Lead in soil and agricultural products in the Huainan Coal Mining Area, Anhui, China: levels, distribution, and health implications

Heavy metal accumulation in agricultural soil is of great concern, as heavy metals can be finally transferred to the human body through the food chain. A field survey was conducted to investigate the lead (Pb) levels and distribution in soil, agricultural products (wheat, paddy, and soybean), and fish, in the Huainan Coal Mining Area (HCMA), Anhui Province, China, to provide reference information to local inhabitants. The daily intake and target hazard quotients of Pb through food consumption were assessed. Results showed that the mean Pb concentration in soil was higher than the Huainan soil background Pb value but lower than the maximum allowance Pb concentration for agricultural soil (GB 15618-2008). The elevated Pb in soil, especially in rainy months (June to August in Huainan), might be related to Pb leaching from ambient coal gangue piles. Excessive Pb concentration was found in the grains of food crops, which would pose a potential health risk to local inhabitants. Therein, wheat showed higher Pb bioaccumulation ability than other crops. With regard to the Pb levels in muscles, fishes were considered to be safe for consumption. The calculations on daily intake and tolerable hazard quotient of Pb suggest that the potential health hazard posed by Pb is currently insignificant for the inhabitants in the HCMA.