Industrial Health
Online ISSN : 1880-8026
Print ISSN : 0019-8366
ISSN-L : 0019-8366
Volume 56, Issue 1
Displaying 1-11 of 11 articles from this issue
Editorial
Original Articles
  • Yuichi FUKUDA, Shinichi IWASAKI, Yasuhiko DEGUCHI, Koichiro OGAWA, Tom ...
    Article type: Original Article
    2018 Volume 56 Issue 1 Pages 2-9
    Published: January 31, 2018
    Released on J-STAGE: February 07, 2018
    Advance online publication: August 19, 2017
    JOURNAL FREE ACCESS

    After workers take long-term sickness absence due to mental disorders (LTSA-MD), the occupational stress of the coworkers in the same work unit might be affected. The aims of this study were to evaluate the effect of the incident of LTSA-MD on the coworkers' occupational stress. A retrospective cohort study of 16,032 public servants was conducted. The Brief Job Stress Questionnaire (BJSQ) was used, which was administered in 2011 and 2012. To analyze the amount of change in occupational stress, the difference between the scores of the BJSQ scales in 2011 and 2012 was calculated. After adjusting for the baseline BJSQ scales, sex, age, total number of workers, and social support, analysis of covariance of the difference between the BJSQ scales' scores showed that job stressors and stress responses worsened among the coworkers after the incident of LTSA-MD. Social support did not change among the coworkers. This study indicates that an incident of LTSA-MD in the same work unit adversely affects the coworkers' occupational stress. Focusing on the coworkers' mental state after an incident of LTSA-MD in the same work unit and an early intervention strategy are needed to prevent secondary mental illness and sickness absence in the coworkers.

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  • Ravi GAUTAM, Yong HEO, GyeongDong LIM, EunSeob SONG, Katharine ROQUE, ...
    Article type: Original Article
    2018 Volume 56 Issue 1 Pages 10-19
    Published: January 31, 2018
    Released on J-STAGE: February 07, 2018
    Advance online publication: August 22, 2017
    JOURNAL FREE ACCESS

    Exposure to bioaerosols in indoor animal farms associates with respiratory illnesses, but little is known about the immune modulation to chicken farmers. This study aimed to compare the general immunity of chicken farmers with those of control subjects with non-agricultural jobs. Blood taken from the farmers and controls was subjected to plasma IgE and IgG subclass measurements. Isolated peripheral blood mononuclear cells (PBMC) were stimulated and cytokine production was measured. Indoor total and respirable dust levels and their endotoxin (LPS) and aflatoxin (AF) levels in the farms were measured. In total, 29 chicken farmers on 19 farms and 14 age- and sex-matched office workers participated. Hematological differences were not observed. The farmers tended to have higher serum IgE and IgG subclass levels with significance for IgG1. The cytokines released by PBMC from farmers indicated skewing toward Type-2 helper T-cell responses: interferon (IFN)-γ:interleukin (IL)-4 and IFNγ:IL-13 ratios were significantly lower than for control PBMC. The farms had 707.1 EU/m3 LPS in total dust, and 15.8 EU/m3 LPS in respirable dust. Farmers exhibited immune skewing towards allergic immune responses that correlated with the LPS levels on their farms. Chicken farmers may be at risk of respiratory allergies due to occupational endotoxin exposure.

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  • Yukari NAKADA, Aya SUGIMOTO, Hiroshi KADOTANI, Naoto YAMADA
    Article type: Original Article
    2018 Volume 56 Issue 1 Pages 20-29
    Published: January 31, 2018
    Released on J-STAGE: February 07, 2018
    Advance online publication: August 29, 2017
    JOURNAL FREE ACCESS

    Short sleep duration is a serious problem that not only enhances the risk of various mental and physical disorders, but also affects the productivity in the workplace. However, in terms of studies focused on workers, there are few reports that evaluated sleeping conditions in an objective way. The purpose of this study is to implement sleep health education in the workplace in terms of primary prevention of mental health disorder and then to investigate the subjective and objective effectiveness of the education using self-administered questionnaires (sleep duration, ESS, AIS, PHQ-9, SF-8) and an activity monitor (MTN-210). Study design is a quasi-randomized controlled trial. Sleep health education was provided through three 50-min lectures (total 150 min) as a single cycle for five months in the Intervention group. We obtained baseline data and then six months later. The study analyzed 70 subjects (36 Intervention group, 34 Control group). The weekday sleep duration for the Control group decreased by 12.9 min, whereas that of the Intervention group increased by 14.3 min (difference of 27.2 min), resulting in a significantly increase in score for the Intervention group. The present study suggests that sleep health education may be beneficial for good sleep habits in workers.

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  • Yasuo MORIMOTO, Hiroto IZUMI, Yukiko YOSHIURA, Yuri FUJISAWA, Kazuhiro ...
    Article type: Original Article
    2018 Volume 56 Issue 1 Pages 30-39
    Published: January 31, 2018
    Released on J-STAGE: February 07, 2018
    Advance online publication: September 05, 2017
    JOURNAL FREE ACCESS

    In order to examine the usefulness of intratracheal instillation of nanoparticles for the screening of the harmful effects of nanoparticles, we performed intratracheal instillation studies of nanomaterials on rats using different delivery devices and postures as a basic study. Multiwall carbon nanotubes (MWCNTs) with a geometric mean length and secondary diameter of 2.16 μm and 752 nm, respectively, were used as the nanomaterials. Male F344 rats were intratracheally exposed to 0.04 or 0.2 mg/rat of MWCNT, were dissected at 1 d and 3 d, and cell analyses of the bronchoalveolar lavage fluid (BALF) were analyzed. Two delivery devices were used for the intratracheal instillation of the MWCNTs: a gavage needle and a microsprayer aerolizer. Both induced neutrophil influx in the lung at 1 and 3 d, and there were no significant differences in neutrophil inflammation between the two delivery devices. The main distribution of pulmonary inflammation by both delivery devices was in the centrilobular spaces in the lung. Two postures were used: an angle of approximately 45 degrees and a standing posture on a board, both of which also induced pulmonary influx in BALF and pulmonary inflammation mainly in the centrilobular spaces, with no large difference in pulmonary inflammation between the two postures. Taken together, the differences in the delivery devices and postures of the rats in the intratracheal instillation did not affect the acute pulmonary toxicity of the nanomaterials.

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  • Jae-Il OH, Hyeon Woo YIM
    Article type: Original Article
    2018 Volume 56 Issue 1 Pages 40-48
    Published: January 31, 2018
    Released on J-STAGE: February 07, 2018
    Advance online publication: October 19, 2017
    JOURNAL FREE ACCESS

    This study aimed to analyze the association between the shift work schedule and metabolic syndrome (MetS). This is a retrospective longitudinal study based on the 2015 health checkup data of 2,090 workers evaluated for MetS in 2010 at a general hospital in Korea. The participants were divided according to their shift work schedule into daytime, three-shift (8-h rotation), and two-shift (12-h rotation) workers. The index that indicates the association between the shift work schedule and MetS is the odds ratio (OR) calculated using multivariate logistic regression. The analysis for the entire group of workers indicated that there was positive association between two-shift rotation and MetS (OR=1.58, 95% confidence interval [CI]: 1.09, 2.29). In the analysis of rotating night-shift workers, the years of rotating night shifts, frequency of night-shift work, and sleep disturbance were added to the confounding variables, and two-shift work remained positively associated with MetS (OR=1.72, 95% CI: 1.10, 2.70). The risk of MetS differs based on the shift work schedules they engage in. Hence, structural changes to the shift work schedules are required to prevent MetS in night-shift workers.

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Short Communication
  • George RACHIOTIS, Konstantinos KOSTIKAS, Dimitra PINOTSI, Christos HAD ...
    Article type: Short Communication
    2018 Volume 56 Issue 1 Pages 49-52
    Published: January 31, 2018
    Released on J-STAGE: February 07, 2018
    Advance online publication: August 22, 2017
    JOURNAL FREE ACCESS

    Greece is a significant cement producing country. The aim of this study was to investigate the prevalence and risk factors of lung function impairment among Greek cement workers. One hundred thirty- seven cement production workers participated in this study. In addition, 110 employees not exposed to cement dust comprised the control group. The concentration of cement total dust at workplace varied from 1.1 to 11.6 mg/m3. In only one of the measurements, the Threshold Limit Level of 10 mg/m3 has been exceeded. Cement production workers presented a higher prevalence of FEV1<80% in comparison to controls (13.9% vs. 2.7%; Chi-Square Test; p=0.002). Multivariate analysis has shown that cement production workers have recorded an almost 5 fold risk of low lung function, as expressed by FEV1<80%, in comparison to the reference population OR=4.92; 95% C.I.=1.22–12.62). Current smoking was associated with an almost 4- fold increased risk of FEV1<80% (OR=3.91;95% C.I.=1.32–11.56). In conclusion, we found a high prevalence of impaired lung function among Greek cement production workers, despite the fact that total and inhalable dust levels were below the occupational exposure limits.

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Field Reports
  • Maria U. KOTTWITZ, Christin GERHARDT, Diana PEREIRA, Lionel ISELI, Ach ...
    Article type: Field Report
    2018 Volume 56 Issue 1 Pages 53-61
    Published: January 31, 2018
    Released on J-STAGE: February 07, 2018
    Advance online publication: August 11, 2017
    JOURNAL FREE ACCESS

    Besides dealing with high workload, being a teacher is challenging with respect to the social context. There is increasing evidence that adverse social job characteristics challenge sleep quality. The current study tests whether restraint sleep quality (defined as worse sleep quality before than during vacation) is related to time-related job stressors, job resources, and social job characteristics. Forty-eight elementary school teachers (42% women) participated both during the last week before and the first week after vacation. Before vacation, teachers were asked for demographics and working conditions with reference to the last 30 d, and sleep quality with reference to the last 7 d. After vacation sleep quality during vacation was assessed and used as reference for working time sleep quality. Results showed mean levels of sleep quality increased during vacation. In teachers with restrained working time sleep quality (38%), experiences of failure at work, social exclusion, and emotional dissonance were more frequent than in teachers with unrestrained working time sleep quality (Ps<0.05). Groups did not differ in time-related stressors, time control and social support from supervisors. Emotion work, social exclusion and individual experience of failure seem to challenge sleep quality in teachers.

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  • A. Virgílio M. OLIVEIRA, Adélio R. GASPAR, António M. RAIMUNDO, Divo A ...
    Article type: Field Report
    2018 Volume 56 Issue 1 Pages 62-77
    Published: January 31, 2018
    Released on J-STAGE: February 07, 2018
    Advance online publication: August 19, 2017
    JOURNAL FREE ACCESS

    The objective of the present contribution is to assess the exposure to hot thermal environments in the Portuguese glass industry. For this purpose a field survey was carried out and the measurements took place in industrial units - five industries and nineteen workplaces were considered–so all the results are based on real working conditions. In order to assess the level of heat exposure the Wet Bulb Globe Temperature (WBGT) index and the Predicted Heat Strain (PHS) model, defined in ISO Standards 7243 (1989) and 7933 (2004), respectively, were used. According to the WBGT index, the results show that almost 80% of the workplaces under analysis are prone to heat stress conditions. If the PHS model is considered, the results highlight that the predicted and the maximum sweat rates present equal values in about 40% of the workplaces. In addition, in almost 25% of the workplaces the estimated rectal temperature was higher than 38°C, just for an exposure period of one hour. Thus, the present study brings to light the characteristics of the glass industry in terms of the occupational exposure to hot environments and places this activity sector as one of the most difficult to deal with.

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Case Report
  • Don-Hee HAN, Yesol PARK, Jae-Jong WOO
    Article type: Field Report
    2018 Volume 56 Issue 1 Pages 78-84
    Published: January 31, 2018
    Released on J-STAGE: February 07, 2018
    Advance online publication: August 31, 2017
    JOURNAL FREE ACCESS

    To get a better fit performance of filtering facepieces, a tight fitting net (TFN) was invented. This study was carried out to evaluate whether the TFN improves fit performance using a quantitative fit test (QNFT). The existing mask was of cup type with an aluminum clip on the nose bridge. The TFN mask was the same as the existing mask, but attached a TFN instead of aluminum clip. One hundred subjects (male 52, female 48) were selected to match fourfold in Korean 25-member facial size category for half-mask (KFCH). Fit factors (FFs) were measured using a QNFT by a Portacount®Pro+8038. Three QNFTs for each mask on the same subject was conducted and geometric mean FF (GMFF) was determined. The mean and median GMFFs of the TFN masks had higher than those of the existing mask (p=<0.001). The existing masks had tendency to have higher GMFFs with common facial size categories, while the TFN masks were regardless of facial size. The result indicates that putting even pressure on the entire parts of filter media would improve fit performance. In conclusion, to get a good fit when wearing filtering facepieces, a TFN would be an alternative to mask designing.

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Country Report
  • Takashi YAMAUCHI, Toru YOSHIKAWA, Takeshi SASAKI, Shun MATSUMOTO, Masa ...
    Article type: Country Report
    2018 Volume 56 Issue 1 Pages 85-91
    Published: January 31, 2018
    Released on J-STAGE: February 07, 2018
    Advance online publication: October 11, 2017
    JOURNAL FREE ACCESS

    In Japan, overwork-related disorders occur among local public employees as well as those in private businesses. However, to date, there are no studies reporting the state of compensation for cerebrovascular/cardiovascular diseases (CCVD) and mental disorders due to overwork or work-related stress among local public employees in Japan over multiple years. This report examined the recent trend of overwork-related CCVD and mental disorders, including the incidence rates of these disorders, among local public employees in Japan from the perspective of compensation for public accidents, using data from the Japanese Government and relevant organizations. Since 2000, compared to CCVD, there has been an overall increase in the number of claims and cases of compensation for mental disorders. Over half of the individuals receiving compensation for mental disorders were either in their 30s or younger. About 47% of cases of mental disorders were compensated due to work-related factors other than long working hours. The incidence rate by job type was highest among "police officials" and "fire department officials" for compensated CCVD and mental disorders cases, respectively. Changes in the trend of overwork-related disorders among local public employees in Japan under a legal foundation should be closely monitored.

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