02-09-2009, 05:16 PM
Interesting tidbit courtesy of Wikipedia:
"The U.S. specifies the optimal level of fluoridation to range from 0.7 to 1.2 mg/L [...]
but groundwater, particularly in volcanic or mountainous areas, can contain as much as 50 mg/L"
"The U.S. specifies the optimal level of fluoridation to range from 0.7 to 1.2 mg/L [...]
but groundwater, particularly in volcanic or mountainous areas, can contain as much as 50 mg/L"