Pre-1980 dioxin link found
By Tony Lascari Midland Daily News
Posted: Friday, January 28, 2011 10:35 am | Updated: 1:14 pm, Fri Jan 28, 2011.
Living in the Midland and Saginaw area before 1980 is associated with having higher levels of a dioxin known as TCDD in your blood than a control group in Jackson and Calhoun counties, but living in this region since 1980 has no effect on dioxin levels in blood, according to a report issued Thursday by the University of Michigan Dioxin Exposure Study team.
Lead researcher David Garabrant said this finding is among the updates to a 2006 report, which at the time indicated TCDD was associated with people living in the region prior to 1960.
"Having lived in the area prior to 1980 is a big predictor," he said. "Once you control for that, there's nothing after 1980 that matters. Your fish eating doesn't matter, the soil doesn't matter, the dust doesn't matter, having burned trash in your back yard recently doesn't seem to matter. ... When we look at everything we've done in the past 25 years -- eating fish, picnicking, kayaking, swimming, water skiing, doing anything on the river -- we're not seeing any association with blood levels."
Researchers conducted interviews and collected samples of blood, household dust and soil in the Tittabawassee River floodplain, near the floodplain, in the Midland plume and other Midland and Saginaw County sites, along with sites in Jackson and Calhoun counties to use as a control group. The investigation looked at pollution released from The Dow Chemical Co.'s Midland site.
Planning began in the fall of 2003 and data collection occurred in 2004 and 2005. After issuing the initial report in 2006, Garabrant and his team shared the information in public meetings in the community.
The study drew concerns from both the Michigan Department of Environmental Quality and the U.S. Environmental Protection Agency. The researchers met with the MDEQ and Michigan Department of Community Health over a period of one year to discuss the results.
"The DEQ requested that we do a tremendous amount of additional analysis of the data. We did all of the analyses that they requested. I had a team of four statisticians that spent a year doing that," Garabrant said. "Their suggestions led to a number of improvements in the way we analyzed our data. It led to some additional insights, and actually helped us to clarify that it was living in Midland and Saginaw prior to 1980 that was such an important predictor for blood levels of TCDD."
Garabrant said tougher air and water regulations were put in place in the 1980s, so dramatically fewer dioxins were being emitted into the ecosystem.
Other updates to the 2006 report
The updated report focuses on three specific toxic chemicals, including TCDD, rather than the previously used Toxic Equivalency, which measures the toxicity of 29 dioxin and dioxin-like compounds.
"This report focuses on three key chemicals rather than the summary TEQ because they give a clearer picture of how dioxins in the environment enter people's bodies," the report states. Full results for all 29 compounds and the TEQ are available on the study website, www.umdioxin.org.
Another change since the 2006 report involves fish consumption. In 2006, researchers said: "People who eat fish from the Tittabawassee River, Saginaw River and Saginaw Bay have higher levels of dioxins in their blood." But, Garabrant now says new data shows that is not actually the case.
Researchers took data from a Michigan State University study and the State of Michigan on how much dioxin contamination was actually in the fish by species and combined it with what people reported eating. After calculating the people's dioxin intake, researchers found eating fish had no relation to their blood levels of dioxin.
Garabrant said it's important to note that people don't tend to eat much of the more highly-contaminated fish, but tend to eat the less-contaminated walleye.
"We still recommend that people follow the Michigan Department of Community Health guidelines on fish consumption from the contaminated areas, and we recommend that people not eat the highly-contaminated fish, like the carp from the contaminated areas," he said. "It's reasonable to think that if people ate a lot of the bottom feeders it would contribute to their blood levels, but what the data show now is what the people do eat is relatively uncontaminated and it's not contributing to their blood levels."
Researchers have also backed away from this statement made in 2006: "People who have higher levels of dioxins in their soil have a higher TEQ (total dioxin-like activity) and higher levels of some specific dioxins in their blood."
Garabrant said they found that the 2006 association was due to a single soil sample that was high in TCDD. He said the absence of an association for every other compound is a strong argument that the single influential observation for TCDD was an anomaly.
"We're very cautious about making conclusions based on one data point," he said.
The final major change since 2006 is in the initial report's finding that blood levels of some dioxins were higher among people who lived in the floodplain, near the floodplain, and other Midland and Saginaw areas than in Jackson and Calhoun.
"Since then, we have done further analyses to understand why this is true. We found that this difference was entirely explained by whether people had lived in Midland/Saginaw prior to 1980," the new report states.
Study coming to an end
Garabrant said he never imagined when the project took shape in 2003 that he'd still be working on it in 2011. Issuing the updated report brings the study closer an end, with more scientific papers expected to be published in the next year.
"This has been an absolutely thrilling and challenging research project, partly because it's such an important issue, partly because we had the funding to do it absolutely right," Garabrant said. "When you talk about spending a year to go back and answer questions from critics, we rarely have the opportunity to do that."
Financial support for the study was provided by from Dow Chemical through an unrestricted grant to U-M. The university had independence to design, carry out and report the results of the study.
"We had the opportunity to collect what I think is one of the best data sets anyone has ever collected on an environmental dioxin exposure site and to analyze it extremely carefully and thoroughly," Garabrant said. "Like anything that you put your heart into, there's a real thrill in doing it, there's a real feeling of accomplishment when you finish it and there's a real feeling of missing the challenge."
Garabrant said he feels the results of the study are correct.
"They should fit the facts as we know them, and fit them well, and this does," he said. "It's pretty clear that somewhere around 1980, it changed. What I find to be absolutely astonishing is that we can pick up in people's blood in 2005 that effect from 25 years ago. That's pretty good."
The most important thing that the study has accomplished is it provides facts that allow people to understand what's going on, Garabrant said.
"Without the study, people were largely making decisions based on guesswork," he said. "The important part of the study is now there's some evidence, a pattern of facts that allow people to be informed about blood dioxin levels, soil levels, household dust levels and what things tell how dioxins get into your body."
It's clear to Garabrant that the issue matters to the Midland community.
"I hope (the study) will be used to, first off, reduce people's concern about living on contaminated soil or having contaminated dust in their homes -- those appear not to be worries," he said. "I hope that it will be used by people to reinforce the idea that dioxins in your body come principally from eating contaminated food and that it's important not to eat food that comes from highly contaminated areas. You shouldn't eat food raised on highly contaminated soil -- beef or chicken or eggs -- and you should follow the MDCH guidelines for consumption of fish."
A four-page summary of the study results will be mailed to 117,000 residential addresses in Midland and Saginaw counties, along with Auburn. The 45-page full report of the study results is also expected to be placed in libraries and other public locations.
RiverRat posted at 1:40 pm on Mon, Jan 31, 2011.
Posts: 1 I also wonder why they did not track down former residents for testing. I lived in the floodplain from 1965-1977 and our home was surrounded by Tittabawassee flood waters many times during those years. Our basement was full of water and our house/yard were surrounded by flood waters as well as living very near the chemical plant. At times we had to wade out or canoe out to the bridge to get into town. Are some of my health problems related to living in this contaminated area? I'm sure I will never find out. The City of Midland gradually bought out the majority of the homes in our neighborhood and tore them down to make parks and baseball diamonds. I have never left the Midland area so it shouldn't be that hard to track down former residents that lived through the mess during those years!
redryder posted at 8:44 pm on Sat, Jan 29, 2011.
Posts: 7 This is only one more example of Garabrant and Dow's Orwellian Doublespeak. Their explanations defy reason and their testing was scientifically inadequate due to the low number of test subjects and limited health follow-up. Did they track down and draw blood from those who left the area after 1975 and never moved back? I've never been tested in spite of the fact I lived near the chemical waste lagoon from birth and then dowtown Midland after the huge flood of the 1970's? Anybody with two eyes and a sphincter would know that has got to be endemically relevant.
Wakemup posted at 5:59 pm on Fri, Jan 28, 2011.
This is confusing. In the beginning, it is stated eating fish from the river isn't a problem:
"Once you control for that, there's nothing after 1980 that matters. Your fish eating doesn't matter, the soil doesn't matter, the dust doesn't matter, having burned trash in your back yard recently doesn't seem to matter. ... When we look at everything we've done in the past 25 years -- eating fish, picnicking, kayaking, swimming, water skiing, doing anything on the river -- we're not seeing any association with blood levels."
Then, it states, "I hope that it will be used by people to reinforce the idea that dioxins in your body come principally from eating contaminated food and that it's important not to eat food that comes from highly contaminated areas. You shouldn't eat food raised on highly contaminated soil -- beef or chicken or eggs -- and you should follow the MDCH guidelines for consumption of fish."
When I first read that eating fish from the contaminated river wasn't a problem, I thought for sure the fish would be a staple in the Dow cafeteria and at Board meetings. Now, I'm not so sure.
greengrass posted at 2:42 pm on Fri, Jan 28, 2011.
Posts: 17 This appears to be great news. I suspect the cynics out there will throw their stones, though I might hope that this would be additional confirmation that there is little to worry about with this issue.
There is likely more danger to the population with the unfounded stress this issue brings vs the current levels of contaminants out there.
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.