Evaluation of Ambient Air Particulate Matter (PM) Concentration in Urban Context and its Public Perception

Abstract

Urban air pollution has become a global issue and vehicle emissions, rapid industrialization, and urbanization are known to be the main contributing factors for air pollution. Therefore, air quality monitoring is essential for detecting air pollution levels mainly in urban areas. Among the main air pollutants, particulate matters (PM) play major roles as an urban air pollutant. The objectives of this research study were (a) to evaluate and compare the PM concentration on ambient air in selected locations in Colombo urban area (b) to calculate air quality index (AQI) to identify the pollutant levels of ambient air in selected study sites and (c) to identify the public perception and awareness regarding the PM-related air pollution. In this research, ambient PM concentrations were measured by ambient fine dust air sampling techniques in selected locations in Colombo urban area representing commercial, construction, and residential sites. Evaluation and comparison of PM concentration and questionnaire survey were analyzed by using suitable statistical approaches and softwares. Results of the study indicated that residential areas having significantly low PM concentrations while both commercial and construction areas having high PM concentrations. The highest PM2.5 concentration was 101.08 μɡ/m3 and it was recorded in Maradana area which came under the commercial category. The lowest PM concentration was recorded in Kotte representing the residential area. There was no any significant difference of PM concentration between commercial and construction sites mainly including Borella, Maradana, Peliyagoda areas. In addition, there was a significant difference between PM concentrations of selected commercial and residential areas and construction and residential areas. PM2.5 concentrations were varied into the range of 17.23 - 101.08 ɥɡ/m3 in commercial and construction areas and 5.68- 26.08 ɥɡ/m3 in residential areas. Calculated AQI by using mean PM concentration values in air sampling locations indicated that commercial and construction areas with moderate air quality level under the AQI category of 51-100 and residential areas with good air quality level under the AQI category of 0-51.