Elemental Analysis and Health Risk Assessment of PM2.5 at An Urban Site of Delhi

In order to comprehend the elemental annual contributions to PM2.5 over Delhi’s urban region from January 2021 to December 2021, this study was carried out. Elemental analysis (Na, Mg, Ca, Cr, Al, P, S, K, Fe, Cu, Zn, Cl, and Mo) of PM2.5 was performed using a non-destructive method (Wavelength Dispersive X-Ray Fluorescence Spectrometry). During the sampling period, the observed annual average concentration of PM2.5 was 105 ± 44 μg m−3, which exceeds the National Ambient Air Quality Standards (NAAQS) limit (40 μg m−3) by approximately 2.5 times. Among elements, majorly Cl (22%), S (21%), and K (19%), Fe (11%), Zn (6%), Ca (5%), Al (4%), Cr (3%) contributed to PM2.5. Whereas Cu, Ga, Mo, Zr, Mg, Na, B, P, Mn, Pd, As, Br, Ni and Ti contributed ≤1%. The diagnostic ratios of Al/Fe, Al/Ca, and Al/Mg indicates their common source of these elements. According to enrichment factor estimation, Fe, Ca, Mg and Na contribute to crustal/ soil dust, while Mo, Cr, Zn, and Cu are likely to be emitted due to industrial activities. The health risk assessment (HRA) evaluated the non-carcinogenic risk of Cr and Pb along with the carcinogenic risk of Cr. The burning of fossil fuels and biomass, industrial pollutants, automobile emissions, and crustal or mineral dust are among the likely sources of the PM2.5 anticipated at Delhi's urban site.