Last week, I wrote about how to find out how much fluoride your water contains. A reader wanted to know what parts of the country contain high levels of fluoride naturally. In the first year dental school, I learned about the “Colorado Brown Stain” story where some dental researchers discovered fluoride in the water in Colorado and found a link between the fluoride and healthier teeth.
I figured that Colorado couldn’t be the only place on earth with high levels of fluoride — and that turns out to be true. There are several areas in the world where fluoride can naturally be found in the water supply.
After a lot of research, I found a research paper entitled, A Systematic Review of the Efficacy and Safety of Fluoridation published by the National Health and Medical Research Council in Australia. Using the data that it contained, I constructed the following map that shows the locations in the world that contain greater than 1.5 ppm of fluoride in the groundwater.
This map visually puts into perspective the fact that water fluoridation isn’t about adding some synthetic chemical to our drinking water, it is simply about adjusting the amount of fluoride in our water to an optimal level that will help prevent tooth decay.