TOPSHAM — Public drinking water in Brunswick and Topsham has contained fluoride since 1955, but last month the amount of the chemical in the water dropped dramatically.
With the equivalent of a flick of a switch, the Brunswick & Topsham Water District cut fluoride levels nearly in half on Jan. 18.
The district wasn’t acting on its own. In the past month, municipal water districts around Maine have been reducing fluoride levels in drinking water from 1.2 parts per million to 0.7 ppm. The change was recommended by the U.S. Environmental Protection Agency and the Department of Health and Human Services in a report issued in December 2010.
Fluoride, which helps prevent tooth decay, was first added to municipal water supplies in the 1940s. According to the EPA and HHS, when water fluoridation began, Americans were not getting enough fluoride. Now there are many more sources, including toothpaste, mouthwash and bottled drinks made with fluoridated water.
Historically, fluoride levels in municipal areas have varied from region to region. In the South, levels were set lower than in the North, because it was believed that residents drank more water in the hotter climate, according to Craig Douglas, district engineer for the local water district.
But new research suggests that water consumption disparities have disappeared, and there has not been a rise in tooth decay among residents of the South who drink less tap water, Douglas said. This led the EPA and HHS to recommend a 0.7 ppm concentration of fluoride in water around the country.
In January, the Maine Drinking Water Program said it would allow utilities to lower the fluoride level to 0.7 ppm while the new level is formalized. A week later, engineers at the Brunswick-Topsham district adjusted their chemical pumps, sending less fluoride out into the water supply for the first time since fluoridation began nearly 60 years ago.
Other local water districts have also made the change, including Bath and Portland. Homes in Harpswell are get drinking water from private wells.
Emily Guerin can be reached at 781-3661 ext. 123 or firstname.lastname@example.org