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.

Background Work-related musculoskeletal disorders (WMSDs) are one of the major occupational health problems faced by bus drivers and should receive special attention. Objective To explore the associations of weekly working hours and sleep quality with neck and lower back WMSDs among bus drivers, as well as assess the potential mediating role of sleep quality. Methods From June to December 2022, we recruited bus drivers from 5 subsidiaries of the Shenzhen Bus Group by convenient sampling method. Demographic characteristics, lifestyles, and work-related features of the bus drivers were collected through a questionnaire survey. The Pittsburgh Sleep Quality Index (PSQI) scale and the Musculoskeletal Disorders Survey Questionnaire were used to assess sleep quality and WMSDs respectively. Logistic regression models were applied to analyze the associations of weekly working hours and sleep quality with WMSDs in neck and lower back. Furthermore, mediation analysis was performed to investigate the role of sleep quality in the associations between weekly work hours and neck and lower back WMSDs. Results A total of 1792 valid questionnaires were collected, with a response rate of 95.07%. Among these, 89.3% of the bus drivers worked more than 40 h per week, and the positive rate of poor sleep quality was 28.2%. The overall positive rate of WMSDs within one year before the survey was 69.12%. Among different body regions, the leading positive rates were identified in neck and lower back regions, at 55.92% and 53.68%, respectively. The logistic regression model showed that compared to the bus drivers with weekly work hours ≤40 h, those weekly worked (40~48] h (OR=1.43, 95%CI: 1.02, 2.01; OR=1.65, 95%CI: 1.17, 2.34), (48~56] h (OR=2.69, 95%CI: 1.89, 3.83; OR=2.30, 95%CI: 1.62, 3.29) and ＞56 h (OR=2.63, 95%CI: 1.86, 3.74; OR=3.23, 95%CI: 2.27, 4.62) had significantly increased risk of WMSDs in neck and lower back. Additionally, when compared to those with good sleep quality, bus drivers with poor sleep quality had higher risks of both neck and lower back WMSDs (OR=4.08, 95%CI: 3.20, 5.23; OR=4.15, 95%CI: 3.26, 5.30, respectively). Further mediation analysis indicated that sleep quality partially mediated the associations between weekly working hours and both neck and lower back WMSDs, with 36.15% and 33.68% as the respective proportion of mediation. Conclusion The positive rate of WMSDs is high among bus drivers, and the most common WMSDs occur in neck and lower back. Long working hours and poor sleep quality are significantly associated with increased risks of neck and lower back WMSDs. Sleep quality may mediate the associations of weekly working hours with neck and lower back WMSDs.

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 analyze the current status and influencing factors of occupational stress among firefighters in Shenzhen City. Methods A total of 5 434 first-line firefighters in Shenzhen City was selected as the study subjects using the judgment sampling method. The Job Content Questionnaire was used evaluate the occupational stress level. Results The detection rate of occupational stress in the study subjects was 52.5% (2 854/ 5 434). The result of dichotomous logistic regression analysis results showed that the risk of occupational stress was higher in firefighters who had a bachelor's degree or above than in those who had junior high school or below (P<0.01), the risk of occupational stress in those with irregular meals was higher than those with regular meals (P<0.01), and the risk of occupational stress was lower in those who exercised 1-3 times a month or ≥3 times a week than in those who did no daily exercise (all P<0.05). The risk of occupational stress was higher with older the weekly working hours, the more frequent the injury and the more firefighting workload (all P<0.01). The risk of occupational stress in firefighters who stand for a long time was higher than that in workers who not-stand for a long time (P<0.05). Conclusion The detection rate of occupational stress among the firefighters in Shenzhen City is relatively high. Educational level, dietary habits, daily exercise, weekly working hours, injury frequency, long-standing work and firefighting workload are all influencing factors for occupational stress in firefighters.

{L-End}Objective To understand the prevalence of work-related musculoskeletal disorders (WMSDs) and sickness absence due to WMSDs among key industry workers in Shenzhen City. {L-End}Methods A total of 14 949 workers exposed to dust, noise, chemical and radiation (hereinafter referred to as "traditional occupational groups") in some key industries in Shenzhen City, as well as bus drivers, teachers, medical staff, policemen, courier, sanitation workers and video operators were selected as the research subjects using stratified cluster sampling. The Musculoskeletal Disorders Questionnaire was used to investigate the prevalence of WMSDs and sickness absence due to WMSDs in the past year. {L-End}Results The overall prevalence of WMSDs among the study subjects was 56.3% (8 423/14 949). The prevalence of WMSDs in different body parts from high to low was neck, waist, shoulder, back, knee, wrist, ankle, hip, and elbow, which was 37.6%, 35.7%, 31.7%, 25.2%, 18.3%, 15.4%, 14.9%, 12.4%, and 11.6%, respectively (P<0.01). The overall prevalence of WMSDs among different occupational groups from high to low was teachers, video operators, bus drivers, couriers, medical staff, policemen, traditional occupational groups, and sanitation workers, which was 82.2%, 75.7%, 74.9%, 73.9%, 67.9%, 64.3%, 43.3%, and 31.9%, respectively (P<0.01). The overall rate of sickness absence due to WMSDs was 18.3% (2 736/14 949). The overall rate of sickness absence among different occupational groups from high to low was bus drivers, couriers, teachers, traditional occupational groups, policemen, video operators, medical staff, and sanitation workers, which was 31.6%, 24.5%, 20.9%, 20.2%, 15.2%, 12.4%, 9.3%, and 6.7%, respectively (P<0.01). Among different parts of the body, the highest correlation coefficient of WMSDs was found between neck and shoulder ［correlatioon cofficient (r)=0.648, P<0.01］, while the lowest was between neck and ankle (r=0.303, P<0.01). {L-End}Conclusion The prevalence of WMSDs and sickness absence due to WMSDs among key industry workers in Shenzhen City is relatively high. Comprehensive prevention and control measures should be taken according to the characteristics of occupational population to reduce the impact of WMSDs on the health of occupational population.

{L-End}Objective To investigate the prevalence of neck and waist work-related musculoskeletal disorders (WMSDs) and its relationship with occupational stress among express delivery workers. {L-End}Methods A total of 437 express delivery workers in Shenzhen City were selected as the research subjects using convenient sampling method. The prevalence of neck and waist WMSDs and the level of occupational stress were investigated by the Musculoskeletal Disorder Questionnaire and Work Content Questionnaire. {L-End}Results The prevalences of neck and waist WMSDs among the workers in the past year were 47.6% (208/437) and 60.2% (263/437), respectively. The detection rate of occupatioonal stress was 51.5%(225/437). The prevalences of neck and waist WMSDs among the workers of the occupational stress group were higher than that in the non-occupational stress group (51.9% vs 42.6%, 66.4% vs 53.0%, both P<0.01). The results of multivariate logistic regression analysis showed that the risk of neck WMSDs was higher in workers with weekly working hours >40 hours, workers with poor working posture, and workers with occupational stress compared with workers with weekly working hours ≤40 hours, workers without poor working posture, and workers without occupational stress, respectively (all P<0.05). The risk of waist WMSDs was higher in workers without weekly exercise, workers with poor working posture, and workers with occupational stress compared with workers with weekly exercise, workers without poor working posture, and workers without occupational stress, respectively (all P<0.05). {L-End}Conclusion The prevalence of neck and waist WMSDs, which may be influenced by occupational stress and poor working postures, is relatively high among express delivery workers.

Objective:To compare the ophthalmic examination indices of different occupational groups in Shenzhen and analyze the possible health problems, so as to provide research basis for further health intervention.Methods:In March 2021, 5426 professionals with ophthalmic examination index data were selected from the basic health database of "Shenzhen occupational population protection action". Among them, radiation workers (694), port operators (1756), sanitation workers (946), teachers (224), video workers (154), police (927) and firefighters (100) were selected as the investigated occupational population. They were exposed to noise 625 workers with traditional occupational hazards such as noise, chemical poisons and dust were used as the control population.Ophthalmic examination indices included right eye vision, left eye vision, outer eye, conjunctiva, cornea, lens, and fundus oculi. The differences of each index in different occupational groups were compared.Results:Compared with the control group, the port operator group showed lower abnormal rates of binocular vision and fundus oculi ( P<0.05), but higher abnormal rates of conjunctiva ( P=0.029), the environmental sanitation worker group showed higher abnormal rates of binocular vision and conjunctiva (all P<0.01), the teacher group had higher abnormal rates of binocular vision, but only the difference of left eye vision was statistically significant ( P=0.021), and the video worker group had higher abnormal rates of right and left eyes vision ( P=0.029、0.006) . Conclusion:There were some degrees of ophthalmic problems in different occupational population, therefore targeted intervention measures should be taken according to the characteristics of each group.

Objective:To understand the occurrence of occupational injuries among sanitation workers in Shenzhen, and provide a scientific basis for the prevention of occupational injuries among sanitation workers.Methods:From May to November 2020, a cluster sampling method was used to select some street sanitation workers in Shenzhen to conduct a questionnaire survey. A total of 2200 questionnaires were recovered, of which 2167 were valid (98.5% effective recovery rate) . The socio-demographic data, length of service, type of work and occurrence of occupational injuries of sanitation workers were collected, and the distribution characteristics of occupational injuries and their relationship with factors such as type of work were analyzed.Results:Among the 2167 sanitation workers, 240 (11.1%) had experienced occupational injuries. The most common occupational injuries among sanitation workers were sharp injury, heat stroke and motor vehicle traffic accident, with the incidence rates of 6.1% (133/2167) , 2.4% (53/2167) and 1.7% (36/2167) respectively. There were statistically significant differences in the distribution of occupational injuries among sanitation workers with different lengths of work and types of work ( P<0.05) . The incidence of occupational injury among sanitation workers with more than 5 years of service was significantly higher than that of workers with less than 5 years of service ( P<0.05) . The incidence of sharp injury among garbage sorting and transportation personnel was higher (7.9%, 21/265) , the incidence of heat stroke among manual cleaners was higher (3.1%, 42/1366) , and the incidence of motor vehicle traffic accident among mechanized cleaners was higher (5.4%, 10/184) . Conclusion:There are many cases of occupational injuries among sanitation workers in Shenzhen. Targeted measures should be taken to prevent the occurrence of different types of work and different types of occupational injuries, and to improve the occupational health level of sanitation workers.

Objective:To compare the ophthalmic examination indices of different occupational groups in Shenzhen and analyze the possible health problems, so as to provide research basis for further health intervention.Methods:In March 2021, 5426 professionals with ophthalmic examination index data were selected from the basic health database of "Shenzhen occupational population protection action". Among them, radiation workers (694), port operators (1756), sanitation workers (946), teachers (224), video workers (154), police (927) and firefighters (100) were selected as the investigated occupational population. They were exposed to noise 625 workers with traditional occupational hazards such as noise, chemical poisons and dust were used as the control population.Ophthalmic examination indices included right eye vision, left eye vision, outer eye, conjunctiva, cornea, lens, and fundus oculi. The differences of each index in different occupational groups were compared.Results:Compared with the control group, the port operator group showed lower abnormal rates of binocular vision and fundus oculi ( P<0.05), but higher abnormal rates of conjunctiva ( P=0.029), the environmental sanitation worker group showed higher abnormal rates of binocular vision and conjunctiva (all P<0.01), the teacher group had higher abnormal rates of binocular vision, but only the difference of left eye vision was statistically significant ( P=0.021), and the video worker group had higher abnormal rates of right and left eyes vision ( P=0.029、0.006) . Conclusion:There were some degrees of ophthalmic problems in different occupational population, therefore targeted intervention measures should be taken according to the characteristics of each group.

Objective:To understand the occurrence of occupational injuries among sanitation workers in Shenzhen, and provide a scientific basis for the prevention of occupational injuries among sanitation workers.Methods:From May to November 2020, a cluster sampling method was used to select some street sanitation workers in Shenzhen to conduct a questionnaire survey. A total of 2200 questionnaires were recovered, of which 2167 were valid (98.5% effective recovery rate) . The socio-demographic data, length of service, type of work and occurrence of occupational injuries of sanitation workers were collected, and the distribution characteristics of occupational injuries and their relationship with factors such as type of work were analyzed.Results:Among the 2167 sanitation workers, 240 (11.1%) had experienced occupational injuries. The most common occupational injuries among sanitation workers were sharp injury, heat stroke and motor vehicle traffic accident, with the incidence rates of 6.1% (133/2167) , 2.4% (53/2167) and 1.7% (36/2167) respectively. There were statistically significant differences in the distribution of occupational injuries among sanitation workers with different lengths of work and types of work ( P<0.05) . The incidence of occupational injury among sanitation workers with more than 5 years of service was significantly higher than that of workers with less than 5 years of service ( P<0.05) . The incidence of sharp injury among garbage sorting and transportation personnel was higher (7.9%, 21/265) , the incidence of heat stroke among manual cleaners was higher (3.1%, 42/1366) , and the incidence of motor vehicle traffic accident among mechanized cleaners was higher (5.4%, 10/184) . Conclusion:There are many cases of occupational injuries among sanitation workers in Shenzhen. Targeted measures should be taken to prevent the occurrence of different types of work and different types of occupational injuries, and to improve the occupational health level of sanitation workers.