Assessment of potential health risk of major contaminants of groundwater in a densely populated agricultural area.

As a key part of Bohai New Area development, Haixing County has been undergoing rapid development. In order to estimate potential risks of chemical parameters to human health of local residents, carcinogenic and non-carcinogenic risks via direct ingestion of drinking water were calculated using human health risk assessment (HHRS) based on triangular fuzzy number. The levels of pH, total dissolved solids, total harness, SO , Na, Cl, SO , F, Fe (total iron), NO , and NO were more or less higher than the permissible limits except parameters As and Mn. The analysis results show that risk level for different crowds in the study area demonstrated an obvious variation, generally in the order of infants > children > adult males > adult females for non-carcinogenic risk values (R ), while the sequence of the carcinogenic risk values (R ) are adult males > adult females > children > infants. When the confidence level was 0.8, the non-carcinogenic risk values (R ) through drinking water intake were higher than 1, and this implied that potential health impacts on human health for local residents. However, the risks of carcinogenic risk values (R ) were lower than 1.0E-4, demonstrating minimal and acceptable health risk. Furthermore, according to the middle values (α = 1) of R , the total non-carcinogenic risks for local residents were obtained in the following order: GW (Gaowan Town) > XJ (Xinji-Xiangfang County) > ZM (Zhaomaotao County) > HX (Haixing-Suji Town) > ZH (Zhanghuiting County) > XS (Xiaoshan County), and ZM > XJ > GW > HX > XS > ZH for R . It was also found that the spatial distribution of fluoride level in drinking water is urgently needed to be identified. In conclusion, the potential health risks to residents should cause enough attention both from society and the academic community.