Does dioxin trigger diabetes
Take too many Hostess Twinkies, subtract fresh fruits and vegetables, exercise and whole grains and toss with some unfortunate genes and what have you got? A good case of diabetes.
Or so we’re told. But while no one disputes that lifestyle and inherited predisposition can bring on the frightening disease, there may be even more chilling news waiting in the scientific wings.
According to a U.S. government report released just six weeks ago, too many french fries and milk shakes may not be the only threat when it comes to diabetes. Dioxin — the deadliest chemical ever invented, a menace in even the most minute quantities — may be an even more lethal culprit.
For the many First Nations communities that have been heavily exposed to the toxin — from the Mohawk Akwesasne reserve near Cornwall to Grassy Narrows near Kenora — and whose people are now suffering epidemic rates of the disease, this finding could be exactly what the doctor ordered to push the corporate-friendly Canadian government into regulation overdrive.
Many jurisdictions worldwide have clamped down on dioxin, reducing allowable emissions to ever more minuscule amounts. Canada, on the other hand, while quick to sign on the dotted line when there’s some international accord being passed around, has become a joke among the globe’s dioxin campaigners.
Dioxin, an industrial contaminant, cycles and recycles in the food chain, accumulating in the milk of mammals, including humans. A wealth of scientific literature shows that it’s a potent endocrine disrupter — an environmental steroid of sorts — capable of distorting hormone levels in animals and people.
The chemical is typically measured in microscopic amounts, nanograms (trillionths of a gram) or even picograms (quadrillionths), a stark illustration of how little it takes to bring about major hormonal changes in our bodies.
The shocking new data on dioxin comes from what at first might seem an unlikely source — the U.S. Air Force.
Thousands of American boys found themselves behind canisters of dioxin during the Vietnam War. It was one of the ingredients in Agent Orange, which was used to kill the lush vegetation that was a convenient cover for their Vietcong enemies.
The study, begun in 1982, compared the health of 1,000 veterans of Operation Ranch Hand, the unit responsible for the aerial spraying of herbicides in Vietnam from 1962 to 1971, to a comparison group of 1,300 vets who served in Southeast Asia during the same period but had no direct contact with the compound.
The study found that veterans with the highest levels of dioxin suffered a 47 per cent higher incidence of diabetes than the comparison group, a compelling finding when you consider that dioxin has already been linked to many health effects in laboratory animals.
Principal investigator Joel Michalek is more than familiar with issues surrounding dioxin in Canada — his father-in-law lives in Lion’s Bay, BC, which is closed to fishing and swimming due to dioxin pollution. But Michalek is quick to caution that this link to dioxin exposure is so far only statistical.
“We are trying to find out if the relation we see in this group is biological,” he says.
Researchers have extracted 12 grams of body fat from 313 study subjects, and those specimens are being sent to the department of toxicology at University of California at Davis, near Sacramento, to see whether there is a relation between the amount of dioxin in the tissue and the cellular measures of diabetes.
As well, 30 men in the study are being sent to Little Rock, Arkansas, for insulin sensitivity testing to further check the diabetes-dioxin hypothesis.
“I’m not in a position to say that dioxin causes diabetes,” he cautions, “and that statement applies to any other study of diabetes and dioxin. I don’t believe anyone has established causation at this point. On the other hand, this is probably the best available data in the world, because this is the only large study that has followed this many people for so long.”
The study is all the more impressive in light of the fact that it was peer-reviewed by leading experts in their fields at the U.S. Center for Disease Control and Prevention, the U.S. National Institutes of Health and the U.S. National Academy of Sciences and by academic experts throughout the world. Its landmark findings could eventually result in additional health benefits for thousands of American vets.
Michalek says the results should not be generalized to other populations, such as Vietnamese civilians or other veteran populations who may have been exposed in different ways.
“It’s a frustrating picture to people who want an answer,” Michalek admits, “but we are using the best available technology to answer the question, and we’re not there yet.”
Indeed, most scientists I interview insist that any link between dioxin contamination and illness among natives remains speculative. “There is really no proof showing that exposure to dioxin causes diabetes,” declares Laurie Chan, associate professor in the school of dietetics and human nutrition at McGill University in Montreal. “There’s some data showing a correlation, but there’s no cause-and-effect relationship.”
Chan does note, however, that varying guideline levels for dioxin exposure are released by different national governments or international bodies. “The Canadian guidelines are quite old, and even though people from Health Canada actually participated in the establishment of the World Health Organization guidelines — which are lower than ours — we have not updated our own guidelines to reflect that change.”
This fact is all the more alarming since suggestive findings stretching back decades have suggested a diabetes-dioxin link.
For instance, a 1981 study of 55 Czechoslovakian workers exposed to dioxin and evaluated 10 years after exposure found 50 per cent to be diabetic or to have abnormal glucose tolerance, an early indicator of diabetes. Several studies of pulp and paper production workers in Sweden also suggest that exposure to dioxin increases the risk of developing diabetes, while a 1992 study by the U.S. National Institute of Occupational Health and Safety found that the risk of diabetes increases 12 per cent for every 100 picograms of dioxin in the blood.
Though evidence strong enough to be called proof of a link between dioxin and diabetes still eludes investigators, some governments are acting anyway. Australian authorities are sufficiently satisfied with the probable link that veterans there are now able to claim benefits for diabetes resulting from exposure to dioxin during service.
That decision, announced last year, followed a comprehensive review of scientific literature on the effects of dioxin by Australia’s Repatriation Medical Authority, an expert independent medical body responsible for determining links between diseases and war service.
In this country, it’s a different story. The illness has reached epic proportions among native populations, striking three times as many aboriginals over 40 compared with other groups. Much of this epidemic of illness has been attributed to changes in diet and lifestyle, with fatty, carbohydrate-rich packaged food replacing the traditional native staples of fish and grains.
Then there’s the fact that many reserves are neighbours to countless pulp and paper operations that once spewed dioxin in the bleaching process.
Regulations under the Canadian Environmental Protection Act have forced the pulp and
paper industry to drastically reduce emissions of dioxin over the last decade, especially in Ontario.But
the effects of years-old pollution still linger, says Delores Broten, executive director of Reach for Unbleached, a national watchdog organization formed in response to fishing closures due to dioxin contamination by pulp mills.
“You still have incredible historical contamination of the food chain,’ she points out.
Dioxins are also produced as by-products of various industrial processes, including the burning of bark and sawmill waste at paper and pulp mills, and municipal incineration.
But judging from a survey of researchers in both government and the private sector, actual research on this question in this country is virtually non-existent, a deeply distressing state of affairs for people like Henry Lickers, who serves as environmental director for the Mohawks of Akwesasne in Cornwall where Domtar has its home.
“If this epidemic of diabetes were in a non-native community,” says Lickers (who suffers from the disease himself), “this would be going through the roof. There would be massive studies in order to see if there is a connection between dioxins and diabetes.”
Instead, Ottawa has pledged slightly less than $60 million over five years to fight diabetes in aboriginal communities, none of which will be spent researching this vexing scientific puzzle. Federal health officials mostly sweep aside concerns over the effects of dioxin and other industrial pollutants on native health, preferring to blame diet and lifestyle for their ills.
Scientists at Health Canada are not only hesitant to identify dioxin as a potential contributor to diabetes in native populations, but they have no plans to conduct their own research into the question. At the medical services branch in Ottawa, Harold Schwartz, acting chief of research and statistics, acknowledges that his department has been following the reports, but that’s about it.
Schwartz recognizes the seriousness of the diabetes epidemic among native communities, but says, “The evidence is that it has to do with a change of lifestyle, going from an active hunting lifestyle to a sedentary one, eating store-bought food high in fat and carbohydrates. We have evolved over hundreds of years eating that diet, where this might be the first or second generation for First Nations people.”
If the dioxin/diabetes theory were valid, Schwartz says, there would also be high levels of diabetes among Inuit communities, which are exposed to much higher levels of dioxin than First Nations farther south. But he says aboriginal people farther north are still practising a traditional lifestyle and don’t show the increase in diabetes that is seen in the south.
Mark Seeley, a toxicologist with the Health Protection Branch’s chemical health hazard assessment division, also thinks the diabetes epidemic among native people is more the result of diet changes than of pollution.
In Seeley’s view, “Decrease of exposure (to dioxins) is a route that has been, at least since the 1990s, adequately addressed.”
Most of the pulping process is now done through alternative processes that have dramatically reduced dioxin levels, according to the environmental and fish-based monitoring programs that Health Canada runs in conjunction with the department of fisheries and oceans.
Seeley adds, however, that “to the best of my knowledge,” there has been no study of First Nations people’s exposure to dioxins.
“Overall, in terms of association, there have been some links shown between occupational exposure and dioxin, but to make a definitive link — especially for First Nations — you would have to have a more definitive way of looking at some of the body-burden calculations.”
Seeley says part of the problem with the cohort studies is that there is limited monitoring at the peak point of exposure. “With the production processes that were in place with (certain) herbicides and their manufacturers, the peak exposure period was probably mid-1970s. So do you then show what the association is, based on their peak exposure period, or the latent exposure period where the body has x period of time to eliminate the dioxin?”
Anyway, he says, the problem of diabetes among natives falls more under the purview of Health Canada’s diabetes program than that of toxicologists.
“I would think that if there were a causal link between some sort of exposure to an environmental contaminant in the First Nations’ traditional diet consumption, that might be something they would want to investigate, but being in a different branch of the government, I have limited exposure or even knowledge of how the First Nations Diabetes Initiative is being run.”
This kind of governmental compartmentalization of expertise is deeply disturbing to activists like Broten.
“As an environmentalist working on toxics, I get all these European studies through my e-mail, and every once in a while I send some of this to a bureaucrat, saying, ‘Sorry to bother you, you’ve probably seen this already.’ And they never have. I don’t quite know where they’re getting their information.’ This lack of awareness of the possible links between dioxin exposure and diabetes isn’t limited to Ottawa, however.
Martin McInally of the Canadian Diabetes Association reports that, after speaking with a number of research scientists both within and outside the association and running a keyword search through the association’s entire database, he can’t find a single reference to research on the possible dioxin/diabetes connection.
“It certainly is an area that needs to be researched,” McInally says.
Alexandra McGregor, the environmental and health policy analyst for the Assembly of First Nations in Ottawa, agrees that while there has been talk of a dioxin/diabetes connection for some time, definitive information has been lacking to date, owing to a number of obstacles.
She says one difficulty is the time delay between exposure and the onset of symptoms. “It’s a difficult and complex situation, particularly for the First Nations, where there is already such an incredible background of dioxins.”
McGregor isn’t optimistic that the latest info will spur the feds in Ottawa to investigate possible dioxin links with First Nations diabetes. “A lot of very valid cases remain in existing treaties on aboriginal rights, so I’m not feeling very confident that this would get any more action on First Nations health care.”
While the feds hem and haw over the causes of the raging aboriginal diabetes epidemic, the deadly chemical continues to seep into the environment in the absence of the tough regulations seen in some European countries.
For example, Belgium suffered a dioxin scandal last year when significant concentrations of PCBs and dioxins were found in animal feed, threatening everything from chocolate to meat. An immediate embargo was placed on the food supply, with most European countries refusing to sell Belgian produce. Alas, Broten notes, “Canada didn’t do anything — we just kept on importing it and selling it.”
Broten charges that toxic waste policy in this country is comparatively weak in the world context, a perception shared by her colleagues south of the border.
“A U.S. dioxin e-mail list was discussing clean water quality standards,” she recalls, “and one environmentalist wrote, ‘After all, it’s not like Canada, where they let you eat it by the teaspoonful.”
Paul Muldoon of the Canadian Environmental Law Association notes that Canada is acting as chair for a legally binding international treaty on POPs (persistent organic pollutants, of which dioxin is one). “One of the key issues left over,” he points out, “is whether dioxins will be eliminated or simply reduced.”
Here in Canada, he says, the standing committee on the environment spent much of last year reviewing the Canadian Environmental Protection Act, gearing it toward the elimination of certain substances, including dioxin. In the fall, in an abrupt about-face, then-environment minister Christine Stewart bowed to industry demands and reversed the recommendations of her own standing committee.
Environment Canada spokesperson Harvey Lerer denies that there was a watering down of the government’s mission. The final amendments, he says, only “added more precision to the process that would have to be undertaken in order to set out the rules for virtual elimination under the law.’
But Muldoon sees it otherwise. “The goal of virtual elimination is still there,’ he admits, “but the implementing features of the bill were gutted by an enormously strong and effective, and I must say now, successful industrial lobby.”
ONTARIO’S TOP DIOXIN HOT SPOTS
* Hydro Agri Canada, Maitland: chemical production
* Hamilton-Wentworth Solid Waste Reduction Unit, Hamilton: municipal incineration
* Ivaco Inc., L’Orignal: steel manufacturing
* Slater Industries, Burlington: steel manufacturing
* Co-Steel Inc. (LASCO), Whitby: steel manufacturing
* Gerdau Courtice Steels, Cambridge: steel manufacturing
* Ontario Hydro, Thunder Bay: electric power generation (fossil fuel)
* Blue Circle Canada Inc., Bowmanville: cement kilns
* Peel Resource Recovery Inc., EFW facility, Brampton: municipal incineration
From Environment Canada Research assistance by Geoffrey Chan
* Health effects in adults: skin disease immune suppression respiratory, cardiovascular and liver disorders reproductive toxicity probable carcinogenicity
* Health effects in unborn children: learning difficulties, problems with development of the reproductive system and the immune system
* Sources: formerly pulp and paper production, now municipal incineration of plastics, some steel-making procedures and burning treated gasoline
* How ingested: primarily through food, i.e., fatty meats, fatty fish and dairy products