https://stevekirsch.substack.com/p/the-case-against-fluoride
A short substack column but long enough to provide details, sauce, and suggestions, including how to filter flouride out of your water. The situation with flouride is similar to that with the "vaccines", as Kirsch describes:
Get your town to stop fluoridating the water. It’s poison. You will have to overcome the same disbelief you get when you tell people the COVID vaccines aren’t safe.
Change the law in your state to outlaw fluoridation. Like vaccines, the science is crystal clear when you look at it; but nobody wants to look at it. After we take down the COVID vaccines, people will hopefully be more receptive to looking at the risk-benefit here.
I wasn't thrilled with the controls when I first read that paper, though I'll go back through the methods. They certainly could be right. If they are, I wonder if it's an honest, unintended consequence of well-meaning people, or if it's cabal trying to keep the poors even stupider. IQ is just notoriously hard to research and control for.
If you’re interested in digging further, checkout a book called The Fluoride Deception. It traces the story back to WWII and the atom bomb. Pretty interesting.