Meek M E, Hughes K
Environmental Health Directorate, Health Canada, Ottawa, Ontario.
Regul Toxicol Pharmacol. 1995 Dec;22(3):206-12. doi: 10.1006/rtph.1995.0002.
The Canadian Environmental Protection Act (CEPA) authorizes the Ministers of the Environment and of Health in Canada to investigate a wide variety of substances that may contaminate the environment and cause adverse effects on the environment and/or on human health. Under the Act, assessments have been completed for 44 environmental contaminants on the first Priority Substances List, including four metals and their compounds. The principles developed for the assessment of risk to human health for priority substances under CEPA are outlined, with specific emphasis on the metals. These include general aspects such as estimation of total exposure from all media, the development of exposure potency indices for carcinogens in lieu of low-dose risk estimates, and incorporation of toxicokinetic and toxicodynamic data, where available, to modify traditionally adopted uncertainty factors for development of tolerable intakes, or concentrations, for nonneoplastic effects. Aspects of the approach to human health risk assessment more specific to the metals considered under CEPA (i.e., arsenic, cadmium, chromium, and nickel) and implications for the subsequent strategic options process are also addressed, including the extent to which various chemical forms could be assessed (i.e., speciation) and essentiality.
《加拿大环境保护法》（CEPA）授权加拿大环境部长和卫生部长调查各种可能污染环境并对环境和/或人类健康造成不利影响的物质。根据该法案，已完成了对第一份优先物质清单上44种环境污染物的评估，其中包括四种金属及其化合物。概述了根据CEPA对优先物质进行人类健康风险评估所制定的原则，特别强调了金属。这些原则包括一些一般方面，如估算来自所有介质的总暴露量、制定致癌物的暴露效力指数以替代低剂量风险估计，以及在可行的情况下纳入毒代动力学和毒效动力学数据，以修改传统上采用的不确定性因素，从而制定非肿瘤效应的可耐受摄入量或浓度。还讨论了CEPA所考虑的金属（即砷、镉、铬和镍）在人类健康风险评估方法中更具体的方面以及对后续战略选择过程的影响，包括可以评估各种化学形态（即形态分析）的程度和必需性。
