The typical outdoor wooden structures that make our yards so comfortable can actually harm our bodies and the environment more than many people realize. Because wood is often treated with toxic preservatives, health hazards may be lurking in decks, playsets, fences, picnic tables and framed garden beds. To be on the safe side, carefully consider the materials involved before you build or buy these common yard amenities.
Perhaps the hottest example of a wood product to consider with caution is pressure-treated lumber injected with chromated copper arsenate (CCA). A chemical agent intended to protect wood from dry rot, fungi, molds, termites and other pests, CCA is particularly controversial because it contains arsenic, the old-fashioned poison. Small amounts of lumber can contain large amounts of arsenic. According to The Environmental Working Group (EWG), a non-profit organization based in Washington, D.C., a 12-foot section of pressure-treated lumber contains about an ounce of arsenic, or enough to kill 250 people. Arsenic is also a known carcinogen. In particular, studies show that exposure to arsenic can increase the risk of lung, bladder, liver, kidney, prostate and skin cancer, according to the Centers for Disease Control and Prevention.
Not surprisingly, industry, environment and government researchers continue to debate the potential risks and benefits associated with CCA-treated lumber. The American Wood Preservers Institute, the national industry trade association representing the pressure-treated wood industry throughout the United States, says on its website that people should not be concerned about arsenic in pressure-treated wood. They also post an article by Louis W. Sullivan, former Secretary of Health and Human Services, urging people to relax about CCA and raising concerns about "the tendency in our society to devote tremendous attention and resources to phantom risks."
Amid the controversy, one thing is clear: The Environmental Protection Agency (EPA) has enough concern to stop new yard use of CCA-treated products. As of the beginning of 2004, EPA has banned these materials for any new outdoor residential uses. Both EPA and the Consumer Product Safety Commission are currently conducting further studies on risks associated with the preservative.
Even though CCA-treated lumber is now being phased out, it remains at issue because old stocks still sit on store shelves, and it continues to be found on public playgrounds as well as in private yards. Although the EPA did not go so far as to mandate destroying existing structures, some consumer advocacy groups, as well as local and state governments, favor junking them. The EWG, for example, found "consumers with old wood structures remain at risk from arsenic that easily wipes off the wood surface." Decks and playsets up to 15 years old expose people to just as much arsenic on the wood surface as newer structures, the group said. Furthermore, "children who play on arsenic-treated playsets and decks are at particularly high risk."
Similarly, in 2002, the state of New York enacted a law prohibiting construction of new playgrounds using CCA-treated lumber. Sandra Steingraber, biology professor and author of Living Downstream: An Ecologist Looks at Cancer and the Environment, wrote in an op-ed piece for the May 14, 2002, Ithaca (N.Y.) Journal, that arsenic "migrates to the surface of the wood where it can easily stick to children's hands and, from there, enter their mouths. It also leaches into the surrounding soil, where it poses a threat to groundwater." Steingraber yanked her daughter from the local nursery school due to arsenic contamination in the playground soil.
Other wood preservatives are also potentially hazardous. Pentachlorophenol ("penta") and creosote, often used to treat utility poles and railroad ties, respectively, are known to cause cancer and birth defects, according to the non-profit group Beyond Pesticides. Commercial grade penta also contains highly toxic dioxins, and can cause acute and chronic health problems including organ damage, neurotoxicity, birth defects, immune suppression and cancer, it says. Also highly hazardous, creosote is known to disrupt our endocrine systems.
Given continuing concerns and ongoing research, we do no harm in erring on the safe side. There are many easy steps we can take to protect ourselves, as well as soil and groundwater, from the arsenic in pressure-treated lumber. We can easily minimize our exposure by washing hands after playing on treated wood playsets, and by using a tablecloth on pressure-treated tables. Groups such as Beyond Pesticides also recommend applying sealants to help contain arsenic. While no studies have confirmed the effectiveness of particular sealants yet, Beyond Pesticides recommends trying such least-toxic products as AFM Safe Coat, Bioshield and Miller Paint. If you decide to remove your pressure-treated structure, do not burn it yourself: EPA says CCA-treated wood should never be burned in open fires, stoves, fireplaces or residential boilers.
The simplest solution is to avoid potentially hazardous lumber in private yards in the first place. This pertains to CCA as well as other lumber treatments, both old and up-and-coming. For example, a charming brick or stone patio can take the place of a deck. Wood that naturally deters insects, such as various kinds of cedar or redwood, makes fine fenceposts. Picnic tables and play structures are available in metal and plastic. Mounds of soil can work just as well for raised garden beds as railroad ties. And then there's the option of simply using untreated pine for certain items. How long do you really need that sandbox to last, anyway?
Next time you're launching a yard project, think twice before using treated lumber. Instead, treat yourself and the earth to natural materials that are both attractive and risk-free.