
Chromated copper arsenate (CCA) is a commonly used wood preservative that was phased out of residential use after arsenic contamination resulted from rainwater leaching. Because CCA-lumber has a useful lifetime of 20-40 years, it is still prevalent in residential neighborhoods, where it is found in fencing, childrens’ playhouses, surrounding raised beds, in decking, picnic tables and exterior stairs. This study evaluated soil contamination outside multi-storied, high-density apartment complexes that have exterior staircases constructed of CCA lumber. High levels of arsenic, averaging 50 ppm, were found surrounding the stairs and had migrated into areas where people and pets have frequent contact with the soil, dust and run-off. Several mitigation strategies are under evaluation, including phytoremediation and other direct barriers to contact.
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