The constant hum of city life often fades into the background, unnoticed by those who live in it. Yet, behind the sound of passing cars, rumbling trains, and the distant whir of traffic lights, an invisible health risk may be growing.
Scientists are now uncovering how this steady noise pollution can do more than disturb sleep – it can shape mental well-being over time.
Traffic noise and mental health
A new LongITools study, published in the journal Environmental Research, shows a clear link between traffic noise and diagnosed depression or anxiety. It is the first study to investigate long-term exposure in children, adolescents, and young adults.
Researchers from the University of Oulu found a sharp rise in mental health risks when traffic noise exceeds 53 decibels (dB) at home. This crosses the safe limit set by the World Health Organization.
The findings support urban planning measures, like designing bedrooms on quieter building sides and lowering speed limits.
Noise pollution as a health threat
Environmental noise from roads, railways, airports, and construction is Europe’s second-largest environmental health concern. It can damage hearing, disrupt sleep, and trigger emotional stress.
Over time, these effects can contribute to cardiovascular issues and neurological diseases.
Noise also activates the body’s stress response through the hypothalamic-pituitary-adrenal axis. This can impair emotional regulation, cognition, and behavior – especially in children whose systems are still developing.
Noise exposure and mental health
The study was focused on 114,353 people born in Finland between 1987 and 1998 who lived in the Helsinki metropolitan area in 2007. Participants were tracked for up to ten years, from ages 8 to 21.
Noise exposure was calculated for the most and least exposed sides of each home. Annual averages included road and railway traffic noise, with extra weighting for evening and nighttime hours.
The researchers examined participants’ medical records to determine whether they had diagnoses of depression or anxiety.
Clear patterns emerged
The World Health Organization advises keeping traffic noise below 53 dB over 24 hours. This study found that risks increase at or above this level. Each 10 dB rise in noise at the most exposed side was linked to a 5% higher risk of depression and 4% higher risk of anxiety.
“Our analysis showed that anxiety risk is lowest when traffic noise is around 45 to 50 dB at the quieter side of dwellings but increases significantly after 53 to 55 dB,” noted Dr. Anna Pulakka, senior author of the study.
“Above 53 dB, noise becomes a significant psychological stressor for young people regardless of whether an individual sleeps on the quieter or noisier side of a dwelling.”
Anxiety links were stronger for males and for those whose parents had no mental health disorders.
Noise, environment, and health effects
The researchers investigated whether air pollution or access to green space could account for the connection between noise and mental health. They found that noise independently impacted mental health, even after accounting for these other factors.
Nighttime noise was strongly associated with depression, supporting the idea that sleep disturbances from noise may be one way it affects mental health.
For anxiety, the biggest impact was seen in places with 60–65 dB noise levels. These places also tended to have more social and environmental challenges, such as poorer living conditions.
Broader implications of the study
“Our findings support further actions towards reducing traffic noise exposure,” explained Yiyan He, lead author of the study.
“For policymakers and urban planners, this should include measures such as ensuring bedrooms are on the quieter side of the dwelling and ensuring there is green space nearby. For transport, quieter tyres or reduced speed limits should also be considered.”
Roughly 10% of young people in the study were diagnosed with depression or anxiety by the time they turned 30.
Since traffic noise is something cities can change, it becomes a possible focus for prevention efforts. Lowering noise levels in living areas could help protect mental health, especially during the years when the brain and emotions are still developing.
The study is published in the journal Environmental Research.
—–
Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.
Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.
—–