This document presents EPAs review of the University of Michigan Dioxin Exposure Study (UMDES). This is one of the largest studies of dioxin exposure ever conducted and is an important contribution to the understanding of levels of dioxin in human blood, house dust, and soils and the factors associated with dioxin exposure. The design of the study was well-suited for meeting the objective of identifying patterns of serum dioxin, furan and PCB levels among adults living in the Midland-Saginaw region and provided the basis for making comparisons with a reference region in Jackson-Calhoun counties, 100 miles to the south. The relatively large number of participants and population based statistical sampling design are important strengths of this study. The data collected support reliable estimates of the distributions of dioxin concentrations in blood, soil and dust.