H on Nostr: Natural fluoride concentrations in water need to be taken into account as well when ...

Natural fluoride concentrations in water need to be taken into account as well when deciding whether to add fluoride. Japan has high natural fluoride concentrations and is a high IQ country.
https://www.researchgate.net/figure/Map-of-world-showing-fluoride-in-ppm-distribution-in-all-countries-This-map-was_fig3_363944578