"For example, fluoride interferes with enzymes where magnesium is an important co-factor, and it can help facilitate the uptake of aluminum and lead into tissues where these metals would not otherwise go (Mahaffey 1976; Allain 1996; Varner 1998).17) Rats fed for one year with 1 ppm fluoride in their water, using either sodium fluoride or aluminum fluo" . . . .