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Inoue A.,University of Occupational and Environmental Health Japan | Kawakami N.,University of Tokyo | Shimomitsu T.,Japan Health Promotion Fitness Foundation | Shimomitsu T.,Tokyo Medical University | And 5 more authors.
Industrial Health | Year: 2014

This study aimed to investigate the reliability and construct validity of a new version of the Brief Job Stress Questionnaire (New BJSQ), which measures an extended set of psychosocial factors at work by adding new scales/items to the current version of the BJSQ. Additional scales/ items were extensively collected from theoretical job stress models and similar questionnaires in several countries. Scales/items were field-tested and refined through a pilot internet survey. Finally, an 84-item questionnaire (141 items in total when combined with the current BJSQ) was developed. A nationally representative survey was administered to employees in Japan (n=1,633) to examine the reliability and construct validity. Most scales showed acceptable levels of internal consistency and test-retest reliability. Principal component analyses showed that the first factor explained 50% or greater proportion of the variance in most scales. A scale factor analysis and a correlation analysis showed that these scales fit the theoretical expectations. These findings provided a piece of evidence that the New BJSQ scales are reliable and valid. Although more detailed content and construct validity should be examined in future study, the New BJSQ is a useful instrument to evaluate psychosocial work environment and positive mental health outcomes in the current workplace. © 2014 National Institute of Occupational Safety and Health.


Yamada K.,Japan Industrial Safety and Health Association | Kumagai S.,University of Occupational and Environmental Health Japan | Kubo S.,Osaka City University | Endo G.,The Institute for Science of Labour
Journal of Occupational Health | Year: 2015

Chemical exposure levels in printing and coating workers with cholangiocarcinoma (third report): Kenichi YAMADA, et al. Occupational Health Research and Development Center, Japan Industrial Safety and Health Association-Objective: This study aimed to identify the chemicals used by five printing workers and one coating worker who developed cholangiocarcinoma and estimate the workers' levels of chemical exposure. Methods: We obtained information on chemicals from the Ministry of Health, Labour and Welfare, Japan, and estimated working environment concentrations of the chemicals in printing and coating rooms and exposure concentrations during the ink and dirt removal processes. We also calculated shift time-weighted averages of exposure concentrations. Results: All five printing workers were exposed to both 1,2-dichloropropane (1,2-DCP) and dichloromethane (DCM). The estimated maximum exposure concentrations for each of the five workers were 190 to 560 ppm for 1,2-DCP and 300 to 980 ppm for DCM, and the estimated shift average exposure concentrations were 0 to 230 ppm for 1,2-DCP and 20 to 470 ppm for DCM. The coating worker was exposed to 1,2-DCP, but not DCM. He did not use ink, and thus was subjected to different conditions than the printing workers. The estimated maximum exposure concentration of 1,2-DCP was 150 ppm, and the estimated shift time-weighted average exposure concentration was 5 to 19 ppm. Conclusions: Our findings support the notion that 1,2-DCP contributes to the development of cholangiocarcinoma in humans and the notion that DCM may also be a contributing factor. The finding that the coating worker was exposed to 1,2-DCP at a lower exposure concentration is important for determining the occupational exposure limit. Furthermore, the subject did not use ink, which suggests that ink did not contribute to the development of cholangiocarcinoma.


Morishima M.,Shinshu University | Kishida K.,The Institute for Science of Labour | Uozumi T.,Muroran Institute of Technology | Kamijo M.,Shinshu University
International Journal of Clothing Science and Technology | Year: 2014

Purpose-In Japan, one of the countermeasures used to avoid the symptoms of hay fever (HF) is a hygiene mask; however, a mask can cause discomfort. The authors believe that co-occurrence analysis, which has been widely in the sciences, will be valuable to this issue. The purpose of this paper is to identify problems associated with the use of hygiene masks and recommend improvements in their function and comfort. The goal of this study was to obtain information for the development of effective hygiene masks for HF sufferers and therefore, improve their quality of life. Design/methodology/approach-The authors conducted a survey of university students with HF (n¼1,519) to identify problems with hygiene masks. Students completed self-report questionnaires and co-occurrence analyses were used to examine the data from a holistic perspective. Moreover, technical data, relative to the problems of wearing a mask were acquired experimentally using thermal, hygroscopic, and airflow properties. Findings-Among Japanese university students, hygiene masks were the most popular countermeasure against HF symptoms. In addition, it was found that wearing a mask was not influenced of the type of symptoms. Most problems were related to the masks’ thermal, hygroscopic, and airflow properties. Originality/value-The paper proposed the use of co-occurrence analysis to analyze problems with hygiene masks. Most problems appear to be related to the thermal, hygroscopic, and airflow properties of the masks. Moreover, such phenomena have been experimentally demonstrated. © Emerald Group Publishing Limited.


Kim Y.-H.,Hanyang University | Yoshikawa E.,Tokyo Medical University | Yoshikawa T.,The Institute for Science of Labour | Kogi K.,The Institute for Science of Labour | Jung M.-H.,Hanyang University
Industrial Health | Year: 2015

The present study’s objective was to determine the mechanisms for enhancing the utility of action checklists applied in participatory approach programs for workplace improvements, to identify the benefts of building consensus and to compare their applicability in Asian countries to fnd the most appropriate confguration for action checklists. Data were collected from eight trainees and 43 trainers with experience in Participatory Action-Oriented Training. Statistical analysis was performed in SPSS using the package PASW, version 19.0. The difference in the mean score for the degree of the utility of action checklists between countries was analyzed using ANOVA methods. Factor analysis was performed to validate the action checklists’ utility. Pearson Correlation Coef-fcients were then calculated to determine the direction and strength of the relationship between these factors. Using responses obtained from trainees’ in-depth interviews, we identified 33 key statements that were then classifed into 11 thematic clusters. Five factors were extracted, namely “ease of application”, “practical solutions”, “group interaction”, “multifaceted perspective” and “active involvement”. The action checklist was useful for facilitating a participatory process among trainees and trainers for improving working . Action checklists showed similar patterns of utility in various Asian countries; particularly when adjusted to local conditions. ©2015 National Institute of Occupational Safety and Health


Itoh H.,Japanese National Institute for Occupational Safety and Health | Mori I.,The Institute for Science of Labour | Matsumoto Y.,Japanese National Institute for Occupational Safety and Health | Maki S.,Japanese National Institute for Occupational Safety and Health | Ogawa Y.,Japanese National Institute for Occupational Safety and Health
Industrial Health | Year: 2011

Seasonal variation in circulating 25-hydroxyvitamin D (25OHD) levels related to seasonal and inter-day fluctuation in sunlight ultraviolet irradiation, may lead to misjudgments concerning 25OHD status in individual workers around threshold levels. Here, to examine seasonal and inter-day variations in plasma 25OHD, we conducted a longitudinal study involving indoor daytime workers. Subjects were four male indoor daytime workers aged 32-57 yr working in Kawasaki City, Japan. Blood samples were obtained on six days within two twoweek periods in February and October, 2008. Plasma 25OHD, serum intact parathyroid hormone (PTH) and 1α,25-dihydroxyvitamin D [1α,25(OH) 2D] were measured. Individual monthly mean 25OHD levels were 16-56% higher in October than in February (p=0.03), while individual monthly mean intact PTH levels were 15-41% lower in October (p=0.09). No seasonal change was observed in 1α,25(OH) 2D (p=0.62). Notably, nearly all measured 25OHD levels in February were lower than the reference value of 20 ng/ml. Our study identified the occurrence of seasonal variation in circulating 25OHD and intact PTH levels, even after accounting for inter-day variability, and hypovitaminosis D in wintertime in indoor daytime male workers in Japan. Due to this variability, single spot measurements of 25OHD may lead to misjudgment of workers' vitamin D status.


PubMed | University of Occupational and Environmental Health Japan, Wakayama Medical University, University of Tokyo, Harvard University and 4 more.
Type: Journal Article | Journal: PloS one | Year: 2015

Bullying in the workplace is an increasingly recognized threat to employee health. We sought to test three hypotheses related to the determinants of workplace bullying: power distance at work; safety climate; and frustration related to perceived social inequality. A questionnaire survey was administered to a nationally representative community-based sample of 5,000 residents in Japan aged 20-60 years. The questionnaire included questions about employment, occupation, company size, education, household income, and subjective social status (SSS). We inquired about both the witnessing and personal experience of workplace bullying during the past 30 days. Among 2,384 respondents, data were analyzed from 1,546 workers. Multiple logistic regression analyses were used to examine the social determinants of workplace bullying. Six percent and 15 percent of the total sample reported experiencing or witnessing workplace bullying, respectively. After adjusting for gender and age, temporary employees (Odds Ratio [OR]: 2.45 [95% Confidence Interval (CI) = 1.03-5.85]), junior high school graduates (OR: 2.62 [95%CI: 1.01-6.79]), workers with lowest household income (OR: 4.13 [95%CI:1.58-10.8]), and workers in the lowest SSS stratum (OR: 4.21 [95%CI:1.66-10.7]) were at increased risk of experiencing workplace bullying. When all variables were entered simultaneously in the model, a significant inverse association was observed between higher SSS and experiencing bullying (p = 0.002). Similarly in terms of witnessing bullying; SSS was significantly inversely associated (p = 0.017) while temporary employees reported a significantly higher risk of witnessing bullying compared to permanent workers (OR: 2.25 [95%CI:1.04 to 4.87]). The significant association between SSS and experiencing/witnessing workplace bullying supports the frustration hypothesis. The power distance hypothesis was also partly supported by the finding that temporary employees experienced a higher prevalence of workplace bullying.


Nagata H.,The Institute for Science of Labour
Industrial Health | Year: 2014

Considering a fatal case of an aged individual, who died due to falling down stairs, the cause of the fatal fall was investigated through experiments. A witness, who was with the victim, when the fatal accident occurred, stated that the aged individual had miss-footed, lost balance at the top of the stairs, and fell accidently from an upper floor to a lower floor. It was very questionable whether or not this witness’s statements were true. The true cause of the fatal fall was unclear, because of the witness’s inconsistent statements, which showed discrepancies between the initial and later statements. The cause of a fatal fall can be presumed from external and internal damages to the body and other circumstantial evidences. But it was difficult to prove the true cause of a fatal fall only from the results of the autopsy and investigation of circumstantial evidences. The author was officially requested to conduct experiments to elucidate possible falling patterns. Judging from the experimental results, deep questions about the witness’s statements arose. These experimental methods and analyses in this paper could be applied to elucidate possible falling patterns of fatal falls from stairs where the fatal causes are controversial. © 2014 National Institute of Occupational Safety and Health.


Terada Y.,Panasonic | Kubotani H.,Panasonic | Kitajima H.,The Institute for Science of Labour | Suzuki K.,The Institute for Science of Labour
19th Intelligent Transport Systems World Congress, ITS 2012 | Year: 2012

This paper describes the detection of a driver's drowsiness level rated by facial expression. An experiment was conducted to evaluate the method for building a model to estimate drowsiness. Thirty-one participants were instructed to follow a high-speed vehicle in a driving simulator to reduce the arousal level. Eleven measurements, including the facial expression, driving behavior, and physiological measurements, were recorded. The correlation between the drowsiness level and measurements were analyzed. The measured values with strong contributions to the estimated drowsiness level were extracted.


Yoshikawa T.,The Institute for Science of Labour
PloS one | Year: 2013

Determining incidence rates of needlestick and sharps injuries (NSIs) using data from multiple hospitals may help hospitals to compare their in-house data with national averages and thereby institute relevant measures to minimize NSIs. We aimed to determine the incidence rate of NSIs using the nationwide EPINet surveillance system. Data were analyzed from 5,463 cases collected between April 2009 and March 2011 from 67 Japanese HIV/AIDS referral hospitals that participated in EPINet-Japan. The NSI incidence rate was calculated as the annual number of cases with NSIs per 100 occupied beds, according to the demographic characteristics of the injured person, place, timing, device, and the patients' infectious status. The NSI incidence rates according to hospital size were analyzed by a non-parametric test of trend. The mean number of cases with NSIs per 100 occupied beds per year was 4.8 (95% confidence interval, 4.1-5.6) for 25 hospitals with 399 or fewer beds, 6.7 (5.9-7.4) for 24 hospitals with 400-799 beds, and 7.6 (6.7-8.5) for 18 hospitals with 800 or more beds (p-trend<0.01). NSIs frequently occurred in health care workers in their 20 s; the NSI incidence rate for this age group was 2.1 (1.6-2.5) for hospitals having 399 or fewer beds, 3.5 (3.0-4.1) for hospitals with 400-799 beds, and 4.5 (3.9-5.0) for hospitals with 800 or more beds (p-trend<0.01). The incidence rate of NSIs tended to be higher for larger hospitals and in workers aged less than 40 years; injury occurrence was more likely to occur in places such as patient rooms and operating rooms. Application of the NSI incidence rates by hospital size, as a benchmark, could allow individual hospitals to compare their NSI incidence rates with those of other institutions, which could facilitate the development of adequate control strategies.


PubMed | The Institute for Science of Labour
Type: Journal Article | Journal: PloS one | Year: 2013

Determining incidence rates of needlestick and sharps injuries (NSIs) using data from multiple hospitals may help hospitals to compare their in-house data with national averages and thereby institute relevant measures to minimize NSIs. We aimed to determine the incidence rate of NSIs using the nationwide EPINet surveillance system.Data were analyzed from 5,463 cases collected between April 2009 and March 2011 from 67 Japanese HIV/AIDS referral hospitals that participated in EPINet-Japan. The NSI incidence rate was calculated as the annual number of cases with NSIs per 100 occupied beds, according to the demographic characteristics of the injured person, place, timing, device, and the patients infectious status. The NSI incidence rates according to hospital size were analyzed by a non-parametric test of trend. The mean number of cases with NSIs per 100 occupied beds per year was 4.8 (95% confidence interval, 4.1-5.6) for 25 hospitals with 399 or fewer beds, 6.7 (5.9-7.4) for 24 hospitals with 400-799 beds, and 7.6 (6.7-8.5) for 18 hospitals with 800 or more beds (p-trend<0.01). NSIs frequently occurred in health care workers in their 20 s; the NSI incidence rate for this age group was 2.1 (1.6-2.5) for hospitals having 399 or fewer beds, 3.5 (3.0-4.1) for hospitals with 400-799 beds, and 4.5 (3.9-5.0) for hospitals with 800 or more beds (p-trend<0.01).The incidence rate of NSIs tended to be higher for larger hospitals and in workers aged less than 40 years; injury occurrence was more likely to occur in places such as patient rooms and operating rooms. Application of the NSI incidence rates by hospital size, as a benchmark, could allow individual hospitals to compare their NSI incidence rates with those of other institutions, which could facilitate the development of adequate control strategies.

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