OBJECTIVE:To investigate the distribution and main influential factors of mental workload of middle school teachers in Nanchang City.METHODS:A total of 504 middle school teachers were sampled by random cluster sampling from middle schools in Nanchang City, and the mental workload level was assessed with National Aeronautics and Space Administration-Task Load Index (NASA-TLX) which was verified in reliability and validity.RESULTS:The mental workload scores of middle school teachers in Nanchang was approximately normal distribution. The mental workload level of middle school teachers aged 31 -35 years old was the highest. For those no more than 35 years old, there was positive correlation between mental workload and age (r = 0.146, P < 0.05). For those more than 35 years old, the levels of their mental workload had no statistically significant difference. There was a negative correlation between mental workload and educational level(r = -0.172, P < 0.05). The middle school teachers with lower educational level seemed to have a higher mental workload (P < 0.01). The longer a middle school teacher worked per day, the higher the mental workload was. Working hours per day was the most influential factor on mental workload in all influential factors (P < 0.001).CONCLUSION:Mental workload of middle school teachers was closely related to age, educational level and work hours per day. Working hours per day was the important risk factor of mental workload. Reducing working hours per day, especially reducing it to be no more than 8 hours per day, may be a significant and useful approach alleviating mental workload of middle school teachers in Nanchang City.

OBJECTIVE:To investigate the change pattern of primary and secondary school teachers' work ability with the changes in their mental workload.METHODS:A total of 901 primary and secondary school teachers were selected by random cluster sampling, and then their mental workload and work ability were assessed by National Aeronautics and Space Administration-Task Load Index (NASA-TLX) and Work Ability Index (WAI) questionnaires, whose reliability and validity had been tested. The effects of their mental workload on the work ability were analyzed.RESULTS:Primary and secondary school teachers' work ability reached the highest level at a certain level of mental workload (55.73< mental workload ≤ 64.10). When their mental workload was lower than the level, their work ability had a positive correlation with the mental workload. Their work ability increased or maintained stable with the increasing mental workload. Moreover, the percentage of teachers with good work ability increased, while that of teachers with moderate work ability decreased. But when their mental workload was higher than the level, their work ability had a negative correlation with the mental workload. Their work ability significantly decreased with the increasing mental workload (P < 0.01). Furthermore, the percentage of teachers with good work ability decreased, while that of teachers with moderate work ability increased (P < 0.001).CONCLUSION:Too high or low mental workload will result in the decline of primary and secondary school teachers' work ability. Moderate mental workload (55.73∼64.10) will benefit the maintaining and stabilization of their work ability.

目的 分析南昌市中学教师职业紧张现状并探讨其影响因素.方法 采用分层随机抽样方法抽取南昌市20所中学共742名中学教师,使用职业紧张量表(OSI-R)中的个体紧张反应问卷(PSQ)对其进行紧张反应测评.结果 南昌市中学教师PSQ得分为95.39±20.82.多元回归结果显示,经济水平越宽裕,PSQ及4个子项目的得分越低(P＜0.01);学校规模、批改作业时间及每周授课数与PSQ、PSY、PHS的得分呈正相关关系(P＜0.05);女性的PSQ、PSY、PHY得分高于男性(P＜0.05);未婚教师的PSQ及IS得分较高(P＜0.05),学生成绩好的教师VS、PSY得分较低(P＜0.05),参加培训次数多的教师PSQ及PSY得分较高(P＜0.05),担任班主任的教师VS得分较高(P＜0.05),非重点中学、教龄长、已生育的教师IS得分较低(P＜0.05).结论 南昌市中学教师的职业紧张反应程度较高,主要影响因素包括经济水平及工作负担.

OBJECTIVE:To investigate the distribution characteristics and influencing factors of mental workload of teachers in primary schools.METHODS:National Aeronautics and Space Administration-Task Load Index (NASA-TLX) was used to assess the mental workload levels for 397 teachers of primary schools in a city.RESULTS:The mental workload (64.34+10.56) of female teachers was significantly higher than that (61.73+ 9.77) of male teachers (P<0.05). The mental workload (65.66+10.42) of "-35" years old group was the highest. When age of teachers was younger than 35 years old, there was a positive correlation between the mental workload and age (r=0.146, P<0.05). When age of teachers was older than 35 years old, there was a negative correlation between the mental workload and age (r=-0.190, P<0.05). The teachers with higher education level felt higher mental workload (unstandardized coefficients B=1.524, standardized coefficients /=0.111, P<0.05). There was a positive correlation between the mental workload and working hours per day (unstandardized coefficients B =4.659, standardized coefficients/3 =0.223, P<0.001).CONCLUSION:Mental workload of the teachers in primary schools is closely related to age, educational level and work hours per day. Work hours per day is an important risk factor for mental workload. Reducing work hours per day (8 hours) is an effective measure of alleviating the mental workload of teachers in primary schools.

Objective To confirm the association between exposure to chrysotile asbestos and lung cancer risk and to demonstrate the combined effect of smoking and asbestos exposure. Methods A case–control study of 1139 asbestos workers identified 41 male lung cancer cases in 2001; each case was matched by age (±5 years) with five controls. Workers in seven workshops were categorised into high-, medium- and low-exposure subgroups, and conditional logistic regression was applied to estimate the odds ratios for lung cancer risk associated with the different exposure levels. Smoking, age at first exposure, and exposure duration were considered as covariates/confounding factors. A joint effect of asbestos exposure and smoking on lung cancer risk was analysed using a conditional logistical model. Results 54% of cases had high exposure and 24% low exposure, while 24% of controls had high exposure and 44% low exposure. Smoking was more common in cases (90%) than in controls (73%). The adjusted OR for lung cancer was 3.66 (95% CI 1.61 to 8.29) for high exposure and was elevated slightly for medium exposure (1.25; 95% CI 0.47 to 3.31). Smoking was related to lung cancer risk (OR 3.33; 95% CI 1.10 to 10.08). In comparison with the low-exposure non-smoking group, the OR for the high-exposure smoking group was 10.39 (1.34 to 82.45), in contrast to 5.23 (0.50 to 54.58) for high-exposure non-smoking workers. Conclusions These results confirm the strong association between exposure to chrysotile asbestos and lung cancer risk, and support an interactive effect of asbestos exposure and smoking which is more than additive.

OBJECTIVE:To test the reliability and the validity of Comprehensive Work Ability Index (CWAI) scales.METHODS:For evaluating the reliability and validity of CWAI scales, 1959 subjects employed in various kinds of occupations were selected with the random cluster sampling method. 245 subjects of them were retested at intervals of 2 to 4 weeks in order to assess the test-retest reliability. The sample for criterion validity consisted of 86 subjects. The inter-item consistency (Cronbach's alpha coefficient, Spearman-Brown coefficient, theta coefficient and Omega coefficient), test-retest reliability (intra-class correlation coefficient) and Pearson correlation were calculated to assess the reliability of CWAI scales. Pearson correlation analysis, and factor analysis were used to assess the validity of CWAI scales.RESULTS:The reliability analysis showed that CWAI was significantly correlated with the item scores (P < 0.01), and most of the correlation coefficients were higher than 0.30. Generally speaking, Cronbach's alpha coefficients (ranging from 0.701 to 0.808), theta coefficient (ranging from 0.703 to 0.845) and Omega coefficient (ranging from 0.802 to 0.942) and Spearman-Brown coefficient (0.860) conformed to the requirements of psychometric study. The intra-class correlation coefficient (ranging from 0.597 to 0.897) suggested that the test-retest consistency was good at intervals of 2 to 4 weeks. In point of the theoretic concept and development method, the content validity of CWAI scales was satisfactory. The intra-class correlation coefficient for the concurrent validity was 0.650 (P < 0.01) when WAI scales were taken as the criterion. Factor analysis revealed that when eight common factors were drawn from the 17 items of CWAI scales, the cumulative variance of eigenvalues amounted to 71.894%. Each item had communality over 0.60 and its factor loading (0.538 approximately 0.948) attached to the relevant common factor was over 0.40. The common factors with higher factor loading were basically consistent with the theoretic concept of CWAI scales.CONCLUSION:CWAI scales are reliable and valid.

目的 探讨工作场所工效学负荷对肌肉骨骼功能的影响.方法 采用现场观察和自评的方法评估人造板制造工人现场工效学负荷,结合实验室测量研究对象的肌肉骨骼功能,包括背肌耐力、手部握力、腹肌力、躯干柔韧性以及肌肉骨骼功能指数(MSFI),运用多元回归分析工效学负荷对肌肉骨骼功能的影响.结果 不同工效学负荷水平肌肉骨骼功能存在明显差异,其中低负荷水平Ⅰ肌肉骨骼功能各指标均高于高负荷水平Ⅳ,在背肌力和MSFI指标上表现得尤为明显,即随着负荷水平的增高,肌肉骨骼功能呈现下降的趋势.分析身体各部位工效学负荷高低对肌肉骨骼功能的影响,显示高负荷组背部的背肌耐力低于低负荷组,高负荷组肩(臂)部位的背肌耐力和手部握力低于低负荷组,高负荷组下肢的各指标均低于低负荷组,差异均有统计学意义(P＜0.05).控制其他混杂因素后,工作场所工效学负荷与肌肉骨骼功能(除腹肌力外)存在明显的负相关(P＜0.05).结论 工作场所工效学负荷的增高在一定程度上使肌肉骨骼功能降低.

BACKGROUND:Malignant mesothelioma has a long latency period and more commonly found in those exposed to amphibole than chrysotile asbestos.METHOD:A 35 years old asbestos worker in an asbestos textile plant in Chongqing, China, developed mesothelioma after only 4 years of employment. He was born and bred in a company residence of an asbestos plant and manually spun asbestos thread during school age. In the plant, not amphibole but only chrysotile has been used.RESULTS:Diagnosis of malignant mesothelioma was confirmed by comprehensive approaches including gross appearance, histology, histochemistry, and immunocytochemistry. In the lung and tumor tissues, huge number of tremolite with exceptional chrysotile was observed despite the reverse proportion in the work environment.DISCUSSION:Residential exposure and home spinning of asbestos seemed contributed to the early development of mesothelioma in this subject. Although only chrysotile was used and contamination of tremolite was low in the work environment, chrysotile seemed to be cleared leaving tremolite remain in the tissue.CONCLUSION:Chrysotile with little contamination of tremolite can lead to early development of malignant mesothelioma when heavily exposed from childhood at a company residence with household exposure. There can be several mechanisms for tremolite to remain in the lung tissue, far exceeding chrysotile in number.

Objective To investigate the relationship between work ability and occupational stress and the influencing factors of work ability among teachers.Methods Work ability and occupational stress were measured on teachers in Flying College CAAC using Work Ability Index(WAI)Questionnaire and Occupational Stress Inventory Revised Edition(OSI-R).According to WAI,work ability level was classified as poor,fair,good and excellent.The differences of occupational stress among different levels of work ability were analyzed.Results The scores of work ability of teachers in the college were all classified over fair.The scores of the teachers' occupational role,strain and coping resources were significantly different among different levels of work ability(P0.05).The higher the teachers' WAI were,the lower their scores of occupational role and strain were,while the higher their scores of coping resources were.The teachers' work ability had a significant negative relationship with occupational role strain,and a significant positive relationship with coping resources(P0.05).Conclusion Occupational stress was an important effective factor to teachers' work ability,thus releasing the level of their occupational stress and increasing their coping resources were effective measures to improve their work ability.

OBJECTIVE:To investigate whether asbestosis is a risk factor for mortality of lung cancer.METHODS:A fixed cohort study was established in an asbestos plant in Chongqing, China, and followed up for 30 years from the beginning of 1972. Basic personal information on life state, cause of death, and diagnosis of asbestosis was collected. Multiple logistic regressions were applied to analyze risk factors.RESULTS:During the 30-year follow-up, 584 male workers constituting a total of 14,664 person-years were monitored and data were analyzed. Among them, 203 (34.8%) died and the mortality rate was 13.8 per 1000 person-years, cancer accounting for 37.4%. Excess risks were observed for lung cancer (OR = 3.72) and nonmalignant respiratory diseases (OR = 2.73) among workers with asbestosis. High-exposure level was another risk factor for lung cancer (OR = 3.20). Workers with category II of asbestosis demonstrated a higher OR of both lung cancer and nonmalignant respiratory diseases than those with category I of asbestosis.CONCLUSION:High asbestos exposure level and asbestosis were the risk factors for death of lung cancer and nonmalignant respiratory diseases. Asbestosis is an independent risk factor for lung cancer among Chinese workers exposed to chrysotile, the risk increases with the increasing profusion of opacities of lung.

Aim: To evaluate the status of medical workers' quality of life and explore the influence of occupational stress on physical health,mental health and quality of life.Methods:A total of 1 630 medical workers were sampled from five provincial and municipal hospitals which were randomly selected using the method of cluster sampling.Measuring instruments(OSI-R and SF-36) were adopted to investigate the status of medical workers' occupational stress and quality of life.Results: The medical workers of 30~40 years old had the worst quality of life(P<0.01);occupational role and personal stress were negatively related with physical component summary,mental component summary and quality of life(P<0.01),whereas personal coping resources was positively correlated with physical component summary,mental component summary and quality of life(P<0.01).The correlation coefficients between occupational role,personal stress,coping resources and mental component summary were greater than those between occupational role,personal stress,coping resources and physical component summary respectively.Occupational role,personal stress and coping resources were more predictive to mental component summary than to physical component summary.The main influencing factors of medical workers' physical component summary were role overload,physical environment,role boundary,role conflict,physical strain response,mental strain response,recreation,social support and self-care,whereas the influencing factors of medical workers' mental component summary were the scales of occupational role,mental strain response,physical strain response,and the scales of personal coping resources.Conclusion: The medical workers' quality of life is different in different age groups.Medical workers who have high level of occupational stress would have lower quality of life.Coping resources could alleviate the impact of occupational stress on quality of life.Different kinds of occupational stress and coping resources could have different impacts on physical and mental health.The influence of occupational stress and coping resources on mental health is larger than that on physical health.

Background: Few safety climate measures have been developed and assessed in Chinese industry.Aims: The aim of this presented paper is to develop a safety climate questionnaire for use in China, and examine its validity and reliability.Methods: A 27-item safety climate questionnaire was developed after a scientific literature review and consultation with Chinese safety experts. 1026 workers in several industrial sectors responded to the questionnaire. A 21-item questionnaire measuring safety climate was extracted from the original 27 items. Exploratory factor analyses and inter-item consistency were applied to examine construct validity and reliability. Comparisons of safety climate scores among various groups by age, years of work experience, accident involvements, and organizations were used to test discriminant validity.Results: The safety climate questionnaire loading on components revealed seven different factors: safety awareness and competence, safety communication, organizational environment, management support, risk judgment, safety precautions, and safety training. These factors explained the 70.5% variance. Coefficients of inter-item consistency met psychometric requirements. Significant differences on some safety climate scales among accidental involvement and organizations were detected.Conclusion: Safety awareness, competence, and safety communication are important factors in safety climate measurement in Chinese industry. Safety climate measurement among Chinese workers with this 21-item questionnaire is valid and reliable. (C) 2007 Elsevier Ltd. All rights reserved.

[目的]探讨工作场所工效学负荷与肌肉骨骼疾患的剂量反应关系,为预防职业性肌肉骨骼疾患提供依据.[方法]用工效学负荷综合评估方法(CQEC)现场评估火力发电和人造板制造行业不同工作场所工人的工效学负荷,用Nordic量表研究调查对象的肌肉骨骼症状,用多因素分析二者间的剂量反应关系.[结果]工效学高负荷组的肌肉骨骼患病率高于低负荷组.且随着负荷增高,症状阳性率亦升高;多因素分析工效学负荷增高是患病的主要危险因素,随着负荷的增高,危险度(OR值)亦逐渐增大,在下背、手腕部位表现尤为明显.[结论]工作场所工效学负荷与肌肉骨骼疾患存在一定的剂量反应关系.尤其是下背和手腕部位的负荷.

The purpose of this study was to explore the status of the job burnout of doctors and the variables associated with this in China. The sample consisted of 543 doctors from three provincial hospitals in China. The Maslach Burnout Inventory-General Survey (MBI-GS) was used to measure burnout, and the occupational stress inventory revised edition was used to measure the two dimensions of occupational adjustment (including occupational stress and coping resources). After the statistical testing for validity and reliability of MBI-GS with nurses in China, the participants' scores were evaluated and analysed. The main results were as follows. The scores of job burnout of the surgeon and physician were significantly higher than the others (p < 0.05). The score of exhaustion (EX) was significantly higher in the 30- to 40-year age group than that in any other groups. The score of professional efficacy (PE) decreased with age, while this increased with educational status. Occupational stress was significantly positively related to all burnout dimensions (p < 0.05), while coping resources correlated negatively to all burnout dimensions. Under multilevel regression, the main significant predictors of EX were role overload, responsibility, physical environment and self-care. The main significant predictors of cynicism were role insufficiency, role overload and responsibility, and of PE were role insufficiency, social support and rational/cognitive coping (p < 0.05). Organizational efforts aimed at reducing occupational stress and strengthening their coping resources among doctors could help prevent job burnout. Copyright (c) 2007 John Wiley & Sons, Ltd.

OBJECTIVE To evaluate the sub-health condition of teachers of the middle schools. METHODS The method of cluster random sampling trial was adopted. The sub-health condition was interviewed by the questionnaire made by ourselves, and was detected by multifunctional microscopy diagnostic instrument for 693 teachers in study group and 970 persons in control group. RESULTS The results showed that the questionnaire could get a good reliability and validity. The results of questionnaire inspection were accordant with the multifunctional microscopy diagnostic instrument in evaluating sub-health condition. The incidences of sub-health condition in study group were more higher (58.8%) than those in the control group (50.0%) (P < 0.05), and the incidences of sub-health condition in female teachers (60.9%) were more hither than those in male teachers(55.9%) (P < 0.05), and the incidences of sub-health condition at the age of 30-45 years (73.0%) were more higher than those in any other ages (P < 0.05). CONCLUSION The results indicated that teachers of the middle schools could easily suffer from sub-health condition.

Aim:To investigate the relationship between the occupational stress and the sub-health condition.Methods:Occupational stress of 685 middle school teachers was investigated by the questionnaire of occupational stress inventory revised edition (OSI-R) and their sub-health condition was evaluated by the questionnaire made by ourselves subjectivey. The activity of neurotransmitter (GABA, GLU, ACHR, 5-HT, ACH, NE,and DA) was detected as objective index for evaluating occupational stress with the advanced encephaloflutuograph technology.Results: The results showed that psychological strain was negatively correlated to the activity of GABA and Glu and positively correlated with the activity of 5-HT, Ach, NE,and DA(P0.05). The scores of occupational role and personal strain were positively correlated to the score of sub-health condition(P0.05). While, there were significantly negative correlations between the score of personal resource and the score of sub-health condition (P0.05). The activity of GABA was negatively correlated to the score of sub-health condition,while the activity of 5-HT was positively correlated to the score of sub-health condition. Results from multiple linear regression showed that psychological strain, physical strain and divorce were the main risk factors of the subhealthy state, while recreation and social support were favorable to the health.Conclusion: The occupational stress is an important risk factor of middle school teacher's sub-health condition. So reducing occupational stress and strengthening their coping resources may be efficient intervention measures for improving sub-health condition.

OBJECTIVE:To investigate the change of neurobehavioral functions of workers with long term exposure to vanadium.METHODS:A total of 106 workers with exposure to vanadium were paired with workers without exposure to vanadium. The WHO-NCTB was employed to assess the neurobehavioral functions.RESULTS:The exposure group had lower scores in the domains measuring positive moods and higher scores in the domains measuring negative moods. The exposure group had poorer performance in Santa Ana dexterity, Benton visual retention and pursuit aiming II than the control group.CONCLUSION:Exposure to vanadium can adversely affect neurobehavioral functions of workers. Workers exposed to vanadium may show mood disorders, decreased vision-memory, and declined motor speed and accuracy.

AIM This article is a report of a study of occupational burnout among nurses in China. BACKGROUND Burnout is described as feelings of emotional exhaustion, depersonalization and reduced personal accomplishment. It is well-known that burnout is a major problem for many professions. Nurses are considered to be particularly susceptible to this. Measuring burnout among nurses is important because their well-being has implications for stability in the healthcare workforce and for the quality of care provided. METHOD The sample consisted of 495 nurses from three provincial hospitals in China. The Maslach Burnout Inventory -- General Survey (MBI-GS) was used to measure burnout, and the Occupational Stress Inventory -- Revised edition was used to measure two dimensions of occupational adjustment (occupational stress and coping resources). After statistical testing for validity and reliability of the MBI-GS with nurses in China, participants' scores were evaluated and analysed. RESULTS Scores for burnout of surgical and medical nurses were statistically significantly higher than those of other nurses (P < 0.05). Lower educational status was associated with lower professional efficacy, and younger nurses reported higher levels of burnout. The most significant predictors of emotional exhaustion were role overload, responsibility, role insufficiency and self-care (P < 0.05). The most significant predictors of cynicism were role insufficiency, role boundary, responsibility and self-care (P < 0.05). The most significant predictors of professional efficacy were role insufficiency, social support and rational/cognitive coping (P < 0.05). CONCLUSION It is important to reduce occupational stress in nurses and to strengthen their coping resources to prevent burnout. This could be achieved with job redesign, modification of shiftwork systems, and by offering occupational health education.

OBJECTIVE:To identify the factors that affect the implementation of workers' manuals of occupational health and safety management system (OHSMS).METHODS:A self-designed questionnaire, which contained 23 items, was used to investigate workers' knowledge, responsibility and supporting environment of the OHSMS. The Logistic Regression Model was developed to identify factors that affect the implementation of the OHSMS.RESULTS:Demographic characteristics did not affect the implementation of the OHSMS manual. Knowledge (six out of seven items), responsibility and supporting environment had significant impact on the implementation of the OHSMS manuals.CONCLUSION:A variety of factors affect workers' compliance to the OHSMS manuals and need to be better controlled.

OBJECTIVE:To develop a measurement of safety climate at workplace and assess its validity and reliability.METHODS:According to the theory of preventive safety culture model, a scale including 7 dimensions of 27 items was developed. 342 workers were selected from among all workers of an artificial board factory and were investigated with the developed scale. Occupational accidents were recorded during the past year. Factor analysis, association validation and inter-item consistency test were applied to assess the scale validity and reliability.RESULTS:After the deletion of 6 items, 21 items composed the safety climate scale, which was loaded on 7 common factors: safety competence and consciousness, safety communication, organizational environment, management support, danger judgment, safety control measure and safety training. The cumulative contribution reached to 70.50%. All item communities (common factor variance) were above 0.6 except one item was 0.595. ANOVA showed that occupational accidents were associated with the safety climate score on total, danger judgment and safety control measure dimension (P < 0.05). There existed significant correlation between the safety climate total score and dimension scores (P < 0.01), the correlation coefficients were 0.700, 0.728, 0.705, 0.703, 0.354, 0.571 and 0.485 respectively. The safety climate scale total Cronbach's alpha coefficient, half-split Spearman-Brown coefficient, theta coefficient and omega coefficient indicated that the safety climate scale had good inter-item consistency among items.CONCLUSION:The measurement of safety climate at workplace is developed. It has good reliability and valid.