Effect of resilience on association between job burnout and sleep disorders among workers in a petrochemical company / 环境与职业医学

Background The risks of unhealthy working mood and physical and mental health problems are high in the workers of petrochemical enterprises. Resilience is a positive psychological factor, which can provide positive ability to manage stress and job burnout, relieve tension, depression, anxiety, and other psychological discomfort. Objective To explore the moderating or mediating effect of resilience on the association between job burnout and sleep disorders in workers of petrochemical enterprises. Methods A survey with questionnaire of general information, resilience, job burnout (including exhaustion, cynicism, and professional efficacy), and sleep disorders was conducted among 1087 workers who were selected by cluster sampling from a petrochemical enterprise in Henan Province in April 2022. Mann-Whitney U test and Kruskal-Wallis H test were used to test the differences of scores among different demographic groups. Resilience, job burnout (including exhaustion, cynicism, and professional efficacy), and sleep disorder scores were analyzed by partial correlation analysis. The moderating effect of resilience was examined by linear regression analysis, and the mediating effect of resilience by Bootstrap method. Results A total of 861 questionnaires were collected, of which 857 were effective, and the effective rate was 99.5%. The M (P25, P75) of job burnout score was 1.24 (0.65, 2.22) and the incidence of job burnout was 36.4% (312/857); the scores [M (P25, P75)] of exhaustion, cynicism, and professional efficacy were 1.40 (0.80, 3.00), 1.00 (0.20, 1.60), and 5.50 (4.00, 6.00), respectively. The M (P25, P75) of resilience score was 36.00 (30.00, 41.00). The M (P25, P75) of sleep disorder score was 11.00 (7.00, 15.00). The partial correlation analysis results showed that job burnout, exhaustion, and cynicism were negatively correlated with resilience (r=−0.387, −0.248, −0.247, P<0.01), and positively correlated with sleep disorders (r=0.455, 0.445, 0.357, P<0.01); professional efficacy was positively correlated with resilience (r=0.366, P<0.01) and negatively correlated with sleep disorders (r=−0.184, P<0.01); resilience was negatively correlated with sleep disorders (r=−0.349, P<0.01). The linear regression analysis results found that job burnout, exhaustion, and cynicism elevated the risk of sleep disorders (P<0.01), resilience lowered the risk of sleep disorders (P<0.01); but the relationship between job burnout (exhaustion, cynicism, and professional efficacy) and sleep disorders was not moderated by resilience (P＞0.05). The mediating effect test showed that resilience played a partial mediating role in the associations of job burnout, exhaustion, cynicism, and professional efficacy with sleep disorders, the mediating effects were 0.522 (95%CI: 0.283-0.777), 0.310 (95%CI: 0.188-0.453), 0.364 (95%CI: 0.228-0.524), −0.542 (95%CI: −0.741-−0.366) and the mediating effects accounted for 17.31%, 14.12%, 19.24%, and 64.72% of the total effects, respectively. Conclusion The relationship between job burnout and sleep disorders is partially mediated by resilience among workers in the selected petrochemical company, but no moderating effect is found.

The moderating and mediating effects of psychological capital in the relationship of job monotony and depressive symptoms / 中华行为医学与脑科学杂志

Objective:To explore the moderating and mediating effects of psychological capital in the associations of job monotony and depressive symptoms.Methods:A convenient sampling method was used to sample 1 473 workers from a natural gas field in southwest China in October 2018.The sociodemographic characteristics, job monotony scale, PsyCap questionnaire and center of epidemiological survey, depression scale(CES-D) were conducted.Data were analyzed by SPSS 22.0 and Process v3.2 softwares.The statistical methods included t-test, one-way ANOVA, χ2 test, partial correlation analysis, multivariate regression analysis or Bootstrap method. Results:A total of 323 workers with depressive symptoms were detected, with a detection rate of 21.9%(323/1 473). The correlation analysis results showed that job monotony (13.67±1.38) was negatively correlated with self-efficacy (25.81±4.56), hope(25.91±4.55), resilience (26.80±3.80) and optimism (24.56±3.17) ( r=-0.26, -0.38, -0.36, -0.42 respectively, all P<0.01), and positively correlated with depressive symptoms ( r=0.50, P<0.01). Self-efficacy ( r=-0.38, P<0.05), hope ( r=-0.44, P<0.05), resilience ( r=-0.43, P<0.01) and optimism ( r=-0.47, P<0.01) were negatively correlated with depressive symptoms.The multivariate regression analysis results showed that self-efficacy and optimism had moderating effects on the associations of job monotony and depressive symptoms (both P<0.05), while hope and resilience had no moderating effects on the associations of job monotony and depressive symptoms (both P>0.05). The mediating effect test results showed that self-efficacy, hope, resilience and optimism played partial mediating roles in the associations of job monotony and depressive symptoms (all P<0.01), and the mediating effects were 0.139, 0.304, 0.232 and 0.339 respectively, and the proportion of mediating effect value to total effect was 12.2%, 23.3%, 18.8% and 25.3% respectively. Conclusion:Self-efficacy and optimism have moderating and mediating effects on the associations of job monotony and depressive symptoms, while hope and resilience have only mediating effects on the relationship between job monotony and depressive symptoms.

Change of occupational stress from 1996 to 2012 among train engine drivers / 中华预防医学杂志

Objective@#To analyze the change of level of occupational stress between 1996 and 2012 among train engine drivers.@*Methods@#the cross-section investigation was conducted by using cluster sampling method, subjects included 1 116 and 1 002 passenger train engine drivers and freight train engine drivers respectively in 1996 and in 2012;occupational stressors, strains, personalities, buffering factors and individual factors were investigated by using Occupational Stress Instruments. Unconditional logistic regression analyses were performed to estimate the associations between job stressors, personalities, buffering factors and individual factors and strains. Multivariate OR(95%CI) were derived from the logistic regression models.@*Results@#From 1996 to 2012, for the passenger train engine drivers the scores of role ambiguity (17.67±5.30 vs.14.11±4.66) increased 25.32%, mental load (10.41±3.56 vs. 16.29±2.08) and physical environment (3.61±2.18 vs. 7.03±1.65) scores decreased 36.10% and 48.64% respectively, sleep disorders (18.04±9.20 vs. 13.35±4.00) and negative affectivity (2.76±1.86 vs. 2.14±1.86) scores increased 33.14% and 28.97% respectively, the differences were statistical significant (P<0.001) . For the freight train engine drivers the scores of sleep disorders (20.33±8.17 vs. 12.47±4.12) and negative affectivity (2.95±1.70 vs. 1.87±1.81) scores increased 57.75% and 60.03% respectively, positive affectivity (2.17±1.60 vs. 2.91±1.50) score decreased 25.43%, the differences were statistical significant (P<0.001) . In general, scores varies in factors related to occupational stress among freight train engine drivers were larger than those among passenger train engine drivers. The risk factor of job dissatisfaction among passenger train drivers in 1996 was insufficient superior support (OR=3.77, 95%CI: 2.23-6.37) , the risk factors in 2012 were insufficient superior support (OR=3.35, 95%CI:1.56-7.17) , poor physical environment (OR=3.61, 95%CI: 1.91-6.80), and fewer positive affectivity (OR=3.47, 95%CI: 1.75-6.82). The risk factor of job dissatisfaction among freight train drivers in 1996 and in 2012 were insufficient superior support (OR (95%CI) were 3.11 (2.31-4.19), 2.59 (1.84-3.65) , respectively).@*Conclusion@#The level of occupational stress among train engine drivers in 2012 was larger than that in 1996, the level of occupational stress among freight train drivers was larger than passenger train drivers, the interventions aimed at reducing occupational stress in the Chinese train engine drivers should take into account promotion for design of job organization and contents and organization management style.

Relationship between depressive symptoms and occupational stress in locomotive drivers / 中华劳动卫生职业病杂志

Objective@#To explore relationship between depressive symptoms and occupational stress in locomotive drivers.@*Methods@#By using cluster sampling method, a cross-sectional study was conducted in 1413 train drivers (including passenger train drivers301, freight train drivers 683, passenger shunting train drivers350, and high speed train drivers79) from a railway bureau. The individual factors, depression, occupational stress, strains, personalities, coping strategy and social support were measured using occupational stress instruments, job content questionnaire and effort-reward imbalance questionnaire.@*Results@#CThe differences of depression scores between take exercise and don't exercise groups were statistical significance (P<0.01) . The differences of depression scores among different age, length of service, job category, educational status,marital status, smoking and drinking groups were`t statistical significance (P>0.05) .Correlation analysis revealed that depression score was related negatively to reward, job satisfaction, self-esteem, promotion opportunities, working stability and positively emotions score (P<0.01) , related positively to sleep disorders, effort, physiological needs, psychological need, daily stress, negative emotions, social support, esponsibility for person, responsibility for thing, conflict in the group, role conflict, role ambiguity score (P<0.01) . Nonparametric test analysis found that train drivers with high depression score reported higher psychological need, effort, promotion opportunities, role ambiguity, role conflict, conflict between groups, responsibility for person, responsibility for thing, physiological needs, daily stress, negative emotions, social support and copping strategies than those with moderate and lower depression score (P<0.01) , but the scores of job satisfaction, reword, self-esteem, working stability, positive emotions were lower than other groups those with moderate and lower depression score (P<0.01) . Multivariate logistic regression analysis revealed the risk of depression for drivers with more sleep disorder, low social support more than three times as high as that for drivers with few sleep disorder, hing social support (OR=3.615,3.266) .High negative emotions, more psychological need, high daily stress were more than twice times as high as that for drivers with low negative emotions, few psychological need, low daily stress (OR:2.444、2.489、2.065) .@*Conclusion@#sleep disorder, low social support and job stress had larger effect on depression. To improve sleep, social support, self-esteem and decrease job stress and negative emotions are main measures of decrease depression for train drivers.

Self-esteem and Occupational Stress Relationship Analysis of 1413 Train Drivers in a Railway Bureau / 中华劳动卫生职业病杂志

Objective@#To investigate self-esteem status of train drivers. @*Methods@#By using cluster sampling method, a cross-sectional study was conducted in 1 413 train drivers (including passenger train drivers 301, freight train drivers683, passenger shunting train drivers350, and high speed train drivers79) from a railway bureau. The occupational stressors, strains, self-esteem and personalities were measured using occupational stress instruments and effort-reward imbalance questionnaire. @*Results@#The level of self-esteem is medium ofthe train drivers. Sself-esteem scores among different among different job category (job title) , marry status, age, length of service groups were statistical significance (P<0.01) . Differences of self-esteem among different educational level, exercise, smoking and drinking groups weren’t statistical significance (P>0.05) . Correlation analysis revealed that self-esteem score was related positively to job satisfaction (r=0.300) , reward (r=0.842) , working stability (r=0.243) , promotion opportunities (r=0.493) , positive affectivity (r=0.216) , responsibility for human beings (r=0.112) and responsibility for things scores (r=0.108) (P<0.01) , negatively to sleep quality (r=-0.103) , social support (r=-0.212) , role conflict (r=-0.007) , role ambiguity (r=-0.169) , physiological needs (r=-0.115) , daily stress (r=-0.150) , negative affectivity (r=-0.252) , depressive symptoms scores (r=-0.215) (P<0.01) . Nonparametric test found that train drivers of group with low self-esteem score reported higher scores for physiological need, role conflict, role ambiguity, social sleep quality, depressive symptoms, negative affectivity, social support and daily stress scores than the medium and higher groups (P<0.01 or<0.05) . But reword, job satisfaction, positive affectivity, copping stratgy, working stability and promotion opportunities scores were lower than the group of medium and higher groups (P<0.01) . Inter-group conflict scores were insignificance (P>0.05) . Multivariate logistic regression analysis revealed that low low self-esteem for drivers occured the risk of job dissatisfaction about 1.5 times as high as that of drivers with higher self-esteem (OR=1.476) @*Conclusion@#Different types of locomotive drivers get different level of self-esteem. Self-esteem was affected by occupational stress largely.

Social support and occupational stress relationship analysis of 1 413 train drivers in a railway bureau / 中华预防医学杂志

Objective@#To investigate the social support status of train drivers.@*Methods@#Using cluster sampling, a cross-sectional study was conducted in 1 413 male train drivers (including 301 passenger train drivers, 683 freight train drivers, 85 guest scheduling train drivers, 265 cargo adjustable drivers, and 79 high-speed train drivers) from a railway bureau depot. The survey included individual factors, social support, occupational stressors, strains, personalities, and coping strategy using occupational stress instruments and effort-reward imbalance questionnaire. We compared the difference in social support scores between different drivers, who were divided according to job type and age. Additionally, the correlation between social support score and job strain-related factors was analyzed. The influence of depressive symptoms and job satisfaction were analyzed using a non-conditional logistic multivariate model.@*Results@#The overall average age P50 (P25,P75) of 1 413 train drivers was 33.92 (27.83,43.58) years. The overall average length of service 12.25 (5.25,22.75) years. A significant difference in social support scores was observed according to job type (H=23.23, P<0.001). The specific scores were passenger driver(27 (23,32)), freight train driver (26 (22,30)), guest scheduling driver (27 (24,30)), cargo adjustable driver (26 (22,31)), and high-speed train driver (30 (26,36)) (P50(P25,P75)). Additionally, social support scores among different age groups were significantly different (H=6.64, P=0.036). The specific scores were ≤30 years (26 (22,31)), 30-40 years (27 (23,33)), and >40 years (27 (22,31)). Correlation analysis revealed that the social support score was negatively associated with job satisfaction (r=-0.43), reward (r=-0.22), working stability (r=-0.23), promotion opportunities (r=-0.12), positive affectivity (r=-0.31), esteem (r=-0.21), and self-esteem (r=-0.20) scores (P<0.001). The social support score was positively associated with sleep disorders (r=0.33), external effort (r=0.21), pay within (r=0.12), role conflict (r=0.20), conflict between groups (r=0.17), conflict in groups (r=0.06), responsibility for the others (r=0.06), responsibility for things (r=0.08), physiological needs (r=0.39), psychological needs (r=0.19), daily stress (r=0.29), negative affectivity (r=0.23), and depressive symptoms (r=0.44) scores (P<0.05). Multivariate logistic regression analysis revealed social support had a great influence on depressive symptoms and low job satisfaction. Compared with high social support, low social support resulted in depressive symptoms (OR=4.12, 95% CI:3.19-5.33) and low job satisfaction (OR=2.18, 95%CI:1.65-2.88).@*Conclusion@#Train drivers obtained various levels of social support. Social support greatly affected occupational stress. High social support was related to reduction in the occurrence of occupational stress, depressive symptoms, and low job satisfaction. Social support is related to mental health of train drivers.

Sleep quality and occupational stress relationship analysis of 1413 train drivers in a railway bureau / 中华劳动卫生职业病杂志

Objective@#To investigate sleep quality status of train drivers.@*Methods@#By using cluster sampling method, a cross-sectional study was conducted in 1413 train drivers (including passenger train drivers 301, freight train drivers 683, passenger shunting train drivers 350, and high speed train drivers 79) from a railway bureau. The occupational stressors, strains, personalities and sleep quality were measured using occupational stress instruments and effort-reward imbalance questionnaire.@*Results@#The train drivers of poor sleep quality was 48.34%. Sleep quality scores among different among different job category (job title) , exercise, smoking and drinking were statistical significance (P<0.01) . Differences of sleep quality among different educational level, marry status, age, length of service groups weren’t statistical significance (P>0.05) .@*Correlation@#analysis revealed that sleep quality score was related negatively to job satisfaction, reward, working stability, promotion opportunities, positive affectivity, esteem and self-esteem scores (r: -0.454, -0.207, -0.329,-0.170, -0.291, -0.103, -0.139, P<0.01 or P<0.05) , positively to social support, effort, role conflict, conflict between groups, conflict in groups, responsibility for person, responsibility for thing, psychological needs, physiological needs, daily stress, negative affectivity, depressive symptoms scores (r: 0.338, 0.524, 0.226, 0.094, 0.182, 0.210, 0.247, 0.190, 0.615, 0.550, 0.345, 0.570, P<0.01) . Nonparametric test found that train drivers of group with high sleep quality score reported higher scores for physiological need, psychological need, effort, role conflict, conflict between groups, social support, daily stress, depressive symptoms, responsibility for person, responsibility for thing, negative affectivity and coping scores than the group of lower sleep quality score (P<0.01) . But reword, job satisfaction, positive affectivity, self-esteem working stability and Promotion opportunities scores were lower than the group of lower sleep quality score (P<0.01) . Multivariate logistic regression analysis revealed the risk for more physiological needs, more effort, more depressive symptoms and more daily stress for drivers occured the risk of poor sleep quality were more than two times as high as that of drivers with less physiological needs, less effort, less depressive symptoms and less daily stress (OR=2.905~2.005) . Conclusions Different types of locomotive drivers get different level of sleep quality. Sleep quality was affected by occupational stress largely. Reducing the occupational stress may contribute to improve the sleep quality of train drivers.

Investigation into the relationship between mitochondrial 12 S rRNA gene, tRNA gene and cytochrome oxidase Ⅱ gene variations and the risk of noise-induced hearing loss / 中华预防医学杂志

Objective@#To explore the relationship between mitochondrial 12 S rRNA gene variation, tRNA gene variation and cytochrome oxidase Ⅱ gene point mutations and the risk of noise-induced hearing loss (NIHL).@*Methods@#A nested case-control study was performed that followed a cohort of 7 445 noise-exposed workers in a steel factory in Henan province, China, from January 1, 2006 to December 31, 2015. Subjects whose average hearing threshold was more than 40 dB(A) in high frequency were defined as the case group, and subjects whose average hearing threshold was less than 35 dB(A) in high frequency and less than 25 dB (A) in speech frequency were defined as the control group. Subjects was recruited into the case group (n=286) and the control group (n=286) according to gender, age, job category and time of exposure to noise, and a 1∶1 case-control study was carried out. We genotyped eight single nucleotide polymorphisms in the mitochondrial 12 S rRNA gene, the mitochondrial tRNA gene and the mitochondrial cytochrome oxidase Ⅱ gene using SNPscan high-throughput genotyping technology from the recruited subjects. The relationship between polymorphic sites and NIHL, adjusted for covariates, was analyzed using conditional logistic regression analysis, as were the subgroup data.@*Results@#The average age of the recruited subjects was (40.3±8.1) years and the length of service exposure to noise was (18.6±8.9) years. The range of noise exposed levels and cumulative noise exposure (CNE) was 80.1- 93.4 dB (A) and 86.8- 107.9 dB (A) · year, respectively. For workers exposed to noise at a CNE level<98 dB (A) · year, smokers showed an increased risk of NIHL of 1.88 (1.16-3.05) compared with non-smokers; for workers exposed to noise at a CNE level ≥98 dB(A) · year, smokers showed an increased risk of NIHL of 2.53 (1.49- 4.30) compared with non-smokers. For workers exposed to noise at a CNE level<98 dB (A) · year, the results of univariate analysis and multifactor analysis, adjusted by smoking and CNE, suggested that the risk of NIHL in workers exposed to noise carrying the GG genotype (G827A) was lower than that of NIHL workers exposed to noise carrying the AA genotype (G827A) [OR (95% CI) were 0.18 (0.04- 0.82) and 0.19 (0.04- 0.88), respectively].@*Conclusion@#Smoking increased the risk of NIHL in the present study. For workers subjected to a CNE<98 dB(A)·year, the mitochondrial genetic variant G827A was found to be significantly associated with the risk of NIHL.

Association between eye absent homolog 4 gene polymorphisms and occupational noise-induced hearing loss / 中华预防医学杂志

Objective@#To identify the association between genetic polymorphisms in the eye absent homolog 4 (EYA4) gene and noise-induced hearing loss (NIHL).@*Method@#A nested case control study was conducted based on a cohort of noise-exposed subjects. In total, 292 cases were selected from a steel factory from 6 297 subjects during Jan 1, 2006 to Dec 12, 2015,who had an average hearing threshold of more than 40 dB(A); 584 matched control subjects for each case were designated on the basis of matched criteria including same gender, age (±5 years) and duration of exposure to noise (±2 years). What's more, the control group had an average hearing threshold of less than 35 dB(A) in high frequency and less than 25 dB(A) in speech frequency. Four single nucleotide polymorphisms (SNPs) of the EYA4 gene were genotyped using a SNPscanTM multiplex SNP genotyping kit. Hardy-Weinberg equilibrium tests were performed using a χ2 test for goodness-of-fit for each SNP among the control group, and the effects of genotypes of the EYA4 gene on NIHL were analyzed by logistic regression. The haplotypes were established and their frequencies in the two groups were assessed using Haploview 4.2 and Phase 2.1 software, and interactive effects between haplotypes and cumulative noise exposure were analyzed.@*Results@#The average age of the subjects was (40.1±8.4) years and the average number of noise-exposed working years was 20.3 (8.4, 27.3) years. The range of noise exposure levels and the cumulative noise exposure were 80.2- 98.8 dB (A) and 86.6- 111.2 dB(A) · year, respectively. After adjustment for covariates including height, blood pressure, drinking status and smoking status, in the noise intensity>85 dB (A) group, subjects carrying the rs3813346 TT genotype had a higher NIHL risk than those carrying the GG genotype, and the adjusted OR (95% CI) value was 2.12 (1.21- 3.69). In the cumulative noise exposure>98 dB (A) · year group, compared with haplotype TGC, haplotype CGT showed a protective effect in the development of NIHL, with an adjusted OR (95% CI) value of 0.60 (0.37-0.97), however, the significance of intercation between EY4 gene of noise was lost after Bonferroni correction.@*Conclusion@#Genetic polymorphism in the EYA4 gene may be a genetic susceptibility factor for NIHL.

Association between variations in protocadherin 15 gene and occupational noise-induced hearing loss / 中华预防医学杂志

Objective@#The aim of this study was to investigate whether genetic variability in the protocadherin 15 (PCDH15) gene may correspond with increased susceptibility to noise-induced hearing loss (NIHL) in a Chinese population.@*Methods@#A nested case-control study was performed that followed a cohort of 7 445 noise-exposed workers in a steel factory of Henan province in China from January 1, 2006 to December 31, 2015. In this study, 394 cases who had an average hearing threshold of more than 40 dB (A) in high frequency were defined as the case group, and 721 controls who had an average hearing threshold of less than 35 dB (A) in high frequency and less than 25 dB (A) in speech frequency were defined as the control group. A questionnaire was completed by participants and a physical test was also conducted. SNP genotyping was performed using the SNPscanTM Kit. Multivariate unconditional logistic regression additive models were used to analyze the genotypes in different groups, and the association with NIHL. Unconditional logistic regression models were used to assess the associations between the genotypes and NIHL.@*Results@#The average age of study participants was (40.5±8.3) years and the median number of noise-exposed working years M (P25, P75) was 21.1 (9.1, 27.3). The range of noise exposed levels and the levels of cumulative noise exposure (CNE) were 80.1- 98.8 dB(A) and 86.6- 111.2 dB(A), respectively. Only the distribution of the genotypes (TT/CC/CT) of rs11004085 in the PCDH15 gene showed a significant difference between the case and control groups (P=0.049). In the case group, the distribution was 370 (93.9%), 24 (6.1%) and 0; in the control group, the distribution was 694 (96.3%), 23 (3.2%) and 1 (0.1% ). After smoking, drinking, hypertension, height and CNE adjustment, compared with the TT genotype individuals with the CC/CT genotype had a 1.90-fold increased risk of NIHL (95% CI: 1.06- 3.40). After stratified these data by the noise exposure level or CNE when the noise exposure level was>85 dB (A), compared with cases with the AA genotype of rs10825113, individuals with the GA/GG genotype had a 2.63-fold increased risk of NIHL (95% CI: 1.12- 6.14). When the CNE was ≤ 98 dB(A), compared with cases with the TT genotype of rs11004085, individuals with the CC/CT genotype had a 2.96-fold increased risk of NIHL (95% CI: 1.33- 6.56). However, these differences were not significant after Bonferroni correction had been applied.@*Conclusions@#The results confirmed that genetic variation within the PCDH15 gene may affect the susceptibility to NIHL.

A cohort study on occupational noise induced hearing loss in workers at an iron and steel plant / 中华预防医学杂志

Objective@#To analyze the incidence rate of occupational noise-induced hearing loss in noise-exposed workers in an iron and steel plant from 2006 to 2015.@*Methods@#Using a cohort study method, workers exposed to occupational noise from Jan 1, 2006 to Dec 12, 2015 were followed up and the pure tone hearing test was conducted. In total, 6 297 subjects completed two or more physical checks and the pure tone hearing test and were included in the analysis. The noise exposure level at the workplace and the equivalent continuous A-weighted sound pressure level for workers was monitored and the cumulative noise exposure dose was evaluated. The subjects were divided into low, middle and high exposure groups according to the noise exposure level, and the equivalent continuous A-weighted sound pressure level for 8 hours for each group was 80.6-85.0, 85.1-90.0 and 90.1-103.4 dB (A), respectively. While the RR and 95% CI were derived from unconditional logistic regression models. In logistic regression analysis, confounding factors such as age, gender, smoking habit, drinking habit, high temperature exposure and chemical hazards exposure level were controlled.@*Results@#During the follow-up period, 392 cases of occupational noise-induced hearing loss were diagnosed among the 6 297 subjects, with an incidence rate of 6.23%; 318 cases of high-frequency hearing loss were diagnosed, with an incidence rate of 5.05%; and 74 cases of occupational noise-induced deafness were diagnosed, with an incidence rate of 1.18% . The incidence rates of hearing loss among the high, medium and low exposure groups were 9.22% (158/1 737), 6.49% (204/3 142) and 2.08% (30/1 442), respectively; the rates of high-frequency hearing loss were 7.41% (127/1 737), 5.25% (165/3 142) and 1.80% (26/1 442), respectively; and the rates of occupational noise-induced deafness were 1.81% (31/1 737), 1.24% (39/3 142) and 0.28% (4/1 442), respectively. For the groups corresponding to cumulative noise exposure doses of ≤84.99, 85.00- 87.99, 88.00- 90.99, 91.00- 93.99, 94.00- 96.99, 97.00- 100.99, 101.00- 102.99 and ≥103.00 dB (A) · year, the incidence rates of hearing loss were 0 (0/185), 1.22% (2/164), 2.52% (17/674), 3.83% (35/913), 5.80% (106/1 827), 6.02% (67/1 113), 9.20% (95/1 003) and 18.04% (70/388), respectively. Compared with the low exposure group, the RR of hearing loss, high-frequency hearing loss and occupational noise-induced deafness for the high exposure group were 4.78 (95% CI: 3.22- 7.11), 4.36 (95% CI: 2.84- 6.69) and 6.63 (95% CI: 2.33- 18.82), respectively; and for the medium exposure group were 3.27 (95% CI: 2.22-4.82), 3.02 (95% CI: 1.99-4.59) and 4.52 (95% CI: 1.61-12.67), respectively.@*Conclusion@#The incidence rate of hearing loss for workers exposed to noise in an iron and steel plant was related to the cumulative noise exposure dose, gender, age, educational level, smoking habits, drinking habits and exposure to high temperature.

Influencing factors for job satisfaction in train drivers in a railway bureau: an analysis of 1413 cases / 中华劳动卫生职业病杂志

Objective@#To investigate the influencing factors for job satisfaction in train drivers.@*Methods@#In March 2012, cluster sampling was used to conduct a cross-sectional survey in 1413 male train drivers (including 301 passenger train drivers, 683 freight train drivers, 350 passenger shunting train drivers, and 79 high-speed train drivers) from a locomotive depot of a railway bureau. The occupational stress instruments, job content questionnaire, and effort-reward imbalance questionnaire were used to analyze job satisfaction, occupational stress factors, stress reaction, individual characteristics, coping strategies, and social support.@*Results@#There were significant differences in job satisfaction score between the drivers with different posts, working years, ages, smoking status, and drinking status (P<0.01). The correlation analysis revealed that job satisfaction score was positively correlated with reward, working stability, promotion opportunity, positive emotion, social support, self-esteem, and coping strategy scores (P<0.01) and negatively correlated with sleep disorders, effort, role conflict, intergroup conflict, responsibility for persons, responsibility for things, psychological needs, physiological needs, daily stress, negative emotion, and depressive symptom scores (P< 0.01). The analysis of variance showed that compared with the moderate and low job satisfaction groups, the high job satisfaction group had significantly higher reward, positive emotion, promotion opportunity, and role ambiguity scores (P<0.01) , as well as significantly lower scores of responsibility for persons and responsibility for things (P<0.01). Compared with the moderate and high job satisfaction groups the low job satisfaction group had significantly higher scores of psychological needs, effort, role conflict, sleep disorders, daily stress, depressive symptom, negative emotion, drug use, intragroup conflict, and social support (P<0.01) , and the moderate job satisfaction group had a significantly higher score of self-esteem than the other two groups (P<0.05). The logistic regression analysis showed that the risk of job dissatisfaction in the drivers with low so-cial support and high daily stress was more than 2 times that in those with high social support and low daily stress (OR=2.176 and 2.171) , and sleep disorders, effort, depressive symptom, low self-esteem, and role conflict were risk factors for job dissatisfaction (OR=1.48-1.625).@*Conclusion@#Occupational stress, stress re-sponse, emotion, individual characteristics, and social support have great influence on job satisfaction. Im-proving social support, increasing positive emotion, and reducing occupational stress are main measures for increasing job satisfaction in train drivers.

Association between grainyhead-like 2 gene polymorphisms and noise-induced hearing loss / 北京大学学报(医学版)

Objective:To investigate association between genetic polymorphism in the grainyhead-like 2 gene (GRHL2)and noise-induced hearing loss (NIHL)in the Chinese population.Methods:A matched case-control association study was employed,In which,3 790 workers exposed to continuous and steady-state occupational noise in a steel factory participated.The questionnaires were adopted to col-lect individual features and audiometry tests performed.In the sstudy,286 subjects were diagnosed as ca-ses,Which were each designated on the basis of the matched criterion,and 286 paired samples were se-lected finally.Noise intensity was measured according to the standards given in ‘Measurement of Noise in the Workplace’(Occupational Health Standard of the People’s Republic of China,GBZ /T1 89.8 -2007).Cumulative noise exposure (CNE)was calculated,according to monitoring data on A-weighed sound pressure level and employment time.Genomic DNA was obtained from peripheral blood samples using 2 mL DNA extraction Kit following the manufacturer’s protocol.Five single nucleotide polymor-phisms (SNPs)of GRHL2 were genotyped by multiplex SNP genotyping kit.The continuous variables and categorical variables were analyzed by t-test and chi-square test respectively.Multivariate Logistic re-gression was used to test the association between genetic frequency and disease status,with adjustments for the possible confounding variables.The haplotypes were established and their frequencies in the two groups were assessed by haploview and phase softwares.Results:All the five SNPs (rs373571 3, rs3824090,rs373571 4,rs373571 5 and rs61 1 41 9)were in Hardy-Weinberg equilibrium (HWE)(P >0.05).The subjects carrying rs373571 5 GG genotype had a higher NIHL risk than those carrying the GA genotype under the co-dominant model (OR =0.644,95% CI:0.442 -0.939,P =0.022)after ad-justment for height,blood pressure,drinking status and smoking status.After being stratified by CNE,in the CNE ≥ 98 dB (A)group,rs373571 5 polymorphism was associated with the NIHL under the co-dominant model (OR =0.509,95% CI:0.281 -0.923,P =0.026)after adjustment for height,blood pressure,drinking status and smoking status as well.However,no statistical significant difference was found in variant genotypes of the other SNPs between the case and control subjects.Four-locus (rs373571 3,rs3824090,rs373571 4 and rs373571 5)haplotypes were constructed,and no risk or protec-tive haplotypes was identified.Conclusion:It is suggested that GRHL2 polymorphisms may be associated with development of NIHL.

Analysis of relationship between shift-work and occupational stress among workers from different companies / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the relationship between work in shifts and occupational stress.</p><p><b>METHODS</b>A total of 5338 employees from 13 companies were investigated by cluster sampling, and occupational stress measuring tools, job content questionnaire, and effort-reward imbalance questionnaire were used to investigate occupational stress factors, stress reaction, and the condition of work in shifts.</p><p><b>RESULTS</b>The employees who worked in shifts accounted for 46.6%. The condition of work in shifts varied significantly across different companies, employees with different individual features (including sex, job title, degree of education, age, working years, smoking, and drinking), and employees with different weekly working times(P<0.01 or P<0.05); health status was associated with work in shifts(P<0.01); compared with the employees who did not work in shifts, those who worked in shifts had significantly lower scores of technology utilization, work control level, psychological need, reward, social support, and job satisfaction(P<0.01 or P<0.05), as well as significantly higher scores of physical demands, effort, depressive symptoms, and negative affectivity(P<0.01).</p><p><b>CONCLUSION</b>Work in shifts can affect health status, and is associated with occupational stress.</p>

Relationship between occupational stressors and serum levels of thyroid hormones in policemen / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship of occupational stressors with the serum levels of triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH).</p><p><b>METHODS</b>Using convenience sampling and cluster sampling methods, 225 policemen from a local police station in China were enrolled as subjects. Questionnaires were used to investigate demographic features and occupational stressors in those subjects. The serum levels of T3, T4, and TSH were measured by radioimmunoassay. The SPSS 13.0 software was used to perform t test or analysis of variance, partial correlation analysis, and multivariate non-conditional logistic regression analysis.</p><p><b>RESULTS</b>Reward was positively correlated with the level of T3(P<0.05). Daily tension was positively correlated with the level of T4(P<0.05). Psychological demand, effort, and daily tension were negatively correlated with the level of TSH (all P<0.05). The quality of sleep was positively correlated with the level of TSH (P<0.05). The logistic regression analysis revealed that the risk of increase in T3 level in the group with a high score for daily tension was 3.19-fold higher than that in the group with a low score, while the risk of increase in T3 level in the group with a high score for negative emotion was 1.32-fold higher than that in the group with a low score. The risk of increase in TSH level in the group with a high score for negative emotion was 0.43-fold that in the group with a low score.</p><p><b>CONCLUSION</b>The occupational stressors are correlated with the serum levels of thyroid hormones. Occupational stress can result in an increase in T3 level and a decrease in TSH level. However, occupational stress has no effect on T4 level.</p>

Depressive symptoms and influencing factors in employees from thirteen enterprises / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore depressive symptoms and influencing factors in employees from 13 enterprises.</p><p><b>METHODS</b>A total of 6711 workers from 13 enterprises were investigated by cluster sampling, and data were collected anonymously between November 2008 and June 2009. Job satisfaction, occupational stressors, strains, coping strategy, and social support were measured using occupational stress instruments, job content questionnaire, and effort-reward imbalance questionnaire.</p><p><b>RESULTS</b>Median and P25~P75 values of depression score were 14 and 9~21, respectively. The depression score of male workers (16.31 ± 10.12) was significantly higher than that of female workers(14.50 ± 9.08) (Z=4.09, P<0.01). The depression score of managers was lowest (12.89 ± 8.70), and the front-line workers scored highest (16.02 ± 9.94), with a significant difference between the two groups (χ² =9.90, P<0.01). The depression score of shift workers (16.79 ± 9.974) was significantly higher than that of non-shift workers (14.81 ± 9.63) (Z=53.43, P<0.01). The depression scores of workers with weekly job times of ≤ 40 h, ~50 h, ~59 h, and ≥ 60 h were (14.70 ± 9.94), (15.76 ± 9.84), (15.46 ± 9.91), and (19.70 ± 10.67), respectively (χ² = 31.79, P <0.01). Correlation analysis revealed that depression score was negatively correlated with the scores of job control (r=-0.236, P <0.01), reward (r=-0.443, P<0.01), job satisfaction (r=-0.418, P<0.01), positive affectivity (r=-0.307, P <0.01), superior support (r=-0.287, P<0.01), colleague support (r=-0.235, P<0.01), and coping strategy (r=-0.208, P<0.01), but positively correlated with the scores of external effort (r=0.225, P<0.01), inherent effort (r=0.248, P<0.01), psychological demands (r = 0.246, P <0.01), physical demands (r=0.246, P<0.01), and negative affectivity (r=0.525, P<0.01). Multivariate logistic regression analysis revealed that the risk of depressive symptoms in workers with high negative affectivity was about four times as high as that in workers with low negative affectivity. The risks of depressive symptoms in workers with low reward, having disease in the past six months, and with high inherent effort were 1.62, 1.50, and 1.48 times, respectively, as high as those for their counterparts.</p><p><b>CONCLUSION</b>Occupational stress, individual factors, health status, and shift work affect the depressive symptoms of workers. Reducing negative affectivity and increasing rewards are main measures to relieve depressive symptoms.</p>

Effects of occupational stress and related factors on depression symptoms in train drivers / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the influence of occupational stress and related factors on depression symptoms in train drives.</p><p><b>METHODS</b>In March 2012, by using cluster sampling method, a cross-sectional epidemiological study was conducted in 1 402 train drivers in China. Questionnaires was investigation was conducted by face to face interview. Sample with missing variables on demographic characteristics questionnaire with missed survey variables, and occupational stress related factors and with over 3 item missing in depression symptoms self-rating scale were exclued. Depression symptoms were measured by Center for Epidemiological Survey Depression Scale. The occupational stress related actors were measured by the revised effort-reward imbalance (ERI) model questionnaires and occupational stress measurement scale. Chi-square test was carried out to analyze the differences of the incidence of depressive symptoms among different general characteristics groups, and multivariate logistic regression analysis was conducted to analyze the influence of occupational stress and related factors on depression symptoms in train drivers.</p><p><b>RESULTS</b>The study showed that the average age of 1 402 subjects was (34.95±9.20) years, the length of service were (13.28±9.78) years, the score of depressive symptoms was (24.14±5.98) scores. 902 subjects (64.3%,902/1 402) were classified as people with depressive symptoms, the incidence of depressive symptoms in EMU or high-speed train drivers were the highest (68.0%,51/75); Incidence of depressive symptoms showed that were statistically significant differences in two groups of technical secondary school and college, and incidence of depressive symptoms in the junior college and above group (68.1%,352/517) was higher than that in the senior high school and below group (62.1%, 550/885) (χ(2)=5.02, P=0.025). The results of the multiple logistic regression analysis revealed that high levels of education (OR=1.63, 95%CI: 1.12-2.19), role conflict (OR=1.65, 95% CI: 1.21-2.24), role ambiguity (OR=1.99, 95% CI: 1.45-2.73), negative emotion(OR=2.87, 95%CI: 2.15-3.82), daily tension(OR=2.86, 95%CI: 2.11-3.86), poor colleagues and family support (OR=1.55, 95% CI: 1.11-2.16 and OR=1.75, 95% CI: 1.27-2.41) were risk factors of depressive symptoms, but positive emotion (OR=0.72, 95% CI: 0.53-0.96), self-esteem (OR=0.22, 95% CI: 0.16-0.30), and job itself satisfaction (OR=0.48, 95%CI: 0.35-0.65) were protective factors of depressive symptoms in train drivers.</p><p><b>CONCLUSION</b>Train drivers, in particular EMU or high-speed train drivers who were prone to depressive symptoms. To arrange reasonably job roles and tasks, increase support from superiors, colleagues, and family, bring up healthy and coordinated personality, keep a good mood, promote job satisfaction, reduce the daily tension have positive effects on reducing the occurrence of depressive symptoms for train drivers.</p>

The effect of occupational stress on depression symptoms among 244 policemen in a city / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the influence of occupational stress related factors on depression symptoms among 244 policemen in a city in China.</p><p><b>METHODS</b>In May 2011, 287 policemen from a city public security bureau were recruited to this survey by cluster sampling method. We deleted questionnaires which include missing variables on demographic characteristics and factors associated with occupational stress questionnaires which include over 3 missing items. 244 policemen were included in this study. Depression symptoms and occupational stressors were measured using Chinese version of depression self-reported questionnaire, job content questionnaire, Chinese version of effort-reward imbalances questionnaire, job hazard scale and occupational stress inventory. Depression symptom scores and the relationship between the variables and occupational stress were analyzed by Spearman correlation analysis and multiple regression analysis.</p><p><b>RESULTS</b>The Median (P25-P75) of depression symptom scores of all respondents was 16.50 (11.00-25.00). 144 were policemen with no depression symptoms and 100 were with depression symptoms. The median (P25-P75) of depression symptoms scores among policemen with length of serves <10, 10-19, 20-29 and ≥30 was 17.00 (8.00-26.00), 16.00 (11.00-24.50), 19.00 (12.00-27.00), and 12.00 (6.25-15.00), respectively. The difference of scores was significant among length of serves groups (χ2=9.52, P=0.023). The scores of psychological demands, sleep disorder, daily life stress and negative affectivity among policemen with depression symptoms were 17.00 (8.00-26.00), 16.00 (11.00-24.50), 19.00 (12.00-27.00), and 12.00 (6.25-15.00), respectively, which were higher than those with no depression symptoms (24.00 (22.00-25.00), 8.00 (5.00-13.00), 8.00 (6.00-10.00), 1.00 (0-2.75)), and the differences were significant (Z=3.82, 5.39, 5.15, 6.41, P<0.001). Spearman correlation analysis revealed that depression symptoms score was positively related to sleep disorder, commitment effort, psychological demands, daily life stress, negative affectivity and job hazards scores. Correlations coefficient were 0.44, 0.28, 0.28, 0.33, 0.38, 0.44, and 0.38, respectively (P<0.001). Multiple linear regression analysis indicated that self-esteem, daily life stress and negative affectivity had bigger contribution on the depression symptoms scores. The standard regression coefficient was -0.46, 0.19 and 0.13, respectively (P<0.001, P=0.001, P=0.030).</p><p><b>CONCLUSION</b>Sleep disorder, commitment effort, psychological demands, daily life stress, negative affectivity and job hazards scores were the inducement of depression symptoms for policemen. To reduce the daily life stress, negative affectivity and improve the quality of sleep, add to self-esteem, reward and social support have positive effects on reducing the occurrence of depressive symptoms for police.</p>

Investigation of coping strategy for occupational stress among workers in thirteen enterprises / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the influential factors for the coping strategy for occupational stress among workers in thirteen enterprises.</p><p><b>METHODS</b>An anonymous survey was conducted in 6711 workers in 13 enterprises selected by cluster sampling from November 2008 to June 2009. Coping strategy, occupational stressors, stress response, and social support were measured using occupational stress instruments, job content questionnaire, and effort-reward imbalance questionnaire. The data from 5338 workers were statistically analyzed; the overall response rate was 79.6%.</p><p><b>RESULTS</b>The median coping strategy score was 26 (23-30) (P25∼P75). The coping strategy score of male workers (26.56±5.30) was significantly higher than that of female workers (26.07±5.37) (Z = 10.02, P < 0.01). Coping strategy score was the highest in managers (27.41±4.86) and the lowest in front-line workers (26.28±5.36), with a significant difference between the two groups (χ(2) = 5.38, P < 0.01). The coping strategy scores of workers with weekly job times of ≤40 h, 41-50 h, 51-59 h, and ≥ 60 h were 26.93±5.36, 26.72±5.11, 25.74±5.30, and 25.09±5.83, respectively (χ(2) = 22.12, P < 0.01). Correlation analysis revealed that coping strategy score was positively correlated with decision level (r = 0.183, P < 0.01), reward (r = 0.207, P < 0.01), positive emotion (r = 0.244, P < 0.01), superior support (r = 0.176, P < 0.01), coworker support (r = 0.176, P < 0.01), and job satisfaction (r = 0.171, P < 0.01), but negatively correlated with psychological demands (r = -0.157, P < 0.01), physical demands (r = -0.099, P < 0.01), negative emotion (r = -0.093, P < 0.01), and depressive symptoms scores (r = -0.208, P < 0.01). Compared with those with middle or low coping strategy scores, workers with high coping strategy scores reported higher decision level, reward, social support, job satisfaction, and positive emotion scores (P < 0.01) but lower depressive symptom and negative emotion scores (P < 0.01).</p><p><b>CONCLUSION</b>Enterprise type, individual factors, health status, and work time, have effects on the coping strategy for occupational stress of occupational stress.</p>

The relationship of occupational stress and the level of some hormone metabolites in urine / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the possibility for 17-OHCS, 17-KS, VMA and HVA in urine as indicators of occupational stress identification and evaluation.</p><p><b>METHODS</b>225 policies were investigated by using convenience sampling and cluster sampling methods, occupational stressors, strains, buffer factors and individual factors were measured by questionnaires. The urine 17-OHCS, 17-KS, VMA and HVA level was tested by ELISA and high performance liquid chromatography method respectively.</p><p><b>RESULTS</b>The urine 17-OHCS level of the groups with high coworker support and job control scores was lower than that of the groups with low score group (P < 0.05), the urine 17-OHCS level of the group with high negative affectivity score was higher than that of the group with low score group (P < 0.05). The urine 17-KS level of the group with high job security score was lower than that of the counterparts (P < 0.05). The urine VMA level of the group with high coworker support score was lower than that of the counterparts (P < 0.05). The urine HVA level of the group with high coping strategy score was lower than that of counterpart (P < 0.05). Logistic regression analysis revealed that the job control and respect were the protective factors of urine 17-OHCS level increase (OR = 0.353 and 0.352 respectively), but over-commitment, self-esteem and daily hassles were the risk factors of urine 17-OHCS with level increase (OR = 3.391, 2.439, and 2.584 respectively). The risk of urine 17-KS level increase for the groups high job control and job security scores were respectively 0.387, 0.356 times than that of the counterparts, the risk of urine VMA level increase for the group with high negative affectivity score was 2.643 times than that of the counterparts.</p><p><b>CONCLUSION</b>The urine 17-OHCS, 17-KS and VMA level were potential indicators for occupational stress evaluation.</p>