Battle renewed over value of fluoridation.

appearing to slowly swing away from the value of fluoridating tap water, the United States Department of Health and Human Services has indicated that it will lower the recommended level of fluoride to be added to drinking water. The partial retreat comes on the heels of city of Calgary, Alberta’s decision to discontinue fluoridation of its drinking water in a bid to save $750 000 per year in direct fluoride costs and a projected $6-million equipment upgrade at its treatment plants. Although fluoridation proponents argue that such moves invite tooth decay, particularly among low-income groups who can’t afford dental care, US and Calgary officials counter that recent scientific evidence suggests that a high intake of fluoride can place people at risk of bone abnormalities and fractures. The Department of Health and Human Services is proposing to lower fluoride concentrations in drinking water to 0.7 mg/L from 0.7–1.2 mg/L, the first time that the department has retreated from standards established in 1962. The lower level “provides the best balance of protection from dental caries [tooth decay] while limiting the risk of dental fluorosis,” the department stated in a release (www.gpo.gov/fdsys /pkg/FR-2011-01-13/pdf/2011-637.pdf). About 73% of American communities fluoridate their water. The new American level is in keeping with that of Canada and reflects a balance between fluoridating water to reduce cavities, while protecting against toxic effects, David Thomas, media relations officer for Health Canada, writes in an email. Calgary recently became the latest of several major Canadian cities to have opted against fluoridation. Montréal, Quebec and Vancouver, British Columbia decided against it in the 1970s, while Québec City voted against it in 2007 and residents of Waterloo, Ontario, narrowly voted to discontinue fluoridation in a 2010 referendum. The announcements have renewed a battle over the value of fluoridation, with advocates of adding fluorides arguing that there are economic consequences to discontinuing the practice. “From an economic perspective, the cost of individual professional fluoride applications to individuals at high risk of dental caries is greater than the cost of community water fluoridation,” Dr. Euan Swan, manager of dental systems for the Canadian Dental Association, writes in an email. Swan adds that the 60-cent per capita News CMAJ