March 10, 2015 — Controversy over fluoride levels in drinking water in Massachusetts has made headlines in recent months as Cambridge, Gloucester, Newburyport, and other towns in Massachusetts relook at the decades-old practice of adding fluoride to public drinking water to reduce dental caries (cavities). Some of the controversy between scientists, dental professionals, anti-fluoride activists, town officials, and others in Massachusetts and across the U.S. might be reduced if the U.S. Health and Human Services (HHS) proposal for lowering fluoride levels in U.S. drinking water was finalized, according to a Harvard T.H. Chan School of Public Health researcher.

“I know that [the Department of] Health and Human Services in Washington has recommended that [U.S. communities] decrease the level of fluoride in water from 1.0 part per million to 0.7 parts per million. I think we ought to do that right away,” Philippe Grandjean, adjunct professor of environmental health, said on WBUR’s Radio Boston on February 5, 2015.

Close to 75% of the U.S. population receives drinking water containing 0.7-1.2 parts per million (ppm) fluoride to prevent tooth decay, levels that were based on recommendations from the federal government made more than four decades ago. The decision to add fluoride to a water supply is made by local or state governments. According to data reported to the Centers for Disease Control and Prevention, communities in Massachusetts generally add fluoride to arrive at a concentration of 1.0 part per million (ppm) to their drinking water.

“Just because we did studies over the last 70 years, it doesn’t mean that we did everything that is necessary to know for sure that fluoridation is not toxic to some processes in the body or development of the brain. Those studies have actually not been done,” said Grandjean, also head of the Research Unit at the University of Southern Denmark and author of Only One Chance: How Environmental Pollution Impairs Brain Development – and How to Protect the Brains of the Next Generation.

In 2011 HHS announced plans to lower its fluoride-level recommendation from 1.0 to 0.7 parts per million. This lower level would still protect against dental caries and limit the risk of dental fluorosis (white specks and pits on a child’s teeth as a result of too much fluoride).

While many dental professionals in the U.S. have gone on record as opposing any changes in the water fluoridation levels, Howard Pollick, who appeared with Grandjean on Radio Boston and is chair of the Fluoridation Advisory Committee at the California Dental Association Foundation, agreed with Grandjean that the HHS proposal to reduce fluoride levels is a good one, noting that fluoride in toothpaste is also an issue. “Young children, unfortunately, tend to swallow fluoride toothpaste — fluoride toothpaste is 1,000 parts per million of fluoride. And the recommendation is to spit it out. Well young children can’t do that very well, they can’t spit, so we recommend a very small, pea sized or even a smear of fluoride on the child’s toothbrush when they are very young,” Pollick said.

Grandjean hopes that more studies can be done on the potential health effects of water fluoridation. “I’ve worked in this field long enough to know that with time, we have found that lead, mercury, and pesticides were more toxic than we originally thought. I am not willing to sit here and say, okay, let’s expose the next generation’s brains and just hope for the best.”

Listen to the WBUR interview: The Fluoride Debate Rages On In Some Massachusetts Cities

Read the HHS fluoride in drinking water recommendations

Read a March 10, 2015 Newsweek interview with Grandjean: Water Fluoridation Linked to Higher ADHD Rates

Learn more



Impact of fluoride on neurological development in children

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– Marge Dwyer



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