HQ Team
May 2, 2024: Exposure to nitrogen dioxide, which comes mainly from traffic emissions, may affect brain development in children between four and eight years, a study finds.
Researchers at the Barcelona Institute for Global Health found exposure to nitrogen dioxide, or NO2 was associated with lower attention capacity in the children belonging to the group.
They assessed the attentional function at 4-6 years and 6-8 years using various tests and models. “Our findings suggest that NO2 exposure during the first two years of life is associated with poorer attentional function in children from 4 to 8 years of age, especially in boys.
“These findings highlight the importance of exploring the long-term effects of traffic-related air pollution exposure in older age groups,” the authors wrote in Environmental International.
Spanish regions
Attentional capacity refers to the ability to focus mental powers upon an object such as careful observing or listening, decision-making, or the ability to concentrate.
Or, it is the amount of information learners can attend to at any one time. The attentional capacity has 5 components: focused, sustained, selective, alternating attention and divided attention.
Data from 1,703 women and children from the INMA Project birth cohorts in four Spanish regions were gathered by the researchers.
Using the home address, the researchers estimated daily residential exposure to NO2 during pregnancy and the first 6 years of childhood.
Working memory
In parallel, 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.
Further, they focused on working memory — the ability to temporarily hold information — at 6-8 years, using validated computerised tests.
The attentional function is crucial for the development of the brain’s executive functions, which manage and control actions, thoughts and emotions to achieve a goal or purpose.
Executive functions make it possible to mentally play with ideas; take the time to think before acting; meet novel, unanticipated challenges; resist temptations; and stay focused.
Boys vulnerable
Anne-Claire Binter, last author of the study and postdoctoral researcher at ISGlobal said: “The prefrontal cortex, a part of the brain responsible for executive functions, develops slowly and it is still maturing during pregnancy and childhood.
“This makes it vulnerable to exposure to air pollution, 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 N02 and attentional function may last longer because their brains mature more slowly, which could make them more vulnerable”, she said.
Future generations
To understand this better, future studies should follow people over time to see how age and gender affect the relationship between air pollution and attention span.
Binter said the study suggested that early childhood, up to the age of two, seemed to be a relevant period for implementing preventive measures.
“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.”
