prenatal exposure associated with autism in young children

THE ESSENTIAL

• Autism affects 700,000 people in France according to Inserm.
• Prenatal exposure to pollutants means that the baby is exposed to pollutants while still in the womb.

In France, autism affects 100,000 young people under the age of 20, according to National Institute of Health and Medical Research (Inserm). Autism is embedded in a larger whole, called Autism Spectrum Disorders (ASD), which typically begin in early childhood and persist into adulthood.

The environmental factors of autism still poorly understood

ASD manifests itself in behavioral difficulties, especially when it comes to communicating or establishing social interactions. According to Inserm, ASDs are linked to very early anomalies – of antenatal origin – of neurodevelopment. Although there is a strong genetic component, the development of autism is multifactorial. Environmental factors during pregnancy are also involved, “but their exact nature is not currently known.”

A study published in the journal Environment International provides part of the answer. According to the researchers, prenatal exposure to traffic-related air pollution, whether car exhaust but also other traffic-related pollutants, is associated with the development of ASD in young children.

To reach their conclusion, the scientists studied data from 318,750 children born in Southern California, United States, between 2001 and 2014. They followed them for five years. Their goal was to understand whether the link between TSA and road traffic came from car exhaust or other forms of road traffic-related pollutants (metals, tire wear, brakes, etc.).

Autism: Car Exhaust and Other ASD-Related Pollutants

Thus, the researchers analyzed the impact of PM2.5 fine particles, with a diameter of less than 2.5 micrometers (µm), mainly present in car exhaust gases. Independently, they also have other pollutants. Finally, they studied the combination of PM2.5 fine particles and other combined pollutants.

Results: the researchers believe that pollutants other than fine particles PM2.5, that is to say those which are not present in the exhaust gases of cars, are also linked to the development of ASD.

According to them, reducing only the level of exhaust gas – and therefore of fine PM2.5 particles – will not be a sufficient measure to eliminate the link between prenatal exposure to road traffic and the development of TSA.