Approach to assessment of risk to human health for priority substances under the Canadian environmental protection act

Abstract 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, 44 substances have been identified, for which priority must be given in assessing potential effects on the environment and human health. In this paper, the principles developed for the approach to assessment of risks to human health associated with exposure of the general population to Priority Substances under CEPA are outlined. These include the development of multimedia exposure estimates, classification of substances on the basis of the nature of the critical effect and the approach to evaluation for substances with different types of critical effects.