From the Harvard University Web Site: http://www.hsph.harvard.edu/news/features/fluoride-childrens-health-grandjean-choi/
Excerpt: In a meta-analysis, researchers from Harvard School of Public Health (HSPH) and China Medical University in Shenyang for the first time combined 27 studies and found strong indications that fluoride may adversely affect cognitive development in children. Based on the findings, the authors say that this risk should not be ignored, and that more research on fluoride’s impact on the developing brain is warranted.