If you have raised garden beds, a deck or a wooden play structure in your back yard that's more than a few years old, you may be exposing your family to toxins such as arsenic and hexavalent chromium through the soil around it.
If you're growing a garden in that soil, it can be especially worrisome. Why garden organically and then grow your veggies in polluted soil?
What are the concerns in CCA-treated wood?
Pressure treated wood is wood that has been treated to protect it from being destroyed by insects, fungus or moisture. Prior to 2004, most pressure treated wood was treated with chromated copper arsenate (CCA), a combination of hazardous chemicals such as arsenic and hexavalent chromium that was used on almost all the pressure-treated lumber in the United States.
At the end of 2003, the EPA banned the sale of lumber treated with CCA for residential use. However, stores were allowed to sell existing stocks, and many residential back yards still contain play structures, garden beds, decks, garden borders, outdoor furniture and other materials made of CCA-treated lumber.
Back then, CCA-treated wood was easy to identify because of its characteristic light green tint. However, that tint fades with time. If you have older wooden structures in your landscape that is not a long-lasting wood such as redwood, there's a high chance that it's CCA-treated lumber.
Studies have shown that toxins do leach from the lumber over time into surrounding soil. One University of Minnesota study found that plants accumulated higher levels of arsenic the closer they were to the lumber. While the plants still contained levels that were considered safe for consumption, there are easy ways to lower your family's exposure.
Here are some easy ways to detox your soil and minimize arsenic exposure from CCA-treated wood.