It took the town of Oak Bluffs forty years to accept what the Centers for Disease Control calls one of the ten great health achievements of the twentieth century — community fluoridation of water. Now the town board of health is considering rolling that back.

What is it that makes some people so willing to dismiss the weight of scientific evidence? Fluoridation, at the very modest levels used in Oak Bluffs and elsewhere to prevent tooth decay, has been repeatedly deemed safe by a succession of surgeons general as well as a long list of medical organizations. More to the point, it is an economical way to lower health care costs, especially for the many people who can’t afford a dentist.

More troubling, if perhaps less surprising, was reaction this week to the third National Climate Assessment, a comprehensive federal report that concluded we are likely to see more extreme weather events, especially in the Northeast, as average temperatures continue to climb. Climate change deniers were quick to point out that, gee, this winter didn’t seem so warm.

It is possible to find evidence to support any position one wants to take. There are studies that show, for example, that for some children, some amount of fluoride may actually harm their teeth.

But the vast majority of the science weighs in favor of fluoride. You can look it up. We urge Oak Bluffs residents not to reverse a hard-won and valuable public health policy on a whim.