北京市幼儿园地面尘中有毒金属浓度及其健康风险

Concentrations and Health Risks of Toxic Metals in Surface Dust in Kindergartens of Beijing

灰尘摄入是儿童金属暴露的重要来源.为了解北京市区幼儿园环境中有毒金属污染水平及其对儿童健康的影响,利用自制采样器采集北京市区代表幼儿园地面尘,并分析其中的Pb、Cd、Hg、As浓度.结果表明Cd、Hg、Pb在室内地面尘中具有不同程度的富集且呈现明显的季节变化特征.夏季地面尘中Pb、Cd、Hg、As浓度的几何均值分别为63.12、1.67、0.06、0.22μg·g-1;冬季分别为117.40、4.52、0.95、0.88μg·g-1.通过计算地理累积指数发现,北京市区幼儿园受到严重的Cd、Pb污染.暴露及健康风险评估结果表明,儿童对地面尘中有毒金属的经口摄入量远大于皮肤摄入量.4种金属对儿童均无显著的致癌和非致癌风险.但相比于其他金属,Pb的非致癌风险较高,其危险指数达0.12,需要引起重视.

Dust intake is an important source of children＇s metal exposure. To explore the contamination level and health risk of toxic metals in kindergartens,surface dust samples were collected with self-made sampler in representative kindergartens in urban Beijing and concentrations of Pb,Hg,Cd,As were analyzed. It was found that Cd,Hg,Pb accumulated in indoor dust in different degrees with a significant seasonal variation. The geometric means of Pb,Cd,Hg,As concentrations were 63. 12 μg·g^-1,1.67 μg·g^-1,0.06μg·g^-1,0.22 μg·g^-1in summer and 117. 40 μg·g^-1,4.52 μg·g^-1,0.95 μg·g^-1,0.88 μg·g^-1in winter,respectively. Geoaccumulation indexes calculated for each metal showed a severe contamination of Pb and Cd in indoor surface dusts. The results of exposure and health risk assessment of target substances displayed that the oral intake of dust metals was much higher than that of dermal pathways for children. However,no obvious carcinogenic and non-carcinogenic risks were found for all metals. The Pb,against other species,had the highest non-carcinogenic risk to children,Hazard Index of which was 0. 12. Therefore,the health risk of Pb in indoor dust should raise the concern.