In response to the growing problem of drinking water contaminated with per- and poly-fluoroalkyl substances (PFAS), a new analysis shows that many states are establishing their own guideline levels for two types of PFAS—PFOA and PFOS—that differ from federal guidelines. The new study appears in the Journal of Exposure Science & Environmental Epidemiology, which is published by Springer Nature. According to Alissa Cordner of Whitman College in the US, the study’s lead author, the findings highlight the need for enforceable federal standards and more health protective limits on these contaminants in drinking water to safeguard the health of millions of people whose water supplies have been contaminated.