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

Science.gov (United States)

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. Copyright © 2014 Elsevier B.V. All rights reserved.

Separation of gaseous air pollutants using membrane contactors

Science.gov (United States)

Sverak, T.; Bulejko, P.; Ostrezi, J.; Kristof, O.; Kalivoda, J.; Kejik, P.; Mayerova, K.; Adamcik, M.

2017-10-01

This work deals with the separation of CO2 gaseous pollutant from gas mixtures to a water solution using the laboratory contactor. The laboratory set process parameters showed the rate of carbon dioxide transition through the interface in a so promising level the contactor separators can be considered as a very promising pathway to reduce the content of this greenhouse gas from the air.

Gaseous radioiodine transport in the air-forage-cow-milk system

International Nuclear Information System (INIS)

Black, S.C.; Douglas, R.L.; Barth, D.S.

1976-04-01

To study the transport of 131 I in the air-forage-cow milk system, a gaseous form of 131 I was released over a field of growing alfalfa which also contained some baled hay and dairy cows in pens. Some of the alfalfa was converted to hay and fed to cows, and some was used as green chop for other cows and goats. The results of this experiment suggest that the deposition velocity of gaseous iodine is much less than that for iodine bound to particulates; that cows ingesting hay secrete a higher percentage of 131 I in milk than cows ingesting green chop; that gaseous forms do not penetrate hay bales to any great extent; that the gaseous form is transferred to milk in a manner similar to particulate forms; that ingestion of contaminated forage results in 80 times as much 131 I transfer to milk as does inhalation exposure to the same cloud; and that goats transfer 131 I from forage to milk more efficiently than do dairy cows

Distribution of gaseous and particle-bound Hg concentrations at the sites representative for urban and non-urban zones of Silesia Province

Directory of Open Access Journals (Sweden)

Pyta Halina

2018-01-01

Full Text Available The basic features of the distribution of total gaseous (TGM and particle-bound mercury (PBM concentrations were determined for a five locations representative for urban (Bielsko-Biała, Lubliniec, Zabrze and rural areas (Godów, Złoty Potok of Silesia Province. Gaseous mercury concentrations were measured (1 continuously - the automatic 1h TGM measurements in Zloty Potok and Zabrze and (2 non-continuously manual 24h TGM measurements with a pre-concentration of the Hg on gold traps (Bielsko-Biała, Lubliniec, Godów. The PBM concentrations were measured non-continuously by taking PM2.5 samples. The Hg content was determined by using a CVAAS method. The highest average concentration of TGM was recorded in Zabrze (2.8ng/m3, significantly lower (2.0ng/m3 in Bielsko-Biała and in the non-urban station in Godów, the lowest concentration (<2.0 ng/m3 was observed in Lubliniec and at the regional background station in Zloty Potok. The results obtained for TGM concentrations exceeded the European average level of 1.5 ng/m3 (AirBase, 2014. The highest average PBM concentration, associated with PM2.5, was obtained in Zabrze (70pg/m3, more than 20% lower results were obtained in Bielsko-Biała and Godów, finally, the lowest one (lower by about 40% in comparison with Zabrze were obtained in Lubliniec and Złoty Potok. Moreover, an enrichment of Hg concentration in PM was observed with the increasing of the PM content, during the heating season.

Incorporating wind availability into land use regression modelling of air quality in mountainous high-density urban environment.

Science.gov (United States)

Shi, Yuan; Lau, Kevin Ka-Lun; Ng, Edward

2017-08-01

Urban air quality serves as an important function of the quality of urban life. Land use regression (LUR) modelling of air quality is essential for conducting health impacts assessment but more challenging in mountainous high-density urban scenario due to the complexities of the urban environment. In this study, a total of 21 LUR models are developed for seven kinds of air pollutants (gaseous air pollutants CO, NO 2 , NO x , O 3 , SO 2 and particulate air pollutants PM 2.5 , PM 10 ) with reference to three different time periods (summertime, wintertime and annual average of 5-year long-term hourly monitoring data from local air quality monitoring network) in Hong Kong. Under the mountainous high-density urban scenario, we improved the traditional LUR modelling method by incorporating wind availability information into LUR modelling based on surface geomorphometrical analysis. As a result, 269 independent variables were examined to develop the LUR models by using the "ADDRESS" independent variable selection method and stepwise multiple linear regression (MLR). Cross validation has been performed for each resultant model. The results show that wind-related variables are included in most of the resultant models as statistically significant independent variables. Compared with the traditional method, a maximum increase of 20% was achieved in the prediction performance of annual averaged NO 2 concentration level by incorporating wind-related variables into LUR model development. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of urban vegetation on air pollution and noise exposure - A case study in Gothenburg, Sweden.

Science.gov (United States)

Klingberg, Jenny; Broberg, Malin; Strandberg, Bo; Thorsson, Pontus; Pleijel, Håkan

2017-12-01

Air pollution levels (NO 2 , PAHs, O 3 ) were investigated, before (BLE) and after (ALE) leaf emergence, in the urban landscape of Gothenburg, Sweden. The aims were to study the 1) spatial and temporal variation in pollution levels between urban green areas, 2) effect of urban vegetation on air pollution levels at the same distance from a major emission source (traffic route), 3) improvement of urban air quality in urban parks compared to adjacent sites near traffic, 4) correlation between air pollution and noise in a park. O 3 varied little over the urban landscape. NO 2 varied strongly and was higher in situations strongly influenced by traffic. Four PAH variables were included: total PAH, total particle-bound PAH, the quantitatively important gaseous phenanthrene and the highly toxic particle-bound benzo(a)pyrene. The variation of PAHs was similar to NO 2 , but for certain PAHs the difference between highly and less polluted sites was larger than for NO 2 . At a vegetated site, NO 2 and particulate PAH levels were lower than at a non-vegetated site at a certain distance from a busy traffic route. This effect was significantly larger ALE compared to BLE for NO 2 , indicating green leaf area to be highly significant factor for air quality improvement. For particulate PAHs, the effect was similar BLE and ALE, indicating that tree bark and branches also could be an important factor in reducing air pollution. Parks represented considerably cleaner local environments (park effect), which is likely to be a consequence of both a dilution (distance effect) and deposition. Noise and air pollution (NO 2 and PAH) levels were strongly correlated. Comparison of noise levels BLE and ALE also showed that the presence of leaves significantly reduced noise levels. Our results are evidence that urban green spaces are beneficial for urban environmental quality, which is important to consider in urban planning. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of height and shape of building roof on air quality in urban street canyons

Science.gov (United States)

Yassin, Mohamed F.

2011-09-01

A building's roof shape and roof height play an important role in determining pollutant concentrations from vehicle emissions and its complex flow patterns within urban street canyons. The impact of the roof shape and height on wind flow and dispersion of gaseous pollutants from vehicle exhaust within urban canyons were investigated numerically using a Computational Fluid Dynamics (CFD) model. Two-dimensional flow and dispersion of gaseous pollutants were analyzed using standard κ- ɛ turbulence model, which was numerically solved based on Reynolds Averaged Navier-Stokes (RANS) equations. The diffusion fields in the urban canyons were examined with three roof heights ( Z H/ H = 0.17, 0.33 and 0.5) and five roof shapes: (1) flat-shaped roof, (2) slanted-shaped roof, (3) downwind wedge-shaped roof, (4) upwind wedge-shaped roof, and (5) trapezoid-shaped roof. The numerical model was validated against the wind tunnels results in order to optimize the turbulence model. The numerical simulations agreed reasonably with the wind tunnel results. The results obtained indicated that the pollutant concentration increased as the roof height decreases. It also decreased with the slanted and trapezoid-shaped roofs but increased with the flat-shaped roof. The pollutant concentration distributions simulated in the present work, indicated that the variability of the roof shapes and roof heights of the buildings are important factors for estimating air quality within urban canyons.

Urban air quality

International Nuclear Information System (INIS)

Fenger, J.

1999-01-01

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

A passive air sampler for characterizing the vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air

International Nuclear Information System (INIS)

Zhang Yuzhong; Deng Shuxing; Liu Yanan; Shen Guofeng; Li Xiqing; Cao Jun; Wang Xilong; Reid, Brian; Tao Shu

2011-01-01

Air-soil exchange is an important process governing the fate of polycyclic aromatic hydrocarbons (PAHs). A novel passive air sampler was designed and tested for measuring the vertical concentration profile of 4 low molecular weight PAHs in gaseous phase (PAH LMW4 ) in near soil surface air. Air at various heights from 5 to 520 mm above the ground was sampled by polyurethane foam disks held in down-faced cartridges. The samplers were tested at three sites: A: an extremely contaminated site, B: a site near A, and C: a background site on a university campus. Vertical concentration gradients were revealed for PAH LMW4 within a thin layer close to soil surface at the three sites. PAH concentrations either decreased (Site A) or increased (Sites B and C) with height, suggesting either deposition to or evaporation from soils. The sampler is a useful tool for investigating air-soil exchange of gaseous phase semi-volatile organic chemicals. - Research highlights: → Design, field test and calibration of the novel passive air sampler, PAS-V-I. → Vertical concentration gradients of PAH LMW4 within a thin layer close to soil. → Comparison of results between PAS-V-I measurement and fugacity approach. → Potential application of PAS-V-I and further modifications. - A novel passive sampling device was developed and tested for measuring vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air.

Air quality and urban management in Europe

Energy Technology Data Exchange (ETDEWEB)

Alberti, M. [Stanford Univ. (United States). Center for Conservation Biology; Joffre, S. [Finnish Meteorological Inst., Helsinki (Finland)

1995-12-31

Important changes in the quality of urban air have occurred in Europe during the last 20 years. Urban air quality trends are clearly correlated to changes in production and consumption processes which have occurred in European cities during the last decades. However, the way these trends are linked with the changes in the urban structure is not yet fully appreciated. A set of indicators is proposed to examine the relationships between air quality, energy consumption and transportation trends. On this basis is argued that the current decentralization of the urban structure and specialization of land use are major driving forces in current urban air pollution. The range of actions and tools to improve urban air quality should include: (1) land use planning, (2) efficient urban management, and (3) measures directed to protecting the quality of the urban environment. (author)

Air quality and urban management in Europe

Energy Technology Data Exchange (ETDEWEB)

Alberti, M [Stanford Univ. (United States). Center for Conservation Biology; Joffre, S [Finnish Meteorological Inst., Helsinki (Finland)

1996-12-31

Important changes in the quality of urban air have occurred in Europe during the last 20 years. Urban air quality trends are clearly correlated to changes in production and consumption processes which have occurred in European cities during the last decades. However, the way these trends are linked with the changes in the urban structure is not yet fully appreciated. A set of indicators is proposed to examine the relationships between air quality, energy consumption and transportation trends. On this basis is argued that the current decentralization of the urban structure and specialization of land use are major driving forces in current urban air pollution. The range of actions and tools to improve urban air quality should include: (1) land use planning, (2) efficient urban management, and (3) measures directed to protecting the quality of the urban environment. (author)

An Assessment of the Relationship between Urban Air Quality and Environmental Urban Factors in Urban Regeneration Areas

Directory of Open Access Journals (Sweden)

Yakup Egercioglu

2016-06-01

Full Text Available Urban air pollution has been increasing due to ever increasing population, rapid urbanization, industrialization, energy usage, traffic density. The purpose of the study is to examine the relation between urban air quality and urban environmental factors in urban regeneration areas. Two common air polluters (SO2 and PM10 are considered in the study. The data are collected for Cigli district, including the level of air pollutants, the local natural gas service lines and planning decisions for the years between 2007 and 2011. According to the examinations, urban environmental factors and planning decisions affect the urban air quality in urban regeneration areas.

A passive air sampler for characterizing the vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air.

Science.gov (United States)

Zhang, Yuzhong; Deng, Shuxing; Liu, Yanan; Shen, Guofeng; Li, Xiqing; Cao, Jun; Wang, Xilong; Reid, Brian; Tao, Shu

2011-03-01

Air-soil exchange is an important process governing the fate of polycyclic aromatic hydrocarbons (PAHs). A novel passive air sampler was designed and tested for measuring the vertical concentration profile of 4 low molecular weight PAHs in gaseous phase (PAH(LMW4)) in near soil surface air. Air at various heights from 5 to 520 mm above the ground was sampled by polyurethane foam disks held in down-faced cartridges. The samplers were tested at three sites: A: an extremely contaminated site, B: a site near A, and C: a background site on a university campus. Vertical concentration gradients were revealed for PAH(LMW4) within a thin layer close to soil surface at the three sites. PAH concentrations either decreased (Site A) or increased (Sites B and C) with height, suggesting either deposition to or evaporation from soils. The sampler is a useful tool for investigating air-soil exchange of gaseous phase semi-volatile organic chemicals. Copyright © 2010 Elsevier Ltd. All rights reserved.

Health impact of urban air pollution: the case of the metropolitan Paris area

International Nuclear Information System (INIS)

Myrto, V.; Menut, L.; Chatignoux, E.

2011-01-01

Urban meteorology and atmospheric composition has become an issue of great public concern. Mega-cities are areas of great population density and also of high rates of gaseous and particulate matter emission. The health of the residents of such large agglomerations will potentially be influenced by the local air-pollution, its formation and dispersion. Efforts are made to link air-pollution and health. Several questions are open: what is the relative contribution of the ambient air-pollution compared to all other exposure factors? What is the 'real' level of exposure reaching the individuals of a population? Can we distinguish the health effects of multiple- pollutants? To answer to these questions we have developed a modeling framework that maps the exposure of the Parisian population to ozone, nitrogen dioxide and fine particles at hourly resolution. This integrated model incorporates a meteorological model, a three-dimensional Eulerian air-quality model and a human exposure module. The first results of this modeling effort suggest new epidemiological evidence of the relationship between ambient air pollution levels and mortality over the city of Paris. (authors)

Urban air quality management. V. 1

International Nuclear Information System (INIS)

1997-01-01

This is the first in a series of reports commissioned by the International Petroleum Industry Environmental Conservation Association (IPIECA) to represent members' views on the management of urban air quality in the growing cities in developing countries. In this report, a general, science based framework is provided as a basis for understanding the nature of the problem in any specific urban area, the range of solutions that might be available, and the potential impact of each solution and its least cost privatisation. The topics covered are: a process for urban air quality management; setting air quality targets; a structured approach to the assessment of current and future air quality modelling methodologies; identification and collation of air quality model input data; development of socio-economic scenarios -long-term trend forecasting; cost effectiveness studies; the IPIECA approach to urban air quality management - development of partnerships; encouraging commitment to implementation of programme recommendations. (7 figures; 2 tables; 18 references). (UK)

The MUMBA campaign: measurements of urban, marine and biogenic air

Science.gov (United States)

Paton-Walsh, Clare; Guérette, Élise-Andrée; Kubistin, Dagmar; Humphries, Ruhi; Wilson, Stephen R.; Dominick, Doreena; Galbally, Ian; Buchholz, Rebecca; Bhujel, Mahendra; Chambers, Scott; Cheng, Min; Cope, Martin; Davy, Perry; Emmerson, Kathryn; Griffith, David W. T.; Griffiths, Alan; Keywood, Melita; Lawson, Sarah; Molloy, Suzie; Rea, Géraldine; Selleck, Paul; Shi, Xue; Simmons, Jack; Velazco, Voltaire

2017-06-01

The Measurements of Urban, Marine and Biogenic Air (MUMBA) campaign took place in Wollongong, New South Wales (a small coastal city approximately 80 km south of Sydney, Australia) from 21 December 2012 to 15 February 2013. Like many Australian cities, Wollongong is surrounded by dense eucalyptus forest, so the urban airshed is heavily influenced by biogenic emissions. Instruments were deployed during MUMBA to measure the gaseous and aerosol composition of the atmosphere with the aim of providing a detailed characterisation of the complex environment of the ocean-forest-urban interface that could be used to test the skill of atmospheric models. The gases measured included ozone, oxides of nitrogen, carbon monoxide, carbon dioxide, methane and many of the most abundant volatile organic compounds. The aerosol characterisation included total particle counts above 3 nm, total cloud condensation nuclei counts, mass concentration, number concentration size distribution, aerosol chemical analyses and elemental analysis.The campaign captured varied meteorological conditions, including two extreme heat events, providing a potentially valuable test for models of future air quality in a warmer climate. There was also an episode when the site sampled clean marine air for many hours, providing a useful additional measure of the background concentrations of these trace gases within this poorly sampled region of the globe. In this paper we describe the campaign, the meteorology and the resulting observations of atmospheric composition in general terms in order to equip the reader with a sufficient understanding of the Wollongong regional influences to use the MUMBA datasets as a case study for testing a chemical transport model. The data are available from PANGAEA (pangaea.de/10.1594/PANGAEA.871982" target="_blank">http://doi.pangaea.de/10.1594/PANGAEA.871982).

Urban Form, Air Pollution, and Health.

Science.gov (United States)

Hankey, Steve; Marshall, Julian D

2017-12-01

Urban form can impact air pollution and public health. We reviewed health-related articles that assessed (1) the relationships among urban form, air pollution, and health as well as (2) aspects of the urban environment (i.e., green space, noise, physical activity) that may modify those relationships. Simulation and empirical studies demonstrate an association between compact growth, improved regional air quality, and health. Most studies are cross-sectional and focus on connections between transportation emissions and land use. The physical and mental health impacts of green space, public spaces that promote physical activity, and noise are well-studied aspects of the urban environment and there is evidence that these factors may modify the relationship between air pollution and health. Urban form can support efforts to design clean, health-promoting cities. More work is needed to operationalize specific strategies and to elucidate the causal pathways connecting various aspects of health.

Global evaluation and calibration of a passive air sampler for gaseous mercury

Science.gov (United States)

McLagan, David S.; Mitchell, Carl P. J.; Steffen, Alexandra; Hung, Hayley; Shin, Cecilia; Stupple, Geoff W.; Olson, Mark L.; Luke, Winston T.; Kelley, Paul; Howard, Dean; Edwards, Grant C.; Nelson, Peter F.; Xiao, Hang; Sheu, Guey-Rong; Dreyer, Annekatrin; Huang, Haiyong; Hussain, Batual Abdul; Lei, Ying D.; Tavshunsky, Ilana; Wania, Frank

2018-04-01

Passive air samplers (PASs) for gaseous mercury (Hg) were deployed for time periods between 1 month and 1 year at 20 sites across the globe with continuous atmospheric Hg monitoring using active Tekran instruments. The purpose was to evaluate the accuracy of the PAS vis-à-vis the industry standard active instruments and to determine a sampling rate (SR; the volume of air stripped of gaseous Hg per unit of time) that is applicable across a wide range of conditions. The sites spanned a wide range of latitudes, altitudes, meteorological conditions, and gaseous Hg concentrations. Precision, based on 378 replicated deployments performed by numerous personnel at multiple sites, is 3.6 ± 3.0 %1, confirming the PAS's excellent reproducibility and ease of use. Using a SR previously determined at a single site, gaseous Hg concentrations derived from the globally distributed PASs deviate from Tekran-based concentrations by 14.2 ± 10 %. A recalibration using the entire new data set yields a slightly higher SR of 0.1354 ± 0.016 m3 day-1. When concentrations are derived from the PAS using this revised SR the difference between concentrations from active and passive sampling is reduced to 8.8 ± 7.5 %. At the mean gaseous Hg concentration across the study sites of 1.54 ng m-3, this represents an ability to resolve concentrations to within 0.13 ng m-3. Adjusting the sampling rate to deployment specific temperatures and wind speeds does not decrease the difference in active-passive concentration further (8.7 ± 5.7 %), but reduces its variability by leading to better agreement in Hg concentrations measured at sites with very high and very low temperatures and very high wind speeds. This value (8.7 ± 5.7 %) represents a conservative assessment of the overall uncertainty of the PAS due to inherent uncertainties of the Tekran instruments. Going forward, the recalibrated SR adjusted for temperature and wind speed should be used, especially if conditions are highly variable or

Air pollution and urban air quality management in Indonesia

Energy Technology Data Exchange (ETDEWEB)

Santosa, Sri J. [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Gadjah Mada University, Yogyakarta (Indonesia); Okuda, Tomoaki; Tanaka, Shigeru [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama (Japan)

2008-06-15

The trade-led industry and economic development after the Asian financial crisis a decade ago has been accelerated in Indonesia to improve the quality of life of its population. This rapid development of Indonesia was in fact heavily fueled by fossil fuels, especially oil, followed by natural gas and coal. The exploitation of fossil fuel in fueling the development resulted in significant environmental quality degradation. Air pollution is perhaps Indonesia's most severe environmental problem. Industry and transportation were the typical main sources of urban air pollutants. Moreover, Indonesia also failed to reach its original 2005 target for a complete phase-out of leaded gasoline. As a result, the level of Pb together with other pollutants such as CO, NO{sub x}, SO{sub 2}, and total suspended particulates has exceeded or at least approached the designated ambient air quality standards. The urban air pollution will not be lesser in extent, but surely will be more severe in the future. Unfortunately, the capability of the Indonesian authorities to manage the urban air quality is still very limited and the portion of the budget allocated to the improvement of urban air quality is still remarkably low, typically 1% of total. This is why the efforts to enhance the capability to manage the urban air quality could not be handled by the environmental authorities in Indonesia's cities themselves, but outside stimulation in the form of man power, consultant and equipment assistance along with financial support has been very important. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

Significance of population centers as sources of gaseous and dissolved PAHs in the lower Great Lakes.

Science.gov (United States)

McDonough, Carrie A; Khairy, Mohammed A; Muir, Derek C G; Lohmann, Rainer

2014-07-15

Polyethylene passive samplers (PEs) were used to measure concentrations of gaseous and dissolved polycyclic aromatic hydrocarbons (PAHs) in the air and water throughout the lower Great Lakes during summer and fall of 2011. Atmospheric Σ15PAH concentrations ranged from 2.1 ng/m3 in Cape Vincent (NY) to 76.4 ng/m3 in downtown Cleveland (OH). Aqueous Σ18PAH concentrations ranged from 2.4 ng/L at an offshore Lake Erie site to 30.4 ng/L in Sheffield Lake (OH). Gaseous PAH concentrations correlated strongly with population within 3-40 km of the sampling site depending on the compound considered, suggesting that urban centers are a primary source of gaseous PAHs (except retene) in the lower Great Lakes region. The significance of distant population (within 20 km) versus local population (within 3 km) increased with subcooled liquid vapor pressure. Most dissolved aqueous PAHs did not correlate significantly with population, nor were they consistently related to river discharge, wastewater effluents, or precipitation. Air-water exchange calculations implied that diffusive exchange was a source of phenanthrene to surface waters, while acenaphthylene volatilized out of the lakes. Comparison of air-water fluxes with temperature suggested that the significance of urban centers as sources of dissolved PAHs via diffusive exchange may decrease in warmer months.

Global evaluation and calibration of a passive air sampler for gaseous mercury

Directory of Open Access Journals (Sweden)

D. S. McLagan

2018-04-01

Full Text Available Passive air samplers (PASs for gaseous mercury (Hg were deployed for time periods between 1 month and 1 year at 20 sites across the globe with continuous atmospheric Hg monitoring using active Tekran instruments. The purpose was to evaluate the accuracy of the PAS vis-à-vis the industry standard active instruments and to determine a sampling rate (SR; the volume of air stripped of gaseous Hg per unit of time that is applicable across a wide range of conditions. The sites spanned a wide range of latitudes, altitudes, meteorological conditions, and gaseous Hg concentrations. Precision, based on 378 replicated deployments performed by numerous personnel at multiple sites, is 3.6 ± 3.0 %1, confirming the PAS's excellent reproducibility and ease of use. Using a SR previously determined at a single site, gaseous Hg concentrations derived from the globally distributed PASs deviate from Tekran-based concentrations by 14.2 ± 10 %. A recalibration using the entire new data set yields a slightly higher SR of 0.1354 ± 0.016 m3 day−1. When concentrations are derived from the PAS using this revised SR the difference between concentrations from active and passive sampling is reduced to 8.8 ± 7.5 %. At the mean gaseous Hg concentration across the study sites of 1.54 ng m−3, this represents an ability to resolve concentrations to within 0.13 ng m−3. Adjusting the sampling rate to deployment specific temperatures and wind speeds does not decrease the difference in active–passive concentration further (8.7 ± 5.7 %, but reduces its variability by leading to better agreement in Hg concentrations measured at sites with very high and very low temperatures and very high wind speeds. This value (8.7 ± 5.7 % represents a conservative assessment of the overall uncertainty of the PAS due to inherent uncertainties of the Tekran instruments. Going forward, the recalibrated SR adjusted for temperature and wind speed

Gaseous pollutants on rural and urban nursery schools in Northern Portugal.

Science.gov (United States)

Nunes, R A O; Branco, P T B S; Alvim-Ferraz, M C M; Martins, F G; Sousa, S I V

2016-01-01

Indoor air quality in nursery schools is different from other schools and this has been largely ignored, particularly in rural areas. Urban and rural nursery schools have different environmental characteristics whose knowledge needs improvement. Thus, this study aimed to evaluate continuously the concentrations of CO2, CO, NO2, O3, CH2O and total VOC in three rural nursery schools and one urban, being the only one comparing urban and rural nurseries with continuous measurements, thus considering occupation and non-occupation periods. Regarding CO2, urban nursery recorded higher concentrations (739-2328 mg m(-3)) than rural nurseries (653-1078 mg m(-3)). The influence of outdoor air was the main source of CO, NO2 and O3 indoor concentrations. CO and NO2 concentrations were higher in the urban nursery and O3 concentrations were higher in rural ones. CH2O and TVOC concentrations seemed to be related to internal sources, such as furniture and flooring finishing and cleaning products. Copyright © 2015 Elsevier Ltd. All rights reserved.

Air sampling program at the Portsmouth Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Hulett, S.H.

1975-01-01

An extensive air sampling program has been developed at the Portsmouth Gaseous Diffusion Plant for monitoring the concentrations of radioactive aerosols present in the atmosphere on plantsite as well as in the environs. The program is designed to minimize exposures of employees and the environment to airborne radioactive particulates. Five different air sampling systems, utilizing either filtration or impaction, are employed for measuring airborne alpha and beta-gamma activity produced from 235 U and 234 Th, respectively. Two of the systems have particle selection capabilities: a personal sampler with a 10-mm nylon cyclone eliminates most particles larger than about 10 microns in diameter; and an Annular Kinetic Impactor collects particulates greater than 0.4 microns in diameter which have a density greater than 12-15 gm/cm 3 . A Hi-Volume Air Sampler and an Eberline Model AIM-3 Scintillation Air Monitor are used in collecting short-term samples for assessing compliance with ''ceiling'' standards or peak concentration limits. A film-sort aperture IBM card system is utilized for continuous 8-hour samples. This sampling program has proven to be both practical and effective for assuring accurate monitoring of the airborne activity associated with plant operations

Air--sea gaseous exchange of PCB at the Venice lagoon (Italy).

Science.gov (United States)

Manodori, L; Gambaro, A; Moret, I; Capodaglio, G; Cescon, P

2007-10-01

Water bodies are important storage media for persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) and this function is increased in coastal regions because their inputs are higher than those to the open sea. The air-water interface is extensively involved with the global cycling of PCBs because it is the place where they accumulate due to depositional processes and where they may be emitted by gaseous exchange. In this work the parallel collection of air, microlayer and sub-superficial water samples was performed in July 2005 at a site in the Venice lagoon to evaluate the summer gaseous flux of PCBs. The total concentration of PCBs (sum of 118 congeners) in air varies from 87 to 273 pg m(-3), whereas in the operationally defined dissolved phase of microlayer and sub-superficial water samples it varies from 159 to 391 pg L(-1). No significant enrichment of dissolved PCB into the microlayer has been observed, although a preferential accumulation of most hydrophobic congeners occurs. Due to this behaviour, we believe that the modified two-layer model was the most suitable approach for the evaluation of the flux at the air-sea interface, because it takes into account the influence of the microlayer. From its application it appears that PCB volatilize from the lagoon waters with a net flux varying from 58 to 195 ng m(-2)d(-1) (uncertainty: +/-50-64%) due to the strong influence of wind speed. This flux is greater than those reported in the literature for the atmospheric deposition and rivers input and reveals that PCB are actively emitted from the Venice lagoon in summer months.

Urban Air Pollution Climates Throughout the World

DEFF Research Database (Denmark)

Hertel, Ole; Goodsite, Michael Evan

2009-01-01

The extent of the urban area, the local emission density, and the temporal pattern in the releases govern the local contribution to air pollution levels in urban environments. However, meteorological conditions also heavily affect the actual pollution levels as they govern the dispersion conditio...... population and provide the right basis for future urban air pollution management....

Air Pollution Surveillance Systems

Science.gov (United States)

Morgan, George B.; And Others

1970-01-01

Describes atmospheric data monitoring as part of total airpollution control effort. Summarizes types of gaseous, liquid and solid pollutants and their sources; contrast between urban and rural environmental air quality; instrumentation to identify pollutants; and anticipated new non-wet chemical physical and physiochemical techniques tor cetection…

Indoor air quality in urban and rural kindergartens: short-term studies in Silesia, Poland.

Science.gov (United States)

Błaszczyk, Ewa; Rogula-Kozłowska, Wioletta; Klejnowski, Krzysztof; Kubiesa, Piotr; Fulara, Izabela; Mielżyńska-Švach, Danuta

2017-01-01

More than 80% of people living in urban areas who monitor air pollution are exposed to air quality levels that exceed limits defined by the World Health Organization (WHO). Although all regions of the world are affected, populations in low-income cities are the most impacted. According to average annual levels of fine particulate matter (PM2.5, ambient particles with aerodynamic diameter of 2.5 μm or less) presented in the urban air quality database issued by WHO in 2016, as many as 33 Polish cities are among the 50 most polluted cities in the European Union (EU), with Silesian cities topping the list. The aim of this study was to characterize the indoor air quality in Silesian kindergartens based on the concentrations of gaseous compounds (SO 2 , NO 2 ), PM2.5, and the sum of 15 PM2.5-bound polycyclic aromatic hydrocarbons (PAHs), including PM2.5-bound benzo(a)pyrene (BaP), as well as the mutagenic activity of PM2.5 organic extracts in Salmonella assay (strains: TA98, YG1024). The assessment of the indoor air quality was performed taking into consideration the pollution of the atmospheric air (outdoor). I/O ratios (indoor/outdoor concentration) for each investigated parameter were also calculated. Twenty-four-hour samples of PM2.5, SO 2 , and NO 2 were collected during spring in two sites in southern Poland (Silesia), representing urban and rural areas. Indoor samples were taken in naturally ventilated kindergartens. At the same time, in the vicinity of the kindergarten buildings, the collection of outdoor samples of PM2.5, SO 2 , and NO 2 was carried out. The content of BaP and the sum of 15 studied PAHs was determined in each 24-h sample of PM2.5 (indoor and outdoor). In the urban site, statistically lower concentrations of SO 2 and NO 2 were detected indoors compared to outdoors, whereas in the rural site, such a relationship was observed only for NO 2 . No statistically significant differences in the concentrations of PM2.5, PM2.5-bound BaP, and Σ15 PAHs

Does urban vegetation mitigate air pollution in northern conditions?

International Nuclear Information System (INIS)

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

2013-01-01

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 (NO 2 , 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. -- Highlights: ► The ability of northern urban vegetation to remove air pollutants is minor. ► Vegetation-related environmental variables had no effect on air pollution levels. ► The ability of vegetation to clean air did not differ between summer and winter. ► Dry deposition passive samplers proved applicable in urban air pollution study. -- The ability of urban vegetation to remove air pollutants seems to be minor in northern climates

The urban air; L'air de la ville

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

This paper presents the abstracts of conferences proposed during the meeting on the urban air, organized by the French Meteorological Society in november 2002. These conferences dealt with the air quality monitoring, the public health impacts, the air pollution in function of the meteorological effects, the pollutants, the main factors of the air quality and the models of the meteorology. (A.L.B.)

Urban structure and air pollution

Science.gov (United States)

Lyons, T. J.; Kenworthy, J. R.; Newman, P. W. G.

Representative driving cycles across the Perth, Western Australia, metropolitan region illustrate a direct relationship to urban land use. Movement away from the central business district results in fewer traffic events, higher speeds, longer cruise periods and shorter stops. The consequent reduction in root mean square acceleration leads to a corresponding reduction in vehicle emission factors. Urban planning implications are pursued and highlight the importance of public transport as an option in reducing urban air pollution.

Dynamic Modeling of Kosovo's Electricity Supply-Demand, Gaseous Emissions and Air Pollution

Directory of Open Access Journals (Sweden)

Sadik Bekteshi

2015-09-01

Full Text Available In this paper is described the developing of an integrated electricity supply–demand, gaseous emission and air pollution model for study of possible baseline electricity developments and available options to mitigate emissions. This model is constructed in STELLA software, which makes use of Systems Dynamics Modeling as the methodology. Several baseline scenarios have been developed from this model and a set of options of possible developments of Kosovo's Electricity Supply–Demand and Gaseous Emissions are investigated. The analysis of various scenarios results in medium growth scenarios (MGS that imply building of generation capacities and increase in participation of the electricity generation from renewable sources. MGS would be 10% of the total electricity generation and ensure sustainable development of the electricity sector. At the same time, by implementation of new technologies, this would be accompanied by reduced GHG (CO2 and NOx emissions by 60% and significant reduction for air pollutants (dust and SO2 by 40% compared to the business-as-usual (BAU case. Conclusively, obtained results show that building of new generation capacities by introducing new technologies and orientation on environmentally friendly energy sources can ensure sustainable development of the electricity sector in Kosovo.  

Exchange pattern of gaseous elemental mercury in an active urban landfill facility.

Science.gov (United States)

Nguyen, Hang Thi; Kim, Ki-Hyun; Kim, Min-Young; Shon, Zang-Ho

2008-01-01

The environmental behavior of gaseous elemental mercury (Hg) in the ambient air was investigated from the center of a municipal landfill site (area approximately 0.6km(2)) located in Dae Gu, Korea in the winter of 2004. In order to provide insight on the Hg exchange processes in strong source areas, we continuously analyzed Hg concentration gradients developed across two heights between 1m and 5m over soil surfaces at hourly intervals. The results displayed Hg concentrations in the lower and upper levels in the range of 1.46-13.1ngm(-3) (3.33+/-1.29ngm(-3): N=139) and 1.20-13.7ngm(-3) (3.27+/-1.23ngm(-3): N=139), respectively. The results of our analysis, when divided separately into emission and dry deposition, showed that emission of Hg was fairly dominant in frequency (up to 58%) over dry deposition. By multiplying our Hg gradient data with the K-values predicted indirectly from the results of previous studies, the emission and deposition fluxes of Hg were estimated as 39.0+/-43.3ngm(-2)h(-1) (N=80) and -60.0+/-80.2ngm(-2)h(-1) (N=59), respectively. Although the magnitudes of exchange were moderately lower than previously investigated anthropogenic sources, the overall results of this study suggest that an active landfill site can act as an important source of Hg in an urban environment along with other man-made activities.

Preliminary study of the distribution of gaseous mercury species in the air of Guiyang city, China

Science.gov (United States)

Shang, L.; Feng, X.; Zheng, W.; Yan, H.

2003-05-01

Total gaseous mercury (TGM) in ambient air consists of Hg^0 and reactive gaseous mercury (RGM) in general. Although RGM only constitutes a small portion of TGM in the air, it contributes the most to both dry and wet deposition of mercury from the atmosphere. TGM and RGM concentrations in ambient air at one site of Guiyang City were determined in March 2002. TGM concentrations were monitored using an automated mercury vapor analyzer Tekran2537A, and RGM in ambient air was sampled using KCI coated tubular denuders. The sampled RGM denuders were analyzed using thermal desorption coupled with CVAFS detection. The average concentrations of TGM and RGM are 7.09 ng m^{-3} and 37.5pg m^{-3} respectively during the sampling period. The primary anthropogenic source for both Hg^0 and RGM is coal combustion in the study area. TGM concentrations are significantly elevated comparing to the global background values, whereas RGM concentrations are only slightly higher than the reported values in remote areas in Europe and US. RGM only constitutes 0.5% ofTGM in the air at the sampling period. There is a significant negative correlation between RGM concentration and relative humidity (RH), with a coefficient correlation of 0.39 (αRGM concentrations observed.

Particulate matter urban air pollution from traffic car

Science.gov (United States)

Filip, G. M.; Brezoczki, V. M.

2017-05-01

The particulate matters (PM) are very important compounds of urban air pollution. There are a lot of air pollution sources who can generate PM and one of the most important of them it is urban traffic car. Air particulate matters have a major influence on human health so everywhere are looking for PM reducing solutions. It is knows that one of the solution for reduce the PM content from car traffic on ambient urban air is the fluidity of urban traffic car by introduction the roundabout intersections. This paper want to present some particulate matter determinations for PM10 and PM2.5 conducted on the two types of urban intersection respectively traffic light and roundabout intersections in Baia Mare town in the approximate the same work conditions. The determinations were carried out using a portable particulate matter monitor Haz - Dust model EPAM - 5000, who can provide a real time data for PM10, PM 2.5.Determinations put out that there are differences between the two locations regarding the PM content on ambient air. On roundabout intersection the PM content is less than traffic light intersection for both PM10 and PM 2.5 with more than 30%.

Gaseous Matter

CERN Document Server

Angelo, Joseph A

2011-01-01

aseous Matter focuses on the many important discoveries that led to the scientific interpretation of matter in the gaseous state. This new, full-color resource describes the basic characteristics and properties of several important gases, including air, hydrogen, helium, oxygen, and nitrogen. The nature and scope of the science of fluids is discussed in great detail, highlighting the most important scientific principles upon which the field is based. Chapters include:. Gaseous Matter An Initial Perspective. Physical Characteristics of Gases. The Rise of the Science of Gases. Kinetic Theory of

Outlier Detection in Urban Air Quality Sensor Networks

NARCIS (Netherlands)

van Zoest, V.M.; Stein, A.; Hoek, Gerard

2018-01-01

Low-cost urban air quality sensor networks are increasingly used to study the spatio-temporal variability in air pollutant concentrations. Recently installed low-cost urban sensors, however, are more prone to result in erroneous data than conventional monitors, e.g., leading to outliers. Commonly

Experimental study of the overpressures generated by the detonation of spherical air-hydrocarbon gaseous mixtures

International Nuclear Information System (INIS)

Brossard, J.

1978-01-01

The characteristics of the pressure waves transmitted by detonation of gaseous mixtures to the surrounding air were measured by tests made near the ground level in 1 to 54 m 3 spherical balloons containing air-acetylene or air-ethylene mixtures. As concerns the peak overpressure Δp, a theoretical dimensional analysis in accordance with the experimental results shows that Δp can be expressed as a function of two independent variables, which are the radial distance R and the volume V of the balloon . A semi-empirical formula, including ground effects, is proposed and its present validity range is given. (author)

Air quality and urban form in U.S. urban areas: evidence from regulatory monitors.

Science.gov (United States)

Clark, Lara P; Millet, Dylan B; Marshall, Julian D

2011-08-15

The layout of an urban area can impact air pollution via changes in emissions and their spatial distribution. Here, we explore relationships between air quality and urban form based on cross-sectional observations for 111 U.S. urban areas. We employ stepwise linear regression to quantify how long-term population-weighted outdoor concentrations of ozone, fine particulate matter (PM(2.5)), and other criteria pollutants measured by the U.S. Environmental Protection Agency depend on urban form, climate, transportation, city size, income, and region. Aspects of urban form evaluated here include city shape, road density, jobs-housing imbalance, population density, and population centrality. We find that population density is associated with higher population-weighted PM(2.5) concentrations (p urban form variables are associated with 4%-12% changes in population-weighted concentrations-amounts comparable, for example, to changes in climatic factors. Our empirical findings are consistent with prior modeling research and suggest that urban form could potentially play a modest but important role in achieving (or not achieving) long-term air quality goals.

Impacts of Roadway Emissions on Urban Fine Particle Exposures: the Nairobi Area Traffic Contribution to Air Pollution (NATCAP) Study

Science.gov (United States)

Gatari, Michael; Ngo, Nicole; Ndiba, Peter; Kinney, Patrick

2010-05-01

quality and transportation planning and management directed at mitigating roadway pollution. Reducing PM emissions from motor vehicles would have direct health benefits for residents of Nairobi and other SSA cities. However, further studies are required to depict the seasonal variations, include gaseous pollution aspect, and strengthen the knowledge on air quality in the region as well as improving the data base for health impact assessment. Acknowledgement This study was initiated and funded by Columbia University's Earth Institute's Center for Sustainable Urban Development (CSUD). CSUD is a Volvo Research and Educational Foundations Center of Excellence for Future Urban Transport. International Science Programs (ISP), Uppsala University, Sweden is recognized for its research support to Institute of Nuclear Science & Technology. Additional technical support for air monitoring and analysis was provided by the Exposure Assessment Facility Core of the Center for Environmental Health in Northern Manhattan (NIEHS P30 ES09089).

Urban Climate and Air Pollution in Ouagadougou, Burkina Faso

Energy Technology Data Exchange (ETDEWEB)

Linden, Jenny

2011-05-15

Africa has recently been singled out by UN Habitat as the fastest urbanizing continent in the world. The most extreme case was found in the Sahelian city of Ouagadougou, Burkina Faso, where the population is expected to almost double over the next ten years. It is well known that the rapid growth of an urban area is among the most important anthropogenic impacts on the environment, and that it has a profound impact on both the urban climate and air quality. Few studies have been focused on cities in the Sahel region, and the lack of information may consequently hinder adaptation to the extreme urbanization rates of these often heavily polluted cities. The main objective of this thesis was to study the nature of, and relationship between, urban climate and air pollution in Ouagadougou, Burkina Faso. Specific objectives were to; examine spatial variations in daily temperature and humidity patterns during early dry season with focus on effects of different land cover; to examine the influence of atmospheric stability on the intra-urban air temperature patterns, the urban wind field and on air pollution levels; and to examine spatial variations in air pollution levels. An additional objective was to document the status and potential development of synoptic meteorological stations in Burkina Faso. Empirical data used in analyses were collected during five field studies between 2003 and 2010. Meteorological and air pollution parameters were measured at fixed sites and through car traverses in areas of different land cover, activity, traffic density and road surface. The most distinct features in thermal patterns found in Ouagadougou were strong intra-urban nocturnal cool islands in vegetated areas, caused by evening evaporative cooling by the vegetation. Extremely stable nocturnal atmospheric conditions were observed during 80 % of days examined in early dry season, during which spatial patterns in temperature and humidity as well as in air pollution were most pronounced

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

Science.gov (United States)

2011-01-01

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

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

Directory of Open Access Journals (Sweden)

D'Amato Gennaro

2011-02-01

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

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

Science.gov (United States)

D'Amato, Gennaro

2011-02-28

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

Gaseous and air decontamination technologies for Clostridium difficile in the healthcare environment.

Science.gov (United States)

Davies, A; Pottage, T; Bennett, A; Walker, J

2011-03-01

The recent data for hospital-acquired infections suggest that infection rates for meticillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile are beginning to decrease. However, while there is still pressure to maintain this trend, the resistance of C. difficile spores to standard detergents continues to present a problem for many UK hospitals trying to prevent its spread or control outbreaks. Alternative disinfection technologies such as gaseous decontamination are currently being marketed to the healthcare sector as an alternative/supplement to manual disinfection, and have been shown to be effective in reducing environmental contamination. When used correctly, they offer a complementary technology to manual cleaning that increases the probability of an effective reduction in viability and provides a comparatively uniform distribution of disinfectant. Three gaseous decontamination technologies are examined for their suitability in reducing environmental contamination with C. difficile: gaseous hydrogen peroxide, chlorine dioxide and ozone. Air decontamination and UV-based technologies are also briefly described. We conclude that while there is a role to play for these new technologies in the decontamination of ward surfaces contaminated with C. difficile, the requirement for both a preclean before use and the limited 'in vivo' evidence means that extensive field trials are necessary to determine their cost-effectiveness in a healthcare setting. Copyright © 2010 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.

Studies of urban climates and air pollution in Switzerland

International Nuclear Information System (INIS)

Wanner, H.; Hertig, J.

1984-01-01

In addition to an assessment of the factors that are responsible for urban climate change, this paper describes climatological studies and peculiarities of some Swiss cities. Although these cities are small, urban air pollution presents a real problem for urban planning. This is a result of the narow street canyons, the high traffic concentration and the complex topography, which favors air stagnation during anticyclonic weather conditions

Urban air pollution in Latin America and the Caribbean

International Nuclear Information System (INIS)

Romieu, I.; Weitzenfeld, H.; Finkelman, J.

1991-01-01

Urban air pollution has become an increasing problem in Latin America and the Caribbean. One reason is the rapid expansion in the size of the urban population. This phenomenon is associated with an increase in the number of vehicles and in energy utilization which, in addition to industrial processes often concentrated in the cities, are the primary sources of air pollution i n Latin American cities. The air quality standards established in such countries are frequently exceeded although control programs have been implemented. The urban areas more affected by anthropogenic pollutant emissions are Sao Paulo, Brazil; Santiago, Chile; and Mexico City. In Latin America, the population of cities with high priority air pollution problems include approximately 81 million people or 26.5 percent of the total urban population of Latin America, corresponding to 30 million children (<15 years), 47 million adults (15-59 years) and 4 million elderly people (≥60 years) who are exposed to air pollutant levels that exceed World Health Organization (WHO) guidelines for adequate health protection

The changing face of urban air pollution

Science.gov (United States)

Lewis, Alastair C.

2018-02-01

The atmospheric chemistry that leads to photochemical smog and climate-active aerosols requires the presence of volatile organic compounds (VOCs) (1, 2). The VOCs in urban air typically derive from the prevailing energy and transport technologies as well as the use of petrochemical-derived products. On page 760 of this issue, McDonald et al. (3) report that a notable change in emissions may be underway in U.S. cities, with effects on secondary pollutants such as organic aerosols. Shifting from an urban atmosphere dominated by transport-related VOCs to one dominated by VOCs from coatings, adhesives, and consumer products would alter predictions of urban air quality and challenge the existing policy framework for emissions control.

Statistical modeling of urban air temperature distributions under different synoptic conditions

Science.gov (United States)

Beck, Christoph; Breitner, Susanne; Cyrys, Josef; Hald, Cornelius; Hartz, Uwe; Jacobeit, Jucundus; Richter, Katja; Schneider, Alexandra; Wolf, Kathrin

2015-04-01

Within urban areas air temperature may vary distinctly between different locations. These intra-urban air temperature variations partly reach magnitudes that are relevant with respect to human thermal comfort. Therefore and furthermore taking into account potential interrelations with other health related environmental factors (e.g. air quality) it is important to estimate spatial patterns of intra-urban air temperature distributions that may be incorporated into urban planning processes. In this contribution we present an approach to estimate spatial temperature distributions in the urban area of Augsburg (Germany) by means of statistical modeling. At 36 locations in the urban area of Augsburg air temperatures are measured with high temporal resolution (4 min.) since December 2012. These 36 locations represent different typical urban land use characteristics in terms of varying percentage coverages of different land cover categories (e.g. impervious, built-up, vegetated). Percentage coverages of these land cover categories have been extracted from different sources (Open Street Map, European Urban Atlas, Urban Morphological Zones) for regular grids of varying size (50, 100, 200 meter horizonal resolution) for the urban area of Augsburg. It is well known from numerous studies that land use characteristics have a distinct influence on air temperature and as well other climatic variables at a certain location. Therefore air temperatures at the 36 locations are modeled utilizing land use characteristics (percentage coverages of land cover categories) as predictor variables in Stepwise Multiple Regression models and in Random Forest based model approaches. After model evaluation via cross-validation appropriate statistical models are applied to gridded land use data to derive spatial urban air temperature distributions. Varying models are tested and applied for different seasons and times of the day and also for different synoptic conditions (e.g. clear and calm

The relationship between urban form and air pollution depends on seasonality and city size.

Science.gov (United States)

Liu, Yupeng; Wu, Jianguo; Yu, Deyong; Ma, Qun

2018-06-01

Understanding how urban form is related to air pollution is important to urban planning and sustainability, but the urban form-air pollution relationship is currently muddled by inconsistent findings. In this study, we investigated how the compositional and configurational attributes of urban form were related to different air pollution measures (PM 2.5 , API, and exceedance) in 83 Chinese cities, with explicit consideration of city size and seasonality. Ten landscape metrics were selected to quantify urban form attributes, and Spearman's correlation was used to quantify the urban form-air pollution relationship. Our results show that the urban form and air pollution relationship was dominated by city size and moderated by seasonality. Specifically, urban air pollution levels increased consistently and substantially from small to medium, large, and megacities. The urban form-air pollution relationship depended greatly on seasonality and monsoons. That is, the relationship was more pronounced in spring and summer than fall and winter, as well as in cities affected by monsoons. Urban air pollution was correlated more strongly with landscape composition metrics than landscape configuration metrics which seemed to affect only PM 2.5 concentrations. Our study suggests that, to understand how air pollution levels are related to urban form, city size and seasonality must be explicitly considered (or controlled). Also, in order to mitigate urban air pollution problems, regional urban planning is needed to curb the spatial extent of built-up areas, reduce the degree of urban fragmentation, and increase urban compactness and contiguity, especially for large and megacities.

Spatial heterogeneity and air pollution removal by an urban forest

Science.gov (United States)

Francisco J. Escobedo; David J. Nowak

2009-01-01

Estimates of air pollution removal by the urban forest have mostly been based on mean values of forest structure variables for an entire city. However, the urban forest is not uniformly distributed across a city because of biophysical and social factors. Consequently, air pollution removal function by urban vegetation should vary because of this spatial heterogeneity....

Air pollution removal and temperature reduction by Gainesville's urban forest

Science.gov (United States)

Francisco Escobedo; Jennifer A. Seitz; Wayne Zipperer

2009-01-01

Poor air quality is a common problem in many urban areas. It can lead to human health problems and reduced visibility, and it can impair the health of plants and wildlife. The urban forest can help improve air quality by removing pollutants and by reducing air temperature through shading and transpiration. Trees also emit volatile...

Modeling the effects of urban vegetation on air pollution

Science.gov (United States)

David J. Nowak; Patrick J. McHale; Myriam Ibarra; Daniel Crane; Jack C. Stevens; Chris J. Luley

1998-01-01

Urban vegetation can directly and indirectly affect local and regional air quality by altering the urban atmospheric environment. Trees affect local air temperature by transpiring water through their leaves, by blocking solar radiation (tree shade), which reduces radiation absorption and heat storage by various anthropogenic surfaces (e.g., buildings, roads), and by...

Removal ratio of gaseous toluene and xylene transported from air to root zone via the stem by indoor plants.

Science.gov (United States)

Kim, K J; Kim, H J; Khalekuzzaman, M; Yoo, E H; Jung, H H; Jang, H S

2016-04-01

This work was designed to investigate the removal efficiency as well as the ratios of toluene and xylene transported from air to root zone via the stem and by direct diffusion from the air into the medium. Indoor plants (Schefflera actinophylla and Ficus benghalensis) were placed in a sealed test chamber. Shoot or root zone were sealed with a Teflon bag, and gaseous toluene and xylene were exposed. Removal efficiency of toluene and total xylene (m, p, o) was 13.3 and 7.0 μg·m(-3)·m(-2) leaf area over a 24-h period in S. actinophylla, and was 13.0 and 7.3 μg·m(-3)·m(-2) leaf area in F. benghalensis. Gaseous toluene and xylene in a chamber were absorbed through leaf and transported via the stem, and finally reached to root zone, and also transported by direct diffusion from the air into the medium. Toluene and xylene transported via the stem was decreased with time after exposure. Xylene transported via the stem was higher than that by direct diffusion from the air into the medium over a 24-h period. The ratios of toluene transported via the stem versus direct diffusion from the air into the medium were 46.3 and 53.7% in S. actinophylla, and 46.9 and 53.1% in F. benghalensis, for an average of 47 and 53% for both species. The ratios of m,p-xylene transported over 3 to 9 h via the stem versus direct diffusion from the air into the medium was 58.5 and 41.5% in S. actinophylla, and 60.7 and 39.3% in F. benghalensis, for an average of 60 and 40% for both species, whereas the ratios of o-xylene transported via the stem versus direct diffusion from the air into the medium were 61 and 39%. Both S. actinophylla and F. benghalensis removed toluene and xylene from the air. The ratios of toluene and xylene transported from air to root zone via the stem were 47 and 60 %, respectively. This result suggests that root zone is a significant contributor to gaseous toluene and xylene removal, and transported via the stem plays an important role in this process.

Differentiating local and regional sources of Chinese urban air pollution based on the effect of the Spring Festival

Science.gov (United States)

Wang, Chuan; Huang, Xiao-Feng; Zhu, Qiao; Cao, Li-Ming; Zhang, Bin; He, Ling-Yan

2017-07-01

The emission of pollutants is extremely reduced during the annual Chinese Spring Festival (SF) in Shenzhen, China. During the SF, traffic flow drops by ˜ 50 % and the industrial plants are almost entirely shut down in Shenzhen. To characterize the variation in ambient air pollutants due to the Spring Festival effect, various gaseous and particulate pollutants were measured in real time in urban Shenzhen over three consecutive winters (2014-2016). The results indicate that the concentrations of NOx, volatile organic compounds (VOCs), black carbon (BC), primary organic aerosols, chloride, and nitrate in submicron aerosols decrease by 50-80 % during SF periods relative to non-Spring Festival periods, regardless of meteorological conditions. This decrease suggests that these pollutants are mostly emitted or secondarily formed from urban local emissions. The concentration variation in species mostly from regional or natural sources, however, is found to be much less, such as for bulk fine particulate matter (PM2. 5). More detailed analysis of the Spring Festival effect reveals an urgent need to reduce emissions of SO2 and VOCs on a regional scale rather than on an urban scale to reduce urban PM2. 5 in Shenzhen, which can also be useful as a reference for other megacities in China.

Gaseous elemental mercury in the marine boundary layer and air-sea flux in the Southern Ocean in austral summer.

Science.gov (United States)

Wang, Jiancheng; Xie, Zhouqing; Wang, Feiyue; Kang, Hui

2017-12-15

Gaseous elemental mercury (GEM) in the marine boundary layer (MBL), and dissolved gaseous mercury (DGM) in surface seawater of the Southern Ocean were measured in the austral summer from December 13, 2014 to February 1, 2015. GEM concentrations in the MBL ranged from 0.4 to 1.9ngm -3 (mean±standard deviation: 0.9±0.2ngm -3 ), whereas DGM concentrations in surface seawater ranged from 7.0 to 75.9pgL -1 (mean±standard deviation: 23.7±13.2pgL -1 ). The occasionally observed low GEM in the MBL suggested either the occurrence of atmospheric mercury depletion in summer, or the transport of GEM-depleted air from the Antarctic Plateau. Elevated GEM concentrations in the MBL and DGM concentrations in surface seawater were consistently observed in the ice-covered region of the Ross Sea implying the influence of the sea ice environment. Diminishing sea ice could cause more mercury evasion from the ocean to the air. Using the thin film gas exchange model, the air-sea fluxes of gaseous mercury in non-ice-covered area during the study period were estimated to range from 0.0 to 6.5ngm -2 h -1 with a mean value of 1.5±1.8ngm -2 h -1 , revealing GEM (re-)emission from the East Southern Ocean in summer. Copyright © 2017 Elsevier B.V. All rights reserved.

L’Aquila Smart Clean Air City: The Italian Pilot Project for Healthy Urban Air

Directory of Open Access Journals (Sweden)

Alessandro Avveduto

2017-11-01

Full Text Available Exposure to atmospheric pollution is a major concern for urban populations. Currently, no effective strategy has been adopted to tackle the problem. The paper presents the Smart Clean Air City project, a pilot experiment concerning the improvement in urban air quality. Small wet scrubber systems will be operating in a network configuration in suitable urban areas of L’Aquila city (Italy. The purpose of this work is to describe the project and show the preliminary results obtained in the characterization of two urban sites before the remediation test; the main operating principles of the wet scrubber system will be discussed, as well as the design of the mobile treatment plant for the processing of wastewater resulting from scrubber operation. Measurements of particle size distributions in the range of 0.30–25 µm took place in the two sites of interest, an urban background and a traffic area in the city of L’Aquila. The mean number concentration detected was 2.4 × 107 and 4.5 × 107 particles/m3, respectively. Finally, theoretical assessments, performed by Computational Fluid Dynamics (CFD codes, will show the effects of the wet scrubber operation on air pollutants under different environmental conditions and in several urban usage patterns.

Air-sea exchange of gaseous mercury in the East China Sea.

Science.gov (United States)

Wang, Chunjie; Ci, Zhijia; Wang, Zhangwei; Zhang, Xiaoshan

2016-05-01

Two oceanographic cruises were carried out in the East China Sea (ECS) during the summer and fall of 2013. The main objectives of this study are to identify the spatial-temporal distributions of gaseous elemental mercury (GEM) in air and dissolved gaseous mercury (DGM) in surface seawater, and then to estimate the Hg(0) flux. The GEM concentration was lower in summer (1.61 ± 0.32 ng m(-3)) than in fall (2.20 ± 0.58 ng m(-3)). The back-trajectory analysis revealed that the air masses with high GEM levels during fall largely originated from the land, while the air masses with low GEM levels during summer primarily originated from ocean. The spatial distribution patterns of total Hg (THg), fluorescence, and turbidity were consistent with the pattern of DGM with high levels in the nearshore area and low levels in the open sea. Additionally, the levels of percentage of DGM to THg (%DGM) were higher in the open sea than in the nearshore area, which was consistent with the previous studies. The THg concentration in fall was higher (1.47 ± 0.51 ng l(-1)) than those of other open oceans. The DGM concentration (60.1 ± 17.6 pg l(-1)) and Hg(0) flux (4.6 ± 3.6 ng m(-2) h(-1)) in summer were higher than those in fall (DGM: 49.6 ± 12.5 pg l(-1) and Hg(0) flux: 3.6 ± 2.8 ng m(-2) h(-1)). The emission flux of Hg(0) from the ECS was estimated to be 27.6 tons yr(-1), accounting for ∼0.98% of the global Hg oceanic evasion though the ECS only accounts for ∼0.21% of global ocean area, indicating that the ECS plays an important role in the oceanic Hg cycle. Copyright © 2016 Elsevier Ltd. All rights reserved.

Meteorological and urban landscape factors on severe air pollution in Beijing.

Science.gov (United States)

Han, Lijian; Zhou, Weiqi; Li, Weifeng; Meshesha, Derege T; Li, Li; Zheng, Mingqing

2015-07-01

Air pollution gained special attention with the rapid development in Beijing. In January 2013, Beijing experienced extreme air pollution, which was not well examined. We thus examine the magnitude of air quality in the particular month by applying the air quality index (AQI), which is based on the newly upgraded Chinese environmental standard. Our finding revealed that (1) air quality has distinct spatial heterogeneity and relatively better air quality was observed in the northwest while worse quality happened in the southeast part of the city; (2) the wind speed is the main determinant of air quality in the city-when wind speed is greater than 4 m/sec, air quality can be significantly improved; and (3) urban impervious surface makes a contribution to the severity of air pollution-that is, with an increase in the fraction of impervious surface in a given area, air pollution is more severe. The results from our study demonstrated the severe pollution in Beijing and its meteorological and landscape factors. Also, the results of this work suggest that very strict air quality management should be conducted when wind speed less than 4 m/sec, especially at places with a large fraction of urban impervious surface. Prevention of air pollution is rare among methods with controls on meteorological and urban landscape conditions. We present research that utilizes the latest air quality index (AQI) to compare air pollution with meteorological and landscape conditions. We found that wind is the major meteorological factor that determines the air quality. For a given wind speed greater than 4 m/sec, the air quality improved significantly. Urban impervious surface also contributes to the severe air pollution: that is, when the fraction of impervious surface increases, there is more severe air pollution. These results suggest that air quality management should be conducted when wind speed is less than 4 m/sec, especially at places with a larger fraction of urban impervious surface.

Capabilities and Gaps Assessments of Urban Air Quality Manage-ment in Uganda

Directory of Open Access Journals (Sweden)

Amin Tamale Kiggundu

2015-06-01

Full Text Available Today, large cities across the globe are facing a pervasive problem of air pollution.  The purpose of this study is to assess the capabilities and gaps in urban air quality management in Uganda as well as proposing strategies for curbing air pollution. This study applied face to face interviews, targeting key informants such as the environmental experts, urbanization researchers and officials from the National Environment Management Authority (NEMA. Results show that rapid motorization, continued dependence on fossil fuels, open waste burning, biomass burning, industrialization, bushfires and urbanization are the key causes of air pollution in Uganda. To reduce air pollution and improve urban air quality it is critical to promote non-motorised mass transport, increase electricity access, regulate open waste burning, establish laboratories, strengthen local research and training capacity, promote collaborations, introduce more fuel efficient vehicles and periodic vehicle inspection and carry out public awareness campaigns about air pollution.

Crowdsourcing urban air temperatures from smartphone battery temperatures

NARCIS (Netherlands)

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

2013-01-01

[1] 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

Urban air quality management : effects of trees on air pollution concentration in urban street canyon

NARCIS (Netherlands)

Salim, S.M.; Buccolieri, R.; Chan, A.; Sabatino, Di S.; Gromke, C.

2009-01-01

The aerodynamic effects of avenue-like tree planting on air flow and traffic-originated pollutant dispersion in urban built-up areas (i.e. street canyons of width to height ratio, W/H=1) are investigated using computational fluid dynamics techniques and complemented with extensive wind tunnel

Air quality and its integration within urban planning: Mexicali, Baja California, Mexico

Directory of Open Access Journals (Sweden)

Elva Alicia Corona–Zambrano

2009-07-01

Full Text Available As a result of world wide urbanization and industrialization, urban air pollution shows a growing trend directly proportional to increasing demands on energy for domestic and industrial activities. From this point of view, cities along with their urban, functional and morphological structure are not being planned with pollution prevention or minimum environmental impacts in mind. This work has two purposes: first, it sets an assessment of air quality in Mexicali by analyzing O3, CO, SO2, NO2 and PM10 emissions in relation to urban structure. And second, the assessment of already implemented urban strategies aimed to minimize environmental impacts. This work also presents a scheme that incorporates air quality issues into town planning and urban management.

Survey of gaseous air pollutants at selected UK sites: XIX. Data digest for Stevenage, Hertfordshire, 1984

Energy Technology Data Exchange (ETDEWEB)

Broughton, G.F.J.; Bower, J.S.; Drury, V.; Lilley, K.; Powell, K.

1987-01-01

Ambient air-quality measurements of six gaseous pollutants continued during 1984 at Stevenage, Hertfordshire sponsored by the Department of the Environment. These data are presented here in the form of frequency distributions, averages, and other parameters for winter, summer, annual, and monthly periods. Time-series graphs of pollutant concentrations for 1984 and of the historical data base between April 1977 and December 1984 are also included.

Dealing with Variations over Space and Time in Urban Vegetation-Air Quality Assessment

Science.gov (United States)

Tan, P. Y.

2017-12-01

Studies on role of urban vegetation ameliorate poor air quality frequently encountered in urban areas should aim to answer a pertinent question: what is the net impact of urban vegetation in improving public health directly or indirectly through removal of air pollutants? Answers to this question need to consider that role of urban vegetation in air quality improvement is not just dependent on physical and physiological processes mediated by plants, it is also highly dependent on atmospheric processes. The roles of these two components thus need to be separated. This uncertainty is further complicated by heterogeneity of air quality over spatial scales and fluctuations in air quality over time. Singapore is used to illustrate these complexities. Between seasons, the main external source of atmospheric pollutants is aerosols from biomass burning in plantations in surrounding SE Asian countries, and air quality is highly dependent on wind directions dictated by monsoon systems. When air quality does deteriorate from transboundary pollution, there are also spatial differences within the city, as air pollutant levels differ in different regions. Rainfall from monsoons and other rain-bearing weather systems over Singapore also dictate the relative amounts of wet and dry deposition and the persistence of particulate matter deposited on vegetation surfaces. For locally generated air pollutants, diurnal fluctuations of anthropogenic activities, such as vehicular emissions between peak and non-peak hours, should also lead to fluctuations over the day. Not only does air quality vary from region to region, air quality within a vertical transect in the urban canopy layer also differs due to urban morphology and urban elements. A pedestrian along a treed street may experience poorer air quality than one living on highrise building, despite proximity to vegetation. There are thus interactions between climate, weather and urban context, which lead to spatial heterogeneity over

Urban air quality in Europe

Energy Technology Data Exchange (ETDEWEB)

Viana, Mar (ed.) [Spanish Research Council - CSIC, Barcelona (Spain). Inst. for Environmental Assessment and Water Research

2013-07-01

This book provides an overview of air quality in urban environments in Europe, focusing on air pollutant emission sources and formation mechanisms, measurement and modeling strategies, and future perspectives. The emission sources described are biomass burning, vehicular traffic, industry and agriculture, but also African dust and long-range transport of pollutants across the European regions. The impact of these emission sources and processes on atmospheric particulate matter, ozone, nitrogen oxides and volatile and semi-volatile organic compounds is discussed and critical areas for particulate matter and nitrogen dioxide in Europe are identified. Finally, this volume presents future perspectives, mainly regarding upcoming air quality monitoring strategies, metrics of interest, such as submicron and nanoparticles, and indoor and outdoor exposure scenarios.

Sampling technologies and air pollution control devices for gaseous and particulate arsenic: a review

International Nuclear Information System (INIS)

Helsen, Lieve

2005-01-01

Direct measurement of arsenic release requires a good sampling and analysis procedure in order to capture and detect the total amount of metals emitted. The literature is extensively reviewed in order to evaluate the efficiency of full field-scale and laboratory scale techniques for capturing particulate and gaseous emissions of arsenic from the thermo-chemical treatment of different sources of arsenic. Furthermore, trace arsenic concentrations in ambient air, national standard sampling methods and arsenic analysis methods are considered. Besides sampling techniques, the use of sorbents is also reviewed with respect to both approaches (1) to prevent the metals from exiting with the flue gas and (2) to react or combine with the metals in order to be collected in air pollution control systems. The most important conclusion is that submicron arsenic fumes are difficult to control in conventional air pollution control devices. Complete capture of the arsenic species requires a combination of particle control and vapour control devices. - Submicron arsenic fumes are difficult to control in conventional air pollution control devices

Urban air quality in the Asian region

International Nuclear Information System (INIS)

Hopke, Philip K.; Cohen, David D.; Begum, Bilkis A.; Biswas, Swapan K.; Ni Bangfa; Pandit, Gauri Girish; Santoso, Muhayatun; Chung, Yong-Sam; Davy, Perry; Markwitz, Andreas; Waheed, Shahida; Siddique, Naila; Santos, Flora L.; Pabroa, Preciosa Corazon B.; Seneviratne, Manikkuwadura Consy Shirani; Wimolwattanapun, Wanna; Bunprapob, Supamatthree; Thu Bac Vuong

2008-01-01

Over the past decade, member states of the Regional Co-operation Agreement (RCA), an intergovernmental agreement for the East Asia and Pacific region under the auspices of the IAEA with the assistance of international organizations and financial institutions such as the World Bank and the Asian Development Bank, have started to set in place policies and legislation for air pollution abatement. To support planning and evaluate the effectiveness of control programs, data are needed that characterizes urban air quality. The focus of this measurement program describe in this report is on size segregated particulate air pollution. Such airborne particulate matter can have a significant impact on human health and urban visibility. These data provide the input to receptor models that may permit the mitigation of these impacts by identification and quantitative apportionment of the particle sources. The aim of this report is to provide an overview of the measurements of concentrations and composition of particulate air pollution in two size fractions across the participating countries. For many of the large cities in this region, the measured particulate matter concentrations are greater than air quality standards or guidelines that have been adopted in developed countries

Urban air quality in the Asian region

Energy Technology Data Exchange (ETDEWEB)

Hopke, Philip K. [Center for Air Resources Engineering and Science, Department of Chemical and Biomolecular Engineering, Clarkson University, Potsdam, NY 13699-5708 (United States)], E-mail: hopkepk@clarkson.edu; Cohen, David D. [Australian Nuclear Science and Technology Organisation (ANSTO), Physics Division, Private Mail Bag 1, Menai 2234, NSW (Australia); Begum, Bilkis A.; Biswas, Swapan K. [Bangladesh Atomic Energy Commission (BAEC), Atomic Energy Centre, Dhaka (AECD), P.O. Box 164, Dhaka (Bangladesh); Ni Bangfa [China Institute of Atomic Energy (CIAE), China National Nuclear Corp. (CNNC), P.O. Box 275-50, Beijing 102413 (China); Pandit, Gauri Girish [Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Santoso, Muhayatun [Center for Nuclear Technology of Material and Radiometry, National Nuclear Energy Agency (BATAN), Jl. Tamansari 71, Bandung 40132 (Indonesia); Chung, Yong-Sam [Hanaro Center, Korea Atomic Energy Research Institute (KAERI), 150 Dukjin-dong, Yusung-ku, P.O. Box 105, Daejon 305-600 (Korea, Republic of); Davy, Perry; Markwitz, Andreas [Institute of Geological and Nuclear Sciences (GNS), 30 Gracefield Road, P.O. Box 31-312, Lower Hutt (New Zealand); Waheed, Shahida; Siddique, Naila [Division of Nuclear Chemistry, PINSTECH, Pakistan Atomic Energy Commission (PAEC), P.O. Box 1482, Nilore, Islamabad (Pakistan); Santos, Flora L.; Pabroa, Preciosa Corazon B. [Philippine Nuclear Research Institute (PNRI), Commonwealth Avenue, Diliman, P.O. Box 213, Quezon City 1101 (Philippines); Seneviratne, Manikkuwadura Consy Shirani [Atomic Energy Authority, 60/460, Baseline Road, Orugodawatta, Wellampitiya (Sri Lanka); Wimolwattanapun, Wanna; Bunprapob, Supamatthree [Thailand Institute of Nuclear Technology (TINT), 16 Vibhavadi Rangsit Road, Bangkok 10900 (Thailand); Thu Bac Vuong [Centre for Radiation Protection, Institute of Nuclear Sciences and Technology, P.O. Box 5T-160, Cau Giay (Viet Nam)] (and others)

2008-10-01

Over the past decade, member states of the Regional Co-operation Agreement (RCA), an intergovernmental agreement for the East Asia and Pacific region under the auspices of the IAEA with the assistance of international organizations and financial institutions such as the World Bank and the Asian Development Bank, have started to set in place policies and legislation for air pollution abatement. To support planning and evaluate the effectiveness of control programs, data are needed that characterizes urban air quality. The focus of this measurement program describe in this report is on size segregated particulate air pollution. Such airborne particulate matter can have a significant impact on human health and urban visibility. These data provide the input to receptor models that may permit the mitigation of these impacts by identification and quantitative apportionment of the particle sources. The aim of this report is to provide an overview of the measurements of concentrations and composition of particulate air pollution in two size fractions across the participating countries. For many of the large cities in this region, the measured particulate matter concentrations are greater than air quality standards or guidelines that have been adopted in developed countries.

Portsmouth Gaseous Diffusion Plant expansion: final environmental statement. Volume 2. Appendices

International Nuclear Information System (INIS)

1977-09-01

Volume 2 is comprised of appendices: Portsmouth Gaseous Diffusion Plant Existing Facilities; Ecology; Civic Involvement; Social Analysis; Population Projections; Toxicity of Air Pollutants to Biota at Portsmouth Gaseous Diffusion Plant; and Assessment of Noise Effects of an Add-On to the Portsmouth Gaseous Diffusion Plant

Sustainability Challenges from Climate Change and Air Conditioning Use in Urban Areas

Directory of Open Access Journals (Sweden)

Karin Lundgren

2013-07-01

Full Text Available Global climate change increases heat loads in urban areas causing health and productivity risks for millions of people. Inhabitants in tropical and subtropical urban areas are at especial risk due to high population density, already high temperatures, and temperature increases due to climate change. Air conditioning is growing rapidly, especially in South and South-East Asia due to income growth and the need to protect from high heat exposures. Studies have linked increased total hourly electricity use to outdoor temperatures and humidity; modeled future predictions when facing additional heat due to climate change, related air conditioning with increased street level heat and estimated future air conditioning use in major urban areas. However, global and localized studies linking climate variables with air conditioning alone are lacking. More research and detailed data is needed looking at the effects of increasing air conditioning use, electricity consumption, climate change and interactions with the urban heat island effect. Climate change mitigation, for example using renewable energy sources, particularly photovoltaic electricity generation, to power air conditioning, and other sustainable methods to reduce heat exposure are needed to make future urban areas more climate resilient.

Estimating the Impact of Urbanization on Air Quality in China Using Spatial Regression Models

Directory of Open Access Journals (Sweden)

Chuanglin Fang

2015-11-01

Full Text Available Urban air pollution is one of the most visible environmental problems to have accompanied China’s rapid urbanization. Based on emission inventory data from 2014, gathered from 289 cities, we used Global and Local Moran’s I to measure the spatial autorrelation of Air Quality Index (AQI values at the city level, and employed Ordinary Least Squares (OLS, Spatial Lag Model (SAR, and Geographically Weighted Regression (GWR to quantitatively estimate the comprehensive impact and spatial variations of China’s urbanization process on air quality. The results show that a significant spatial dependence and heterogeneity existed in AQI values. Regression models revealed urbanization has played an important negative role in determining air quality in Chinese cities. The population, urbanization rate, automobile density, and the proportion of secondary industry were all found to have had a significant influence over air quality. Per capita Gross Domestic Product (GDP and the scale of urban land use, however, failed the significance test at 10% level. The GWR model performed better than global models and the results of GWR modeling show that the relationship between urbanization and air quality was not constant in space. Further, the local parameter estimates suggest significant spatial variation in the impacts of various urbanization factors on air quality.

Air Inflated Greenhouse as Urban Farming Facilities: Architectural Overview

OpenAIRE

Abidin, Syed Zainol; Nasihien, Ronny D; Budiyanto, Hery

2017-01-01

Urban Farming utilizing land intensification, in order to meet the needs of fresh vegetables and fruits everyday for the community residential / housing in urban areas. Air Inflated Greenhouse as urban farming facilities, can be built and transferred to a residential location / specific housing is easy, safe, fast and lightweight (0,55mm PVC tarpaulin) so that urban farming products closer to consumers in urban settlements, the price impact getting cheaper, but quality. Long-term goal is to d...

Chromosomal Aberrations in Humans Induced by Urban Air Pollution

DEFF Research Database (Denmark)

Knudsen, Lisbeth E.; Norppa, Hannu; Gamborg, Michael O.

1999-01-01

We have studied the influence of individual susceptibility factors on the genotoxic effects of urban air pollution in 106 nonsmoking bus drivers and 101 postal workers in the Copenhagen metropolitan area. We used the frequency of chromosomal aberrations in peripheral blood lymphocytes as a biomar......We have studied the influence of individual susceptibility factors on the genotoxic effects of urban air pollution in 106 nonsmoking bus drivers and 101 postal workers in the Copenhagen metropolitan area. We used the frequency of chromosomal aberrations in peripheral blood lymphocytes...... that long-term exposure to urban air pollution (with traffic as the main contributor) induces chromosome damage in human somatic cells. Low DNA repair capacity and GSTM1 and NAT2 variants associated with reduced detoxification ability increase susceptibility to such damage. The effect of the GSTM1 genotype......, which was observed only in the bus drivers, appears to be associated with air pollution, whereas the NAT2 genotype effect, which affected all subjects, may influence the individual response to some other common exposure or the baseline level of chromosomal aberrations....

Performance Evaluation of "Low-cost" Sensors for Measuring Gaseous and Particle Air Pollutants: Results from Two Years of Field and Laboratory Testing

Science.gov (United States)

Feenstra, B. J.; Polidori, A.; Tisopulos, L.; Papapostolou, V.; Zhang, H.; Pathmanabhan, J.

2016-12-01

In recent years great progress has been made in development of low-cost miniature air quality sensing technologies. Such low-cost sensors offer a prospect of providing a real-time spatially dense information on pollutants, however, the quality of the data produced by these sensors is so far untested. In an effort to inform the general public about the actual performance of commercially available low-cost air quality sensors, in June 2014 the South Coast Air Quality Management District (SCAQMD) has established the Air Quality Sensor Performance Evaluation Center (AQ-SPEC). This program performs a thorough characterization of low-cost sensors under ambient (in the field) and controlled (in the laboratory) conditions. During the field testing, air quality sensors are operated side-by-side with Federal Reference Methods and Federal Equivalent Methods (FRM and FEM, respectively), which are routinely used to measure the ambient concentration of gaseous or particle pollutants for regulatory purposes. Field testing is conducted at two of SCAQMD's existing air monitoring stations, one in Rubidoux and one near the I-710 freeway. Sensors that demonstrate an acceptable performance in the field are brought back to the lab where a "characterization chamber" is used to challenge these devices with known concentrations of different particle and gaseous pollutants under different temperature and relative humidity levels. Testing results for each sensor are then summarized in a technical report and, along with other relevant information, posted online on a dedicated website (www.aqmd.gov/aq-spec) to educate the public about the capabilities of commercially available sensors and their potential applications. During this presentation, the results from two years of field and laboratory testing will be presented. The major strengths and weaknesses of some of the most commonly available particle and gaseous sensors will be discussed.

Public health implications of urban air pollution in developing countries

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-31

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

Public health implications of urban air pollution in developing countries

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

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

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

Science.gov (United States)

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

2018-04-01

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.

New considerations for PM, Black Carbon and particle number concentration for air quality monitoring across different European cities

Directory of Open Access Journals (Sweden)

C. Reche

2011-07-01

Full Text Available In many large cities of Europe standard air quality limit values of particulate matter (PM are exceeded. Emissions from road traffic and biomass burning are frequently reported to be the major causes. As a consequence of these exceedances a large number of air quality plans, most of them focusing on traffic emissions reductions, have been implemented in the last decade. In spite of this implementation, a number of cities did not record a decrease of PM levels. Thus, is the efficiency of air quality plans overestimated? Do the road traffic emissions contribute less than expected to ambient air PM levels in urban areas? Or do we need a more specific metric to evaluate the impact of the above emissions on the levels of urban aerosols?

This study shows the results of the interpretation of the 2009 variability of levels of PM, Black Carbon (BC, aerosol number concentration (N and a number of gaseous pollutants in seven selected urban areas covering road traffic, urban background, urban-industrial, and urban-shipping environments from southern, central and northern Europe.

The results showed that variations of PM and N levels do not always reflect the variation of the impact of road traffic emissions on urban aerosols. However, BC levels vary proportionally with those of traffic related gaseous pollutants, such as CO, NO₂ and NO. Due to this high correlation, one may suppose that monitoring the levels of these gaseous pollutants would be enough to extrapolate exposure to traffic-derived BC levels. However, the BC/CO, BC/NO₂ and BC/NO ratios vary widely among the cities studied, as a function of distance to traffic emissions, vehicle fleet composition and the influence of other emission sources such as biomass burning. Thus, levels of BC should be measured at air quality monitoring sites.

During morning traffic rush hours, a narrow variation in the N/BC ratio was evidenced, but a wide variation of

Survey of gaseous air pollutants at selected UK sites: XX. Data digest for Central London Laboratory, 1984

Energy Technology Data Exchange (ETDEWEB)

Broughton, G.F.J.; Bower, J.; Drury, V.J.; Lilley, K.; Powell, K.

1987-01-01

Ambient air-quality measurements of six gaseous pollutants plus black smoke and particulate lead continued during 1984 at the Central London Laboratory. The data are presented here in the form of frequency distributions, averages, and other parameters for winter, summer, annual and monthly periods. Time-series graphs of pollutant concentrations for 1984 and of the historical data base between July 1972 and December 1984 are also included.

Examination of the Relationship between Urban Air Pollution and Urban Planning Decisions in Cigli Case, Izmir (Turkey

Directory of Open Access Journals (Sweden)

Nur Sinem Ozcan

2016-06-01

Full Text Available The air pollution problem remains, although significant improvements have been seen in urban air quality over the last years. Despite the size and variety of studies on urban air pollution, the usage of spatial statistics has been extremely limited. This study aims to show that the spatial statistic techniques can well be used to examine and explain the air pollution levels in urban areas. The data for the sulphur dioxide (SO2 and nitrogen dioxide (NO2 concentrations are measures using passive diffusion tubes at the 67 monitoring sites in the district of Çiğli (Izmir, which are selected through a spatial systematic sampling process. The tubes were exposed for a 2-week period in August 2015. For the determination of the level of clustering for high values and low values of SO2 and NO2 concentrations, Getis-Ord G* local statistics are calculated. There are five points with high values of SO2 surrounded by low values, three points of NO2, where the results are statistically significant at the 0.10 level. The findings indicate that the presence of the industrial zone, the form of fossil fuels (coal or natural gas used in heating, and topography are the strong determinants urban air pollution.

Short-Term Effects of Gaseous Pollutants and Particulate Matter on Daily Hospital Admissions for Cardio-Cerebrovascular Disease in Lanzhou: Evidence from a Heavily Polluted City in China

Directory of Open Access Journals (Sweden)

Shan Zheng

2013-01-01

Full Text Available Panel studies show a consistent association between increase in the cardiovascular hospitalizations with air pollutants in economically developed regions, but little evidence in less developed inland areas. In this study, a time-series analysis was used to examine the specific effects of major air pollutants [particulate matter less than 10 microns in diameter (PM10, sulfur dioxide (SO2, and nitrogen dioxides (NO2] on daily hospital admissions for cardio-cerebrovascular diseases in Lanzhou, a heavily polluted city in China. We examined the effects of air pollutants for stratified groups by age and gender, and conducted the modifying effect of seasons on air pollutants to test the possible interaction. The significant associations were found between PM10, SO2 and NO2 and cardiac disease admissions, SO2 and NO2 were found to be associated with the cerebrovascular disease admissions. The elderly was associated more strongly with gaseous pollutants than younger. The modifying effect of seasons on air pollutants also existed. The significant effect of gaseous pollutants (SO2 and NO2 was found on daily hospital admissions even after adjustment for other pollutants except for SO2 on cardiac diseases. In a word, this study provides the evidence for the detrimental short-term health effects of urban gaseous pollutants on cardio-cerebrovascular diseases in Lanzhou.

The impacts of road traffic management on urban air quality

Energy Technology Data Exchange (ETDEWEB)

Oduyemi, K.O.K. [School of Construction and Environment, University of Abertay Dundee, Dundee (United Kingdom); Davidson, B. [Department of Environmental Health and Consumer Protection, Dundee City Council, Tayside House, Crichton Street, Dundee (United Kingdom)

1998-07-11

The effects of road traffic emissions on urban air quality are investigated, using long-term nitrogen dioxide (NO{sub 2}) data. The effectiveness of the several traffic management measures that have been made in Dundee city centre, UK, within the last 5 years in relation to urban air quality is discussed. The information assessed during this study indicates that the annual mean NO{sub 2} levels at all the study sites are, at present, below the current EC and WHO (long-term) air quality standards for NO{sub 2} concentration in the ambient air. Traffic restrictions appear to be effective in protecting urban air quality. The annual mean NO{sub 2} concentration at two of the study sites is currently close to 40 {mu}g/m{sup 3}, a value published in the Air Quality Regulations 1997 for the air quality objective to be achieved by the year 2005. Proactive traffic management mitigation measures are proposed for these sites and a methodology for the consideration of traffic management alternatives, based upon traffic flow modal split, is described. Some measures proposed are based upon a survey of vehicle occupancy rates, carried out at the busiest of the four study sites. The methodology and assessment procedures presented should be invaluable to assessors of traffic management and local air quality management in a small city, both at the planning and at the auditing stage

Atmospheric concentrations and air–soil gas exchange of polycyclic aromatic hydrocarbons (PAHs) in remote, rural village and urban areas of Beijing–Tianjin region, North China

Science.gov (United States)

Wang, Wentao; Simonich, Staci; Giri, Basant; Chang, Ying; Zhang, Yuguang; Jia, Yuling; Tao, Shu; Wang, Rong; Wang, Bin; Li, Wei; Cao, Jun; Lu, Xiaoxia

2013-01-01

Forty passive air samplers were deployed to study the occurrence of gas and particulate phase PAHs in remote, rural village and urban areas of Beijing–Tianjin region, North China for four seasons (spring, summer, fall and winter) from 2007 to 2008. The influence of emissions on the spatial distribution pattern of air PAH concentrations was addressed. In addition, the air–soil gas exchange of PAHs was studied using fugacity calculations. The median gaseous and particulate phase PAH concentrations were 222 ng/m3 and 114 ng/m3, respectively, with a median total PAH concentration of 349 ng/m3. Higher PAH concentrations were measured in winter than in other seasons. Air PAH concentrations measured at the rural villages and urban sites in the northern mountain region were significantly lower than those measured at sites in the southern plain during all seasons. However, there was no significant difference in PAH concentrations between the rural villages and urban sites in the northern and southern areas. This urban–rural PAH distribution pattern was related to the location of PAH emission sources and the population distribution. The location of PAH emission sources explained 56%–77% of the spatial variation in ambient air PAH concentrations. The annual median air–soil gas exchange flux of PAHs was 42.2 ng/m2/day from soil to air. Among the 15 PAHs measured, acenaphthylene (ACY) and acenaphthene (ACE) contributed to more than half of the total exchange flux. Furthermore, the air–soil gas exchange fluxes of PAHs at the urban sites were higher than those at the remote and rural sites. In summer, more gaseous PAHs volatilized from soil to air because of higher temperatures and increased rainfall. However, in winter, more gaseous PAHs deposited from air to soil due to higher PAH emissions and lower temperatures. The soil TOC concentration had no significant influence on the air–soil gas exchange of PAHs. PMID:21669328

A review of urban air pollution monitoring and exposure assessment methods

OpenAIRE

Xie, Xingzhe; Semanjski, Ivana; Gautama, Sidharta; Tsiligianni, Evaggelia; Deligiannis, Nikos; Rajan, Raj; Pasveer, Frank; Philips, Wilfried

2017-01-01

The impact of urban air pollution on the environments and human health has drawn increasing concerns from researchers, policymakers and citizens. To reduce the negative health impact, it is of great importance to measure the air pollution at high spatial resolution in a timely manner. Traditionally, air pollution is measured using dedicated instruments at fixed monitoring stations, which are placed sparsely in urban areas. With the development of low-cost micro-scale sensing technology in the...

Review on urban vegetation and particle air pollution - Deposition and dispersion

Science.gov (United States)

Janhäll, Sara

2015-03-01

Urban vegetation affects air quality through influencing pollutant deposition and dispersion. Both processes are described by many existing models and experiments, on-site and in wind tunnels, focussing e.g. on urban street canyons and crossings or vegetation barriers adjacent to traffic sources. There is an urgent need for well-structured experimental data, including detailed empirical descriptions of parameters that are not the explicit focus of the study. This review revealed that design and choice of urban vegetation is crucial when using vegetation as an ecosystem service for air quality improvements. The reduced mixing in trafficked street canyons on adding large trees increases local air pollution levels, while low vegetation close to sources can improve air quality by increasing deposition. Filtration vegetation barriers have to be dense enough to offer large deposition surface area and porous enough to allow penetration, instead of deflection of the air stream above the barrier. The choice between tall or short and dense or sparse vegetation determines the effect on air pollution from different sources and different particle sizes.

Air pollution in urban area of Foligno (Italy)

International Nuclear Information System (INIS)

Peirone, E.; Gubbini, P.; Peppoloni, A.; Pompei, M.; Segoni, M.

1998-01-01

This work shows the air pollution levels, based on air's quality laws, detected around the urban area of the city of Foligno (Perugia-Italy)). The preliminary study done, has shown a general result of a good quality of the air, even if there were some excesses of the Attention Levels, during situations not alarming, as these situations occurred in particular conditions, characterized by intense traffic and unfavorable meteorological conditions [it

Air pollution removal by urban trees and shrubs in the United States

Science.gov (United States)

David J. Nowak; Daniel E. Crane; Jack C. Stevens

2006-01-01

A modeling study using hourly meteorological and pollution concentration data from across the coterminous United States demonstrates that urban trees remove large amounts of air pollution that consequently improve urban air quality. Pollution removal (03, PM10, NO2, SO2, CO)...

DIFFUSIVE EXCHANGE OF GASEOUS POLYCYCLIC AROMATIC HYDROCARBONS AND POLYCHLORINATED BIPHENYLS ACROSS THE AIR-WATER INTERFACE OF THE CHESAPEAKE BAY. (R825245)

Science.gov (United States)

Dissolved and gas-phase concentrations of nine polycyclic aromatic hydrocarbons and 46 polychlorinated biphenyl congeners were measured at eight sites on the Chesapeake Bay at four different times of the year to estimate net diffusive air-water gas exchange rates. Gaseous PAHs ar...

Air quality effects of urban trees and parks

Science.gov (United States)

David Nowak; Gordon Heisler

2010-01-01

Parks are significant parts of the urban landscape and comprise about 6% of city and town areas in the conterminous United States. These urban parks are estimated to contain about 370 million trees with a structural value of approximately $300 billion. The number of park trees varies by region of the country, but they can produce significant air quality effects in and...

Consequences of urban pollution on Health

Energy Technology Data Exchange (ETDEWEB)

Adedeji, A. [Lagos state Environmental Protection Agency (LASEPA), (Nigeria)

2000-07-01

In most urban areas, the major air pollutants as earlier highlighted are CO, PbO. SO{sub 2}. NO{sub x}. Hydrocarbons, particulate matters and even excess CO{sub 2}. Some of these have direct effects on health while some are of indirect effects. Other common gaseous emissions from industries are toxic waste fumes and dust/ fluff from spinning, weaving and other processes. In most cases when not properly taken care of may lead to human and plant lives being endangered. For instance it is an established fact that prolonged inhalation of fluff can also lead to Prysinosis with attendant symptoms of chest tightening and pain. In advanced stage, the situation could lead to tuberculosis. Similarly, heavy air pollution leads to acute and chronic harmful effects such as chronic bronchitis, asthma. dermatitis allergy and hypersensitivity. The processing houses produce substantial quantity of volatile chemicals. which pollute the air and could result in health impairment in human beings. It is sad to note that most African Countries including Nigeria still use leaded gasoline. The air quality degradation by these pollutants causes or aggravates most of the respiratory and air-borne diseases like asthma. tuberculosis etc which are rampant in a typical urban city like Lagos. The chart below buttresses this fact. (author)

Survey of gaseous air pollutants at selected UK sites: XXI. Data digest for Cromwell Road, London, 1984

Energy Technology Data Exchange (ETDEWEB)

Broughton, G.F.J.; Bower, J.; Drury, V.J.; Lilley, K.; Powell, K.

1987-01-01

Ambient air-quality measurements of four gaseous pollutants plus black smoke and particulate lead continued during 1984 at the Cromwell Road kerbside site sponsored by the Department of the Environment. These data are presented here in the form of frequency distributions, averages, and other parameters for winter, summer, annual and monthly periods. Time-series graphs of pollutant concentrations for 1984 and of the historical data base between March 1973 and December 1984 are also included.

Thia-arenes as source apportionment tracers for urban air particulate

International Nuclear Information System (INIS)

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

1995-01-01

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

Portsmouth Gaseous Diffusion Plant expansion: final environmental statement. Volume 2. Appendices. [Appendices only

Energy Technology Data Exchange (ETDEWEB)

Liverman, James L.

1977-09-01

Volume 2 is comprised of appendices: Portsmouth Gaseous Diffusion Plant Existing Facilities; Ecology; Civic Involvement; Social Analysis; Population Projections; Toxicity of Air Pollutants to Biota at Portsmouth Gaseous Diffusion Plant; and Assessment of Noise Effects of an Add-On to the Portsmouth Gaseous Diffusion Plant. (LK)

Treatment of Radioactive Gaseous Waste

International Nuclear Information System (INIS)

2014-07-01

Radioactive waste, with widely varying characteristics, is generated from the operation and maintenance of nuclear power plants, nuclear fuel cycle facilities, research laboratories and medical facilities. The waste needs to be treated and conditioned as necessary to provide waste forms acceptable for safe storage and disposal. Although radioactive gaseous radioactive waste does not constitute the main waste flow stream at nuclear fuel cycle and radioactive waste processing facilities, it represents a major source for potential direct environmental impact. Effective control and management of gaseous waste in both normal and accidental conditions is therefore one of the main issues of nuclear fuel cycle and waste processing facility design and operation. One of the duties of an operator is to take measures to avoid or to optimize the generation and management of radioactive waste to minimize the overall environmental impact. This includes ensuring that gaseous and liquid radioactive releases to the environment are within authorized limits, and that doses to the public and the effects on the environment are reduced to levels that are as low as reasonably achievable. Responsibilities of the regulatory body include the removal of radioactive materials within authorized practices from any further regulatory control — known as clearance — and the control of discharges — releases of gaseous radioactive material that originate from regulated nuclear facilities during normal operation to the environment within authorized limits. These issues, and others, are addressed in IAEA Safety Standards Series Nos RS-G-1.7, WS-G-2.3 and NS-G-3.2. Special systems should be designed and constructed to ensure proper isolation of areas within nuclear facilities that contain gaseous radioactive substances. Such systems consist of two basic subsystems. The first subsystem is for the supply of clean air to the facility, and the second subsystem is for the collection, cleanup and

Effects of Compact Urban Development on Air Pollution: Empirical Evidence from Korea

Directory of Open Access Journals (Sweden)

Hee-Sun Cho

2014-09-01

Full Text Available This study investigates the effects of compact urban development on air pollution, taking into account both the spatial distribution of pollutants resulting from an increase in inner urban densities and the dispersion of pollutants associated with an increase in outer green open spaces. The empirical analysis is based upon a panel data model covering 17 cities in Korea from 1996–2009; this approach is used because urban air pollution is influenced by spatial and temporal changes. Measuring the air pollution level by distance from city centers demonstrates that the spatial concentration of emission sources does not necessarily increase air pollution levels. The two-way fixed effects model, which is employed to control both individual (regional and time effects, shows that SO2 decreases as the proportion of green area increases, while a rise in net density leads to an increase of NO2. Both effects are observed in the case of CO dispersion by green area as well as emission source concentration by high densities. Therefore, there is no clear impact of compact urban development on air quality, which is instead related to pollutant-specific characteristics and the emission source.

Capabilities and Gaps Assessments of Urban Air Quality Manage-ment in Uganda

OpenAIRE

Amin Tamale Kiggundu

2015-01-01

Today, large cities across the globe are facing a pervasive problem of air pollution.  The purpose of this study is to assess the capabilities and gaps in urban air quality management in Uganda as well as proposing strategies for curbing air pollution. This study applied face to face interviews, targeting key informants such as the environmental experts, urbanization researchers and officials from the National Environment Management Authority (NEMA). Results show that rapid motorization, cont...

URBAN MORPHOLOGY AND AIR QUALITY IN DENSE RESIDENTIAL ENVIRONMENTS: CORRELATIONS BETWEEN MORPHOLOGICAL PARAMETERS AND AIR POLLUTION AT STREET-LEVEL

Directory of Open Access Journals (Sweden)

PRIYANTHA EDUSSURIYA

2014-02-01

Full Text Available This study is the second part of the series that identifies whether site-specific urban morphological parameters are correlated with air quality. This study aims to identify the most important urban morphological parameters that affects air quality at street level that affect air quality in metropolis like Hong Kong through field measurements and statistical analyses. The study considers 20 urban residential areas in five major districts of Hong Kong and real-time street level air pollutant and microclimatic data are collected from these areas. 21 morphological variables are identified and calculated based on the geometry of the urban fabric. Using principal component analyses, it is shown that out of the many urban morphological factors, only five morphological variables (plan area density, occlusivity, aerodynamic roughness height, mean built volume, compactness factor and four land development factors (aspect ratio, distance between building, mean building height and standard deviation of building height correlate with particulate matter. Besides mineralisation factor, contiguity and canyon ratio marginally correlate with particulate matter. On the other hand, nine variables (plan area density, compactness factor, occlusivity, aerodynamic roughness height, average size of building volume, aspect ratio, distance between buildings, mean building height and standard deviations of building heights correlate with NOx. All others play insignificant roles in street-level pollution effect. Moreover statistical analyses show little correlation between CO and ozone with urban morphological parameters. It is also established that the key microclimatic variables that connects PM and NOx with the urban morphological factors are northerly wind, relative humidity and temperature, which in turn translates to affecting the street-level air pollution.

Health impact of urban air pollution: the case of the metropolitan Paris area; Impact de la pollution urbaine sur la sante: le cas de la region parisienne

Energy Technology Data Exchange (ETDEWEB)

Myrto, V.; Menut, L. [Institut Pierre Simon Laplace, Lab. de Meteorologie Dynamique, CNRS UMR 8539, Ecole Polytechnique, 91 - Palaiseau (France); Chatignoux, E. [Observatoire Regional de la Sante d' Ile de France, 75 - Paris (France)

2011-05-15

Urban meteorology and atmospheric composition has become an issue of great public concern. Mega-cities are areas of great population density and also of high rates of gaseous and particulate matter emission. The health of the residents of such large agglomerations will potentially be influenced by the local air-pollution, its formation and dispersion. Efforts are made to link air-pollution and health. Several questions are open: what is the relative contribution of the ambient air-pollution compared to all other exposure factors? What is the 'real' level of exposure reaching the individuals of a population? Can we distinguish the health effects of multiple- pollutants? To answer to these questions we have developed a modeling framework that maps the exposure of the Parisian population to ozone, nitrogen dioxide and fine particles at hourly resolution. This integrated model incorporates a meteorological model, a three-dimensional Eulerian air-quality model and a human exposure module. The first results of this modeling effort suggest new epidemiological evidence of the relationship between ambient air pollution levels and mortality over the city of Paris. (authors)

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

Science.gov (United States)

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ambient Air Conditions and Variation in Urban Trail Use

OpenAIRE

Holmes, Ann M.; Lindsey, Greg; Qiu, Chenchen

2009-01-01

This study examines the effect of air quality and administrative policies on use of urban trails in Indianapolis, IN. Attention is focused on two policy variables: (1) issuance of air pollution advisories and (2) the adoption of Daylight Savings Time. Results suggest that while trail use varies with air quality, current public advisories regarding air pollution may be of limited effectiveness in reducing trail users’ exposures to hazardous pollutants. In contrast, the adoption of Daylight Sav...

Quantifying air pollution attenuation within urban parks: An experimental approach in Shanghai, China

International Nuclear Information System (INIS)

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. - Highlights: → We examined markedly air pollution decline in urban vegetation patches by field experiments. → Crown volume coverage (CVC) served to characterize vegetation condition among different species. → CVC and pollutants diffusion distance were key predictors affecting air pollution attenuation within parks. - Crown volume coverage (CVC) and pollutants diffusion distance had been proved as key predictors influencing attenuation effect on levels of air pollutants in urban parks.

Quantifying air pollution attenuation within urban parks: An experimental approach in Shanghai, China

Energy Technology Data Exchange (ETDEWEB)

Yin Shan [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China); Institute of Urban and Regional Development, University of California, 316 Wurster Hall, Berkeley, CA 94720 (United States); Shen Zhemin [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China); Zhou Pisheng [School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China); Zou Xiaodong [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China); Che Shengquan [School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China); Wang Wenhua, E-mail: whwang@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd, Shanghai 200240 (China)

2011-08-15

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{sub 2}) and nitrogen dioxide (NO{sub 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{sub 2} and 2.6% of NO{sub 2}. The results could be considered for a better park planning and improving air quality. - Highlights: > We examined markedly air pollution decline in urban vegetation patches by field experiments. > Crown volume coverage (CVC) served to characterize vegetation condition among different species. > CVC and pollutants diffusion distance were key predictors affecting air pollution attenuation within parks. - Crown volume coverage (CVC) and pollutants diffusion distance had been proved as key predictors influencing attenuation effect on levels of air pollutants in urban parks.

Crowdsourcing urban air temperatures from smartphone battery temperatures

Science.gov (United States)

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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. - Highlights: ► Air quality regulation functions and ecosystem structure of a peri-urban forest in Mexico were quantified. ► Air pollution removal-formation dynamics were estimated using the UFORE and WRF-Chem models. ► Peri-urban forests positively contributed to air qualtiy improvement in Mexico City. ► Results can be used to quantify the ecosystem services of peri-urban forests. - Coupled models estimated air quality improvement and pollution removal-formation by peri-urban forest ecosystems in the Mexico City airshed.

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

International Nuclear Information System (INIS)

Kim, Kyoung-Soo; Masunaga, Shigeki

2005-01-01

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

Public Perception of Urban Air Pollution in Four Spanish Cities

International Nuclear Information System (INIS)

Oltra, C.; Jorcano, A.; Sala, R.

2015-01-01

This report presents the results of a study on public reactions to urban air pollution. An on-line survey was implemented in four Spanish cities. Various psychosocial dimensions were assessed: perception of local air quality; attention, understanding and public awareness of the problem of air pollution; perceived impacts on health and quality of life; beliefs of severity, susceptibility and controllability associated with the risk; emotional responses and related self-protection and involvement behaviors. Results show that residents in the four cities pay little attention to the quality of air in their daily life. They perceive air quality in their city as regular. Nevertheless, significant differences exist among cities that could be explained by air pollution levels. Participants believe that air pollution has significant impacts on their health and quality of life; however the degree of information and knowledge about air quality effects seems to be low. Fatalistic beliefs and low controllability regarding the possibility to protect from air pollution were found. Participants declare performing very few self-protection or involvement behaviors. Differences between cities were also found in this dimension. Those findings could be useful for risk communication programs and public involvement strategies in the field of urban air pollution.

Unified Data Model of Urban Air Pollution Dispersion and 3D Spatial City Models: Groundwork Assessment towards Sustainable Urban Development for Malaysia

DEFF Research Database (Denmark)

Ujang, Uznir; Anton, François; Rahman, Alias Abdul

2013-01-01

air pollution in urban areas encompasses sophisticated air quality modeling and data acquisition. However, rapid developments in major cities cause difficulties in acquiring the city geometries. The existing method in acquiring city geometries data via ground or space measurement inspection....... Therefore this paper aims is to perform groundwork assessment and discuss on the current scenario in Malaysia in the aspect of current policies towards SUD, air quality monitoring stations, scale model and detail discussion on air pollution dispersion model used called the Operational Street Pollution Model......Understanding the behavior of urban air pollution is important en route for sustainable urban development (SUD). Malaysia is on its mission to be a developed country by year 2020 comprehends dealing with air pollution is one of the indicators headed towards it. At present monitoring and managing...

Identifying the contribution of different urban highway air pollution sources

International Nuclear Information System (INIS)

Peace, H.; Owen, B.; Raper, D.W.

2004-01-01

This paper describes the methodology and results, and draws conclusions from a large-scale source apportionment study undertaken in a large urban conurbation in the northwest of England. Annual average oxides of nitrogen (NOx) emission and ambient air pollution contributions have been estimated for road traffic sources. Ground level air pollution concentrations were estimated over a 1552-km 2 area with a resolution of up to 20 m, using emissions estimates and the second generation ADMS-Urban Gaussian dispersion model. Road traffic emissions were split into car and motorcycles; heavy and light goods vehicles; and buses to represent domestic users; commercial users and bus companies. Car related emissions were split further in to journey lengths under 3 km; journeys between 3 and 8 km; and journeys over 8 km to represent journeys which could be either walked or cycled; journeys for which a bus can easily be used and other journeys. These source sections were chosen so that the relevant authorities could target key groups in terms of reducing air pollution. The results confirm that the areas most likely to exceed air quality objectives are typically close to main arterial routes and close to urban centres and that the major culprits of road traffic related air pollution are goods vehicles and car journeys over 8 km. The paper also discusses the implications of the results and suggests how these can be used in the assessment of actions to reduce air pollution concentrations

Identifying the contribution of different urban highway air pollution sources.

Science.gov (United States)

Peace, H; Owen, B; Raper, D W

2004-12-01

This paper describes the methodology and results, and draws conclusions from a large-scale source apportionment study undertaken in a large urban conurbation in the northwest of England. Annual average oxides of nitrogen (NOx) emission and ambient air pollution contributions have been estimated for road traffic sources. Ground level air pollution concentrations were estimated over a 1552-km(2) area with a resolution of up to 20 m, using emissions estimates and the second generation ADMS-Urban Gaussian dispersion model. Road traffic emissions were split into car and motorcycles; heavy and light goods vehicles; and buses to represent domestic users; commercial users and bus companies. Car related emissions were split further in to journey lengths under 3 km; journeys between 3 and 8 km; and journeys over 8 km to represent journeys which could be either walked or cycled; journeys for which a bus can easily be used and other journeys. These source sections were chosen so that the relevant authorities could target key groups in terms of reducing air pollution. The results confirm that the areas most likely to exceed air quality objectives are typically close to main arterial routes and close to urban centres and that the major culprits of road traffic related air pollution are goods vehicles and car journeys over 8 km. The paper also discusses the implications of the results and suggests how these can be used in the assessment of actions to reduce air pollution concentrations.

Air quality measurements in urban green areas - a case study

Science.gov (United States)

Kuttler, W.; Strassburger, A.

The influence of traffic-induced pollutants (e.g. CO, NO, NO 2 and O 3) on the air quality of urban areas was investigated in the city of Essen, North Rhine-Westphalia (NRW), Germany. Twelve air hygiene profile measuring trips were made to analyse the trace gas distribution in the urban area with high spatial resolution and to compare the air hygiene situation of urban green areas with the overall situation of urban pollution. Seventeen measurements were made to determine the diurnal concentration courses within urban parks (summer conditions: 13 measurements, 530 30 min mean values, winter conditions: 4 measurements, 128 30 min mean values). The measurements were carried out during mainly calm wind and cloudless conditions between February 1995 and March 1996. It was possible to establish highly differentiated spatial concentration patterns within the urban area. These patterns were correlated with five general types of land use (motorway, main road, secondary road, residential area, green area) which were influenced to varying degrees by traffic emissions. Urban parks downwind from the main emission sources show the following typical temporal concentration courses: In summer rush-hour-dependent CO, NO and NO 2 maxima only occurred in the morning. A high NO 2/NO ratio was established during weather conditions with high global radiation intensities ( K>800 W m -2), which may result in a high O 3 formation potential. Some of the values measured found in one of the parks investigated (Gruga Park, Essen, area: 0.7 km 2), which were as high as 275 μg m -3 O 3 (30-min mean value) were significantly higher than the German air quality standard of 120 μg m -3 (30-min mean value, VDI Guideline 2310, 1996) which currently applies in Germany and about 20% above the maximum values measured on the same day by the network of the North Rhine-Westphalian State Environment Agency. In winter high CO and NO concentrations occur in the morning and during the afternoon rush-hour. The

Air pollution and decreased semen quality: A comparative study of Chongqing urban and rural areas

International Nuclear Information System (INIS)

Zhou, Niya; Cui, Zhihong; Yang, Sanming; Han, Xue; Chen, Gangcai; Zhou, Ziyuan; Zhai, Chongzhi; Ma, Mingfu; Li, Lianbing; Cai, Min; Li, Yafei; Ao, Lin; Shu, Weiqun; Liu, Jinyi; Cao, Jia

2014-01-01

To investigate the association and effects of air pollution level on male semen quality in urban and rural areas, this study examines the outdoor concentrations of particulate matter (PM 10 ), sulfur dioxide (SO 2 ), nitrous dioxide (NO 2 ) and semen quality outcomes for 1346 volunteers in both urban and rural areas in Chongqing, China. We found the urban area has a higher pollution level than the rural area, contrasted with better semen quality in the rural residents, especially for sperm morphology and computer assistant semen analysis (CASA) motility parameters. A multivariate linear regression analysis demonstrates that concentrations of PM 10 , SO 2 , and NO 2 significantly and negatively are associated with normal sperm morphology percentage (P  10 , SO 2 , and NO 2 in urban ambient air may account for worse semen quality in urban males. - Highlights: • We investigate the distributions of PM 10 , SO 2 and NO 2 in urban and rural areas in Chongqing, China. • We explore the associations of air pollution and male semen quality. • The concentrations of PM 10 , SO 2 , and NO 2 are significantly higher in urban areas. • Median values of some semen quality parameters in rural male were higher than urban male. • PM 10 , SO 2 , and NO 2 were negatively associated with semen quality parameters. - Air pollution is higher in the urban area while there is better semen quality in rural males. Polluted air may thus account for worse semen quality in urban males

Numerical modeling on air quality in an urban environment with changes of the aspect ratio and wind direction.

Science.gov (United States)

Yassin, Mohamed F

2013-06-01

Due to heavy traffic emissions within an urban environment, air quality during the last decade becomes worse year by year and hazard to public health. In the present work, numerical modeling of flow and dispersion of gaseous emissions from vehicle exhaust in a street canyon were investigated under changes of the aspect ratio and wind direction. The three-dimensional flow and dispersion of gaseous pollutants were modeled using a computational fluid dynamics (CFD) model which was numerically solved using Reynolds-averaged Navier-Stokes (RANS) equations. The diffusion flow field in the atmospheric boundary layer within the street canyon was studied for different aspect ratios (W/H=1/2, 3/4, and 1) and wind directions (θ=90°, 112.5°, 135°, and 157.5°). The numerical models were validated against wind tunnel results to optimize the turbulence model. The numerical results agreed well with the wind tunnel results. The simulation demonstrated that the minimum concentration at the human respiration height within the street canyon was on the windward side for aspect ratios W/H=1/2 and 1 and wind directions θ=112.5°, 135°, and 157.5°. The pollutant concentration level decreases as the wind direction and aspect ratio increase. The wind velocity and turbulence intensity increase as the aspect ratio and wind direction increase.

Air Quality and Air Pollution Management in Urban Areas in Less Developed Countries

DEFF Research Database (Denmark)

Madsen, P. V.

2007-01-01

The working group will address the complexity of air pollution management in the growing urban sphere in the less developed countries, and will discus and evaluate how Danish and Scandinavian research institutions, universities and private companies can initiate a more progressive role...... in development aid and capacity development in relation to air pollution. For further information on the actions objective, activities and dissemination plan...

Assessing the genotoxicity of urban air pollutants using two in situ plant bioassays

Energy Technology Data Exchange (ETDEWEB)

Villarini, M.; Fatigoni, C.; Dominici, L.; Maestri, S. [Department of Medical-Surgical Specialties and Public Health, University of Perugia, I-06126 (Italy); Ederli, L.; Pasqualini, S. [Department of Applied Biology, University of Perugia, I-06121 (Italy); Monarca, S. [Department of Medical-Surgical Specialties and Public Health, University of Perugia, I-06126 (Italy); Moretti, M., E-mail: massimo.moretti@unipg.i [Department of Medical-Surgical Specialties and Public Health, University of Perugia, I-06126 (Italy)

2009-12-15

Genotoxicity of urban air has been analysed almost exclusively in airborne particulates. We monitored the genotoxic effects of airborne pollutants in the urban air of Perugia (Central Italy). Two plant bioindicators with different genetic endpoints were used: micronuclei in meiotic pollen mother cells using Tradescantia-micronucleus bioassay (Trad-MCN) and DNA damage in nuclei of Nicotiana tabacum leaves using comet assay (Nicotiana-comet). Buds of Tradescantia clone no. 4430 and young N. tabacum cv. Xanthi plants were exposed for 24 h at three sites with different pollution levels. One control site (indoor control) was also used. The two bioassays showed different sensitivities toward urban pollutants: Trad-MCN assay was the most sensitive, but DNA damage in N. tabacum showed a better correlation with the pollutant concentrations. In situ biomonitoring of airborne genotoxins using higher plants combined with chemical analysis is thus recommended for characterizing genotoxicity of urban air. - Plant bioassays used to explore in situ the correlation between air pollution and genotoxicity.

Assessing the genotoxicity of urban air pollutants using two in situ plant bioassays

International Nuclear Information System (INIS)

Villarini, M.; Fatigoni, C.; Dominici, L.; Maestri, S.; Ederli, L.; Pasqualini, S.; Monarca, S.; Moretti, M.

2009-01-01

Genotoxicity of urban air has been analysed almost exclusively in airborne particulates. We monitored the genotoxic effects of airborne pollutants in the urban air of Perugia (Central Italy). Two plant bioindicators with different genetic endpoints were used: micronuclei in meiotic pollen mother cells using Tradescantia-micronucleus bioassay (Trad-MCN) and DNA damage in nuclei of Nicotiana tabacum leaves using comet assay (Nicotiana-comet). Buds of Tradescantia clone no. 4430 and young N. tabacum cv. Xanthi plants were exposed for 24 h at three sites with different pollution levels. One control site (indoor control) was also used. The two bioassays showed different sensitivities toward urban pollutants: Trad-MCN assay was the most sensitive, but DNA damage in N. tabacum showed a better correlation with the pollutant concentrations. In situ biomonitoring of airborne genotoxins using higher plants combined with chemical analysis is thus recommended for characterizing genotoxicity of urban air. - Plant bioassays used to explore in situ the correlation between air pollution and genotoxicity.

gaseous emissions from some industries at ama industrial complex ...

African Journals Online (AJOL)

user

2015-08-11

Aug 11, 2015 ... air quality standards. Therefore, it is recommended that these companies should determine appropriate control measures to reduce these toxic emissions. Key words: Toxic gaseous emissions, type, concentrations, Ama Industrial Complex, Nigeria. INTRODUCTION. Air pollutants such as carbon dioxide ...

AIR POLLUTION OF URBAN AREAS

Directory of Open Access Journals (Sweden)

MAKAROVA V. N.

2016-04-01

Full Text Available Raising of problem. Any manufacturing processes related to the generation of waste. Year after year, a growing mass of waste is one of the main factors reducing the quality of the environment and destruction of natural landscapes. Industrial development inevitably enhances human impacts on the environment and disrupts the ecological balance [3]. Atmospher air is a vital element of the environment. The development of industry, the growth of cities, increasing the number of transport, active exploration of near-Earth space lead to a change in the gas composition of the atmosphere and disruption of its natural balance. Air quality affects the health of the population [5]. Without water or food a person can do for a while, but without air he can not live a few minutes, therefore saving air breathable is an urgent problem. Purpose. The results of geological studies clearly indicate that the contamination of the surface layer of the atmosphere is the most powerful permanent factor of influence on the human food chain and the environment. This problem was reflected in the scientific literature [2; 3; 6], and the second significant indicator of ecological well-being of the region is the number of generation and accumulation of waste. According to this indicator, Dnipropetrovsk region is in the lead, as relates to the industrialized regions. The idea of the article is to consider the air pollution of the urban environment in terms of the accumulation of waste in the territory of enterprises, in particular slag dumps metallurgical production. Conclusion. Slag dumps located on the premises are a significant source of air pollution urbanized areas due to the permanent nature of the spread of contamination. Slag dump of PAT "Nikopol Ferroalloy Plant" is a source of manganese, zinc, nickel emissions. As a conclusion about the magnitude of pollution of the atmospheric boundary layer can say the following: on the border of the sanitary protection zone (SPZ, in

Ambient air conditions and variation in urban trail use.

Science.gov (United States)

Holmes, Ann M; Lindsey, Greg; Qiu, Chenchen

2009-11-01

This study examines the effect of air quality and administrative policies on use of urban trails in Indianapolis, IN. Attention is focused on two policy variables: (1) issuance of air pollution advisories and (2) the adoption of Daylight Savings Time. Results suggest that while trail use varies with air quality, current public advisories regarding air pollution may be of limited effectiveness in reducing trail users' exposures to hazardous pollutants. In contrast, the adoption of Daylight Savings Time was associated with a statistically significant increase in traffic levels.

The Impacts of Urbanization on Meteorology and Air Quality in the Los Angeles Basin

Science.gov (United States)

Li, Y.; Zhang, J.; Sailor, D.; Ban-Weiss, G. A.

2017-12-01

Urbanization has a profound influence on regional meteorology in mega cities like Los Angeles. This influence is driven by changes in land surface physical properties and urban processes, and their corresponding influence on surface-atmosphere coupling. Changes in meteorology from urbanization in turn influences air quality through weather-dependent chemical reaction, pollutant dispersion, etc. Hence, a real-world representation of the urban land surface properties and urban processes should be accurately resolved in regional climate-chemistry models for better understanding the role of urbanization on changing urban meteorology and associated pollutant dynamics. By incorporating high-resolution land surface data, previous research has improved model-observation comparisons of meteorology in urban areas including the Los Angeles basin, and indicated that historical urbanization has increased urban temperatures and altered wind flows significantly. However, the impact of urban expansion on air quality has been less studied. Thus, in this study, we aim to evaluate the effectiveness of resolving high-resolution heterogeneity in urban land surface properties and processes for regional weather and pollutant concentration predictions. We coupled the Weather Research and Forecasting model with Chemistry to the single-layer Urban Canopy Model to simulate a typical summer period in year 2012 for Southern California. Land cover type and urban fraction were determined from National Land Cover Data. MODIS observations were used to determine satellite-derived albedo, green vegetation fraction, and leaf area index. Urban morphology was determined from GIS datasets of 3D building geometries. An urban irrigation scheme was also implemented in the model. Our results show that the improved model captures the diurnal cycle of 2m air temperature (T2) and Ozone (O3) concentrations. However, it tends to overestimate wind speed and underestimate T2, which leads to an underestimation of O

Seasonal atmospheric deposition and air-sea gaseous exchange of polycyclic aromatic hydrocarbons over the Yangtze River Estuary, East China Sea: Implication for the source-sink processes

Science.gov (United States)

Jiang, Y.; Guo, Z.

2017-12-01

As the home of the largest port in the world, the Yangtze River Estuary (YRE) in the East China Sea (ECS) is adjacent to the largest economic zone in China with more than 10% of Chinese population and provides one-fifth of national GDP. The YRE is under the path of contaminated East Asian continental outflow. These make the YRE unique for the pollutant biogeochemical cycling in the world. In this work, 94 pairs of air samples and 20 surface seawater samples covering four seasons were collected from a remote receptor site in the YRE from March 2014 to January 2015, in order to explore the seasonal fluxes of air-sea gaseous exchange and atmospheric dry and wet deposition of 15 polycyclic aromatic hydrocarbons (PAHs) and their source-sink processes at the air-sea interface. The average dry and wet deposition fluxes of 15 PAHs were estimated as 879 ± 1393 ng m-2 d-1 and 755 ± 545 ng m-2 d-1, respectively. The gaseous PAHs were released from seawater to atmosphere during the whole year with an average of 3039 ± 2030 ng m-2 d-1. The gaseous exchange of PAHs was referred as the dominant process at the air-sea interface in the YRE as the magnitude of volatilization flux of PAHs exceeded that of the total dry and wet deposition. The gaseous PAH exchange flux was dominated by 3-ring PAHs, with the highest value in summer while lowest in winter, depicting a strong seasonal variation due to temperature, wind speed and air-sea concentration gradient difference among seasons. Based on the simplified mass balance estimation, net 9.6 tons/y of PAHs was volatilized from seawater to atmosphere with an area of approximately 20000 km2 in the YRE. Apart from Yangtze River input and ocean ship emissions in the entire year, the selective release of low molecular weight PAHs from sediments in winter due to re-suspension triggered by the East Asian winter monsoon could be another possible source for dissolved PAHs. This work suggests that the source-sink processes of PAHs at air

Sorption tubes packed with polydimethylsiloxane: a new and promising technique for the preconcentration of volatiles and semi-volatiles from air and gaseous samples

NARCIS (Netherlands)

Baltussen, H.A.; David, F.; Sandra, P.J.F.; Janssen, J.G.M.; Cramers, C.A.M.G.

1998-01-01

This paper is concerned with the determination of volatile and semi-volatile organic components in air and gaseous (headspace) samples, focusing primarily on polar analytes. Samples were analyzed by preconcentration on different (ad)sorbents followed by thermal desorption and analysis by capillary

Urban Landscape Characterization Using Remote Sensing Data For Input into Air Quality Modeling

Science.gov (United States)

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

2005-01-01

The urban landscape is inherently complex and this complexity is not adequately captured in air quality models that are used to assess whether urban areas are in attainment of EPA air quality standards, particularly for ground level ozone. This inadequacy of air quality models to sufficiently respond to the heterogeneous nature of the urban landscape can impact how well these models predict 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 meteorological and air quality models focusing on the Atlanta, Georgia metropolitan area as a case study. 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 Community Multiscale Air Quality (CMAQ) modeling schemes. Use of these data have been found to better characterize low density/suburban development as compared with USGS 1 km land use/land cover data that have traditionally been used in modeling. Air quality prediction for future 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. This allows the State Environmental Protection agency to evaluate how these transportation plans will affect future air quality.

Experiments for detection of gaseous Po-210 originated from microbial activity in the environment

International Nuclear Information System (INIS)

Ishimoto, A.; Momoshima, N.

2006-01-01

We attempted to detect gaseous Po-210 (half-life 138d) emitted from organisms in the environment. Gaseous Po-210 was tried to collect in 0.5 M nitric acid solution after passing the atmospheric air through filters and a distilled water bubbler, which would remove aerosols existing in the air. The activity of Po-210 was determined by alpha spectrometry after radiochemical separation and electrolytic deposition of Po-210 on a silver disk. Twenty seven point four mBq of Po-210 was observed when 800 m 3 atmospheric air was sampled. Blank of Po-210 in regents and the sampling system was 4.9-6.8 mBq. The concentration of Po-210 observed in the atmospheric air was, thus about 5 times higher than the background; the results strongly support existence of gaseous Po-210 in the environment. (author)

The implementation challenge of urban air quality

Energy Technology Data Exchange (ETDEWEB)

Lint, R.J.T. van; Buitenkamp, S.; Zebregs, M. [Ministry of Housing, The Hague (Netherlands). Air Quality and Acidification Abatement Div.

1995-12-31

In recent years, the policy followed has booked some significant successes in the structural reduction of the emissions by a number of air polluting substances (e.g. sulphur dioxide and lead). However, the Third Environmental Outlook 1993-2015 has determined that the policy goals for a number of other air polluting substances will not be achieved, particularly in urban areas. This concerns fine dust (PM-10) and polycyclic aromatic hydrocarbons (PAHs), nitrogen dioxide, benzene and black smoke. The policy goals for the above priority substances have been set so as to protect the population against the negative effects on health from too high concentrations of these substances. Forty-six per cent of the Dutch population live in cities of more than 100,000 inhabitants, and, hence, many people are exposed to (too) high concentrations. For this reason, the Netherlands` Second National Environmental Policy Plan lays down that government, provinces and municipalities will together develop a plan of action to reduce urban air pollution to acceptable levels. The formulated strategy is presented in the document here. To that end, the problem analysis and current policy related to the issue are considered in more detail below. On the basis of this, the additional policy strategy is formulated. (author)

The implementation challenge of urban air quality

Energy Technology Data Exchange (ETDEWEB)

Lint, R J.T. van; Buitenkamp, S; Zebregs, M [Ministry of Housing, The Hague (Netherlands). Air Quality and Acidification Abatement Div.

1996-12-31

In recent years, the policy followed has booked some significant successes in the structural reduction of the emissions by a number of air polluting substances (e.g. sulphur dioxide and lead). However, the Third Environmental Outlook 1993-2015 has determined that the policy goals for a number of other air polluting substances will not be achieved, particularly in urban areas. This concerns fine dust (PM-10) and polycyclic aromatic hydrocarbons (PAHs), nitrogen dioxide, benzene and black smoke. The policy goals for the above priority substances have been set so as to protect the population against the negative effects on health from too high concentrations of these substances. Forty-six per cent of the Dutch population live in cities of more than 100,000 inhabitants, and, hence, many people are exposed to (too) high concentrations. For this reason, the Netherlands` Second National Environmental Policy Plan lays down that government, provinces and municipalities will together develop a plan of action to reduce urban air pollution to acceptable levels. The formulated strategy is presented in the document here. To that end, the problem analysis and current policy related to the issue are considered in more detail below. On the basis of this, the additional policy strategy is formulated. (author)

Influence of roadside hedgerows on air quality in urban street canyons

Science.gov (United States)

Gromke, Christof; Jamarkattel, Nabaraj; Ruck, Bodo

2016-08-01

Understanding pollutant dispersion in the urban environment is an important aspect of providing solutions to reduce personal exposure to vehicle emissions. To this end, the dispersion of gaseous traffic pollutants in urban street canyons with roadside hedges was investigated. The study was performed in an atmospheric boundary layer wind tunnel using a reduced-scale (M = 1:150) canyon model with a street-width-to-building-height ratio of W/H = 2 and a street-length-to-building-height ratio of L/H = 10. Various hedge configurations of differing height, permeability and longitudinal segmentation (continuous over street length L or discontinuous with clearings) were investigated. Two arrangements were examined: (i) two eccentric hedgerows sidewise of the main traffic lanes and (ii) one central hedgerow between the main traffic lanes. In addition, selected configurations of low boundary walls, i.e. solid barriers, were examined. For a perpendicular approach wind and in the presence of continuous hedgerows, improvements in air quality in the center area of the street canyon were found in comparison to the hedge-free reference scenario. The pollutant reductions were greater for the central hedge arrangements than for the sidewise arrangements. Area-averaged reductions between 46 and 61% were observed at pedestrian head height level on the leeward side in front of the building for the centrally arranged hedges and between 18 and 39% for the two hedges arranged sidewise. Corresponding area-averaged reductions ranging from 39 to 55% and from 1 to 20% were found at the bottom of the building facades on the leeward side. Improvements were also found in the areas at the lateral canyon ends next to the crossings for the central hedge arrangements. For the sidewise arrangements, increases in traffic pollutants were generally observed. However, since the concentrations in the end areas were considerably lower compared to those in the center area, an overall improvement remained

Gaseous emissions from coal stockpiles

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-01-15

Stockpiled coal undergoes atmospheric oxidation and desorption processes during open air storage. These processes release gases to the environment which may effect health and safety by their toxicity and flammability. In extreme cases, this could lead to a fire. This report discusses gaseous emissions from coal stockpiles. It covers gas emission mechanisms, and gas sampling and testing methods, before examining in more detail the principal gases that have been emitted. It concludes that there is limited research in this area and more data are needed to evaluate the risks of gaseous emissions. Some methods used to prevent coal self-heating and spontaneous combustion can be applied to reduce emissions from coal stockpiles.

Congestion, air pollution, and road safety in urban areas

Energy Technology Data Exchange (ETDEWEB)

Shefer, Daniel [Department of Urban and Regional Economics and Transport, Technion-Israel Institute of Technology, Haifa (Israel)

1993-06-01

The continuous rapid growth in Vehicle Miles Travelled (VMT), 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 process and to secure safe and healthy environments and improve the quality of life in our cities, it is paramount to initiate and implement programs which jointly treat traffic congestion, air quality, and road safety. A host of 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, and perhaps should, be employed jointly within an overall strategy. In view of the conflicting objectives which may exist between improving urban air quality and reducing road fatalities and traffic congestion, it is of great importance to thoroughly investigate these functional relationships. The results of such studies will help decision makers identify the `socially optimal level of congestion` which will yield the highest net social benefit. 2 figs., 43 refs.

A first-approximation urban-air-quality indicator

Science.gov (United States)

David M. Paproski; Julian R. Walker

1977-01-01

Development of the first-approximation-urban-air-quality indicator was reported by the Economic Council of Canada. The indicator takes account of ambient concentrations of five pollutants: sulfur dioxide, particulate matter, oxides of nitrogen, carbon monoxide, and total oxidants. Epidemiological evidence indicating the potential impact of these pollutants on human...

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

Science.gov (United States)

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.

Usage Proposal of a common urban decorative tree (Salix alba L.) to monitor the dispersion of gaseous mercury: A case study from Turda (Romania).

Science.gov (United States)

Esbrí, J M; Cacovean, H; Higueras, P

2018-02-01

Closure of chloralkali plants poses a risk of abandonment of important sources of gaseous mercury. In this work, an assessment has been made of the potential for pollution from one of these plants in the proximity of a densely populated town in central Romania. The work involved a comparison between two major types of monitoring survey: biomonitoring using leaves of a tree common in urban environments; and LUMEX-based gaseous mercury analysis. For biomonitoring, 21 samples from Salix alba L. trees were taken in Turda area. Atmospheric monitoring included two mobile surveys and one at a fixed location. The results from both monitoring systems show similarities in gaseous mercury dispersion patterns, with high mercury contents clearly related to the presence of the chloralkali plant. Particularly high levels were measured in the following situations: (i) in a 'smog' area related with thermal inversion and (ii) during dusk. Direct monitoring suffered from limitations in acquiring information, especially in a medium-long time range, but biomonitoring provided these data and is capable of covering studies on temporary trends or comparative assessments between European cities with contrasting gaseous mercury sources. The thermal speciation of mercury contents indicates that the whole fraction of mercury in leaves corresponds to organic mercury. This finding implies a non-reversible uptake process, which in turn ensures the applicability of this technique to biomonitor long-term exposure. As a conclusion, the assessment of gaseous mercury pollution based on biomonitoring using S. alba has proven to be a useful, reliable and cost-effective methodology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Air pollution

International Nuclear Information System (INIS)

Nelson, P.

2000-01-01

Australian cites experience a number of current and emerging air pollution problems. Concentrations of traditional primary pollutants such as CO, lead and dust have fallen in recent years as a consequence of air pollutant control measures, and the widespread introduction of lead-free petrol. However, recommended guidelines for ozone, the principal component of photochemical smog, are regularly exceeded in major capital cities in the summer months. In addition, it is predicted that extensive urban expansion will lead to much greater dependence on the motor vehicle as the primary means of transportation. Effects of air pollution are felt at a variety of scales. Traditionally, concerns about gaseous and particulate emissions from industrial and vehicular sources were focused on local impacts due to exposure to toxic species such as CO and lead. As noted above, concentrations of these pollutants have been reduced by a variety of control measures. Pollutants which have effects at a regional scale, such as photochemically-produced ozone, and acidic gases and particles have proved more difficult to reduce. In general, these pollutants arc not the result of direct emissions to atmosphere, but result from complex secondary processes driven by photochemical reactions of species such as NO 2 and aldehydes. In addition, global effects of gaseous and particulate emissions to the atmosphere have received significant recent attention, concentrations of atmospheric CO 2 with predicted impacts on global climate, and ozone depletion due to anthropogenic emissions of chlorine-containing chemicals are the two major examples. Combustion processes from petrol- and diesel-fuelled vehicles, make major contributions to air pollution, and the magnitude of this contribution is discussed in this article

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

Science.gov (United States)

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

2018-01-01

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.

Metallic corrosion in the polluted urban atmosphere of Hong Kong.

Science.gov (United States)

Liu, Bo; Wang, Da-Wei; Guo, Hai; Ling, Zhen-Hao; Cheung, Kalam

2015-01-01

This study aimed to explore the relationship between air pollutants, particularly acidic particles, and metallic material corrosion. An atmospheric corrosion test was carried out in spring-summer 2012 at a polluted urban site, i.e., Tung Chung in western Hong Kong. Nine types of metallic materials, namely iron, Q235 steel, 20# steel, 16Mn steel, copper, bronze, brass, aluminum, and aluminum alloy, were selected as specimens for corrosion tests. Ten sets of the nine materials were all exposed to ambient air, and then each set was collected individually after exposure to ambient air for consecutive 6, 13, 20, 27, 35, 42, 49, 56, 63, and 70 days, respectively. After the removal of the corrosion products on the surface of the exposed specimens, the corrosion rate of each material was determined. The surface structure of materials was observed using scanning electron microscopy (SEM) before and after the corrosion tests. Environmental factors including temperature, relative humidity, concentrations of gaseous pollutants, i.e., sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), ozone (O₃), and particulate-phase pollutants, i.e., PM₂.₅ (FSP) and PM₁₀ (RSP), were monitored. Correlation analysis between environmental factors and corrosion rate of materials indicated that iron and carbon steel were damaged by both gaseous pollutants (SO₂ and NO₂) and particles. Copper and copper alloys were mainly corroded by gaseous pollutants (SO₂ and O₃), while corrosion of aluminum and aluminum alloy was mainly attributed to NO₂ and particles.

Research on Value Assessment and Compensation for Health Hazards of Urban Air Pollution-A Case Study of Urumqi

OpenAIRE

Yu, Chen; Hui, Sun

2016-01-01

ABSTRACT With the acceleration of urbanization and industrialization, urban air pollution has become a serious threat to the health of urban residents. In this study, to investigate health hazards caused by air pollution for urban residents, concentrations of main air pollutants and annual coal consumption amounts during the period from 2000 to 2013 were analyzed. Our results showed that economic losses of Urumqi caused by air pollution amounted to 63.155 million yuan in 2013, accounting for ...

Determination of 1-octanol-air partition coefficient using gaseous diffusion in the air boundary layer.

Science.gov (United States)

Ha, Yeonjeong; Kwon, Jung-Hwan

2010-04-15

Exact determination of the partition coefficient between 1-octanol and air (K(OA)) is very important because it is a key descriptor for describing the thermodynamic partitioning between the air and organic phases. In spite of its importance, the number and quality of experimental K(OA) values for hydrophobic organic chemicals are limited because of experimental difficulties. Thus, to measure K(OA) values, a high-throughput method was developed that used liquid-phase extraction with 1-octanol drop at the tip of a microsyringe needle. The concentration in the headspace surrounding the 1 muL octanol drop was equilibrated with liquid octanol containing polycyclic aromatic hydrocarbons (PAHs). The change in concentrations of PAHs in the octanol drop was measured to obtain mass transfer rate constants, and these rate constants were then converted into K(OA) values using a film diffusion model. Thirteen polycyclic aromatic hydrocarbons with log K(OA) between 5 and 12 were chosen for the proof of the principle. Experimental determination of log K(OA) was accomplished in 30 h for PAHs with their log K(OA) less than 11. The measured log K(OA) values were very close to those obtained by various experimental and estimation methods in the literature, suggesting that this new method can provide a fast and easy determination of log K(OA) values for many chemicals of environmental interests. In addition, the applicability of the method can be extended to determine Henry's law constant for compounds with low vapor pressure and to estimate gaseous transfer rate of semivolatile compounds for environmental fate modeling.

Low energy consumption method for separating gaseous mixtures and in particular for medium purity oxygen production

Science.gov (United States)

Jujasz, Albert J.; Burkhart, James A.; Greenberg, Ralph

1988-01-01

A method for the separation of gaseous mixtures such as air and for producing medium purity oxygen, comprising compressing the gaseous mixture in a first compressor to about 3.9-4.1 atmospheres pressure, passing said compressed gaseous mixture in heat exchange relationship with sub-ambient temperature gaseous nitrogen, dividing the cooled, pressurized gaseous mixture into first and second streams, introducing the first stream into the high pressure chamber of a double rectification column, separating the gaseous mixture in the rectification column into a liquid oxygen-enriched stream and a gaseous nitrogen stream and supplying the gaseous nitrogen stream for cooling the compressed gaseous mixture, removing the liquid oxygen-enriched stream from the low pressure chamber of the rectification column and pumping the liquid, oxygen-enriched steam to a predetermined pressure, cooling the second stream, condensing the cooled second stream and evaporating the oxygen-enriched stream in an evaporator-condenser, delivering the condensed second stream to the high pressure chamber of the rectification column, and heating the oxygen-enriched stream and blending the oxygen-enriched stream with a compressed blend-air stream to the desired oxygen concentration.

Lead and cadmium in indoor air and the urban environment

International Nuclear Information System (INIS)

Komarnicki, Guenter J.K.

2005-01-01

The present study was conducted to find potential terrestrial biomonitors for heavy metals in indoor air in an urban environment. TSP, PM 10 , and PM 2.5 were collected in three retirement facilities in the urban area of Vienna. In addition, particulate matter and soil, vegetation, and isopods (Porcellio scaber L.) were collected in the adjacent garden areas. Aerosols were sampled with a low-volume air sampler. The sampled materials were wet ashed and total lead and cadmium contents were determined. Water-soluble heavy metal concentrations were measured in aqueous extracts from air exposed filters, soil, and vegetation. Lead and cadmium were analyzed by graphite furnace AAS. Lead contents in the vegetation were inferred from water-soluble lead in soils. Lead in isopods generally reflected the contents in vegetation. Cadmium in plants probably derived from soil solutions as well as from atmospheric input. Isopods reflected the total cadmium contents in soils. Particulate matter was dominated by PM 2.5 , both with respect to mass concentrations and to heavy metal contents. The indoor aerosol was found to be influenced by human activity, indoor sources, and outdoor particles. Relationships between indoor airborne heavy metals and the contents in vegetation (lead and cadmium: positive) and isopods (lead: negative) were identified to have the potential for biomonitoring indoor air quality. - Urban vegetation and isopods are potential indicators for indoor aerial heavy metals

A Numerical Simulation of Traffic-Related Air Pollution Exposures in Urban Street Canyons

Science.gov (United States)

Liu, J.; Fu, X.; Tao, S.

2016-12-01

Urban street canyons are usually associated with intensive vehicle emissions. However, the high buildings successively along both sides of a street block the dispersion of traffic-generated air pollutants, which enhances human exposure and adversely affects human health. In this study, an urban scale traffic pollution dispersion model is developed with the consideration of street distribution, canyon geometry, background meteorology, traffic assignment, traffic emissions and air pollutant dispersion. Vehicle exhausts generated from traffic flows will first disperse inside a street canyon along the micro-scale wind field (generated by computational fluid dynamics (CFD) model) and then leave the street canyon and further disperse over the urban area. On the basis of this model, the effects of canyon geometry on the distribution of NOx and CO from traffic emissions were studied over the center of Beijing, China. We found that an increase of building height along the streets leads to higher pollution levels inside streets and lower pollution levels outside, resulting in higher domain-averaged concentrations over the area. In addition, street canyons with equal (or highly uneven) building heights on two sides of a street tend to lower the urban-scale air pollution concentrations at pedestrian level. Our results indicate that canyon geometry strongly influences human exposure to traffic pollutants in the populated urban area. Carefully planning street layout and canyon geometry in consideration of traffic demand as well as local weather pattern may significantly reduce the chances of unhealthy air being inhaled by urban residents.

Evaluating strategies to reduce urban air pollution

Science.gov (United States)

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.

Atmospheric pollutants in peri-urban forests of Quercus ilex: evidence of pollution abatement and threats for vegetation.

Science.gov (United States)

García-Gómez, Héctor; Aguillaume, Laura; Izquieta-Rojano, Sheila; Valiño, Fernando; Àvila, Anna; Elustondo, David; Santamaría, Jesús M; Alastuey, Andrés; Calvete-Sogo, Héctor; González-Fernández, Ignacio; Alonso, Rocío

2016-04-01

Peri-urban vegetation is generally accepted as a significant remover of atmospheric pollutants, but it could also be threatened by these compounds, with origin in both urban and non-urban areas. To characterize the seasonal and geographical variation of pollutant concentrations and to improve the empirical understanding of the influence of Mediterranean broadleaf evergreen forests on air quality, four forests of Quercus ilex (three peri-urban and one remote) were monitored in different areas in Spain. Concentrations of nitrogen dioxide (NO2), ammonia (NH3), nitric acid (HNO3) and ozone (O3) were measured during 2 years in open areas and inside the forests and aerosols (PM10) were monitored in open areas during 1 year. Ozone was the only air pollutant expected to have direct phytotoxic effects on vegetation according to current thresholds for the protection of vegetation. The concentrations of N compounds were not high enough to directly affect vegetation but could be contributing through atmospheric N deposition to the eutrophization of these ecosystems. Peri-urban forests of Q. ilex showed a significant below-canopy reduction of gaseous concentrations (particularly NH3, with a mean reduction of 29-38%), which indicated the feasibility of these forests to provide an ecosystem service of air quality improvement. Well-designed monitoring programs are needed to further investigate air quality improvement by peri-urban ecosystems while assessing the threat that air pollution can pose to vegetation.

Trace emissions from gaseous combustion

Energy Technology Data Exchange (ETDEWEB)

Seebold, J.G. [Chevron Research and Technology Co., Richmond, CA (United States)

2000-07-01

The U.S. Clean Air Act (CAA) was amended in 1990 to include the development of maximum achievable control technology (MACT) emission standards for hazardous air pollutants (HAPs) for certain stationary sources by November 2000. MACT emissions standards would affect process heaters and industrial boilers since combustion processes are a potential source for many air toxins. The author noted that one of the problems with MACT is the lack of a clear solid scientific footing which is needed to develop environmentally responsible regulations. In order to amend some of these deficiencies, a 4-year, $7 million research project on the origin and fate of trace emissions in the external combustion of gaseous hydrocarbons was undertaken in a collaborative effort between government, universities and industry. This collaborative project entitled the Petroleum Environmental Research Forum (PERF) Project 92-19 produced basic information and phenomenological understanding in two important areas, one basic and one applied. The specific objectives of the project were to measure emissions while operating different full-scale burners under various operating conditions and then to analyze the emission data to identify which operating conditions lead to low air toxic emissions. Another objective was to develop new chemical kinetic mechanisms and predictive models for the formation of air toxic species which would explain the origin and fate of these species in process heaters and industrial boilers. It was determined that a flame is a very effective reactor and that trace emissions from a typical gas-fired industry burner are very small. An unexpected finding was that trace emissions are not affected by hydrocarbon gaseous fuel composition, nor by the use of ultra low nitrous oxide burners. 2 refs., 8 figs.

Sensitivity of a complex urban air quality model to input data

International Nuclear Information System (INIS)

Seigneur, C.; Tesche, T.W.; Roth, P.M.; Reid, L.E.

1981-01-01

In recent years, urban-scale photochemical simulation models have been developed that are of practical value for predicting air quality and analyzing the impacts of alternative emission control strategies. Although the performance of some urban-scale models appears to be acceptable, the demanding data requirements of such models have prompted concern about the costs of data acquistion, which might be high enough to preclude use of photochemical models for many urban areas. To explore this issue, sensitivity studies with the Systems Applications, Inc. (SAI) Airshed Model, a grid-based time-dependent photochemical dispersion model, have been carried out for the Los Angeles basin. Reductions in the amount and quality of meteorological, air quality and emission data, as well as modifications of the model gridded structure, have been analyzed. This paper presents and interprets the results of 22 sensitivity studies. A sensitivity-uncertainty index is defined to rank input data needs for an urban photochemical model. The index takes into account the sensitivity of model predictions to the amount of input data, the costs of data acquistion, and the uncertainties in the air quality model input variables. The results of these sensitivity studies are considered in light of the limitations of specific attributes of the Los Angeles basin and of the modeling conditions (e.g., choice of wind model, length of simulation time). The extent to which the results may be applied to other urban areas also is discussed

Urban land use, air toxics and public health: Assessing hazardous exposures at the neighborhood scale

International Nuclear Information System (INIS)

Corburn, Jason

2007-01-01

Land use data are increasingly understood as important indicators of potential environmental health risk in urban areas where micro-scale or neighborhood level hazard exposure data are not routinely collected. This paper aims to offer a method for estimating the distribution of air toxics in urban neighborhoods using land use information because actual air monitoring data rarely exist at this scale. Using Geographic Information System spatial modeling tools, we estimate air toxics concentrations across neighborhoods in New York City and statistically compare our model with the US Environmental Protection Agency's National Air Toxic Assessment and air monitoring data across three NYC neighborhoods. We conclude that land use data can act as a good proxy for estimating neighborhood scale air toxics, particularly in the absence of monitoring data. In addition, the paper suggests that land use data can expand the reach of environmental impact assessments that routinely exclude analyses of potential exposures to urban air toxics at the neighborhood scale

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

Science.gov (United States)

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.

Developing effective urban air quality management systems in the United Kingdom. Case studies

Energy Technology Data Exchange (ETDEWEB)

Elsom, D.M.; Crabbe, H. [Oxford Brookes Univ. (United Kingdom). Geography Unit

1995-12-31

During the past few years an increasing number of local authorities have expressed concern about the ambient levels of nitrogen dioxide, carbon monoxide, benzene and fine particulates that residents may be experiencing in traffic-congested parts of towns and cities. Although recent legislation is intended to reduce vehicle emissions (e.g. stricter exhaust emission standards requiring new cars to be equipped with catalytic converters), the growth in the number of motor vehicles, their frequency of use and the congestion they are causing in urban centres have resulted in little or no improvement in air quality. Although total vehicle emissions of nitrogen oxides, carbon monoxide and volatile organic compounds (VOCs) are expected to fall significantly during the next ten years, air quality will still remain a problem in some urban areas. Clearly, not all local air quality problems can be eliminated by the use of national legislation. For several years, local authorities and environmental organisations (e.g. National Society for Clean Air and Environmental Protection) have argued for local authorities to be given a statutory duty, together with appropriate funding from central government, to produce local air quality management plans which assess the seriousness of any air quality problems and which, if necessary, set out how poor air quality can be improved. This presentation examines the progress towards urban air quality management in the UK. (author)

Developing effective urban air quality management systems in the United Kingdom. Case studies

Energy Technology Data Exchange (ETDEWEB)

Elsom, D M; Crabbe, H [Oxford Brookes Univ. (United Kingdom). Geography Unit

1996-12-31

During the past few years an increasing number of local authorities have expressed concern about the ambient levels of nitrogen dioxide, carbon monoxide, benzene and fine particulates that residents may be experiencing in traffic-congested parts of towns and cities. Although recent legislation is intended to reduce vehicle emissions (e.g. stricter exhaust emission standards requiring new cars to be equipped with catalytic converters), the growth in the number of motor vehicles, their frequency of use and the congestion they are causing in urban centres have resulted in little or no improvement in air quality. Although total vehicle emissions of nitrogen oxides, carbon monoxide and volatile organic compounds (VOCs) are expected to fall significantly during the next ten years, air quality will still remain a problem in some urban areas. Clearly, not all local air quality problems can be eliminated by the use of national legislation. For several years, local authorities and environmental organisations (e.g. National Society for Clean Air and Environmental Protection) have argued for local authorities to be given a statutory duty, together with appropriate funding from central government, to produce local air quality management plans which assess the seriousness of any air quality problems and which, if necessary, set out how poor air quality can be improved. This presentation examines the progress towards urban air quality management in the UK. (author)

Estimation of the Impact of Traveler Information Apps on Urban Air Quality Improvement

Directory of Open Access Journals (Sweden)

Wenke Huang

2018-04-01

Full Text Available With the rapid growth of vehicle population and vehicle miles traveled, automobile emission has become a severe issue in the metropolitan cities of China. There are policies that concentrate on the management of emission sources. However, improving the operation of the transportation system through apps on mobile devices, especially navigation apps, may have a unique role in promoting urban air quality. Real-time traveler information can not only help travelers avoid traffic congestion, but also advise them to adjust their departure time, mode, or route, or even to cancel trips. Will such changes in personal travel patterns have a significant impact in decreasing emissions? If so, to what extent will they impact urban air quality? The aim of this study is to determine how urban traffic emission is affected by the use of navigation apps. With this work, we attempt to answer the question of whether the real-time traffic information provided by navigation apps can help to improve urban air quality. Some of these findings may provide references for the formulation of urban traffic and environmental policies. Keywords: Real-time traffic information, Mobile devices, Environmental benefits, Agent-based model

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

Science.gov (United States)

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

2016-09-06

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

The effect of gaseous ammonia on cobalt perrhenate

International Nuclear Information System (INIS)

Maslov, L.P.; Men'shikov, O.D.; Borisov, V.V.; Sorokin, S.I.; Krutovertsev, S.A.; Kharkevich, S.I.; Ivanova, O.M.

1994-01-01

The influence of humid air ammonia mixture on crystal pentahydrate of cobalt(2) perrhenate has been studied by the methods of PES, IR spectroscopy thermal analysis and electrophysical measurements. It is shown that with an increase in ammonia content in gaseous phase cobalt perrhenate successively transforms into diaquodiammine-, tetrammine- and μ-dioxo-bis-(tetrammine) derivatives of cobalt. Reversibility of dioxocomplex formation and a correlation between the change in electrophysical properties of crystal sample and change in ammonia content in gaseous phase are pointed out. 16 refs.; 4 figs.; 1 tab

Wildfire Emissions and Their Interaction with Urban and Rural Pollution: Data and Simulations

Science.gov (United States)

Singh, H. B.

2014-01-01

In recent years NASA has conducted a series of airborne campaigns (e. g. SEAC4RS*, ARCTAS, INTEX-A/B) over North America using an instrumented DC-8 aircraft equipped to measure a very large number of gaseous and aerosol constituents including several unique tracers. In these campaigns wild fires were extensively sampled near source as well as downwind after aging. The data provided detailed information on the composition and chemistry of fire emissions under a variety of atmospheric conditions as well as their interactions with rural and urban air pollution. Major fires studied including the California Rim fire in 2013 (SEAC4RS), the 2008 California wildfires (ARCTAS), and the Alaskan fires downwind over eastern US (INTEX-A). Although some fire plumes contained virtually no O3 enhancement, others showed significant ozone formation. Over Los Angeles, the highest O3 mixing ratios were observed in fire influenced urban air masses. Attempts to simulate these interactions using state of the art models were only minimally successful and indicated several shortcomings in simulating fire emission influences on urban smog formation. A variety of secondary oxidation products (e. g. O3, PAN, HCHO) were substantially underestimated. We will discuss the data collected in fire influenced air masses and their potential air quality implications.

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

Science.gov (United States)

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

Vegetation and other development options for mitigating urban air pollution impacts

Science.gov (United States)

Richard Baldauf; David J. Nowak

2014-01-01

While air pollution control devices and programs are the primary method of reducing emissions, urban air pollution can be further mitigated through planning and design strategies, including vegetation preservation and planting, building design and development, installing roadside and near-source structures, and modifying surrounding terrain features.

Impacts of Realistic Urban Heating. Part II: Air Quality and City Breathability

Science.gov (United States)

Nazarian, Negin; Martilli, Alberto; Norford, Leslie; Kleissl, Jan

2018-03-01

Urban morphology and inter-building shadowing result in a non-uniform distribution of surface heating in urban areas, which can significantly modify the urban flow and thermal field. In Part I, we found that in an idealized three-dimensional urban array, the spatial distribution of the thermal field is correlated with the orientation of surface heating with respect to the wind direction (i.e. leeward or windward heating), while the dispersion field changes more strongly with the vertical temperature gradient in the street canyon. Here, we evaluate these results more closely and translate them into metrics of "city breathability," with large-eddy simulations coupled with an urban energy-balance model employed for this purpose. First, we quantify breathability by, (i) calculating the pollutant concentration at the pedestrian level (horizontal plane at z≈ 1.5 -2 m) and averaged over the canopy, and (ii) examining the air exchange rate at the horizontal and vertical ventilating faces of the canyon, such that the in-canopy pollutant advection is distinguished from the vertical removal of pollution. Next, we quantify the change in breathability metrics as a function of previously defined buoyancy parameters, horizontal and vertical Richardson numbers (Ri_h and Ri_v , respectively), which characterize realistic surface heating. We find that, unlike the analysis of airflow and thermal fields, consideration of the realistic heating distribution is not crucial in the analysis of city breathability, as the pollutant concentration is mainly correlated with the vertical temperature gradient (Ri_v ) as opposed to the horizontal (Ri_h ) or bulk (Ri_b ) thermal forcing. Additionally, we observe that, due to the formation of the primary vortex, the air exchange rate at the roof level (the horizontal ventilating faces of the building canyon) is dominated by the mean flow. Lastly, since Ri_h and Ri_v depend on the meteorological factors (ambient air temperature, wind speed, and

Over-urbanization and air pollution: a cross-country analysis

OpenAIRE

Raufan Salahodajev

2014-01-01

This paper investigates the effect of overurbanization on different measures of air pollution in a diverse sample of developed and developing countries. The main finding is that overurbanization increases greenhouse gas emissions, measured by CO2, NOx and SO2 emissions per capita. This effect is robust to controlling for various antecedents of air pollution. Our findings provide a contribution to the ongoing debate over the role of urbanization in environmental changes.

Urban air pollution; La pollution de l'air dans la ville

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

The theme of this congress concerns air pollution in urban areas. Cities are accumulation of populations and economic activities, and then pollutants activities. The first articles are devoted to pollutants and their effects on health. Then come articles relative to measurements and modeling. Finally, the traffic in city and the automobile pollution are examined. Transportation systems as well technology in matter of gas emissions are reviewed. (N.C.)

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

Science.gov (United States)

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...

Relationship between meteorological phenomena and air pollution in an urbanized and industrialized coastal area in northern France

Science.gov (United States)

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

Research on Value Assessment and Compensation for Health Hazards of Urban Air Pollution-A Case Study of Urumqi

Directory of Open Access Journals (Sweden)

Chen Yu

Full Text Available ABSTRACT With the acceleration of urbanization and industrialization, urban air pollution has become a serious threat to the health of urban residents. In this study, to investigate health hazards caused by air pollution for urban residents, concentrations of main air pollutants and annual coal consumption amounts during the period from 2000 to 2013 were analyzed. Our results showed that economic losses of Urumqi caused by air pollution amounted to 63.155 million yuan in 2013, accounting for 0.2 ‰ of its GDP and 5.7% of public utility expenditures for that year. The compensation mechanism analysis suggested that it is necessary to further improve the health care system and increase corporate environmental taxes. More environmental health protection taxes should be levied on key monitoredenterprises in Urumqi to achieve effective compensations for urban residents affected by air pollution-related health hazards.

The diffusion and deposition of the gaseous and solid alpha radionuclides/aerosols in air

International Nuclear Information System (INIS)

Danis, A.; Ciubotariu, M.; Oncescu, M.; Mocsy, I.

1999-01-01

The diffusion and deposition of gaseous and solids alpha radionuclides and aerosols in air are processes which implicate low element amounts and therefore their studies require the using of very accurate and sensitive analysis methods. The alpha track method meets these requirements. The used alpha radionuclides were: Rn-222, as gaseous radionuclide and its solid descendants genetically related as solid radionuclides and the descendants attached to different particles from air as alpha aerosols. All these radionuclides were obtained from a calibrated Ra-226 source. The source was included into an air tight device with a well known volume and used after 40 days when the Ra-226 and its alpha descendants were under radioactive equilibrium. The relative amount and activity of each decay product, at any duration, for any initial mass of Ra-226 parent radionuclide, were calculated using a programme for computation of the U-238 radioactive series gamma accumulation, UURASE, adapted for alpha accumulation as ALFAURASE programme. The radon, Rn-222, as well as the solid alpha radionuclides and aerosols were measured using a new alpha monitoring device with or without paper filter for solid radionuclides and aerosols stopping. The track detectors of CR-39 type were incorporated with these monitoring devices. In order to calibrate the CR-39 detectors, a radon intercomparison programme was established with the participation of the SSNTD group from the Institute of Nuclear Research ATOMKI, Debrecen, Hungary, Institute of Public Health, Cluj-Napoca and SSNTD research group from IFIN-HH. We have used for radon calibration a special experimental device and a Ra-226 source. Using an air tight diffusion and deposition device, coupled with the source device, the concentration of radon and solid alpha radionuclides and aerosols were determined using the alpha track method. The alpha monitoring devices were fixed vertically at different distances from the place of radon penetration into

Health status and air pollution related socioeconomic concerns in urban China.

Science.gov (United States)

Jiao, Kaishan; Xu, Mengjia; Liu, Meng

2018-02-05

China is experiencing environmental issues and related health effects due to its industrialization and urbanization. The health effects associated with air pollution are not just a matter of epidemiology and environmental science research, but also an important social science issue. Literature about the relationship of socioeconomic factors with the environment and health factors is inadequate. The relationship between air pollution exposure and health effects in China was investigated with consideration of the socioeconomic factors. Based on nationwide survey data of China in 2014, we applied the multilevel mixed-effects model to evaluate how socioeconomic status (represented by education and income) contributed to the relationship between self-rated air pollution and self-rated health status at community level and individual level. The findings indicated that there was a non-linear relationship between the community socioeconomic status and community air pollution in urban China, with the highest level of air pollution presented in the communities with moderate socioeconomic status. In addition, health effects associated air pollution in different socioeconomic status groups were not equal. Self-rated air pollution had the greatest impact on self-rated health of the lower socioeconomic groups. With the increase of socioeconomic status, the effect of self-rated air pollution on self-rated health decreased. This study verified the different levels of exposure to air pollution and inequality in health effects among different socioeconomic groups in China. It is imperative for the government to urgently formulate public policies to enhance the ability of the lower socioeconomic groups to circumvent air pollution and reduce the health damage caused by air pollution.

Urban Air Environmental Health Indicators for Kuala Lumpur City

International Nuclear Information System (INIS)

Leh, O.L.H.; Shaharuddin Ahmad; Kadaruddin Aiyub; Yaakob Mohd Jani; Hwa, T.K.

2012-01-01

Air environmental health indicators were defined operationally as a combination of air quality and air-related health indicators. Clean air is a basic precondition of human health. Air pollutants had been identified with potential negative impact on health especially on respiratory and cardiovascular diseases. Thus, studies are necessary to identify and understand the state of environmental health. This study was aimed to examine and analyses the air environmental health condition in city of Kuala Lumpur by using a set of indicators. House to house questionnaire survey was carried out to collect air-related health data, and air quality sampling was carried out to identify ambient air quality level of the city. In general, city of Kuala Lumpur was found to have a moderate level of air quality. Air-related illnesses indicated by acute respiratory infection and asthma were found to be higher in more developed or higher density zones, as compared to other zones. Besides, air-related illnesses were significantly correlated to respondents exposure to air pollution. The findings imply that human health can be improved by managing the urban development and its environmental quality properly. (author)

Crowdsourcing urban air temperature measurements using smartphones

Science.gov (United States)

Balcerak, Ernie

2013-10-01

Crowdsourced data from cell phone battery temperature sensors could be used to contribute to improved real-time, high-resolution air temperature estimates in urban areas, a new study shows. Temperature observations in cities are in some cases currently limited to a few weather stations, but there are millions of smartphone users in many cities. The batteries in cell phones have temperature sensors to avoid damage to the phone.

Analysis of the Impact of Urban Microclimate on Air Conditioning Load Control

Directory of Open Access Journals (Sweden)

Hu Xiaoqing

2016-01-01

Full Text Available Due to the presence of urban heat island effect (UHIE, high humidity and other urban microclimate, temperature of city central area rises. This causes that the actual air-conditioning energy consumption (ACEC in the urban central area is much higher than that in the suburbs. Load control of air-conditioners (ACs is considered to be equivalent to a power plant of the same capacity, and it can greatly reduce the system pressure to peak load shift. In this paper, a simplified second order transfer function control model of ACs is presented, and its parameters will be influenced by the ambient temperature and urban microclimate. The temperature is obtained by using the temperature inversion algorithm of the heat island effect. Then, the heat index is calculated by combining temperature and humidity. The ambient temperature index of urban central area is modified based on the above microclimate, and the second order linear time invariant model of aggregated ACs is upgraded to the linear time varying model. Furthermore, the consequent parameter changes of the second order transfer function model are studied and the influence of urban microclimate on AC load control is analyzed. The proposed method is verified on numerical examples

Variability of aerosol, gaseous pollutants and meteorological characteristics associated with continental, urban and marine air masses at the SW Atlantic coast of Iberia

Science.gov (United States)

Diesch, J.-M.; Drewnick, F.; Zorn, S. R.; von der Weiden-Reinmüller, S.-L.; Martinez, M.; Borrmann, S.

2011-12-01

Measurements of the ambient aerosol were performed at the Southern coast of Spain, within the framework of the DOMINO (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) project. The field campaign took place from 20 November until 9 December 2008 at the atmospheric research station "El Arenosillo" (37°5'47.76" N, 6°44'6.94" W). As the monitoring station is located at the interface between a natural park, industrial cities (Huelva, Seville) and the Atlantic Ocean a variety of physical and chemical parameters of aerosols and gas phase could be characterized in dependency on the origin of air masses. Backwards trajectories were examined and compared with local meteorology to classify characteristic air mass types for several source regions. Aerosol number and mass as well as polycyclic aromatic hydrocarbons and black carbon concentrations were measured in PM1 and size distributions were registered covering a size range from 7 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol was measured by means of an Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS). Gas phase analyzers monitored various trace gases (O3, SO2, NO, NO2, CO2) and a weather station provided meteorological parameters. Lowest average submicron particle mass and number concentrations were found in air masses arriving from the Atlantic Ocean with values around 2 μg m-3 and 1000 cm-3. These mass concentrations were about two to four times lower than the values recorded in air masses of continental and urban origins. For some species PM1-fractions in marine air were significantly larger than in air masses originating from Huelva, a closely located city with extensive industrial activities. The largest fraction of sulfate (54%) was detected in marine air masses and was to a high degree not neutralized. In addition small concentrations of methanesulfonic acid (MSA), a product of biogenic dimethyl sulfate (DMS) emissions could be identified in the particle phase. In all

Air ion concentrations in various urban outdoor environments

Science.gov (United States)

Ling, Xuan; Jayaratne, Rohan; Morawska, Lidia

2010-06-01

Atmospheric ions are produced by many natural and anthropogenic sources and their concentrations vary widely between different environments. There is very little information on their concentrations in different types of urban environments, how they compare across these environments and their dominant sources. In this study, we measured airborne concentrations of small ions, particles and net particle charge at 32 different outdoor sites in and around a major city in Australia and identified the main ion sources. Sites were classified into seven groups as follows: park, woodland, city centre, residential, freeway, power lines and power substation. Generally, parks were situated away from ion sources and represented the urban background value of about 270 ions cm -3. Median concentrations at all other groups were significantly higher than in the parks. We show that motor vehicles and power transmission systems are two major ion sources in urban areas. Power lines and substations constituted strong unipolar sources, while motor vehicle exhaust constituted strong bipolar sources. The small ion concentration in urban residential areas was about 960 cm -3. At sites where ion sources were co-located with particle sources, ion concentrations were inhibited due to the ion-particle attachment process. These results improved our understanding on air ion distribution and its interaction with particles in the urban outdoor environment.

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

International Nuclear Information System (INIS)

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. - Highlights: • CFD is used to study impact of traffic-flow patterns on urban air quality. • Facilitating free-flow patterns induce more turbulence in street canyons. • Traffic-generated turbulence alters pollutant levels in urban street canyons. - This study investigates the effect of vehicle-induced-turbulence generated during free-flow traffic pattern in reduction of air pollutant concentrations in urban street canyons.

Air quality high resolution simulations of Italian urban areas with WRF-CHIMERE

Science.gov (United States)

Falasca, Serena; Curci, Gabriele

2017-04-01

The new European Directive on ambient air quality and cleaner air for Europe (2008/50/EC) encourages the use of modeling techniques to support the observations in the assessment and forecasting of air quality. The modelling system based on the combination of the WRF meteorological model and the CHIMERE chemistry-transport model is used to perform simulations at high resolution over the main Italian cities (e.g. Milan, Rome). Three domains covering Europe, Italy and the urban areas are nested with a decreasing grid size up to 1 km. Numerical results are produced for a winter month and a summer month of the year 2010 and are validated using ground-based observations (e.g. from the European air quality database AirBase). A sensitivity study is performed using different physics options, domain resolution and grid ratio; different urban parameterization schemes are tested using also characteristic morphology parameters for the cities considered. A spatial reallocation of anthropogenic emissions derived from international (e.g. EMEP, TNO, HTAP) and national (e.g. CTN-ACE) emissions inventories and based on the land cover datasets (Global Land Cover Facility and GlobCover) and the OpenStreetMap tool is also included. Preliminary results indicate that the introduction of the spatial redistribution at high-resolution allows a more realistic reproduction of the distribution of the emission flows and thus the concentrations of the pollutants, with significant advantages especially for the urban environments.

Urban air pollution, study of Mexico City

Energy Technology Data Exchange (ETDEWEB)

Bauer, M [PUE-UNAM (Mexico); Guzman, F [Inst. Mexicano del Petroleo (Mexico); Navarro, B [Univ. Autonoma Metropolitana (Mexico)

1996-12-01

The Metropolitan Area of Mexico City (MAMC) is an outstanding case of a fast urban development with lagging, and thus insufficient, massive transportation facilities. This has given rise to a distorted transportation system that accounts for most of the air pollution problem of the city and constitutes a drag on economic development. In this paper, we first describe the MAMC geographical conditions, its growth in physical and economic terms, its transportation system, the ensuring air pollution problems together with some of the mitigation actions undertaken. Afterwards the results of a survey of the displacements of individuals within the city and the time spent on these are presented, to then draw some considerations on the negative economic impact it represents. (EG)

Incidence of real-world automotive parent and halogenated PAH in urban atmosphere.

Science.gov (United States)

Gao, Pan-Pan; Zhao, Yi-Bo; Ni, Hong-Gang

2018-06-01

This study reports results from a tunnel experiment impact of real-world traffic-related particle and gas parent and halogenated polycyclic aromatic hydrocarbons (PAHs and HPAHs) on urban air. The traffic related emission characteristics and subsequent environmental behavior of these compounds were investigated. To understand the significance of real-world transport emissions to the urban air, traffic-related mass emissions of PAHs and HPAHs were estimated based on measured emission factors. According to our results, PAHs and HPAHs emissions via particulate phase were greater than those via gaseous phase; particles in 2.1-3.3 μm size fraction, have the major contribution to particulate PAHs and HPAHs emissions. Over all, contribution of traffic-related emission of PAHs (only ∼3% of the total PAHs emission in China) is an overstated source of PAHs pollution in China. Actually, exhaust pipe emission contributed much less than the total traffic-related emission of pollutants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Urban air pollution; La pollution de l'air dans la ville

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

The theme of this congress concerns air pollution in urban areas. Cities are accumulation of populations and economic activities, and then pollutants activities. The first articles are devoted to pollutants and their effects on health. Then come articles relative to measurements and modeling. Finally, the traffic in city and the automobile pollution are examined. Transportation systems as well technology in matter of gas emissions are reviewed. (N.C.)

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

Science.gov (United States)

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.

Diesel engines and air pollution: facts and figures

International Nuclear Information System (INIS)

Chaaban, Farid

1998-01-01

Traffic densities and resulting air pollution, in any country are directly related to the degree of urbanization and the size and characteristics of the transportation sector. In Lebanon, the car ownership rate is among the highest in the world and its consequence is the drastic deterioration in ambient air quality in Greater Beirut and other organized regions. In this article, features of diesel engines are described. The environmental impacts of diesel engines, in relation of petrol engines are briefly presented. Pollutants provocated by diesel fuel, due to its contents in Carbon , Sulfur and gaseous emissions (noise level, smoke, Carbon Monoxide emissions, smell) as well as the economical aspects are given in comparison with petrol engines. Conclusion is given that diesel engines will help in reducing air pollution caused by transport sector in Lebanon, only if some required vehicles conditions are satisfied

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

Directory of Open Access Journals (Sweden)

Anoop Singh

2003-01-01

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

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

Science.gov (United States)

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.

An Argument for the Keyhole Template for Close Air Support on the Urban Battlefield

Science.gov (United States)

2009-03-04

An Argument for the Keyhole Template for Close Air Support on the Urban Battlefield Captain BT Taggart Major RC... Keyhole Template for Close Air Support on the Urban Battlefield 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...graphic (GRG). Using the target building as the keyhole , or center of the engagement area, Lightning 62 requested a laser guided Maverick to destroy

Research on the Coupling Coordination Relationship between Urbanization and the Air Environment: A Case Study of the Area of Wuhan

Directory of Open Access Journals (Sweden)

Lei Ding

2015-10-01

Full Text Available China’s high-speed socioeconomic development has been characterized by rapid urbanization and a series of ecological environment issues, especially air pollution. This paper proposed a comprehensive indicator system for the evaluation of urbanization and the air environment in Wuhan, a metropolis in central China, and then investigated the relationship between urbanization and the air environment from the perspective of coupling coordination theory. Furthermore, a coupling coordination degree model (CCDM was constructed to estimate the relationship by using panel data collected from 1996–2013. The results showed the following: (1 Spatial urbanization and air environment quality make the greatest contributions to the compound system compared to other first grade indicators, indicating that they are critical factors to consider when the government is making relevant decisions about urban sprawl. (2 The comprehensive level of the air environment initially decreased from 1996–1998 and then increased with fluctuations in Wuhan, with several inflection points, meaning that the variation process of the air environment is unstable and repetitive, and efforts to improve the air environment must persist over a long period of time. Lastly, (3 the degree of coordinated coupling between urbanization and the air environment exhibited an S-shaped curve, indicating that Wuhan changed from having slightly unbalanced development to barely balanced development and then entered into a period of superiorly balanced development, with the air environment lagging. Thus, the ambient urban air quality has been subject to great pressure, and the government should continue to take effective action to improve it.

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

Science.gov (United States)

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

Impacts of urban land-surface forcing on ozone air quality in the Seoul metropolitan area

Directory of Open Access Journals (Sweden)

Y.-H. Ryu

2013-02-01

Full Text Available Modified local meteorology owing to heterogeneities in the urban–rural surface can affect urban air quality. In this study, the impacts of urban land-surface forcing on ozone air quality during a high ozone (O₃ episode in the Seoul metropolitan area, South Korea, are investigated using a high-resolution chemical transport model (CMAQ. Under fair weather conditions, the temperature excess (urban heat island significantly modifies boundary layer characteristics/structures and local circulations. The modified boundary layer and local circulations result in an increase in O₃ levels in the urban area of 16 ppb in the nighttime and 13 ppb in the daytime. Enhanced turbulence in the deep urban boundary layer dilutes pollutants such as NO_x, and this contributes to the elevated O₃ levels through the reduced O₃ destruction by NO in the NO_x-rich environment. The advection of O₃ precursors over the mountains near Seoul by the prevailing valley-breeze circulation in the mid- to late morning results in the build-up of O₃ over the mountains in conjunction with biogenic volatile organic compound (BVOC emissions there. As the prevailing local circulation in the afternoon changes to urban-breeze circulation, the O₃-rich air masses over the mountains are advected over the urban area. The urban-breeze circulation exerts significant influences on not only the advection of O₃ but also the chemical production of O₃ under the circumstances in which both anthropogenic and biogenic (natural emissions play important roles in O₃ formation. As the air masses that are characterized by low NO_x and high BVOC levels and long OH chain length are advected over the urban area from the surroundings, the ozone production efficiency increases in the urban area. The relatively strong vertical mixing in the urban boundary layer embedded in the

Urban air pollution in megacities of the world

Science.gov (United States)

Mage, David; Ozolins, Guntis; Peterson, Peter; Webster, Anthony; Orthofer, Rudi; Vandeweerd, Veerle; Gwynne, Michael

Urban air pollution is a major environmental problem in the developing countries of the world. WHO and UNEP created an air pollution monitoring network as part of the Global Environment Monitoring System. This network now covers over 50 cities in 35 developing and developed countries throughout the world. The analyses of the data reported by the network over the past 15-20 yr indicate that the lessons of the prior experiences in the developed countries (U.S.A., U.K.) have not been learned. A study of air pollution in 20 of the 24 megacities of the world (over 10 million people by year 2000) shows that ambient air pollution concentrations are at levels where serious health effects are reported. The expected rise of population in the next century, mainly in the developing countries with a lack of capital for air pollution control, means that there is a great potential that conditions will worsen in many more cities that will reach megacity status. This paper maps the potential for air pollution that cities will experience in the future unless control strategies are developed and implemented during the next several decades.

Impact of urbanization on the air pollution “holiday effect” in Taiwan

Science.gov (United States)

Tan, Pei-Hua; Chou, Chia; Chou, Charles C.-K.

2013-05-01

The spatio-temporal characteristics of the “holiday effect”, defined as the difference in air pollutant concentrations between the holiday (Chinese New Year) and non-holiday periods during 1994-2008, and its association with the degree of urbanization in Taiwan are examined. Daily surface measurements of six major pollutants from 54 monitoring stations of the Taiwan Environmental Protection Administration are used. Holiday effects are found for almost all air pollutants in all divisions and individual stations. A widespread holiday effect with consistent signs suggests a high degree of urbanization over Taiwan. Holiday effects are stronger in the west than in the east, due to urban-rural differences, and have a distinct north-south difference in the west, due to different emission sources. In the spatial distribution, as the population (motor vehicle) number in the division increases, holiday effects of NOx, CO and NMHC are intensified. Holiday effects of pollutants can also be stronger when the associated dominant anthropogenic sources in the division have larger emissions. Both imply the association of a stronger holiday effect with a higher degree of urbanization in the division. In the temporal variation, on the other hand, holiday effects and pollutant concentrations tend to weaken and reduce in almost all the urban divisions for all six pollutants except O3. These weakening trends imply possible contributions of other effects, such as the mature state of urbanization for the urban division, the effective pollution-control measures and behavioral pattern changes.

Rapid monitoring of gaseous fission products in BWRs using a portable spectrometer

International Nuclear Information System (INIS)

Yeh, Wei-Wen; Lee, Cheng-Jong; Chen, Chen-Yi; Chung, Chien

1996-01-01

Rapid, quantitative determination of gaseous radionuclides is the most difficult task in the field of environmental monitoring for radiation. Although the identification of each gaseous radionuclide is relatively straightforward using its decayed gamma ray as an index, the quantitative measurement is hampered by the time-consuming sample collection procedures, in particular for the radioactive noble gaseous fission products of krypton and xenon. In this work, a field gamma-ray spectrometer consisting of a high-purity germanium detector, portable multichannel anlayzer, and a notebook computer was used to conduct rapid scanning of radioactive krypton and xenon in the air around a nuclear facility

Vertically resolved characteristics of air pollution during two severe winter haze episodes in urban Beijing, China

Science.gov (United States)

Wang, Qingqing; Sun, Yele; Xu, Weiqi; Du, Wei; Zhou, Libo; Tang, Guiqian; Chen, Chen; Cheng, Xueling; Zhao, Xiujuan; Ji, Dongsheng; Han, Tingting; Wang, Zhe; Li, Jie; Wang, Zifa

2018-02-01

We conducted the first real-time continuous vertical measurements of particle extinction (bext), gaseous NO2, and black carbon (BC) from ground level to 260 m during two severe winter haze episodes at an urban site in Beijing, China. Our results illustrated four distinct types of vertical profiles: (1) uniform vertical distributions (37 % of the time) with vertical differences less than 5 %, (2) higher values at lower altitudes (29 %), (3) higher values at higher altitudes (16 %), and (4) significant decreases at the heights of ˜ 100-150 m (14 %). Further analysis demonstrated that vertical convection as indicated by mixing layer height, temperature inversion, and local emissions are three major factors affecting the changes in vertical profiles. Particularly, the formation of type 4 was strongly associated with the stratified layer that was formed due to the interactions of different air masses and temperature inversions. Aerosol composition was substantially different below and above the transition heights with ˜ 20-30 % higher contributions of local sources (e.g., biomass burning and cooking) at lower altitudes. A more detailed evolution of vertical profiles and their relationship with the changes in source emissions, mixing layer height, and aerosol chemistry was illustrated by a case study. BC showed overall similar vertical profiles as those of bext (R2 = 0.92 and 0.69 in November and January, respectively). While NO2 was correlated with bext for most of the time, the vertical profiles of bext / NO2 varied differently for different profiles, indicating the impact of chemical transformation on vertical profiles. Our results also showed that more comprehensive vertical measurements (e.g., more aerosol and gaseous species) at higher altitudes in the megacities are needed for a better understanding of the formation mechanisms and evolution of severe haze episodes in China.

Modelling the influence of peri-urban trees in the air quality of Madrid region (Spain)

International Nuclear Information System (INIS)

Alonso, Rocio; Vivanco, Marta G.; Gonzalez-Fernandez, Ignacio; Bermejo, Victoria; Palomino, Inmaculada; Garrido, Juan Luis; Elvira, Susana; Salvador, Pedro; Artinano, Begona

2011-01-01

Tropospheric ozone (O 3 ) is considered one of the most important air pollutants affecting human health. The role of peri-urban vegetation in modifying O 3 concentrations has been analyzed in the Madrid region (Spain) using the V200603par-rc1 version of the CHIMERE air quality model. The 3.7 version of the MM5 meteorological model was used to provide meteorological input data to the CHIMERE. The emissions were derived from the EMEP database for 2003. Land use data and the stomatal conductance model included in CHIMERE were modified according to the latest information available for the study area. Two cases were considered for the period April-September 2003: (1) actual land use and (2) a fictitious scenario where El Pardo peri-urban forest was converted to bare-soil. The results show that El Pardo forest constitutes a sink of O 3 since removing this green area increased O 3 levels over the modified area and over down-wind surrounding areas. - Highlights: → Role of peri-urban vegetation in modifying O 3 pollution in Madrid (Spain). → The CHIMERE air quality model was adapted to Mediterranean conditions. → Preserving the peri-urban forest lowers O 3 concentrations over the surrounding areas. → Evergreen broadleaf and deciduous forests removed more atmospheric O 3 than conifers. - Peri-urban forests contribute to ameliorate ozone air pollution.

Analysis of tree bark samples for air pollution biomonitoring of an urban area

International Nuclear Information System (INIS)

Martins, Ana Paula G.; Negri, Elnara M.; Saldiva, Paulo H.N.

2009-01-01

Air pollution is receiving much attention as a public health problem around the world due to its adverse health effects from exposures by urban populations. Within this context, the use of vegetal biomonitoring to evaluate air quality has been investigated throughout the world. Air pollutant levels are high in the city of Sao Paulo, SP, Brazil and being the vehicle emissions its main source. The aim of this study was to evaluate concentrations of As, Ba, Br, Ca, Co, Cr, Cu, Fe, Mn, Pb, S, Sb and Zn in tree bark samples used as biomonitor of urban air pollution. Concentrations of these elements were determined in barks collected in trees of the Ibirapuera Park, one of the biggest and most visited parks of the city of Sao Paulo city. Samples of tree barks were also collected in a site outside the city of Sao Paulo, in a rural area of Embu-Guacu, considered as a control site. The element concentrations were determined by the methods of Instrumental Neutron Activation Analysis (INAA) and of Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF). The findings of this study showed that tree bark samples may be used as biomonitors of urban air pollution in a micro scale, and both techniques, INAA and EDXRF, can be used to evaluate element concentrations in tree bark samples. (author)

Gaseous waste deposition preventive device for glass melting furnace

International Nuclear Information System (INIS)

Takano, Sueo

1998-01-01

The device of the present invention comprises a heater for heating pressurized air and a moisturizer for mixing steams with the pressurized air heated by the heater to make moisturized pressurized air. Steams are mixed to rise humidity by the moisturizing up to the saturated vapor pressure at the temperature of the heating by heating pressurized air as an object of moisturizing by the heater to prevent dew condensation while increasing the amount of steams to be mixed. With such procedures, moisture enriched pressurized air can be jetted out thereby enabling to prevent deposition of solid materials and crystallized materials of gaseous wastes. (T.M.)

Estimating the Impact of Urbanization on Air Quality in China Using Spatial Regression Models

OpenAIRE

Fang, Chuanglin; Liu, Haimeng; Li, Guangdong; Sun, Dongqi; Miao, Zhuang

2015-01-01

Urban air pollution is one of the most visible environmental problems to have accompanied China’s rapid urbanization. Based on emission inventory data from 2014, gathered from 289 cities, we used Global and Local Moran’s I to measure the spatial autorrelation of Air Quality Index (AQI) values at the city level, and employed Ordinary Least Squares (OLS), Spatial Lag Model (SAR), and Geographically Weighted Regression (GWR) to quantitatively estimate the comprehensive impact and spatial variati...

Urban air pollution induces micronuclei in peripheral erythrocytes of mice in vivo

International Nuclear Information System (INIS)

Soares, S.R.C.; Bueno-Guimaraes, H.M.; Ferreira, C.M.; Rivero, D.H.R.F.; Castro, I. de; Garcia, M.L.B.; Saldiva, P.H.N.

2003-01-01

In this study, we explored the role of chronic exposure to urban air pollution in causing DNA damage (micronuclei frequency in peripheral erythrocytes) in rodents in vivo. Mice (n=20) were exposed to the urban atmosphere of Sao Paulo for 120 days (February to June 1999) and compared to animals (n=20) maintained in the countryside (Atibaia) for the same period. Daily levels of inhalable particles (PM10), CO, NO 2 , and SO 2 , were available for Sao Paulo. Occasional measurements of CO and O 3 were made in Atibaia, showing negligible levels of pollution in the area. The frequency of micronuclei (repeated-measures ANOVA) increased with aging, the highest values obtained for the 90th day of experiment (P 2 (P<0.001), and PM10 (P<0.001). Our results support the concept that urban levels of air pollution may cause somatic mutations

Urban compaction vs city sprawl: impact of road traffic on air quality in the greater Paris

Science.gov (United States)

Etuman Arthur, Elessa; Isabelle, Coll; Vincent, Viguie; Nicolas, Coulombel; Julie, Prud'homme

2017-04-01

Urban pollution remains a major sanitary and economic concern. In France, particulate pollution is known to cause 48,000 premature deaths every year (Santé Publique France, 2016), while the economic cost of air pollution reaches almost 25 billion euros per year (CGDD, 2012). In the Greater Paris, despite strengthened emission standards, restricted traffic areas, car-sharing and incentives for electric vehicle use, road transport plays a substantial role in the exposure of inhabitants to high levels of pollutants. In this context, urban planning could possibly constitute an innovative strategy to reduce emissions from road traffic, through its actions on transport demand, travel distances, modal shift (public transportation, cycling, walking...) or even proximity to emitters. We have developed a multi-scalar modeling of urban pollution by coupling an urban economic growth model NEDUM (CIRED), a model for urban mobility (LISA), a traffic emission model (LISA) and the CHIMERE Chemistry-Transport model (CTM) for air quality simulation (LISA). The innovative aspect of this modeling system is to integrate into a classic CTM the mechanisms underlying the dynamics of an urban system. This way, we establish a quantitative and comprehensive link between a given urban scenario, the associated public and individual transport matrix, and local air quality. We then make it possible to highlight the levers of energy consumption reductions inside compact or sprawled cities. We have been working on the Ile de France region (centered on the Paris agglomeration) which relies on a broad urban structure of megacity, a high density of housing and an expanding urban peripheral zone, clearly raising the issue of transport demand, mobility and traffic congestion. Two scenarios, considering opposite urban development policies from the 1960s to 2010, have been simulated over the whole modelling chain. The first one promotes a dense and compact city while the second favors city spread

Differences in airborne particle and gaseous concentrations in urban air between weekdays and weekends

Science.gov (United States)

Morawska, L.; Jayaratne, E. R.; Mengersen, K.; Jamriska, M.; Thomas, S.

Airborne particle number concentrations and size distributions as well as CO and NO x concentrations monitored at a site within the central business district of Brisbane, Australia were correlated with the traffic flow rate on a nearby freeway with the aim of investigating differences between weekday and weekend pollutant characteristics. Observations over a 5-year monitoring period showed that the mean number particle concentration on weekdays was (8.8±0.1)×10 3 cm -3 and on weekends (5.9±0.2)×10 3 cm -3—a difference of 47%. The corresponding mean particle number median diameters during weekdays and weekends were 44.2±0.3 and 50.2±0.2 nm, respectively. The differences in mean particle number concentration and size between weekdays and weekends were found to be statistically significant at confidence levels of over 99%. During a 1-year period of observation, the mean traffic flow rate on the freeway was 14.2×10 4 and 9.6×10 4 vehicles per weekday and weekend day, respectively—a difference of 48%. The mean diurnal variations of the particle number and the gaseous concentrations closely followed the traffic flow rate on both weekdays and weekends (correlation coefficient of 0.86 for particles). The overall conclusion, as to the effect of traffic on concentration levels of pollutant concentration in the vicinity of a major road (about 100 m) carrying traffic of the order of 10 5 vehicles per day, is that about a 50% increase in traffic flow rate results in similar increases of CO and NO x concentrations and a higher increase of about 70% in particle number concentration.

Proposed methodology for estimating the impact of highway improvements on urban air pollution.

Science.gov (United States)

1971-01-01

The aim of this methodology is to indicate the expected change in ambient air quality in the vicinity of a highway improvement and in the total background level of urban air pollution resulting from the highway improvement. Both the jurisdiction in w...

Gaseous elemental mercury depletion events observed at Cape Point during 2007–2008

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E.-G. Brunke

2010-02-01

Full Text Available Gaseous mercury in the marine boundary layer has been measured with a 15 min temporal resolution at the Global Atmosphere Watch station Cape Point since March 2007. The most prominent features of the data until July 2008 are the frequent occurrences of pollution (PEs and depletion events (DEs. Both types of events originate mostly within a short transport distance (up to about 100 km, which are embedded in air masses ranging from marine background to continental. The Hg/CO emission ratios observed during the PEs are within the range reported for biomass burning and industrial/urban emissions. The depletion of gaseous mercury during the DEs is in many cases almost complete and suggests an atmospheric residence time of elemental mercury as short as a few dozens of hours, which is in contrast to the commonly used estimate of approximately 1 year. The DEs observed at Cape Point are not accompanied by simultaneous depletion of ozone which distinguishes them from the halogen driven atmospheric mercury depletion events (AMDEs observed in Polar Regions. Nonetheless, DEs similar to those observed at Cape Point have also been observed at other places in the marine boundary layer. Additional measurements of mercury speciation and of possible mercury oxidants are hence called for to reveal the chemical mechanism of the newly observed DEs and to assess its importance on larger scales.

Respiratory alterations due to urban air pollution: An experimental study in rats

International Nuclear Information System (INIS)

Saldiva, P.H.N.; King, M.; Delmonte, V.L.C.; Macchione, M.; Parada, M.A.C.; Daliberto, M.L.; Sakae, R.S.; Criado, P.M.P.; Silveira, P.L.P.; Zin, W.A.; Boehm, G.M.

1992-01-01

In order to assess the adverse effects of urban levels of air pollution, rats were used as biological indicators in a chronic exposure experiment. Animals were housed for 6 months in the center of Sao Paulo and were compared to controls kept for the same period in a clean area. Pollution levels were obtained from a State air pollution monitoring station, 200 m distant from the exposure place, which provided the levels of CO, SO 2 , particulates, and ozone. The animals were submitted to several tests focusing on the respiratory system, comprising pulmonary function tests, studies on mucociliary clearance and mucus rheology, histochemical evaluation of airways, bronchoalveolar lavage, and ultrastructural studies of the epithelium of the airways. Rats exposed to air pollution developed secretory cell hyperplasia in the airways, ultrastructural ciliary alterations, and a more rigid mucus, changes that caused mucociliary clearance impairment. In addition, nasal resistance and the number of inflammatory cells recovered by bronchoalveolar lavage were increased in air pollution exposed animals. The results obtained in the present investigation suggest that chronic exposure to urban levels of air pollution may cause respiratory lesions in rats

Multi-scale dynamic modeling of atmospheric pollution in urban environment

International Nuclear Information System (INIS)

Thouron, Laetitia

2017-01-01

Urban air pollution has been identified as an important cause of health impacts, including premature deaths. In particular, ambient concentrations of gaseous pollutants such as nitrogen dioxide (NO 2 ) and particulate matter (PM10 and PM2.5) are regulated, which means that emission reduction strategies must be put in place to reduce these concentrations in places where the corresponding regulations are not respected. Besides, air pollution can contribute to the contamination of other media, for example through the contribution of atmospheric deposition to runoff contamination. The multifactorial and multi-scale aspects of urban make the pollution sources difficult to identify. Indeed, the urban environment is a heterogeneous space characterized by complex architectural structures (old buildings alongside a more modern building, residential, commercial, industrial zones, roads, etc.), non-uniform atmospheric pollutant emissions and therefore the population exposure to pollution is variable in space and time. The modeling of urban air pollution aims to understand the origin of pollutants, their spatial extent and their concentration/deposition levels. Some pollutants have long residence times and can stay several weeks in the atmosphere (PM2.5) and therefore be transported over long distances, while others are more local (NO x in the vicinity of traffic). The spatial distribution of a pollutant will therefore depend on several factors, and in particular on the surfaces encountered. Air quality depends strongly on weather, buildings (canyon-street) and emissions. The aim of this thesis is to address some of these aspects by modeling: (1) urban background pollution with a transport-chemical model (Polyphemus / POLAIR3D), which makes it possible to estimate atmospheric pollutants by type of urban surfaces (roofs, walls and roadways), (2) street-level pollution by explicitly integrating the effects of the building in a three-dimensional way with a multi-scale model of

A Novel Approach in Quantifying the Effect of Urban Design Features on Local-Scale Air Pollution in Central Urban Areas.

Science.gov (United States)

Miskell, Georgia; Salmond, Jennifer; Longley, Ian; Dirks, Kim N

2015-08-04

Differences in urban design features may affect emission and dispersion patterns of air pollution at local-scales within cities. However, the complexity of urban forms, interdependence of variables, and temporal and spatial variability of processes make it difficult to quantify determinants of local-scale air pollution. This paper uses a combination of dense measurements and a novel approach to land-use regression (LUR) modeling to identify key controls on concentrations of ambient nitrogen dioxide (NO2) at a local-scale within a central business district (CBD). Sixty-two locations were measured over 44 days in Auckland, New Zealand at high density (study area 0.15 km(2)). A local-scale LUR model was developed, with seven variables identified as determinants based on standard model criteria. A novel method for improving standard LUR design was developed using two independent data sets (at local and "city" scales) to generate improved accuracy in predictions and greater confidence in results. This revised multiscale LUR model identified three urban design variables (intersection, proximity to a bus stop, and street width) as having the more significant determination on local-scale air quality, and had improved adaptability between data sets.

Characterisation and modelling of mercury speciation in urban air affected by gold mining - assessment of bioavailability

Directory of Open Access Journals (Sweden)

Cukrowska E. M.

2013-04-01

Full Text Available The growing global concern over the release of mercury to the environment has prompted specific inventories that quantify mercury emissions from various sources. Investigations of atmospheric mercury have been mostly done on gaseous species. Although, to assess human expose to mercury, especially in urban areas, the inhalable dust should be included in a study. The Witwatersrand Basin in South Africa is one of the most important gold mining regions in the world. Mercury (Hg, which occurs in gold-bearing ores, was also used for gold recoveries in previous centuries (19th and early 20th century and presently in illegal artisanal mining. The consequences of these mining activities were the release of Hg to the environment, mainly due to AMD from tailings dumps which are presently reprocessed. The city of Johannesburg is a multimillion population exposed strongly to industrial pollution. The aim of this study was to determine the magnitude of mercury pollution in this urban area and assess its bioavailability. The gaseous samples were collected by trapping mercury on various gold traps. Dust samples were collected from a ground and on inhalation levels (1–2 m above a ground. They were later separated into different fractions by micro sieving. Bioavailability of mercury in inhalable dust (25 μm was tested by leaching collected samples with artificial lung fluid (ALF, pH 4.5, Gray’s solution (pH 7.4 and water. The leaching conditions were selected to mimic lungs environment (incubator at 30°C, time 24 hrs, rotation of samples 150 rpm. Total concentrations of mercury in dust fractions were also determined after microwave digestion. The results showed extremely high concentration levels of mercury in air and dust in industrial areas. Especially high levels were found around presently reprocessed old gold tailings dumps, up to 900 000 μgl–1. The levels dropped significantly in CBD area but still showing elevated concentrations up to 10 μgl−1

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

Science.gov (United States)

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 (urban population (R(2) = 0.99, P urban second industry fraction (R(2) = 0.71, P urbanization had considerable impact on PM2.5 concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Health status and air pollution related socioeconomic concerns in urban China

OpenAIRE

Jiao, Kaishan; Xu, Mengjia; Liu, Meng

2018-01-01

Background China is experiencing environmental issues and related health effects due to its industrialization and urbanization. The health effects associated with air pollution are not just a matter of epidemiology and environmental science research, but also an important social science issue. Literature about the relationship of socioeconomic factors with the environment and health factors is inadequate. The relationship between air pollution exposure and health effects in China was investig...

A pilot study of gaseous pollutants' measurement (NO2, SO2, NH3, HNO3 and O3) in Abidjan, Côte d'Ivoire: contribution to an overview of gaseous pollution in African cities

Science.gov (United States)

Bahino, Julien; Yoboué, Véronique; Galy-Lacaux, Corinne; Adon, Marcellin; Akpo, Aristide; Keita, Sékou; Liousse, Cathy; Gardrat, Eric; Chiron, Christelle; Ossohou, Money; Gnamien, Sylvain; Djossou, Julien

2018-04-01

This work is part of the DACCIWA FP7 project (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) in the framework of the Work Package 2 Air Pollution and Health. This study aims to characterize urban air pollution levels through the measurement of NO2, SO2, NH3, HNO3 and O3 in Abidjan, the economic capital of Côte d'Ivoire. Measurements of inorganic gaseous pollutants, i.e. NO2, SO2, NH3, HNO3 and O3 were performed in Abidjan during an intensive campaign within the dry season (15 December 2015 to 16 February 2016), using INDAAF (International Network to study Deposition and Atmospheric chemistry in AFrica) passive samplers exposed in duplicate for 2-week periods. Twenty-one sites were selected in the district of Abidjan to be representative of various anthropogenic and natural sources of air pollution in the city. Results from this intensive campaign show that gas concentrations are strongly linked to surrounding pollution sources and show a high spatial variability. Also, NH3, NO2 and O3 gases were present at relatively higher concentrations at all the sites. NH3 average concentrations varied between 9.1 ± 1.7 ppb at a suburban site and 102.1 ± 9.1 ppb at a domestic fires site. NO2 mean concentration varied from 2.7 ± 0.1 ppb at a suburban site to 25.0 ± 1.7 ppb at an industrial site. Moreover, we measured the highest O3 concentration at the two coastal sites of Gonzagueville and Félix-Houphouët-Boigny International Airport located in the southeast of the city, with average concentrations of 19.1 ± 1.7 and 18.8 ± 3.0 ppb, respectively. The SO2 average concentration never exceeded 7.2 ± 1.2 ppb over all the sites, with 71.5 % of the sampling sites showing concentrations ranging between 0.4 and 1.9 ppb. The HNO3 average concentration ranged between 0.2 and 1.4 ppb. All these results were combined with meteorological parameters to provide the first mapping of gaseous pollutants on the scale of the district of Abidjan using geostatistical analysis

Reduced detonation kinetics and detonation structure in one- and multi-fuel gaseous mixtures

Science.gov (United States)

Fomin, P. A.; Trotsyuk, A. V.; Vasil'ev, A. A.

2017-10-01

Two-step approximate models of chemical kinetics of detonation combustion of (i) one-fuel (CH4/air) and (ii) multi-fuel gaseous mixtures (CH4/H2/air and CH4/CO/air) are developed for the first time. The models for multi-fuel mixtures are proposed for the first time. Owing to the simplicity and high accuracy, the models can be used in multi-dimensional numerical calculations of detonation waves in corresponding gaseous mixtures. The models are in consistent with the second law of thermodynamics and Le Chatelier’s principle. Constants of the models have a clear physical meaning. Advantages of the kinetic model for detonation combustion of methane has been demonstrated via numerical calculations of a two-dimensional structure of the detonation wave in a stoichiometric and fuel-rich methane-air mixtures and stoichiometric methane-oxygen mixture. The dominant size of the detonation cell, determines in calculations, is in good agreement with all known experimental data.

Treatment of gaseous and airborne radioactive waste

International Nuclear Information System (INIS)

Leichsenring, C.H.

1982-01-01

Gaseous and airborne radionuclides in the fuel cycle are retained in vessel off-gas filter systems and in the dissolver off-gas cleaning system. Those systems have to meet the regulatory requirements for both normal and accident conditions. From the solutions liquid aerosols are formed during liquid transfer (air lifts, steam jets) or by air sparging or by evaporation processes. During dissolution the volatile radionuclides i.e. 85 Kr, 129 I and 14 C are liberated and enter into the dissolver off-gas cleaning system. Flow sheets of different cleaning systems and their stage of development are described. (orig./RW)

A numerical study on the characteristics of gaseous pollutant absorbed by a moving liquid aerosol

International Nuclear Information System (INIS)

Deng, J.J.; Du, Y.G.; Yu, Y.; Ding, J.

2008-01-01

Atmospheric pollution involving aerosols is becoming increasingly problematic. Since aerosols are small in size and have large specific surface areas, they can enhance some chemical reactions. Liquid aerosols in the air can absorb gaseous pollutants to adversely affect air quality and human health. This paper studied the characteristics of liquid aerosols and the absorption process of gaseous pollutants. Specifically, the paper presented a model to depict the characteristic of the absorption process of gaseous pollutant by a liquid aerosol with internal circulation and chemical reaction. The model assumed that liquid aerosols retain a spherical shape while moving freely in air. The finite volume method was used to develop an algorithm used to numerically simulate the experimental work of Walcek. The paper also discussed the numerical evaluation of the transient momentum and mass transfer characteristics of sulphur dioxide into a droplet. It was concluded that the chemical reaction increased the rate of mass transfer and the quasi-saturation time of aerosols, which provided a theoretical basis for the heterogeneous reaction of liquid aerosols. 3 refs., 6 figs

Mitigation of severe urban haze pollution by a precision air pollution control approach.

Science.gov (United States)

Yu, Shaocai; Li, Pengfei; Wang, Liqiang; Wu, Yujie; Wang, Si; Liu, Kai; Zhu, Tong; Zhang, Yuanhang; Hu, Min; Zeng, Liming; Zhang, Xiaoye; Cao, Junji; Alapaty, Kiran; Wong, David C; Pleim, Jon; Mathur, Rohit; Rosenfeld, Daniel; Seinfeld, John H

2018-05-25

Severe and persistent haze pollution involving fine particulate matter (PM 2.5 ) concentrations reaching unprecedentedly high levels across many cities in China poses a serious threat to human health. Although mandatory temporary cessation of most urban and surrounding emission sources is an effective, but costly, short-term measure to abate air pollution, development of long-term crisis response measures remains a challenge, especially for curbing severe urban haze events on a regular basis. Here we introduce and evaluate a novel precision air pollution control approach (PAPCA) to mitigate severe urban haze events. The approach involves combining predictions of high PM 2.5 concentrations, with a hybrid trajectory-receptor model and a comprehensive 3-D atmospheric model, to pinpoint the origins of emissions leading to such events and to optimize emission controls. Results of the PAPCA application to five severe haze episodes in major urban areas in China suggest that this strategy has the potential to significantly mitigate severe urban haze by decreasing PM 2.5 peak concentrations by more than 60% from above 300 μg m -3 to below 100 μg m -3 , while requiring ~30% to 70% less emission controls as compared to complete emission reductions. The PAPCA strategy has the potential to tackle effectively severe urban haze pollution events with economic efficiency.

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

Science.gov (United States)

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

Reassessment of urbanization effect on surface air temperature trends at an urban station of North China

Science.gov (United States)

Bian, Tao; Ren, Guoyu

2017-11-01

Based on a homogenized data set of monthly mean temperature, minimum temperature, and maximum temperature at Shijiazhuang City Meteorological Station (Shijiazhuang station) and four rural meteorological stations selected applying a more sophisticated methodology, we reanalyzed the urbanization effects on annual, seasonal, and monthly mean surface air temperature (SAT) trends for updated time period 1960-2012 at the typical urban station in North China. The results showed that (1) urbanization effects on the long-term trends of annual mean SAT, minimum SAT, and diurnal temperature range (DTR) in the last 53 years reached 0.25, 0.47, and - 0.50 °C/decade, respectively, all statistically significant at the 0.001 confidence level, with the contributions from urbanization effects to the overall long-term trends reaching 67.8, 78.6, and 100%, respectively; (2) the urbanization effects on the trends of seasonal mean SAT, minimum SAT, and DTR were also large and statistically highly significant. Except for November and December, the urbanization effects on monthly mean SAT, minimum SAT, and DTR were also all statistically significant at the 0.05 confidence level; and (3) the annual, seasonal, and monthly mean maximum SAT series at the urban station registered a generally weaker and non-significant urbanization effect. The updated analysis evidenced that our previous work for this same urban station had underestimated the urbanization effect and its contribution to the overall changes in the SAT series. Many similar urban stations were being included in the current national and regional SAT data sets, and the results of this paper further indicated the importance and urgency for paying more attention to the urbanization bias in the monitoring and detection of global and regional SAT change based on the data sets.

The Influence of Urban Planning Affected Static and Stable Meteorological Field on Air Pollution

Science.gov (United States)

Zhang, Yue; Zhang, Liyuan; Zhang, Yunwei

2018-02-01

Accompany with the rapid urbanized and industrialized process, the built-up area and the number of high-rise buildings increased fast. Urban air quality is facing with the challenge caused by the rapid increase in energy consumption, motor vehicles owned, and the city construction. Long term high precision analysis on Beijing-Tianjin-Hebei region has been conducted in this article, so as to explore the influence of rapid increase in urban size and tall building amount on occurrence frequency of urban static and stable meteorological conditions as well as the contribution to urban PM2.5 pollution.

Particulate Matter Air Pollution in an Urban Area : a Case Study

Directory of Open Access Journals (Sweden)

Piotr Holnicki

2016-01-01

Full Text Available Many European agglomerations suffer from high concentrations of particulate matter (PM, which is now one of the most detrimental pollutants characterizing the urban atmospheric environment. This paper addresses the problem of PM10 pollution in the Warsaw metropolitan area, including very harmful fine fractions (PM2.5, and also some heavy metals. The analysis of air quality in the Warsaw agglomeration discussed in this study is based on results from computer modeling presented elsewhere, and refers to emission and meteorological data for the year 2012. The range of emissions considered in this analysis includes the main sectors of municipal activity: energy generation, industry, urban transport, residential sector. The trans-boundary inflow of the main pollutants coming from distant sources is also taken into account. The regional scale computer model CALPUFF was used to assess the annual mean concentrations of major pollutants in the urban area. The results show the regions where the air quality limits are exceeded and indicate the dominant sources of emission which are responsible for these violations (source apportionment. These are the key data required to implement efficient regulatory actions. (original abstract

Relation between lead in air and in petrol in two urban areas of Britain

Science.gov (United States)

Pattenden, N. J.; Branson, J. R.

The recent reduction in the lead content of petrol in the United Kingdom, following government legislation, has been used to investigate the relationship between lead in petrol and in outside air in urban environments. In parts of London and Manchester, the airborne lead concentration closely followed the petrol lead concentration, within a time resolution of about 1 month. These results indicate that, in these areas, the petrol lead content has a fairly direct and prompt effect on the urban air lead concentration, i.e. any environmental lead reservoirs in the pathway from petrol to air (and hence to man by inhalation) are not significant on this timescale. A small component of the airborne lead, apparently independent of the petrol lead, was also observed.

Urban Air Pollution in Taiwan before and after the Installation of a Mass Rapid Transit System.

Science.gov (United States)

Ding, Pei-Hsiou; Wang, Gen-Shuh; Chen, Bing-Yu; Wan, Gwo-Hwa

2016-09-01

Urbanization causes air pollution in metropolitan areas, coupled with meteorological factors that affect air quality. Although previous studies focused on the relationships of urbanization, air pollution, and climate change in Western countries, this study evaluated long-term variations of air quality and meteorological factors in Taiwanese metropolitan areas (Taipei area, Taichung City, and Kaohsiung City) and a rural area (Hualien County) between 1993 and 2012. The influence of a mass rapid transit (MRT) system on air quality was also evaluated. Air pollutant concentrations and meteorology data were collected from Taiwan Environmental Protection Administration (TEPA) air monitoring stations and Central Weather Bureau stations in the surveyed areas, respectively. Analyses indicate that levels of air pollution in metropolitan areas were greater than in the rural area. Kaohsiung City had the highest levels of O, SO, and particulate matter 2.5 or 10 µm in diameter (PM and PM). Clear downward trends for CO, NO, PM, PM, and especially SO concentrations were found in the surveyed areas, whereas O showed no decrease. Both O and PM concentrations showed similar bimodal seasonal distributions. Taiwan's air quality has improved significantly since 1993, indicating the effectiveness of promoting air pollution strategies and policies by the TEPA. Air pollution had an obvious improvement in Taipei area after the MRT system began operations in 1996. Because global climate may potentially affect urban air pollution in Taiwan, further study to clarify the mechanisms by which air pollution may affect human health and other biological effects is warranted. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Assessment on pattern of urban air quality by using chemometric ...

African Journals Online (AJOL)

The study evaluate the relationship between the main daily concentrations of criteria air pollutants in urban areas and their associations by using chemometric technique. Data were gathered from the Department of Environmental for three years observations (2011-2013) consisting of 5 major pollutants such as SO2, NO2, ...

Total particulate and reactive gaseous mercury in ambient air on the eastern slope of the Mt. Gongga area, China

International Nuclear Information System (INIS)

Fu Xuewu; Feng Xinbin; Zhu Wanze; Zheng Wei; Wang Shaofeng; Lu, Julia Y.

2008-01-01

Total particulate mercury (TPM) and reactive gaseous mercury (RGM) concentrations in ambient air on the eastern slope of the Mt. Gongga area, Sichuan Province, Southwestern China were monitored from 25 May, 2005 to 29 April, 2006. Simultaneously, Hg concentrations in rain samples were measured from January to December, 2006. The average TPM and RGM concentrations in the study site were 30.7 and 6.2 pg m -3 , which are comparable to values observed in remote areas in Northern America and Europe, but much lower than those reported in some urban areas in China. The mean seasonal RGM concentration was slightly higher in spring (8.0 pg m -3 ) while the minimum mean concentration was observed in winter (4.0 pg m -3 ). TPM concentrations ranged across two orders of magnitude from 5.2 to 135.7 pg m -3 and had a clear seasonal variation: winter (74.1 pg m -3 ), autumn (22.5 pg m -3 ), spring (15.3 pg m -3 ) and summer (10.8 pg m -3 ), listed in decreasing order. The annual wet deposition was 9.1 μg m -2 and wet deposition in the rainy season (May-October) represented over 80% of the annual total. The temporal distribution of TPM and RGM suggested distinguishable dispersion characteristics of these Hg species on a regional scale. Elevated TPM concentration in winter was probably due to regional and local enhanced coal burning and low wet deposition velocity. The RGM distribution pattern is closely related to daily variation in UV radiation observed during the winter sampling period indicating that photo-oxidation processes and diurnal changes in meteorology play an important role in RGM generation

Atmospheric ammonia and its impacts on regional air quality over the megacity of Shanghai, China

Science.gov (United States)

Wang, Shanshan; Nan, Jialiang; Shi, Chanzhen; Fu, Qingyan; Gao, Song; Wang, Dongfang; Cui, Huxiong; Saiz-Lopez, Alfonso; Zhou, Bin

2015-01-01

Atmospheric ammonia (NH3) has great environmental implications due to its important role in ecosystem and global nitrogen cycle, as well as contribution to secondary particle formation. Here, we report long-term continuous measurements of NH3 at different locations (i.e. urban, industrial and rural) in Shanghai, China, which provide an unprecedented portrait of temporal and spatial characteristics of atmospheric NH3 in and around this megacity. In addition to point emission sources, air masses originated from or that have passed over ammonia rich areas, e.g. rural and industrial sites, increase the observed NH3 concentrations inside the urban area of Shanghai. Remarkable high-frequency NH3 variations were measured at the industrial site, indicating instantaneous nearby industrial emission peaks. Additionally, we observed strong positive exponential correlations between NH4+/(NH4++NH3) and sulfate-nitrate-ammonium (SNA) aerosols, PM2.5 mass concentrations, implying a considerable contribution of gas-to-particle conversion of ammonia to SNA aerosol formation. Lower temperature and higher humidity conditions were found to favor the conversion of gaseous ammonia to particle ammonium, particularly in autumn. Although NH3 is currently not included in China’s emission control policies of air pollution precursors, our results highlight the urgency and importance of monitoring gaseous ammonia and improving its emission inventory in and around Shanghai. PMID:26514559

Adsorption of gaseous RuO4 by various sorbents. II

International Nuclear Information System (INIS)

Vujisic, L.; Nikolic, R.

1983-01-01

Sorption of gaseous RuO 4 on impregnated Alcoa Alumina H-151, impregnated charcoal, silica gel and HEPA filter was investigated. The results obtained on various sorbents are compared and discussed in connection with possibilities to use the chosen material in air cleaning systems

Effects of canyon geometry on the distribution of traffic-related air pollution in a large urban area: Implications of a multi-canyon air pollution dispersion model

Science.gov (United States)

Fu, Xiangwen; Liu, Junfeng; Ban-Weiss, George A.; Zhang, Jiachen; Huang, Xin; Ouyang, Bin; Popoola, Olalekan; Tao, Shu

2017-09-01

Street canyons are ubiquitous in urban areas. Traffic-related air pollutants in street canyons can adversely affect human health. In this study, an urban-scale traffic pollution dispersion model is developed considering street distribution, canyon geometry, background meteorology, traffic assignment, traffic emissions and air pollutant dispersion. In the model, vehicle exhausts generated from traffic flows first disperse inside street canyons along the micro-scale wind field generated by computational fluid dynamics (CFD) model. Then, pollutants leave the street canyon and further disperse over the urban area. On the basis of this model, the effects of canyon geometry on the distribution of NOx and CO from traffic emissions were studied over the center of Beijing. We found that an increase in building height leads to heavier pollution inside canyons and lower pollution outside canyons at pedestrian level, resulting in higher domain-averaged concentrations over the area. In addition, canyons with highly even or highly uneven building heights on each side of the street tend to lower the urban-scale air pollution concentrations at pedestrian level. Further, increasing street widths tends to lead to lower pollutant concentrations by reducing emissions and enhancing ventilation simultaneously. Our results indicate that canyon geometry strongly influences human exposure to traffic pollutants in the populated urban area. Carefully planning street layout and canyon geometry while considering traffic demand as well as local weather patterns may significantly reduce inhalation of unhealthy air by urban residents.

Radiolytical oxidation of gaseous iodine by beta radiation

International Nuclear Information System (INIS)

Kaerkelae, Teemu; Auvinen, Ari; Kekki, Tommi; Kotiluoto, Petri; Lyyraenen, Jussi; Jokiniemi, Jorma

2015-01-01

Iodine is one of the most radiotoxic fission product released from fuel during a severe nuclear power plant accident. Within the containment building, iodine compounds can react e.g. on the painted surfaces and form gaseous organic iodides. In this study, it was found out that gaseous methyl iodide (CH 3 I) is oxidised when exposed to beta radiation in an oxygen containing atmosphere. As a result, nucleation of aerosol particles takes place and the formation of iodine oxide particles is suggested. These particles are highly hygroscopic. They take up water from the air humidity and iodine oxides dissolve within the droplets. In order to mitigate the possible source term, it is of interest to understand the effect of beta radiation on the speciation of iodine.

Radiolytical oxidation of gaseous iodine by beta radiation

Energy Technology Data Exchange (ETDEWEB)

Kaerkelae, Teemu; Auvinen, Ari; Kekki, Tommi; Kotiluoto, Petri; Lyyraenen, Jussi [VTT Technical Research Centre of Finland, Espoo (Finland); Jokiniemi, Jorma [VTT Technical Research Centre of Finland, Espoo (Finland); Eastern Finland Univ., Kuopio (Finland)

2015-07-01

Iodine is one of the most radiotoxic fission product released from fuel during a severe nuclear power plant accident. Within the containment building, iodine compounds can react e.g. on the painted surfaces and form gaseous organic iodides. In this study, it was found out that gaseous methyl iodide (CH{sub 3}I) is oxidised when exposed to beta radiation in an oxygen containing atmosphere. As a result, nucleation of aerosol particles takes place and the formation of iodine oxide particles is suggested. These particles are highly hygroscopic. They take up water from the air humidity and iodine oxides dissolve within the droplets. In order to mitigate the possible source term, it is of interest to understand the effect of beta radiation on the speciation of iodine.

Statistical Analysis of Spatiotemporal Heterogeneity of the Distribution of Air Quality and Dominant Air Pollutants and the Effect Factors in Qingdao Urban Zones

Directory of Open Access Journals (Sweden)

Xiangwei Zhao

2018-04-01

Full Text Available Air pollution has impacted people’s lives in urban China, and the analysis of the distribution and driving factors behind air quality has become a current research focus. In this study, the temporal heterogeneity of air quality (AQ and the dominant air pollutants across the four seasons were analyzed based on the Kruskal-Wallis rank-sum test method. Then, the spatial heterogeneity of AQ and the dominant air pollutants across four sites were analyzed based on the Wilcoxon signed-rank test method. Finally, the copula model was introduced to analyze the effect of relative factors on dominant air pollutants. The results show that AQ and dominant air pollutants present significant spatiotemporal heterogeneity in the study area. AQ is worst in winter and best in summer. PM10, O3, and PM2.5 are the dominant air pollutants in spring, summer, and winter, respectively. The average concentration of dominant air pollutants presents significant and diverse daily peaks and troughs across the four sites. The main driving factors are pollutants such as SO2, NO2, and CO, so pollutant emission reduction is the key to improving air quality. Corresponding pollution control measures should account for this heterogeneity in terms of AQ and the dominant air pollutants among different urban zones.

Estimating the burden of disease attributable to urban outdoor air ...

African Journals Online (AJOL)

PM10 and PM2.5 data from air-quality assessment studies in areas not covered by the network were also included. Population-attributable fractions calculated using risk coefficients presented in the WHO study were weighted by the proportion of the total population (33%) in urban environments, and applied to revised ...

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

International Nuclear Information System (INIS)

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

2015-01-01

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. - Highlights: • Embryotoxicity of airborne organic compounds collected in urban and rural areas. • Ultrafine particles (<0.5 μm) accumulated most of the observed toxicity. • Strong seasonal differences in rural areas, probably linked to wood combustion. • Rural and urban samples showed quantitative and qualitative differences in toxicity. • At least one independent toxic modes of action especially linked to urban emissions. - Quantitative and qualitative differences in embryotoxic effects of airborne particulate matter from urban and rural areas.

Porphyrin pattern and methemoglobin levels in Columba livia applied to assess toxicological risk by air pollution in urban areas.

Science.gov (United States)

Sicolo, Matteo; Tringali, Maria; Orsi, Federica; Santagostino, Angela

2009-11-01

The study has explored two conservative biomarkers, porphyrin pattern in guano and methemoglobin levels in blood of Columba livia, in order to assay their potential use for monitoring toxic effects induced by exposure to urban air pollution. Fieldwork was conducted between October 2003 and June 2005 in the city of Milan, Italy, by sampling the pigeons in different areas almost twice a week. Six air contaminants, CO, PM10, NO(2), O(3), SO(2), and C(6)H(6), plus polycyclic aromatic hydrocarbons (PAHs) in fine particles, temperature, and UV index, were considered. Protoporphyrins from pigeon excreta sampled outdoors were always higher than in indoor animals, particularly in winter. A positive correlation (p urban air showed significant differences from season to season but only in summer and autumn did the outdoor pigeons show higher values than indoor animals. In summer, a regression model with a positive correlation between O(3) and benzene was determined (p urban air pollution as well as for detecting complex interactions between contaminants in the urban air pollutant mixture was discussed.

Gaseous nebulae

International Nuclear Information System (INIS)

Williams, R.E.

1976-01-01

Gaseous nebulae are large, tenuous clouds of ionized gas that are associated with hot stars and that emit visible light because of the energy that they receive from the ultraviolet radiation of the stars. Examples include H II regions, planetary nebulae, and nova/supernova remnants. The emphasis is on the physical processes that occur in gaseous nebulae as opposed to a study of the objects themselves. The introduction discusses thermodynamic vs. steady-state equilibrium and excitation conditions in a dilute radiation field. Subsequent sections take up important atomic processes in gaseous nebulae (particle--particle collision rates, radiative interaction rates, cross sections), the ionization equilibrium (sizes of H II regions, ionization of the heavier elements), kinetic temperature and energy balance (heating of the electrons, cooling of the electrons), and the spectra of gaseous nebulae (line fluxes in nebulae). 7 figures, 5 tables

Long-term exposure to gaseous air pollutants and cardio-respiratory mortality in Brisbane, Australia

Directory of Open Access Journals (Sweden)

Xiao Yu Wang

2009-05-01

Full Text Available This study examines the association of long-term exposure to gaseous air pollution with cardio-respiratory mortality in Brisbane, Australia, in the period 1996-2004. The pollutant concentrations were estimated using geographical information system (GIS techniques at the statistical local area (SLA level. The generalized estimating equations model was used to investigate the impact of nitrogen dioxide (NO2, ozone (O3 and sulphur dioxide (SO2 on mortality due to cardio-respiratory disease after adjusting for a range of potential confounders. An increase of 4.7% (95% confidence interval = 0.7-8.9% in cardio-respiratory mortality for 1 part per billion (ppb increment in annual average concentration of SO2 was estimated. However, there was no significant association between long-term exposures to NO2 or O3 and death due to cardio-respiratory disease. The results indicate that the annual average concentration of SO2 is associated with cardio-respiratory mortality at the SLA level and this association appears to vary with the geographical area.

Evaluation of Urban air quality models for regulatory use: Refinement of an approach

International Nuclear Information System (INIS)

Downton, M.W.; Dennis, R.L.

1985-01-01

Statistical measures for evaluating the performance of urban air quality models have recently been strongly recommended by several investigators. Problems that were encountered in the use of recommended performance measures in an evaluation of three versions of an urban photochemical model are described. The example demonstrates the importance of designing an evaluation to take into account the way in which the model will be used in regulatory practice, and then choosing performance measures on the basis of that design. The evaluation illustrates some limitations and possible pitfalls in the use and interpretation of statistical measures of model performance. Drawing on this experience, a procedure for evaluation of air quality models for regulatory use is suggested

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

Science.gov (United States)

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.

Dispersion model computations of urban air pollution in Espoo, Finland

Energy Technology Data Exchange (ETDEWEB)

Valkonen, E.; Haerkoenen, J.; Kukkonen, J.; Rantakrans, E.; Jalkanen, L.

1997-12-31

This report presents the numerical results of air quality studies of the city of Espoo in southern Finland. This city is one of the four cities in the Helsinki metropolitan area, having a total population of 850 000. A thorough emission inventory was made of both mobile and stationary sources in the Helsinki metropolitan area. The atmospheric dispersion was evaluated using an urban dispersion modelling system, including a Gaussian multiple-source plume model and a meteorological pre-processing model. The hourly time series of CO, NO{sub 2} and SO{sub 2} concentrations were predicted, using the emissions and meteorological data for the year 1990. The predicted results show a clear decrease in the yearly mean concentrations from southeast to northwest. This is due in part to the denser traffic in the southern parts of Espoo, and in part to pollution from the neighbouring cities of Helsinki and Vantaa, located east of Espoo. The statistical concentration parameters found for Espoo were lower than the old national air quality guidelines (1984); however, some occurrences of above-threshold values were found for NO{sub 2} in terms of the new guidelines (1996). The contribution of traffic to the total concentrations varies spatially from 30 to 90 % for NO{sub 2} from 1 to 65 % for SO{sub 2} while for CO it is nearly 100 %. The concentrations database will be further utilised to analyse the influence of urban air pollution on the health of children attending selected day nurseries in Espoo. The results of this study can also be applied in traffic and city planning. In future work the results will also be compared with data from the urban measurement network of the Helsinki Metropolitan Area Council. (orig.) 19 refs.

EMMA model: an advanced operational mesoscale air quality model for urban and regional environments

International Nuclear Information System (INIS)

Jose, R.S.; Rodriguez, M.A.; Cortes, E.; Gonzalez, R.M.

1999-01-01

Mesoscale air quality models are an important tool to forecast and analyse the air quality in regional and urban areas. In recent years an increased interest has been shown by decision makers in these types of software tools. The complexity of such a model has grown exponentially with the increase of computer power. Nowadays, medium workstations can run operational versions of these modelling systems successfully. Presents a complex mesoscale air quality model which has been installed in the Environmental Office of the Madrid community (Spain) in order to forecast accurately the ozone, nitrogen dioxide and sulphur dioxide air concentrations in a 3D domain centred on Madrid city. Describes the challenging scientific matters to be solved in order to develop an operational version of the atmospheric mesoscale numerical pollution model for urban and regional areas (ANA). Some encouraging results have been achieved in the attempts to improve the accuracy of the predictions made by the version already installed. (Author)

Urban scale air quality modelling using detailed traffic emissions estimates

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Sustainability Challenges from Climate Change and Air Conditioning Use in Urban Areas

OpenAIRE

Lundgren, Karin; Kjellström, Tord

2013-01-01

Global climate change increases heat loads in urban areas causing health and productivity risks for millions of people. Inhabitants in tropical and subtropical urban areas are at especial risk due to high population density, already high temperatures, and temperature increases due to climate change. Air conditioning is growing rapidly, especially in South and South-East Asia due to income growth and the need to protect from high heat exposures. Studies have linked increased total hourly elect...

Hydrogenating gaseous hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Nicolardot, P L.F.

1930-08-06

Gaseous hydrocarbons obtained by the destructive distillation of carbonaceous materials are simultaneously desulfurized and hydrogenated by passing them at 350 to 500/sup 0/C, mixed with carbon monoxide and water vapor over lime mixed with metallic oxides present in sufficient amount to absorb the carbon dioxide as it is formed. Oxides of iron, copper, silver, cobalt, and metals of the rare earths may be used and are mixed with the lime to form a filling material of small pieces filling the reaction vessel which may have walls metallized with copper and zinc dust. The products are condensed and fixed with absorbents, e.g. oils, activated carbon, silica gels. The metallic masses may be regenerated by a hot air stream and by heating in inert gases.

Disinfection of indoor air microorganisms in stack room of university library using gaseous chlorine dioxide.

Science.gov (United States)

Hsu, Ching-Shan; Lu, Ming-Chun; Huang, Da-Ji

2015-02-01

As with all indoor public spaces in Taiwan, the stack rooms in public libraries should meet the air quality guidelines laid down by the Taiwan Environmental Protection Administration. Accordingly, utilizing a university library in Taiwan for experimental purposes, this study investigates the efficiency of gaseous chlorine dioxide (ClO2) as a disinfection agent when applied using three different treatment modes, namely a single-daily disinfection mode (SIM), a twice-daily disinfection mode (TWM), and a triple-daily disinfection mode (TRM). For each treatment mode, the ClO2 is applied using an ultrasonic aerosol device and is performed both under natural lighting conditions and under artificial lighting conditions. The indoor air quality is evaluated before and after each treatment session by measuring the bioaerosol levels of bacteria and fungi. The results show that for all three disinfection modes, the application of ClO2 reduces the indoor bacteria and fungi concentrations to levels lower than those specified by the Taiwan EPA (i.e., bacteria <1500 CFU/m(3), fungi <1000 CFU/m(3)), irrespective of the lighting conditions under which the disinfection process is performed. For each disinfection mode, a better disinfection efficiency is obtained under natural lighting conditions since ClO2 readily decomposes under strong luminance levels. Among the three treatment modes, the disinfection efficiencies of the TWM and TRM modes are very similar under natural lighting conditions and are significantly better than that of the SIM mode. Thus, overall, the results suggest that the TWM treatment protocol represents the most cost-effective and efficient method for meeting the indoor air quality requirements of the Taiwan EPA.

PARTICULATE MATTER IN ATMOSPHERIC AIR IN URBAN AGGLOMERATION

Directory of Open Access Journals (Sweden)

Halina Marczak

2017-05-01

Full Text Available The study aimed to determine the mass concentration of PM10 in the air in urban area. The specific objective of the research was to analyze and assess the impact of transport road emissions on the level of concentration of particulate matter in the atmosphere in the Lublin agglomeration. The measuring points were located in places at different distances from the communications emission sources and, at the same time, possibly varying degrees of air pollution dust. Measuring the concentration of dust at the measuring points was performed using an indirect method using a laser photometer. In the research point which was not under direct influence of a heavy traffic road dust levels lower by 10.5% to 65.4% than in the vicinity of the transport route were reported. Small particle air pollution at all the points covered by the study increased significantly during the heating season. Based on the comparison of the obtained values of PM10 concentrations with legal standards, it was found that the air pollution exceeded the limits in all measurement points only during a series of measurements in the months of November-December. The recorded increase in air pollution during the heating season should be associated with an increased dust emissions in this period from the "low" emitters - local house boilers and detached houses.

Vertically resolved characteristics of air pollution during two severe winter haze episodes in urban Beijing, China

Directory of Open Access Journals (Sweden)

Q. Wang

2018-02-01

Full Text Available We conducted the first real-time continuous vertical measurements of particle extinction (bext, gaseous NO2, and black carbon (BC from ground level to 260 m during two severe winter haze episodes at an urban site in Beijing, China. Our results illustrated four distinct types of vertical profiles: (1 uniform vertical distributions (37 % of the time with vertical differences less than 5 %, (2 higher values at lower altitudes (29 %, (3 higher values at higher altitudes (16 %, and (4 significant decreases at the heights of ∼ 100–150 m (14 %. Further analysis demonstrated that vertical convection as indicated by mixing layer height, temperature inversion, and local emissions are three major factors affecting the changes in vertical profiles. Particularly, the formation of type 4 was strongly associated with the stratified layer that was formed due to the interactions of different air masses and temperature inversions. Aerosol composition was substantially different below and above the transition heights with ∼ 20–30 % higher contributions of local sources (e.g., biomass burning and cooking at lower altitudes. A more detailed evolution of vertical profiles and their relationship with the changes in source emissions, mixing layer height, and aerosol chemistry was illustrated by a case study. BC showed overall similar vertical profiles as those of bext (R2 = 0.92 and 0.69 in November and January, respectively. While NO2 was correlated with bext for most of the time, the vertical profiles of bext ∕ NO2 varied differently for different profiles, indicating the impact of chemical transformation on vertical profiles. Our results also showed that more comprehensive vertical measurements (e.g., more aerosol and gaseous species at higher altitudes in the megacities are needed for a better understanding of the formation mechanisms and evolution of severe haze episodes in China.

Estimating the burden of disease attributable to urban outdoor air ...

African Journals Online (AJOL)

Outdoor air pollution in urban areas in South Africa was estimated to cause 3.7% of the national mortality from cardiopulmonary disease and 5.1 % of mortality attributable to cancers of the trachea, bronchus and lung in adults aged 30 years and older, and 1.1 % of mortality from ARis in children under 5 years of age.

Impact of the volume of gaseous phase in closed reactors on ANC results and modelling

Science.gov (United States)

Drapeau, Clémentine; Delolme, Cécile; Lassabatere, Laurent; Blanc, Denise

2016-04-01

The understanding of the geochemical behavior of polluted solid materials is often challenging and requires huge expenses of time and money. Nevertheless, given the increasing amounts of polluted solid materials and related risks for the environment, it is more and more crucial to understand the leaching of majors and trace metals elements from these matrices. In the designs of methods to quantify pollutant solubilization, the combination of experimental procedures with modeling approaches has recently gained attention. Among usual methods, some rely on the association of ANC and geochemical modeling. ANC experiments - Acid Neutralization Capacity - consists in adding known quantities of acid or base to a mixture of water and contaminated solid materials at a given liquid / solid ratio in closed reactors. Reactors are agitated for 48h and then pH, conductivity, redox potential, carbon, majors and heavy metal solubilized are quantified. However, in most cases, the amounts of matrix and water do not reach the total volume of reactors, leaving some space for air (gaseous phase). Despite this fact, no clear indication is given in standard procedures about the effect of this gaseous phase. Even worse, the gaseous phase is never accounted for when exploiting or modeling ANC data. The gaseous phase may exchange CO2 with the solution, which may, in turn, impact both pH and element release. This study lies within the most general framework for the use of geochemical modeling for the prediction of ANC results for the case of pure phases to real phase assemblages. In this study, we focus on the effect of the gaseous phase on ANC experiments on different mineral phases through geochemical modeling. To do so, we use PHREEQC code to model the evolution of pH and element release (including majors and heavy metals) when several matrices are put in contact with acid or base. We model the following scenarios for the gaseous phase: no gas, contact with the atmosphere (open system

National Gas Survey. Synthesized gaseous hydrocarbon fuels

Energy Technology Data Exchange (ETDEWEB)

None

1978-06-01

The supply-Technical Advisory Task Force-Synthesized Gaseous Hydrocarbon Fuels considered coal, hydrocarbon liquids, oil shales, tar sands, and bioconvertible materials as potential feedstocks for gaseous fuels. Current status of process technology for each feedstock was reviewed, economic evaluations including sensitivity analysis were made, and constraints for establishment of a synthesized gaseous hydrocarbon fuels industry considered. Process technology is presently available to manufacture gaseous hydrocarbon fuels from each of the feedstocks. In 1975 there were eleven liquid feedstock SNG plants in the United States having a capacity of 1.1 billion SCFD. There can be no contribution of SNG before 1982 from plants using feedstocks other than liquids because there are no plants in operation or under construction as of 1977. Costs for SNG are higher than current regulated prices for U.S. natural gas. Because of large reserves, coal is a prime feedstock candidate although there are major constraints in the area of coal leases, mining and water permits, and others. Commercial technology is available and several new gasification processes are under development. Oil shale is also a feedstock in large supply and commercial process technology is available. There are siting and permit constraints, and water availability may limit the ultimate size of an oil shale processing industry. Under projected conditions, bioconvertible materials are not expected to support the production of large quantities of pipeline quality gas during the next decade. Production of low or medium Btu gas from municipal solid wastes can be expected to be developed in urban areas in conjunction with savings in disposal costs. In the economic evaluations presented, the most significant factor for liquid feedstock plants is the anticipated cost of feedstock and fuel. The economic viability of plants using other feedstocks is primarily dependent upon capital requirements.

Correlation between air pollution and weather data in urban areas: Assessment of the city of Rome (Italy) as spatially and temporally independent regarding pollutants

Science.gov (United States)

Battista, Gabriele; de Lieto Vollaro, Roberto

2017-09-01

Air pollution represents the biggest environmental risk for health. It is so widespread and it represents one of the main problems of the worldwide, especially because it is emitted by so many different types of sources. The pollutants can originate directly by exhausted or they can be formed because of the reaction with the atmosphere. The first one includes particulate matter and gaseous pollutants such as sulfur oxides, nitrogen oxides, and carbon oxides. The second one includes the ozone formed from nitrogen oxides and hydrocarbons, and particulate sulfate and nitrate aerosols created in the atmosphere from sulfur and nitrogen oxide gases. During the entire life course, people are exposed to the pollutants and suffer from different consequences depending on the age. The first nine month of life are generally recognized as more critical than latter time periods. The mortality associated to air pollutant exposure is main related to the concentrations of NOx , ozone, carbon monoxide, sulfur dioxides and particular matter. More than 92% of the world's population lives in places where air quality levels exceed the standards. In 2012, one out of every nine deaths was the result of air pollution-related conditions. In 2016 about 3 million deaths a year were linked to exposure to outdoor air pollution. In the last few years many epidemiological studies have shown associations between air pollutant concentrations and human health. Apart from people, even monuments and artworks can be damaged by pollution, especially in city centres. Furthermore, urbanization modified microclimate conditions of the cities, and, together with traffic and domestic heating, led to a discomfort of living conditions. For these reasons, there is the necessity to improve the research on the impact of pollutant and microclimate conditions inside urban areas. In this work different kinds of pollutants in Rome from 2006 to 2015 were analysed, and different techniques of post elaboration were used

Biomonitoring of air quality in the metropolitan region of Recife, PE, Brazil

International Nuclear Information System (INIS)

Santos, Thiago Oliveira dos

2016-01-01

The interest on questions related to environmental conservation has increased in recent decades, being air pollution one of the main public health problems in huge urban centers. Major part of this atmospheric contamination is caused by gaseous pollutants and inhalable particulate matter. One of the main sources is the burning of fossil fuels mainly emitted by motor vehicles. Some organisms, like lichen and atmospheric bromeliad, are able to accumulate chemical elements in their tissues, thereby becoming excellent tools for air quality studies of monitoring. The present work evaluated the air quality in the Metropolitan Region of Recife (RMR) using the lichen Cladonia verticillaris and the bromeliad Tillandsia recurvata, through the quantification of chemical elements associated to vehicles traffic. The biomonitors were transferred to 40 points distributed in the RMR with different intensities of the vehicle traffic. After the exposition period of six months, Al, Ba, Ca, Cd, Cl, Fe, Mg, Mn, P, Pb, Sb, Sr, Th, V and Zn were quantified by Energy Dispersive X-Ray Fluorescence (EDXRF) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The organisms were complementary, being appropriated tools for monitoring the air quality. The vehicle traffic was considered one of the major contributor for increasing chemical elements in the RMR urban atmosphere. (author)

Calibration of low-cost gas sensors for an urban air quality monitoring network

Science.gov (United States)

Scott, A.; Kelley, C.; He, C.; Ghugare, P.; Lehman, A.; Benish, S.; Stratton, P.; Dickerson, R. R.; Zuidema, C.; Azdoud, Y.; Ren, X.

2017-12-01

In a warming world, environmental pollution may be exacerbated by anthropogenic activities, such as climate change and the urban heat island effect, as well as natural phenomena such as heat waves. However, monitoring air pollution at federal reference standards (approximately 1 part per billion or ppb for ambient ozone) is cost-prohibitive in heterogeneous urban areas as many expensive devices are required to fully capture a region's geo-spatial variability. Innovation in low-cost sensors provide a potential solution, yet technical challenges remain to overcome possible imprecision in the data. We present the calibrations of ozone and nitrous dioxide from a low-cost air quality monitoring device designed for the Baltimore Open Air Project. The sensors used in this study are commercially available thin film electrochemical sensors from SPEC Sensor, which are amperometric, meaning they generate current proportional to volumetric fraction of gas. The results of sensor calibrations in the laboratory and field are presented.

A pilot study of gaseous pollutants' measurement (NO2, SO2, NH3, HNO3 and O3 in Abidjan, Côte d'Ivoire: contribution to an overview of gaseous pollution in African cities

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J. Bahino

2018-04-01

Full Text Available This work is part of the DACCIWA FP7 project (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa in the framework of the Work Package 2 Air Pollution and Health. This study aims to characterize urban air pollution levels through the measurement of NO2, SO2, NH3, HNO3 and O3 in Abidjan, the economic capital of Côte d'Ivoire. Measurements of inorganic gaseous pollutants, i.e. NO2, SO2, NH3, HNO3 and O3 were performed in Abidjan during an intensive campaign within the dry season (15 December 2015 to 16 February 2016, using INDAAF (International Network to study Deposition and Atmospheric chemistry in AFrica passive samplers exposed in duplicate for 2-week periods. Twenty-one sites were selected in the district of Abidjan to be representative of various anthropogenic and natural sources of air pollution in the city. Results from this intensive campaign show that gas concentrations are strongly linked to surrounding pollution sources and show a high spatial variability. Also, NH3, NO2 and O3 gases were present at relatively higher concentrations at all the sites. NH3 average concentrations varied between 9.1 ± 1.7 ppb at a suburban site and 102.1 ± 9.1 ppb at a domestic fires site. NO2 mean concentration varied from 2.7 ± 0.1 ppb at a suburban site to 25.0 ± 1.7 ppb at an industrial site. Moreover, we measured the highest O3 concentration at the two coastal sites of Gonzagueville and Félix-Houphouët-Boigny International Airport located in the southeast of the city, with average concentrations of 19.1 ± 1.7 and 18.8 ± 3.0 ppb, respectively. The SO2 average concentration never exceeded 7.2 ± 1.2 ppb over all the sites, with 71.5 % of the sampling sites showing concentrations ranging between 0.4 and 1.9 ppb. The HNO3 average concentration ranged between 0.2 and 1.4 ppb. All these results were combined with meteorological parameters to provide the first mapping of gaseous pollutants

Urban sprawl and air quality in large US cities.

Science.gov (United States)

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.

Influence of a gaseous atmosphere on fatigue crack propagation

International Nuclear Information System (INIS)

Henaff, G.

2002-01-01

The paper presents a review of the current knowledge on the influence of gaseous atmospheres, and primarily ambient air, on fatigue crack propagation in metallic alloys. Experimental evidence of the effect of exposure to ambient air or any moist environment on fatigue crack propagation in steels is first proposed. The different interacting processes are analyzed so as to clearly uncouple the influence of the various factors on crack growth resistance. Two distinct mechanisms are identified: the adsorption of vapour molecules and hydrogen assisted fracture at crack tip. (author)

Greater Baltimore Open Air: an Internet of Things (IoT) approach to citizen science and community-driven climate, air quality, and urban heat island monitoring

Science.gov (United States)

Scott, A.; Kelley, C.; Azdoud, Y.; Ambikapathi, R.; Hobson, M.; Lehman, A.; Ghugare, P.; He, C.; Zaitchik, B. F.; Waugh, D.; McCormack, M.; Baja, K.

2017-12-01

Anthropogenic activities alter the urban surface and surface atmosphere, generating heat and pollutants that have known detrimental impacts on health. Monitoring these environmental variables in urban environments is made difficult by the spatial heterogeneity of urban environments, meaning that two nearby locations may have significantly different temperatures, humidities, or gas concentrations. Thus, urban monitoring often requires more densely placed monitors than current standards or budgets allow. Recent advances in low-cost sensors and Internet of Things (IoT) enabled hardware offer possible solutions. We present an autonomous wireless, open-source, IoT-enabled environmental monitor called a WeatherCube, developed for the Greater Baltimore Open Air project, funded in part by the EPA SmartCity Challenge. The WeatherCube is suitable for urban monitoring and capable of measuring meteorological variables (temperature and humidity) as well as air quality (ozone, nitrogen dioxide, and sulfur dioxide). The WeatherCube devices were built in collaboration with Johns Hopkins University, local government, and community members, including through an innovative job training program. Monitors are hosted by community partners and libraries throughout Baltimore city and surrounding communities. We present the first wave of data collected by the Greater Baltimore Open Air project and compare it to data collected by the Maryland Department of the Environment (MDE). Additionally, we will provide an overview of our experience engaging with the local makers, citizen scientists, and environmental groups to improve their urban environmental monitoring. By developing low-cost devices tailored for urban environmental monitoring, we present an innovative model for both conducting research and community outreach.

Assessing the Future Vehicle Fleet Electrification: The Impacts on Regional and Urban Air Quality.

Science.gov (United States)

Ke, Wenwei; Zhang, Shaojun; Wu, Ye; Zhao, Bin; Wang, Shuxiao; Hao, Jiming

2017-01-17

There have been significant advancements in electric vehicles (EVs) in recent years. However, the different changing patterns in emissions at upstream and on-road stages and complex atmospheric chemistry of pollutants lead to uncertainty in the air quality benefits from fleet electrification. This study considers the Yangtze River Delta (YRD) region in China to investigate whether EVs can improve future air quality. The Community Multiscale Air Quality model enhanced by the two-dimensional volatility basis set module is applied to simulate the temporally, spatially, and chemically resolved changes in PM 2.5 concentrations and the changes of other pollutants from fleet electrification. A probable scenario (Scenario EV1) with 20% of private light-duty passenger vehicles and 80% of commercial passenger vehicles (e.g., taxis and buses) electrified can reduce average PM 2.5 concentrations by 0.4 to 1.1 μg m -3 during four representative months for all urban areas of YRD in 2030. The seasonal distinctions of the air quality impacts with respect to concentration reductions in key aerosol components are also identified. For example, the PM 2.5 reduction in January is mainly attributed to the nitrate reduction, whereas the secondary organic aerosol reduction is another essential contributor in August. EVs can also effectively assist in mitigating NO 2 concentrations, which would gain greater reductions for traffic-dense urban areas (e.g., Shanghai). This paper reveals that the fleet electrification in the YRD region could generally play a positive role in improving regional and urban air quality.

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

Science.gov (United States)

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.

Portsmouth Gaseous Diffusion Plant expansion, Piketon, Ohio. Volume 2. Draft environmental statement

Energy Technology Data Exchange (ETDEWEB)

Pennington, W. H.

1976-06-01

The need for additional uranium enrichment facilities and the environmental impacts of the add-on gaseous diffusion plant proposed for the Portsmouth Gaseous Diffusion Plant are discussed. A detailed description of the proposed facilities is included and unavoidable adverse environmental effects, possible alternatives, and anticipated benefits from the proposed facilities are considered. The flora and fauna of the area are tabulated and possible effects of air and water pollution on aquatic and terrestrial ecosystems are postulated. The extent of anticipated noise impact on the vicinity and the anticipated extent of civic envolvement are discussed. (CH)

Portsmouth Gaseous Diffusion Plant expansion, Piketon, Ohio. Volume 2. Draft environmental statement

International Nuclear Information System (INIS)

1976-06-01

The need for additional uranium enrichment facilities and the environmental impacts of the add-on gaseous diffusion plant proposed for the Portsmouth Gaseous Diffusion Plant are discussed. A detailed description of the proposed facilities is included and unavoidable adverse environmental effects, possible alternatives, and anticipated benefits from the proposed facilities are considered. The flora and fauna of the area are tabulated and possible effects of air and water pollution on aquatic and terrestrial ecosystems are postulated. The extent of anticipated noise impact on the vicinity and the anticipated extent of civic envolvement are discussed

Device for filtering gaseous media

International Nuclear Information System (INIS)

Benzel, M.

1978-01-01

The air filter system for gaseous radioactive substances consists of a vertical chamber with filter material (charcoal, e.g. impregnated). On one side of the chamber there is an inlet compartment and an outlet compartment. On the other side a guiding compartment turns the gas flow coming from the natural-air side through the lower part of filter chamber to the upper part of the filter. The gas flow leaves the upper part through the outlet conpartment as cleaned-air flow. The filter material may be filled into the chamber from above and drawn off below. For better utilization of the filter material the filter chamber is separated by means of a wall between the inlet and outlet compartment. This partition wall consist of two sheets arranged one above the other provided with slots which may be superposed in alignment. In this case filter material is tickling from the upper part of the chamber into the lower part avoiding to form a crater in the filter bed. (DG) [de

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

Science.gov (United States)

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%.

How to Design a Park and Its Surrounding Urban Morphology to Optimize the Spreading of Cool Air?

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Jérémy Bernard

2018-02-01

Full Text Available Green areas induce smaller increases in the air temperature than built-up areas. They can offer a solution to mitigating the urban heat island impacts during heat waves, since the cool air generated by a park is diffused into its immediate surroundings through forced or natural convection. The purpose of this study is to characterize the effect of several variables (park size, morphology of surrounding urban area, and wind speed on the spreading of cool air. A parametric study is performed to run computational fluid dynamics simulations. The air temperature entering the computational domain was set at 35 °C, and the 2-m high surface included within the 34 °C isotherm was defined as an indicator of cool air spreading. The effects of park shape and orientation were negligible in comparison with size effects. The number of buildings was better correlated with the cooled surface area than the typical urban parameters identified in the literature (i.e., building density, aspect ratio, or mean building height. Since the number of buildings is obviously related to the number of streets, this result suggests that the greater the number of streets around a park, the wider the area that cool air spreads.

Urban political ecologies of informal recyclers׳ health in Buenos Aires, Argentina.

Science.gov (United States)

Parizeau, Kate

2015-05-01

Buenos Aires׳ informal recyclers (cartoneros) confront multiple health hazards in their work. Based in a survey with (n=397) informal recyclers, this study establishes that these workers experience uneven health landscapes as evidenced through their health outcomes, the social determinants of their health, and their living and working environments. I argue that the analytical framework of urban political ecology can provide insights to the ways that the urban environments where cartoneros live and work are socially-constructed phenomena, drawing on concepts of crisis, metabolism, and multi-scalar analyses. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fundamental study on the simultaneous removal of gaseous and particulate matters in room environment by fibrous filters

International Nuclear Information System (INIS)

Otani, Y.; Emi, H.; Mori, J.

1991-01-01

In order to achieve simultaneous removal of gaseous and particulate room air pollutants, two approaches were taken. The use of activated carbon fiber (ACF) filter, focusing on the improvement of its particle collection efficiency by using electrostatic charge caused by surface modification with chemicals and enhancement of adsorption capacity by chemical impregnation, and conversion of gaseous components to particles so as to collect them by air filters. It was shown that the immersion of ACF filter in hydrogen peroxide solution brings electrostatic charge on the fibers, which markedly increases the collection efficiency for charged particles. The impregnation of aniline is very effective for the adsorption of acetaldehyde, and by the use of corona discharge, acetaldehyde is decomposed to other gaseous matters, but some olefin compounds in cigarette smoke are converted to particles via a reaction with ozone. (author)

Public engagement on urban air pollution: an exploratory study of two interventions.

Science.gov (United States)

Oltra, Christian; Sala, Roser; Boso, Àlex; Asensio, Sergi López

2017-06-01

The use of portable sensors to measure air quality is a promising approach for the management of urban air quality given its potential to improve public participation in environmental issues and to promote healthy behaviors. However, not all the projects that use air quality mobile sensors consider the potential effects of their use on the attitudes and behaviors of non-expert individuals. This study explores the experiences, perceptions, attitudes, and behavioral intentions of 12 participants who used a real-time NO 2 sensor over a period of 7 days in the metropolitan area of Barcelona and compares them with 16 participants who did not have access to the device but rather to documentary information. The study design is based on recombined focus groups who met at the beginning and end of a 7-day activity. The results suggest that the experience with the sensors, in comparison with the traditional information, generates greater motivation among participants. Also, that the use of the sensor seems to support a more specific awareness of the problem of air pollution. In relation to risk perception, the textual and visual information seems to generate stronger beliefs of severity among participants. In both groups, beliefs of low controllability and self-efficacy are observed. Neither using the sensor nor reading the documentary information seems to contribute positively in this sense. The results of the study aim to contribute to the design of public involvement strategies in urban air pollution.

Total particulate and reactive gaseous mercury in ambient air on the eastern slope of the Mt. Gongga area, China

Energy Technology Data Exchange (ETDEWEB)

Fu, X.W.; Feng, X.B.; Zhu, W.Z.; Zheng, W.; Wang, S.F.; Lu, J.Y. [Chinese Academy of Sciences, Guiyang (China)

2008-03-15

Total particulate mercury (TPM) and reactive gaseous mercury (RGM) concentrations in ambient air on the eastern slope of the Mt. Gongga area, Sichuan Province, Southwestern China were monitored from 25 May, 2005 to 29 April, 2006. Simultaneously, Hg concentrations in rain samples were measured from January to December, 2006. The average TPM and RGM concentrations in the study site were 30.7 and 6.2 pg m{sup -3}, which are comparable to values observed in remote areas in Northern America and Europe, but much lower than those reported in some urban areas in China. The mean seasonal RGM concentration was slightly higher in spring (8.0 pg m{sup -3}) while the minimum mean concentration was observed in winter (4.0 pg m{sup -3}). TPM concentrations ranged across two orders of magnitude from 5.2 to 135.7 Pg m{sup -3} and had a clear seasonal variation: winter (74.1 pg m{sup -3}), autumn (22.5 Pg m{sup -3}), spring (15.3 Pg m{sup -3}) and summer (10.8 Pg m{sup -3}), listed in decreasing order. The annual wet deposition was 9.1 {mu} g m{sup -2} and wet deposition in the rainy season (May-October) represented over 80% of the annual total. The temporal distribution of TPM and RGM suggested distinguishable dispersion characteristics of these Hg species on a regional scale. Elevated TPM concentration in winter was probably due to regional and local enhanced coal burning and low wet deposition velocity. The RGM distribution pattern is closely related to daily variation in UV radiation observed during the winter sampling period indicating that photo-oxidation processes and diurnal changes in meteorology play an important role in RGM generation.

Total particulate and reactive gaseous mercury in ambient air on the eastern slope of the Mt. Gongga area, China

Energy Technology Data Exchange (ETDEWEB)

Fu Xuewu [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Graduate University of the Chinese Academy Sciences, Beijing 100049 (China); Feng Xinbin [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China)], E-mail: fengxinbin@vip.skleg.cn; Zhu Wanze [Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041 (China); Zheng Wei; Wang Shaofeng [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Graduate University of the Chinese Academy Sciences, Beijing 100049 (China); Lu, Julia Y. [Department of Chemistry and Biology, Ryerson University, Toronto, Ont., M5B 2K3 (Canada)

2008-03-15

Total particulate mercury (TPM) and reactive gaseous mercury (RGM) concentrations in ambient air on the eastern slope of the Mt. Gongga area, Sichuan Province, Southwestern China were monitored from 25 May, 2005 to 29 April, 2006. Simultaneously, Hg concentrations in rain samples were measured from January to December, 2006. The average TPM and RGM concentrations in the study site were 30.7 and 6.2 pg m{sup -3}, which are comparable to values observed in remote areas in Northern America and Europe, but much lower than those reported in some urban areas in China. The mean seasonal RGM concentration was slightly higher in spring (8.0 pg m{sup -3}) while the minimum mean concentration was observed in winter (4.0 pg m{sup -3}). TPM concentrations ranged across two orders of magnitude from 5.2 to 135.7 pg m{sup -3} and had a clear seasonal variation: winter (74.1 pg m{sup -3}), autumn (22.5 pg m{sup -3}), spring (15.3 pg m{sup -3}) and summer (10.8 pg m{sup -3}), listed in decreasing order. The annual wet deposition was 9.1 {mu}g m{sup -2} and wet deposition in the rainy season (May-October) represented over 80% of the annual total. The temporal distribution of TPM and RGM suggested distinguishable dispersion characteristics of these Hg species on a regional scale. Elevated TPM concentration in winter was probably due to regional and local enhanced coal burning and low wet deposition velocity. The RGM distribution pattern is closely related to daily variation in UV radiation observed during the winter sampling period indicating that photo-oxidation processes and diurnal changes in meteorology play an important role in RGM generation.

Health and Cellular Impacts of Air Pollutants: From Cytoprotection to Cytotoxicity

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Karine Andreau

2012-01-01

Full Text Available Air pollution as one of the ravages of our modern societies is primarily linked to urban centers, industrial activities, or road traffic. These atmospheric pollutants have been incriminated in deleterious health effects by numerous epidemiological and in vitro studies. Environmental air pollutants are a heterogeneous mixture of particles suspended into a liquid and gaseous phase which trigger the disruption of redox homeostasis—known under the term of cellular oxidative stress—in relation with the establishment of inflammation and cell death via necrosis, apoptosis, or autophagy. Activation or repression of the apoptotic process as an adaptative response to xenobiotics might lead to either acute or chronic toxicity. The purpose of this paper is to highlight the central role of oxidative stress induced by air pollutants and to focus on the subsequent cellular impacts ranging from cytoprotection to cytotoxicity by decreasing or stimulating apoptosis, respectively.

Participatory measurements of individual exposure to air pollution in urban areas

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Potential Cardiovascular and Total Mortality Benefits of Air Pollution Control in Urban China.

Science.gov (United States)

Huang, Chen; Moran, Andrew E; Coxson, Pamela G; Yang, Xueli; Liu, Fangchao; Cao, Jie; Chen, Kai; Wang, Miao; He, Jiang; Goldman, Lee; Zhao, Dong; Kinney, Patrick L; Gu, Dongfeng

2017-10-24

Outdoor air pollution ranks fourth among preventable causes of China's burden of disease. We hypothesized that the magnitude of health gains from air quality improvement in urban China could compare with achieving recommended blood pressure or smoking control goals. The Cardiovascular Disease Policy Model-China projected coronary heart disease, stroke, and all-cause deaths in urban Chinese adults 35 to 84 years of age from 2017 to 2030 if recent air quality (particulate matter with aerodynamic diameter ≤2.5 µm, PM 2.5 ) and traditional cardiovascular risk factor trends continue. We projected life-years gained if urban China were to reach 1 of 3 air quality goals: Beijing Olympic Games level (mean PM 2.5 , 55 μg/m 3 ), China Class II standard (35 μg/m 3 ), or World Health Organization standard (10 μg/m 3 ). We compared projected air pollution reduction control benefits with potential benefits of reaching World Health Organization hypertension and tobacco control goals. Mean PM 2.5 reduction to Beijing Olympic levels by 2030 would gain ≈241,000 (95% uncertainty interval, 189 000-293 000) life-years annually. Achieving either the China Class II or World Health Organization PM 2.5 standard would yield greater health benefits (992 000 [95% uncertainty interval, 790 000-1 180 000] or 1 827 000 [95% uncertainty interval, 1 481 00-2 129 000] annual life-years gained, respectively) than World Health Organization-recommended goals of 25% improvement in systolic hypertension control and 30% reduction in smoking combined (928 000 [95% uncertainty interval, 830 000-1 033 000] life-years). Air quality improvement in different scenarios could lead to graded health benefits ranging from 241 000 life-years gained to much greater benefits equal to or greater than the combined benefits of 25% improvement in systolic hypertension control and 30% smoking reduction. © 2017 American Heart Association, Inc.

Impacts of large-scale circulation on urban ambient concentrations of gaseous elemental mercury in New York, USA

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H. Mao

2017-09-01

Full Text Available The impact of large-scale circulation on urban gaseous elemental mercury (GEM was investigated through analysis of 2008–2015 measurement data from an urban site in New York City (NYC, New York, USA. Distinct annual cycles were observed in 2009–2010 with mixing ratios in warm seasons (i.e., spring–summer 10–20 ppqv ( ∼  10–25 % higher than in cool seasons (i.e., fall–winter. This annual cycle was disrupted in 2011 by an anomalously strong influence of the US East Coast trough in that warm season and was reproduced in 2014 associated with a particularly strong Bermuda High. The US East Coast trough axis index (TAI and intensity index (TII were used to characterize the effect of the US East Coast trough on NYC GEM, especially in winter and summer. The intensity and position of the Bermuda High appeared to have a significant impact on GEM in warm seasons. Regional influence on NYC GEM was supported by the GEM–carbon monoxide (CO correlation with r of 0.17–0.69 (p ∼  0 in most seasons. Simulated regional and local anthropogenic contributions to wintertime NYC anthropogenically induced GEM concentrations were averaged at  ∼  75 % and 25 %, with interannual variation ranging over 67 %–83 % and 17 %–33 %, respectively. Results from this study suggest the possibility that the increasingly strong Bermuda High over the past decades could dominate over anthropogenic mercury emission control in affecting ambient concentrations of mercury via regional buildup and possibly enhancing natural and legacy emissions.

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

Science.gov (United States)

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

Paducah Gaseous Diffusion Plant Environmental report for 1990

Energy Technology Data Exchange (ETDEWEB)

Counce-Brown, D. (ed.)

1991-09-01

This two-part report, Paducah Gaseous Diffusion Plant Site Environmental Report for 1990, is published annually. It reflects the results of a comprehensive, year-round program to monitor the impact of operations at Paducah Gaseous Diffusion Plant (PGDP) on the area's groundwater and surface waters, soil, air quality, vegetation, and wildlife. In addition, an assessment of the effect of PGDP effluents on the resident human population is made. PGDP's overall goal for environmental management is to protect the environment and PGDP's neighbors and to maintain full compliance with all current regulations. The current environmental strategy is to identify any deficiencies and to develop a system to resolve them. The long-range goal of environmental management is to minimize the source of pollutants, to reduce the formation of waste, and to minimize hazardous waste by substitution of materials.

Dry deposition study using filter packs at a rural and an urban monitoring sites

International Nuclear Information System (INIS)

Siti Mariam Sumari; Rusdin Laiman; Kantasamy, Nesamalar; Sinyaw, S.U.

2008-01-01

Air samples were collected from 2004 to 2005 using four-staged filter packs at an urban site Petaling Jaya (PJ) and a rural-agricultural site Tanah Rata (TR). The samples were analysed for reactive gases consisting of NH 3 , HNO 3 , HCL and SO 2 while the aerosol components were analysed for SO 4 2- , NO 3 - , Cl - , Na + , K + , Ca 2+ , Mg 2+ and NH 4 + . For both PJ and TR, analysis indicates the dry deposition was dominated by the gaseous components. They range from about 78 % to 80 % of total compositions for urban PJ and 59 % to 63 % for rural TR. Among the four reactive gases, NH 3 is the most dominating component at both sites. Elevated NH 3 concentration in TR was mainly attributed to the use of nitrogenous fertilizer. For PJ high NH 3 could be due to local air pollution created by industries as well as agricultural activities. The acidic species associated with SO x and NO x are typically more abundant at PJ than TR. Their presence, and for most other chemical species, show similar increasing trend, and this reflect the growing use of fossil fuels associated with urbanization and industrialization, especially for PJ. (author)

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

Directory of Open Access Journals (Sweden)

Forouzanfar Mohammad

2006-08-01

Full Text Available Abstract 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

Ventilation and Air Quality in City Blocks Using Large-Eddy Simulation—Urban Planning Perspective

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Mona Kurppa

2018-02-01

Full Text Available Buildings and vegetation alter the wind and pollutant transport in urban environments. This comparative study investigates the role of orientation and shape of perimeter blocks on the dispersion and ventilation of traffic-related air pollutants, and the street-level concentrations along a planned city boulevard. A large-eddy simulation (LES model PALM is employed over a highly detailed representation of the urban domain including street trees and forested areas. Air pollutants are represented by massless and passive particles (non-reactive gases, which are released with traffic-related emission rates. High-resolution simulations for four different city-block-structures are conducted over a 8.2 km 2 domain under two contrasting inflow conditions with neutral and stable atmospheric stratification corresponding the general and wintry meteorological conditions. Variation in building height together with multiple cross streets along the boulevard improves ventilation, resulting in 7–9% lower mean concentrations at pedestrian level. The impact of smaller scale variability in building shape was negligible. Street trees further complicate the flow and dispersion. Notwithstanding the surface roughness, atmospheric stability controls the concentration levels with higher values under stably stratified inflow. Little traffic emissions are transported to courtyards. The results provide urban planners direct information to reduce air pollution by proper structural layout of perimeter blocks.

Synthetic musk fragrances in urban and rural air of Iowa and the Great Lakes

Science.gov (United States)

Peck, Aaron M.; Hornbuckle, Keri C.

Synthetic musk fragrances are semivolatile organic compounds used to scent a variety of household and personal care products. In this study, six polycyclic musk fragrances (HHCB, AHTN, ATII, AHMI, ADBI, and DPMI) and two nitro musk fragrances (musk xylene and musk ketone) were evaluated in 181 air samples collected at urban, suburban, and rural sites in Iowa and the Great Lakes. This is the largest reported study of the compounds in ambient air and reveals the ubiquitous nature of these environmental contaminants. HHCB and AHTN were detected most frequently and at the highest concentrations at all sites. Synthetic musk fragrance concentrations were highest in urban locations, including Milwaukee, WI (previously reported) and an urban location in Cedar Rapids, IA. Urban concentrations of HHCB and AHTN are on the order of 1-5 ng m -3 and background terrestrial concentrations are about an order of magnitude less. In rural Iowa, the concentrations and frequency of detection of the synthetic musk fragrances are comparable to (and often greater than) gas-phase pesticide concentrations. The concentrations measured at the suburban location in Iowa City, IA and over the Lakes Erie, Ontario, and Michigan were generally intermediate of those measured at the rural and urban locations. Concentrations of HHCB and AHTN were correlated with temperature at the sampling sites in Iowa.

Development of gaseous photomultiplier

International Nuclear Information System (INIS)

Tokanai, F.; Sumiyoshi, T.; Sugiyama, H.; Okada, T.

2014-01-01

We have been developing gaseous photomultiplier tubes (PMTs) with alkali photocathode combined with micropattern gas detectors (MPGDs). The potential advantage of the gaseous PMT is that it can achieve a very large effective area with adequate position and timing resolutions. In addition, it will be easily operated under a very high magnetic field, compared with the conventional vacuum-based PMT. To evaluate the gaseous PMTs filled with Ne and Ar based gas mixture, we have developed gaseous PMTs with an alkali photocathode combined with MPGDs such as a glass capillary plate, GEM, and Micromegas detector. We describe the recent development of the gaseous PMTs, particularly the production of the photocathode, gas gain, ion and photon feedbacks, quantum efficiency, and the characteristics in the magnetic field environment. (author)

Study of the air quality in the surroundings of an urban park: A micrometeorological approach

Science.gov (United States)

Sastre, Mariano; Yagüe, Carlos; Arrillaga, Jon A.; Román-Cascón, Carlos; Maqueda, Gregorio; Artíñano, Begoña; Díaz-Ramiro, Elías; Gómez-Moreno, Francisco J.; Barreiro, Marcos; Borge, Rafael; Narros, Adolfo; Pérez, Javier; Quaassdorff, Christina

2017-04-01

In this work we study the differences showed by two types of pollutants, particulate matter (PM) and NOx, by comparing ambient concentration measurements within an urban park versus the corresponding values nearby (but outside) it. The results are linked to both proximity to emission sources, such as road traffic, and the microscale atmospheric conditions. The work is motivated by the fact that poor air quality is a crucial issue of current cities. For some of them it is not uncommon to face this problem with occasional traffic restrictions when high concentrations of pollutants are reached. These events occur more frequently with specific large-scale atmospheric conditions, for example when a strong anticyclone is present. As the meteorological conditions may significantly influence the pollutants concentrations, the research project TECNAIRE-CM (Innovative technologies for the assessment and improvement of urban air quality) aims to provide new approaches to obtain proper descriptions of the urban pollution and its dynamics at different spatial and temporal scales, not only the synoptic scale. So far, a few field campaigns have been developed within TECNAIRE-CM at two locations in the city of Madrid, which are considered hot spots according to the air quality network records. Here we use the data from a field campaign carried out during summer 2016, which consider standard pollution and meteorological measurements, as well as sonic anemometer data. The latter help to include atmospheric turbulence as a significant agent for air quality characterization. The instrumentation was deployed at a location with considerable traffic density, but nearby a border of the main urban park of the city, so that its influence might be investigated. Supplementary data considered for this work correspond to permanent instrumentation within the park. With this extra information we can compare both measurements inside and outside the park. Therefore, we study the effect on wind

Concentrations, Trends, and Air-Water Exchange of PAHs and PBDEs Derived from Passive Samplers in Lake Superior in 2011.

Science.gov (United States)

Ruge, Zoe; Muir, Derek; Helm, Paul; Lohmann, Rainer

2015-12-01

Polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenylethers (PBDEs) are both currently released into the environment from anthropogenic activity. Both are hence primarily associated with populated or industrial areas, although wildfires can be an important source of PAHs, as well. Polyethylene passive samplers (PEs) were simultaneously deployed in surface water and near surface atmosphere to determine spatial trends and air-water gaseous exchange of 21 PAHs and 11 PBDEs at 19 sites across Lake Superior in 2011. Surface water and atmospheric PAH concentrations were greatest at urban sites (up to 65 ng L(-1) and 140 ng m(-3), respectively, averaged from June to October). Near populated regions, PAHs displayed net air-to-water deposition, but were near equilibrium off-shore. Retene, probably depositing following major wildfires in the region, dominated dissolved PAH concentrations at most Lake Superior sites. Atmospheric and dissolved PBDEs were greatest near urban and populated sites (up to 6.8 pg L(-1) and 15 pg m(-3), respectively, averaged from June to October), dominated by BDE-47. At most coastal sites, there was net gaseous deposition of BDE-47, with less brominated congeners contributing to Sault Ste. Marie and eastern open lake fluxes. Conversely, the central open lake and Eagle Harbor sites generally displayed volatilization of PBDEs into the atmosphere, mainly BDE-47.

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

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Hiren B. Soni

2018-01-01

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

Amine Measurements in Boreal Forest Air

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Hemmilä, Marja; Hellén, Heidi; Makkonen, Ulla; Hakola, Hannele

2015-04-01

Amines are reactive, volatile bases in the air with a general formula of RNH2, R2NH or R3N. Especially small amines can stabilize sulphuric acid clusters and hence affect nucleation. Amines react rapidly with hydroxyl radical (OH˙) thus affecting oxidative capacity of the atmosphere. The amine concentrations are higher in forest air than in urban air (Hellén et al., 2014), but the sources are not known. In order to get more information concerning amine sources, we conducted a measurement campaign in a boreal forest. At SMEAR II station at Hyytiälä, Southern Finland (61°510'N, 24°170'E, 180 m a.s.l.) The measurements cover seven months, from June to December 2014. For sampling and measuring we used MARGA (The instrument for Measuring AeRosols and Gases in Ambient air) which is an on-line ion chromatograph (IC) connected to a sampling system. The IC component of the MARGA system was coupled to an electrospray ionization quadrupole mass spectrometer (MS) to improve sensitivity of amine measurements. This new set-up enabled amine concentration measurements in ambient air both in aerosol and gas phases with a time resolution of only 1 hour. With MARGA-MS we analysed 7 different amines: monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA), propylamine (PA) and butylamine (BA). In preliminary data-analysis we found out, that in June and July most of the measured amines were in gas phase, and particle phase amine concentrations were mostly under detection limits (<1.7 pptv). In June the gaseous amine concentrations were higher than in July. The measured concentrations of gaseous amines followed temperature variation, which could indicate that amines are produced and emitted from the environment or re-emitted from the surfaces as temperature rises after deposition during night-time. All measured amines had similar diurnal variation with maxima during afternoon and minima during night. Results from other months will also

Green spaces are not all the same for the provision of air purification and climate regulation services: The case of urban parks.

Science.gov (United States)

Vieira, Joana; Matos, Paula; Mexia, Teresa; Silva, Patrícia; Lopes, Nuno; Freitas, Catarina; Correia, Otília; Santos-Reis, Margarida; Branquinho, Cristina; Pinho, Pedro

2018-01-01

The growing human population concentrated in urban areas lead to the increase of road traffic and artificial areas, consequently enhancing air pollution and urban heat island effects, among others. These environmental changes affect citizen's health, causing a high number of premature deaths, with considerable social and economic costs. Nature-based solutions are essential to ameliorate those impacts in urban areas. While the mere presence of urban green spaces is pointed as an overarching solution, the relative importance of specific vegetation structure, composition and management to improve the ecosystem services of air purification and climate regulation are overlooked. This avoids the establishment of optimized planning and management procedures for urban green spaces with high spatial resolution and detail. Our aim was to understand the relative contribution of vegetation structure, composition and management for the provision of ecosystem services of air purification and climate regulation in urban green spaces, in particular the case of urban parks. This work was done in a large urban park with different types of vegetation surrounded by urban areas. As indicators of microclimatic effects and of air pollution levels we selected different metrics: lichen diversity and pollutants accumulation in lichens. Among lichen diversity, functional traits related to nutrient and water requirements were used as surrogates of the capacity of vegetation to filter air pollution and to regulate climate, and provide air purification and climate regulation ecosystem services, respectively. This was also obtained with very high spatial resolution which allows detailed spatial planning for optimization of ecosystem services. We found that vegetation type characterized by a more complex structure (trees, shrubs and herbaceous layers) and by the absence of management (pruning, irrigation and fertilization) had a higher capacity to provide the ecosystems services of air

Impact of energy consumption on urban warming and air pollution in Tokyo metropolitan area

International Nuclear Information System (INIS)

Saitoh, T.S.; Hoshi, H.

1995-01-01

The rapid progress of industrialization and urbanization due to economic growth and concentration of social function in the urban areas in Japan have had an adverse effect on the urban environment. In most cities, it has become evident that the increase in energy consumption is causing environmental problems, including a temperature rise in the urban atmosphere (urban heat island) and air pollution. This paper reports the results of field observations and three dimensional simulations of the urban heat island using a three-dimensional modelling vorticity-velocity vector potential formation, in the Tokyo metropolitan area. According to the simulation for urban warming in the study area for the year 2031, the maximum temperature of a summer evening (18:00) would exceed 43 degrees celsius, indicating that Tokyo would no longer be comfortable for its inhabitants. It is concluded that in the near future, the problem of the urban heat island will become a more important issue than that of global warming because the rate of urban warming is greater. For this reason, the urban heat island could be fatal to humans unless resolved in the near future. (author). 1 tab., 11 figs., 18 refs

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

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Peng Liu

2016-03-01

Full Text Available 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.

Lifecycle impacts of natural gas to hydrogen pathways on urban air quality

International Nuclear Information System (INIS)

Wang, Guihua; Ogden, Joan M.; Nicholas, Michael A.

2007-01-01

In this paper we examine the potential air quality impacts of hydrogen transportation fuel from a lifecycle analysis perspective, including impacts from fuel production, delivery, and vehicle use. We assume that hydrogen fuel cell vehicles are introduced in a specific region, Sacramento County, California. We consider two levels of market penetration where 9% or 20% of the light duty fleet are hydrogen fuel cell vehicles. The following three natural gas to hydrogen supply pathways are assessed in detail and compared in terms of emissions and the resulting changes in ambient air quality: (1) onsite hydrogen production; (2) centralized hydrogen production with gaseous hydrogen pipeline delivery systems; and (3) centralized hydrogen production with liquid hydrogen truck delivery systems. All the pathways examined use steam methane reforming (SMR) of natural gas to produce hydrogen. The source contributions to incremental air pollution are estimated and compared among hydrogen pathways. All of the hydrogen pathways result in extremely low contributions to ambient air concentrations of NO x , CO, particulates, and SO x , typically less than 0.1% of the current ambient pollution for both levels of market penetration. Among the hydrogen supply options, it is found that the central SMR with pipeline delivery systems is the lowest pollution option available provided the plant is located to avoid transport of pollutants into the city via prevailing winds. The onsite hydrogen pathway is comparable to the central hydrogen pathway with pipeline systems in terms of the resulting air pollution. The pathway with liquid hydrogen trucks has a greater impact on air quality relative to the other pathways due to emissions associated with diesel trucks and electricity consumption to liquefy hydrogen. However, all three hydrogen pathways result in negligible air pollution in the region. (author)

Introduction to investigations of the negative corona and EHD flow in gaseous two-phase fluids

Science.gov (United States)

Jerzy, MIZERACZYK; Artur, BERENDT

2018-05-01

Research interests have recently been directed towards electrical discharges in multi-phase environments. Natural electrical discharges, such as lightning and coronas, occur in the Earth’s atmosphere, which is actually a mixture of gaseous phase (air) and suspended solid and liquid particulate matters (PMs). An example of an anthropogenic gaseous multi-phase environment is the flow of flue gas through electrostatic precipitators (ESPs), which are generally regarded as a mixture of a post-combustion gas with solid PM and microdroplets suspended in it. Electrical discharges in multi-phase environments, the knowledge of which is scarce, are becoming an attractive research subject, offering a wide variety of possible discharges and multi-phase environments to be studied. This paper is an introduction to electrical discharges in multi-phase environments. It is focused on DC negative coronas and accompanying electrohydrodynamic (EHD) flows in a gaseous two-phase fluid formed by air (a gaseous phase) and solid PM (a solid phase), run under laboratory conditions. The introduction is based on a review of the relevant literature. Two cases will be considered: the first case is of a gaseous two-phase fluid, initially motionless in a closed chamber before being subjected to a negative corona (with the needle-to-plate electrode arrangement), which afterwards induces an EHD flow in the chamber, and the second, of a gaseous two-phase fluid flowing transversely with respect to the needle-to-plate electrode axis along a chamber with a corona discharge running between the electrodes. This review-based introductory paper should be of interest to theoretical researchers and modellers in the field of negative corona discharges in single- or two-phase fluids, and for engineers who work on designing EHD devices (such as ESPs, EHD pumps, and smoke detectors).

An evaluation of the ecosystem services provided by urban trees: The role of Krasiński Gardens in air quality and human health in Warsaw (Poland

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Szkop Zbigniew

2016-12-01

Full Text Available Trees remove air pollution by the interception of particulate matter on plant surfaces and the absorption of gaseous pollutants through leaf stomata. However, to date, we have rather few empirical studies on the magnitude and value of the effects of trees on air quality and human health, especially especially within the climatic conditions of Central Europe. To investigate the significance of urban trees from the point of view of air pollution removal, an i-Tree Eco model was implemented. The results indicate that the 932 trees in Krasiński Gardens (Warsaw, Poland absorb 267.12 kg of pollutants per year: 149.9 kg of O3, 94.4 kg of NO2, 11.8 kg of SO2 and 10.9 kg of PM2.5. That makes an average removal per tree (calculated by summarizing the values of all of the pollutants of 0.287 kg/year. Furthermore, health values were used to estimate their pollution removal services in monetary terms. The total benefit of air purification by trees in Krasiński Gardens is estimated at 26250 PLN/year with an average value per tree of: 28 PLN. Although PM2.5 removal is the lowest among the four air pollutants analysed, accounting for only 4% of the total mass reduction, it provides 69% of the total economic value. The benefit associated with absorption of O3 provided 28% of the value, with the absorption of NO2 and SO2 at just 3%. The results also show that large tree species (with a crown diameter of 14-15m can provide around 10 times higher benefits, than small ones (5-6m.

Bicyclists' Uptake of Traffic-Related Air Pollution: Effects of the Urban Transportation System

Science.gov (United States)

2014-10-27

While bicyclists and other active travelers obtain health benefits from increased physical activity, they also risk uptake of traffic-related air pollution. But pollution uptake by urban bicyclists is not well understood due to a lack of direct measu...

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

Science.gov (United States)

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 ...

Monitoring Gaseous and Particulate Air Pollutants near Major ...

African Journals Online (AJOL)

High traffic volume and traffic congestion on Nigerian roads have led to increase in the concentration of pollutants in the air t posing health risks for human population. This study investigates air quality due to vehicular emissions in some busy roads in Abeokuta metropolis, Nigeria. Air pollutants such as CO, CO2, NO, NO2, ...

Gaseous and Freely-Dissolved PCBs in the Lower Great Lakes Based on Passive Sampling: Spatial Trends and Air-Water Exchange.

Science.gov (United States)

Liu, Ying; Wang, Siyao; McDonough, Carrie A; Khairy, Mohammed; Muir, Derek C G; Helm, Paul A; Lohmann, Rainer

2016-05-17

Polyethylene passive sampling was performed to quantify gaseous and freely dissolved polychlorinated biphenyls (PCBs) in the air and water of Lakes Erie and Ontario during 2011-2012. In view of differing physical characteristics and the impacts of historical contamination by PCBs within these lakes, spatial variation of PCB concentrations and air-water exchange across these lakes may be expected. Both lakes displayed statistically similar aqueous and atmospheric PCB concentrations. Total aqueous concentrations of 29 PCBs ranged from 1.5 pg L(-1) in the open lake of Lake Erie (site E02) in 2011 spring to 105 pg L(-1) in Niagara (site On05) in 2012 summer, while total atmospheric concentrations were 7.7-634 pg m(-3) across both lakes. A west-to-east gradient was observed for aqueous PCBs in Lake Erie. River discharge and localized influences (e.g., sediment resuspension and regional alongshore transport) likely dominated spatial trends of aqueous PCBs in both lakes. Air-water exchange fluxes of Σ7PCBs ranged from -2.4 (±1.9) ng m(-2) day(-1) (deposition) in Sheffield (site E03) to 9.0 (±3.1) ng m(-2) day(-1) (volatilization) in Niagara (site On05). Net volatilization of PCBs was the primary trend across most sites and periods. Almost half of variation in air-water exchange fluxes was attributed to the difference in aqueous concentrations of PCBs. Uncertainty analysis in fugacity ratios and mass fluxes in air-water exchange of PCBs indicated that PCBs have reached or approached equilibrium only at the eastern Lake Erie and along the Canadian shore of Lake Ontario sites, where air-water exchange fluxes dominated atmospheric concentrations.

Gaseous poison injection device

International Nuclear Information System (INIS)

Kubota, Ryuji; Sugisaki, Toshihiko; Inada, Ikuo.

1983-01-01

Purpose: To rapidly control the chain reaction due to thermal neutrons in a reactor core by using gaseous poisons as back-up means for control rod drives. Constitution: Gaseous poisons having a large neutron absorption cross section are used as back-up means for control rod drives. Upon failure of control rod insertion, the gaseous poisons are injected into the lower portion of the reactor core to control the reactor power. As the gaseous poisons, vapors at a high temperature and a higher pressure than that of the coolants in the reactor core are injected to control the reactor power due to the void effects. Since the gaseous poisons thus employed rapidly reach the reactor core and form gas bubbles therein, the deccelerating effect of the thermal neutrons is decreased to reduce the chain reaction. (Moriyama, K.)

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

Science.gov (United States)

Tian, Tao; Chen, Yuhuai; Zhu, Jing; Liu, Pengling

2015-08-01

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. 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. 27.8% of old people had psychological disorders. Air pollution significantly influenced the mental health of the elderly, showing a positive "U-shaped" curve (Phealth problems. Marriage, education, and social activities had positive effects on the mental health of the elderly. 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.

Analyzing the cost effectiveness of Santiago, Chile's policy of using urban forests to improve air quality

Science.gov (United States)

Francisco J. Escobedo; John E. Wagner; David J. Nowak; Carmen Luz De la Maza; Manuel Rodriguez; Daniel E. Crane

2008-01-01

Santiago, Chile has the distinction of having among the worst urban air pollution problems in Latin America. As part of an atmospheric pollution reduction plan, the Santiago Regional Metropolitan government defined an environmental policy goal of using urban forests to remove particulate matter less than 10 µm (PM10) in the Gran...

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

Science.gov (United States)

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.

Monitoring of volatile and non-volatile urban air genotoxins using bacteria, human cells and plants.

Science.gov (United States)

Ceretti, E; Zani, C; Zerbini, I; Viola, G; Moretti, M; Villarini, M; Dominici, L; Monarca, S; Feretti, D

2015-02-01

Urban air contains many mutagenic pollutants. This research aimed to investigate the presence of mutagens in the air by short-term mutagenicity tests using bacteria, human cells and plants. Inflorescences of Tradescantia were exposed to air in situ for 6h, once a month from January to May, to monitor volatile compounds and micronuclei frequency was computed. On the same days PM10 was collected continuously for 24h. Half of each filter was extracted with organic solvents and studied by means of the Ames test, using Salmonella typhimurium TA98 and TA100 strains, and the comet assay on human leukocytes. A quarter of each filter was extracted with distilled water in which Tradescantia was exposed. PM10 concentration was particularly high in the winter season (> 50 μg/m(3)). In situ exposure of inflorescences to urban air induced a significant increase in micronuclei frequency at all the sites considered, but only in January (p bacteria, human cells and plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Estimation of daily maximum and minimum air temperatures in urban landscapes using MODIS time series satellite data

Science.gov (United States)

Yoo, Cheolhee; Im, Jungho; Park, Seonyoung; Quackenbush, Lindi J.

2018-03-01

Urban air temperature is considered a significant variable for a variety of urban issues, and analyzing the spatial patterns of air temperature is important for urban planning and management. However, insufficient weather stations limit accurate spatial representation of temperature within a heterogeneous city. This study used a random forest machine learning approach to estimate daily maximum and minimum air temperatures (Tmax and Tmin) for two megacities with different climate characteristics: Los Angeles, USA, and Seoul, South Korea. This study used eight time-series land surface temperature (LST) data from Moderate Resolution Imaging Spectroradiometer (MODIS), with seven auxiliary variables: elevation, solar radiation, normalized difference vegetation index, latitude, longitude, aspect, and the percentage of impervious area. We found different relationships between the eight time-series LSTs with Tmax/Tmin for the two cities, and designed eight schemes with different input LST variables. The schemes were evaluated using the coefficient of determination (R2) and Root Mean Square Error (RMSE) from 10-fold cross-validation. The best schemes produced R2 of 0.850 and 0.777 and RMSE of 1.7 °C and 1.2 °C for Tmax and Tmin in Los Angeles, and R2 of 0.728 and 0.767 and RMSE of 1.1 °C and 1.2 °C for Tmax and Tmin in Seoul, respectively. LSTs obtained the day before were crucial for estimating daily urban air temperature. Estimated air temperature patterns showed that Tmax was highly dependent on the geographic factors (e.g., sea breeze, mountains) of the two cities, while Tmin showed marginally distinct temperature differences between built-up and vegetated areas in the two cities.

How Can Urban Policies Improve Air Quality and Help Mitigate Global Climate Change: a Systematic Mapping Review.

Science.gov (United States)

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.

Behaviour of gaseous alkali compounds in coal gasification; Kaasumaisten alkaliyhdisteiden kaeyttaeytyminen kivihiilien kaasutuksessa

Energy Technology Data Exchange (ETDEWEB)

Nykaenen, J [Imatran Voima Oy, Vantaa (Finland)

1997-10-01

In this project the behaviour of alkali compounds emitting from CO{sub 2}/O{sub 2}- and airblown gasification are studied. This research project is closely connected to an EU-project coordinated by the Delft University of Technology (DUT). In that project alkali emissions from a 1.6 MW pilot plant will be measured. The results from those measurements will be compared with the calculations performed in this LIEKKI 2 project. The equilibrium calculations show that the major gaseous alkali compounds emitting from combustion and gasification are chlorides and hydroxides. This applies both to air- and CO{sub 2}/O{sub 2}-blown processes. In all the cases studied the concentration of gaseous alkali compounds is determined mainly by the amount of chlorides. The key parameters, with respect to alkali behaviour, are the temperature of the process and chlorine content of the coal. By cooling the gases down to 600 deg C prior to a ceramic filter the alkali concentration can be kept about at 100 ppbv. In combustion, the addition of calcium carbonate increases the amount of gaseous alkali compounds by decreasing the amount of alkali sulphates. In the case of gasification the importance of limestone is negligible. The difference between air- and CO{sub 2}/O{sub 2}-blown processes, in terms of gaseous alkali emissions, is small. This is because CO{sub 2} concentration of the gas does not have a strong impact on alkali chlorides. Furthermore, the effect of CO{sub 2}/O{sub 2}-ratio of the recirculation process is negligible. (orig.)

Air filtration and indoor air quality

DEFF Research Database (Denmark)

Bekö, Gabriel

2006-01-01

Demands for better indoor air quality are increasing, since we spend most of our time indoors and we are more and more aware of indoor air pollution. Field studies in different parts of the world have documented that high percentage of occupants in many offices and buildings find the indoor air...... decent ventilation and air cleaning/air filtration, high indoor air quality cannot be accomplished. The need for effective air filtration has increased with increasing evidence on the hazardous effects of fine particles. Moreover, the air contains gaseous pollutants, removal of which requires various air...... cleaning techniques. Supply air filter is one of the key components in the ventilation system. Studies have shown that used ventilation filters themselves can be a significant source of indoor air pollution with consequent impact on perceived air quality, sick building syndrome symptoms and performance...

The sources and fate of (210)Po in the urban air: A review.

Science.gov (United States)

Długosz-Lisiecka, Magdalena

2016-09-01

The origin of (210)Po activity and its fluctuations in the air are discussed in this paper. In the case of atmospheric aerosol samples, a comparison of the (210)Po/(210)Pb and (210)Bi/(210)Pb activity ratios makes it possible not only to determine aerosol residence times but also to appraise the contribution of the unsupported (210)Po coming from other sources than (222)Rn decay, such as human industrial activities, especially coal combustion. A simple mathematical method makes it possible to observe the seasonal fluctuations of the anthropogenic excess of (210)Po in the urban air. The average doses of (210)Po intake with food (including drinking water) and inhalation of urban aerosols are usually lower than those from (210)Po intake by cigarette smokers and negligible in comparison to total natural radiation exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Particle growth in an isoprene-rich forest: Influences of urban, wildfire, and biogenic air masses

Science.gov (United States)

Gunsch, Matthew J.; Schmidt, Stephanie A.; Gardner, Daniel J.; Bondy, Amy L.; May, Nathaniel W.; Bertman, Steven B.; Pratt, Kerri A.; Ault, Andrew P.

2018-04-01

Growth of freshly nucleated particles is an important source of cloud condensation nuclei (CCN) and has been studied within a variety of environments around the world. However, there remains uncertainty regarding the sources of the precursor gases leading to particle growth, particularly in isoprene-rich forests. In this study, particle growth events were observed from the 14 total events (31% of days) during summer measurements (June 24 - August 2, 2014) at the Program for Research on Oxidants PHotochemistry, Emissions, and Transport (PROPHET) tower within the forested University of Michigan Biological Station located in northern Michigan. Growth events were observed within long-range transported air masses from urban areas, air masses impacted by wildfires, as well as stagnant, forested/regional air masses. Growth events observed during urban-influenced air masses were prevalent, with presumably high oxidant levels, and began midday during periods of high solar radiation. This suggests that increased oxidation of biogenic volatile organic compounds (BVOCs) likely contributed to the highest observed particle growth in this study (8 ± 2 nm h-1). Growth events during wildfire-influenced air masses were observed primarily at night and had slower growth rates (3 ± 1 nm h-1). These events were likely influenced by increased SO2, O3, and NO2 transported within the smoke plumes, suggesting a role of NO3 oxidation in the production of semi-volatile compounds. Forested/regional air mass growth events likely occurred due to the oxidation of regionally emitted BVOCs, including isoprene, monoterpenes, and sesquiterpenes, which facilitated multiday growth events also with slower rates (3 ± 2 nm h-1). Intense sulfur, carbon, and oxygen signals in individual particles down to 20 nm, analyzed by transmission electron microscopy with energy dispersive X-ray spectroscopy (TEM-EDX), suggest that H2SO4 and secondary organic aerosol contributed to particle growth. Overall, aerosol

Effects of radiation and impurities on gaseous iodine behavior in a containment vessel

International Nuclear Information System (INIS)

Takahashi, Masato; Watanabe, Atsushi; Hashimoto, Takashi

2000-01-01

In order to estimate the effect of impurities and radiation on gaseous iodine behavior in containment vessel, NUPEC has improved IMPAIR-3 code developed by PSI. Several modifications on the iodine oxidation by radiolysis and the production of nitric acid, the existence of boric acid, and the reaction of silver particle with iodine were newly added in evaluating the effect of radiolysis and impurities. pH change resulting from presence of boric acid, nitric acid production by radiolysis of air, and sodium hydroxide addition by AM operation, was also considered. The code verification for pH change was performed using the RTF experimental results. Additionally, the effects of boric acid and silver impurities on gaseous iodine behavior were evaluated by the sensitivity analysis. As a result, the experimental results of iodine concentration transient under pH change were well simulated. The following results were also obtained from the sensitive analysis. The gaseous iodine behavior was not affected by the existence of boric acid. In the case of silver existence in liquid phase, the gaseous iodine concentration rapidly decreased because a large amount of iodine changed into AgI species in liquid phase. The restraint effect of silver on gaseous iodine, production was larger than that of pH change. (author)

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

Science.gov (United States)

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. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of different numerical methodologies for dispersion of air pollutants in an urban environment

International Nuclear Information System (INIS)

Mumovic, D.; Crowther, J.M.; Stevanovic, Z.

2003-01-01

Since 1950 the world population has more than doubled but meanwhile the global number of cars has increased by a factor of 10. In that same period the fraction of people living in urban areas has increased by a factor of 4. Apart from large point-sources of local air pollution, traffic induced pollution is now the most significant contributor to urban air quality in city centres, particularly for carbon monoxide, oxides of nitrogen and fine particulate matter. Until recently, pollutant dispersion in urban areas has usually been numerically investigated by using empirical models, such as the Gaussian plume model, or by extensions of this technique to line sources and multiple sources. More recently, advanced computational fluid dynamics (CFD) simulations have been attempted but have been mainly two-dimensional and often encompassing only a single street canyon. This paper provides a comprehensive, critical evaluation of dispersion of pollutants in urban areas. A three-dimensional flow model has been set-up for a staggered crossroad, using the Navier-Stokes equations and the conservation equation for species concentration. The effect of using several different turbulence models, including the k-ε model, modifications and extensions, has been investigated. Cartesian coordinates have been used in connection with the Partial Solution Algorithm (PARSOL) and Body Fitted Coordinates (BFC). The effects of several different numerical algorithms for discretization of differential equations have also been studied. More than thirty cases are analysed, and the main results are compared with wind tunnel experiments. The numerical results are presented as non-dimensional values to facilitate comparison between experimental and numerical studies. It has been shown that the numerical studies have been able to simulate the air-flow in urban areas and confirm, qualitatively, the previous field observations and wind tunnel results. This success encouraged the authors to extend such

Evaluation of different numerical methodologies for dispersion of air pollutants in an urban environment

Energy Technology Data Exchange (ETDEWEB)

Mumovic, D.; Crowther, J.M. [Glasgow Caledonian Univ., School of Built and Natural Environment, Glasgow (United Kingdom)]. E-mail: dmumov10@caledonian.ac.uk; Stevanovic, Z. [Univ. of Belgrade, Inst. of Nuclear Sciences, Belgrade (Serbia and Montenegro)

2003-07-01

Since 1950 the world population has more than doubled but meanwhile the global number of cars has increased by a factor of 10. In that same period the fraction of people living in urban areas has increased by a factor of 4. Apart from large point-sources of local air pollution, traffic induced pollution is now the most significant contributor to urban air quality in city centres, particularly for carbon monoxide, oxides of nitrogen and fine particulate matter. Until recently, pollutant dispersion in urban areas has usually been numerically investigated by using empirical models, such as the Gaussian plume model, or by extensions of this technique to line sources and multiple sources. More recently, advanced computational fluid dynamics (CFD) simulations have been attempted but have been mainly two-dimensional and often encompassing only a single street canyon. This paper provides a comprehensive, critical evaluation of dispersion of pollutants in urban areas. A three-dimensional flow model has been set-up for a staggered crossroad, using the Navier-Stokes equations and the conservation equation for species concentration. The effect of using several different turbulence models, including the k-{epsilon} model, modifications and extensions, has been investigated. Cartesian coordinates have been used in connection with the Partial Solution Algorithm (PARSOL) and Body Fitted Coordinates (BFC). The effects of several different numerical algorithms for discretization of differential equations have also been studied. More than thirty cases are analysed, and the main results are compared with wind tunnel experiments. The numerical results are presented as non-dimensional values to facilitate comparison between experimental and numerical studies. It has been shown that the numerical studies have been able to simulate the air-flow in urban areas and confirm, qualitatively, the previous field observations and wind tunnel results. This success encouraged the authors to extend

Evaluation of leafy vegetables as bioindicators of gaseous mercury pollution in sewage-irrigated areas.

Science.gov (United States)

Zheng, Shun-An; Wu, Zeying; Chen, Chun; Liang, Junfeng; Huang, Hongkun; Zheng, Xiangqun

2018-01-01

Mercury (Hg) can evaporate and enter the plants through the stomata of plant leaves, which will cause a serious threat to local food safety and human health. For the risk assessment, this study aimed to investigate the concentration and accumulation of total gaseous mercury (TGM) in five typical leafy vegetables (Chinese chives (Allium tuberosum Rottler), amaranth (Amaranthus mangostanus L.), rape (Brassica campestris L.), lettuce (Lactuca sativa L.), and spinach (Spinacia oleracea L.)) grown on sewage-irrigated areas in Tianjin, China. The following three sites were chosen to biomonitor Hg pollution: a paddy field receiving sewage irrigation (industrial and urban sewage effluents) for the last 30 years, a vegetable field receiving sewage irrigation for 15 years, and a grass field which did not receive sewage irrigation in history. Results showed that the total Hg levels in the paddy (0.65 mg kg -1 ) and vegetation fields (0.42 mg kg -1 ) were significantly higher than the local background level (0.073 mg kg -1 ) and the China national soil environment quality standard for Hg in grade I (0.30 mg kg -1 ). The TGM levels in ambient air were significantly higher in the paddy (71.3 ng m -3 ) and vegetable fields (39.2 ng m -3 ) relative to the control (9.4 ng m -3 ) and previously reported levels (1.45 ng m -3 ), indicating severe Hg pollution in the atmospheric environment of the sewage-irrigated areas. Furthermore, gaseous mercury was the dominant form of Hg uptake in the leaves or irreversibly bound to leaves. The comparison of Hg uptake levels among the five vegetables showed that the gradient of Hg accumulation followed the order spinach > red amaranth > Chinese chives > rape > lettuce. These results suggest that gaseous Hg exposure in the sewage-irrigated areas is a dominant Hg uptake route in leafy vegetables and may pose a potential threat to agricultural food safety and human health.

Assessment of long-term and large-scale even-odd license plate controlled plan effects on urban air quality and its implication

Science.gov (United States)

Zhao, Suping; Yu, Ye; Qin, Dahe; Yin, Daiying; He, Jianjun

2017-12-01

To solve traffic congestion and to improve urban air quality, long-lasting and large-scale even-odd license plate controlled plan was implemented by local government during 20 November to 26 December 2016 in urban Lanzhou, a semi-arid valley city of northwest China. The traffic control measures provided an invaluable opportunity to evaluate its effects on urban air quality in less developed cities of northwest China. Based on measured simultaneously air pollutants and meteorological parameters, the abatement of traffic-related pollutants induced by the implemented control measures such as CO, PM2.5 and PM10 (the particulate matter with diameter less than 2.5 μm and 10 μm) concentrations were firstly quantified by comparing the air quality data in urban areas with those in rural areas (uncontrolled zones). The concentrations of CO, NO2 from motor vehicles and fine particulate matter (PM2.5) were shown to have significant decreases of 15%-23% during traffic control period from those measured before control period with hourly maximum CO, PM2.5, and NO2/SO2 reduction of 43%, 35% and 141.4%, respectively. The influence of the control measures on AQI (air quality index) and ozone was less as compared to its effect on other air pollutants. Therefore, to alleviate serious winter haze pollution in China and to protect human health, the stringent long-term and large-scale even-odd license plate controlled plan should be implemented aperiodically in urban areas, especially for the periods with poor diffusion conditions.

Comparison of different statistical modelling approaches for deriving spatial air temperature patterns in an urban environment

Science.gov (United States)

Straub, Annette; Beck, Christoph; Breitner, Susanne; Cyrys, Josef; Geruschkat, Uta; Jacobeit, Jucundus; Kühlbach, Benjamin; Kusch, Thomas; Richter, Katja; Schneider, Alexandra; Umminger, Robin; Wolf, Kathrin

2017-04-01

Frequently spatial variations of air temperature of considerable magnitude occur within urban areas. They correspond to varying land use/land cover characteristics and vary with season, time of day and synoptic conditions. These temperature differences have an impact on human health and comfort directly by inducing thermal stress as well as indirectly by means of affecting air quality. Therefore, knowledge of the spatial patterns of air temperature in cities and the factors causing them is of great importance, e.g. for urban planners. A multitude of studies have shown statistical modelling to be a suitable tool for generating spatial air temperature patterns. This contribution presents a comparison of different statistical modelling approaches for deriving spatial air temperature patterns in the urban environment of Augsburg, Southern Germany. In Augsburg there exists a measurement network for air temperature and humidity currently comprising 48 stations in the city and its rural surroundings (corporately operated by the Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health and the Institute of Geography, University of Augsburg). Using different datasets for land surface characteristics (Open Street Map, Urban Atlas) area percentages of different types of land cover were calculated for quadratic buffer zones of different size (25, 50, 100, 250, 500 m) around the stations as well for source regions of advective air flow and used as predictors together with additional variables such as sky view factor, ground level and distance from the city centre. Multiple Linear Regression and Random Forest models for different situations taking into account season, time of day and weather condition were applied utilizing selected subsets of these predictors in order to model spatial distributions of mean hourly and daily air temperature deviations from a rural reference station. Furthermore, the different model setups were

Severity and Susceptibility Beliefs Associated with Urban Air Pollution: Results of a Qualitative Study

International Nuclear Information System (INIS)

Oltra, C.; Sala, R.

2015-01-01

In this report we present the results of a qualitative study based on recombined focus groups with lay citizens. The main objective is to analyze individuals’ beliefs on urban air pollution and perceived benefits and barriers of some self-protective actions, such as using special masks, avoidance of polluted streets, etc. The analytical framework on which the study is based is the Health Belief Model, whose basic idea is that it is more likely that individuals take actions to protect themselves if they think they are potentially susceptible to a serious threat to your health, if they think adopting certain actions has advantages, and if they think there are no significant barriers for such conduct. A secondary objective is to explore the perception of different existing materials to inform the public about air pollution. The results of the study are intended to contribute to the design of interventions aimed at reducing health impacts of urban air pollution and, specifically, to the design of messages in the context of information campaigns on health and environmental risk.

Crowdsourcing urban air temperatures through smartphone battery temperatures in São Paulo, Brazil

NARCIS (Netherlands)

Droste, A.M.; Pape, J.J.; Overeem, A.; Leijnse, H.; Steeneveld, G.J.; Delden, van A.J.; Uijlenhoet, R.

2017-01-01

Crowdsourcing as a method to obtain and apply vast datasets is rapidly becoming prominent in meteorology, especially for urban areas where routine weather observations are scarce. Previous studies showed that smartphone battery temperature readings can be used to estimate the daily and citywide air

Research project on “A Study in Urban Air Pollution Improvement in Asia”

OpenAIRE

2017-01-01

This final report of the joint research project “A study in urban air pollution improvement in Asia” is submitted by the Asian Institute of Technology (AIT) on behalf of the project team following the contract between AIT and the Japan International Cooperation Agency (JICA) for the project period of March 2015 - December 2017. Technical support is provided by the Asia Center for Air Pollution Research (ACAP) Japan and the operational support is provided by the Pollution Control Department (P...

Variability of air ion concentrations in urban Paris

Science.gov (United States)

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

Land-Use Regression Modelling of Intra-Urban Air Pollution Variation in China: Current Status and Future Needs

Directory of Open Access Journals (Sweden)

Baihuiqian He

2018-04-01

Full Text Available Rapid urbanization in China is leading to substantial adverse air quality issues, particularly for NO2 and particulate matter (PM. Land-use regression (LUR models are now being applied to simulate pollutant concentrations with high spatial resolution in Chinese urban areas. However, Chinese urban areas differ from those in Europe and North America, for example in respect of population density, urban morphology and pollutant emissions densities, so it is timely to assess current LUR studies in China to highlight current challenges and identify future needs. Details of twenty-four recent LUR models for NO2 and PM2.5/PM10 (particles with aerodynamic diameters <2.5 µm and <10 µm are tabulated and reviewed as the basis for discussion in this paper. We highlight that LUR modelling in China is currently constrained by a scarcity of input data, especially air pollution monitoring data. There is an urgent need for accessible archives of quality-assured measurement data and for higher spatial resolution proxy data for urban emissions, particularly in respect of traffic-related variables. The rapidly evolving nature of the Chinese urban landscape makes maintaining up-to-date land-use and urban morphology datasets a challenge. We also highlight the importance for Chinese LUR models to be subject to appropriate validation statistics. Integration of LUR with portable monitor data, remote sensing, and dispersion modelling has the potential to enhance derivation of urban pollution maps.

Air Quality Deterioration of Urban Areas Caused by Wildfires in a Natural Reservoir Forest of Mexico

Directory of Open Access Journals (Sweden)

Noel Carbajal

2015-01-01

Full Text Available Many regions of the world suffer loss of vegetation and reduced air quality due to wildfires. Studies on aerosol emissions by wildfires often discuss the negative effects of atmospheric contaminants from a regional or mesoscale perspective. The occurrence of wildfires reveals that a high percentage takes place close to large urban areas. Very high concentration of pollutants and PM10 particulate matter reach urban zones and millions of inhabitants. These events of high pollutant concentrations are seasonally recurrent. There are many large urban areas in the world that often undergo severe air deterioration due to wildfires smoke. We document the extreme impact of wildfire that occurs in the Protected Area of Flora and Fauna La Primavera located in neighborhood of Guadalajara, a large urban zone in Mexico. The simultaneous emissions of aerosols by 60 wildfires were simulated and compared with observed data. The plume generated by the wildfires reached large areas of the central part of Mexico. The principal characteristics of smog emissions (CO, NO2, and PM10 over the urban area were acceptably reproduced. Observed and modeled CO, PM10, and NO2 data indicated that aerosol plumes generated by the wildfires increased notably the concentrations over the metropolitan zone of Guadalajara.

Impacts of city-block-scale countermeasures against urban heat-island phenomena upon a building's energy-consumption for air-conditioning

Energy Technology Data Exchange (ETDEWEB)

Kikegawa, Yukihiro [Department of Environmental Systems, Meisei University, 2-1-1 Hodokubo, Hino-shi, Tokyo 191-8506 (Japan); Genchi, Yutaka [Research Center for Life Cycle Assessment, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Kondo, Hiroaki [Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569 (Japan); Hanaki, Keisuke [Department of Urban Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

2006-06-15

This study quantifies the possible impacts of urban heat-island countermeasures upon buildings' energy use during summer in Tokyo metropolis. Considering the dependency of the buildings air temperature upon the local urban canopy structure, Tokyo urban canopies were classified in the city-block-scale using the sky-view factor (svf). Then, a multi-scale model system describing the interaction between buildings' energy use and urban meteorological conditions was applied to each classified canopy. In terms of urban warming alleviation and cooling energy saving, simulations suggested that the reduction in the air-conditioning anthropogenic heat could be the most effective measure in office buildings' canopies, and that vegetative fraction increase on the side walls of buildings in residential canopies. Both measures indicated daily and spatially averaged decreases in near-ground summer air temperature of 0.2-1.2{sup o}C. The simulations also suggested these temperature decreases could result in the buildings' cooling energy-savings of 4-40%, indicating remarkable savings in residential canopies. These temperature drops and energy savings tended to increase with the decrease of the svf of urban canopies. (author)

Dispersion of UO2F2 aerosol and HF vapor in the operating floor during winter ventilation at the Paducah Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Kim, S.H.; Chen, N.C.J.; Taleyarkhan, R.P.; Keith, K.D.; Schmidt, R.W.; Carter, J.C.

1996-01-01

The gaseous diffusion process is currently employed at two plants in the US: the Paducah Gaseous Diffusion Plant and the Portsmouth Gaseous Diffusion Plant. As part of a facility-wide safety evaluation, a postulated design basis accident involving large line-rupture induced releases of uranium hexafluoride (UF 6 ) into the process building of a gaseous diffusion plant (GDP) is evaluated. When UF 6 is released into the atmosphere, it undergoes an exothermic chemical reaction with moisture (H 2 O) in the air to form vaporized hydrogen fluoride (HF) and aerosolized uranyl fluoride (UO 2 F 2 ). These reactants disperse in the process building and transport through the building ventilation system. The ventilation system draws outside air into the process building, distributes it evenly throughout the building, and discharges it to the atmosphere at an elevated temperature. Since air is recirculated from the cell floor area to the operating floor, issues concerning in-building worker safety and evacuation need to be addressed. Therefore, the objective of this study is to evaluate the transport of HF vapor and UO 2 F 2 aerosols throughout the operating floor area following B-line break accident in the cell floor area

Air-quality measurements in mega-cities: Focus on gaseous organic and particulate pollutants and comparison between two contrasted cities, Paris and Beijing

International Nuclear Information System (INIS)

Gros, V.; Sciare, J.; Yu, T.

2007-01-01

The rapid and important development of large urban areas ('mega-cities'), especially in developing countries, causes and will cause serious air-quality problems. Pollutant measurements in these cities help to characterize the chemical nature and the quantity of these pollutants and to constrain air-quality models. This paper focuses on measurements of volatile organic compounds and aerosols that have an important impact on air quality. We present a brief review on existing measurements and experimental strategies in mega-cities and then we show results from recent measurement campaigns that took place in two contrasted mega-cities: Paris and Beijing. (authors)

Variability of carbonaceous aerosols in remote, rural, urban and industrial environments in Spain: implications for air quality policy

Science.gov (United States)

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

We interpret here the variability of levels of carbonaceous aerosols based on a 12 yr database from 78 monitoring stations across Spain specially compiled for this article. Data did not evidence any spatial trends of carbonaceous aerosols across the country. Conversely, results show marked differences in average concentrations from the cleanest, most remote sites (around 1 μg m-3 of non-mineral carbon (nmC), mostly made of organic carbon (OC) with very little elemental carbon (EC), around 0.1 μg m-3; OC / EC = 12-15), to the highly polluted major cities (8-10 μg m-3 of nmC; 3-4 μg m-3 of EC; 4-5 μg m-3 of OC; OC / EC = 1-2). Thus, urban (and very specific industrial) pollution was found to markedly increase levels of carbonaceous aerosols in Spain, with much lower impact of biomass burning and of biogenic emissions. Correlations between yearly averaged OC / EC and EC concentrations adjust very well to a potential equation (OC = 3.37 EC0.326, R2 = 0.8). A similar equation is obtained when including average concentrations obtained at other European sites (OC = 3.60EC0.491, R2 = 0.7). A clear seasonal variability in OC and EC concentrations was detected. Both OC and EC concentrations were higher during winter at the traffic and urban sites, but OC increased during the warmer months at the rural sites. Hourly equivalent black carbon (EBC) concentrations at urban sites accurately depict road traffic contributions, varying with distance from road, traffic volume and density, mixing-layer height and wind speed. Weekday urban rush-hour EBC peaks are mimicked by concentrations of primary gaseous emissions from road traffic, whereas a single midday peak is characteristic of remote and rural sites. Decreasing annual trends for carbonaceous aerosols were observed between 1999 and 2011 at a large number of stations, probably reflecting the impact of the EURO4 and EURO5 standards in reducing the diesel PM emissions. This has resulted in some cases in an increasing trend for

Lidar system for air-pollution monitoring over urban areas

Science.gov (United States)

Moskalenko, Irina V.; Shcheglov, Djolinard A.; Molodtsov, Nikolai A.

1997-05-01

The atmospheric environmental situation over the urban area of a large city is determined by a complex combination of anthropogenic pollution and meteorological factors. The efficient way to provide three-dimensional mapping of gaseous pollutants over wide areas is utilization of lidar systems employing tunable narrowband transmitters. The paper presented describes activity of RRC 'Kurchatov Institute' in the field of lidar atmospheric monitoring. The project 'mobile remote sensing system based on tunable laser transmitter for environmental monitoring' is developed under financial support of International Scientific and Technology Center (Moscow). The objective of the project is design, construction and field testing of a DIAL-technique system. The lidar transmitter consists of an excimer laser pumping dye laser, BBO crystal frequency doubler, and scanning flat mirror. Sulfur dioxide and atomic mercury have been selected as pollutants for field tests of the lidar system under development. A recent large increase in Moscow traffic stimulated taking into consideration also the remote sensing of lower troposphere ozone because of the photochemical smog problem. The status of the project is briefly discussed. The current activity includes also collecting of environmental data relevant to lidar remote sensing. Main attention is paid to pollutant concentration levels over Moscow city and Moscow district areas.

Mapping urban air quality in near real-time using observations from low-cost sensors and model information.

Science.gov (United States)

Schneider, Philipp; Castell, Nuria; Vogt, Matthias; Dauge, Franck R; Lahoz, William A; Bartonova, Alena

2017-09-01

The recent emergence of low-cost microsensors measuring various air pollutants has significant potential for carrying out high-resolution mapping of air quality in the urban environment. However, the data obtained by such sensors are generally less reliable than that from standard equipment and they are subject to significant data gaps in both space and time. In order to overcome this issue, we present here a data fusion method based on geostatistics that allows for merging observations of air quality from a network of low-cost sensors with spatial information from an urban-scale air quality model. The performance of the methodology is evaluated for nitrogen dioxide in Oslo, Norway, using both simulated datasets and real-world measurements from a low-cost sensor network for January 2016. The results indicate that the method is capable of producing realistic hourly concentration fields of urban nitrogen dioxide that inherit the spatial patterns from the model and adjust the prior values using the information from the sensor network. The accuracy of the data fusion method is dependent on various factors including the total number of observations, their spatial distribution, their uncertainty (both in terms of systematic biases and random errors), as well as the ability of the model to provide realistic spatial patterns of urban air pollution. A validation against official data from air quality monitoring stations equipped with reference instrumentation indicates that the data fusion method is capable of reproducing city-wide averaged official values with an R 2 of 0.89 and a root mean squared error of 14.3 μg m -3 . It is further capable of reproducing the typical daily cycles of nitrogen dioxide. Overall, the results indicate that the method provides a robust way of extracting useful information from uncertain sensor data using only a time-invariant model dataset and the knowledge contained within an entire sensor network. Copyright © 2017 The Authors. Published

Mosses as indicators of the air pollution by radionuclides in urban areas

International Nuclear Information System (INIS)

Todorovic, D.; Popovic, D.; Ajtic, J.; Todorovic, D.)

2007-01-01

The paper presents preliminary results on the contents of radionuclides in mosses exposed to air pollution in central urban area (a Belgrade city park). Activity of natural and anthropogenic radionuclides ( 40 K, 210 Pb, 137 Cs, 7 Be) was determined on two HPGe detectors (Canberra, relative efficiency 20% and 23%) by standard gamma spectrometry. (author) [sr

Spatiotemporal influence of temperature, air quality, and urban environment on cause-specific mortality during hazy days.

Science.gov (United States)

Ho, Hung Chak; Wong, Man Sing; Yang, Lin; Shi, Wenzhong; Yang, Jinxin; Bilal, Muhammad; Chan, Ta-Chien

2018-03-01

Haze is an extreme weather event that can severely increase air pollution exposure, resulting in higher burdens on human health. Few studies have explored the health effects of haze, and none have investigated the spatiotemporal interaction between temperature, air quality and urban environment that may exacerbate the adverse health effects of haze. We investigated the spatiotemporal pattern of haze effects and explored the additional effects of temperature, air pollution and urban environment on the short-term mortality risk during hazy days. We applied a Poisson regression model to daily mortality data from 2007 through 2014, to analyze the short-term mortality risk during haze events in Hong Kong. We evaluated the adverse effect on five types of cause-specific mortality after four types of haze event. We also analyzed the additional effect contributed by the spatial variability of urban environment on each type of cause-specific mortality during a specific haze event. A regular hazy day (lag 0) has higher all-cause mortality risk than a day without haze (odds ratio: 1.029 [1.009, 1.049]). We have also observed high mortality risks associated with mental disorders and diseases of the nervous system during hazy days. In addition, extreme weather and air quality contributed to haze-related mortality, while cold weather and higher ground-level ozone had stronger influences on mortality risk. Areas with a high-density environment, lower vegetation, higher anthropogenic heat, and higher PM 2.5 featured stronger effects of haze on mortality than the others. A combined influence of haze, extreme weather/air quality, and urban environment can result in extremely high mortality due to mental/behavioral disorders or diseases of the nervous system. In conclusion, we developed a data-driven technique to analyze the effects of haze on mortality. Our results target the specific dates and areas with higher mortality during haze events, which can be used for development of

A dispersion modelling system for urban air pollution

Energy Technology Data Exchange (ETDEWEB)

Karppinen, A.; Kukkonen, J.; Nordlund, G.; Rantakrans, E.; Valkama, I.

1998-10-01

An Urban Dispersion Modelling system UDM-FMI, developed at the Finnish Meteorological Institute is described in the report. The modelling system includes a multiple source Gaussian plume model and a meteorological pre-processing model. The dispersion model is an integrated urban scale model, taking into account of all source categories (point, line, area and volume sources). It includes a treatment of chemical transformation (for NO{sub 2}) wet and dry deposition (for SO{sub 2}) plume rise, downwash phenomena and dispersion of inert particles. The model allows also for the influence of a finite mixing height. The model structure is mainly based on the state-of-the-art methodology. The system also computes statistical parameters from the time series, which can be compared to air quality guidelines. The relevant meteorological parameters for the dispersion model are evaluated using data produced by a meteorological pre-processor. The model is based mainly on the energy budget method. Results of national investigations have been used for evaluating climate-dependent parameters. The model utilises the synoptic meteorological observations, radiation records and aerological sounding observations. The model results include the hourly time series of the relevant atmospheric turbulence 51 refs.

Strategies to reduce gaseous KCl and chlorine in deposits during combustion of biomass in fluidised bed boilers

Energy Technology Data Exchange (ETDEWEB)

Kassman, Haakan

2012-11-01

Combustion of a biomass with an enhanced content of alkali and chlorine (Cl) can result in operational problems including deposit formation and superheater corrosion. The strategies applied to reduce such problems include co-combustion and the use of additives. In this work, measures were investigated in order to decrease the risk of superheater corrosion by reducing gaseous KCl and the content of chlorine in deposits. The strategies applied were sulphation of KCl by sulphur/sulphate containing additives (i.e. elemental sulphur (S) and ammonium sulphate (AS)) and co-combustion with peat. Both sulphation of KCl and capture of potassium (K) in ash components can be of importance when peat is used. The experiments were mainly performed in a 12 MW circulation fluidised bed (CFB) boiler equipped for research purposes but also in a full-scale CFB boiler. The results were evaluated by means of IACM (on-line measurements of gaseous KCl), conventional gas analysis, deposit and corrosion probe measurements and ash analysis. Ammonium sulphate performed significantly better than elemental sulphur. Thus the presence of SO{sub 3} (i.e. AS) is of greater importance than that of SO{sub 2} (i.e. S) for sulphation of gaseous KCl and reduction of chlorine in deposits. Only a minor reduction of gaseous KCl was obtained during co-combustion with peat although chlorine in the deposits was greatly reduced. This reduction was supposedly due to capture of K by reactive components from the peat ash in parallel to sulphation of KCl. These compounds remained unidentified. The effect of volatile combustibles on the sulphation of gaseous KCl was investigated. The poorest sulphation was attained during injection of ammonium sulphate in the upper part of the combustion chamber during the lowest air excess ratio. The explanation for this is that SO{sub 3} was partly consumed by side reactions due to the presence of combustibles. These experimental results were supported by modelling, although the

Scientific research in urban areas air quality

International Nuclear Information System (INIS)

Allegrini, I.

1998-01-01

The presence of consistent amounts of polluting agents in the urban atmosphere is a fact widely confirmed which poses serious problems to the people responsible for the environment management. It is well known that the majority of the polluting agents are produced by the intense traffic or vehicles which introduces in the atmosphere a large quantity of compounds. The toxic effect of some of these (primary polluters) is direct; others (secondary polluters) are the result of chemical reactions occurring within the atmosphere. Consequently, the management of the atmospheric environment requires the knowledge of a great number of processes, which begin with the emission of the polluting agents, and continue with their diffusion in the air, their transformation, the way they move, and how they are deposited or removed [it

Companded total condensation loxboil air distillation

International Nuclear Information System (INIS)

Erickson, D.C.

1989-01-01

This patent describes a dual pressure cryogenic distillation process for producing gaseous oxygen from a supply of compressed and cleaned air, comprising: a. cooling a major fraction of the compressed and cleaned air; b. rectifying the major fraction in a high pressure rectifier to liquid nitrogen overhead product and kettle liquid bottom product; c. distilling the kettle liquid in a low pressure column to liquid oxygen bottom product and gaseous nitrogen overhead product; d. working expanding a compensating vapor comprised of at least 77% N/sub 2/ thereby producing refrigeration; and e. further compressing the remaining minor fraction comprising no more than about 30% of the compressed, cleaned warm air in a compressor powered by the expansion

Study of urban air pollution in Thailand

International Nuclear Information System (INIS)

Chueinta, W.; Bunprapob, S.; Suksamran, C.; Sirinuntavid, A.

2004-01-01

The Office of Atoms for Peace has conducted a monitoring study of urban air pollution in Thailand for years. The primary objective of the project was to support the use of nuclear-related techniques for research and monitoring studies on air pollution. The databases obtained have been analyzed and interpreted by statistical methods including source identification using receptor model. This paper reports the work of 2002 at a heavy traffic area in Bangkok. A Gent sampler was set at the curbside of a major road in Bangkok to collect fine and coarse particles routinely on a weekday for 24 hours, once a week. The filter samples were analyzed for elemental concentrations by use of instrumental neutron activation analysis. Black carbon was separately determined by means of the reflectance measurement of the filter sample. In the report, the methodologies and the results of analyses of fine and coarse particles on filters collected in 2002 are presented. The study of the applicability of certified reference material was done by analyses of two standard reference materials provided by JAERI, i.e., NIST 1632c and NIES No.8. The comparisons of the measured and certified values are also given in the paper. (author)

A comparative study on the transdermal penetration effect of gaseous and aqueous plasma reactive species

Science.gov (United States)

Liu, Xin; Gan, Lu; Ma, Mingyu; Zhang, Song; Liu, Jingjing; Chen, Hongxiang; Liu, Dawei; Lu, Xinpei

2018-02-01

To improve the depth of plasma active species in the skin, it is very important to develop skin disease treatment using plasma. In this article, an air plasma source was used to work directly with the skin of a mouse. A tortuous pathway, hair follicles, electroporation and a microneedle do not aid the transdermal delivery of gaseous plasma active species, therefore these gaseous plasma active species cannot penetrate mouse skin with a thickness of ~0.75 mm. The plasma activated water (PAW) produced by the air plasma source was used to study the transdermal penetration of the aqueous plasma activated species. This aqueous plasma activated species can penetrate the skin through hair follicles, intercellular and transcellular routes. The pH of the PAW did not affect the penetration efficiency of the aqueous plasma active species.

Seasonal and diurnal variation in concentrations of gaseous and particulate phase endosulfan

Science.gov (United States)

Li, Qingbo; Wang, Xianyu; Song, Jing; Sui, Hongqi; Huang, Lei; Li, Lu

2012-12-01

Successive 52-week air monitoring of α-endosulfan (α-E), β-endosulfan (β-E) and endosulfan sulfate (E.S) in the gaseous and particulate phases was conducted in Dalian city, northeast China by using an active high-volume sampler. Significant seasonal and diurnal variations in endosulfan concentrations were observed. It was found that the concentration of gaseous-phase α-E peaked in the summer and the concentration of particulate phase α-E peaked in the winter. For E.S, both gaseous and particulate phase concentrations peaked in the summer. α-E was distributed predominantly in the gas phase in the summer but was distributed mainly in the particulate phase in the winter. β-E was distributed mainly in the gas phase in the summer and in the particulate phase at other times of the year. E.S was distributed mainly in the particulate phase throughout the year. Elevated temperatures facilitated the volatilization of α-E from particle surfaces but exerted little effect on β-E and had almost no effect on E.S. Trajectory-based analysis indicates that the seasonal variation in atmospheric concentrations of endosulfan in Dalian city was influenced strongly by the land and sea air masses. In addition, differences in endosulfan concentrations in the particulate phase between day and night were likely due to the circulation of sea/land breezes. The 'cold-condensation' effect occurring during the night may result in the attachment of endosulfan to the particulate phase.

Air Pollution Abatement Performances of Green Infrastructure in Different Urban Environments – A Review

Science.gov (United States)

Intensifying the proportion of urban green infrastructure has been considered as one of the remedies for air pollution levels in cities, yet the impact of numerous vegetation types deployed in different built environments has to be fully synthesised and quantified. This review ex...

Role of urbanization and air pollution in adolescent asthma: a mass screening in Taiwan.

Science.gov (United States)

Lin, R S; Sung, F C; Huang, S L; Gou, Y L; Ko, Y C; Gou, H W; Shaw, C K

2001-10-01

The prevalence of asthma in school children in Taiwan is increasing. This study used mass screening among middle school children in Taiwan to determine the prevalence of asthma and related factors. Data were collected from parents using a self-reported questionnaire and from children using the International Study of Asthma and Allergies in Childhood (ISAAC) video questionnaire. Six study teams conducted the survey nationwide in 1995-1996, with the assistance of middle school nurses and teachers. Among the 1,018,031 students at 795 middle schools who returned questionnaires, 8.5% had a history of asthma (ranging in prevalence from 4.2% to 13% in 25 areas). The prevalence of asthma was higher in boys than in girls (10.0% vs 7%) and was highest in more urbanized areas (11.2%), followed by moderately urbanized areas (7.4%) and less urbanized and rural areas (6.5%). Controlling for age, family smoking, family incense burning, and parental education level, multivariate logistic regression models indicated that children living in an area with heavy air pollution were more likely to have asthma than those in an area with no or light pollution (odds ratio, OR = 2.01 and 95% confidence interval, CI = 1.94-2.09 based on parental ranking of pollution level, or OR = 1.30 and 95% CI = 1.18-1.42 based on pollution level reported by the Environmental Protection Administration). Adolescent asthma in Taiwan is most prevalent in the most urbanized areas and decreases in prevalence in less urbanized areas. This study also found that higher parental education level and higher area air pollution were associated with higher adolescent asthma prevalence.

Effects of anaerobic digestion and aerobic treatment on gaseous emissions from dairy manure storages

Science.gov (United States)

Effects of anaerobic digestion and aerobic treatment on the reduction of gaseous emissions from dairy manure storages were evaluated in this study. Screened dairy manure containing 3.5% volatile solids (VS) was either anaerobically digested or aerobically treated prior to storage in air-tight vessel...

The power of perception: Health risk attributed to air pollution in an urban industrial neighborhood

Energy Technology Data Exchange (ETDEWEB)

Elliott, S.J.; Cole, D.C.; Krueger, P.; Voorberg, N.; Wakefield, S.

1999-08-01

This paper describes a multi-stakeholder process designed to assess the potential health risks associated with adverse air quality in an urban industrial neighborhood. The paper briefly describes the quantitative health risk assessment conducted by scientific experts, with input by a grassroots community group concerned about the impacts of adverse air quality on their health and quality of life. In this case, rather than accept the views of the scientific experts, the community used their powers of perception to advantage by successfully advocating for a professionally conducted community health survey. This survey was designed to document, systematically and rigorously, the health risk perceptions community members associated with exposure to adverse air quality in their neighborhood. This paper describes the instructional and community contexts within which the research is situated as well as the design, administration, analysis, and results of the community health survey administered to 402 households living in an urban industrial neighborhood in Hamilton, Ontario, Canada. These survey results served to legitimate the community's concerns about air quality and to help broaden operational definitions of health. In addition, the results of both health risk assessment exercises served to keep issues of air quality on the local political agenda. Implications of these findings for their understanding of the environmental justice process as well as the ability of communities to influence environmental health policy are discussed.

Paducah Gaseous Diffusion Plant Annual Site Environmental Report for 1993

International Nuclear Information System (INIS)

1994-10-01

The purpose of this document is to summarize effluent monitoring and environmental surveillance results and compliance with environmental laws, regulations, and orders at the Paducah Gaseous Diffusion Plant (PGDP). Environmental monitoring at PGDP consists of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring is direct measurement or the collection and analysis of samples of liquid and gaseous discharges to the environment. Environmental surveillance is direct measurement or the collection and analysis of samples of air, water, soil, foodstuff, biota, and other media. Environmental monitoring is performed to characterize and quantify contaminants, assess radiation exposures of members of the public, demonstrate compliance with applicable standards and permit requirements, and detect and assess the effects (if any) on the local environment. Multiple samples are collected throughout the year and are analyzed for radioactivity, chemical content, and various physical attributes

Modelling the urban air quality in Hamburg with the new city-scale chemistry transport model CityChem

Science.gov (United States)

Karl, Matthias; Ramacher, Martin; Aulinger, Armin; Matthias, Volker; Quante, Markus

2017-04-01

Air quality modelling plays an important role by providing guidelines for efficient air pollution abatement measures. Currently, most urban dispersion models treat air pollutants as passive tracer substances or use highly simplified chemistry when simulating air pollutant concentrations on the city-scale. The newly developed urban chemistry-transport model CityChem has the capability of modelling the photochemical transformation of multiple pollutants along with atmospheric diffusion to produce pollutant concentration fields for the entire city on a horizontal resolution of 100 m or even finer and a vertical resolution of 24 layers up to 4000 m height. CityChem is based on the Eulerian urban dispersion model EPISODE of the Norwegian Institute for Air Research (NILU). CityChem treats the complex photochemistry in cities using detailed EMEP chemistry on an Eulerian 3-D grid, while using simple photo-stationary equilibrium on a much higher resolution grid (receptor grid), i.e. close to industrial point sources and traffic sources. The CityChem model takes into account that long-range transport contributes to urban pollutant concentrations. This is done by using 3-D boundary concentrations for the city domain derived from chemistry-transport simulations with the regional air quality model CMAQ. For the study of the air quality in Hamburg, CityChem was set-up with a main grid of 30×30 grid cells of 1×1 km2 each and a receptor grid of 300×300 grid cells of 100×100 m2. The CityChem model was driven with meteorological data generated by the prognostic meteorology component of the Australian chemistry-transport model TAPM. Bottom-up inventories of emissions from traffic, industry, households were based on data of the municipality of Hamburg. Shipping emissions for the port of Hamburg were taken from the Clean North Sea Shipping project. Episodes with elevated ozone (O3) were of specific interest for this study, as these are associated with exceedances of the World

Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia

Directory of Open Access Journals (Sweden)

G. C. Edwards

2013-05-01

Full Text Available This paper presents the first gaseous elemental mercury (GEM air-surface exchange measurements obtained over naturally enriched and background (−1 Hg terrestrial landscapes in Australia. Two pilot field studies were carried out during the Australian autumn and winter periods at a copper-gold-cobalt-arsenic-mercury mineral field near Pulganbar, NSW. GEM fluxes using a dynamic flux chamber approach were measured, along with controlling environmental parameters over three naturally enriched and three background substrates. The enriched sites results showed net emission to the atmosphere and a strong correlation between flux and substrate Hg concentration, with average fluxes ranging from 14 ± 1 ng m−2 h−1 to 113 ± 6 ng m−2 h−1. Measurements at background sites showed both emission and deposition. The average Hg flux from all background sites showed an overall net emission of 0.36 ± 0.06 ng m−2 h−1. Fluxes show strong relationships with temperature, radiation, and substrate parameters. A compensation point of 2.48, representative of bare soils was determined. For periods of deposition, dry deposition velocities ranged from 0.00025 cm s−1 to 0.0083 cm s−1 with an average of 0.0041 ± 0.00018 cm s−1, representing bare soil, nighttime conditions. Comparison of the Australian data to North American data suggests the need for Australian-specific mercury air-surface exchange data representative of Australia's unique climatic conditions, vegetation types, land use patterns and soils.

Description of saturation curves and boiling process of dry air

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Vestfálová Magda

2018-01-01

Full Text Available Air is a mixture of gases forming the gas wrap of Earth. It is formed by dry air, moisture and other pollutants. Dry air is a substance whose thermodynamic properties in gaseous state, as well as the thermodynamic properties of its main constituents in gaseous state, are generally known and described in detail in the literature. The liquid air is a bluish liquid and is industrially used to produce oxygen, nitrogen, argon and helium by distillation. The transition between the gaseous and liquid state (the condensation process, resp. boiling process, is usually displayed in the basic thermodynamic diagrams using the saturation curves. The saturation curves of all pure substances are of a similar shape. However, since the dry air is a mixture, the shapes of its saturation curves are modified relative to the shapes corresponding to the pure substances. This paper deals with the description of the dry air saturation curves as a mixture, i.e. with a description of the process of phase change of dry air (boiling process. The dry air saturation curves are constructed in the basic thermodynamic charts based on the values obtained from the literature. On the basis of diagrams, data appearing in various publications are interpreted and put into context with boiling process of dry air.

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

Science.gov (United States)

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.

Microscale air quality impacts of distributed power generation facilities.

Science.gov (United States)

Olaguer, Eduardo P; Knipping, Eladio; Shaw, Stephanie; Ravindran, Satish

2016-08-01

The electric system is experiencing rapid growth in the adoption of a mix of distributed renewable and fossil fuel sources, along with increasing amounts of off-grid generation. New operational regimes may have unforeseen consequences for air quality. A three-dimensional microscale chemical transport model (CTM) driven by an urban wind model was used to assess gaseous air pollutant and particulate matter (PM) impacts within ~10 km of fossil-fueled distributed power generation (DG) facilities during the early afternoon of a typical summer day in Houston, TX. Three types of DG scenarios were considered in the presence of motor vehicle emissions and a realistic urban canopy: (1) a 25-MW natural gas turbine operating at steady state in either simple cycle or combined heating and power (CHP) mode; (2) a 25-MW simple cycle gas turbine undergoing a cold startup with either moderate or enhanced formaldehyde emissions; and (3) a data center generating 10 MW of emergency power with either diesel or natural gas-fired backup generators (BUGs) without pollution controls. Simulations of criteria pollutants (NO2, CO, O3, PM) and the toxic pollutant, formaldehyde (HCHO), were conducted assuming a 2-hr operational time period. In all cases, NOx titration dominated ozone production near the source. The turbine scenarios did not result in ambient concentration enhancements significantly exceeding 1 ppbv for gaseous pollutants or over 1 µg/m(3) for PM after 2 hr of emission, assuming realistic plume rise. In the case of the datacenter with diesel BUGs, ambient NO2 concentrations were enhanced by 10-50 ppbv within 2 km downwind of the source, while maximum PM impacts in the immediate vicinity of the datacenter were less than 5 µg/m(3). Plausible scenarios of distributed fossil generation consistent with the electricity grid's transformation to a more flexible and modernized system suggest that a substantial amount of deployment would be required to significantly affect air quality on

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

Science.gov (United States)

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). Copyright © 2014 Elsevier Ltd. All rights reserved.

Ice-nucleating particle concentrations unaffected by urban air pollution in Beijing, China

Science.gov (United States)

Chen, Jie; Wu, Zhijun; Augustin-Bauditz, Stefanie; Grawe, Sarah; Hartmann, Markus; Pei, Xiangyu; Liu, Zirui; Ji, Dongsheng; Wex, Heike

2018-03-01

Exceedingly high levels of PM2.5 with complex chemical composition occur frequently in China. It has been speculated whether anthropogenic PM2.5 may significantly contribute to ice-nucleating particles (INP). However, few studies have focused on the ice-nucleating properties of urban particles. In this work, two ice-nucleating droplet arrays have been used to determine the atmospheric number concentration of INP (NINP) in the range from -6 to -25 °C in Beijing. No correlations between NINP and either PM2.5 or black carbon mass concentrations were found, although both varied by more than a factor of 30 during the sampling period. Similarly, there were no correlations between NINP and either total particle number concentration or number concentrations for particles with diameters > 500 nm. Furthermore, there was no clear difference between day and night samples. All these results indicate that Beijing air pollution did not increase or decrease INP concentrations in the examined temperature range above values observed in nonurban areas; hence, the background INP concentrations might not be anthropogenically influenced as far as urban air pollution is concerned, at least in the examined temperature range.

Multisite study of particle number concentrations in urban air.

Science.gov (United States)

Harrison, Roy M; Jones, Alan M

2005-08-15

Particle number concentration data are reported from a total of eight urban site locations in the United Kingdom. Of these, six are central urban background sites, while one is an urban street canyon (Marylebone Road) and another is influenced by both a motorway and a steelworks (Port Talbot). The concentrations are generally of a similar order to those reported in the literature, although higher than those in some of the other studies. Highest concentrations are at the Marylebone Road site and lowest are at the Port Talbot site. The central urban background locations lie somewhere between with concentrations typically around 20 000 cm(-3). A seasonal pattern affects all sites, with highest concentrations in the winter months and lowest concentrations in the summer. Data from all sites show a diurnal variation with a morning rush hour peak typical of an anthropogenic pollutant. When the dilution effects of windspeed are accounted for, the data show little directionality at the central urban background sites indicating the influence of sources from all directions as might be expected if the major source were road traffic. At the London Marylebone Road site there is high directionality driven by the air circulation in the street canyon, and at the Port Talbot site different diurnal patterns are seen for particle number count and PM10 influenced by emissions from road traffic (particle number count) and the steelworks (PM10) and local meteorological factors. Hourly particle number concentrations are generally only weakly correlated to NO(x) and PM10, with the former showing a slightly closer relationship. Correlations between daily average particle number count and PM10 were also weak. Episodes of high PM10 concentration in summer typically show low particle number concentrations consistent with transport of accumulation mode secondary aerosol, while winter episodes are frequently associated with high PM10 and particle number count arising from poor dispersion of

Morbidity Forecast in Cities: A Study of Urban Air Pollution and Respiratory Diseases in the Metropolitan Region of Curitiba, Brazil.

Science.gov (United States)

de Souza, Fabio Teodoro

2018-05-29

In the last two decades, urbanization has intensified, and in Brazil, about 90% of the population now lives in urban centers. Atmospheric patterns have changed owing to the high growth rate of cities, with negative consequences for public health. This research aims to elucidate the spatial patterns of air pollution and respiratory diseases. A data-based model to aid local urban management to improve public health policies concerning air pollution is described. An example of data preparation and multivariate analysis with inventories from different cities in the Metropolitan Region of Curitiba was studied. A predictive model with outstanding accuracy in prediction of outbreaks was developed. Preliminary results describe relevant relations among morbidity scales, air pollution levels, and atmospheric seasonal patterns. The knowledge gathered here contributes to the debate on social issues and public policies. Moreover, the results of this smaller scale study can be extended to megacities.

Air-soil exchange of PCBs: levels and temporal variations at two sites in Turkey.

Science.gov (United States)

Yolsal, Didem; Salihoglu, Güray; Tasdemir, Yücel

2014-03-01

Seasonal distribution of polychlorinated biphenyls (PCBs) at the air-soil intersection was determined for two regions: one with urban characteristics where traffic is dense (BUTAL) and the other representing the coastal zone (Mudanya). Fifty-one air and soil samples were simultaneously collected. Total PCB (Σ82 PCB) levels in the soil samples collected during a 1-year period ranged between 105 and 7,060 pg/g dry matter (dm) (BUTAL) and 110 and 2,320 pg/g dm (Mudanya). Total PCB levels in the gaseous phase were measured to be between 100 and 910 pg/m(3) (BUTAL) and 75 and 1,025 pg/m(3) (Mudanya). Variations in the concentrations were observed depending on the season. Though the PCB concentrations measured in the atmospheres of both regions in the summer months were high, they were found to be lower in winter. However, while soil PCB levels were measured to be high at BUTAL during summer months, they were found to be high during winter months in Mudanya. The direction and amount of the PCB movement were determined by calculating the gaseous phase change fluxes at air-soil intersection. While a general PCB movement from soil to air was found for BUTAL, the PCB movement from air to soil was calculated for the Mudanya region in most of the sampling events. During the warmer seasons PCB movement towards the atmosphere was observed due to evaporation from the soil. With decreases in the temperature, both decreases in the number of PCB congeners occurring in the air and a change in the direction of some congeners were observed, possibly caused by deposition from the atmosphere to the soil. 3-CB and 4-CB congeners were found to be dominant in the atmosphere, and 4-, 5-, and 6-CBs were found to dominate in the surface soils.

Evaluation of Air Pollution Tolerance Index of Plants and Ornamental Shrubs in Enugu City: Implications for Urban Heat Island Effect

Directory of Open Access Journals (Sweden)

2016-11-01

Full Text Available The study compared the air pollution tolerance indices (APTI of five plant species and five ornamental shrubs in Enugu Urban Center. Laboratory analysis was performed on the four physiological and biological parameters including leaf relative water content (RWC, ascorbic acid (AA content, total leaf chlorophyll (TCH and leaf extract pH. These parameters were used to develop an air pollution tolerance index. Factor analysis and descriptive statistics were utilized in the analysis to examine the interactions between these parameters. Vegetation monitoring in terms of its APTI acts as a \\'Bioindicator\\' of air pollution. The study also showed the possibility of utilizing APTI as a tool for selecting plants or ornamental shrubs for urban heat Island mitigation in Enugu City. The result of APTI showed order of tolerance for plants as Anacarduim occidentale (23.20, Pinus spp (22.35, Catalpa burgei (22.57, Magifera indica (23.37, and Psidum guajava (24.15.The result of APTI showed increasing order of sensitivity for ornamental shrubs from ixora red (14.32, yellow ficus(12.63, masquerade pine(12.26, Tuja pine(11.000,to Yellow bush(10.60. The APTI of all the plants examined were higher than those of ornamental shrubs. Thus suggesting that plants in general were more tolerant to air pollution than ornamental shrubs. The ornamental shrubs with lower APTI values (sensitive were recommended as bioindicator of poor urban air quality while plants with high APTI values (tolerant are planted around areas anticipated to have high air pollution load. The result of this current study is therefore handy for future planning and as well provides tolerant species for streetscape and urban heat island mitigation.

Assessing environmental inequalities in ambient air pollution across urban Australia.

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Knibbs, Luke D; Barnett, Adrian G

2015-04-01

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

GASEOUS ELEMENTAL MERCURY IN THE MARINE BOUNDARY LAYER: EVIDENCE FOR RAPID REMOVAL IN ANTHROPOGENIC POLLUTION

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In this study, gas-phase elemental mercury (Hg0) and related species (including inorganic reactive gaseous mercury (RGM) and particulate mercury (PHg)) were measured at Cheeka Peak Observatory (CPO), Washington State, in the marine boundary layer (MBL) during 2001-2002. Air of...

Quantification of air plasma chemistry for surface disinfection

International Nuclear Information System (INIS)

Pavlovich, Matthew J; Clark, Douglas S; Graves, David B

2014-01-01

Atmospheric-pressure air plasmas, created by a variety of discharges, are promising sources of reactive species for the emerging field of plasma biotechnology because of their convenience and ability to operate at ambient conditions. One biological application of ambient-air plasma is microbial disinfection, and the ability of air plasmas to decontaminate both solid surfaces and liquid volumes has been thoroughly established in the literature. However, the mechanism of disinfection and which reactive species most strongly correlate with antimicrobial effects are still not well understood. We describe quantitative gas-phase measurements of plasma chemistry via infrared spectroscopy in confined volumes, focusing on air plasma generated via surface micro-discharge (SMD). Previously, it has been shown that gaseous chemistry is highly sensitive to operating conditions, and the measurements we describe here extend those findings. We quantify the gaseous concentrations of ozone (O 3 ) and nitrogen oxides (NO and NO 2 , or NO x ) throughout the established ‘regimes’ for SMD air plasma chemistry: the low-power, ozone-dominated mode; the high-power, nitrogen oxides-dominated mode; and the intermediate, unstable transition region. The results presented here are in good agreement with previously published experimental studies of aqueous chemistry and parameterized models of gaseous chemistry. The principal finding of the present study is the correlation of bacterial inactivation on dry surfaces with gaseous chemistry across these time and power regimes. Bacterial decontamination is most effective in ‘NO x mode’ and less effective in ‘ozone mode’, with the weakest antibacterial effects in the transition region. Our results underscore the dynamic nature of air plasma chemistry and the importance of careful chemical characterization of plasma devices intended for biological applications. (paper)

Quantification of air plasma chemistry for surface disinfection

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Pavlovich, Matthew J.; Clark, Douglas S.; Graves, David B.

2014-12-01

Atmospheric-pressure air plasmas, created by a variety of discharges, are promising sources of reactive species for the emerging field of plasma biotechnology because of their convenience and ability to operate at ambient conditions. One biological application of ambient-air plasma is microbial disinfection, and the ability of air plasmas to decontaminate both solid surfaces and liquid volumes has been thoroughly established in the literature. However, the mechanism of disinfection and which reactive species most strongly correlate with antimicrobial effects are still not well understood. We describe quantitative gas-phase measurements of plasma chemistry via infrared spectroscopy in confined volumes, focusing on air plasma generated via surface micro-discharge (SMD). Previously, it has been shown that gaseous chemistry is highly sensitive to operating conditions, and the measurements we describe here extend those findings. We quantify the gaseous concentrations of ozone (O3) and nitrogen oxides (NO and NO2, or NOx) throughout the established ‘regimes’ for SMD air plasma chemistry: the low-power, ozone-dominated mode; the high-power, nitrogen oxides-dominated mode; and the intermediate, unstable transition region. The results presented here are in good agreement with previously published experimental studies of aqueous chemistry and parameterized models of gaseous chemistry. The principal finding of the present study is the correlation of bacterial inactivation on dry surfaces with gaseous chemistry across these time and power regimes. Bacterial decontamination is most effective in ‘NOx mode’ and less effective in ‘ozone mode’, with the weakest antibacterial effects in the transition region. Our results underscore the dynamic nature of air plasma chemistry and the importance of careful chemical characterization of plasma devices intended for biological applications.

Can TiO2-based photocatalytic textiles be used to improve the urban air quality?

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

2017-04-01

Despite current legislation and efforts made to improve urban air quality, significant negative effects still persist. That is the case of traffic, which impact on air pollution is a growing problem. For this reason, depollution measures are necessary to reach safer air quality levels. Recently, the use of titanium dioxide (TiO2) based photocatalytic self-cleaning and de-polluting materials has been considered to remove air pollutants, especially NOx. TiO2 can be found in the market under different formats for environmental purposes, and its effectiveness depends not only on the support (concrete, paints, etc) but also on the impregnation method (layer, embedded, etc). By combining laboratory and field campaigns, the LIFE PHOTOCITYTEX project was conceived to demonstrate the effectiveness of using TiO2-based photocatalytic nanomaterials in textiles as a way of alleviating the air pollution in urban areas. Within the project, which is already within its last year, two one-year extensive passive dosimetric campaigns have already been completed to assess their impact on the selected urban sites, measuring before and after the installation of the photocatalytic textile prototypes, respectively. Also, intensive active measurement campaigns (using active dosimetry, monitors and instrumentation for physical parameters) have been conducted to account for winter and summer conditions. Besides, lab-tests have been concluded to determine optimal photocatalytic formulations on textiles, and these have been tested at the EUPHORE simulation chambers under typical environmental conditions of various European cities. Besides the effect on NOx, which has been the main focus of the study, VOCs formation and abatement has been assessed, yielding in a better overall understanding of the whole process and its implications. Very promising results on the deep reduction of NOx have been observed at EUPHORE. From the calculation of the uptake coefficient, a mathematical model tool foresees

Gas separation process using membranes with permeate sweep to remove CO.sub.2 from gaseous fuel combustion exhaust

Science.gov (United States)

Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

2012-05-15

A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.

Generation of hydroxyl radicals by urban suspended particulate air matter. The role of iron ions

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Valavanidis, Athanasios; Salika, Anastasia; Theodoropoulou, Anna

Recent epidemiologic studies showed statistical associations between particulate air pollution in urban areas and increased morbidity and mortality, even at levels well within current national air quality standards. Inhalable particulate matter (PM 10) can penetrate into the lower airways where they can cause acute and chronic lung injury by generating toxic oxygen free radicals. We tested inhalable total suspended particulates (TSP) from the Athens area, diesel and gasoline exhaust particles (DEP and GED), and urban street dusts, by Electron Paramagnetic Resonance (EPR). All particulates can generate hydroxyl radicals (HO ṡ), in aqueous buffered solutions, in the presence of hydrogen peroxide. Results showed that oxidant generating activity is related with soluble iron ions. Leaching studies showed that urban particulate matter can release large amounts of Fe 3+ and lesser amounts of Fe 2+, as it was shown from other studies. Direct evidence of HO ṡ was confirmed by spin trapping with DMPO and measurement of DMPO-OH adduct by EPR. Evidence was supported with the use of chelator (EDTA), which increases the EPR signal, and the inhibition of the radical generating activity by desferrioxamine or/and antioxidants ( D-mannitol, sodium benzoate).

Effects of income and urban form on urban NO2: global evidence from satellites.

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Bechle, Matthew J; Millet, Dylan B; Marshall, Julian D

2011-06-01

Urban air pollution is among the top 15 causes of death and disease worldwide, and a problem of growing importance with a majority of the global population living in cities. A important question for sustainable development is to what extent urban design can improve or degrade the environment and public health. We investigate relationships between satellite-derived estimates of nitrogen dioxide concentration (NO(2), a key component of urban air pollution) and urban form for 83 cities globally. We find a parsimonious yet powerful relationship (model R(2) = 0.63), using as predictors population, income, urban contiguity, and meteorology. Cities with highly contiguous built-up areas have, on average, lower urban NO(2) concentrations (a one standard deviation increase in contiguity is associated with a 24% decrease in average NO(2) concentration). More-populous cities tend to have worse air quality, but the increase in NO(2) associated with a population increase of 10% may be offset by a moderate increase (4%) in urban contiguity. Urban circularity ("compactness") is not a statistically significant predictor of NO(2) concentration. Although many factors contribute to urban air pollution, our findings suggest that antileapfrogging policies may improve air quality. We find that urban NO(2) levels vary nonlinearly with income (Gross Domestic Product), following an "environmental Kuznets curve"; we estimate that if high-income countries followed urban pollution-per-income trends observed for low-income countries, NO(2) concentrations in high-income cities would be ∼10× larger than observed levels.

Estimation of radionuclide releases in atmosphere from Cernavoda NPP based on continuous gaseous effluent monitoring

International Nuclear Information System (INIS)

Bobric, E.; Murgoci, S.; Popescu, I.; Ibadula, R.

2001-01-01

Monitoring of gaseous effluents from Cernavoda NPP is performed to assess the environmental impact of the plant operation. The results of the monitoring program are used to evaluate the population doses in order to ensure that the emissions of radionuclides in air are below regulatory limits and radiation doses are maintained ALARA. It complements, but is independent from the Operational Environmental Monitoring Program for Cernavoda NPP. Gaseous effluent monitors provide continuous indication of the radioactivity content in atmospheric emissions. Except for noble gases, these monitors also collect samples for later detailed analysis in the station Health Physics Laboratory. This paper presents the main equipment and the results of the gaseous effluents monitoring program in order to assess the impact of Cernavoda NPP operation and to predict the future releases as function of radionuclides concentrations in CANDU systems, based on the identified trends.(author)

Assessing theEffects of Nitrogen Dioxide in Urban Air on Health of West and Southwest Cities of Iran

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Zallaghi

2014-10-01

Full Text Available Background Nitrogen dioxide (NO2 is a corrosive, strong oxidant and a physiologic stimulant of lower respiratory tract. Every human being inhales an average of 10-m3 air per day; therefore, assessment of the effect of inhaled air on health is a vital issue. The main source NO2 in urban regions is intra-urban public transport system. The annual average of determined air quality for NO2 is 40 μg/m3. Objectives The present study aimed to estimate and compare epidemiologic indices attributed to the pollutant NO2 in the urban air of southwest cities of Iran, namely, Ahvaz, Kermanshah, and Bushehr, in 2011. Materials and Methods In the present study, data relevant to the air-pollutant NO2 in 2011 was obtained from the Iranian Department of Environment and meteorological organizations of the studied cities. Raw data processing by Excel software included instruction set correction of averaging, coding, and filtering. Then the meteorological parameters were converted as input file to the Air Q model. Finally, by using epidemiologic formulas, relative risk (RR and attributed part to NO2 in the three studied cites were estimated. Results The results showed that in summer, winter, and the whole year, Kermanshah and Bushehr had on average the maximum and minimum NO2 concentration, respectively, in 2011. In addition, accumulative number of cases attributed to exposure with NO2 in the studied cities was maximum in Kermanshah (21 cases and minimum in Bushehr (one case. The results revealed that approximately, the maximum number of death cases attributed to NO2 were observed in Kermanshah due to heart problems (1.06%, acute infarction (1.8%, and obstructive pulmonary disease (1.9% with concentration > 20 μg/m3. Conclusions Every 10 μg/m3 increase in the concentration of the pollutant NO2 in the studied cities led to increase in the RR of myocardial infarction, cardiovascular diseases, and obstructive pulmonary disease by 0.4%, 0.2%, and 0.4%, respectively, in

Impacts of urbanization and agricultural development on observed changes in surface air temperature over mainland China from 1961 to 2006

Science.gov (United States)

Han, Songjun; Tang, Qiuhong; Xu, Di; Yang, Zhiyong

2018-03-01

A large proportion of meteorological stations in mainland China are located in or near either urban or agricultural lands that were established throughout the period of rapid urbanization and agricultural development (1961-2006). The extent of the impacts of urbanization and agricultural development on observed air temperature changes across different climate regions remains elusive. This study evaluates the surface air temperature trends observed by 598 meteorological stations in relation to the urbanization and agricultural development over the arid northwest, semi-arid intermediate, and humid southeast regions of mainland China based on linear regressions of temperature trends on the fractions of urban and cultivated land within a 3-km radius of the stations. In all three regions, the stations surrounded by large urban land tend to experience rapid warming, especially at minimum temperature. This dependence is particularly significant in the southeast region, which experiences the most intense urbanization. In the northwest and intermediate regions, stations surrounded by large cultivated land encounter less warming during the main growing season, especially at the maximum temperature changes. These findings suggest that the observed surface warming has been affected by urbanization and agricultural development represented by urban and cultivated land fractions around stations in with land cover changes in their proximity and should thus be considered when analyzing regional temperature changes in mainland China.

Transfer of gaseous iodine to Tradescantia

International Nuclear Information System (INIS)

Nakamura, Yuji; Ohmomo, Yoichiro.

1984-01-01

Transfer rates of gaseous elemental iodine and methyliodide from atmosphere to Tradescantia were investigated in relation to supposed genetic mutation due to radioactive iodine released from nuclear facilities. The estimated transfer rate of elemental iodine to the young buds of Tradescantia, which was given as the ratio of iodine uptake rate per unit weight of the plant to the concentration of the element in the air, was approximately 7 x 10 -2 cm 3 /g.sec, about 30 to 40 times higher than that of methyliodide. The contribution of direct deposition of elemental iodine was suggested to be significant, although methyliodide was mainly absorbed by respiration through stomata of the plant. (author)

Aerosol composition of urban plumes passing over a rural monitoring site

International Nuclear Information System (INIS)

Ellestad, T.G.

1980-01-01

A field study conducted at a ground site 100 km north of St. Louis, Mo., to measure the aerosol composition and gaseous concentrations of urban plumes passing the site is discussed. Coarse and fine aerosol elemental concentrations, height scattering, meteorological data and concentrations of SO 2 , CO, O 3 , and NO-NO/sub x/ were measured and then analyzed together with data from associate investigators on fluorocarbon-11, total hydrocarbons, and size distributions. The results show that: (1) gaseous and elemental aerosol concentrations at the ground site 100 km from the St. Louis urban area were clearly influenced by the St. Louis urban plume, (2) the urban plumes of Chicago and Indianapolis, 350 km from the ground site, may have been detected, (3) sulfur compounds, presumably sulfates, accounted for 30-40% of the mass loading within the St. Louis urban plume, and resided almost entirely within the size range below 2.5 microns, (4) the most reliable urban-plume tracers in this study were fine Pb, fluorocarbon-11, total nonmethane hydrocarbons, and CO, and (5) over a period of several days, there may have been a regional buildup of fine S, light scattering, aerosol mass, O 3 , and NO/sub x/ and, to a lesser extent, CO and fluorocarbon-11

Urban air quality improvement by using a CNG lean burn engine for city buses

NARCIS (Netherlands)

Merétei, T.; Ling, J.A.N. van; Havenith, C.

1998-01-01

The use of compressed natural gas (CNG)-fuelled lean-burn city bus engines has a significant potential for air quality improvement in urban areas. Particularly important is the reduction of NO, as well as particulate and non regulated HC-emissions. For this reason, a CNG-fuelled, lean-burn,

Does Urban Form Affect Urban NO2? Satellite-Based Evidence for More than 1200 Cities.

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Bechle, Matthew J; Millet, Dylan B; Marshall, Julian D

2017-11-07

Modifying urban form may be a strategy to mitigate urban air pollution. For example, evidence suggests that urban form can affect motor vehicle usage, a major contributor to urban air pollution. We use satellite-based measurements of urban form and nitrogen dioxide (NO 2 ) to explore relationships between urban form and air pollution for a global data  set of 1274 cities. Three of the urban form metrics studied (contiguity, circularity, and vegetation) have a statistically significant relationship with urban NO 2 ; their combined effect could be substantial. As illustration, if findings presented here are causal, that would suggest that if Christchurch, New Zealand (a city at the 75th percentile for all three urban-form metrics, and with a network of buses, trams, and bicycle facilities) was transformed to match the urban form of Indio - Cathedral City, California, United States (a city at the 25th percentile for those same metrics, and exhibiting sprawl-like suburban development), our models suggest that Christchurch's NO 2 concentrations would be ∼60% higher than its current level. We also find that the combined effect of urban form on NO 2 is larger for small cities (β × IQR = -0.46 for cities urban population and are where much of the future urban growth is expected to occur. This work highlights the need for future study of how changes in urban form and related land use and transportation policies impact urban air pollution, especially for small cities.

Development of an Urban High-Resolution Air Temperature Forecast System for Local Weather Information Services Based on Statistical Downscaling

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Chaeyeon Yi

2018-04-01

Full Text Available The Korean peninsula has complex and diverse weather phenomena, and the Korea Meteorological Administration has been working on various numerical models to produce better forecasting data. The Unified Model Local Data Assimilation and Prediction System is a limited-area working model with a horizontal resolution of 1.5 km for estimating local-scale weather forecasts on the Korean peninsula. However, in order to numerically predict the detailed temperature characteristics of the urban space, in which surface characteristics change rapidly in a small spatial area, a city temperature prediction model with higher resolution spatial decomposition capabilities is required. As an alternative to this, a building-scale temperature model was developed, and a 25 m air temperature resolution was determined for the Seoul area. The spatial information was processed using statistical methods, such as linear regression models and machine learning. By comparing the accuracy of the estimated air temperatures with observational data during the summer, the machine learning was improved. In addition, horizontal and vertical characteristics of the urban space were better represented, and the air temperature was better resolved spatially. Air temperature information can be used to manage the response to heat-waves and tropical nights in administrative districts of urban areas.

Siting Background Towers to Characterize Incoming Air for Urban Greenhouse Gas Estimation: A Case Study in the Washington, DC/Baltimore Area

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Mueller, K.; Yadav, V.; Lopez-Coto, I.; Karion, A.; Gourdji, S.; Martin, C.; Whetstone, J.

2018-03-01

There is increased interest in understanding urban greenhouse gas (GHG) emissions. To accurately estimate city emissions, the influence of extraurban fluxes must first be removed from urban greenhouse gas (GHG) observations. This is especially true for regions, such as the U.S. Northeastern Corridor-Baltimore/Washington, DC (NEC-B/W), downwind of large fluxes. To help site background towers for the NEC-B/W, we use a coupled Bayesian Information Criteria and geostatistical regression approach to help site four background locations that best explain CO2 variability due to extraurban fluxes modeled at 12 urban towers. The synthetic experiment uses an atmospheric transport and dispersion model coupled with two different flux inventories to create modeled observations and evaluate 15 candidate towers located along the urban domain for February and July 2013. The analysis shows that the average ratios of extraurban inflow to total modeled enhancements at urban towers are 21% to 36% in February and 31% to 43% in July. In July, the incoming air dominates the total variability of synthetic enhancements at the urban towers (R2 = 0.58). Modeled observations from the selected background towers generally capture the variability in the synthetic CO2 enhancements at urban towers (R2 = 0.75, root-mean-square error (RMSE) = 3.64 ppm; R2 = 0.43, RMSE = 4.96 ppm for February and July). However, errors associated with representing background air can be up to 10 ppm for any given observation even with an optimal background tower configuration. More sophisticated methods may be necessary to represent background air to accurately estimate urban GHG emissions.

Chemical characterization of urban air particulate matter of Kuala Lumpur 2002-2004

International Nuclear Information System (INIS)

Wee Boon Siong; Ab. Khalik Bin Haji Wood

2006-01-01

Urban air particulate samples of Kuala Lumpur ambient air have been collected characterize according to fine and coarse airborne particulates. The air filters containing particulate matter were collected using GENT stack filter unit fitted with appropriate polycarbonate filters. The sampling location site (Lat: 03deg 10'30''; Long: 101deg 43'24.2'') is approximately 1 km from the Kuala Lumpur city center. All the sampling conducted from January 2002 until October 2004 was included in the analysis and results were reported. The mass loading for finest air particulate matter (PM 2.5) in Kuala Lumpur are 199±55 μg (2002), 171±53 μg (2003), and 171±61 μg (2004), respectively. The mass loading for coarse air particulate matter (PM 10) in Kuala Lumpur were 125±29 μg (2002), 134±48 μg (2003), and 137 ± 57 μg (2004), respectively. The elemental concentration of the air filters were determined using INAA technique utilizing both short and long irradiation facilities at MINT's TRIGA MKII reactor. Upon irradiation the air filters were counted at suitable counting time using HPGe gamma-ray detectors. The elements reported for this monitoring are Al, As, Br, Co, Cr, K, Lu, Mn, Na, Sb, Sc, Ti, V, and Zn. Certified reference materials were also included in the sample analysis function as quality control materials. (author)

Methodology for setup and data processing of mobile air quality measurements to assess the spatial variability of concentrations in urban environments

International Nuclear Information System (INIS)

Van Poppel, Martine; Peters, Jan; Bleux, Nico

2013-01-01

A case study is presented to illustrate a methodology for mobile monitoring in urban environments. A dataset of UFP, PM 2.5 and BC concentrations was collected. We showed that repeated mobile measurements could give insight in spatial variability of pollutants at different micro-environments in a city. Streets of contrasting traffic intensity showed increased concentrations by a factor 2–3 for UFP and BC and by 2.5 . The first quartile (P25) of the mobile measurements at an urban background zone seems to be good estimate of the urban background concentration. The local component of the pollutant concentrations was determined by background correction. The use of background correction reduced the number of runs needed to obtain representative results. The results presented, are a first attempt to establish a methodology for setup and data processing of mobile air quality measurements to assess the spatial variability of concentrations in urban environments. -- Highlights: ► Mobile measurements are used to assess the variability of air pollutants in urban environments. ► PM 2.5 , BC and UFP concentrations are presented for zones with different traffic characteristics. ► A methodology for background correction based on the mobile measurements is presented. ► The background concentration is estimated as the 25th percentile of the urban background data. ► The minimum numbers of runs for a representative estimate is reduced after background correction. -- This paper shows that the spatial variability of air pollutants in an urban environment can be assessed by a mobile monitoring methodology including background correction

Development and application of a mobile laboratory for measuring emissions from diesel engines. 1. Regulated gaseous emissions.

Science.gov (United States)

Cocker, David R; Shah, Sandip D; Johnson, Kent; Miller, J Wayne; Norbeck, Joseph M

2004-04-01

Information about in-use emissions from diesel engines remains a critical issue for inventory development and policy design. Toward that end, we have developed and verified the first mobile laboratory that measures on-road or real-world emissions from engines at the quality level specified in the U.S. Congress Code of Federal Regulations. This unique mobile laboratory provides information on integrated and modal regulated gaseous emission rates and integrated emission rates for speciated volatile and semivolatile organic compounds and particulate matter during real-world operation. Total emissions are captured and collected from the HDD vehicle that is pulling the mobile laboratory. While primarily intended to accumulate data from HDD vehicles, it may also be used to measure emission rates from stationary diesel sources such as back-up generators. This paper describes the development of the mobile laboratory, its measurement capabilities, and the verification process and provides the first data on total capture gaseous on-road emission measurements following the California Air Resources Board (ARB) 4-mode driving cycle, the hot urban dynamometer driving schedule (UDDS), the modified 5-mode cycle, and a 53.2-mi highway chase experiment. NOx mass emission rates (g mi(-1)) for the ARB 4-mode driving cycle, the hot UDDS driving cycle, and the chase experimentwerefoundto exceed current emission factor estimates for the engine type tested by approximately 50%. It was determined that congested traffic flow as well as "off-Federal Test Procedure cycle" emissions can lead to significant increases in per mile NOx emission rates for HDD vehicles.

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

Science.gov (United States)

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.

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

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Anna Mainka

2015-07-01

Full Text Available 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.

Response to gaseous NO2 air pollutant of P. fluorescens airborne strain MFAF76a and clinical strain MFN1032

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Tatiana eKondakova

2016-03-01

Full Text Available Human exposure to nitrogen dioxide (NO2, an air pollutant of increasing interest in biology, results in several toxic effects to human health and also to the air microbiota. The aim of this study was to investigate the bacterial response to gaseous NO2. Two Pseudomonas fluorescens strains, namely the airborne strain MFAF76a and the clinical strain MFN1032 were exposed to 0.1, 5 or 45 ppm concentrations of NO2, and their effects on bacteria were evaluated in terms of motility, biofilm formation, antibiotic resistance, as well as expression of several chosen target genes. While 0.1 and 5 ppm of NO2 did not lead to any detectable modification in the studied phenotypes of the two bacteria, several alterations were observed when the bacteria were exposed to 45 ppm of gaseous NO2. We thus chose to focus on this high concentration. NO2-exposed P. fluorescens strains showed reduced swimming motility, and decreased swarming in case of the strain MFN1032. Biofilm formed by NO2-treated airborne strain MFAF76a showed increased maximum thickness compared to non-treated cells, while NO2 had no apparent effect on the clinical MFN1032 biofilm structure. It is well known that biofilm and motility are inversely regulated by intracellular c-di-GMP level. The c-di-GMP level was however not affected in response to NO2 treatment. Finally, NO2-exposed P. fluorescens strains were found to be more resistant to ciprofloxacin and chloramphenicol. Accordingly, the resistance nodulation cell division (RND MexEF-OprN efflux pump encoding genes were highly upregulated in the two P. fluorescens strains. Noticeably, similar phenotypes had been previously observed following a NO treatment. Interestingly, an hmp-homologue gene in P. fluorescens strains MFAF76a and MFN1032 encodes a NO dioxygenase that is involved in NO detoxification into nitrites. Its expression was upregulated in response to NO2, suggesting a possible common pathway between NO and NO2 detoxification. Taken

Equilibrium sorptive enrichment on poly(dimethylsiloxane) particles for trace analysis of volatile compounds in gaseous samples

NARCIS (Netherlands)

Baltussen, H.A.; David, F.; Sandra, P.J.F.; Janssen, J.G.M.; Cramers, C.A.M.G.

1999-01-01

A novel approach for sample enrichment, namely, equilibrium sorptive enrichment (ESE), is presented. A packed bed of sorption (or partitioning) material is used to enrich volatiles from gaseous samples. Normally, air sampling is stopped before breakthrough occurs, but this approach is not very

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

International Nuclear Information System (INIS)

Taha, Haider; Hammer, Hillel; Akbari, Hashem

2002-01-01

The study described in this report is part of a project sponsored by the Toronto Atmospheric Fund, performed at the Lawrence Berkeley National Laboratory, to assess the potential role of surface property modifications on energy, meteorology, and air quality in the Greater Toronto Area (GTA), Canada. Numerical models were used to establish the possible meteorological and ozone air-quality impacts of increased urban albedo and vegetative fraction, i.e., ''cool-city'' strategies that can mitigate the urban heat island (UHI), significantly reduce urban energy consumption, and improve thermal comfort, particularly during periods of hot weather in summer. Mitigation is even more important during critical heat wave periods with possible increased heat-related hospitalization and mortality. The evidence suggests that on an annual basis cool-city strategies are beneficial, and the implementation of such measures is currently being investigated in the U.S. and Canada. We simulated possible scenari os for urban heat-island mitigation in the GTA and investigated consequent meteorological changes, and also performed limited air-quality analysis to assess related impacts. The study was based on a combination of mesoscale meteorological modeling, Lagrangian (trajectory), and photochemical trajectory modeling to assess the potential meteorological and ozone air-quality impacts of cool-city strategies. As available air-quality and emissions data are incompatible with models currently in use at LBNL, our air-quality analysis was based on photochemical trajectory modeling. Because of questions as to the accuracy and appropriateness of this approach, in our opinion this aspect of the study can be improved in the future, and the air-quality results discussed in this report should be viewed as relatively qualitative. The MM5 meteorological model predicts a UHI in the order of 2 to 3 degrees C in locations of maxima, and about 1 degree C as a typical value over most of the urban area

Gaseous waste processing facility

International Nuclear Information System (INIS)

Konno, Masanobu; Uchiyama, Yoshio; Suzuki, Kunihiko; Kimura, Masahiro; Kawabe, Ken-ichi.

1992-01-01

Gaseous waste recombiners 'A' and 'B' are connected in series and three-way valves are disposed at the upstream and the downstream of the recombiners A and B, and bypass lines are disposed to the recombiners A and B, respectively. An opening/closing controller for the three-way valves is interlocked with a hydrogen densitometer disposed to a hydrogen injection line. Hydrogen gas and oxygen gas generated by radiolysis in the reactor are extracted from a main condenser and caused to flow into a gaseous waste processing system. Gaseous wastes are introduced together with overheated steams to the recombiner A upon injection of hydrogen. Both of the bypass lines of the recombiners A and B are closed, and recombining reaction for the increased hydrogen gas is processed by the recombiners A and B connected in series. In an operation mode not conducting hydrogen injection, it is passed through the bypass line of the recombiner A and processed by the recombiner B. With such procedures, the increase of gaseous wastes due to hydrogen injection can be coped with existent facilities. (I.N.)

Influence of Urban Microclimate on Air-Conditioning Energy Needs and Indoor Thermal Comfort in Houses

Directory of Open Access Journals (Sweden)

Feng-Chi Liao

2015-01-01

Full Text Available A long-term climate measurement was implemented in the third largest city of Taiwan, for the check of accuracy of morphing approach on generating the hourly data of urban local climate. Based on observed and morphed meteorological data, building energy simulation software EnergyPlus was used to simulate the cooling energy consumption of an air-conditioned typical flat and the thermal comfort level of a naturally ventilated typical flat. The simulated results were used to quantitatively discuss the effect of urban microclimate on the energy consumption as well as thermal comfort of residential buildings. The findings of this study can serve as a reference for city planning and energy management divisions to study urban sustainability strategies in the future.

The indicative effects of inefficient urban traffic flow on fuel cost and exhaust air pollutant emissions

CSIR Research Space (South Africa)

Moselakgomo, M

2015-07-01

Full Text Available Poor urban traffic management such as poor intersection controls, congestions, illegal roadway blockages and construction works causes “stop-go” driving conditions with excessive idling resulting in wasted fuel and increased air pollutant emissions...

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

Energy Technology Data Exchange (ETDEWEB)

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.

Characterization of process holdup material at the Portsmouth Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Boyd, D.E.; Miller, R.R.

1986-01-01

The cascade material balance area at the Portsmouth Gaseous Diffusion Plant is characterized by continuous, large, in-process inventories of gaseous uranium hexafluoride (UF 6 ) and very large inputs and outputs of UF 6 over a complete range of 235 U enrichments. Monthly inventories are conducted to quantify the in-place material, but the inventory techniques are blind to material not in the gas phase. Material is removed from the gas phase by any one of four mechanisms: (1) freeze-outs which are the solidification of UF 6 , (2) inleakage of wet air which produces solid uranium oxyfluorides, (3) consumption of uranium through UF 6 reaction with internal metal surfaces, and (4) adsorption of UF 6 on internal surfaces. This presentation describes efforts to better characterize and, where possible, to eliminate or reduce the effects of these mechanisms on material accountability. Freeze-outs and wet air deposits occur under absormal operating conditions, and techniques are available to prevent, detect and reverse them. Consumption and adsorption occur under normal operating conditions and are more complex to manage, however, computer models have been developed to quantify monthly the net effects due to consumption and adsorption. These models have shown that consumption and adsorption effects on inventory differences are significant

NUMERICAL ANALYSIS OF AN INVERSE PROBLEM ORIGINATED IN PHENOMENON OF POLLUTION AIR URBAN

Directory of Open Access Journals (Sweden)

Aníbal Coronel

2016-12-01

Full Text Available This paper presents the calibration study of a two - dimensional mathematical model for the problem of urban air pollution. It is mainly assumed that air pollution is afected by wind convection, diffusion and chemical reactions of pollutants. Consequently, a convection-diffusion-reaction equation is obtained as a direct problem. In the inverse problem, the determination of the diffusion is analyzed, assuming that one has an observation of the pollutants in a nite time. To solve it numerically the nite volume method is used, the least squares function is considered as cost function and the gradient is calculated with the sensitivity method.

Influence of cetane improvers on the air quality in an urban street canyon

International Nuclear Information System (INIS)

Huang, H.; Akutsu, Y.; Arai, M.; Tamura, M.

2000-01-01

The concentration distributions of NO x , PM, HC and CO in an urban street canyon have been estimated using a two-dimensional air quality numerical model based on the k-e turbulent model and the atmospheric convection diffusion equation when various cetane improvers were used in diesel fuels. A wind vortex can be found within the street canyon, and the pollutants emitted from the bottom of the street canyon tend to follow the course of the wind field, moving circularly. The addition of cetane improvers can improve the air quality in a street canyon, all of the pollutants were found to decrease with increasing cetane number. (Author)

An experimental evaluation on air purification performance of Clean-Air Heat Pump (CAHP) air cleaner

DEFF Research Database (Denmark)

Sheng, Ying; Fang, Lei; Sun, Yuexia

2018-01-01

was 96.8%, which indicated that the most of gaseous pollutants were not accumulated in the CAHP. The regeneration temperature for the wheel could affect the air purification performance of CAHP. At 70 °C of regeneration temperature, the air-cleaning efficiency reached 96.7%. Up to 70% of the outdoor air......The escalation of energy consumption in buildings and heightened concerns about acceptable indoor air quality stimulate interest in the usage of air cleaner as an adjunct for indoor environmental conditioning. A regenerative desiccant wheel integrated into a ventilation system termed Clean-Air Heat...... Pump (CAHP) can improve the air quality during the process of dehumidification without using additional energy. An experimental study in a field lab was performed to investigate the air cleaning performance of CAHP. Photoacoustic gas analyzer-INNOVA was used to characterize chemical removal of indoor...

Heavy metal contamination in an urban stream fed by contaminated air-conditioning and stormwater discharges.

Science.gov (United States)

O'Sullivan, Aisling; Wicke, Daniel; Cochrane, Tom

2012-03-01

Urban waterways are impacted by diffuse stormwater runoff, yet other discharges can unintentionally contaminate them. The Okeover stream in Christchurch, New Zealand, receives air-conditioning discharge, while its ephemeral reach relies on untreated stormwater flow. Despite rehabilitation efforts, the ecosystem is still highly disturbed. It was assumed that stormwater was the sole contamination source to the stream although water quality data were sparse. We therefore investigated its water and sediment quality and compared the data with appropriate ecotoxicological thresholds from all water sources. Concentrations of metals (Zn, Cu and Pb) in stream baseflow, stormwater runoff, air-conditioning discharge and stream-bed sediments were quantified along with flow regimes to ascertain annual contaminant loads. Metals were analysed by ICP-MS following accredited techniques. Zn, Cu and Pb concentrations from stormflow exceeded relevant guidelines for the protection of 90% of aquatic species by 18-, 9- and 5-fold, respectively, suggesting substantial ecotoxicity potential. Sporadic copper (Cu) inputs from roof runoff exceeded these levels up to 3,200-fold at >4,000 μg L⁻¹ while Cu in baseflow from air-conditioning inputs exceeded them 5.4-fold. There was an 11-fold greater annual Cu load to the stream from air-conditioning discharge compared to stormwater runoff. Most Zn and Cu were dissolved species possibly enhancing metal bioavailability. Elevated metal concentrations were also found throughout the stream sediments. Environmental investigations revealed unsuspected contamination from air-conditioning discharge that contributed greater Cu annual loads to an urban stream compared to stormwater inputs. This discovery helped reassess treatment strategies for regaining ecological integrity in the ecosystem.

Radiological air quality in a depleted uranium (DU) storage vault

International Nuclear Information System (INIS)

Robinson, T.; Cucchiara, A.L.

1999-01-01

The radiological air quality of two storage vaults, one with depleted uranium (DU) and one without, was evaluated and compared. The intent of the study was to determine if the presence of stored DU would significantly contribute to the gaseous/airborne radiation level compared to natural background. Both vaults are constructed out of concrete and are dimensionally similar. The vaults are located on the first floor of the same building. Neither vault has air supply or air exhaust. The doors to both vaults remained closed during the evaluation period, except for brief and infrequent access by the operational group. One vault contained 700 KG of depleted uranium, and the other vault contained documents inside of file cabinets. Radon detectors and giraffe air samplers were used to gather data on the quantity of gaseous/airborne radionuclides in both vaults. The results of this study indicated that there was no significant difference in the quantity of gaseous/airborne radionuclides in the two vaults. This paper gives a discussion of the effects of the stored DU on the air quality, and poses several theories supporting the results

Problems of protection of urban ambient air pollution from industrial dust emissions

Directory of Open Access Journals (Sweden)

Azarov Valeriy

2017-01-01

Full Text Available The development of large cities accompanied by the development of the industry hashistorically led to the fact that now residential areas are located side by side with the industrial production. For instance, exactly this situation has developed in the city of Volgograd, as well as in other Russian cities, where sometimes the distance from large enterprises to a living area is 100 m or less. In addition, small-scale entrepreneurs usually place their production directly in their past places of residence. As a result, the content of harmful substances in the air of city blocks is much higher than the standards of hygiene require. It is obvious that the current situation can be improved through the use of modern, more advanced technologies. However, increasing the efficiency of air systems to protect the city from pollution and industrial emissions is an urgent task. The authors propose a version of the system layout, designed to reduce dust emissions in urban air.

Addressing equity in interventions to reduce air pollution in urban areas: a systematic review.

Science.gov (United States)

Benmarhnia, Tarik; Rey, Lynda; Cartier, Yuri; Clary, Christelle M; Deguen, Séverine; Brousselle, Astrid

2014-12-01

We did a systematic review to assess quantitative studies investigating the association between interventions aiming to reduce air pollution, health benefits and equity effects. Three databases were searched for studies investigating the association between evaluated interventions aiming to reduce air pollution and heath-related benefits. We designed a two-stage selection process to judge how equity was assessed and we systematically determined if there was a heterogeneous effect of the intervention between subgroups or subareas. Of 145 identified articles, 54 were reviewed in-depth with eight satisfying the inclusion criteria. This systematic review showed that interventions aiming to reduce air pollution in urban areas have a positive impact on air quality and on mortality rates, but the documented effect on equity is less straightforward. Integration of equity in evidence-based public health is a great challenge nowadays. In this review we draw attention to the importance of considering equity in air pollution interventions. We also propose further methodological and theoretical challenges when assessing equity in interventions to reduce air pollution and we present opportunities to develop this research area.

RECOMMENDED OPERATING PROCEDURE NO. 56: COLLECTION OF GASEOUS GRAB SAMPLES FROM COMBUSTION SOURCES FOR NITROUS OXIDE MEASUREMENT

Science.gov (United States)

The document is a recommended operating procedure, prepare or use in research activities conducted by EPA's Air and Energy Engineering Research Laboratory (AEERL). The procedure applies to the collection of gaseous grab samples from fossil fuel combustion sources for subsequent a...

Laser-Excited Luminescent Tracers for Planar Concentration Measurements in Gaseous Jets

Science.gov (United States)

Lozano, Antonio

Tracers currently used in planar laser-induced fluorescence concentration measurements are not ideal for some experimental conditions, e.g., non-reacting turbulent gaseous flows at standard temperature and pressure. In this work, a number of chemicals have been evaluated, through consideration of their physical and photophysical properties, for use as luminescent concentration markers in turbulent gaseous flows. Two selected substances, biacetyl and acetone, have been studied in more detail. Acetone PLIF concentration images have been acquired in a non-reacting air jet, and the results have been compared to similar images obtained seeding with biacetyl. Acetone has proven to be a superior tracer when imaging fluorescence emission. Acetone has also been used as a fuel marker in hydrogen and methane diffusion flames. This single -laser technique enables simultaneous recording of the acetone and OH fluorescence emissions, as well as Mie scattering from ambient air dust particles. Acetone-sensitized, collisionally-induced biacetyl phosphorescence has been used to visualize molecular mixing in gaseous flows. Initial attempts to produce quantitative results with this method through simultaneous imaging of acetone fluorescence and collisionally-induced biacetyl emission, are described. Using laser-induced biacetyl phosphorescence imaging, a data set of cross-cut concentration images has been acquired in a nitrogen coflowing jet (Re = 5,000). The images have been statistically analyzed. Very simple models of the instantaneous concentration profile have been compared to the experimental data. Of all the tested models, a paraboloid has resulted to be the best approximation to the instantaneous 2-D profile. Finally, an experiment to study jet mixing in crossflow using acetone PLIF imaging has been designed. The flow facility has been constructed, and preliminary images obtained with a high quantum efficiency, thinned CCD detector have revealed the presence of jet structures

Background air pollution studies in urban and rural areas in Bangladesh. Appendix 3

International Nuclear Information System (INIS)

Khaliquzzaman, M.; Biswas, S.K.; Tarafdar, S.A.; Islam, A.; Khan, A.H.

1995-01-01

Air particulate matter at two size fractions have been collected at an urban station (Dhaka) in Bangladesh for one year using a 'Gent' PM-10 stacked filter unit (SFU). Of the samples collected, 73 sets of samples (coarse and fine fractions) extending over a period of six months have been analyzed to find elemental concentrations using PIXE. These results of the analyses are presented and discussed. (author)

Ambient air pollution and thrombosis.

Science.gov (United States)

Robertson, Sarah; Miller, Mark R

2018-01-03

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

Three-Dimensional Mapping of Air Flow at an Urban Canyon Intersection

Science.gov (United States)

Carpentieri, Matteo; Robins, Alan G.; Baldi, Sandro

2009-11-01

In this experimental work both qualitative (flow visualisation) and quantitative (laser Doppler anemometry) methods were applied in a wind tunnel in order to describe the complex three-dimensional flow field in a real environment (a street canyon intersection). The main aim was an examination of the mean flow, turbulence and flow pathlines characterising a complex three-dimensional urban location. The experiments highlighted the complexity of the observed flows, particularly in the upwind region of the intersection. In this complex and realistic situation some details of the upwind flow, such as the presence of two tall towers, play an important role in defining the flow field within the intersection, particularly at roof level. This effect is likely to have a strong influence on the mass exchange mechanism between the canopy flow and the air aloft, and therefore the distribution of pollutants. This strong interaction between the flows inside and outside the urban canopy is currently neglected in most state-of-the-art local scale dispersion models.

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

Science.gov (United States)

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