I encourage you to read the writings of Andrew Cutler, PhD. He'll explain how Hg fouls up the body's ability to move "transport" other elements, toxic and essential. This will typically cause a hair test to look very abnormal. You can see over 500 of them from a number of Cutler groups including several very large yahoo chelation groups. http://livingnetwork.co.za/chelationnetwork/hairtest/hairtest3/