Keywords: 
• soil /
• copper /
• bioaccessibility /
• oral ingestion /
• health risk

Abstract: Fifteen soil samples were collected from typical sites in China to study the bioaccessibility of soil copper(Cu) based on the PBET(physiologically based extraction test) method.The relationship between the soil properties and the bioaccessibility as well as the health risk assessment of the oral ingestion soil was also investigated.The results showed that comparing with Chinese environmental quality standard for soils,the concentrations of Cu in two soil samples were higher than the third standard(<400 mg·kg^-1) and the concentrations in eight soil samples exceeded the secondary standard(<50 mg·kg^-1,pH < 6.5;< 100 mg·kg^-1,6.5 < pH < 7.5;< 100 mg·kg^-1,pH > 7.5).The high variability of dissolved and bioaccessible Cu of soils were observed.The concentrations of bioaccessible Cu ranged from 5.2-308.8 mg·kg^-1 with a mean of 74.8 mg·kg^-1 in the gastric phase and 5.9-348.5 mg·kg^-1 with a mean of 82.0 mg·kg^-1 in the small intestinal phase.The Cu bioaccessibility ranged from 183% -66.6% with a mean of 44.2% in the gastric phase and 21.3% -77.4% with a mean of 51.1% in the small intestinal phase.The significant positive correlations between the Cu bioaccessibility with soil pH,organic matter were observed in the gastrointestinal phase.The negative correlations with clay in the gastric phase and with the concentrations of Cu and Mn-oxide in the small intestinal phase were observed.For children,the highest contribution of the oral ingestion soil Cu to the tolerable daily intake(TDI)that estimated by WHO was 2.51% in the gastric phase and 2.83% in the small intestinal phase,but the contribution rate of 12 soil samples was lower than 1.00% in the gastrointestinal phase.The health risk from the oral ingestion of soil Cu was low in most of collected soil samples.