Evaluating health risks of PM2.5-bound heavy elements in Faridabad, Haryana (India): an industrial perspective

The present study is focused on investigating the heavy/toxic metals (Al, Ni, Cr, Pb, Cu, As, Mn, and Zn) of PM_2.5 and assessing their associated human health risks. During the study period (July 2022 to July 2023), the PM_2.5 samples were collected from two distinct sites in Faridabad (92 samples from site 1 and 85 samples from site 2). In this study, the US EPA’s Risk Assessment Guidance for Superfund (RAGS) was followed to evaluate the human health risk associated with PM_2.5-bound heavy elements. The annual average of PM_2.5 concentrations was 108 ± 16 µg m⁻³ at site 1 and 154 ± 11 µg m⁻³ at site 2, approximately three to four times higher than the national ambient air quality standards (annual, 40 µg m⁻³). The analysis of enrichment factors (EFs) for the elements Cr, As, Zn, Cu, Mn, Pb, and Ni indicates that the heavy elements associated with PM_2.5 primarily originate from anthropogenic sources. The application of the conditional bivariate probability function (CBPF) model for Faridabad revealed local pollution sources contributing to elevated mass concentrations at the receptor site from the southern (S), northwestern (NW), northeastern (NE), southwestern (SW), and southeastern (SE) regions. Furthermore, positive matrix factorization (PMF) analysis identified the predominant sources of PM_2.5-bound heavy elements as industrial emissions (41%), vehicular emissions (34%), and combustion processes (25%). After a thorough assessment of health hazards, Cr appeared as a significant carcinogenic risk factor. Children with elevated hazard quotient (HQ) values for Mn and Cr indicated non-carcinogenic health problems. Ultimately, this analysis reinforces the necessity for rigorous monitoring and intervention to safeguard public health from the potentially harmful effects of heavy elements.