Ecological and human health risk assessment of chromite ore processing residue (COPR) dumpsites in Northern India: A multi–pathways based probabilistic risk approach

Abstract

In this study, ecological and human health risk assessment (HHRA) of the subsurface environment was performed due to the presence of six different contaminants, i.e., Cr(VI), U, F-, As, NO3-, and Mo, in the proximity of chromite ore processing residue (COPR) dumping sites of Northern India. The analysis covered a probabilistic risk assessment approach comprised of 10,000 Monte Carlo simulations (MCS) for multi-exposure scenarios following soil and water pathways. The results of ecological risk indexes indicated considerable (contamination factor (CF) = 5.6) to very high (maximum CF ~ 11.0) contamination of soil near the Rania contaminant site. The maximum and 95th percentile of CF obtained due to Cr(VI) were 4.547 and 11.129, respectively, during the monsoon season. Cancer risk (CR) value for dermal contact exposure via soil pathway for the Rania site was > 1–2 orders higher than the safe limit, posing a serious threat to human health. Further, oral ingestion and skin dermal exposure to groundwater in the proximity of Chhiwali dumping site were posing the highest risk with CR = 18.5 and 54.9 (>10−6), respectively to the adult population. Overall, the study recommends an urgent need to take intensive remediation action for these COPR dumpsites to ensure human health safety.