By Brady Dennis
Excerpt: Drinking water supplies serving more than six million Americans contain unsafe levels of a widely used class of industrial chemicals linked to potentially serious health problems, according to a new study from Harvard University researchers.
The chemicals — known as polyfluoroalkyl and perfluoroalkyl substances, or PFASs — have been used for decades in a range of industrial and commercial products, including non-stick coatings on pans, food wrappers, water-repellent clothing and firefighting foam. Long-term exposure has been linked to increased risks of kidney cancer, thyroid problems, high cholesterol and hormone disruption, among other issues.
“Virtually all Americans are exposed to these compounds,” said Xindi Hu, the study’s lead author. “They never break down. Once they are released into the environment, they are there.”
As part of the study, which was published Tuesday in Environmental Science & Technology Letters, the researchers examined concentrations of six types of PFAS chemicals in drinking water supplies around the country. The data came from more than 36,000 samples collected by the Environmental Protection Agency between 2013 and 2015.
They also looked at sites where the chemicals are commonly found — industrial plants that use them in manufacturing, military bases and civilian airports where fire-fighting foam is used and wastewater treatment plants.
What they found: 194 of 4,864 water supplies across nearly three dozen states had detectable levels of the chemicals. Sixty-six of those water supplies, serving about six million people, had at least one sample that exceeded the EPA’s recommended safety limit of 70 parts per trillion for two types of chemicals — perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA).
“It’s a big problem in a lot of communities,” said Richard Clapp, professor emeritus at Boston University’s school of public health. “It’s happening in a lot of places.”
From Decatur, Ala., to Merrimack, N.H., residents have been wrestling with high levels of the potentially harmful chemicals, and public officials have been scrambling to figure out how to prevent them from contaminating drinking water supplies.
The federal government does not currently regulate PFAS chemicals. But they are on the EPA’s list of “unregulated contaminants” that the agency monitors, with the goal of restricting those that most endanger public health. Partly because the rules that it must follow are complicated and contentious, officials have failed to successfully regulate any new contaminant in two decades.