LANSING – Controversy swirls around a suppressed federal report about health risks to millions of people living around the Great Lakes, including “areas of concern” near the Kalamazoo, Clinton and Rouge rivers, Deer Lake and River Raisin.

While some officials from the agency that conducted the study question the validity of its science, critics are asking why it was kept from the public.

The report was prepared between 2001 and 2007 by the Agency for Toxic Substances and Disease Registry (ATSDR), a division of the U.S. Centers for Disease Control and Prevention. It compares already public data for levels of toxic materials and community health.

ATSDR found elevated rates of various cancers, as well as infant mortality and low birth weight, among people living in areas with high levels of lead, dioxin, mercury and other toxins.

The “areas of concern” were designated in a water quality agreement between the U.S. and Canada as areas with water that contains abnormally high levels of contamination from persistent chemicals that don’t quickly dilute or degrade.

The report referred to 11 such areas in Michigan. The others are near the Saginaw River and Bay, the Menominee and Manistique rivers, and Muskegon, Torch and White lakes.

Just days before the study was to be made public last July, after more than three years of expert review and revision, ATSDR declined to release it because “significant scientific shortcomings were identified,” the agency said.

In early March, ATSDR released the report in response to pressure from U.S. Reps. Bart Stupak, D-Menominee, and John Dingell, D-Dearborn, after portions were published by the Center for Public Integrity, a Washington, D.C.-based journalism group.

Dingell and Stupak have launched an investigation into the suppression of the report and the demotion of its lead author.

“Pollution in our Great Lakes can have very real health consequences for the millions of Americans who live in and around the Great Lakes basin,” Dingell said. “If the administration has willfully withheld a report from the public, it raises questions about whether they are putting the public health at risk and about the scientific integrity of the Centers for Disease Control and Prevention.”

But Linda Dykema, who manages the toxicology and response section of the Michigan Department of Community Health’s Division of Environmental Health, said it’s important to remember that while the report shows there may be a relationship between living in a contaminated area and getting sick, it doesn’t demonstrate cause-and-effect.

“What concerns me with the report is it left the perception that the health effects for a given region are attributable to toxic sites,” she said. “That could be, but there are so many other factors to consider that it’s unfair, almost, to give the public that perception.”

Many of those other factors are socio-economic, Dykema said, such as availability of good prenatal care or lead-based paint in low-income housing.

Dykema also said that the report’s toxicity data refer to “areas of concern,” while the health data are from the county level. So, for instance, data could suggest that a person got cancer from toxins in a river, even though he or she lives in a part of a county outside that river’s watershed.

Molly Polverento, health program director for the Michigan Environmental Council, said the report was “probably the best that could be done with the resources and data available,” and that it makes the case that further research is needed.

Polverento said what’s needed is long-term, boots-on-the-ground research that uses biological data from people living in the areas of concern to establish a clear cause-and-effect relationship.

“Nobody wants to spend the money to do it, but it’s what we need to do,” she said.

But while that kind of research would be ideal, it is “extraordinarily expensive,” according to Dykema.

“Unfortunately the state budget doesn’t allow us to do very much about that,” she said.

Jeff Spoelstra, coordinator of the Kalamazoo-based Kalamazoo River Watershed Council, said there’s not much local groups can do, either.

“We’re all kind of cautiously waiting to see how the agencies involved settle their differences,” he said. “The most important thing to me is, ‘What happens next?’”

The study is being reviewed for scientific validity by the Institute of Medicine, a national health advisory organization. The group plans to release its report on the study by July.

Department of Environmental Quality press secretary Bob McCann said that if the institute finds ATSDR used good science, “it would certainly raise a few alerts.”

Spoelstra said that if the institute decides the quality of the report is poor, on the other hand, “then the obvious next step is to do the study appropriately.”

But how would a new study be funded?

“I wish I could answer that,” Spoelstra said.