PART THREE ...continued frm Part 2
In a recently published commentary, Kyle Steenland, an epidemiologist at Emory University’s Rollins School of Public Health, wrote that human testicular and kidney cancers have the strongest associations with PFAS exposure, “although the literature remains rather sparse for both.” Most of the human evidence for these two cancers comes from highly exposed populations, Steenland pointed out, citing the example of communities near the DuPont Washington Works plant in Washington, West Virginia, which dumped PFOA-contaminated wastewater into the Ohio River for half a century. In an email, Steenland stated he was unable to comment publicly on the cancer evidence, given that he was preparing for an upcoming World Health Organization meeting during which participants will rate PFOA and PFAS carcinogenicity.
To provide more clarity on PFAS health impacts, the 2022 National Academies of Science report broke out the risks by their associated blood levels. The report reached the conclusion that people with PFAS blood levels under 2,000 ppt likely face no risk from the chemicals. Those with blood levels ranging between 2,000 ppt and 20,000 ppt — especially sensitive populations — were advised to seek screening for elevated cholesterol and breast cancer. Pregnant people were also advised to be checked for hypertension. PFAS at blood levels higher than that were further associated with potential thyroid problems, ulcerative colitis, and signs of kidney and testicular cancer. In 2018, the CDC released data showing that blood levels of PFOA and PFOS fell sharply in the general U.S. population after the chemicals were phased out. Average PFOA levels were 1,400 ppt in 2018, which is 70 percent lower than average measurements taken in 1999 to 2000. Similarly, PFOS levels fell 85 percent over the same time frame — to 4,300 ppt. More recent data are not available, but in an email to Undark, Calonge wrote that, “I would expect there would not be a steady state and that levels will continue to go down over time.”
Calonge, chair of the National Academies panel that produced the report, added that the members tried to distinguish between health effects for which there was sufficient as opposed to more limited evidence. But a key limitation in assessing the potential risks — one that also fuels Calonge’s skepticism towards the new MCL — is that scientists still haven’t resolved how PFAS levels in blood and drinking water relate to each other.
The chemicals are slowly excreted from the body in urine and during menstruation, so “how much would you have to drink before you reached the serum level that would put you into an area of concern?” Calonge, who is also the chief medical officer for the Colorado Department of Public Health and Environment, asked. No one knows that, and that’s “the problem with the EPA standard.” The EPA should base its MCL on a concentration that leads to harmful blood serum levels, Calonge said, instead of just analytical detection limits.
THE MAXIMUM PFAS concentration detected so far at GAUD’s Riverside well was PFOA at a level of 7.3 ppt, in November 2022. To drop below 4 ppt, GAUD plans to install a multimillion-dollar system that works by trapping PFAS molecules in granular activated carbon. Tarbuck said that system will be housed in a facility outfitted with heating, ventilation, and air conditioning, and will require permitting and additional labor to sustain operations. Disposal of the spent carbon filters is also an issue since they’re contaminated with PFAS and “that’s material that nobody wants to touch,” Tarbuck said.
How to get rid of PFAS and other pollutants that build up in granular activated carbon is an ongoing area of research. One option is to incinerate the material, thereby regenerating it for repeat use. But that should be done in ways that ensure PFAS are destroyed completely, Knappe said. Jennifer Kocher, a spokesperson for the National Association of Water Companies, which lobbies on behalf of water utilities, said the EPA still hasn’t come with a plan for how to manage the wastes. “Water and wastewater companies do not create or use any of these PFAS, PFOAs — any of these chemicals — within their processes at all, and yet here we are, now we’re being charged with cleaning it up,” she said. And PFAS waste disposal could pose a “huge logistical obstacle for our water systems.” The association is now attempting to secure an exemption from federal hazardous waste laws, she said, that could shift potential cleanup costs onto PFAS manufacturers.
Does the effort to lower PFAS concentrations at most locations by just a few parts per trillion represent the best use of money spent with regard to water safety? Oregon State University’s DeWitt insisted the answer is yes, given that the only completely risk-free level of “these compounds that were not really ever designed to go into human bodies” is zero.
Offering a counterargument, Boobis suggested that small PFAS reductions in water are “not going to make a huge difference to overall exposure unless you do something else.” Along those lines, some states are setting laws to ban the sale and distribution of PFAS containing products. Maine, which was the first to move in this direction, set a deadline of 2030 for the ban and has called on companies to report the presence of PFAS in their products beginning January 1, 2025.
Still, thousands of companies have requested and received extensions to the law’s notification requirements. Some of those companies insist the chemicals are irreplaceable, especially in microchip-making and battery production. And on a national level, legislative proposals to regulate PFAS in everyday items have repeatedly failed in Congress.
Moody said there’s another option: Raise the MCL from 4 ppt to 10 ppt. Doing that, the AWWA asserts, would allow limited resources to be targeted on areas with the worst PFAS contamination. Numerous water systems in the U.S. have PFAS at levels in the “hundreds or thousands of ppt,” Moody said. Investing in those communities first “makes a lot more sense,” he said, especially since it’s unclear “whether or not reducing drinking water exposure at single-digit ppt will impact the blood levels.”
Steps towards finalizing the rule are “quite involved,” Dourson said. The EPA first had to compare the standard’s anticipated health benefits with its estimated costs and evaluate whether PFAS exposures in drinking water are sufficient to justify national rulemaking. Dourson said the EPA sent the rule to the White House Office of Management and Budget for approval, likely in late 2023.
Tarbuck said GAUD’s exceedance has been a tough pill to swallow. The utility recently obtained a $200,000 grant from the Maine Department of Health and Human Services to pilot-test some PFAS removal technology. The funding will help, but it’s not enough to avoid passing much of the $3 to 5 million cost on to households in GAUD’s service areas. “The gut reaction is that it will be expensive for our rate payers to fix this,” Tarbuck said.
Tarbuck worries that higher water bills could be especially hard on people of limited means and said the upcoming compliance cost will now add to the financial burden of replacing aging infrastructure. “We can remove it, we will remove it,” he said. If the PFAS is as risky as they say it is, Tarbuck added, then it’s appropriate to spend the money. But the levels are not so high that they have caused a major public health concern, Tarbuck said, and that “could be hard for us to explain to rate payers.”
Charles Schmidt is a senior contributor to Undark and has also written for Science, Nature Biotechnology, Scientific American, Discover Magazine, and The Washington Post, among other publications.
UPDATE: An earlier version of this story referred imprecisely to the chemical compound HFPO-DA, a member of the class of per- and polyfluoroalkyl substances known as PFAS, and to a commercial chemical process known as GenX. The story has been updated to clarify that the name GenX generally refers to both HFPO-DA as well its ammonium salt, and to more precisely distinguish GenX chemicals from other forms of PFAS.
https://undark.org/2024/01/15/drinking-water-pfas-cost/?utm_source=pocket-newtab-en-us