Heavy metal contamination in the groundwater of the southern expanse of the Northwestern Himalayan region: an evaluation by Nemerow pollution index and health risks utilizing Mathematical Modelling.

The presence of heavy metals in groundwater exceeding recommended levels significantly impacts human health. This study scrutinized heavy metal levels in 25 borewell water samples from the southern part of the northwestern Himalayan region, encompassing four Kashmir districts (Anantnag, Pulwama, Shopian, and Kulgam), both pre- and post-monsoon, using atomic absorption spectroscopy. Employing the Nemerow pollution index, water quality assessment revealed varying degrees: Dooru Shahabad exhibited excellent quality, Hillar and Kakapura were classified as good, while Wanpoh and Zeewan displayed moderate quality. The remaining 20 samples showed poor quality consistently. Spatial distribution of heavy metals (Pb, Ni, Mn, Cd, Cu, Fe, Zn) was mapped using contour maps. Statistical analysis showed no significant variations in Pb, Ni, Cd, Cu, Fe, and Zn means (p > 0.05). The contamination extent underscores the necessity to evaluate its human health impact. Subsequently, total health risk, incorporating non-carcinogenic risks for seven heavy metals and carcinogenic risks for three, was mathematically computed. Non-carcinogenic risk rankings across districts were Pb>Ni>Mn>Cd>Cu>Fe>Zn. Pb posed the highest carcinogenic risk, contributing 72% to the total health risk, followed by Ni, Cd, and Mn in both seasons. This research illuminates the extent of heavy metal pollution in a region of paramount importance, urging further investigation into its health implications and necessitating prompt remedial measures.