Mental health problems have recently increased among Japan Overseas Cooperation volunteers since 1965, when the Ministry of Foreign Affairs (Japan International Cooperation Agency) launched this volunteer work project for improving hygiene and socioeconomic conditions in developing countries. There was little research on job stress among them dispatched despite previous surveys indicating job as an important stressor. To investigate stress and job-related stressors among them, we conducted a cross-sectional epidemiological study from October to December in 2003. The subjects were all 1,084 Japan Overseas Cooperation volunteers aged 20-40, who worked in 67 countries worldwide at the time of this study (485 and 599 males and females, 316, 332 and 436 for those staying overseas for 11, 7 and 4 months, respectively). Approximately 80% were involved in their dispatching occupational organizations as professionals in information technology, health & welfare, education, and research. Our main outcome measure used was the Brief Job Stress Questionnaire, which was developed to assess stress and job-related stressors or buffers for Japanese workers. Demographic and personality (Egogram) characteristics as well as other health information were obtained. The response rate was 86.9%. For psychological stress, prevalence was 5.5% (n = 49). Means (Å}SD) were 4.22 (Å}3.98), and 4.89 (Å}4.40) for males and females (p < 0.05), and 5.15 (Å}4.17), 5.05 (Å}4.45), 3.93 (Å}4.40) for those staying overseas for 11, 7 and 4 months (p < 0.01), respectively. For physical stress, prevalence was 2.9% (n = 26). Means (Å}SD) were 1.10 (Å}1.68), and 1.41 (Å}1.74) for males and females (p < 0.01), and 1.47 (Å}1.77), 1.35 (Å}1.89), 1.11 (Å}1.55) for those staying overseas for 11, 7 and 4 months (p < 0.05), respectively. The factors significantly associated with psychological stress were high job demand, poor human relationships at work, low job suitability, low social support from supervisors and colleagues, and being dissatisfied with their life, according to multiple logistic regression analysis. The present study suggested that psychological stress was more prevalent than physical. It also implied a significant relationship between psychological stress and job-related stressors among the subjects of this study as in employees in Japan. Mental health check-ups and counseling in the early stage of psychological stress is important from the viewpoint of prevention of developing stress-related mental health disorders. Education on stress-coping skills should be considered in a training program before they are sent overseas. (San Ei Shi 2004; 46: 191-200)
With the spread of visual display terminals (VDT) in offices, the numbers of workers using VDT and the working hours at such equipment have increased rapidly in recent years. Also, preventive measures for fatigue have been proposed and the office-working environment has been improved. To examine the effects of the rapid changes in working conditions and environment on the health of VDT workers, we conducted a questionnaire survey in 2002. A self-reported questionnaire was distributed to 3,927 office workers; 2,374 (60.5%) responded. Subjects whose questionnaires had missing data were excluded from analysis. As a result, 1,406 (male: 1,069, female: 337) workers aged 20 to 59 were subjected to analysis. By a logistic regression model, we examined the association between VDT use and visual and musculoskeletal symptoms. Prevalence of eye strain and/or pain (72.1%) was the highest, followed by neck stiffness and/or pain (59.3%), low back stiffness and/or pain (30.0%) and hand or arm strain and/or pain (13.9%). Women consistently reported more discomfort than men. As a result of the logistic regression model, eye strain and/or pain was associated with dissatisfaction with airflow, but not with factors affecting visual symptoms as reported in previous studies, for example, reflection of light and blurred characters on the screen. It was thought that airflow appeared as a risk factor because the lighting environment had been improved in offices to prevent reflection of light on the screen. Neck stiffness and/or pain was associated with raising the shoulders during VDT work, the unsuitable shape of the computer mouse for a hand, and the inconvenient arrangement of the mouse in relation to the body. Hand or arm strain and/or pain were associated with the arrangement of the mouse and inappropriate height of the desk. Low back stiffness and/or pain were associated with dissatisfaction with the chair and using the keyboard without a wrist rest. Although measures to prevent fatigue had been implemented for VDT workers, risk factors for musculoskeletal symptoms would be the same as in previous studies.
In order to investigate the reliability and validity of the short version of the 30-item Organizational Climate Scale (OCS-30; Toshima and Matsuda, 1992, 1995), a self-administered questionnaire was conducted in a sample of 819 employees of two medium-sized private companies in Japan by using the OCS-30, the Generic Job Stress Questionnaire (GJSQ), and the 12-item General Health Questionnaire (GHQ-12). The OCS has two subscales, i.e., the Tradition Scale (TS) and the Organizational Environment Scale (OES). The organizational climate perceived by each worker can be grouped into four categories based on the subscale scores: low TS and high OES (Active), high TS and high OES (Governed), low TS and low OES (Disorganized), and high TS and low OES (Reluctant). Principal component analysis for the OCS-30 was submitted (varimax rotation, the number of factors=2), and 6 items for each factor, with factor loadings greater than 0.50, were selected for the short version, which constituted the 12-item Organizational Climate Scale (OCS-12). Cronbach's alpha reliability coefficients of the two subscales of the OCS-12 were acceptable; 0.63 for the TS and 0.71 for the OES. Both two subscales of the OCS-12 were significantly correlated with the GHQ-12 and many subscales of the GJSQ, which indicated the good constructive validity of the OCS-12. Among 4 types of organizational climate categorized by the OCS-12, the "Active" group showed the lowest job stress scores. It is suggested that the OCS-12 could be a reliable and valid instrument for assessing workers' perception of workplace climate.
In order to determine the relationship between exposure to hand-arm vibration through the use of vibration tools and dysfunction in the maintenance of postural balance, 106 male forestry workers were examined by stabilometry for deflection in the center of gravity and in the air conduction hearing levels. A questionnaire survey was also conducted among the workers in order to obtain details regarding their age, the types of tools used by them, and the duration for which they had used a chain saw. The vibration acceleration of a chain saw has been limited to a level of 3 G or less since 1976 in accordance with the notification from the Japanese Forestry Agency and the Ministry of Labor. In fact, chain saws with significantly reduced vibration acceleration in comparison with those used before 1976 have been available. Therefore, in 2000, we conducted a test on forestry workers who were divided into two groups-workers who had used a chain saw for 25 years or more (25-yr-or-more group) and workers who had used a chain saw for 24 yr or less (24-yr-or-less group). Compared to the 24-yr-or-less group, the 25-yr-or-more group exhibited significantly higher levels of average deflection in the center of gravity, expressed as the enveloped (aENV) and rectangular (aREC) areas, and in the hearing levels at 500, 1000, 2000, 4000 and 8000 Hz. For the aENV, the correlation coefficients revealed significant relationships between the hearing levels at 4,000 Hz, the duration of use of a chain saw, and age. Since the duration of use of a chain saw exhibited a significant relationship with age, it was necessary to eliminate the effect of age on the aENV. Subsequently, we divided all the workers into age groups spanning ten years each (from 20 to 70 yr) and compared the aENV among the same age groups in both the 25-yr-or-more and the 24-yr-or-less groups. The averages of the aENV for each age group were higher in the 25-yr-or-more group than in the 24-yr-or-less group. In particular, a significant difference was observed in the group of workers in their 40s. Moreover, the average of aENV value was significantly higher in the 25-yr-or-more group than in the 24-yr-or-less group among the workers between 46 and 68 yr, with their ages being congruent in both groups. While investigating the impact on the workers who had used chain saws, it might be difficult to examine the effect of occupational vibration independent of the noise load. Nevertheless, this study suggests the possibility that a decrease in the maintenance of postural balance has a stronger relationship with exposure to thumping vibration in the past than with the age factor.