Risk assessment of metals from groundwater in northeast Rajasthan

The present study was conducted to investigate trace metal (Li, Be, B, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As Se, Mo, Cd, Sb, Ba and Pb) concentrations of drinking water samples in northeast Rajasthan, India. Furthermore, the study aimed to ascertain carcinogenic and non-carcinogenic health risks of metals by ingestion and dermal absorption pathways to the local residents. Metal concentrations were analyzed by using high resolution inductively coupled plasma mass spectrometry and compared with permissible limits set by the Bureau of Indian Standards, United States Environmental Protection Agency and World Health Organization. The results indicate that the concentrations of Be, B, Al, Cr, Fe, Cu, Zn, As, Mo, Sb and Ba were lower than their respective permissible limits, whereas the concentrations of Mn, Ni, Se, Cd and Pb in some samples were higher than their permissible limits.The total hazard index (summing the hazard index through ingestion and dermal routes) at all the sampling sites exceeded or nearing unity, indicating the presence of noncarcinogenic health effects from ingestion of water and dermal contact with water. The results indicate that the total excess lifetime cancer risk (considering both ingestion and dermal exposure pathways) of metals exposure was in accordance to the acceptable lifetime risks for carcinogens in drinking water (10(-6)-10(-4)). Both carcinogenic and non-carcinogenic risks were mainly attributed to the ingestion pathways.