BACKGROUND: Health problems derived from the exposure to ultrafine particles is a major gap of knowledge, especially their effects on brain neurodevelopment. School children constitute the main risk group to UPF exposure, due to the importance of the brain development in this period but also because of their higher vulnerability and susceptibility to environmental threats.
OBJECTIVES: The BREATHE project evaluates whether traffic-related air pollutants (TRAPs) may impair brain development of school children in the city of Barcelona. The aim is to asses the ecological association of TRAP levels with the cognitive performance.
Methods: TRAPs were continuously measured in 39 schools, within a classroom, in the school courtyard, and in one urban background air fixed quality monitoring station at Barcelona. Two paired schools based on socioeconomic conditions were evaluated at the same time. Computer tests for working memory and sustained attention were conducted in around 3,000 children aged 7 to 9 years in the 39 schools during four times resulting in around 11,000 child-tests.
RESULTS: Working memory was negatively correlated with elemental carbon levels (EC; both indoor and outdoor) and Cu (outdoor), as well as ultrafine particle number and PM2.5 (though in a weaker way). Working memory was also negatively correlated with response rate but not with socio-economical conditions, noise, hyperactivity, inattention, or school performance. Sustained attention showed weaker negative associations with EC and Cu.
CONCLUSIONS: TRAPs were correlated with cognitive performance at ecological level, which should be further evaluated using semi-individual analysis.
