State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; School of Earth Sciences, China University of Geosciences, Wuhan 430074, China.
State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China.
J Hazard Mater. 2015 Oct 30;297:191-7. doi: 10.1016/j.jhazmat.2015.04.074. Epub 2015 Apr 28.
In this study, ground surface dust samples from two contrasting areas, a former zinc smelting area in Guizhou Province and a common urban district in Wuhan city, Hubei Province, China, were assessed for in vitro Pb bioaccessibility using a physiologically based extraction test (PBET). Extremely elevated concentrations of Pb (220-6348 mg/kg) and other trace metals were observed in the zinc smelting area. While moderate high metal concentrations (79-1544 mg/kg of Pb) in the urban dusts were attributed to various urban activities, coal combustion and traffic emissions. Lead bioaccessibility in the stomach-phase varied from 17.6 to 76.1% and no significant difference was found between industrial and urban dust samples. Compared with the stomach-phase, Pb bioaccessibility in the more alkaline intestinal-phase was considerably lower (1.2-21.8%). A significantly negative correlation was found between dust Ca concentrations and Pb bioaccessibility in the intestinal-phase, suggesting that Ca plays an important role in reducing the bioaccessible Pb in the intestinal-phase. The estimated Pb exposure based on gastric bioaccessible Pb was 13.9 and 1.8 μg/kg day for children living in the industrial and urban areas, respectively, accounting for 85% and 41% of their corresponding total Pb exposure.
本研究采用基于生理学的提取试验（PBET），评估了来自中国贵州省一个前锌冶炼区和湖北省武汉市一个普通城区的两个对比地区的地表灰尘样本中的体外 Pb 生物可给性。在锌冶炼区，观察到 Pb（220-6348mg/kg）和其他微量元素的浓度极高。而城市灰尘中中等偏高的金属浓度（Pb 为 79-1544mg/kg）归因于各种城市活动、煤炭燃烧和交通排放。胃相中的 Pb 生物可给性在 17.6%至 76.1%之间变化，工业和城市灰尘样本之间没有发现显著差异。与胃相相比，碱性更强的肠相中的 Pb 生物可给性明显较低（1.2-21.8%）。发现灰尘 Ca 浓度与肠相中 Pb 的生物可给性之间呈显著负相关，表明 Ca 在降低肠相中生物可给的 Pb 方面发挥了重要作用。基于胃中生物可给性 Pb 估计，生活在工业区和城区的儿童的 Pb 暴露量分别为 13.9 和 1.8μg/kg·天，分别占其总 Pb 暴露量的 85%和 41%。
