The PFCs are also contaminating water supplies in other parts of the country, including West Virginia and Ohio, near a DuPont production plant that manufactured the chemicals.
Officials with the Environmental Protection Agency and the Centers for Disease Control and Prevention met with more than 100 people in Minnesota Wednesday, including state lawmakers, government researchers and environmental groups.
Many in the audience said they were pleased to finally hear from the agencies. But some were also frustrated with the pace of the federal response.
The EPA's Mary Dominiak began her talk by warning the audience that they were not going to hear any definitive answers from the federal agency on human health risks from PFC exposure -- even though the EPA has been investigating the stain and water-resistant chemicals for the past seven years.
"These chemicals really are a puzzle," said Dominiak. "We're still in the process of trying to put the pieces together and see what picture they would actually make. We don't have all the pieces yet."
To date, EPA officials have no evidence that the chemicals are harmful to humans. But that's based on just a handful of studies. More human exposure studies are in the pipeline, some of them at the EPA, that could help officials complete their puzzle eventually. But the federal research process is slow.
Dominiak says her agency has been working for the past two years just to establish guidelines for one of its PFC risk studies. The EPA's scientific advisory board recently recommended some changes to the agency's proposal, so Dominiak says EPA staffers are now sorting through those suggestions.
"When the assessment is complete, which will be a few years yet -- don't hold you're breath -- we will again be submitting it to the science advisory board for peer review, to make certain that our science is sound and our conclusions are sound," Dominiak explained.
In the meantime, Dominiak says the EPA doesn't think it would be appropriate for the agency to establish a level of PFC exposure for humans that's considered safe.
Without that EPA guidance, the Minnesota Department of Health has had to figure out its own set of safety levels for Minnesotans who are exposed to the chemicals.
"You'd think Minnesota would look really sexy with PFOA and PFOS and PFBA, and it seems like a researcher's dream. So we are struggling to find ways to engage you."
Federal officials praised the state Health Department for its work on the issue so far. CDC epidemiologist Tom Sinks with the National Center for Environmental Health said Minnesota officials are on the right path.
"Local people need to act locally. Please do not wait for the federal government to ride in on a silver charger and help you, because you may be waiting," said Sinks.
But some audience members argued that federal agencies should be the ones leading the effort.
Cindy Weckwerth with the Washington County Public Health Department complained that Minnesota has been ignored by federal officials. She said they have spent far more of their time focusing on contamination in Ohio and West Virginia, where DuPont has a major PFC operation.
"You'd think Minnesota would look really sexy with PFOA and PFOS and PFBA, and it seems like a researcher's dream. So we are struggling to find ways to engage you," said Weckwerth. "Perhaps you are engaged more with the state, but from the local perspective we seem isolated from what's going on at the federal level."
CDC officials replied that they spent more of their time in Ohio and West Virginia because the contamination in those areas is more significant and the states needed more assistance.
After the meeting, Rep. Julie Bunn, DFL-Lake Elmo, said it's unfortunate that Minnesota hasn't gotten more federal help. But she said it's not clear that federal guidance would be that helpful anyway.
"If we waited that long there'd just be a sense of chaos. You know, property values would be lowered. We would hope what the feds heard will encourage them to maybe do what they can to speed up the process," said Bunn. "But it also makes us recognize that we'll have to go it alone to some extent, and use the information we do have in the next year or so to make progress on some policy conclusions."
Minnesota lawmakers did approve a number of initiatives this session that hasten the state's investigation of PFCs. They passed laws that establish biomonitoring programs for residents exposed to PFCs, and they required the Minnesota Health Department to adopt formal health-based limits for the chemicals.