UPDATE 12/17/2013: This post has been updated with two more studies, making a total of four pioneering studies on the association between autism and prenatal air pollution exposure.
A child could carry a gene for autism and show no signs of it unless that gene was triggered by exposure to polluted air, according to research led by scientists at the Keck School of Medicine of the University of Southern California.
Our research shows that children with both the risk genotype and exposure to high air pollutant levels were at increased risk of autism spectrum disorder compared to those without the risk genotype and lower air pollution exposure. —Heather E. Volk, PhD, MPH, Assistant Professor of research in preventive medicine and pediatrics at the Keck School of Medicine of USC and principal investigator at The Saban Research Institute of Children’s Hospital Los Angeles, ScienceDaily.com article 12/2/2013
The researchers found air pollution may compromise the healthy functioning of a child’s brain and immune system leading to autism in those who inherited a particular gene.
“This is the first demonstration of a specific interaction between a well-established genetic risk factor and an environmental factor that independently contribute to autism risk. The MET gene variant has been associated with autism in multiple studies, controls expression of MET protein in both the brain and the immune system, and predicts altered brain structure and function,” according to Daniel B. Campbell, PhD, Assistant Professor of psychiatry and the behavioral sciences at the Keck School of Medicine of USC and the study’s senior author. Keck School of Medicine article 12/2/2013
Autism spectrum disorder (ASD) is a lifelong neurodevelopmental disability characterized by problems with social interaction, communication and repetitive behaviors. The US Centers for Disease Control and Prevention estimates that one in 50 children in the United States has an ASD. Forbes 3/20/2013 and Center for Disease Control autism fact sheet 3/20/2013
Previously, health studies have shown significant associations between exposure to fine particulate pollution (PM 2.5) and premature death from heart and lung disease. PM 2.5 pollution can aggravate heart and lung diseases and has been linked to effects including cardiovascular symptoms; cardiac arrhythmias; heart attacks; strokes; blood clots; diabetes; chemical sensitivity; asthma attacks; respiratory infections such as bronchitis and pneumonia; COPD; chronic bronchitis; low birth weight; and reduced IQ.
An earlier study, perhaps the first national study to associate autism with air pollution, was published by the National Institute of Environmental Health Sciences journal Environmental Health Perspectives 8/2013, available here. This NIEHS study was covered by Autism Speaks.
Two related studies:
Becerra T, Wilhelm M, Olsen J, Cockburn M, Ritz B. Ambient Air Pollution and Autism in Los Angeles County, California. Environ Health Perspect 121:380–386 (3/2013). http://ehp.niehs.nih.gov/1205827 [Online 12/18/2012.]
Volk H, Lurmann F, Penfold B, Hertz-Picciotto I, McConnell R. Traffic-Related Air Pollution, Particulate Matter, and Autism. JAMA Psychiatry 2013;70(1):71-77. doi:10.1001/jamapsychiatry.2013.266. http://archpsyc.jamanetwork.com/article.aspx?articleid=1393589 [Online 12/2012.]