武汉市幼儿园降尘Pb污染特征及其生物有效性

幼儿园降尘铅污染是儿童对环境铅暴露的重要途径.从武汉市不同功能区幼儿园采集69个降尘样品,分析了其中铅的含量与空间分布,同时根据体外模拟实验方法（PBET）研究降尘中铅的生物可给行,目的是阐明武汉市幼儿园降尘铅的分布特征、污染程度,评估降尘中的铅对人体（尤其是儿童）的生物有效性.结果表明,武汉市幼儿园降尘中全铅含量为36.3～1 523mg.kg-1,平均值为169 mg.kg-1;与国内外部分城市对比发现,武汉市降尘中铅含量水平较低.武汉市降尘中铅分布空间差异大,局部污染严重.降尘铅在胃和小肠阶段的生物可给性分别为35%±15%和7.6%±5.8%.采用国际上认可度较高的综合暴露吸收生物动力学模型（IEUBK）,预测儿童（0～6）岁群体环境铅暴露后血铅几何均值2.73μg.dL-1;超过10μg.dL-1的概率〈0.001%,超过5μg.dL-1的概率为3.32%.

Distribution Characteristic and Bioaccessibility of Lead in Kindergarten Dust of Wuhan City

The characteristics of lead pollution and the associated health risk of children for the dust samples from 69 representative kindergartens in different type districts of Wuhan were investigated. Total lead concentration and bioaccessibility according to physiologically based extraction test (PBET) were determined. Results showed that the levels of lead concentration in dust ranged from 36.3 to 1 523 mg x kg(-1) with an average value of 169 mg x kg(-1), lower than published data from other areas. The great spatial variation of Pb in dust indicated that specific sites have been seriously contaminated by Pb. The bioaccessibilities of Pb in dusts were 35% +/- 15% at gastric phases and 7.6% +/- 5.8% at intestinal phases. According to the predicted model with the Integration Exposure Uptake Biokinetic Model (IEUBK), the geometric mean blood lead of children (0-6 years) was 2.73 microg x dL(-1), of which over 10 microg x dL(-1) was less than 0.001% and exceeded 5 microg x dL(-1) was 3.32%.