http://www.calrecycle.ca.gov/publications/Documents/Tires%5C62206013.pdf
California funded this study of recycled tires’ toxicity, specifically in playground and running tracks. The Office of Environmental Health Hazard Assessment produced detailed analysis of chemicals and elements in waste tires. OEHHA also analyzed the devastating effect of these chemicals on surrounding plan and animal life over time. OEHHA, January 2007