With President-elect Donald Trump's preference for Health and Human Services secretary sharing disinformation about fluoride, here's how much of Massachusetts uses the mineral in its drinking.

Since 1986, fluoride has been added to the city's water supply system, but on Wednesday night, commissioners voted three to two to stop adding higher levels. The mineral is naturally in water and can help prevent cavities or tooth decay,

The City Commission meeting Tuesday became a raucous debate between residents, commissioners and medical professionals on fluoride's effect on the body.