Heavy metal contamination and health risk assessment in Dabao Mountain,China

The food chain is the main pathway of heavy metals transfer from the environment to humans. This study focused on the acid mine contamination and health effects of Pb, Zn, Cd, and Cu in Shangba village, Guangdong province, China. The results showed that the mean concentrations of Pb, Zn, Cd and Cu were 0.80, 22.45, 0.28 and 1.07 mg·kg-1 in vegetables and 2.81, 60.83, 0.58 and 6.54 mg·kg-1 in rice, respectively. Further, Pb, Zn and Cd concentrations in rice were 7.2, 3.4, 2.9 times greater than the tolerance level. The health risks associated with these heavy metals were assessed based on the Target Hazard Quotients (THQs), which can be derived from concentrations of heavy metals in drinking water, rice and vegetables consumed by the inhabitants. The THQ of Pb, Zn, Cd, and Cu in rice were greater than 1. THQ values indicated that consumption of both rice and vegetables would lead to high potential health risks especially for children. The THQs results from drinking water consumption showed that the health risk for humans was low. The Cd concentrations were 4.69 μg·L-1 and 3.41 μg·g-1 creatine in blood and urine, respectively. The results showed that Cd and Pb were the most important metals affecting the inhabitants in this contaminated area. The health risk from Cd and Pb was slightly more than that of uncontaminated areas in other countries and districts.