Global Courant
TRAVERSE CITY, Michigan (AP) — Drinking water from nearly half of U.S. faucets likely “perpetually contains chemicals” that can cause cancer and other health problems, according to a government study released Wednesday.
The synthetic compounds collectively known as PFAS contaminate drinking water to varying degrees in large cities and small towns — and in private wells and public systems, according to the U.S. Geological Survey.
Researchers described the study as the first nationwide attempt to test PFAS in tap water from private sources in addition to regulated sources. It builds on previous scientific findings that the chemicals are widespread, showing up in consumer products as diverse as nonstick cookware, food packaging and waterproof clothing, and making their way into water supplies.
Because the USGS is a scientific research agency, the report does not make policy recommendations. But the information “can be used to evaluate the risk of exposure and make decisions about whether or not to treat your drinking water, get it tested or get more information from your state” about the situation on the ground, said lead author Kelly Smalling, a research hydrologist.
The U.S. Environmental Protection Agency proposed the first federal drinking water limits in March for six forms of PFAS, or per- and polyfluorinated substances, that remain in the human body for years and do not degrade in the environment. A final decision is expected later this year or in 2024.
But the government has not banned companies using the chemicals from dumping them into public wastewater systems, said Scott Faber, a senior vice president of the Environmental Working Group, an advocacy group.
“We should be tackling this problem where it starts, rather than putting a stoplight after the accident,” he said. “We should require polluters to treat their own waste.”
Animal studies have found possible links between PFAS chemicals and some cancers, including kidney and testicular cancer, plus problems like high blood pressure and low birth weight.
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Federal and state programs typically measure exposure to contaminants such as PFAS at water treatment plants or groundwater wells that supply them, Smalling said. In contrast, the USGS report relied on samples from faucets at 716 locations, including 447 that rely on public utilities and 269 using private sources.
The samples were taken between 2016 and 2021 at various locations, mainly homes, but also some schools and offices. They include protected areas such as national parks; residential and rural areas with no identified PFAS sources; and urban centers with industry or landfills known to generate PFAS.
Most taps were sampled only once. Three were sampled multiple times over a three-month period, with the results changing little, Smalling said.
Scientists have tested for 32 PFAS compounds – most of them detectable by available methods. Thousands of others are believed to exist but cannot be detected with current technology, Smalling said.
The types most commonly encountered were PFBS, PFHxS and PFOA. PFOS, one of the most common in the entire country, was also a regular occurrence.
Positive samples contained as many as nine varieties, although most were closer to two. The median concentration was about seven parts per trillion for all 32 PFAS types, although for PFOA and PFOS it was about four parts per trillion — the limit EPA has proposed for those two compounds.
The heaviest exposures were in cities and near potential sources of the compounds, particularly in the East Coast; Great Lakes and Great Plains urban centers; and central and southern California. Many of the tests, mostly in rural areas, found no PFAS.
Based on the data, researchers estimate that at least one form of PFAS could be found in about 45% of tap water samples nationwide.
The study underscores that private well users should have their water tested for PFAS and consider installing filters, said Faber of the Environmental Working Group. Activated carbon filters or reverse osmosis membranes can remove the compounds.
The USGS study is “further evidence that PFAS is incredibly ubiquitous and that people who rely on private resources are particularly vulnerable to the harm caused by these chemicals,” Faber said.
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