Autism and Environmental Exposures and Risk Factors

EHIB's research has shown  that pregnant women living in areas with more air pollution may be more likely to have babies who develop ASD[1]. Our work also shows that if a woman gains a lot of weight during pregnancy, or is obese before she becomes pregnant, her child might be more likely to develop ASD{2]. We also found that pregnant women who have polychlorinated biphenyls (PCBs)[3] are more likely to have a child with ASD[4]. PCBs are a group of chemicals that were used to make older electronic equipment, plastics, and other products. Our work and other research have shown that older mothers may be more likely to have a child with ASD[5].

EHIB and other scientists have also learned that some environmental factors may protect against ASD. Working with the Centers for Disease Control and Prevention, EHIB researchers found that babies who breastfeed for longer than six months might be less likely to develop ASD[6]. We also found that, in certain sub-groups, pregnant women with high levels of vitamin D may be less likely to have a child that develops ASD[7]. We did not find that very low levels of vitamin D are related to developing ASD[8], but some scientists think they may be.