BACKGROUND: The influence of air pollution on the brain development is unknown. Accumulating evidence suggests that air pollution may have a significant impact on inflammation of the central nervous system and consequently on behaviour and school performance. The BREATHE project evaluates whether traffic-related air pollutants (TRAPs) may impair brain development of school children in the city of Barcelona. BREATHE combines epidemiological, psychometric, genetic, neuroimaging and mathematical approaches.
OBJECTIVES: The aim of the present work is to describe the project.
METHODS: The study was conducted during the period from January 2012 to February 2013. The components in the BREATHE project are: 1) TRAPs were measured in 39 schools during two campaigns of one week periods, including black carbon, ultrafine particles counts, PM1, PM2.5, PM10, NO2 levels and mass and patterns of chemical elements in PM0.2, PM0.2-2.5 and PM2.5-10. Noise was also measured. 2) Computer tests for working memory (n-back test) and attention were conducted four times in 2,745 children aged 7 to 9 years in the 39 schools. ADHD symptomatology and school achievement of children were reported by teachers and parents filled in the Strengths and Difficulties Questionnaire (SDQ). 3) DNA was extracted from oral cells to study gene-environment interactions. 4) Neuroimaging in a subset of the children was conducted to study structural alterations.
RESULTS: 54 % of the invited children accepted to participate. Participating children did not differ in terms of age and sex, but had a higher good school achievement and a lower prevalence of ADHD tan non-participating. The frequency of ADHD was high as well as the average of the SDQ and the frequency of the poor school performance. The overall median of the outcomes (n-back test) among all the children was very similar to the median per school.
CONCLUSIONS: Overall, we present the largest study on the cognitive and structural effects of school air pollution.
