A new study has found that high levels of fluoride in the water can affect IQ levels of children before they are even born.

Researchers looked at nearly 500 sets of mothers and children in Mexico where fluoride is not added to public water supplies but naturally occurs.

The study found a drop in scores on intelligence tests the higher the fluoride levels, but this was only for prenatal exposure.

Researchers say fluoride levels did not affect brain development after the children were born.

*Original article online, as well as TV program, at http://wtnh.com/2017/09/21/study-finds-fluoride-in-water-linked-to-iq-levels/