[hyeonwho4]

Yikes!

> Nineteen of those studies were considered to be high quality; of these, 18 reported an inverse association between estimated fluoride exposure and IQ in children. The 18 studies, which include 3 prospective cohort studies and 15 cross-sectional studies, were conducted in 5 different countries. Forty-six of the 53 low-quality studies in children also found evidence of an inverse association between estimated fluoride exposure and IQ in children.

> https://ntp.niehs.nih.gov/publications/monographs/mgraph08

They're estimating a 3 to 5 point IQ drop due to fluorinated water in childhood. On that basis I would have to support switching to free mouthwash.