Lead (Pb) and arsenic (As) bioaccessibility in various soils from south China

Seventeen soil samples with various concentrations of lead (Pb) and arsenic (As) were collected from five provinces of south China, and bioaccessibility of Pb and As in the soils were examined using a physiologically based extraction test. The results showed that the bioaccessibility ranged from 24.6% to 82.5% and 2.3% to 57.5% for Pb, 2.5% to 65.5% and 1.2% to 31.8% for As in the gastric and small intestinal phases, respectively. The effect of soil properties on the bioaccessible of Pb/As was evaluated. Path analysis showed that coefficients of determination (R2) for the bioaccessible Pb were 0.93 in the both gastric and small intestinal phases and for the bioaccessible As were 0.98 and 0.99 in the gastric and small intestinal phases, respectively. Among all the soil characteristics, OM, DCBFe, CEC, and WAs were significant for controlling PbD, and CEC, CaCl2–Pb, and WAs were important for controlling PbI. Partitioning by path analysis also showed significant direct effects by CaCl2–Pb and WAs on AsD, and OM, CEC, CaCl2–Pb, and WAs on AsI.