http://times-news.com/letters2/x1004927893/Chinese-fluoride-is-a-homelan...
From the page:
"Recently, it has come to my attention in an engineering report for the city of Boulder, Colo., that they did an evaluation of fluoridation chemicals and sources and found that much of the fluoride chemicals used for water fluoridation are now coming out of China with arsenic and lead levels of 50 and 40 milligrams respectively per bag and non-existent regulatory monitoring of the salt or acid compounds from these imports."
Update:
http://naturalnews.tv/v.asp?v=42652E035A1B1BAAAE1F340B54694975