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Archived LHEI Article
CONCERNS OVER ARSENIC PRESSURE TREATED WOOD IN PLAYGROUND SETS, DECKS, PICNIC TABLES, FENCES, AND OTHER BACKYARD WOOD STRUCTURES BILL RAVANESI, MA, MPH FOUNDING MEMBER OF THE LONGMEADOW HEALTH AND ENVIRONMENT INITIATIVE October 29, 2003 Arsenic in backyard decks and other outdoor wood structures around the home is considered a potential cancer risk to young children who touch the wood and then have frequent hand to mouth contact. Studies have shown that children who have 3-hours of contact per week with Chromated Copper Arsenate (CCA) as a wood preservative is enough to be considered significant exposure—unless the structures are regularly sealed with a non-water based sealant.
The Problem: CCA contains chromium, copper, and arsenic, each contributes to the wood-preservative properties of the compound. Copper acts as a fungicide, chromium acts as a fixative agent, and the arsenic protects against insect damage. And, the use of CCA wood has significant health and environmental impacts throughout its lifecycle. There are 51 wood preservation sites on the EPA Superfund National Priority List. The use of CCA-treated wood preservative represents the largest use of arsenic in the US. 100% of the arsenic used here is imported, mostly from China. 70% of the U.S. arsenic supply goes into CCA-treated wood preservative. In 1996, more than 144 million pounds of CCA were used to treat 460 million square feet of commercial lumber. Chromium and arsenic leach from the wood adding to soil and groundwater contamination.
Back in May 2001 two non-profit organizations, Environmental Working Group[EWG] ( www.ewg.org/reports/poisonedplaygrounds/es.html for their report on CCA) and Healthy Building Network [HBN] (www.healthybuilding.net) submitted a request to the US Consumer Product Safety Commission (CPSC) that it enact an immediate ban on CCA in playground equipment and review its safety of CCA for general use. Both EWG and HBN asserted that “ recent research has shown that arsenic is more carcinogenic than previously recognized, that arsenic is present at significant concentrations on CCA treated wood and in underlying soil, that the health risk posed by this wood are greater than previously recognized, and that past risk assessments were incomplete.” Further, they urged CPSC to consider new information on arsenic, including a study by the National Research Council of the National Academy of Science concluding that arsenic is a more potent carcinogen than was previously recognized and that it causes bladder and lung cancer which had not been previously accepted.
As pressure was building from these non-profit organizations an agreement was reached in February, 2002 between manufacturers and the Environmental Protection Agency which required manufacturers to voluntarily withdraw their product from the residential market on December 31, 2003. Wood treated prior to Dec 31, 2003 can still be sold until stock is depleted and CCA wood may still be used for commercial uses (“industrial uses,” accounts for about 15% of treated wood sales.) It is likely that we will continue to see CCA wood sold for residential uses in the US until mid-2004. More than 90% of all current wooden playsets and decks made from CCA treated wood.
What is the risk from arsenic exposure in CCA-treated playgrounds?
CPSC’s staff calculated the increased lifetime risk of developing lung or bladder cancer from exposure to arsenic for the individual who plays on CCA-treated wood playsets during early childhood. This increased cancer risk ranges from about 2 in a million to 100 in a million (or, 1 in ten thousand). EPA ‘s “comfort level” is 1 excess death in a million.
Health Impacts: Arsenic and chromium components of CCA pose the most significant human health concerns, due to their carcinogenicity. Hexavalent chromium and arsenic are Class A human carcinogens. Copper, which is not a recognized or suspected carcinogen, is considered to pose much less of a health concern. Exposure may occur occupationally at treatment facilities, construction practices and to users through contact with CCA-treated wood and CCA-contaminated soil.
Prevention Opportunities:
Reaching for alternatives is certainly a solution and would solve disposal problems—using CCA wood is simple not a sustainable practice. It should be noted that CCA wood waste should be separately collected for disposal in lined landfills. Prior to purchasing wood chips for use around ones home it is advisable to inquire whether or not the chipped wood came from recycled CCA wood.
And, if you have CCA pressure treated playsets, decks, picnic tables, etc, they should be coated each year with a non-water base sealant or removed.
A variety of alternative wood treatment applications are available on the marketplace. These include:
WEB Sites: http://www.healthybuilding.net
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