Valberg P A, Beck B D, Bowers T S, Keating J L, Bergstrom P D, Boardman P D
Gradient Corporation, 44 Brattle Street, Cambridge, Massachusetts 02138, USA.
Regul Toxicol Pharmacol. 1997 Oct;26(2):219-29. doi: 10.1006/rtph.1997.1148.
Health risk assessments often do not take into account the unique aspects of evaluating exposures to arsenic in soil. For example, risks from ingestion of arsenic in soil are often based on toxicity factors derived from studies of arsenic (soluble arsenate or arsenite) in drinking water. However, the toxicity of arsenic in drinking water cannot be directly extrapolated to toxicity of soil arsenic because of differences in chemical form, bioavailability, and excretion kinetics. Because of the differences between soil arsenic and water arsenic, we conclude that risks from arsenic in soil are lower than what would be calculated using default toxicity values for arsenic in drinking water. Site-specific risk assessments for arsenic in soil can be improved by characterizing the form of arsenic in soil, by conducting animal feeding or in vitro bioavailability studies using site soils, and by conducting studies to evaluate the relationship between urinary arsenic and soil arsenic levels. Such data could be used to more accurately measure the contribution that soil arsenic makes to total intake of arsenic. Available data suggest that arsenic usually makes a small contribution to this total.
健康风险评估往往没有考虑到评估土壤中砷暴露的独特方面。例如，土壤中砷摄入的风险通常基于饮用水中砷（可溶性砷酸盐或亚砷酸盐）研究得出的毒性因子。然而，由于化学形态、生物可利用性和排泄动力学的差异，饮用水中砷的毒性不能直接外推至土壤砷的毒性。由于土壤砷和水中砷存在差异，我们得出结论，土壤中砷的风险低于使用饮用水中砷的默认毒性值所计算出的风险。通过表征土壤中砷的形态、使用场地土壤进行动物喂养或体外生物可利用性研究，以及开展研究评估尿砷与土壤砷水平之间的关系，可以改进针对土壤中砷的特定场地风险评估。这些数据可用于更准确地衡量土壤砷对砷总摄入量的贡献。现有数据表明，砷通常在这一总量中占比很小。
