Michigan Dioxin Exposure Study
It’s customary for scientists to remain emotionally detached from the human subjects ultimately impacted by their findings. In many cases, and rightly so, science is about as emotional as a starched white lab coat.
It’s also customary, in community disputes, for one vocal opposition group to form while everyone else sort of mills about, neutral. But in late 2003, when the University of Michigan began a dioxin exposure study in Saginaw County, nothing about the torn community was customary, and the research was much more than basic, white-lab-coat science. The study was public health in its purest form, and has become a model for how to do science in a highly charged, extremely emotional community overshadowed by mistrust and a years-long tug-of-war between stakeholders on all sides.
In the end, the angry rhetoric has died down, because the UM study has provided some answers to people’s concerns. The dioxin study results eased the worries of hundreds of homeowners who have spent the last few years scanning the shores and brown waters of the Tittabawassee River, hoping for a hint of what the future held.
By the time the dioxin study began, many homeowners along the Tittabawassee River in Midland and Saginaw Counties weren’t simply emotional, they were raging—and with good reason. Not long before, dozens of residents in the Tittabawassee River floodplain and surrounding areas had received letters informing them that the Department of Environmental Quality had declared their properties “facilities,” based on elevated levels of dioxins in the river floodplain—even though, in most cases, no measurements had been performed on their property. It was thought that Dow Chemical Company in Midland had caused the elevated dioxin levels.
“It was really, we felt, an infringement on our personal property rights,” said Leonard Heinzman of Freeland, a life-long area resident. Nine years ago Heinzman built a towering log home on a park-like setting along the Tittabawassee, never dreaming that he would one day spearhead a group of residents bent on proving to the world that his land was not a toxic sponge.
“It’s not something that people were not aware of,” he said. “People knew and there was talk of dioxin for years, but it was just one of those things that you lived with. When you looked at the health of the areas, you just kind of said, ‘So?’”
Other residents, like Marcia Woodman, who lives north of Freeland in the floodplain, were scared to death. “I did initially wear a mask when I cut the grass. I don’t anymore but I probably should,” she said. “I’m just very cautious raking leaves. I always wear gloves now. I have separate clothes for the yard.”
Woodman has joined a class-action lawsuit against Dow because she wants her children financially taken care of if health problems arise in the future because of the contamination.
Dioxins are toxic chemicals that are produced as unwanted byproducts of some types of industrial activities and by combustion. The family of chemical includes polychlorinated dibenzodioxins, polychlorinated dibenzofurans, and certain PCBs that have a common toxic effect. They bind to the aryl hydrocarbon receptor (Ah receptor) that is part of an important signaling pathway for many effects on DNA. There is concern that dioxins may be linked to cancer, developmental effects, and disruption of the endocrine system. Because industrial processes have produced dioxins (especially prior to the 1980s when they began to be tightly regulated), and they have gotten into the food chain, people all over the world have measurable levels of dioxins in their blood. Additionally, dioxins exist naturally in the environment, caused by such events as forest fires, volcanic eruptions and even compost heaps, and dioxins occur naturally in many clays.
By the time the UM study began, many residents had filed lawsuits against the Dow Chemical Co. Homeowners along the river were divided: some, like Heinzman, thought the levels harmless. Others feared health problems and falling property values. Both sides created websites and key messages with spokespeople; both stumped their views to the media and to local and state politicians.
Reporter Jeremiah Stettler covered the story in Saginaw for three years. Inevitably after a story he’d receive hate mail from one side or both. “I have never in my life seen an issue that has created two counter campaigns by citizen groups, and I think that it is a more polarizing issue than any other one that I have dealt with.”
This is what David Garabrant and Al Franzblau, the lead researchers on the 20-person team, walked into. Both scientists had worked on emotional community-research and occupational-safety projects previously in their careers. Garabrant, as a professor of environmental health sciences, professor of epidemiology, and associate professor of emergency medicine, had done work on, among other things, pancreatic cancer and the health effects of DDT and other chlorinated pesticides. Franzblau is a professor of environmental health sciences, associate professor of emergency medicine, and associate research scientist in the College of Engineering, and he has worked on, among other projects, musculoskeletal disorders and asbestos exposure in workers. Between them they have roughly 65 years of science experience. Neither had seen anything like this.
“I think what is unique in this issue was how polarized the community is,” Garabrant
said. “There are many people in Midland who are deeply committed to Dow and believe
that Dow is a very responsible company and a good neighbor. Those people are committed
to finding the truth but are very loyal to seeing that Dow is not inappropriately
accused. Then there are people in the community who have the view that Dow has done
something terribly wrong and that Dow should be punished to an extreme degree.”
Not only did researchers have to grapple with the turmoil in the community surrounding the issue, but they had to confront the distrust fueled by the fact that Dow—which was believed to have caused the contamination—had funded the UM study. The Michigan Department of Environmental Quality requires companies that emit pollutants to assess the extent and impact of their emissions, and this study assists Dow in meeting those obligations. To many residents, this was akin to putting the fox in charge of the henhouse. For this reason, the UM team had a problem on its hands if the public wasn’t convinced that a firewall existed between the UM research and Dow, Franzblau said.
“It was a challenge,” Franzblau said of the negative perception caused by the source of funding. “It still is.”
In order to preserve scientific integrity, the UM researchers negotiated a contract with Dow that, among other things, gives Dow no access to the data, now or ever. Dow receives word of study results at public meetings along with residents—a potential public relations risk that Dow agreed to for the sake of transparency, Franzblau said.
“I think Dow felt the credibility of this research was the most important result that could be achieved,” Garabrant said.
The research team spent the year prior to the start of the actual fieldwork laying the groundwork in the communities that would eventually be tested for dioxin. They held community meetings and interviews with key community leaders to learn about concerns. They established two community advisory panels, one in Midland-Saginaw and the other in the Jackson-Calhoun County control group. Membership on the panels was wide-ranging and included, among others, a school superintendent, a chamber of commerce officer, a minister, and a parks chairman.
The research team did radio and newspaper interviews and appeared on local cable-access television. They submitted op-eds to explain the research process. They developed the protocol for the study and invited comment, and responded to each set of comments in writing. Eventually, they changed several key parts of the study based on community feedback. All written comments and responses are posted on the study website (www.umdioxin.org). They established an independent scientific advisory board to which they report results. This board consisted of national and international experts chosen for their scientific stature and expertise, independence, and research qualifications.
Above all, the focus was on the science, and the message was transparency. Still, the community meetings were sometimes rough—“I would just be prepared for anything,” Franzblau recalled—and the team became used to dodging darts while remaining professional.
For instance, at a meeting after the fieldwork had finished, an elderly man stood in front of the crowd and told the research team seated at the front of the room that he’d received a letter from the university with blood results, but he had not participated in the study. Instantly, a crowd seated around the man began chanting, among other things, “Junk science! Junk science!”
Garabrant’s heart raced: Had there been a mistake? The team will look into it, Garabrant told the jeering crowd. That’s all he could say.
It was a worrisome night and following day of anxiety, a flurry of phone calls to general counsel and the scientific advisory board. Had the team’s credibility been irretrievably damaged? Then, a few days later, the Saginaw News reported that the man from the meeting had recanted his story. The news story said the man had simply forgotten that he’d participated—an honest mistake made by an individual whose memory had temporarily failed him.
The UM team also had to overcome the potential economic risk placed on people who agreed to participate in the study, Franzblau said. If a subject agreed to participate and have her soil tested, she was required by law to disclose those results to buyers. This could cause property values to fall. So, researchers gave subjects the option of deciding whether to receive results of chemical analyses of soil, house dust, and blood. In the end, about 98 percent of the subjects chose to know their blood results, but only 67 percent chose to be notified of their soil and house-dust test results, Franzblau said.
The team’s intensive community outreach work paid off and yielded an unheard of study participation rate of about 80 percent. Usually, such studies have a 50 percent or less participation rate.
Researchers gathered eight vials of blood, plus soil and household dust, from each of hundreds of randomly selected residents in five geographic areas in Midland and Saginaw and the Jackson control group, focusing primarily on the Tittabawassee River floodplain. The results were reported at a series of community meetings in August 2006, and showed that some people had elevated levels of dioxin, but not much higher than the folks in the control regions.
For many residents, like Heinzman, the results confirmed what they had maintained all along: people and land along the floodplain and in other tested areas are just as healthy as anywhere else. Other residents remain skeptical and believe dioxin has made them sick, or could do so in the future. The results didn’t answer everything. Because the dioxin study did not address risk but instead just measured exposure—a necessary first step before risk can be addressed—additional questions remain, and Dow has given more money to UM for further study.
Although the community is still divided, there is much more reasoned progress toward deciding what to do about the pollution. The UM study has provided concrete answers to questions about whether polluted soil contributes to people’s blood dioxin levels—the contribution is small, Garabrant said. It also shows that eating fish from the polluted waters is a more important pathway for dioxins to get into people’s blood.
The research team in its entirety went to Saginaw Valley State University in August 2006 to report the initial results of the study to a crowd of around 250 people. Team members answered two hours of questions posed by community members in the audience, and when they’d answered the last question of the evening, the community that had initially been so skeptical gave the team a standing ovation.
Garabrant and his team then flew to Oslo, Norway, to report the same results to an international gathering of scientists who praised the study for its pathbreaking design. One researcher in Oslo said, “This shows how populations should be studied to tell how dioxins in the environment contribute to body burdens. It sets a new standard for understanding what the environment has to do with people.” This fall, the team will present findings from the study at several international meetings, including Dioxin 2007 in Tokyo.
“Although there is still a lot of dissent in Midland and Saginaw about what to do about the pollution, there is no disagreement that the UM study has settled the toughest questions about the consequences of living on contaminated soil,” Garabrant said. “Now, the next steps are to use the data to inform the risk assessment being done by the state, and to decide what levels of contamination warrant cleanup and which to leave alone. This is public health in its highest form. To go into a community with real public health concerns and bring answers and rationality where there was only emotion. That’s what public health professionals are supposed to do, and that is what we’ve done.”
By Laura Bailey.
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Michigan Dioxin Exposure Study
“I have never in my life seen an issue that has created two counter campaigns by citizen groups, and I think that it is a more polarizing issue than any other one that I have dealt with.”
--Saginaw-based news reporter Jeremiah Stettler