The use of information on susceptibility in risk assessment: state of the science and potential for improvement.

The aim of this paper is to evaluate the use of information on susceptibility or variability in risk assessment. Are we using it well? Are we not using it well or not at all? And finally, what can we do to improve the use of information on variability in risk assessment? The presentation is organized using the risk assessment paradigm developed by the National Research Council in 1983 (National Research Council, 1983. Risk Assessment in the Federal Government: Managing the Process. National Academy Press, Washington, DC.) which conceptualized risk assessment as consisting of four phases: hazard identification, dose response assessment, exposure assessment, and risk characterization. Because risk assessment procedures differentiate cancer risk from risk for systemic toxicity (i.e. non-cancer), cancer and noncancer risk assessment are discussed separately.