This study of 180 pressure-treated wood samples shows that treated wood is a much greater source of arsenic exposure for children than arsenic-contaminated drinking water. The report determines that an average 5-year-old, playing less than 2 weeks on a chromated-copper-arsenate-treated (CCA) wood play set would exceed the lifetime cancer risk considered acceptable under federal pesticide law. Chapters examine the study's evidence, explain why the Federal Safety Study by the U.S. Consumer Product Safety Commission is outdated and inadequate, and explore why the CCA risk is mounting. The report's final chapter presents study conclusions and recommendations. An appendix presents a summary of data for surface arsenic levels of CCA wood and soil beneath treated wood structures. (Contains 28 references.) (GR)