A new study published in the Proceedings of the National Academy of Sciences (PNAS)  finds that conventional municipal wastewater treatment plants in the United States discharge high levels of organofluorine compounds. These chemicals, known broadly as PFAS (per and poly-fluoroalkyl substances) and related fluorinated compounds, are not entirely removed during treatment and can contaminate downstream drinking water supplies.

According to the researchers, only a small fraction of these compounds are the six federally regulated PFAS, with much of the total organofluorine coming from widely prescribed fluorinated pharmaceuticals. Using a national model, the team estimates that more than 20 million Americans could be exposed to potentially unsafe levels of these chemicals during periods of low river flow.

The study highlights the need for improved wastewater treatment technologies, clearer regulatory definitions of PFAS and related fluorinated chemicals, and better tracking of fluorinated pharmaceuticals. The authors recommend further investigation into the toxicity and behavior of these substances to prevent ongoing contamination of U.S. water supplies.

Visit PNAS to learn more about this study.