CBC News, Erica Johnson
Published March 20, 2005
It's a puzzle that scientists around the world are trying to piece together.
How is a chemical showing up everywhere? The clues reside in everyday consumer products: carpeting, dental floss, a pair of men's pants, a child's watch.
What do they have in common? Could everyday consumer products have a secret life - that could be harmful?
Hot on the trail of the mystery is Scott Mabury, an environmental chemist at the University of Toronto. Mabury is conducting his experiments on everyday consumer products that have been treated with Teflon. Mabury has published dozens of papers on pollutants. He isn't interested in the use of the material on non-stick pots and pans -- he's investigating the Teflon stain repellents used in consumer items.
Scott Mabury is conducting experiments on everyday consumer products that have been treated with Teflon stain repellents.
'They acted like crazy cattle'
The first clue in Scott Mabury's investigation into stain repellents used in consumer products takes us hundreds of kilometres away from his lab, to Parkersburg, West Virginia.
In the late 1990s, cows on a farm there started dying inexplicably. First they developed pink eye. And then they started acting strangely. "They acted like crazy cattle," recalls farmer Della Tennant. "You had to be careful when you got out in the field with them, because they would chase you."
In the end, the Tennants lost almost 300 cattle. "They died horrible deaths," says Della. "It was awful... it was the most terrifying thing I had ever seen."
In the end, the Tennants lost nearly 300 cattle.
What could be the cause? The Tennants didn't have to look further than a nearby creek. They noticed frothy foam that Della says would sometimes rise six feet above the top of the water. "The fish were dying. That's when we started getting suspicious," she says.
The Tennants were suspicious of a corporate giant located just over the hill from their farm: DuPont, known for the brand name Teflon.
The Tennants sued DuPont. The case was settled out of court.
The Tennant's lawsuit paved the way for another case, a class action over contaminated drinking water. DuPont settled again in that case.
"We felt that people needed to know what was in their water," says Della. What was in the water was the chemical at the heart of our investigation: high levels of perfluorooctanoic acid, or PFOA. It's a chemical DuPont makes at its plant in Parkersburg, West Virginia.
Secret memos speak of birth defects and cancer
DuPont water tower.
The lawsuits uncover another clue in the stain-repellent mystery: secret internal DuPont memos that expose how dangerous PFOA can be. The documents reveal that:
* DuPont knew for decades that rats exposed to PFOA had developed liver damage.
* Two workers with high levels of PFOA in their blood had babies with eye and face defects.
DuPont dumped the same chemical, PFOA, into a landfill. It leached into a creek that the Tennants' cattle drank from. "It makes me really sad that a company as big and as well-known as Dupont could do such a thing," says Della.
The mystery deepens when it's discovered that the Teflon chemical PFOA isn't just polluting the fields around DuPont's West Virginia plant. It's showing up thousands of kilometres north, on Canadian soil.
Pollution containing PFOA hasn't just turned up around the manufacturing plants that produce the chemical.
PFOA has been discovered thousands of kilometres away, in the blood of polar bears in the Arctic.
Part of the mystery is that PFOA isn't made anywhere near those polar bears - and it doesn't travel through the atmosphere.
Scott Mabury, an environmental chemist at the University of Toronto, says his team was surprised to find PFOA in the polar bears' blood in "such high concentrations."
The other surprise in the mystery is that PFOA has been found in the blood of people on four continents. In fact, almost every Canadian has small --but detectable-- levels of PFOA in their blood.
Does PFOA cause harm to humans?
"There's been no human health impacts associated with PFOA," says Jennifer Hooper, Director of Safety, Health, the Environment and Sustainability for DuPont Canada. "The fact that this PFOA is present in the environment and in human blood is concerning, and we need to get answers and we need to understand the issue more fully."
Image of meeting members sitting, watching a slideshow presentation.
"There's really no potential or detectable exposure for consumers as they use our products, their pots and pans with Teflon coating, or their carpets, shirts and blouses that have a stain-resist coating," she adds.
In the United States, the Environmental Protection Agency (EPA) has charged DuPont with withholding information first revealed in the West Virginia lawsuits about PFOA.
Mabury cracks the case
Still, the big question in our mystery is: if this Teflon chemical doesn't travel through the atmosphere, and there's no direct exposure to people from consumer products, where's it coming from? Environmental chemist Scott Mabury thinks he's cracked the case.
Mabury has made a startling discovery: some of the chemical in Teflon stain repellents applied to the surface of products (such as a pair of pants) actually breaks away from the products into the atmosphere and then degrades into the toxic chemical, PFOA.
"We've shown that they get away from these materials," says Mabury, "in sufficient quantities to represent the bulk of what we measure in the atmosphere."
Mabury thinks this groundbreaking research is so important that he's shared it with Marketplace before publishing it in a scientific journal.
When asked Jennifer Hooper, head of safety and the environment for DuPont Canada, to respond to the Mabury's findings. But Hooper tells us she can't because she's not familiar with his study.
When we asked what DuPont would do if Mabury's research turns out to be true, she tells us: "I think Dupont's record speaks for itself. Where there's, you know, sound science-based rationale to take action, we take action."
But DuPont's not convinced the problem's coming from products treated with Teflon stain repellents.
Environment Canada's not waiting for the EPA's report on health risks. It's concerned enough to ban three new stain repellents from the market for at least two years.
Should you toss your Teflon products?
The Teflon chemical can be found "in all kinds of products," says Timothy Kropp, a toxicologist with the Environmental Working Group watchdog organization. "Whether you're eating [fast] food, or wearing the clothes, or cleaning with this product, or using these paper plates, you're going to find it."
So what should you do with the things in your home that are treated with Teflon stain repellents? Even environmentalists like Kropp say you shouldn't throw them away. He suggests you just don't buy new products with the stain resistant treatments: "The next time you go out to buy clothing, you don't have to buy the stain resistant clothes. You know, we've kept really nice, clean clothes for all these years and we don't necessarily need that... if you have a chemical that doesn't break down at all and stays in your body for decades, you should err on the side of caution."
That's exactly what Della Tennant and her husband Jim decided to do. "I try to buy things that don't have it on, and we took the carpet up off the floor," says Della. "I feel like it's very important that the people in the United States of America and all over Canada and everywhere else -- need to know what's in their water and what's on the clothes that they're wearing."
Environmental chemist Scott Mabury says there is a solution to this chemical mess: companies like DuPont could reformulate their stain repellents so they don't release a chemical that breaks down into PFOA. "Once we understand the problem, there are reasonable and practical suggestions for solving it," he says. "If we don't do it, then we're simply making a long-term mistake."
What's the next step in the investigation? As part of a legal settlement, DuPont has agreed to pay for an independent study of 80,000 Americans to find out what the health risks are of having PFOA in our blood.
Perfluorooctanoic acid, or PFOA (also sometimes referred to as "C8"), is a man-made chemical that does not occur naturally in the environment.
Companies use PFOA to make fluoropolymers, which are used in consumer products such as non-stick cookware, breathable, all-weather clothing, and stain-resistant materials.
Teflon itself is not PFOA, but PFOA is used to manufacture Teflon. PFOA is emitted into air and water at Teflon manufacturing plants. But according to research conducted by Scott Mabury, an environmental chemist at the University of Toronto, consumer products treated with Teflon can also break down into PFOA after the manufacturing process:
ERICA JOHNSON (MARKETPLACE REPORTER): What have you discovered is happening in our environment?
SCOTT MABURY: What we've discovered is that we can measure in the atmosphere fluorinated alcohols that we think are escaping from a variety of consumer products: carpet, coatings for water and stain repellency. Those fluorinated polymers that are used to coat that carpet, some of the residual material is escaping into the atmosphere. We can measure it all across North America... We know it will last in the atmosphere about 20 days, sufficient time to be transported to really remote areas, like the Arctic.
We know that Mother Nature, in trying to rid itself of chemical pollutants, transforms that fluorinated alcohol into much more persistent and bioaccumulative materials called perfluorinated carboxylic acids things like PFOA.
JOHNSON: What might be going on in my house?
MABURY: Off-gassing of these fluorotelomer alcohols. The fluorinated alcohols themselves are off-gassing of consumer materials. And these initial studies suggest that the concentrations inside homes are higher than outside.
... There's not much PFOA itself in these consumer products, but the precursor's are there. And I guess it was one of our contributions to actually make that linkage. It's not PFOA itself moving around the world, it's the precursor. The travel agent is the fluorinated alcohol - that's the one that has sufficient volatility, vapour pressure, it escapes in the atmosphere, moves long distances in the atmosphere, before being transformed into PFOA, and then potentially moving up the food chain.
Persistent in the environment
PFOA has been used since the early 1950s in the manufacture of non-stick cookware, rain-repellent clothing and hundreds of other products made by common household brands such as Teflon, Gore-Tex, Scotchguard, and Stainmaster.
PFOA is very persistent in the environment. It has been found at very low levels in the blood of humans around the world.
Timothy Kropp, a toxicologist with the Environmental Working Group watchdog organization, says a big problem is PFOA's persistence:
"PCB's do actually degrade in the environment, albeit very slowly, whereas these don't. So if you look at that sort of comparison, you can see what type of chemical that we're talking about and why we're so concerned about it."
Impact of PFOA on our health
To date, no human health effects are known to be caused by PFOA, but the chemical has been shown to cause developmental and other adverse effects in laboratory animals.
The Environmental Protection Agency in the U.S. is working with the industries that use PFOA to learn more about the chemical and the impact it might be having on human health. The EPA is currently drafting a risk assessment of PFOA.
The EPA says at this point there is no reason for consumers to stop using those items, but since many unresolved questions remain about PFOA, the agency is asking an outside panel of experts to assess the risks.
Timothy Kropp, with the Environmental Working Group watchdog organization, believes there are links between PFOA and human health effects: "In animals it causes cancer, it causes liver cancer, it causes breast cancers. It causes pancreatic tumours as well as testicular tumours.
"We do have solid scientific evidence that these are causing some types of harms in humans," he adds. "And for many of these, they just haven't been investigated. You can't say that they haven't been shown, when you've never looked."
DuPont counters that we have a lot of chemicals in our bodies from exposure to other things. "There haven't been any human health studies to suggest that there are implications with its presence," says Jennifer Hooper, Director of Safety, Health, the Environment and Sustainability for DuPont Canada.
ERICA JOHNSON (MARKETPLACE REPORTER): Critics would say there aren't any studies to show there are adverse health effects, because DuPont hasn't done them. You haven't looked to see whether PFOA is leading to increased rates of cancer, or birth defects in babies.
JENNIFER HOOPER (DUPONT CANADA): Well, we have done health effects, health studies on our industrial workers.
JOHNSON: But not that looked at those things.
HOOPER: And again, I can't get into the protocols of the tests and their adequacy because I'm just not an epidemiologist.
Companies that manufacture PFOA
According to the EPA, the 3M Company used to manufacture PFOA in the United States, but began phasing out its production of the chemical in 2000. Currently, DuPont is the only American manufacturer of PFOA (although other companies may manufacture PFOA elsewhere in the world).
When it first hit the market, Teflon revolutionized the way we cook. These days it's on more than pots and pans.
The Teflon
