Short-term exposure to traffic-related air pollution and dynamic brain connectivity in adolescents

There is some evidence which suggests short-term effects of traffic-related air pollution on brain function in adults. We aimed to examine these associations at ages 10 and 14 years using dynamic functional brain connectivity. We included participants from a population-based birth cohort with brain connectivity and air pollution data at home (n = 3608) or school (n = 2305) in at least one visit. We used land use regression models to estimate levels of air pollutants, including nitrogen oxides (NO_X) and particulate matter (PM), during the week before the outcome measurement. Using resting-state functional magnetic resonance imaging data, we generated five connectivity patterns. We calculated the mean time spent in each pattern for each participant and visit. We performed linear mixed effects models adjusted for relevant confounders. The median levels of NO_X at the two visits and at home and school were between 36 and 47 μg/m³ and the median levels of PM_2.5 were between 11 and 12 μg/m³. We found a weak association between higher air pollution exposure and less time spent in a low modularized connectivity pattern (e.g. coefficient=-0.031 [95 % confidence interval=-0.056; -0.006] per 20 μg/m³ increase in NO_X at home). However, this association did not remain after multiple testing correction. Further research that explores these associations at other exposure levels and other age periods is warranted.