湘中某工矿区农户菜园重金属污染分析与健康风险评价

Heavy metal pollution and health risk in vegetables and soils in a industrial and mining area in Hunan Province

为研究湘中某工矿区对周边农户菜园土壤和蔬菜的影响,采集矿区周边18个蔬菜样地15个品种计80个蔬菜样品,分析土壤及蔬菜中重金属Pb、Cd、Cu、Zn的含量,并采用污染指数法和健康风险评价模型对土壤和蔬菜重金属污染进行评价.研究表明,矿区蔬菜地土壤受到严重的重金属污染,Cd污染最为严重.从综合污染指数来看,蔬菜均受到中、重度污染,苋菜污染最严重.各元素在蔬菜中的富集能力大小为:Cd>Zn>Cu>Pb.重金属暴露接触对人体的风险评估结果表明,蔬菜可食部分Cd与Pb的危险度(HQ)均大于1,居民通过蔬菜途径摄入的Pb和Cd对人体健康存在较大的潜在风险.建议农户菜园在不能改制改种的情况下,种植根茎类蔬菜.

In order to assess the effect of mining and smelting on vegetable soils and vegetables around a zinc-lead mining area in central Hunan Province, 80 samples of 15 types of vegetables were collected from 18 vegetable fields around the mining area. The concentrations of Pb, Cd, Cu, and Zn were analyzed and heavy metal pollution of soils and vegetables were evaluated based on the pollution index method and health risk assessment model. The results showed that the soils were polluted by heavy metals seriously, especially by Cd. The vegetables were polluted by Cd, Pb and Zn to various degrees. According to the comprehensive pollution index, vegetables were polluted moderately or seriously. Above all, the Three-colored amaranth was polluted most severely. In addition, the vegetable＇s enrichment capacity for the different metal elements was i.e. Cd〉Zn〉Cu〉Pb. Heavy metal exposure on human risk assessment indicated that hazard quotient （HQ） of Cd and Pb for an adult through consumption of vegetables was higher than 1, which suggested that consumption of contaminated vegetables has high potential health risk for an adult. If the farmers＇ vegetable garden can＇t be restructured or replant, they are recommended to plant root vegetables.