In a study published on October 23, 2011 in the medical journal Pediatrics, researchers find that unborn baby girls' exposure to bisphenol A, a chemical used in plastics found in packaged foods, causes the children at toddler age to have higher rates of emotional problems, including hyperactivity, aggression, anxiety and depressed behavior.  

http://www.ens-newswire.com/ens/oct2011/2011-10-24-01.html
http://www.washingtonpost.com/blogs/on-parenting/post/pregnant-womens-exposure-to-bpa-linked-to-behavior-
of-toddler-girls-study-says/2011/10/25/gIQAweqIGM_blog.html