wellness

Children exposed to the same common household chemicals that have contaminated groundwater near a number of 3M Co. sites in the St. Paul suburbs have weakened immune systems that make them more vulnerable to infections, according to research published this week.

The study is the first to confirm the suspected link between immune function and PFCs, a family of compounds used in everything from Teflon pans to microwave popcorn bags. Published in the Journal of the American Medical Association (JAMA), it's the latest in a growing number of scientific studies raising questions about the health implications of the compounds, which have become ubiquitous in the environment, animals and people.

The chemicals are of particular concern in the east metro area, where groundwater and drinking water were contaminated after 3M made and used the compounds for decades at its Cottage Grove plant to make products like Scotchgard, nonstick cookware and firefighting foam. 3M stopped using the chemicals in 2002. But many people who live nearby have elevated levels of the compounds in their blood -- significantly higher than do the Scottish children who were studied in the research published by JAMA. That means their immune systems could be even more affected, Minnesota health officials said.

"It would raise that question, certainly," said Jean Johnson, an epidemiologist with the Minnesota Department of Health who directs the state's public health tracking program. "We think the finding is important, but we think this needs more research and follow-up to see if it holds true."

Scottish families

The study, headed by Harvard University environmental health professor Dr. Philippe Grandjean, followed 656 children in the Faroe Islands northwest of Scotland from 1999 to 2001. They were chosen because they are exposed to PFCs through their diet, which is high in fish. But analysis showed that their average PFC blood concentrations were about the same as most children in the United States.

The researchers took blood samples from their mothers while they were pregnant, and then from the children at ages 5 and 7. Altogether, they looked at six different PFC compounds.

They found that after being vaccinated for tetanus and diphtheria, two common childhood immunizations, the children developed a weak antibody response -- meaning they were not well protected from the disease. At age 7, for instance, children with twice the PFC concentrations had half as many antibodies as they should.

The antibody effect was worst with PFOS, the contaminant of greatest concern in the Twin Cities east metro groundwater and the Mississippi River.

"PFC exposure may increase a child's risk for not being protected against diphtheria and tetanus, despite a full schedule of vaccinations," the study said.

But it also said that the study did not prove PFCs caused the weak immune response, only that there is a strong relationship.

Legislator: 'That's bad news'

A 3M spokeswoman, Donna Fleming Runyon, responded: "It does not alter our position, which is that there are no adverse health effects shown to be caused by PFCs at the level of exposure in the general population."

Still, the researchers said, the connection is likely to hold true for other vaccines and raises questions about the effect of PFC exposure on other immune system diseases like diabetes and some cancers, or even resistance to common infections like the flu.

"That's bad news," said Sen. Katie Sieben, DFL-Newport, who represents some of the affected communities. She is co-sponsoring legislation this session that would give the Health Department $270,000 starting in 2013 to continue its study of PFC contamination in residents of the east metro communities.

Last month, the Health Department reported that PFC concentrations in a group of 164 adults it has been following have fallen by 13 to 26 percent since 2008, when they stopped drinking contaminated water. But they still have levels that are much higher than average -- 24.3 parts per billion vs. 13.2.

None of the Minnesota study subjects are children. But Johnson said that if the Legislature approves the funding, health officials would work with affected communities on how to proceed with future research. One option, she said, "would be to look at younger people."

Josephine Marcotty • 612-673-7394