锑矿区土壤重金属生物可给性及人体健康风险评估

Bioaccessibility and Human Health Risk Assessment of Heavy Metals in Soils of Antimony Mine Area

采集湖南省冷水江市锡矿山锑矿区29个土壤样品,测定土壤中的重金属(Fe、Mn、Cu、Zn、Pb、Cd、As和Sb)浓度,并对其污染状况作出评价;用简化生物可给性提取(simplified bioaccessibility extraction test,SBET)法研究重金属生物可给性,并用人体健康风险模型评估该地区土壤重金属经口腔摄入后对成人的健康风险。结果表明,锑矿区土壤As和Sb的污染最为严重,且具有同源性,受人类活动影响较大。不同重金属生物可给性差异很大,重金属生物可给性平均值为Mn(36.7%)>Cd(30.7%)>Pb(24.4%)>Zn(23.1%)>Cu(12.0%)>As(5.89%)>Fe(3.88%)>Sb(2.13%),表明经口摄入重金属大部分不被人体吸收;用总量评估经口摄入途径风险时过高估计了实际的人体健康风险,用生物可给性进行调整后风险值显著降低,总非致癌风险(HI)和总致癌风险(TCR)平均值分别降低约97%和92%。主导健康危害效应的主要污染因子是Sb和As,调整后尾矿坝(S5)处仍有部分采样点总非致癌风险超过风险阈值,需要特别关注。

The total contents and investigated in 29 soil samples Province. The sim metals in soils. In pollution status of heavy metals （ Fe, Mn, collected from antimony mine area in Xiku ple bioaccessibility extraction test （SBET） addition, the human health risk assessment Cu, Zn, Pb, Cd, As and Sb） were angshan, Lengshuijiang City, Hunan was used to evaluate the bioaccessibility of heavy of the oral ingestion soil for adults was carried out based on the human health risk model. The results showed that As and Sb are the main pollution elements in the soils, and they have high homology and are easily affected by human activities. Bioaccessibility of soil heavy metals covered a wide range, the rate of bioaccessibility of heavy metals decreased in the order of Mn （ 36.7% ） 〉 Cd（30.7%） 〉 Pb（24.4%） 〉Zn（23.1%） 〉 Cu（12.0%） 〉 As（5.89%） 〉 Fe（3.88%） 〉 Sb（2.13%）, indicating that most of the heavy metals through oral ingestion could not be adsorbed by human body. The results based on total metal contents might overestimate the actual human health risks. After adjustment by bioaccessibility, the health risk values were greatly reduced, the average hazard index （HI） and total carcinogenic risk （TCR） values were reduced by 97% and 92%, respectively. Sb and As are two predominant contributors to human health risks. In addition, the hazard index values of some samples in tailing dam area were still higher than the risk threshold value after adjustment by bioaccessibility and deserved special attention.