State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 201146, China; Soil Water Science Department, University of Florida, Gainesville, FL 32611, United States.
Soil Water Science Department, University of Florida, Gainesville, FL 32611, United States.
Environ Int. 2015 Sep;82:35-40. doi: 10.1016/j.envint.2015.04.012. Epub 2015 May 22.
Concern about children's exposure to arsenic (As) from wood treated with chromated-copper-arsenate (CCA) led to its withdrawal from residential use in 2004. However, due to its effectiveness, millions of American homes still have CCA-wood decks on which children play. This study evaluated the effects of three deck-cleaning methods on formation of dislodgeable As and hexavalent chromium (CrVI) on CCA-wood surfaces and in leachate. Initial wipes from CCA-wood wetted with water showed 3-4 times more dislodgeable As than on dry wood. After cleaning with a bleach solution, 9.8-40.3μg/100cm(2) of CrVI was found on the wood surface, with up to 170μg/L CrVI in the leachate. Depending on the cleaning method, 699-2473mg of As would be released into the environment from cleaning a 18.6-m(2)-deck. Estimated As doses in children aged 1-6 after 1h of playing on a wet CCA-wood deck were 0.25-0.41μg/kg. This is the first study to identify increased dislodgeable As on wet CCA-wood and to evaluate dislodgeable CrVI after bleach application. Our data suggest that As and CrVI in 25-year old CCA-wood still show exposure risks for children and potential for soil contamination.
对儿童接触用铬酸铜砷酸盐（CCA）处理过的木材中的砷（As）的担忧导致其在 2004 年退出住宅使用。然而，由于其有效性，数以百万计的美国家庭仍然拥有 CCA 木材制成的露台，儿童在上面玩耍。本研究评估了三种甲板清洁方法对 CCA 木材表面和浸出液中可剥落砷和六价铬（CrVI）形成的影响。用湿布擦拭CCA 木材时，其可剥落砷含量比在干燥木材上高 3-4 倍。用漂白剂溶液清洁后，木材表面发现了 9.8-40.3μg/100cm(2)的 CrVI，浸出液中 CrVI 含量高达 170μg/L。根据清洁方法的不同，清洁 18.6 平方米的露台会将 699-2473mg 的 As 释放到环境中。在一个潮湿的 CCA 木材露台上玩耍 1 小时后，1-6 岁儿童的估计砷剂量为 0.25-0.41μg/kg。这是第一项确定湿 CCA 木材中可剥落 As 增加以及评估漂白剂应用后可剥落 CrVI 的研究。我们的数据表明，25 年历史的 CCA 木材中的 As 和 CrVI 仍然对儿童构成暴露风险，并有可能污染土壤。
