Just for yuks --

Looks like Flouride levels in my state are between .8 an 1.5 mg/L.

http://www.doh.wa.gov/ehp/dw/fluoride-data.xls

"The World Health Organization recommends a guideline maximum fluoride value of 1.5 mg/L as a level at which fluorosis should be minimal.[59]"

"the only clear adverse effect is dental fluorosis, which can alter the appearance of children's teeth during tooth development; this is mostly mild and is unlikely to represent any real effect on aesthetic appearance or on public health.[10]"

(http://en.wikipedia.org/wiki/Water_fluoridation#Safety)

-john