Background Long working hours are a risk factor for occupational health, particularly in labor-intensive sectors such as manufacturing. Prolonged working hours may have adverse effects on the sleep and mental health of employees. Objective To investigate the impact of long working hours on insomnia, anxiety, and depression symptoms among manufacturing industry employees and provide scientific evidence for relevant occupational health interventions. Methods A cross-sectional study was conducted involving 1524 employees from eight manufacturing enterprises in Shenzhen. Data were collected using a structured questionnaire, which included demographic characteristics, work conditions (e.g., years of employment, job type, shift work, night shifts, weekly working hours), personal behaviors (e.g., smoking and drinking habits), and the occurrence of insomnia (by the Athens Insomnia Scale), anxiety (by the Generalized Anxiety Disorder Scale), and depression (by the Patient Health Questionnaire). Participants were classified into two groups based on working hours: long working hours (≥55 h per week) and normal working hours (35-40 h per week). Binary logistic regression was used to analyze the association between long working hours and the occurrences of insomnia, anxiety, and depression symptoms. Results A total of 1491 manufacturing industry employees were included in the study (response rate: 97.8%). The sample consisted of 54.19% males and 45.81% females, with the largest proportion was those aged 40-49 years (45.48%). The proportion of workers with long working hours in the total population was 31.52%, with the highest proportion among production and technical employees (36.49%). The prevalence of insomnia, anxiety, and depression symptoms was 56.2%, 26.6%, and 23.8%, respectively in the long working hours group, significantly higher than those in the normal working hours group (P<0.05). After adjusting for potential confounders, the logistic regression analysis showed that long working hours were significantly associated with increased risks of insomnia (OR=2.16, 95%CI: 1.60, 2.91), anxiety (OR=1.94, 95%CI: 1.34, 2.81), and depression symptoms (OR=1.62, 95%CI: 1.11, 2.38) compared to normal working hours. Conclusion Long working hours significantly increase the risks of insomnia, anxiety, and depression symptoms among manufacturing industry employees. It is recommended that measures should be implemented to limit working hours, increase rest periods, and provide occupational health education and psychological support to improve the sleep and mental health of employees.

Objective To assess the impact of long working hours on sleep disorders among manufacturing workers and explore the roles of alcohol consumption and mental health factors(anxiety and depressive symptoms)in this association.Methods A cross-sectional study design was used to survey 1 336 manufacturing workers in Shenzhen.We collected the data of their demographic characteristics,work-related factors,personal behaviors,sleep disorders,and mental health status.Multivariate Logistic regression analysis was used to assess the association between long working hours and sleep disorders.Stratified analysis and mediation effect models were applied to examine the effect modification by alcohol consumption and the mediating role of mental health factors,respectively.Results Among the study samples,31.8％reported long working hours and 45.6％had sleep disorders.Multivariate Logistic regression analysis showed that long working hours significantly increased the risk of sleep disorders(adjusted OR=2.073,95％ CI:1.478-2.907,P＜0.001).Stratified analysis revealed that the association between long working hours and sleep disorders was more pronounced among alcohol consumers(adjusted OR=2.556,95％ CI:1.432-4.562,P=0.001).Mediation effect analysis showed that anxiety and depressive symptoms partially mediated the relationship between long working hours and sleep disorders,with indirect effects accounting for 25.71％ and 27.14％,respectively.Conclusion Long working hours increase the risk of sleep disorders among manufacturing workers,particularly among those who consume alcohol.Anxiety and depressive symptoms partially explain the association between long working hours and sleep disorders.

Objective To assess the impact of long working hours on sleep disorders among manufacturing workers and explore the roles of alcohol consumption and mental health factors(anxiety and depressive symptoms)in this association.Methods A cross-sectional study design was used to survey 1 336 manufacturing workers in Shenzhen.We collected the data of their demographic characteristics,work-related factors,personal behaviors,sleep disorders,and mental health status.Multivariate Logistic regression analysis was used to assess the association between long working hours and sleep disorders.Stratified analysis and mediation effect models were applied to examine the effect modification by alcohol consumption and the mediating role of mental health factors,respectively.Results Among the study samples,31.8％reported long working hours and 45.6％had sleep disorders.Multivariate Logistic regression analysis showed that long working hours significantly increased the risk of sleep disorders(adjusted OR=2.073,95％ CI:1.478-2.907,P＜0.001).Stratified analysis revealed that the association between long working hours and sleep disorders was more pronounced among alcohol consumers(adjusted OR=2.556,95％ CI:1.432-4.562,P=0.001).Mediation effect analysis showed that anxiety and depressive symptoms partially mediated the relationship between long working hours and sleep disorders,with indirect effects accounting for 25.71％ and 27.14％,respectively.Conclusion Long working hours increase the risk of sleep disorders among manufacturing workers,particularly among those who consume alcohol.Anxiety and depressive symptoms partially explain the association between long working hours and sleep disorders.

{L-End}Objective To analyze the spectrum characteristics of noise hazards in the metal products industry. {L-End}Methods A total of six metal product industries were selected as research subjects using stratified sampling method. The noise intensity (A/C-weighted) and noise spectrum (Z-weighted) of workplaces and job positions were detected. The characteristics of the noise spectrum of each job position were analyzed using the difference between equivalent continuous C-weighted sound pressure level (L_Ceq)-equivalent continuous A-weighted sound pressure level (L_Aeq), the dominant frequency of the noise spectrum, and cluster analysis methods. {L-End}Results The workplace noise and job position noise of 11 main noise positions in the metal products industry were exceeded national standard, with incidence of 69.2% and 78.1%, respectively. The average of normalization of equivalent continuous A-weighted sound pressure level to a normal 40 hours working week exceeded the national standard in 100.0% of hydraulic workers, welders, and ultrasonic cleaning workers. The result of spectrum analysis showed that the noise in the metal product industry was mainly broadband. The noise of the collision welder position was classified as low-frequency broadband noise, while the noise of the painter position was classified as low-frequency narrowband noise. The noise spectrum characteristics of other positions were similar and classified into one category, all of which were broadband noise. Among them, numerical control lathe workers, welders, threaders, machinists, and cutters were exposed to high-frequency broadband noise, while press workers were exposed to mid-frequency broadband noise, and grinders, hydraulic workers, and ultrasonic cleaning workers were exposed to low-frequency broadband noise. The detection rate of binaural high-frequency hearing threshold improvement among workers was 61.7%, and there was no statistical correlation between the detection rate of binaural high-frequency hearing threshold improvement and the noise level intensity of each spectrum. {L-End}Conclusion The level of noise hazards in the metal products industry is severe. Effective engineering control measures and hearing protection measures should be implemented based on the spectral characteristics of noises.

Objective: To apply GBZ/T298-2017 "Guidelines for occupational health risk assessment of chemicals in the workplace" to conduct an occupational health risk assessment of 2-butoxyethanol exposure in a printing enterprise, in order to protect the laborers' health. Methods: Conducted a worksite survey of occupational health include data collection, site investigation, determination 2-butoxyethanol in workplace air and raw and auxiliary material, determination 2-butoxyacetic acid in urine after shift from May 17 to 24, 2017, using the above results, conducting 2-butoxyethanol occupational health risk assessment. Results: Concentrations of 2-butoxyethanol in the workplace air ranged from 1.2-30.8 mg/m³. Concentrations of 2-butoxyaceticacid in urine ranged from 35.5 mg/L to 563.3 mg/L. The printing shop with the highest concentration of air in the workplace in the enterprise was a medium risk for 2-butoxyethanol occupational health risks, and the binding workshop printer was a low risk for 2-butoxyethanol occupational health risks. The occupational health risk of 2-butoxyethanol in the print shop was medium. Conclusion Occupational health risks of 2-butoxyethanol for companies is medium, which should be included in the evaluation of routine occupational hazards and provide more targeted recommendations based on the action levels.