珠三角电子垃圾拆解区积尘中重金属的赋存特征、生物可给性及健康风险

Characteristics,Bioaccessibility and Health Risk of Heavy Metals Bound-in Dust in E-waste Dismantling Area of Pearl River Delta

为探究电子垃圾拆解区周边积尘中重金属的赋存特征及基于生物可给性的健康风险,对珠三角某电子垃圾拆解区6个点位及对照区3个点位室外积尘中重金属的污染水平进行分析,并研究基于地累积指数的赋存特征,解析重金属的来源,评估经口摄入对人体造成的健康风险。结果表明,暴露区8种重金属的平均含量超过当地土壤背景值1.45倍以上,其中Cd和Cu的污染程度较高,与电子垃圾拆解行为相关。此外,重金属在胃模拟阶段的生物可给性略高于胃肠模拟阶段2%。最后,综合分析8种重金属的健康风险发现,成人与儿童中Cr的致癌风险指数均>10^(-6),属于不可接受水平。

Characteristics and health risks based on bioaccessibility of heavy metals in outdoor dust collected from 6 e-waste recycling sites and 3 background sites in Pearl River Delta were investigated.Geoaccumulation index was used to evaluate features of pollution,and multivariate statistical analysis was adopted to understand sources of pollution.Health risk assessment model was utilized to assess the oral bioaccessibility of heavy metals for both adults and children.Results showed that the average concentrations of 8 heavy metals in the exposed area exceeded the local soil background value by more than 1.45 times.Analysis of the geoaccumulation index indicated that Cd and Cu contents in outdoor dust samples were at serious pollution levels,which might be related to the disordered disassembly behavior of e-waste.In addition,the average bioaccessibility of heavy metals in stomach phase was about 2%higher than that in intestine phase.The carcinogenic risk of Cr is over 10^(-6),indicating unacceptable level to human health.