This study was conducted to assess the concentrations of cadmium (Cd) and lead (Pb) in soils of tobacco field and plants were collected in the edge of Sichuan Basin, China (Panzihua, Guangyuan, Luzhou and Yibin). Ecological risk of Cd and Pb in soil and human health risk from tobacco leaves were also assessed. The maximum Cd and Pb concentrations in soil were obtained in Yibin (2.94 mg/kg) and Luzhou (54.2 mg/kg), respectively. Ecological risk of Cd and Pb in tobacco soils was assessed based on geoaccumulation index, potential ecological risk (PER) and toxic units. Among four study sites, Cd and Pb concentrations in leaves and stems of Yibin were higher than all samples collected from other three study sites. Health risk was estimated from the concentration of Cd and Pb in tobacco leaves. The carcinogenic risk range for Cd was 7.9E - 04 to 1.4E - 01 and for Pb was 5.7E - 03 to 2.8E - 02, respectively. The increased chronic carcinogenic values for Cd in Luzhou and Yibin crossed the USEPA acceptable limit (> 1.00E - 4) indicating that Cd poses cancer risk after consumption of tobacco leaves.
Keywords: Cancer risk; China; Heavy metal; Tobacco; Transfer factor.