While recent studies have shown some of the physical health effects of kids’ exposure to traffic pollution, a new study conducted by researchers from the Barcelona Institute for Global Health looked at the cognitive impacts of that kind of exposure. They learned that when kids are exposed to a lot of traffic noise at school they may be at a higher risk for slower cognitive development.
“Our study supports the hypothesis that childhood is a vulnerable period during which external stimuli such as noise can affect the rapid process of cognitive development that takes place before adolescence,” said researcher Jordi Sunyer.
Cognitive impact of traffic noise
For the study, the researchers analyzed data from nearly 3,000 kids between the ages of seven and 10. The children went to 38 different schools in Barcelona, and the team collected data on their exposure to traffic noise from 2012 through 2013. The researchers also administered cognitive tests four times throughout the course of the study to understand how traffic may affect cognitive development.
It was clear to the researchers that exposure to more noise at school affected kids’ development – specifically their attention and memory abilities. Complex working memory was the most affected by traffic noise, as exposure to an extra 5 decibels was linked with a nearly 24% slower than average development of that skill. Similarly, working memory developed more than 11% slower, and attention capacity developed nearly 5% slower when exposed to an additional 5 decibels of noise.
The researchers also learned that traffic noise negatively affected students’ performance on tests. The more noise the kids were exposed to in school, the poorer they scored on tests in every subject.
“This finding suggests that noise peaks inside the classroom may be more disruptive to neurodevelopment than average decibel level,” said researcher Maria Foraster. “This is important because it supports the hypothesis that noise characteristics may be more influential than average noise levels, despite the fact that current policies are based solely on average decibels.”
After estimating the kids’ exposure to traffic noise at home, the researchers found that there was no link between their exposure and cognitive development. Now, the team plans to do more work to better understand if this association between traffic noise and cognitive development holds up in cities around the world.