Fluoridated water is lauded as one of the greatest public health achievements of the 20th century. Yet, more Americans are questioning it.

Fluoride exposure appears to slightly decrease IQ scores in children, a new federal meta-analysis has concluded -- but not at the low levels recommended for U.S. drinking water.

A new report that analyzes research on fluoride and IQ scores finds that the more fluoride a child is exposed to, the lower he or she tends to score on intelligence tests. The findings' relevance to the U.

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.

Heavy fluoride exposure appears to slightly decrease IQ scores in children However, the exposure was at levels higher than those allowed in the U.S. Critics noted none of the studies took place in the U.

A new study commissioned by the National Institute of Environmental Health Sciences looked at the effect that high fluoride consumption can have on childre