A new report linking fluoridated drinking water to lower IQ scores in children is sure to ratchet up the debate over a practice that's considered one of the greatest public health achievements of the 20th century.

A review of 74 medical studies links higher fluoride exposure to lower IQ in kids — but mostly draws on research that took place outside of the U.S. and had a high risk of biased results. Why it matters: The federally funded analysis could further stoke the debate over adding fluoride to drinking water as Robert F.

The U.S. Toxicology Program just published a study reviewing past research on the safety of fluoride for children. Reporting in JAMA Pediatrics, they found a slight decrease in IQ scores as fluoride blood levels increased.