Utah could soon become the first U.S. state to ban the addition of fluoride to drinking water.

On Friday, the Utah State Senate approved a bill that prohibits adding the mineral to public water systems. If signed by Governor Spencer Cox, the measure would go into effect on May 7. The governor has not publicly commented on whether he supports the bill.

The passage of the Utah bill comes roughly two weeks after the confirmation of Robert F. Kennedy, Jr., as health secretary. In November, Mr. Kennedy vowed that the Trump administration would “advise all U.S. systems to remove fluoride from public water.”

In 2022, about 44 percent of Utah residents supplied with public drinking water were drinking fluoridated water. Fluoride is added to drinking water because it prevents cavities, a benefit first observed over a century ago. The Centers for Disease Control and Prevention has heralded water fluoridation as one of the 10 greatest public health achievements of the 20th century.

“The evidence that addition of fluoride to the water reduces cavities and tooth decay is unequivocal,” said Dr. F. Perry Wilson, a physician and chronic disease epidemiologist at the Yale School of Medicine.

Opponents of water fluoridation, including Mr. Kennedy and Utah State Representative Stephanie Gricius, who introduced the bill, argue that the chemical could have harmful neurological effects on fetuses and young children. In a recent review paper, researchers with the National Institutes of Health analyzed the results of 74 studies and concluded that high levels of prenatal or childhood fluoride exposure were linked with lower IQ scores in childhood.

However, the fluoride levels associated with lower IQ scores were twice as high as the water fluoridation levels recommended by the C.D.C. Typically, high levels of fluoride exposure are associated not with community water fluoridation, Dr. Wilson said, but with natural fluoride contamination from water running over rocks and soil.