Using Uncertainty Analysis to Improve Consistency in Regulatory Assessments of Criteria Pollutant Standards

This article identifies an additional source for subjective judgment regarding a key epistemic uncertainty i n RIAs for National Ambient Air Quality Standards (NAAQS)—the regulator's degree of confidence in continuation of the relationship between pollutant concentration and health effects at varying concentration levels. An illustrative example is provided based on the 2013 decision on the NAAQS for fin e particulate matter (PM2.5). It shows how the regulator's justification for setting that NAAQS was structured around the regulator's subjective confidence in the continuation of health risks at different concentration levels, and it illustrates how such expressions of uncertainty might be directly incorporated into the risk reduction calculations used in the rule's RIA. The resulting confidence ‐weighted quantitative risk estimates are found to be substantially different from those in the RIA for that rule. This approach for accounting for an important source of subjective uncertainty also offers the advantage of establishing consistency between the scientific assumptions underlying RIA risk and benefit estimates and the science‐based judgments developed when deciding on the relevant standards for important air pollutants such as PM2.5.

Source: Risk Analysis - October 23, 2019 Category: International Medicine & Public Health Authors: Anne E. Smith Tags: Perspective Source Type: research