A report from the federal government's National Toxicology Program concludes that fluoride in drinking water at twice the recommendedl limit is linked with lower IQ in children. The report's based on an analysis of previously published research. Fluoride strengthens teeth and reduces cavities, and the additions of low levels to drinking water has long been considered one of the greatest public health achievements of the last century. But this report marks the first time a federal agency has concluded there is a link between higher levels and lower IQ in kids. I'm Ben Thomas.