Association between Traffic-Related Air Pollution in Schools and Cognitive Development in Primary School Children: A Prospective Cohort Study (24 age pdf, Jordi Sunyer, Mikel Esnaola, Mar Alvarez-Pedrerol, Joan Forns, Ioar Rivas, Mònica López-Vicente, Elisabet Suades-González, Maria Foraster, Raquel Garcia-Esteban, Xavier Basaga, Mar Viana, Marta Cirach, Teresa Moreno, Andrés Alastuey, Núria Sebastian-Galles, Mark Nieuwenhuijsen, Xavier Querol, PLoS Med, Mar. 3, 2015)
Also discussed here: Monitoring Roadside Air Pollution and Urban Health Impacts (Pollution Free Cities, Feb. 15, 2013)
Today we review research into the impact on brain development of children at schools exposed to high and low pollution levels produced by traffic emissions in Barcelona, Spain. Results indicate that students in low pollution areas have almost twice the increase in working memory (11.5%) per year compared to children in high pollution areas (7.4%). This is a warning to urban planners concerning the locations of schools: locate them at least 500 m from heavy traffic or take responsibility for the health impacts to the young children who attend these schools. Unfortunately many cities have schools located on major roads with traffic (in Ottawa, for example, more than 50% of day-cares (and 20% of schools) are located within 50 m of heavy traffic).
“Air pollution is a suspected developmental neurotoxicant. Many schools are located in close proximity to busy roads, and traffic air pollution peaks when children are at school. We aimed to assess whether exposure of children in primary school to traffic-related air pollutants is associated with impaired cognitive development.”
“Human brain development is a complex and lengthy process. During pregnancy, the basic structures of the brain are formed, and the neural circuits that will eventually control movement, speech, memory, and other cognitive (thinking) functions, as well as the function of many organs, begin to be established…Much of the development of the cerebral cortex happens during the first two years of life. For example, babies usually learn to crawl at about nine months. Other aspects of brain function take longer to develop. Thus, the cognitive functions that are essential for learning undergo considerable development between the ages of 6 and 10 years, and further brain changes occur during adolescence.
“there was an 11.5% 12-month increase in working memory at the lowly polluted schools but only a 7.4% 12-month increase in working memory at the highly polluted schools. Other analyses indicated that children attending schools with higher levels of traffic-related air pollutants in either the courtyard or in the classroom experienced a substantially smaller increase over the 12-month study in all three cognitive measurements than those attending schools with lower levels of pollutants.”
“ the developing brain may be vulnerable to traffic-related air pollution well into middle childhood, a conclusion that has implications for the design of air pollution regulations and for the location of new schools.