Journal of Occupational Health
Online ISSN : 1348-9585
Print ISSN : 1341-9145
ISSN-L : 1341-9145
Volume 50, Issue 2
Displaying 1-17 of 17 articles from this issue
Rapid Communication
Original
  • Rie Sakai, Som-Arch Wongkhomthong, Eiji Marui, Suchart Laobhripatr
    Article type: Original
    2008 Volume 50 Issue 2 Pages 103-113
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    Objective of this study is to clarify the health-related conditions of Japanese male expatriates in Thailand. Records of Japanese male expatriates in their 30s to 50s who consulted outpatient clinics at Bangkok Hospital in 2005 were analyzed for number and type of outpatient visits then compared with data from the "Patient Survey" 2005 for age-matched males in Japan. "Diseases of the respiratory system" and "Certain infectious and parasitic diseases" had a higher rate of diagnosis among Japanese men living in Thailand than those living in Japan. "Endocrine, nutritional and metabolic diseases," and "Mental and behavioral disorders" had a lower rate of diagnosis among Japanese men living in Thailand than those in Japan. "Acute upper respiratory infections" accounted for 87.4% of "Diseases of the respiratory system" and "intestinal infections" accounted for 59.9% of "Certain infectious and parasitic diseases" among expatriates. Japanese male expatriates have a tendency of not visiting hospital when they have no subjective or objective symptoms. To support a healthy expatriate life, health information should be propagated widely and available support services, such as counseling via e-mail or fax, should be actively promoted. Expatriates should be informed of the availability of these services before they go abroad and during their stay.
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  • Xiaojiang Tang, Bingling Que, Xiangrong Song, Senhua Li, Xiaojun Yang, ...
    Article type: Original
    2008 Volume 50 Issue 2 Pages 114-121
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    Trichloroethylene (TCE) can induce non-dose-related hepatitis, possibly classified as delayed-type hypersensitivity (immune-mediated hepatitis), as well as dose-related toxic liver injury. However, the difference in pathophysiology between the two kinds of hepatitis remains unknown. This study aimed to characterize the liver injury associated with hypersensitive skin reactions induced by TCE in guinea pigs. As a model of dose-related acute toxic liver injury, the animals were treated with intradermal injection (ii) (0, 167, 500, 1500 or 4500 mg/kg of TCE) or dermal patch (dp) (0 or 900 mg/kg of TCE). The guinea pig maximization test (GPMT) was also carried out as a model of immune-mediated liver injury, in which the total TCE dosage was below 340 mg/kg. In the group of TCE 4500 mg/kg (ii), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increased (p<0.01), while total protein and globulin decreased (p<0.05). Evident fatty degeneration, hepatic sinusoid dilation and inflammatory cell infiltration were observed. No significant change was found in animals treated with TCE of doses below 500 mg/kg (ii) or 900 mg/kg (dp). In the GPMT, sensitization rates of TCE-induced dermal allergy were 66%. ALT, AST, lactate dehydrogenase and the relative liver weight increased significantly (p<0.05) while albumin, IgA and γ-glutamyl transpeptidase decreased significantly (p<0.05). Lesions of ballooning changes were observed in liver pathology. Thus, TCE could cause both acute-type toxic liver injury and immune-mediated liver injury, the so-called delayed-type hypersensitivity at doses below the dosage for toxic liver injury. Interestingly, the histopathological features were quite different: fatty degeneration was most prominent in the former, and ballooning in the latter.
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  • Pornpimol Kongtip, Bantoon Tangprakorn, Witaya Yoosook, Suttinun Chant ...
    Article type: Original
    2008 Volume 50 Issue 2 Pages 122-129
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    The purpose of this research was to develop an applicable sampling and analytical method to determine airborne 4-vinyl-1-cyclohexene concentrations which are usually found in the atmosphere of polybutadiene factories. A solid sorbent tube, containing two sections (100 mg in the front and 50 mg in the back) of activated coconut-shell charcoal was chosen for sampling 4-vinyl-1-cyclohexene vapor. The 4-vinyl-1-cyclohexene in the charcoal samples was desorbed with carbon disulfide and analyzed by gas chromatography equipped with a flame ionization detector. The suitable air flow rate, adsorption capacity, sample storage stability, desorption efficiency and reliability of the method for sampling and analysis of 4-vinyl-1-cyclohexene were evaluated. The method was applied to sampling and analysis of 4-vinyl-1-cyclohexene in the rubber industry. The results indicated a suitable air flow rate of 0.3 to 1.5 l/min. The adsorption capacity of 4-vinyl-1-cyclohexene on 100 mg of charcoal was 0.2134 mg. The 4-vinyl-1-cyclohexene adsorbed on the charcoal was stable for 7 d at room temperature or 21 d in a refrigerated condition. The average percent desorption efficiency of 4-vinyl-1-cyclohexene ranged from 90.45% to 97.04% with the loaded amount ranging from 0.412 to 8.250 μg using 1 ml carbon disulfide. The limit of detection of 4-vinyl-1-cyclohexene was 0.044 ng. The average percent recoveries (n=6) of 4-vinyl-1-cyclohexene adsorbed on charcoal ranging from 0.46 to 8.87 μg were 96.78-102.87% with relative standard deviations (RSDs) of 0.34-1.92%, respectively. The concentrations of 4-vinyl-1-cyclohexene ranged from 0.011 to 0.105 mg/m3 in the working environment of a polybutadiene factory.
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  • Dong-Hee Koh, Jonguk Won, Yeon-Soon Ahn, Hyoung-Ryoul Kim, Sang-Beak K ...
    Article type: Original
    2008 Volume 50 Issue 2 Pages 130-135
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    Workers in the dye industry are exposed to various chemicals, of which reactive dye is a well-known occupational asthmagen. This study examined the relationship between asthma mortality and occupational exposure in the dye industry. The cohort comprised 66,089 male workers, including 904 workers in the dye industry, who underwent medical examinations from 1995 to 2003 at a medical service institute located in Incheon, Korea. Deaths were also observed during the 1995 to 2003 period. The mortality was analyzed using the standardized mortality ratio (SMR) compared to the Korean general population, and the mortalities from asthma in dye manufacturing workers and other workers were compared using the standardized rate ratio (SRR). The all-cause mortality in dye industry workers was significantly lower than in the general population (SMR=0.40, 95% CI 0.24-0.63), while the asthma mortality (SMR=9.03, 95% CI 1.86-26.39) was significantly higher. Deaths from non-malignant respiratory diseases were higher in dye industry workers, but were not statistically significant (SMR=2.0, 95% CI 0.41-5.86). In the internal comparison, the all-cause mortality was the same in both groups, while the mortalities from non-malignant respiratory diseases (SRR=6.04, 95% CI 4.00-9.44) and asthma (SRR=23.29, 95% CI 11.05-58.83) were higher in dye industry workers than in workers in other industries. Because asthma is a life-threatening disease, special consideration and preventive measures must be taken for workers in the dye industry.
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  • Hiroteru Okamoto, Tooru Tsunoda, Koji Teruya, Nobuo Takeda, Takamoto U ...
    Article type: Original
    2008 Volume 50 Issue 2 Pages 136-146
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    This study was conducted to evaluate the occupational health of Japanese physicians in emergency medicine. Subjects participating in this study were eighty-nine physicians working at 12 medical facilities (10 critical care emergency centers) in Japan. Participants were asked to complete a questionnaire of work conditions and to provide blood samples for immune variable measurements (CD4, CD8, CD56 and natural killer cell (NK cell) activity) before commencing their work. The data collected from seventy-four of 89 participating physicians were analyzed. The traditional work group comprised of 39 emergency physicians, who were significantly overworked compared to other two groups: the shift work group and the day work group. Among these three groups, no immune variable was significantly different except lymphocyte, number of CD4, and NK cell activity; and the NK cell activity of the shift work group was significantly lower than those of the traditional work group (p<0.01) and the day work group (p<0.01) in terms of Bonferroni's multiple comparison, probably due to circadian rhythm. It was indicated that NK cell activity was significantly lower in samples collected at night versus in the morning (OR=8.34, 95%CI: 1.95-35.6, p<0.01) through multiple logistic regression analyses. NK cell activity was significantly lower in individuals taking 0-3 days off per month, as compared to those taking 4 or more days off (OR=4.65, 95%CI: 1.27-17.0, p=0.02), according to multiple logistic regression analyses. Therefore, the low NK cell activity appears to have reflected the extent of fatigue arising from physicians' overwork. Overwork would have been a potential risk for the physicians' health, resulting in a lower quality of Japanese emergency medical services than that which could have been achieved otherwise. This study suggests that it would be better for the Japanese emergency physicians to take 4 or more days off per month for their health and the quality of their services.
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  • Hidetoshi Hama, Osamu Yamanoshita, Momoko Chiba, Iwao Takeda, Tamie Na ...
    Article type: Original
    2008 Volume 50 Issue 2 Pages 147-154
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    Selenium-enriched Japanese radish sprouts (Se-enriched JRS), in which Se-methylselenocysteine accounted for 80% of Se compounds, inhibited mammary tumorigenesis induced by 7,12-dimethylbenz[a]anthracene in rats. The effects of Se-enriched JRS on the oxidative stress-scavenging enzymes were investigated in rats. F344 female rats were fed test diets, in which Se-enriched JRS was added at 0, 2.4, 5.0, 8.8 or 12.5 ppm Se to commercial rodent chow for 3 wk. Glutathione peroxidase (GPx) and glutathione S-transferase (GST) in rat livers, kidneys and lungs were measured. Tissue Se concentrations at the highest Se dose (12.5 ppm) were high in order as follows: kidney > liver > lung. The diet at 12.5 ppm Se reduced the increase in body weight and, conversely, increased the liver weight. The Se test diets decreased hepatic and renal GPx activity at more than 2.4 ppm and 5.0 ppm, respectively. In contrast, the test diets increased pulmonary GPx activity at more than 2.4 ppm Se. The diets increased hepatic GST activity at more than 2.4 ppm Se dose dependently, whereas they reduced pulmonary GST activity at more than 2.4 ppm. The diet of 12.5 ppm Se induced GST Yp in all 3 organs and GST Yb1 in the liver. Thus, Se-enriched JRS influenced GPx and GST activity in a symmetrical manner in the livers and lungs of rats, with hepatic GST possibly affected, in part, by the induction of GST Yb1.
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  • Shanfa Yu, Guizhen Gu, Wenhui Zhou, Sheng Wang
    Article type: Original
    2008 Volume 50 Issue 2 Pages 155-162
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    To investigate the effects of the job demand-control (DC) model and the effort-reward imbalance (ERI) model on worker's well-being, self-reports for psychosocial work conditions and well-being were made by a sample of 878 workers at a thermal power plant in China using the main dimensions of DC and ERI questionnaires. Logistic regression analyses were employed controlling for age, gender, and educational level, and negative and positive affection among others. Workers reporting high job demands and low job control or high efforts and low rewards had elevated risks of job dissatisfaction, psychosomatic complaints and depressive symptoms. Odds ratios were generally higher in workers reporting both high efforts and low rewards. Furthermore, low reward proved to be a stronger predictor of poor well-being when both job stress models were simultaneously adjusted. To some extent, interaction effects were found for social support, but no interaction effects were found for overcommitment. The findings indicate independent effects of both the DC model and the ERI model on well-being. Future work should explore the combined effects of these two models of psychosocial stress at work on health more thoroughly.
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  • Huei-Sheng Shiue, Chih-Wei Lu, Chiou-Jong Chen, Tung-Shen Shih, Shiao- ...
    Article type: Original
    2008 Volume 50 Issue 2 Pages 163-168
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    To investigate the incidence of musculoskeletal disorders (MSDs) and the particular MSDs to which Chinese restaurant cooks are most at risk in Taiwan, National Health Insurance Data from1998 to 2002 were used to identify MSDs for study populations, including 52,261 certified cooks and 209,044 references matched for age and sex. The annual incidence of MSDs was around 25% and 20% for cooks and references, respectively, and the cook-to-reference risk ratios ranged from 1.29 to 1.35 (p<0.001). The most frequently affected body part was the low back, but the epicondyle was at higher risk (OR>2) than other sites for the cooks. Cooks are at higher risk of having MSDs complaints and MSDs related to the elbow show the highest risk.
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  • Kayoko Takashima, Yuki Ito, Frank J Gonzalez, Tamie Nakajima
    Article type: Original
    2008 Volume 50 Issue 2 Pages 169-180
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    Di (2-ethylhexyl) phthalate (DEHP) exposure is thought to lead to hepatocellular hypertrophy and hyperplasia in rodents mediated via peroxisome proliferator-activated receptor alpha (PPARα). A recent study revealed that long-term exposure to relatively low-dose DEHP (0.05%) caused liver tumors including hepatocellular carcinomas, hepatocellular adenomas, and chologiocellular carcinomas at a higher incidence in Pparα-null mice (25.8%) than in wild-type mice (10.0%). Using tissues with hepatocellular adenoma, microarray (Affymetrix MOE430A) as well as, in part, real-time quantitative PCR analysis was conducted to elucidate the mechanisms of the adenoma formation resulting from DEHP exposure in both genotyped mice. The microarray profiles showed that the up- or down-regulated genes were quite different between hepatocellular adenoma tissues of wild-type and Pparα-null mice exposed to DEHP. The gene expressions of apoptotic peptidase activating factor 1 (Apaf1) and DNA-damage-inducible 45 alpha (Gadd45a) were increased in the hepatocellular adenoma tissues of wild-type mice exposed to DEHP, whereas they were unchanged in corresponding tissues of Pparα-null mice. On the other hand, the expressions of cyclin B2 and myeloid cell leukemia sequence 1 were increased only in the hepatocellular adenoma tissues of Pparα-null mice. Taken together, DEHP may induce hepatocellular adenomas, in part, via suppression of G2/M arrest regulated by Gadd45a and caspase 3-dependent apoptosis in Pparα-null mice, but these genes may not be involved in tumorigenesis in the wild-type mice. In contrast, the expression level of Met was notably increased in the liver adenoma tissue of wild-type mice, which may suggest the involvement of Met in DEHP-induced tumorigenesis in wild-type mice.
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  • Yukiko Seki
    Article type: Original
    2008 Volume 50 Issue 2 Pages 181-190
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    In Japan, the most common reason for medical errors is a lack of cross-checking. To prevent errors, efforts to strengthen cross-checking behaviors are being adopted. However, time pressures also lead to errors, and increasing cross-checking activities leads to an increased workload and even greater time pressures. The purpose of this study was to identify working conditions that lead to time pressure for nurses, and to find ways to reduce time pressure and prevent subsequent errors. Self-reporting questionnaires were distributed over 10 days to 416 nurses working in 17 wards at two hospitals; 357 nurses (85.8%) responded anonymously, providing data on 2,150 person-days. In multivariate analyses, medical support services and the number of nurse calls answered were associated with subjective assessments of time pressures and nursing service delays due to busyness. Moreover, working the "evening-day shift" (when a nurse works a day shift after working the evening shift with no days off in between) led to a high level of fatigue before work and was associated with nursing service delays due to busyness. Reducing time pressures and preventing errors requires an adequate number of nurses, shift plans that consider rest periods and order of rotation, increased task discretion for nurses, and the prevention of chronic fatigue.
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Short Communication
Case Study
Field Study
  • Chalermrat Kamchuchat, Virasakdi Chongsuvivatwong, Suparnee Oncheunjit ...
    Article type: Field Study
    2008 Volume 50 Issue 2 Pages 201-207
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    This study aimed to document the characteristics of workplace violence directed at nursing staff, an issue which has rarely been studied in a developing country. Two study methods, a survey and a key informant interview, were conducted at a general hospital in southern Thailand. A total of 545 out of 594 questionnaires sent were returned for statistical analysis (response rate=91.7%). The 12-month prevalence of violence experience was 38.9% for verbal abuse, 3.1% for physical abuse, and 0.7% for sexual harassment. Psychological consequences including poor relationships with colleagues and family members were the major concerns. Patients and their relatives were the main perpetrators in verbal and physical abuse while co-workers were the main perpetrators in cases of sexual harassment. Common factors to incidents of violence were psychological setting, illness of the perpetrators, miscommunication, and alcohol use. Logistic regression analysis showed younger age to be a personal risk factor. Working in the out-patient unit, trauma and emergency unit, operating room, or medical or surgical unit increased the odds of violence by 80%. Training related to violence prevention and control was found to be effective and decreased the risk of being a victim of violence by 40%. We recommend providing training to high risk groups as a means of controlling workplace violence directed at nursing staff.
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  • Oner Dikensoy, Resat Kervancioglu, Ibrahim Ege, Nevin Uysal, Osman Elb ...
    Article type: Field Study
    2008 Volume 50 Issue 2 Pages 208-211
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    The objective is to investigate the prevalence of parenchymal lung diseases among tinners. Twenty-four tinners who signed an informed consent form in the Gaziantep area were the subjects of this study. Demographics, spirometric test results, and high resolution computed tomography (HRCT) scans were obtained for all the tinners. Out of 24 tinners, eleven tinners (46%) had HRCTs consistent with DPLD. Of these 11 subjects, HRCT findings were consistent with respiratory bronchiolitis interstitial lung disease in nine, usual interstitial pneumonia pattern in one, and non-specific interstitial pneumonia in one. HRCT patterns consistent with DPLDs are significantly prevalent among Turkish tinners. This is the first field study reporting this occupational lung hazard in tinners. Future research is needed to uncover the underlying mechanisms.
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  • Dong-Uk Park, Ku-Won Jin, Dong-Hee Koh, Byung-Kyu Kim, Kyu-Sang Kim, D ...
    Article type: Field Study
    2008 Volume 50 Issue 2 Pages 212-220
    Published: 2008
    Released on J-STAGE: April 10, 2008
    JOURNAL FREE ACCESS
    The main objective of this study was to determine the association between synthetic metalworking fluid (MWF) and rhinitis-related symptoms. At a plant manufacturing piston rings for automobiles, we interviewed grinders (19) and manufacturing workers (142) in operations where synthetic or semisynthetic MWF is handled, and administrative office workers (44) regarding the principal symptoms of rhinitis (nasal stuffiness, runny nose, anosmia, nasal itchiness, rhinorrhea, headache, epistaxis, and post-nasal drip). In addition, we assessed the current exposure of workers handling MWF to MWF aerosols, fungi, and endotoxins. Logistic regression analysis was used to examine the association between MWF surrogates indicative of MWF exposure and each rhinitis-related nasal symptom. Odds ratios (ORs) and 95% confidence intervals were adjusted for sex, age, smoking habit, and duration of employment. Among grinders handling synthetic MWF, the frequency of complaints of the dominant symptoms was 66.7% for nasal stuffiness, 77.8% for anosmia, 77.8% for runny nose, and 50.0% for headache. These rates are quite high even allowing for the common occurrence of rhinitis in the general population. Twenty eight of 34 grinding and manufacturing workers (82.4%) sampled were exposed to MWF mist above the threshold limit of 0.2 mg/m3 listed as a notice of intended change by the American Conference for Governmental Industrial Hygienists (ACGIH). The percentage of workers exposed to MWF mist >0.5 mg/m3 was 17.6%. Most workers were exposed to fungi levels >103 CFU/m3. All exposures to endotoxins were <50 EU/m3. Logistic regression analysis found that use of synthetic MWF was significantly associated with excess risk of nasal stuffiness (OR 3.5), nasal itchiness (OR 2.0), and runny nose (OR 2.1). The use of semi-synthetic MWF had little or no impact on the risk of developing rhinitis-related nasal symptoms. Grinding workers handling synthetic MWF had an increased risk of nasal stuffiness (OR 7.9), anosmia (OR 23.2), nasal itchiness (OR 8.3), runny nose (OR 20.4), post nasal drip (OR 18.4), and headache (OR 7.4) compared to administrative workers. Synthetic MWF may play an important role in the development of the dominant symptoms of rhinitis. Further study is needed to establish the risk of rhinitis or rhinitis-related symptoms according to MWF type.
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