- 著者
- Kozo Okamoto Hiromi Owada Tadashi Fujita Masahiro Kazumori Michiko Otsuka Hiromu Seko Yoshifumi Ota Naotaka Uekiyo Hiroshi Ishimoto Masahiro Hayashi Haruma Ishida Akiyoshi Ando Masaya Takahashi Kotaro Bessho Hironobu Yokota
- 出版者
- Meteorological Society of Japan
- 雑誌
- SOLA (ISSN:13496476)
- 巻号頁・発行日
- vol.16, pp.162-168, 2020 (Released:2020-09-05)
- 参考文献数
- 21
- 被引用文献数
- 14
To discuss the feasibility of the Himawari follow-on program, impacts of a hyperspectral sounder on a geostationary satellite (GeoHSS) is assessed using an observing system simulation experiment. Hypothetical GeoHSS observations are simulated by using an accurate reanalysis dataset for a heavy rainfall event in western Japan in 2018. The global data assimilation experiment demonstrates that the assimilation of clear-sky radiances of the GeoHSS improves the forecasts of the representative meteorological field and slightly reduces the typhoon position error. The regional data assimilation experiment shows that assimilating temperature and relative humidity profiles derived from the GeoHSS improves the heavy rainfall in the Chugoku region of western Japan as a result of enhanced southwesterly moisture flow off the northwestern coast of the Kyushu Island. These results suggest that the GeoHSS provides valuable information on frequently available vertically resolved temperature and humidity and thus improves the forecasts of severe events.
- 著者
- Masao TSUCHIYA Masaya TAKAHASHI Keiichi MIKI Tomohide KUBO Shuhei IZAWA
- 出版者
- 独立行政法人 労働安全衛生総合研究所
- 雑誌
- Industrial Health (ISSN:00198366)
- 巻号頁・発行日
- vol.55, no.2, pp.173-179, 2017-03-31 (Released:2017-04-07)
- 参考文献数
- 16
- 被引用文献数
- 15
A daily rest period (DRP; rest taken from daily work during a 24 h period), is essential to work recovery. This study examined DRPs' distribution and association with health outcomes among information technology workers recruited from an internet panel (N=1,811). Participants completed a web questionnaire examining psychological distress as a primary outcome, along with non-restorative sleep, fatigue (stress reaction), and work performance. Logistic regression analysis showed elevated psychological distress when DRP was <12 h (OR: 2.54; 95% CI: 1.47–4.42) and <11 h (OR: 2.48, 95% CI: 1.17–5.26), although the 95% CI included 1 after adjusting for age, sex, and working and commuting hours. After the above adjustment, similar associations were found with non-restorative sleep and fatigue, but not work performance, when DRP was <12 h. These findings constitute the first analysis of a dose-response relationship between DRP and subjective health outcomes among white-collar workers.
- 著者
- Takashi YAMAUCHI Toru YOSHIKAWA Masahiro TAKAMOTO Takeshi SASAKI Shun MATSUMOTO Kotaro KAYASHIMA Tadashi TAKESHIMA Masaya TAKAHASHI
- 出版者
- National Institute of Occupational Safety and Health
- 雑誌
- Industrial Health (ISSN:00198366)
- 巻号頁・発行日
- vol.55, no.3, pp.293-302, 2017-05-31 (Released:2017-06-08)
- 参考文献数
- 18
- 被引用文献数
- 21 69
Overwork-related disorders, such as cerebrovascular/cardiovascular diseases (CCVD) and mental disorders due to overwork, are a major occupational and public health issue worldwide, particularly in East Asian countries. This report discusses the recent trend of overwork-related disorders in Japan from the perspective of workers' compensated occupational diseases, as well as the development of a national policy for preventive measures against overwork-related disorders in Japan. Recently, the number of claimed and compensated cases of occupational mental disorders has increased substantially, particularly among young workers, as compared to those of occupational CCVD. In response to these situations and action from society, the Japanese Government passed the "Act on Promotion of Preventive Measures against Karoshi and Other Overwork-Related Health Disorders" in June 2014 to develop a national initiative towards the prevention of overwork-related disorders. Changes in the trend of overwork-related disorders in Japan under a legal foundation and an initiative by the central government should be closely monitored so that other countries can benefit from the experiences.
- 著者
- Kozo Okamoto Hiromi Owada Tadashi Fujita Masahiro Kazumori Michiko Otsuka Hiromu Seko Yoshifumi Ota Naotaka Uekiyo Hiroshi Ishimoto Masahiro Hayashi Haruma Ishida Akiyoshi Ando Masaya Takahashi Kotaro Bessho Hironobu Yokota
- 出版者
- Meteorological Society of Japan
- 雑誌
- SOLA (ISSN:13496476)
- 巻号頁・発行日
- pp.2020-028, (Released:2020-07-10)
- 被引用文献数
- 14
To discuss the feasibility of the Himawari follow-on program, impacts of a hyperspectral sounder on a geostationary satellite (GeoHSS) is assessed using an observing system simulation experiment. Hypothetical GeoHSS observations are simulated by using an accurate reanalysis dataset for a heavy rainfall event in western Japan in 2018. The global data assimilation experiment demonstrates that the assimilation of clear-sky radiances of the GeoHSS improves the forecasts of the representative meteorological field and slightly reduces the typhoon position error. The regional data assimilation experiment shows that assimilating temperature and relative humidity profiles derived from the GeoHSS improves the heavy rainfall in the Chugoku region of western Japan as a result of enhanced southwesterly moisture flow off the northwestern coast of the Kyushu Island. These results suggest that the GeoHSS provides valuable information on frequently available vertically resolved temperature and humidity and thus improves the forecasts of severe events.
- 著者
- Akihito SHIMAZU Ko MATSUDAIRA Jan DE JONGE Naoya TOSAKA Kazuhiro WATANABE Masaya TAKAHASHI
- 出版者
- National Institute of Occupational Safety and Health
- 雑誌
- Industrial Health (ISSN:00198366)
- 巻号頁・発行日
- vol.54, no.3, pp.282-292, 2016-05-31 (Released:2016-06-10)
- 参考文献数
- 54
- 被引用文献数
- 32 36
This study examined whether a higher level of psychological detachment during non-work time is associated with better employee mental health (Hypothesis 1), and examined whether psychological detachment has a curvilinear relation (inverted U-shaped pattern) with work engagement (Hypothesis 2). A large cross-sectional Internet survey was conducted among registered monitors of an Internet survey company in Japan. The questionnaire included scales for psychological detachment, employee mental health, and work engagement as well as for job characteristics and demographic variables as potential confounders. The hypothesized model was tested with moderated structural equation modeling techniques among 2,234 respondents working in the tertiary industries with regular employment. Results showed that psychological detachment had curvilinear relations with mental health as well as with work engagement. Mental health improved when psychological detachment increased from a low to higher levels but did not benefit any further from extremely high levels of psychological detachment. Work engagement showed the highest level at an intermediate level of detachment (inverted U-shaped pattern). Although high psychological detachment may enhance employee mental health, moderate levels of psychological detachment are most beneficial for his or her work engagement.
- 著者
- Masaya Takahashi
- 出版者
- Japan Society for Occupational Health
- 雑誌
- Journal of Occupational Health (ISSN:13419145)
- 巻号頁・発行日
- vol.61, no.4, pp.269-277, 2019-07-20 (Released:2019-07-25)
- 参考文献数
- 48
- 被引用文献数
- 35
Objectives: Cerebrovascular and cardiovascular diseases (CCVDs) and mental disorders, including suicide, are prevalent among overworked individuals in Japan. The 2014 legislation regarding the prevention of overwork-related deaths and disorders has accelerated the research in this field and ultimately the implementation of preventive actions.Methods: To understand the current problematic situations, the Research Center for Overwork-Related Disorders of the National Institute of Occupational Safety and Health, Japan, conducted analyses of compensated claims for overwork-related CCVDs and mental disorders that were recognized from January 2010 to March 2015.Results: The majority of CCVD cases were the men in their 50s. Transport and postal activities was the highest risk industry. Cerebrovascular cases were higher than cardiovascular ones. Long working hours was the principal factor for CCVDs. The mental disorder cases comprised approximately 70% men and affected younger age groups (peak in the third decade) with various industries at risk. In men, there was an almost equal number of F3 (Mood [affective] disorders) and F4 (Neurotic, stress-related, and somatoform disorders) diagnoses according to the 10th revision of the International Classification of Diseases and Related Health Problems. A larger number of women were diagnosed to have F4. The mental disorder cases were associated not only with long working hours, but also with injuries and disasters as well as interpersonal conflict at work.Conclusions: Multiple, simultaneous actions need to be made by employees, employers, researchers, and the authorities to achieve the goal of reducing the number of workers suffering from the overwork-related CCVDs and mental disorders.
- 著者
- Sang-il LEE Takeshi NISHI Masaya TAKAHASHI Shigekazu HIGUCHI
- 出版者
- National Institute of Occupational Safety and Health
- 雑誌
- Industrial Health (ISSN:00198366)
- 巻号頁・発行日
- vol.59, no.6, pp.393-402, 2021-09-27 (Released:2021-11-29)
- 被引用文献数
- 4
A nighttime nap is expected to mitigate melatonin suppression during night work by blocking light input to the retina, but it is unclear. In the present study, we investigated the effects of a nap break on melatonin level, subjective sleepiness, and vigilance performance during simulated night work. Eleven healthy young males (mean ± SD age: 22.2 ± 4.1 years) participated in counterbalanced crossover design experiments with two conditions (nap vs. no nap). The subjects performed 12-hour simulated night work from 21:00 to 09:00 h (illuminance: ~500 lx). Subjects with a nap condition took a nap for 2 hours in a dark room from 03:00, while subjects with a no nap condition continued the simulated night work. The results showed that immediately after the 2-h nap break, the melatonin level at 05:00 h temporarily recovered from light-induced melatonin suppression during the simulated night work but significantly suppressed again at 07:00 and 09:00 h. Subjective alertness and vigilance performance were impaired immediately after the nap break but subsequently enhanced. The results suggest that a single nap break for 2 hours could be a strategy to enhance alertness during the last part of night shift but inadequate for mitigating melatonin suppression.
- 著者
- Sang-il LEE Takeshi NISHI Masaya TAKAHASHI Shigekazu HIGUCHI
- 出版者
- National Institute of Occupational Safety and Health
- 雑誌
- Industrial Health (ISSN:00198366)
- 巻号頁・発行日
- pp.2020-0245, (Released:2021-09-28)
- 被引用文献数
- 4
A nighttime nap is expected to mitigate melatonin suppression during night work by blocking light input to the retina, but it is unclear. In the present study, we investigated the effects of a nap break on melatonin level, subjective sleepiness, and vigilance performance during simulated night work. Eleven healthy young males (mean ± SD age: 22.2 ± 4.1 years) participated in counterbalanced crossover design experiments with two conditions (nap vs. no nap). The subjects performed 12-hour simulated night work from 21:00 to 9:00 h (illuminance: ~500 lx). Subjects with a nap condition took a nap for 2 hours in a dark room from 3:00, while subjects with a no nap condition continued the simulated night work. The results showed that immediately after the 2-h nap break, the melatonin level at 5:00 h temporarily recovered from light-induced melatonin suppression during the simulated night work but significantly suppressed again at 7:00 and 9:00 h. Subjective alertness and vigilance performance were impaired immediately after the nap break but subsequently enhanced. The results suggest that a single nap break for 2 hours could be a strategy to enhance alertness during the last part of night shift but inadequate for mitigating melatonin suppression.
- 著者
- Yuki NISHIMURA Takeshi SASAKI Toru YOSHIKAWA Tomohide KUBO Tomoaki MATSUO Xinxin LIU Masaya TAKAHASHI
- 出版者
- National Institute of Occupational Safety and Health
- 雑誌
- Industrial Health (ISSN:00198366)
- 巻号頁・発行日
- pp.2020-0058, (Released:2020-07-01)
- 被引用文献数
- 5
While a number of work-related events have been proposed as risk factors for depression, a majority of studies have focused only on a few events in a single study. Therefore, we conducted a web-based longitudinal study to comprehensively investigate the impact of various work-related events on depressive symptoms. Ten thousand Japanese workers representing the Japanese working population were recruited online and questioned on their experiences of 36 work-related events in the past year. Their depressive symptoms were also assessed based on the Center for Epidemiologic Studies Depression Scale. Two years later, 3,098 participants responded to a follow-up study. By excluding 1,030 participants who were classified as being depressed in the baseline survey, data of 2,068 participants were analyzed. Odds ratios (OR) were calculated using multivariate logistic regression to assess the effect of work-related events on depressive symptoms. Eighteen events were found to be risk factors and were sorted into four types as follows: experience of an accident or disaster (OR: 4.78–7.67), excessive responsibility (OR: 3.01–3.62), drastic change in workstyle or workload (OR: 2.38–3.08), and interpersonal conflict (OR: 2.41–11.16). The current results, including magnitude relationship of ORs, should be utilized for promoting psychosocially healthy work environment.
- 著者
- Takashi YAMAUCHI Toru YOSHIKAWA Takeshi SASAKI Shun MATSUMOTO Masaya TAKAHASHI Machi SUKA Hiroyuki YANAGISAWA
- 出版者
- National Institute of Occupational Safety and Health
- 雑誌
- Industrial Health (ISSN:00198366)
- 巻号頁・発行日
- vol.56, no.1, pp.85-91, 2018-01-31 (Released:2018-02-07)
- 参考文献数
- 11
- 被引用文献数
- 1 15
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.
- 著者
- Kenji IWASAKI Masaya TAKAHASHI Akinori NAKATA
- 出版者
- 独立行政法人 労働安全衛生総合研究所
- 雑誌
- Industrial Health (ISSN:00198366)
- 巻号頁・発行日
- vol.44, no.4, pp.537-540, 2006 (Released:2006-11-02)
- 参考文献数
- 27
- 被引用文献数
- 58 134
Late in the 1970s, serious social concern over health problems due to long working hours has arisen in Japan. This report briefly summarizes the Japanese circumstances about long working hours and what the Government has achieved so far. The national statistics show that more than 6 million people worked for 60 h or more per week during years 2000 and 2004. Approximately three hundred cases of brain and heart diseases were recognized as labour accidents resulting from overwork (Karoshi) by the Ministry of Health, Labour and Welfare (MHLW) between 2002 and 2005. Consequently, the MHLW has been working to establish a more appropriate compensation system for Karoshi, as well as preventive measures for overwork related health problems. In 2001, the MHLW set the standards for clearly recognizing Karoshi in association with the amount of overtime working hours. These standards were based on the results of a literature review and medical examinations indicating a relationship between overwork and brain and heart diseases. In 2002, the MHLW launched the program for the prevention of health impairment due to overwork, and in 2005 the health guidance through an interview by a doctor for overworked workers has been enacted as law. Long working hours are controversial issues because of conflicts between health, safety, work-life balance, and productivity. It is obvious that we need to continue research regarding the impact on worker health and the management of long working hours.