CCA chemical treated wood. It has been banned from retail sales but has some kind of exemption for coastal areas - which is nuts.


http://www.origen.net/ccawood.html
http://www.epa.gov/oppad001/reregistration/cca/
http://www.atsdr.cdc.gov/csem/arsenic/routes.html
http://www.ecologycenter.org/factsheets ... _wood.html
http://www.beyondpesticides.org/photost ... eek_40.htm