Traffic noise harms teen brains

Road traffic in Zurich: noise had a bigger effect on the mental performance of young people whose bedroom looked out onto a busy road © Keystone / Gaetan Bally

Teenagers exposed to road traffic noise can suffer memory and concentration deficits, according to a Basel study. However, the effects are considered to be slight.

In research supported by the Swiss National Science Foundation (SNSF), Martin Röösli, professor of environmental epidemiology at the Swiss Tropical and Public Health Institute in Basel, shows that chronic exposure to road traffic noise at home affects young people’s cognitive abilities.

For a year Röösli followed a group of almost 900 adolescents aged ten to 17 exposed to different levels of noise from road traffic in their homes. At the beginning and end of this period he assessed their cognitive abilities through questionnaires and tests.

He found that for every 10dB increase in average traffic noise – corresponding to a doubling of perceived loudness – figural memory, a form of memory that involves images, was reduced by 0.27 points. In addition, ability to maintain concentration was reduced by 0.13 points.

“To get an idea of what [these figures] mean, we can compare the difference in cognitive performance between the start and end of the study with the difference in the cognitive performance of different secondary school levels, for example between level B and level A or between level A and upper secondary level”, Röösli said in a statementExternal link released by the SNSF on Thursday.

The decline in figural memory recorded in the course of the study was equivalent to one third of the difference observed between two school levels, while the reduction in ability to concentrate consistently was roughly the same as the difference observed between two school levels.

Disturbed sleep

“The noise probably affects the cognitive performance of the adolescents because it disturbs their sleep”, Röösli suggested.

He found that noise had a bigger effect on the mental performance of young people whose bedroom looked out onto a busy road. However, he pointed out that the effects highlighted are slight and need to be confirmed.

This work is published in the journal Environmental ResearchExternal link.

A study in 2017, also by Röösli, found that traffic noise from cars, lorries, trains and planes could have negative health consequences, such as increased risk of heart-related illnesses and diabetes.