Sörman, Karolina; Tekwe, Carmen; Calderón-Garcidueñas, Lilian

    2015-07-01

    Rapid rural-urban migration has created overcrowded areas characterized by concentrated poverty and increases in indoor and outdoor air pollutants. These "hotspots" constitute an increased risk of violence and disease outbreaks. We hypothesize that the effects of poverty and associated air pollution-related stress on impaired cognitive skills are mediated by inflammatory cytokines. A research framework is proposed, encompassing (i) an epidemiological investigation of associations between poverty, high concentrations of air pollutants, violence and health, (ii) a longitudinal follow-up of working memory capacities and inflammatory markers, and (iii) intervention programs aiming to strengthen employability and decreased exposures to toxic air pollutants.

  12. Effects of Urban Morphology on Intra-Urban Temperature Differences: Two Squares in Glasgow City Centre

    NASA Astrophysics Data System (ADS)

    Drach, P. R. C.; Emmanuel, R.

    2014-12-01

    The perspective of climate change increases the necessity of tackling the urban over heating effects, by developing strategies to mitigate/adapt to changes. Analysing the influence of urban form on intra-urban temperature dynamics could be a helpful way of reducing its negative consequences. Also, it would help untangle the urban effect from the effect caused by atmospheric conditions. The present paper presents the effect of atmospheric conditions as exemplified by atmospheric stability (modified Pasquill-Gifford-Turner classification system) and urban morphology as measured by the Sky View Factor (SVF) on intra-urban variations in air temperature in a cold climate city, in and around the mature urban area of Glasgow, UK (55° 51' 57.294"N, 4° 15' 0.2628"W). The aim is to highlight their combined importance and to make preliminary investigations on the local warming effect of urban morphology under specific atmospheric stability classes. The present work indicates that the maximum intra-urban temperature differences (i.e. temperature difference between the coolest and the warmest spots in a given urban region) is strongly correlated with atmospheric stability. The spatial patterns in local temperature variations consistently show that water bodies and urban parks have lower temperature variations. Thus, greenery and urban materials could play an important role in influencing the local climate in cold cities. The knowledge of urban morphology's influence on local temperature variations could be an important tool for devising appropriate planning/design strategies to face urban overheating in the coming years as the background climate continues to warm.

  13. Uncertainty in mapping urban air quality using crowdsourcing techniques

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; Castell, Nuria; Lahoz, William; Bartonova, Alena

    2016-04-01

    Small and low-cost sensors measuring various air pollutants have become available in recent years owing to advances in sensor technology. Such sensors have significant potential for improving high-resolution mapping of air quality in the urban environment as they can be deployed in comparatively large numbers and therefore are able to provide information at unprecedented spatial detail. However, such sensor devices are subject to significant and currently little understood uncertainties that affect their usability. Not only do these devices exhibit random errors and biases of occasionally substantial magnitudes, but these errors may also shift over time. In addition, there often tends to be significant inter-sensor variability even when supposedly identical sensors from the same manufacturer are used. We need to quantify accurately these uncertainties to make proper use of the information they provide. Furthermore, when making use of the data and producing derived products such as maps, the measurement uncertainties that propagate throughout the analysis need to be clearly communicated to the scientific and non-scientific users of the map products. Based on recent experiences within the EU-funded projects CITI-SENSE and hackAIR we discuss the uncertainties along the entire processing chain when using crowdsourcing techniques for mapping urban air quality. Starting with the uncertainties exhibited by the sensors themselves, we present ways of quantifying the error characteristics of a network of low-cost microsensors and show suitable statistical metrics for summarizing them. Subsequently, we briefly present a data-fusion-based method for mapping air quality in the urban environment and illustrate how we propagate the uncertainties of the individual sensors throughout the mapping system, resulting in detailed maps that document the pixel-level uncertainty for each concentration field. Finally, we present methods for communicating the resulting spatial uncertainty

  14. Urbanization Effects on Manaus Microclimate

    NASA Astrophysics Data System (ADS)

    Souza, D. O. D.; Nascimento, M. G. D.; Alvalá, R.

    2014-12-01

    Urban growth, related to urbanization and consequent land use and land cover changes, can directly modify the Surface Energy Balance (SEB), generating changes in the atmosphere that can vary from local to regional scales. Trying to understand these effects, the main objective of this work is to study the influence of urbanization on the local microclimate of the city of Manaus through numerical simulations using three different scenarios of urban area growth. These scenarios consider a representation of the anthropogenic energy fluxes and physical characteristics of the urban area of Manaus, with a scenario related to urban characteristics in 2008, 1973 and a future scenario considering that the physical area of Manaus will be duplicated as well as anthropogenic fluxes. A first analysis of the results showed that the model has an excellent skill in representing the diurnal cycle of temperature and humidity in urban area. It was observed that the presence of the urban area modifies significantly the SEB, generating a thermal gradient between the city adjacent regions, favoring the formation and intensification of local atmospheric circulations. The growth of the urban area of Manaus had a direct influence on the SEB, where it was observed that with increase in its area there is an increase in temperature, a decrease in moisture and water vapor, as well as significant changes in the flow at low levels (Figure 1) and the structure and characteristic of ABL on the urban region. Was also observed that the flow at low levels, related with breeze circulations, has greater intensity mainly due to the intensification of the thermal gradient. In the general context of the results it was observed that the process of urbanization and the consequently increased of anthropogenic heat fluxes is directly related to changes in local microclimate. It is emphasized so that public policies that aim an organized growth of urban areas and the comfort of the population are necessary for

  15. Variability of air ion concentrations in urban Paris

    NASA Astrophysics Data System (ADS)

    Dos Santos, V. N.; Herrmann, E.; Manninen, H. E.; Hussein, T.; Hakala, J.; Nieminen, T.; Aalto, P. P.; Merkel, M.; Wiedensohler, A.; Kulmala, M.; Petäjä, T.; Hämeri, K.

    2015-12-01

    Air ion concentrations influence new particle formation and consequently the global aerosol as potential cloud condensation nuclei. We aimed to evaluate air ion concentrations and characteristics of new particle formation events (NPF) in the megacity of Paris, France, within the MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric Pollution and climate effects, and Integrated tools for assessment and mitigation) project. We measured air ion number size distributions (0.8-42 nm) with an air ion spectrometer and fine particle number concentrations (> 6 nm) with a twin differential mobility particle sizer in an urban site of Paris between 26 June 2009 and 4 October 2010. Air ions were size classified as small (0.8-2 nm), intermediate (2-7 nm), and large (7-20 nm). The median concentrations of small and large ions were 670 and 680 cm-3, respectively, (sum of positive and negative polarities), whereas the median concentration of intermediate ions was only 20 cm-3, as these ions were mostly present during new particle formation bursts, i.e. when gas-to-particle conversion produced fresh aerosol particles from gas phase precursors. During peaks in traffic-related particle number, the concentrations of small and intermediate ions decreased, whereas the concentrations of large ions increased. Seasonal variations affected the ion population differently, with respect to their size and polarity. NPF was observed in 13 % of the days, being most frequent in spring and late summer (April, May, July, and August). The results also suggest that NPF was favoured on the weekends in comparison to workdays, likely due to the lower levels of condensation sinks in the mornings of weekends (CS weekdays 09:00: 18 × 10-3 s-1; CS weekend 09:00: 8 × 10-3 s-1). The median growth rates (GR) of ions during the NPF events varied between 3 and 7 nm h-1, increasing with the ion size and being higher on workdays than on weekends for intermediate and large ions. The median GR of

  16. Response of London's urban heat island to a marine air intrusion in an easterly wind regime

    NASA Astrophysics Data System (ADS)

    Chemel, C.; Sokhi, R. S.

    2010-09-01

    London is long known to develop a pronounced urban heat island (UHI) resulting primarily from the storage of heat in the urban fabric during the day and released during the night, the differences in thermal and radiative properties of the surface between urban and rural areas, and lack of evapotranspiration in urban areas. Under calm, clear, and dry weather conditions, the difference in near-surface air temperature between two representative urban centre and rural locations at a given time typically reaches several degrees (i.e. warming) during the night and can be negative (i.e. cooling) during the day. Like the majority of large cities in the world, London is located in a coastal area. On certain occasions cooler marine air from the North Sea is advected across London by a sea breeze or easterly winds. In our work we examine the effects of a marine air intrusion, in an easterly wind regime, on the structure of London's UHI for a case study on 7 May 2008. For this purpose, numerical simulations with the Weather Research and Forecast (WRF) model are performed for multiple nested domains with the innermost domain covering London and its rural surroundings at the kilometre scale. A sensitivity study is undertaken to assess how the categorisation of the urban land use and the parameterisation of the urban canopy in the model affect its performance characteristics for the near-surface air temperature field. The categorisation of the urban landuse, according to the fractional area that is built-up within each grid cell, is found to be key to capturing the spatial pattern of the temperature field. Using a multilayer rather than single layer urban canopy model improves the representation of the variability of the pattern and the intensity of the UHI. A notable outcome of this work is that the inclusion of building anthropogenic fluxes is comparatively less important as regards model performance for near-surface air temperature. The effects of the marine air intrusion on

  17. Application of MM5/CMAQ for modelling urban air pollution a case study for London, UK

    NASA Astrophysics Data System (ADS)

    Kitwiroon, N.; Fragkou, E.; Sokhi, R. S.; San Jose, R.; Pérez Camaño, J. L.; Middleton, D.

    2003-04-01

    Urban air pollution has been particularly studied for the last few decades because of its recognised environmental dangers and health implications. The complexity of the urban surface characteristics and turbulence patterns has dictated the use of numerical models by environmental research agencies and regulators in order to predict and manage urban air pollution. However, most of these models are not specifically adapted to urban applications and normally do not include detailed urban parameterisation, such as for surface roughness or urban heat fluxes. Flow structure and dispersion of air pollutants within cities, however, are influenced by urban features such as increased surface roughness. This paper presents a study using MM5 and CMAQ to assess the effect of urban boundary layer features on meteorological parameters, and hence London's air quality. MM5 is a non-hydrostatic (version 3), terrain-following sigma-coordinate model designed to simulate mesoscale and regional-scale atmospheric circulation. This paper employs an improved surface roughness treatment on meteorological profiles and pollution dispersion. A surface roughness scale has been developed for London and the surrounding region. The land cover data was derived from the Centre for Ecology and Hydrology (CEH) data, with a spatial resolution of 25 × 25 m. These z_o values are employed with MM5 for modelling meteorological parameters over London, covering an inner domain area of 49 × 49 km. The outputs of MM5 have been coupled to CMAQ photochemical model to predict concentrations of particles, NO_2 and O_3 for London and the surrounding regions at a spatial resolution of 1 × 1 km. The predicted concentrations have been compared with monitored data obtained from a range of national air quality monitoring sites including Central London (Bloomsbury, Brent), East London (Bexley) and West London (Hillingdon). Comparison of hourly model predictions with measured data is made for pollution levels for

  18. Remote Sensing Characterization of the Urban Landscape for Improvement of Air Quality Modeling

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale A.; Estes, Maurice G., Jr.; Khan, Maudood

    2005-01-01

    The urban landscape is inherently complex and this complexity is not adequately captured in air quality models, particularly the Community Multiscale Air Quality (CMAQ) model that is used to assess whether urban areas are in attainment of EPA air quality standards, primarily for ground level ozone. This inadequacy of the CMAQ model to sufficiently respond to the heterogeneous nature of the urban landscape can impact how well the model predicts ozone pollutant levels over metropolitan areas and ultimately, whether cities exceed EPA ozone air quality standards. We are exploring the utility of high-resolution remote sensing data and urban growth projections as improved inputs to the meteorology component of the CMAQ model focusing on the Atlanta, Georgia metropolitan area as a case study. These growth projections include "business as usual" and "smart growth" scenarios out to 2030. The growth projections illustrate the effects of employing urban heat island mitigation strategies, such as increasing tree canopy and albedo across the Atlanta metro area, in moderating ground-level ozone and air temperature, compared to "business as usual" simulations in which heat island mitigation strategies are not applied. The National Land Cover Dataset at 30m resolution is being used as the land use/land cover input and aggregated to the 4km scale for the MM5 mesoscale meteorological model and the (CMAQ) modeling schemes. Use of these data has been found to better characterize low densityhburban development as compared with USGS 1 km land use/land cover data that have traditionally been used in modeling. Air quality prediction for fiture scenarios to 2030 is being facilitated by land use projections using a spatial growth model. Land use projections were developed using the 2030 Regional Transportation Plan developed by the Atlanta Regional Commission, the regional planning agency for the area. This allows the state Environmental Protection agency to evaluate how these

  19. Simulating Hydrologic Effects of Urbanization

    NASA Astrophysics Data System (ADS)

    Downer, C. W.; Ogden, F. L.; Pradhan, N.

    2012-12-01

    Urbanization of watersheds introduces multiple effects on hydrology and water quality. Roads, parking lots, roof tops and other impervious areas increase total runoff production. Soils are extensively modified through compaction and importation of fill and placement of sod. Streams are modified, moved, and replaced with lined channels, further increasing runoff and storm peaks. Subsurface drainage may supplement or supplant the function of natural streams, compounding the effects of channel modifications. Increased runoff results in increased erosion and transport of sediment and associated contaminants. Efforts to mitigate the effects of urbanization, channel improvements, levees, low impact development, detention basins, grassed swales, and other best management practices further complicate the issue. These attempts may or may not affect the overall system response as anticipated or desired. Analysis of the effects of urbanizing watersheds and design of abatement measures using simplified empirical methods and/or analyzing only the local effects may produce erroneous results. In this paper we will present and discuss simulation results from various studies related to the application of models to predicting the effects of urbanizing watersheds. We will contrast physics based hydrologic modeling efforts to simpler, empirical methods. We will also discuss the relative importance of various urbanizing features and modeling strategies to incorporate the important features. Dead Run Watershed

  20. Air quality assessment of Estarreja, an urban industrialized area, in a coastal region of Portugal.

    PubMed

    Figueiredo, M L; Monteiro, A; Lopes, M; Ferreira, J; Borrego, C

    2013-07-01

    Despite the increasing concern given to air quality in urban and industrial areas in recent years, particular emphasis on regulation, control, and reduction of air pollutant emissions is still necessary to fully characterize the chain emissions-air quality-exposure-dose-health effects, for specific sources. The Estarreja region was selected as a case study because it has one of the largest chemical industrial complexes in Portugal that has been recently expanded, together with a growing urban area with an interesting location in the Portuguese coastland and crossed by important road traffic and rail national networks. This work presents the first air quality assessment for the region concerning pollutant emissions and meteorological and air quality monitoring data analysis, over the period 2000-2009. This assessment also includes a detailed investigation and characterization of past air pollution episodes for the most problematic pollutants: ozone and PM10. The contribution of different emission sources and meteorological conditions to these episodes is investigated. The stagnant meteorological conditions associated with local emissions, namely industrial activity and road traffic, are the major contributors to the air quality degradation over the study region. A set of measures to improve air quality--regarding ozone and PM10 levels--is proposed as an air quality management strategy for the study region.

  1. Urban Air Pollution in Russia: Observations and Assessment

    NASA Astrophysics Data System (ADS)

    Skorokhod, Andrey; Elansky, Nikolai; Lavrova, Olga; Pankratova, Natalia; Belikov, Igor; Falaleeva, Victoria; Mel'nikova, Irina; Remizov, Andrey; Sitnikova, Irina

    2013-04-01

    Urban air pollution is actual topic because of its influence on air quality and climate processes on both regional and global scale. There is a lack of up-to-date information about real state of air quality in Russian cities because of very few contemporary observations. Obukhov Institute of Atmospheric Physics possesses significant database of automated measurements of air composition including data of train-based TROICA experiments in 1995-2010 as well as permanent observations in Moscow since 2002. In general numerous crosses of about 100 urban settlements of different size and location have been performed that allowed us to compose detailed pattern of urban air pollution in Russia nowadays. All cities were separated at three groups: megacities (more then 500 000 citizens), middle cities (50 000-500 000 citizens) and little cities (less then 50 000 citizens). Each urban settlement has been divided into railway station area, urban zone and city (or town) surroundings. Concentrations of main polluting gases (NO, NO2, CO, SO2, NMHC, O3) and aerosols have been averaged for each settlement as well as for each group of urban settlements for day and night, and for winter and summer. Main features of air urban pollution in Russia are presented. Variations of main pollutants including anthropogenic VOCs because of daytime and seasons, as well as temperature vertical structure are studied. Concentrations of O3, CO, SO2 and NMHC are usually below MPC level. NO2 is often enhanced especially near auto-roads. In general, polluting gases have greater concentrations in winter time due to heating and stronger temperature inversions. Particulate matter is likely to be the most persistent pollutant that determines more than 90% of pollution cases. Strong pollution cases are often caused by extraordinary situations like fires, industrial pollution under unfavorable meteorological conditions. High ozone photochemical generation is quite rare. Spatial pollution structure is usually

  2. Allometric scaling of UK urban emissions: interpretation and implications for air quality management

    NASA Astrophysics Data System (ADS)

    MacKenzie, Rob; Barnes, Matt; Whyatt, Duncan; Hewitt, Nick

    2016-04-01

    Allometry uncovers structures and patterns by relating the characteristics of complex systems to a measure of scale. We present an allometric analysis of air quality for UK urban settlements, beginning with emissions and moving on to consider air concentrations. We consider both airshed-average 'urban background' concentrations (cf. those derived from satellites for NO2) and local pollution 'hotspots'. We show that there is a strong and robust scaling (with respect to population) of the non-point-source emissions of the greenhouse gases carbon dioxide and methane, as well as the toxic pollutants nitrogen dioxide, PM2.5, and 1,3-butadiene. The scaling of traffic-related emissions is not simply a reflection of road length, but rather results from the socio-economic patterning of road-use. The recent controversy regarding diesel vehicle emissions is germane to our study but does not affect our overall conclusions. We next develop an hypothesis for the population-scaling of airshed-average air concentrations, with which we demonstrate that, although average air quality is expected to be worse in large urban centres compared to small urban centres, the overall effect is an economy of scale (i.e., large cities reduce the overall burden of emissions compared to the same population spread over many smaller urban settlements). Our hypothesis explains satellite-derived observations of airshed-average urban NO2 concentrations. The theory derived also explains which properties of nature-based solutions (urban greening) can make a significant contribution at city scale, and points to a hitherto unforeseen opportunity to make large cities cleaner than smaller cities in absolute terms with respect to their airshed-average pollutant concentration.

  3. FACILITATING ADVANCED URBAN METEOROLOGY AND AIR QUALITY MODELING CAPABILITIES WITH HIGH RESOLUTION URBAN DATABASE AND ACCESS PORTAL TOOLS

    EPA Science Inventory

    Information of urban morphological features at high resolution is needed to properly model and characterize the meteorological and air quality fields in urban areas. We describe a new project called National Urban Database with Access Portal Tool, (NUDAPT) that addresses this nee...

  4. Congestion, air pollution, and road fatalities in urban areas.

    PubMed

    Shefer, D

    1994-08-01

    The continuous rapid growth in vehicle miles travelled coupled with the rapid increase in traffic congestion on highways of virtually every large urban area, explain a major portion of the observed deterioration of urban air quality. To halt this deterioration and to secure safe and healthy environments and improve the quality of life in our cities, it is useful to initiate and implement programs that treat jointly traffic congestion, air quality, and road safety. Market-based strategies, driven by price mechanisms, have been proposed as the best and most efficient way to decrease traffic congestion and to reduce vehicle emission. Congestion pricing, emission fees, reducing emissions of high-polluting vehicles, and introducing more efficient vehicle and/or fuel technologies are not mutually exclusive strategies and therefore they can be employed jointly within an overall strategy. In view of the conflicting objectives that may exist between improving urban air quality and reducing road fatalities and traffic congestion, it is of great importance to investigate thoroughly these functional relationships. The results of such studies will help decision makers identify the "socially optimal level of congestion" that will yield the highest net social benefit.

  5. Low-Cost Sensor Units for Measuring Urban Air Quality

    NASA Astrophysics Data System (ADS)

    Popoola, O. A.; Mead, M.; Stewart, G.; Hodgson, T.; McLoed, M.; Baldovi, J.; Landshoff, P.; Hayes, M.; Calleja, M.; Jones, R.

    2010-12-01

    Measurements of selected key air quality gases (CO, NO & NO2) have been made with a range of miniature low-cost sensors based on electrochemical gas sensing technology incorporating GPS and GPRS for position and communication respectively. Two types of simple to operate sensors units have been designed to be deployed in relatively large numbers. Mobile handheld sensor units designed for operation by members of the public have been deployed on numerous occasions including in Cambridge, London and Valencia. Static sensor units have also been designed for long-term autonomous deployment on existing street furniture. A study was recently completed in which 45 sensor units were deployed in the Cambridge area for a period of 3 months. Results from these studies indicate that air quality varies widely both spatially and temporally. The widely varying concentrations found suggest that the urban environment cannot be fully understood using limited static site (AURN) networks and that a higher resolution, more dispersed network is required to better define air quality in the urban environment. The results also suggest that higher spatial and temporal resolution measurements could improve knowledge of the levels of individual exposure in the urban environment.

  6. Assessment of the impacts of vehicular pollution on urban air quality.

    PubMed

    Ghose, Mrinal K; Paul, R; Banerjee, S K

    2004-01-01

    Air quality crisis in cities is mainly due to vehicular emissions. Owing to the expanding economic base Indian cities are growing at a faster rate. Transportation systems are increasing everywhere and the improved technology is insufficient to counteract growth. The effect of vehicular emission on urban air quality and human health has been described. A survey has been conducted in an Indian mega city to evaluate the status of air pollution at traffic intersections and the unique problem arising out of vehicular emissions in the study area has been narrated. Approach for the selection of the air monitoring stations, methodology adopted for data collection and the results have been discussed. Vulnerability analysis (VA) has been carried out to identify the zones at what pollution stress. Options for reducing mobile source emission have been discussed and a strategic air quality management plan has been proposed to mitigate the air pollution in the city.

  7. Vehicular air pollution: Experiences from seven Latin american urban centers. World Bank Technical Paper No. 373

    SciTech Connect

    Onursal, B.; Gautam, S.P.

    1997-09-01

    Air pollution caused by motor vehicles is a major environmental problem in many Latin American urban centers. If appropriate measures are not taken soon, vehicular air pollution in the region is likely to worsen, posing a great threat to human health and welfare. This report analyzes the pollutants emitted by motor vehicles, their effects, and pollutant-control measures targeted at vehicles, fuels, and transport management. Case studies for Mexico City, Mexico, Santiago, Chile, Sao Paulo, Brazil, Belo Horizonte, Brazil, Buenos Aires, Argentina, Rio de Janeiro, Brazil, and Botota, Colombia, illustrate how these measures have been used in the region and how they can be strengthened.

  8. 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.

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

    PubMed

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

    2012-04-01

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

  10. Roles of Urban Tree Canopy and Buildings in Urban Heat Island Effects: Parameterization and Preliminary Results

    NASA Technical Reports Server (NTRS)

    Loughner, Christopher P.; Allen, Dale J.; Zhang, Da-Lin; Pickering, Kenneth E.; Dickerson, Russell R.; Landry, Laura

    2012-01-01

    Urban heat island (UHI) effects can strengthen heat waves and air pollution episodes. In this study, the dampening impact of urban trees on the UHI during an extreme heat wave in the Washington, D.C., and Baltimore, Maryland, metropolitan area is examined by incorporating trees, soil, and grass into the coupled Weather Research and Forecasting model and an urban canopy model (WRF-UCM). By parameterizing the effects of these natural surfaces alongside roadways and buildings, the modified WRF-UCM is used to investigate how urban trees, soil, and grass dampen the UHI. The modified model was run with 50% tree cover over urban roads and a 10% decrease in the width of urban streets to make space for soil and grass alongside the roads and buildings. Results show that, averaged over all urban areas, the added vegetation decreases surface air temperature in urban street canyons by 4.1 K and road-surface and building-wall temperatures by 15.4 and 8.9 K, respectively, as a result of tree shading and evapotranspiration. These temperature changes propagate downwind and alter the temperature gradient associated with the Chesapeake Bay breeze and, therefore, alter the strength of the bay breeze. The impact of building height on the UHI shows that decreasing commercial building heights by 8 m and residential building heights by 2.5 m results in up to 0.4-K higher daytime surface and near-surface air temperatures because of less building shading and up to 1.2-K lower nighttime temperatures because of less longwave radiative trapping in urban street canyons.

  11. The effect of man made source processes on the behavior of total gaseous mercury in air: a comparison between four urban monitoring sites in Seoul Korea.

    PubMed

    Kim, Ki-Hyun; Shon, Zang-Ho; Nguyen, Hang Thi; Jung, Kweon; Park, Chan-Goo; Bae, Gwi Nam

    2011-09-01

    Concentrations of total gaseous mercury (TGM) were measured continuously at four urban residential locations (G (Guro-gu); N (Nowon-gu); S (Songpa-gu); and Y (Yongsan-gu)) in Seoul, Korea from 2004 to 2009. The mean concentrations of Hg at these sites were found on the order of N (3.98±1.68 ng m(-3)), S (3.87±1.56 ng m(-3)), G (3.80±1.60 ng m(-3)), and Y (3.36±1.55 ng m(-3)). Evidence indicates that the spatial distribution of Hg should be affected by the combined effects of both local anthropogenic (incineration facilities and thermal power plants) and natural (soil) emission sources in association with the meteorological parameters. Inspection of the Hg temporal patterns indicates the co-existence of contrasting seasonal patterns between the central site Y (winter dominance) and all other outbound sites near city borders (summer dominance). The long-term trend of Hg, if examined by combining our previous studies and the present one, shows that Hg levels in this urban area declined gradually across decadal periods despite slight variabilities in spatial scale: (1) above 10 ng m(-3) in the late 1980s, (2) ~5 ng m(-3) in the late 1990s, and (3) ~3 ng m(-3) toward the late 2000s. The results of the principal component analysis along with observed differences in seasonal patterns (between study sites) suggest that Hg distributions between different urban sites are greatly distinguishable with strong source signatures at each individual site.

  12. Project ATLANTA (ATlanta Land-use ANalysis: Temperature and Air quality): A Study of how the Urban Landscape Affects Meteorology and Air Quality Through Time

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale A.; Luvall, Jeffrey C.; Estes, Maurice G.; Lo, C. P.; Kidder, Stanley Q.; Hafner, Jan; Taha, Haider; Bornstein, Robert D.; Gillies, Robert R.; Gallo, Kevin P.

    1998-01-01

    It is our intent through this investigation to help facilitate measures that can be Project ATLANTA (ATlanta Land-use ANalysis: applied to mitigate climatological or air quality Temperature and Air-quality) is a NASA Earth degradation, or to design alternate measures to sustain Observing System (EOS) Interdisciplinary Science or improve the overall urban environment in the future. investigation that seeks to observe, measure, model, and analyze how the rapid growth of the Atlanta. The primary objectives for this research effort are: 1) To In the last half of the 20th century, Atlanta, investigate and model the relationship between Atlanta Georgia has risen as the premier commercial, urban growth, land cover change, and the development industrial, and transportation urban area of the of the urban heat island phenomenon through time at southeastern United States. The rapid growth of the nested spatial scales from local to regional; 2) To Atlanta area, particularly within the last 25 years, has investigate and model the relationship between Atlanta made Atlanta one of the fastest growing metropolitan urban growth and land cover change on air quality areas in the United States. The population of the through time at nested spatial scales from local to Atlanta metropolitan area increased 27% between 1970 regional; and 3) To model the overall effects of urban and 1980, and 33% between 1980-1990 (Research development on surface energy budget characteristics Atlanta, Inc., 1993). Concomitant with this high rate of across the Atlanta urban landscape through time at population growth, has been an explosive growth in nested spatial scales from local to regional. Our key retail, industrial, commercial, and transportation goal is to derive a better scientific understanding of how services within the Atlanta region. This has resulted in land cover changes associated with urbanization in the tremendous land cover change dynamics within the Atlanta area, principally in transforming

  13. Mobile lidar investigation of air quality over urban areas

    NASA Astrophysics Data System (ADS)

    Kolev, Ivan N.; Parvanov, Orlin; Kaprielov, Boiko K.

    1996-12-01

    Various mesoscale meteorological phenomena often determine the transportation, changes and spreading of the atmospheric pollutant over urban and rural areas with a developed industry. The corresponding investigations can be performed by combined use of remote (lidar) and conventional means. The present investigation aims at applying the accumulated experience for a determination of the air quality over large area (400 sq km) including residential districts of settlement in a vicinity of oil-refinery and for a determination of the mesoscale phenomena influence on the air quality of the resort in the coastal zone. We used a mobile aerosol lidar, a tethered balloon, pilot balloon measurements and point chemical analyses for the purposes of the mentioned investigation. The measurements were carried out from 14 April to 9 May 1992 in the Bourgas region.

  14. The Conundrum of Impacts of Climate Change on Urbanization and the Urban Heat Island Effect

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale A.

    2011-01-01

    The twenty-first century is the first urban century according to the United Nations Development Program. The focus on cities reflects awareness of the growing percentage of the world's population that lives in urban areas. In 2000, approximately 3 billion people representing about 40% of the global population resided in urban areas. The United Nations estimates that by 2025, 60% of the world s population will live in urban areas. As a consequence, the number of megacities (those cities with populations of 10 million inhabitants or more) will increase by 100 by 2025. Thus, there is a critical need to understand the spatial growth of urban areas and what the impacts are on the environment. Moreover, there is a critical need to assess how under global climate change, cities will affect the local, regional, and even global climate. As urban areas increase in size, it is anticipated there will be a concomitant growth of the Urban Heat Island effect (UHI), and the attributes that are related to its spatial and temporal dynamics. Therefore, how climate change, including the dynamics of the UHI, will affect the urban environment, must be explored to help mitigate potential impacts on the environment (e.g., air quality, heat stress, vectorborne disease) and on human health and well being, to develop adaptation schemes to cope with these impacts.

  15. Estimating the Urban Bias of Surface Shelter Temperatures Using Upper-Air and Satellite Data

    NASA Astrophysics Data System (ADS)

    Epperson, David Lee

    An alternative method is presented for estimating the urban bias of surface shelter temperatures due to the effect of the urban heat island Multivariate regression techniques were utilized to predict surface shelter temperatures for the time period 1986-89 using upper-air data from the European Centre for Medium-Range Weather Forecasting (ECMWF) to represent the background climate, site-specific data to represent the local landscape, and satellite-derived data--the Normalized Difference Vegetation Index (NDVI) and the Defense Meteorological Satellite Program (DMSP) nighttime brightness data--to represent the urban landscape. Models for the United States (US) were developed for mean monthly maximum, mean, and minimum temperatures using data from over 1000 stations in the US Co-operative (COOP) Network and over 1150 stations in the Global Historical Climate Network (GHCN, mean temperatures only). Urban biases for the US and for individual stations were calculated and compared with the results of other research. The urban bias of US temperatures, as derived from all US stations (urban and rural) used in the models, averaged near 0.40 ^circC for minimum temperatures, near 0.25^circC for mean temperatures, and near 0.10^circC for maximum temperatures. On an annual basis, the urban biases of minimum temperatures for individual stations ranged from near -1.1^circC for rural stations to 2.4^circC for stations from the largest urban areas. The urban bias of US mean temperatures in this study (0.25^ circC) was shown to be larger than the US (0.05-0.15^circC) and global (0.01-0.10^circC) urban biases from other studies, where the confidence in the estimated urban biases was less. Thus, there is a need to assess the urban bias that is present in the global temperature record using the methodology presented in this study. The results of this study indicate minimal problems for global application, once the global NDVI and DMSP data become available, as opposed to other studies

  16. Profile of an Effective Urban Music Educator

    ERIC Educational Resources Information Center

    Baker, Vicki D.

    2012-01-01

    The purpose of this study was to develop a profile of an effective urban music educator in an effort to provide strategies for university teacher training programs to prepare students to teach in urban schools. The study examined urban music teachers' (N = 158) educational background, effective and ineffective characteristics, perceived…

  17. Concentrations of mobile source air pollutants in urban microenvironments.

    PubMed

    Fujita, Eric M; Campbell, David E; Arnott, W Patrick; Johnson, Ted; Ollison, Will

    2014-07-01

    Human exposures to criteria and hazardous air pollutants (HAPs) in urban areas vary greatly due to temporal-spatial variations in emissions, changing meteorology, varying proximity to sources, as well as due to building, vehicle, and other environmental characteristics that influence the amounts of ambient pollutants that penetrate or infiltrate into these microenvironments. Consequently, the exposure estimates derived from central-site ambient measurements are uncertain and tend to underestimate actual exposures. The Exposure Classification Project (ECP) was conducted to measure pollutant concentrations for common urban microenvironments (MEs) for use in evaluating the results of regulatory human exposure models. Nearly 500 sets of measurements were made in three Los Angeles County communities during fall 2008, winter 2009, and summer 2009. MEs included in-vehicle, near-road, outdoor and indoor locations accessible to the general public. Contemporaneous 1- to 15-min average personal breathing zone concentrations of carbon monoxide (CO), carbon dioxide (CO2), volatile organic compounds (VOCs), nitric oxide (NO), nitrogen oxides (NO(x)), particulate matter (< 2.5 microm diameter; PM2.5) mass, ultrafine particle (UFP; < 100 nm diameter) number black carbon (BC), speciated HAPs (e.g, benzene, toluene, ethylbenzene, xylenes [BTEX], 1,3-butadiene), and ozone (O3) were measured continuously. In-vehicle and inside/outside measurements were made in various passenger vehicle types and in public buildings to estimate penetration or infiltration factors. A large fraction of the observed pollutant concentrations for on-road MEs, especially near diesel trucks, was unrelated to ambient measurements at nearby monitors. Comparisons of ME concentrations estimated using the median ME/ambient ratio versus regression slopes and intercepts indicate that the regression approach may be more accurate for on-road MEs. Ranges in the ME/ambient ratios among ME categories were generally

  18. Urban scale air quality modelling using detailed traffic emissions estimates

    NASA Astrophysics Data System (ADS)

    Borrego, C.; Amorim, J. H.; Tchepel, O.; Dias, D.; Rafael, S.; Sá, E.; Pimentel, C.; Fontes, T.; Fernandes, P.; Pereira, S. R.; Bandeira, J. M.; Coelho, M. C.

    2016-04-01

    The atmospheric dispersion of NOx and PM10 was simulated with a second generation Gaussian model over a medium-size south-European city. Microscopic traffic models calibrated with GPS data were used to derive typical driving cycles for each road link, while instantaneous emissions were estimated applying a combined Vehicle Specific Power/Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (VSP/EMEP) methodology. Site-specific background concentrations were estimated using time series analysis and a low-pass filter applied to local observations. Air quality modelling results are compared against measurements at two locations for a 1 week period. 78% of the results are within a factor of two of the observations for 1-h average concentrations, increasing to 94% for daily averages. Correlation significantly improves when background is added, with an average of 0.89 for the 24 h record. The results highlight the potential of detailed traffic and instantaneous exhaust emissions estimates, together with filtered urban background, to provide accurate input data to Gaussian models applied at the urban scale.

  19. Government employees' perception of urban air pollution and willingness to pay for improved quality: a cross-sectional survey study in Nanchang, China.

    PubMed

    Liu, Xiaojun; Wu, Yanyan; Hu, Yongxin; Liu, Denglai; Zhang, Jin; Chen, Cheng; Yuan, Zhaokang; Lu, Yuanan

    2016-11-01

    To improve the public's awareness of urban air pollution and promote establishment of more efficient policy toward urban air pollution, we investigated the government employees' perceptions of current urban air pollution and their willingness to pay (WTP) taxes for improved quality in Nanchang, China. Stratified cluster sampling strategy was used to distribute 629 questionnaires, and 608 were completed anonymously, yielding a 96.7 % response rate. Descriptive statistics frequencies and proportions were used to summarize the sample characteristics, and logistic regression models were performed to assess the associations of perception of urban air quality and WTP versus demographic variables. We found low awareness of urban air pollution (34.5 %) as well as low WTP (44.9 %), especially among the middle aged people (age 30-39 and age 40-49). Our study shows that female employees have better awareness of urban air pollution but much less willingness to pay for air quality improvement. Majority of the government employees showed their support to the government for more effective policies toward environmental protection, indicating more enhanced public education and environmental protection campaigns to improve the public's awareness of air pollution and work with every citizen to improve air quality. This study also obtained baseline information useful to the local regional and even national government in developing nations in their attempt to control urban air pollution in future.

  20. Aeolian Dust and Forest Fire Smoke in Urban Air

    NASA Astrophysics Data System (ADS)

    Brimblecombe, P.

    2006-12-01

    Particles of aeolian dust and forest fire smoke are now regularly detected in urban air. Although dusts are common on the Asian Pacific Rim and forest fire smoke characteristic of South East Asia they also frequently detected elsewhere. In the past dust was treated as though it was fairly inert and reactions on the surface limited to the neutralizing ability of alkaline minerals. More recent work shows that that dust has a complex organic chemistry. Observations in China found fatty acids from urban areas (oleic acid and linoleic acid from cooking) on dust derived aerosols. The fatty acids and PAHs decreased sharply after dust storms, suggesting a role for dust in removal processes. When silica particles absorb unsaturated compounds they can react with ozone and release compounds such as formaldehyde. Particles from forest fires have a similarly complex chemistry and the acid-alkaline balance may vary depend on the balance of removal rates of alkaline materials (ammonia, potassium carbonate) and inorganic and organic acids. Airborne dust and forest fire soot can contain humic like substances (HULIS) either as primary material or as secondary oxidation products of the surface of soot. This paper will report on the role polluted air masses in the generation humic materials, particularly those that are surface active. These materials of high molecular weight oxygen rich organic compounds, which exhibit a range of properties of importance in aerosols: they can form complexes with metal ions and thus enhance their solubility, photosensitize the oxidation of organic compounds and lower the surface tension of aqueous aerosols. HULIS can be oxidized to form a range of simpler acids such as formic, acetic and oxalic acid. Dust and forest fire smoke particles have a different composition and size range to that of typical urban combustion particles, so it is likely that the health impacts will be different, yet current regulation often does not recognize any significant

  1. ADDRESSING HUMAN EXPOSURES TO AIR POLLUTANTS AROUND BUILDINGS IN URBAN AREAS WITH COMPUTATIONAL FLUID DYNAMICS MODELS

    EPA Science Inventory

    This paper discusses the status and application of Computational Fluid Dynamics (CFD) models to address challenges for modeling human exposures to air pollutants around urban building microenvironments. There are challenges for more detailed understanding of air pollutant sour...

  2. Vegetation and other development options for mitigating urban air pollution impacts

    EPA Science Inventory

    In addition to installing air pollution control devices and reducing emissions activities, urban air pollution can be further mitigated through planning and design strategies including vegetation planting, building design, installing roadside and near source structures, and modif...

  3. Observations of Cooling Summer Daytime Temperatures (1948-2005) in Growing Urban Coastal California Air Basins

    NASA Astrophysics Data System (ADS)

    Bornstein, R.; Lebassi, B.; Gonzalez, J.

    2008-12-01

    The study evaluated long-term (1948-2005) air temperatures in California (CA) during summer (June- August). The aggregate CA results showed asymmetric warming, as daily minimum temperatures increased faster than daily maximum temperatures. The spatial distributions of daily maximum temperatures in the heavily urbanized South Coast and San Francisco Bay Area air basins, however, exhibited a complex pattern, with cooling at low-elevation (mainly urban) coastal-areas and warming at (mainly rural) inland areas. Previous studies have suggested that cooling summer max temperatures in CA were due to increased irrigation, coastal upwelling, or cloud cover. The current hypothesis, however, is that this temperature pattern arises from a 'reverse-reaction' to greenhouse gas (GHG) induced global-warming. In this hypothesis, the global warming of inland areas resulted in an increased (cooling) sea breeze activity in coastal areas. The coastal cooling thus resulted as urban heat island (UHI) warming was weaker than the reverse-reaction cooling; if there was no UHI effect, then the cooling would be even stronger. The cooling or warming trends at several pairs of nearby urban and non- urban sites were compared in an effort to separate out the urban heat island (UHI) and global warming components of the trend. Average temperatures from global circulation models show warming that decreases from inland areas of California to its coastal areas. Such large scale models, however, cannot resolve these smaller scale topographic and coastal effects. Meso-scale modeling on a 4 km grid is thus being carried out to evaluate the contributions from GHG global-warming and land-use changes, including UHI development, to the observed trends. Significant societal impacts may result from this observed reverse-reaction to GHG- warming; possible beneficial effects include decreased maximum: O3 levels, human thermal-stress, and per- capita energy requirements for cooling.

  4. Pulmonary Health Effects of Air Pollution

    PubMed Central

    Kurt, Ozlem Kar; Zhang, Jingjing; Pinkerton, Kent E.

    2016-01-01

    Purpose of the review Air pollution continues to be a major public health concern affecting nine out of ten individuals living in urban areas worldwide. Exposure to air pollution is the ninth leading risk factor for cardiopulmonary mortality. The aim of this review is to examine the current literature for the most recent updates on health effects of specific air pollutants and their impact on asthma, chronic obstructive pulmonary disease (COPD), lung cancer and respiratory infection. Recent findings A total of 53 publications were reviewed to establish new insights as to how air pollution is associated with pulmonary morbidity and mortality. Considerable past evidence suggests that air pollution is an important factor that enhances pulmonary disease, while also causing greater harm in susceptible populations, such as children, the elderly and those of low socio-economic status worldwide. Asthma, COPD, lung cancer and respiratory infections all seem to be exacerbated due to exposure to a variety of environmental air pollutants with the greatest effects due to particulate matter (PM), ozone and nitrogen oxides. New publications reviewed reaffirm these findings. Summary Continued vigilence will be essential to lessen the effects of air pollution on human health and pulmonary disease. Cooperation at a multi-national level will be required on the part of governments, industry, energy-based enterprises and the public working together to solve our air quality issues at the local, national and global level. PMID:26761628

  5. Satellite and in-situ monitoring of urban air pollution in relation with children's asthma

    NASA Astrophysics Data System (ADS)

    Dida, Mariana R.; Zoran, Maria A.

    2013-10-01

    Urban air pollution and especially aerosols have significant negative health effects on urban population, of which children are most exposed for the rapid increase of asthma disease. An allergic reaction to different allergens is a major contributor to asthma in urban children, but new research suggests that the allergies are just one part of a more complex story. Very early exposure to certain components of air pollution can increase the risk of developing of different allergies by age 7. The epidemiological research on the mutagenic effects of airborne particulate matter pointed their capability to reach deep lung regions, being vehicles of toxic substances. The current study presents a spatio-temporal analysis of the aerosol concentrations in relation with meteorological parameters in two size fractions (PM10 and PM2.5) and possible health effects in Bucharest metropolitan area. Both in-situ monitoring data as well as MODIS Terra/Aqua time-series satellite data of particle matter PM2.5 and PM10 concentrations have been used to qualitatively assess distribution of aerosols in the greater metropolitan are of Bucharest comparative with some other little towns in Romania during 2010- 2011 period. It was found that PM2.5 and PM10 aerosols exhibit their highest concentration mostly in the central part of the towns, mainly due to road traffic as well as in the industrialized parts outside of city's centre. Pediatric asthma can be managed through medications prescribed by a healthcare provider, but the most important aspect is to avoid urban locations with high air pollution concentrations of air particles and allergens.

  6. Urban air pollution and lung cancer in Stockholm.

    PubMed

    Nyberg, F; Gustavsson, P; Järup, L; Bellander, T; Berglind, N; Jakobsson, R; Pershagen, G

    2000-09-01

    We conducted a population-based case-control study among men 40-75 years of age encompassing all cases of lung cancer 1985-1990 among stable residents of Stockholm County 1950-1990. Questionnaires to subjects or next-of-kin (primarily wives or children) elicited information regarding smoking and other risk factors, including occupational and residential histories. A high response rate (>85%) resulted in 1,042 cases and 2,364 controls. We created retrospective emission databases for NOx/NO2 and SO2 as indicators of air pollution from road traffic and heating, respectively. We estimated local annual source-specific air pollution levels using validated dispersion models and we linked these levels to residential addresses using Geographical Information System (GIS) techniques. Average traffic-related NO2 exposure over 30 years was associated with a relative risk (RR) of 1.2 (95% confidence interval 0.8-1.6) for the top decile of exposure, adjusted for tobacco smoking, socioeconomic status, residential radon, and occupational exposures. The data suggested a considerable latency period; the RR for the top decile of average traffic-related NO2 exposure 20 years previously was 1.4 (1.0-2.0). Little association was observed for SO2. Occupational exposure to asbestos, diesel exhaust, and other combustion products also increased the risk of lung cancer. Our results indicate that urban air pollution increases lung cancer risk and that vehicle emissions may be particularly important.

  7. Indoor air quality of houses located in the urban environment of Agra, India.

    PubMed

    Taneja, Ajay; Saini, Renuka; Masih, Amit

    2008-10-01

    Increased concern over the adverse health effects of air pollution has highlighted the need for air-pollution measurements, especially in urban areas, where many sources of air pollutants are normally monitored outdoors as part of obligations under the National Air Quality Strategies. Very little is known about air pollution indoors. In fact, the largest exposure to health-damaging indoor pollution probably occurs in the developing world, not in households, schools, and offices of developed countries where most research and control efforts have been focused to date. As a result much of the health impacts from air pollution worldwide seem to occur among the poorest and most vulnerable populations. The authors in their earlier studies have confirmed the importance of ambient air in determining the quality of air indoors. In this study an observation of air quality indoors and outdoors of domestic homes located in an urban environment from October 2004 to December 2005 in Agra, north central India, is performed. The purpose of this study was to characterize the indoor/outdoor (I/O) relationship of airborne pollutants and recognize their probable source in all three seasons, that is, winter, summer, and rainy season. Concentrations of SO(2), NO(2), CO(2), Cl(2), H(2)S, NH(3), RSPM, and PAH were monitored simultaneously and I/O ratios were calculated. In order to investigate the effect of seasonality on indoor and ambient air quality, winter to summer and winter to monsoon average ratios were calculated. It is apparent that there is a general pattern of increasing levels from monsoon to summer to winter, and similarly from outdoor to indoor air. Regressions analysis had been done to further investigate the influence of outdoor air-pollutant concentrations on indoor concentrations. The most probable categories of sources for these pollutants have been identified by using principal-component analysis. Indoor air pollution is a complex function of energy housing and

  8. Adaptational strategy of a tropical shrub Carissa Carandas L. to urban air pollution.

    PubMed

    Pandey, J; Pandey, U

    1996-12-01

    This paper reports the adaptational response of a tropical shrub Carissa Carandas L. to urban air pollution stress in Varanasi, India. Saplings of C. carandas were grown at a density of one per pot and kept for two years at 25 selected sites in the urban environment. Different sites received different levels of air pollution input. Changes in vegetative growth pattern (leafing and branching), in morphological features and in the distribution of biomass to above and below ground structures were considered in relation to the ambient air quality.Different levels of air pollution input produced different sets of harmful effects. Although the air pollution level at Varanasi reduced the plant height, basal diameter, canopy area, leaf area and total plant biomass of C. carandas, this species retained a major fraction of its photosynthate to above-ground plant parts where foliage assumes predominance. Since carbon gain is dependent not only on the rate of carbon acquisition per unit leaf tissue but also on the amount of photosynthetic tissue present, a shift in relative contribution of photosynthate to leaf production and shoot growth appears to be a pollution-induced adaptive response in C. carandas.

  9. High-Density, High-Resolution, Low-Cost Air Quality Sensor Networks for Urban Air Monitoring

    NASA Astrophysics Data System (ADS)

    Mead, M. I.; Popoola, O. A.; Stewart, G.; Bright, V.; Kaye, P.; Saffell, J.

    2012-12-01

    Monitoring air quality in highly granular environments such as urban areas which are spatially heterogeneous with variable emission sources, measurements need to be made at appropriate spatial and temporal scales. Current routine air quality monitoring networks generally are either composed of sparse expensive installations (incorporating e.g. chemiluminescence instruments) or higher density low time resolution systems (e.g. NO2 diffusion tubes). Either approach may not accurately capture important effects such as pollutant "hot spots" or adequately capture spatial (or temporal) variability. As a result, analysis based on data from traditional low spatial resolution networks, such as personal exposure, may be inaccurate. In this paper we present details of a sophisticated, low-cost, multi species (gas phase, speciated PM, meteorology) air quality measurement network methodology incorporating GPS and GPRS which has been developed for high resolution air quality measurements in urban areas. Sensor networks developed in the Centre for Atmospheric Science (University of Cambridge) incorporated electrochemical gas sensors configured for use in urban air quality studies operating at parts-per-billion (ppb) levels. It has been demonstrated that these sensors can be used to measure key air quality gases such as CO, NO and NO2 at the low ppb mixing ratios present in the urban environment (estimated detection limits <4ppb for CO and NO and <1ppb for NO2. Mead et al (submitted Aug., 2012)). Based on this work, a state of the art multi species instrument package for deployment in scalable sensor networks has been developed which has general applicability. This is currently being employed as part of a major 3 year UK program at London Heathrow airport (the Sensor Networks for Air Quality (SNAQ) Heathrow project). The main project outcome is the creation of a calibrated, high spatial and temporal resolution data set for O3, NO, NO2, SO2, CO, CO2, VOCstotal, size-speciated PM

  10. Modeling urban air pollution with optimized hierarchical fuzzy inference system.

    PubMed

    Tashayo, Behnam; Alimohammadi, Abbas

    2016-10-01

    Environmental exposure assessments (EEA) and epidemiological studies require urban air pollution models with appropriate spatial and temporal resolutions. Uncertain available data and inflexible models can limit air pollution modeling techniques, particularly in under developing countries. This paper develops a hierarchical fuzzy inference system (HFIS) to model air pollution under different land use, transportation, and meteorological conditions. To improve performance, the system treats the issue as a large-scale and high-dimensional problem and develops the proposed model using a three-step approach. In the first step, a geospatial information system (GIS) and probabilistic methods are used to preprocess the data. In the second step, a hierarchical structure is generated based on the problem. In the third step, the accuracy and complexity of the model are simultaneously optimized with a multiple objective particle swarm optimization (MOPSO) algorithm. We examine the capabilities of the proposed model for predicting daily and annual mean PM2.5 and NO2 and compare the accuracy of the results with representative models from existing literature. The benefits provided by the model features, including probabilistic preprocessing, multi-objective optimization, and hierarchical structure, are precisely evaluated by comparing five different consecutive models in terms of accuracy and complexity criteria. Fivefold cross validation is used to assess the performance of the generated models. The respective average RMSEs and coefficients of determination (R (2)) for the test datasets using proposed model are as follows: daily PM2.5 = (8.13, 0.78), annual mean PM2.5 = (4.96, 0.80), daily NO2 = (5.63, 0.79), and annual mean NO2 = (2.89, 0.83). The obtained results demonstrate that the developed hierarchical fuzzy inference system can be utilized for modeling air pollution in EEA and epidemiological studies.

  11. Inhalable desert dust, urban emissions, and potentially biotoxic metals in urban Saharan-Sahelian air

    USGS Publications Warehouse

    Garrison, Virginia H.; Majewski, Michael S.; Konde, Lassana; Wolf, Ruth E.; Otto, Richard D.; Tsuneoka, Yutaka

    2014-01-01

    Saharan dust incursions and particulates emitted from human activities degrade air quality throughout West Africa, especially in the rapidly expanding urban centers in the region. Particulate matter (PM) that can be inhaled is strongly associated with increased incidence of and mortality from cardiovascular and respiratory diseases and cancer. Air samples collected in the capital of a Saharan–Sahelian country (Bamako, Mali) between September 2012 and July 2013 were found to contain inhalable PM concentrations that exceeded World Health Organization (WHO) and US Environmental Protection Agency (USEPA) PM2.5 and PM10 24-h limits 58 – 98% of days and European Union (EU) PM10 24-h limit 98% of days. Mean concentrations were 1.2-to-4.5 fold greater than existing limits. Inhalable PM was enriched in transition metals, known to produce reactive oxygen species and initiate the inflammatory response, and other potentially bioactive and biotoxic metals/metalloids. Eroded mineral dust composed the bulk of inhalable PM, whereas most enriched metals/metalloids were likely emitted from oil combustion, biomass burning, refuse incineration, vehicle traffic, and mining activities. Human exposure to inhalable PM and associated metals/metalloids over 24-h was estimated. The findings indicate that inhalable PM in the Sahara–Sahel region may present a threat to human health, especially in urban areas with greater inhalable PM and transition metal exposure.

  12. Inhalable desert dust, urban emissions, and potentially biotoxic metals in urban Saharan-Sahelian air.

    PubMed

    Garrison, V H; Majewski, M S; Konde, L; Wolf, R E; Otto, R D; Tsuneoka, Y

    2014-12-01

    Saharan dust incursions and particulates emitted from human activities degrade air quality throughout West Africa, especially in the rapidly expanding urban centers in the region. Particulate matter (PM) that can be inhaled is strongly associated with increased incidence of and mortality from cardiovascular and respiratory diseases and cancer. Air samples collected in the capital of a Saharan-Sahelian country (Bamako, Mali) between September 2012 and July 2013 were found to contain inhalable PM concentrations that exceeded World Health Organization (WHO) and US Environmental Protection Agency (USEPA) PM2.5 and PM10 24-h limits 58 - 98% of days and European Union (EU) PM10 24-h limit 98% of days. Mean concentrations were 1.2-to-4.5 fold greater than existing limits. Inhalable PM was enriched in transition metals, known to produce reactive oxygen species and initiate the inflammatory response, and other potentially bioactive and biotoxic metals/metalloids. Eroded mineral dust composed the bulk of inhalable PM, whereas most enriched metals/metalloids were likely emitted from oil combustion, biomass burning, refuse incineration, vehicle traffic, and mining activities. Human exposure to inhalable PM and associated metals/metalloids over 24-h was estimated. The findings indicate that inhalable PM in the Sahara-Sahel region may present a threat to human health, especially in urban areas with greater inhalable PM and transition metal exposure.

  13. Acute symptoms related to air pollution in urban areas: a study protocol

    PubMed Central

    Yunesian, Masud; Asghari, Fariba; Vash, Javad Homayoun; Forouzanfar, Mohammad Hossein; Farhud, Dariush

    2006-01-01

    Background The harmful effects of urban air pollution on general population in terms of annoying symptoms are not adequately evaluated. This is in contrast to the hospital admissions and short term mortality. The present study protocol is designed to assess the association between the level of exposure to certain ambient air pollutants and a wide range of relevant symptoms. Awareness of the impact of pollution on the population at large will make our estimates of the pertinent covert burden imposed on the society more accurate. Methods/design A cross sectional study with spatial analysis for the addresses of the participants was conducted. Data were collected via telephone interviews administered to a representative sample of civilians over age four in the city. Households were selected using random digit dialling procedures and randomization within each household was also performed to select the person to be interviewed. Levels of exposure are quantified by extrapolating the addresses of the study population over the air pollution matrix of the city at the time of the interview and also for different lag times. This information system uses the data from multiple air pollution monitoring stations in conjunction with meteorological data. General linear models are applied for statistical analysis. Discussion The important limitations of cross-sectional studies on acute effects of air pollution are personal confounders and measurement error for exposure. A wide range of confounders in this study are controlled for in the statistical analysis. Exposure error may be minimised by employing a validated geographical information system that provides accurate estimates and getting detailed information on locations of individual participants during the day. The widespread operation of open air conditioning systems in the target urban area which brings about excellent mixing of the outdoor and indoor air increases the validity of outdoor pollutants levels that are taken as

  14. Evaluation of urban surface parameterizations in the WRF model using measurements during the Texas Air Quality Study 2006 field campaign

    NASA Astrophysics Data System (ADS)

    Lee, S.-H.; Kim, S.-W.; Angevine, W. M.; Bianco, L.; McKeen, S. A.; Senff, C. J.; Trainer, M.; Tucker, S. C.; Zamora, R. J.

    2011-03-01

    The performance of different urban surface parameterizations in the WRF (Weather Research and Forecasting) in simulating urban boundary layer (UBL) was investigated using extensive measurements during the Texas Air Quality Study 2006 field campaign. The extensive field measurements collected on surface (meteorological, wind profiler, energy balance flux) sites, a research aircraft, and a research vessel characterized 3-dimensional atmospheric boundary layer structures over the Houston-Galveston Bay area, providing a unique opportunity for the evaluation of the physical parameterizations. The model simulations were performed over the Houston metropolitan area for a summertime period (12-17 August) using a bulk urban parameterization in the Noah land surface model (original LSM), a modified LSM, and a single-layer urban canopy model (UCM). The UCM simulation compared quite well with the observations over the Houston urban areas, reducing the systematic model biases in the original LSM simulation by 1-2 °C in near-surface air temperature and by 200-400 m in UBL height, on average. A more realistic turbulent (sensible and latent heat) energy partitioning contributed to the improvements in the UCM simulation. The original LSM significantly overestimated the sensible heat flux (~200 W m-2) over the urban areas, resulting in warmer and higher UBL. The modified LSM slightly reduced warm and high biases in near-surface air temperature (0.5-1 °C) and UBL height (~100 m) as a result of the effects of urban vegetation. The relatively strong thermal contrast between the Houston area and the water bodies (Galveston Bay and the Gulf of Mexico) in the LSM simulations enhanced the sea/bay breezes, but the model performance in predicting local wind fields was similar among the simulations in terms of statistical evaluations. These results suggest that a proper surface representation (e.g. urban vegetation, surface morphology) and explicit parameterizations of urban physical

  15. Evaluation of Urban Air Quality By Passive Sampling Technique

    NASA Astrophysics Data System (ADS)

    Nunes, T. V.; Miranda, A. I.; Duarte, S.; Lima, M. J.

    Aveiro is a flat small city in the centre of Portugal, close to the Atlantic coast. In the last two decades an intensive development of demographic, traffic and industry growth in the region was observed which was reflected on the air quality degrada- tion. In order to evaluate the urban air quality in Aveiro, a field-monitoring network by passive sampling with high space resolution was implemented. Twenty-four field places were distributed in a area of 3x3 Km2 and ozone and NO2 concentrations were measured. The site distribution density was higher in the centre, 250x250 m2 than in periphery where a 500x500 m2 grid was used. The selection of field places took into consideration the choice criteria recommendation by United Kingdom environmental authorities, and three tubes and a blank tube for each pollutant were used at each site. The sampling system was mounted at 3m from the ground usually profiting the street lampposts. Concerning NO2 acrylic tubes were used with 85 mm of length and an in- ternal diameter of 12mm, where in one of the extremities three steel grids impregnated with a solution of TEA were placed and fixed with a polyethylene end cup (Heal et al., 1999); PFA Teflon tube with 53 mm of length and 9 mm of internal diameter and three impregnated glass filters impregnated with DPE solution fixed by a teflon end cup was used for ozone sampling (Monn and Hargartner, 1990). The passive sampling method for ozone and nitrogen dioxide was compared with continuous measurements, but the amount of measurements wasnSt enough for an accurate calibration and validation of the method. Although this constraint the field observations (June to August 2001) for these two pollutants assign interesting information about the air quality in the urban area. A krigger method of interpolation (Surfer- Golden Software-2000) was applied to field data to obtain isolines distribution of NO2 and ozone concentration for the studied area. Even the used passive sampling method has many

  16. Quantifying the impact of land cover composition on intra-urban air temperature variations at a mid-latitude city.

    PubMed

    Yan, Hai; Fan, Shuxin; Guo, Chenxiao; Hu, Jie; Dong, Li

    2014-01-01

    The effects of land cover on urban-rural and intra-urban temperature differences have been extensively documented. However, few studies have quantitatively related air temperature to land cover composition at a local scale which may be useful to guide landscape planning and design. In this study, the quantitative relationships between air temperature and land cover composition at a neighborhood scale in Beijing were investigated through a field measurement campaign and statistical analysis. The results showed that the air temperature had a significant positive correlation with the coverage of man-made surfaces, but the degree of correlation varied among different times and seasons. The different land cover types had different effects on air temperature, and also had very different spatial extent dependence: with increasing buffer zone size (from 20 to 300 m in radius), the correlation coefficient of different land cover types varied differently, and their relative impacts also varied among different times and seasons. At noon in summer, ∼ 37% of the variations in temperature were explained by the percentage tree cover, while ∼ 87% of the variations in temperature were explained by the percentage of building area and the percentage tree cover on summer night. The results emphasize the key role of tree cover in attenuating urban air temperature during daytime and nighttime in summer, further highlighting that increasing vegetation cover could be one effective way to ameliorate the urban thermal environment.

  17. Urban air pollution & its assessment in Lucknow City--the second largest city of North India.

    PubMed

    Lawrence, Alfred; Fatima, Nishat

    2014-08-01

    Investigations were carried out during the summer season (March-June 2012) to observe the quality of indoor air by monitoring the levels of some selected air pollutants at 15 different houses covering the urban areas of Lucknow City. Concentrations of CO2, CO, PM10, PM2.5, SO2 and NO2 were monitored indoors and outdoors simultaneously and I/O ratios were calculated. Regression analysis for I/O relationship was performed to assess the contribution of outdoor sources to indoor air quality. Air Quality Index (AQI) for indoor air was also calculated to have an idea about the quality of indoor air and their health effects. In collaboration with the medical college doctors of the city, we surveyed 197 persons to find out different diseases/symptoms being faced due to indoor air pollution. Results of the study revealed that the average levels of PM10 and PM2.5 were above the permissible limits laid by WHO at densely populated and roadside sites with 189 μg/m(3) (PM2.5 76 μg/m(3)) and 226 μg/m(3) (PM2.5 91 μg/m(3)) respectively. Correlation analysis showed positive results. At sites like Alambagh and Chowk, the indoor AQI range was alarming with the values of 302 and 209. Survey results also showed that 46% of urban people suffered from acute respiratory infections like bronchial asthma, headache, depression and dizziness and these people were mostly from Roadside colonies.

  18. Global Cooling: Effect of Urban Albedo on Global Temperature

    SciTech Connect

    Akbari, Hashem; Menon, Surabi; Rosenfeld, Arthur

    2007-05-22

    In many urban areas, pavements and roofs constitute over 60% of urban surfaces (roof 20-25%, pavements about 40%). The roof and the pavement albedo can be increased by about 0.25 and 0.10, respectively, resulting in a net albedo increase for urban areas of about 0.1. Many studies have demonstrated building cooling-energy savings in excess of 20% upon raising roof reflectivity from an existing 10-20% to about 60%. We estimate U.S. potential savings in excess of $1 billion (B) per year in net annual energy bills. Increasing albedo of urban surfaces can reduce the summertime urban temperature and improve the urban air quality. Increasing the urban albedo has the added benefit of reflecting more of the incoming global solar radiation and countering the effect of global warming. We estimate that increasing albedo of urban areas by 0.1 results in an increase of 3 x 10{sup -4} in Earth albedo. Using a simple global model, the change in air temperature in lowest 1.8 km of the atmosphere is estimated at 0.01K. Modelers predict a warming of about 3K in the next 60 years (0.05K/year). Change of 0.1 in urban albedo will result in 0.01K global cooling, a delay of {approx}0.2 years in global warming. This 0.2 years delay in global warming is equivalent to 10 Gt reduction in CO2 emissions.

  19. The Effect of Urban Heat Island on Climate Warming in the Yangtze River Delta Urban Agglomeration in China.

    PubMed

    Huang, Qunfang; Lu, Yuqi

    2015-07-27

    The Yangtze River Delta (YRD) has experienced rapid urbanization and dramatic economic development since 1978 and the Yangtze River Delta urban agglomeration (YRDUA) has been one of the three largest urban agglomerations in China. We present evidence of a significant urban heat island (UHI) effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal (nighttime) and maximal (daytime) air temperature in the YRDUA using 41 meteorological stations observation data. The effect of the UHI on climate warming shows a large spatial variability. The average warming rates of average air temperature of huge cities, megalopolises, large cities, medium-sized cities, and small cities are 0.483, 0.314 ± 0.030, 0.282 ± 0.042, 0.225 ± 0.044 and 0.179 ± 0.046 °C/decade during the period of 1957-2013, respectively. The average warming rates of huge cities and megalopolises are significantly higher than those of medium-sized cities and small cities, indicating that the UHI has a significant effect on climate warming (t-test, p < 0.05). Significantly positive correlations are found between the urbanization rate, population, built-up area and warming rate of average air temperature (p < 0.001). The average warming rate of average air temperature attributable to urbanization is 0.124 ± 0.074 °C/decade in the YRDUA. Urbanization has a measurable effect on the observed climate warming in the YRD aggravating the global climate warming.

  20. The Effect of Urban Heat Island on Climate Warming in the Yangtze River Delta Urban Agglomeration in China

    PubMed Central

    Huang, Qunfang; Lu, Yuqi

    2015-01-01

    The Yangtze River Delta (YRD) has experienced rapid urbanization and dramatic economic development since 1978 and the Yangtze River Delta urban agglomeration (YRDUA) has been one of the three largest urban agglomerations in China. We present evidence of a significant urban heat island (UHI) effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal (nighttime) and maximal (daytime) air temperature in the YRDUA using 41 meteorological stations observation data. The effect of the UHI on climate warming shows a large spatial variability. The average warming rates of average air temperature of huge cities, megalopolises, large cities, medium-sized cities, and small cities are 0.483, 0.314 ± 0.030, 0.282 ± 0.042, 0.225 ± 0.044 and 0.179 ± 0.046 °C/decade during the period of 1957–2013, respectively. The average warming rates of huge cities and megalopolises are significantly higher than those of medium-sized cities and small cities, indicating that the UHI has a significant effect on climate warming (t-test, p < 0.05). Significantly positive correlations are found between the urbanization rate, population, built-up area and warming rate of average air temperature (p < 0.001). The average warming rate of average air temperature attributable to urbanization is 0.124 ± 0.074 °C/decade in the YRDUA. Urbanization has a measurable effect on the observed climate warming in the YRD aggravating the global climate warming. PMID:26225986

  1. Evaluation of a possible association of urban air toxics and asthma.

    PubMed Central

    Leikauf, G D; Kline, S; Albert, R E; Baxter, C S; Bernstein, D I; Buncher, C R

    1995-01-01

    The prevalence of asthma, measured either as the frequency of hospital admissions or number of deaths attributed to asthma, has increased over the last 15 to 20 years. Rapid increases in disease prevalence are more likely to be attributable to environmental than genetic factors. Inferring from past associations between air pollution and asthma, it is feasible that changes in the ambient environment could contribute to this increase in morbidity and mortality. Scientific evaluation of the links between air pollution and the exacerbation of asthma is incomplete, however. Currently, criteria pollutants [SOx, NOx, O3, CO, Pb, particulate matter (PM10)] and other risk factors (exposure to environmental tobacco smoke, volatile organic compounds, etc.) are constantly being evaluated as to their possible contributions to this situation. Data from these studies suggest that increases in respiratory disease are associated with exposures to ambient concentrations of particulate and gaseous pollutants. Similarly, exposure to environmental tobacco smoke, also a mixture of particulate and gaseous air toxics, has been associated with an increase in asthma among children. In addition, current associations of adverse health effects with existing pollution measurements are often noted at concentrations below those that produce effects in controlled animal and human exposures to each pollutant alone. These findings imply that adverse responses are augmented when persons are exposed to irritant mixtures of particles and gases and that current measurements of air pollution are, in part, indirect in that the concentrations of criteria pollutants are acting as surrogates of our exposure to a complex mixture. Other irritant air pollutants, including certain urban air toxics, are associated with asthma in occupational settings and may interact with criteria pollutants in ambient air to exacerbate asthma. An evaluation of dose-response information for urban air toxics and biological

  2. Air pollution prevention through urban heat island mitigation: An update on the urban heat island pilot project

    SciTech Connect

    Gorsevski, V.; Taha, H.; Quattrochi, D.; Luvall, J.

    1998-07-01

    Urban heat islands increase the demand for cooling energy and accelerate the formation of smog. They are created when natural vegetation is replaced by heat-absorbing surfaces such as building roofs and walls, parking lots, and streets. Through the implementation of measures designed to mitigate the urban heat island, communities can decrease their demand for energy and effectively cool the metropolitan landscape. In addition to the economic benefits, using less energy leads to reductions in emission of CO{sub 2}--a greenhouse gas--as well as ozone (smog) precursors such as NOx and VOCs. Because ozone is created when NOx and VOCs photochemically combine with heat and solar radiation, actions taken to lower ambient air temperature can significantly reduce ozone concentrations in certain areas. Measures to reverse the urban heat island include afforestation and the widespread use of highly reflective surfaces. To demonstrate the potential benefits of implementing these measures, EPA has teamed up with NASA and LBNL to initiate a pilot project with three US cities. As part of the pilot, NASA will use remotely-sensed data to quantify surface temperature, albedo, the thermal response number and NDVI vegetation of each city. This information will be used by scientists at Lawrence Berkeley National Laboratory (LBNL) along with other data as inputs to model various scenarios that will help quantify the potential benefits of urban heat island mitigation measures in terms of reduced energy use and pollution. This paper will briefly describe this pilot project and provide an update on the progress to date.

  3. Meteorology applied to urban air pollution problems: concepts from COST 715

    NASA Astrophysics Data System (ADS)

    Fisher, P.; Kukkonen, J.; Piringer, M.; Rotach, M. W.; Schatzmann, M.

    2005-08-01

    This selective review of the COST 715 considers simple descriptive concepts in urban meteorology with particular attention to air pollution assessment. It is shown that these are helpful for understanding the complex structure of the urban boundary layer, but that simple concepts only apply under a limited number of occasions. However such concepts are necessary for insight into how both simple and complex air pollution models perform. Wider considerations are needed when considering routine air quality assessments involving an air quality model's formulation and pedigree. It is argued that there is a reluctance from model developers to move away from familiar concepts of the atmospheric boundary layer even if they are not appropriate to urban areas. An example is given from COST 715 as to how routine urban meteorological measurements of wind speed may be used and adapted for air quality assessments. Reference to the full COST 715 study is made which provides further details.

  4. Meteorology applied to urban air pollution problems: concepts from COST 715

    NASA Astrophysics Data System (ADS)

    Fisher, B.; Kukkonen, J.; Piringer, M.; Rotach, M. W.; Schatzmann, M.

    2006-02-01

    The outcome of COST 715 is reviewed from the viewpoint of a potential user who is required to consider urban meteorology within an air pollution assessment. It is shown that descriptive concepts are helpful for understanding the complex structure of the urban boundary layer, but that they only apply under a limited number of conditions. However such concepts are necessary to gain insight into both simple and complex air pollution models. It is argued that wider considerations are needed when considering routine air quality assessments involving an air quality model's formulation and pedigree. Moreover there appears to be a reluctance from model developers to move away from familiar concepts of the atmospheric boundary layer even if they are not appropriate to urban areas. An example is given from COST 715 as to how routine urban meteorological measurements of wind speed may be used and adapted for air quality assessments. Reference to the full COST 715 study is made which provides further details.

  5. Urban and Rural Air Pollution: A Cross-Age Study of School Students' Ideas.

    ERIC Educational Resources Information Center

    Myers, George; Boyes, Edward; Stanisstreet, Martin

    2000-01-01

    Explores ideas about the causes and consequences of urban and rural air pollution of secondary school students aged 11-16 years (n=786) using a questionnaire. Students thought the air in towns and cities was more polluted than the air in the countryside. (Author/SAH)

  6. Hybrid Air Quality Modeling Approach For Use in the Near-Road Exposures to Urban Air Pollutant Study (NEXUS)

    EPA Science Inventory

    The Near-road EXposures to Urban air pollutant Study (NEXUS) investigated whether children with asthma living in close proximity to major roadways in Detroit, MI, (particularly near roadways with high diesel traffic) have greater health impacts associated with exposure to air pol...

  7. The Atlanta Urban Heat Island Mitigation and Air Quality Modeling Project: How High-Resoution Remote Sensing Data Can Improve Air Quality Models

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale A.; Estes, Maurice G., Jr.; Crosson, William L.; Khan, Maudood N.

    2006-01-01

    The Atlanta Urban Heat Island and Air Quality Project had its genesis in Project ATLANTA (ATlanta Land use Analysis: Temperature and Air quality) that began in 1996. Project ATLANTA examined how high-spatial resolution thermal remote sensing data could be used to derive better measurements of the Urban Heat Island effect over Atlanta. We have explored how these thermal remote sensing, as well as other imaged datasets, can be used to better characterize the urban landscape for improved air quality modeling over the Atlanta area. For the air quality modeling project, the National Land Cover Dataset and the local scale Landpro99 dataset at 30m spatial resolutions have been used to derive land use/land cover characteristics for input into the MM5 mesoscale meteorological model that is one of the foundations for the Community Multiscale Air Quality (CMAQ) model to assess how these data can improve output from CMAQ. Additionally, land use changes to 2030 have been predicted using a Spatial Growth Model (SGM). SGM simulates growth around a region using population, employment and travel demand forecasts. Air quality modeling simulations were conducted using both current and future land cover. Meteorological modeling simulations indicate a 0.5 C increase in daily maximum air temperatures by 2030. Air quality modeling simulations show substantial differences in relative contributions of individual atmospheric pollutant constituents as a result of land cover change. Enhanced boundary layer mixing over the city tends to offset the increase in ozone concentration expected due to higher surface temperatures as a result of urbanization.

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

    PubMed

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

    2004-07-01

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

  9. Assessment of selected metals in the ambient air PM10 in urban sites of Bangkok (Thailand).

    PubMed

    Pongpiachan, Siwatt; Iijima, Akihiro

    2016-02-01

    Estimating the atmospheric concentrations of PM10-bounded selected metals in urban air is crucial for evaluating adverse health impacts. In the current study, a combination of measurements and multivariate statistical tools was used to investigate the influence of anthropogenic activities on variations in the contents of 18 metals (i.e., Al, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Sb, Ba, La, Ce and Pb) in ambient air. The concentrations of PM10-bounded metals were measured simultaneously at eight air quality observatory sites during a half-year period at heavily trafficked roads and in urban residential zones in Bangkok, Thailand. Although the daily average concentrations of Al, V, Cr, Mn and Fe were almost equivalent to those of other urban cities around the world, the contents of the majority of the selected metals were much lower than the existing ambient air quality guidelines and standard limit values. The sequence of average values of selected metals followed the order of Al > Fe > Zn > Cu > Pb > Mn > Ba > V > Sb > Ni > As > Cr > Cd > Se > Ce > La > Co > Sc. The probability distribution function (PDF) plots showed sharp symmetrical bell-shaped curves in V and Cr, indicating that crustal emissions are the predominant sources of these two elements in PM10. The comparatively low coefficients of divergence (COD) that were found in the majority of samples highlight that site-specific effects are of minor importance. A principal component analysis (PCA) revealed that 37.74, 13.51 and 11.32 % of the total variances represent crustal emissions, vehicular exhausts and the wear and tear of brakes and tires, respectively.

  10. 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.

  11. Multicriteria methodological approach to manage urban air pollution

    NASA Astrophysics Data System (ADS)

    Vlachokostas, Ch.; Achillas, Ch.; Moussiopoulos, N.; Banias, G.

    2011-08-01

    Managing urban air pollution necessitates a feasible and efficient abatement strategy which is characterised as a defined set of specific control measures. In practice, hard budget constraints are present in any decision-making process and therefore available alternatives need to be hierarchised in a fast but still reliable manner. Moreover, realistic strategies require adequate information on the available control measures, taking also into account the area's special characteristics. The selection of the most applicable bundle of measures rests in achieving stakeholders' consensus, while taking into consideration mutually conflicting views and criteria. A preliminary qualitative comparison of alternative control measures would be most handy for decision-makers, forming the grounds for an in-depth analysis of the most promising ones. This paper presents an easy-to-follow multicriteria methodological approach in order to include and synthesise multi-disciplinary knowledge from various stakeholders so as to result into a priority list of abatement options, achieve consensus and secure the adoption of the resulting optimal solution. The approach relies on the active involvement of public authorities and local stakeholders in order to incorporate their environmental, economic and social preferences. The methodological scheme is implemented for the case of Thessaloniki, Greece, an area considered among the most polluted cities within Europe, especially with respect to airborne particles. Intense police control, natural gas penetration in buildings and metro construction equally result into the most "promising" alternatives in order to control air pollution in the GTA. The three optimal alternatives belong to different thematic areas, namely road transport, thermal heating and infrastructure. Thus, it is obvious that efforts should spread throughout all thematic areas. Natural gas penetration in industrial units, intense monitoring of environmental standards and regular

  12. Odonata Diversity and Synanthropy in Urban Areas: A Case Study in Avellaneda City, Buenos Aires, Argentina.

    PubMed

    Ramos, L S; Lozano, F; Muzón, J

    2017-04-01

    The increase of human population, especially in urban areas, correlates with an alarming destruction of green spaces. Therefore, understanding the mechanisms by which urbanization processes affect biodiversity is crucial in integrating the environment in a proper urban planning. The main urban center of Argentina is known as the Greater Buenos Aires (GBA), and it includes the autonomous city of Buenos Aires and 24 surrounding districts. Avellaneda, one of the districts of the GBA, is an important urban and industrial center with green areas and low level of urbanization on the coastal area of the Río de la Plata. This paper provides the first Odonata inventory for Avellaneda, determines the species' level of synanthropy with the Nuorteva index, and assess the Odonata species replacement along a latitudinal gradient on the occidental margin of the Río de la Plata.

  13. Urban air pollution and atmospheric diffusion research in China

    NASA Astrophysics Data System (ADS)

    Ning, Datong; Whitney, Joseph B.; Yap, David

    1987-11-01

    Air pollution has become a serious problem in China as a result of that country's efforts in the last 30 years to become a great industrial power. The burning of coal, which currently provides over 70% of all China's energy needs, is a major source of air pollution. Because Chinese coal is high in sulfur and ash content and because most combustion devices in China have low efficiencies, SO2 and particulate emissions are a serious problem and are comparable to or exceed those found in many countries that are much more industrialized. Although most coal is burned in North China, acid precipitation is most severe in South China because of the lack of buffering loess dust found in the former region. The Chinese government has already taken major steps to mitigate air pollution, such as relocating polluting industries, supplying coal with lower sulfur content, using gas instead of coal for residential heating, and levying fines on industries that exceed pollution standards. Atmospheric environmental impact assessment (AEIA) is also required for all major new projects. This article describes three types of mathematical diffusion models and field and wind-tunnel experiments that are used in such assessments. The Chinese authorities believe that a range of technological, managerial, locational, and behavioral changes must be effected before the air of Chinese cities can be significantly improved.

  14. Enhancement of local air pollution by urban CO(2) domes.

    PubMed

    Jacobson, Mark Z

    2010-04-01

    Data suggest that domes of high CO(2) levels form over cities. Despite our knowledge of these domes for over a decade, no study has contemplated their effects on air pollution or health. In fact, all air pollution regulations worldwide assume arbitrarily that such domes have no local health impact, and carbon policy proposals, such as "cap and trade", implicitly assume that CO(2) impacts are the same regardless of where emissions occur. Here, it is found through data-evaluated numerical modeling with telescoping domains from the globe to the U.S., California, and Los Angeles, that local CO(2) emissions in isolation may increase local ozone and particulate matter. Although health impacts of such changes are uncertain, they are of concern, and it is estimated that that local CO(2) emissions may increase premature mortality by 50-100 and 300-1000/yr in California and the U.S., respectively. As such, reducing locally emitted CO(2) may reduce local air pollution mortality even if CO(2) in adjacent regions is not controlled. If correct, this result contradicts the basis for air pollution regulations worldwide, none of which considers controlling local CO(2) based on its local health impacts. It also suggests that a "cap and trade" policy should consider the location of CO(2) emissions, as the underlying assumption of the policy is incorrect.

  15. URBAN SPRAWL MODELING, AIR QUALITY MONITORING AND RISK COMMUNICATION: THE NORTHEAST OHIO PROJECT

    EPA Science Inventory

    The Northeast Ohio Urban Sprawl, Air Quality Monitoring, and Communications Project (hereafter called the Northeast Ohio Project) provides local environmental and health information useful to residents, local officials, community planners, and others in a 15 county region in the ...

  16. Effects of urbanization on groundwater evolution in an urbanizing watershed

    NASA Astrophysics Data System (ADS)

    Reyes, D.; Banner, J. L.; Bendik, N.

    2011-12-01

    The Jollyville Plateau Salamander (Eurycea tonkawae), a candidate species for listing under the Endangered Species Act, is endemic to springs and caves within the Bull Creek Watershed of Austin, Texas. Rapid urbanization endangers known populations of this salamander. Conservation strategies lack information on the extent of groundwater contamination from anthropogenic sources in this karst watershed. Spring water was analyzed for strontium (Sr) isotopes and major ions from sites classified as "urban" or "rural" based on impervious cover estimates. Previous studies have shown that the 87Sr/86Sr value of municipal water is significantly higher than values for natural streamwater, which are similar to those for the Cretaceous limestone bedrock of the region's watersheds. We investigate the application of this relationship to understanding the effects of urbanization on groundwater quality. The use of Sr isotopes as hydrochemical tracers is complemented by major ion concentrations, specifically the dominant ions in natural groundwater (Ca and HCO3) and the ions associated with the addition of wastewater (Na and Cl). To identify high priority salamander-inhabited springs for water quality remediation, we explore the processes controlling the chemical evolution of groundwater such as municipal water inputs, groundwater-soil interactions, and solution/dissolution reactions. 87Sr/86Sr values for water samples from within the watershed range from 0.70760 to 0.70875, the highest values corresponding to sites located in the urbanized areas of the watershed. Analyses of the covariation of Sr isotopes with major ion concentrations help elucidate controls on spring water evolution. Springs located in rural portions of the watershed have low 87Sr/86Sr, high concentrations of Ca and HCO3, and low concentrations of Na and Cl. This is consistent with small inputs of municipal water. Three springs located in urban portions of the watershed have high 87Sr/86Sr, low Ca and HCO3, and

  17. The effect of urban design parameters on the local microclimate

    SciTech Connect

    Kakoniti, Androula; Georgiou, Gregoria; Neophytou, Marina; Marakkos, Konstantinos

    2015-01-22

    Two-dimensional steady-state simulations have been performed using the standard k-e turbulence model coupled with the heat transfer models available in the CFD software FLUENT 6.1, in order to examine the impact of radiation on the Urban Heat Island phenomenon. Specifically, the impact of radiation in three typical urban areas of Cyprus during the summer period is examined. The first geometry considered represents a typical suburban area and is termed as the reference geometry. The second geometry represents an area at the centre of a town with higher buildings and relatively narrower roads. The third geometry, on the other hand, describes a suburban area with wider roads and larger houses than the reference model. Computed values for air temperature in the urban street canyon have indicated that the increase in temperature associated with radiative heat transfer can be reduced by optimising the canyon geometry and, ultimately, help to mitigate the human thermal discomfort. The present study has also revealed that the selection of construction materials can be optimised to offer further reductions in the air temperature of the urban environment. It can be concluded that the combined effect of these remedies can lead to reductions in the energy consumption for building air-conditioning over the summer period.

  18. Analysis of air quality and nighttime light for Indian urban regions

    NASA Astrophysics Data System (ADS)

    Misra, Prakhar; Takeuchi, Wataru

    2016-06-01

    Indian urban regions suffer severe air pollution issues. A 2014 study by WHO highlighted that out of 20 cities globally with worst air quality, 13 lie in India. Although insufficient ground monitoring data and incomplete air pollution source characterization impedes putting policy measures to tackle this issue, remote sensing and GIS can overcome this hurdle to some extent. To find out how much of this hazard is due to economic growth, past researches have tried to make use of socio-economic growth indicators like GDP, population or urban area to establish its correlation with air quality in urban centres. Since nightlight has been found to correlate well with economic conditions at national and city level, an attempt has been made to analyse it with air quality levels to find regions with high contribution of anthropogenic emissions. Nighttime light activity was observed through DayNight Band (DNB) of VIIRS sensor while the air quality levels were obtained for ANG and AOD (using MODIS sensor) and SO2 and NO2 (using OMI sensor). We have classified Indian landmass into 4 air-quality and DNB classes: LowLight- HighPollution, HighLight-HighPollution, LowLight-LowPollution and HighLight- LowPollution for each air quality species using June 2014 data. It was found that around half of urban regions show high AOD and ANG values. On the other hand almost all urban regions exhibit high SO2 and NO2 values.

  19. Solutions Network Formulation Report. NASA's Potential Contributions for Using Solar Ultraviolet Radiation in Conjunction with Photocatalysis for Urban Air Pollution Mitigation and Increasing Air Quality

    NASA Technical Reports Server (NTRS)

    Underwood, Lauren; Ryan, Robert E.

    2007-01-01

    This Candidate Solution is based on using NASA Earth science research on atmospheric ozone and aerosols data as a means to predict and evaluate the effectiveness of photocatalytically created surfaces (building materials like glass, tile and cement) for air pollution mitigation purposes. When these surfaces are exposed to near UV light, organic molecules, like air pollutants and smog precursors, will degrade into environmentally friendly compounds. U.S. EPA (Environmental Protection Agency) is responsible for forecasting daily air quality by using the Air Quality Index (AQI) that is provided by AIRNow. EPA is partnered with AIRNow and is responsible for calculating the AQI for five major air pollutants that are regulated by the Clean Air Act. In this Solution, UV irradiance data acquired from the satellite mission Aura and the OMI Surface UV algorithm will be used to help understand both the efficacy and efficiency of the photocatalytic decomposition process these surfaces facilitate, and their ability to reduce air pollutants. Prediction models that estimate photocatalytic function do not exist. NASA UV irradiance data will enable this capability, so that air quality agencies that are run by state and local officials can develop and implement programs that utilize photocatalysis for urban air pollution control and, enable them to make effective decisions about air pollution protection programs.

  20. Air quality variability near a highway in a complex urban environment

    NASA Astrophysics Data System (ADS)

    Baldauf, Richard W.; Heist, David; Isakov, Vlad; Perry, Steven; Hagler, Gayle S. W.; Kimbrough, Sue; Shores, Richard; Black, Kevin; Brixey, Laurie

    2013-01-01

    In response to growing public health concerns regarding elevated air pollutant exposures and adverse human health effects for near-road populations, a study was conducted to assess how complex urban roadway configurations affect local-scale air quality. This study combined fixed-site and mobile air quality measurements with laboratory wind tunnel experiments to examine how the transport and dispersion of traffic-emitted pollutants varies with changing roadway configuration, notably with at-grade and cut section designs. Results of the study indicated that short-term maximum concentrations occurred with measurements made along at-grade locations, however, average concentrations tended to be higher at the top of the cut section compared with the at-grade location, most often occurring during lower air pollutant events. Wind flow and NO2/NOx ratios indicated that the cut section moderated peak concentrations through increased transport and dispersion, as well as reducing the influence of turbulence from vehicle activity near the road. The at-grade locations also experienced a higher impact from primary vehicle emissions than those measurements made at similar distances along a cut section. Mobile monitoring suggested that these peak concentrations quickly conformed to concentration levels measured near cut sections within 50-100 m of the source highway. Wind tunnel simulations of the study site with and without the cut section present indicated that the cut section reduced the concentrations of primary emitted vehicle pollutants by 15-25 percent for receptors located approximately 20 m from the highway. The wind tunnel simulations also revealed that buildings and other urban features influenced local-scale pollutant transport and need to be considered when evaluating near-road air quality.

  1. Assessing relocation strategies of urban air quality monitoring stations by GA-based compromise programming.

    PubMed

    Tseng, C C; Chang, N B

    2001-06-01

    This paper presents a GA-based compromise programming technique for assessing the relocation strategy of urban air quality monitoring network with respect to the multi-objective and multi-pollutant design criteria. While the impact of conservative, quasi-stable, and reactive pollutants are considered in the design principles via a simulation analysis, cost, effectiveness, and efficiency characteristics are postulated in the optimization process. Therefore, technical coverage for illustrating the needs of siting air quality monitoring stations (AQMS) includes both the air quality simulation and optimization modeling analyses in a two-stage analytical framework simultaneously. It starts from determining the spatial interrelationship among those candidate sites using various types of air quality simulation models as an integrated means. And the outputs drawn from the simulation models can then be used as the required inputs in the compromise programming model in order to screen all those siting alternatives that may satisfy the planning goals subject to the essential constraints throughout the multi-objective optimization process. For the illustrating purposes, a series of technical settings for finding the optimal relocation scenarios of AQMS were examined in the case study for the city of Kaohsiung in South Taiwan where the long-term violations of official standards of ozone and particulates turn out to be critical. It not only expresses the ideas of relocation strategy but also indicates how to utilize those alternatives in the decision-making process for improving the functionality of air quality monitoring in the urban environment. Experience gained in this study clearly indicates that the more the number of pollutants and objectives considered simultaneously, the higher the number of candidate sites to be selected in the relocation strategy.

  2. Indoor air quality in urban nurseries at Porto city: Particulate matter assessment

    NASA Astrophysics Data System (ADS)

    Branco, P. T. B. S.; Alvim-Ferraz, M. C. M.; Martins, F. G.; Sousa, S. I. V.

    2014-02-01

    Indoor air quality in nurseries is an interesting case of study mainly due to children's high vulnerability to exposure to air pollution (with special attention to younger ones), and because nursery is the public environment where young children spend most of their time. Particulate matter (PM) constitutes one of the air pollutants with greater interest. In fact, it can cause acute effects on children's health, as well as may contribute to the prevalence of chronic respiratory diseases like asthma. Thus, the main objectives of this study were: i) to evaluate indoor concentrations of particulate matter (PM1, PM2.5, PM10 and PMTotal) on different indoor microenvironments in urban nurseries of Porto city; and ii) to analyse those concentrations according to guidelines and references for indoor air quality and children's health. Indoor PM measurements were performed in several class and lunch rooms in three nurseries on weekdays and weekends. Outdoor PM10 concentrations were also obtained to determine I/O ratios. PM concentrations were often found high in the studied classrooms, especially for the finer fractions, reaching maxima hourly mean concentrations of 145 μg m-3 for PM1 and 158 μg m-3 PM2.5, being often above the limits recommended by WHO, reaching 80% of exceedances for PM2.5, which is concerning in terms of exposure effects on children's health. Mean I/O ratios were always above 1 and most times above 2 showing that indoor sources (re-suspension phenomena due to children's activities, cleaning and cooking) were clearly the main contributors to indoor PM concentrations when compared with the outdoor influence. Though, poor ventilation to outdoors in classrooms affected indoor air quality by increasing the PM accumulation. So, enhancing air renovation rate and performing cleaning activities after the occupancy period could be good practices to reduce PM indoor air concentrations in nurseries and, consequently, to improve children's health and welfare.

  3. Investigating the Urban Heat Island Effect with a Collaborative Inquiry Project.

    ERIC Educational Resources Information Center

    George, Linda A.; Becker, William G.

    2003-01-01

    Explains a collaborative research project in which students study a phenomenon known as the Urban Heat Island (UHI) effect which is a measure of the near-surface air temperature contrast between urbanized and adjoining rural areas. Includes background content and literature review, preliminary studies, development of research questions,…

  4. Impacts of Lowered Urban Air Temperatures on Precursor Emission and Ozone Air Quality.

    PubMed

    Taha, Haider; Konopacki, Steven; Akbari, Hashem

    1998-09-01

    Meteorological, photochemical, building-energy, and power plant simulations were performed to assess the possible precursor emission and ozone air quality impacts of decreased air temperatures that could result from implementing the "cool communities" concept in California's South Coast Air Basin (SoCAB). Two pathways are considered. In the direct pathway, a reduction in cooling energy use translates into reduced demand for generation capacity and, thus, reduced precursor emissions from electric utility power plants. In the indirect pathway, reduced air temperatures can slow the atmospheric production of ozone as well as precursor emission from anthropogenic and biogenic sources. The simulations suggest small impacts on emissions following implementation of cool communities in the SoCAB. In summer, for example, there can be reductions of up to 3% in NOx emissions from in-basin power plants. The photochemical simulations suggest that the air quality impacts of these direct emission reductions are small. However, the indirect atmospheric effects of cool communities can be significant. For example, ozone peak concentrations can decrease by up to 11% in summer and population-weighted exceedance exposure to ozone above the California and National Ambient Air Quality Standards can decrease by up to 11 and 17%, respectively. The modeling suggests that if these strategies are combined with others, such as mobile-source emission control, the improvements in ozone air quality can be substantial.

  5. Regional/Urban Air Quality Modeling Assessment over China Using the Models-3/CMAQ System

    NASA Astrophysics Data System (ADS)

    Fu, J. S.; Jang, C. C.; Streets, D. G.; Li, Z.; Wang, L.; Zhang, Q.; Woo, J.; Wang, B.

    2004-12-01

    China is the world's most populous country with a fast growing economy that surges in energy comsumption. It has become the second largest energy consumer after the United States although the per capita level is much lower than those found in developed or developing countries. Air pollution has become one of the most important problems of megacities such as Beijing and Shanghai and has serious impacts on public health, causes urban and regional haze. The Models-3/CMAQ modeling application that has been conducted to simulate multi-pollutants in China is presented. The modeling domains cover East Asia (36-kmx36-km) including Japan, South Korea, Korea DPR, Indonesia, Thailand, India and Mongolia, East China (12-kmx12-km) and Beijing/Tianjing, Shanghai (4-kmx4-km). For this study, the Asian emission inventory based on the emission estimates of the year 2000 that supported the NASA TRACE-P program is used. However, the TRACE-P emission inventory was developed for a different purpose such as global modeling. TRACE-P emission inventory may not be practical in urban area. There is no China national emission inventory available. Therefore, TRACE-P emission inventory is used on the East Asia and East China domains. The 8 districts of Beijing and Shanghai local emissions inventory are used to replace TRACE-P in 4-km domains. The meteorological data for the Models-3/CMAQ run are extracted from MM5. The model simulation is performed during the period January 1-20 and July 1-20, 2001 that presented the winter and summer time for China areas. The preliminary model results are shown O3 concentrations are in the range of 80 -120 ppb in the urban area. Lower urban O3 concentrations are shown in Beijing areas, possibly due to underestimation of urban man-made VOC emissions in the TRACE-P inventory and local inventory. High PM2.5 (70ug/m3 in summer and 150ug/m3 in winter) were simulated over metropolitan & downwind areas with significant secondary constituents. More comprehensive

  6. The Influence of Traffic on Air Quality in an Urban Neighborhood: A Community–University Partnership

    PubMed Central

    Lee, Harrison J.; Levy, Jonathan I.

    2009-01-01

    Objectives. We evaluated the spatial and temporal patterns of traffic-related air pollutants in an urban neighborhood to determine factors contributing to elevated concentrations and to inform environmental justice concerns. Methods. In the summer of 2007, we continuously monitored multiple air pollutants at a community site in the Mission Hill neighborhood of Boston, Massachussetts, and local high school students conducted mobile continuous monitoring throughout the neighborhood. We used regression models to explain variability in concentrations, considering various attributes of traffic, proximity to major roadways, and meteorology. Results. Different attributes of traffic explained variability in fixed-site concentrations of ultrafine particles, fine particulate matter, and black carbon, with diurnal patterns and meteorological effects indicative of a greater local effect on ultrafine particles and black carbon. Mobile monitoring demonstrated that multiple traffic variables predict elevated levels of ultrafine particles, with concentrations of ultrafine particles decreasing by 50% within 400 meters of 2 major roadways. Conclusions. Unlike fine particulate matter, ultrafine particles demonstrate significant spatial and temporal variability within an urban neighborhood, contributing to environmental justice concerns, and patterns can be well characterized with a community-based participatory research design. PMID:19890168

  7. Urban air quality of kathmandu valley "Kingdom of Nepal"

    NASA Astrophysics Data System (ADS)

    Sharma, C. K.

    The oval shaped tectonic basin of Kathmandu valley, occupying about 656 sq.km is situated in the middle sector of Himalayan range. There are three districts in the valley, i.e. Kathmandu, Lalitpur and Bhaktapur. Out of the three, the most populated is Kathmandu city (the capital of Kingdom of Nepal) which has a population of 668,00 in an area of approximately 50 km 2. The energy consumption of the city population is about 1/3 of the total import to Nepal of gasoline, diesel, kerosene, furnace oil and cooking gas. This has resulted heavy pollution of air in the city leading to bronchitis, and throat and chest diseases. Vehicles have increased several fold in recent months and there are 100,000 in number on the road and they have 900 km of road, out of which only 25% is metalled. Most of the two and three wheelers are polluting the air by emission of gases as well as dust particulate. SO 2 has been found to go as high as 202 μg cm -3 and NO 2 to 126 μg cm -3 particularly in winter months when a thick layer of fog covers the valley up to 10 am in the morning. All the gases are mixed within the limited air below the fog and the ground. This creates the problem. Furthermore, municipal waste of 500 m 3 a day and also liquid waste dumped directly into the Bagmati river at the rate of 500,000 ℓ d -1 makes the city ugly and filthy. Unless pollution of air, water and lard are controlled in time, Nepal will lose much of its foreign exchange earnings from the tourist industry. It is found that tourist arrivals have considerably reduced in recent years and most of hotels occupancy is 50-60% in peak time. Nepal is trying to introduce a legal framework for pollution control but it will take time to become effective.

  8. Increasing the spatial resolution of air quality assessments in urban areas: A comparison of biomagnetic monitoring and urban scale modelling

    NASA Astrophysics Data System (ADS)

    Hofman, Jelle; Lefebvre, Wouter; Janssen, Stijn; Nackaerts, Ruben; Nuyts, Siegmund; Mattheyses, Lars; Samson, Roeland

    2014-08-01

    Increasing the spatial resolution of air quality assessments in urban environments is designated as a priority area within current research. Biomagnetic monitoring and air quality modelling are both methodologies able to provide information about the spatial variation of particulate pollutant levels within urban environments. This study evaluates both methods by comparing results of a biomagnetic monitoring campaign at 110 locations throughout Antwerp, Belgium, with modelled pollutant concentrations of PM10 and NO2. Due to the relation of biomagnetic monitoring with railway traffic, analyses were conducted for both all locations (n = 110) and railway traffic excluded locations (n = 67). While the general spatial variation, land use comparison and the relation with traffic intensity were comparable between the two applied methodologies, an overall bad agreement is obtained when the methodologies are correlated to each other. While no correlation was found between SIRM and PM10 results (p = 0.75 for n = 110 and p = 0.68 for n = 67), a significant but low (r ≤ 0.33) correlation was found between SIRM and NO2 (p < 0.01 for n = 110 and p = 0.04 for n = 67). While biomagnetic monitoring and air quality modelling are both able to provide high spatial resolution information about urban pollutant levels, we need to take into account some considerations. While uncertainty in the biomagnetic monitoring approach might arise from the processes that determine leaf particulate deposition and the incorporation of multiple emission sources with diverging magnetic composition, air quality modelling remains an approximation of reality which implies its dependency on accurate emission factors, implication of atmospheric processes and representation of the urban morphology. Therefore, continuous evaluation of model performance against measured data is essential to produce reliable model results. Nevertheless, this study demonstrates that in addition to telemetric monitoring networks

  9. Impact of urbanization level on urban air quality: a case of fine particles (PM(2.5)) in Chinese cities.

    PubMed

    Han, Lijian; Zhou, Weiqi; Li, Weifeng; Li, Li

    2014-11-01

    We examined and compared PM2.5 concentrations in urban and the surrounding regions, and further investigated the impact of urbanization on urban PM2.5 concentrations at the Chinese prefectures. Annual PM2.5 concentrations in most prefectures were greater than 10 μg/m(3), the air quality guideline of the World Health Organization. Those prefectures were mainly distributed along the east coast and southeast of Sichuan province; The urban PM2.5 concentrations ( [Formula: see text] ) in 85 cities were greater than (>10 μg/m(3)) those in the surrounding area. Those cities were mainly located in the Beijing-Sichuan and Shanghai-Guangxi belts. In addition, [Formula: see text] was less than (<0 μg/m(3)) that in surrounding areas in only 41 prefectures, which were located in western China or nearby mega cities; Significant positive correlations were found between [Formula: see text] and urban population (R(2) = 0.99, P < 0.05), and between [Formula: see text] and urban second industry fraction (R(2) = 0.71, P < 0.05), suggesting that urbanization had considerable impact on PM2.5 concentrations.

  10. AIR QUALITY MODELING AT COARSE-TO-FINE SCALES IN URBAN AREAS

    EPA Science Inventory

    Urban air toxics control strategies are moving towards a community based modeling approach, with an emphasis on assessing those areas that experience high air toxic concentration levels, the so-called "hot spots". This approach will require information that accurately maps and...

  11. Urban and peri-urban precipitation and air temperature trends in mega cities of the world using multiple trend analysis methods

    NASA Astrophysics Data System (ADS)

    Ajaaj, Aws A.; Mishra, Ashok K.; Khan, Abdul A.

    2017-03-01

    Urbanization plays an important role in altering local to regional climate. In this study, the trends in precipitation and the air temperature were investigated for urban and peri-urban areas of 18 mega cities selected from six continents (representing a wide range of climatic patterns). Multiple statistical tests were used to examine long-term trends in annual and seasonal precipitation and air temperature for the selected cities. The urban and peri-urban areas were classified based on the percentage of land imperviousness. Through this study, it was evident that removal of the lag-k serial correlation caused a reduction of approximately 20 to 30% in significant trend observability for temperature and precipitation data. This observation suggests that appropriate trend analysis methodology for climate studies is necessary. Additionally, about 70% of the urban areas showed higher positive air temperature trends, compared with peri-urban areas. There were not clear trend signatures (i.e., mix of increase or decrease) when comparing urban vs peri-urban precipitation in each selected city. Overall, cities located in dry areas, for example, in Africa, southern parts of North America, and Eastern Asia, showed a decrease in annual and seasonal precipitation, while wetter conditions were favorable for cities located in wet regions such as, southeastern South America, eastern North America, and northern Europe. A positive relationship was observed between decadal trends of annual/seasonal air temperature and precipitation for all urban and peri-urban areas, with a higher rate being observed for urban areas.

  12. Road traffic impact on urban water quality: a step towards integrated traffic, air and stormwater modelling.

    PubMed

    Fallah Shorshani, Masoud; Bonhomme, Céline; Petrucci, Guido; André, Michel; Seigneur, Christian

    2014-04-01

    Methods for simulating air pollution due to road traffic and the associated effects on stormwater runoff quality in an urban environment are examined with particular emphasis on the integration of the various simulation models into a consistent modelling chain. To that end, the models for traffic, pollutant emissions, atmospheric dispersion and deposition, and stormwater contamination are reviewed. The present study focuses on the implementation of a modelling chain for an actual urban case study, which is the contamination of water runoff by cadmium (Cd), lead (Pb), and zinc (Zn) in the Grigny urban catchment near Paris, France. First, traffic emissions are calculated with traffic inputs using the COPERT4 methodology. Next, the atmospheric dispersion of pollutants is simulated with the Polyphemus line source model and pollutant deposition fluxes in different subcatchment areas are calculated. Finally, the SWMM water quantity and quality model is used to estimate the concentrations of pollutants in stormwater runoff. The simulation results are compared to mass flow rates and concentrations of Cd, Pb and Zn measured at the catchment outlet. The contribution of local traffic to stormwater contamination is estimated to be significant for Pb and, to a lesser extent, for Zn and Cd; however, Pb is most likely overestimated due to outdated emissions factors. The results demonstrate the importance of treating distributed traffic emissions from major roadways explicitly since the impact of these sources on concentrations in the catchment outlet is underestimated when those traffic emissions are spatially averaged over the catchment area.

  13. Urban air pollution and climate change as environmental risk factors of respiratory allergy: an update.

    PubMed

    D'Amato, G; Cecchi, L; D'Amato, M; Liccardi, G

    2010-01-01

    The incidence of allergic respiratory diseases and bronchial asthma appears to be increasing worldwide, and people living in urban areas more frequently experience these conditions than those living in rural areas. One of the several causes of the rise in morbidity associated with allergic respiratory diseases is the increased presence of outdoor air pollutants resulting from more intense energy consumption and exhaust emissions from cars and other vehicles. Urban air pollution is now a serious public health hazard. Laboratory studies confirm epidemiologic evidence that air pollution adversely affects lung function in asthmatics. Damage to airway mucous membranes and impaired mucociliary clearance caused by air pollution may facilitate access of inhaled allergens to the cells of the immune system, thus promoting sensitization of the airway. Consequently, a more severe immunoglobulin (Ig) E-mediated response to aeroallergens and airway inflammation could account for increasing prevalence of allergic respiratory diseases in polluted urban areas. The most abundant components of urban air pollution in urban areas with high levels of vehicle traffic are airborne particulate matter, nitrogen dioxide, and ozone. In addition, the earth's temperature is increasing, mainly as a result of anthropogenic factors (e.g., fossil fuel combustion and greenhouse gas emissions from energy supply, transport, industry, and agriculture), and climate change alters the concentration and distribution of air pollutants and interferes with the seasonal presence of allergenic pollens in the atmosphere by prolonging these periods.

  14. Numerical Study on a Detailed Air Flows in an Urban Area Using a CFD model

    NASA Astrophysics Data System (ADS)

    Kwon, A.

    2014-12-01

    In this study, detailed air flows in an urban area were analyzed using a computational fluid dynamics (CFD) model. For this model buildings used as the surface boundary in the model were constructed using Los Angeles Region Imagery Acquisition Consortium 2 Geographic Information System (LARIAC2 GIS) data. Three target areas centered at the cross roads of Broadway & 7th St., Olive & 12th St., and Wilshire blvd. & Carondelet, Los Angeles, California were considered. The size of each numerical domain is 400 m, 400 m, and 200 m in the x‒, y‒, and z‒directions, respectively. The grid sizes in the x‒, y‒, and z‒directions are 2 m, 2 m, and 2 m, respectively. Based on the inflow wind data provided by California Air Resources Board, detailed flow characteristics were investigated for each target area. Descending air flow were developed at the leeward area of tall building and ascending air current were occurred on the windward area of tall building. Vertically rotating vortices were formed in spaces between buildings, so-called, street canyons and horizontally rotating vortices appeared near cross roads. When flows came into narrow street canyon from wide street canyon, channeling effects appeared and flow speed increased for satisfying mass continuity.

  15. Differential embryotoxicity of the organic pollutants in rural and urban air particles.

    PubMed

    Mesquita, Sofia R; van Drooge, Barend L; Oliveira, Eva; Grimalt, Joan O; Barata, Carlos; Vieira, Natividade; Guimarães, Laura; Piña, Benjamin

    2015-11-01

    Airborne particulate matter (PM) is a recognized risk factor for human populations. Here we assessed the toxic potential of the organic constituents from PM collected in urban and rural sites during warm and cold periods of 2012/2013, and fractionated into 6 size fractions. The finest PM fraction (<0.5 μm) showed the highest biological activity (dioxin-like activity and fish embryotoxicity) in all samples, and the maximal activity was observed in rural samples from the cold period. Zebrafish embryo transcriptome analysis showed a strong induction of the AhR signaling pathway correlated to PAH concentrations. Oxidative stress-related genes and pancreatic and eye-lens gene markers appeared de-regulated in embryos exposed to urban extracts, whereas exposure to rural extracts affected genes implicated in basic cellular functions. The observed effects can be directly related to air pollution-related human disorders, suggesting different potential adverse outcomes for human populations exposed to air pollution from specific sources.

  16. The potential for reducing urban air temperatures and energy consumption through vegetative cooling

    SciTech Connect

    Kurn, D.M.; Bretz, S.E.; Huang, B.; Akbari, H.

    1994-05-01

    A network of 23 weather stations was used to detect existing oases in Southern California. Four stations, separated from one another by 15--25 miles (24--40 km), were closely examined. Data were strongly affected by the distance of the stations from the Pacific Ocean. This and other city-scale effects made the network inadequate for detection of urban oases. We also conducted traverse measurements of temperature and humidity in the Whittier Narrows Recreation Area in Los Angeles County on September 8--10, 1993. Near-surface air temperatures over vegetated areas were 1--2{degrees}C lower than background air temperatures. We estimate that vegetation may lower urban temperatures by 1{degrees}C, while the establishment of vegetative canopies may lower local temperatures by an additional 2{degrees}C. An increase in vegetation in residential neighborhoods may reduce peak loads in the Los Angeles area by 0.3 GW, and reduce energy consumption by 0.2 BkWh/year, saving $20 million annually. Large additional savings would result from regional cooling.

  17. The use of NOAA AVHRR data for assessment of the urban heat island effect

    NASA Technical Reports Server (NTRS)

    Gallo, K. P.; Mcnab, A. L.; Karl, T. R.; Brown, J. F.; Hood, J. J.; Tarpley, J. D.

    1993-01-01

    The objective of the study was to evaluate the use of a satellite-derived vegetation index and surface temperature estimates for the assessment of the difference in urban and rural air temperature due to the urban heat island effect. The difference in the ND (normalized difference) index between urban and rural regions appears to be an indicator of the difference in surface properties (evaporation and heat storage capacity) between the two environments that are responsible for the urban heat island effect. The use of the approach proposed here may provide a globally consistent method for assessing this phenomenon.

  18. The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

    PubMed

    Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

    2011-09-01

    Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration.

  19. Impacts of land use and land cover on surface and air temperature in urban landscapes

    NASA Astrophysics Data System (ADS)

    Crum, S.; Jenerette, D.

    2015-12-01

    Accelerating urbanization affects regional climate as the result of changing land cover and land use (LCLU). Urban land cover composition may provide valuable insight into relationships among urbanization, air, and land-surface temperature (Ta and LST, respectively). Climate may alter these relationships, where hotter climates experience larger LULC effects. To address these hypotheses we examined links between Ta, LST, LCLU, and vegetation across an urban coastal to desert climate gradient in southern California, USA. Using surface temperature radiometers, continuously measuring LST on standardized asphalt, concrete, and turf grass surfaces across the climate gradient, we found a 7.2°C and 4.6°C temperature decrease from asphalt to vegetated cover in the coast and desert, respectively. There is 131% more temporal variation in asphalt than turf grass surfaces, but 37% less temporal variation in concrete than turf grass. For concrete and turf grass surfaces, temporal variation in temperature increased from coast to desert. Using ground-based thermal imagery, measuring LST for 24 h sequences over citrus orchard and industrial use locations, we found a 14.5°C temperature decrease from industrial to orchard land use types (38.4°C and 23.9°C, respectively). Additionally, industrial land use types have 209% more spatial variation than orchard (CV=0.20 and 0.09, respectively). Using a network of 300 Ta (iButton) sensors mounted in city street trees throughout the region and hyperspectral imagery data we found urban vegetation greenness, measured using the normalized difference vegetation index (NDVI), was negatively correlated to Ta at night across the climate gradient. Contrasting previous findings, the closest coupling between NDVI and Ta is at the coast from 0000 h to 0800 h (highest r2 = 0.6, P < 0.05) while relationships at the desert are weaker (highest r2 = 0.38, P < 0.05). These findings indicate that vegetation cover in urbanized regions of southern

  20. RAQ–A Random Forest Approach for Predicting Air Quality in Urban Sensing Systems

    PubMed Central

    Yu, Ruiyun; Yang, Yu; Yang, Leyou; Han, Guangjie; Move, Oguti Ann

    2016-01-01

    Air quality information such as the concentration of PM2.5 is of great significance for human health and city management. It affects the way of traveling, urban planning, government policies and so on. However, in major cities there is typically only a limited number of air quality monitoring stations. In the meantime, air quality varies in the urban areas and there can be large differences, even between closely neighboring regions. In this paper, a random forest approach for predicting air quality (RAQ) is proposed for urban sensing systems. The data generated by urban sensing includes meteorology data, road information, real-time traffic status and point of interest (POI) distribution. The random forest algorithm is exploited for data training and prediction. The performance of RAQ is evaluated with real city data. Compared with three other algorithms, this approach achieves better prediction precision. Exciting results are observed from the experiments that the air quality can be inferred with amazingly high accuracy from the data which are obtained from urban sensing. PMID:26761008

  1. "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.

  2. Erroneous mass transit system and its tended relationship with motor vehicular air pollution (An integrated approach for reduction of urban air pollution in Lahore).

    PubMed

    Aziz, Amer; Bajwa, Ihsan Ullah

    2008-02-01

    Air pollution is threat to the lives of people living in big cities of Pakistan. In Lahore 1,250 people die annually because of air pollution. Mass transit system that can be put forth as solution to urban air pollution is contingent with right choice of system and its affiliation with motorized vehicles and nature of urban air pollution. Existing mass transit system in Lahore due to untrue operation causes surfeit discharge of motor vehicular carbon monoxide. Tended relationships of mass transit system with motorized vehicles and urban air pollution are quite noteworthy. The growing motor vehicles (a consequence of flawed public mass transit system) are potential source of urban air pollution. This paper attempts to highlight correlations and regression curves of existing mass transit system. Further it recommends a two facet approach for reduction of motor vehicular air pollution in Lahore.

  3. Urban tree effects on soil organic carbon.

    PubMed

    Edmondson, Jill L; O'Sullivan, Odhran S; Inger, Richard; Potter, Jonathan; McHugh, Nicola; Gaston, Kevin J; Leake, Jonathan R

    2014-01-01

    Urban trees sequester carbon into biomass and provide many ecosystem service benefits aboveground leading to worldwide tree planting schemes. Since soils hold ∼75% of ecosystem organic carbon, understanding the effect of urban trees on soil organic carbon (SOC) and soil properties that underpin belowground ecosystem services is vital. We use an observational study to investigate effects of three important tree genera and mixed-species woodlands on soil properties (to 1 m depth) compared to adjacent urban grasslands. Aboveground biomass and belowground ecosystem service provision by urban trees are found not to be directly coupled. Indeed, SOC enhancement relative to urban grasslands is genus-specific being highest under Fraxinus excelsior and Acer spp., but similar to grasslands under Quercus robur and mixed woodland. Tree cover type does not influence soil bulk density or C∶N ratio, properties which indicate the ability of soils to provide regulating ecosystem services such as nutrient cycling and flood mitigation. The trends observed in this study suggest that genus selection is important to maximise long-term SOC storage under urban trees, but emerging threats from genus-specific pathogens must also be considered.

  4. Urban Tree Effects on Soil Organic Carbon

    PubMed Central

    Edmondson, Jill L.; O'Sullivan, Odhran S.; Inger, Richard; Potter, Jonathan; McHugh, Nicola; Gaston, Kevin J.; Leake, Jonathan R.

    2014-01-01

    Urban trees sequester carbon into biomass and provide many ecosystem service benefits aboveground leading to worldwide tree planting schemes. Since soils hold ∼75% of ecosystem organic carbon, understanding the effect of urban trees on soil organic carbon (SOC) and soil properties that underpin belowground ecosystem services is vital. We use an observational study to investigate effects of three important tree genera and mixed-species woodlands on soil properties (to 1 m depth) compared to adjacent urban grasslands. Aboveground biomass and belowground ecosystem service provision by urban trees are found not to be directly coupled. Indeed, SOC enhancement relative to urban grasslands is genus-specific being highest under Fraxinus excelsior and Acer spp., but similar to grasslands under Quercus robur and mixed woodland. Tree cover type does not influence soil bulk density or C∶N ratio, properties which indicate the ability of soils to provide regulating ecosystem services such as nutrient cycling and flood mitigation. The trends observed in this study suggest that genus selection is important to maximise long-term SOC storage under urban trees, but emerging threats from genus-specific pathogens must also be considered. PMID:25003872

  5. The effectiveness of air bags.

    PubMed

    Barry, S; Ginpil, S; O'Neill, T J

    1999-11-01

    Previous research has shown that the installation of air bags in vehicles significantly reduces crash related deaths, but these analyses have used statistical techniques which have not been capable of controlling for other major determinants of crash survival. This study analysed data from the US FARS database of fatal crashes using conditional logistic regression which is simultaneously able to estimate occupant protection effects for a range of variables. Results of the analysis provided a comparative quantification of both the effect of the air bag as well as other well known determinants of occupant crash survival (age, seat belt use, and gender). When potentially confounding variables were controlled, both the driver and passenger side air bag devices were shown to significantly reduce the probability of death in direct frontal collisions, but the effect size calculated was small compared to the effect of the seat belt. The effect size may also be very small in absolute terms depending on the severity of the crash involved. Given the limited benefit of the air bag, efforts to promote air bags seem particularly difficult to justify in countries such as the United States where the vastly superior occupant protection of the seat belt is under-utilised.

  6. Suppression of rain and snow by urban and industrial air pollution

    PubMed

    Rosenfeld

    2000-03-10

    Direct evidence demonstrates that urban and industrial air pollution can completely shut off precipitation from clouds that have temperatures at their tops of about -10 degrees C over large areas. Satellite data reveal plumes of reduced cloud particle size and suppressed precipitation originating from major urban areas and from industrial facilities such as power plants. Measurements obtained by the Tropical Rainfall Measuring Mission satellite reveal that both cloud droplet coalescence and ice precipitation formation are inhibited in polluted clouds.

  7. Urban air pollution by odor sources: Short time prediction

    NASA Astrophysics Data System (ADS)

    Pettarin, Nicola; Campolo, Marina; Soldati, Alfredo

    2015-12-01

    A numerical approach is proposed to predict the short time dispersion of odors in the urban environment. The model is based on (i) a three dimensional computational domain describing the urban topography at fine spatial scale (1 m) and on (ii) highly time resolved (1 min frequency) meteorological data used as inflow conditions. The time dependent, three dimensional wind velocity field is reconstructed in the Eulerian framework using a fast response finite volume solver of Navier-Stokes equations. Odor dispersion is calculated using a Lagrangian approach. An application of the model to the historic city of Verona (Italy) is presented. Results confirm that this type of odor dispersion simulations can be used (i) to assess the impact of odor emissions in urban areas and (ii) to evaluate the potential mitigation produced by odor abatement systems.

  8. Associations between urban air pollution and pediatric asthma control in El Paso, Texas.

    PubMed

    Zora, Jennifer E; Sarnat, Stefanie Ebelt; Raysoni, Amit U; Johnson, Brent A; Li, Wen-Whai; Greenwald, Roby; Holguin, Fernando; Stock, Thomas H; Sarnat, Jeremy A

    2013-03-15

    Exposure to traffic-related pollutants poses a serious health threat to residents of major urban centers around the world. In El Paso, Texas, this problem is exacerbated by the region's arid weather, frequent temperature inversions, heavy border traffic, and an aged, poorly maintained vehicle fleet. The impact of exposure to traffic pollution, particularly on children with asthma, is poorly understood. Tracking the environmental health burden related to traffic pollution in El Paso is difficult, especially within school microenvironments, because of the lack of sensitive environmental health indicator data. The Asthma Control Questionnaire (ACQ) is a survey tool for the measurement of overall asthma control, yet has not previously been considered as an outcome in air pollution health effect research. We conducted a repeated measure panel study to examine weekly associations between ACQ scores and traffic- and non-traffic air pollutants among asthmatic schoolchildren in El Paso. In the main one- and two-pollutant epidemiologic models, we found non-significant, albeit suggestive, positive associations between ACQ scores and respirable particulate matter (PM10), coarse particulate matter (PM10-2.5), fine particulate matter (PM2.5), black carbon (BC), nitrogen dioxide (NO2), benzene, toluene, and ozone (O3). Notably, associations were stronger and significant for some subgroups, in particular among subjects taking daily inhaled corticosteroids. This pattern may indicate heightened immune system response in more severe asthmatics, those with worse asthma "control" and higher ACQ scores at baseline. If the ACQ is appropriately used in the context of air pollution studies, it could reflect clinically measurable and biologically relevant changes in lung function and asthma symptoms that result from poor air quality and may increase our understanding of how air pollution influences asthma exacerbation.

  9. Active moss biomonitoring for extensive screening of urban air pollution: Magnetic and chemical analyses.

    PubMed

    Vuković, Gordana; Urošević, Mira Aničić; Goryainova, Zoya; Pergal, Miodrag; Škrivanj, Sandra; Samson, Roeland; Popović, Aleksandar

    2015-07-15

    In this study, active magnetic biomonitoring of moss for particulate air pollution and an assessment of heavy metals and polycyclic aromatic hydrocarbons (PAHs) were performed for the entire metropolitan area of Belgrade. Two mosses, Sphagnum girgensohnii (a species of the most recommended biomonitoring moss genus) and Hypnum cupressiforme (a common moss in the study area), were used. During the summer of 2013, moss bags were exposed at 153 sampling sites, forming a dense network of sites. A type II regression model was applied to test the interchangeable use of the two moss species. Significantly higher levels of all measured pollutants were recorded by S. girgensohnii in comparison with H. cupressiforme. Based on the results, the mosses could not be interchangeably used in urban areas, except for the biomonitoring of Cu. Nevertheless, according to the relative accumulation factors obtained for both moss species, similar city zones related to high, moderate and low levels of air pollution were distinguished. Moreover, new pollution hotspots, omitted by regulatory monitoring, were identified. The results demonstrate that moss magnetic analysis represents an effective first step for obtaining an overview of particulate air pollution before more expensive chemical analyses. Active moss biomonitoring could be applied as a pragmatic approach for optimizing the representativeness of regulatory monitoring networks.

  10. Understanding urban vehicular pollution problem vis-a-vis ambient air quality--case study of a megacity (Delhi, India).

    PubMed

    Goyal, S K; Ghatge, S V; Nema, P; M Tamhane, S

    2006-08-01

    Air pollution has become a growing problem in megacities and large urban areas through out the globe, and transportation is recognized as the major source of air pollution in many cities, especially in developing countries. Contribution of automobiles is reported in the range of 40 to 80% of the total air pollution. The challenge facing megacities is how to reduce the adverse environmental impacts and other negative effects of transportation without giving up the benefits of mobility. The dilemma becomes most pressing under conditions of rapid urban growth, which is likely to increase travel demand significantly. The paper is aimed at understanding the problem of vehicular pollution vis-a-vis ambient air quality for a highly traffic affected megacity, Delhi, wherein, the contribution of transport sector was estimated to be as high as 72%. An effort has been made to review and evaluate the benefits (in terms of improved air quality) of the technological interventions/policies adopted for vehicular pollution control in Delhi. It also highlights the outcome of the efforts and suggests further improvements thereon. The importance of public participation and awareness are also discussed. The paper focuses on deriving the benefits of the implementation of management strategies, supported by scientific and technical data/interpretation, so that the people can realize and participate in the government's endeavor for clean city drive in a more effective manner.

  11. Decision support system for the evaluation of urban air pollution control options: application for particulate pollution in Thessaloniki, Greece.

    PubMed

    Vlachokostas, Ch; Achillas, Ch; Moussiopoulos, Nu; Hourdakis, E; Tsilingiridis, G; Ntziachristos, L; Banias, G; Stavrakakis, N; Sidiropoulos, C

    2009-11-15

    Development of strategies to control urban air pollution is a complex and multi-disciplinary process involving a wide range of scientists with different expertise and interests. This paper presents an integrated assessment methodological scheme for the evaluation of air pollution control measures that are put forward in order to reduce sufficiently air pollution levels in urban areas. Forming long-term, efficient air pollution control strategies requires knowledge of the costs associated with their implementation, the emission inventories and emission reductions to be achieved, as well as the concentration variations that represent air quality levels in the area examined. In contrast to the majority of the currently employed assessment approaches, the presented scheme enables the evaluation of any proposed air pollution control option in terms of its combined impact on air quality and social welfare, by correlating economic and health impact assessment issues. The approach presented in this paper brings together air quality modelling and mathematical programming techniques and provides a decision support system for the determination of optimal bundles of air pollution control options according to the particular features and needs of the areas examined. Both cost-effectiveness and cost-benefit approaches are taken into account in order to put the problem on the basis of economic efficiency from a societal perspective. The methodology is implemented for the case of Thessaloniki, Greece, which is selected on the grounds that the area is considered as one of the most polluted--if not the most polluted--cities within Europe, especially with respect to airborne particles.

  12. Assessment of potential cancer risk in children exposed to urban air pollution in Bangkok, Thailand.

    PubMed

    Ruchirawat, Mathuros; Settachan, Daam; Navasumrit, Panida; Tuntawiroon, Jantamas; Autrup, Herman

    2007-02-05

    Urban air pollution resulting from traffic is a major problem in many cities in Asia, including Bangkok, Thailand. This pollution originates mainly from incomplete fossil fuel combustion, e.g. transportation, and the composition of which is very complex. Some of the compounds are carcinogenic in experimental animals and in man. Polycyclic aromatic hydrocarbons (PAHs) and benzene are among the major carcinogenic compounds found in urban air pollution from motor vehicle emissions. In major cities in Asia, the levels of PAHs and benzene are relatively high compared with those in Europe or in the United States and thus people are exposed to higher levels. Biomarkers of exposure and early biological effects have been used to study the potential health effects of exposure to PAHs and benzene in air pollution in school children attending schools in inner-city Bangkok compared to those attending schools in rural areas. Bangkok school children are exposed to total PAHs at levels 3.5-fold higher than those in the rural area. Urinary 1-hydroxypyrene, a metabolite of PAH, was also significantly higher, while PAH-DNA adducts in lymphocytes were five-fold higher in Bangkok school children than rural school children. Benzene exposure in Bangkok school children was approximately two-fold higher than in rural school children. This is in agreement with the levels of biomarkers of internal benzene dose, i.e. blood benzene and urinary t,t-muconic acid. The potential health risks from exposure to genotoxic substances were assessed through DNA-damage levels and DNA repair capacity. DNA strand breaks were significantly higher, whereas DNA repair capacity was significantly reduced in Bangkok children. Genetic polymorphisms have been detected in glutathione-S-transferases (GSTs) and cytochrome P450 (CYP450) enzymes involved in the metabolism of benzene and PAHs, but these polymorphisms had no significant effects on the biomarkers of PAH exposure. Our results indicate that children living

  13. Age of air and air exchange efficiency in high-rise urban areas and its link to pollutant dilution

    NASA Astrophysics Data System (ADS)

    Hang, Jian; Li, Yuguo

    2011-10-01

    By means of computational fluid dynamic (CFD) simulations, this paper investigated how rural winds transport relatively clean air into high-rise urban areas to dilute airborne pollutants. Two ventilation concepts for indoor environments were applied: the age of air to quantify the time taken by rural young air to reach a given place after it enters an urban area and the air exchange efficiency to evaluate the efficiency of rural winds flushing the entire urban canopy layer. Several square building arrays with street aspect ratios (building height/street width, H/ W) ranging from 1.5 to 5.3 and building area densities of 0.25 (medium) or 0.4 (compact) were considered as the approaching wind is parallel to the main street whose length varies from street scales to neighborhood scales (330-510 m to 1.03-1.65 km in full-scale). Results show that considerable young rural air enters windward entries but a major fraction of air is vertically driven out as flowing deeper into such high-rise building arrays. So air exchange efficiencies are less than 50% in street-scale arrays, and smaller in longer (neighborhood-scale) or narrower arrays. For the neighborhood-scale medium arrays, considering the power-law velocity profile in the upstream free flow, a taller array gains a larger inflow rate across its windward entry and experiences younger air and greater air exchange efficiency than a lower one. If all buildings are theoretically open-based in a neighborhood-scale compact array, air becomes much younger everywhere and the air exchange efficiency doubles. In arrays of buildings with different heights, the secondary streets in front of taller buildings get younger air due to the downward flows within them. Although further investigations are still required before providing a practical framework, this paper is one of the first attempts to find ways in improving the ventilation performance in high-rise cities like Hong Kong.

  14. Exploiting crowdsourced observations: High-resolution mapping of real-time urban air quality throughout Europe

    NASA Astrophysics Data System (ADS)

    Schneider, Philipp; Castell, Nuria; Vallejo, Islen; van den Bossche, Joris; Lahoz, William; Bartonova, Alena

    2016-04-01

    With the technology of air quality sensors improving rapidly in recent years and with an increasing number of initiatives for collecting air quality information being established worldwide, there is a rapidly increasing amount of information on air quality. Such datasets can provide unprecedented spatial detail and thus exhibit a significant potential for allowing to create observation-based high-resolution maps of air quality in the urban environment. However, most datasets of observations made within a citizen science or crowdsourcing framework tend to have highly variable characteristics in terms of quantity, accuracy, measured parameters, and representativeness, and many more. It is therefore currently unknown how to best exploit this information for mapping purposes. In order to address this challenge we present a novel approach for combining crowdsourced observations of urban air quality with model information, allowing us to produce near-real-time, high-resolution maps of air quality in the urban environment. The approach is based on data fusion techniques, which allow for combining observations with model data in a mathematically objective way and therefore provide a means of adding value to both the observations and the model. The observations are improved by filling spatio-temporal gaps in the data and the model is improved by constraining it with observations. The model further provides detailed spatial patterns in areas where no observations are available. As such, data fusion of observations from high-density low-cost sensor networks together with air quality models can contribute to significantly improving urban-scale air quality mapping. The system has been implemented to run in an automated fashion in near real-time (once every hour) for several cities in Europe. Evaluation of the methodology is being carried out using the leave-one-out cross validation technique and simulated datasets. We present case studies demonstrating the methodology for

  15. Effectiveness of Urban Shelter-in-Place. III: Commercial Districts

    SciTech Connect

    Chan, Wanyu R.; Chan, Wanyu R.; Nazaroff, William W.; Price, Phillip N.; Gadgil, Ashok J.

    2007-12-28

    In the event of a toxic chemical release to the atmosphere, shelter-in-place (SIP) is an emergency response option available to protect public health. This paper is the last in a three-part series that examines the effectiveness of SIP at reducing adverse health effects in communities. We model a hypothetical chemical release in an urban area, and consider SIP effectiveness in protecting occupants of commercial buildings. Building air infiltration rates are predicted from empirical data using an existing model. We consider the distribution of building air infiltration rates both with mechanical ventilation systems turned off and with the systems operating. We also consider the effects of chemical sorption to indoor surfaces and nonlinear chemical dose-response relationships. We find that commercial buildings provide effective shelter when ventilation systems are off, but that any delay in turning off ventilation systems can greatly reduce SIP effectiveness. Using a two-zone model, we find that there can be substantial benefit by taking shelter in the inner parts of a building that do not experience direct air exchange with the outdoors. Air infiltration rates vary substantially among buildings and this variation is important in quantifying effectiveness for emergency response. Community-wide health metrics, introduced in the previous papers in this series, can be applied in pre-event planning and to guide real-time emergency response.

  16. Urban air pollution patterns, land use, and thermal landscape: an examination of the linkage using GIS.

    PubMed

    Weng, Qihao; Yang, Shihong

    2006-06-01

    This article investigates the relationship of local air pollution pattern with urban land use and with urban thermal landscape using a GIS approach. Ambient air quality measurements for sulfur dioxide, nitrogen oxide, carbon monoxide, total suspended particles, and dust level were obtained for Guangzhou City in South China between 1981 and 2000. Landsat TM images and aerial photo derived maps were used to examine city's land use and land cover at different times and changes. Landsat thermal infrared data were employed to compute land surface temperatures and to assess urban thermal patterns. Relationships among the spatial patterns of air pollution, land use, and thermal landscape were sought through GIS and correlation analyses. Results show that the spatial patterns of air pollutants probed were positively correlated with urban built-up density, and with satellite derived land surface temperature values, particularly with measurements taken during the summer. It is suggested that further studies investigate the mechanisms of this linkage, and that remote sensing of air pollution delves into how the energy interacts with the atmosphere and the environment and how sensors see pollutants. Thermal infrared imagery could play a unique role in monitoring and modeling atmospheric pollution.

  17. Indoor Air Quality in Urban and Rural Preschools in Upper Silesia, Poland: Particulate Matter and Carbon Dioxide.

    PubMed

    Mainka, Anna; Zajusz-Zubek, Elwira

    2015-07-08

    Indoor air quality (IAQ) in preschools is an important public health challenge. Particular attention should be paid to younger children, because they are more vulnerable to air pollution than higher grade children and because they spend more time indoors. Among air pollutants, particulate matter (PM) is of the greatest interest mainly due to its acute and chronic effects on children's health. In addition, carbon dioxide (CO2) levels indicate ventilation conditions. In this paper, we present the concentrations of PM (PM1, PM2.5, PM10 and total-TSP) and CO2 monitored in four naturally ventilated nursery schools located in the area of Gliwice, Poland. The nursery schools were selected to characterize areas with different degrees of urbanization and traffic densities during the winter season. The results indicate the problem of elevated concentrations of PM inside the examined classrooms, as well as that of high levels of CO2 exceeding 1000 ppm in relation to outdoor air. The characteristics of IAQ were significantly different, both in terms of classroom occupation (younger or older children) and of localization (urban or rural). To evaluate the children's exposure to poor IAQ, indicators based on air quality guidelines were proposed to rank classrooms according to their hazard on the health of children.

  18. Indoor Air Quality in Urban and Rural Preschools in Upper Silesia, Poland: Particulate Matter and Carbon Dioxide

    PubMed Central

    Mainka, Anna; Zajusz-Zubek, Elwira

    2015-01-01

    Indoor air quality (IAQ) in preschools is an important public health challenge. Particular attention should be paid to younger children, because they are more vulnerable to air pollution than higher grade children and because they spend more time indoors. Among air pollutants, particulate matter (PM) is of the greatest interest mainly due to its acute and chronic effects on children’s health. In addition, carbon dioxide (CO2) levels indicate ventilation conditions. In this paper, we present the concentrations of PM (PM1, PM2.5, PM10 and total—TSP) and CO2 monitored in four naturally ventilated nursery schools located in the area of Gliwice, Poland. The nursery schools were selected to characterize areas with different degrees of urbanization and traffic densities during the winter season. The results indicate the problem of elevated concentrations of PM inside the examined classrooms, as well as that of high levels of CO2 exceeding 1000 ppm in relation to outdoor air. The characteristics of IAQ were significantly different, both in terms of classroom occupation (younger or older children) and of localization (urban or rural). To evaluate the children’s exposure to poor IAQ, indicators based on air quality guidelines were proposed to rank classrooms according to their hazard on the health of children. PMID:26184249

  19. Simultaneous determination of trace pesticides in urban air

    NASA Astrophysics Data System (ADS)

    Haraguchi, Kimiko; Kitamura, Eri; Yamashita, Toshiro; Kido, Azuma

    Thirty-nine kinds of pesticides in the air were monitored in Kitakyushu City. Air samples were collected by a high-volume air sampler equipped with a quartz fiber filter and XAD-2 resin trap. After sampling about 700 m' of air, pesticides were extracted with dichloromethane from the quartz fiber filter and XAD-2 resin separately by ultrasonic method. The extracts were concentrated and fractionated by silica gel column chromatography. After adding internal standards, the sample solutions were analysed by gas chromatography/mass spectrometry with a selected ion monitor (GC/MS-SIM) using a fused silica capillary column for the quantification of 39 kinds of pesticides. In order to evaluate the accuracy of this method, a recovery test was performed. Standard compounds were spiked into the XAD-2 resin trap at a concentration level of l μg by sucking 700 m 3 of sample air. The recovery efficiencies of almost all tested pesticides yielded more than 70% and their relative standard deviations were less than 20%. This method was applied to monitor pesticides in air collected in summer and spring seasons in Kitakyushu City. Of the 39 pesticides examined, 23 were detected in summer and 21 detected in spring. The concentration of Isofenphos, 10 ng m ·, was the highest in the summer sample and the concentration of propoxur, 11 ng m -3, in the spring sample.

  20. Impact of urbanization and industrial development on holiday effect

    NASA Astrophysics Data System (ADS)

    Tan, P.; Chou, C.; Chen, P.

    2011-12-01

    Our study is to examine the "holiday effect", defined as the difference in air pollutant concentrations between holiday and non-holiday periods, and associated factors controlling the strength of holiday effect in Taiwan. This holiday effect can be applied to other countries with similar national or cultural holidays. Daily surface measurements of six major air pollutants from fifty-four air quality monitoring stations of the Taiwan Environmental Protection Administration (TEPA) during the Chinese New Year (CNY) and non-Chinese New Year (NCNY) periods of 1994-2008 are used. The air pollutant concentrations are significantly different between the CNY and NCNY periods, in almost all the Taiwan area, except CO in the eastern part which is a relatively less-developed area. The strengths of holiday effects of NOx, CO, NMHC and O3 are larger in the north than in the south, and those of SO2 and PM10 are larger in the south than in the north. Factors controlling the strength of holiday effect such as the degree of urbanization and anthropogenic sources are examined. The population number and motor vehicle number rather than the population number density and motor vehicle number density have a significantly positive relationship with the strengths of holiday effects of NOx, CO and NMHC. The strengths of holiday effects of NOx and CO are mainly contributed from mobile sources and those of SO2 and PM10 are from stationary sources and that of NMHC is from both mobile and stationary sources. As the dominant anthropogenic sources in the air quality division have larger emissions, holiday effect strengths of associated air pollutants are found to be stronger.

  1. The impact of traffic-flow patterns on air quality in urban street canyons.

    PubMed

    Thaker, Prashant; Gokhale, Sharad

    2016-01-01

    We investigated the effect of different urban traffic-flow patterns on pollutant dispersion in different winds in a real asymmetric street canyon. Free-flow traffic causes more turbulence in the canyon facilitating more dispersion and a reduction in pedestrian level concentration. The comparison of with and without a vehicle-induced-turbulence revealed that when winds were perpendicular, the free-flow traffic reduced the concentration by 73% on the windward side with a minor increase of 17% on the leeward side, whereas for parallel winds, it reduced the concentration by 51% and 29%. The congested-flow traffic increased the concentrations on the leeward side by 47% when winds were perpendicular posing a higher risk to health, whereas reduced it by 17-42% for parallel winds. The urban air quality and public health can, therefore, be improved by improving the traffic-flow patterns in street canyons as vehicle-induced turbulence has been shown to contribute significantly to dispersion.

  2. 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…

  3. Thia-arenes as source apportionment tracers for urban air particulate

    SciTech Connect

    McCarry, B.E.; Allan, L.M.; Mehta, S.; Marvin, C.H.

    1995-12-31

    Over sixty respirable air particulate samples were selected from a large number of filters collected in Hamilton, Ontario, Canada. Depending on the wind direction these sites were either predominantly upwind or predominantly downwind of the industrial sources. The sixty filters were extracted and analyzed using GC-MS for a range of PAH and sulfur-containing PAH (thia-arenes). Various reference standards (coal tar, diesel exhaust, urban air particulate) and source samples (coke oven condensate) were analyzed as well. A set of air particulate samples collected in another city alongside a highway provided an urban vehicular air sample. Unique thia-arene profiles were noted in the reference and source samples which provided the basis for this source apportionment work; two main approaches were used: (1) analysis of alkylated derivatives of thia-arenes with a molecular mass of 184 amu and (2) analysis of 234 amu isomers. The diesel exhaust and urban vehicular samples gave identical profiles while the coal tar and coke oven samples also had identical profiles but in different respects. The air samples collected at samplers located upwind of the coke ovens showed thia-arene profiles which were similar to the profile observed with a diesel exhaust reference material. However, air samples collected downwind of the coke ovens were heavily loaded samples and resembled the coal tar coke and oven condensate samples.

  4. On the feasibility of measuring urban air pollution by wireless distributed sensor networks.

    PubMed

    Moltchanov, Sharon; Levy, Ilan; Etzion, Yael; Lerner, Uri; Broday, David M; Fishbain, Barak

    2015-01-01

    Accurate evaluation of air pollution on human-wellbeing requires high-resolution measurements. Standard air quality monitoring stations provide accurate pollution levels but due to their sparse distribution they cannot capture the highly resolved spatial variations within cities. Similarly, dedicated field campaigns can use tens of measurement devices and obtain highly dense spatial coverage but normally deployment has been limited to short periods of no more than few weeks. Nowadays, advances in communication and sensory technologies enable the deployment of dense grids of wireless distributed air monitoring nodes, yet their sensor ability to capture the spatiotemporal pollutant variability at the sub-neighborhood scale has never been thoroughly tested. This study reports ambient measurements of gaseous air pollutants by a network of six wireless multi-sensor miniature nodes that have been deployed in three urban sites, about 150 m apart. We demonstrate the network's capability to capture spatiotemporal concentration variations at an exceptional fine resolution but highlight the need for a frequent in-situ calibration to maintain the consistency of some sensors. Accordingly, a procedure for a field calibration is proposed and shown to improve the system's performance. Overall, our results support the compatibility of wireless distributed sensor networks for measuring urban air pollution at a sub-neighborhood spatial resolution, which suits the requirement for highly spatiotemporal resolved measurements at the breathing-height when assessing exposure to urban air pollution.

  5. 40 CFR 85.1403 - Particulate standard for pre-1994 model year urban buses effective at time of engine rebuild or...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... model year urban buses effective at time of engine rebuild or engine replacement. 85.1403 Section 85...) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Urban Bus Rebuild Requirements § 85.1403 Particulate standard for pre-1994 model year urban buses effective at time of engine rebuild or engine replacement....

  6. 40 CFR 85.1403 - Particulate standard for pre-1994 model year urban buses effective at time of engine rebuild or...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... model year urban buses effective at time of engine rebuild or engine replacement. 85.1403 Section 85...) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Urban Bus Rebuild Requirements § 85.1403 Particulate standard for pre-1994 model year urban buses effective at time of engine rebuild or engine replacement....

  7. 40 CFR 85.1403 - Particulate standard for pre-1994 model year urban buses effective at time of engine rebuild or...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... model year urban buses effective at time of engine rebuild or engine replacement. 85.1403 Section 85...) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Urban Bus Rebuild Requirements § 85.1403 Particulate standard for pre-1994 model year urban buses effective at time of engine rebuild or engine replacement....

  8. Microalgal biofilms on common yew needles in relation to anthropogenic air pollution in urban Prague, Czech Republic.

    PubMed

    Nováková, Radka; Neustupa, Jiří

    2015-03-01

    Excessive occurrence of microalgae on needles of gymnosperms was reported for the first time in the 1980s from the Scandinavian countries. Since then, it has been repeatedly encountered on needles from various European forest habitats. The abundance of these biofilms has been related to the climatic conditions, such as temperature and precipitation, as well as to the air pollution by nitrogen and sulfur oxides. Urban areas typically have relatively homogenous climates and profound variation in levels of air pollution. Therefore, variation in the occurrence of biofilms in localities within an urban area may be related to local anthropogenic air pollution. We investigated the abundance of biofilms occurring on needles of the common yew (Taxus baccata) in the city of Prague, Czech Republic. The biofilms were composed of algae, fungi and particulate matter. The cover area of the biofilms was marginally explained by a positive influence of short-term maximum atmospheric levels of nitrogen dioxide (NO2). The amounts of the microalgae were also positively influenced by short-term maximum NO2 levels. In addition, high atmospheric levels of particulate matter (PM10) were related to low abundance of algae. The microbial biofilms growing on widely cultivated conifers, such as the common yew, form one of the few commonly occurring natural communities in highly urbanized central areas of temperate European cities. Consequently, we propose that microscopic analysis of biofilms may be used as a rapid and cheap method to collect ecological data. Such data may be used in biomonitoring schemes illustrating the effects of anthropogenic air pollution on natural microcommunities in urban areas.

  9. Effects of urbanization on climate of İstanbul and Ankara

    NASA Astrophysics Data System (ADS)

    Karaca, Mehmet; Tayanç, Mete; Toros, Hüseyi˙n.

    The purpose of this work is to study regional climate change and investigate the effects of urbanization on climates of two largest cities in Turkey: İstanbul and Ankara. Air temperature (mean, maximum and minimum) data of İstanbul and Ankara are analyzed to study regional climate change and to understand the possible effects of urbanization on the climate of these regions owing to industrialization and large flux of migration from rural parts of the country. For the trend analysis, linear regression and the sequential version of the Mann-Kendall test is used. A significant upward trend is found in the urban temperatures of southern İstanbul, which is the most highly populated and industrialized part of the city compared to its rural parts. Northern stations do not show any warming trend; instead, they have a cooling trend. Urbanization and industrialization in the southern part of İstanbul has a negative effect on regional cooling. In spite of Ankara's urban geometry and air pollution problem, the urban station in Ankara does not show any warming trend. A significant urban heat island intensity ( urban-rural) is not observed in Ankara.

  10. Multiple satellite estimates of urban fractions and climate effects at regional scale

    NASA Astrophysics Data System (ADS)

    Jia, G.; Xu, R.; He, Y.

    2014-12-01

    Regional climate is controlled by large scale forcing at lateral boundary and physical processes within the region. Landuse in East Asia has been changed substantially in the last three decades, featured with expansion of urban built-up at unprecedented scale and speed. The fast expansion of urban areas could contribute to local even regional climate change. However, current spatial datasets of urban fractions do not well represent extend and expansion of urban areas in the regions, and the best available satellite data and remote sensing techniques have not been well applied to serve regional modeling of urbanization impacts on near surface temperature and other climate variables. Better estimates of localized urban fractions and urban climate effects are badly needed. Here we use high and mid resolution satellite data to estimate urban fractions and to assess effects of urban heat islands at local and regional scales. With our fractional cover, data fusion, and differentiated threshold approaches, estimated urban extent was greater than previously reported in many global datasets. Many city clusters were merging into each other, with gradual blurring boundaries and disappearing of gaps among member cities. Cities and towns were more connected with roads and commercial corridors, while wildland and urban greens became more isolated as patches among built-up areas. Those new estimates are expected to effectively improve climate simulation at local and regional scales in East Asia. There were significant positive relations between urban fraction and urban heat island effects as demonstrated by VNIR and TIR data from multiple satellites. Stronger warming was detected at the meteorological stations that experienced greater urbanization, i.e., those with a higher urbanization rate. While the total urban area affects the absolute temperature values, the change of the urban area (urbanization rate) likely affects the temperature trend. Increases of approximately 10% in

  11. Mixing layer height and air pollution levels in urban area

    NASA Astrophysics Data System (ADS)

    Schäfer, Klaus; Wagner, Patrick; Emeis, Stefan; Jahn, Carsten; Muenkel, Christoph; Suppan, Peter

    2012-10-01

    Ceilometers are applied by KIT/IMK-IFU to detect layering of the lower atmosphere continuously. This is necessary because not only wind speed and direction but also atmospheric layering and especially the mixing layer height (MLH) influence exchange processes of ground level emissions. It will be discussed how the ceilometer monitoring information is used to interpret the air pollution near the ground. The information about atmospheric layering is continuously monitored by uninterrupted remote sensing measurements with the Vaisala ceilometer CL51 which is an eye-safe commercial mini-lidar system. Special software for this ceilometer provides routine retrievals of lower atmosphere layering from vertical profiles of laser backscatter data. An intensive measurement period during the winter 2011/2012 is studied. The meteorological influences upon air pollutant concentrations are investgated and the correlations of air pollutant concentrations with ceilometer MLH are determined. Benzene was detected by department of Applied Climatology and Landscape Ecology, University of Duisburg-Essen (UDE) with a gas chromatograph during the measurement period. The meteorological data are collected by UDE and the monitoring station Essen of the German national meteorological service DWD. The concentrations of the air pollutants NO, NO2 and PM10 are provided by the national air pollution network LANUV.

  12. Urban air quality management using emission inventory estimates for three Indian cities: Faridabad, Lucknow and Pune.

    PubMed

    Panwar, T S; Sharma, Sumit

    2012-10-01

    Urban air quality is an issue of major concern across many cities and towns in India. In particular, high levels of particulate matter (both suspended particulate matter (SPM) and respirable suspended particulate matter (RSPM)) are responsible for non-compliance against air quality standards. This paper analyses the status of air quality in the 16 most polluted Indian cities identified for priority action by the Hon'ble Supreme Court of India. Each city has its own unique problems depending on the nature of activities being undertaken. Thus, three cities, Pune, Lucknow, and Faridabad, which represent a top-ten urban agglomerate (based on population), a predominantly residential city and an industrial town are chosen for detailed analyses of the air quality problem. The causal factors for poor air quality are determined and sectoral emission loads are estimated for each city adopting a uniform approach that facilitates comparative evaluation. These provide an estimate of the major contributors to air pollution with specific reference to particulate matter, which is a major pollutant of concern. For each of these cities, an air quality management plan is suggested that specifically accounts for the contributing factors in each city. Further, quantitative estimates of the likely improvements due to implementation of some of the specific measures are also provided. An overall comparative assessment of the air quality issues across different cities can provide useful insights in the development of the management plan for the remaining cities as well.

  13. Urban air quality assessment using monitoring data of fractionized aerosol samples, chemometrics and meteorological conditions.

    PubMed

    Yotova, Galina I; Tsitouridou, Roxani; Tsakovski, Stefan L; Simeonov, Vasil D

    2016-01-01

    The present article deals with assessment of urban air by using monitoring data for 10 different aerosol fractions (0.015-16 μm) collected at a typical urban site in City of Thessaloniki, Greece. The data set was subject to multivariate statistical analysis (cluster analysis and principal components analysis) and, additionally, to HYSPLIT back trajectory modeling in order to assess in a better way the impact of the weather conditions on the pollution sources identified. A specific element of the study is the effort to clarify the role of outliers in the data set. The reason for the appearance of outliers is strongly related to the atmospheric condition on the particular sampling days leading to enhanced concentration of pollutants (secondary emissions, sea sprays, road and soil dust, combustion processes) especially for ultra fine and coarse particles. It is also shown that three major sources affect the urban air quality of the location studied-sea sprays, mineral dust and anthropogenic influences (agricultural activity, combustion processes, and industrial sources). The level of impact is related to certain extent to the aerosol fraction size. The assessment of the meteorological conditions leads to defining of four downwind patterns affecting the air quality (Pelagic, Western and Central Europe, Eastern and Northeastern Europe and Africa and Southern Europe). Thus, the present study offers a complete urban air assessment taking into account the weather conditions, pollution sources and aerosol fractioning.

  14. PREFACE SPECIAL ISSUE ON MODEL EVALUATION: EVALUATION OF URBAN AND REGIONAL EULERIAN AIR QUALITY MODELS

    EPA Science Inventory

    The "Preface to the Special Edition on Model Evaluation: Evaluation of Urban and Regional Eulerian Air Quality Models" is a brief introduction to the papers included in a special issue of Atmospheric Environment. The Preface provides a background for the papers, which have thei...

  15. A diagnostic model for studying daytime urban air quality trends

    NASA Technical Reports Server (NTRS)

    Brewer, D. A.; Remsberg, E. E.; Woodbury, G. E.

    1981-01-01

    A single cell Eulerian photochemical air quality simulation model was developed and validated for selected days of the 1976 St. Louis Regional Air Pollution Study (RAPS) data sets; parameterizations of variables in the model and validation studies using the model are discussed. Good agreement was obtained between measured and modeled concentrations of NO, CO, and NO2 for all days simulated. The maximum concentration of O3 was also predicted well. Predicted species concentrations were relatively insensitive to small variations in CO and NOx emissions and to the concentrations of species which are entrained as the mixed layer rises.

  16. 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.

  17. Hydrology for urban land planning--A guidebook on the hydrologic effects of urban land use

    USGS Publications Warehouse

    Leopold, Luna Bergere

    1968-01-01

    The application of current knowledge of the hydrologic effects of urbanization to the Brandywine should be viewed as a forecast of conditions which may be expected as urbanization proceeds. By making such forecasts in advance of actual urban development, the methods can be tested, data can be extended, and procedures improved as verification becomes possible.

  18. Urban air quality: the challenge of traffic non-exhaust emissions.

    PubMed

    Amato, Fulvio; Cassee, Flemming R; Denier van der Gon, Hugo A C; Gehrig, Robert; Gustafsson, Mats; Hafner, Wolfgang; Harrison, Roy M; Jozwicka, Magdalena; Kelly, Frank J; Moreno, Teresa; Prevot, Andre S H; Schaap, Martijn; Sunyer, Jordi; Querol, Xavier

    2014-06-30

    About 400,000 premature adult deaths attributable to air pollution occur each year in the European Region. Road transport emissions account for a significant share of this burden. While important technological improvements have been made for reducing particulate matter (PM) emissions from motor exhausts, no actions are currently in place to reduce the non-exhaust part of emissions such as those from brake wear, road wear, tyre wear and road dust resuspension. These "non-exhaust" sources contribute easily as much and often more than the tailpipe exhaust to the ambient air PM concentrations in cities, and their relative contribution to ambient PM is destined to increase in the future, posing obvious research and policy challenges. This review highlights the major and more recent research findings in four complementary fields of research and seeks to identify the current gaps in research and policy with regard to non-exhaust emissions. The objective of this article is to encourage and direct future research towards an improved understanding on the relationship between emissions, concentrations, exposure and health impact and on the effectiveness of potential remediation measures in the urban environment.

  19. Urban air quality and carboxyhemoglobin levels in a group of traffic policemen.

    PubMed

    Bono, R; Piccioni, P; Traversi, D; Degan, R; Grosa, M; Bosello, G; Gilli, G; Arossa, W; Bugiani, M

    2007-04-15

    Toxicological potential of carbon monoxide (CO) on humans is well known. Nevertheless, CO is still considered as a useful marker to detect some environmental and occupational human risk factors typical of cities. The role played by traffic pollution, indoor air quality in offices and tobacco smoke on the expression of carboxyhemoglobin (COHb%) levels was investigated in a large group of traffic policemen in Torino city (North-Western Italy). At the end of the working shift, 228 policemen responded to a questionnaire, weight and height recorded, urine spot samples collected to measure cotinine as biomarker of tobacco smoke exposure, and an arterial blood sample was taken to measure COHb levels. Data of outdoor urban air-CO were collected and to each subject a "CO outdoor air measurement" was related to his/her COHb level. Considering the annual trend of air-CO pollution from 2002 to 2004, one can assume that a general improvement of air quality in Torino was evident. Taking into account the environments where policemen work (urban outdoor and indoor), and analyzing their COHb% content, the traffic-congested areas, and, in general, the outdoor urban environment were equally risky as offices. Furthermore, if compared to CO arising from traffic-congested areas or other outdoor environments, the traffic policemen in Torino city demonstrate COHb% levels largely due to smoking habits.

  20. Diurnal variation of on-road air pollution in an urban street canyon in Seoul

    NASA Astrophysics Data System (ADS)

    Ho, Woo, Sung; Lee, Seung-Bok; Kim, Kyung Hwan; Bae, Gwi-Nam; Sunwoo, Young; Ma, Young-Il; Han, Dokyoung; Song, Sanghoo

    2014-05-01

    Motor vehicles are a major source of CO, NOx and particulate matters. Especially, in the surroundings of high-raised buildings, so-called an urban street canyon, air pollution levels increase due to limited dispersion of vehicle emissions. In this study, a mobile laboratory was used to measure diurnal variation of on-road concentrations of air pollutants such as NOx, particle-bound polycyclic aromatic hydrocarbons, black carbon and particle number in the urban street canyon on the Teheran road with eight lanes in Seoul, Korea from 5th to 8th November 2013. Each traveling distance was about 3.3km. Traveling vehicle at the middle of the Teheran road was recorded by video camera, and then the car counting by vehicle types. On road measurements conducted for 3~6 hours per day. Hourly average of air pollutant concentration in morning rush hour more than two times higher than those at the daybreak. We will analyze the correlation between air pollution levels and traffic volume by vehicle types. We will discuss about spatial characteristics of on-road air pollution levels in the urban street canyon.

  1. Influence of roadside hedgerows on air quality in urban street canyons

    NASA Astrophysics Data System (ADS)

    Gromke, Christof; Jamarkattel, Nabaraj; Ruck, Bodo

    2016-08-01

    for the street canyon. The configuration of a sidewise arranged discontinuous hedgerow resulted in general in area-averaged increases in concentrations in the range of 3-19%. For a parallel approach wind, reduced concentrations of up to 30% at the facades and up to 60% at pedestrian level were measured with a sidewise continuous hedgerow arrangement. It is concluded that continuous hedgerows can effectively be employed to control concentrations of traffic pollutants in urban street canyons. They can advantageously affect the air quality at street level and can be a significant remedy to the pedestrians' and residents' exposure in the most polluted center area of a street canyon.

  2. Urban Air Pollution from Ethanol (E85) in the Presence of Aqueous Aerosols and Fog

    NASA Astrophysics Data System (ADS)

    Ginnebaugh, D. L.; Jacobson, M. Z.

    2010-12-01

    This is a study to examine the effect of ethanol (E85) versus gasoline on urban air pollution in the presence of aqueous aerosols and fog. In previous work, we analyzed the temperature-dependence of ethanol and gasoline exhaust chemistry and its impact on urban air pollution considering only gas-phase chemistry. We used the near-explicit Master Chemical Mechanism (MCM, version 3.1, LEEDS University) with the SMVGEAR II chemical ordinary differential solver to provide the speed necessary to simulate explicit chemistry. The MCM has over 13,500 organic reactions and 4,600 species. SMVGEAR II is a sparse-matrix Gear solver that reduces the computation time significantly while maintaining any specified accuracy. We found that the average ozone concentrations through the range of temperatures tested could be higher with E85 than with gasoline by up to 8 parts per billion volume (ppbv) at room temperature but much higher at cold temperatures and low sunlight (winter conditions) for a region with a high nitrogen oxide (NOx) to non-methane organic gases (NMOG) ratio. We also found that the solution to chemistry in a 3-D urban airshed model was practical. We now extend our study to include aqueous chemistry in the presence of aerosols and fog. We combine the Chemical Aqueous Phase Radical Mechanism, CAPRAM 3.0 with the MCM 3.1 and gas-particle transfer in box model calculations. CAPRAM treats aqueous phase chemistry among 390 species and 829 reactions (including 51 gas-to-aqueous phase reactions). We investigate the impact aqueous reactions have on unburned ethanol and acetaldehyde mixing ratios in the atmosphere in particular because acetaldehyde is an ozone precursor and carcinogen, and aqueous oxidation has potential to speed the conversion of unburned ethanol to acetaldehyde. Acetaldehyde also forms acetic acid in aqueous solution. Acetic acid vapor is an eye, nose, and lung irritant, so both species contribute negatively to human health. We look at the impact of aerosol

  3. A cost-efficiency and health benefit approach to improve urban air quality.

    PubMed

    Miranda, A I; Ferreira, J; Silveira, C; Relvas, H; Duque, L; Roebeling, P; Lopes, M; Costa, S; Monteiro, A; Gama, C; Sá, E; Borrego, C; Teixeira, J P

    2016-11-01

    When ambient air quality standards established in the EU Directive 2008/50/EC are exceeded, Member States are obliged to develop and implement Air Quality Plans (AQP) to improve air quality and health. Notwithstanding the achievements in emission reductions and air quality improvement, additional efforts need to be undertaken to improve air quality in a sustainable way - i.e. through a cost-efficiency approach. This work was developed in the scope of the recently concluded MAPLIA project "Moving from Air Pollution to Local Integrated Assessment", and focuses on the definition and assessment of emission abatement measures and their associated costs, air quality and health impacts and benefits by means of air quality modelling tools, health impact functions and cost-efficiency analysis. The MAPLIA system was applied to the Grande Porto urban area (Portugal), addressing PM10 and NOx as the most important pollutants in the region. Four different measures to reduce PM10 and NOx emissions were defined and characterized in terms of emissions and implementation costs, and combined into 15 emission scenarios, simulated by the TAPM air quality modelling tool. Air pollutant concentration fields were then used to estimate health benefits in terms of avoided costs (external costs), using dose-response health impact functions. Results revealed that, among the 15 scenarios analysed, the scenario including all 4 measures lead to a total net benefit of 0.3M€·y(-1). The largest net benefit is obtained for the scenario considering the conversion of 50% of open fire places into heat recovery wood stoves. Although the implementation costs of this measure are high, the benefits outweigh the costs. Research outcomes confirm that the MAPLIA system is useful for policy decision support on air quality improvement strategies, and could be applied to other urban areas where AQP need to be implemented and monitored.

  4. Combatting urban air pollution through Natural Gas Vehicle (NGV) analysis, testing, and demonstration

    SciTech Connect

    1995-03-01

    Deteriorating urban air quality ranks as a top concern worldwide, since air pollution adversely affects both public health and the environment. The outlook for improving air quality in the world`s megacities need not be bleak, however, The use of natural gas as a transportation fuel can measurably reduce urban pollution levels, mitigating chronic threats to health and the environment. Besides being clean burning, natural gas vehicles (NGVs) are economical to operate and maintain. The current cost of natural gas is lower than that of gasoline. Natural gas also reduces the vehicle`s engine wear and noise level, extends engine life, and decreases engine maintenance. Today, about 700,000 NGVs operate worldwide, the majority of them converted from gasoline or diesel fuel. This article discusses the economic, regulatory and technological issues of concern to the NGV industry.

  5. Urban air pollution in Sub-Saharan Africa: Time for action.

    PubMed

    Amegah, A Kofi; Agyei-Mensah, Samuel

    2017-01-01

    Air quality in cities of Sub-Saharan African (SSA) countries has deteriorated with the situation driven by rapid population growth and its attendant increased vehicle ownership, increased use of solid fuels for cooking and heating, and poor waste management practices. Industrial expansion in these cities is also a major contributor to the worsening air pollution. Exposure to ambient air pollution is a major threat to human health in SSA with 176,000 deaths and 626,000 DALYs in the region attributable to ambient air pollution exposure. These estimates are however likely to be much higher than reported due to the limited data emanating from the region. Recently, the adoption of the World Health Assembly resolution on air pollution and health, and Sustainable Development Goals are a welcome boost for urban air pollution control efforts in SSA. In this article, we have outlined within the broad framework of these international policy instruments, measures for addressing urban air pollution and its associated health impacts in SSA sustainably.

  6. Remote Sensing of Urban Thermal Landscape Characteristics and Their Affects on Local and Regional Meteorology and Air Quality: An Overview of NASA EOS-IDS Project Atlanta

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale A.; Luvall, Jeffrey C.; Estes, Maurice G., Jr.

    1999-01-01

    As an entity, the city is a manifestation of human "management" of the land. The act of city-building, however, drastically alters the biophysical environment, which ultimately, impacts local and regional land-atmosphere energy exchange processes. Because of the complexity of both the urban landscape and the attendant energy fluxes that result from urbanization, remote sensing offers the only real way to synoptically quantify these processes. One of the more important land-atmosphere fluxes that occurs over cities relates to the way that thermal energy is partitioned across the heterogeneous urban landscape. The individual land cover and surface material types that comprise the city, such as pavements and buildings, each have their own thermal energy regimes. As the collective urban landscape, the individual thermal energy responses from specific surfaces come together to form the urban heat island phenomena, which prevails as a dome of elevated air temperatures over cities. Although the urban heat island has been known to exist for well over 150 years, it is not understood how differences in thermal energy responses for land covers across the city interact to produce this phenomenon, or how the variability in thermal energy responses from different surface types drive its development. Additionally, it can be hypothesized that as cities grow in size through time, so do their urban heat islands. The interrelationships between urban sprawl and the respective growth of the urban heat island, however, have not been investigated. Moreover, little is known of the consequential effects of urban growth, land cover change, and the urban heat island as they impact local and regional meteorology and air quality.

  7. Urban heat island and its effect on the cooling and heating demands in urban and suburban areas of Hong Kong

    NASA Astrophysics Data System (ADS)

    Memon, Rizwan Ahmed; Leung, Dennis Y. C.; Liu, Chun-Ho; Leung, Michael K. H.

    2011-03-01

    This study investigates the urban heat island characteristics of four major areas of Hong Kong. The areas of study include a densely populated and well-developed commercial area (i.e., Tsim Sha Tsui) and three suburban areas (i.e., Cheung Chau, Lau Fau Shan and Sha Tin) with differing degrees of development. The weather station data of respective areas were acquired from the Hong Kong Observatory. The urban heat island intensity, determined as the air-temperature difference between the selected urban/suburban area and the reference rural area (i.e., Ta Kuw Ling) with thin population and lush vegetation, was used for the analysis. Results showed stronger heat island effect during winter and nighttime than during summer and daytime. An investigation of the cooling and heating degree days indicate that all areas have observed higher number of cooling degree days. However, the cooling degree days were the maximum while heating degree days were the minimum in the urban area (i.e., Tsim Sha Tsui). Clearly, the minimum heating degree days and the maximum cooling degree days in the urban area were a direct consequence of urban heat island. The 10-year (i.e., from 1995 to 2005) average shows that Cheung Chau experienced the least number of cooling degree days while Lau Fau Shan experienced the highest number of heating degree days. Seemingly, the area of Cheung Chau offers better thermal comfort conditions with the minimum number of cooling and heating degree days.

  8. Urbanization effects on tree growth in the vicinity of New York City.

    PubMed

    Gregg, Jillian W; Jones, Clive G; Dawson, Todd E

    2003-07-10

    Plants in urban ecosystems are exposed to many pollutants and higher temperatures, CO2 and nitrogen deposition than plants in rural areas. Although each factor has a detrimental or beneficial influence on plant growth, the net effect of all factors and the key driving variables are unknown. We grew the same cottonwood clone in urban and rural sites and found that urban plant biomass was double that of rural sites. Using soil transplants, nutrient budgets, chamber experiments and multiple regression analyses, we show that soils, temperature, CO2, nutrient deposition, urban air pollutants and microclimatic variables could not account for increased growth in the city. Rather, higher rural ozone (O3) exposures reduced growth at rural sites. Urban precursors fuel the reactions of O3 formation, but NO(x) scavenging reactions resulted in lower cumulative urban O3 exposures compared to agricultural and forested sites throughout the northeastern USA. Our study shows the overriding effect of O3 despite a diversity of altered environmental factors, reveals 'footprints' of lower cumulative urban O3 exposures amidst a background of higher regional exposures, and shows a greater adverse effect of urban pollutant emissions beyond the urban core.

  9. Simulation of urban and regional air pollution in Bangladesh

    NASA Astrophysics Data System (ADS)

    Muntaseer Billah Ibn Azkar, M. A.; Chatani, Satoru; Sudo, Kengo

    2012-04-01

    We have developed a regional scale air quality simulation using the Weather Research and Forecasting (WRF) - Community Multiscale Air Quality Model (CMAQ) to assess the suitability of such an advanced modeling system for predicting the air quality of Bangladesh and its surrounding region. The Regional Emission Inventory in Asia (REAS) was used as the emission input in this modeling approach. Both meteorological and chemical model performance were evaluated with observations including satellite data. Comparison between simulated and observed meteorological parameters revealed that the WRF can generate the necessary meteorological inputs for CMAQ. Comparison of observed and simulated concentrations of different air pollutants revealed that CMAQ greatly underestimates the concentrations of key pollutants. Comparison with satellite observations revealed that CMAQ reproduces the spatial distribution of NO2with some underestimation in Bangladesh and India. The simulated AOD and satellite-retrieved AOD showed good temporal and spatial agreement mutually, with a correlation coefficient of 0.58. Sensitivity simulation using higher horizontal resolution emission data made by re-gridding the REAS inventory with the population distribution improved the CMAQ performance. Nevertheless, CMAQ underestimated the pollutant concentrations in Dhaka. Uncertainties in the emission inventory and in the lack of time variation in emissions input mainly contributed to the model underestimation. Model predictions show that 36-72% PM10 and 15-60% PM2.5 in Dhaka might be contributed from brick kiln emissions in monthly average of January 2004. The chemical composition of PM2.5showed that the considerable amounts of secondary aerosols in Dhaka and carbonaceous components (particularly organic carbon) are most responsible for the model underestimation. Results suggest that improvements of emission inputs and more detailed sensitivity analysis of CMAQ model are important to assess the reliability

  10. Olfactory dysfunction, olfactory bulb pathology and urban air pollution

    PubMed Central

    Calderón-Garcidueñas, Lilian; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Osnaya, Norma; González-Maciel, Angelica; Reynoso-Robles, Rafael; Villarreal-Calderon, Rafael; Herritt, Lou; Brooks, Diane; Keefe, Sheyla; Palacios-Moreno, Juan; Villarreal-Calderon, Rodolfo; Torres-Jardón, Ricardo; Medina-Cortina, Humberto; Delgado-Chávez, Ricardo; Aiello-Mora, Mario; Maronpot, Robert R.; Doty, Richard L

    2010-01-01

    Mexico City (MC) residents are exposed to severe air pollution and exhibit olfactory bulb inflammation. We compared the olfactory function of individuals living under conditions of extreme air pollution to that of controls from a relatively clean environment and explore associations between olfaction scores, apolipoprotein E (APOE) status, and pollution exposure. The olfactory bulbs (OBs) of 35 MC and 9 controls 20.8 ± 8.5 y were assessed by light and electron microscopy. The University of Pennsylvania Smell Identification Test (UPSIT) was administered to 62 MC / 25 controls 21.2 ±2.7 y. MC subjects had significantly lower UPSIT scores: 34.24 ± 0.42 versus controls 35.76 ± 0.40, p=0.03. Olfaction deficits were present in 35.5% MC and 12% of controls. MC APOE ε 4 carriers failed 2.4 ± 0.54 items in the 10-item smell identification scale from the UPSIT related to Alzheimer's disease, while APOE 2/3 and 3/3 subjects failed 1.36 ± 0.16 items, p = 0.01. MC residents exhibited OB endothelial hyperplasia, neuronal accumulation of particles (2/35), and immunoreactivity to beta amyloid βA42 (29/35) and/or α-synuclein (4/35) in neurons, glial cells and/or blood vessels. Ultrafine particles were present in OBs endothelial cytoplasm and basement membranes. Control OBs were unremarkable. Air pollution exposure is associated with olfactory dysfunction and OB pathology, APOE 4 may confer greater susceptibility to such abnormalities, and ultrafine particles could play a key role in the OB pathology. This study contributes to our understanding of the influences of air pollution on olfaction and its potential contribution to neurodegeneration. PMID:19297138

  11. Mineralogical, chemical and toxicological characterization of urban air particles.

    PubMed

    Čupr, Pavel; Flegrová, Zuzana; Franců, Juraj; Landlová, Linda; Klánová, Jana

    2013-04-01

    Systematic characterization of morphological, mineralogical, chemical and toxicological properties of various size fractions of the atmospheric particulate matter was a main focus of this study together with an assessment of the human health risks they pose. Even though near-ground atmospheric aerosols have been a subject of intensive research in recent years, data integrating chemical composition of particles and health risks are still scarce and the particle size aspect has not been properly addressed yet. Filling this gap, however, is necessary for reliable risk assessment. A high volume ambient air sampler equipped with a multi-stage cascade impactor was used for size specific particle collection, and all 6 fractions were a subject of detailed characterization of chemical (PAHs) and mineralogical composition of the particles, their mass size distribution and genotoxic potential of organic extracts. Finally, the risk level for inhalation exposure associated to the carcinogenic character of the studied PAHs has been assessed. The finest fraction (<0.45 μm) exhibited the highest mass, highest active surface, highest amount of associated PAHs and also highest direct and indirect genotoxic potentials in our model air sample. Risk assessment of inhalation scenario indicates the significant cancer risk values in PM 1.5 size fraction. This presented new approach proved to be a useful tool for human health risk assessment in the areas with significant levels of air dust concentration.

  12. Detection of the Urban Release of a Bacillus anthracis Simulant by Air Sampling

    PubMed Central

    Garza, Alexander G.; Van Cuyk, Sheila M.; Brown, Michael J.

    2014-01-01

    In 2005 and 2009, the Pentagon Force Protection Agency (PFPA) staged deliberate releases of a commercially available organic pesticide containing Bacillus amyloliquefaciens to evaluate PFPA's biothreat response protocols. In concert with, but independent of, these releases, the Department of Homeland Security sponsored experiments to evaluate the efficacy of commonly employed air and surface sampling techniques for detection of an aerosolized biological agent. High-volume air samplers were placed in the expected downwind plume, and samples were collected before, during, and after the releases. Environmental surface and personal air samples were collected in the vicinity of the high-volume air samplers hours after the plume had dispersed. The results indicate it is feasible to detect the release of a biological agent in an urban area both during and after the release of a biological agent using high-volume air and environmental sampling techniques. PMID:24697146

  13. Detection of the urban release of a bacillus anthracis simulant by air sampling.

    PubMed

    Garza, Alexander G; Van Cuyk, Sheila M; Brown, Michael J; Omberg, Kristin M

    2014-01-01

    In 2005 and 2009, the Pentagon Force Protection Agency (PFPA) staged deliberate releases of a commercially available organic pesticide containing Bacillus amyloliquefaciens to evaluate PFPA's biothreat response protocols. In concert with, but independent of, these releases, the Department of Homeland Security sponsored experiments to evaluate the efficacy of commonly employed air and surface sampling techniques for detection of an aerosolized biological agent. High-volume air samplers were placed in the expected downwind plume, and samples were collected before, during, and after the releases. Environmental surface and personal air samples were collected in the vicinity of the high-volume air samplers hours after the plume had dispersed. The results indicate it is feasible to detect the release of a biological agent in an urban area both during and after the release of a biological agent using high-volume air and environmental sampling techniques.

  14. Hydrogen sulfide (H 2S) in urban ambient air

    NASA Astrophysics Data System (ADS)

    Kourtidis, K.; Kelesis, A.; Petrakakis, M.

    Despite indications of high hydrogen sulfide levels in some urban environments, only sparse measurements have been reported in the literature. Here we present one full year of hydrogen sulfide measurements in an urban traffic site in the city of Thessaloniki, Greece. In this 1-million-population city the H 2S concentrations were surprisingly high, with a mean annual concentration of 8 μg m -3 and wintertime mean monthly concentrations up to 20 μg m -3 (12.9 ppb). Daily mean concentrations in the winter were up to 30 μg m -3 (19.3 ppb), while hourly concentrations were up to 54 μg m -3 (34.8 ppb). During calm (wind velocity < 0.5 m s -1) conditions, mainly encountered during night-time hours, hourly values of H 2S were highly correlated with those of CO ( r2 = 0.75) and SO 2 ( r2 = 0.70), pointing to a common traffic source from catalytic converters. Annual mean concentrations are above the WHO recommendation for odor annoyance; hence, H 2S might play a role to the malodorous episodes that the city occasionally experiences. The high ambient H 2S levels might also be relevant to the implementation of preservation efforts for outdoor marble and limestone historical monuments that have been targeting SO 2 emissions as an atmospheric acidity source, since the measurements presented here suggest that about 19% of the annual sulfur (SO 2 + H 2S) emissions in Thessaloniki are in the form of H 2S.

  15. Using Mobile Monitoring to Assess Spatial Variability in Urban Air Pollution Levels: Opportunities and Challenges (Invited)

    NASA Astrophysics Data System (ADS)

    Larson, T.

    2010-12-01

    Measuring air pollution concentrations from a moving platform is not a new idea. Historically, however, most information on the spatial variability of air pollutants have been derived from fixed site networks operating simultaneously over space. While this approach has obvious advantages from a regulatory perspective, with the increasing need to understand ever finer scales of spatial variability in urban pollution levels, the use of mobile monitoring to supplement fixed site networks has received increasing attention. Here we present examples of the use of this approach: 1) to assess existing fixed-site fine particle networks in Seattle, WA, including the establishment of new fixed-site monitoring locations; 2) to assess the effectiveness of a regulatory intervention, a wood stove burning ban, on the reduction of fine particle levels in the greater Puget Sound region; and 3) to assess spatial variability of both wood smoke and mobile source impacts in both Vancouver, B.C. and Tacoma, WA. Deducing spatial information from the inherently spatio-temporal measurements taken from a mobile platform is an area that deserves further attention. We discuss the use of “fuzzy” points to address the fine-scale spatio-temporal variability in the concentration of mobile source pollutants, specifically to deduce the broader distribution and sources of fine particle soot in the summer in Vancouver, B.C. We also discuss the use of principal component analysis to assess the spatial variability in multivariate, source-related features deduced from simultaneous measurements of light scattering, light absorption and particle-bound PAHs in Tacoma, WA. With increasing miniaturization and decreasing power requirements of air monitoring instruments, the number of simultaneous measurements that can easily be made from a mobile platform is rapidly increasing. Hopefully the methods used to design mobile monitoring experiments for differing purposes, and the methods used to interpret those

  16. Review of the efficacy of low emission zones to improve urban air quality in European cities

    NASA Astrophysics Data System (ADS)

    Holman, Claire; Harrison, Roy; Querol, Xavier

    2015-06-01

    Many cities still exceed the European Union (EU) air quality limit values for particulate matter (PM10, particles with an aerodynamic diameter less than 10 μm) and/or nitrogen dioxide (NO2). In an attempt to reduce emissions approximately 200 low emission zones (LEZs) have been established in 12 EU countries. These restrict the entry of vehicles based on the emission standard the vehicles were originally constructed to meet, but the restrictions vary considerably. This paper reviews the evidence on the efficacy of LEZs to improve urban air quality in five EU countries (Denmark, Germany, Netherlands, Italy and UK), and concludes that there have been mixed results. There is some evidence from ambient measurements that LEZs in Germany, which restrict passenger cars as well as heavy duty vehicles (HDVs), have reduced long term average PM10 and NO2 concentrations by a few percent. Elsewhere, where restrictions are limited to HDVs, the picture is much less clear. This may be due to the large number of confounding factors. On the other hand there is some, albeit limited, evidence that LEZs may result in larger reductions in concentrations of carbonaceous particles, due to traffic making a larger contribution to ambient concentrations of these particles than to PM10 and PM2.5. The effects of day to day variations in meteorology on concentrations often mask more subtle effects of a LEZ. In addition, separating the direct effects of a LEZ from the effects of other policy measures, the economy and the normal renewal of the vehicle fleet is not easy, and may give rise to false results.

  17. Urban leakage of liquefied petroleum gas and its impact on Mexico City air quality

    SciTech Connect

    Blake, D.R.; Rowland, F.S.

    1995-08-18

    Alkane hydrocarbons (propane, isobutane, and n-butane) from liquefied petroleum gas (LPG) are present in major quantities throughout Mexico City air because of leakage of the unburned gas from numerous urban sources. These hydrocarbons, together with olefinic minor LPG components, furnish substantial amounts of hydroxyl radical reactivity, a major precursor to formation of the ozone component of urban smog. The combined processes of unburned leakage and incomplete combustion of LPG play significant role in causing the excessive ozone characteristic of Mexico City. Reductions in ozone levels should be possible through changes in LPG composition and lowered rates of leakage. 23 refs., 3 tabs.

  18. An airborne remote sensing system for urban air quality

    NASA Technical Reports Server (NTRS)

    Duncan, L. J.; Friedman, E. J.; Keitz, E. L.; Ward, E. A.

    1974-01-01

    Several NASA sponsored remote sensors and possible airborne platforms were evaluated. Outputs of dispersion models for SO2 and CO pollution in the Washington, D.C. area were used with ground station data to establish the expected performance and limitations of the remote sensors. Aircraft/sensor support requirements are discussed. A method of optimum flight plan determination was made. Cost trade offs were performed. Conclusions about the implementation of various instrument packages as parts of a comprehensive air quality monitoring system in Washington are presented.

  19. PHOTOCITYTEX - A LIFE project on the air pollution treatment in European urban environments by means of photocatalytic textiles

    NASA Astrophysics Data System (ADS)

    Ródenas, Milagros; Fages, Eduardo; Fatarella, Enrico; Herrero, David; Castagnoli, Lidia; Borrás, Esther; Vera, Teresa; Gómez, Tatiana; Carreño, Javier; López, Ramón; Gimeno, Cristina; Catota, Marlon; Muñoz, Amalia

    2016-04-01

    In urban areas, air pollution from traffic is becoming a growing problem. In recent years the use of titanium dioxide (TiO2) based photocatalytic self-cleaning and de-polluting materials has been considered to remove these pollutants. TiO2 is now commercially available and used in construction material or paints for environmental purposes. Further work, however, is still required to clarify the potential impacts from wider TiO2 use. Specific test conditions are required to provide objective and accurate knowledge. Under the LIFE PHOTOCITYTEX project, the effectiveness of using TiO2-based photocatalytic nanomaterials in building textiles as a way of improving the air quality in urban areas will be assessed. Moreover, information on secondary products formed during the tests will be obtained, yielding a better overall understanding of the whole process and its implications. For this purpose, a series of demonstrations are foreseen, comprising 1. lab-test and development of textile prototypes at lab scale, 2. larger scale demonstration of the use of photocatalytic textiles in the depollution of urban environments employing the EUPHORE chambers to simulate a number of environmental conditions of various European cities and 3. field demonstrations installing the photocatalytic textiles in two urban locations in Quart de Poblet, a tunnel and a school. A one-year extensive passive dosimetric campaign has already being carried out to characterize the selected urban sites before the installation of the photocatalytic textile prototypes, and a similar campaign after their installation is ongoing. Also, more comprehensive intensive active measurement campaigns have been conducted to account for winter and summer conditions. In parallel, lab-tests have already been completed to determine optimal photocatalytic formulations on textiles, followed by experiments at EUPHORE. Information on the deployment of the campaigns is given together with laboratory conclusions and first

  20. Evaluation of air pollution phytotoxicity in a seasonally dry tropical urban environment.

    PubMed

    Pandey, J; Pandey, U

    1994-12-01

    This study was conducted in the urban environment of Varanasi, India, to evaluate the plant responses to urban air pollution. Twenty sites were selected in four different zones of the city. At each site, seven woody perennials of same age classes were selected. Out of the four zones (I, II, III and IV), zone IV was used as a reference (control) zone as it received the minimum pollution input. Plant species growing in polluted and control areas were compared with respect to foliar dust load, per cent leaf area injury, leaf area, specific leaf weight and chlorophyll, ascorbic acid, SO 4 (2-) S and total N concentration in the leaves. Results indicated that the air pollution level in Varanasi causes leaf damage, reduces leaf area, specific leaf weight and chlorophyll, ascorbic acid and total N concentrations in the leaves. Sulphur concentration in leaves increased with increasing level of SO2 in the ambient air. The magnitude of such changes was maximum at the zone receiving maximum pollution load. Carissa carandas was found to be the most sensitive species and Bougainvillea spectabilis, the least. The study shows that the urban air pollution level in Varanasi is detrimental for the growth of plants involved in this study.

  1. Air quality perception of pedestrians in an urban outdoor Mediterranean environment: A field survey approach.

    PubMed

    Pantavou, Katerina; Lykoudis, Spyridon; Psiloglou, Basil

    2017-01-01

    Perception plays a significant role on people's response to preventive measures. In the view of public awareness, the aim of this study was to explore factors that affect air quality perception and to reveal its potential patterns. Air quality perception of individuals, in terms of dust and overall air quality, was examined in relation to air pollutants concentrations, meteorological variables, personal characteristics as well as their thermal sensation and health condition. The data used were obtained from environmental measurements, in situ and from stations, and questionnaire surveys conducted in an outdoor urban Mediterranean area, Athens, Greece. The participants were asked to report their air quality perception and thermal sensation based on predefined scales. A thermal index, Physiological Equivalent Temperature (PET), was estimated to obtain an objective measure of thermal sensation. Particulate matter (PM10) and nitrogen oxide (NO) were associated with dust perception. Nitrogen oxides (NOx) and carbon monoxide (CO) were associated to air quality perception. Age, area of residence, health symptoms and thermal sensation also affected the perception of air quality. Dusty or poor air quality conditions were more likely to be reported when pollutants' concentrations were increased. Younger people, participants residing in the city center, experiencing health symptoms or warm thermal sensation showed a trend towards reporting more unfavorable air quality conditions.

  2. Assessment of the urban heat island effect through the use of satellite data

    NASA Technical Reports Server (NTRS)

    Price, J. C.

    1979-01-01

    A recent NASA satellite is obtaining high spatial resolution thermal infrared data at times of day appropriate for the study of the urban heat island effect. Quantitative estimates of the extent and intensity of urban surface heating are obtained by analysis of digital data acquired over the New York City-New England area. In many large cities satellite sensed temperatures are 10-15 C warmer than in surrounding rural areas. A thorough interpretation of the elevated urban surface temperature will require studies of (1) the relationship between remotely sensed surface temperatures and air temperatures, and (2) compensation for observed very localized heating due to industry and/or power plants.

  3. Mathematical Modeling of Air Flowfield at Urban Environment: the Case of Road Network at the Historical Centre of Kifissia's Municipality

    NASA Astrophysics Data System (ADS)

    Papakonstantinou, K.; Belias, C.

    2008-09-01

    The present paper refers to the numerical analysis of air flowfield at urban environments and the conducting thermal comfort after the evaluation of the examined space using CFD methods, taking into account bioclimatic principles at the architectural design. More specially, the paper draws attention to the physical procedures governing air movement at an urban environment (a road network) at Kifissia (a Municipality of north Athens), trying to form them in such way that will lead to the thermal comfort of the area's users. The study presents a mathematical model, implemented in a general computer code that can provide detailed information on velocity, prevailing in three-dimensional spaces of any geometrical complexity. Turbulent flow is simulated and buoyancy effects are taken into account. This simulation procedure is intended to contribute to the effort towards designing urban environments, using thermal comfort criteria at the bioclimatic design. A computer model of this kind will provide the architects or the environmental engineers with powerful and economical means of evaluating alternative spaces' designs.

  4. Satellite observation of biophysical indicators related to urban heat island effect

    NASA Astrophysics Data System (ADS)

    Zoran, Maria

    Urban ecosystem is a highly complex area characterized by many different biophysical parameters with spatial, temporal and spectral scales variability: spatial variability due to the varied landscape; temporal variations are attributed to periodic seasonal changes over the year; spectral variability is due to the great variety of materials and structured associated with the urban area. Of these, land surface temperature is one of the key parameters controlling the physical, chemical and biological processes of urban climate. It modifies the air temperature of the atmospheric boundary layer and is a key component in the surface energy balance. Change in urban land surface temperature can have significant effects on local weather and climate. Since atmospheric temperature is basically affected by the surface heat balance, the contribution of these factors can be estimated by quantifying the surface heat balance, especially in urban areas and megacities. Remote sensing is a key application in global-change science and urban climatology. Urbanization, the conversion of other types of land to uses associated with growth of populations and economy has a great impact on both micro-climate as well as macro-climate. Urban areas tend to experience a relatively higher temperature compared with the surrounding rural areas. This thermal difference, in conjunction with waste heat released from urban houses, transportation and industry, contribute to the development of urban heat island (UHI). The aim of this study is to examine the changes in land use/cover pattern in a rapidly changing area of Bucharest metropolitan area in relation to urbanization since the 1987s till 2007 and then to investigate the impact of such changes on the intensity and spatial pattern of the UHI effect in the region. Investigation of radiative properties, energy balance and heat fluxes is based on satellite data provided by various sensors Landsat TM, ETM+, ASTER and IKONOS. So called effect of "urban

  5. The Urban Heat Island Phenomenon: How Its Effects Can Influence Environmental Decision Making in Your Community

    NASA Technical Reports Server (NTRS)

    Estes, Maurice G., Jr.; Quattrochi, Dale; Stasiak, Elizabeth

    2003-01-01

    Reinvestment in urban centers is breathing new life into neighborhoods that have been languishing as a result of explosive suburban development over the past several decades. In cities all over the country, adaptive reuse, brownfields redevelopment, transforming urban landscapes, economies, and quality of life. However, the way in which this development occurs has the potential to exacerbate the urban heat island (UHI) phenomenon, an existing problem in many areas and one which poses a threat to the long-term sustainability and environmental quality of cities. The UHI phenomenon is rooted in the science of how the land covers respond to solar heating and can adversely effect the environment. This phenomenon is responsible for urban centers having higher air temperatures and poorer air quality than suburban areas. In addition, the UHI phenomenon causes metrological occurrences, degrades water quality, increases energy demands, poses threats to public health and contributes to global warming. While the name of the phenomenon implies that is solely an urban issue, research has shown that the effects of the UHI are becoming prevalent in suburbs, as well. The UHI phenomenon can plague regions - urban centers and their suburbs. Furthermore, heat islands have been found to exist in both city centers and suburban communities. As suburban areas increasingly develop using land covers and building materials common to urban areas, they are inheriting urban problems - such as heat islands. In this way, it may be necessary for non-urban communities to engage in heat island mitigation. The good news is that through education and planning, the effects of the UHI phenomenon can be prevented and mitigated. Heat islands are more a product of urban design rather than the density of development. Therefore, cities can continue to grow and develop without exacerbating the UHI by employing sustainable development strategies.

  6. Effects of urbanization on carnivore species distribution and richness

    USGS Publications Warehouse

    Ordenana, Miguel A.; Crooks, Kevin R.; Boydston, Erin E.; Fisher, Robert N.; Lyren, Lisa M.; Siudyla, Shalene; Haas, Christopher D.; Harris, Sierra; Hathaway, Stacie A.; Turschak, Greta M.; Miles, A. Keith; Van Vuren, Dirk H.

    2010-01-01

    Urban development can have multiple effects on mammalian carnivore communities. We conducted a meta-analysis of 7,929 photographs from 217 localities in 11 camera-trap studies across coastal southern California to describe habitat use and determine the effects of urban proximity (distance to urban edge) and intensity (percentage of area urbanized) on carnivore occurrence and species richness in natural habitats close to the urban boundary. Coyotes (Canis latrans) and bobcats (Lynx rufus) were distributed widely across the region. Domestic dogs (Canis lupus familiaris), striped skunks (Mephitis mephitis), raccoons (Procyon lotor), gray foxes (Urocyon cinereoargenteus), mountain lions (Puma concolor), and Virginia opossums (Didelphis virginiana) were detected less frequently, and long-tailed weasels (Mustela frenata), American badgers (Taxidea taxus), western spotted skunks (Spilogale gracilis), and domestic cats (Felis catus) were detected rarely. Habitat use generally reflected availability for most species. Coyote and raccoon occurrence increased with both proximity to and intensity of urbanization, whereas bobcat, gray fox, and mountain lion occurrence decreased with urban proximity and intensity. Domestic dogs and Virginia opossums exhibited positive and weak negative relationships, respectively, with urban intensity but were unaffected by urban proximity. Striped skunk occurrence increased with urban proximity but decreased with urban intensity. Native species richness was negatively associated with urban intensity but not urban proximity, probably because of the stronger negative response of individual species to urban intensity.

  7. The use of NOAA AVHRR data for assessment of the urban heat island effect

    SciTech Connect

    Gallo, K.P.; Tarpley, J.D. ); McNab, A.L.; Karl, T.R. ); Brown, J.F. ); Hood, J.J. )

    1993-05-01

    A vegetation index and a radiative surface temperature were derived from satellite data acquired at approximately 1330 LST for each of 37 cities and for their respective nearby rural regions from 28 June through 8 August 1991. Urban-rural differences for the vegetation index and the surface temperatures were computed and then compared to observed urban-rural differences in minimum air temperatures. The purpose of these comparisons was to evaluate the use of satellite data to assess the influence of the urban environment on observed minimum air temperatures (the urban heat island effect). The temporal consistency of the data, from daily data to weekly, biweekly, and monthly intervals, was also evaluated. The satellite-derived normalized difference (ND) vegetation-index data, samples over urban and rural regions composed of a variety of land surface environments, were linearly related to the difference in observed urban and rural minimum temperatures. The relationship between the ND index and observed differences in minimum temperature was improved when analyses were restricted by elevation differences between the sample locations and when biweekly or monthly intervals were utilized. The difference in the ND index between urban and rural regions appears to be an indicator of the difference in surface properties (evaporation and heat storage capacity) between the two environments that are responsible for differences in urban and rural minimum temperatures. The urban and rural differences in the ND index explain a greater amount of the variation observed in minimum temperature differences than past analyses that utilized urban population data. The use of satellite data may contribute to a globally consistent method for analysis of urban heat island bias. 36 refs., 7 figs., 4 tabs.

  8. THE EFFECT OF AIR POLLUTION ON INNER-CITY CHILDREN WITH ASTHMA

    EPA Science Inventory

    The effect of daily ambient air pollution was examined within a cohort of 846 asthmatic children residing in eight urban areas of the USA, using data from the National Cooperative Inner-City Asthma Study. Daily air pollution concentrations were extracted from the Aerometric Infor...

  9. Development and application of a high resolution hybrid modelling system for the evaluation of urban air quality

    NASA Astrophysics Data System (ADS)

    Pepe, N.; Pirovano, G.; Lonati, G.; Balzarini, A.; Toppetti, A.; Riva, G. M.; Bedogni, M.

    2016-09-01

    worsened around 1-3% (e.g. from 0.84 to 0.81 at Senato site), due to the concentration peaks produced by AUSTAL2000 during nighttime stable conditions. Additionally, the HMS results showed that it was unable to correctly take into account some local scale features (e.g. urban canyon effects), pointing out that the emission spatialization and time modulation criteria, especially those from road traffic, need further improvement. Nevertheless, a second important outcome of the work is that some of the most relevant discrepancies between modelled and observed concentrations were not related to the horizontal resolution of the dispersion models but to larger scale meteorological features not captured by the meteorological model, especially during winter period. Finally, the estimated contribution of the local emission sources accounted on the annual average for about 25-30% of the computed concentration levels in the innermost urban domain. This confirmed that the whole Milan urban area as well as the outside background areas, accounting all sources outside the innermost domain, play a key role on air quality. The result suggests that strictly local emission policies could have a limited and indecisive effect on urban air quality, although this finding could be partially biased by model underestimation of the observed concentration.

  10. Meteorological and air quality impacts of increased urban albedo and vegetative cover in the Greater Toronto Area, Canada

    SciTech Connect

    Taha, Haider; Hammer, Hillel; Akbari, Hashem

    2002-04-30

    . Our si mulations suggest that cool-city strategies can typically reduce local urban air temperature by 0.5-1 degrees C; as more sporadic events, larger decreases (1.5 degrees C, 2.5-2.7 degrees C and 4-6 degrees C) were also simulated. With regard to ozone mixing ratios along the simulated trajectories, the effects of cool-city strategies appear to be on the order of 2 ppb, a typical decrease. The photochemical trajectory model (CIT) also simulates larger decreases (e.g., 4 to 8 ppb), but these are not taken as representative of the potential impacts in this report. A comparison with other simulations suggest very crudely that a decrease of this magnitude corresponds to significant ''equivalent'' decreases in both NOx and VOCs emissions in the region. Our preliminary results suggest that significant UHI control can be achieved with cool-cities strategies in the GTA and is therefore worth further study. We recommend that better input data and more accurate modeling schemes be used to carry out f uture studies in the same direction.

  11. Sustainable development of urban transport systems and human exposure to air pollution.

    PubMed

    Colvile, R N; Kaur, S; Britter, R; Robins, A; Bell, M C; Shallcross, D; Belcher, S E

    2004-12-01

    DAPPLE (Dispersion of Air Pollution and Penetration into the Local Environment, http://www.dapple.org.uk) is a major research project that will provide the understanding necessary to assess the sustainability of urban road transport in terms of exposure to traffic-related air pollution as an alternative to current indicators based on emissions, roadside, or far-from-road air pollution levels. The methodology is described, which combines on-street and laboratory measurement with modelling of the movement of air, vehicles, and vehicle exhaust emissions. The relationship between this kind of assessment and more realistic indicators of sustainability is discussed. The value of large-scale interdisciplinary research in this area is thus demonstrated.

  12. Assessing the ecosystem service of air pollutant removal by urban trees in Guangzhou (China).

    PubMed

    Jim, C Y; Chen, Wendy Y

    2008-09-01

    In Chinese cities, air pollution has become a serious and aggravating environmental problem undermining the sustainability of urban ecosystems and the quality of urban life. Besides technical solutions to abate air pollution, urban vegetation is increasingly recognized as an alternative ameliorative method by removing some pollutants mainly through dry deposition process. This paper assesses the capability and monetary value of this ecosystem service in Guangzhou city in South China. The results indicated an annual removal of SO(2), NO(2) and total suspended particulates at about 312.03 Mg, and the benefits were valued at RMB90.19 thousand (US$1.00=RMB8.26). More removal was realized by recreational land use due to a higher tree cover. Higher concentration of pollutants in the dry winter months induced more removal. The lower cost of pollution abatement in China generated a relatively subdued monetary value of this environmental benefit in comparison with developed countries. Younger districts with more extensive urban trees stripped more pollutants from the air, and this capacity was anticipated to increase further as their trees gradually reach final dimensions and establish a greater tree cover. Tree cover and pollutant concentration constitute the main factors in pollutant removal by urban trees. The efficiency of atmospheric cleansing by trees in congested Chinese cities could be improved by planting more trees other than shrubs or grass, diversifying species composition and biomass structure, and providing sound green space management. The implications for greenery design were discussed with a view to maximizing this ecosystem service in Chinese cities and other developing metropolises.

  13. Air quality influenced by urban heat island coupled with synoptic weather patterns.

    PubMed

    Lai, Li-Wei; Cheng, Wan-Li

    2009-04-01

    Few studies have discussed the association between the urban heat island (UHI) phenomenon and air quality under synoptic weather patterns conducive to UHI. In this study, the authors used statistical analyses to study this association in the Taichung metropolis region. The air quality data obtained from government-owned observation stations and wind field profiles obtained from tethersonde monitoring (performed during 21-29 October 2004) were combined with the simulations of the horizontal wind fields at different heights by the air pollution model (TAPM). The results show that certain specific synoptic weather patterns worsen the air quality and induce the UHI phenomenon: Taichung's UHI appears clearly under the synoptic weather patterns featuring light air or breezes (0.56 m/s < or =wind speed <2.2 m/s) mainly from the north and west. Furthermore, under these weather patterns, the concentrations of air pollutants (NO2, CO2 and CO) increase significantly (P<0.05) with the UHI intensity. The convergence usually associated with nocturnal UHI causes the accumulation of O3 precursors, as well as other air pollutants, thereby worsening the air quality at that time and also during the following daytime period.

  14. A new approach for highly resolved air temperature measurements in urban areas

    NASA Astrophysics Data System (ADS)

    Buttstädt, M.; Sachsen, T.; Ketzler, G.; Merbitz, H.; Schneider, C.

    2011-02-01

    In different fields of applied local climate investigation, highly resolved data of air temperature are of great importance. As a part of the research programme entitled City2020+, which deals with future climate conditions in agglomerations, this study focuses on increasing the quantity of urban air temperature data intended for the analysis of their spatial distribution. A new measurement approach using local transport buses as "riding thermometers" is presented. By this means, temperature data with a very high temporal and spatial resolution could be collected during scheduled bus rides. The data obtained provide the basis for the identification of thermally affected areas and for the investigation of factors in urban structure which influence the thermal conditions. Initial results from the ongoing study, which show the temperature distribution along different traverses through the city of Aachen, are presented.

  15. Preliminary analysis of hazardous air pollutant emission inventories from three major urban areas

    SciTech Connect

    Jones, J.W.; Campbell, D.; Murphy, P.; Smith, R.

    1993-01-01

    The paper reports EPA/AEERL's progress on emissions inventory evaluation and improvement under a hazardous air pollutant (HAP) emissions research program in support of the Urban Area Source Program required under Title III of the Clean Air Act Amendments of 1990 (CAAA). The paper summarizes results of three current projects and indicates HAP emissions inventory needs. HAP inventories for three urban areas--Chicago, San Francisco, and Seattle/Tacoma--were analyzed to identify area sources as defined in the CAAA. One inventory focused on area sources; the other two were basically point source inventories that had facilities that met the area source definition. The HAPs that contribute most of the area source emissions in each inventory were identified, and 22 HAPs that were common to the inventories were selected for further analysis.

  16. The Marine Air-Ground Team: Still Not Adequately Training for the Urban Fight/The Marine Air-Ground Team: Still Not Adequately Trained for the Urban Fight

    DTIC Science & Technology

    2006-02-01

    1 The Marine Air-Ground Team: Still Not Adequately Training for the Urban Fight Subject Area Training EWS 2006...The Marine Air-Ground Team: Still Not Adequately Training for the Urban Fight Submitted by Captain RC Rybka to Majors GC Schreffler and RR...estimated to average 1 hour per response , including the time for reviewing instructions, searching existing data sources, gathering and maintaining the

  17. Occupational Exposure to Urban Air Pollution and Allergic Diseases

    PubMed Central

    Vimercati, Luigi; Gatti, Maria Franca; Baldassarre, Antonio; Nettis, Eustachio; Favia, Nicola; Palma, Marco; Martina, Gabriella Lucia Maria; Di Leo, Elisabetta; Musti, Marina

    2015-01-01

    Exposure to air pollution is associated with increased morbidity from cardiovascular diseases, lung cancer, respiratory and allergic diseases. The aim of this study was to investigate allergic diseases in 111 traffic wardens compared to a control group of 101 administrative employees. All participating subjects underwent a physical examination, in which a complete medical history was taken and a dedicated allergological questionnaire administered. Spirometry, Specific IgE dosage (RAST) and skin prick tests (SPT) were done. Diagnostic investigations such as the nasal cytology, a specific nasal provocation test and rhinomanometry were also performed. Statistical analyses were performed using STATA version 11. The percentage of subjects with a diagnosis of allergy was higher in the exposed workers than in the controls. As regards the clinical tests, the positivity was higher for the group of exposed subjects. Among the exposed workers, those who worked on foot or motorcycle had a higher positivity in clinical trials compared to the traffic wardens who used the car. Our study showed a higher percentage of allergic subjects in the group of workers exposed to outdoor pollutants than in the controls. These results suggest that allergological tests should be included in the health surveillance protocols for workers exposed to outdoor pollutants. PMID:26501303

  18. Environmental and biological monitoring of arsenic in outdoor workers exposed to urban air pollutants.

    PubMed

    Ciarrocca, Manuela; Tomei, Gianfranco; Palermo, Paola; Caciari, Tiziana; Cetica, Carlotta; Fiaschetti, Maria; Gioffrè, Pier Agostino; Tasciotti, Zaira; Tomei, Francesco; Sancini, Angela

    2012-11-01

    The aim of this study is to evaluate personal exposure to As in urban air in two groups of outdoor workers (traffic policemen and police drivers) of a big Italian city through: (a) environmental monitoring of As obtained by personal samples and (b) biological monitoring of total urinary As. The possible influence of smoking habit on urinary As was evaluated. We studied 122 male subjects, all Municipal Police employees: 84 traffic policemen and 38 police drivers exposed to urban pollutants. Personal exposure to As in air was significantly higher in traffic policemen than in police drivers (p=0.03). Mean age, length of service, alcohol drinking habit, number of cigarettes smoked/day and BMI were comparable between the groups of subjects studied. All subjects were working in the same urban area where they had lived for at least 5 yrs. Dietary habits and consumption of water from the water supply and/or mineral water were similar in traffic policemen and in police drivers. The values of total urinary As were significantly higher in traffic policemen (smokers and non smokers) than in police drivers (smokers and non smokers) (p=0.02). In the subgroup of non-smokers the values of total urinary As were significantly higher in traffic policemen than in police drivers (p=0.03). In traffic policemen and in police drivers total urinary As values were significantly correlated to the values of As in air (respectively r=0.9 and r=0.8, p<0.001). This is the first research in literature studying the exposure to As in outdoor workers occupationally exposed to urban pollutants, such as traffic policemen and police drivers. Personal exposure to As in the air, as well as the urinary excretion of As, is significantly higher in traffic policemen compared to drivers. These results can provide information about exposure to As in streets and in car for other categories of outdoor workers similarly exposed.

  19. Volatile methyl siloxanes (VMS) concentrations in outdoor air of several Catalan urban areas

    NASA Astrophysics Data System (ADS)

    Gallego, E.; Perales, J. F.; Roca, F. J.; Guardino, X.; Gadea, E.

    2017-04-01

    Volatile methyl siloxanes (VMS) were evaluated in ten Catalan urban areas with different industrial impacts, such as petrochemical industry, electrical and mechanical equipment, metallurgical and chemical industries, municipal solid waste treatment plant and cement and food industries, during 2013-2015. 24 h samples were taken with LCMA-UPC pump samplers specially designed in our laboratory, with a flow range of 70 ml min-1. A sorbent-based sampling method, successfully developed to collect a wide-range of VOC, was used. The analysis was performed by automatic thermal desorption coupled with capillary gas chromatography/mass spectrometry detector. The presented methodology allows the evaluation of VMS together with a wide range of other VOC, increasing the number of compounds that can be determined in outdoor air quality assessment of urban areas. This aspect is especially relevant as a restriction of several VMS (D4 and D5) in consumer products has been made by the European Chemicals Agency and US EPA is evaluating to include D4 in the Toxic Substances Control Act, regarding the concern of the possible effects of these compounds in human health and the environment. ΣVMS concentrations (L2-L5, D3-D6 and trimethylsilanol) varied between 0.3 ± 0.2 μg m-3 and 18 ± 12 μg m-3, determined in a hotspot area. Observed VMS concentrations were generally of the same order of magnitude than the previously determined in Barcelona, Chicago and Zurich urban areas, but higher than the published from suburban sites and Arctic locations. Cyclic siloxanes concentrations were up to two-three orders of magnitude higher than those of linear siloxanes, accounting for average contributions to the total concentrations of 97 ± 6% for all samples except for the hotspot area, where cyclic VMS accounted for 99.9 ± 0.1%. D5 was the most abundant siloxane in 5 sampling points; however, differing from the generally observed in previous studies, D3 was the most abundant compound in the

  20. CONTINUED DEVELOPMENT AND TESTING OF A NEW THERMODYNAMIC AEROSOL MODULE FOR URBAN AND REGIONAL AIR QUALITY MODELS. (R824793)

    EPA Science Inventory

    A computationally efficient and rigorous thermodynamic model (ISORROPIA) that predicts the physical state and composition of inorganic atmospheric aerosol is presented. The advantages of this particular model render it suitable for incorporation into urban and regional air qualit...

  1. SPATIAL ANALYSIS OF AIR POLLUTION AND DEVELOPMENT OF A LAND-USE REGRESSION ( LUR ) MODEL IN AN URBAN AIRSHED

    EPA Science Inventory

    The Detroit Children's Health Study is an epidemiologic study examining associations between chronic ambient environmental exposures to gaseous air pollutants and respiratory health outcomes among elementary school-age children in an urban airshed. The exposure component of this...

  2. Impact of traffic volume and composition on the air quality and pedestrian exposure in urban street canyon

    NASA Astrophysics Data System (ADS)

    Rakowska, Agata; Wong, Ka Chun; Townsend, Thomas; Chan, Ka Lok; Westerdahl, Dane; Ng, Simon; Močnik, Griša; Drinovec, Luka; Ning, Zhi

    2014-12-01

    Vehicle emissions are identified as a major source of air pollution in metropolitan areas. Emission control programs in many cities have been implemented as part of larger scale transport policy interventions to control traffic pollutants and reduce public health risks. These interventions include provision of traffic-free and low emission zones and congestion charging. Various studies have investigated the impact of urban street configurations, such as street canyon in urban centers, on pollutants dispersion and roadside air quality. However, there are few investigations in the literature to study the impact of change of fleet composition and street canyon effects on the on-road pollutants concentrations and associated roadside pedestrian exposure to the pollutants. This study presents an experimental investigation on the traffic related gas and particle pollutants in and near major streets in one of the most developed business districts in Hong Kong, known as Central. Both street canyon and open roadway configurations were included in the study design. Mobile measurement techniques were deployed to monitor both on-road and roadside pollutants concentrations at different times of the day and on different days of a week. Multiple traffic counting points were also established to concurrently collect data on traffic volume and fleet composition on individual streets. Street canyon effects were evident with elevated on-road pollutants concentrations. Diesel vehicles were found to be associated with observed pollutant levels. Roadside black carbon concentrations were found to correlate with their on-road levels but with reduced concentrations. However, ultrafine particles showed very high concentrations in roadside environment with almost unity of roadside/on-road ratios possibly due to the accumulation of primary emissions and secondary PM formation. The results from the study provide useful information for the effective urban transport design and bus route

  3. Ozone production during an urban air stagnation episode over Nashville, Tennessee

    NASA Astrophysics Data System (ADS)

    Valente, R. J.; Imhoff, R. E.; Tanner, R. L.; Meagher, J. F.; Daum, P. H.; Hardesty, R. M.; Banta, R. M.; Alvarez, R. J.; McNider, R. T.; Gillani, N. V.

    1998-09-01

    The highest O3 levels observed during the 1995 Southern Oxidants Study in middle Tennessee occurred during a period of air stagnation from July 11 through July 15. Extensive airborne (two fixed wing and one helicopter) and ground-based measurements of the chemistry and meteorology of this episode near Nashville, Tennessee, are presented. In situ airborne measurements include O3, NOy, NO, NO2, SO2, CO, nitrate, hydrocarbons, and aldehydes. Airborne LIDAR O3 measurements are also utilized to map the vertical and horizontal extent of the urban plume. The use of multiple instrumented research aircraft permitted highly detailed mapping of the plume chemistry in the vertical and horizontal dimensions. Interactions between the urban Nashville plume (primarily a NOx and hydrocarbon source) and the Gallatin coal-fired power plant plume (primarily a NOx and SO2 source) are also documented, and comparisons of ozone formation in the isolated and mixed urban and power plant plume are presented. The data suggest that during this episode the background air and the edges of the urban plume are NOx sensitive and the core of the urban plume is hydrocarbon sensitive. Under these worst case meteorological conditions, ambient O3 levels well over the level of the new National Ambient Air Quality Standard (NAAQS) for ozone (80 ppb) were observed over and just downwind of Nashville. For example, on July 12, the boundary layer air upwind of Nashville showed 60 to 70 ppb O3, while just downwind of the city the urban plume maximum was over 140 ppb O3. With a revised ozone standard set at 80 ppb (8 hour average) and upwind levels already within 10 or 20 ppb of the standard, only a slight increase in ozone from the urban area will cause difficulty in attaining the standard at monitors near the core of the urban plume during this type of episode. The helicopter mapping and LIDAR aircraft data clearly illustrate that high O3 levels can occur during stagnation episodes within a few kilometers of

  4. Effective Literacy Instruction for Urban Children: Voices from the Classroom

    ERIC Educational Resources Information Center

    Scott, Jerrie L.; Teale, William H.

    2009-01-01

    In an attempt to bring readers "on-the-ground" insights about effective urban literacy instruction, the authors interviewed three literacy educators who have extensive experience with learners in urban school environments. Each of them has taught literacy and developed teaching practices for urban schools, as well as conducted action research to…

  5. The effect of the indoor environment on the fate of organic chemicals in the urban landscape.

    PubMed

    Cousins, Anna Palm

    2012-11-01

    To assess the effect of the indoor environment on the urban fate of organic chemicals, an 8-compartment indoor-inclusive steady state multimedia chemical fate model was developed. The model includes typical urban compartments (air, soil, water, sediment, and urban film) and a novel module representing a generic indoor environment. The model was parameterized to the municipality of Stockholm, Sweden and applied to four organic chemicals with different physical-chemical characteristics and use patterns: formaldehyde, 2,4,6-tribromophenol, di-ethylhexylphthalate and decabromodiphenyl ether. The results show that emissions to indoor air may increase the steady state mass and residence time in the urban environment by a factor of 1.1 to 22 for the four chemicals, compared to if emissions are assigned to outdoor air. This is due to the nested nature of the indoor environment, which creates a physical barrier that prevents chemicals from leaving the urban system with outflowing air. For DEHP and BDE 209, the additional partitioning to indoor surfaces results in a greater importance of the indoor removal pathways from surfaces. The outdoor environmental concentrations of these chemicals are predicted to be lower if emitted to indoor air than if emitted to outdoor air because of the additional indoor removal pathways of dust and indoor film, leading to loss of chemical from the system. For formaldehyde and 2,4,6-TBP outdoor environmental concentrations are not affected by whether the release occurs indoors or outdoors because of the limited partitioning to indoor surfaces. A sensitivity analysis revealed that there appears to be a relationship between logK(OA) and the impact of the ventilation rate on the urban fate of organic chemicals.

  6. 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.

  7. 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

  8. Urban morphology and air quality in dense residential environments in Hong Kong. Part I: District-level analysis

    NASA Astrophysics Data System (ADS)

    Edussuriya, P.; Chan, A.; Ye, A.

    2011-09-01

    The link between urban morphology and air quality in various dense residential environments of Hong Kong are investigated through field measurements and statistical analysis. With regard to the myriads of parameters available in the literature, this study aims to identify the most important urban morphological parameters in the street-level and district levels that affect air quality dispersion in Hong Kong. The study postulates that there is an association between urban morphology and urban air quality and a statistical model is developed to explain the relationship amongst urban air quality, micro-meteorology and urban morphological dimension. The study considered 20 different urban residential areas in five major districts of Hong Kong and real-time street-level air pollutant and microclimatic data are collected. 21 morphological variables are identified and calculated based on the geometry of the urban fabric. This study is the first part of a series which focuses to identify whether district demarcation is correlated with air quality. According to the findings of statistical analysis, only 6 out of 21 morphological variables (complete aspect ratio, occlusivity, roughness height, zero-plane displacement height, total building volume/number of buildings, and standard deviation of height) report distinguishable variability at the district level. Their R2 (correlation coefficient) values vary from 0.2937 (plan area index) to 0.5457 (occlusivity) which is considered moderate to high. All these parameters describe the overall feature of the site rather than the specific geometric features of the street. It translates to the fact that in spite of the large in-district variations in morphological variables amongst the five districts, air pollution variations are insignificant for most of the variables and it means that air quality in Hong Kong are distinguishable not by district-level variable but rather in-site fabrics.

  9. 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.

  10. Study on the association between ambient air pollution and daily cardiovascular and respiratory mortality in an urban district of Beijing.

    PubMed

    Zhang, Fengying; Li, Liping; Krafft, Thomas; Lv, Jinmei; Wang, Wuyi; Pei, Desheng

    2011-06-01

    The association between daily cardiovascular/respiratory mortality and air pollution in an urban district of Beijing was investigated over a 6-year period (January 2003 to December 2008). The purpose of this study was to evaluate the relative importance of the major air pollutants [particulate matter (PM), SO2, NO2] as predictors of daily cardiovascular/respiratory mortality. The time-series studied comprises years with lower level interventions to control air pollution (2003-2006) and years with high level interventions in preparation for and during the Olympics/Paralympics (2007-2008). Concentrations of PM10, SO2, and NO2, were measured daily during the study period. A generalized additive model was used to evaluate daily numbers of cardiovascular/respiratory deaths in relation to each air pollutant, controlling for time trends and meteorological influences such as temperature and relative humidity. The results show that the daily cardiovascular/respiratory death rates were significantly associated with the concentration air pollutants, especially deaths related to cardiovascular disease. The current day effects of PM10 and NO2 were higher than that of single lags (distributed lags) and moving average lags for respiratory disease mortality. The largest RR of SO2 for respiratory disease mortality was in Lag02. For cardiovascular disease mortality, the largest RR was in Lag01 for PM10, and in current day (Lag0) for SO2 and NO2. NO2 was associated with the largest RRs for deaths from both cardiovascular disease and respiratory disease.

  11. Concentrations of vehicle-related air pollutants in an urban parking garage.

    PubMed

    Kim, Sung R; Dominici, Francesca; Buckley, Timothy J

    2007-11-01

    There is growing evidence that traffic-related air pollution poses a public health threat, yet the dynamics of human exposure are not well understood. The urban parking garage is a microenvironment that is of concern but has not been characterized. Using time-resolved measurement methods, we evaluated air toxics levels within an urban parking garage and assessed the influence of vehicle activity and type on their levels. Carbon monoxide (CO) and particle-bound polycyclic aromatic hydrocarbons (pPAH) were measured with direct-reading instruments. Volatile organic compounds (VOCs) were measured in 30 min intervals using a sorbent tube loaded sequential sampler. Vehicle volume and type were evaluated by video recording. Sampling was conducted from June 24 to July 17, 2002. We observed garage traffic median volumes of 71 counts/h on weekdays and 6 counts/h on weekends. The 12-fold reduction in traffic volume from weekday to weekend corresponded with a decrease in median air pollution that varied from a minimum 2- (CO) to a maximum 7 (pPAH)-fold. The actual 30-min median weekday and weekend values were: CO--2.6/1.2 ppm; pPAH--19/2.6 ng/m(3); 1,3-butadiene-0.5/0.2 microg/m(3), MTBE-7.4/0.4 microg/m(3); and benzene-2.7/0.3 microg/m(3). The influence of traffic was quantified using longitudinal models. The pollutant coefficients provide an indication of the average air pollution vehicle source contribution and ranged from 0.31 (CO) to 1.08 (pPAH) percent increase/vehicle count. For some pollutants, a slightly higher (0.5-0.6%) coefficient was observed for light-trucks relative to cars. This study has public health relevance in providing a unique assessment of air pollution levels and source contribution for the urban parking garage.

  12. AN INTERDISCIPLINARY APPROACH TO ADDRESSING NEIGHBORHOOD SCALE AIR QUALITY CONCERNS: THE INTEGRATION OF GIS, URBAN MORPHOLOGY, PREDICTIVE METEOROLOGY, AND AIR QUALITY MONITORING TOOLS

    EPA Science Inventory

    The paper describes a project that combines the capabilities of urban geography, raster-based GIS, predictive meteorological and air pollutant diffusion modeling, to support a neighborhood-scale air quality monitoring pilot study under the U.S. EPA EMPACT Program. The study ha...

  13. Estimating the urban bias of surface shelter temperatures using upper-air and satellite data. Part 2: Estimation of the urban bias

    NASA Technical Reports Server (NTRS)

    Epperson, David L.; Davis, Jerry M.; Bloomfield, Peter; Karl, Thomas R.; Mcnab, Alan L.; Gallo, Kevin P.

    1995-01-01

    A methodology is presented for estimating the urban bias of surface shelter temperatures due to the effect of the urban heat island. Multiple regression techniques were used to predict surface shelter temperatures based on the time period 1986-89 using upper-air data from the European Centre for Medium-Range Weather Forecasts (ECMWF) to represent the background climate, site-specific data to represent the local landscape, and satellite-derived data -- the normalized difference vegetation index (NDVI) and the Defense Meteorological Satellite Program (DMSP) nighttime brightness data -- to represent the urban and rural landscape. Local NDVI and DMSP values were calculated for each station using the mean NDVI and DMSP values from a 3 km x 3 km area centered over the given station. Regional NDVI and DMSP values were calculated to represent a typical rural value for each station using the mean NDVI and DMSP values from a 1 deg x 1 deg latitude-longitude area in which the given station was located. Models for the United States were then developed for monthly maximum, mean, and minimum temperatures using data from over 1000 stations in the U.S. Cooperative (COOP) Network and for monthly mean temperatures with data from over 1150 stations in the Global Historical Climate Network (GHCN). Local biases, or the differences between the model predictions using the observed NDVI and DMSP values, and the predictions using the background regional values were calculated and compared with the results of other research. The local or urban bias of U.S. temperatures, as derived from all U.S. stations (urban and rural) used in the models, averaged near 0.40 C for monthly minimum temperatures, near 0.25 C for monthly mean temperatures, and near 0.10 C for monthly maximum temperatures. The biases of monthly minimum temperatures for individual stations ranged from near -1.1 C for rural stations to 2.4 C for stations from the largest urban areas. The results of this study indicate minimal

  14. Differential exposure of the urban population to vehicular air pollution in Hong Kong.

    PubMed

    Fan, Xiaopeng; Lam, Kin-che; Yu, Qi

    2012-06-01

    This study aims to characterize the spatial variations in, and examine the influence of socio-economic class on, the exposure of urban population of Hong Kong to air pollution from vehicular sources. Hong Kong provides a unique and interesting case for an in-depth study of environmental inequality because of its dense environment and housing provision mechanism through which about half of the population is accommodated in public housing estates provided by the government. To estimate the exposure of the urban population to vehicular air pollution, the IMMIS(net) air dispersion model developed for city-wide air quality assessment was used. The annual mean concentrations of CO, NO(x), SO(2) and PM(10) were estimated for various assessment points of 275 public and 295 private building groups. The results show more pronounced inequality among residents living in private than in public housing estates. Elderly people and those of lower socio-economic status were found to be exposed to relatively higher levels of vehicular air pollution compared with groups of higher socio-economic status. However, when all the residents in Hong Kong were pooled together for analysis, no distinct class-biased patterns were found. This could be ascribed to the housing provision mechanism, in which less well-off people are accommodated in public housing estates where the air quality is relatively better. This study highlights the importance of government intervention in housing provision, through which the deprived groups in Hong Kong are inadvertently more protected from air pollution exposure.

  15. Simulating the impact of urban sprawl on air quality and population exposure in the German Ruhr area. Part I: Reproducing the base state

    NASA Astrophysics Data System (ADS)

    De Ridder, Koen; Lefebre, Filip; Adriaensen, Stefan; Arnold, Ute; Beckroege, Wolfgang; Bronner, Christine; Damsgaard, Ole; Dostal, Ivo; Dufek, Jiri; Hirsch, Jacky; IntPanis, Luc; Kotek, Zdenek; Ramadier, Thierry; Thierry, Annette; Vermoote, Stijn; Wania, Annett; Weber, Christiane

    Compact city forms are associated with minimal consumption of land and energy, hence, they are often promoted as being the more sustainable thus preferred mode of urban development. In this context, numerical simulations were performed to evaluate the effect of urban sprawl on air quality and associated human exposure. Working on a highly urbanised area in the German Ruhrgebiet, models dealing with satellite data processing, traffic flows, pollutant emission and atmospheric dispersion were applied in an integrated fashion, under conditions representative of the urbanised area as it is today. A fair agreement was obtained between simulated and observed meteorological variables, as well as between simulated and observed concentrations of ozone and particulate matter. Simulated atmospheric pollution fields were found to closely reflect urbanisation patterns. In a companion paper [De Ridder, K., Lefebre, F., Adriaensen, S., Arnold, U., Beckroege, W., Bronner, C., Damsgaard, O., Dostal, I., Dufek, J., Hirsch, J., IntPanis, L., Kotek, Z., Ramadier, T., Thierry, A., Vermoote, S., Wania, A., Weber, C., 2008. Simulating the impact of urban sprawl on air quality and population exposure in the German Ruhr area. Part II: Development and evaluation of an urban growth scenario], the results of this base case simulation will be compared with those of a scenario simulation, designed to mimic urban sprawl, so as to allow the evaluation of the latter on air quality and associated human exposure.

  16. 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.

  17. The impact of an urban park on air pollution and noise levels in the Mediterranean city of Tel-Aviv, Israel.

    PubMed

    Cohen, Pninit; Potchter, Oded; Schnell, Izhak

    2014-12-01

    This study examines the influence of urban parks on air quality and noise in the city of Tel-Aviv, Israel, by investigation of an urban park, an urban square and a street canyon. Simultaneous monitoring of several air pollutants and noise levels were conducted. The results showed that urban parks can reduce NOx, CO and PM10 and increase O3 concentrations and that park's mitigation effect is greater at higher NOx and PM10 levels. During extreme events, mean values of 413 ppb NOx and 80 μG/m3 PM10 were measured in the street while mean values of 89 ppb NOx and 24 μG/m3 PM10 were measured in the park. Whereas summer highest O3 values of 84 ppb were measured in the street, 94 ppb were measured in the park. The benefit of the urban park in reducing NOx and PM10 concentrations is more significant than the disadvantage of increased O3 levels. Furthermore, urban parks can reduce noise by ∼5 dB(A).

  18. Airborne PCDD/F profiles in rural and urban areas of Buenos Aires Province, Argentina.

    PubMed

    Cappelletti, N; Astoviza, M; Migoya, M C; Colombo, J C

    2016-12-15

    Passive air samplers were deployed in 18 rural and urban locations in the densely populated Buenos Aires district to investigate airborne polychlorinated dibenzo-p-dioxin and polychlorinated-dibenzofuran (PCDD/Fs) profiles, sources and spatial patterns. Atmospheric concentrations reported as total toxic equivalents (TEQs), 2378-substituted (∑17PCDD/F) and 4-8 homologous groups (∑4-8PCDD/F) were highly variable and significantly correlated to urban scale. The rural average (3.0±2.7fgTEQm(-3)) was thirty times less than metropolitan values (90±51fgTEQm(-3)), with urban cluster (5.4±4.0fgTEQm(-3)) and urbanized area (33±50fgTEQm(-3)) in an intermediate position. A rural outlier exhibited the highest TEQ values (295-296fgTEQm(-3)) suggesting a local source. Principal component analyses (PCA) performed for ∑17PCDD/F and ∑4-8PCDD/F to identify source contributions showed more significant results for homologue groups compared to 17 congeners (83 and 45% of total variability explained, respectively) pointing to dominant diesel emissions enriched in TeCDF in rural areas, and open burning and industrial sources characterized by TeCDD, PeCDD contributing most in urbanized and metropolitan areas. Homologue group PCA also performed better clustering samples according to sources and TEQ concentrations. The PCDD/Fs profile of the rural outlier dominated by HxCDF and HpCDD/F showed a typical municipal incineration signature confirming the presence of local source.

  19. Monitoring temporal trends of air pollution in an urban area using mosses and lichens as biomonitors.

    PubMed

    Gerdol, Renato; Marchesini, Roberta; Iacumin, Paola; Brancaleoni, Lisa

    2014-08-01

    Monitoring air quality by using living organisms as biomonitors has received increasing attention in recent years. However, rather few studies were based on the concomitant use of passive biomonitoring (based on the different sensitivity of living organisms to air pollution) and active biomonitoring (based on their capacity to accumulate pollutants in the tissues). We carried out a repeated survey of an urban area in Northern Italy, with the objective of comparing temporal trends of different kinds of air pollutants with bioindication (passive biomonitoring) and bioaccumulation (active biomonitoring) techniques. During a five-year interval, temporal patterns of moss metal concentrations underwent significant changes probably due to intercurring variations in the importance of different pollution sources. Nitrogen (N) concentration in moss tissues also decreased and was paralleled by increasing diversity of epiphytic lichens. Increasing δ(15)N in moss tissues suggested a higher contribution of oxidized N species compared with reduced N species.

  20. Migration of polycyclic aromatic hydrocarbons (PAHs) in urban treatment sludge to the air during PAH removal applications.

    PubMed

    Karaca, Gizem; Cindoruk, S Siddik; Tasdemir, Yücel

    2014-05-01

    In the present study, the amounts of polycylic aromatic hydrocarbons (PAHs) penetrating into air during PAH removal applications from the urban treatment sludge were investigated. The effects of the temperature, photocatalyst type, and dose on the PAH removal efficiencies and PAH evaporation were explained. The sludge samples were taken from an urban wastewater treatment plant located in the city of Bursa, with 585,000 equivalent population. The ultraviolet C (UV-C) light of 254 nm wavelength was used within the UV applications performed on a specially designed setup. Internal air of the setup was vacuumed through polyurethane foam (PUF) columns in order to collect the evaporated PAHs from the sludge during the PAH removal applications. All experiments were performed with three repetitions. The PAH concentrations were measured by gas chromatography-mass spectrometry (GC-MS). It was observed that the amounts of PAHs penetrating into the air were increased with increase of temperature, and more than 80% of PAHs migrated to the air consisted of 3-ring compounds during the UV and UV-diethylamine (DEA) experiments at 38 and 53 degrees C. It was determined that 40% decrease was ensured in sigma12 (total of 12) PAH amounts with UV application and 13% of PAHs in sludge penetrated into the air. In the UV-TiO2 applications, a maximum 80% of sigma12 PAH removal was obtained by adding 0.5% TiO2 of dry weight of sludge. The quantity of PAH penetrating into air did not exceed 15%. UV-TiO2 applications ensured high levels of PAH removal in the sludge and also reduced the quantity of PAH penetrating into the air. Within the scope of the samples added with DEA, there was no increase in PAH removal efficiencies and the penetration of PAHs into air was not decreased. In light of these data, it was concluded that UV-TiO2 application is the most suitable PAH removal alternative that restricts the convection of PAH pollution.

  1. Multi-scale modeling of urban air pollution: development of a Street-in-Grid model

    NASA Astrophysics Data System (ADS)

    Kim, Youngseob; Wu, You; Seigneur, Christian; Roustan, Yelva

    2016-04-01

    A new multi-scale model of urban air pollution is presented. This model combines a chemical-transport model (CTM) that includes a comprehensive treatment of atmospheric chemistry and transport at spatial scales greater than 1 km and a street-network model that describes the atmospheric concentrations of pollutants in an urban street network. The street-network model is based on the general formulation of the SIRANE model and consists of two main components: a street-canyon component and a street-intersection component. The street-canyon component calculates the mass transfer velocity at the top of the street canyon (roof top) and the mean wind velocity within the street canyon. The estimation of the mass transfer velocity depends on the intensity of the standard deviation of the vertical velocity at roof top. The effect of various formulations of this mass transfer velocity on the pollutant transport at roof-top level is examined. The street-intersection component calculates the mass transfer from a given street to other streets across the intersection. These mass transfer rates among the streets are calculated using the mean wind velocity calculated for each street and are balanced so that the total incoming flow rate is equal to the total outgoing flow rate from the intersection including the flow between the intersection and the overlying atmosphere at roof top. In the default option, the Leighton photostationary cycle among ozone (O3) and nitrogen oxides (NO and NO2) is used to represent the chemical reactions within the street network. However, the influence of volatile organic compounds (VOC) on the pollutant concentrations increases when the nitrogen oxides (NOx) concentrations are low. To account for the possible VOC influence on street-canyon chemistry, the CB05 chemical kinetic mechanism, which includes 35 VOC model species, is implemented in this street-network model. A sensitivity study is conducted to assess the uncertainties associated with the use of

  2. The concentrations of culturable microorganisms in relation to particulate matter in urban air

    NASA Astrophysics Data System (ADS)

    Haas, D.; Galler, H.; Luxner, J.; Zarfel, G.; Buzina, W.; Friedl, H.; Marth, E.; Habib, J.; Reinthaler, F. F.

    2013-02-01

    The ambient air consists not only of gases but also of bioaerosols and particulate matter. The concentrations of particulate matter in relation to the culturable microorganisms in the urban ambient air and their dependence on air temperature and relative humidity were investigated. The seasonal distribution of particles sizes, the concentrations of aerobic mesophilic bacteria and xerophilic fungi in the air were evaluated. Moreover, the identification of the fungal genera Cladosporium, Aspergillus and Penicillium were conducted. Within one year at 177 days particle and microorganism concentrations in the ambient air were recorded in the city centre of Graz/Austria. The results show that the concentrations of fine particles and coarse particles were the highest in winter and decreased continuously to a minimum in the summer months depending on temperature and air humidity. The concentrations of xerophilic fungi showed no correlation to the different particle concentrations. The spore concentrations of Cladosporium spp. showed the same results of xerophilic fungi whereas the genera Penicillium and Aspergillus increased with the increase of fine particles. The concentrations of mesophilic bacteria were positively correlated with all particle counts. The maximum mesophilic bacteria concentrations were found in the winter months. Further studies are required to evaluate the concentrations of specific microorganisms in the natural environment in relation to the particulate matter.

  3. Evaluation of a possible association of urban air toxics and asthma

    SciTech Connect

    Leikauf, G.D.; Kline, S.; Albert, R.E.; Baxter, C.S.

    1995-09-01

    The prevalence of asthma, measured either as the frequency of hospital admission or number of deaths attributed to asthma, has increased over the last 15 to 20 years. Rapid increases in disease prevalence are more likely to be attributable to environmental than genetic factors. inferring from past associations between air pollution and asthma, it is feasible that changes in the ambient environment could contribute to this increase in morbidity and mortality. Scientific evaluation of the links between air pollution and the exacerbation of asthma is incomplete, however. Currently, criteria pollutants [SO{sub x}NO{sub x}, O{sub 3}, CO, Pb, particulate matter (PM{sub 10})] and other risk factors (exposure to environmental tobacco smoke, volatile organic compounds, etc.) are constantly being evaluated as to their possible contributions to this situation. Data from these studies suggest that increases in respiratory disease are associated with exposures to ambient concentrations of particulate and gaseous pollutants. Similarly, exposure to environmental tobacco smoke, also a mixture of particles and gases and that current measurements of air pollution are, in part, indirect in that the concentrations of criteria pollutants are acting as surrogates of our exposure to a complex mixture. Other irritant air pollutants, including certain urban air toxics, are associated with asthma in occupational settings and may interact with criteria pollutants in ambient air to exacerbate asthma. 179 refs., 2 figs., 18 tabs.

  4. Mineral content of urban plants as an indicator of air sulphate pollution

    SciTech Connect

    Ufimtseva, M.D.; Zaickina, L.I.

    1996-08-01

    Phytogeochemical indication constitutes one of the promising methods of urban environment monitoring. Usually the phytogeochemical assessment includes the estimation of heavy metal content in urban plants in reference to the regional background level. The indication, based on the diversity of the biological response reactions to the industrial contamination, allows us to use the other parameters for the characterization of current condition of the urban environment (and particularly the atmospheric contamination) as well. As it is well known, mineral phytolites which may constitute up to 85% of dry weight are formed in plant tissues. The mineral composition of plants does not seem to be studied well enough as yet, and the data on mineral complexes in urban plants are absent completely. The authors` attempt was to study the peculiarities of urban plant mineral content and to reveal the value of the quantitative proportion of different mineral compounds for the air pollution indication. Urban plant mineral composition was tested in the samples of ashes by means of the infrared (IR) spectroscopy method which is usually used for the estimation of mineral compounds in rock. The IR absorption spectra were taken for the samples of bark or leaf ashes, taken from the tree, shrub, and herbaceous species that were most common and widely distributed both throughout the industrial areas and in the areas without noticeable pollution. These spectra look like curves with a lot of peales with different range which evidently correspond not to clear substances but to the mixtures of different minerals. The variation of absorbtion intensities in the observed lands makes it possible to estimate the quantitative contribution of different minerals (carbonates, sulphates, phosphates, quartz, feldspar, etc.) to the general IR spectrum.

  5. Monitoring of urban air pollution from MODIS and AERONET Aerosol Optical Thickness (AOT) data

    NASA Astrophysics Data System (ADS)

    Tijani, K.; Chiaradia, M.; Guerriero, L.; Pasquariello, G.; Morea, A.; Nutricato, R.; Preziosa, G.

    2012-12-01

    Air pollution, caused by fuel industries and urban traffic and its environmental impact, are of considerable interest to studies in air quality. In this paper, the monitoring of the air pollution over urban areas in Italy through Aerosol Optical Thickness (AOT) data retrieved from Moderate Resolution Imaging Spectroradiometer (MODIS) measurements is presented. The high spatio-temporal frequency of MODIS AOT products (twice per day at 470nm, 1km full resolution) demonstrates that this satellite can be potentially used to routinely monitor the air pollution over land, especially urban area, which is the main source of aerosol particles. In this work AOT data derived by MODIS from November 2010 to February 2011 (winter period) and from May 2011 to August 2011 (summer period) were compared with AOT measurements from 6 different Aerosol Robotic Network (AERONET) stations over Italy (Bari, Lecce, Roma, Ispra, Potenza, Etna). The statistical analysis shows a good agreement between the ground based AOT measurements and the values retrieved using space based sensors, as shown in Figure 1. For all the stations the mean error is negligible, with a correlation ranging from 0.725 (in the worst case) to 0.96 (see Table 1). Moreover, LANDSAT-panchromatic images were used to discriminate urban and rural areas, based on the typical finger-like projections of urban land uses. The results of this study will be presented and commented. Acknowledgements This work was funded by Apulian Region in the framework of the ECOURB project. (Analisi e Modelli di inquinamento atmosferico e termico per sistemi di ECOlabeling URBano, 2009-2012). Figure 1: Scatter plot between AOT derived from MODIS and AERONET for Lecce City in summer period from May 2011 to August 2011. Y = - 0.023+0.86x (fit) ; Table 1: Statistical Analysis Report on the difference between AOT derived from MODIS and AERONET from May 2011 to August 2011 (summer period) for 6 different Aerosol Robotic Network (AERONET) stations

  6. Impact of maritime air mass trajectories on the Western European coast urban aerosol.

    PubMed

    Almeida, S M; Silva, A I; Freitas, M C; Dzung, H M; Caseiro, A; Pio, C A

    2013-01-01

    Lisbon is the largest urban area in the Western European coast. Due to this geographical position the Atlantic Ocean serves as an important source of particles and plays an important role in many atmospheric processes. The main objectives of this study were to (1) perform a chemical characterization of particulate matter (PM2.5) sampled in Lisbon, (2) identify the main sources of particles, (3) determine PM contribution to this urban area, and (4) assess the impact of maritime air mass trajectories on concentration and composition of respirable PM sampled in Lisbon. During 2007, PM2.5 was collected on a daily basis in the center of Lisbon with a Partisol sampler. The exposed Teflon filters were measured by gravimetry and cut into two parts: one for analysis by instrumental neutron activation analysis (INAA) and the other by ion chromatography (IC). Principal component analysis (PCA) and multilinear regression analysis (MLRA) were used to identify possible sources of PM2.5 and determine mass contribution. Five main groups of sources were identified: secondary aerosols, traffic, calcium, soil, and sea. Four-day backtracking trajectories ending in Lisbon at the starting sampling time were calculated using the HYSPLIT model. Results showed that maritime transport scenarios were frequent. These episodes were characterized by a significant decrease of anthropogenic aerosol concentrations and exerted a significant role on air quality in this urban area.

  7. Scavenging of urban air emissions by Fog at Delhi, India

    NASA Astrophysics Data System (ADS)

    Saxena, P.; Kulshrestha, U. C.

    2015-12-01

    The present study focuses upon the understanding of fog water chemistry in Delhi city. Total seventy fog water samples were collected at two different sites in Delhi during December 2014 to March 2015. Selected parameters such as pH, major anions (Cl-, F-, NO3- and SO42-) and major cations (NH4+, K+, Ca2+, Mg2+, Na+) were determined in the samples. The pH of the fog water collected during the monitoring period at Site I (traffic intersection) varied from 4.68 to 5.58 indicating the acidic nature of fog water while at the site II (green cover area), it ranged from 6.11 to 6.88 having slightly lower acidity. At the Site I, the average concentration of Cl-, Na+, SO42-, NH4+ was recorded as 1.5 X 10-2, 8 X 10-3, 4 X 10-3 and 1 X 10-2 μEqu/L respectively. Such values of ionic species may be attributed to the local sources, including factories, motor vehicle emissions and civil construction etc. However, non-local sources such as moderate- and long-range transport of sea salt also had significant influence on ionic content of fog water. In general the Na+ ratio values were found to be higher side suggesting the influence of non-marine sources. Extremely high values of Cl-/ Na+ ratios indicated the contribution from combustion of organochlorine compounds. Hence, the higher ratios of inorganic ions and acidic pH revealed that fog is an effective mechanism for the scavenging of various pollutants emitted by different sources in the city.

  8. Interactive Effects of Urban Land Use and Climate Change on Biogeochemical Cycles (Invited)

    NASA Astrophysics Data System (ADS)

    Pouyat, R. V.

    2009-12-01

    Urban land-use change can affect biogeochemical cycles through altered disturbance regimes, landscape management practices (e.g., irrigation and fertilization), built structures, and altered environments (heat island effect, pollution, introduction of non-native species, loss of native species). As a result, the conversion of native to urban ecological systems has been shown to significantly affect carbon, nitrogen, and water cycles at local, regional, and global scales. These changes have created novel habitats and ecosystems, which have no analogue in the history of life. Nonetheless, some of the environmental changes occurring in urban areas are analogous to the changes expected in climate by the end of the century, e.g. atmospheric increase in CO2 and an increase in air temperatures, which can be utilized as a “natural experiment” to investigate global change effects on large scale ecosystem processes. Moreover, as analogues of expected future environments, urban ecological systems may act as reservoirs of plant and animal species for adjoining landscapes that are expected to undergo relatively rapid climate changes in the next 100 years. Urban land-use change by itself may contribute to changes in regional weather patterns and long-term changes in global climate, which will depend on the net effect of converting native systems to urban systems and the comparison of per capita “footprints” between urban, suburban, and rural inhabitants. My objectives are to 1) assess the impact of changes in urban land-use on climate change and in turn how climate change may affect urban biogeochemical cycles and 2) discuss the potential for urban ecosystems to mitigate green house gas emissions.

  9. Results from the Phoenix Urban Heat Island (UHI) experiment: effects at the local, neighbourhood and urban scales

    NASA Astrophysics Data System (ADS)

    di Sabatino, S.; Leo, L. S.; Hedquist, B. C.; Carter, W.; Fernando, H. J. S.

    2009-04-01

    This paper reports on the analysis of results from a large urban heat island experiment (UHI) performed in Phoenix (AZ) in April 2008. From 1960 to 2000, the city of Phoenix experienced a minimum temperature rise of 0.47 °C per decade, which is one of the highest rates in the world for a city of this size (Golden, 2004). Contemporaneously, the city has recorded a rapid enlargement and large portion of the land and desert vegetation have been replaced by buildings, asphalt and concrete (Brazel et al., 2007, Emmanuel and Fernando, 2007). Besides, model predictions show that minimum air temperatures for Phoenix metropolitan area in future years might be even higher than 38 °C. In order to make general statements and mitigation strategies of the UHI phenomenon in Phoenix and other cities in hot arid climates, a one-day intensive experiment was conducted on the 4th-5th April 2008 to collect surface and ambient temperatures within various landscapes in Central Phoenix. Inter alia, infrared thermography (IRT) was used for UHI mapping. The aim was to investigate UHI modifications within the city of Phoenix at three spatial scales i.e. the local (Central Business District, CBD), the neighborhood and the city scales. This was achieved by combining IRT measurements taken at ground level by mobile equipment (automobile-mounted and pedicab) and at high elevation by a helicopter. At local scale detailed thermographic images of about twenty building façades and several street canyons were collected. In total, about two thousand images were taken during the 24-hour campaign. Image analysis provides detailed information on building surface and pavement temperatures at fine resolution (Hedquist et al. 2009, Di Sabatino et al. 2009). This unique dataset allows us several investigations on local air temperature dependence on albedo, building thermal inertia, building shape and orientation and sky view factors. Besides, the mosaic of building façade temperatures are being analyzed

  10. Urban air pollution and emergency room admissions for respiratory symptoms: a case-crossover study in Palermo, Italy

    PubMed Central

    2011-01-01

    Background Air pollution from vehicular traffic has been associated with respiratory diseases. In Palermo, the largest metropolitan area in Sicily, urban air pollution is mainly addressed to traffic-related pollution because of lack of industrial settlements, and the presence of a temperate climate that contribute to the limited use of domestic heating plants. This study aimed to investigate the association between traffic-related air pollution and emergency room admissions for acute respiratory symptoms. Methods From January 2004 through December 2007, air pollutant concentrations and emergency room visits were collected for a case-crossover study conducted in Palermo, Sicily. Risk estimates of short-term exposures to particulate matter and gaseous ambient pollutants including carbon monoxide, nitrogen dioxide, and sulfur dioxide were calculated by using a conditional logistic regression analysis. Results Emergency departments provided data on 48,519 visits for respiratory symptoms. Adjusted case-crossover analyses revealed stronger effects in the warm season for the most part of the pollutants considered, with a positive association for PM10 (odds ratio = 1.039, 95% confidence interval: 1.020 - 1.059), SO2 (OR = 1.068, 95% CI: 1.014 - 1.126), nitrogen dioxide (NO2: OR = 1.043, 95% CI: 1.021 - 1.065), and CO (OR = 1.128, 95% CI: 1.074 - 1.184), especially among females (according to an increase of 10 μg/m3 in PM10, NO2, SO2, and 1 mg/m3 in CO exposure). A positive association was observed either in warm or in cold season only for PM10. Conclusions Our findings suggest that, in our setting, exposure to ambient levels of air pollution is an important determinant of emergency room (ER) visits for acute respiratory symptoms, particularly during the warm season. ER admittance may be considered a good proxy to evaluate the adverse effects of air pollution on respiratory health. PMID:21489245

  11. Tetraglyme Trap for the Determination of Volatile Organic Compounds in Urban Air: Projects for Undergraduate Analytical Chemistry

    ERIC Educational Resources Information Center

    Hope, Wilbert W.; Johnson, Clyde; Johnson, Leon P.

    2004-01-01

    The differences in the levels of volatile organic compounds (VOCs), in the ambient air from the two urban locations, were studied by the undergraduate analytical chemistry students. Tetraglyme is very widely used due to its simplicity and its potential for use to investigate VOCs in ambient and indoor air employing a purge-and-trap concentrator…

  12. IMPLEMENTATION OF AN URBAN CANOPY PARAMETERIZATION IN MM5 FOR MESO-GAMMA-SCALE AIR QUALITY MODELING APPLICATIONS

    EPA Science Inventory

    The U.S. Environmental Protection Agency (U.S. EPA) is extending its Models-3/Community Multiscale Air Quality (CMAQ) Modeling System to provide detailed gridded air quality concentration fields and sub-grid variability characterization at neighborhood scales and in urban areas...

  13. Urban air pollution and meteorological factors affect emergency department visits of elderly patients with chronic obstructive pulmonary disease in Taiwan.

    PubMed

    Ding, Pei-Hsiou; Wang, Gen-Shuh; Guo, Yue-Leon; Chang, Shuenn-Chin; Wan, Gwo-Hwa

    2017-05-01

    Both air pollution and meteorological factors in metropolitan areas increased emergency department (ED) visits from people with chronic obstructive pulmonary disease (COPD). Few studies investigated the associations between air pollution, meteorological factors, and COPD-related health disorders in Asian countries. This study aimed to investigate the relationship between the environmental factors and COPD-associated ED visits of susceptible elderly population in the largest Taiwanese metropolitan area (Taipei area, including Taipei city and New Taipei city) between 2000 and 2013. Data of air pollutant concentrations (PM10, PM2.5, O3, SO2, NO2 and CO), meteorological factors (daily temperature, relative humidity and air pressure), and daily COPD-associated ED visits were collected from Taiwan Environmental Protection Administration air monitoring stations, Central Weather Bureau stations, and the Taiwan National Health Insurance database in Taipei area. We used a case-crossover study design and conditional logistic regression models with odds ratios (ORs), and 95% confidence intervals (CIs) for evaluating the associations between the environmental factors and COPD-associated ED visits. Analyses showed that PM2.5, O3, and SO2 had significantly greater lag effects (the lag was 4 days for PM2.5, and 5 days for O3 and SO2) on COPD-associated ED visits of the elderly population (65-79 years old). In warmer days, a significantly greater effect on elderly COPD-associated ED visits was estimated for PM2.5 with coexistence of O3. Additionally, either O3 or SO2 combined with other air pollutants increased the risk of elderly COPD-associated ED visits in the days of high relative humidity and air pressure difference, respectively. This study showed that joint effect of urban air pollution and meteorological factors contributed to the COPD-associated ED visits of the susceptible elderly population in the largest metropolitan area in Taiwan. Government authorities should review

  14. The statistical evaluation and comparison of ADMS-Urban model for the prediction of nitrogen dioxide with air quality monitoring network.

    PubMed

    Dėdelė, Audrius; Miškinytė, Auksė

    2015-09-01

    In many countries, road traffic is one of the main sources of air pollution associated with adverse effects on human health and environment. Nitrogen dioxide (NO2) is considered to be a measure of traffic-related air pollution, with concentrations tending to be higher near highways, along busy roads, and in the city centers, and the exceedances are mainly observed at measurement stations located close to traffic. In order to assess the air quality in the city and the air pollution impact on public health, air quality models are used. However, firstly, before the model can be used for these purposes, it is important to evaluate the accuracy of the dispersion modelling as one of the most widely used method. The monitoring and dispersion modelling are two components of air quality monitoring system (AQMS), in which statistical comparison was made in this research. The evaluation of the Atmospheric Dispersion Modelling System (ADMS-Urban) was made by comparing monthly modelled NO2 concentrations with the data of continuous air quality monitoring stations in Kaunas city. The statistical measures of model performance were calculated for annual and monthly concentrations of NO2 for each monitoring station site. The spatial analysis was made using geographic information systems (GIS). The calculation of statistical parameters indicated a good ADMS-Urban model performance for the prediction of NO2. The results of this study showed that the agreement of modelled values and observations was better for traffic monitoring stations compared to the background and residential stations.

  15. Characteristics and transport of organochlorine pesticides in urban environment: air, dust, rain, canopy throughfall, and runoff.

    PubMed

    Zhang, Wei; Ye, Youbin; Hu, Dan; Ou, Langbo; Wang, Xuejun

    2010-11-01

    Characteristics and transport of organochlorine pesticides (OCPs) in urban multiple environments, including air, dust, rain, canopy throughfall, and runoff water, are explored in this study. Hexachlorocyclohexanes (HCHs) dominated in both air and rain water, and dichlorodiphenyltrichloroethane (DDT) related substances showed a higher affinity to dust. Relatively high concentrations of DDT and dichlorodiphenyldichloroethylene (DDE) in air, rain and dust imply that technical DDT in the environment has been degrading, and there may be unknown local or regional emission sources that contain DDTs in the study area. Source identification showed that DDTs in Beijing urban environments with a fresh signature may originate from the atmospheric transport from remote areas. The ratio of α-/γ-HCH in dust, rain, canopy throughfall and runoff were close to 1, indicating the possible use of lindane. OCPs in runoff were transported from various sources including rain, dust, and canopy throughfall. In runoff, DDTs and hexachlorobenzene (HCB) were mainly transported from dust, and HCHs were mainly from rain and canopy throughfall.

  16. Pollutant transfer through air and water pathways in an urban environment

    SciTech Connect

    Brown, M.; Burian, S.; McPherson, T.; Streit, G.; Costigan, K.; Greene, B.

    1998-12-31

    The authors are attempting to simulate the transport and fate of pollutants through air and water pathways in an urban environment. This cross-disciplinary study involves linking together models of mesoscale meteorology, air pollution chemistry and deposition, urban runoff and stormwater transport, water quality, and wetland chemistry and biology. The authors are focusing on the transport and fate of nitrogen species because (1) they track through both air and water pathways, (2) the physics, chemistry, and biology of the complete cycle is not well understood, and (3) they have important health, local ecosystem, and global climate implications. The authors will apply their linked modeling system to the Los Angeles basin, following the fate of nitrates from their beginning as nitrate-precursors produced by auto emissions and industrial processes, tracking their dispersion and chemistry as they are transported by regional winds and eventually wet or dry deposit on the ground, tracing their path as they are entrained into surface water runoff during rain events and carried into the stormwater system, and then evaluating their impact on receiving water bodies such as wetlands where biologically-mediated chemical reactions take place. In this paper, the authors wish to give an overview of the project and at the conference show preliminary results.

  17. Biomagnetic monitoring as a validation tool for local air quality models: a case study for an urban street canyon.

    PubMed

    Hofman, Jelle; Samson, Roeland

    2014-09-01

    Biomagnetic monitoring of tree leaf deposited particles has proven to be a good indicator of the ambient particulate concentration. The objective of this study is to apply this method to validate a local-scale air quality model (ENVI-met), using 96 tree crown sampling locations in a typical urban street canyon. To the best of our knowledge, the application of biomagnetic monitoring for the validation of pollutant dispersion modeling is hereby presented for the first time. Quantitative ENVI-met validation showed significant correlations between modeled and measured results throughout the entire in-leaf period. ENVI-met performed much better at the first half of the street canyon close to the ring road (r=0.58-0.79, RMSE=44-49%), compared to second part (r=0.58-0.64, RMSE=74-102%). The spatial model behavior was evaluated by testing effects of height, azimuthal position, tree position and distance from the main pollution source on the obtained model results and magnetic measurements. Our results demonstrate that biomagnetic monitoring seems to be a valuable method to evaluate the performance of air quality models. Due to the high spatial and temporal resolution of this technique, biomagnetic monitoring can be applied anywhere in the city (where urban green is present) to evaluate model performance at different spatial scales.

  18. Effects of urbanization on occupancy of stream salamanders.

    PubMed

    Price, Steven J; Cecala, Kristen K; Browne, Robert A; Dorcas, Michael E

    2011-06-01

    Urban development is the most common form of land conversion in the United States. Using a before-after control-impact study design, we investigated the effects of urbanization on larval and adult stages of southern two-lined salamanders (Eurycea cirrigera) and northern dusky salamanders (Desmognathus fuscus). Over 5 years, we estimated changes in occupancy and probabilities of colonization and survival in 13 stream catchments after urbanization and in 17 catchments that were not urbanized. We also examined effects of proportion of urbanized area in a catchment and distance of the salamander population to the nearest stream on probabilities of colonization and survival. Before urbanization, adult and larval stages of the two salamander species occupied nearly all surveyed streams, with occupancy estimates ranging from 1.0 to 0.78. Four years after urbanization mean occupancy of larval and adult two-lined salamanders had decreased from 0.87 and 0.78 to 0.57 and 0.39, respectively. Estimates of mean occupancy of larval northern dusky salamanders decreased from 1.0 to 0.57 in urban streams 4 years after urbanization; however, adult northern dusky salamander occupancy remained close to 1.0 in urban streams over 5 years. Occupancy estimates in control streams were similar for each species and stage over 5 years. Urbanization was associated with decreases in survival probabilities of adult and larval two-lined salamanders and decreases in colonization probabilities of larval dusky salamanders. Nevertheless, proportion of impervious surface and distance to nearest stream had little effect on probabilities of survival and colonization. Our results imply that in the evaluation of the effects of urbanization on species, such as amphibians, with complex life cycles, consideration of the effects of urbanization on both adult and larval stages is required.

  19. Participatory measurements of individual exposure to air pollution in urban areas

    NASA Astrophysics Data System (ADS)

    Madelin, Malika; Duché, Sarah; Dupuis, Vincent

    2016-04-01

    Air pollution is a major environmental issue in urban areas. Chronic and high concentration exposure presents a health risk with cardiovascular and respiratory problems and longer term nervous, carcinogenic and endocrine problems. In addition to the estimations based on simulations of both background and regional pollution and of the pollution induced by the traffic, knowing exposure of each individual is a key issue. This exposure reflects the high variability of pollution at fine spatial and time scales, according to the proximity of emission sources and the urban morphology outside. The emergence of citizen science and the progress of miniaturized electronics, low-cost and accessible to (almost) everyone, offers new opportunities for the monitoring of air pollution, but also for the citizens' awareness of their individual exposure to air pollution. In this communication, we propose to present a participatory research project 'What is your air?' (project funded by the Île-de-France region), which aims at raising awareness on the theme of air quality, its monitoring with sensors assembled in a FabLab workshop and an online participatory mapping. Beyond the discussion on technical choices, the stages of manufacture or the sensor calibration procedures, we discuss the measurements made, in this case the fine particle concentration measurements, which are dated and georeferenced (communication via a mobile phone). They show high variability between the measurements (in part linked to the substrates, land use, traffic) and low daily contrasts. In addition to the analysis of the measurements and their comparison with the official data, we also discuss the choice of representation of information, including mapping, and therefore the message about pollution to communicate.

  20. High Resolution Aerosol Data from MODIS Satellite for Urban Air Quality Studies

    NASA Technical Reports Server (NTRS)

    Chudnovsky, A.; Lyapustin, A.; Wang, Y.; Tang, C.; Schwartz, J.; Koutrakis, P.

    2013-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) provides daily global coverage, but the 10 km resolution of its aerosol optical depth (AOD) product is not suitable for studying spatial variability of aerosols in urban areas. Recently, a new Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm was developed for MODIS which provides AOD at 1 km resolution. Using MAIAC data, the relationship between MAIAC AOD and PM(sub 2.5) as measured by the 27 EPA ground monitoring stations was investigated. These results were also compared to conventional MODIS 10 km AOD retrievals (MOD04) for the same days and locations. The coefficients of determination for MOD04 and for MAIAC are R(exp 2) =0.45 and 0.50 respectively, suggested that AOD is a reasonably good proxy for PM(sub 2.5) ground concentrations. Finally, we studied the relationship between PM(sub 2.5) and AOD at the intra-urban scale (10 km) in Boston. The fine resolution results indicated spatial variability in particle concentration at a sub-10 kilometer scale. A local analysis for the Boston area showed that the AOD-PM(sub 2.5) relationship does not depend on relative humidity and air temperatures below approximately 7 C. The correlation improves for temperatures above 7 - 16 C. We found no dependence on the boundary layer height except when the former was in the range 250-500 m. Finally, we apply a mixed effects model approach to MAIAC aerosol optical depth (AOD) retrievals from MODIS to predict PM(sub 2.5) concentrations within the greater Boston area. With this approach we can control for the inherent day-to-day variability in the AOD-PM(sub 2.5) relationship, which depends on time-varying parameters such as particle optical properties, vertical and diurnal concentration profiles and ground surface reflectance. Our results show that the model-predicted PM(sub 2.5) mass concentrations are highly correlated with the actual observations (out-of-sample R(exp 2) of 0.86). Therefore, adjustment

  1. Urbanization impacts on mammals across urban-forest edges and a predictive model of edge effects.

    PubMed

    Villaseñor, Nélida R; Driscoll, Don A; Escobar, Martín A H; Gibbons, Philip; Lindenmayer, David B

    2014-01-01

    With accelerating rates of urbanization worldwide, a better understanding of ecological processes at the wildland-urban interface is critical to conserve biodiversity. We explored the effects of high and low-density housing developments on forest-dwelling mammals. Based on habitat characteristics, we expected a gradual decline in species abundance across forest-urban edges and an increased decline rate in higher contrast edges. We surveyed arboreal mammals in sites of high and low housing density along 600 m transects that spanned urban areas and areas turn on adjacent native forest. We also surveyed forest controls to test whether edge effects extended beyond our edge transects. We fitted models describing richness, total abundance and individual species abundance. Low-density housing developments provided suitable habitat for most arboreal mammals. In contrast, high-density housing developments had lower species richness, total abundance and individual species abundance, but supported the highest abundances of an urban adapter (Trichosurus vulpecula). We did not find the predicted gradual decline in species abundance. Of four species analysed, three exhibited no response to the proximity of urban boundaries, but spilled over into adjacent urban habitat to differing extents. One species (Petaurus australis) had an extended negative response to urban boundaries, suggesting that urban development has impacts beyond 300 m into adjacent forest. Our empirical work demonstrates that high-density housing developments have negative effects on both community and species level responses, except for one urban adapter. We developed a new predictive model of edge effects based on our results and the literature. To predict animal responses across edges, our framework integrates for first time: (1) habitat quality/preference, (2) species response with the proximity to the adjacent habitat, and (3) spillover extent/sensitivity to adjacent habitat boundaries. This framework will

  2. Particle size distribution and air pollution patterns in three urban environments in Xi'an, China.

    PubMed

    Niu, Xinyi; Guinot, Benjamin; Cao, Junji; Xu, Hongmei; Sun, Jian

    2015-10-01

    Three urban environments, office, apartment and restaurant, were selected to investigate the indoor and outdoor air quality as an inter-comparison in which CO2, particulate matter (PM) concentration and particle size ranging were concerned. In this investigation, CO2 level in the apartment (623 ppm) was the highest among the indoor environments and indoor levels were always higher than outdoor levels. The PM10 (333 µg/m(3)), PM2.5 (213 µg/m(3)), PM1 (148 µg/m(3)) concentrations in the office were 10-50% higher than in the restaurant and apartment, and the three indoor PM10 levels all exceeded the China standard of 150 µg/m(3). Particles ranging from 0.3 to 0.4 µm, 0.4 to 0.5 µm and 0.5 to 0.65 µm make largest contribution to particle mass in indoor air, and fine particles number concentrations were much higher than outdoor levels. Outdoor air pollution is mainly affected by heavy traffic, while indoor air pollution has various sources. Particularly, office environment was mainly affected by outdoor sources like soil dust and traffic emission; apartment particles were mainly caused by human activities; restaurant indoor air quality was affected by multiple sources among which cooking-generated fine particles and the human steam are main factors.

  3. Revisiting Atmospheric Lead in NYC - Comparison of Archived Air Filters to Urban Park Sediments and Soils

    NASA Astrophysics Data System (ADS)

    Chillrud, S. N.; Ross, J. M.; Yan, B.; Bopp, R.

    2015-12-01

    Urban lake sediments have the potential to be used for reconstructing history of aerosols, providing data before the start of urban air quality monitoring. In a previous study, the similarity between radionuclide and excess Pb inventories (57 g/m^2) in Central Park Lake (CPL) sediments and those same parameters in Central Park soils (CPS) was interpreted to indicate that urban lake sediment cores from CPL represent deposition of atmospheric aerosols over the history of the park, which was constructed in the 1860s. Furthermore, metal ratios and metal chronologies indicated that incineration was the major source of Pb to the NYC atmosphere over the 20th century. In this report, we compare the lake chronologies for metals to a set of archived air filters collected by the Department of Energy's Environmental Measurement Lab (EML). These weekly filters of total suspended particulates (TSP) were collected by a high volume sampler located in lower Manhattan for radionuclides as part of the program focused on documenting radioactive fallout from nuclear weapons testing. Metal concentrations measured in subsamples of the EML filters collected between the 1970s to 1990s showed Pb decreasing more slowly than the records of Pb added to gasoline. Metal ratios in the filters were similar to the ratios measured in CPL sediments; the Pb to Sn ratios were roughly 20:1 and the Pb to Zn ratios were in close to 1. The similarity of the ratios provides additional solid support that the CP Lake sediment cores reflect atmospheric inputs. The enrichment of Pb in the large aerosol particle fraction (TSP), relative to fine PM2.5 fraction, demonstrates that the resuspended NYC soils and their historical contaminant burden, are the primary, current source of Pb to NYC air.

  4. 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.

  5. Air-leakage effects on stone cladding panels

    NASA Astrophysics Data System (ADS)

    Colantonio, Antonio

    1995-03-01

    This paper looks at the effects of air leakage on insulated stone clad precast panels used in present day construction of large commercial buildings. The building investigated was a newly built twenty story office building in a high density urban setting. Air leakage was suspected as a possible cause for thermal comfort complaints at isolated locations within the perimeter zones of the building. During the warrantee period the building owner asked for a quality control inspection of the air barrier assembly of the building envelope. Infrared thermography was used to locate areas of suspected air leakage within the building envelope. In order to differentiate thermal patterns produced by air leakage, conduction and convection as well as radiation from external sources, the building was inspected from the exterior; (1) after being pressurized for three hours, (2) one hour after the building was depressurized and (3) two and a half hours after total building depressurization was maintained by the building mechanical systems. Thermal images from similar locations were correlated for each time and pressure setting to verify air leakage locations within the building envelope. Areas exhibiting air leakage were identified and contractors were requested to carry out the necessary repairs. The pressure differential across the building envelope needs to be known in order to properly carry out an inspection to identify all locations of air leakage within a building envelope. As well the direction of the air movement and the density of the cladding material need to be accounted for in the proper inspection of these types of wall assemblies.

  6. Cooling Effect of Evapotranspiration (ET) and ET Measurement by Thermal Remote Sensing in Urban

    NASA Astrophysics Data System (ADS)

    Qiu, G. Y.; Yang, B.; Li, X.; Guo, Q.; Tan, S.

    2015-12-01

    Affected by global warming and rapid urbanization, urban thermal environment and livability are getting worse over the world. Global terrestrial evapotranspiration (ET) can annually consume 1.483 × 1023 joules of solar energy, which is about 300 times of the annual human energy use on the earth (4.935×1020 joules). This huge amount of energy use by ET indicates that there is great potential to cool the urban by regulating ET. However, accurately measurement of urban ET is quiet difficult because of the great spatial heterogeneity in urban. This study focuses on to quantify the cooling effects ET by mobile traverse method and improve a methodology to measure the urban ET by thermal remote sensing. The verifying experiment was carried out in Shenzhen, a sub-tropical mega city in China. Results showed that ET of vegetation could obviously reduce the urban temperature in hot season. Daily transpiration rate of a small-sized Ficus tree (Ficus microcarpa, 5 m in height and 20 cm of trunk diameter, measured by sap-flow method) was 36-55 kg and its cooling effect was equivalent to a 1.6-2.4 kWh air conditioner working for 24 hours. A 10% increase in the vegetated area could decrease urban temperature by 0.60°C at hot night. Moreover, it was found that a region with a vegetated area ratio over 55% had obvious effect on temperature decreasing. In addition, a methodology by using "thermal remote sensing + three-temperature model" was improved to measure the urban ET. Results showed that the urban ET could be reasonably measured by the proposed method. The daily ET of an urban lawn was 0.01-2.86 mm and monthly ET was 21-60 mm. This result agreed well with the verification study (Bowen ratio method, r=0.953). These results are very useful for urban planning, urban lower impact development, and improving of urban thermal environment.

  7. Solar driven nitrous acid formation on building material surfaces containing titanium dioxide: A concern for air quality in urban areas?

    NASA Astrophysics Data System (ADS)

    Langridge, Justin M.; Gustafsson, R. Joel; Griffiths, Paul T.; Cox, R. Anthony; Lambert, Richard M.; Jones, Roderic L.

    The photoenhanced uptake of nitrogen dioxide (NO 2) to the surface of commercially available self-cleaning window glass has been studied under controlled laboratory conditions. This material is one of an array of modern building products which incorporate titanium dioxide (TiO 2) nanoparticles and are finding increasing use in populated urban areas. Amongst the principal drivers for the use of these materials is that they are thought to facilitate the irreversible removal of pollutants such as NO 2 and organic molecules from the atmosphere and thus act to remediate air quality. While it appears that TiO 2 materials do indeed remove organic molecules from built environments, in this study we show that the photoenhanced uptake of NO 2 to one example material, self-cleaning window glass, is in fact accompanied by the substantial formation (50-70%) of gaseous nitrous acid (HONO). This finding has direct and serious implications for the use of these materials in urban areas. Not only is HONO a harmful respiratory irritant, it is also readily photolysed by solar radiation leading to the formation of hydroxyl radicals (OH) together with the re-release of NO x as NO. The net effect of subsequent OH initiated chemistry can then be the further degradation of air quality through the formation of secondary pollutants such as ozone and VOC oxidation products. In summary, we suggest that a scientifically conceived technical strategy for air quality remediation based on this technology, while widely perceived as universally beneficial, could in fact have effects precisely opposite to those intended.

  8. Hydrocarbon emissions from twelve urban shade trees of the Los Angeles, California, Air Basin

    NASA Astrophysics Data System (ADS)

    Corchnoy, Stephanie B.; Arey, Janet; Atkinson, Roger

    The large-scale planting of shade trees in urban areas to counteract heat-island effects and to minimize energy use is currently being discussed. Among the costs to be considered in a cost/benefit analysis of such a program is the potential for additional reactive organic compounds in the atmosphere due to emissions from these trees. In this program, 15 species of potential shade trees for the Los Angeles Air Basin were studied and emission rates were determined for 11 of these trees, with one further tree (Crape myrtle) exhibiting no detectable emissions. The emission rates normalized to dry leaf weight and corrected to 30°C were (in μg g -1 h -1), ranked from lowest to highest emission rate: Crape myrtle, none detected; Camphor, 0.03; Aleppo pine, 0.15; Deodar cedar, 0.29; Italian Stone pine, 0.42; Monterey pine, 0.90; Brazilian pepper, 1.3; Canary Island pine, 1.7; Ginkgo, 3.0; California pepper, 3.7; Liquidambar, 37; Carrotwood, 49. In addition to the emission rates per unit biomass, the biomass per tree must be factored into any assessment of the relative merits of the various trees, since some trees have higher biomass constants than others. The present data shows that there are large differences in emission rates among different tree species and this should be factored into decision-making as to which shade trees to plant. Based solely on the presently determined emission rates, the Crape myrtle and Camphor tree are good choices for large-scale planting, while the Carrotwood tree and Liquidambar are poor choices due to their high isoprene emission rates.

  9. Factors influencing indoor air quality in an urban high rise apartment building (retitled as "Air Pollution and air exchange in an urban high rise apartment building")

    EPA Science Inventory

    The National Exposure Research Laboratory (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA mission to protect human health and the environment. HEASD research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EP...

  10. Disentangling urban habitat and matrix effects on wild bee species

    PubMed Central

    2016-01-01

    In face of a dramatic decline of wild bee species in many rural landscapes, potential conservation functions of urban areas gain importance. Yet effects of urbanization on pollinators, and in particular on wild bees, remain ambiguous and not comprehensively understood. This is especially true for amenity grassland and extensively managed wastelands within large-scale residential housing areas. Using Berlin as a study region, we aimed to investigate (a) if these greenspaces are accepted by wild bee assemblages as foraging habitats; (b) how assemblage structure of bees and individual bee species are affected by different habitat (e.g., management, flower density) and urban matrix variables (e.g., isolation, urbanization); and (c) to what extent grassland restoration can promote bees in urban environments. In summer 2012, we collected 62 bee species belonging to more than 20% of the taxa known for Berlin. Urbanization significantly affected species composition of bees; 18 species were affiliated to different levels of urbanization. Most bee species were not affected by any of the environmental variables tested, and urbanization had a negative effect only for one bee species. Further, we determined that restoration of diverse grasslands positively affected bee species richnesss in urban environments. We conclude that differently structured and managed greenspaces in large-scale housing areas can provide additional foraging habitats and refuges for pollinators. This supports approaches towards a biodiversity friendly management within urban regions and may be of particular importance given that anthropogenic pressure is increasing in many rural landscapes. PMID:27917318

  11. Effects of urban sprawl on obesity.

    PubMed

    Zhao, Zhenxiang; Kaestner, Robert

    2010-12-01

    In this paper, we examine the effect of changes in population density-urban sprawl-between 1970 and 2000 on BMI and obesity of residents in metropolitan areas in the U.S. We address the possible endogeneity of population density by using a two-step instrumental variables approach. We exploit the plausibly exogenous variation in population density caused by the expansion of the U.S. Interstate Highway System, which largely followed the original 1947 plan for the Interstate Highway System. We find a negative association between population density and obesity, and estimates are robust across a wide range of specifications. Estimates indicate that if the average metropolitan area had not experienced the decline in the proportion of population living in dense areas over the last 30 years, the rate of obesity would have been reduced by approximately 13%.

  12. Pollution Response Score of Tree Species in Relation to Ambient Air Quality in an Urban Area.

    PubMed

    Mukherjee, Arideep; Agrawal, Madhoolika

    2016-02-01

    Multivariate statistical techniques were employed on twelve leaf traits in four selected common tree species (Mangifera indica L., Polyalthia longifolia Sonn., Ficus benghalensis L. and Psidium guajava L.) to evaluate their responses with respect to major air pollutants in an urban area. Discriminant analysis (DA) identified chlorophyll/carotenoid ratio, leaf dry matter content, carotenoids, net water content and ascorbic acid as the major discriminating leaf traits, which varied maximally with respect to the pollution status. Pollution response score (PRS), calculated on the basis of discriminate functional coefficient values, increased with an increase in air pollution variables for all the tested species, with the highest increase in P. longifolia and the lowest in F. benghalensis. The study highlights the usefulness of DA for evaluation of plant specific traits and PRS for selection of tolerant species.

  13. Spatial and temporal patterns of air pollutants in rural and urban areas of India.

    PubMed

    Sharma, Disha; Kulshrestha, U C

    2014-12-01

    In this study, we analysed spatial and temporal patterns of Suspended Particulate Matter (SPM) concentrations across India. We have also assessed MODIS-derived aerosol optical depth (AOD) variations to characterize the air quality and relate it to SPM, NO2 and SO2 in different areas. In addition, the pollutant concentrations have been mapped using geospatial techniques. The results indicated significant differences in air pollutant levels across rural and urban areas. In general, districts of central and northern India had relatively higher SPM concentrations compared to southern India. Out of the top ten SPM polluted districts in India, nine were located in the state of Uttar Pradesh (UP). We observed significant correlations between the SPM and AOD at different sites. Although spatial and temporal patterns of NO2 and SO2 matched AOD patterns, the correlation strength (r2) varied based on location. The causes and implications of these findings are presented.

  14. Winter climate change effects on soil C and N cycles in urban grasslands.

    PubMed

    Durán, Jorge; Rodríguez, Alexandra; Morse, Jennifer L; Groffman, Peter M

    2013-09-01

    Despite growing recognition of the role that cities have in global biogeochemical cycles, urban systems are among the least understood of all ecosystems. Urban grasslands are expanding rapidly along with urbanization, which is expected to increase at unprecedented rates in upcoming decades. The large and increasing area of urban grasslands and their impact on water and air quality justify the need for a better understanding of their biogeochemical cycles. There is also great uncertainty about the effect that climate change, especially changes in winter snow cover, will have on nutrient cycles in urban grasslands. We aimed to evaluate how reduced snow accumulation directly affects winter soil frost dynamics, and indirectly greenhouse gas fluxes and the processing of carbon (C) and nitrogen (N) during the subsequent growing season in northern urban grasslands. Both artificial and natural snow reduction increased winter soil frost, affecting winter microbial C and N processing, accelerating C and N cycles and increasing soil : atmosphere greenhouse gas exchange during the subsequent growing season. With lower snow accumulations that are predicted with climate change, we found decreases in N retention in these ecosystems, and increases in N2 O and CO2 flux to the atmosphere, significantly increasing the global warming potential of urban grasslands. Our results suggest that the environmental impacts of these rapidly expanding ecosystems are likely to increase as climate change brings milder winters and more extensive soil frost.

  15. Exposure to urban air pollution and bone health in clinically healthy six-year-old children.

    PubMed

    Calderón-Garcidueñas, Lilian; Mora-Tiscareño, Antonieta; Francolira, Maricela; Torres-Jardón, Ricardo; Peña-Cruz, Bernardo; Palacios-López, Carolina; Zhu, Hongtu; Kong, Linglong; Mendoza-Mendoza, Nicolás; Montesinoscorrea, Hortencia; Romero, Lina; Valencia-Salazar, Gildardo; Kavanaugh, Michael; Frenk, Silvestre

    2013-01-01

    Air pollution induces systemic inflammation, as well as respiratory, myocardial and brain inflammation in children. Peak bone mass is influenced by environmental factors. We tested the hypothesis that six-year-olds with lifetime exposures to urban air pollution will have alterations in inflammatory markers and bone mineral density (BMD) as opposed to low-polluted city residents when matched for BMI, breast feeding history, skin phototype, age, sex and socioeconomic status. This pilot study included 20 children from Mexico City (MC) (6.17 years ± 0.63 years) and 15 controls (6.27 years ± 0.76 years). We performed full paediatric examinations, a history of outdoor exposures, seven-day dietary recalls, serum inflammatory markers and dual-energy X-ray absorptiometry (DXA). Children in MC had significantly higher concentrations of IL-6 (p=0.001), marked reductions in total blood neutrophils (p= 0.0002) and an increase in monocytes (p=0.005). MC children also had an insufficient Vitamin D intake and spent less time outdoors than controls (p<0.001) in an environment characterized by decreased UV light, with ozone and fine particulates concentrations above standard values. There were no significant differences between the cohorts in DXA Z scores. The impact of systemic inflammation, vitamin D insufficiency, air pollution, urban violence and poverty may have long-term bone detrimental outcomes in exposed paediatric populations as they grow older, increasing the risk of low bone mass and osteoporosis. The selection of reference populations for DXA must take into account air pollution exposures.

  16. 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

  17. Opportunities for Saving Energy and Improving Air Quality in Urban Heat Islands

    SciTech Connect

    Akbari, Hashem

    2007-07-01

    World energy use is the main contributor to atmospheric CO2. In 2002, about 7.0 giga metric tons of carbon (GtC) were emitted internationally by combustion of gas, liquid, and solid fuels (CDIAC, 2006), 2 to 5 times the amount contributed by deforestation (Brown et al., 1988). The share of atmospheric carbon emissions for the United States from fossil fuel combustion was 1.6 GtC. Increasing use of fossil fuel and deforestation together have raised atmospheric CO{sub 2} concentration some 25% over the last 150 years. According to global climate models and preliminary measurements, these changes in the composition of the atmosphere have already begun raising the Earth's average temperature. If current energy trends continue, these changes could drastically alter the Earth's temperature, with unknown but potentially catastrophic physical and political consequences. During the last three decades, increased energy awareness has led to conservation efforts and leveling of energy consumption in the industrialized countries. An important byproduct of this reduced energy use is the lowering of CO{sub 2} emissions. Of all electricity generated in the United States, about one-sixth is used to air-condition buildings. The air-conditioning use is about 400 tera-watt-hours (TWh), equivalent to about 80 million metric tons of carbon (MtC) emissions, and translating to about $40 billion (B) per year. Of this $40 B/year, about half is used in cities that have pronounced 'heat islands'. The contribution of the urban heat island to the air-conditioning demand has increased over the last 40 years and it is currently at about 10%. Metropolitan areas in the United States (e.g., Los Angeles, Phoenix, Houston, Atlanta, and New York City) have typically pronounced heat islands that warrant special attention by anyone concerned with broad-scale energy efficiency (HIG, 2006). The ambient air is primarily heated through three processes: direct absorption of solar radiation, convection of heat

  18. Impact assessment of PM10 cement plants emissions on urban air quality using the SCIPUFF dispersion model.

    PubMed

    Leone, Vincenzo; Cervone, Guido; Iovino, Pasquale

    2016-09-01

    The Second-order Closure Integrated Puff (SCIPUFF) model was used to study the impact on urban air quality caused by two cement plants emissions located near the city of Caserta, Italy, during the entire year of 2015. The simulated and observed PM10 concentrations were compared using three monitoring stations located in urban and sub-urban area of Caserta city. Both simulated and observed concentrations are shown to be highest in winter, lower in autumn and spring and lowest in summer. Model results generally follow the pattern of the observed concentrations but have a systematic under-prediction of the concentration values. Measures of the bias, NMSE and RMSE indicate a good correlation between observed and estimated values. The SCIPUFF model data analysis suggest that the cement plants are major sources for the measured PM10 values and are responsible for the deterioration of the urban air quality in the city of Caserta.

  19. A low-cost sensing system for cooperative air quality monitoring in urban areas.

    PubMed

    Brienza, Simone; Galli, Andrea; Anastasi, Giuseppe; Bruschi, Paolo

    2015-05-26

    Air quality in urban areas is a very important topic as it closely affects the health of citizens. Recent studies highlight that the exposure to polluted air can increase the incidence of diseases and deteriorate the quality of life. Hence, it is necessary to develop tools for real-time air quality monitoring, so as to allow appropriate and timely decisions. In this paper, we present uSense, a low-cost cooperative monitoring tool that allows knowing, in real-time, the concentrations of polluting gases in various areas of the city. Specifically, users monitor the areas of their interest by deploying low-cost and low-power sensor nodes. In addition, they can share the collected data following a social networking approach. uSense has been tested through an in-field experimentation performed in different areas of a city. The obtained results are in line with those provided by the local environmental control authority and show that uSense can be profitably used for air quality monitoring.

  20. Influence of Ship Emissions on Urban Air Quality: A Comprehensive Study Using Highly Time-Resolved Online Measurements and Numerical Simulation in Shanghai.

    PubMed

    Liu, Zhanmin; Lu, Xiaohui; Feng, Junlan; Fan, Qianzhu; Zhang, Yan; Yang, Xin

    2017-01-03

    Shanghai has become an international shipping center in the world. In this study, the multiyear measurements and the high resolution air quality model with hourly ship emission inventory were combined to determine the influence of ship emissions on urban Shanghai. The aerosol time-of-flight mass spectrometer (ATOFMS) measurements were carried out at an urban site from April 2009 to January 2013. During the entire sampling time, most of the half-hourly averaged number fractions of primary ship emitted particles varied between 1.0-10.0%. However, the number fraction could reach up to 50% during the ship plume cases. Ship-plume-influenced periods usually occurred in spring and summer. The simulation of Weather Research and Forecasting/Community Multiscale Air Quality model (WRF/CMAQ) with hourly ship emission inventory provided the highly time-resolved concentrations of ship-related air pollutants during a ship plume case. It showed ships could contribute 20-30% (2-7 μg/m(3)) of the total PM2.5 within tens of kilometers of coastal and riverside Shanghai during ship-plume-influenced periods. Our results showed that ship emissions have substantial contribution to the air pollution in urban Shanghai. The control measures of ship emission should be taken considering its negative environment and human health effects.

  1. Sources of organochlorine pesticides in air in an urban Mediterranean environment: volatilisation from soil.

    PubMed

    Lammel, Gerhard; Klánová, Jana; Erić, Ljiljana; Ilić, Predrag; Kohoutek, Jiří; Kovacić, Igor

    2011-12-01

    Organochlorine pesticide (OCP) cycling was studied in the area of Banja Luka, Bosnia and Herzegovina, over 3 days in summer with high temporal (4 h-means) and spatial (3 sites distanced 3-6 km) resolutions. Elevated levels of DDX compounds (i.e. o,p'- and p,p'-isomers of DDT, DDE and DDD, 44-74 pg m(-3) at the urban sites and 27 pg m(-3) as a background level), HCH (α-, β- and γ-isomers, 52-70 vs. 147 pg m(-3)), HCB (34-48 vs. <0.1 pg m(-3)) and pentachlorobenzene (6.8-9.9 vs. 6.0 pg m(-3)) were found. The variation of OCP levels at the two urban sites was not in phase, except for most DDX compounds. This was related to background levels, which for HCH were higher than in the urban area. Vertical profiles between samples collected from 1.1 and 2.3 m (part of the time 0.6 and 2.3 m) above a soil, which was only moderately contaminated by OCPs (0.12 ng g(-1) HCH, 0.11 ng g(-1) DDX, 0.44 ng g(-1) HCB) were analysed. Volatilisation from the ground caused negative vertical concentration gradients of HCH isomers (day and night), but not for HCB (except for 1 day-time sample) and DDX compounds (except p,p'-DDD, day-time, sporadically). The concentration in air and the vertical concentration gradient of the HCH isomers varied with air temperature (day-time maxima), while the variation of the HCB concentration was inversely related to air temperature and was determined by mixing (night-time maxima). α- and β-HCH were volatilised from soil throughout the three days, even during periods of cooling. Fugacity calculations, based on the absorption in soil organic matter as the process determining retention in soil, underestimated the volatilisation of β-HCH and p,p'-DDD. It is concluded that the representativeness of point measurements of OCPs in urban areas is limited by the spatial variability of soil contamination.

  2. A field evaluation of a SO 2 passive sampler in tropical industrial and urban air

    NASA Astrophysics Data System (ADS)

    Cruz, Lícia P. S.; Campos, Vânia P.; Silva, Adriana M. C.; Tavares, Tania M.

    Passive samplers have been widely used for over 30 years in the measurement of personal exposure to vapours and gases in the workplace. These samplers have just recently been applied in the monitoring of ambient air, which presents concentrations that are normally much smaller than those found in occupational environments. The locally constructed passive sampler was based on gas molecular diffusion through static air layer. The design used minimizes particle interference and turbulent diffusion. After exposure, the SO 2 trapped in impregnated filters with Na 2CO 3 was extracted by means of an ultrasonic bath, for 15 min, using 1.0×10 -2 mol L -1 H 2O 2. It was determined as SO 4-2 by ion chromatography. The performance of the passive sampler was evaluated at different exposure periods, being applied in industrial and urban areas. Method precision as relative standard deviation for three simultaneously applied passive samplers was within 10%. Passive sampling, when compared to active monitoring methods under real conditions, used in urban and industrial areas, showed an overall accuracy of 15%. A statistical comparison with an active method was performed to demonstrate the validity of the passive method. Sampler capacity varied between 98 and 421 μg SO 2 m -3 for exposure periods of one month and one week, respectively, which allows its use in highly polluted areas.

  3. Air quality modeling in the Oviedo urban area (NW Spain) by using multivariate adaptive regression splines.

    PubMed

    Nieto, P J García; Antón, J C Álvarez; Vilán, J A Vilán; García-Gonzalo, E

    2015-05-01

    The aim of this research work is to build a regression model of air quality by using the multivariate adaptive regression splines (MARS) technique in the Oviedo urban area (northern Spain) at a local scale. To accomplish the objective of this study, the experimental data set made up of nitrogen oxides (NO x ), carbon monoxide (CO), sulfur dioxide (SO2), ozone (O3), and dust (PM10) was collected over 3 years (2006-2008). The US National Ambient Air Quality Standards (NAAQS) establishes the limit values of the main pollutants in the atmosphere in order to ensure the health of healthy people. Firstly, this MARS regression model captures the main perception of statistical learning theory in order to obtain a good prediction of the dependence among the main pollutants in the Oviedo urban area. Secondly, the main advantages of MARS are its capacity to produce simple, easy-to-interpret models, its ability to estimate the contributions of the input variables, and its computational efficiency. Finally, on the basis of these numerical calculations, using the MARS technique, conclusions of this research work are exposed.

  4. ADVANCED URBANIZED METEOROLOGICAL MODELING AND AIR QUALITY SIMULATIONS WITH CMAQ AT NEIGHBORHOOD SCALES

    EPA Science Inventory

    We present results from a study testing the new boundary layer parameterization method, the canopy drag approach (DA) which is designed to explicitly simulate the effects of buildings, street and tree canopies on the dynamic, thermodynamic structure and dispersion fields in urban...

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

    SciTech Connect

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

    1986-01-01

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

  6. Occurrence of pesticides in rain and air in urban and agricultural areas of Mississippi, April-September 1995

    USGS Publications Warehouse

    Coupe, R.H.; Manning, M.A.; Foreman, W.T.; Goolsby, D.A.; Majewski, M.S.

    2000-01-01

    In April 1995, the US Geological Survey began a study to determine the occurrence and temporal distribution of 49 pesticides and pesticide metabolites in air and rain samples from an urban and an agricultural sampling site in Mississippi. The study was a joint effort between the National Water-Quality Assessment and the Toxic Substances Programs and was part of a larger study examining the occurrence and temporal distribution of pesticides in air and rain in the Mississippi River basin. Concurrent high-volume air and wet-only deposition samples were collected weekly. The air samplers consisted of a glass-fiber filter to collect particles and tandem polyurethane foam plugs to collect gas-phase pesticides. Every rain and air sample collected from the urban and agricultural sites had detectable levels of multiple pesticides. The magnitude of the total concentration was 5-10 times higher at the agricultural site as compared to the urban site. The pesticide with the highest concentration in rain at both sites was methyl parathion. The pesticide with the highest concentration in the air samples from the agricultural site was also methyl parathion, but from the urban site the highest concentration was diazinon followed closely by chlorpyrifos. More than two decades since p,p'-DDT was banned from use in the United States, p,p'-DDE, a metabolite of p,p'-DDT, was detected in every air sample collected from the agricultural site and in more than half of the air samples from the urban site. Copyright (C) 2000 Elsevier Science B.V.

  7. The footprint of urban heat island effect in China.

    PubMed

    Zhou, Decheng; Zhao, Shuqing; Zhang, Liangxia; Sun, Ge; Liu, Yongqiang

    2015-06-10

    Urban heat island (UHI) is one major anthropogenic modification to the Earth system that transcends its physical boundary. Using MODIS data from 2003 to 2012, we showed that the UHI effect decayed exponentially toward rural areas for majority of the 32 Chinese cities. We found an obvious urban/rural temperature "cliff", and estimated that the footprint of UHI effect (FP, including urban area) was 2.3 and 3.9 times of urban size for the day and night, respectively, with large spatiotemporal heterogeneities. We further revealed that ignoring the FP may underestimate the UHI intensity in most cases and even alter the direction of UHI estimates for few cities. Our results provide new insights to the characteristics of UHI effect and emphasize the necessity of considering city- and time-specific FP when assessing the urbanization effects on local climate.

  8. The footprint of urban heat island effect in China

    PubMed Central

    Zhou, Decheng; Zhao, Shuqing; Zhang, Liangxia; Sun, Ge; Liu, Yongqiang

    2015-01-01

    Urban heat island (UHI) is one major anthropogenic modification to the Earth system that transcends its physical boundary. Using MODIS data from 2003 to 2012, we showed that the UHI effect decayed exponentially toward rural areas for majority of the 32 Chinese cities. We found an obvious urban/rural temperature “cliff”, and estimated that the footprint of UHI effect (FP, including urban area) was 2.3 and 3.9 times of urban size for the day and night, respectively, with large spatiotemporal heterogeneities. We further revealed that ignoring the FP may underestimate the UHI intensity in most cases and even alter the direction of UHI estimates for few cities. Our results provide new insights to the characteristics of UHI effect and emphasize the necessity of considering city- and time-specific FP when assessing the urbanization effects on local climate. PMID:26060039

  9. Analysis of Regional Climate Changes adjusted Future Urban Growth Scenarios and possibility of the future air quality prediction in Seoul Metropolitan Area (SMA), Korea

    NASA Astrophysics Data System (ADS)

    Kim, H.; Kim, Y.; Jeong, J.

    2012-12-01

    Land-use changes give effects to physical properties such as albedo, moisture availability and roughness length in the atmosphere, but future urban growth has not been considered widely to predict the future regional climate change because it is hard to predict the future land-use changes. In this study, we used the urban growth model called SLEUTH (Slope, Land-use, Excluded, Urban, Transportation, Hill-shade) based on Cellular Automata (CA) technique to predict the future land-use (especially, urban growth) changes. Seoul Metropolitan Area (SMA), the research area in this study, is the most explosively developed region in the Korean peninsula due to the continuous industrialization since 1970s. SLEUTH was calibrated to know the pattern and process of the urban growth and expansion in SMA with historical data for 35 years (1975-2000) provided from WAter Management Information System (WAMIS) in Korea and then future urban growth was projected out to 2050 assuming three different scenarios: (1) historical trends of urban growth (SC1), (2) future urban policy and plan (SC2), (3) ecological protection and growth (SC3). We used the FNL data of NCEP/NCAR for one month, Oct. in 2005 to evaluate the performance of the WRF on the long-term climate simulation and compared results of WRF with the ASOS/AWS (Automated Surface Observing Systems and Automated Weather System) observation data of the Korea Meteorology Administration. Based on the accuracy of the model, we performed various numerical experiments by the urban growth scenarios using the 6 hourly data of ECHAM5/OM-1 A1B scenarios generated by Max-Plank Institute for Meteorology in Hamburg, Germany on Oct. for 5 years (2046-2050), respectively. The difference of urban ratio under various urban growth scenarios in SMA consequently caused the spatial distributions of temperature to change, the average temperature to increase in the urban area. PBL height with a maximum of about 200m also appeared locally in newly

  10. The 1977 emissions inventory for southeastern Virginia. [environment model of air quality based on exhaust emission from urban areas

    NASA Technical Reports Server (NTRS)

    Brewer, D. A.; Remsberg, E. E.; Woodbury, G. E.; Quinn, L. C.

    1979-01-01

    Regional tropospheric air pollution modeling and data compilation to simulate the time variation of species concentrations in and around an urban area is discussed. The methods used to compile an emissions inventory are outlined. Emissions factors for vehicular travel in the urban area are presented along with an analysis of the emission gases. Emission sources other than vehicular including industrial wastes, residential solid waste disposal, aircraft emissions, and emissions from the railroads are investigated.

  11. Observations of Cl2, Br2, and I2 in Coastal Urban Air

    NASA Astrophysics Data System (ADS)

    Finley, B. D.; Saltzman, E. S.

    2006-12-01

    Halogen radicals can both produce and destroy ozone in urban air, but there are few direct measurements of reactive halogens and their precursors. This study reports observations of the dihalogens Cl2, Br2, and I2 at a coastal urban site using negative ion atmospheric pressure chemical ionization tandem mass spectrometry. Measurements were made from the Scripps pier, 10 m above the sea surface, from January 1 to January 29, 2006. These are the first measurements of Br2 at a coastal urban site and the first measurements of I2 using triple quadrupole mass spectrometry. Fifteen minute average mixing ratios ranged from below the detection limit of 3 ppt to 28 ppt for Cl2, 20 ppt for Br2, and 11 ppt for I2. Cl2 exhibited a strong diurnal variability, with higher Cl2 levels during the day and lower Cl2 levels at night, suggesting a photochemical production mechanism. I2 also showed a consistent diurnal pattern, exceeding detection limits only during nighttime. I2 was associated with air flow over nearby coastal kelp beds. Br2 was detectable both day and night and did not exhibit a consistent diurnal pattern. The Cl2 levels observed in this study imply significant (> 10 ppb/day) ozone production due to oxidation of hydrocarbons by chlorine atoms. The Br2 levels observed suggest that catalytic destruction of ozone by bromine radicals may also be significant (> 8 ppb/day) in polluted coastal regions. The observed I2 levels imply that iodine radicals do not have a significant impact on ozone levels, accounting for < 1 ppb/day ozone destruction.

  12. Study on the Association between Ambient Air Pollution and Daily Cardiovascular and Respiratory Mortality in an Urban District of Beijing

    PubMed Central

    Zhang, Fengying; Li, Liping; Krafft, Thomas; Lv, Jinmei; Wang, Wuyi; Pei, Desheng

    2011-01-01

    The association between daily cardiovascular/respiratory mortality and air pollution in an urban district of Beijing was investigated over a 6-year period (January 2003 to December 2008). The purpose of this study was to evaluate the relative importance of the major air pollutants [particulate matter (PM), SO2, NO2] as predictors of daily cardiovascular/respiratory mortality. The time-series studied comprises years with lower level interventions to control air pollution (2003–2006) and years with high level interventions in preparation for and during the Olympics/Paralympics (2007–2008). Concentrations of PM10, SO2, and NO2, were measured daily during the study period. A generalized additive model was used to evaluate daily numbers of cardiovascular/respiratory deaths in relation to each air pollutant, controlling for time trends and meteorological influences such as temperature and relative humidity. The results show that the daily cardiovascular/respiratory death rates were significantly associated with the concentration air pollutants, especially deaths related to cardiovascular disease. The current day effects of PM10 and NO2 were higher than that of single lags (distributed lags) and moving average lags for respiratory disease mortality. The largest RR of SO2 for respiratory disease mortality was in Lag02. For cardiovascular disease mortality, the largest RR was in Lag01 for PM10, and in current day (Lag0) for SO2 and NO2. NO2 was associated with the largest RRs for deaths from both cardiovascular disease and respiratory disease. PMID:21776219

  13. 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.

  14. Perfluorinated acids in air, rain, snow, surface runoff, and lakes: relative importance of pathways to contamination of urban lakes.

    PubMed

    Kim, Seung-Kyu; Kannan, Kurunthachalam

    2007-12-15

    Concentrations of perfluorinated acids (PFAs) were measured in various environmental matrices (air, rain, snow, surface runoff water, and lake water) in an urban area, to enable identification of sources and pathways of PFAs to urban water bodies. Total PFA concentrations ranged from 8.28 to 16.0 pg/ m3 (mean 11.3) in bulk air (sum of vapor and particulate phases), 0.91 to 13.2 ng/L (6.19) in rainwater, 0.91 to 23.9 ng/L (7.98) in snow, 1.11-81.8 ng/L (15.1 ng/L) in surface runoff water (SRW), and 9.49 to 35.9 ng/L (21.8) in lake water. Perfluorooctanoic acid (PFOA) was the predominant compound, accounting for > 35% of the total PFA concentrations, in all environmental matrices analyzed. Concentrations and relative compositions of PFAs in SRW were similar to those found for urban lakes. SRW contributes to contamination by PFOA in urban lakes. The measured concentration ratios of FTOH to PFOA in air were 1-2 orders of magnitude lower than the ratios calculated based on an assumption of exclusive atmospheric oxidation of FTOHs. Nevertheless, the mass balance analysis suggested the presence of an unknown input pathway that could contribute to a significant amount of total PFOA loadings to the lake. Flux estimates of PFOA at the air-water interface in the urban lake suggest net volatilization from water.

  15. An Indoor-Outdoor Building Energy Simulator to Study Urban Modification effects on Building Energy Use

    NASA Astrophysics Data System (ADS)

    Yaghoobian, N.; Kleissl, J. P.

    2011-12-01

    While there have been significant advances in energy modeling of individual buildings, reviews of the literature highlight the need for improved understanding of how the interaction between buildings and their surroundings modifies the energy savings obtained through green engineering measures. IOBES (Indoor-Outdoor Building Energy Simulator) is a building-to-canopy model that simulates indoor and outdoor building surface temperatures and associated heat fluxes in an urban area to estimate cooling/heating loads and energy use in buildings. In this model the indoor and outdoor energy balance processes are dynamically coupled taking into account real weather conditions, indoor heat sources, building and urban material properties and composition of the building envelope (e.g. windows, insulation), and HVAC equipment. IOBES is also capable to simulate effects of the waste heat from air-conditioning systems on urban canopy air temperature. IOBES performance in simulating transient heat conduction is validated against an analytical solution of interior wall surface temperature response to a step change in outside air temperature. Also performance of IOBES in simulating cooling and heating loads for specific days validated against well-known models like CBS-MASS, BLAST, and TARP. In addition the annual cooling and heating load of other whole building energy simulators are compared to IOBES. An application of IOBES to study the impact of urban heat island mitigation measures such as reflective pavements is presented.

  16. Geostatistical uncertainty of assessing air quality using high-spatial-resolution lichen data: A health study in the urban area of Sines, Portugal.

    PubMed

    Ribeiro, Manuel C; Pinho, P; Branquinho, C; Llop, Esteve; Pereira, Maria J

    2016-08-15

    In most studies correlating health outcomes with air pollution, personal exposure assignments are based on measurements collected at air-quality monitoring stations not coinciding with health data locations. In such cases, interpolators are needed to predict air quality in unsampled locations and to assign personal exposures. Moreover, a measure of the spatial uncertainty of exposures should be incorporated, especially in urban areas where concentrations vary at short distances due to changes in land use and pollution intensity. These studies are limited by the lack of literature comparing exposure uncertainty derived from distinct spatial interpolators. Here, we addressed these issues with two interpolation methods: regression Kriging (RK) and ordinary Kriging (OK). These methods were used to generate air-quality simulations with a geostatistical algorithm. For each method, the geostatistical uncertainty was drawn from generalized linear model (GLM) analysis. We analyzed the association between air quality and birth weight. Personal health data (n=227) and exposure data were collected in Sines (Portugal) during 2007-2010. Because air-quality monitoring stations in the city do not offer high-spatial-resolution measurements (n=1), we used lichen data as an ecological indicator of air quality (n=83). We found no significant difference in the fit of GLMs with any of the geostatistical methods. With RK, however, the models tended to fit better more often and worse less often. Moreover, the geostatistical uncertainty results showed a marginally higher mean and precision with RK. Combined with lichen data and land-use data of high spatial resolution, RK is a more effective geostatistical method for relating health outcomes with air quality in urban areas. This is particularly important in small cities, which generally do not have expensive air-quality monitoring stations with high spatial resolution. Further, alternative ways of linking human activities with their

  17. Effects of Green Space and Land Use/Land Cover on Urban Heat Island in a Subtropical Mega-city in China

    NASA Astrophysics Data System (ADS)

    Qiu, G. Y.; Li, X.; Li, H.; Guo, Q.

    2014-12-01

    With the quick expansion of urban in size and population, its urban heat island intensity (UHII, expressed as the temperature difference between urban and rural areas) increased rapidly. However, very few studies could quantitatively reveal the effects of green space and land use/land cover (LULC) on urban thermal environment because of lacking of the detailed measurement. This study focuses on quantifying the effects of green space and LULC on urban Heat Island (UHI) in Shenzhen, a mega subtropical city in China. Extensive measurements (air temperature and humidity) were made by mobile traverse method in a transect of 8 km in length, where a variety of LULC types were included. Measurements were carried out at 2 hours interval for 2 years (totally repeated for 7011 times). According to LULC types, we selected 5 different LULC types for studying, including water body, village in the city, shopping center (commercial area), urban green space (well-vegetated area) and suburb (forest). The main conclusions are obtained as follows: (1) The temperature difference between the 5 different urban landscapes is obvious, i.e. shopping center > village in the city > urban water body > urban green space > suburb; (2) Air temperature and UHII decreases linearly with the increase of green space in urban; (3) Green space and water body in urban have obvious effects to reduce the air temperature by evapotranspiration. Compared to the commercial areas, urban water body can relieve the IUHI by 0.9℃, while the urban green space can relieve the IUHI by 1.57℃. The cooling effect of the urban green space is better than that of the urban water body; (4) Periodic activity of human being has obvious effects on urban air temperature. The UHII on Saturday and Sunday are higher than that from Monday to Friday, respectively higher for 0.65, 0.57, 0.26 and 0.21℃. Thursday and Friday have the minimum air temperature and UHII. These results indicate that increase in urban evapotranspiration

  18. Blue gamma grass and compost effects on urban soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Urban construction sites often have excessive erosion and compaction after topsoil removal, scraping, and grading. The purpose of this study is to determine if compaction remediation efforts are effective on a simulated urban site. The sod and topsoil were removed, the area was graded to a 1% slope,...

  19. Assessing PM10 source reduction in urban agglomerations for air quality compliance.

    PubMed

    Aleksandropoulou, Victoria; Eleftheriadis, Konstantinos; Diapouli, Evangelia; Torseth, Kjetil; Lazaridis, Mihalis

    2012-01-01

    The objective of this work was to study PM(10) and PM(2.5) concentration data available from monitoring stations in two large urban agglomerations in Greece and to estimate the emissions reduction required for compliance with the EU Air Quality Standards (AQS) for particulate matter. The cities studied are namely the Athens and Thessaloniki Metropolitan Areas (AMA and TMA, respectively). PM(10) concentrations during the period 2001-2010 have been evaluated for 15 air quality monitoring stations in the two urban areas. It was found that the concentrations of PM(10) during the period studied constantly exceeded the threshold values at the traffic and industrial stations in TMA and most of the traffic sites in AMA. Most of the occurrences of non-attainment to the daily AQSs were observed during the winter period at all stations (more pronounced for TMA stations). The reduction in current emission source strength to meet the air quality goal was calculated by the rollback equation using PM(10) day-averaged concentrations over the selected period at each station. Among the lognormal and Weibull distributions, the lognormal distribution was found to best fit the frequency distributions of PM(10) concentrations at the selected stations. The results showed that the minimum reduction required in order to meet the AQS in the AMA ranges from approximately 20 to 38% and up to 11% for traffic and background stations, respectively. Reductions in the range of 31% for traffic and 44% for industrial areas in TMA are also required. The same methodology was applied to PM(2.5) concentrations in the AMA and showed that emission reductions up to 31% are necessary in order to meet the 2020 EU AQS. Finally, continuous concentration data of organic (OC) and elementary carbon (EC) in PM(2.5) were used to study the possibility of achieving specific emission attenuation objectives in AMA.

  20. Modeling Spatial Patterns of Traffic-Related Air Pollutants in Complex Urban Terrain

    PubMed Central

    Zwack, Leonard M.; Paciorek, Christopher J.; Spengler, John D.; Levy, Jonathan I.

    2011-01-01

    Background The relationship between traffic emissions and mobile-source air pollutant concentrations is highly variable over space and time and therefore difficult to model accurately, especially in urban settings with complex terrain. Regression-based approaches using continuous real-time mobile measurements may be able to characterize spatiotemporal variability in traffic-related pollutant concentrations but require methods to incorporate temporally varying meteorology and source strength in a physically interpretable fashion. Objective We developed a statistical model to assess the joint impact of both meteorology and traffic on measured concentrations of mobile-source air pollutants over space and time. Methods In this study, traffic-related air pollutants were continuously measured in the Williamsburg neighborhood of Brooklyn, New York (USA), which is affected by traffic on a large bridge and major highway. One-minute average concentrations of ultrafine particulate matter (UFP), fine particulate matter [≤ 2.5 μm in aerodynamic diameter (PM2.5)], and particle-bound polycyclic aromatic hydrocarbons were measured using a mobile-monitoring protocol. Regression modeling approaches to quantify the influence of meteorology, traffic volume, and proximity to major roadways on pollutant concentrations were used. These models incorporated techniques to capture spatial variability, long- and short-term temporal trends, and multiple sources. Results We observed spatial heterogeneity of both UFP and PM2.5 concentrations. A variety of statistical methods consistently found a 15–20% decrease in UFP concentrations within the first 100 m from each of the two major roadways. For PM2.5, temporal variability dominated spatial variability, but we observed a consistent linear decrease in concentrations from the roadways. Conclusions The combination of mobile monitoring and regression analysis was able to quantify local source contributions relative to background while

  1. Contribution of area sources to hazardous air pollutant emissions in three urban areas. Report for November 1992-October 1994

    SciTech Connect

    Jones, J.W.; Campbell, D.L.

    1995-04-01

    The paper discusses the contribution of area sources to hazardous air pollutant (HAP) emissions in three urban areas--Baltimore, Chicago, and Seattle-Tacoma (Puget Sound). U.S. Environmental Protection Agency (EPA) has implemented the Urban Area Source Program (UASP) required until Title III of the 1990 Clean Air Act Amendments (CAAA). The HAPs emitted in the greatest quantities in these area source inventories are from degreasing and dry cleaning. Another important source category is fossil fuel combustion. The best approach to use in developing a HAP area source emissions inventory may be to combine the top-down method with local surveys of small manufacturing facilities and service industies.

  2. 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.

  3. Soil surface temperatures reveal moderation of the urban heat island effect by trees and shrubs.

    PubMed

    Edmondson, J L; Stott, I; Davies, Z G; Gaston, K J; Leake, J R

    2016-09-19

    Urban areas are major contributors to air pollution and climate change, causing impacts on human health that are amplified by the microclimatological effects of buildings and grey infrastructure through the urban heat island (UHI) effect. Urban greenspaces may be important in reducing surface temperature extremes, but their effects have not been investigated at a city-wide scale. Across a mid-sized UK city we buried temperature loggers at the surface of greenspace soils at 100 sites, stratified by proximity to city centre, vegetation cover and land-use. Mean daily soil surface temperature over 11 months increased by 0.6 °C over the 5 km from the city outskirts to the centre. Trees and shrubs in non-domestic greenspace reduced mean maximum daily soil surface temperatures in the summer by 5.7 °C compared to herbaceous vegetation, but tended to maintain slightly higher temperatures in winter. Trees in domestic gardens, which tend to be smaller, were less effective at reducing summer soil surface temperatures. Our findings reveal that the UHI effects soil temperatures at a city-wide scale, and that in their moderating urban soil surface temperature extremes, trees and shrubs may help to reduce the adverse impacts of urbanization on microclimate, soil processes and human health.

  4. Soil surface temperatures reveal moderation of the urban heat island effect by trees and shrubs

    PubMed Central

    Edmondson, J. L.; Stott, I.; Davies, Z. G.; Gaston, K. J.; Leake, J. R.

    2016-01-01

    Urban areas are major contributors to air pollution and climate change, causing impacts on human health that are amplified by the microclimatological effects of buildings and grey infrastructure through the urban heat island (UHI) effect. Urban greenspaces may be important in reducing surface temperature extremes, but their effects have not been investigated at a city-wide scale. Across a mid-sized UK city we buried temperature loggers at the surface of greenspace soils at 100 sites, stratified by proximity to city centre, vegetation cover and land-use. Mean daily soil surface temperature over 11 months increased by 0.6 °C over the 5 km from the city outskirts to the centre. Trees and shrubs in non-domestic greenspace reduced mean maximum daily soil surface temperatures in the summer by 5.7 °C compared to herbaceous vegetation, but tended to maintain slightly higher temperatures in winter. Trees in domestic gardens, which tend to be smaller, were less effective at reducing summer soil surface temperatures. Our findings reveal that the UHI effects soil temperatures at a city-wide scale, and that in their moderating urban soil surface temperature extremes, trees and shrubs may help to reduce the adverse impacts of urbanization on microclimate, soil processes and human health. PMID:27641002

  5. Soil surface temperatures reveal moderation of the urban heat island effect by trees and shrubs

    NASA Astrophysics Data System (ADS)

    Edmondson, J. L.; Stott, I.; Davies, Z. G.; Gaston, K. J.; Leake, J. R.

    2016-09-01

    Urban areas are major contributors to air pollution and climate change, causing impacts on human health that are amplified by the microclimatological effects of buildings and grey infrastructure through the urban heat island (UHI) effect. Urban greenspaces may be important in reducing surface temperature extremes, but their effects have not been investigated at a city-wide scale. Across a mid-sized UK city we buried temperature loggers at the surface of greenspace soils at 100 sites, stratified by proximity to city centre, vegetation cover and land-use. Mean daily soil surface temperature over 11 months increased by 0.6 °C over the 5 km from the city outskirts to the centre. Trees and shrubs in non-domestic greenspace reduced mean maximum daily soil surface temperatures in the summer by 5.7 °C compared to herbaceous vegetation, but tended to maintain slightly higher temperatures in winter. Trees in domestic gardens, which tend to be smaller, were less effective at reducing summer soil surface temperatures. Our findings reveal that the UHI effects soil temperatures at a city-wide scale, and that in their moderating urban soil surface temperature extremes, trees and shrubs may help to reduce the adverse impacts of urbanization on microclimate, soil processes and human health.

  6. Effects of antecedent land cover on physical, chemical, and biological responses to urbanization in streams across the conterminous United States

    NASA Astrophysics Data System (ADS)

    Cuffney, T. F.; Qian, S.

    2012-12-01

    The effects of urbanization on physical, chemical, and biological characteristics of streams were assessed across gradients of urbanization in 9 metropolitan areas of the conterminous US (Boston, MA; Raleigh; NC, Birmingham, AL; Atlanta, GA; Milwaukee-Green Bay, WI; Denver, CO; Dallas-Fort Worth, TX; Salt Lake City, UT; and Portland, OR) as a part of the U.S. Geological Survey's National Water Quality Assessment Program. Gradients of urbanization were established on the basis of a multimetric index of urban intensity that combined land cover, population, and road density. Simple regression models established that the condition of biological communities (e.g., invertebrate responses) showed statistically significant degradation as urbanization increased in six (Boston, Raleigh, Birmingham, Atlanta, Salt Lake, and Portland) of the nine metropolitan areas. Multiple regression models incorporating basin-scale land cover (e.g., forest, agricultural land) and environmental variables (e.g., water temperature, chemistry, hydrology) did not substantially improve the explanatory power of the regressions and could not explain differences in responses among metropolitan areas. Multilevel hierarchical models incorporating basin- and regional-scale predictors demonstrated that regional-scale climate (air temperature and precipitation) and antecedent land cover (i.e., land cover being converted to urban) predicted invertebrate responses to urbanization. The lack of identifiable urban responses for Milwaukee-Green Bay, Denver, and Dallas-Fort Worth were associated with high levels of antecedent agriculture (row crops and grazing) that degraded the biological communities and obscured the effects of urbanization. Urbanization was associated with increases in conductivity, nutrients, pesticides, and hydrologic variability. Levels of these variables at background sites were higher in regions with high antecedent agriculture; consequently, the effects of urbanization appeared to be

  7. Urban Air Pollution Produces Up-Regulation of Myocardial Inflammatory Genes and Dark Chocolate Provides Cardioprotection

    PubMed Central

    Villarreal-Calderon, Rodolfo; Reed, William; Palacios-Moreno, Juan; Keefe, Sheyla; Herritt, Lou; Brooks, Diane; Torres-Jardón, Ricardo; Calderón-Garcidueñas, Lilian

    2010-01-01

    Air pollution is a serious environmental problem. Elderly subjects show increased cardiac morbidity and mortality associated with air pollution exposure. Mexico City (MC) residents are chronically exposed to high concentrations of fine particulate matter (PM2.5) and PM-associated lipopolysaccharides (PM-LPS). To test the hypothesis that chronic exposure to urban pollution produces myocardial inflammation, female Balb-c mice age 4 weeks were exposed for 16 months to two distinctly different polluted areas within MC: Southwest (SW) and Northwest (NW). SW mice were given either no treatment or chocolate 2g/9.5 mg polyphenols/3 times per week. Results were compared to mice kept in clean air. Key inflammatory mediator genes: cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), and the LPS receptor CD14 (cluster of differentiation antigen 14) were measured by real time polymerase chain reaction. Also explored were target NFκB (Nuclear Factor κ B), oxidative stress and antioxidant defense genes. TNF-α, IL-6, and COX-2 were significantly increased in both NW and SWMC mice (p=0.0001). CD14 was up-regulated in SW mice in keeping with the high exposures to particulate matter associated endotoxin. Chocolate administration resulted in a significant down-regulation of TNF-α (p<0.0001), IL-6 (p=0.01), and IL-1β (p=0.02). The up-regulation of antioxidant enzymes and the down-regulation of potent oxidases, toll-like receptors, and pro-apoptotic signaling genes completed the protective profile. Exposure to air pollution produces up-regulation of inflammatory myocardial genes and endotoxin plays a key role in the inflammatory response. Regular consumption of dark chocolate may reduce myocardial inflammation and have cardioprotective properties in the setting of air pollution exposures. PMID:20932730

  8. Urban air pollution produces up-regulation of myocardial inflammatory genes and dark chocolate provides cardioprotection.

    PubMed

    Villarreal-Calderon, Rodolfo; Reed, William; Palacios-Moreno, Juan; Keefe, Sheyla; Herritt, Lou; Brooks, Diane; Torres-Jardón, Ricardo; Calderón-Garcidueñas, Lilian

    2012-05-01

    Air pollution is a serious environmental problem. Elderly subjects show increased cardiac morbidity and mortality associated with air pollution exposure. Mexico City (MC) residents are chronically exposed to high concentrations of fine particulate matter (PM(2.5)) and PM-associated lipopolysaccharides (PM-LPS). To test the hypothesis that chronic exposure to urban pollution produces myocardial inflammation, female Balb-c mice age 4 weeks were exposed for 16 months to two distinctly different polluted areas within MC: southwest (SW) and northwest (NW). SW mice were given either no treatment or chocolate 2g/9.5 mg polyphenols/3 times per week. Results were compared to mice kept in clean air. Key inflammatory mediator genes: cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), and the LPS receptor CD14 (cluster of differentiation antigen 14) were measured by real-time polymerase chain reaction. Also explored were target NFκB (nuclear factor κB), oxidative stress and antioxidant defense genes. TNF-α, IL-6, and COX-2 were significantly increased in both NW and SWMC mice (p=0.0001). CD14 was up-regulated in SW mice in keeping with the high exposures to particulate matter associated endotoxin. Chocolate administration resulted in a significant down-regulation of TNF-α (p<0.0001), IL-6 (p=0.01), and IL-1β (p=0.02). The up-regulation of antioxidant enzymes and the down-regulation of potent oxidases, toll-like receptors, and pro-apoptotic signaling genes completed the protective profile. Exposure to air pollution produces up-regulation of inflammatory myocardial genes and endotoxin plays a key role in the inflammatory response. Regular consumption of dark chocolate may reduce myocardial inflammation and have cardioprotective properties in the setting of air pollution exposures.

  9. High Spatial Resolution Thermal Infrared Remote Sensing Data for Analysis of the Atlanta, Georgia, Urban Heat Island Effect and Its Impacts on the Environment

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale A.

    2007-01-01

    The twenty-first century is the first "urban century" according to the United Nations Development Program. The focus of cities reflects awareness of the growing percentage of the world's population that lives in urban areas. In environmental terms, cities are the original producers of many of the global problems related to waste disposal, air and water pollution, and associated environmental and ecological challenges. Expansion of cities, both in population and areal extent, is a relentless process. In 2000, approximately 3 billion people representing about 40% of the global population, resided in urban areas. Urban population will continue to rise substantially over the next several decades according to UN estimates, and most of this growth will Occur in developing countries. The UN estimates that by 2025, 60% of the world's population will live in urban areas. As a consequence, the number of"megacities" (those cities with populations of 10 million inhabitants or more) will increase by 100 by 2025. Thus, there is a critical need to understand urban areas and what their impacts are on environmental, ecological and hydrologic resources, as well as on the local, regional, and even global climate. One of the more egregious side effects of urbanization is the increase in surface and air temperatures that lead to deterioration in air quality. In the United States, under the more stringent air quality guidelines established by the U.S. Environmental Protection Agency in 1997, nearly 300 counties in 34 states will not meet these new air quality standards for ground level ozone. Mitigation of the urban heat island (UHI) effect is actively being evaluated as a possible way to reduce ground ozone levels in cities and assist states in improving air quality. Foremost in the analysis of how the UHI affects air quality and other environmental factors is the use of remote sensing technology and data to characterize urban land covers in sufficient detail to quantifiably measure

  10. A method for targeting air samplers for facility monitoring in an urban environment

    NASA Astrophysics Data System (ADS)

    Bieringer, Paul E.; Longmore, Scott; Bieberbach, George; Rodriguez, Luna M.; Copeland, Jeff; Hannan, John

    2013-12-01

    There are a variety of applications that require the use of comprehensive specification of the weather conditions combined with an analysis that uses detailed modeling and simulation. The combination of these two elements can make it difficult to achieve the desired level of fidelity in a logistically feasible way. An example of this type of application is the deployment of surface-based sensors/samplers, which is a common practice for emission, and air quality monitoring purposes where the proper selection of sites for the measurement equipment is critical to an accurate characterization of the emissions. This is particularly true in urban environments where the limited availability of suitable sites and the non-intuitive dispersion patterns associated with the wind flow around the buildings and through the urban canyons make site selection difficult. This article demonstrates an improved methodology for optimally locating for air quality monitoring equipment within this complex and challenging environment. The methodology involves a) the utilization of a longer climatological record of meteorological observations or gridded reanalysis products to better represent the full range of representative meteorological conditions; b) reduction of the full climatological record into a subset of characteristic meteorological patterns and associated frequencies of occurrence, utilizing a multi-dimensional feature extraction and classification technique known as a Self Organizing Map (SOM); c) downscaling and diagnosis of the urban area building-aware wind flow fields for each characteristic meteorological pattern; d) atmospheric transport and dispersion (AT&D) simulations for each downscaled meteorological pattern, utilizing a building aware Lagrangian particle dispersion model; and finally e) the combination of predicted downwind concentrations/dosages for each meteorological pattern with their associated frequency of occurrence are used to generate Probability of Detection

  11. Cardiac arrhythmogenesis in urban air pollution: Optical mapping in a tissue-engineered model

    NASA Astrophysics Data System (ADS)

    Bien, Harold H.

    Recent epidemiological evidence has implicated particulate matter air pollution in cardiovascular disease. We hypothesized that inflammatory mediators released from lung macrophages after exposure to particulate matter predisposes the heart to disturbances in rhythm. Using a rational design approach, a fluorescent optical mapping system was devised to image spatiotemporal patterns of excitation in a tissue engineered model of cardiac tissue. Algorithms for automated data analysis and characterization of rhythm stability were developed, implemented, and verified. Baseline evaluation of spatiotemporal instability patterns in normal cardiac tissue was performed for comparison to an in-vitro model of particulate matter air pollution exposure. Exposure to particulate-matter activated alveolar macrophage conditioned media resulted in paradoxical functional changes more consistent with improved growth. These findings might be indicative of a "stress" response to particulate-matter induced pulmonary inflammation, or may be specific to the animal model (neonatal rat) employed. In the pursuit of elucidating the proposed pathway, we have also furthered our understanding of fundamental behaviors of arrhythmias in general and established a model where further testing might ultimately reveal the mechanism for urban air pollution associated cardiovascular morbidity.

  12. Climatic impact of urbanization in Eastern China: modeling the combined urban heat island and aerosol effects

    NASA Astrophysics Data System (ADS)

    Qian, Y.; Yang, B.; Zhao, C.; Leung, L. R.; Yan, H.; Fan, J.

    2014-12-01

    In this study we investigate the climatic impact of urbanization, including both Urban Heat Island (UHI) and aerosol effects, over the Yangtze-Delta metropolitan clusters region of Eastern China, based on a series of simulations with prescribed land use/land cover and emissions of aerosols and their precursors for the 2000s and 1970s , respectively. We conduct simulations for each land use/land cover and emission scenario from 2006-2010 using the Weather Research and Forecasting (WRF) model, with online chemistry/aerosol and urban canopy models, at a 3-km grid spacing. Overall the model can reasonably capture the spatial pattern of temperature and precipitation as well as the phase of precipitation diurnal cycle in summer. Simulations results show a very clear UHI effect, i.e. expanded urban surface decreases surface latent heat flux, increases sensible heat flux and PBL height, and reduces surface wind over urban areas, with a more significant change in summer. Aerosol has much less obvious impact on local surface heat flux and temperature, but shows more remote impacts downwind due to dispersion and transport of pollutants and aerosol-cloud interaction. Aerosol also has a larger impact on precipitation amount and areal coverage than UHI. While UHI increases precipitation over urban regions during daytime especially when the southeasterly monsoonal flow prevails, aerosol remarkably suppresses precipitation, especially for light to moderate rain events, and increases the frequency of dry days in the entire model region.

  13. Evaluation of VOC measurments in the EXPOLIS study. Air Pollution Exposure Distributions within Adult Urban Urban Populations in Europe.

    PubMed

    Jurvelin, J; Edwards, R; Saarela, K; Laine-Ylijoki, J; De Bortoli, M; Oglesby, L; Schläpfer, K; Georgoulis, L; Tischerova, E; Hänninen, O; Jantunen, M

    2001-02-01

    Personal exposures and microenvironment concentrations of 30 target VOCs were measured for 401 participants living in five European cities as a part of the EXPOLIS (Air Pollution Exposure Distributions within Adult Urban Populations in Europe) study. Measurements in Basel used an active charcoal (Carbotech) adsorbent as opposed to the Tenax TA used in the other study centres. In addition, within each centre, personal and microenvironment VOC sampling required different sampling pumps and, because of different sampling durations, different sampling flow rates. Thus, careful testing of the sampling and analysis procedures was required to ensure accuracy and comparability of collected data. Monitor comparison tests using Tenax TA showed a mean VOC concentration ratio of 0.95 between the personal and microenvironment monitors. The LODs for the target VOCs using Tenax TA ranged from 0.7 to 5.2 microg m(-3). The LODs for the 14 target compounds quantifiable using Carbotech ranged from 0.9 to 3.2 microg m(-3). Tenax TA field blanks showed no remarkable contamination with the target VOCs, except benzaldehyde, a known artefact with this adsorbent. Thus, the diffusion barrier system used prevented contamination of Tenax TA samples by passive diffusion during non-sampling periods. Duplicate and parallel evaluations of the Tenax TA and Carbotech showed an average difference of < 17% in VOC concentrations within the sampling methods, but a systematic difference between the methods (Tenax TA: Carbotech concentration ratio = 1.18-2.36). These field evaluations and quality assurance tests showed that interpretation and comparison of the results in any VOC monitoring exercise should be done on a compound by compound basis. It is also apparent that carefully planned and realised QA and QC (QA/QC) procedures are needed in multi-centre studies, where a common sampling method and laboratory analysis technique are not used, to strengthen and simplify the interpretation of observed VOC

  14. Applicability of the Environmental Relative Moldiness Index for Quantification of Residential Mold Contamination in an Air Pollution Health Effects Study

    EPA Science Inventory

    As part of the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) investigating the respiratory health impacts of traffic-related air pollutants on asthmatic children in Detroit, Michigan, residential dust samples were collected to quantify mold exposure. Sett...

  15. Immediate health effects of an urban wildfire.

    PubMed Central

    Shusterman, D; Kaplan, J Z; Canabarro, C

    1993-01-01

    To document the immediate health effects of the urban wildfire that swept through parts of Alameda County, California, on October 20 and 21, 1991, we conducted a retrospective review of emergency department and coroner's records. Nine hospitals (6 local and 3 outlying) were surveyed for the week beginning October 20, 1991. Coroner's reports were reviewed for 25 identified fire-related deaths. A total of 241 fire-related emergency encounters, including 44 inpatient admissions, were recorded for 227 persons. Nearly a fourth of emergency department patients were seen for work-related injuries, more than half of which occurred among professional firefighters. Smoke-related disorders constituted more than half of all emergency department cases; of these, 61% had documented bronchospasm. Major trauma and burns contributed 1% and 4% of principal diagnoses, respectively; these were exceeded in number by corneal abrasions (13%), other medical problems (8%), and minor trauma (7%), among other diagnoses. All coroner's cases involved extensive burns, many with documented smoke inhalation injury. While the Oakland-Berkeley fire storm resulted in a high case-fatality ratio among major burn cases (25/31), those who survived the initial fire storm did well clinically. Among emergency department patients, medical (particularly smoke-related) disorders outnumbered traumatic presentations by a ratio of more than 2 to 1. Images PMID:8434462

  16. Promoted Relationship of Cardiovascular Morbidity with Air Pollutants in a Typical Chinese Urban Area

    PubMed Central

    Tong, Ling; Li, Kai; Zhou, Qixing

    2014-01-01

    Background A large number of studies about effects of air pollutants on cardiovascular mortality have been conducted; however, those investigating association between air pollutants and cardiovascular morbidity are limited, especially in developing countries. Methods A time-series analysis on the short-term association between outdoor air pollutants including particulate matter (PM) with diameters of 10 µm or less (PM10), sulfur dioxide (SO2) and nitrogen dioxide (NO2) and cardiovascular morbidity was conducted in Tianjin, China based on 4 years of daily data (2008–2011). The morbidity data were stratified by sex and age. The effects of air pollutants during the warm season and the cool season were also analyzed separately. Results Each increase in PM10, SO2, and NO2 by increments of 10 µg/m3 in a 2-day average concentration was associated with increases in the cardiovascular morbidity of 0.19% with 95 percent confidence interval (95% CI) of 0.08–0.31, 0.43% with 95% CI of 0.03–0.84, and 0.52% with 95% CI of −0.09–1.13, respectively. The effects of air pollutants were more evident in the cool season than those in the warm season, females and the elderly were more vulnerable to outdoor air pollution. Conclusions All estimated coefficients of PM10, SO2 and NO2 are positive but only the effect of SO2 implied statistical significance at the 5% level. Moreover, season, sex and age might modify health effects of outdoor air pollutants. This work may bring inspirations for formulating local air pollutant standards and social policy regarding cardiovascular health of residents. PMID:25247693

  17. Local warming of groundwaters caused by the urban heat island effect in Istanbul, Turkey

    NASA Astrophysics Data System (ADS)

    Yalcin, Tolga; Yetemen, Omer

    2009-07-01

    The urban heat island (UHI) is a result of urbanization, causing local microclimatologic changes such as increase in ambient temperature. Factors causing the UHI effect are anthropogenic energy release, energy absorption by concrete, tarmac structures and traffic, although the main factor is the replacement of vegetation with man-made structures. These factors cause heating of not only local air but also subsurface and groundwater. Observations of groundwater temperatures from the urban, southern part of Istanbul (Turkey) and the rural, northern part of Istanbul revealed that the urban groundwater temperatures were 3.5°C higher than the rural. Urbanization is a direct consequence of improvements in technology and modern life. However, this comes at the cost of an ever-increasing demand for energy. Exploitation of low-enthalpy geothermal energy is an attractive alternative to fossil fuel based energies. From the environmental point of view, clean and cheap energy is the most preferable, with heat pumps being the best choice for recovery purposes. Usage of elevated groundwater temperature in the heat pumps in urban areas increases the efficiency of the heat pump system and yields more thermal energy than that of rural groundwater. This system may be applicable to Istanbul.

  18. Urban irrigation effects on WRF-UCM summertime forecast skill over the Los Angeles metropolitan area

    NASA Astrophysics Data System (ADS)

    Vahmani, P.; Hogue, T. S.

    2015-10-01

    In the current study, we explicitly address the impacts of urban irrigation on the local hydrological cycle by integrating a previously developed irrigation scheme within the coupled framework of the Weather Research and Forecasting-Urban Canopy Models (WRF-UCM) over the semiarid Los Angeles metropolitan area. We focus on the impacts of irrigation on the urban water cycle and atmospheric feedback. Our results demonstrate a significant sensitivity of WRF-UCM simulated surface turbulent fluxes to the incorporation of urban irrigation. Introducing anthropogenic moisture, vegetated pixels show a shift in the energy partitioning toward elevated latent heat fluxes. The cooling effects of irrigation on daily peak air temperatures are evident over all three urban types, with the largest influence over low-intensity residential areas (average cooling of 1.64°C). The evaluation of model performance via comparison against CIMIS (California Irrigation Management Information System) evapotranspiration (ET) estimates indicates that WRF-UCM, after adding irrigation, performs reasonably during the course of the month of July, tracking day-to-day variability of ET with notable consistency. In the nonirrigated case, CIMIS-based ET fluctuations are significantly underestimated by the model. Our analysis shows the importance of accurate representation of urban irrigation in modeling studies, especially over water-scarce regions such as the Los Angeles metropolitan area. We also illustrate that the impacts of irrigation on simulated energy and water cycles are more critical for longer-term simulations due to the interactions between irrigation and soil moisture fluctuations.

  19. Evaluation of urban surface parameterizations in the WRF model using measurements during the Texas Air Quality Study 2006 field campaign

    NASA Astrophysics Data System (ADS)

    Lee, S.-H.; Kim, S.-W.; Angevine, W. M.; Bianco, L.; McKeen, S. A.; Senff, C. J.; Trainer, M.; Tucker, S. C.; Zamora, R. J.

    2010-10-01

    The impact of urban surface parameterizations in the WRF (Weather Research and Forecasting) model on the simulation of local meteorological fields is investigated. The Noah land surface model (LSM), a modified LSM, and a single-layer urban canopy model (UCM) have been compared, focusing on urban patches. The model simulations were performed for 6 days from 12 August to 17 August during the Texas Air Quality Study 2006 field campaign. Analysis was focused on the Houston-Galveston metropolitan area. The model simulated temperature, wind, and atmospheric boundary layer (ABL) height were compared with observations from surface meteorological stations (Continuous Ambient Monitoring Stations, CAMS), wind profilers, the NOAA Twin Otter aircraft, and the NOAA Research Vessel Ronald H. Brown. The UCM simulation showed better results in the comparison of ABL height and surface temperature than the LSM simulations, whereas the original LSM overestimated both the surface temperature and ABL height significantly in urban areas. The modified LSM, which activates hydrological processes associated with urban vegetation mainly through transpiration, slightly reduced warm and high biases in surface temperature and ABL height. A comparison of surface energy balance fluxes in an urban area indicated the UCM reproduces a realistic partitioning of sensible heat and latent heat fluxes, consequently improving the simulation of urban boundary layer. However, the LSMs have a higher Bowen ratio than the observation due to significant suppression of latent heat flux. The comparison results suggest that the subgrid heterogeneity by urban vegetation and urban morphological characteristics should be taken into account along with the associated physical parameterizations for accurate simulation of urban boundary layer if the region of interest has a large fraction of vegetation within the urban patch. Model showed significant discrepancies in the specific meteorological conditions when nocturnal

  20. Relationship between meteorological phenomena and air pollution in an urbanized and industrialized coastal area in northern France

    NASA Astrophysics Data System (ADS)

    Gengembre, Cyril; Zhang, Shouwen; Dieudonné, Elsa; Sokolov, Anton; Augustin, Patrick; Riffault, Véronique; Dusanter, Sébastien; Fourmentin, Marc; Delbarre, Hervé

    2016-04-01

    Impacts of global climate evolution are quite uncertain at regional and local scales, especially on air pollution. Air quality is associated with local atmospheric dynamics at a time scale shorter than a few weeks, while the climate change time scale is on the order of fifty years. To infer consequences of climate evolution on air pollution, it is necessary to fill the gap between these different scales. Another challenge is to understand the effect of global warming on the frequency of meteorological phenomena that influence air pollution. In this work, we classified meteorological events related to air pollution during a one-year long field campaign in Dunkirk (northern France). Owing to its coastal location under urban and industrial exposures, the Dunkirk agglomeration is an interesting area for studying gaseous and aerosols pollutants and their relationship with weather events such as sea breezes, fogs, storms and fronts. The air quality in the northern region of France is also greatly influenced by highly populated and industrialized cities along the coast of the North Sea, and by London and Paris agglomerations. During a field campaign, we used simultaneously a three-dimensional sonic anemometer and a weather station network, along with a scanning Doppler Lidar system to analyse the vertical structure of the atmosphere. An Aerosol Chemical Speciation Monitor enabled investigating the PM1 behaviour during the studied events. Air contaminants such as NOx (NO and NO2) were also measured by the regional pollution monitoring network ATMO Nord Pas-de-Calais. The events were identified by finding specific criteria from meteorological and turbulent parameters. Over a hundred cases of sea breezes, fog periods, stormy days and atmospheric front passages were investigated. Variations of turbulent parameters (vertical sensible heat flux and momentum flux) give estimations on the transport and the dispersal of pollutants. As the fluxes are weak during fogs, an increase

  1. Satellite and Ground-Based Measurements of Urban Air Quality in Relation with Children's Asthma

    NASA Astrophysics Data System (ADS)

    Zoran, Maria; Dida, Mariana Rodica

    2016-08-01

    The adverse health effects from aerosol particulate matter PM pollution, especially with aerodynamic diameter ≤2.5 μm PM2.5 must be considered in developing policies to improve air quality. Epidemiologic studies demonstrated that exposure to ambient particulate matter PM is associated with increased morbidity and mortality, particularly associated with cardiopulmonary disease and asthma of which children are most exposed for the rapid increase of asthma disease. Very early exposure to certain components of air pollution can increase the risk of developing of different allergies by age 7. The present study attempts to retrieve the aerosol load in terms of aerosol optical depth (AOD) related to air quality in the Bucharest metropolitan area. In this study is presented a spatio-temporal analysis of the aerosol concentrations in relation with meteorological parameters in two size fractions (PM10 and PM2.5) and Air Qualiy Index and possible health effects on children's asthma.

  2. Long-term study of air urban quality together with mixing layer height

    NASA Astrophysics Data System (ADS)

    Schäfer, Klaus; Ling, Hong; Münkel, Christoph; Emeis, Stefan

    2013-10-01

    Air pollution episodes in urban areas often occur during low wind speeds and low mixing layer height (MLH) and can not only be ascribed to increased local anthropogenic emissions. The continuous knowledge of MLH is supporting the understanding of processes directing air quality. If the MLH is located near to the ground, which occurs mainly during winter and night-time, air pollution can be high due to a strongly limited air mass dilution. The Vaisala ceilometer CL31, which is an eye-safe commercial mini-lidar system, is used for long-term continuous remote sensing of MLH. The ceilometer measurements provide information about the range-dependent aerosol concentration; gradient minima within this profile mark the borders of mixed layers. Special software for this ceilometer developed with MATLAB provides routine retrievals of lower atmosphere layering from vertical profiles of laser backscatter data. To study the gaseous pollutants and those compounds important for secondary aerosol formation like NO and NO2 as well as O3 The data retrieval software is extended to improve remote sensing of MLH. The original 10-minute-interval values are used to calculate continuous 1-hour-mean values. Gaps and strong variations of the original data are considered. The results of investigations of the meteorological influences and the role of emissions within the context of the air quality in Augsburg are discussed. a DOAS is operated since March 2012 in Augsburg. Information about different road traffic emissions is provided by this one instrument i.e. by path-integrated air pollution information in different directions. The DOAS contains an analyser and an emitter/receiver unit pointing to three retroreflectors. The retroreflectors were installed at lamp masts so that the paths were about 10 m above street level and perpendicular across the streets. The emitter/receiver unit was in a distance of about 20 m to an in situ air pollution measurement station at the ground. Ground

  3. Impacts of compact growth and electric vehicles on future air quality and urban exposures may be mixed.

    PubMed

    Yu, Haofei; Stuart, Amy L

    2017-01-15

    'Smart' growth and electric vehicles are potential solutions to the negative impacts of worldwide urbanization on air pollution and health. However, the effects of planning strategies on distinct types of pollutants, and on human exposures, remain understudied. The goal of this work was to investigate the potential impacts of alternative urban designs for the area around Tampa, Florida USA, on emissions, ambient concentrations, and exposures to oxides of nitrogen (NOx), 1,3-butadiene, and benzene. We studied three potential future scenarios: sprawling growth, compact growth, and 100% vehicle fleet electrification with compact growth. We projected emissions in the seven-county region to 2050 based on One Bay regional visioning plan data. We estimated pollutant concentrations in the county that contains Tampa using the CALPUFF dispersion model. We applied residential population projections to forecast acute (highest hour) and chronic (annual average) exposure. The compact scenario was projected to result in lower regional emissions of all pollutants than sprawl, with differences of -18%, -3%, and -14% for NOx, butadiene, and benzene, respectively. Within Hillsborough County, the compact form also had lower emissions, concentrations, and exposures than sprawl for NOx (-16%/-5% for acute/chronic exposures, respectively), but higher exposures for butadiene (+41%/+30%) and benzene (+21%/+9%). The addition of complete vehicle fleet electrification to the compact scenario mitigated these in-county increases for the latter pollutants, lowering predicted exposures to butadiene (-25%/-39%) and benzene (-5%/-19%), but also resulted in higher exposures to NOx (+81%/+30%) due to increased demand on power plants. These results suggest that compact forms may have mixed impacts on exposures and health. 'Smart' urban designs should consider multiple pollutants and the diverse mix of pollutant sources. Cleaner power generation will also likely be needed to support aggressive adoption

  4. A dynamic urban air pollution population exposure assessment study using model and population density data derived by mobile phone traffic

    NASA Astrophysics Data System (ADS)

    Gariazzo, Claudio; Pelliccioni, Armando; Bolignano, Andrea

    2016-04-01

    A dynamic city-wide air pollution exposure assessment study has been carried out for the urban population of Rome, Italy, by using time resolved population distribution maps, derived by mobile phone traffic data, and modelled air pollutants (NO2, O3 and PM2.5) concentrations obtained by an integrated air dispersion modelling system. More than a million of persons were tracked during two months (March and April 2015) for their position within the city and its surroundings areas, with a time resolution of 15 min and mapped over an irregular grid system with a minimum resolution of 0.26 × 0.34 Km2. In addition, demographics information (as gender and age ranges) were available in a separated dataset not connected with the total population one. Such BigData were matched in time and space with air pollution model results and then used to produce hourly and daily resolved cumulative population exposures during the studied period. A significant mobility of population was identified with higher population densities in downtown areas during daytime increasing of up to 1000 people/Km2 with respect to nigh-time one, likely produced by commuters, tourists and working age population. Strong variability (up to ±50% for NO2) of population exposures were detected as an effect of both mobility and time/spatial changing in pollutants concentrations. A comparison with the correspondent stationary approach based on National Census data, allows detecting the inability of latter in estimating the actual variability of population exposure. Significant underestimations of the amount of population exposed to daily PM2.5 WHO guideline was identified for the Census approach. Very small differences (up to a few μg/m3) on exposure were detected for gender and age ranges population classes.

  5. Association of Roadway Proximity with Indoor Air Pollution in a Peri-Urban Community in Lima, Peru

    PubMed Central

    Underhill, Lindsay J.; Bose, Sonali; Williams, D’Ann L.; Romero, Karina M.; Malpartida, Gary; Breysse, Patrick N.; Klasen, Elizabeth M.; Combe, Juan M.; Checkley, William; Hansel, Nadia N.

    2015-01-01

    The influence of traffic-related air pollution on indoor residential exposure is not well characterized in homes with high natural ventilation in low-income countries. Additionally, domestic allergen exposure is unknown in such populations. We conducted a pilot study of 25 homes in peri-urban Lima, Peru to estimate the effects of roadway proximity and season on residential concentrations. Indoor and outdoor concentrations of particulate matter (PM2.5), nitrogen dioxide (NO2), and black carbon (BC) were measured during two seasons, and allergens were measured in bedroom dust. Allergen levels were highest for dust mite and mouse allergens, with concentrations above clinically relevant thresholds in over a quarter and half of all homes, respectively. Mean indoor and outdoor pollutant concentrations were similar (PM2.5: 20.0 vs. 16.9 μg/m3, BC: 7.6 vs. 8.1 μg/m3, NO2: 7.3 vs. 7.5 ppb), and tended to be higher in the summer compared to the winter. Road proximity was significantly correlated with overall concentrations of outdoor PM2.5 (rs = −0.42, p = 0.01) and NO2 (rs = −0.36, p = 0.03), and outdoor BC concentrations in the winter (rs = −0.51, p = 0.03). Our results suggest that outdoor-sourced pollutants significantly influence indoor air quality in peri-urban Peruvian communities, and homes closer to roadways are particularly vulnerable. PMID:26516875

  6. Atmospheric pollution: a case study of degrading urban air quality over Punjab, India.

    PubMed

    Sehra, Parmjit Singh

    2007-01-01

    This paper presents the results of a case study of urban air quality over a densely populated city Ludhiana situated in Punjab, India, in the form of monthly and annual average concentrations of Suspended Particulate Matter (SPM), NO2 and SO2 for the periods 1988-1989, 1994-1999 and 2001-2005 which is generally found to be increasing with time and thus requires immediate corrective measures lest the situation becomes totally uncontrollable. The present situation is as bad as in other metropolitan Indian cities, although it seems to have somewhat improved as indicated by the latest 2001-2005 data in comparison with the past 1988-1989 and 1994-1999 data, but much more still needs to be done. In addition to the industrial and vehicular pollution, the agricultural pollution due to the burning of wheat and rice straws by the farmers should also be checked because it also creates tremendous pollution in the atmosphere.

  7. Urban ozone air quality impact of emissions from vehicles using reformulated gasolines and M85

    NASA Astrophysics Data System (ADS)

    Chock, D. P.; Winkler, S. L.; Chang, T. Y.; Rudy, S. J.; Shen, Z. K.

    The urban ozone air quality impact of exhaust emissions from vehicles using reformulated gasolines and flexible/variable-fuel vehicles using M85 has been studied using emissions data from the Auto/Oil Air Quality Improvement Research Program and a single-cell trajectory air quality model with two different chemical mechanisms (the updated version of Carbon-Bond-IV (CB4) and the LCC mechanism). Peak ozone concentrations are predicted for each fuel for all combinations of the following ambient conditions: low and high atmospheric dilution or mixing height, four NMOG/NO x ratios, two each of the initial NMOG concentration, the vehicular contribution to the ambient air, and the NMOG composition of the initial ambient mixture. The ozone impact of a fuel dependent strongly on the atmospheric dilution and NMOG/NO x ratio of an area. The differences in ozone impact among fuels are limited under the condition of high atmospheric dilution and a high NMOG/NO x ratio. The ozone-forming potentials (OFPs) for the exhaust emissions based on the maximum incremental reactivities (MIRs) for various fuels are generally well correlated with model-calculated peak ozone levels at a low NMOG/NO x ratio. These OFPs can serve to separate out fuels with rather different reactivities, but not fuels with comparable reactivities. Model-calculated ozone levels for various fuels based on CB4 and LCC mechanisms are relatively well correlated at low NMOG/NO x ratios, but much less so at higher ratios. Fuels with a high aromatic content, including high-toluene fuels, tend to be ranked more favorably by CB4 than by LCC. On the other hand, M85 is ranked more favorably by LCC than by CB4. Fuels with a low 90% boiling point and a low content of aromatics and olefins are generally less reactive. M85 would be an attractive fuel if the formaldehyde emissions could be curtailed significantly.

  8. Urban Chagas disease in children and women in primary care centres in Buenos Aires, Argentina

    PubMed Central

    Moscatelli, Guillermo; Berenstein, Ada; Tarlovsky, Ana; Siniawski, Susana; Biancardi, Miguel; Ballering, Griselda; Moroni, Samanta; Schwarcz, Marta; Hernández, Susana; García-Bournissen, Facundo; Cozzi, Andrés Espejo; Freilij, Héctor; Altcheh, Jaime

    2015-01-01

    The primary objective of this study was to estimate the prevalence of this disease in women of childbearing age and children treated at health centres in underserviced areas of the city of Buenos Aires. Demographic and Chagas disease status data were collected. Samples for Chagas disease serology were obtained on filter paper and the reactive results were confirmed with conventional samples. A total of 1,786 subjects were screened and 73 positive screening results were obtained: 17 were from children and 56 were from women. The Trypanosoma cruzi infection risk was greater in those individuals who had relatives with Chagas disease, who remember seeing kissing bugs, who were of Bolivian nationality or were born in the Argentine province of Santiago del Estero. The overall prevalence of Chagas disease was 4.08%. Due to migration, Chagas disease is currently predominantly urban. The observed prevalence requires health programme activities that are aimed at urban children and their mothers. Most children were infected congenitally, which reinforces the need for Chagas disease screening of all pregnant women and their babies in Argentina. The active search for new cases is important because the appropriate treatment in children has a high cure rate. PMID:26222020

  9. Indoor-Air Microbiome in an Urban Subway Network: Diversity and Dynamics

    PubMed Central

    Leung, Marcus H. Y.; Wilkins, David; Li, Ellen K. T.; Kong, Fred K. F.

    2014-01-01

    Subway systems are indispensable for urban societies, but microbiological characteristics of subway aerosols are relatively unknown. Previous studies investigating microbial compositions in subways employed methodologies that underestimated the diversity of microbial exposure for commuters, with little focus on factors governing subway air microbiology, which may have public health implications. Here, a culture-independent approach unraveling the bacterial diversity within the urban subway network in Hong Kong is presented. Aerosol samples from multiple subway lines and outdoor locations were collected. Targeting the 16S rRNA gene V4 region, extensive taxonomic diversity was found, with the most common bacterial genera in the subway environment among those associated with skin. Overall, subway lines harbored different phylogenetic communities based on α- and β-diversity comparisons, and closer inspection suggests that each community within a line is dependent on architectural characteristics, nearby outdoor microbiomes, and connectedness with other lines. Microbial diversities and assemblages also varied depending on the day sampled, as well as the time of day, and changes in microbial communities between peak and nonpeak commuting hours were attributed largely to increases in skin-associated genera in peak samples. Microbial diversities within the subway were influenced by temperature and relative humidity, while carbon dioxide levels showed a positive correlation with abundances of commuter-associated genera. This Hong Kong data set and communities from previous studies conducted in the United States formed distinct community clusters, indicating that additional work is required to unravel the mechanisms that shape subway microbiomes around the globe. PMID:25172855

  10. MUTATIONS INDUCED BY URBAN AIR AND DRINKING WATER: DO THEY LEAVE A MUTATIONAL SIGNATURE IN HUMAN TUMORS?

    EPA Science Inventory

    Mutations Induced by Urban Air and Drinking Water: Do They Leave a Mutational Signature in Human Tumors?

    Mutation spectra of complex environmental mixtures have been determined thus far only in Salmonella. We have determined mutation spectra for the particulate organics ...

  11. Urbanization Effects on the Microclimate of Manaus: a Modeling Study

    NASA Astrophysics Data System (ADS)

    Souza, D.; Alvalá, R.; Nascimento, M. G. D.

    2015-12-01

    Activities associated with land use and land cover changes and urbanization induce local impacts, such as changes in atmospheric composition in water and energy balances and changes in the ecosystem. Therefore, more studies are needed to evaluate the possible relationship between urban growth and local and regional changes. In the last 30 years, the population of Manaus grew by over 500%, with approximately 1.9 million inhabitants in 2010. Trying to understand the effects of urban growth of the city of Manaus on its microclimate and atmospheric processes, the present study aims to evaluate the possible physical mechanisms related to the urbanization process observed through a study of atmospheric modeling. The results allowed to assess that the presence of the urban area significantly modifies the Surface Energy Balance (SEB), generating a thermal gradient between the city and surrounding regions, favoring the formation and intensification of local atmospheric circulations. The results indicated that with urban growth there is an increase in temperature, decrease in the atmospheric water content and significant changes in the flow at low levels, mainly in the breeze circulations, with significant changes observed in the structure and characteristic of the Planetary Boundary Layer (PBL) over the study area. A positive correlation between the increase of the urban area and increased rainfall was also observed. From the results, it was possible to observe that there is a direct relationship between urban growth and changes in the local microclimate in Manaus.

  12. Urbanization effects on the microclimate of Manaus: A modeling study

    NASA Astrophysics Data System (ADS)

    Souza, Diego Oliveira de; Alvalá, Regina Célia dos Santos; Nascimento, Marília Guedes do

    2016-01-01

    Activities associated with land use and land cover changes and urbanization induce local impacts, such as changes in atmospheric composition in water and energy balances and changes in the ecosystem. Therefore, more studies are needed to evaluate the possible relationship between urban growth and local and regional changes. In the last 30 years, the population of Manaus grew by over 500%, with approximately 1.9 million inhabitants in 2010. Trying to understand the effects of the urban growth of the city of Manaus on its microclimate and atmospheric processes, the present study aims to evaluate the possible physical mechanisms related to the urbanization process observed through a study of atmospheric modeling. The results allowed to assess that the presence of the urban area significantly modifies the surface energy balance (SEB), generating a thermal gradient between the city and the surrounding regions, favoring the formation and intensification of local atmospheric circulations. The results indicated that with urban growth there is an increase in temperature, decrease in the atmospheric water content and significant changes in the flow at low levels, mainly in the breeze circulations, with significant changes observed in the structure and characteristic of the planetary boundary layer (PBL) over the study area. A positive correlation between the increase of the urban area and increased rainfall was also observed. From the results, it was possible to observe that there is a direct relationship between urban growth and changes in the local microclimate in Manaus.

  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. BACT analysis: Are there cost effective air quality benefits from trees?

    SciTech Connect

    McPherson, E.G.; Simpson, J.R.; Scott, K.I.

    1996-12-31

    Trees absorb gaseous pollutants through leaf stomata and can bind or dissolve water soluble pollutants onto moist leaf surfaces. Tree canopies also intercept particulates and reduce local air temperatures. Urban trees may reduce ambient air ozone concentrations, either by direct absorption of ozone or other pollutants such as NO{sub 2}, or by reducing air temperatures, which reduces hydrocarbon emission and ozone formation rates. On the other hand, biogenic hydrocarbon emissions from trees may play a role in ozone formation. The role of trees in air quality has become coupled with concern over the costs and benefits of large-scale urban free planting programs. Air quality management districts provide pollution abatement credits to businesses and institutions by permitting the use of controls or processes, provided they are technically feasible and cost effective, based upon guidelines in Best Available Control Technology (BACT) manuals. Typically BACT analysis is applied to stationary sources, but the authors apply it here to determine if a large-scale urban tree planting can be a cost effective means to improve air quality.

  15. A Study of the Effects of Different Urban Wind Models on Dispersion Patterns Using Joint Urban 2003 Data

    SciTech Connect

    Gowardhan, A A; Brown, M J

    2012-02-21

    The Quick Urban & Industrial Complex (QUIC) Dispersion Modeling System has been developed to rapidly compute the transport and dispersion of toxic agent releases in the vicinity of buildings. It is composed of a wind solver, an 'urbanized' Lagrangian random-walk model, and a graphical user interface. QUIC has two different wind models: (a) The QUIC-URB wind solver, an empirically-based diagnostic wind model and (b) The QUIC-CFD (RANS) solver, based on the 3D Reynolds-Averaged Navier-Stokes (RANS) equations. In this paper, we discuss the effect of different wind models on dispersion patterns in dense built-up areas. The model-computed wind from the two urban wind models- QUIC-URB and QUIC-CFD are used to drive the dispersion model. The concentration fields are then compared to measurements from the Oklahoma City Joint Urban 2003 field experiment. QUIC produces high-resolution 3-D mean wind and concentration fields around buildings, in addition to deposition on the ground and building surfaces. It has options for different release types, including point, moving point, line, area, and volumetric sources, as well as dense gas, explosive buoyant rise, multi-particle size, bioslurry, and two-phase releases. Other features include indoor infiltration, a pressure solver, outer grid simulations, vegetative canopies, and population exposure calculations. It has been used for biological agent sensor siting in cities, vulnerability assessments for heavier-than-air chemical releases at industrial facilities, and clean-up assessments for radiological dispersal device (RDD) releases in cities (e.g., see Linger et al., 2005; Brown, 2006a, b). QUIC has also been used for dust transport studies (Bowker et al., 2007a) and for the impact of highway sound barriers on the transport and dispersion of vehicle emissions (Bowker et al., 2007b).

  16. Human health effects of air pollution.

    PubMed Central

    Folinsbee, L J

    1993-01-01

    Over the past three or four decades, there have been important advances in the understanding of the actions, exposure-response characteristics, and mechanisms of action of many common air pollutants. A multidisciplinary approach using epidemiology, animal toxicology, and controlled human exposure studies has contributed to the database. This review will emphasize studies of humans but will also draw on findings from the other disciplines. Air pollutants have been shown to cause responses ranging from reversible changes in respiratory symptoms and lung function, changes in airway reactivity and inflammation, structural remodeling of pulmonary airways, and impairment of pulmonary host defenses, to increased respiratory morbidity and mortality. Quantitative and qualitative understanding of the effects of a small group of air pollutants has advanced considerably, but the understanding is by no means complete, and the breadth of effects of all air pollutants is only partially understood. PMID:8354181

  17. Numerical study of urbanization effect on a heavy storm event in Beijing

    NASA Astrophysics Data System (ADS)

    Liu, Z.

    2015-12-01

    In the past few decades, Great Beijing area has experienced rapid and widespread urbanization, which has substantially modified the land surface physical characteristics and affected urban regional weather and climate. A single layer urban canopy module has been developed based on the Community Land Surface Model Urban Module (CLMU) with several improvements: the energy balances on the five surface conditions (building roof, sun side and shaded side wall, pervious and impervious land surfaces) are considered separately. A method to calculate sky view factor is developed based on the physically process while most urban models simply provide an empirical value. This method improves the solar and long wave radiation simulation on each surface. The latent heat flux on both wall and impervious land is calculated; the anthropogenic heat is considered in terms of industrial production, domestic wastes, vehicles and air conditions. The urban effect on summer convective precipitation over Beijing was investigated by simulating a heavy storm event on July 21st 2012, when precipitation of averagely 164 mm was brought to Beijing within 6 hours, which is the heaviest during the past 60 years' record in the region. Numerical simulating experiment was set up by coupling Weather Research and Forecast (WRF)/SSiB3 model with the Modified CLMU (MCLMU). Several control cases without MCLMU were set up. The horizontal resolution in the inner domains was set to be 2 km. While all of the control results drastically underestimate the urban precipitation, the result of WRF/SSiB3/MCLMU is much closer to the observation. Sensitive experiments show that although large areas of impervious surfaces restrain the surface latent heat flux in urban, the anthropogenic heat and enhanced sensible heat flux warmed up the lower atmospheric layer then strengthen the vertical stratification instability, which is the key factor for heavy storm while moisture is sufficient.

  18. Numerical Study of Urbanization Effect on 2012 Heavy Storm Precipitation in Beijing

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Liu, S.; Xue, Y.; Oleson, K. W.

    2014-12-01

    In the past few decades, Great Beijing area has experienced rapid and widespread urbanization, which has significantly modified the land surface physical characteristics and affects urban regional climate.A single layer urban canopy module has been developed based on the Community Land Surface Model Urban Module (CLMU) with improvements: the energy balances on the five surface conditions are considered separately: building roof, sun side and shaded side wall, pervious and impervious land surface. A method to calculate sky view factor is developed based on the physically process while most urban models simply provide an empirical value. This method improves the solar and long wave radiation simulation on each surface; a new scheme for calculating the latent heat flux is applied on both wall and impervious land; the anthropogenic heat is considered in terms of industrial production, domestic wastes, vehicles and air condition. The urban effect on summer convective precipitation under the unstable atmospheric condition over Beijing was investigated by simulating a heavy storm event in July 21st 2012. In this storm, precipitation of averagely 164 mm was brought to Beijing within 6 hours, which is the record of past 60 years in the region. Numerical simulating experiment was set up by coupling Weather Research and Forecast (WRF)/SSiB3 model with the Modified CLMU (MCLMU). Several control cases without MCLMU were set up. The horizontal resolution in the inner domains was set to be 2 km. While all of the control results drastically underestimate the urban precipitation, the result of WRF/SSiB3/MCLMU is much closer to the observation. Sensitive experiments show that the existence of large area of impervious surfaces restrain the surface evaporation and latent heat flux in urban while the anthropogenic heat and enhanced sensible heat flux warm up the lower atmospheric layer and strengthen the vertical stratification instability, which is the key factor for storm while

  19. Radiation fog and urban climate

    SciTech Connect

    Sachweh, M.; Koepke, P.

    1995-05-01

    Fog data of Southern Germany from the period 1949-1990 indicate a significant urban influence on fog frequency. An increase of the urban building density is connected with a reduction in the average number of fog days, which is interpreted as an effect of the urban heat island and moisture deficit. Feedback mechanisms which intensify the urban-rural contrast are discussed. The results are transferable to large cities with relatively good air quality.

  20. Trends of air pollution in the Western Mediterranean Basin from a 13-year database: A research considering regional, suburban and urban environments in Mallorca (Balearic Islands)

    NASA Astrophysics Data System (ADS)

    Cerro, J. C.; Cerdà, V.; Pey, J.

    2015-02-01

    This study is focused in the evolution of NO, NO2, SO2, O3 and PM10 concentrations, from 2000 to 2012, at urban, suburban and regional observatories in the Balearic Islands (Spain), an insular region in the Western Mediterranean. At urban and suburban areas, daily patterns of most pollutants are strongly linked to land-traffic emissions, being the regional background less influenced. SO2 variations, however, are mostly driven by the impact of other sources different from road traffic, including shipping emissions and power generation. Urban NOx, SO2 and PM10 concentrations exhibit a common weekly pattern, with a very slight accumulation during the weekdays and sharp decreases (15-39%) on weekends. Our long-term database displays clear decreasing NO and NO2 concentrations from 2000 onwards, prominent in the urban environment (-1.1 μg/m3 year), and moderate in suburban and regional areas (up to -0.3 μg/m3 year). At urban sites, O3 behaviour (+1.0 μg/m3 year) is opposite to that of NO, one of its main depletion agents. A moderate O3 increasing trend (+0.5 μg/m3 year) is detected at regional background areas, whereas a modest decreasing trend occurred at the suburban background (-0.4 μg/m3 year), probably caused by enhanced vehicular emissions over these areas induced by urban planning and mobility policies. Finally, substantial PM10 drops are obvious, -0.7 μg/m3 year at urban and suburban areas, and -0.5 μg/m3 year in the regional background. Our results link the sharpest declines to air masses from western to northern sectors, pointing to effective pollution abatement strategies at a European scale. Some additional benefits are connected to the implementation of diverse local policies. The effect of the North Atlantic Oscillation (NAO) was investigated. Negative NAO phases were related to additional air quality benefits, while positive phases mostly contributed to air degradation.

  1. Urban pollution.

    PubMed

    Sancini, Angela; Tomei, Francesco; Tomei, Gianfranco; Caciari, Tiziana; Di Giorgio, Valeria; André, Jean-Claude; Palermo, Paola; Andreozzi, Giorgia; Nardone, Nadia; Schifano, Maria Pia; Fiaschetti, Maria; Cetica, Carlotta; Ciarrocca, Manuela

    2012-01-01

    Air pollution represents a health risk for people living in urban environment. Urban air consists in a complex mixture of chemicals and carcinogens and its effects on health can be summarized in acute respiratory effects, neoplastic nonneoplastic (e.g. chronic bronchitis) chronic respiratory effects, and effects on other organs and systems. Air pollution may be defined according to origin of the phenomena that determine it: natural causes (natural fumes, decomposition, volcanic ash) or anthropogenic causes which are the result of human activities (industrial and civil emissions). Transport is the sector that more than others contributes to the deterioration of air quality in cities. In this context, in recent years, governments of the territory were asked to advance policies aimed at solving problems related to pollution. In consideration of the many effects on health caused by pollution it becomes necessary to know the risks from exposure to various environmental pollutants and to limit and control their effects. Many are the categories of "outdoor" workers, who daily serve the in urban environment: police, drivers, newsagents, etc.

  2. An Investigation of Urban Air Pollution in Xi'an, China

    NASA Astrophysics Data System (ADS)

    Jobson, B. T.; VanReken, T. M.; VanderSchelden, G.; Erickson, M. H.; Wallace, H. W.; Mwaniki, G. R.; Cao, J.; Tie, X.; O'Keeffe, P.; Lamb, B. K.; Waldo, S.

    2012-12-01

    As the world's urban population continues to grow, the environmental problems associated with large population centers continue to be exacerbated. Because of this, understanding the environmental impacts of the world's large urban areas is becoming more and more important, especially in areas of the world for which limited data exists. In this study, measurements of a suite of air pollutants were made in Xi'an, China in August of 2011, to assess the concentrations and emission trends of air pollutants in an emerging Chinese megacity. The study site was located on the campus of Jaiotong University, with the sampling inlet positioned at the top of a 23 meter scaffold tower which was on top of a 100 meter tall building. In this study, measurements of nitrogen oxides (NOx) were made by chemiluminescence, measurements of carbon monoxide (CO) and ozone (O3) were made by absorption spectroscopy, and measurements of volatile organic compounds (VOCs) were made by proton transfer reaction mass spectrometer (PTR-MS). CO, O3, and VOC data were taken for approximately three weeks, while NOx data were taken for ten days at the end of the campaign. VOC data was in the form of low frequency mass scans for the first half of the campaign and of high frequency measurements of acetaldehyde, benzene, and toluene for the second half. The diel trends in the mixing ratios of CO, NOx, acetaldehyde, benzene, and toluene displayed an increase at sunrise associated with morning vehicle traffic, a maximum in the mid morning and a minimum in the late afternoon. Ozone mixing ratios displayed the trend typical to urban areas, increasing after sunrise to a maximum in the late afternoon and decreasing to a minimum in the early morning. CO-to-NOx molar ratios were calculated by plotting CO against NOx and creating a linear fit to the data. This linear fit had a slope of 12.2 and an R2 of 0.39. This ratio is greater than what is typically observed in US cities. Data from the Xi'an campaign were

  3. The effectiveness of cool and green roofs as urban heat island mitigation strategies

    NASA Astrophysics Data System (ADS)

    Li, Dan; Bou-Zeid, Elie; Oppenheimer, Michael

    2014-05-01

    Mitigation of the urban heat island (UHI) effect at the city-scale is investigated using the Weather Research and Forecasting (WRF) model in conjunction with the Princeton Urban Canopy Model (PUCM). Specifically, the cooling impacts of green roof and cool (white/high-albedo) roof strategies over the Baltimore-Washington metropolitan area during a heat wave period (7 June-10 June 2008) are assessed using the optimal set-up of WRF-PUCM described in the companion paper by Li and Bou-Zeid (2014). Results indicate that the surface UHI effect (defined based on the urban-rural surface temperature difference) is reduced significantly more than the near-surface UHI effect (defined based on urban-rural 2 m air temperature difference) when these mitigation strategies are adopted. In addition, as the green and cool roof fractions increase, the surface and near-surface UHIs are reduced almost linearly. Green roofs with relatively abundant soil moisture have comparable effect in reducing the surface and near-surface UHIs to cool roofs with an albedo value of 0.7. Significant indirect effects are also observed for both green and cool roof strategies; mainly, the low-level advection of atmospheric moisture from rural areas into urban terrain is enhanced when the fraction of these roofs increases, thus increasing the humidity in urban areas. The additional benefits or penalties associated with modifications of the main physical determinants of green or cool roof performance are also investigated. For green roofs, when the soil moisture is increased by irrigation, additional cooling effect is obtained, especially when the ‘unmanaged’ soil moisture is low. The effects of changing the albedo of cool roofs are also substantial. These results also underline the capabilities of the WRF-PUCM framework to support detailed analysis and diagnosis of the UHI phenomenon, and of its different mitigation strategies.

  4. Day and night variation in chemical composition and toxicological responses of size segregated urban air PM samples in a high air pollution situation

    NASA Astrophysics Data System (ADS)

    Jalava, P. I.; Wang, Q.; Kuuspalo, K.; Ruusunen, J.; Hao, L.; Fang, D.; Väisänen, O.; Ruuskanen, A.; Sippula, O.; Happo, M. S.; Uski, O.; Kasurinen, S.; Torvela, T.; Koponen, H.; Lehtinen, K. E. J.; Komppula, M.; Gu, C.; Jokiniemi, J.; Hirvonen, M.-R.

    2015-11-01

    Urban air particulate pollution is a known cause for adverse human health effects worldwide. China has encountered air quality problems in recent years due to rapid industrialization. Toxicological effects induced by particulate air pollution vary with particle sizes and season. However, it is not known how distinctively different photochemical activity and different emission sources during the day and the night affect the chemical composition of the PM size ranges and subsequently how it is reflected to the toxicological properties of the PM exposures. The particulate matter (PM) samples were collected in four different size ranges (PM10-2.5; PM2.5-1; PM1-0.2 and PM0.2) with a high volume cascade impactor. The PM samples were extracted with methanol, dried and thereafter used in the chemical and toxicological analyses. RAW264.7 macrophages were exposed to the particulate samples in four different doses for 24 h. Cytotoxicity, inflammatory parameters, cell cycle and genotoxicity were measured after exposure of the cells to particulate samples. Particles were characterized for their chemical composition, including ions, element and PAH compounds, and transmission electron microscopy (TEM) was used to take images of the PM samples. Chemical composition and the induced toxicological responses of the size segregated PM samples showed considerable size dependent differences as well as day to night variation. The PM10-2.5 and the PM0.2 samples had the highest inflammatory potency among the size ranges. Instead, almost all the PM samples were equally cytotoxic and only minor differences were seen in genotoxicity and cell cycle effects. Overall, the PM0.2 samples had the highest toxic potential among the different size ranges in many parameters. PAH compounds in the samples and were generally more abundant during the night than the day, indicating possible photo-oxidation of the PAH compounds due to solar radiation. This was reflected to different toxicity in the PM

  5. The use of electrochemical sensors for monitoring urban air quality in low-cost, high-density networks

    NASA Astrophysics Data System (ADS)

    Mead, M. I.; Popoola, O. A. M.; Stewart, G. B.; Landshoff, P.; Calleja, M.; Hayes, M.; Baldovi, J. J.; McLeod, M. W.; Hodgson, T. F.; Dicks, J.; Lewis, A.; Cohen, J.; Baron, R.; Saffell, J. R.; Jones, R. L.

    2013-05-01

    Measurements at appropriate spatial and temporal scales are essential for understanding and monitoring spatially heterogeneous environments with complex and highly variable emission sources, such as in urban areas. However, the costs and complexity of conventional air quality measurement methods means that measurement networks are generally extremely sparse. In this paper we show that miniature, low-cost electrochemical gas sensors, traditionally used for sensing at parts-per-million (ppm) mixing ratios can, when suitably configured and operated, be used for parts-per-billion (ppb) level studies for gases relevant to urban air quality. Sensor nodes, in this case consisting of multiple individual electrochemical sensors, can be low-cost and highly portable, thus allowing the deployment of scalable high-density air quality sensor networks at fine spatial and temporal scales, and in both static and mobile configurations. In this paper we provide evidence for the performance of electrochemical sensors at the parts-per-billion level, and then outline results obtained from deployments of networks of sensor nodes in both an autonomous, high-density, static network in the wider Cambridge (UK) area, and as mobile networks for quantification of personal exposure. Examples are presented of measurements obtained with both highly portable devices held by pedestrians and cyclists, and static devices attached to street furniture. The widely varying mixing ratios reported by this study confirm that the urban environment cannot be fully characterised using sparse, static networks, and that measurement networks with higher resolution (both spatially and temporally) are required to quantify air quality at the scales which are present in the urban environment. We conclude that the instruments described here, and the low-cost/high-density measurement philosophy which underpins it, have the potential to provide a far more complete assessment of the high-granularity air quality structure

  6. Evaluating the effectiveness of air quality interventions.

    PubMed

    van Erp, Annemoon M M; O'Keefe, Robert; Cohen, Aaron J; Warren, Jane

    2008-01-01

    Evaluating the extent to which air quality regulations improve public health--sometimes referred to as accountability--is part of an emerging effort to assess the effectiveness of environmental regulatory policies. Air quality has improved substantially in the United States and Western Europe in recent decades, with far less visible pollution and decreasing concentrations of several major pollutants. In large part, these gains were achieved through increasingly stringent air quality regulations. The costs associated with compliance and, importantly, the need to ensure that the regulations are achieving the intended public health benefits underscore the importance of accountability research. To date, accountability research has emphasized measuring the effects of actions already taken to improve air quality. Such research may also contribute to estimating the burden of disease that might be avoided in the future if certain actions are taken. The Health Effects Institute (HEI) currently funds eight ongoing studies on accountability, which cover near-term interventions to improve air quality including (1) a ban on the sale of coal, (2) replacing old wood stoves with cleaner ones, (3) decreasing sulfur content in fuel, (4) measures to reduce traffic, and (5) longer term, wide-ranging actions or events (such as complex changes associated with the reunification of Germany). HEI is also funding the development of methods and research to assess regulations that are implemented incrementally over extended periods of time, such as Title IV of the 1990 Clean Air Act Amendments, which reduces sulfur dioxide emissions from power plants in the eastern United States.

  7. A numerical investigation of the impact of low boundary walls on pedestrian exposure to air pollutants in urban street canyons.

    PubMed

    McNabola, A; Broderick, B M; Gill, L W

    2009-01-01

    A previous investigation into methods of exposure reduction for the pedestrian in the urban commuter environment highlighted the impact of a low boundary wall on the dispersion of air pollutants from adjacent traffic sources. The impact of low boundary walls on the dispersion of air pollutants in street canyons has been brought forward in this investigation to examine them, in more generic terms, with a view to highlighting exposure reduction strategies for pedestrians. 3D Computational Fluid Dynamics (CFD) models were used to examine this effect for varying wind speeds and directions in different street canyon geometries. The results of this investigation show that a low boundary wall located at the central median of the street canyon creates a significant reduction in pedestrian exposure on the footpath. Reductions of up to 40% were found for perpendicular wind directions and up to 75% for parallel wind directions, relative to the same canyon with no wall. The magnitude of the exposure reduction was also found to vary according to street canyon geometry and wind speed.

  8. Traffic contribution to air pollution in urban street canyons: Integrated application of the OSPM, moss biomonitoring and spectral analysis

    NASA Astrophysics Data System (ADS)

    Lazić, Lazar; Urošević, Mira Aničić; Mijić, Zoran; Vuković, Gordana; Ilić, Luka

    2016-09-01

    To investigate the air pollutant distribution within the ambient of urban street canyon, Operational Street Pollution Model (OSPM) was used to predict hourly content of NOX, NO, NO2, O3, CO, BNZ and PM10. The study was performed in five street canyons in Belgrade (Serbia) during 10-week summer period. The model receptors were located on each side of street canyons at 4 m, 8 m and 16 m height. To monitor airborne trace element content, the moss bag biomonitors were simultaneously exposed with the model receptors at two heights-4 m and 16 m. The results of both methods, modelling and biomonitoring, showed significantly decreasing trend of the air pollutants with height. The results indirectly demonstrate that biomonitoring, i.e., moss bag technique could be a valuable tool to verify model performance. In addition, spectral analysis was applied to investigate weekly variation of the daily background and modelled data set. Typical periodicities and weekend effect, caused by anthropogenic influences, have been identified.

  9. Analysis of Mexico City urban air pollution using nitrogen dioxide column density measurements from UV/Visible spectroscopy

    NASA Astrophysics Data System (ADS)

    Garcia Payne, D. G.; Grutter, M.; Melamed, M. L.

    2010-12-01

    The differential optical absorption spectroscopy method (DOAS) was used to get column densities of nitrogen dioxide (NO2) from the analysis of zenith sky UV/visible spectra. Since the optical path length provides critical information in interpreting NO2 column densities, in conjunction with NO2 column densities, the oxygen dimer (O4) column density was retrieved to give insight into the optical path length. We report observations of year round NO2 and O4 column densities (from august 2009 to september 2010) from which the mean seasonal levels and the daily evolution, as well as the occurrence of elevated pollution episodes are examined. Surface nitric oxide (NO) and NO2 from the local monitoring network, as well as wind data and the vertical aerosol density from continuous Lidar measurements are used in the analysis to investigate specific events in the context of local emissions from vehicular traffic, photochemical production and transport from industrial emissions. The NO2 column density measurements will enhance the understanding Mexico City urban air pollution. Recent research has begun to unravel the complexity of the air pollution problem in Mexico City and its effects not only locally but on a regional and global scale as well.

  10. 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.

  11. The Bigger, the Better? The Influence of Urban Green Space Design on Cooling Effects for Residential Areas.

    PubMed

    Jaganmohan, Madhumitha; Knapp, Sonja; Buchmann, Carsten M; Schwarz, Nina

    2016-01-01

    It is well known that the cooling effect of an urban green space extends into its surroundings, cooling the immediate environment and mitigating urban heat problems. However, the effects of size, shape, and type of an urban green space on cooling remain uncertain. The objectives of our study were to quantify and compare the strength of the cooling effects of urban parks and forests, to determine how far the cooling effects extend into the surrounding residential environment, and to better understand how temperature gradients are driven by physical characteristics of the green space and the surroundings. Mobile air temperature measurements were performed in 62 urban parks and forests in the city of Leipzig, Germany, in the summer of 2013. Three indicators of cooling were calculated: the change in temperature (ΔT) at the park-width distance, the maximum ΔT, and the cooling distance. The relationships of these variables to the physical characteristics of the green spaces and their surroundings were examined in multiple regression models. Analyzing all three indicators revealed that cooling effects were greater in urban forests than in parks. Cooling increased with increasing size but in a different manner for forests and parks, whereas the influence of shape was the same for forests and parks. Generally, the characteristics of the green spaces were more important than the characteristics of the residential surroundings. These findings have the potential to assist in better planning and designing of urban green spaces to increase their cooling effects.

  12. How Can Urban Policies Improve Air Quality and Help Mitigate Global Climate Change: a Systematic Mapping Review.

    PubMed

    Slovic, Anne Dorothée; de Oliveira, Maria Aparecida; Biehl, João; Ribeiro, Helena

    2016-02-01

    Tackling climate change at the global level is central to a growing field of scientific research on topics such as environmental health, disease burden, and its resulting economic impacts. At the local level, cities constitute an important hub of atmospheric pollution due to the large amount of pollutants that they emit. As the world population shifts to urban centers, cities will increasingly concentrate more exposed populations. Yet, there is still significant progress to be made in understanding the contribution of urban pollutants other than CO2, such as vehicle emissions, to global climate change. It is therefore particularly important to study how local governments are managing urban air pollution. This paper presents an overview of local air pollution control policies and programs that aim to reduce air pollution levels in megacities. It also presents evidence measuring their efficacy. The paper argues that local air pollution policies are not only beneficial for cities but are also important for mitigating and adapting to global climate change. The results systematize several policy approaches used around the world and suggest the need for more in-depth cross-city studies with the potential to highlight best practices both locally and globally. Finally, it calls for the inclusion of a more human rights-based approach as a mean of guaranteeing of clean air for all and reducing factors that exacerbate climate change.

  13. Field comparison of portable and stationary instruments for outdoor urban air exposure assessments

    NASA Astrophysics Data System (ADS)

    Viana, M.; Rivas, I.; Reche, C.; Fonseca, A. S.; Pérez, N.; Querol, X.; Alastuey, A.; Álvarez-Pedrerol, M.; Sunyer, J.

    2015-12-01

    The performance of three portable monitors (micro-aethalometer AE51, DiscMini, Dusttrak DRX) was assessed for outdoor air exposure assessment in a representative Southern European urban environment. The parameters evaluated were black carbon, particle number concentration, alveolar lung-deposited surface area, mean particle diameter, PM10, PM2.5 and PM1. The performance was tested by comparison with widely used stationary instruments (MAAP, CPC, SMPS, NSAM, GRIMM aerosol spectrometer). Results evidenced a good agreement between most portable and stationary instruments, with R2 values mostly >0.80. Relative differences between portable and stationary instruments were mostly <20%, and <10% between different units of the same instrument. The only exception was found for the Dusttrak DRX measurements, for which occasional concentration jumps in the time series were detected. Our results validate the performance of the black carbon, particle number concentration, particle surface area and mean particle diameter monitors as indicative instruments (tier 2) for outdoor air exposure assessment studies.

  14. Levels and seasonal variations of organochlorine pesticides in urban and rural background air of southern Ghana.

    PubMed

    Adu-Kumi, Sam; Kareš, Radovan; Literák, Jaromír; Borůvková, Jana; Yeboah, Philip O; Carboo, Derick; Akoto, Osei; Darko, Godfred; Osae, Shiloh; Klánová, Jana

    2012-07-01

    Urban, suburban and rural background air samples were collected in southern Ghana in 2008 employing polyurethane foam disc passive air samplers (PAS). PAS were analysed for organochlorine pesticides (OCPs), namely hexachlorocyclohexanes (α-, β-, γ- and δ-hexachlorocyclohexane), dichlorodiphenyltrichloroethane including metabolites (o,p'- and p,p'-DDT, DDE and DDD), hexachlorobenzene, pentachlorobenzene, aldrin, dieldrin, endrins (endrin, endrin aldehyde and endrin ketone), isodrin, heptachlors (heptachlor, heptachlor epoxide A and heptachlor epoxide B), chlordanes (α-, β-chlordane, oxychlordane and trans-nonachlor), endosulfans (α- and β-endosulfan and endosulfan sulphate), methoxychlor and mirex using a gas chromatograph coupled to a mass spectrometer. The levels of OCPs ranged for the individual pesticides from below limit of quantification to 750 pg m(-3) (for α-endosulfan), and current agricultural application seemed to be the main primary source of most abundant pesticides. Re-volatilization of previously used pesticides from contaminated soils could not be ruled out either as potential secondary source of contamination, especially in warm and dry seasons and periods of intensive agricultural activities. Higher atmospheric concentrations were observed in November and December during the dry season compared to lower concentrations observed in June, July and August when the country experiences heavy rains. The highest seasonal variation was observed for currently used pesticides as α-endosulfan. A p,p'-DDT/p,p'-DDE ratio suggested recent inputs of fresh technical DDT.

  15. Inverse air pollution modelling of urban-scale carbon monoxide emissions

    NASA Astrophysics Data System (ADS)

    Mulholland, Michael; Seinfeld, John H.

    A new recursive least-squares technique is developed to give spatial and temporal definition to the adjustments necessary in an emission inventory, to fit ambient concentration observations optimally. The CIT Photochemical Airshed Model is used to compute CO concentration distributions arising from 29 separate source domains in the South Coast Air Basin of California. A Kalman filter integrated within the model matches predictions with CO observations at 27 locations by superposing the computed distributions with optimal weighting factors. The filter structure allows control of the extent to which adjusted emission inventories are allowed to deviate from a base-case, which already has high spatial and temporal definition. Applied to the Southern California Air Quality Study, 27-29 August 1987, strong temporal dependence was noted in the necessary adjustment to the available CO emission inventory, with a peak factor of 3.0 at midday on weekdays. The spatial resolution of the technique revealed new high-emission zones for CO in a corridor between Pasadena and San Bernardino, in the Riverside-Corona area, and along the Pacific coast on Saturday. In this first such application to an urban environment, some success was also achieved in correcting the phasing of emissions for errors arising from the neglect of source-receptor lags in the inverse modelling technique.

  16. Impact of urban emission on air-quality over central Europe: present day and future emissions perspective

    NASA Astrophysics Data System (ADS)

    Huszar, Peter; Belda, Michal; Halenka, Tomas; Karlicky, Jan

    2016-04-01

    The purpose of the study is to quantify the impact of present-day and future urban emission from central European cities on the regional air-quality (AQ), based on a modeling couple of the regional climate model RegCM4.2 and the chemistry transport model CAMx, including two-way interactions. A series of simulations was carried out for the present (2001-2010) decade and two future decades (2026-2035 and 2046-2055) either with all urban emissions included (base case) or without considering urban emissions. As we are interested on the impact of emission changes only, the impact of different driving meteorological conditions in the future (due to climate change) are not considered. The emissions used is the TNO MEGAPOLI European emission database that includes country/sector based scenarios for years 2030 and 2050, which were used for the encompassing decades. Further, the sensitivity of ozone production to urban emissions was examined by performing reduction experiments with -20% emission perturbation of NOx and/or NMVOC. The model was also validated using surface measurements of key pollutants. Selected air-quality measures were used as metrics describing the cities emission impact on regional air pollution. Due to urban emissions, significant ozone titration occurs over cities while over rural areas further from, ozone production is modeled, mainly in terms of number of exceedances and accumulated exceedances over the threshold of 40 ppbv. Urban NOx, SO2 and PM2.5 emissions also significantly contribute to concentrations in the cities themselves (up to 50-70% for NOx and SO2 , and up to 55% for PM2.5), but the contribution is large over rural areas as well (10-20%). Although air pollution over cities is largely determined by the local urban emissions, considerable (often a few tens of %) fraction of the concentration is attributable to other sources from rural areas and minor cities. The future urban emission AQ fingerprint is, in general, slightly smaller than in

  17. Real-time sensors for indoor air monitoring and challenges ahead in deploying them to urban buildings.

    PubMed

    Kumar, Prashant; Skouloudis, Andreas N; Bell, Margaret; Viana, Mar; Carotta, M Cristina; Biskos, George; Morawska, Lidia

    2016-08-01

    Household air pollution is ranked the 9(th) largest Global Burden of Disease risk (Forouzanfar et al., The Lancet 2015). People, particularly urban dwellers, typically spend over 90% of their daily time indoors, where levels of air pollution often surpass those of outdoor environments. Indoor air quality (IAQ) standards and approaches for assessment and control of indoor air require measurements of pollutant concentrations and thermal comfort using conventional instruments. However, the outcomes of such measurements are usually averages over long integrated time periods, which become available after the exposure has already occurred. Moreover, conventional monitoring is generally incapable of addressing temporal and spatial heterogeneity of indoor air pollution, or providing information on peak exposures that occur when specific indoor sources are in operation. This article provides a review of new air pollution sensing methods to determine IAQ and discusses how real-time sensing could bring a paradigm shift in controlling the concentration of key air pollutants in billions of urban houses worldwide. We also show that besides the opportunities, challenges still remain in terms of maturing technologies, or data mining and their interpretation. Moreover, we discuss further research and essential development needed to close gaps between what is available today and needed tomorrow. In particular, we demonstrate that awareness of IAQ risks and availability of appropriate regulation are lagging behind the technologies.

  18. The use of a vegetation index for assessment of the urban heat island effect

    NASA Technical Reports Server (NTRS)

    Gallo, K. P.; Mcnab, A. L.; Karl, T. R.; Brown, J. F.; Hood, J. J.; Tarpley, J. D.

    1993-01-01

    A vegetation index and radiative surface temperature were derived from NOAA-11 Advanced Very High Resolution Radiometer (AVHRR) data for the Seattle, WA region from 28 June through 4 July 1991. The vegetation index and surface temperature values were computed for locations of weather observation stations within the region and compared to observed minimum air temperatures. These comparisons were used to evaluate the use of AVHRR data to assess the influence of the urban environment on observed minimum air temperatures (the urban heat island effect). AVHRR derived normalized difference vegetation index (NDVI) and radiant surface temperature data from a one week composite product were both related significantly to observed minimum temperatures, however, the vegetation index accounted for a greater amount of the spatial variation observed in mean minimum temperatures. The difference in the NDVI between urban and rural regions appears to be an indicator of the difference in surface properties (i.e., evaporation and heat storage capacity) between the two environments that are responsible for differences in urban and rural minimum temperatures.

  19. 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.

  20. Effects of Urban Landscape Pattern on PM2.5 Pollution—A Beijing Case Study

    PubMed Central

    Wu, Jiansheng; Xie, Wudan; Li, Weifeng; Li, Jiacheng

    2015-01-01

    PM2.5 refers to particulate matter (PM) in air that is less than 2.5μm in aerodynamic diameter, which has negative effects on air quality and human health. PM2.5 is the main pollutant source in haze occurring in Beijing, and it also has caused many problems in other cities. Previous studies have focused mostly on the relationship between land use and air quality, but less research has specifically explored the effects of urban landscape patterns on PM2.5. This study considered the rapidly growing and heavily polluted Beijing, China. To better understand the impact of urban landscape pattern on PM2.5 pollution, five landscape metrics including PLAND, PD, ED, SHEI, and CONTAG were applied in the study. Further, other data, such as street networks, population density, and elevation considered as factors influencing PM2.5, were obtained through RS and GIS. By means of correlation analysis and stepwise multiple regression, the effects of landscape pattern on PM2.5 concentration was explored. The results showed that (1) at class-level, vegetation and water were significant landscape components in reducing PM2.5 concentration, while cropland played a special role in PM2.5 concentration; (2) landscape configuration (ED and PD) features at class-level had obvious effects on particulate matter; and (3) at the landscape-level, the evenness (SHEI) and fragmentation (CONTAG) of the whole landscape related closely with PM2.5 concentration. Results of this study could expand our understanding of the role of urban landscape pattern on PM2.5 and provide useful information for urban planning. PMID:26565799

  1. Effects of Urban Landscape Pattern on PM2.5 Pollution--A Beijing Case Study.

    PubMed

    Wu, Jiansheng; Xie, Wudan; Li, Weifeng; Li, Jiacheng

    2015-01-01

    PM2.5 refers to particulate matter (PM) in air that is less than 2.5 μm in aerodynamic diameter, which has negative effects on air quality and human health. PM2.5 is the main pollutant source in haze occurring in Beijing, and it also has caused many problems in other cities. Previous studies have focused mostly on the relationship between land use and air quality, but less research has specifically explored the effects of urban landscape patterns on PM2.5. This study considered the rapidly growing and heavily polluted Beijing, China. To better understand the impact of urban landscape pattern on PM2.5 pollution, five landscape metrics including PLAND, PD, ED, SHEI, and CONTAG were applied in the study. Further, other data, such as street networks, population density, and elevation considered as factors influencing PM2.5, were obtained through RS and GIS. By means of correlation analysis and stepwise multiple regression, the effects of landscape pattern on PM2.5 concentration was explored. The results showed that (1) at class-level, vegetation and water were significant landscape components in reducing PM2.5 concentration, while cropland played a special role in PM2.5 concentration; (2) landscape configuration (ED and PD) features at class-level had obvious effects on particulate matter; and (3) at the landscape-level, the evenness (SHEI) and fragmentation (CONTAG) of the whole landscape related closely with PM2.5 concentration. Results of this study could expand our understanding of the role of urban landscape pattern on PM2.5 and provide useful information for urban planning.

  2. Variability of carbonaceous aerosols in remote, rural, urban and industrial environments in Spain: implications for air quality policy

    NASA Astrophysics Data System (ADS)

    Querol, X.; Alastuey, A.; Viana, M.; Moreno, T.; Reche, C.; Minguillón, M. C.; Ripoll, A.; Pandolfi, M.; Amato, F.; Karanasiou, A.; Pérez, N.; Pey, J.; Cusack, M.; Vázquez, R.; Plana, F.; Dall'Osto, M.; de la Rosa, J.; de la Campa Sánchez, A.; Fernández-Camacho, R.; Rodríguez, S.; Pío, C.; Alados-Arboledas, L.; Titos, G.; Artíñano, B.; Salvador, P.; Dos Santos García, S.; Patier Fernández, R.

    2013-03-01

    standards have been much less effective for the abatement of NOx exhaust emissions in passenger diesel cars. This study concludes that EC, EBC, and especially nmC and OC+EC are very good candidates for new air quality standards since they cover both emission impact and health related issues.

  3. Variability of carbonaceous aerosols in remote, rural, urban and industrial environments in Spain: implications for air quality policy

    NASA Astrophysics Data System (ADS)

    Querol, X.; Alastuey, A.; Viana, M.; Moreno, T.; Reche, C.; Minguillón, M. C.; Ripoll, A.; Pandolfi, M.; Amato, F.; Karanasiou, A.; Pérez, N.; Pey, J.; Cusack, M.; Vázquez, R.; Plana, F.; Dall'Osto, M.; de la Rosa, J.; Sánchez de la Campa, A.; Fernández-Camacho, R.; Rodríguez, S.; Pio, C.; Alados-Arboledas, L.; Titos, G.; Artíñano, B.; Salvador, P.; García Dos Santos, S.; Fernández Patier, R.

    2013-07-01

    NO2 / (OC + EC) ratios as these standards have been much less effective for the abatement of NOx exhaust emissions in passenger diesel cars. This study concludes that EC, EBC, and especially nmC and OC + EC are very good candidates for new air quality standards since they cover both emission impact and health-related issues.

  4. Measuring of urban ultrafine aerosol as a part of regular air pollution monitoring activities

    NASA Astrophysics Data System (ADS)

    Hejkrlík, Libor; Plachá, Helena

    2015-04-01

    Number size distribution of UFP has been measured since June 2012 to present time (end of 2014) at a background urban site in Northern Bohemia in the frame of UltraSchwarz Project. The project sustainability guarantees at least five years further measuring thus this highly specific activity already becomes part of existing air pollution monitoring system of Czech Hydrometeorological Institute. Number concentrations of UFP were measured by SMPS in a diameter range of 10 to 800 nm in 7 channels with time resolution of 10 minutes. For the purposes of this study the data were re-arranged into series of one-hour means in three size categories: nucleation mode (10-30 nm), Aitken mode (30-100 nm) and accumulation mode (100-800 nm). At the same measuring site 7 other air pollutants (PM1-BC, NO, NOX, NO2, O3, PM10 and SO2) were measured with identical time resolution. The successive daily courses of submicron particles in three size modes as well as of seven other ambient air pollutants were drawn in the form of 3D surface diagrams expressing different behavior of specific substances in the course of 26 months of continuous measuring campaign, allowing for analysis of both diurnal and seasonal changes. The three modes of UFP manifest diverse pictures, the nucleation mode is apparent mainly during warm seasons, the particles in Aitken mode behave rather indifferently to the period of the year and the accumulation mode has close relationship to coarse particles. Month by month correlation analysis indicate that nucleation mode nanoparticles are positively correlated especially with increasing O3 and SO2 concentration and that there exists connection between Aitken and accumulation modes and nitrogen oxides. In order to better understand fine time patterns we plan to calculate moving correlation indices over shorter time periods. Good idea would also be to make use of large database of data from nearby stations of CHMI to analyze the role of meteorological conditions.

  5. The Effectiveness of Light Shelf in Tropical Urban Context

    NASA Astrophysics Data System (ADS)

    Binarti, Floriberta; Dewi, Sinta

    2016-12-01

    Light shelf was developed to create uniform indoor illuminance. However, in hot climates the unshaded clerestory above the shelf transmits high solar heat gain. In dense urban context, these advantages and disadvantages might vary regarding the context and position of the fenestration. This study employed an integrated energy simulation software to investigate the effectiveness of light shelf application in a tropical urban context in terms of building energy consumption. Radiance and EnergyPlus based simulations performed the effects of urban canyon aspect ratio and external surface albedo on the daylighting performances, space cooling load, as well as the lighting energy consumption of the building equipped with lightshelves in 2 humid tropical cities. Comparison of the energy performances of 3 fenestration systems, i.e. fenestration without any shading device, with overhangs, and with light shelves, yielded some recommendations concerning the best application of light shelf on the certain floor levels and aspect ratio of the urban context.