The health activist created a public website for people to write in their favored candidates for over 4,000 positions in the incoming Trump administration.

Now it’s being called out by Robert F. Kennedy, Jr. —possibly on track to become head of health initiatives for the incoming presidential administration—as a practice that should be halted. He recently asserted that Donald Trump would push to remove fluoride from drinking water on his first day in office.

The CDC calls the practice of adding fluoride to tap water systems one of the 10 greatest public health achievements of the last century.

Fluoride prevents cavities in a quarter of adults and children but excess and prolonged exposure can lead to health risks