Analysis of Source and Source Region of Coarse Mode Aerosol (PM10) in Varanasi, India

Abstract

In this study, we conducted source apportionment and source region analysis of elemental concentrations of coarse mode aerosol (PM<inf>10</inf>) using principal component analysis (PCA), trajectory analysis, and conditional bivariate probability function (CBPF) in Varanasi, situated over central Indo-Gangetic Plain (IGP) of India. In this case, 34 elements (Mg, Na, Al, Si, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Zr, Mo, Ag, Pm, Y, Rb, Pd, Fr, U, Pb, B, P, S, Cl, Br, Nb, Sr, F, As, and Ba) were extracted from PM<inf>10</inf> samples using WD-XRF technique. PCA identified six sources (crustal/soil/road dust, biomass burning, industrial emissions, agricultural activities, combustion, and vehicular emissions) of elemental concentrations of PM<inf>10</inf> over Varanasi. Trajectory analysis indicated contribution to PM<inf>10</inf> concentration transported from Uttar Pradesh, Punjab, Haryana, Delhi, partially from Rajasthan, Gujarat, West Bengal, and some parts of Madhya Pradesh, with additional transboundary emissions from Pakistan, Afghanistan, and Nepal. CBPF analysis predicted the local PM<inf>10</inf> emissions from North-East, South, West, and North-West directions, with major contributors including Ganga ghats, religious places, market areas, and traffic activities. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.