Journal of Occupational Health
Online ISSN : 1348-9585
Print ISSN : 1341-9145
ISSN-L : 1341-9145
Volume 38, Issue 2
Displaying 1-10 of 10 articles from this issue
  • Makoto FUTATSUKA
    1996 Volume 38 Issue 2 Pages 47-53
    Published: 1996
    Released on J-STAGE: May 15, 2006
    JOURNAL FREE ACCESS
    Dose-Response Relationship for HandArm Vibration Syndrome: Makoto FUTATSUKA. Department of Public Health, Kumamoto University School of Medicine-Dose-effect relationships for hand-arm vibration involve relating a complex physical agent to the production of a variable and a not fully understood set of disorders. The physical agent, vibration, may be of variable magnitude, frequency, direction and duration; it is often intermittent and may contain shocks. The method of holding a tool, its physical characteristics, the ambient temperature and other factors may effect the severity of vibration exposure. The first occurrence of white finger is the effect of hand-arm vibration most usually considered in dose-response relationships. Neither the identification nor the diagnosis of this disorder is always reliable and it may not be the only significant adverse effect of exposure to hand-arm vibration. Data from cross-sectional studies show that the prevalence of white finger generally increases with increases in the vibration magnitude. The frequency weighting often employed in vibration measurement standard is loosely based on studies of subjective response to vibration and has a velocity characteristic over this frequency range. There have been few studies of the influence of vibration exposure duration on the development of relevant signs and symptoms. In a cohort of persons exposed to the same vibration, the mean latency increases with increasing duration of exposure until all persons are affected. It is becoming common for the daily exposure to vibration to be assessed on a so-called energy basis and expressed as an equivalent 8h exposure or an equivalent 4h exposure. This time-dependency is convenient because it enables exposures to be quantified by means of root-mean-square averaging. (J Occup Health 1996; 38: 47-53)
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  • Jian TONG, Hai-lin TIAN
    1996 Volume 38 Issue 2 Pages 54-56
    Published: 1996
    Released on J-STAGE: May 15, 2006
    JOURNAL FREE ACCESS
    Biochemical Changes as Biomarkers of Pyrethroid Toxicity in Rats :TONG Jian, et al. Department of Public Health, Suzhou Medical College-Biochemical changes reflecting toxic effects of two pyrethroid pesticides were pursued under experimental conditions of single and multiple exposures. Two pesticides, fenvalerate and cypermethrin, were administered to rats, and biochemical indices such as levels of enzymes and proteins in blood and bronchoalveolar lavage fluid (BALF) were measured. Results indicated that with multiple oral administration of cypermethrin to rats, a significant decrease in blood cholinesterase (ChE) activity could be observed after 1 wk of daily treatment, which suggested a secondary and indirect response. On the other hand, lung damage induced by fenvalerate seemed to be an acute effect, since all the biochemical effects measured in the present study appeared within 1 d after the single exposure, and could no longer be detected 1 wk later. These findings indicated that biochemical changes in biological samples could be used as biomarkers, which in turn may provide a supplementary means for the recognition of potential adverse effects of the pesticides as well as for the protection of sensitive individuals in an occupational context. (J Occup Health 1996; 38: 54-56)
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  • Shuchun LIU, Ning LIU, Jie LI
    1996 Volume 38 Issue 2 Pages 57-62
    Published: 1996
    Released on J-STAGE: May 15, 2006
    JOURNAL FREE ACCESS
    Silicosis Caused by Rice Husk Ashes: Shuchun LIU, et al. School of Public Health, Harbin Medical Univeraity-The processing of rough rice (paddy) can produce rice husk which is about 20% of paddy. Rice husk is utilized as an energy resource in many countries. Rice husk ash is used to a great extent as an industrial raw material in the ceramic and metallurgical industries. A number of workers are exposed to rice husk ash dust. Whether rice husk ashes can cause pneumoconiosis and other adverse effects is still a problem awaiting solution. In this connection, we performed epidemiological, experimental and aetiological studies. Rice husk ash dust can cause silicosis characterized by diffuse interstitial fibrosis and nodules. The free silica content increased as the treatment temperature for rice husk rose, and so did cristobalite and tridymite content. When rice husk was treated at 1, 300°C, free silica content amounted to 93.8%, of which cristobalite was 38.0% and tridymite 6.1%. These products are the main agents in the development of diffuse pulmonary fibrosis and silicotic nodules. (J Occup Health 1996; 38: 57-62)
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  • Yoneatsu OSAKI, Kimiko ANADA, Masumi MINOWA
    1996 Volume 38 Issue 2 Pages 63-66
    Published: 1996
    Released on J-STAGE: May 15, 2006
    JOURNAL FREE ACCESS
    Medical Costs of Cigarette Smoking among Employees in a Company: Yoneatsu OSAKI, et al. Department of Epidemiology, Institute of Public Health-We analyzed the association between smoking status and medical costs for employees in a company to determine the direct influence of smoking on medical costs. Data on smoking status and cigarette consumption per day were linked to data on individual medical costs. Data for 1, 381 persons out of 1, 531 employees in a given age group were analyzed. The age range and mean age of the subjects were 30-75 and 41.5±7.4 years old, respectively. The proportion of employees who received any medical care was not significantly different among smokers, ex-smokers, and non-smokers. Although the average per capita costs (hereafter referred to as population average costs) by age group were not significantly different by smoking status, the medical costs for smokers tended to be lower than those of ex-smokers and non-smokers. When the medical costs per employee who received any medical care were compared among the three smoking status groups, a similar association was observed. No significant dose-response relationship between cigarette consumption and medical costs was observed statistically. These results indicate that medical costs for smokers are not higher than those for other smoking status groups. These results do not support antismoking measures in the workplace, but may be due to a small sample size, because no cases of death or malignant respiratory disease with the accompanying higher medical costs were observed during the study. A large sample study observing a direct relationship between smoking status and medical costs is therefore required for a more appropriate example of the harmfulness of smoking in the workplace. (J Occup Health 1996; 38: 63-66)
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  • Ayako UEKI, Masamitsu NAKASHIMA, Takumi KISHIMOTO, Junichiro NAKAMURA, ...
    1996 Volume 38 Issue 2 Pages 67-70
    Published: 1996
    Released on J-STAGE: May 15, 2006
    JOURNAL FREE ACCESS
    Analysis of the expression of TcR Vβ repertoires in patients with silicosis.: Ayako UEKI, et al. Department of Hygiene, Kawasaki Medical School-Several environmental factors have been reported to induce autoimmune diseases, e. g. progressive systemic sclerosis in the patients with silicosis. In previous papers, we reported the superantigenicity of silicate to human lymphocytes in vitro. This study was intended to determine whether the modulation of TcR Vβ repertoires can be observed in peripheral blood lymphocytes from patients with silicosis. Twenty-four patients with silicosis and 1 1 individuals who had no experience of exposure to silica dust donated periphral blood only after their informed consent was obtained. Peripheral blood mononuclear cells (PBMC) were separated from 10 m/ of blood by the Ficoll-Hypaque density centrifugation method, stained with fluorescein isothiocyanate (FITC)-conjugated monoclonal antibody specific to the TcR Vβ repertoires, and analyzed flow cytometrically. The Vβ repertoires analyzed were Vβ 5.3+5.2, 5.2, 5.1, 6.7, 8, and 12. Some distinct Vβ repertoires, Vβ 5.2+5.3 and Vβ 5.3 were predominantly but not significantly expressed in the peripheral blood lymphocytes from the patients compared with the control group, and at the same time the repertoire Vβ 8 decreased in the patients, especially those with profusion rate (PR) 3. These results support the possibility that silicate acts as a superantigen in human beings as in the observations in vitro. (J Occup Health 1996; 38: 67-70)
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  • Takamoto UEMURA
    1996 Volume 38 Issue 2 Pages 71-79
    Published: 1996
    Released on J-STAGE: May 15, 2006
    JOURNAL FREE ACCESS
    Develompment of Pulmonary Lesions Following Acute Exposure to Diborane in Male ICR Mice: Takamoto UEMURA. Department of Preventive Medicine and Public Health, School of Medicine, Keio University-In order to investigate the sequential development of respiratory injuries following acute exposure to diborane, male ICR mice were exposed to 15 ppm diborane for four hours and histopathological, hematological and serum biochemical examinations were conducted immediately, one day, three days and two weeks after exposure. Immediately after exposure, polymorphonuclear neutrophil infiltration of the bronchiolar lumens was observed. On the following day, macrophages had infiltrated into the alveolar and bronchiolar lumen. Multifocal and disseminated inflammatory obstructive changes, edema and congestion diffusely developed at the respiratory bronchiolus, and were diagnosed as diffuse panbronchiolitis (DPB)-like lesions. These changes progressed most severely on day 3, and lung weight significantly increased with the severity of the pulmonary lesions. Transmission electron microscopy revealed deposition of fine fibrillar materials in the alveoli sacs immediately after exposure and phagocytosis of the materials by macrophages on day 3. At two weeks, few inflammatory cells in the bronchiolar lumen remained, and peribronchiolar thickening was disseminated at almost the same sites where DPB-like inflammatory foci had been detected. These sequential changes in the histopathological observations from this study corroborated very well with the clinical signs and symptoms of human acute diborane poisoning cases reported in the 1960s. No significant changes in the nasal cavity or major bronchi were detected at any time. No particular trends were identifiable in the blood biochemistry findings. Further studies are necessary to elucidate the pathogenetic mechanism responsible for the respiratory organ damage caused by diborane. (J Occup Health 1996; 38: 71-79)
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  • Ichiyo MATSUZAKI, Akio NISHIMURA, Nobuaki MORITA, Shinji SATOH, Toshio ...
    1996 Volume 38 Issue 2 Pages 80-81
    Published: 1996
    Released on J-STAGE: May 15, 2006
    JOURNAL FREE ACCESS
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  • Qiao Niu, Tianwang LIU, Tang LI, Hanchao TANG, Yuanping BAI, Tianshu G ...
    1996 Volume 38 Issue 2 Pages 82-88
    Published: 1996
    Released on J-STAGE: May 15, 2006
    JOURNAL FREE ACCESS
    Coal Workers'' Pneumoconiosis and Related Risk Indices: Qiao NIU, et al. Department of Public Health, Shanxi Medical College-Cross sectional epidemiological studies were carried out in three coal mines (Mines A, B and C), that produce differnt types of coal in order to examine the relationship between the prevalence of coal workers'' pneumoconiosis (CWP) and factors contributing to the development and seriousness of CWP. Seven factors were taken into consideration and two of them were calculated as “risk indices”. They concerned composition (including carbon, ash, volatile content of coal, free silica in coal dust and rock dust) and exposure factors (including dust concentration, duration of exposure and type of operation). Composition factors were: carbon 90%, ash 23.13%, volatile content 13.85%, free silica in coal dusts 2.58% and free silica in rock dusts 32.88% in Mine A. Carbon 82%, ash 8%, volatile content 28.5%, free silica in coal dusts 5.90% and free silica in rock dusts 33.0% in Mine B. Carbon 94%, ash 20.46%, volatile content 10.76%, free silica in coal dusts 2.04% and free silica in rock dusts 24.04% in Mine C. Differences in the coal dust concentration over a period of 20 to 30 years were not significant in the three mines. The rock dust concentration in Mine B was much higher than those in the other two mines. The CWP prevalence was 2.22% in Mine A, 13.20% in Mine B and 1.86% in Mine C. Analysis has shown that both composition and exposure factors were related to CWP prevalence, but the strength of the relationship between the factors was different in the three mines, especially in Mine B, where there was a high CWP prevalence, and the association of CWP with free silica and high volatile content was strong. It was interesting that, though the rank of coal in Mine B was much lower than those in Mine A and Mine C, the prevalence of CWP in Mine B was much higher than those in Mine A and Mine C. This result was in contrast with those reported before. Thecalculation of risk indices indicated that there was a positive correlation between the risk indices and exposure duration. (J Occup Health 1996; 38: 82-88)
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  • K. C. WAN
    1996 Volume 38 Issue 2 Pages 89-93
    Published: 1996
    Released on J-STAGE: May 15, 2006
    JOURNAL FREE ACCESS
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  • J. L. MATTSSON
    1996 Volume 38 Issue 2 Pages 94-96
    Published: 1996
    Released on J-STAGE: May 15, 2006
    JOURNAL FREE ACCESS
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