
Children born to mothers experiencing economic hardship, who were also exposed during pregnancy to high levels of PAH (polycyclic aromatic hydrocarbons), scored significantly lower on IQ tests at age 5 compared with children born to mothers with greater economic security and less exposure to the pollutants.
http://feeds.sciencedaily.com/~r/sciencedaily/~3/7lLXPDxntcc/150429182438.htm