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.

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 L_denmax and 1.06 (95% CI, 1.04-1.08) in L_denmin.

“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.”