Journal of Occupational Health
Online ISSN : 1348-9585
Print ISSN : 1341-9145
ISSN-L : 1341-9145
Volume 52, Issue 1
Displaying 1-12 of 12 articles from this issue
Editorial
Original
  • Delphine S. Courvoisier, Thomas V. Perneger
    Article type: Original
    2010 Volume 52 Issue 1 Pages 5-13
    Published: 2010
    Released on J-STAGE: February 15, 2010
    Advance online publication: November 13, 2009
    JOURNAL FREE ACCESS
    Objective: To examine the construct validity of different formulations of job strain based on the demand-control(-support) model in the context of a hospital-based survey. Methods: We defined the best measure of job strain as the one that would be better predicted by professional status and job characteristics and better predict health outcomes, stress and back-pain leave. We received 1,298 responses from collaborators at the University Hospitals of Geneva who responded to a questionnaire survey including all the constructs cited above and the Job Content Questionnaire. Results: The difference between decision latitude and psychological demands (strain by subtraction), corresponded to the definition of the best measure of job strain and significantly, albeit weakly, predicted all outcomes. The logarithmic approach was the second best measure of job strain and was in fact a better predictor of stress. Conclusions: We would encourage researchers to explore different formulations of job strain, in particular the subtraction approach, to compute strain from demands and decision latitude.
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  • Akiyo Tanaka, Miyuki Hirata, Toshiaki Homma, Yutaka Kiyohara
    Article type: Original
    2010 Volume 52 Issue 1 Pages 14-22
    Published: 2010
    Released on J-STAGE: February 15, 2010
    Advance online publication: November 25, 2009
    JOURNAL FREE ACCESS
    Objectives: The aim of this study was to clarify the chronic toxicological effects of indium-tin oxide (ITO) and indium oxide (In2O3) on laboratory animals. Methods: Male Syrian golden hamsters were intratracheally administered 3 mg/kg or 6 mg/kg of ITO particles, or 2.7 mg/kg or 5.4 mg/kg of In2O3 particles, containing 2.2 mg/kg or 4.5 mg/kg of indium, twice a week, for 8 wk. Control hamsters were given vehicle of distilled water only. The hamsters were euthanized serially up to 78 wk after the final instillation and the toxicological effects were determined. Results: Body weight gain was significantly suppressed in the ITO 6 mg/kg-treated hamsters compared with the control group, but not in the ITO 3 mg/kg-treated or In2O3-treated hamsters. Relative lung weights among all the indium-treated groups were significantly increased compared to that in the control group throughout the observation period. The serum indium concentration among all the indium-treated groups gradually increased up to the end of the observation period. Histopathologically, foci of slight to severe pulmonary inflammatory response with diffuse alveolar or bronchiolar cell hyperplasia, expansion of the alveolar spaces and interstitial fibrotic proliferation were present in all the indium-treated hamsters and the severity of these lesions worsened with the passage of time. Lung benign adenomas were only manifest in 3 out of 15 of the ITO 6 mg/kg-treated hamsters. Conclusions: The present results clearly demonstrate that ITO and In2O3 particles caused chronic pulmonary toxicity when repeated intratracheal instillations were given to hamsters.
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  • Han-Yan Yuan, Ying Tang, You-Xin Liang, Ling Lei, Guo-Bing Xiao, Sheng ...
    Article type: Original
    2010 Volume 52 Issue 1 Pages 23-30
    Published: 2010
    Released on J-STAGE: February 15, 2010
    Advance online publication: December 16, 2009
    JOURNAL FREE ACCESS
    Objectives: To investigate the occupational and genetic risk factors inducing lumbar disc degeneration in a Chinese population, and to explore their synergistic interactions. Methods: A case-control study involving 178 low back pain patients with lumbar disc degeneration and 284 controls was carried out. Five types of work-related factors were investigated using questionnaires. Polymerase chain reaction and restriction fragments length polymorphism was used to detect the polymorphisms of MMP-3 (matrix metalloproteinase-3)(rs731236), VDR-Taq (vitamin D receptor-Taq) and VDR-Apa (vitamin D receptor-Apa)(rs35068180). Rothman's synergy index was used to measure the synergistic interactions between gene polymorphisms and occupational risk factors. Results: Family history of lumbar disc diseases, back injury history, whole-body vibration, bending/twisting, heavy physical workload, age, mutation alleles 5A of MMP-3 and A of VDR-Apa were significantly associated with lumbar disc degeneration (OR=12.70, 11.79, 8.96, 5.46, 1.05, 1.96 and 1.70, respectively, p<0.05). Synergistic interactions existed between the mutation allele 5A of MMP-3 and whole-body vibration exposure, the mutation allele 5A of MMP-3 and bending/twisting, and the mutation allele A of VDR-Apa and bending/twisting (SI=13.27, 2.91, 2.35, respectively, p<0.05). Conclusions: The results of this study suggest that gene-occupation interaction might play a certain role in exaggerating lumbar disc degeneration. There is a possibility that subjects who carry mutation alleles 5A of MMP-3 and/or A of VDR-Apa are more vulnerable to lumbar disc degeneration when they are exposed to whole-body vibration and/or bending/twisting under ergonomic loads.
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  • Monica Amati, Marco Tomasetti, Marida Ciuccarelli, Laura Mariotti, Luc ...
    Article type: Original
    2010 Volume 52 Issue 1 Pages 31-38
    Published: 2010
    Released on J-STAGE: February 15, 2010
    Advance online publication: December 22, 2009
    JOURNAL FREE ACCESS
    Objective: To examine the relationship between job satisfaction, psychological distress, psychosocial processes and stress-related biological factors, and to evaluate whether over time changes of work satisfaction could affect the immunological-inflammatory status of workers. Methods: One hundred and one nurses were enrolled at the Clinic of Occupational Medicine, Polytechnic University of Marche, Ancona, Italy. Perceived job satisfaction, psychological distress, and social support were assessed every 4 mo over a 1-yr period using 4 self-reported questionnaires. T lymphocytes CD3, CD4+, CD8+, CD8+-CD57+, B lymphocyte CD19+, NK cells CD56+, and NK cell activity were determined. Results: Job satisfaction was associated with reduced psychological distress and was characterized by low cell numbers of CD8+ suppressor T cells, CD8+-CD57+ activated T cells, CD56+ NK cells and low IL-6 levels. Over time changes in psychological parameters were related to changes in the immunological-inflammatory variables. Subjects who increased their job satisfaction showed a reduced psychological stress associated with reduced number of CD8+-CD57+ activated T cells and inflammatory cytokines. Conclusions: Job (dis)satisfaction is related with psychological mechanisms in stress affecting cellular immune function.
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  • Toshimasa Takanishi, Takeshi Ebara, Gen-i Murasaki, Tomohide Kubo, Nor ...
    Article type: Original
    2010 Volume 52 Issue 1 Pages 39-47
    Published: 2010
    Released on J-STAGE: February 15, 2010
    Advance online publication: December 22, 2009
    JOURNAL FREE ACCESS
    Objectives: The aims of the study were to investigate the systematic classification of subsidiary behaviors during visual display terminal (VDT) work and discuss the interpretation of these behaviors through an interactive model of subsidiary behaviors, work performance and autonomic nerve activity. Methods: Twelve university students were instructed to perform continuous 120-min English transcription tasks in a sedentary posture. Data on subsidiary behaviors, work performance (mean keystroke and mean error rates), and autonomic nervous system balance (log-transformed low frequency (LF) / high frequency (HF) ratio) were recorded every 5 min during VDT work. Results: The subsidiary behaviors were categorized into 3 qualitatively independent factors: distractive behaviors against monotony (DBM), sleepiness-related behaviors (SRB), and habitual behaviors (HB). A cross-correlation analysis indicated that an increase of DBM, which is considered as a sign of workers' attempt to escape from monotonous task operations, was related to a decline in performance. A decrease in the LF/HF ratio was followed by SRB after 5 min passed (r=-0.57, p<0.05), eventually leading to a restriction of the deterioration in performance. An increase of DBM was predictive of an increase in errors (r=0.54, p<0.05), and a significant negative correlation (r=-0.46, p<0.05) between HB and autonomic nerve activity at 10 min after the appearance of HB was observed. Conclusion: It emerged from the results that the factor structure of subsidiary behaviors consists of 3 mutually independent factors. The interactive model suggests that subsidiary behaviors are possibly precursory signs of errors and changes in autonomic nervous system balance.
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  • Ge Meng, Jian Zhao, He-Mei Wang, Ri-Gao Ding, Xian-Cheng Zhang, Chun-Q ...
    Article type: Original
    2010 Volume 52 Issue 1 Pages 48-57
    Published: 2010
    Released on J-STAGE: February 15, 2010
    Advance online publication: December 25, 2009
    JOURNAL FREE ACCESS
    Objectives: To investigate the complete process of cell injuries in the blood-air barrier after perfluoroisobutylene (PFIB) exposure. Methods: Rats were exposed to PFIB (140 mg/m3) for 5 min. The pathological changes were evaluated by lung wet-to-dry weight ratio, total protein concentration of bronchoalveolar lavage fluid and HE stain. Ultrastructural changes were observed by transmission electron microscope. Apoptosis was detected by in situ apoptosis detection. Changes of actin in the lung tissue were evaluated by western blot assay. Results: No significant pulmonary edema or increased permeability was observed within the first 4 h, post PFIB exposure. However, inflammatory cell infiltration and alveolar wall thickening were observed from 2 h. Destruction of the alveoli constitution integrity, edema and protein leakage were observed at 8 h. The injuries culminated at 24 h and then recovered gradually. The ultrastructural injuries of alveolar type I epithelial cells, alveolar type II epithelial cells and pulmonary microvascular endothelial cells were observed at 30 min post PFIB exposure. Some injuries were similar to apoptosis. Compared with control, more serious injuries were observed in PFIB-exposed rats after 30 min. At 8 h, some signs of cell necrosis were observed. The injuries culminated at 24 h and then ameliorated. The number of apoptotic cells abnormally increased at 30 min post PFIB exposure, the maximum appeared at 24 h, and then ameliorated gradually. Western blot analysis revealed that the level of actin in the lung showed no significant changes within the first 4 h post PFIB exposure. However, it decreased at 8 h, reached a nadir at 24 h, and then recovered gradually. Conclusions: The pathological processes were in progress persistently post PFIB exposure. The early injuries probably were the result of the direct attack of PFIB and the advanced injuries probably arose from the inflammatory reaction induced by PFIB.
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Field Study
  • Sami Abdo Radman Al-Dubai, Krishna Gopal Rampal
    Article type: Field Study
    2010 Volume 52 Issue 1 Pages 58-65
    Published: 2010
    Released on J-STAGE: February 15, 2010
    Advance online publication: November 10, 2009
    JOURNAL FREE ACCESS
    Objectives: This study aimed to determine the level and factors contributing to burnout among doctors in Sana'a City, Yemen and to determine the relationship between burnout and psychological morbidity. Methods: This was a cross-sectional study of 563 working doctors in the four main hospitals in Sana'a City, Yemen. The 12-item version of the General Health Questionnaire (GHQ12) was used as a measure of psychological morbidity and the 22-item Maslach Burnout Inventory (MBI) was used to measure emotional exhaustion, depersonalization, and personal accomplishment. Sources of job stress were determined using a 37-item scale questionnaire. The questionnaire elicited information about socio-demographic and work characteristics. Results: On the MBI, 356 doctors showed high emotional exhaustion (63.2%), 109 showed high depersonalization (19.4%) and 186 showed low personal accomplishment (33.0%). Sixty six doctors (11.7%) were identified as experiencing a high degree of burnout (high emotional exhaustion and depersonalization and low personal accomplishment). The prevalence of high degree of burnout was significantly higher in those with duration of work ≤10 yr (OR=2.8, 95% CI 1.18-6.8), in those working ≥40 h/wk (OR=2.1, 95% CI 1.25-3.62) and in those who had psychological morbidity (OR=5.3, 95% CI 2.22-12.39). Thirteen out of 37 sources of stress were significantly associated with high degree of burnout. In multivariate analysis, the significant predictors of high burnout were: dealing with patient's psychosocial problems, feeling of isolation, disturbance of home/family life by work, not chewing khat, long working hours and psychological morbidity. Conclusion: The prevalence of high degree of burnout as well as emotional exhaustion in Yemeni doctors was higher than those reported internationally and was associated with psychological morbidity and many important sources of job stress.
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  • Jiro Takaki, Akira Minoura, Hirohiko Irimajiri, Asako Hayama, Yuri Hib ...
    Article type: Field Study
    2010 Volume 52 Issue 1 Pages 66-73
    Published: 2010
    Released on J-STAGE: February 15, 2010
    Advance online publication: November 10, 2009
    JOURNAL FREE ACCESS
    Objectives: Recent prospective evidence drawn from the Whitehall II cohort reported by Kivimäki et al. implies that stressful situations are related to decreased body weight in thin men and increased body weight in obese men, whereas no corresponding interactive effects are observed in women. The mechanism underlying this phenomenon remains unknown, and the purpose of this study was to confirm our hypothesis that the relevant mechanism is behavioral (e.g., over-eating). Methods: The subjects of this survey were 607 Japanese workers (response rate: 60.5%) in four organizations. The questionnaire solicited demographic information and included the Bulimia scale of the Eating Disorder Inventory-EZ to measure tendencies toward over-eating as well as the Japanese version of the Effort-Reward Imbalance Questionnaire (ERIQ). Body mass index (BMI) was calculated on the basis of data obtained during medical check-ups. We tested for linear and interactive effects with hierarchical regression analyses. Results: BMI was significantly (p<0.05) associated with over-eating both univariately and after adjusting for age in both sexes. Significant (p<0.05) interactions showed that ERIQ effort scores and effort-reward ratios were more positively associated with over-eating in men with higher BMIs, and ERIQ reward and financial remuneration scores were more negatively associated with over-eating in men with higher BMIs. No corresponding interactive effects were observed among women. Conclusions: The results demonstrate that stressful situations are more associated with over-eating in men with higher BMIs. This might explain, in part, the mechanism underpinning the interactive effects proposed by Kivimäki et al.
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  • Jiro Takaki, Akizumi Tsutsumi, Yasuhito Fujii, Toshiyo Taniguchi, Kumi ...
    Article type: Field Study
    2009 Volume 52 Issue 1 Pages 74-81
    Published: 2009
    Released on J-STAGE: February 15, 2010
    Advance online publication: November 25, 2009
    JOURNAL FREE ACCESS
    Objectives: Interest in workplace bullying and harassment has been increasing in Japan. At present, the Negative Acts Questionnaire (NAQ) is one of the most frequently used questionnaires for assessing these issues. The purpose of this study was to develop a Japanese version of the NAQ. Methods: We translated the original version of the NAQ using a back-translation method. Participants in this study were recruited from 737 workers at a manufacturing company in Japan. Data were obtained from questionnaires completed by 517 respondents (response rate: 70.1%). Results: We used a cross-validation approach. A three-factor model was obtained from exploratory factor analyses. The confirmatory factor analysis for this model revealed values of 0.94, 0.91, 0.95, and 0.054 for the goodness-of-fit index, the adjusted goodness-of-fit index, the comparative fit index, and the root mean square error of approximation, respectively. Pearson's correlation coefficients for the NAQ scores with the Job Content Questionnaire (JCQ) support scores and the Effort-Reward Imbalance Questionnaire scores for respect and job security were significant (p<0.001) and the direction of these associations were consistent with our expectations, with the exceptions of the correlations between the NAQ sexual harassment score and the JCQ support scores. Cronbach's alpha coefficients for the scores on the entire NAQ scale and on three subscales (person-related bullying, work-related bullying, and sexual harassment) were 0.90, 0.84, 0.60, and 0.60, respectively. Conclusions: A Japanese version of the NAQ was developed and it appears to have acceptable levels of internal consistency reliability and factor- and construct-validity.
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  • Yongwen Chen, Jinxi Chen, Yuwei Sun, Yimin Liu, Likang Wu, Ya Wang, Sh ...
    Article type: Field Study
    2010 Volume 52 Issue 1 Pages 82-88
    Published: 2010
    Released on J-STAGE: February 15, 2010
    Advance online publication: December 22, 2009
    JOURNAL FREE ACCESS
    Objectives: The aim of the study was to develop a model of basic occupational health services (BOHS) in Baoan, which could provide occupational health services (OHS) universally for workers and control occupational hazards. Methods: Steps involved in the BOHS strategy included construction of the BOHS system, capacity building, health training and education, surveillance of workplaces and the health of workers, risk assessment, control and evaluation processes. Results: This model provided BOHS to employees universally, especially migrant workers in small- and medium-sized enterprises (SMEs) who had been underserved. It expanded the coverage of OHS and improved their content. The knowledge and recognition rate of occupational diseases, the coverage rates of working places and workers rose significantly after three years development. Furthermore, BOHS were cost-effective and accepted by both employers and employees. Conclusions: Our experience suggests that a BOHS strategy might be a feasible and effective way of protecting the health of workers confronted with occupational hazards.
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Occupational Health/Safety in the World
  • Prasit Kachaiyaphum, Nopporn Howteerakul, Dusit Sujirarat, Sukhontha S ...
    Article type: Occupational Health / Safety in the World
    2010 Volume 52 Issue 1 Pages 89-98
    Published: 2010
    Released on J-STAGE: February 15, 2010
    Advance online publication: December 16, 2009
    JOURNAL FREE ACCESS
    Objective: To estimate the prevalence of, and factors associated with, abnormal serum cholinesterase (SChE) levels among chilli-farm workers in Chatturat District, Chaiyaphum Province. Methods: A total of 350 chilli-farm workers aged 18-60 yr were randomly sampled and interviewed. A reactive-paper finger-blood test was used to assess SChE levels. Results: The prevalence of abnormal SChE levels was 32.0%. The most common pesticide-related symptoms were dizziness (38.0%), headache (30.9%), nausea/vomiting (26.9%), and fever (26.9%). Multiple logistic regression analysis revealed 7 factors were independently associated with abnormal SChE level: male gender, single/separated/divorced, being a permanent worker, spraying pesticide more than 3 times per month, having moderate or poor pesticide-use behaviors, and low perceived susceptibility and severity of pesticide use. Conclusions: The prevalence of abnormal SChE levels among chilli-farm workers was quite high. It would be beneficial to decrease pesticide use and encourage alternative measures. Effective preventive interventions to increase correct perceptions of pesticide use, the use of personal protective measures and continuing monitoring for blood cholinesterase, especially for male permanent farm workers, are recommended.
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