Comment by NoahZuniga

> For fluoride measured in water, associations remained inverse when exposed groups were restricted to less than 4 mg/L or less than 2 mg/L but not when restricted to less than 1.5 mg/L;

So this study found no negative effects on IQ when the fluoride concentration is less than 1.5mg/L

The U.S. Public Health Service recommends 0.7mg/L of fluoride[1]. This study supports the idea that the amount of fluoride used in the US drinking water is safe.

I couldn't find any information on how much fluoride is in utah drinking water as a whole, but a report from Davis County shows that they stay between 0.6mg/L and 0.8mg/L [2]. I'd say its fair to assume basically all the water in Utah doesn't have too much fluoride, and if it did, lowering the amount to 0.7mg/L would be enough to address the health concerns.

1: https://pmc.ncbi.nlm.nih.gov/articles/PMC4547570 2: https://www.utah.gov/pmn/files/962361.pdf