Treated Lumber a Health Hazard?

A just-released study by two environmental groups has found high levels of arsenic on the surface of pressure-treated wood products. The Environmental Working Group and the Healthy Building Network tested pressure-treated wood purchased from home improvement stores in 13 cities. In releasing their findings, the groups are calling for a ban on the use of the lumber in construction. Their findings add to the growing concern about the safety of the chemicals used to treat this wood. Those chemicals are now being re-evaluated by both the Canadian and American governments. But as the Great Lakes Radio Consortium’s Karen Kelly reports, the two governments are approaching the issue differently:

Transcript

A just released study by two environmental groups has found high levels of arsenic on the surface of pressure-treated wood products. The Environmental Working Group and the Healthy Building Network tested pressure-treated wood purchased from home improvement stores in 13 cities. In releasing their findings, the groups are calling for a ban on the use of the lumber in construction. Their findings add to the growing concern about the safety of the chemicals used to treat this wood. Those chemicals are now being re-evaluated by both the Canadian and American governments. But as the Great Lakes Radio Consortium’s Karen Kelly reports, the two governments are approaching the issue differently.


For years, Don Houston at the Canadian Institute of Child Health has been calling for warning labels on pressure-treated wood. The lumber is used in playground structures and picnic tables throughout North America. And it’s treated with a preservative called Chromated Copper Arsenate, which protects the wood from insects and fungi. The preservative is made from arsenic, chromium and copper. And Houston says children who are exposed to the wood may be exposed to those chemicals, as well.


“It’s not just children’s play structures. I’d rather suspect even more problematic is the deck that’s on the back of their house because often times children spend more time there. It’s all sorts of structures that are put in outdoors – decks, balconies, retaining walls; even the telephone pole that might be in a schoolyard might be problematic.”


Houston says the problem arises when arsenic and chromium, which are both carcinogens, remain on the surface of the wood. A study of ten playgrounds conducted by Health Canada in the late 1980’s detected both substances on the surface of play structures made with pressure treated wood. Arsenic and chromium were also found in the nearby soil. Health Canada warns people who work with pressure-treated wood to wear gloves and a mask and to thoroughly wash clothing and exposed skin once they’re finished. The agency also warns against burning pressure treated wood. But Houston says there are still no guidelines for children.


“It doesn’t make a lot of sense for the guy who’s building it to use gloves and then the child ten minutes after it’s built to be walking over it and running on it barefoot and having greater potential health impact from the exposure.”


But scientists at Health Canada say the research findings have been mixed. They point to studies conducted by the U.S. EPA in the late 1980’s that found minimal health risks. Now, fifteen years since they last evaluated these chemicals, both Health Canada and the EPA are taking another look. The update is required by law in both countries. Richard Martin is a toxicologist at Health Canada’s Pest Management Regulatory Agency. He says the presence of arsenic is not always a cause for concern.


“Although there’s a number of reports out there of arsenic being found in soil, and although they’re useful, arsenic is found in all soil. So we need to go the extra step to determine to what extent there’s potential for exposure to children and that type of thing.”


Martin says his agency is reviewing research to determine the effect of exposure on both adults who work with cca-treated wood and children who play near it. But the U.S. Environmental Protection Agency is taking the review a step further. Jim Jones, the deputy director of the EPA’s office of pesticide programs, says they’re concentrating on the exposure to children first.


“It was the children’s exposure through cca-treated wood we think are the most important to look at as they’re the group in the population that is likely to have the greatest exposures, just because of the way in which they interact with playground equipment and on decks.”


The EPA also plans to take soil samples near cca-treated wood structures in 75 playgrounds around the United States. And it’s considering a recommendation that people apply sealants to pressure-treated wood in the interim. The EPA’s scientific advisory panel suggested the agency take that measure. The EPA and Health Canada are collaborating on the re-evaluation – sharing their findings and their recommendations. Don Houston of the Canadian Institute of Child Health hopes that will lead to legislation in both countries that will restrict the use of this lumber in places where children play. The EPA and Health Canada are expected to announce their recommendations next spring.


For the Great Lakes Radio Consortium, I’m Karen Kelly.

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