Heavy Metals in Food Crops and the Associated Potential for Combined Health Risk due to Interactions between Metals
Cao HB (Cao, Hongbin)1,2, Zhu HY (Zhu, Haiyan)1, Jia YJ (Jia, Yijing) 1, Chen JJ (Chen, Jianjiang) 1, Zhang H (Zhang, Hui) 1, Qiao L (Qiao, Li) 1
1. Beijing Normal Univ, Coll Resources Sci & Technol, Beijing 100875, Peoples R China
2. Beijing Normal Univ, State Key Lab Earth Surface Proc & Resource Ecol, Beijing 100875, Peoples R China
Abstract: Chromium, copper, zinc, cadmium, mercury, and lead are frequently found at high concentrations simultaneously in the soils of contaminated sites. Greater-than-additive and less-than-additive interactions have been found between pairs of these metals of concern. We performed a target-organ toxicity dose (TTD) approach and a weight-of-evidence (WOE) analysis to estimate the potential cumulative health risks of multiple metals accounting for joint toxic effects. As a case study, dietary exposure via consumption of locally planted rice and vegetables was assessed along with the associated combined health risk of the six metals for inhabitants in the vicinity of an industrial zone in southern Jiangsu, China. The Hazard Index (HI) values of each endpoint for neurological, renal, cardiovascular, hematological, testicular, and hepatic effects were 0.61, 0.54, 0.12, 0.48, 0.05, and 0.12, respectively, all less than 1. Interactions between Cd and Pb were greater than additive for testicular effects with relatively high confidence. Given that the HI value for testicular effects was only 0.05 and most interactions between metals were less-than-additive, a non-carcinogenic health hazard from exposure to heavy metals in locally planted rice and garden vegetables is unlikely.
Keyword: heavy metals; food crops; joint human health risk; target-organ toxicity dose; weight-of-evidence analysis
Published in HUMAN AND ECOLOGICAL RISK ASSESSMENT, 2011, 17(3): 700-711.