Comment by kilimounjaro

The solution to ALL of this is a very simple randomised controlled trial. Identify 1000 pregnant women in a fluorinated area, give half of them free unfluorinated bottled water for their pregnancy and first 2 years of babies life, and let the other half drink tap water, then measure all of the kids’ iqs at 5 years.

Sadly noone has done this because the topic is too radioactive for most researchers or science funders to touch.