Objective To investigate the insomnia status among male workers in a petrochemical enterprise, identify influencing factors for insomnia, and promote the physical and mental health of workers in the petrochemical industry.

Methods A total of 866 male workers who participated in occupational health examinations from 2018 to 2021 in a petrochemical enterprise in Sichuan Province were surveyed with the questionnaires, including a basic information questionnaire, the Weinstein Noise Sensitivity Scale (WNS), the stress subscale of the Depression Anxiety Stress Scales-21 Items (DASS-21), and the Athens Insomnia Scale (AIS-8). Bayesian multilevel regression model and multiple mediation model were established to analyze the relevant influencing factors and mediation pathways of insomnia among these workers.

Results The insomnia rate in this petrochemical enterprise ranged from 39.33% to 49.04% during 2018 and 2021, showing an overall downward trend. The Bayesian linear regression model indicated that stronger noise sensitivity, higher monthly income and educational level, regular exercise, extra tasks, and more complex exposure situations were associated with lower insomnia scores. Higher levels of occupational stress, frontline positions, more night shifts, fewer naps, poor living conditions, working at the self-perceived loud noise workplace, longer daily noise exposure time, and alcohol consumption habits were associated with higher insomnia scores. The posterior probability distributions of each variable showed that daily noise exposure time (99.8%), self-reported workplace noise exposure (98.0%), and occupational stress (100%) were important predictors of increased insomnia scores. Noise sensitivity (100%), educational level (98.0%), regular physical activity (99.2%), and occupational exposure situation (94.3%) were generally strongly associated with lower insomnia scores. The multiple mediation model revealed that work at the self-perceived noisy workplace and occupational stress had multiple mediating effects between job position and insomnia, with the mediating effect accounting for 65.45% of the total effect. The three indirect paths were job position → self-perceived workplace noise → insomnia; job position → occupational stress → insomnia; and job position → self-perceived workplace noise → occupational stress → insomnia.

Conclusions The insomnia rate among workers in this petrochemical enterprise was relatively high. Attention should be paid to the important mediating role of occupational stress between job position and insomnia. It is necessary to strengthen noise control management, alleviate work pressure, improve working and dormitory conditions, promote healthy lifestyles, and protect the physical and mental health of workers.