Risk assessment of metals from shallow groundwater in Lianhuashan District, China

Abstract

The present study was conducted to investigate trace metal (Fe, Mn, Cd, Pb, Zn, Cu, Al, As, Se, Hg, Sr, Ba, Li, Co, B, Ni, Ag, Mo and Cr) concentrations of drinking water samples in Lianhuashan District, China. 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 compared with permissible limits set by the Chinese Standards, USEPA and WHO. The average concentrations of the analyzed elements are in the order of Fe > Sr > Mn > Al > Ba > Mo > Zn > B > Li > Pb > Cr > Ni > Cu > Ag > Co > As > Se > Cd > Hg. The results indicate that the concentrations of Cd, Zn, Cu, Ni, Se, Hg, Ba and Cr were lower than their respective permissible limits, whereas the concentrations of Fe, Mn, Pb, Al, As and Mo at some sampling sites exceeded the permissible limits. The total hazard index (HQtotal) of the metals (Cd, Zn, Cu, Al, Se, Hg, Sr, Ba, B, Ni, Ag, Cr) calculated through ingestion and dermal absorption pathways for adults and children were found to be lower than unity, indicating that the metals would not pose any adverse effect and non-carcinogenic health risk to the habitants. The results of carcinogenic risk assessment indicate that the Excess Lifetime Cancer Risk (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 non-carcinogenic and carcinogenic risks were mainly attributed to the ingestion pathways.