While the emerging contaminant levels remain below the federal advisory level in drinking water, scientists consider this level may not be sufficient
Previously unreleased test results revealed that per- and polyfluoralkyl substances (PFAS) have been on the rise in Ann Arbor, Mich., drinking water this year. The detected levels of the emerging contaminants have been as high as 119.6 ppt in Ann Arbor’s intake water from the Huron River this year and 88.1 ppt in the treated water.
The test results were obtained by The Ann Arbor News/MLive under the Freedom of Information Act and show that while perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) have stayed mostly below minimum-risk levels, the overall levels of other PFAS chemicals have quadrupled since April 2018. This means that in Ann Arbor, PFAS in drinking water has increased from 12.6 ppt in April to between 53.2 and 88.1 ppt in recent months.
According to local news source MLive, city officials are not sure what is causing the increases, but hope installing new carbon filters at the city’s water treatment plant will fix the issue. While overall emerging contaminant levels are generally before the U.S. EPA health advisory of 70 ppt, scientists have questioned whether this advisory level is strict enough. The Agency for Toxic Substances and Disease Registry (ATSDR) recently published new minimum-risk levels for four types of PFAS at levels as low as 14 ppt for PFOS, 21 ppt for PFOA, 21 ppt for PFNA and 140 ppt for PFHxS for children, following a study which revealed the contaminant may pose a threat at lower levels.
Scientists from Michigan’s PFAS initiative recently reaffirmed that the 70 ppt standard for PFOA and PFOS is likely too high. Lead Researcher Dr. David Savitz, professor of epidemiology at Brown University, presented his team’s findings Dec. 18 and recommendations for managing PFAS contamination in Michigan.
“Information is evolving,” Savitz said, and that will help “reconcile scientific evidence and the kinds of decisions the state is facing now and will face into the future.”
While Savitz acknowledged that based off of toxicology data the current advisory level is insufficient, he was not able to recommend a new level. Instead, he hopes future technology will more effectively address PFAS contamination and cleanup efforts.
“The proprietary nature of the PFAS composition of products and goods in the marketplace is problematic for states like Michigan as it impedes the ability to monitor and plan mitigation of human exposure where needed,” the report said. “While concealing the identity of PFAS and other components in products may be important to protect intellectual property and patents, it is problematic when chemicals like PFAS end up in the environment, impacting soil, water, food quality, and ultimately the ecosystem and human health.”