Three separate studies have researched the effects of pesticides on IQ levels.
The results show that infants who live on or near farms that use pesticides on crops or in homes where pesticide-laden household products are used have lower IQs than children who don't.
What's To Blame?
In one study through the University of California, Berkeley, scientists tested the urine of pregnant women who lived on or near farms for traces of the pesticide organophosphates' byproduct, metabolites. When the children were born, the researchers screened them through grade school.
What they found is that mothers with higher levels of pesticide metabolites in their urine had children with lower IQs at age 7.
Another study at Colombia University tested for the pesticide chlorpyrifos, a common pesticide that's used to kill bugs and pests. Scientists measured umbilical blood and found that at age seven, the children had a much lower IQ than those without pesticide traces.
Chlorpyrifos is now banned for household use, but it's still sprayed along roadways and on food crops. According to Virginia Rauh, professor of population and family health at Columbia, many people have some level of it in their blood.
In Our Blood In More Ways Than One?
Mount Sinai School of Medicine in New York City conducted a third study that concluded one in three people is more genetically susceptible to the risks associated with pesticide exposure than others.
Unfortunately, the study could not determine how to tell which folks are more prone to the risks and which aren't
- Mothers' Pesticide Exposure Linked To Kids' IQs (NPR)
- Prenatal Pesticide Exposure linked to diminished IQ (Envionmental Working Group)