Objectives: In our previous study, we reported that even a sublethal dose of hydrofluoric acid (HFA) could cause acute toxic effects 60 min after intravenous injection. This study was designed to investigate the time- and dose-dependent changes associated with these disorders. The serum fluoride (F) kinetics are also considered in the discussion of the relationship between the concentrations of serum F and the disorders. Methods: Rats were injected with HFA (1.6 or 9.6 mg/kg body weight) for the dose-response relationship study. For each dose, the rats were assigned to one of seven groups. Blood samples of the 0-min group were obtained from the carotid artery prior to injection as a control. The other six groups were labeled according to sampling times (5, 10, 30, 60, 120 and 300-min) in the time-dependent study. Results: The 1.6 mg/kg dose decreased the ionized calcium (Ca²⁺) level significantly after 30 min, and it also decreased the total calcium (Ca) level after 300 min. The 9.6 mg/kg dose rapidly worsened renal dysfunction after 60 min. It increased the serum potassium level after 60 and 120 min and it decreased Ca and Ca²⁺ levels until 300 min. Although there was respiratory compensation, the base excess and HCO₃^- level and had not completely recovered by 300 min. Conclusions: Even low exposure to HFA caused renal dysfunction, and electrolyte abnormalities and metabolic acidosis lasted for several hours in rats. Therefore, persons involved in HFA accidental exposure should be closely monitored over time, even if the exposure is less than the sublethal dose.

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Objectives: The purpose of this study was to evaluate the effectiveness of a multi-component worksite stress management training (SMT) program among employees belong to Japanese steel company. Methods: Five workplaces were assigned to an intervention group and two workplaces to a control group. SMT with monthly 30-min sessions were provided to the intervention group for 6 mo. Intention-to-treat analyses were conducted among respondents of the intervention (n=96) and control groups (n=53). Results: Significant favorable intervention effects were found on knowledge (p<0.001) and marginally significant ones on professional efficacy (p=0.074) at one-month after completing the program. No significant intervention effects were observed on psychological distress, physical complaints, or job performance (p>0.05). However, in per-protocol analyses of those who attended all sessions, significant favorable effects were observed on psychological distress and job performance, as well as knowledge and professional efficacy (p<0.05). In addition, subgroup analyses revealed that those with initial low job control showed a favorable intervention effect only on knowledge (p<0.001), whereas those with initial high job control showed favorable intervention effects on knowledge (p<0.001), professional efficacy (p=0.023) and anxiety (p=0.033). Conclusions: The results suggest that the multi-component SMT program is effective at improving knowledge and professional efficacy, although job control appeared to moderate the effect of the program on professional efficacy. The program may also be effective at reducing psychological distress and increasing job performance, if participants complete all sessions.

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Objectives: The aims of this study of Japanese married employees were: 1) to examine the relationship between work-related factors and work-to-family conflict (WFC); 2) to examine the relationship between WFC and fatigue and depression; and 3) to explore the role of family togetherness in a path between WFC and health. Methods: A cross-sectional survey was conducted among employees belonging to a labor union federation of the chemical industry. All analyses were conducted by subgroup according to gender and parental status. Results: Data was collected from 12 companies located in the Tokyo metropolitan area from September to October 2005. The data of 961 married employees were analyzed. The main findings by regression analyses were: 1) high job demands, low job control, and unsupportive work-family culture were associated with high level of WFC; 2) WFC was positively associated with fatigue and depression regardless of gender and parental status; and 3) maintaining family togetherness was slightly, yet significantly associated with fatigue in the father group. Conclusions: WFC was unfavorably related to fatigue and depression in both genders regardless of parental status, and plays a role linking unfavorable work situations and health. As possible work-related factors of WFC, the data indicate not only individual workplace variables but also an organizational support. Additionally, maintaining family togetherness appears to benefit fathers by preventing fatigue. Strategies for reduction of WFC are therefore necessary to promote health among married workers of both genders.

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Objectives: To determine the one year prevalence of workplace abuse and sexual harassment and to determine the extent of their associations with symptoms of depression. Methods: A total of 387 female faculty and staff from colleges in Awassa, Ethiopia completed a self-administered questionnaire which collected information about relationships, mood and feelings, thoughts and satisfaction concerning the workplace, and experiences with sexual harassment. Symptoms of depression were evaluated using the Patient Health Questionnaire (PHQ-9). Logistic regression procedures were employed to calculate odds ratios (OR) and 95% confidence intervals (CI). Results: The 12 mo prevalence of either workplace abuse or sexual harassment was 86.3%; with 39.5% reporting workplace abuse only, 4.1% of them reporting sexual harassment only, and 42.6% reporting experiences of both sexual harassment and workplace abuse. Overall, the mean depression score for this cohort was 3.7 (standard deviation 4.2, range 0-19), and 9.3% of the cohort were identified as having moderate or moderately severe depression. The proportion of participants with depression were statistically significantly elevated in relation to reported experience of workplace abuse and sexual harassment (p=0.001). Compared with women reporting no experience with workplace abuse or sexual harassment, those who reported experiencing both workplace abuse and sexual harassment had an 8.00 fold increased risk of depression (OR=8.00, 95% CI:1.05-60.85). Inferences from this analysis are limited by our relatively small sample size as reflected by the wide 95% CI. Conclusions: Workplace abuse and sexual harassment are highly prevalent, and are positively correlated with symptoms of depression among college female faculty and staff in Awassa, Ethiopia. Future policies should include a combination of education, health, and public policy initiatives that clearly outline the problem and consequences of workplace abuse and sexual harassment in educational settings.

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Objectives: Prevention of horse-related injuries is considered difficult because horse behavior is unpredictable. Therefore, risk factors for injuries related to professional horse racing need to be investigated. We conducted a study to determine whether body mass index (BMI) and γ-glutamyltransferase (GGT) levels are associated with professional horse racing-related injuries. Methods: A baseline healthy survey of 546 male grooms and exercise riders aged 40-70 yr working at Miho Training Center, the largest racing-horse training facility in Japan, was performed in May 2003. A total of 93 occupational injuries occurred from June 1, 2003 to December 31, 2005. The Cox proportional hazards model was used to examine associations between the risk of injury and BMI and GGT. Results: Grooms and exercise riders with BMI <20 kg/m² or with BMI ≥25 kg/m² compared to BMI=20.0-22.9 kg/m² had 2.5 to 3.5-fold higher age-adjusted risks of injuries. The multivariate hazard ratios (95% confidence interval) after adjustment for age, GGT, smoking habit, and history of injuries were 3.5 (1.5 to 8.4) and 2.4 (1.2 to 4.8) for grooms, 3.1 (1.2 to 8.2) and 1.9 (0.4 to 10.1) for exercise riders, respectively. The age-adjusted hazard ratio of injuries for persons with GGT ≥100 IU/l was 2.0 to 2.5-fold higher than for those with GGT <60 IU/l. The multivariate hazard ratios were 1.9 (1.0 to 3.6) for grooms and 2.5 (1.0 to 6.2) for exercise riders. Conclusions: Low and high BMI and high GGT were associated with professional horse racing-related injuries.

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Objectives: Independent exposure to noise or organic solvents is reported to be associated with cardiovascular effects, but the effect of joint exposure is unclear. The present study aimed to investigate effects of noise, a mixture of organic solvents (N,N-dimethylformamide (DMF) and toluene) and their interaction on hypertension. Methods: We recruited 59 volunteers working in a synthetic leather manufacturing company during 2005-2006. Both personal noise exposure and airborne co-exposure to DMF and toluene at work were measured and used to calculate the mixed hazard index (HI). Multivariate logistic regressions were conducted to estimate between-group differences of hypertension by controlling for potential confounders. Results: We found that 18 co-exposure workers (82.22 ± 2.70 dBA and a mixed HI of 0.53 ± 0.20) had the highest prevalence of hypertension (55.6%) compared to 15 solvent-exposure workers (a mixed HI of 0.32 ± 0.18; 46.7%), 9 noise-exposure workers (84.13 ± 2.30 dBA; 44.4%) and 17 low-exposure workers (11.8%). The adjusted odds ratio (OR) of hypertension compared to low-exposure workers increased from 7.9 times (95% confidence interval (CI)=0.9-66.3; p=0.06) in solvent-exposure workers and 9.1 times (OR=9.1, 95% CI=1.0-81.1; p<0.05) in noise-exposure workers to 13.5 times (95% CI=1.5-117.8; p<0.05) in co-exposure workers. Conclusions: Our findings suggest that co-exposure to noise, DMF and toluene is associated with hypertension in synthetic leather workers. Simultaneous exposure to noise and a mixture of organic solvents may have a sub-additive effect on the risk of hypertension.

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Objectives: To develop tools offering definite orientation for managers and employees to support their work improvement through occupational mental health. This research was a part of the Mental Health Improvement & Reinforcement Study (MIR study), conducted from October 2004 to March 2006. Methods: We developed a trial version named the Kaizen Check List (KCL) by referring to problem solving methods for quality management. Then we improved it for a formal version named MIR Research of Recognition (MIRROR). A feedback form named MIR Action Guidance (MIRAGe) was also developed. We analyzed data from 1,953 respondents at five manufacturing enterprises in Japan using MIRROR and the Brief Job Stress Questionnaire (BJSQ) to determine whether or not the workers requesting work improvement had more stress than other workers. Results: The KCL had 47 items, which indicated desirable working conditions for mental health at work, and four answer categories. MIRROR has 45 selected items and improved answer categories. MIRAGe displays the results of MIRROR and step-by-step guidance for work improvement. Respondents with request had significantly higher scores in stressor and lower scores in buffer factors compared with respondents without request in many items of MIRROR. Conclusions: A combinational use of MIRROR and stress scales is useful for finding worksites with high risk factors for mental health and for directing focus on work improvement at these worksites according to workers' requests.

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Objectives: This study aimed to elucidate causes of aggression from clinical records of a psychiatric ward of a major urban public hospital where aggression towards Health Care Workers [HCWs] was the second leading cause of hospital work-related injuries after needlesticks. Methods: Psychiatric patients'clinical records for the period 2002-2005 were examined and coded. Data were analysed with the case-control approach to identify the determinants of the aggressive behavior towards HCWs, after adjustment for age, gender, nationality and diagnosis of the patients. Results: We examined 2.196 records and identified 321 individuals who had become violent at least once towards nurses, pshysicians or other patients or relatives during their hospitalization. The victims of the aggressive behavior were mainly nurses. A history of involuntary admission was strongly associated with aggression [OR 4.5, 95% CI 3.4-5.9]. Diagnosis, gender and nationality of the patients were not predictive of aggressive behavior towards HCWs. Conclusions: Involuntary admission to a psychiatric ward might be a cause of violent behavior towards health care workers, mainly nurses.

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Objectives: This study aimed to estimate the prevalence of workplace violence involving radiographers in Hong Kong, to evaluate underlying factors contributing to incidents and their impact, and to suggest improvements in management and training. Methods: Frontline radiographers, from seven regional hospitals, who performed duties in general radiography, were provided with a workplace violence questionnaire. General radiography refers to plain film X-ray services in general rooms (including out patient clinics), A&E and portable services on wards. Materials relating to workplace violence, for example guidelines and training information, were provided by hospital managers. Results: Out of 281 questionnaires, 150 were returned (response rate of 53%). Sixty-one percent of radiographers had experienced violence in the past 3 yr and 34% of victims had encountered incidents more than 5 times. From respondents who had experienced abuse, verbal abuse (97%) was most frequently reported, and the predominant source of violence was patients (p<0.0001). Respondents identified long waiting times, communication issues and understaffing as key risk factors. The Accident & Emergency Department was the highest risk area (p<0.0001). Almost two thirds (65.91%) of radiographers who experienced verbal abuse ignored events. Although no severe injury was reported, indirect impact, including increased work stress, job dissatisfaction, depression and increased sick leave, were highlighted as negative consequences of violence. 77% of respondents felt that support from departments was inadequate and only 11% had attended courses on prevention of occupational violence. Conclusions: Workplace violence is a critical problem in Hong Kong. Further research is recommended to investigate the problem.

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Objective: To determine whether working under relative humidity (RH) around 55 ± 5% may lead to dry symptoms among workers in tropical regions. Methods: We recruited 3,154 Taiwanese workers who had no history of skin diseases and compared dry symptoms between clean room workers (RH around 55 ± 5%) and other workers (RH around 65 ± 5%). Results: Clean room workers had higher prevalences of dry symptoms of the eye (odds ratio [OR]=1.62, 95% confidence interval [CI]: 1.40 to 1.86), nose and throat (OR=2.15, 95% CI: 1.66 to 2.79), and skin (OR=1.46, 95% CI: 1.23 to 1.73). In clean room workers, however, dry skin symptoms affected the palms (OR=1.72, 95% CI: 1.24 to 2.39), which are covered by gloves, more frequently than the face (OR=0.65, 95% CI: 0.45 to 0.94), which is exposed to the room air. We found working in clean rooms (adjusted OR [AOR]=1.38, 95% CI: 1.08 to 1.77), 24 to 30 yr of age (AOR=0.78, 95% CI: 0.62 to 0.99), family history of atopic diseases (AOR=1.75, 95% CI: 1.37 to 2.25), and skin moisturizer use (AOR=1.64, 95% CI: 1.30 to 2.06) were independent predictors of skin symptoms. In addition, working in clean rooms was an independent predictor of dry eye (AOR=1.30, 95% CI: 1.06 to 1.60) and dry nose and throat (AOR=1.70, 95% CI: 1.28 to 2.26) symptoms. Conclusions: Whereas the humidity in such working environments is not very low, for workers living in a high humidity environment, the relatively low humidity may still cause dry symptoms of the eye, nose, and throat.

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Objectives: The purpose of this study was to construct and test the feasibility and potential utility of a Participatory Action Oriented Training for Hospital Nurses (PAOTHN) program to prevent work-related musculoskeletal disorders. The PAOTHN program emphasized the active participation of nurses, resulting in practical and low-cost solutions for improving their work environment by reducing risk factors of musculoskeletal disorders. Methods: The PAOTHN program was conducted in a hospital located in a suburb of Seoul, South Korea. Of the 24 units in the hospital, 16 units participated in the study. The main components of the intervention were a series of structured workshops, continuous technical assistance by the research team, and periodical forums for sharing "best practices" among the participants. Results: Through the workshops, head nurses of the participating units identified a total of 46 strategic (23 short-term and 23 long-term) plans for reducing musculoskeletal disorders risks across five dimensions: (1) patient care and treatment, (2) safe handling of drugs, medical devices, and equipment, (3) workstation design, (4) physical environment, and (5) welfare facilities and administration. Over the course of the year-long project, 18 of the suggested plans were completed, for an overall completion rate of 39.1%. Conclusions: The PAOTHN program was found to be feasible and potentially useful in reducing the musculoskeletal disorder risks faced by hospital nurses, and in identifying both risk factors and improvement opportunities at the individual and organizational levels.

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