Toronto Star, Peter Calamai
Published February 4, 2006
Fluorinated polymers are everywhere, even though most people have never heard of them.
Microwave popcorn bags, stain-free carpets, fast-food wrappers, denture cleaners, windshield washer fluid - this is just a sample of the consumer products that contain some compound from this vast chemical family.
Such widespread use means big dollars. Manufacturing millions of kilograms of fluorinated polymers (and the chemicals used to make them) generates billions of dollars in annual revenue for chemical giants like Dupont Co. in the U.S., Clariant in Germany and Daikin in Japan.
Yet, these ubiquitous compounds are shaping up to be as big an environmental and potential health problem as their better known chemical cousins like PCB and DDT. Possibly even bigger, say some experts like University of Toronto's Scott Mabury.
"There was nothing known about these chemicals when we started investigating five years ago. It was a clean slate for research, which is one of the things that makes it so fascinating," says Mabury, who heads an international team considered tops in this specialized research field.
The fascination for Mabury and others isn't the fluorinated polymers themselves but what they eventually become through degradation and other poorly understood processes - a group of nasty chemicals called PFCAs for perfluorocarboxylates.
PFCAs really do turn up everywhere in Canada and around the globe, including in human blood, in household air and dust and - in heavier concentrations - in the blood of polar bears and seals in the Arctic, thousands of kilometres from any possible industrial source. Concentrations in seals are doubling every five years, a phenomenal rate, Mabury says.
Not only have PFCAs spread around the world in recent decades but they have been linked to cancer and other developmental effects in animal experiments, and are expected to persist in the soil and elsewhere for hundreds of years.
In the U.S., the Environmental Protection Agency is debating whether to classify PFCAs as likely or probably causing cancer. In Canada, the federal government in 2004 banned four new fluorinated polymers from being manufactured or imported for two years out of concern over the environmental and health effects of PFCAs, the first country in the world to take such action.
That ban expires for three of the chemicals in June. Next week, Environment Canada is holding a consultation among PFCA experts from industry, environmental groups, government and the universities to discuss making the ban permanent and clamping down on existing fluorinated polymers.
"We took a precautionary approach in the case of the new substances. We didn't want to add more to the environment," says Bernard Made, who directs Environment Canada's office dealing with new substances.
Made says the department wants "early action" to deal with the potential environmental threat posed by fluorinated polymers already being widely used in Canada. That would mean either voluntary action by industry or imposing controls through government regulations, he said.
The big scientific puzzle concerning PFCAs is how they have become so widespread in the environment, since they are not directly used as commercial or industrial products.
Environment Canada based its temporary ban on a complex chain reaction that hasn't yet been conclusively demonstrated. When they slowly degrade chemically, the fluorinated polymers supposedly release one of the chemicals used in making them, called fluorotelomer alcohols. These alcohols can be borne long distances on the wind and then degrade further into the troublesome PFCAs.
The general assumption was that this pollution began when chemicals were spilled or deliberately discharged at manufacturing plants or from leakage when being applied in places like carpet factories.
Now, Mabury and fellow U of T chemist Mary Joyce Dinglasan-Panlilio have discovered an even simpler explanation, eliminating one stage of that chain reaction and opening the door for faster remedial action.
In a study published online last week by the American Chemical Society, the two researchers instead point the finger at sloppy production of the chemicals in the first place. Testing six consumer and industrial products like carpet stain repellents and windshield washer fluid, they found levels of the fluorotelomer alcohols as high as 4 per cent.
In effect, the alcohols are chemical leftovers, unwanted residues that remain because the manufacturing process failed to incorporate all of the starting materials into the polymers. This is the first evidence in the scientific literature that the products themselves are sources, not just manufacturing or application processes.
Says Mabury: "In essence, they're just waste products. If you turn off the residual tap, you may very well solve the pollution problem of chemicals in the Arctic."
The highest levels of the alcohols, up to 3.8 per cent, were in industrial additives used in paints and polishes, the lowest in Teflon Advance, a spray-on carpet protector with 0.34 per cent, and in Motormaster Windshield Washer fluid, at 0.36 per cent.
Based on industry estimates of production of the fluorinated polymers, such residual levels would mean annual emissions of at least 100,000 kilograms of fluorotelomer alcohols, enough to account for a substantial amount of the PFCAs being found.
One of the investigators tracking these PFCAs is Tom Harner, an Environment Canada research scientist in Downsview, who draws a parallel with the better-known POPs, or persistent organic pollutants now controlled by a global treaty.
"We call them domestic POPs because we think there are many sources in the home, and these may be an important source of these things to the wider environment," he says.
In the winter of 2002-2003, Harner and colleagues were checking air and dust samples from 66 homes in Ottawa for contaminants called brominated flame retardants. They found as well a type of fluorinated polymers known as FOSEs. The concentrations were 10 to 20 times higher than in the outdoor air, although still at the modest level of a billionth of a gram in every cubic metre.
"These things linger so you're going to continue to see high indoor concentrations. The windows and doors are closed in winter and a lot of people use air conditioning in the summer, so there's not that much ventilation," Harner says.
A final piece of the fluorinated polymers puzzle is how these chemicals get to such remote places as the Arctic, and quickly, too. When the 3M Corp. withdrew its popular Scotchgard product five years ago because of concerns over the PCFA content, Environment Canada scientists saw levels of the specific Scotchgard chemical drop in seal blood within a year.
Some researchers, mostly in industry, contend ocean currents are largely responsible for transporting fluorinated polymers that were dumped by factories in years past.
Mabury disagrees: "It has to be spread by the atmosphere. It would take decades for these chemicals to reach the Arctic through the oceans."
