Storms are dropping big snow on Lake Tahoe resorts, and there's been a flurry of activity at the California Ski Co. as hordes of skiers and snowboarders prepare to hit the slopes.
In a cluttered workroom at the back of the Berkeley shop, technician Bobby Panighetti readies a pair of skis for their first tracks, infusing the bottoms with hot wax. This essential ritual is being performed at winter sports centers around the world as the ski season gets under way.
But new scientific research suggests that ski wax can expose users to potentially dangerous chemicals that can build up in bodies and may carry serious health risks, including cardiovascular disease, liver damage, hormone disruption and cancer.
Racers in particular use waxes with high amounts of fluorine-containing compounds, which can include substances known as perfluorochemicals. These so-called high-fluoro waxes make the skis go faster, but that speed could come at a cost - especially for parents who may layer on race wax week after week without knowing how to handle it safely.
The studies, conducted in Sweden and Norway, found that wax technicians working for World Cup ski race teams had very high levels of perfluorochemicals in their blood. Their median levels of one compound, perfluorooctanoic acid or PFOA, were up to 45 times higher than the general population's. The second-highest compound was perfluorononanoic acid or PFNA, a contaminant often found in wildlife that is now on the rise in people.
This was no surprise to Greg Whitehouse, who owns California Ski Co.
"With the fluoro, we all know it's a little bit on the nasty side," he said. "We prefer to not be around it."
Costing as much as $100 a gram, high-fluoro waxes are too expensive for most recreational skiers and boarders. But the products are in big demand at competitions, he said.
At most resorts and shops, wax is applied in a ventilated area, but at competitions, high-fluoro race waxes are used in a largely unregulated environment, Whitehouse said.
Junior ski and snowboard racing draw thousands of young competitors, starting at about 9 years old.
He added that events for youngsters may present a special risk. "The junior racers, the parents are there trying to tune their skis, do the best they can. And they probably don't have much information on safety."
Secret wax formulas
Once seen as miracles of modern chemistry, perfluorochemicals are compounds with fluorine atoms tightly bound to carbon chains. The results are slick molecules with remarkable endurance that also repel grease and water.
Perfluorochemicals have long been prized for their ability to keep things from sticking, leading to their use in nonstick cookware, stain-resistant furnishings and water-repellent clothing.
Little information is available on the chemical composition of ski waxes because companies closely guard their formulas. Many, especially the waxes designed to boost speed, contain at least some fluorine compounds, but manufacturers do not reveal whether these include the perfluorinated chemicals turning up in human blood.
However, when the researchers in Norway analyzed 11 different race waxes, they found perfluorochemicals in every one.
The chemicals do not break down naturally. Because they are nearly indestructible, they're found in wildlife and humans around the world. The U.S. Centers for Disease Control and Prevention have found them in nearly every person who has ever been examined for them, said Jay Dempsey, the centers' health communications specialist.
The main sources appear to be from consumer products, drinking water and food.
One compound, former Scotchgard ingredient perfluorooctane sulfonate, was phased out by 3M in 2000. U.S. industries also agreed in 2006 to begin phasing out PFOA, which is used in the manufacture of Teflon. But these pervasive substances continue to be found in a variety of items and in the environment.
Chemicals in blood
Erle Flad's 13-year-old daughter is on a race team at the Dodge Ridge ski resort in Pinecrest (Nevada County). He agreed that many of the parents don't use race wax correctly.
"They're all going crazy, scraping and brushing and overlaying their kids' skis to make them as fast as possible."
Flad, who has been going to junior races since his oldest child, now 23, was on the team, said he's never seen parents use a respirator when applying wax. But he doesn't think that poses much danger because most parents only wax once a week or so.
In Sweden, researchers followed eight technicians through the 2007-08 World Cup cross-country competitions, analyzing their blood and samples of the workroom air. In Norway, a research group led by Dag Ellingsen, of the Norwegian National Institute of Occupational Health, conducted similar analyses on 13 professional waxers during the 2008-09 World Cup season. The studies were published in September.
Both groups found high levels of PFOA and PFNA in the technicians' blood. Both also found perfluorochemical levels rising with the number of years on the job, indicating that the compounds build up in humans, piling up faster than the body can eliminate them.
"We cannot say how (the chemicals) will affect the waxers' health later on," said one study's lead author, Helena Nilsson of Sweden's Orebro University. "But there are a number of biological alterations in relation to (perfluorochemical) exposure shown in animal studies."
Ski workrooms are not the only places affected, Nilsson said. She plans to publish data on perfluorochemical levels in snow.
"The wax definitely rubs off on the snow," she said, adding, "Many kilos ... end up on the floor in the cabins and are simply being put in the trash."
Health risks shown
Research on the health effects of perfluorochemical exposure is still in early stages, and most studies have focused on PFOA.
The compound causes cancer in laboratory animals, and the Environmental Protection Agency declared it likely to be carcinogenic to humans. Studies of people living near a West Virginia DuPont plant that manufactured PFOA found elevated risks of liver damage, birth defects, high cholesterol and excessive uric acid, which is linked to hypertension and strokes.
One recent study of nearly 4,000 U.S. adults found an elevated rate of thyroid disease in those with the highest PFOA exposure. Animal tests also show that it may act as a hormone disrupter, mimicking estrogen.
Adding to the concern, one of the studies suggested that the ski technicians may be manufacturing PFOA and PFNA in their own bodies from other chemicals they inhale.
Although the researchers detected airborne perfluorochemicals in the workrooms, the amounts were not enough to account for the high concentrations in the technicians' blood. So Nilsson and colleagues tested the air for chemicals known to break down into PFOA and PFNA.
One stood out: a fluorotelomer alcohol, a common industrial chemical that was found in concentrations as much as 800 times greater than PFOA in the workroom air. The researchers concluded that metabolism of the fluorotelomer alcohol fumes that waxers inhaled day after day was the main source of the PFOA and PFNA in their blood.
That process, known as biotransformation, has been demonstrated in animal studies, and Nilsson said her group's research has shown for the first time "direct evidence of human biotransformation."
The research provides a key piece to the puzzle of how perfluorochemicals build up in the human body, said Olga Naidenko, a senior scientist with the Environmental Working Group, an advocacy organization.
"This study is really important because it shows that this process is happening in humans," she said. "We already knew that it happens in animals."
More risks posed
Exposure to perfluorochemicals is just one of the potential health risks facing ski waxers.
Breathing high levels of airborne dust and particles, especially tiny nanoparticles, could lead to respiratory and cardiovascular disease, Nilsson said. While technicians in Norway and Sweden now work in specially designed, ventilated trucks, "most nations still have the traditional wax cabins with no or very poor ventilation," she said.
As for do-it-yourselfers, Nilsson advises: "Make sure that the room is ventilated. A (respirator) with a proper filter is also recommended." However, concerns are greatest for professionals like those in the studies, who waxed as many as 20 pairs of skis a day.
For more on this story, go to www.environmentalhealthnews.org.
