The main documented side effect to over-fluoridation is fluorosis, a condition marked by white marks on the teeth. There are proven great benefits to low fluoride amounts to decreasing dental caries. Most people in the U. S are already getting fluoride directly on their teeth in the form of toothpaste and dental rinses. The NPR link above notes some believe fluoridation at higher levels is linked to other problems including thyroid issues, skeletal fluorosis, and ADHD.
Much of the western world has already eliminated or decreased fluoride amounts in water supplies. There are some areas of the world that have naturally occurring fluoride which is over 1.5 mg/l (See world map here.) The high fluoride levels are linked to types of granite with the naturally occurring fluorite mineral (the purplish mineral in the pinkish granite below):
The mineral fluorite, CaF2, is a member of the halide sequence.
And, of course, fluorite is the namesake poster child for fluorescence under ultraviolet light:
I am curious to hear about your views on the fluoride controversy. What is yours? Surely, the decreasing of the acceptable level by half is significant.
Going with the fluo,