Potential Arsenic Exposures To Children Associated With In-service And Recycled CCA-treated Wood In Tropical Environments
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T. Shibata, H. M. Solo-Gabriele, L. E. Fleming, S. L. Shalat, Y. Cai & T. Townsend
CCA-treated wood, which has been a widely used preservative for treating outdoor wood structures, e.g. playsets, has been reported to release arsenic. The objectives of the study were to estimate the potential levels of arsenic exposure to children at CCA-treated wood equipped playgrounds and to evaluate factors that affect the magnitude arsenic releases for pathways which may result in the exposures. Two types of releasable arsenic were evaluated: dislodgeable arsenic released by rubbing the wood and leachable arsenic released by rainfall. Dislodgeable arsenic was tested using synthetic wipes and leachable arsenic was assessed by monitoring outdoor decks and recycled wood mulch. The potential level of arsenic on a child’s hand after individual contact with in-service CCAtreated wood playsets was 2.9 µg/(100 cm2·hand-est) based on the synthetic wipe method. However, such an exposure level can be affected by physical factors such as age of wood, frequency of rubbing, amount of arsenic in the wood, and climate. Arsenic concentration in the surface sand below a CCA-treated deck after 6 and 24 months of arsenic leaching was 4.5 mg/kg and 13.4 mg/kg respectively. Based on these contamination levels, the potential level of arsenic on a child’s hand after contact with sand under the CCA-treated wood structure was computed as 0.05 µg/(100 cm2·hand-est) after 6 months of the installation and increased to 0.15 µg/(100 cm2·hand-est) after 24 month of the installation. Exposure levels from soil can be influenced by soil type and characteristics of the wood structure and rainfall. Overall, this study showed that arsenic releases from CCA-treated playgrounds can be available for potential arsenic exposures to children and the levels are influenced by many environmental factors. In most cases the releases exceeded the risk-based regulatory guidelines. Keywords: arsenic exposure, children, CCA-treated wood, playgrounds, tropical environments.
arsenic exposure, children, CCA-treated wood, playgrounds, tropical environments.