Can deadly arsenic come out of the woodwork?

Banned in some countries, pressure-treated lumber has the potential to poison people

            

Can deadly arsenic come out of the woodwork?  Banned in some countries, pressure-treated lumber has the potential to poison people

Globe and Mail

LISA PRIEST INVESTIGATIONS UNIT

Saturday, March 31, 2001 

It has been banned in three countries and is now the subject of a North American probe, but most Canadians who haul it home from the lumber yard don't know that the wood they're about to turn into decks, play sets or picnic tables is laced with arsenic.

There is mounting fear the greenish pressure-treated wood poses a risk to humans. Canada produced 110 million cubic feet (34 million cubic metres) of it in 1999. That's the equivalent of 800,000 decks measuring 12 feet by 16 feet (four metres by 5 metres), said Henry Walthert, executive director of the Canadian Institute of Treated Wood, an industry association.

As deck-building weather approaches, many families are unaware that the wood, injected with a powerful pesticide brew of chromated copper arsenic to give it longer life, has come under scrutiny by federal officials on both sides of the border.

"We're doing a reassessment to see if we still consider it safe," said David Deegan, spokesman for the Environmental Protection Agency in Washington, which is studying the risks of CCA with Health Canada.

"It's possible nothing will change or additional restrictions will be put on it. Or [the] EPA could conclude that they want it taken out of the marketplace. It's just way too early to say."

Long term, repeated exposure to arsenic -- through breathing, repeated skin contact or ingestion -- can cause cancers of the skin, bladder, lung and liver.

Switzerland, Vietnam and Indonesia aren't waiting for next year's results from the North American study. They have already banned CCA-treated wood. Japan, Denmark, Sweden, Germany, Australia and New Zealand have restricted or proposed restrictions on it.

The ash is so toxic that a family that repeatedly used CCA-treated wood to heat their home suffered blackouts and severe seizures. Also, their hair fell out and their plants and fish died, according to a report in the Journal of the American Medical Association.

In Minnesota, 22 cows were killed when a farmer spread fireplace ashes from CCA-treated wood in the field where they were grazing.

"There is a lot of activity going on in terms of questioning the product," said Mr. Walthert, who stressed that scientific studies have repeatedly shown CCA-treated wood is safe when properly handled. "There's this stigma attached to it that it's a poison and suddenly there's an alarm. I don't believe it's anything to worry about."

Dr. Garn Wallace, a biochemist at the Wallace Laboratory in El Segundo, Calif., a private lab that specializes in plant nutrition, soil composition testing and heavy metals research, has conducted studies showing arsenic from CCA-treated wood stunts plant growth and turns leaves yellow.

"Arsenic was the poison of choice in the Middle Ages and it worked very well," Dr. Wallace said. "I think we need to re-evaluate that approval and use something safer than CCA for wood treatments in areas with high human contact."

He is especially concerned about children who rub their hands on the wood, adding that "it gets on their clothes, some kids even eat it."

"I avoid having CCA wood around my family. I don't take a chance with it."

Virtually all pressure-treated lumber for residential use is made using CCA applied at high pressure to penetrate the wood.

The copper acts as a fungicide, the arsenic is effective against insects, and the chromium ensures the other two chemicals stay in the wood. CCA makes the wood last five to 10 times longer and has been credited with saving millions, if not billions, of dollars and trees.

In Canada, it's very popular, with $600-million worth of CCA-treated wood produced in 1999.

Roughly seven million kilograms of CCA chemicals were impregnated into wood in that same year, of which 1.5 million kilograms was arsenic.

Though the wood, made in 67 treatment plants across Canada, contains toxic pesticides, it's not mandatory for retailers to provide fact sheets to consumers.

"Those sheets exist in Canada, but they're not being distributed well," said Dr. Paul Cooper, associate professor of wood science at the University of Toronto. "Depending on the training of the salespeople, they may or may not hand them out. If people don't ask for them, there's a good chance they won't get them."

Many working with the wood may not be aware they should use goggles, gloves and a mask when sawing it. The arsenic-laced sawdust should be disposed of and it should never be burned. Nor should it be used as a cutting surface for food.

At issue is how much arsenic can be absorbed from touching the wood, how much of it leaches from boards following acidic rainfalls, and if it poses a threat.

The EPA reviewed CCA-treated wood during the 1980s and found it did not pose "unreasonable risks" to the public. But it did issue new requirements in 1988 for protecting workers who deal with it daily.

Those in the wood preservative industry stress CCA-treated wood has been vigorously studied hundreds of times since it was invented in India in 1933 and found to be safe. The key, they say, is to properly "fixate" the chemicals into the wood, which greatly reduces any chance of arsenic leaching.

"There's no question it's used in very low concentrate and with absolutely no risk to the environment or to humans," said Richard Goodfellow, vice-president of Goodfellow Inc. of Montreal, a company that treats wood with CCA.

Dr. Cooper, the wood scientist, also agrees the wood is safe, saying it's riskier for children to play outside in the sun without sunscreen than to touch CCA-treated playground equipment.

He acknowledged, however, that "these materials, in high enough concentrations, are toxic. And so anything we can do to minimize the amount that comes off, we should do."

Handling CCA-treated wood

• Wear gloves, a dust mask and eye goggles when sawing or machining wood, especially in confined areas.

• Wash exposed areas after skin contact. Wash hands before eating, drinking or smoking.

• If preservatives or sawdust get on clothes, launder them separately before use.

• Never burn it as the smoke and ash are toxic.

• Don't use for cutting boards or countertops.

• Don't allow contact with drinking water.

• Never use to store food or animal feed.

• Never use for wood chips or mulch.

• Keep children and pets out from under decks.

• Don't use near edible plants.

• Use a plastic liner for CCA boards used to frame gardens.

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