电子垃圾拆解区土壤-水稻系统重金属分布特征及健康风险评价

Distribution Characteristics and Health Risk Assessment of Heavy Metals in a Soil-Rice System in an E-waste Dismantling Area

选取广东省贵屿镇为研究区域,测定土壤中15种金属(As、Be、Cd、Co、Cr、Cu、Hg、Li、Mn、Ni、Sb、Sn、Pb、V和Zn)的含量,并确定研究区域大米中重金属(As、Cd、Cr、Cu、Hg、Ni、Pb和Zn)的含量;运用多元统计分析法和人体健康风险评价模型研究土壤-水稻系统重金属分布特征和健康风险.结果表明,电子垃圾拆解区周边表层土壤中Hg、Sb、Sn具有明显的积累效应,Cd、Hg的平均含量超过了《土壤环境质量标准》(GB 156182-1995)Ⅱ级标准限值,贵屿镇相较于陈店镇、司马浦镇污染较严重.多元统计分析表明,Cu、Sb、Ni、Zn、Sn、Pb、Hg来源于周边电子垃圾拆解活动,Cd、Be来源于其他人为污染源,V、Li、Cr、Co、As、Mn来源于自然源.土壤-水稻系统重金属迁移积累于稻米中的重金属评价富集量符合国家食品卫生标准,富集能力Cd>Zn>Cu>Ni>As>Cr>Hg>Pb.土壤重金属健康风险评估结果显示儿童更易受到重金属污染威胁,经手-口摄入是土壤暴露风险的主要途径,且各镇土壤重金属的非致癌风险和致癌风险均在可接受范围.贵屿镇通过摄取稻米途径所引起健康风险主要来自As、Cr、Cu、Ni元素.

This study selected Guiyu Town,Guangdong Province as the research area,the content of 15 kinds of metals（ As,Be,Cd,Co,Cr,Cu,Hg,Li,Mn,Ni,Sb,Sn,Pb,V,and Zn） in the soil was determined,and the content of heavy metals（ As,Cd,Cr,Cu,Hg,Ni,Pb,and Zn in the rice of this research area was identified. Multivariate statistical analysis and a human health risk assessment model were used to investigate the distribution characteristics and health risk of heavy metals in a soil-rice system. The results showed that Hg,Sb,and Sn in the surface soil surrounding the electronic waste dismantling area have obvious accumulation effect. The average content of Cd and Hg exceeds the Ⅱ standard limit of the＂Environmental Quality Standard for Soil＂（ GB 156182-1995）,and that Guiyu Town is more seriously polluted than Chendian Town and Simapu Town. The multivariate statistical analysis showed that Cu,Sb,Ni,Zn,Sn,Pb,and Hg originated from the surrounding electronic waste dismantling activities,Cd and Be originated from other man-made sources of pollution,and V,Li,Cr,Co,As,and Mn originated from natural sources. Heavy metal evaluation concentration in the soil-rice system by heavy metal migration accumulated in rice are in compliance with national food hygiene standards,and the enrichment ability is Cd 〉Zn〉 Cu 〉Ni 〉As〉 Cr〉 Hg〉 Pb. Soil heavy metal health risk assessment results showed that children are more susceptible to heavy metal pollution,and handling-oral ingestion is the main way of soil exposure risk. The non-carcinogenic risk and carcinogenic risk of heavy metals in the soil of each town are acceptable. The health risk in Guiyu Town through ingestion of rice is mainly from the elements that include As,Cr,Cu,and Ni.