3M chemicals in human blood are linked to high cholesterol levels, according to three studies published in the past three weeks. The research, conducted nationally and in West Virginia, is part of mounting evidence about health effects from the Scotchgard-type chemicals that have been detected in the groundwater in the east metro area.
At the same time, the Environmental Protection Agency is taking a closer look at the chemicals in light of public health concerns.
3M made the compounds, known as perfluorinated chemicals or PFCs, from the late 1940s until 2002 in Cottage Grove and disposed of waste in area dumps that the company is now cleaning up.
The company said again this week that the chemicals have not caused health problems for its own employees, who were exposed to much higher levels than the public.
Dr. Larry Zobel, 3M corporate medical director, pointed to other studies that do not show a connection between cholesterol and 3M chemicals. “People do not need to be concerned about the relationship,” he said.
The most recent national study, published last week, analyzed blood in 860 adults as part of the National Health and Nutrition Examination Survey, ongoing research by the Centers for Disease Control and Prevention. Unlike other studies that have examined blood from exposed workers or residents who lived near manufacturing plants, this study looked at background levels of PFCs in the general U.S. population.
It found that those who had higher blood concentrations of two former 3M chemicals — PFOS and PFOA — also had higher total cholesterol levels and higher non-HDL (“bad cholesterol”) levels.
“We do feel that these findings are potentially important,” said Jessica Nelson, study author and researcher at the Boston University School of Public Health. The chemicals are persistent in the environment and ubiquitous in people’s bodies, she said. “We need to know whether the associations that we saw and that others have seen are a real cause-and-effect relationship. If so, they certainly are a health concern,” she said.
The results do not prove that PFCs cause higher cholesterol, she said, only that they seem to go hand-in-hand with each other. The study was published in Environmental Health Perspectives, a national scientific journal.
Minnesota numbers compare
The top 250 adults in the study with the highest cholesterol averaged 6.9 parts per billion (ppb) of PFOA in their blood and 38 ppb of PFOS.
Those numbers are similar to a Minnesota Department of Health study in the east metro area of 196 adults who drank contaminated water from city wells in Oakdale and private wells in Lake Elmo and Cottage Grove. Blood concentrations in that group averaged 15.4 ppb for PFOA and nearly 36 ppb for PFOS.
Minnesota did not analyze the blood for cholesterol, said report author Jean Johnson, because it was beyond the scope and funding of the legislatively mandated study. However, Johnson told a panel of legislators last week, preliminary findings show that Minnesotans with higher concentrations of PFCs in their blood also tended to be those with higher concentrations of the chemicals in their private wells.
The blood concentrations in the U.S. population are about 4 parts per billion for PFOA, and 20 ppb for PFOS.
Lake Elmo resident David Moore had the highest levels of 3M chemicals of anyone in the Minnesota study, with 177 ppb PFOA and 448 ppb PFOS.
“I feel as though I have a black cloud hanging over my head that has 3M’s emblem on it, and I’m not very comfortable with that,” he said.
Moore said that he and his wife drank water from their private well for 12 years before health officials tested it and found PFCs. His wife died of cancer in 2008, he said, and doctors told him the cause was likely chemical exposure.
Moore said he didn’t know his cholesterol level. He believes 3M should pay for blood tests and health monitoring for all east metro residents who drank tainted water.
New data from eastern study
That’s what happened in six water districts contaminated with PFOA near a DuPont plant in West Virginia that made nonstick cookware and other products. A class-action court settlement required DuPont to pay for a major health survey of those who lived, worked and went to school near the plant and drank contaminated water.
More than 69,000 residents submitted blood samples and filled out extensive questionnaires in 2005 and 2006.
The first studies emerging from that survey also show statistical associations between high cholesterol and PFOA concentrations in blood.
West Virginia researchers found that higher levels of PFOA “were significantly associated with higher cholesterol and LDL” in the blood of about 12,500 children under 18, according to a summary filed in Wood Circuit Court in West Virginia on Oct. 30. The study has not been peer-reviewed.
Another study of more than 46,000 adults near the West Virginia plant reached similar conclusions and was published Oct. 21 in the American Journal of Epidemiology. If there is a cause-and-effect relationship between high cholesterol and PFOA or PFOS, the study concluded, “there could be potentially serious consequences in the form of increased risk of cardiovascular disease.”
Zobel said 3M and DuPont have looked at that question. Two recent mortality studies looked at workers exposed to the chemicals and found “no evidence at all of coronary artery disease in occupational [groups] associated with PFOA exposure,” Zobel said
He said some studies have shown statistical relationships between PFCs and cholesterol levels, but other studies have not. Not only is the research inconsistent and inconclusive, he said, there isn’t any biological reason why low levels of PFCs should affect cholesterol.
What happens next
Minnesota health officials are aware of the latest research, but said that so far they do not have plans to change the groundwater health standards for PFOA and PFOS allowed in drinking water, set last year at 0.3 parts per billion.
Moore said the state should be far more aggressive instead of simply following the West Virginia research. “The whole thing has been kind of ‘sweep it out the door, we don’t want to deal with it in Minnesota,'” he said. “It’s almost like 3M has the state in its back pocket.
The Environmental Protection Agency announced in late September that PFCs are now a top priority — one of only six chemicals at the top of the list to be reassessed. They were chosen because they are persistent and accumulate in blood, and many people have been exposed to them, said Wendy Hamnett, acting director of the EPA’s Office of Pollution Prevention and Toxics.
The EPA is reviewing all that is known about PFCs, said Hamnett, and will publish an “action plan” in the next few months. “We intend to increase the pace of our efforts to address these chemicals that may present a risk to the public,” she said.