GenX, a chemical compound found in the drinking water of more than 1 million North Carolinians, is far more toxic that scientists originally believed, according to the EPA.
The agency yesterday released a final toxicology assessment for the compound, showing that even lower levels of GenX in drinking water could harm human health, particularly the liver.
The EPA assessment is not a national drinking water standard, but the new data — an update from a 2018 draft — can be used by states to develop new, more stringent health advisories.
A health advisory goal is not legally enforceable, but it is among the steps toward a national drinking water standard, which is law.
In North Carolina, the Department of Health and Human Services has established a health advisory goal of 140 parts per trillion for GenX; based on the new EPA data, the threshold would decrease to between 4 ppt and 5 ppt.
However, a DHHS spokeswoman said the agency is not currently updating the health advisory goal, but will likely adopt the EPA’s recommendation when it is announced next spring.
GenX is in the family of PFAS, which stands for perfluorinated or polyfluoroalkyl compounds. There are at least 5,000 types of PFAS, known as “forever chemicals” because they don’t degrade in the environment. They are used in many consumer products: microwave popcorn bags, stain- and grease-resistant clothing and furnishings, Teflon cookware, and fast food packaging.
A major source of GenX in North Carolina is Chemours’ Fayetteville Works plant near the Bladen-Cumberland County line. (International Paper and DAK Americas also discharge the compound in lesser amounts.)
Chemours and its predecessor, DuPont, discharged GenX into the Cape Fear River for decades, contaminating not only the drinking water source for the City of Wilmington, Brunswick County and Pender County, but also private drinking water wells near the plant.
It is difficult to remove the compounds from drinking water using traditional treatment methods; upgrades to public water systems cost millions of dollars. Private well owners with high levels of GenX are advised to install treatment systems, which are also expensive.
Chemours and the chemical industry in general had claimed GenX was safer than older “legacy” types of PFAS. GenX replaced PFOA, which major U.S. manufacturers phased out by 2015.
Yet the EPA’s new assessment suggests GenX is as toxic, if not more so, than many other types of PFAS. Anna Reade, staff scientist at the Natural Resources Defense Council, issued a statement, saying, “GenX is marketed as the ‘safe replacement’ for PFOA, but the fact that EPA indicates that GenX poses health concerns at levels 10 times lower than PFOA makes clear that those claims are not supported by science.”
GenX has been linked to several health effects, including reproductive problems, low birth weight, high cholesterol and several types of cancers. The new assessment said the liver “is particularly sensitive” to the effects of GenX.
The EPA’s latest assessment added safety factors to account for some of the uncertainty about the health effects of GenX. “It’s relevant that the EPA is taking a more protective health approach because of the complexity of PFAS and how they interact with the body,” said David Andrews, senior scientist with the nonprofit Environmental Working Group. “At lower and lower concentrations, it expands the scope of how widespread the chemicals are in our drinking water.”
Jamie DeWitt, a toxicologist and associate professor at East Carolina University, said that while the human body tends to clear GenX more quickly than other PFAS, animal studies suggest it is more potent. “It doesn’t take as much to produce a health effect,” DeWitt said, cautioning that there are not yet human data.
Dewitt said there are animal studies showing that GenX can cross the placenta in pregnant people. “Whatever mom took in, it went to the baby,” DeWitt said.
Chemours spokeswoman Lisa Randall told Policy Watch via email that the company is reviewing the technical information and data that underpins the EPA’s new assessment. “We are unaware of data that would support the conclusions drawn by the agency,” Randall said.
If DHHS and DEQ adopt a more stringent health advisory goal for GenX, it would have implications for Chemours.
Under a 2019 consent order between DEQ, the company, and Cape Fear River Watch, Chemours must provide alternative water sources to households whose private wells contain GenX.
The order requires Reverse Osmosis systems installed and serviced for individual PFAS, including GenX, at 10 ppt or higher, or any combined PFAS at levels above 70 ppt. The specific GenX level of 140 triggers a whole house replacement of either municipal hookup (which comes with a caveat of being under $75,000) or whole-house granular activated carbon or they can choose RO if they like
Households whose wells contain GenX at or above 140 ppt are eligible for a whole-house granular activated carbon system, municipal water (as long as the connection cost is less than $75,000) or reverse osmosis.
Based on the consent order, if that advisory goal is reduced to 5 parts per trillion, more homes would become eligible for alternative water, or an upgrade in the current systems, at Chemours’ expense.
As of June 2021, 6,103 wells had been tested more than 17 miles from the plant, according to DEQ. Of those, 235 had levels of GenX at or above 140 ppt.
Geoff Gisler, an attorney with the Southern Environmental Law Center, which represents Cape Fear River Watch, said the consent order also requires Chemours to notify downstream utilities if it discharges GenX at concentrations above the health advisory goal.
Chemours has reduced, although not fully eliminated, its GenX discharges because of treatment systems required by the consent order.
Those controls have helped decrease the levels of GenX entering the public water systems. However, based on a stricter health advisory goal of 5 ppt, Brunswick County’s “finished water” — which has been treated — showed levels this spring and summer above that threshold in 16 of 18 weeks.
The Cape Fear Public Utility Authority, which serves Wilmington, has tested for GenX in finished water at its Sweeney plant each week since January 2018. Levels have exceeded 5 ppt a dozen times this year.
Vaughn Hagerty, spokesman for the utility, said CFPUA staff is contacting state officials “to help us understand the implications” of the EPA’s GenX toxicity assessment and how it may impact the state’s 140 ppt lifetime-exposure health goal for GenX in drinking water.”
Cape Fear River Watch, a nonprofit group based in Wilmington, said based on the EPA’s findings, DHHS should immediately revise the state’s 140 ppt health goal for GenX , which indicates it should be closer to 4.5 ppt.
There are also data gaps on the effects of mixtures of PFAS in drinking water, which the EPA acknowledges. That’s important because if GenX is detected in drinking water, there are usually other PFAS in it as well.
As part of a 2019 GenX exposure study, Jane Hoppin of NC State, along with DeWitt of ECU and other researchers studied 85 private wells in Cumberland and Bladen counties. In addition to GenX, researchers found 10 other PFAS in more than 50% of the wells.
Public water systems have reported similar results. In Brunswick County, treated drinking water contained 31 types of PFAS, including GenX. CPFUA reported 19, including GenX, according to utility data.
The EPA is also re-evaluating the toxicity of PFOA and PFOS. If the agency also lowers health advisory levels for those compounds, said Andrews of the Environmental Working Group, “it could have enormous implications.”
There is a larger policy lesson in the EPA’s latest findings, said Geoff Gisler of SELC. “It should be that we can’t keep doing this. This story [about GenX] broke four and half years ago. It was a major contamination issue with a clear source and lots of people affected in a state with amazing scientists. We had all the right ingredients to respond and it’s still been four and half years. If we have to wait that long for each of these chemicals, we’ll never clean up our water.”
This story has been corrected to show that Smithfield Foods does not discharge the compound. A DEQ database showed concentrations, but this was due to laboratory detection limits and state requirements that zero be represented as a five or 10.