2018年我国中东部局部地区农田土壤典型重金属健康风险评估

Health risk assessment of typical heavy metals in farmland soils in parts of central and eastern China in 2018

目的评价我国中东部局部地区农田土壤中铅、镉和六价铬的健康风险。方法于2018年,在我国中东部局部地区中随机抽取了112个县(区)377个行政村,在每个行政村采集1份村民居住地生活周边的农田土壤样品,检测铅、镉、总铬的含量。采用我国推荐的土壤中污染物健康风险评价模型和人群暴露参数计算镉和六价铬的致癌风险和铅、镉和六价铬的非致癌健康风险。结果农村居民生活周边农田土壤样品中铅、镉、总铬的含量的中位数分别为23.40、0.14和63.00 mg/kg。镉对成人和儿童的致癌风险分别为1.13×10-9和5.23×10-10;六价铬成人和儿童致癌风险分别为4.41×10-5和4.57×10-5,均未超过可接受风险的上限。铅、镉和六价铬主要经口摄入暴露,非致癌性风险从高到低依次为HICr(1.66)>HIPb(1.01)>HICd(1.10×10-2),前两者略大于非致癌风险阈值1。结论本研究区域农田存在局部的铅、镉和铬的土壤环境污染。土壤中的镉不会给人体带来健康危害。六价铬的致癌风险尚可接受。六价铬和铅引起的非致癌风险需引起重视,加强监测。

Objective To assess the health risks of Pb,Cd and Cr(Ⅵ) in farmland soils in parts of central and eastern China.Methods A total of 377 administrative villages in 112 counties(districts) in parts of central and eastern China were randomly chosen. One sample of farmland soil around the villagers’ living areas in each administrative village was collected to detect the contents of Pb,Cd and Cr in 2018. The carcinogenic risk of Cd and Cr(Ⅵ) and the non-carcinogenic health risks of Pb,Cd and Cr(Ⅵ) were assessed based on the health risk assessment model and population exposure parameters recommended by China.Results The medians contents of Pb,Cd and Cr in the samples of farmland soil around the villagers’ living areas were23.40,0.14 and 63.00 mg/kg respectively. The carcinogenic risk of Cd in the samples for adults and children were 1.13×10-9和5.23×10-10 respectively;The carcinogenic risk of Cr(Ⅵ) for adults and children were 4.41×10-5 and 4.57×10-5 respectively,both of which were less than the maximum acceptable carcinogenic risk. The non-carcinogenic high-risk pathways of Pb,Cd and Cr(Ⅵ)were all oral intake. The total hazard quotient of each pathway ranked as HICr(1.66)>HIPb(1.01)>HICd(1.10×10-2),the first two were slightly higher than the risk threshold. Conclusion Parts of the field soil in this study are contaminated with Pb,Cd and Cr. Cd in soil does not cause health hazards. The carcinogenic risk of Cr (Ⅵ) is acceptable. The non-carcinogenic risks caused by Cr(Ⅵ) and Pb need to be paid more attention to and monitoring should be enhanced also.