In a remarkable turnabout, many Americans are getting too much fluoride, which is causing spots on children's teeth and perhaps other, more serious problems, federal health officials say.
The U.S. Department of Health and Human Services announced plans Friday to lower the recommended level of fluoride in drinking water for the first time in nearly 50 years, based on a fresh review of the science.
The fluoride level in Davis County's water is already in compliance.
In October, the Davis County Health Department changed the level of fluoride in drinking water from 0.8 milligrams per liter to 0.7 milligrams per liter, said Lewis Garrett, health department director.
In 2004, after voters approved -- for the second time -- to have fluoride in Davis County's drinking water, county health department officials met with federal officials to discuss how much fluoride was too much.
From 2000 to 2004, 1.0 mpl of fluoride was added to the water.
"We had the same concerns that (The Centers for Disease Control and Prevention) had and held two meetings with CDC people and discussed the issue of fluorosis," Garrett said.
County health officials met again in 2010 with CDC officials and decided to lower the level of fluoride.
On Friday, CDC and the U.S. Department of Health and Human Services announced a proposal to change the recommended fluoride level nationwide to 0.7 mpl of water.
The Environmental Protection Agency will review whether the maximum cutoff of 4 mpl is too high.
The standard since 1962 has been a range of 0.7 to 1.2 mpl.
The government also is expected to release two related EPA studies that look at the ways Americans are exposed to fluoride and the potential health effects.
This shift away from government's long-standing praise of the benefits of fluoride is sure to re-energize groups that still oppose it.
Fluoride is a mineral that exists naturally in water and soil. Scientists in the early 1940s discovered that people who lived where water supplies naturally had more fluoride also had fewer cavities. Some locales have naturally occurring fluoridation levels above 1.2 mpl.
The CDC reports that the splotchy tooth condition, fluorosis, is unexpectedly common in kids ages 12 through 15. And it appears to have grown much more common since the 1980s.
Fluorosis is a discoloration of teeth that most of the time cannot be seen except by a dentist using lights and a microscope, Garrett said.
In severe cases, the teeth are brown, pitted and brittle.
"Cosmetically, it's just not pleasing to look at," Garrett said.
Today, most public drinking water supplies are fluoridated, especially in larger cities. Counting everyone, including those who live in rural areas, about 64 percent of Americans drink fluoridated water.
Weber County does not have fluoride in its drinking water, said Lori Buttars, spokeswoman for the health department.
Fluoridation has been fought for decades by people worried about its effects.
"It has taken many years for government to finally admit that fluoride at recommended doses is discoloring teeth," said Dave A. Hansen, chairman of Citizens for Safe Drinking Water Davis County.
"This discoloration is a result of the fluoride poisoning the enzymes that produce the enamel in the tooth. This isn't the only poisoning going on in the body with fluoridation, but it will likely take the government another decade to admit to other ill effects."
Hansen fought the fluoridation issue when it went to the voters in 2004.
He is also concerned with the amount of fluoride infants consume.
"Infants drink a larger amount of water in proportion to their body mass than do adults, so children getting formula mixed with fluoridated water are being significantly overdosed by government standard," Hansen said.
"The recommended amount for newborn infants should be zero. Our local health boards ought to be taking the lead on warning mothers of this danger."
Hansen said the tooth decay rates are no different in Hawaii, where only 11 percent of the residents have fluoridated water compared with Maryland, where the majority of residents receive fluoridated water.
"We could have saved ourselves millions of dollars in fluoridation costs and given children far better dental care using these dollars for real dental care rather than for the unproven fluoridation method," Hansen said.
The Associated Press contributed to this article.