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Whistleblowing scientist accuses 3M of PFAS contamination cover-up in Minnesota

WCCO Investigates: PFAS Problems
WCCO Investigates: PFAS Problems 04:36

AFTON, Minn. — A former 3M scientist says she now believes executives knew PFAS were potentially harmful long before they shared that information.

It's apparent at Kris Hansen's Afton home that she has a deep love for the environment.

"We've got our tomatoes here and some nice kale around the sides," Hansen said. "It makes me feel good and it's something I used to do a lot with my dad."

But it also inspired her career as a scientist.

"My dad worked at 3M for over 40 years. He was the highest-ranked scientist that they had," she said.

A life-changing assignment

In 1996, Hansen followed in her father's footsteps and joined 3M, first working in its environmental lab. A year later, at age 28, she says her boss gave her an assignment: find out what was showing up in random human blood samples.

"I figured out that the interferent was PFOS, which is a fluorochemical compound manufactured, at the time, exclusively by 3M," she said.

3M created PFOS, a specific fluorochemical, for its products. PFOS is now included in a larger group of chemicals known as PFAS.

They don't break down in the environment, and we now know they build up in our bodies and can make us sick. But Hansen says she didn't know that part in the '90s. 

To be sure of her findings, Hansen says she tested more samples from across the United States and other countries. She says what she uncovered in 1997 was like finding a big 3M nametag.

"All of those samples had a strong signal for PFOS," she said. "The process that 3M uses is very distinct and patented."

Hansen says she was "really shaken" by the discovery.

"I felt like I had discovered that PFOS, a compound that was really unique to 3M, was widespread in the general population," she said.

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Kris Hansen WCCO

So she told her boss.

"He looked at it and he said, 'This changes everything,' and he walked into his office. It's a very distinct memory for me," she said.

From Hansen's perspective, what followed was inaction.

"I really thought that they would be as kind of appalled and surprised and shocked as I was, and that they would want to say, 'How did this happen and how do we fix it?'" she said. "And I didn't sense that for months."

Hansen says she tested blood samples from the '50s from Korean War recruits. They were negative. 

"It just so happens that was before the commercialization of any 3M fluorochemical products," she said. "At that point, the doubters were quiet."

Hansen says it was in a 1998 meeting with a 3M scientist that she learned her discovery wasn't the first.

"He said, 'I don't understand why they're making such a big deal about this. We knew about this in 1975,'" she said.

Documents underline 3M's early knowledge of PFOS dangers

Documents released in 3M's 2018 settlement with the state of Minnesota reveal results from fluorochemical testing on animals. Tests on 10 rats in 1976 killed seven of them within two weeks of exposure.

A once-confidential document of notes from a 1979 meeting reveals a consultant sharing this takeaway on fluorochemicals with 3M executives: "If the levels are high and widespread and the half-life is long, we could have a serious problem." In science, a half-life is how long it takes for something to break down.

The memo also suggests the company should look into the health effects of the chemicals.

Documents show in 1998, 3M reported fluorochemicals in the blood of the general population to the U.S. Environmental Protection Agency. They also acknowledged they knew that in the 1970s, but said they didn't have a reasonable basis to believe it presented "a substantial risk of injury to health or the environment."

"[The CEO] fell asleep during my presentation"

In 1999, Hansen says she secured a meeting with the CEO to share her findings.

"That was another meeting that did not go how I thought it would. The CEO who was sitting at the head of the table the whole time we were talking actually fell asleep during my presentation," she said. "In hindsight, what I believe is that the CEO knew."

Hansen says she was told not to share her data with anyone outside the company — the same directive she says was given to the scientist who tipped her off to the 1970s discovery.

"It made me understand that there had been some amount of coverup in the company. And I think it's one thing to lose track of a chemical. Unforgivable. But it's another thing to intentionally cover it up," she said. 

Hansen tells us she was reassigned, but stayed with 3M until 2022.

"For most of my life, certainly for my career at 3M, I believed 3M's line that they were not toxic," she said. "I feel guilty, I feel disappointed, I feel angry."

3M's response

3M did not want to go on camera, but in a statement said in part: "As the science and technology of PFAS, societal and regulatory expectations, and our expectations of ourselves have evolved, so has how we manage PFAS." 

The company also cited its exit from making other fluorochemicals and vowed to exit PFAS manufacturing by the end of next year.

"Over decades, 3M has shared significant information about PFAS, including by publishing many of its findings regarding PFAS in publicly available scientific journals dating back to the early 1980s. Those journals were and remain available to the scientific community and the public," the statement read.

Hansen's hopes for the future


Hansen says she has "a ton of faith in scientists and engineers at 3M and in other places," and believes her former employer's financial obligations in the matter are far from over.

"I think the fact they are trying to get out of the business, I think ultimately that's what needs to happen," she said.

She calls the scale of groundwater contamination caused by 3M "heartbreaking."

"Maplewood, Minnesota, is ground zero for one of the biggest environmental contamination stories of our time," she said.

Hansen first shared her story with ProPublica, a nonprofit investigative journalism organization.

Thursday on WCCO 4 News at 6, we'll look at how Minnesota is leading the way to protect you from forever chemicals with new rules that kick in next year.

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