A new report on fluoride levels in drinking water has advocates on both sides claiming the results support their cause. The report recommended that the EPA lower the maximum allowable levels of fluoride in the nation's water to avoid health risks, but only about 200,000 Americans currently consume water above those levels.

Fluoride occurs naturally in water, but communities where natural levels are lower add additional fluoride. The practice has long been recommended by dentists because it reduces the risk of cavities, saves money, and helps low-income families without access to dental care. According to the American Dental Association, fluoride in water helps reduce tooth decay by as much as 40 percent.

The new report, by the National Research Council, concluded that levels in some areas are too high, a point that anti-fluoridation groups have been drilling home for years. Too much fluoride can cause loss of tooth enamel and weakening of bones, and may cause other health problems such as bone cancer (though the evidence for this is inconclusive).

In Boulder, Colorado, where the fluoride levels are only a quarter of the maximum EPA allowance, a group of residents used the release of the report to file their own anti-fluoride petition, according to the Daily Camera. The group is trying to get a fluoride referendum on the ballot in November, saying that fluoride is a "preventive medicine that shouldn't be broadly prescribed."

For more on the fluoride debate, click here.

Photo credit: ADA