Yes, I know it looks like a stupid question!   But it is an interesting introduction to the dangers of Fluoride. 

Even if we were to momentarily discount the arguments about the ethics of forcing people to take a medication without their consent by putting it in our drinking water, Fluoride was originally intended as a TOPICAL application.

For more about the dangerous source of the Flouride used in our water supply, and interesting information about its effects taken interrnally, go here