I heard fluoride is a poison. Is this true?

Yes. Fluoride is an acute toxin with a rating slightly higher than that of lead. According to "Clinical Toxicology of Commercial products," 5th Edition, 1984, lead is given a toxicity rating of 3 to 4, and Fluoride is rated at 4 (3 = moderately toxic, 4 = very toxic). On December 7, 1992, the new EPA Maximum Contaminant Level (MCL) for lead was set at 0.015 ppm, with a goal of 0.0ppm. The MCL for fluoride is currently set for 4.0ppm - that's over 350 times the permissible level of lead.

Fluoride is also considered toxic waste. It is one of the most bone seeking elements known to mankind. The US Public Health Service has stated that fluoride makes the bones more brittle and the dental enamel more porous.