土壤镉污染的人体健康风险评价研究:生物有效性与毒性效应

Human Health Risk Assessment of Cadmium in Soils:Role of Bioavailability and Toxic Effects

镉(Cd)作为最重要的土壤污染物之一,会对人体健康造成严重威胁。Cd污染土壤的健康风险评估受到广泛关注。目前,Cd污染土壤的人体健康风险评价多基于总含量,往往高估其健康风险。近年来,以污染物生物有效性作为评价基础的研究受到广泛认可。本文系统分析了体内外方法(动物模型、体外胃肠模拟方法和肠细胞模型)测定Cd生物有效性的优缺点,综述了各方法在分析土壤Cd生物有效性的影响因素以及生物有效态Cd对动物和细胞模型的毒性效应;提出弄清土壤总Cd含量-生物有效态Cd-毒性效应之间的剂量效应关系,构建基于生物有效性和毒性效应为基础的人体健康风险评估模型,来准确评估其健康风险的思路,以期为土壤Cd健康风险评估及有效阻控提供一定参考。

Cadmium(Cd)is one of the most serious soil contaminants in China,posing an increasing risk to human health as large amounts of Cd are emitted into the environment.Given that,human health risk assessment of Cd-contaminated soil attracts scientific community.Based on literature,most of existing health risk assessment models are dependent on the Cd total content,which may overestimate the risk.Recently,some scientists demonstrated that bioavailable Cd is more accurate to predict its health risk since it reflects actual fraction of human absorption.In recent years,many approaches including in vitro and in vivo models were widely employed to evaluate the potential health risk of Cd in soils.In this review,we summarized the characteristics of existing models(i.e.,animal models,in vitro gastrointestinal simulation,and cellular models),analyzed the factors affecting its bioavailability and the toxic effects of bioavailable Cd on animal and cell models.Therefore,we proposed that the scientists should figure out the quantitative relations among the total concentration Cd in soils,bioavailable Cd and induced toxic effects,and then construct the new models based on bioavailability and toxic effects to accurately assess the health risks of soil Cd.Taken together,our review could provide the perspective on the accurate assessment of health risk of heavy metals contaminated soil.