According to American researchers, there is believed to be a correlation between the increase in the number of people suffering from autism spectrum disorders (ASDs) and exposure to air pollution.
1| Pollution possibly a cause of ASDs
Autism spectrum disorders are developmental disorders characterized by communication problems and difficulties with social interactions.1 These disorders are believed to be induced by various genetic risk factors but also environmental risk factors.
Indeed, new evidence suggests that the environment plays a role in the development of autism spectrum disorders, but to date, there are still very few data on the pathophysiological mechanisms which could explain this link, and which could be used to develop the appropriate preventive measures.
American researchers have conducted a study in order to determine if there is a relationship between traffic-related air pollution, air quality and ASDs. According to them, pollution is believed to be a risk factor for autism spectrum disorders.2
2| Study conducted in California on 524 children shows a close link between pollution and ASD
The study included a total of 524 children age 24 to 60 months, of which 279 autistic children and 245 control children with normal development. The researchers noted the mother’s place of residence during her pregnancy and also during the first year of life with the child.
To conduct the study, a questionnaire was sent to the families of the children in the study to gather demographic and medical data in order to detect ASDs. A precise analysis of air quality data was also performed in addition to the questionnaire. Exposure to nitrogen dioxide and fine particles during pregnancy and to nitrogen dioxide during the first year of life were also associated with ASD.
Exposure to traffic-related air pollution, to particules and to nitrogen dioxide could therefore have effects on neurological development and increase the risk of ASD.
According to the study results, autistic children were more likely to live in housing with a high level of exposure to air pollution during the pregnancy and the first year of life, than the other children in the study.
According to the researchers, a pregnant woman regularly exposed to a high level of fine particles is believed to be at higher risk of giving birth to an autistic child. According to them, fetuses exposed to high levels of pollution are believed to be three times more likely to develop autism.
Further research is required to confirm this avenue further and help prevent autism spectrum disorders.
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association; 2000