Occupational Exposure to Chemicals

The goal of this study is to test the efficacy and feasibility of Colesevelam administration (50% of the recommended dose) to reduce serum PFAS concentration in the Veteran population who have serum PFAS levels that exceed the National Academies Science criteria (PFASsix \> 20 ng/ml) using a double blind-placebo controlled study. Based on PFAS prevalence in serum samples, we anticipate recruiting up to n=500 Veterans to meet the goal of n=50 study participants to receive intervention or placebo. The primary outcome will be initial and final PFAS content in serum (total and 7 individual PFAS). The secondary outcome will be initial and final serum biomarkers related to lipid metabolism. As an exploratory aspect to the proposal, we will also measure fecal PFAS, bile acids, and microbial diversity to examine associations between PFAS content and bile acid levels and microbiome. Fecal PFAS, bile acid content, and microbiome may also be measured.

This randomized, placebo-controlled crossover trial will test the feasibility and acceptability of using colesevelam in male firefighters with high per- and polyfluoroalkyl substances (PFAS) exposure. This trial will also explore whether colesevelam lowers blood PFAS levels and urine environmental toxicant and mold mycotoxin levels.