Advances in Evaluating the Oral Bioavailability of Inorganics in Soil for Use in Human Health Risk Assessment

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• 作者：M. V. Ruby ; R. Schoof ; W. Brattin ; M. Goldade ; G. Post ; M. Harnois ; D. E. Mosby ; S. W. Casteel ; W. Berti ; M. Carpenter ; D. Edwards ; D. Cragin ; and W. Chappell
• 刊名：Environmental Science & Technology
• 出版年：1999
• 出版时间：November 1, 1999
• 年：1999
• 卷：33
• 期：21
• 页码：3697 - 3705
• 全文大小：124K
• 年卷期：v.33,no.21(November 1, 1999)
• ISSN：1520-5851

文摘

Cleanup goals for sites affected by inorganic contaminantsoften are established on the basis of risk assessments,and these assessments rely on the estimated oral toxicityof the substances of concern. These toxicity estimatestypically are based on historical studies in which a solublesalt of the metal was dissolved in water or mixed infood and then ingested by an animal or human. However,these toxicity studies do not account for the characteristicsof a metal in soil or the limitations that these characteristicsplace on enteric absorption of that metal. Therefore, amore accurate risk assessment must account for thebioavailability of the metal in site-specific soil, relative tothe bioavailability of the metal in the form administered in thetoxicity study (i.e., the relative bioavailability of theelement in soil). Historically, relative bioavailability estimatesfor metals in soil have been based on in vivo studies inlaboratory animals. Given the costs and time constraintsassociated with such studies, it is clear that a more efficientalternative is desirable. The most promising optioninvolves the development and validation of in vitro extractiontests that are predictive of oral metals bioavailabilityfrom soil. Such tests would provide a rapid and inexpensivemethod for developing more accurate exposure estimatesfor use in human health risk assessments. This paperreviews the site-specific in vivo studies that have beenconducted to estimate the relative bioavailability of arsenicand lead in soil, discusses the soil and mineralogicalfactors that influence the bioavailability of these elements,and reviews the research to date on the development ofbioavailability-predictive extraction tests for metals in soil.Finally, this paper outlines an ongoing collaborativeresearch project to formally validate an in vitro extractiontest for use in estimating the oral bioavailability ofarsenic and lead in soil.