Journal of Occupational Health
Online ISSN : 1348-9585
Print ISSN : 1341-9145
ISSN-L : 1341-9145
57 巻, 2 号
選択された号の論文の14件中1~14を表示しています
Originals
  • Teresa Wrońska-Nofer, Anna Pisarska, Małgorzata Trzcinka-Ochocka, Tade ...
    2015 年 57 巻 2 号 p. 91-99
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2015/01/10
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    Objectives: Occupational exposure to lead may produce kidney damage, but existing data on the dose range associated with nephrotoxicity are inconclusive. We here assessed renal function under conditions of low to moderate lead exposure using renal scintigraphy. Methods: Fifty-three male foundrymen (exposed group) and fourty male office workers (control group) from a steel plant were included in the study. Glomerular and tubular renal function were assessed by means of 99mTc-DTPA and 99mTc-EC clearance, respectively. Urinary markers of glomerular dysfunction (albumin) and tubular damage (α1-microglobulin (α1M), β2-microglobulin (β2M), retinol-binding protein (RBP), N-acetyl-β-glucosaminidase (NAG) activity) were determined using latex beads tests or colorimetry. The lead concentration in blood was measured with atomic absorption spectrometry. Results: The blood lead concentrations were 145.8 (121.3–175.3) and 39.3 (35.1–44.1) µg/l (geometric mean, 95th CI, p<0.001) in the exposed and control groups, respectively. Subjects exposed to lead presented with increased 99mTc-DTPA clearance (158.3 (148.4–168.8) vs. 135.9 (127.9–144.4) ml/min; p<0.01) and urinary albumin excretion (7.61 (6.28–9.22) vs. 4.78 (4.05–5.65) mg/g creatinine; p<0.001). 99mTc-EC clearance and excretion of α1M, β2M, RBP and NAG were not significantly different between the groups. Significant correlations between 99mTc-DTPA clearance and blood lead concentrations (r=0.45; p<0.01) and between urinary albumin excretion and blood lead concentrations (r=0.71; p<0.001) were noted. Conclusions: Use of renal scintigraphy in present study revealed measurable alterations of renal function under the conditions of low-level lead exposure and suggest that increased glomerular filtration may be an early indicator of kidney damage in subjects occupationally exposed to lead.(J Occup Health 2015; 57: 91–99)
  • Arpalak Paksaichol, Chaipat Lawsirirat, Prawit Janwantanakul
    2015 年 57 巻 2 号 p. 100-109
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2014/12/04
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    Objective: The etiology of nonspecific neck pain is widely accepted to be multifactorial. Each risk factor has not only direct effects on neck pain but may also exert effects indirectly through other risk factors. This study aimed to test this hypothesized model in office workers. Methods: A one-year prospective cohort study of 559 healthy office workers was conducted. At baseline, a self-administered questionnaire and standardized physical examination were employed to gather biopsychosocial data. Follow-up data were collected every month for the incidence of neck pain. A regression model was built to analyze factors predicting the onset of neck pain. Path analysis was performed to examine direct and indirect associations between identified risk factors and neck pain. Results: The onset of neck pain was predicted by female gender, having a history of neck pain, monitor position not being level with the eyes, and frequently perceived muscular tension, of which perceived muscular tension was the strongest effector on the onset of neck pain. Gender, history of neck pain, and monitor height had indirect effects on neck pain that were mediated through perceived muscular tension. History of neck pain was the most influential effector on perceived muscular tension. Conclusions: The results of this study support the hypothesis that each risk factors may contribute to the development of neck pain both directly and indirectly. The combination of risk factors necessary to cause neck pain is likely occupation specific. Perceived muscular tension is hypothesized to be an early sign of musculoskeletal symptoms.(J Occup Health 2015; 57: 100–109)
  • Younmo Cho, Min Choi, Jun-Pyo Myong, Hyoung-Ryoul Kim, HyeEun Lee, Tae ...
    2015 年 57 巻 2 号 p. 110-117
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2014/12/17
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    Objectives: Bronchial anthracofibrosis (BAF) is associated with occupational hazardous dust exposure. The aim of the present study was to determine the prevalence of BAF and BAC without fibrosis in patients with pneumoconiosis, and to evaluate the associations between BAC/BAF and occupational dust exposure and clinical manifestations among patients with pneumoconiosis. Methods: A retrospective cross-sectional study (n=170) among individuals who were diagnosed with pneumoconiosis or suspicious pneumoconiosis and underwent bronchoscopy between January 2000 and February 2013 was performed. Multiple logistic regression analysis was performed to estimate associations. Results: In total, 153 eligible subjects were included in the study because their records contained all the required information. Of these, 81 (53%) and 63 (41%) had BAC and BAF, respectively. Occupational coal dust exposure increased the risk of BAF and BAC (odds ratio [OR]=2.980, 95% confidence interval [CI]=1.184–8.128; OR=2.840, 95% CI=1.092–7.926, respectively). Profusion category 3 pneumoconiosis also increased the risk of BAC (OR=33.887, 95% CI=5.317–394.729). Conclusions: BAF and BAC are associated with occupational exposure to coal dust. Therefore, clinicians should consider occupational history when they investigate the association between BAC/BAF and risk factors such as tuberculosis, lung cancer, and biomass fuel exposure.(J Occup Health 2015; 57: 110–117)
  • Hiroko Fukui, Hitoshi Iwahashi, Shigehisa Endoh, Keiko Nishio, Yasukaz ...
    2015 年 57 巻 2 号 p. 118-125
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2015/01/10
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    Objectives: It is known that inhalation of zinc oxide nanoparticles (ZnO NPs) induces acute pulmonary dysfunction, including oxidative stress, inflammation, and injury, but there are no reports on how to prevent these adverse effects. We have previously reported that the pulmonary symptoms caused by ZnO NPs were associated with oxidative stress; in the present study, we therefore investigated the use of ascorbic acid (AA), which is known as vitamin C, to prevent these toxic effects. Methods: A ZnO NP dispersion was introduced into rat lungs by intratracheal injection, and thereafter a 1% aqueous AA solution was given as drinking water. Bronchoalveolar lavage fluid was collected at 1 day and 1 week after injection, and lactate dehydrogenase (LDH) activity, heme oxygenase-1 (HO-1), and interleukin-6 (IL-6) levels were measured. In addition, expression of the chemokine cytokine-induced neutrophil chemoattractants (CINCs), HO-1, and metallothionein-1 (MT-1) genes in the lungs were determined. Results: Acute oxidative stress induced by ZnO NPs was suppressed by supplying AA. Increases in LDH activity and IL-6 concentration were also suppressed by AA, as was the expression of the CINC-1, CINC-3, and HO-1 genes. Conclusions: Oral intake of AA prevents acute pulmonary oxidative stress and inflammation caused by ZnO NPs. Intake of AA after unanticipated exposure to ZnO NPs is possibly the first effective treatment for the acute pulmonary dysfunction they cause.(J Occup Health 2015; 57: 118–125)
  • Koji Mori, Masako Nagata, Mika Hiraoka, Megumi Kudo, Tomohisa Nagata, ...
    2015 年 57 巻 2 号 p. 126-141
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2015/01/10
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    Objectives: The aim of this study was to study the necessary competencies for specialist occupational physicians in Japan and the effective training methods for acquiring them. Methods: A competency list (61 items) was developed for the questionnaires in the study by making use of existing competency lists from the Japan Society for Occupational Health (JSOH) as well as lists from the US and Europe. Certified senior occupational physicians (CSOPs) in the certification program of the JSOH completed a questionnaire on the necessary competencies. Examiners of the examination for certified occupational physicians (COPs) completed another questionnaire on effective training methods. Results: All 61 competencies in the questionnaires were evaluated as “necessary”. Some of the competencies in the list from the JSOH were evaluated lower than the items added from the American and European lists. When the respondents were categorized into a “practical group”, the members of which mainly provided occupational health services, an “academic group”, the members of which belonged to research or education institutes such as medical schools, and all others, the practical group evaluated some competencies significantly higher than the academic group, particularly those related to work accommodation. Among three options for training methods, the most effective methods were lectures and textbooks for 5 competency items, on-the-job training (OJT) for 30 items, and case-based learning (CBL) for 29 items. Conclusions: Some competencies should be added to the JSOH list. CBL should be introduced in training programs for specialist occupational physicians.(J Occup Health 2015; 57: 126—141)
  • Toshio Hayashi, Yuko Odagiri, Tomoko Takamiya, Yumiko Ohya, Shigeru In ...
    2015 年 57 巻 2 号 p. 142-150
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2015/01/20
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    Objectives: Organizational justice (OJ) is an important psychosocial factor and it consists of several components. Previous studies have shown that low perceived OJ is associated with various health problems. However, the relationships between each justice component and health outcomes have not been fully examined. The purpose of this study was to clarify the relationships between OJ and insomnia, including OJ components and insomnia symptoms. Methods: Cross-sectional self-reported questionnaire data from 1,893 employees (92.2% of subjects) were collected. OJ was measured using the Japanese version of the OJ questionnaire, which has four components (distributive, procedural, interpersonal and informational). Insomnia was assessed with the Athens Insomnia Scale. Logistic regression analysis, with insomnia as a dependent variable and OJ as an independent variable, was conducted. Results: Subjects with low overall OJ had a higher risk of insomnia (adjusted odds ratio (AOR), 2.37; 95% confidence interval (CI), 1.59 to 3.53) and two insomnia symptoms (AOR of 2.47 and 95% CI of 1.68 to 3.65 for sleep induction problem; AOR of 1.73 and 95% CI of 1.21 to 2.48 for sleep maintenance problem). The four justice components were all associated with insomnia and sleep induction problems. Sleep maintenance problems were associated with only the distributive justice component. Conclusions: All four justice components were associated with both insomnia and sleep induction problems. Sleep maintenance problems, however, showed different features. Specifically, the distributive justice component seemed to be a key factor in the relationship between OJ and insomnia. These findings might provide useful information for preventing the adverse effects of insomnia.(J Occup Health 2015; 57: 142–150)
  • Jef Adriaenssens, Veronique De Gucht, Stan Maes
    2015 年 57 巻 2 号 p. 151-160
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2015/01/20
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    Objectives: Goal orientation is a mindset towards the achievement of work-related goals, and it has been found to be related to occupational well-being. This study explored to what extent the 4-dimensional model of goal orientation adds additional variance to the explanation of burnout and work engagement in emergency nurses, after controlling for demographics, job characteristics and organizational variables. Methods: Self-report questionnaires including the Leiden Quality of Work Questionnaire for Nurses, Goal Orientation Questionnaire, Maslach Burnout Inventory and Utrecht Work Engagement Scale were completed by 170 out of 274 emergency nurses from 13 secondary Belgian hospitals (response rate 62%). Hierarchical multiple regression analyses were conducted. Results: Goal orientation explained 14 and 13% of the variance in burnout and work engagement respectively. Job control was predictive of both outcomes. Job demands was a predictor of burnout, and social support predicted work engagement. Reward was related to work engagement. The mastery-approach goal orientation was strongly related to an increase in work engagement and to a decrease in burnout. The performance-avoidance goal orientation was strongly related to a decrease in work engagement and to an increase in burnout. The performance-approach and mastery-avoidance goal orientations were not predictive for the two outcome variables. Conclusions: Goal orientation explains additional variance in burnout and work engagement over and above work characteristics and organizational variables. A mastery-approach goal orientation appears to be beneficial while a performance-avoidance goal orientation is not. Hospital management should therefore invest in personal involvement and growth of ER-nurses and in a rewarding organizational culture.(J Occup Health 2015; 57: 151–160)
  • Takenori Yamauchi, Yuko Yamano, Kenzo Yamanaka, Akihisa Hata, Toshio N ...
    2015 年 57 巻 2 号 p. 161-168
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2015/01/20
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    Objectives: Arsine is an arsenic compound generated as a by-product in metal refineries. Accidental poisoning occurs sporadically; however, the administrative level for workers has not been established. Thus, it is essential to identify a highly specific biomarker for risk management in the workplace. The aim of this study was to identify an arsenic adduct, a potential biomarker, in the plasma. Methods: Preserved mouse blood was exposed to arsine in vitro, and the plasma was separated. The residual clot of the control sample was hemolyzed using ultrapure water, and the supernatant was collected. Plasma from mice exposed to arsine in vivo was also separated from blood. Immunoprecipitation assays were conducted using all samples after ultrafiltration, and three fractions were collected. The total arsenic concentration in each fraction was quantified using inductively coupled plasma mass spectrometry (ICP-MS). The three in vitro samples and the eluate fraction from immunoprecipitation were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Results: In the exposed samples, the arsenic concentration in the fraction containing immunocomplexes was higher when immunoprecipitation was conducted with an anti-globin antibody. Three peaks were specifically observed in arsine-exposed samples after MALDI-TOF-MS analysis. Two of them were around m/z 15,000, and the other was m/z 15,700. The latter peak was confirmed even after immunoprecipitation. Conclusions: Globin forms an adduct with arsenic after both in vitro and in vivo exposure to arsine. This adduct together with hemoglobinuria could be a candidate biomarker of acute arsine poisoning in plasma.(J Occup Health 2015; 57: 161–168)
  • Risa Kimura, Makiko Mori, Miyuki Tajima, Hironori Somemura, Norio Sasa ...
    2015 年 57 巻 2 号 p. 169-178
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2015/01/27
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    Objectives: Efforts to improve performance in the workplace with respect to positive mental health have increased, and cognitive behavioral therapy (CBT) has recently attracted attention as an intervention measure to this end. Here, we conducted a randomized controlled trial to evaluate the effectiveness of a brief training program on CBT for improving work performance of employees. Methods: The participants were employees of an electric company in Japan. The intervention consisted of 1 group session of CBT (120 min) and web-based CBT homework for 1 month. We evaluated employees in both the intervention and control groups at baseline and follow-up after three months. The main outcome was work performance, which was evaluated by a subjective score from 1 to 10. The secondary outcome was self-evaluation of cognitive flexibility. Analyses were conducted based on ITT. Results: In the intervention group, 84 participants attended the group session, with 79 subsequently completing at least 1 instance of online homework. ITT analysis showed that the subjective performance of the intervention group was significantly improved compared with that of the control group (1.47 vs. 0.69, mean difference 0.78 [95% confidence interval {CI}, 0.05 to 1.51], Cohen's d=0.31). The ability to recognize dysfunctional thinking patterns and change them to positive ones significantly improved in the intervention group compared to the control group (0.71 vs. 0.26, mean difference 0.45 [95% CI 0.06 to 0.83], d=0.33). However, after adjustment for baseline scores, no significant difference was observed. The ability to view a situation from multiple perspectives and expand one's repertoire of thought patterns in the intervention group also significantly improved (0.83 vs. 0.35, mean difference 0.48 [95% CI 0.35 to 0.95], d=0.29), but here again, significance was lost after adjusting for baseline scores. Discussion: Our results suggest that a brief training program that combines a group CBT session with web-based CBT homework improved subjective work performance. In addition, this program might help improve employees' cognitive flexibility.(J Occup Health 2015; 57: 169–178)
Field Study
  • Chantal Imhof, Katherine Clark, Thierry Meyer, Kaspar Schmid, Michael ...
    2015 年 57 巻 2 号 p. 179-188
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2015/01/27
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    電子付録
    Objectives: Many nanomaterials (materials with structures smaller than 100 nm) have chemical, physical and bioactive characteristics of interest for novel applications. Considerable research efforts have been launched in this field. This study aimed to study exposure scenarios commonly encountered in research settings. Methods: We studied one of the leading Swiss universities and first identified all research units dealing with nanomaterials. After a preliminary evaluation of quantities and process types used, a detailed analysis was conducted in units where more than a few micrograms were used per week. Results: In the investigated laboratories, background levels were usually low and in the range of a few thousand particles per cubic centimeter. Powder applications resulted in concentrations of 10,000 to 100,000 particles/cm3 when measured inside fume hoods, but there were no or mostly minimal increases in the breathing zone of researchers. Mostly low exposures were observed for activities involving liquid applications. However, centrifugation and lyophilization of nanoparticle-containing solutions resulted in high particle number levels (up to 300,000 particles/cm3) in work spaces where researchers did not always wear respiratory protection. No significant increases were found for processes involving nanoparticles bound to surfaces, nor were they found in laboratories that were visualizing properties and structure of small amounts of nanomaterials. Conclusions: Research activities in modern laboratories equipped with control techniques were associated with minimal releases of nanomaterials into the working space. However, the focus should not only be on processes involving nanopowders but should also be on processes involving nanoparticle-containing liquids, especially if the work involves physical agitation, aerosolization or drying of the liquids.(J Occup Health 2015; 57: 179–188)
Brief Reports
  • Akiyo Tanaka, Miyuki Hirata, Nagisa Matsumura, Yutaka Kiyohara
    2015 年 57 巻 2 号 p. 189-192
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2015/01/10
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    Objectives: The aim of this study was to analyze the tissue distribution of indium after intratracheally instilling indium-tin oxide (ITO) into the lungs of hamsters. Methods: Male Syrian hamsters received an intratracheal dose of 3 mg/kg or 6 mg/kg of ITO particles containing 2.2 mg/kg or 4.5 mg/kg of indium, twice weekly for 8 weeks. In parallel, control hamsters received only an intratracheal dose of distilled water. A subset of hamsters was euthanized periodically throughout the study from 8 up to 78 weeks after the final instillation. The distribution of indium in the lungs, liver, kidneys and spleen, as well as pathological changes in the liver, kidneys, and spleen, was determined. Results: The contents of indium in the lungs in the two ITO groups gradually decreased over the 78-week observation period, with elimination half-lives of approximately 142 weeks for the 3 mg/kg ITO group and 124 weeks for the 6 mg/kg ITO. The indium concentrations in the liver, kidneys, and spleen gradually increased throughout the observation period. Although foci of the lesions were observed histopathologically in the extrapulmonary organs among the two ITO groups, the control group showed similar lesions. Conclusions: The results clearly demonstrate that the clearance of indium from the body is extremely slow after intratracheal instillation in hamsters.(J Occup Health 2015; 57: 189–192)
  • Seung-Je Shin, Won-Gyu Yoo
    2015 年 57 巻 2 号 p. 193-196
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2015/01/10
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    Objectives: To determine the activity of the upper trapezius, serratus anterior, anterior deltoid, biceps brachii. and lower trapezius muscles in healthy adults during below-the-knee assembly work. Methods: Fifteen right-handed male subjects participated in this study. The electrical activities, measured by EMG, of the right upper trapezius, serratus anterior, anterior deltoid, biceps brachii. and lower trapezius were measured during below-the-knee assembly work at four workstations of varying height and distance from the participant (workstation 1, below-the-knee assembly work with a height of 15 cm above the floor and a reach distance of 30 cm; workstation 2, height of 15 cm and distance of 45 cm; workstation 3, height of 30 cm and distance of 30 cm; workstation 4, height of 30 cm and distance of 45 cm). Muscle activity at the four workstations was represented as a percentage of the reference voluntary isometric contraction (RVIC). Results: Height: Upper and lower trapezius activity increased significantly during below the knee assembly work as height above the floor increased. The activities of the serratus anterior and biceps brachii muscles increased significantly during low-height below-the-knee assembly work. Distance: The activities of the upper trapezius, serratus anterior, anterior deltoid and biceps brachii increased significantly during below-the-knee assembly work at a far distance (45 cm). The lower trapezius muscle activity increased significantly during below-the-knee assembly work at a close distance (30 cm). Conclusions: Below-knee workers should engage in work close to themselves, since distance appears to be a stronger risk factor for injury than height above the floor.(J Occup Health 2015; 57: 193–196)
  • Toshio Kawai, Koji Mitsuyoshi, Masayuki Ikeda
    2015 年 57 巻 2 号 p. 197-199
    発行日: 2015年
    公開日: 2015/04/25
    [早期公開] 公開日: 2015/01/20
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    Objectives: The aim of this study was to examine the applicability of urinalysis for unmetabolized solvent to biomonitor 1,2-dichloropropane (1,2-DCP) exposure. Methods: Thirty three male printers exposed to 1,2-DCP and 5 nonexposed male controls participated in the study. The 8-hr average levels of exposure to 1,2-DCP in air and 1,2-DCP in the end-of-shift urine samples were measured with capillary FID-GC. Results: The geometric mean (the maximum) concentrations was 7.1 ppm (23.1 ppm) for 1,2-DCP in air, and the level in urine (without correction for urine density) was 77 µg/l (247 µg/l). A regression analysis showed a correlation coefficient of 0.909 (p<0.01). No 1,2-DCP was detected in the urine samples from nonexposed subjects. Conclusions: The high correlation and low background (essentially zero) showed that urinalysis for unmetabolized 1,2-DCP is a promising tool for biomonitoring of occupational exposure to this carcinogenic solvent at lower levels (e.g. <1 ppm).(J Occup Health 2015; 57: 197–199)
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