Air pollutant concentrations

About: Air pollutant concentrations is a research topic. Over the lifetime, 1652 publications have been published within this topic receiving 36138 citations.

Assessment of Air Quality in Commercial Places of Chennai through Air Quality Index

Abstract: Air quality indices are used for local and regional air quality management in many metro cities of the world. The present investigation was carried out to find the significance of air pollutant concentrations at commercial areas of Chennai. Suspended Particulate Matter (SPM), Respirable Suspended Particulate Matter (RSPM), Sulphur dioxide (SO2) and Oxides of nitrogen (NOX) were analyzed over two sites namely T.Nagar and Kilpauk in Chennai. Both the sampling stations selected are located in commercial areas. Several concepts and indicators exist to measure and rank the urban areas in terms of their socio-economic infrastructure and environment related parameters. In this paper an air quality index (AQI) considering the combined level of three criteria pollutants (oxides of nitrogen, sulphur dioxide, and Respirable suspended particulate matter ) is proposed.

Variational Trend and Characteristics of Air Pollution in Baoding City

Abstract: To understand the trends and characteristics of air pollution in Baoding in recent years, an analysis of air quality and air pollutant concentrations in Baoding from 2013 to 2018 was carried out. The results showed that: 1 from 2013 to 2018, the comprehensive index of Baoding dropped from 11.6 to 6.6, the days of severe pollution decreased from 114 days to 27 days, and cumulative concentration of pollutants during severe pollution decreased from 57.34% to 20.59%. This indicated that the air quality of Baoding city has improved year on year from 2013 to 2018. Not only has the number of heavy pollution days and the annual average concentration of pollutants decreased, but also the proportion of cumulative concentrations of pollutants during heavy pollution has decreased. the difference between the average concentration level of Baoding city and "2+26" Cities is getting smaller and smaller. ② Summer ρ(O3-8h) increased year on year. In 2017 and 2018, the heavy pollution days caused by O3 accounted for 17.0% and 14.8% of the heavy pollution days of the year, respectively, and the ozone pollution gradually became prominent; the characteristic value of NO2 in autumn was higher than that of SO2, CO, PM2.5, and PM10, indicating that the type of pollution in autumn was more motorized. The sources of pollution in winter changed from the partial combustion of coal in 2013-2014 to a mixed influence of partial combustion of coal and incomplete combustion in 2015-2018. ③ In 2016, 2017, and 2018, a high cumulative concentrations of PM2.5 during the high pollution season that accounted for 5.56%, 6.21%, and 2.58% declined as compared to that during the same period in 2015; this was the largest decline among the six pollutants; PM10 followed; The decreases of SO2 and NO2 were small, indicating that the emergency measures were better in cutting peaks of particulate matter than the gaseous pollutants during heavy pollution in Baoding. In a heavy pollution event during the high pollution season in 2018, partial-burning coal-type pollution increased as compared to that during the high pollution season in 2017, indicating that the coal combustion was still one of the pollution sources that Baoding city needed to control. In summary, Baoding should strengthen the management and control of motor vehicles in autumn, and gradually change from the original coal control measures to a combination of coal control and diesel control in winter; in the future, the focus of air pollution prevention and control should be strengthened toward O3 pollution.

Methodology and Guidelines for Regulating Traffic Flows under Air Quality Constraints in Metropolitan Areas

Abstract: This project developed a methodology to couple a new pollutant dispersion model with a traffic assignment process to contain air pollution while maximizing mobility. The overall objective of the air quality modeling part of the project is to develop a model to predict the air quality at receptor sites in metropolitan areas using traffic data from a coupled traffic model and real time meteorological data. Most of the air dispersion models in use do not have a full description of the physical and chemical processes to describe the formation and transformation of pollutants in the metropolitan areas relating to traffic flow and thus cannot provide complete information that is necessary in traffic planning and regulating. The reactive dispersion air quality model developed in this project includes a state-of-the-art gas chemistry mechanism (Statewide Air Pollution Research Center, or SAPRC, model) to predict the ozone, NOx, CO, benzene, acetaldehyde, formaldehyde and 1,3-butadiene concentrations, and a complete particulate matter module with thermal dynamics to predict the concentrations of primary and secondary particulate pollutants including diesel particulate matter. With the air quality model developed in this project, traffic assignments can be conducted taking air quality into account. The air quality can be considered as a form of constraint that limits the pollutants under certain acceptable levels in parts of the transportation network. This consideration will be an added constraint in addition to the roadway segment capacity constraint in the assignment process. The air quality can also be considered as an additional objective function while assigning traffic flow in the metropolitan transportation network.

Traffic-related Environmental Impact Mapping In Downtown Amsterdam

Abstract: Traffic-related environmental impact mapping includes an inventory of all downtown city streets known to have a traffic density surpassing a maximum number of cars per day. The environmental components to be taken into account are carbon monoxide, nitrogen dioxide and benzene as air pollutants, on the one hand, and the noise nuisance level on the other. The impact mapping has been done by applying the CAR-model for the calculation of air pollutant concentrations and the Standard Calculus I-model for the calculation of the noise levels involved. Both models have been extensively validated and are mandatory under Dutch law. The models are able to forecast an average air pollutant and noise nuisance level which is valid for a street trajectory with an average length of 200 meters. Comparison of calculated values with standard values results in a map of street trajectories where ambient air quality and noise level standards will be exceeded. The results of the study in downtown Amsterdam demonstrate that the ambient air quality standards for both carbon monoxide and nitrogen dioxide were exceeded for a total street length of 27 and 49 kilometers, respectively in 1987. For noise, the total length of street trajectories not in compliance with the standard to be observed was 240 kilometers in that year. Starting from the position that no environmental quality standard may be exceeded, the models are able to calculate to what extent traffic flow density must be restricted in the future in the various street trajectories concerned. The environmental impact map thus obtained for the year 2000 may be designated as the Standard Alternative Traffic Flow Pattern Map. It is shown that the ambient air quality standard for carbon monoxide will not be exceeded in 2000 at all because of an improved automotive exhaust quality. Transactions on Ecology and the Environment vol 3, © 1994 WIT Press, www.witpress.com, ISSN 1743-3541 386 Computer Simulation In order to avoid any further standard violations for benzene and nitrogen dioxide, traffic flow should be curtailed by at most 50% over a total street length of 27 kilometers. For noise, a reduction in traffic flow of at most 75% has to be achieved over a total street length of nearly 180 kilometers. It can be concluded that noise nuisance is the critical factor in the design of traffic flow density limitations in downtown Amsterdam.

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.