Drinking water contamination with fluorinated chemicals known as PFAS may be more prevalent than previously reported, a suggested.
Dozens of cities throughout the country had per- and polyfluoroalkyl substances () -- a group of man-made chemicals used to make fluoropolymer coatings and products that resist heat, oil, stains, and water -- in their tap water, according to independent lab testing commissioned by the Washington watchdog organization Environmental Working Group (EWG).
"The results confirm that the number of Americans exposed to PFAS from contaminated tap water has been dramatically underestimated by previous studies," Scott Faber, EWG senior vice president for government affairs, said in a press briefing.
"Of the tap water samples taken from 44 places in 31 states and the District of Columbia, only one location had no detectable PFAS," he added. "On average, six or seven different PFAS chemicals were detected in these samples. For 34 of the 44 places where the samples were taken, PFAS contamination was confirmed for the first time."
CDC scientists have found four PFAS -- PFOA, which was found in the Teflon chemical; PFOS, an ingredient formerly used in 3M's Scotchgard; and two others -- in the serum of nearly all people tested in the (NHANES), indicating widespread exposure of these "forever chemicals" in the U.S. population.
PFAS are not regulated and utilities that have chosen to test independently are not required to make results public. While the of 70 parts per trillion (ppt) for PFOA and PFOS, many states, including , have proposed levels considerably lower.
"The EPA guidance for PFOA and PFOS were based on older studies in laboratory animals, yet, new epidemiological research studies -- studies of actual people exposed to PFAS chemicals in their environment -- show that PFAS chemicals are much more toxic than what EPA previously stated," Olga Naidenko, PhD, vice president of EWG's science investigations, told 鶹ý.
"The more the scientific community looks into PFAS and the more scientific data that emerges, the lower and lower the proposed drinking water levels are going," said attorney Rob Bilott, who helped uncover health risks of PFOA contamination and wrote about this work in his book .
"Sounding the alarm is important, but that is not enough," said actor and activist Mark Ruffalo, who produced the movie Dark Waters about citizens of West Virginia who fought DuPont. Ruffalo played Rob Bilott in the film.
"We have not stopped industrial release of PFAS into the air and water," Ruffalo said in the EWG press briefing. "We have not stopped PFAS from being used in food packaging, cookware, cosmetics, and other everyday consumer products. Nor have we cleaned up any legacy PFAS pollution. There is still no legal requirement to filter PFAS from tap water, so more than 100 million Americans are likely drinking water contaminated with PFAS."
In the EWG study, were collected from May to December 2019 and analyzed by an accredited independent laboratory which used a modified version of to detect 30 different PFAS compounds. Overall PFAS detection limits were set at 1 ppt, and minimum levels were set for each of the 30 compounds.
Some of the highest PFAS levels detected were found in samples from major metropolitan areas, including Miami, Philadelphia, New Orleans, and the northern New Jersey suburbs of New York City. PFOA and PFOS were found in 30 and 34 samples out of 44, respectively.
What this means for human health is unclear. "PFAS have been linked to numerous health conditions already, such as excess weight gain, poor bone health, diabetes, and certain types of cancer," noted Qi Sun, MD, ScD, of Harvard T.H. Chan School of Public Health in Boston, who wasn't involved with the EWG study.
And based on what we know from animal experiments, PFAS may be also linked to other conditions, Sun told 鶹ý.
"In addition, these chemicals exert adverse health consequences not only to adults, but to infants and children. However, we still need much evidence to substantiate or to establish the effects of PFAS on human health," especially examining these chemicals in relation to risks of chronic conditions among people who initially are free of disease, Sun pointed out.
"With PFAS, the more scientists study this group of chemicals, the more data comes to light about their toxicity," said Naidenko, adding that EWG would be conducting more tests for PFAS in drinking water later this year.