Residential Exposure to Road Traffic Noise May Lead to Tinnitus in Women

Residential exposure to transportation noise, specifically road traffic noise, increases the risk of developing tinnitus, especially in women, according to study findings published in the journal Environmental Health Perspectives.

Emerging knowledge suggests a link between residential exposure to transportation noise and nonauditory health outcomes such as diabetes, stroke, and cardiovascular disease. However, the impact of residential exposure to transportation noise on auditory health outcomes, like tinnitus, has not been explored in depth. To determine whether residential exposure to transportation noise increases the risk for tinnitus, Danish researchers conducted a nationwide cohort study across Denmark between January 2000 and December 31, 2017.

Researchers obtained data on 40,692 individuals aged 30 years and older who were born after 1920. This data included each individual’s address history from the Building and Housing Register as well as the incident diagnosis of tinnitus using unique national personal identification numbers to link to health information on the Danish National Patient Register. They also collected information on each individual’s occupation to adjust for occupational factors during analysis.

Researchers modeled traffic and railway transportation noise at the center of all residential building façades, accounting for location and height corresponding to specific floors. They used an A-weighted scale to calculate both minimum and maximum sound pressure levels in decibels at frequencies perceived by the human ear.

Additionally, for railway noise, they incorporated variables such as train length, speed, and type. For traffic noise, they input annual daily traffic, vehicle distribution, road type, and travel speed. They also considered ground absorption and noise reflections by neighborhood noise barriers, berms, and other buildings blocking the pathway to the sound.

After analyzing all of these variables, the researchers found a positive correlation between road traffic noise and increased tinnitus risk for every 10-decibel increase in minimum (hazard ratio [HR], 1.06; 95% CI, 1.04-1.08) and maximum noise exposures (HR, 1.02; 95% CI, 1.01-1.03).

They observed that highest risk for noise exposures increasing risk for tinnitus occurred in:

• women;
• people without hearing loss;
• people with higher socioeconomic and educational status; and
• people who never held a blue-collar job.

Interestingly, railway noise was not associated with a 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 noted. They added, “Besides, 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.”

Study limitations included potential underrepresentation of tinnitus cases since patients with milder cases may not seek medical care, and lack of generalizability of results outside of the Danish population. Moreover, the restriction of noise exposure assessment only to the person’s place of residence without consideration of occupational exposures, exposures during commuting, or preventative measures taken to protect the home, including superior window quality and bedroom location was also a limitation.

Researchers noted their study found consistent associations between road traffic noise and tinnitus, especially when they measured noise at the least exposed façade. “This study adds to the evidence of road traffic noise as a harmful pollutant with a growing health burden,” they concluded.

Disclosures: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see original source for full list of disclosures.