I believe it’s generally accepted that adding fluoride to drinking water is generally a good thing; it helps with dental health and the mild mind control effects help to keep a society peaceful.
What I’m curious about though is whether there are other substances that could be added to the general drinking water supply that could be safe, beneficial and I suppose cost effective (but that’s less important, we can assume an infinitely rich city if necessary for an interesting addition).
I was thinking Vitamin D for far north/south places but it turns out it’s not water soluble.
The one reasonable argument against it that I’ve seen is that it’s not very cost-effective: you’re paying to fluoridate the water for everybody, but the only people who have been shown to really need it are kids. Other delivery methods could be more cost effective, e.g. the fluoride pills my parents gave to me and my siblings when we were kids - but of course this assumes that every parent would give those pills to their kids. They won’t. So I guess the counterargument is that while water fluoridation may not be the most cost-effective method of getting fluoride to every kid, it’s damn reliable.
What else can we add to the water supply? How about folate? Deficiencies can cause neural tube defects in a developing fetus. The US mandates supplementing various foods with it, and recommends that newly-pregnant women take an extra supplement. But like fluoride intake, there are plenty of women who won’t hear/heed the message. Dental cavities suck, sure, but having your spinal cord dangling in the breeze instead of being stored safely next to your spine is a whole different kind of suck; it’s obviously bad for the victim’s quality of life, but it also presents an enormous health care cost. Want to make sure every pregnancy starts out with adequate folate? Howzabout we treat the water supply with it?
There was a premise like this in a short story by Stephen King called The End of the Whole Mess, where the guy’s brother isolates some chemical in the water of a Texas town that makes the people very peaceful, he creates a way to spread it around in rain or something to the whole world, his plan works, but he failed to also find that the chemical causes some form of Dementia or Alzheimer’s or something and he basically kills the whole world.
I haven’t read all of this study, and it seems to be devoted to clinical doses of lithium.
But doses measured in less than 10mg, or possibly mcg can supposedly have an anti-suicide effect too. Seeing how suicide is a leading cause of death for people under 55, that could be an issue.