But no one knows how serious kids' exposure is, one toxicologist says
Milwaukee Journal Sentinel, Annysa Johnson
Published August 12, 2001
There's arsenic in the wooden play set at Lake Park.
And in one at Richards Elementary School in Whitefish Bay. The one at Cedarburg Pool, Brookfield Elementary and in every other wooden play set tested by the Journal Sentinel.
In fact, chances are that any wooden play set in any backyard in southeastern Wisconsin - unless it's made of redwood or cedar - has been treated with chromated copper arsenate, an arsenic-based pesticide designed to ward off insects and rot.
But what that means for the long-term health of the children is not as clear-cut.
The problem, said one toxicologist, is that no one really knows at what low levels arsenic begins to cause cancer. In addition, he said, the available data can be interpreted to suggest that the long-term risk of cancer from exposure to treated lumber is either dangerous or negligible.
It's all about the assumptions factored into the equation - assumptions about factors ranging from the amount of arsenic on the wood to how much is actually ingested, the frequency and duration of play, and more, said Steve Roberts, a University of Florida toxicologist who reviewed the available research for the Florida Department of Environmental Protection.
"Depending on how you looked at the data, the risk could be very low or very high," Roberts said.
That's little consolation to Kay Rolston of Fox Point, whose wooden play set registered the highest amount of arsenic of eight tested by the Journal Sentinel in Milwaukee, Waukesha and Ozaukee counties.
Of the eight, the amount of arsenic ranged from 2.4 to 91.4 micrograms picked up with a cloth wiped across a 100-square-centimeter section of wood. The average was 43.6 micrograms.
That's nothing, says Christopher Teaf, a Florida State University toxicologist hired by the wood-treatment industry to assess the research. He said that children can play on wood with levels as high as 400 micrograms with no adverse effect and that very little arsenic makes its way onto a child's hands and mouth.
But Rene Sharp of the Washington-based Environmental Working Group and lead writer of the recent report titled "Poisoned Playgrounds," said studies suggest exposure to even 1 microgram of arsenic daily can increase the risk of cancer.
"It's a question of exposure," said Lynda Knobeloch, a toxicologist with the Wisconsin Department of Health and Family Services. "If a child goes to the park once a week for three years, he's probably at low risk. But if you're working with it every day, that's a different ball game."
One high-risk group, she said, is children in day care centers, where it might not be unusual to play on wooden playground equipment five days a week year-round, depending on the weather.
For the most part, schools and municipalities in southeastern Wisconsin have moved away from wooden playground equipment in favor of metal and plastic components, to comply with safety guidelines and the recommendations of insurers. It has nothing to do with arsenic, they say, but with such things as soft landings and splinters and the amount of space between bars.
The wooden play set at Lake Park on Milwaukee's east side, which registered 55.9 micrograms of arsenic, is one of the few wooden sets left in the Milwaukee County Parks system, said Mike Raap, a landscape architect who heads the park equipment program. The program spent more than $2 million over the last three years to upgrade play equipment.
"They just don't have the longevity that the new steel and plastic ones have," he said.
Still, wooden sets can be found in an occasional schoolyard or park, and thousands dot back yards throughout the suburban landscape. In many cases, if not most, consumers have no idea that the wood contains arsenic, said Sharp, of the Environmental Working Group.
She blames the wood-treatment industry, saying it has not adequately followed through on a voluntary consumer awareness program it agreed to in the 1980s.
Information sheets, critics say, are made available in some retail outlets only upon request. And in others, even when the sheets are posted, they offer vague and seemingly conflicting information.
At the Home Depot store in Glendale, for example, information and handling sheets are posted sporadically on wood pieces throughout the treated lumber aisle, though many are posted too high to be read by shoppers. Similar information can be found on the back of a particular company's literature, available for the taking from pads hanging in the aisle.
But the information, labeled "approved by the U.S. Environmental Protection Agency," only alludes to "certain hazards" and never mentions risk of cancer.
Literature by one Wisconsin company, whose wood is sold at Home Depot, includes the EPA-approved cautions, but also a litany of reasons that such treated lumber is safe. Among them: that "laboratory studies prove that CCA-treated wood is no more acutely toxic to humans and mammals than ordinary table salt."
The Consumer Product Safety Commission recommends sealing children's play sets preserved with chromated copper arsenate.
"Sealants on CCA are very effective," said Stan Lebow, a research wood scientist at the U.S. Forest Products Lab in Madison.
He said a recent study by the lab found no detectable leaching of chromated copper arsenate from wood treated with latex, oil-based and deck stain products and exposed to the national average of 30 inches of rain.
In part because of concerns over arsenic in wood, the Friends of the Playground sealed every inch of the half-acre playground it built in Franksville in Racine County last year, said Jo Gleason, who coordinated the construction effort that pulled together 3,000 volunteers over six days.
"Every board was coated twice, if not three times, with a linseed-oil-based sealer," Gleason said. And $20,000 has been set aside so it can be resealed annually beginning next year, she said.
Today Playworks, which serves primarily day care centers, uses recycled plastic and a plastic-wood composite instead of treated lumber in the playground equipment it manufactures.
Playworks moved to non-arsenic preservatives as soon as they were available and stopped using treated lumber altogether about six years ago, owner Gerry Slater said.
"It's not as strong as wood," Slater said of the particular brand he uses. "But I don't have to worry about preservatives, it's a recycled product, and the customer never has to worry about sealing the wood."
