[defrost]

With the usual caveat that in G20 countries, fluoridation is recommended at a concentration of 0.7 mg/L .. ie only added if levels are below that.

Fluoride meta studies, such as the one above, look at areas with extremely high levels of natural fluoridation, starting at least at one and half times the recommended dose and looking at areas with double, triple, and more that level.

There are issues in areas with high fluoridation levels, the fluoride and the other high metals levels in these regions in China and Mexico ...

But not basis for back propagating issues at high doses in multi metals areas to infer issues at the lower recommended dose rates.