For copies of lab results showing aluminum, barium, manganese, thorium, nickel, and many other toxic heavy metals at levels 100's of X over the max limit for human exposure. See http://arizonaskywatch.com and click on the 2008 and 2009 results.
http://www.infowars.com/shhh-what-if-it-was-reported-that-they-are-spraying-aluminum/
http://systembreakdown.net