Dioxin study reaction mixed
08/16/2006
 Kathie Marchlewski , Midland Daily News

Some call it comforting that the impact of local dioxin contamination on people is small. Some experiencing the impact disagree.
 "They make it sound normal," said Vito Damore, a Tittabawassee River flood plain resident who took part in the University of Michigan dioxin exposure study, the results of which were released Tuesday.

 Damore said dioxin at any level isn’t normal or natural. Whether it comes from The Dow Chemical Co. or from the national food supply, which it does, it is a concern, he said. "No one is born with it."

But Dow officials see good news in the research led by Dr. David Garabrant. Most of the more than 695 local people who took part in the $15 million, company-funded study have dioxin levels within the national range.

The study found that residents of the Tittabawassee River flood plain had levels 28 percent higher than a control group in Jackson and Calhoun counties. Part of the increase, however, was due to age. The Jackson/Calhoun group averaged four years younger than residents here, skewing the 28 percent increase by about half. Older people have accumulated more dioxin in their lifetimes.

The study, which drew blood samples and measured dioxin levels on land and in house dust, found that age, diet and all other factors aside, living in Saginaw or Midland counties near the Dow plant, on contaminated soil, increases dioxin levels by about 1 percentage point.

The study also found that eating contaminated fish contributes to dioxin levels at a rate of about 2 percent a year for each year consumed, and that for each 1,000 parts per trillion of dioxin on property, dioxin levels in the body increase by about 2 percent.

Dow spokesman John Musser said people should be reassured by the findings. "It really only matters a little, not a lot, where you live," he said.

Len Heinzman, who lives along the Tittabawassee River’s flood plain, agrees that the study brings good news. "This is pure science. This is what we’ve been preaching about," he said. "I think the information is getting more and more positive."

He and others have been eyeing the study as a solution to too-strict state standards, regulations and potential remediation plans.

"Anyone who dismisses it, if it doesn’t change how things are regulated in the state, that’s an error," said Midland Tomorrow Executive Director Scott Walker.

 But for people like Damore, who took part in the study, any increase is a problem. Damore’s dioxin level is around 21 parts per trillion, which puts him within the national average, but at its high end. His yard has levels of dioxin measuring as high as 323 ppt, more than three times the state’s allowable level.

 Damore’s wife, who has lived in the flood plain all of her 58 years, more than 30 with him, believes the results give the Michigan Department of Environmental Quality "ammunition" to move forward with river and residence cleanup. "I’m glad the study is showing there is a problem in this area. Now we can move forward," she said.

 DEQ Deputy Director Jim Sygo, who like other stakeholders just began reviewing the document released Tuesday via Internet and at a 1 p.m. meeting at Ashman Court Marriott Hotel and Conference Center, said it’s too soon to tell how the study might affect requirements of Dow’s operating license or state regulations.

 "I think there’s a lot of value in the data that’s presented," he said. "There’s still a lot of data analysis we have to look at."

The U-M study to date only shows total toxic equivalency factor levels for 29 congeners – the different types of dioxins, furans and PCBs – with closer examination of the seven most visible in blood. While two of the most prevalent congeners contaminating the flood plain – the duo of furans makes up about 80 percent of the contamination – also appear in blood, they show up in much smaller levels. U-M researchers still are analyzing results and hope to explain the variance. It’s possible that that those furans are being ingested by people, but are expelled more readily from bodies than other types of dioxins.

Researchers also plan to analyze results of different population groups within the study, Garabrant said. The initial report includes statistics and averages considering the entire group of more than 900 people. The hope is that results derived from subsections would be consistent with the whole, further validating the results.

Dow officials are hoping the results are incorporated into the state’s site-specific criteria for dioxin, the allowable dioxin levels for land. They also want it built into the human health risk assessment they plan to complete and will submit a plan for at year end. Specifically, Dow wants the data inserted into a state algorithm used to set the 90 parts per trillion residential contact criteria – the level the state considers safe for contact. That algorithm is based on assumptions about how much dioxin enters the body through activities such as soil ingestion and skin contact.

 "We would hope the facts will find their way into that equation," Musser said. "They should be different because they’re based on models, not on real data."

 Dow also is suggesting that other recent scientific releases – including a National Academy of Sciences review of the Environmental Protection Agency’s reassessment of dioxin that suggests using both linear and non-linear models to determine risk, and a World Health Organization reassessment of some dioxinlike compounds’ toxicity – be included. That information wasn’t available when Dow last year submitted a human health risk assessment plan deemed unacceptable by the DEQ and EPA.

 EPA project manager Gregory Rudloff said the agency has just begun to review the U-M study, and that so far, it is along the lines of what it expected – that dioxin in soil does not have as large an impact on human dioxin levels as eating contaminated fish.

"We think Michigan is on the right track to deal with this issue," he said.

Determining the nature and extent of the dioxin contamination, a project Dow currently is working on as it examines the Tittabawassee River’s dynamics, remains important, Rudloff said. The goal is to interrupt dioxin exposure pathways.

"From our standpoint, it’s not just human health, but the environment we need to protect," he said. "The only way to get a handle on that is to remove and get control of the contamination."

Of the more than 3,000 samples U-M researchers had analyzed for dioxin content, 42 percent in the flood plain were above the state’s 90 ppt allowable level. Near the floodplain, 11 percent were above that level, in Midland, 30 percent, and elsewhere in Midland and Saginaw counties, 5 percent. In Jackson and Calhoun counties, the average level was 4 to 5 ppt. Fourteen percent of the properties in the floodplain tested over 1,000 ppt, compared with 3 percent of properties in Midland.

A summary of the U-M dioxin exposure study and supporting documents are available at the study website, www.umdioxin.org .
 

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.