Estimated Fluoride Intake and IQ
A 1-mg increase in fluoride intake was associated with a 3.66 (95% CI, −7.16 to −0.15; P = .04) lower FSIQ score among boys and girls
The scales chosen in the study make it sound a lot more scary, though, given the unfluoridated mean intake was 0.3 mg and the fluoridated mean intake was 0.93mg. Still, this is an estimated difference of two whole IQ points between the populations.
I'm on Detroit water and just checked the latest water test I could find -- .57ppm fluoride. If I did the math right, there is 1mg fluoride in every .46 gallons of water.
Additionally, the maximum level allowed in my city is 16mg per gallon, and has been since I was born. However, in the year I was born(1992) the maximum measured level per the city test was 48mg per gallon.
The scales chosen in the study make it sound a lot more scary, though, given the unfluoridated mean intake was 0.3 mg and the fluoridated mean intake was 0.93mg. Still, this is an estimated difference of two whole IQ points between the populations.