This cross-sectional study aimed to explore work and rest conditions associated with overfatigue in truck drivers. A total of 1,911 male truck drivers participated in a questionnaire survey regarding their employment conditions, work habits, rest habits, sleep habits, health status, and subjective fatigue. Compared to local drivers who worked during the day (60%), local drivers operating during the night (22:00–5:00) (14%) engaged in significantly higher levels of monthly overtime longer than 100 hours and reported shorter sleep on working days. The local/nightworking drivers also reported a significantly greater level of incomplete recovery from daily fatigue. While long-haul drivers with two or more days away from home (12%) had significantly fewer days off, they engaged in significantly longer sleep on both working days and days off, with similar levels of incomplete recovery from daily/weekly fatigue as those of local/day-working drivers. Among work and rest conditions, shorter (< 7 hours) sleep on days off and fewer (< 4 days) days off were significantly associated with incomplete recovery from weekly fatigue. These results highlight the fact that overfatigue among truck drivers can be prevented by proper management of rest and sleep according to their respective schedules of driving work.

View full abstract

In hospitals, sexual harassment toward staff by patients or their family members is an especially critical issue. Therefore, we conducted a cross-sectional survey on 478 staff members— across both genders and all ranges of medical professionals— from a hospital in the Chugoku region of Japan. Results revealed that 42.7% of staff had been sexually harassed by patients or their family members; the nature of the sexual harassment varied. The results of logistic regression analysis showed that sexual harassment acts such as “remark about appearance” for nursing or care staff; “hugs” and “dirty talk” for rehabilitation workers; and “sexual questions” for clerical workers are more common compared to other occupations. Furthermore, 46.5% of the victims did not ask for any advice or assistance, at the time of the incident or afterward, for various reasons such as : “It was meaningless to seek help,” and “I thought I just had to endure it.” The results of this study suggest that: 1) a more appropriate understanding of the actual situation is possible by not defining occupations and gender, and by presenting definitions and specific examples of sexual harassment; 2) effective strategies for promoting help-seeking behavior should be examined based on each inhibitory factor.

View full abstract

Health and Productivity Management (HPM) in Small and Medium Enterprises (SMEs) is one of the important topics at occupational health. In this study, we evaluated the utility of HPM in SMEs, from the two viewpoints of company presidents’ recognition and employees’ health indicators and health-related productivity. Among the SMEs that had no experience in practicing HPM, three presidents and 149 employees from three companies were recruited. Interviews with the presidents and self-reported questionnaires to employees were conducted. There were no statistically significant differences between before and after HPM in all quantitative indicators. In two companies with fewer than 50 employees, presenteeism showed a downward trend (p = 0.13). Health indicators were also slightly improved. The interview survey showed that three presidents’ recognition to HPM changed from negative towards positive. At first, they thought employees had to manage their health condition by themselves without the support of the company; however, subsequently they turned to think that company’s intervention to employees’ health promotion was not costs, but the investment that could provide returns. Together, our findings indicated that in the smaller company it may take a shorter time to reveal quantitative indicators change than in more than 50 employees company.

View full abstract

Recently, several workers from other countries have been engaging in work and practical training at Japanese work sites as Foreign Technical Interns. However, they sometimes meet with accidents at work sites because they do not understand Japanese precautional statements or warnings. In this study, we attempted to develop suitable colours and design of manga signboards to raise risk perception and safety attitudes of foreign technical interns at presented work sites. The study had 21 Indonesian, 20 Filipino, and 9 Vietnamese participants. We initially determined the common colours that foreigners associate with the words, “danger”, “accident”, and “safe”. Similar to the results of past studies, we found that red was connected to danger and green to safe. Next, the proper contents that remind individuals of danger and promote safety attitudes were examined. The participants tended to prefer a 4-series manga to a single illustration and presentation of accident examples to improvement examples and description of whole accident situations to parts of causes. Finally, regarding the flame of signboard, a diagonal stripe of black and yellow or red and yellow were found to attract the most attention. In future studies, we intend to study the effects of a manga signboard developed based on the results of this study.

View full abstract

As hydraulic excavators are widely used as construction machines, they are a cause of many labour accidents. In recent years, hydraulic excavators equipped with a crane function have been developed and widely used; however, many labour accidents during crane operation have also occurred. In this study, we analysed the fatal accidents (involving 179 workers) caused by hydraulic excavators during the five years from 2010 to 2014, and investigated their causes. The analysis revealed that 23.5% (42 workers) cases of fatal accidents were caused by the crane operations.

In addition, the dynamic behaviour of a lifted load on a propelling excavator was measured by using an actual machine. It was observed that it is important to confirm the flatness of the site and decrease the propelling speed in order to reduce the fluctuation in the lifted load during the propelling of an excavator.

View full abstract

Powder handling operations are conducted to support our daily lives and industrial society. However, industrial accidents caused by electrostatic charges or/and discharges on powder still happen along with the use of insulating flexible intermediate bulk containers（ FIBC）. This paper examines the surface voltages of charged FIBC along with the electrostatic discharges generated from charged FIBE during powder loading and unloading. A conveyor type test facility including FIBC and about 300 kg of polypropylene powder（ PP, 2 mm） was used for this test. As a result, the maximum surface voltage exceeded 100 kV during both loading and unloading. As for the polarity, the charge was negative during loading and positive during unloading in this study. The surface voltage decreased with increasing relative humidity, However, even at above 75% humidity, about -50 kV with loading（ about 45 kV in unlading） still remained, which still does not meet the safety level. In the case where the grounded metal spheres approached the charged FIBC, the maximum discharge amount of electrostatic （brush） discharges was above 200 nC, which may ignite combustible liquids and very sensitive powders.

View full abstract

Effects of the introduction and establishment of the occupational safety and health management system (OSHMS) on work-related accident rates were investigated in local government workplaces during seventeen years. Risk assessment was carried out in a participatory manner in these workplaces. The average work-related accident rates were calculated for blue-collar and white-collar workplaces over three periods: before OSHMS introduction (2002-2006), during OSHMS introduction (2007-2011), and the period of OSHMS establishment (2012-2018) in which the OSHMS achievement degree exceeded 90% in all the evaluation axes of the occupational safety and health activities evaluation worksheet. The accident rates at the white-collar or clerical workplaces were lower than the blue-collar workplaces before OSHMS introduction. There was no significant reduction in work-related accidents during the introduction and establishment of OSHMS. Conversely, accident rates noticeably reduced with the introduction and establishment of OSHMS in blue-collar workplaces, such as garbage collection sites, school lunch kitchens, or hospitals etc. During the establishment period, the average rate of accidents was significantly lower than the national average in blue collar local government workplaces ( p<0.01). It was indicated that work-related accidents were reduced by the in troduction and establishment of OSHMS in blue-collar local government workplaces.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract