The chemicals that were studied are called organophosphates or OPs. They're found in everything from the pesticides sprayed on crops to the bug killers we use in our homes.
Three different studies in the journal Environmental Health Perspectives found a correlation between prenatal OP exposure and lower IQ in children. Pesticide levels in pregnant moms were measured.
One study found that women with the higher levels went on to have children who had an IQ average seven points lower than other children.
The research is considered significant because it followed mothers and their offspring over time.