Road traffic noise exposure linked to Parkinson’s disease

Long-term exposure to road traffic noise appears to contribute to an increased risk of Parkinson’s disease (PD), and this risk is mitigated by having a quiet facade, according to a Danish nationwide prospective cohort study.

Researchers looked at Danish residents aged 40 years and older and estimated the 10-year time-weighted residential exposure to road traffic noise at the most and least exposed facades based on residential address.

The analysis included 3,103,577 participants (mean baseline age 50.9 years, 51.2 percent female), of whom 20,587 developed PD during the 17-year follow-up.

Each 11.5-dB increase in road traffic noise at the most exposed facade (LDEN-Max) was associated with a 3-percent increase in the risk of PD (hazard ratio [HR], 1.03, 95 percent confidence interval [CI], 1.00–1.05) in Cox proportional models adjusted for individual- and area-level sociodemographics, air pollution (fine particulate matter and ultrafine particles), and green space.

A difference of ≥10 dB between noise at the most and least exposed facades was associated with a decline in PD risk across different levels of LDEN-Max above 50 dB.

Every 8.9-dB increase in road traffic noise at the least exposed facade was also associated with increased PD risk (HR, 1.04, 95 percent CI, 1.02–1.07) per interquartile increment of 8.9 dB.

The observed associations were consistent across subgroups defined by sex, education, income, cohabiting status, and population density, as well as persisted despite additional adjustment for smoking and physical activity.

The findings support strategies ensuring a quiet residential area to mitigate the risk of PD.