A report from the National Academy of Sciences’ National Research Council recommends that the Environmental Protection Agency standard for fluoride in drinking water be reassessed. The report, released March 22, says about 200,000 Americans have drinking water sources with at least 4 mg of fluoride per liter, the maximum allowed. NRC recommends that EPA reassess the standard in light of health risks associated with high fluoride levels, including bone fractures after lifetime exposure and tooth discoloration and pitting.

“Any change in the fluoride standard will be considered after the agency has completed reviewing all the data, of which the NRC report is a significant addition,” says an EPA spokesman.