There’s no reason to debate the merits of fluoride for dental health. I’m not disputing that. Pat yourself on the back, your marketing campaign worked. The issue was, and remains: should governments be allowed to adulterate drinking water, even if it’s “for our own good”? For many years, I thought so — and (like the article author) I thought that opponents were uneducated paranoids. Then, I listened to one of those opponents, and came to realize that the issue is forced medication.
As for question about lithium, you must be aware that there’s a bit of a movement for adding it to drinking water — mainly to reduce the suicide rate. Surely, preventing suicide is at least as much a public health issue as preventing dental caries. The question is: do you want government adding mental-health medication to your drinking water? DesertRhino mentioned (in jest, I hope!) adding Quaaludes in some places. Perhaps inner cities would be a lot safer, if everyone was dozing on Quaaludes — but, do you really want government to add that to your drinking water? Where do you draw the line.
By the way, Victoria B.C. is, in many ways Canada’s answer to Portland Oregon, and other granola cities (fruits, nuts, and a lot of flakes). It’s very “green”, and mostly votes in socialists at every level of government (the right-wing provincial government is “Liberal”). When I moved here from the far north, I was struck by the comparative lack of freedom. It seems that every week something is being regulated or banned. Imagine my disbelief, when I discovered that the regional water district does not fluoridate the water.
Moreover, it's a benefit that people can't achieve on their own. To my knowledge, while you can buy fluoridated toothpastes and obtain topical treatment in the dentist's office, there is no practical way to fluoridate one's water.
Ergo, fluoridation is a legitimate public health benefit that can only be provided on a community-wide basis.
The benefits of lithium, however, are neither demonstrable nor universal...nor necessarily beneficial. Ergo, there is no legitimate public health benefit to be obtained.