南方某典型矿冶污染场地健康风险评价及修复建议

Health risk assessment and remediation suggestion of a typical smelter contaminated site in Southern China

矿区及周边土壤重金属污染不容忽视,砷、镉和铅等对周边人群造成较高的健康风险隐患。以南方红壤区某铅锌冶炼矿区污染场地为研究对象,开展危害识别、暴露评估、毒性评估及风险表征,并讨论场地修复目标值与修复技术。结果表明:土壤受到重金属复合污染,关注污染物为四类重金属,包括铅、砷、镉和锌,集中于表层土壤(0~0.6 m),并呈现空间分布规律性;场地未来用地类型为工业用地,对比污染物(不包括铅)各层(第1层0~0.3 m、第2层0.3~0.6 m、第3层0.6~1.0 m)风险表征值,污染物(砷、镉)存在致癌风险与非致癌危害,研究区重金属污染累积风险水平不可接受;分析风险控制值及国内外相关标准限值等,初步建议砷、镉和铅的修复目标值分别为13.41、21.50和600 mg·kg^(-1);同时,针对场地污染现状及健康风险,建议源控制与修复技术并用,并与当地工业园区建设统筹开展。

Heavy metal contamination of soil is often encountered in the vicinity of mining areas.Arsenic, cadmium, and lead probably pose greater health risks than other heavy metals to people living nearby.Hazard identification, exposure assessment, toxicity assessment, and risk characterization are discussed in this paper for a lead and zinc smelter contamination site in the red soil area of southern China.Moreover, site cleanup goals and potential remedies are discussed.The results indicate that the soil at the site has been contaminated with a number of heavy metals, including lead, arsenic, cadmium, and zinc.These heavy metals are primarily present in the surface soil （0-0.6 m）.Based on an industrial land use as the planned future land use, risk assessment was completed on these heavy metals, except lead, for each layer （0-0.3 m, 0.3-0.6 m, and 0.6-1.0 m） and the levels of each heavy metal were calculated and compared.Unacceptable cancer risk （arsenic and cadmium） and noncancer risk both exist.Based on a comparison with risk control values and/or relevant national or international standards, the proposed cleanup goals for arsenic, cadmium, and lead were determined as 13.41, 21.50, and 600 mg·kg-1, respectively.Furthermore, it is suggested that source control measures and other remedial action be implemented concurrently with construction of the industrial park, based on the distribution of existing contamination and associated health risks thereof.