Answer: There are two "camps" on this subject. There are those who cite studies showing that, indeed, some of the materials in pressure-treated wood do leach into the soil. On the other side are studies showing that no leaching occurs. Since there is no definitive answer, I usually recommend people err on the side of caution and not use these materials in their vegetable gardens. As far as whether or not your soil is contaminated, I would recommend you have a soil test done. Contact your local Extension Service for a soil test kit; their number is 708/223-8627. Explain your situation and request they test for copper, chromium, and arsenic (and whatever else they recommend). Alternatives to pressure-treated lumber or railroad ties include cedar, hemlock, and "timbers" made from recycled plastic.
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