Assessment of Variability and Uncertainty Distributions for Practical Risk Analyses

摘要: In recent years the U.S. Environmental Protection Agency has been challenged both externally and internally to move beyond its traditional conservative single-point treatment of various input parameters in risk assessments. first section, we assess when more involved distribution-based analyses might be indicated for such common types assessment applications as baseline assessments Superfund sites. Then two subsequent sections, give an overview with some case studies technical (A) variability/heterogeneity (B) uncertainty. By “inter-individual variability” is meant real variation among individuals exposure-producing behavior, exposures, or other parameter (such differences individual municipal solid waste incinerators emissions). contrast, “uncertainty” a description imperfection knowledge true value particular variability group. general uncertainty reducible by additional information-gathering analysis activities (better data, better models), whereas will not change (although it may accurately known) result extensive measurements. The purpose rather long-winded exposition these final sections show between different things, which are described using language probability distributions.