Potentially harmful chemicals in the blood of some Minnesotans are dropping after three communities found a new water supply or started filtering their old one.
In 2008, The Minnesota Department of Health tested residents in Oakdale, Lake Elmo and Cottage Grove for perfluorochemicals after finding the manmade chemicals in their water. The chemicals known as PFCs are used in products like pots and pans, carpets and food packaging. Studies have shown that they cause liver damage and developmental problems in the offspring of animals.
Every person tested had PFC levels higher than the national average.
The city of Oakdale installed carbon filters at its water treatment plant to remove potentially harmful chemicals. Photo: Doug Wallick (Flickr)
So, officials took action.
Carbon filters were installed at two of Oakdale’s wells, and an additional 290 homes were either plugged into city water or given the filters to absorb contaminants.
And results have been encouraging. A follow-up project found fewer PFCs in people’s blood. Levels of the three major PFC types went down by 26, 21 and 13 percent. The follow-up tested 164 of the 196 adults sampled in 2008 in the three communities that are about 10 miles east of St. Paul.
While the chemicals have been used for decades, Minnesota officials considered water the main exposure route.
“For people that live in those communities where there are PFCs in the drinking water, that’s definitely the primary way that they’re getting exposed,” said Jessica Nelson, program coordinator and epidemiologist with the Minnesota Department of Health.
Officials compared the findings to other studies.
“We’ve compared the drops in these participants to similar communities after similar exposures ended … and it’s telling us the efforts to filter water worked,” Nelson said.
Oakdale has nine wells, but the other seven that didn’t get filters do not have health-threatening levels of the contaminants, said Brian Bachmeier, the city’s public works director.
A nearby 3M Company facility that uses PFCs in some products paid for the filters.
“These findings confirm what we have believed all along — that 3M’s efforts to remove PFCs from the environment are having a positive impact on humans and the community,” Jean Sweeney, 3M’s vice president of health, safety and environmental operations, said in a prepared statement.
The company has been working with the Minnesota Pollution Control Agency for years to identify PFCs in the environment around its factories. It says it is phasing out their use, but as recently as October the state agency reported levels increasing at a 3M dump site.
PFCs’ effects on people are not fully understood. There are no published studies providing evidence that they increase the risk of disease in humans, according to the Minnesota Department of Health.
But Minnesota officials aren’t taking chances.
The next step is to look for other ways the chemicals are getting into people. The additional research is needed to start giving residents practical suggestions, Nelson said.
“We just don’t have enough data to give recommendations for people to reduce exposure,” Nelson said. “Beyond water, it’s very hard to get at what foods and products are causing the elevated levels.”