Recent evidence suggests that fluoride (F) and arsenic (As) in drinking water may adversely affect intelligence quotient (IQ) scores.
Similar results were observed for Fluoride in drinking water and Arsenic in drinking water. The data suggests that children exposed to either Fluoride or Arsenic in water have increased risks of reduced IQ scores. Rocha-Amador D.et al.,Decreased intelligence in children and exposure to fluoride and arsenic in drinking water. Cad Saude Publica. 2007;23 Suppl 4:S579-87.