Health risk assessment of oral bioaccessibility of heavy metal in soil from coalfield in Huaibei City, China

To investigate heavy metal accumulation in mine soils and evaluate health risk through soil digestion, a total of 30 soils were collected from coal mine of Huaibei City, Anhui Province, China, one of the most important coalfields. The mean concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were 0.162 +/- 0.054, 11.82 +/- 3.27, 12.03 +/- 5.42, 21.86 +/- 7.78, 55.09 +/- 12.41, and 41.46 +/- 32.07 mg kg(-1), respectively. The percentages of heavy metals exceeding background value of soil were 86.7% for Cd, 13.3% for Cu, 16.7% for Ni, 100.0% for Pb, and 20% for Zn. The percentages of heavy metal contents exceeding Grade I of Environmental Quality Standard for soil were 23.3% for Cd, 96.7% for Pb, and 10.0% for Zn. The heavy metal contents did not exceed guideline values according to Grade II of Environmental Quality Standard for soil. Average accessibility of Cd and Pb in the intestinal phase were lower than the gastric phase while a contrary result for Cr, Cu, Ni, and Zn. Both adults and children may not experience non-carcinogenic and carcinogenic health risk through soil digestion.