“CDC-Playground Injuries.” Center for Disease Control and Prevention. 19 Jan. 2009. 29 Nov. 2011. <www.cdc.gov>.
http://www.homesafetycouncil.org/ Safe Kids USA/Worldwide
These websites provide information and statistics on the amount of injuries that occur on public and school playgrounds each year. The pages can give you some perspective on how safe certain things really are.