You may have heard Dr. Allen or myself speak of the problems with heavy metals and chemicals in tap water.  In light of recent questions and concerns with fluoride, I felt this should be discussed in more detail.  Fluoride is another chemical commonly found in the municipal water supply.  Water contaminated with fluoride is an alarming concern.   The type found in city water is termed silica fluoride which is actually a sister compound to floral acetate (found in rat poison).  Consider this; ¼ gram of toothpaste (about a pea size) has enough fluoride in it to require a call to poison control if ingested.