矿区家庭灰尘中重金属污染及其潜在生态风险

为进一步了解我国西南某矿区周边家庭灰尘中重金属的污染水平和潜在生态风险,选取西南某矿区周边3个村庄(A村、B村和C村)的家庭作为研究区域,分析了102个家庭灰尘样品中Cd、Cr、Pb、As、Hg 5种重金属的含量水平及其分布特征,并采用潜在生态危害指数法(RI)进行生态风险评价.结果表明,西南某矿区周边3个村庄家庭灰尘中重金属的含量水平从高到底的顺序为:w(Pb)w(Cr)w(Cd)w(As)w(Hg).Cd、Pb、Hg在不同家庭灰尘中均有不同程度的累积,其中Cd的累积程度最为严重,最高累积系数为226.30,其次为Pb和Hg;Cr和As在不同家庭灰尘中累积系数均小于1.分别对3个村庄家庭灰尘中重金属进行相关分析,结果表明:A村家庭灰尘中Cd和Pb、Cd和As、Cr和Hg、Pb和As均具有较好的相关性;B村家庭灰尘中Cd和Pb、Cd和Hg具有较好的相关性;C村家庭灰尘中各元素均不存在显著相关性.主成分分析结果表明,研究区域家庭灰尘中Cd、Pb和Hg主要来源于室外环境,包括周边铅锌矿采选和冶炼及汽车尾气排放等.潜在生态风险评价显示:A村、B村和C村家庭灰尘中重金属的综合潜在生态危害均达到了极强生态危害水平.

The pollution and potential ecological risk assessment of the heavy metals in household dusts from mineral areas

Household dust is important exposure routs of heavy metals for human health. In the present study, Cd, Cr, Pb, As and Hg in 102 household dusts from three villages around the mineral areas, Southwest of China were analyzed and assessed the potential ecological risk. The results indicated that the concentrations of heavy metals in household dusts from three villages were w(Pb)>w(Cr)>w(Cd)>w(As)>w(Hg). Cd, Cr, Pb, As and Hg in household dusts accumulated in different degree. Cumulative coefficients of Cd, Pb and Hg in the household dusts were higher than those of Cr and As. Cd had the highest cumulative coefficient of 226.30, followed by Pb and Hg. The cumulative coefficients of Cr and As were less than 1. Correlation analysis indicated that significant correlation among Cd, Cr, Pb, As and Hg has been found in household dusts of village A and village B, respectively. However, there was no significant correlation among the heavy metals in household dusts of village C. According to principal component analysis, Cd, Pb and Hg contamination mainly from outdoor, including the metal smelting and mining as well as vehicle exhaust gas emissions, waste and so on. The potential ecological risk index indicated that comprehensive potential ecological hazards of heavy metals in household dusts of village A, B and C had reached a very strong level.