Recent research indicates that exposure to air pollution, particularly during pregnancy and childhood, could have adverse effects on brain development. A new study has revealed that exposure to nitrogen dioxide (NO2) during the first two years of life is linked to decreased attention capacity in children aged 4 to 8, particularly in boys. NO2 is a pollutant primarily emitted from traffic sources.
ISGlobal, a health center supported by the “la Caixa” Foundation, has discovered that children aged 4 to 8 who were exposed to nitrogen dioxide (NO2) during their first two years of life have a lower attention capacity, especially in boys. NO2 is a pollutant that mainly comes from traffic emissions.
The study, which was published in Environment International, reveals that higher exposure to NO2 was linked to poorer attention function in children aged 4 to 6, with the second year of life being particularly susceptible to this pollutant. This association remained significant even at anAt the ages of 6 to 8, boys are more susceptible to the effects of NO2 pollution, with an even greater vulnerability from birth to 2 years old. Researchers analyzed information from 1,703 women and their children in four Spanish regions as part of the INMA Project birth cohorts. By using their home addresses, the researchers estimated the daily exposure to NO2 during pregnancy and the first 6 years of the child’s life. They also evaluated the children’s attentional function at ages 4-6 and 6-8, as well as their working memory at ages 6-8. These assessments were done using validated computerized tests.
According to a previous study by INMA, it was found that exposure to NO2 during pregnancy and childhood led to impaired attentional function in children aged 4-5 years old. The current study expands on this by finding that:
- Increased exposure to NO2 between 1.3 and 1.6 years of age was linked to higher hit reaction time standard error, which is an indicator of speed consistency, in the attentional function test at 4-6 years of age.
- Greater exposure to NO2 between 1.5 and 2.2 years of age was associated with more omission errors.
- Boys aged 6-8 years showed higher hit reaction time standard error when exposed to NO2 levels between 0.3 and 2.2 years, but no similar association was found in girls.
- There were no links found between increased NO2 exposure and working memory in children aged 6 to 8 years.
“These results highlight the potential impact of elevated traffic-related air pollution on the delayed development of attentional capacity and emphasize the need for further research on the long-term effects of air pollution in older age groups,” said Anne-Claire Binter, the study’s last author and postdoctoral researcher.er, an expert at ISGlobal.
As the brain develops
Attentional function is vital for the growth of the brain’s executive functions, which regulate actions, thoughts, and emotions to accomplish a goal. Binter states, “The prefrontal cortex, responsible for executive functions, evolves slowly and continues to mature during pregnancy and childhood.” This makes it susceptible to the effects of air pollution, which has been connected to inflammation, oxidative stress, and impaired energy metabolism in the brain in animal studies.
“In boys, the link between exposure to N02 and cognitive function might have a longer duration due to their slower brain maturation, making them more susceptible,” she explains. To gain a better understanding of this, future research should track individuals over time to examine how age and gender impact the link between air pollution and attention span, particularly among older age brackets.
To sum up, “this study indicates that the early years of childhood, up to age 2, appear to be a critical period for implementing preventive actions,” Binter notes. “Even a minor impact at the individual level from relatively low levels of exposure, as observed in this study, can have significant ramifications at the population level.”The level of nitrogen dioxide exposure can have an impact on the attention and working memory of children between the ages of 4 and 8. This exposure can affect children’s health from the prenatal stage to childhood. The study concluded that traffic-related air pollution is a determining factor in the health of future generations.
Journal Reference:
Kellie L.H.A. Crooijmans, Carmen Iñiguez, Kristina W. Withworth, Marisa Estarlich, Aitana Lertxundi, Ana Fernández-Somoano, Adonina Tardón, Jesús Ibarluzea, Jordi Sunyer, Mònica Guxens, Anne-Claire Binter. Nitrogen dioxide exposure, attentional function, and working memory in children from 4 to 8 years: Periods of susceptibility from pregnancy to childhood. Environment International, 2024; 186: 108604 DOI: <a hrThe link to the article is “http://dx.doi.org/10.1016/j.envint.2024.108604” and it can be accessed by clicking the underlined text.