4 March 2015. Air pollution from trucks harms children’s brain development, a new study from Barcelona, Spain shows. The researchers found that greater degrees of air pollution were associated with slowed development of brain functions in 2,700 primary school students. They were followed for a year with computerized testing every three months. The tests reflected working memory and attention span – functions that are under rapid development at ages 7-10 years. All children improved their scores during the year of testing, but the one exposed to air pollution at the school tended to lag behind. The study was published yesterday in PLoS Medicine, a major scientific journal.
The children from the most highly polluted schools showed an average improvement in working memory of 7.4 %, while children in less polluted schools improved their scores by 11.5 %. Different aspects of the air pollution was repeatedly measured in the school courtyard and inside the classrooms. Elemental carbon (soot), nitrogen dioxide, and ultrafine particle numbers all showed a negative association with the children’s performance. The researchers took other important factors into regard, such as parents’ education, commuting time, smoking in the home and green spaces at school.
While previous studies and animal models have shown negative associations with brain functions, this new study is prospective and therefore more convincing. In addition, the results show that the development at school age may be negatively affected by air pollution. The air pollution in Barcelona mostly originates from trucks, but children worldwide breathe air-borne soot, nitrogen oxides and ultrafine particles – components that have now been linked to chemical brain drain.