Human health risk assessment is a systematic framework within which scientific information relating to the nature and magnitude of threats to human health is organized and evaluated. The typical goal of a human health risk assessment is to develop a statement regarding the likelihood, or probability, that exposures arising from a given source, or in some cases from multiple sources, will harm human health (NRC, 1983). The risks to a given population are a function of the hazards of a given chemical and the exposure that the population experiences.
Risk communication “is an interactive process of exchange of information and opinion among individuals, groups, and institutions. It involves multiple messages about the nature of risk and other messages, not strictly about risk, that express concerns, opinions, or reactions to risk messages or to legal and institutional arrangements for risk management” (NRC, 1989, p. 21).
Risk management refers to the process whereby the results of a risk assessment are considered, together with the results of other technical analyses and nonscientific factors, to reach a decision about the need for and extent of risk reduction to be sought in particular circumstances and of the means for achieving and maintaining that reduction (NRC, 1983). At the EPA, risk management is typically linked to a regulatory decision, whereas risk assessment involves the evaluation of the scientific evidence about risks that inform that regulatory decision. As discussed in Science and Decisions: Advancing Risk Assessment (NRC, 2009), a conceptual distinction between risk assessment and risk management is maintained as it is “imperative that risk assessments used to evaluate risk-management options not be inappropriately influenced by the preferences of [decision makers]” (p. 12).
production. The EPA uses a health risk assessment and risk-management model to identify the nature and estimate the magnitude of risks from chemicals and other agents and to determine the best way to manage or mitigate those risks (EPA, 2004). As discussed in Chapter 1, the process of risk assessment and using it for regulatory decisions was first described in the seminal 1983 National Academy of Sciences report Risk Assessment in The Federal Government: Managing the Process (NRC, 1983) (hereafter the Red Book)1 and in a series of expert reports issued since that time (NRC, 1994, 1996, 2007, 2009). All of those reports emphasize the need for a conceptual distinction between risk assessment and risk management. Box 2-1 offers descriptions of some of the important terms in this area.
1 The National Research Council study that led to the Red Book was congressionally mandated and was requested “to strengthen the reliability and objectivity of scientific assessment that forms the basis for federal regulatory policies applicable to carcinogens and other public health hazards” (NRC, 1983, p. iii).