In March of 2023, the first National Pri-mary Drinking Water Standards for per- and poly-fluoroalkyl substances (PFAS) were announced. The fourth Regulatory Determination that led to this development also included several other con-taminants for consideration: 1,4-dioxane (dioxane), 1,2,3-trichloropropane (TCP), and strontium, which faced no determination at this time. In this study, the relative risks associated with these three con-taminants and the two regulated PFAS, perfluorooc-tanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), are analyzed on a subregion level, consider-ing socioeconomic and racial factors in national expo-sure and risk levels for the U.S. population. Read more.