Fluoride in Water Tied to Kids' Cognition, Study Finds

Pregnant mothers who lived in neighborhoods where public drinking water fluoride levels were near or above the current U.S. recommended levels tended to have children who scored lower on tests of fluid reasoning as fluoride levels increased, according to a new study supported by the National Institutes of Health's Environmental influences on Child Health Outcomes (ECHO) Program.

Fluoride occurs naturally in some water sources and is commonly added to public water systems to help prevent cavities. The paper's authors note that a recent National Toxicology Program review examined evidence linking fluoride exposure levels above 1,500 micrograms per liter in drinking water with lower IQ scores in children. However, most U.S. public water systems have lower fluoride levels, and questions remain about associations at lower levels typically found in the United States.