Bioaccessibility of uranium in soil samples from Port Hope, Ontario, Canada.
Bioaccessibility of uranium in soil samples from Port Hope, Ontario, Canada.
复制标题
加拿大安大略省霍普港土壤样品中铀的生物可接近性。
DOI：
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发表时间：
2012
影响因子：
11.4
通讯作者：
Larry Wong
中科院分区：
文献类型：
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作者：
S. Jovanovic;P. Pan;Larry Wong
根据生物利用度数据，对危险废物场址铀污染对人类健康的风险进行充分评估，这是确定清理战略的一个重要步骤。受污染土壤中铀的生物利用度尚未得到适当的测定。生物可及性是对生物利用度的体外保守估计，因此经常用于特定地点的风险评估。采用生理提取试验（PBET）对加拿大安大略省霍普港地区33个土壤样品中铀的生物可及性进行了测定。胃+肠期的生物可及性值（48.4%±16.8%）高于胃期（20.8%±11.7%），这很可能是由于富含碳酸盐离子的肠液对土壤中铀的提取效率更高所致。根据土壤样品的扫描电镜检查结果，讨论了生物可达性测量值的变异性。铀在胃（酸性）相和胃+肠（中性）相的生物可及性值在含铀颗粒较小的土壤样品中较高，在含铀颗粒较大的样品中较低。我们认为，造成霍普港土壤样品生物可达性测量值变化的最重要原因可能是含铀颗粒粒径的差异。
Adequate assessment of human health risk of uranium contamination at hazardous waste sites, which is an important step in determining the cleanup strategy, is based on bioavailability data. Bioavailability of uranium from contaminated soil has not been properly determined yet. Bioaccessibility is an in vitro conservative estimate of bioavailability and is thus frequently used for site-specific risk assessment. Bioaccessibility of uranium was measured in 33 soil samples from the Port Hope area in Ontario, Canada, by the physiologically based extraction test (PBET). Higher bioaccessibility values in the gastric plus intestinal phase, 48.4% ± 16.8%, than in the gastric phase, 20.8% ± 11.7%, are very probably the result of more efficient extraction of uranium from soil by intestinal fluid rich in carbonate ions. The observed variability of measured bioaccessibility values is discussed in light of the results of scanning electron microscope examination of the soil samples. Uranium bioaccessibility values in both gastric (acidic) and gastric plus intestinal (neutral) phases are higher in soil samples with smaller uranium-bearing particles and lower in samples where the uranium-bearing particles are larger. We postulate that the most important reason for variability of measured bioaccessibility values in Port Hope soil samples may be the difference in particle size of uranium-bearing particles.