Health officials: PFC levels drop in group of Washington County residentsState experts reported a significant decline in perfluorochemical levels found in residents of Cottage Grove and other east-metro communities where the 3M-manufactured chemical had polluted drinking water, but lingering concerns have some officials calling for continued study.
By: Scott Wente, South Washington County Bulletin
State experts reported a significant decline in perfluorochemical levels found in residents of Cottage Grove and other east-metro communities where the 3M-manufactured chemical had polluted drinking water, but lingering concerns have some officials calling for continued study.
The Minnesota Department of Health said last week that a biomonitoring pilot project showed a decline in PFC blood levels in a sampling of Washington County citizens living near areas of documented PFC ground contamination. PFCs were made by 3M at its Cottage Grove plant for decades and used as stain repellants and fire retardants. Waste containing the chemical was lawfully dumped for decades at sites in Washington County, including near the Cottage Grove-Woodbury border.
The Health Department project tested the blood of 164 people from Cottage Grove and Lake Elmo with private well water and Oakdale residents on the city’s municipal water system and compared their PFCs levels to similar tests conducted on them and about 30 more people in 2008.
“Our findings showed that blood levels of the three PFCs that are found in all participants have declined substantially since 2008,” Dr. Jessica Nelson, the Health Department’s biomonitoring program coordinator, reported.
Health officials attributed the decline to ongoing remediation work aimed at reducing PFC exposure in drinking water.
“All of the efforts that were made to filter the drinking water in the east-metro and move people to alternative sources of drinking water were effective at reducing those drinking water exposures,” Nelson said.
PFC levels exceeding so-called “health-based exposure limits” had been found in drinking water in those three communities. As remediation has occurred in the years since, three types of PFCs saw substantial declines, the Health Department reported: Individual levels of PFOS dropped 26 percent; PFOA levels were down 21 percent, PFHxS 13 percent.
However, the study found that PFC levels still were two to three times higher than levels found in the general U.S. population.
That is still a concern, said Sen. Katie Sieben, DFL-Cottage Grove. Sieben authored legislation in 2007 that established the biomonitoring project.
“I think it’s easy for people to jump to the conclusion that, ‘oh, the levels dropped, that’s great news,’” she said. “Of course that’s great news.”
However, she added: “I think there are still questions that merit (study). It’s not like this is conclusive.”
State officials and 3M say there are no known adverse health effects caused by PFC exposure levels that exceed the health-based exposure limits. Nelson said health officials understand that such a link is a “big concern” for people, but scientists still do not fully understand how PFCs affect human health.
“We do know,” Nelson added, “that based on published studies we don’t see clear evidence that PFCs increase the risk of disease in people.”
Yet, Sieben countered, scientists in West Virginia studying human health effects of exposure to a perfluorochemical concluded just last week that there is a probable link between exposure to the chemical and health problems for pregnant women.
Minnesota’s biomonitoring project was not intended only to measure PFC levels in residents, but to explore whether there is a link to health problems, Sieben said.
Funding for the state project will expire by 2013, and Sieben said she has talked to other lawmakers about whether to attempt to continue paying for the work.
“It’s just important to continue to look at the research that’s going on around the country,” she said.
While PFC levels decreased in most of the east metro residents tested, roughly 30 people did not record a drop in PFC levels between 2008 and 2010. Nelson said it is not clear how many of those people actually had real increases in PFC concentration. The next phase of the Health Department’s project will include reviewing a lengthy questionnaire filled out by the participants that could identify other possible reasons for above-average PFC levels.
The numbers are expected to decline, but two years is “just too short a time” to see a drop to U.S. general population levels, Nelson said
The Health Department attributed the decline to ongoing PFC remediation. State officials and 3M have worked on PFC remediation efforts for several years, with 3M paying tens of millions of dollars for the cleanup. Carbon filtration units were installed at Oakdale’s water treatment plant. Additionally, roughly 290 homes with private wells in areas affected by the PFC contamination were either added to city water service or given carbon filtration devices. The Health Department said it continues to test wells to be sure that water levels are below the health-based exposure limits. It discussed the project findings and future plans at an open house Monday in Oakdale.
“The results we’re seeing in the reduction of PFCs in blood levels in the east metro are a clear testament to what can be accomplished with collaboration among state agencies, local government, business and citizens,” Health Commissioner Dr. Edward Ehlinger said in a statement.
The Health Department project was paid for with a portion of some $3.25 million in state funding that has been appropriated to state public health tracking and biomonitoring since 2007, said Jean Johnson, the agency’s environmental public health tracking and biomonitoring program director.