河南省焦作市中小学土壤重金属污染状况及健康风险评价

Pollution and Health Risk Assessment of Heavy Metals in Soils from Primary and Secondary Schools of Jiaozuo,Henan Province

以焦作市部分城乡结合部学校、市区学校以及农村学校为研究对象,测定其土壤重金属含量,并进行富集因子分析以及健康风险评价。结果表明：焦作市采样点学校土壤中Zn、Cr、Ni、Cu的平均含量分别为142、65、31、22 mg/kg,均高于河南省土壤背景值;土壤重金属污染程度呈现出城乡结合部学校〉城市学校〉农村学校。重金属富集因子分析表明除城乡结合部学校中希望实验学校Zn呈现出显著富集之外,其他学校土壤重金属整体污染比较轻微。焦作市学校土壤重金属对儿童的非致癌健康总风险（HI）排序为Cr〉Ni〉Cu〉Zn,但是均小于1,不存在非致癌健康风险;Cr的总致癌风险大于10-4,存在致癌风险,Ni的总致癌风险在10-6～10-4之间,其致癌风险在可接受范围。从不同途径看,致癌风险和非致癌风险均是表现为手口摄入〉皮肤摄入〉呼吸摄入;从不同的学校类型来看,致癌风险和非致癌风险均表现为城乡结合部学校〉城市学校〉农村学校。总体而言,焦作市部分学校的儿童存在一定的健康风险,应予以重视。

Concerning schools in the urban,peri-urban,and rural areas of Jiaozuo,the heavy metal contents in soils from selected school areas were measured and health risks were assessed by enrichment factor analyses. The results showed that average concentrations of Zn,Cr,Ni and Cu in soils were 142,65,31,22 mg/kg,respectively,higher than soil background values of the Henan Province. Enrichment factor analyses showed that,except the Jiaozuo Xiwangshiyan school area significantly enriched Zn,heavy metals pollutions in the selected school area were slight. The pollution levels followed a trend of Peri-urban schools〉 urban schools〉 rural schools. The health risk assessment results showed that the non carcinogenic risks（ HI） of all heavy metals were lower than 1 and ranked as Cr〉 Ni〉 Cu〉 Zn,indicated no none carcinogenic risk was found,and that the total carcinogenic risk（ TCR） of Cr was greater than 10-4,indicated a considerable carcinogenic risk,the TCR of Ni was between 10-6-10-4,indicated an acceptable carcinogenic risk. In terms of the exposure pathway,the exposure risks for both non-carcinogenic and carcinogenic were hand-mouth intake skin intake〉 breath intake; in terms of site types,the order was Peri-urban schools urban schools rural schools for both non-carcinogenic and carcinogenic risks.