Reasonably thorough report from ABC News:
http://abcnews.go.com/Health/Stossel/story?id=4636224
Ridding Yourself of Toxins, or Money?
April 11, 2008
FTA: The Kinoki ads' claim that we're brimming with things like heavy metals, toxins and parasites scares people. "20/20" asked NMS Labs, a national laboratory in Willow Grove, Pa., that performs toxicology testing, to analyze the used Kinoki and Avon pads from eight of our group to see what we could find on the pads.
The lab tested for a lot of things, including heavy metals like arsenic and mercury and 23 solvents, including benzene, tolulene and styrene and found none of these on the used pads.
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Related:
http://scienceblogs.com/insolence/2008/04/your_friday_dose_of_woo_when_two_woos_go_to_war.php