Thanks for this, Steve. There's a story still to be told here. In the
1940s, the American Dental Association issued strong warnings about the
dangers of fluoride, which was contained naturally in the water supplies
in some locations (no one was thinking about putting a toxin in the
water supply in those days). The ADA then did a very rapid turnaround
about 1950. Some people say the reason was that fertilizer
manufacturers were looking for a way to dispose large quantities of a
toxic byproduct; but that has naturally been disputed, and I haven't
done the research to evaluate it. A controlled study of the effects of
fluoride was never done. The John Birch Society vigorously publicized
the dangers of fluoridation, but their efforts were unfortunately
counterproductive, because they insisted that fluoridation was a
Communist plot, giving conspiracy theories a bad name for all time.
Their championing of Laetrile in the 1970s also helped to kill that
promising cancer treatment.