Pratap, V; Kumar, A; Tiwari, S; Kumar, P; Tripathi, AK; Singh, AK (2020). Chemical characteristics of particulate matters and their emission sources over Varanasi during winter season. JOURNAL OF ATMOSPHERIC CHEMISTRY, 77(3), 83-99.

The chemical composition of particulate matter impacts both human health and climate. In this study, the chemical characteristics of particulate matter was measured for four months (November 2016-February 2017) at Varanasi, which is located in the middle of the Indo-Gangetic Basin (IGB). The daily observed mean values of PM10 and PM2.5 are 134 +/- 48 and 213 +/- 80 mu g/m(3), respectively, which exceeds both national and international standards. The average value of PM2.5/PM10 ratio is 0.64 +/- 0.16 which indicates a relatively higher fraction of fine particles that are attributed to anthropogenic emission sources (biomass/post-harvest burning) as corroborated by MODIS fire counts and back trajectory analysis. Ion chromatographic measurements showed that SO42-, Cl-, K+, NO3-, Na+, Ca2+, Mg2+ are the major ionic species present in the aerosol. Scanning Electron Microscopy with Energy Dispersive X-Ray (SEM-EDX) analysis shows the prevalence of carbon-rich particles at Varanasi which is likely due to biomass burning and other anthropogenic sources.