The chemicals called “PFAS” have been in the news a lot lately — like the recent revelation that the U.S. Environmental Protection Agency was allowing PFAS-contaminated water to be treated in Lowell and discharged into the Merrimack River, or the news that chemical giant 3M is suing the state of New Hampshire over the state’s strict PFAS drinking water standards.
So, what are these chemicals, anyway? And should we be worried about them? Here’s what you need to know:
What are PFAS?
There are around 4,700 chemicals in the PFAS family, and they all have two things in common:
- They’re all man-made.
- They contain linked chains of carbon and fluorine.
The bond between carbon and fluorine atoms is one of the strongest in nature. That means that PFAS chemicals don’t degrade easily; they stick around in the human body and the environment for a long time, and are very stable in water. That’s why some people call them “forever chemicals.”
Where do they come from?
PFAS chemicals were invented in the 1930s, and found to have some useful qualities for consumer products because they repel oil, water and grease. Companies used these chemicals in many common items, like paper food packaging (think microwave popcorn bags and pizza boxes), stain-proof rugs, waterproof clothing, some types of dental floss and nonstick cookware.
The two PFAS chemicals you’re most likely to hear about are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Neither of them are made in the United States any longer — manufacturers started voluntarily phasing them out in the early-2000s — but because they were manufactured here for decades, they remain the most widespread in the environment, most-studied and best understood. Manufacturers from other countries still produce PFOS and PFOA, and can ship products made with them into the U.S.
U.S. manufacturers have replaced PFOA and PFOS with other members of the PFAS family. The effects of these next-generation PFAS chemicals are not as well understood.
The bottom line is there are still PFAS chemicals in the everyday products we buy.
What is the effect of PFAS chemicals on health? And how do we know?
Because these chemicals have been used in many consumer products for many decades, most people have been exposed to them. The chemicals probably enter our bodies through the food we eat, like microwave popcorn, food in takeout containers or fish from contaminated water. But some people are exposed through highly contaminated drinking water, according to Laurel Schaider, a research scientist with the Silent Spring Institute. People can also inhale PFAS-contaminated air or dust. According to the CDC, studies have shown that only a small amount of PFAS can be absorbed through your skin. Studies estimate that 98% of Americans have detectable levels of PFAS in their blood.
Scientific studies have provided “strong evidence” linking PFAS exposure to elevated cholesterol, thyroid disease, damage to the liver and kidneys, effects on fertility and low birth weight, according to Schaider. Research also suggests that exposure to PFAS chemicals might suppress the immune systems of young children, potentially making vaccines less effective.
Some studies also suggest an elevated risk of testicular and kidney cancer in people exposed to higher levels of PFAS. Scientists are less certain about the health effects of newer PFAS compounds that replaced PFOS and PFOA, and the effects of low level exposure, Schaider says.
Despite the remaining uncertainty, scientists have found that PFAS chemicals affect “every major organ in the human body,” says Elsie Sunderland, a PFAS researcher at the Harvard T.H. Chan School of Public Health. “So that is scary for me.”
But, she says, since PFOS was phased out of production around the year 2000, blood levels have dropped dramatically. “If you stop producing it, yes, you can still find it,” she says. “But we also saw a very fast and dramatic reduction in both environmental samples and people’s blood.”
“If you stop producing it, yes, you can still find it.”Elsie Sunderland
How do these chemicals get into drinking water?
PFAS chemicals were widely used in firefighting foams on military bases, airports and firefighting training facilities. They are also found in landfills when products containing PFAS break down, and in fertilizer made from human waste or sewage. All these sources can contaminate nearby drinking water supplies.
Estimates about the extent of contaminated drinking water vary widely, based on testing methods and sensitivity. The Environmental Working Group, a consumer-education nonprofit, estimates that 1,500 drinking water systems across the country may be contaminated, affecting 110 million Americans.
Between 2013 and 2015, the EPA tested 158 public water systems and 13 smaller systems in Massachusetts for six PFAS chemicals. Nine drinking water sources in the state, including municipal water supplies in Hyannis, Westfield and Hudson, were found to have PFAS levels above EPA guidelines, according to the Massachusetts Department of Environmental Protection. More testing has been done since then; a DEP map of test sites was last updated in October 2019.
Northeastern University also maintains an interactive map of PFAS contamination in the U.S.
Some areas responded quickly to high levels of PFAS chemicals in their water supply; both Hyannis and Ayer have spent millions of dollars installing municipal filtration systems. In September Gov. Charlie Baker proposed adding $20 million to the state budget for PFAS remediation.
How do I know if my drinking water is contaminated? What do I do if it is?
A good place to start is the Environmental Working Group’s Tap Water Database. Enter your ZIP code and see if there are any contaminants in your home water (you may want to double check with your supplier if any numbers are concerning).
If you want to decrease the PFAS chemicals in your water, Phil Brown, a PFAS researcher at Northeastern, suggests installing a home water filter that uses activated carbon or a reverse osmosis system.
“Obviously we want to protect ourselves and our families,” he says, “but we also want to focus on getting cities and states and the federal government to their job.”
How do I avoid eating PFAS with my food?
“Don’t eat microwave popcorn — that’s an easy one,” Sunderland says. She also says to avoid food packaging and take-out boxes when possible, opting instead for fresh food in reusable containers.
Should I stop using nonstick cookware?
Experts are divided on nonstick cookware. Some say don’t use it at all, while others say it’s OK as long you don’t use it on high heat, and the coating isn’t flaking off.
What else can I do to limit my exposure to PFAS chemicals?
Skip the stain-resistant carpets and upholstery. Use uncoated dental floss, or at least floss coated with natural wax. Sunderland also notes that some companies, like Ikea, Lowe’s and Columbia Sportswear, are starting to phase PFAS chemicals out of some of their products, so you can look for items that are PFAS-free. The Green Science Policy Institute’s list of PFAS-free products is a good resource. The Silent Spring Institute offers a free mobile app called Detox Me, which includes a buying guide.
What is the federal standard for PFAS in drinking water?
There are no federal drinking water limits for PFAS chemicals.
“Public water supplies aren’t required to test for these on a routine basis, and there’s no enforceable actions that are needed if high levels are found in a public water supply,” Schaider says.
There are, however, federal guidelines. In 2016 the EPA issued “health advisory levels" for public water supplies at 70 parts per trillion for PFOS and PFOA combined. These levels are guidelines only, and cover only the two most common PFAS chemicals.
What’s the Massachusetts standard and how does it compare to other states?
Massachusetts released regulations for PFAS limits in drinking water in September, 2020. The rule establishes a limit of 20 parts per trillion for the sum of six PFAS compounds, including PFOS and PFOA. Managers of all public water systems in the state are required to test for these six compounds, and take action when they detect PFAS levels above the limit.
Other states, most notably New Jersey and New Hampshire, also have strict requirements. The New Hampshire rules list the limits for individual PFAS compounds, rather than grouping them together: 12 parts per trillion for PFOA, 15 parts per trillion for PFOS, 18 parts per trillion for PFHxS and 11 parts per trillion for PFNA.
Before September 2020, MassDEP guidelines said that the combined levels of PFOS, PFOA and three other PFAS chemicals combined should be below 70 parts per trillion.
Any chance the federal guidelines will change anytime soon?
In February 2019, the EPA announced a plan to start regulating PFOS and PFOA by the end of the year; specifically, listing them as hazardous substances under the Superfund law to help communities clean up contamination, and also recover costs. The EPA is also gathering information to determine if it should regulate other PFAS chemicals.
Experts are skeptical that the EPA will follow through.
“They have been overturning regulations day by day,” Brown says. “They’re so anti-regulatory that it seems unlikely.”
And even if the EPA does set legal limits, Brown says, they are likely to set them at the current advisory levels of 70 parts per trillion. Some researchers are recommending a limit of 1 part per trillion, or even lower.
“EPA is following through on its commitment under the PFAS Action Plan,” said EPA Administrator Andrew Wheeler in a statement released Nov. 7. He noted that the EPA is committed providing communities "with the tools and information they need to better monitor, detect and address PFAS.”
Why do PFAS chemicals seem to be in the news so much lately?
Brown says a turning point came in 2015, when the EPA’s first broad sampling of PFAS chemicals in water showed widespread contamination. That added on to data gathered from the CDC’s National Health and Nutrition Examination Survey, showing that “virtually everybody in the country has PFAS in their blood,” as Brown puts it.
More recently, a number of lawsuits and legal settlements, as well as new data about contaminated military sites, has kept the issue in the public eye. Brown says the buzz around PFAS chemicals is unusual.
“You never really see this much happening with one set of contaminants in such a short time,” he says.
Is there any way to really, truly, get rid of these things?
“One of the few things that will get rid of PFAS are very high temperatures,” Schaider says.
Water-treatment facilities, for instance, will often send their PFAS-infused filters to incinerators for disposals. Sunderland says that if the incineration isn’t complete, there is concern that the chemicals and their precursors will be released back into the environment.
The Department of Defense is researching other ways to deal with the chemicals.
Editor's note: this story was updated on September 26, 2020 to reflect new state regulations.