In August 2019, Vera Harrington put a quarter cup of her breast milk into the refrigerator. She gave this milk not to her daughter, Flora, but a team of researchers investigating a pervasive class of chemicals that have found their way into humans all over the world.

These chemicals are called Per- and polyfluoroalkyl substances — or PFAS — and have been used over the decades in products ranging from firefighting foams to cosmetics, nonstick pans, rain gear, stain-protected sofas, some types of fast food wrappers and even dental floss.

Harrington, who lives in an Eastlake town house in Seattle, was one of 50 Puget Sound area first-time mothers who participated in the study. This past April, she got the results, which documented nine types of PFAS in her breast milk.

Harrington’s cumulative tally of 146 parts per trillion was modestly higher than the median contamination levels of 121 parts per trillion for all 50 study participants. But for Harrington, now pregnant with her second child, the findings were jarring. Reading through the results, she wondered what might have been the sources of the chemicals in her breast milk, and how they could have been avoided.

A confidentiality cloak typically protects participants in clinical studies. Harrington decided she wanted to speak to The Seattle Times to help raise public awareness about PFAS chemicals.

“I was really really concerned, and upset. I started thinking … I would have to buy new furniture, and it became kind of overwhelming,” Harrington said. “Then I had this moment when I realized that I could do the best job I could, and I would still run into things out of my control. Then it just was really, really frustrating.”


The potential health impacts of these chemicals is a focal point of ongoing research by the National Institutes of Health and other organizations. Though much has been learned during the past two decades, there still is uncertainty about impacts of some chemicals, and what levels pose significant health threats.

Some PFAS have been found in laboratory animals to pose increased risks of liver toxicity, reduced birthrates and disruption of the immune and endocrine systems.

The unsettling findings do not mean that mothers should shy away from breast feeding. The study co-authors and other health researchers say that the advantages of breast feeding, which include improved protection against infections and increased immune response, still far outweigh the risks that the chemicals pose to infants.

“Definitely, the evidence still shows that breast is best — there are so many benefits,” said Dr. Sheela Sathyanarayana, a co-author of the study and professor at the University of Washington Medical Center whose research focuses on pediatric environmental health.

Legacy of PFAS

The first PFAS were developed the middle of the last century. They now consist of a class of more than 4,000 chemicals and their breakdown components, many of them characterized by strong bonds between carbon and fluorine atoms that make them persist in the environment, and have gained them the nickname “forever chemicals.”

Some of the worst U.S. pollution has been documented in sites where PFAS was used in manufacturing, such as a Dupont plant in West Virginia that made Teflon. In 2017, DuPont and a spinoff company, Chemours, agreed to pay more than $670 million to settle more than 3,500 lawsuits filed by Ohio and West Virginia residents who allege that PFAS pollution released into the air, ground and water had sickened them. The chemicals have been widely used in industries across the country and an Environmental Working Group study released last week — based on a review of federal data — identified almost 30,000 sites that potentially discharged PFAS.


In Washington, some water systems in Issaquah and Whidbey Island as well as Pierce and Spokane counties were found to have PFAS contamination from firefighting foams used in training. In Washington, new regulatory standards for these chemicals have been proposed for drinking water. Also, the Legislature has passed laws to phase out some products that contain PFAS.

“Washington is absolutely at the forefront. Our state is the first to pass legislation banning PFAS, as a class, in firefighting foam, and other states have followed our lead,” said Erika Schreder, a co-author of the breast milk study and science director at Seattle-based Toxic-Free Future, a group that has advocated for new regulation.

These chemicals can make their way into the human body through many pathways, including food, food wrappers or drinking water as well as by breathing in dust and air inside buildings where stain protectants or PFAS-coated materials are present.

One survey indicated that they are now present, to some degree, in the blood of 98% of Americans. From the blood, PFAS migrates to tissues, moving through the placenta to the fetus and also into the milk that is for their nourishment.

The PFAS study of the 50 Puget Sound women was a cooperative effort involving researchers from Indiana University, the University of Washington’s Children’s Research Institute and Toxic-Free Future. Their findings went through peer review, and were published in a May edition of Environmental Science & Technology.

This study represented the first PFAS analysis of breast milk in U.S. women since 2004, and offered a mixed progress report.


Two older chemicals that U.S. manufacturers no longer produce — PFOS and PFOA — were detected at less than half the levels found in a 2008 study. But both of these chemicals can linger in the body for years, and they still represented nearly 40% of the total PFAS contamination.

Meanwhile, new PFAS, with shorter chains of carbon molecules, are showing up at higher concentrations than in the earlier study, a trend also detected by researchers in other countries. Two of these, PFHxA and PFHpA, were detected in most of the milk samples of the Puget Sound-area women.

“These findings make it clear that the switch to newer PFAS over the last decade didn’t solve the problem,” said Dr. Amina Salamova, study co-author and associate research scientist at Indiana University. “This study provides more evidence that current-use PFAS are building up in people. What this means is that we need to address the entire class of PFAS chemicals, not just legacy-use variations.”

Moves to phaseout

The unfolding saga of PFAS pollution has prompted some companies to pledge to move away from using any of these chemicals, including eight fast-food and restaurant chains with more than $130 billion in annual sales, according to Toxic-Free Future.

McDonald’s, for example, announced this year that by 2025 it would stop using PFAS — typically for grease resistance — in all packaging. The action came after a 2020 investigation by Toxic-Free Future and Mind-the-Store detected the presence of fluorines that suggested PFAS on a McDonald’s small fry bag, a Big Mac clamshell and a cookie bag, which resulted in a petition drive urging the fast-food chain to stop using PFAS.

In Olympia, Toxic-Free Future has lobbied for legislative action to curb the use of PFAS products, including a 2018 law that requires the Ecology Department to ban PFAS in food packaging as safer alternatives and cost-efficient alternatives are identified.


In a report released in February, the Ecology Department found substitutes for four of 10 packaging categories. That means those categories — wraps and liners, plates, pizza boxes and “food boats” used to serve up hot dogs — must be free of intentionally used PFAS by February 2023, according to Rae Eaton, an Ecology Department chemist.

The Ecology Department has embarked on a second round of assessments that is likely to result in more requirements for substitutes. The department also is developing protocols to test for PFAS before spreading biosolids — treated sewage effluents — on farm land.

Meanwhile, the state Department of Health, responding to a petition filed by Toxic-Free Future, is preparing to release proposed “action levels” for five PFAS chemicals in drinking water systems that cover most of the state’s population.

These levels range from just 10 parts per trillion for PFOA, the long-lived older chemical, to 345 parts per trillion for PFBS, which clears much more quickly from the human body, but has been shown to affect thyroids and development in mice.

If managers of a water system find PFAS levels that exceed these limits, then they must notify customers and continue surveillance, and would be eligible for state assistance to install filters that can capture the contaminants.

The standards are expected to be finalized this year and would be set low enough to protect someone who might be drinking this water over a lifetime.


“We need to be concerned with the biggest risks of exposure … and we have to take protective action even when we don’t have all the information,” said Barbara Morrissey, the state Department of Health toxicologist who helped to develop the proposed standards.

Living with PFAS

Harrington has found no obvious red flags as she has investigated the potential sources of PFAS that ended up in her body.

Harrington is a marathon and trail runner who favors organic foods, although not exclusively. She was raised in Chicago, studied at Indiana University and made her way to Boston before she moved with her husband Neil Harrington to take a job in the tech industry.

In her study sample, the highest measurement was for PFOS, which was phased out of U.S. production in 2003. Still, it could have been used as a stain resistant on old furniture or an old rug in one of the buildings she has lived or worked in through the years.

And she also is taking a look around her condominium to try to spot current sources of PFAS contamination, such as a rocker she bought to nurse her daughter that could have a stain-resistant coating of a newer formulation PFAS and a carpet that was purchased by an earlier owner of the house.

“I didn’t live my life trying to avoid these substances because I didn’t know they were going to impact me and my future child,” Harrington said.


Harrington is now preparing for the arrival of her second child, due in October, and plans once again to breast feed. She is considering abandoning the stain-resistant rocker she bought before her first pregnancy that now sits in her daughter’s room. She also wants to do away with any chemical treatments when her carpets are cleaned.

By the time she starts breast feeding once again, she hopes that the PFAS contaminant levels will have eased.

“I think that everyone is left with a little bit of the unknowns,” Harrington said.