Water Fluoridation: Public Health, Not Poison

BY HARRIET HALL, M.D.

I THINK WE CAN ALL AGREE THAT “LOOK, Mom—no cavities!” is good news. But we continue to disagree about the best way to achieve that. Fluoridation of public water sources remains controversial as a public health measure despite the strong evidence that fluoride prevents tooth decay. Public debates can become quite heated, with one side praising water fluoridation as an essential preventive and the other side demonizing it as coerced ingestion of a poison. Recently fluoridation has faced new accusations that it lowers IQ. Which side is right? Let’s see how the evidence and the arguments on each side hold up to scrutiny.

Optimal Level of Fluoride in Drinking Water

The natural fluoride content of drinking water varies widely by geographic location. Studies have shown that people whose water is low in fluoride are more likely to develop cavities. If the fluoride content is too high, they can develop fluorosis, with tooth discoloration and other problems. The EPA has set maximum levels of fluoride at 2 ppm to prevent enamel fluorosis and 4 ppm to prevent skeletal fluorosis. The World Health Organization has set the recommended maximum level at 1.5 ppm.

In 2015, the U.S. Department of Health and Human Services updated the optimal fluoride level in drinking water to 0.7 mg of fluoride per liter of water (equivalent to 0.7 parts per million or ppm). This was based on extensive research and consideration of other sources of fluoride. If the natural fluoride content of drinking water is lower than 0.7 ppm, water fluoridation can raise it to 0.7. If it is over the recommended maximum level, there are ways to lower it. Estonia had levels as high as 7 ppm (10 times the optimum), and they were able to successfully lower the fluoride exposure of their citizens by using reverse osmosis technology and drilling new wells.1 Fluorosis should not occur at currently recommended levels of water fluoridation.