我国土壤重金属污染的多暴露途径健康风险评估

Health risk assessment of multiple exposure pathways of soil heavy metals pollution in China

土壤重金属(SHMs)污染因其高毒性、隐蔽性、持久性和生物累积性而受到广泛关注,因此,精准量化SHMs的人体输入途径及其危害风险对于保障人民生命健康至关重要。通过多样本实测和文献检索相结合,选取856篇参考文献和收集的563个实测样本,从全国尺度重构了多类别土壤混合的SHMs(Cu、Pb、Zn、Cd、Cr、As、Ni和Hg)含量融合数据集,基于本土化和精细化构建的土壤—膳食食物链富集模式,改进了健康风险评估模型,通过食物摄入、皮肤接触和吸入3种通道,肉类、蛋类、谷类、蔬菜、水果、鱼类6种精细食物链,精准量化了SHMs的非致癌和致癌健康风险,并对主要人体输入途径进行识别。结果表明:中国南方SHMs的平均含量通常高于北方,土壤中Zn的平均含量(84.35 mg·kg^(-1))比Hg(0.12 mg·kg^(-1))高702倍,Cd是中国土壤中最常见的污染物,约90%采样点的Cd含量超过了最新的风险筛查值;食物摄入是SHMs输入人体最多的途径,其次是皮肤接触,其中食物摄入对人体暴露的非致癌风险指数(HI)和致癌风险指数(CRI)的贡献分别达到了88%和86%;值得注意的是,除As在湖南有一定非致癌风险外,Cu、Pb、Zn、Cd、Cr、Ni和Hg的HI均不超过1,Cd、Cr、As和Ni的CRI介于10^(-4)至10^(-6)之间,对人体的致癌危害在可以接受范围内;研究的六条精细食物链中,肉类和谷类分别是造成SHMs污染人体膳食暴露最多的动物型和植物性食物链。总体而言,SHMs污染对人体造成的健康风险影响在可接受范围内。本研究将对制定精准的SHMs健康风险管理策略和保护环境有一定的价值。

Soil heavy metals(SHMs)contamination has been widely concerned owing to its high toxicity,concealment,persistence,and bioaccumulation.Therefore,accurately quantifying the human input pathways and their harm risks of SHMs is crucial to safeguarding people's lives and health.This study reconstructed a multicategory hybrid soil HM(Cu,Pb,Zn,Cd,Cr,As,Ni,and Hg)concentration fusion dataset at the national scale through a combination of multiple sample measurements and literature retrieval,selected 856 references and 563measurement samples collected in the past three years,and improved a health risk assessment model based on the localized and refined soil-dietary food chain enrichment model.Through three channels of food intake,skin contact,and inhalation,six fine food chains of meat,eggs,grains,vegetables,fruits,and fish,the noncarcinogenic and carcinogenic health risks of SHM were accurately quantified,and the main human input pathways were identified.The results showed that the average concentration of SHM in southern China was generally higher than that in northern China,Zn(84.35 mg·kg^(-1))was 702 times higher than Hg(0.12 mg·kg^(-1))in soil.Cd was the most common pollutant in China soil,about 90%of total Cd of sampling sites exceeded the latest risk screening values.Food ingestion is the most common pathway for SHMs to enter the human body,followed by skin contact.Among them,food intake contributes 88%and 86%to the Non-carcinogenic Hazard index(HI)and Carcinogenic Risk index(CRI)of human exposure,respectively.It is worth noting that the HI of Cu,Pb,Zn,Cd,Cr,Ni,and Hg did not exceed 1,except for some non-carcinogenic risks of As in Hunan,and Cd,Cr,As,and Ni had acceptable carcinogenic risk for CRI was within the range of threshold values(10^(-4)to 10^(-6)).Among the six fine food chains studied herein,meat and grains are the animal and plant food chains that result in the highest exposure of SHMs to the human body.Overall,the health risks caused by HM-contaminated soil on humans are within acceptable limits.This study will be of value in developing accurate SHMs health risk management strategies and protecting the environment.