Relationship between self-perceived noise intensity and sleep quality in noise-exposed workers—A mediating role of negative emotions

Background Studies on the relationships of environmental noise exposure with negative emotions and sleep quality have long been reported. Self-perceived noise intensity is not only related to environmental noise exposure, but also reflects an individual's susceptibility to noise; however, few studies on self-perceived noise intensity, negative emotions, and sleep quality have been reported, and it is not clear whether negative emotions play a mediating role in the relationship between self-perceived noise intensity and sleep quality.

Objective To analyze the mediating role of negative emotions (anxiety, depression, and stress) in the relationship between self-perceived noise intensity and sleep quality in noise-exposed workers, and to provide a scientific basis for addressing psychological problems and sleep quality induced by noise exposure.

Methods Stratified cluster sampling was used to select noise-exposed workers from a large equipment manufacturing plant in Chengdu from May to June 2023, and demographic characteristics were investigated using a self-designed general information questionnaire; self-perceived noise intensity was reported by the study subjects as the noise intensity of their workplaces; sleep quality was synthesized from three indicators: night sleep duration, self-perceived sleep quality, and sleep-related symptoms; the Anxiety-Depression-Stress Scale (DASS-21 scale) was used to evaluate anxiety, depression, and stress of a worker. Structural equation modeling was used to analyze the pathways of negative emotions (anxiety, depression, and stress) between self-perceived noise intensity and sleep quality.

Results The positive rates of negative emotions were 33.1% (anxiety symptoms, 215/649), 26.0% (depression symptoms, 169/649), and 14.0% (stress symptoms, 91/649), respectively in a total of 649 noise-exposed workers. Self-perceived noise intensity was positively correlated with sleep quality score (r=0.218, P<0.001) and negative emotions (anxiety, depression, and stress) (r=0.167, 0.145, 0.167, P<0.001); sleep quality score was positively correlated with negative emotions (anxiety, depression, and stress) (r=0.512, 0.447, 0.513, P<0.001). The results of path analysis showed that the negative emotions (anxiety, depression, and stress) partially mediated between self-perceived noise intensity and sleep quality (β=0.123, P<0.001). Self-perceived noise intensity was positively correlated with negative emotions and sleep quality, and there was a path of self-perceived noise intensity → negative emotion → sleep quality (P<0.001), and the mediating effect accounted for 42.71%.

Conclusion The positive rates of anxiety, depression, and stress are high among the noise-receiving workers in this manufacturing industry, and negative emotions characterized by anxiety, depression, and stress partially mediate the relationship between self-perceived noise intensity and sleep quality.