Utah has become the first US state to ban the use of fluoride in its public water, following concerns raised by Health Secretary Robert F Kennedy that the mineral poses potential health risks.
Governor Spencer Cox signed the ban into law this week, which will go into effect on 7 May.
Other states, including Florida and Ohio, are weighing similar legislation.
Fluoride has been added to US drinking water since 1945 to prevent cavities.
Utah’s move to remove the mineral has been criticised by experts, who worry it will have consequences for oral health, especially for children.
The bill, signed by Cox on Thursday, prohibits communities from adding fluoride to their public water supplies.
The law does not mention any public health concerns related to the mineral, but Republican state lawmaker Stephanie Gricius – who introduced the bill in the state legislature – has argued that there is research suggesting fluoride could have possible cognitive effects in children.
Gricius has said that her bill would give citizens a choice whether they want to consume fluoride or not.
This concern over fluoride was previously raised by Kennedy, the US health secretary, who said in November that “the Trump White House will advise all US water systems to remove fluoride from public water”.
He alleged the chemical found in toothpaste and regularly used by dentists “is an industrial waste associated with arthritis, bone fractures, bone cancer, IQ loss, neurodevelopmental disorders, and thyroid disease”.
