Objective: This study determined the applicability of Japanese working environment measurements to assessment of personal exposure concentrations of chemicals by comparing both levels of concentrations. Methods: The chemicals measured in this study comprised eight kinds of vaporous chemicals as well as two kinds of chemicals in dust. Personal exposure measurements, Japanese working environment measurements and spot sampling measurements were undertaken in 70 companies. Results: Personal exposure concentrations and the arithmetic mean value (E_A2) of the working environment measurement concentrations obtained according to the Japanese working environment control system had statistically positive correlations (r=0.732−0.893, p<0.01) after logarithmic transformation. The 5th to 95th percentile values of personal exposure concentrations divided by E_A2 ranged from 0.17 to 7.69 for vaporous chemicals and from 0.27 to 18.06 for dust. There was a relatively large difference between the personal exposure concentrations and the E_A2 obtained in weighing, forming and bonding use-processes. In such cases, the B-value measured in ten minutes in the Japanese working environment control system, which is almost the same as the spot measurement concentration in this study, is supposed to be substituted for the E_A2 value. Conclusions: Ten times the E_A2 of the working environment measurement concentrations, or ten times the B-value, obtained according to the Japanese working environment control system can be used to conservatively estimate the personal exposure concentrations in EU workplaces as well as in occupational exposure scenarios of the Regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals.(J Occup Health 2014; 56: 85-92)

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Objectives: Job stress is one of the factors that increase the likelihood of turnover. Intent to leave work is one of the most accurate predictors of turnover. This cross-sectional study was created to evaluate the intent of nurses working at hospitals to continue working and to determine the relationship between job stress and intent to stay at work. Methods: The subjects were 514 female hospital nurses aged 21–58 years old, who had worked full time at the study hospitals for at least 1 year. Data were collected using a self-administered questionnaire, which included sections on demographic characteristics, the Thai version of the Job Content Questionnaire (JCQ), and intent to stay at work. Multiple regression analysis was used to identify factors related to intent to stay at work. Results: The prevalences of high job strain and low intent to stay at work were 17.5 and 22.4%, respectively. The mean (SD) scores of the nurses for psychological job demand, decision latitude, workplace social support, and intent to stay at work were 33.5 (4.4), 70.7 (6.9), 23.8 (2.8), and 14.6 (2.9), respectively. Multiple regression analysis indicated that intent to stay at work was significantly correlated with only supervisor support among the nurses with high-strain jobs and with coworker support in nurses with active jobs. Conclusions: The findings suggest that different job types need different sources of social support in the workplace. Proactive steps by nurse managers to increase workplace social support might lead to an increase in intent to stay and reduce nursing turnover in hospitals and possibly other settings.(J Occup Health 2014; 56: 93-99)

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Objectives: Hairdressers have several work-related health hazards. Little is known of their strategies for the work environment. The aim of this study was to explore female hairdressers' own views on their physical, social and psychological work environment and possibilities of influencing it, implementation of their knowledge, financial impacts and how work-related symptoms affect their views. Methods: Fourteen hairdressers working for four years were subjected to open-ended interviews covering aspects of the physical, social and psychological work environment. Content analysis was applied. Results: An awareness of the impact of the work environment and the possibilities of influencing it emerged, but also an inability to achieve preventive improvements. This included reflections concerning ventilation, health issues, job strain, hair products, financial issues, knowledge from school and concern for having to leave the profession. The organization and acceptance of the work environment were important issues. Making the work environment an active part of their business was not common. Conclusions: Female hairdressers had an awareness of their work environment but lacked the means and strategies to make it an active part of their business. The main focus was on the customers and the work techniques. Having various symptoms did not alter this. Organizational and financial issues could put limitations on the work environment. Teachers were crucial in making the work environment interesting. Hairdressing was seen with advantages and disadvantages, and its future was seen as being insecure in terms of the occupational health risks. The hairdressers expressed a great pride in their profession providing possibilities for development.(J Occup Health 2014; 56: 100-110)

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Objectives: Several previous studies showed that the lack of organizational justice was associated with poor mental health. However, no study examined the effect modification by internal factor, such as coping strategies, on the association of organizational justice with mental health. The purpose of the present study was to investigate the effect modification by coping strategies on the association of organizational justice with psychological distress. Methods: A total of 471 men and 764 women from a manufacturing company in Japan completed self-administered questionnaires, including the Organizational Justice Questionnaire, K6 scale (i.e., psychological distress scale), Brief Scales for Coping Profile, and demographic characteristics. Multiple logistic regression analyses were conducted for each coping strategy. Results: After adjusting for demographic characteristics, the association of the lack of procedural justice with psychological distress was greater among the low changing a point of view group than among their counterparts. Furthermore, the interaction term of procedural justice with changing a point of view was significant. The association of the lack of procedural justice and interactional justice with psychological distress was also greater among the high emotional expression involving others group than among their counterparts, while the interaction terms of procedural justice and interactional justice with emotional expression involving others were marginally significant. Conclusions: Positive emotion-focused coping strategies, such as changing a point of view, may effectively prevent psychological distress when there is a lack of organizational justice, while problem-focused coping strategies may have no effects, and negative emotion-focused coping strategies, such as emotional expression involving others, may have harmful effects on the association.(J Occup Health 2014; 56: 111-123)

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Background: The Work Limitations Questionnaire (WLQ) was recently developed to measure health-related decrements in ability to perform job roles among employed individuals. The purpose of this study was to develop and test a Japanese version of the WLQ. Methods: Developing the Japanese version of the WLQ involved translations, back-translations, and a pilot study. Using data obtained from a nationwide survey, 4,600 people aged ≥20 years were selected from the entire population of Japan by stratified random sampling. We ultimately used data from a total of 1,358 workers out of 2,266 subjects who filled out the self-administered questionnaire. We computed the proportion of missing data, measured internal consistency reliability, and tested for convergent and discriminant validity, concurrent validity, known-groups validity, and the factor structure of this instrument. Results: For the Japanese version of the WLQ, the percentages of missing values for each scale ranged from 3.6% to 7.8%. Internal consistency reliability was high, and Cronbach's α was ≥0.7 for all subscales. Subjects with headache and orthopedic pain had significantly higher WLQ subscale scores than subjects without. Higher WLQ subscale scores were associated with depressive symptoms as measured with the Hospital Anxiety and Depression Scale (p<0.001). Conclusions: The Japanese WLQ provides reliable and valid information on at-work disability for group-level comparisons and tracking therapeutic outcomes.(J Occup Health 2014; 56: 124-133)

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Objectives: The aim of the study was to assess both personal and occupational risk factors for non-specific neck disorder (ND) in a representative working population characterized by various levels of exposure to work-related constraints. ND during the preceding 7 days was assessed in 3,710 workers surveyed by 83 occupational physicians between 2002 and 2005. Personal risk factors and work exposure were assessed by a standardized examination and a self-administered questionnaire. Associations between ND and personal and occupational factors were analyzed using logistic regression modeling separately in men and in women. Results: The personal risk factors for ND were age (OR for 1-year increment 1.02, 95% CI 1.01 to 1.03 in men and 1.03 [1.01–1.04] in women) and previous history of arthritis disease (OR 2.39 [1.17–4.91] in men and 3.95 [1.92–8.12] in women). The risk of ND increased with previous history or upper limb musculoskeletal disorders in men (OR 1.58 [1.17–2.13]) and decreased with BMI in women (OR for 1-kg/m² increment 0.96, [0.93–0.99]). The work-related risk factors of ND were sustained or repeated arm abduction (OR 2.08 [1.35–3.21] in men and 2.22 [1.27–3.86] in women) and neck flexion (OR 1.64 [1.26–2.12] in women). Work pace dependent on customers (OR 1.42 [1.10–1.83]) and psychological demand of the task (OR 1.49 [1.15–1.92]) increased the risk of ND in men. Work pace dependent on quantified targets (OR 1.37 [1.05–1.79]) and low supervisor support (OR 1.68 [1.30–2.17]) increased the risk of ND in women. This study highlighted the multifactorial nature of ND.(J Occup Health 2014; 56: 134-140)

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Aims: The aim of this study was to investigate age-related differences in the relationship between work-related factors and heavy drinking. Methods: This study in 3,398 male workers at a factory in Japan examined data on heavy drinking, defined as an alcohol consumption >40 g/day, and work-related factors including occupation, shift work, and job stress evaluated using the Japanese version of the Karasek's Job Content Questionnaire (JCQ). In the present cross-sectional study, alcohol consumption was assessed using a self-administered diet history questionnaire (DHQ). Results: The prevalence of heavy drinkers in the study population was 15.5% and rose with increasing age. An increase in the odds ratio (OR) for heavy drinking was observed consistently in blue-collar workers compared with white-collar workers in all age groups. In subjects aged 20–29 years, shift work had also increased the OR for heavy drinking. In subjects aged 40–49 years, the two groups with a lower decision latitude had an increased OR compared with the highest group. In subjects aged 20–29 years, the age adjusted OR for individuals who received the lowest level of social support in the workplace was increased significantly compared with the highest group (4.22 [95%CI, 1.07–16.62] ). On the other hand, social support showed a positive association with heavy drinking in subjects aged 40–49 and 50–59 years. Job demand was not related to heavy drinking in any of the age groups. Conclusions: Our findings suggest that occupation and work schedule are related to alcohol use more apparently in a younger age group and that psychosocial factors are related to enhancement or prevention of alcohol use.(J Occup Health 2014; 56: 141-149)

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Objectives: This study examined the changes in neck and back pain visual analog scale (VAS) scores, cervical range of motion (CROM), cervical flexion-relaxation ratio (FRR) and lumbar FRR after below-knee assembly work. Methods: Fifteen young male workers were recruited. Neck and back pain VAS scores, active CROM and cervical and lumbar FRRs were measured in all subjects once before and once after 10 minutes of below-knee assembly work. Results: The VAS scores for both neck and back pain increased significantly with below-knee assembly work. The CROM for all measures decreased significantly with below-knee assembly work. Both the cervical and lumbar FRRs on the left and right sides decreased significantly with below-knee assembly work. Conclusions: We postulate that 10 minutes of below-knee assembly work can increase neck and back pain and cause changes in the active CROM and cervical and lumbar FRRs.(J Occup Health 2014; 56: 150-156)

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Objective: Hairdressers have a high incidence of occupational diseases, owing to excessive wet work and exposure to chemical substances. The objective of this study was to assess the prevalence of occupational diseases in a population of self-employed hairdressers, matched for age and sex with a control group of wage-earning hairdressers. Method: A health questionnaire was administered to both groups by an occupational health practitioner. Results: Irritative skin diseases were reported by 1.5% of the self-employed hairdressers versus 9.1% of the wage earners. Conversely, the rates of respiratory diseases and cumulative musculoskeletal injuries were much higher among self-employed hairdressers. Conclusions: This study shows that the overall health of self-employed hairdressers is lower than that of their wage-earning counterparts. This can be attributed to several aspects of work exposure, organization, including longer working hours, fewer protective measures and the absence of preventive medicine in the workplace.(J Occup Health 2014; 56: 157-163)

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Objectives: Previously, the author reported a cluster of 11 cholangiocarcinoma cases exposed to 1,2-dichloropropane (1,2-DCP) and/or dichloromethane (DCM) in an offset proof-printing company. Before that report, the association between the two chemicals and cholangiocarcinoma had not been known. The current study describes two cholangiocarcinoma patients exposed to 1,2-DCP or DCM in different offset printing companies. Methods: The author obtained medical records for the patients, and interviewed the surviving patient and a relative of the deceased patient about their occupational history. Results: Case 1 was a man born in 1950. He worked in the printing section in a proof-printing company for 26 years. He was diagnosed as cholangiocarcinoma in 1998 and died in 2000. In proof-printing operations, he used gasoline for 14 years and 1,2-DCP for 11 years to remove ink from a rubber transcription roller (blanket). The exposure concentration of 1,2-DCP was estimated to be between 72 and 5,200 ppm. Case 2 was a man born in 1963. He worked in the printing section in a general offset printing company for 11 years. He was diagnosed with cholangiocarcinoma in 2007. In printing operations, he used both kerosene and a mixture of 50% DCM and 50% 1,1,1-trichloroethane (1,1,1-TCE) for 11 years to remove ink from a blanket. The exposure concentration of DCM was estimated to be between 240 and 6,100 ppm. He was simultaneously exposed to similar levels of 1,1,1-TCE. Conclusions: Because the offset printing process may cause cholangiocarcinoma, occupational history should be examined for patients with this cancer.(J Occup Health 2014; 56: 164-168)

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