Assessment of Atmospheric Particles in Urban Areas of Khulna

Abstract

Urban air pollution has been an increasing concern for developing countries due to rapid industrialization, urbanization and energy production. In Bangladesh, particulate matter (PM) pollution is more severe than gaseous pollution. The overall objective of this study is to assess the air pollution with respect to atmospheric particles in urban areas of Khulna. In this study, analysis of the seasonal variation of atmospheric particles with meteorological parameters was conducted by using different statistical methods. Also measurement of the mass concentration by HANDHELD 3016 IAQ laser particle counter and analyze the size distribution of atmospheric particles were performed. By using HYSPLIT-4 model, it was also calculated the long range transport of PM. From the analysis of monitoring data collected from CAMS-5, Khulna from February 2013 to January 2014, a significant variation was found in seasonal average of PM10 and PM2.5 mass concentrations with maximum in winter, reaching 297 μg/m3 and 168 μg/m3, respectively whereas minimum in monsoon, reaching 73 μg/m3 and 31 μg/m3, respectively. In addition, the average PM2.5/PM10 value was 50% and ranged between 42%–61% again proving that fine particles are the main issue for PM pollution in Khulna City. The PM concentrations were found higher in sites (measured in dry season) than in sites (measured in wet season). The comparison between different sizes particle fractions showed the significant contribution of fine particles (Dp < 2.5μm) to PM10 was 49-88%. The highest abundance in the range of aerodynamic diameter from 3.75 to 7.5μm was found for Sonadanga Bus Stand, Ship Yard Rupsa, Nagarbavan, Fulbarigate and Rupsa Bridge sites and from 0.4 to 1.75μm for Nirala R/A and KUET Campus sites. For the Rupsa Bridge site, the maximum average MMAD was found than other sites indicating coarse particles dominated in this site. Backward trajectory of transboundary air pollutants showed that the pollutants resolutely cross the boundary line of Bangladesh and influence of transboundary traveling of PM concentrations was considerable. The outcomes of this study may assist the development of improved particle monitoring programs and also establish an elemental modality dataset which can be incorporated in the exposure and health risk assessments of atmospheric particles.