Showing papers on "Air pollutant concentrations published in 2004"

Emissions of Air Pollutants

Abstract: Well founded and reliable emission data are necessary to implement strategies to investigate and control air pollution caused by the transport and chemical transformation of air pollutants. This book contains a wealth of new information that enables environmental scientists and authorities dealing with air pollution to design methods for measuring and modelling emission rates related to specific pollution sources, and thus to generate improved emission inventories and reduction strategies. Furthermore, it provides information for policy makers and environmental stakeholders concerning the main sources of emissions and the uncertainties of emission data. Scientists will obtain the know-how to carry out experiments to verify emission data, including tunnel and open motorway studies, comprehensive city experiments and tracer experiments. Readers interested in policy applications have access here to valuable information about the sources of air pollutants.

Air pollution and cardiac arrhythmias in patients with implantable cardioverter defibrillators.

Abstract: Epidemiological studies have demonstrated associations between short-term increases in outdoor air pollution concentrations and adverse cardiovascular effects, including cardiac mortality and hospitalizations One possible mechanism behind this association is that air pollution exposure increases the risk of developing a cardiac arrhythmia To investigate this hypothesis, dates of implantable cardioverter defibrillator (ICD) discharges were abstracted from patient records in patients attending the two ICD clinics in Vancouver, BC, for the years 1997–2000 Daily outdoor air pollutant concentrations and daily meteorological data from the Vancouver region were obtained for the same 4-yr period Generalized estimating equations were used to assess the association between short-term increases in air pollutant concentrations and ICD discharges while controlling for temporal trends, meteorology, and serial correlation in the data Air pollution concentrations in the Vancouver region were relatively low from 1997

Air pollution: from sources of emissions to health effects

Abstract: Key points Immissions (=concentration of air pollutants in the ambient atmosphere) result from the intensity and the type of emissions of air pollutants, the dispersion of air pollutants and their transportation. The main air pollution indicators are SO 2 , NO x , PM, CO, VOC and O 3 . Road traffic has become the first source of air pollution in urban areas. Health effects caused by air pollutants depend on the absorbed dose, the type of pollutants and the individual susceptibility. Educational aims To provide a thorough presentation of sources, dispersion and transformation of major air pollutants. To describe the health effects of these air pollutants. To explain the differences between emissions, immissions, exposure and absorbed dose. To help readers to understand what is at stake in the topical scientific and political debate on air pollution. Summary Air pollution, particularly in urban areas, constitutes a public health concern, as it has a harmful effect on the health, survival and activities of humans and other living organisms. Here, the main types of air pollution commonly found in urban environments are presented, along with their sources, levels of emissions, mechanisms of dispersion, transformation, concentrations in ambient air (=immissions), and effects on the environment and health. In particular, the concepts of exposure, absorbed dose and individual susceptibility are explained. The recent evolution in air pollutant emissions and immissions due to the growing weight of road traffic is also described. Finally, European air quality criteria are highlighted.

Traffic-related air pollutants: self-reported traffic intensity versus gis modelled exposure

Abstract: BACKGROUND In epidemiological studies of the potential health effects of traffic related air pollution, self reported traffic intensity is a commonly used, but rarely validated, exposure variable. METHODS As part of a study on the impact of Traffic Related Air Pollution on Childhood Asthma (TRAPCA), data from 2633 and 673 infants from the Dutch and the German-Munich cohorts, respectively, were available. Parents subjectively assessed traffic intensity at the home address. Objective exposures were estimated by a combination of spatial air pollution measurements and geographic information system (GIS) based modelling using an identical method for both cohorts. RESULTS The agreement rates between self reported and GIS modelled exposure--accumulated over the three strata of self assessed traffic intensity--were 55-58% for PM(2.5), filter absorbance (PM(2.5) abs), and nitrogen dioxide in Munich and 39-40% in the Netherlands. Of the self reported low traffic exposed group, 71-73% in Munich and 45-47% in the Netherlands had low modelled exposure to these three air pollutants. Of the self assessed high exposed subgroups in Munich (15% of the total population) and the Netherlands (22% of the total population), only 22-33% and 30-32% respectively had high modelled exposure to the three air pollutants. The subjective assessments tend to overestimate the modelled estimates for PM(2.5) and NO2 in both study areas. When analysis was restricted to the portion of the Dutch cohort living in non-urban areas, the agreement rates were even lower. CONCLUSIONS Self reported and modelled assessment of exposure to air pollutants are only weakly associated.

Comparison of air pollutant concentrations between weekdays and weekends in Athens, Greece for various meteorological conditions.

Abstract: The objective of the present study is to contribute to the understanding of the "ozone weekend effect" as it occurs in the Greater Area of Athens, Greece both in the summer and wintertime. Therefore, weekly cycles of CO, NO and O3 concentrations for the 18-year-period 1983-2000 are studied. Each day of the week is considered separately, while sites with different levels of primary pollutants are examined. The reduction of the meteorological influence in the O3 mechanisms is achieved by applying meteorological classifications. The analysis for the cold period reveals that CO and NO display decreasing concentrations from weekdays to weekends, whereas O3 shows increasing concentrations. During the warm period, although primary pollutants display decreased concentrations compared to the cold period, their weekly cycles remain the same. On the other hand, meteorological changes affect the weekly cycle of ozone peaks. During days with unfavourable meteorology to ozone production, weekend ozone concentrations ar...

Air quality model simulating photochemical formation of pollutants: the Sao Paulo Metropolitan Area, Brazil

Abstract: The main sources of ozone precursors in the atmosphere of the Sao Paulo Metropolitan Area (SPMA) in Brazil are emissions from gasoline-, ethanol-, and diesel-powered vehicles. Ozone is a significant air quality problem in the SPMA. To come into compliance with the National Ambient Air quality Standard for Ozone, emission reduction policies must be established. An adequate emissions inventory and a description of the meteorology and chemistry involved are needed in order to evaluate the effectiveness of methodologies that reduce the effect of vehicle emissions on ozone formation. During the period 10–12 August 1999, concentrations of ozone in the SPMA and the impact of the official emissions inventory were simulated through application of an urban-scale Eulerian model. We found that using the official inventory in simulations resulted in ozone values much lower than those observed and nitrogen oxide emission profiles that were overestimated by a factor of approximately two.

Design of an environmental assessment model on the effect of vehicle emission in greater Tehran on air pollution with economic sensitivity

Abstract: Air pollution is the presence of pollutants in the atmosphere from anthropogenic or natural substances in quantities likely to harm human, plant or animal life; to damage human-made materials and structures; to bring about changes in weather or climate; or to interfere with enjoyment of life or property. With regard to the quality of air in most of the megacities of the world, vehicular air pollution plays an important role in deteriorating air quality. Air pollution in Tehran (Capital of the Islamic Republic of Iran) occurs in highly urbanized areas due to mobile anthropogenic sources which in-turn is hastened by unfavorable tohion sector is responsible for much of urban air pollution and can result in high ambient concentrations that harm people, structures, and environment. This paper examines and estimates the tonnage, concentrations and impacts of air pollutants along with control measures aimed at reducing the effect of pollutants released by transportation navigation, in Tehran.

Indoor Air Quality Guidelines and Standards - A State of the Art Review

Abstract: It is only fairly recently that scientific and public concerns have focused on the probable health risk that the presence of air pollutants can cause in residential or non-industrial buildings. Several reasons have contributed to the deterioration of indoor air quality (IAQ) including some aspects of trends in the construction sector, most important of which are the design of buildings with increased air tightness for the sake of energy conservation but also the use of innovative building materials based on complex synthetic chemical substances. The degradation of indoor microenvironments and the realization of the possible risks that may occur due to the combination of anthropogenic indoor activities and of long term exposure, even to low air pollutant concentrations, activated the scientific community and the involved organisations to face the IAQ problem. The development and application of IAQ guidelines and standards are the result of these efforts. After several regressions, the world communi...

Monitoring of air pollution in Indian metropolitan cities: modelling and quality indexing

Abstract: Air quality in cities is the result of a complex interaction between natural and anthropogenic environmental conditions. Delhi, as well as many other cities in India, is facing problems concerning air pollution. The increase in industrialisation and the vehicle fleet, poor control on emissions and little use of catalytic converters, produce a great amount of particulate and toxic gases. Data on air pollutants and meteorological variables were collected in the metropolitan cities Delhi, Kolkata, Mumbai and Chennai for the period July–August, 2001. Data were treated with the bivariate regression model to explore the influence of the meteorological variables on air pollutant concentrations, and were also used to compute an Air Quality Index, using the weighted arithmetic mean method. The proposed index seems to be applicable in the assessment of overall air quality with respect to air pollutants.

Heterogeneity of daily pulmonary function in response to air pollution among asthmatic children.

Abstract: Several epidemiological studies have demonstrated the association of short-term exposure to air pollution with transient declines in pulmonary function. Although the magnitudes of declines in pulmonary function found in these studies are relatively small, the effects vary among children. This study examined whether the variation is evidence of biological heterogeneity or due to random varia- tion by analyzing data from a panel study of 83 asthmatic school children exposed to SO 2 and PM 10 in the Mae Moh district of Thailand. Daily pulmonary function testing was performed on the children for 61 days. General linear mixed models were used to examine and test for the null hypothesis of no variation in the subject-specific slopes of pulmonary functions in response to the air pollutants. The individual daily pulmonary functions measured were FVC, FEV1, PEFR, and FEF 25-75% . These were used as an outcome to compare with air pollutant concentrations as random effects, adjusting for height, gender, time, and temperature. The results indicate evidence of inter-individual variation for subject-specific changes in FVC, FEV 1 , and PEFR due to the effects of SO 2 and PM 10 on children. In conclusion, even at low concentrations of daily SO 2 and PM 10 in the study area, there is evidence of a heterogeneous response to short-term exposure to SO 2 and PM 10 in children.

Air pollution and the influence of sources on Paulínia (Brazil) and surroundings

Abstract: The air quality in the industrial area and surroundings of the city of Paulinia (state of Sao Paulo, Brazil) has been investigated by analysing the concentration of air pollutants (SO2, PM10, NO, NO2, CO and ozone) and identifying the main sources of air pollution. A mobile pollutant monitoring unit was used to collect the data at five different sites from November 2000 to July 2002. Critical pollutants were determined based on air quality standards, and sources were identified by principal component analysis. Photochemical reactions play an important role in Paulinia's air pollution: three out of five monitored sites showed levels exceeding the standard air quality of ozone. SO2 and PM10 appeared as pollutants deserving special attention. All the monitored sites showed vehicles and industrial plants (which release SO2) to be significant sources of pollution. Depending on the location, ozone was related mainly with vehicular or industrial sources.

A Dynamic Air Pollution Prediction System ForCape Town, South Africa

Abstract: The objective of the Dynamic Air Pollution Prediction System (DAPPS) is to combine a meteorological forecast model and a photochemical dispersion model to predict the ambient concentration of selected pollutants. The Penn State/UCAR MM5 mesoscale model, nested to 1.7 km, is used to predict gridded 12 hour, 24 hour and 36 hour meteorological fields. A comprehensive emission data base comprises emissions from industry, petrol and diesel powered motor vehicles and domestic wood and paraffin burning. It includes information on their physical and chemical characteristics, together with their spatial attributes and temporal variations. Emissions data and forecast meteorological data are input to the Comprehensive Air Quality Model with Extensions (CAMx) to estimate air pollutant concentrations over the metropolitan area for the following day. The forecast information is conveyed to the users by means of an Air Pollution Index (API), based on health risk of exposure to individual pollutants and combinations of pollutants via a web site and in other forms of media. A Haze Index (HI) is used to convey forecast visibility degradation or atmospheric haze, based on the concentrations of haze precursors at various levels in the near surface layer. DAPPS is being piloted in the City of Cape Town.

Screening and scenarios of traffic emissions at Trier, Germany.

Abstract: In the course of the European Council Directive on permissible air pollutant limit values, valid starting from 2005 there is an urgent call for action, particularly for fine dust (PM10). Current investigations (Junk & Helbig 2003, Reuter & Baumuller 2003) show that the limit values in certain places in congested areas are exceeded. Only if it is possible to locate these Hot Spots purposeful measures to reduce the ambient air pollution can be conducted. For an efficient identification of these Hot Spots numerical computer models or establishing special measurements networks are too expensive. Using the statistical model STREET 5.0 (KTT 2003) a cost-effective screening of the air pollution situation caused by the traffic can be done. STREET is based on the 3-dimensional micro-scale non-hydrostatic flow- and dispersion model MISCAM (Eichhorn 1989). The results of over 100.000 different calculations with MISCAM are stored in a Database and used to calculate the emissions with STREET. In collaboration with the city council of Trier more than 150 streets were investigated, mapped, and calculated. A special urban climate measuring network supplies the necessary meteorological input data about the wind field and precipitation events in the valley of the Moselle. Information about road width and road orientation as well as building density was derived from aerial photographs. Traffic censuses and mobile air pollutants measurements supplied the remaining input data. We calculated the mean annual air pollutant concentrations for NO2, CO, SO2, O3, benzene as well as PM10-. A comparison of the model results with the values obtained from the stations of the central emission measuring network of Rhineland-Palatinate (ZIMEN, annual report 2002) shows very good agreements. The model was not only used to calculate the annual air pollutant but also for urban planning and management. The absolute level of the air pollutant is mainly dependent on the amount of traffic in the street canyons. Therefore four different case-scenarios with varying quantity of traffic were calculated and interpreted for each street. The results of the calculation show that on the basis of the mean values for both NO2 and benzene, it is not to be expected that the limits will be exceeded significantly. Furthermore the model can be used to find the maximum tolerable numbers of cars for a street without exceeding the air pollutant thresholds.

Air Quality and Pollution Control

Abstract: The Engineer’s Joint Council on Air Pollution and Its Control defines air pollution as “the presence in the outdoor atmosphere of one or more contaminants, such as dust, fumes, gas, mist, odor, smoke or vapor in quantities, of characteristics, and of duration, such as to be injurious to human, plant, or property, or which unreasonably interferes with the comfortable enjoyment of life and property.”

Reducing Urban Pollution Exposure from Road Transport (RUPERT)

Abstract: This paper presents the preliminary results of a two-year study on reducing urban pollution exposure from road transport (RUPERT). The main aim of this project is to develop a new modelling framework for nitrogen dioxide, carbon monoxide and particulate matter to simulate exposures of different population groups across a city, and to assess the impact of roadside concentrations on these exposures. This will be achieved by modelling the frequency distribution of personal exposures (PEFDs) as a function of urban background and roadside concentrations, under different traffic conditions. The modelling approach combines new and existing models relating traffic and air pollution data, with particular emphasis of the impact of congestion, and the probabilistic modelling framework of personal exposure. Modelling of roadside concentrations consists of two main elements, namely the analysis of concentrations patterns at different roadside sites and of the relationship between traffic conditions and added roadside pollution. Roadside concentrations are predicted using empirically derived relationships; statistical models, novel statistics and artificial neural networks namely feed forward neural network and radial basis neural network. The exposure modelling is carried out by linking two models: the INDAIR model, which is designed to simulate probabilistically diurnal profiles of air pollutant concentrations in a range of microenvironments, and the EXPAIR model, which is designed to simulate population exposure patterns based on population time-activity patterns and a library of micro-environmental concentrations derived from the INDAIR model.

Control of Hazardous Air Pollution

Abstract: This article begins with an overview of ecosystem and human health impacts of hazardous air pollutants (HAPs) and is followed by a synopsis of the early efforts to control HAPs that were based on common law and the Clean Air Act (CAA) prior to 1990. In the CAA Amendments of 1990 Congress added a twenty-fold expansion of the statutory provisions aimed at the control of HAPs . In the decade that followed the Environmental Protection Agency (EPA) has generated thousands of pages of rules and guidance to implement the 1990 statutory changes. This article provides an analysis of these requirements and the program created to implement them. Several categories of HAPs are the subject of a more in depth analysis including asbestos, synthetic organic chemicals, and emissions from incineration. The article then examines the requirements aimed at preventing accidental catastrophic environmental releases of HAPs and the risk management plans that must be developed by about 70,000 facilities that handle regulated chemicals. The emergency planning and reporting requirements imposed in 1986 by the Emergency Planning and Community Right to Know Act (EPCRA) also are addressed.

Human health implications of air pollution emissions from transport

Abstract: While greenhouse gases have little direct effect on human health, there is ample evidence that other pollutants generated by combustion can have very significant effects on the health of human populations. This paper examines the contribution of the various surface transport options to emissions of locally acting air pollutants and it also reviews the evidence that those pollutants are having an impact on public health. Specific studies of the health effects of living in close proximity to major roads are also considered.

Estimation of Emission Strength and Air Pollutant Concentrations by Lagrangian Particle Modeling

Abstract: Air quality modeling integrates the knowledge of how physical and chemical processes affect pollutants in the atmosphere. One category of air quality modeling is Lagrangian particle modeling that has been widely applied to pollutant dispersion in the atmospheric boundary layer (ABL). It treats the migration of a pollutant as a random process and accounts for extensive details of atmospheric turbulence and meteorology. The motivation of this thesis is the importance of applying this modeling technique as a tool to estimating emission strength and pollutant concentrations using data from direct measurement. The main theme of the thesis deals with the development and application of a Lagrangian particle model (LPM) to estimating emission strength and air pollutant concentrations specifically for the short-range dispersion of an air pollutant in the ABL. The model performance was evaluated with two experimental data sets: one obtained from the Rubbertown field study and the other from the Project Prairie Grass (PPG) experiments. Satisfactory agreement was found between model predictions and PPG data, and the LPM was used as the platform of parametric uncertainty analysis. Uncertainty in model formulation, resolution, and parameters typically exist and are of importance because such uncertainty can considerably affect model results. In this thesis, effects of uncertainties in five parameters (Monin-Obukhov length, friction velocity, roughness height, mixing height, and the universal constant of the random component) of the LPM on mean ground-level concentrations were examined under slightly and moderately stable conditions. The analysis was performed under a probabilistic

Changes in daily air pollution and mortality in Perth : a case crossover study

Abstract: The monitoring of the common air pollutants in Perth has shown that concentrations exceed national standards for particles and photochemical oxidants (measured as ozone [O3]) on occasions in winter and summer respectively. By contrast, concentrations of sulphur dioxide (SO2), nitrogen dioxide (NO2) and carbon monoxide (CO) are all below national standards. In this study, a time stratified case crossover design was used to investigate the relationship between changes in daily air pollutant concentrations and mortality in Perth. The data were analysed using conditional logistic regression to produce odds ratios. Mortality data were categorised into cardiovascular disease, respiratory disease, and 'other mortality' and were obtained for the period 1992 through 1998. Network air quality data and meteorological data were obtained for the same period. The results showed significant relationships between cardiovascular mortality and NO2 and O3 concentrations. Increased odds ratios were also observed for O3 concentrations and respiratory mortality, however, only for the 8-hour O3 concentration was the increase statistically significant. A significant odds ratio was also observed for changes in CO concentrations and 'other mortality'. The data support the findings of other Australian and international studies and will assist in the evaluation of strategies designed to reduce air pollution in Perth.