Trace elements contamination in groundwater and associated human health risk in the industrial region of southern Sonbhadra, Uttar Pradesh, India

The present study assesses the pollution load of the groundwater with reference to the trace elements (i.e. As, Hg, Cd, Cr, Cu, Fe, Mn, Zn, Ni, Co and Pb) and the potential health risk by its consumption for the residents of Obra, Renukoot and Anpara industrial clusters of Southern Sonbhadra, Uttar Pradesh, India. For this, 220 groundwater samples were collected during post- and premonsoon seasons in 2015. pH varied from slightly acidic to alkaline in both the seasons. Geochemical analysis of the area showed that all the three clusters are severely contaminated with Fe, Pb, Cd, Cr, As and Hg during both the seasons. High concentration of heavy metals indicates that groundwater was contaminated with natural as well as anthropogenic sources. For all the three clusters, the mean values of heavy metal pollution index were found above the critical index in both the seasons with Anpara in lead. For the majority of groundwater samples across the clusters during both the seasons, substantial non-cancer health risk was observed due to target hazard quotient values of Cr, Cd, As, Pb and Hg higher than unity. The hazard index value for children was very high compared to adults which means that children are more susceptible to health impairment in terms of non-carcinogenic health risk. Carcinogenic risk was higher for adults than children in the entire study area.