Felter S P, Dourson M L
TERA, Cincinnati, Ohio 45223, USA.
Regul Toxicol Pharmacol. 1997 Feb;25(1):43-59. doi: 10.1006/rtph.1996.1073.
Risk assessment involves establishing scientifically defensible dose-response relationships for end points of concern. For Cr(VI)-contaminated soils, this includes conducting dose-response assessments for blood, liver, and kidney toxicity following oral exposure; lung cancer following inhalation exposure; and allergic contact dermatitis following dermal exposure. This dose-response information is then integrated with a site-specific exposure assessment (or default assumptions) in order to develop a site-specific (or generic) soil criterion within the framework of a comprehensive risk characterization. Risk managers develop cleanup standards designed to protect against all possible adverse effects, taking into account these site-specific (or generic) criteria and other factors such as technical feasibility, cost-benefit analyses, and socio-political concerns. Recently a push for cost-benefit analyses of environmental decisions has occurred, further supporting the need for risk assessors to prepare a comprehensive risk characterization, with its attendant uncertainties. These risk assessment and management issues are brought to the forefront by risk assessors and risk managers dealing with Cr(VI)-contaminated soils. This article offers a review and analysis of the risk characterization of Cr(VI)-contaminated soils, showing that the differing toxicities with route of exposures do not necessarily lead to different characterizations or risk. Soil concentrations in the range of 130 to 450 ppm appear to protect against noncancer toxicity from oral exposure, cancer toxicity from inhalation exposure, and allergic contact dermatitis from dermal exposure.
风险评估涉及为相关终点确定具有科学依据的剂量-反应关系。对于受六价铬污染的土壤，这包括进行口服暴露后血液、肝脏和肾脏毒性的剂量-反应评估；吸入暴露后肺癌的剂量-反应评估；以及皮肤暴露后过敏性接触性皮炎的剂量-反应评估。然后，将这些剂量-反应信息与特定场地的暴露评估（或默认假设）相结合，以便在全面风险特征描述的框架内制定特定场地（或通用）的土壤标准。风险管理者制定旨在防止所有可能的不利影响的清理标准，同时考虑这些特定场地（或通用）标准以及其他因素，如技术可行性、成本效益分析和社会政治问题。最近，人们开始推动对环境决策进行成本效益分析，这进一步支持了风险评估人员进行全面风险特征描述的必要性，以及随之而来的不确定性。处理受六价铬污染土壤的风险评估人员和风险管理者将这些风险评估和管理问题推到了前沿。本文对受六价铬污染土壤的风险特征进行了综述和分析，结果表明，不同暴露途径导致的不同毒性不一定会导致不同的特征描述或风险。130至450 ppm范围内的土壤浓度似乎可以预防口服暴露导致的非癌症毒性、吸入暴露导致的癌症毒性以及皮肤暴露导致的过敏性接触性皮炎。
