The concern over CCA in pressure-treated wood products actually began a few years ago, when researchers discovered that the ash from wood-fired incinerators contained high levels of arsenic and chromium, both of which are known toxins and carcinogens.
Further investigation revealed that CCA-treated wood scrap had been burned as fuel in these incinerators, leaving behind arsenic and chromium in the ash. The level of arsenic in CCA wood scrap is high enough that one tablespoon of arsenic-tainted CCA wood ash is considered lethal to humans.
http://www.beyondpesticides.org/pestici ... ts/cca.pdfhttp://www.epa.gov/oppad001/reregistration/cca/http://www.bancca.org/Health_Hazards/cca_hlth_hzrds.htmhttp://www.healthybuilding.net/arsenic/index.htmlhttp://www.ct.gov/dph/lib/dph/environme ... d_wood.pdf