Spatial distribution of metal(loid)s in groundwater of a mining dominated area: recognising metal(loid) sources and assessing carcinogenic and non-carcinogenic human health risk

The study represents the first systematic risk assessment study in East Singhbhum district, Jharkhand, India for the safety of ground-water for drinking purpose with respect to metal(loid)s. The district is known for its mining and related activities. The results demonstrated that concentrations of the metal(loid) s showed significant spatial variation with Al, Mn, Fe, Ni and Zn exceeding the drinking water standards. Principal component analysis resulted in extraction of four factors explaining 76.3% of the data variability. The extracted principal components pointed towards both geogenic and anthropogenic activities governing the groundwater quality. Risk assessment was quantified by the hazard quotient (HQ) and cancer risk for both adult and child. The risk on human health posed by the metal(loid) s was found to be adverse for Mn with HQ > 1 for child. The chronic risks to the local population were largely contributed by Mn, Co and As. However, the carcinogenic risk for As was within the acceptable cancer risk value of 1 x 10(-4). Considering the geometric mean of the metal(loid) s in the study area, the hazard index (HI) for adult was above unity. Considering all the locations, the HI varied from 0.23 to 13.03 and 0.20 to 11.15 for adult and child, respectively, suggesting that the groundwater is unsuitable for drinking without treatment at most of the locations.