宝鸡市长青镇冶炼厂周围土壤重金属污染与健康风险评估

POLLUTION AND HEALTH RISK ASSESSMENT OF HEAVY METALS IN SOIL AROUND A SMELTER IN CHANGQING TOWN OF BAOJI CITY

以宝鸡市长青镇冶炼厂周围土壤为研究对象,分析了Pb、Zn、Cr和Cu的含量,评估了其健康风险,对污染源进行解析。研究结果表明:Pb、Zn、Cr和Cu的含量均高于背景值,且从表层向下浓度逐渐降低;均处于中污染-重污染以内,污染顺序为:Pb≥Cr≥Zn>Cu;儿童日暴露量、单因子非致癌健康风险和总非致癌健康风险均大于成人,成人和儿童的日暴露量和非致癌健康风险顺序为经口摄入>皮肤接触吸收>呼吸吸入,均不存在非致癌健康风险和总风险;Cr对儿童经呼吸暴露的致癌健康风险大于成人,且均不可能造成致癌健康影响;源解析显示Pb、Cr和Cu具有相同的污染源,而Zn有不同的污染源。

This paper investigated soil around smelter in Changqing Town of Baoji City in Northwest China,analyzed quantitatively the soil heavy metals of Pb,Zn,Cr and Cu,assessed health risks associated with four metals,and discriminated the pollution sources. The results showed that the concentrations of Pb,Zn,Cr and Cu were higher than background values,and heavy metals concentration decreased gradually from the topsoil. The soils were contaminated between pollution and heavy pollution by heavy metals,in the following order: Pb≥Cr≥Zn > Cu. The children were more vulnerable than adults for daily exposure doses,single factor non-carcinogenic risk and composite non-carcinogenic risk. Daily exposure doses and noncarcinogenic risk of corresponding different exposure routes for adults and children were in the following order: Oral intake >dermal contact intake > inhalation intake. Non-carcinogenic risk and composite total risk for adults and children didn' t exist.Children were more vulnerable than adults for Cr carcinogenic risk of inhalation intake,but there was no carcinogenic risk for adults and children. The pollution sources discrimination indicated that Pb,Cr and Cu had a common source,but Zn had different source.