Let's talk about water fluoridation. And, being that I'm a dentist, you'll probably be a little surprised by my stance on it. At least in terms of it being included in water.
As you likely know, fluoride is a chemical that is commonly found in most toothpaste brands. People use fluoridated toothpaste as a means to strengthen teeth (i.e. prevent cavities) and normally don't think much further about it. Which is fine -- that's pretty much how it's marketed.
Since the late 1990s, the United States Food and Drug Administration has made it mandatory for toothpastes to carry a warning in regards to fluoride usage. But why would the FDA post a warning on a toothpaste ingredient? Doing research on what fluoride is reveals that the chemical is now considered a potential toxic drug, and ingesting enough of the ingredient could be harmful.
Now, I don't want to scare you -- brushing your teeth with fluoride toothpaste isn't harmful. Nor is a dentist using a gel-type fluoride treatment when you get your checkup. Uses like that are topical usages -- you don't ingest it. And even if you do ingest some toothpaste (etc), the levels of fluoride aren't going to pose any threat. And it does prevent cavities.
But in terms of it being added to water, I'm not so sure that's a good thing. Adding fluoride has been a standard in many countries for years. However, several countries (mainly Europe) have taken an active stance on banning fluoride from their drinking water. And I'm with them -- I do not see the good in fluoridating our drinking water. I definitely see the reasoning why countries would add it -- it helps prevent cavities. But as a dentist, I think cavity prevention can be done just as effectively without putting fluoride in our water. To me, the "bad" it can (potentially) do outweighs the good.