for improvements in health, the pace of technological change, the importance of recreational areas, and the cost to the private sector of implementing new rules.

As part of a systematic approach to decision making, EPA should plan its analysis of the uncertainty analyses in estimates of health risks and those other factors around the needs of the decision makers beginning at the outset of the decision-making process; in other words, uncertainty analyses should not be an afterthought. Characterizations of health risk estimates, benefits, costs, technological availability, and other factors should reflect those uncertainty analyses. The implications of those different sources of uncertainty are presented in Box 7-1.

The appropriate uncertainty analysis depends, in part, on the type of uncertainty (variability and heterogeneity, model and parameter uncertainty, or deep uncertainty). Statistical analyses are often appropriate for assessing variability and heterogeneity, expert judgments and elicitations work well for model and parameter uncertainty, and robust decision-making approaches and scenario analysis will be needed for decision making in the presence of deep uncertainty.

Good communication among analysts, decision makers, and stakeholders is critical to ensuring a high-quality, comprehensive decision-making process and a high-quality, comprehensive decision. A process that includes such communication will help identify stakeholder concerns and potential uncertainties and to build social trust among the participants in the process. Each EPA decision is unique, and there is no universal best approach or tool for communicating uncertainties. The most appropriate strategy for communicating uncertainty will depend on the context of the decision, the purpose of the communication, the type of uncertainty, and the characteristics of the audience, including the level of technical expertise, personal and group biases, and the level of social trust.

Analyzing and communicating the uncertainty in the various factors that affect EPA’s decisions might require specialized expertise (for example, expertise in the analysis of benefits and cost and the uncertainties in each and also in communicating those uncertainties), and some of the necessary skills may be different from those found among EPA’s current personnel.

The committee’s specific findings and recommendations are presented below.



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