Children with autism are at greater risk of being hospitalized if exposed to air pollution, even in the short term. This was concluded by a team of South Korean researchers, whose work was published in the journal BMJ Open.
Autism spectrum disorders (ASD) are chronic disorders of human development characterized by abnormalities in social interactions and communication, verbal or non-verbal. They can affect all children, regardless of their social origin, the level of education of the parents or even their ethnic origin: it is estimated today that one child in 100 is affected.
A level of inflammation made worse by air pollution
While previous studies have shown that ASD is often accompanied by inflammation of the brain and body, Korean researchers found that exposure to air pollution for days to weeks, can increase this level of inflammation, and therefore the risk of having to be hospitalized. And this, in particular in children, whose nervous system is still developing, and therefore more sensitive to air pollution than that of adults.
To reach these conclusions, the scientists collected official Korean Health Insurance data on daily hospitalizations for ASD among children aged 5 to 14 between 2011 and 2015, before comparing them to levels of fine particles (c i.e. less than 2.5 microns in size), nitrogen dioxide and ozone in sixteen regions of South Korea over a six-day period. Between 2011 and 2015, the average number of children admitted to hospital each day was 8.6 (7 for boys, compared to 1.6 for girls).
Autistic symptoms aggravated by a high level of fine particles
In detail, the researchers found that an increase in the levels of fine particles, nitrogen dioxide and ozone were respectively associated with a risk of hospitalization for autism of 17%, 9% and 3% higher. “Short-term exposure to air pollution worsens ASD symptoms, especially in boys”they concluded in a press release.
This is not the first time that researchers have made the link between autism and air pollution. A 2014 study had already shown that children with ASD were more likely to have been exposed to higher levels of toxic particles in the air during pregnancy and the first two years of their life than children with ASD. children without these disorders.