Studies show that exposure to air pollution leads to autism. Pregnant women exposed to the highest level of the traffic-related pollutant, nitric oxide, were more likely to give birth to children later diagnosed with autism. Studies also showed children exposed to vehicle exhaust and industrial emissions were at a 78% greater risk of developing an autism spectrum disorder.
These findings come from two recent studies, one from Vancouver and another from Shanghai. The Vancouver study analyzed the records of 129,436 children born in Vancouver from 2004 through 2009. They compared autism rates in children with mothers who had been exposed to the least amount of air pollution during pregnancy and the rates in children with mothers exposed to the most pollution.
Autism spectrum disorder (ASD), is a developmental disability characterized by communication and social interaction difficulties with repetitive behavior patterns.
For the Shanghai study researchers compared 124 children with ASD and 1240 healthy children as a control over a nine-year period, examining the association between air pollution and ASD. All three measures of air pollution; particulate matter, nitrogen dioxide and nitric oxide showed a similar association with autism.
The studies show an association between prenatal exposure and early childhood exposure to exhaust and emissions and autism rates. They do not, however, prove that air pollution caused autism.
Previous studies, including a study out of Los Angeles, show living close to a highway is a possible trigger of autism, but a study that looked at Sweden, the Netherlands, Spain and Italy did not prove an association.