Occupational exposure to noise and depression incidence: a nationwide cohort study of workers in Denmark, 2000-2017

Research on the association between occupational noise and incident depression is limited. We investigated whether long-term occupational noise was associated with depression risk, both independently and in combination with other stress-related factors.

In a Danish nationwide register-based cohort of 2 424 542 workers aged 25-64 years, individual-level occupational histories were linked to noise exposure using a job exposure matrix. Noise exposure was aggregated as 5-year running means. During follow-up from 2000 to 2017, 142 370 women and 119 900 men developed incident depression, identified through hospital and prescription registers. HRs were estimated using Cox models with adjustment for individual and area-level factors. Subgroup analyses assessed effect modification by stress-related factors.

A 10 dBA higher 5-year mean occupational noise (≥65 dBA) was associated with HRs (95% CIs) of 1.09 (1.07 to 1.12) for women and 1.13 (1.10 to 1.15) for men aged 25-39 years and 1.09 (1.04 to 1.14) for women aged 40-64 years. Higher risks were mainly observed among workers with low education, low to median income, blue-collar jobs or financial stress. Among men aged 40-64 years, the corresponding HR was 0.98 (0.97 to 1.00), with inverse associations mainly observed among those with high income, white-collar occupations and no financial stress.

Long-term exposure to occupational noise seemed associated with higher depression risk among women as well as men younger than 40 years. Associations were mainly observed among workers of low socioeconomic status, suggesting that noise reduction may be particularly relevant for prevention in vulnerable worker groups.