EXPOSURE to air pollution, particularly during pregnancy and childhood, can detrimentally affect brain development, says a recent study led by the Barcelona Institute for Global Health, Spain. Nitrogen dioxide (NO2) is primarily a result of traffic emissions, and has been associated with poorer attentional function in children between the ages of 4‒6, with a critical vulnerability period from birth to 2 years. This study revealed that NO2 exposure in the first 2 years of life decreases attention capacity in children aged 4–8, particularly in males.
The researchers utilised data from 1,703 females and their children from the Infancia y Medio Ambiente (INMA) project in four Spanish regions, estimating their daily NO2 exposure during pregnancy and the first 6 years of childhood, based on their home addresses. They also evaluated the attentional function and working memory in children aged 4–6 and 6–8, respectively, using validated computerised tests.
This study identified specific periods of susceptibility to NO2 exposure, and found higher NO2 exposure between 1.3–1.6 years, correlated with an indicator of speed consistency in the attentional function test at 4–6 years. Elevated NO2 exposure between 1.5–2.2 years linked with more omission errors. NO2 exposure between 0.3 –2.2 years associated with an indicator of speed consistency at 6–8 years, particularly in males. However, no associations were found with working memory in children aged 6–8.
These findings underscore the potential impact of traffic-related air pollution on delayed attentional capacity development, emphasising the need for further research on air pollution’s long-term effects, especially in older age groups. Attentional function plays a pivotal role in developing the brain’s executive functions, governing actions, thoughts, and emotions towards achieving goals. The prefrontal cortex, responsible for these functions, matures slowly during pregnancy and childhood, making it susceptible to air pollution exposure. In males, this association between exposure to NO2 and attentional function may endure longer due to slower brain maturation, heightening vulnerability.
Future research should track individuals over time, to assess how age and sex influence the air pollution‒attention span relationship, particularly in older age groups.
Reference
Crooijmans KLHA et al. Nitrogen dioxide exposure, attentional function, and working memory in children from 4 to 8 years: periods of susceptibility from pregnancy to childhood. Environ Int. 2024;186:108604.
