A new scientific study just released examined the extent of IQ loss linked to toxic chemicals over a 15 year period in the U.S.  Flame retardants and pesticides, and to a lesser extent, heavy metals like lead, resulted in more than a million cases of intellectual disability in the United States between 2001 and 2016. As a result of significantly fewer restrictions, flame retardants and pesticides now represent the bulk of that cognitive loss.