Assessing and Managing Exposure from Arsenic in CCA- Treated Wood Play Structures

Background: Chromated copper arsenate (CCA)-treated wood has been widely used for outdoor play structures. There is a growing scientific concern about children’s exposure to the arsenic that leaches from these structures. The purpose of this study was to measure arsenic from CCA-treated wood play structures owned by the City of Toronto to guide an appropriate exposure reduction strategy. Methods: In the fall of 2002, 4 soil and 2 wood surface samples (dislodgeable arsenic) were collected from 217 play structures and analyzed for total arsenic content. Soil arsenic concentrations were compared to the federal soil guideline of 12 µg/g. Dislodgeable arsenic concentrations were compared to a Toronto Public Health-derived interim action level of 100 µg/100 cm2. Results: Soil arsenic levels in samples taken from within one metre of CCA-treated wood were low (mean 2.1; range 0.5-10 µg/g). However, the means of the arsenic level in the composite soil samples taken from beneath an elevated platform were significantly greater (p<0.01) than the background soil sample and soil from within one metre of the CCA