Dioxin expert questioned in Midland

When the head of health research for the Environmental Protection Agency, a world-renowned expert and author of more than 100 peer-reviewed publications on dioxin, gives a presentation in Midland, the audience isn't an average one.

Dr. Linda Birnbaum spoke at the Grace A. Dow Memorial Library Tuesday to a crowd of about 50, which included a number of dioxin experts in their own rights -- retired Dow Chemical scientists who were among the first to detect and study the manufacturing byproduct.

As a public health scientist with a mission of protecting health and the environment, Birnbaum warns that the background levels of dioxin in people put them at risk for a multitude of health effects: diabetes and cancer, as well as thyroid, immune, reproductive and neurobehavioral problems.

Scientists and doctors in the audience were not so sure, pointing out that a cause-and-effect relationship between disease and dioxin never has been established. They were annoyed by the use of phrases like "studies suggest," "has been linked to" and "associated with," and add that Midland's population is healthier than most, despite possible environmental and work-related dioxin exposure.

Samuel Shaheen, a physician with more than 50 years of experience in Saginaw, said he's been asking other local doctors what they think. "I couldn't find one doctor who could say he could find one disease entity caused by dioxin." he said.

Birnbaum countered that scientific studies show repeated links between dioxin exposure and disease -- even at background levels in the general population. "We have strong and repeated associations in human studies," she said. "We believe they are real."

She acknowledged it is impossible to tell on a case-by-case basis if a health issue is the direct result of dioxin. "The effects that you see could be caused by dioxin, or they could be caused by many other things." Cancer is one such example: The risk because of dioxin exposure is slight when compared with the already existing risk for developing the disease. One in three, maybe one in two, people will develop the disease in their lifetimes. Dioxin exposure is expected by some to add a nearly invisible additional risk of 1 in 1,000.

Some at the meeting said existing scientific evidence is enough to make dioxin contamination a serious concern. "I think there is a feeling that we have to wait until there is definitive research, when the better approach is to deal with it if there is a suggestion that it could be problematic," said Terry Miller of Bay City-based Lone Tree Council.

Birnbaum agreed, though she doubted local contaminated soil will contribute to higher-than-average body burdens. "For the average American, food is going to be the major source," she said. "I don't think for anyone soil is going to be a major, direct contributor."

She said the key to defining dioxin-related risk in the Saginaw Valley will be the University of Michigan exposure study. She sits on the scientific advisory board for the project and said finding out if residents along the Tittabawassee River and in Midland have increased levels of dioxin in blood is the first step in determining whether they have an increased risk for disease.

Even if soil isn't a major contributor, Birnbaum said the dioxin all people are exposed to is a problem. That's because as it moves from the environment up the food chain, it biomagnifies along the way. "The higher you are on the food chain, the higher the level of these chemicals," Birnbaum said.

Government and industry have worked to drastically reduce the amount of dioxin in the environment, so what is left is mostly historic and is being recycled and redistributed. The task is to reduce residuals. "We still have reservoir sources out there we would like to reduce," Birnbaum said.

The Tittabawassee River is one such reservoir.

"I could be convinced, if you had sediment that stayed put and was buried, you should leave it there. When you have a river, that's not the case," Birnbaum said. "It keeps moving and re-exposing."

At least one person in the audience was not convinced that the problems posed by dioxin are large enough to garner all of the attention and money tossed their way.

"The question is: So what?" said John Wagner, who came to the meeting from the Detroit area. He said he wasn't trying to sound flippant, but suggested the government use taxpayer money to address problems with more certain circumstance.

"This is subtle. Let's deal with the things that are not so subtle," he said. "I'm concerned about the bang for our buck." He added that exposure to things such as mercury and risk of bioterrorism pose more definable, relevant risk.

©Midland Daily News 2005

For additional articles like this one, go to the Tittabawassee River Watch web site www.trwnews.net for complete coverage of the Tittabawassee River Dow Chemical dioxin contamination saga. . The Newspaper / Media page of our site contains an extensive archive of media articles dating back to January 2002. The source organization's web site link is listed to the right of the article, visit often for other news in our area. The Newspaper / Media page may be accessed by scrolling down to the bottom of the CONTENTS section and clicking on the Newspaper/Media link.