GRN Reports

US health officials have lowered the safe threshold for fluoride in drinking water to 0.7 milligrams per liter, because Americans now get fluoride from a variety of sources and no longer need as much in their tap water.

The new standard replaces the one set in 1962 that provided for city water systems to have a range of fluoride from 0.7 milligrams per liter up to 1.2 milligrams per liter.

This move by the Health and Human Services Department comes after studies showed that significant number of young people today exhibit dental fluorosis, or spots on their teeth. The mottling was usually mild, but it indicated to public health officials that the cumulative levels of fluoride that American kids were consuming — in their water, juice, tea and prepackaged drinks — was rising to higher than necessary levels.

“The change was recommended because Americans now have access to more sources of fluoride, such as toothpaste and mouth rinses, than they did when water fluoridation was first introduced in the United States. As a result, there has been an increase in fluorosis, which, in most cases, manifests as barely visible lacy white marking or spots on the tooth enamel,” the Department of Health and Human Services wrote in a statement. “The new recommended level will maintain the protective decay prevention benefits of water fluoridation and reduce the occurrence of dental fluorosis.”

Fluoride in tap water continues to be needed and is responsible for “dramatic declines in both the prevalence and severity of tooth decay” over the decades, HHS said, noting that  the Centers for Disease Control’s has proclaimed fluoridation to be one of the 10 major public health advancements of the 20th Century..

More than 70 percent of US municipalities fluoride their water and this helps strengthen tooth enamel beyond what fluoride in dental products can accomplish, said Deputy Surgeon General Rear Admiral Boris D. Lushniak, M.D., M.P.H. “While additional sources of fluoride are more widely used than they were in 1962, the need for community water fluoridation still continues,”  Lushniak said. “Community water fluoridation continues to reduce tooth decay in children and adults beyond that provided by using only toothpaste and other fluoride-containing products.”

Fluoridation opponents disagree with that statement. They say that better dental care and toothbrushing has improved dental health and that fluoridation has not been the magic solution to dental decay that US authorities insist.

The Fluoride Action Network (FAN), which serves as a clearinghouse for anti-fluoridation groups  that have rolled back fluoridation in dozens of US cities and towns, maintains that fluoridation is not necessary and could be harmful. FAN cites studies showing that too much fluoride can cause health effects far worse than mottled teeth, such as weaker bones and lowered cognitive development of children.

FAN points to Western Europe, where tooth decay rates have declined as they have in the US, even though most countries stopped fluoridation or never fluoridated their water.

“This raises serious questions about the CDC’s assertion that the decline of tooth decay in the United States since the 1950s is largely attributable to the advent of water fluoridation,” FAN writes on its website.

A recent review looking at the dental health of 12-year-olds by the World Health Organization (WHO) found that virtually all western countries enjoyed major declines in dental decay in the last 40 years, whether or not the nation fluoridated.

Tooth Decay declines with or without fluoridation -- WHO study

FAN asserts that fluoridation of water is unethical, a “dangerous relic from a 1950s public health culture that viewed mass distribution of chemicals much differently than scientists do today, and needlessly puts Americans at risk for the negative health effects related to excess fluoride ingestion.

To FAN, mottled teeth are the least of it. The group reports on studies showing that excess fluoride intake could be worsening arthritis and playing a role in thyroid imbalances.

In conjunction with the HHS move to lower the safe threshold of fluoride, the US Food and Drug Administration (FDA) has lowered the threshold for added fluoride in bottled water.

FDA sent a letter to bottled water manufacturers and importers to limit the amount of fluoride  in water they add to bottled water so that it contains no more than 0.7 milligrams per liter (mg/l).

The new level for bottled water “provides the best balance of protection from dental caries while limiting the risk of dental fluorosis,” the FDA said in a statement. It applies only to fluoride that is added to bottled water and does not affect the levels of fluoride permitted under the FDA’s bottle water regulations. (If that statement is confusing, remember that a lot of bottled water comes from city water systems, so it may already contain fluoride; hence the fluoride can be from an additive or it can already be in the water being bottled.)

These are the limits for fluoride that’s actually in the finished bottled water product can still range from between 0.8 and 1.7 milligrams per liter (mg/L) fluoride, depending on annual average air temperatures at the location where the bottled water is sold at retail, according to the FDA. Imported bottled water cannot contain more than 0.8 mg/L fluoride.

You can find more details on the (confusing) fluoride rules for bottled water in this letter.

(Photo above: Wikimedia.)