A municipal worker in Vermont who secretly lowered the amount of fluoride in a local water supply has resigned.
Kendall Chamberlin, the former water superintendent for the town of Richmond, said in his resignation letter that fluoride levels in the water have been lower than recommended for more than 10 years.
Flouride is added to municipal water supplies in the US to strengthen teeth and prevent cavities.
Mr Chamberlin added that he did not believe the town’s fluoridation policy was “legally required” or “scientifically sound.”
Previously, it was thought that fluoride levels had been too low for around four years, reports the Associated Press.
While water fluoridation is not mandatory in Vermont, water systems that do add fluoride must do so toward state-recommended levels, AP adds.
Vermont says water fluoride levels should be maintained around 0.7 milligrams per litre (mg/L). In his resignation letter (obtained by local news outlet VTDigger), Mr Chamberlin said that average annual fluoride levels had fluctuated between 0.33 mg/L to 0.63 mg/L since 2011.
Fluoride levels in Richmond’s water have been maintained between 0.6 mg/L and 0.7 mg/L since earlier this month after the initial story had come out, Town Manager Josh Arneson told the outlet.
The initial report that fluoride levels were lower than believed left some Richmond residents “gobsmacked”, VTDigger reports.
Some people have criticized the use of fluoride in water, claiming that poses a public health risk that outweighs the benefits.
While fluoride is toxic in very large doses, it’s a naturally occurring component of much freshwater in small doses, the US Center for Disease Control notes. And in small amounts, the mineral has been proven to greatly reduce tooth decay and prevent cavities.
About 200 million Americans regularly drink fluoridated water, the CDC says – and its impact on dental health led the agency to name water fluoridation as one of the top ten most important public health achievements of the 20th century.