To investigate the impact of occupational noise exposure, personality traits, and their interactions on the risk of depression among working populations, to identify potential high-risk groups for depression, and to provide scientific evidence for the early prevention and personalized intervention of depression among occupational populations.

In this study, individual occupational noise exposure levels were assessed using cumulative noise exposure (CNE) for employees in a transport rail enterprise and automobile manufacturing unit in Guangzhou City in 2024. Depression, personality traits, and other relevant information were collected through questionnaires and occupational health examinations. Associations of occupational noise exposure, personality traits, and depression symptoms were statistically analyzed using logistic regression models and restricted cubic spline analysis. Interactions between occupational noise exposure and personality traits were analyzed using additive models to identify subgroups that may be at different risk or benefit as a result of the interaction.

1 046 employees from two units in Guangzhou City were included in the final study. The median age of the study subjects was 29.0 (8.0) years, with a median CNE exposure level of 90.9 dB-years. A total of 390 individuals were identified as having depressive symptoms. The results of the logistic regression model indicate that CNE (OR=1.013, 95% CI: 1.008 to 1.018) and neuroticism (OR=1.106, 95% CI: 1.087 to 1.126) are risk factors for positive depressive symptoms. Agreeableness (OR=0.906, 95% CI: 0.884 to 0.927), Conscientiousness (OR=0.929, 95% CI: 0.909 to 0.948), openness (OR=0.947, 95% CI: 0.927 to 0.966), and extraversion (OR=0.877, 95% CI: 0.855 to 0.898) were protective factors against positive depressive symptoms. Simultaneously, RCS results indicated that agreeableness and extraversion exhibited linear dose-response relationships with depressive symptoms (P for overall <0.05, P for nonlinear >0.05), while cumulative noise exposure, neuroticism, conscientiousness, and openness demonstrated non-linear dose-response relationships (P for overall <0.05, P for nonlinear <0.05). Moreover, high neuroticism, low agreeableness, and low extraversion each exhibited additive interactions with occupational noise exposure. The relative excess risk due to interaction (RERI) values were 3.332, 2.653, and 4.579; the synergy index (SI) values were 2.315, 1.852, and 2.979；and the attributable proportions of interaction (AP) were 0.485, 0.392, and 0.580, respectively.

Occupational noise exposure and personality traits are influencing factors in the development of depressive symptoms among employees, with occupational noise exposure exhibiting an additive interaction with high neuroticism, low agreeableness, and low extraversion. Consequently, organizations should strengthen noise control measures in the workplace and implement targeted psychological interventions for employees exhibiting specific personality characteristics within this environment.