Is air pollution sapping your child’s concentration? New study links NO2 exposure to attention span
Air pollution is weakening children’s attention span, a new study suggests.
Exposure to nitrogen dioxide (NO2) - a pollutant largely pumped out by road traffic - is linked to poorer attention span in children aged four to eight years old.
This is particularly pronounced in boys, according to the researchers at Barcelona Institute for Global Health (ISGlobal).
Their study, published in the Environment International journal, adds to a growing body of evidence about the negative impact of air pollution during pregnancy and childhood on brain development.
Only seven countries in the world breathe safe air. Three of them are in Europe
‘Problem child’: Transport on track to produce nearly half of Europe’s emissions by 2030
When are children most impacted by air pollution?
Using data from more than 1,700 women and their children in four Spanish regions, the researchers estimated daily exposure to NO2 during pregnancy and the first six years of childhood, taking into account each family’s home address.
Alongside this, they assessed the attentional function (the ability to choose what to pay attention to and what to ignore) at 4-6 years and 6-8 years. As well as working memory (the ability to temporarily hold information) at 6-8 years, using computer tests.
The findings show that children exposed to higher levels of NO2 are more likely to have poorer attentional function at 4-6 years old. They are most susceptible to this pollutant at 2 years old.
The link between air pollution and attention span continued for boys aged 6-8 years old.
Why are boys more impacted by air pollution at this age than girls?
Attentional function is crucial for the development of our brain’s executive functions, which control actions, thoughts and emotions to achieve a goal or purpose.
“The prefrontal cortex, a part of the brain responsible for executive functions, develops slowly and it is still maturing during pregnancy and childhood,” says Anne-Claire Binter, last author of the study and postdoctoral researcher at ISGlobal.
This makes it vulnerable to air pollution exposure, which has been linked in animal studies to inflammation, oxidative stress, and impaired energy metabolism in the brain.
“In boys, the association between exposure to NO2 and attentional function may last longer because their brains mature more slowly, which could make them more vulnerable,” Binter explains.
Interestingly, a previous study by ISGlobal researchers found that it is girls who are most negatively impacted by prenatal exposure to the pollutant.
Preventive measures are needed, say pollution researchers
“This study suggests that early childhood, up to the age of 2, seems to be a relevant period for implementing preventive measures,” says Binter.
“Even a small effect at the individual level from relatively low levels of exposure, as in this study, can have large consequences at the population level. Exposure to traffic-related air pollution is therefore a determinant of the health of future generations.”
It adds to the long list of reasons for decarbonising our transport systems.
More than 1,200 children and teenagers are killed by air pollution in Europe every year, the European Environment Agency (EEA) estimates.
Although this number is low compared to overall deaths from air pollution - which experts put at 311,000 in 2020 - the impact of death or chronic illness in early life is considered greater.
