Spectroscopic fingerprinting, pollution characterization, and health risk assessment of potentially toxic metals from urban particulate matter

The unprecedented stride of urbanization and industrialization has given rise to anthropogenic input of tiny particulates into the air. Urban particulate matter (PM) armored with potentially toxic metals (PTMs) could be lethal to the environment and human health. Therefore, the present study was planned to investigate the spectroscopic fingerprinting, pollution status and health risk of PM-associated PTMs collected from ten functional areas of Lahore, Pakistan. The diverged results of studied qualitative and quantitative analyses showed distinct compositional and pollution characteristics of PTMs in urban PM with respect to selected functional areas. The XRD results evident the fractional presence of metal-containing minerals, i.e., pyrite (FeS₂), calcite (CaCO₃), zinc sulfate (ZnSO₄), and chalcostibite (CuSbS₂). Several chemical species of Zn, Pb, and As were found in PM of various functional areas. However, morphologies of PM showed anthropogenic influence with slight quantitative support of PTMs presence. The cumulative representation of PTMs pollution of all selected areas depicted that Cd was heavily polluted (Igeo=3.21) while Cr (Igeo=1.82) and Ni (Igeo=2.11) were moderately polluted PTMs. The industrial area having high pollution status of Cd (Igeo=5.54 and EF=18.07), Cu (Igeo=6.4 and EF=32.61), Cr (Igeo=4.03 and EF=6.53), Ni (Igeo=5.7 and EF=20.17), and Zn (Igeo=4.87 and EF=11.27) was prominent among other studied areas. The PTMs were likely to pose a high non-cancerous risk in IndAr (HI = 7.48E+00) and HTV (HI = 1.22E +00) areas predominantly due to Zn with HQ > 1. However, Cr was prominent to cause cancerous risks with values beyond the tolerable range (1.00E-04 to 1.00E-06).