Higher dioxin levels found in people near Dow plant

8/15/2006, 6:43 p.m. ET By JOHN FLESHER The Associated Press

 

(AP) — Residents near the Dow Chemical Co. plant in Midland have more dioxin in their blood than those of a comparable area farther away, according to a University of Michigan report released Tuesday.

But pollution from the plant is just one reason for the discrepancy and a minor factor among many that determined the dioxin levels in people examined, the report said.

Age was the most important, as older people tend to have more dioxin in their bodies. The two counties closest to the plant — Midland and Saginaw — have an older population than in Jackson and Calhoun counties, the control group selected for the study.

Dow, which acknowledges having polluted the Tittabawassee River floodplain with dioxins for many years, funded the $15 million, three-year study as it negotiates with the Michigan Department of Environmental Quality over a cleanup plan.

But University of Michigan epidemiologist Dr. David Garabrant, who directed the study, said the company wasn't involved in its planning or execution. "It was done completely independently" and monitored by an advisory board of scientists, he said.

"This study provides facts that will allow the people of Midland and Saginaw and the people of Michigan to develop a plan for dealing with the contamination that is factually based and not based on speculation," Garabrant said.

DEQ spokesman Bob McCann said it would take time for the agency to analyze the findings.

"Taking it on its face value, it's a good representation of the different exposure methods of dioxin and shows us there is an increase if you're living in the floodplain," he said.

Dioxins are a family of chemicals produced by combustion or other industrial processes. The study focused on 29 key chemicals within that group, at least one of which is known to cause cancer. Dioxins generated at the Dow plant settled into soil and river sediment along at least 22 miles of the floodplain downstream from company headquarters.

The study did not attempt to determine how dioxins have affected people's health, Garabrant said. But he said dioxin levels measured in the region around the plant were "dramatically below" those detected in studies after industrial accidents involving dioxins.

Company spokesman John Musser said the results support Dow's contention that elevated dioxin levels downstream from the plant do not "represent a significant or imminent health threat to people living in this area."

Michelle Hurd Riddick of the Lone Tree Council, a citizens' activist group critical of Dow, said the report confirmed that tainted soil was boosting dioxin levels.

"We didn't need this study to tell us what to do, but it does reinforce our position that the soil is contaminated, people are taking it up, and Michigan's largest watershed deserves to be cleaned up," Hurd Riddick said.

University researchers studied dioxin levels in soil, household dust and blood samples. They interviewed residents about their age, body mass, diet, land use and other habits. Blood samples were taken from 695 people in Midland and Saginaw counties.

Jackson and Calhoun counties, located more than 100 miles from the Dow plant, were chosen as the control group because they have similar demographics — even though the average age of people tested there was 49, compared to 53 in Midland and Saginaw counties.

People tested in Jackson and Calhoun had a median 25 parts of dioxin for every trillion parts of blood, just above the national median of 24 parts per trillion. In Midland and Saginaw, the median was 32 parts per trillion.

Age is the primary determinant of dioxin levels because older people have spent more time eating the animal fats through which the toxins get into the body, and because metabolism and excretion rates slow as people age, Garabrant said. Also, pollution levels have fallen over the years, so younger people have had less exposure.

Eating fish from the Tittabawassee River, the Saginaw River and Lake Huron's Saginaw Bay also boosted some people's dioxin levels, the report said. Other factors explaining the higher levels included diets heavy with wild game, meat, dairy and eggs and having contaminated household dust.

Living in the contaminated areas of Saginaw and Midland counties also caused higher levels but was less important, the study said.

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EDITOR'S NOTE — John Flesher is the AP correspondent in Traverse City, Mich., and has covered environmental issues since 1992.

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