There was a collective gasp around Philadelphia last month when a new Environmental Working Group report said “forever chemicals” were detected in a Philadelphia tap water sample.
Of the 44 samples the Washington D.C.-based environmental health nonprofit collected from different locations around the country, the one representing Philly had “some of the highest PFAS levels detected.”
But other urban water experts, including those from the Philadelphia Water Department, say the EWG study is misleading, citing concerns over research methods and the scientific community’s evolving understanding of PFAS.
“I don’t think people should be avoiding drinking tap water because of this,” said Howard Neukrug, a former Philly Water Commissioner and current executive director of The Water Center at the University of Pennsylvania and member of the EPA’s National Drinking Water Advisory Council.
“Drinking water in the U.S. today is a higher quality than at anywhere in the world at any time in history,” he continued, squashing the idea that in a previous era, humans drank pure, uncontaminated water.
PFAS refers to per- and polyfluoroalkyl substances, or a group of man-made chemicals most often found in products that are water-resistant or stain-repellent.
Commonly associated with Teflon and Scotch-Gard, PFAS are prevalent in a variety of consumer goods, including pizza boxes, raincoats, and nonstick cookware. The chemicals also have industrial uses and can be found in paints, cleaning products, and fire-fighting foams.
The use of PFAS is so widespread that a measurable amount could likely be found in every American.
The most-studied PFAS are PFOA and PFOS, according to the EPA, though it remains unclear how exposure to such low levels impacts human health.
“Studies of laboratory animals given large amounts of PFAS have found that some PFAS may affect growth and development, reproduction, thyroid function, the immune system, and injure the liver,” according to the Centers for Disease Control and Prevention.
That doesn’t mean those exposure levels are great enough and you live long enough and you drink enough water that you will get cancer from [PFAS.]”
Howard Neukrug, Executive Director of The Water Center at the University of Pennsylvania
The CDC cautions, however, that humans exposed to PFAS through their daily activities are far off from the levels experienced by the animals studied. “Finding a measurable amount of PFAS in serum does not imply that the levels of PFAS cause an adverse health effect.”
Neukrug puts it even more plainly. “Everything is everywhere,” he said, explaining that technology advancements are allowing scientists to detect minute amounts of chemicals that previously went unseen.
He notes that putting a microscope on the air we breathe would also reveal potentially harmful chemicals.
“There are carcinogens that we are exposed to all the time,” he said. “That doesn’t mean those exposure levels are great enough and you live long enough and you drink enough water that you will get cancer from [PFAS.]”
EWG’s study, “PFAS Contamination of Drinking Water Far More Prevalent Than Previously Reported,” said the Philadelphia water sample had 11 different PFAS compounds, each registering at different levels, ranging from 0.8 parts per trillion to 8.3 parts per trillion.
Together, the compounds totaled 46.3 parts per trillion, a figure that put Philly water among the worst of EWG’s samples.
The number seems alarming at first glance, but Neukrug said context is essential — one part per trillion is equal to a grain of sand in an Olympic-size swimming pool. “You wouldn’t drink that much over the course of a lifetime,” he said.
Just a single sample, collected Aug. 27, 2019, in “the likely service area of the Philadelphia Water Department,” led to EWG’s conclusions. For PWD and others in research, that’s a red flag.
“One observation does not constitute a significant body of data and does not hold up under scientific scrutiny,” PWD said in its position statement on the report. Collecting and assessing multiple samples, a standard research practice, helps verify the accuracy of findings and reduce the chance that human error impacted study outcomes.
Tasha Stoiber, an EWG senior scientist, and study co-author, recognized the single sample isn’t enough data to wholly vilify Philly’s tap water.
“This is just one snapshot at a specific point in time,” she said. “There is going to be variability, of course.”
The study wasn’t set up to analyze Philadelphia’s or any other specific metro’s water safety, explained Stoiber, it “was designed to assess how far-reaching the contamination was.”
That finding, while disheartening, is not a surprise.
PWD points out PFAS “are widespread around the world, even found in remote environments such as the Arctic region.” Their pervasiveness means even bottled water, since it also pulled from the planet’s waterways, is likely to have these compounds.
In Pennsylvania, prior to the EWG report, Gov. Tom Wolf made PFAS more of a priority, saying in December 2019 that plans include setting a state limit for PFAS in drinking water.
Those efforts are critical, according to Stoiber, but even more action is needed.
“It is the bigger picture here,” she said, “holding industry and the manufacturers of these chemicals accountable for the pollution they have caused.”
Lead support is provided by the William Penn Foundation.
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