A new European study finds that students attending schools in areas of high traffic-related air pollution appear to have slower cognitive development.
Researchers from the Centre for Research in Environmental Epidemiology (CREAL), Spain, studied seven to 10 year old children in Barcelona. Study results have been published in the journal PLOS Medicine.
The investigators measured three cognitive outcomes (working memory, superior working memory, and attentiveness) every three months over a 12-month period in 2715 primary school children attending 39 schools.
Researchers then compared the development of these cognitive outcomes in the children attending schools where exposure to air pollution was high to those children attending a school with a similar socio-economic index where exposure to pollution was low.
This review discovered that the increase in cognitive development over time among children attending highly polluted schools was less than among children attending paired lowly polluted schools, even after adjusting for additional factors that affect cognitive development.
For example, there was an 11.5 percent 12-month increase in working memory at the lowly polluted schools but only a 7.4 percent 12-month increase in working memory at the highly polluted schools.
These results were confirmed using direct measurements of traffic related pollutants at schools.
The findings suggest that the developing brain may be vulnerable to traffic-related air pollution well into middle childhood.
This conclusion has implications for the design of air pollution regulations and for the location of new schools.
However, while the authors controlled for socioeconomic factors, the accuracy of these findings may be limited by other unknown factors that affected their cognitive development. Thus, the need for additional research to confirm the findings.