Residential exposure to traffic noise was linked to an increased risk for tinnitus, a finding that researchers said adds to the evidence of traffic noise as a growing health burden.
According to Manuella Lech Cantuaria, PhD, an assistant professor at the Mærsk McKinney Møller Institute in the University of Southern Denmark, and colleagues, residential exposure to transportation noise has previously been linked to several health outcomes via stress reactions, including heart disease, diabetes and stroke. Auditory outcomes like tinnitus, however, “are virtually unexplored,” they wrote in Environmental Health Perspectives.
Data derived from: Cantuaria ML, et al. Environ Health Perspect. 2023;doi.org/10.1289/EHP11248.
The researchers conducted a national cohort study that included every resident in Denmark aged at least 30 years. Among them, 40,692 were diagnosed with tinnitus.
The researchers calculated 1-, 5-, and 10-year time-weighted mean noise exposure of Danish addresses from 1990 to 2017 using a model of traffic and noise at the most and least exposed facades — Ldenmax and Ldenmin, respectively. They additionally recovered detailed information on area- and individual-level socioeconomic covariates.
Cantuaria and colleagues found positive associations between risk for tinnitus and exposure to road traffic noise. Per 10-decibel increase in 10 years, the HRs were 1.02 (95% CI, 1.01-1.03) in Ldenmax and 1.06 (95% CI, 1.04-1.08) in Ldenmin.
“For every 10 decibels more noise in people’s home, the risk of developing tinnitus increases by 6%,” Cantuaria said in a press release.
According to the researchers, the risk was higher for:
women;
people with high education and income;
people who never had a blue-collar job; and
people without hearing loss.
Notably, though, railway noise was not linked to higher risk for tinnitus.
“Railway noise is usually perceived as less annoying than road traffic noise, which could explain why this noise source is not sufficient to aggravate tinnitus symptoms,” the researchers wrote. “The Danish railway system consists mostly of passenger trains, which usually do not operate during the night, thus not causing sleep disturbances to the same extent as road traffic sources.”
The researchers wrote that the underlying mechanisms behind their findings may include “noise-induced stress reactions and disturbance of sleep, which would increase people’s awareness of tinnitus, likely exacerbating the condition.”
“It affects our sleep, which is so important for restoring both our physical and mental health,” Cantuaria said in the release. “Therefore, it is worth considering whether you can do something to improve your sleep if you live next to a busy road.”
Summary: People exposed to noise pollution as a result of heavy traffic close to their homes are at greater risk of developing tinnitus, a new study reports.
Source: University of Southern Denmark
If you live near a busy road, it may increase your stress levels and affect your sleep. When we are under stress and sleep poorly, we may be at a higher risk of developing tinnitus.
In a new study with data from 3.5 million Danes, researchers from the Department of Clinical Research and the Mærsk Mc-Kinney Møller Institute at the University of Southern Denmark (SDU) have found that the more traffic noise Danish residents are exposed to in their homes, the more they are at risk of developing tinnitus.
Tinnitus is most clearly manifested by annoying whistling tones in the ears, which are disturbing for many.
Risk increases with noise levels
It is the first time that researchers have found a link between residential traffic noise exposure and hearing-related outcomes.
-In our data, we have found more than 40,000 cases of tinnitus and can see that for every ten decibels more noise in people’s home, the risk of developing tinnitus increases by six percent, says Manuella Lech Cantuaria, PhD., Assistant Professor at the Mærsk Mc-Kinney-Møller Institute and affiliated to the the Department of Clinical Research at SDU.
She and her colleague Jesper Hvass Schmidt, Associate Professor at the Department of Clinical Research and Chief Physician at Odense University Hospital (OUH) are concerned about the many health problems that traffic noise seems to cause. In 2021, they found a correlation between traffic noise and dementia.
-There is a need for more focus on the importance of traffic noise for health. It is alarming that noise seems to increase the risk of tinnitus, cardiovascular diseases and dementia, among other diseases, says Jesper Hvass Schmidt.
Tip of the iceberg
It is at hearing clinics, such as the one at OUH, where Jesper Hvass Schmidt works, that patients can get the diagnosis of tinnitus. But only the worst cases are referred from their own doctor or an otorhinolaryngologist . The high number of reported cases of tinnitus are probably only the tip of the iceberg, he believes.
-In general, about ten percent of the population experience tinnitus from time to time. It is associated with stress and poor sleep, which can be worsened by traffic noise, and here we have a potential cycle.
More studies are needed so that researchers can be sure that traffic noise causes tinnitus, and how this happens.
-But we know that traffic noise can make us stressed and affect our sleep. And that tinnitus can get worse when we live under stressful situations and we do not sleep well, Jesper Hvass Schmidt says.
Noise at night is worse
The researchers believe that noise at nighttime can be even worse for health
– It affects our sleep, which is so important for restoring both our physical and mental health. Therefore, it is worth considering whether you can do something to improve your sleep if you live next to a busy road, Manuella Lech Cantuaria says.
What to do
In the study, higher associations were found when noise was measured at the quiet side of their houses, that is, the side facing away from the road. This is where most people would place their bedroom whenever possible, therefore researchers believe this is a better indicator of noise during sleep.
-There are different things one can do to reduce noise in their homes, for example by sleeping in a room that does not face the road or by installing soundproof windows.
But not everyone has those options.
-It is therefore necessary that traffic noise is considered a health risk that must be taken into account in urban planning and political decisions, says Manuella Lech Cantuaria.
Facts about traffic noise:
The Danish guidance level for harmful traffic noise is 58 decibels. It is estimated that 1.4 million Danes are exposed to noise over 58 decibels in their homes. You can see the noise level for your place of residence here: dingeo.dk
It is a myth that replacing fuel cars by electric cars can significantly reduce traffic noise exposure at people’s houses. The noise comes mainly from the contact between the tires and the road.
It is the first time that researchers have found a link between residential traffic noise exposure and hearing-related outcomes. Image is in the public domain
In Germany, speed limits have been lowered in some places at night, in order to minimize the disturbance of sleep for residents near roads.
Another way to reduce traffic noise is by placing noise barriers along the road or changing the road surface to one that dampens the tire noise.
Facts on tinnitus: Tinnitus is a subjective experience of sound that does not come from an external source. It can be described as a ringing, buzzing, humming or other form of sound in the ears or in the head. Tinnitus can be a symptom of an underlying disease or injury, but can also be idiopathic, which means the cause is not known. Very often tinnitus occurs in connection with hearing loss. Tinnitus can have a negative impact on quality of life as it can cause sleep problems, difficulty concentrating, and depression. There are several possibilities to reduce tinnitus symptoms, including psychological treatment and hearing aids.
Abstract
Transportation Noise and Risk of Tinnitus: A Nationwide Cohort Study from Denmark
Background:
There is a growing body of evidence linking residential exposure to transportation noise with several nonauditory health outcomes. However, auditory outcomes, such as tinnitus, are virtually unexplored.
Objectives:
We aimed to investigate the association between residential transportation noise and risk of incident tinnitus.
Methods:
We conducted a nationwide cohort study including all residents in Denmark age ≥30y≥30y, of whom 40,692 were diagnosed with tinnitus. We modeled road traffic and railway noise at the most (LdenmaxLdenmax) and least (LdenminLdenmin) exposed façades of all Danish addresses from 1990 until 2017. For all participants, we calculated 1-, 5-, and 10-y time-weighted mean noise exposure and retrieved detailed information on individual- and area-level socioeconomic covariates. We conducted analyses using Cox proportional hazards models.
Results:
We found positive associations between exposure to road traffic noise and risk of tinnitus, with hazard ratios of 1.06 [95% confidence interval (CI): 1.04, 1.08] and 1.02 (95% CI: 1.01, 1.03) per 10-dB increase in 10-y LdenminLdenmin and LdenmaxLdenmax, respectively. Highest risk estimates were found for women, people without a hearing loss, people with high education and income, and people who had never been in a blue-collar job. The association with road LdenminLdenmin followed a positive, monotonic exposure–response relationship. We found no association between railway noise and tinnitus.
Discussion:
To our knowledge, this is the first study to show that residential exposure to road traffic noise may increase risk of tinnitus, suggesting noise may negatively affect the auditory system. If confirmed, this finding adds to the growing evidence of road traffic noise as a harmful pollutant with a substantial health burden.
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