Impact of commuting exposure to traffic-related air pollution on cognitive development in children walking to school

Álvarez Pedrerol, Mar; Rivas, Ioar; López Vicente, Mònica, 1988-; Suades González, Elisabet; Donaire González, David; Cirach, Marta; de Castro, Montserrat; Esnaola, Mikel; Basagaña Flores, Xavier; Dadvand, Payam; Nieuwenhuijsen, Mark J.; Sunyer Deu, Jordi

doi:http://dx.doi.org/10.1016/j.envpol.2017.08.075

Impact of commuting exposure to traffic-related air pollution on cognitive development in children walking to school

Citation

Alvarez-Pedrerol M, Rivas I, López-Vicente M, Suades-González E, Donaire-Gonzalez D, Cirach M et al. Impact of commuting exposure to traffic-related air pollution on cognitive development in children walking to school. Environ Pollut. 2017 Dec;231(Pt 1):837-44. DOI: 10.1016/j.envpol.2017.08.075

Abstract

A few studies have found associations between the exposure to traffic-related air pollution at school and/or home and cognitive development. The impact on cognitive development of the exposure to air pollutants during commuting has not been explored. We aimed to assess the role of the exposure to traffic-related air pollutants during walking commute to school on cognitive development of children. We performed a longitudinal study of children (n = 1,234, aged 7-10 y) from 39 schools in Barcelona (Catalonia, Spain) who commuted by foot to school. Children were tested four times during a 12-month follow-up to characterize their developmental trajectories of working memory (d' of the three-back numbers test) and inattentiveness (hit reaction time standard error of the Attention Network Test). Average particulate matter ≤2.5 μm (PM2.5), Black Carbon (BC) and NO2 concentrations were estimated using Land Use Regression for the shortest walking route to school. Differences in cognitive growth were evaluated by linear mixed effects models with age-by-pollutant interaction terms. Exposure to PM2.5 and BC from the commutes by foot was associated with a reduction in the growth of working memory (an interquartile range increase in PM2.5 and BC concentrations decreased the annual growth of working memory by 5.4 (95% CI [-10.2, -0.6]) and 4.6 (95% CI [-9.0, -0.1]) points, respectively). The findings for NO2 were not conclusive and none of the pollutants were associated with inattentiveness. Efforts should be made to implement pedestrian school pathways through low traffic streets in order to increase security and minimize children's exposure to air pollutants.