Characteristics Seasonality Spatial Variation and Source Apportionment of Carbonaceous Ionic and Metal Components in Fine Aerosols

Abstract

Fine particles or aerosols (PM2.5) are ubiquitous component of atmosphere and have a complex chemical composition. PM2.5, in particular, is among the criteria air pollutants defined by national and international agencies. The levels of PM2.5 in ambient air are typically influenced by different sources, site characteristics and prevailing meteorology at similar or different locations. Fine particles are composed of various chemical components like Water Soluble Inorganic Ions, Carbonaceous aerosols and Heavy Metals that are emitted from different types of sources. Therefore, the present study was conducted at two different sites (sub-urban and rural) with the aim of characterizing PM2.5 particles in terms of their characteristics, seasonal and spatial variation and source identification. PM2.5 mass concentrations were monitored during different study periods from October 2015 to February 2017. Average PM2.5 mass concentrations during the study period were 91.0 ± 50.8 µg/m3 (October 2015- January 2017) at sub-urban site and 77.1 ± 48.6 µg/m3 (February 2016-January 2017) at rural site. Although numerous studies are available on chemical characterization of PM2.5 and its sources, simultaneous measurements on PM2.5 chemical characterization, source apportionment through different receptor models and health risk analysis are rare in India. Therefore, this study was conducted to bridge this gap. This study consists of three major observations. In the first observation, characteristics of water soluble inorganic ions, their formation, spatial variation and sources are discussed. Also a case study on biomass burning in rural site has been conducted. The second observation reports levels, sources and health risk of heavy metals during foggy and non-foggy periods. Finally, the third observation reports about the overall chemical composition of PM2.5 during summer and winter season and the major sources of chemical species at the two sites. newline newline newline