Arsenic-treated wood is a fixture in many of our homes, where it has commonly been used to construct tough, long-lasting decks, fences, and play structures. But arsenic leaches from treated lumber and rubs off the wood when people or animals come in contact with it.

In 2002, after various risks assessments indicated elevated childhood cancer risk from arsenic exposure, EPA reached an agreement with manufacturers to phase out the use of arsenic for residential wood treatment. However, many homes still have arsenic-treated wood in place, as well as soil contaminated from this lumber. As with lead, Washington’s soils are tainted in many areas with arsenic from smelters and pesticides. Arsenic continues to be used in other products, too, including paints, dyes, metals, soaps, and drugs (EPA 2005). Other major sources of arsenic, depending on diet and location, are drinking water and seafood. While seafood may contain large amounts of arsenic, most of its arsenic is believed to be in the less-toxic inorganic form. The test in our study analyzed for the toxic, inorganic form found in drinking water and other sources.