Cancer risk assessment: present and future.

Risk assessment is a process based on available scientific information about properties of a given agent, and its effect on biological processes to evaluate potential adverse consequences of exposure to that particular agent. Occupational cancer risk assessment might be considered as a more specific application of the process aimed at finding out whether a particular workplace exposure would lead to cancer. In 1983, a comprehensive model or paradigm of risk assessment was developed by the US National Academy of Sciences (NAS). The overall risk assessment process comprises the following elements: (a) hazard identification, which involves the qualitative determination of whether a particular agent causes a particular adverse effect in humans; (b) dose-response assessment, which describes how such effects are related to the dose; (c) exposure assessment, which estimates the level of human exposure to the substance with and/or without regulatory controls; (d) risk characterization as summary judgments on the existence and magnitude of the public health problem. In this article the authors discuss all the elements of the risk assessment process and present current approaches to this problem as well as research needs in this area.