Elevated Dioxin Levels Found In People Living Near Dow Plant

People living in parts of two counties near the massive Dow Chemical complex in Midland, Mich., have slightly higher levels of dioxins in their blood than do people who live elsewhere in the state, according to a two-year study by the University of Michigan (UM).

Much of the increased amount of dioxins in Midland and Saginaw County residents is related to age, the study found. Nationally, older people have higher levels of dioxins, which are a family of toxic chemicals produced by combustion or industrial processes. One of the chemicals, TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin), is known to cause cancer in humans.

Some of the increase was associated with eating certain foods such as fish from local waters downwind from Dow or having worked at the company's plant from 1940 to 1959. Only a small portion of the increase was related to living on soil contaminated by Dow.

"This study provides facts that will allow people to develop a plan for dealing with the contamination that is factually based and not based on speculation," says UM epidemiologist David Garabrant, who directed the study.

The $15 million study was financed by Dow but was controlled and conducted by UM researchers. Research decisions were reviewed by an independent scientific advisory board.

Dow, which acknowledges having polluted the Tittabawassee River floodplain with dioxins for decades, is negotiating a cleanup plan with the Michigan Department of Environmental Quality.

The company is required under agreements with the state to provide data about contamination of Midland and Saginaw Counties, including identifying how dioxins enter people's bodies. The study, which was announced in January 2004, is expected to help guide potential remediation efforts.

Garabran says that the research examined the extent of human exposure to dioxins, not the health effects of that exposure. "This is the first major study to show exactly how much exposure to dioxin people have in this area and how the dioxins get into their bodies," he notes.

The study found that people in one of the areas studied, the Tittabawassee River floodplain, had 28% higher median levels of dioxin-like chemicals in their blood than members of a comparison group in Jackson and Calhoun Counties. Those counties were chosen because they are near the Midland-Saginaw area but are more than 100 miles from the Dow complex.

Because combustion and industrial processes are widespread in the U.S., the study says, all Americans have some dioxins in their blood.