Objective: At High altitude (HA) (elevation >2,500 m), hypobaric hypoxia may lead to the development of symptoms associated with low oxygen pressure in many sojourners. High-altitude pulmonary edema (HAPE) is a potentially fatal condition, occurring at altitudes greater than 3,000 m and affecting rapidly ascending, non-acclimatized healthy individuals. It is a multifactorial disease involving both environmental and genetic risk factors. Since thousands of lowlanders travel to high altitude areas for various reasons every year, we thought it would be interesting to review pathological aspects related to hypobaric hypoxia, particularly HAPE. Method: Since the pathogenesis of HAPE is still a subject of study, we systematically identified and categorized a broad range of facets of HAPE such as its incidence, symptoms, physiological effects, pathophysiology including physiological and genetic factors, prevention and treatment. Results: This review focuses on HA-related health problems in general with special reference to HAPE, which is one of the primary causes of deaths at extreme altitudes. Hence, it is extremely important, as it summarizes the literature in this area and provides an overview of this severe HA malady for evaluation of physiological, biochemical and genetic responses during early induction and acclimatization to HA. This article could be of broad scientific interest for researchers working in the field of high altitude medicine.(J Occup Health 2014; 56: 235-243)
Objectives: There are high levels of global and national underemployment, but limited information is available on the impact of this phenomenon on the quality of employees' working lives. This study examines the relations among perceived employer support for creative work, different forms of underemployment and employee quality of life, including job satisfaction, perceived job security and job satisfaction. Methods: The study was performed using cross-sectional data from the Canadian 2010 Work and Lifelong Learning Survey (WALL), which included 1,042 randomly selected currently employed participants between the ages of 18 and 64 years of age. Results: The study found a significant inverse association between employer support for innovative work and different forms of underemployment. It also suggested a strong relationship between support for such work and participation in work-related informal learning. The results from this study confirmed the hypothesis that employer support for creative work is significantly associated with the quality of employees' working lives, as manifested through increased job security and job satisfaction. Employees experiencing greater support for workplace creativity report less job-related stress. The present study identified relatively low employer support for creative work and significant differences in the perception of support among managers and workers. Conclusions: The results of this study indicate that employer support for innovative work can mitigate significant underutilization of employee knowledge and skills. Such support can contribute to the reduction of job-related stress, increased job satisfaction and perceived job security. This kind of support can also improve the quality of life of employees and facilitate creativity and overall organizational and social development.(J Occup Health 2014; 56: 244-251)
Objective: We evaluated the percutaneous absorption of N,N-dimethylformamide (DMF) in DMF-exposed workers in the summer and winter by assessing their urinary levels of DMF metabolites. Methods: Breathing-zone concentrations of DMF and workers' urinary levels of N-methylformamide (NMF) and N-acetyl-S-(N-methylcarbamoyl)-cysteine (AMCC) were simultaneously measured in the summer and winter in 193 male workers wearing a respirator and chemical protective gloves. Results: The mean breathing-zone concentrations of DMF in both seasons were below the occupational exposure limit of 10 ppm. Although there was no significant seasonal difference in the breathing-zone concentrations of DMF, workers' urinary levels of NMF and AMCC were significantly higher in the summer than in the winter. Log-transformed urinary levels of the metabolites were significantly correlated with log-transformed breathing-zone concentrations of DMF in the summer, whereas no significant correlation between AMCC and DMF was found in the winter. The urinary levels of AMCC were dispersed more widely than those of NMF, suggesting that urinary AMCC reflected the cumulative exposure to DMF over a workweek. Conclusions: Percutaneous absorption was the principal route of exposure to DMF for the respirator-wearing workers. Increased urinary levels of NMF and AMCC in the summer were attributed to increased percutaneous absorption of DMF resulting from the increased amount of water-soluble DMF absorbed by sweaty skin caused by the increased summertime room temperature and humidity.(J Occup Health 2014; 56: 252-259)
Objectives: Pharmaceutical workers involved with the production of antimicrobial drugs are exposed to various antimicrobial chemicals in different steps of manufacturing such as grinding, sieving, compression, granulation, mixing and filling. These exposures may lead to the development of multidrug resistance (MDR) in bacteria. Scientific reports on the occupational health hazard of pharmaceutical workers involved in manufacturing antibiotics are scarce. The present study aimed to compare the degree of bacterial resistance in pharmaceutical workers in Bangladesh to that of individuals not involved in the pharmaceutical field. Methods: Twenty male workers from five local pharmaceutical companies and twenty male subjects not involved in the pharmaceutical field (non-pharmaceutical subjects) were randomly selected. Nasal fluid, mucus/cough and stool specimens were collected from each subject and were cultured separately at 37°C for 24 hours to obtain bacterial growth. The cultured species were then identified, isolated and subjected to microbial sensitivity testing against 18 different antibiotics from eight different groups by the disk diffusion method. Staphylococcus spp., Pseudomonas spp. and Escherichia coli were identified and isolated from the culture of nasal fluids, mucuses and stools, respectively. Results: All the isolated species of bacteria exhibited significant enhancement of the degree of MDR in pharmaceutical workers compared with non-pharmaceutical subjects. Workers with a longer working history had greater degree of antibiotic resistance and vice versa. It can be certainly considered that the exposure of pharmaceutical workers to antibiotic agents resulted in a high incidence of multidrug resistance. Conclusions: Effective steps should be taken to minimize inherent exposure of pharmaceutical workers to antibiotics during work to prevent antimicrobial drug resistance.(J Occup Health 2014; 56: 260-270)
Objectives: The purpose of this research was to evaluate the relationship between overtime work hours and CAVI, a new index of arterial stiffness. Methods: We measured CAVI of Japanese workers (3,862 men) aged 26 to 59 years. Simultaneously, we obtained information on their monthly overtime work hours for the past few months using a self-administered questionnaire, with responses divided into five groups: <45, ≥45 and <60, ≥60 and <80, ≥80 and <100 and ≥100 hours/month. We calculated the odds ratios of CAVI≥9.0 for each group of overtime work hours. Results: In the full sample, there was no significant association between the average CAVI and overtime work hours. Taking<45 overtime hours/month as the reference category, the odds ratios of CAVI≥9.0 were as follows: OR=1.11, 95% CI=0.73–1.69 (≥45 and <60 hours/month); OR=0.92, 95% CI=0.48–1.76 (≥60 and <80 hours/month); OR=1.50, 95% CI=0.50–4.49 (≥80 and <100 hours/month); and OR=2.65, 95% CI=0.82–8.54 (≥100 hours/month). However, for workers in their 50 s, the odds ratio of CAVI≥9.0 was significantly higher among subjects with≥100 hours/month than among those with<45 hours/month (OR=4.26, 95% CI=1.2–15.1) Conclusions: The present study suggests that CAVI is more likely to be 9.0 or higher in workers in their 50 s when they work≥100 hours of overtime per month.(J Occup Health 2014; 56: 271-278)
Objectives: We previously reported a cluster of cholangiocarcinoma patients among proof-printing workers who were exposed to 1,2-DCP for a long term. The present study was conducted to evaluate blood parameters in these proof-printing workers during and after exposure. Methods: Health examination records during employment and after retirement were obtained for ten cholangiocarcinoma patients to analyze their blood parameters. The patients and/or their relatives were also interviewed about lifestyle and occupational history. Results: All study patients were exposed to 1,2-DCP for 6–17 years. Red blood cells, hemoglobin, hematocrit, total cholesterol, triglycerides, and fasting plasma glucose were within the standard ranges for almost all patients, but the γ-glutamyl transpeptidase (γ-GTP) levels exceeded the standard range during 1,2-DCP exposure for six patients. Two of the six patients were diagnosed with cholangiocarcinoma during 1,2-DCP exposure, and the other four patients were diagnosed 1–9 years after termination of exposure. The remaining four patients had γ-GTP levels within the standard range during 1,2-DCP exposure, but had increased γ-GTP levels thereafter, and were diagnosed with cholangiocarcinoma 4–10 years after termination of exposure. Aspartate aminotransferase and alanine aminotransferase levels started to increase following the increase in γ-GTP levels. Conclusions: Workers exposed to 1,2-DCP should be provided with periodic health examinations during and after exposure. In the examination, even small increases in γ-GTP levels should be considered a signal of early development of cholangiocarcinoma.(J Occup Health 2014; 56: 279-284)
Objectives: There is concern that sound via earphones and headphones attached to headsets used in workplaces may be a risk factor for noise-induced hearing loss (NIHL). Although there are some previous studies investigating exposure to noise from headphones, almost none have assessed the risks to workers who use earphones. We assessed exposure to noise among workers who regularly wear earphones in noisy workplaces. Methods: The subjects of this study were 21 workers who regularly wear earphones in three manufacturing companies in Japan. The sound pressure output from earphones and personal exposure to occupational noise was measured for each worker. A noise-dosimeter was used to measure individual exposure to occupational noise. The sound pressure output from the earphones was measured by recording the electric signal with a data recorder attached to the earphones, and the recording was analyzed by playing it back in the laboratory through a sound analyzer via an ear simulator. Results: The mean scores for personal exposure and earphone output LAeq were 87.9 dB and 87.6 dB, respectively. Earphone output LAeq exceeded 85 dB for two-thirds of the subjects. Nearly all the subjects lacked hearing protection devices (HPDs) on their earphones. Conclusions: The results suggest that workers who use earphones in noisy workplaces are exposed to the following NIHL risk factors: (1) they are deprived of the opportunity to fit appropriate HPDs, and (2) the sound pressure output from the earphones themselves exceeds the occupational exposure limit.(J Occup Health 2014; 56: 285-291)
Objectives: “Intention to leave” (ITL) has been used interchangeably with the more positive construct “intention to stay” (ITS). The implicit assumption appears to be that both constructs represent different sides of the same coin. This study challenges this assumption. The objectives were (i) to test whether these constructs were similar measures of the same construct, and (ii) to assess the strength of the relationships between ITL and ITS with work-related outcomes. Methods: The Workforce Dynamics Questionnaire (WDQ) was administered to 298 staff. The WDQ included two items on ITL and was supplemented with three items on ITS. Structural equation modelling (SEM) was used. Results: The response rate was 43%. The correlation between the two constructs was negative and quite high (r=−0.84), indicating potential issues with discriminant validity. However, the constructs behaved differently in relation to job satisfaction and job integration. ITS was a strong predictor (0.95, p<0.001), whereas ITL was not significantly related (0.34, p=0.195) to JS. The direct effects of JI on ITS was 0.30 and on ITL was −0.42. The indirect effects of JI were more contrasting, being 0.56 for ITS and −0.30 for ITL, via job satisfaction. Conclusions: This is the first study amongst British health and social care workers that has demonstrated that ITS and ITL are not measuring the same construct. While there is overlap, care should be taken when using these constructs interchangeably, particularly when measuring these concepts in organizations and when developing retention programs, policies, or activities to modify ITS and ITL.(J Occup Health 2014; 56: 292-300)
Objectives: Current diagnostic standards of pneumoconiosis, which is the most serious occupational disease in China, are based on film-screen radiography (FSR). However, parenchymal structure overlap limits the sensitivity of FSR in the clinic. High-resolution computerized tomography (HRCT) has the advantage of identifying nodular pulmonary parenchymal changes. In this study, we aimed to compare HRCT and FSR for recognition of the profusion of small opacities, opacity shape and opacity coalescence in coal miners with or without radiographic evidence of coal workers' pneumoconiosis (CWP) and evaluate the possible role of HRCT in CWP diagnosis. Methods: There were 96 coal miners with radiographic evidence of CWP, 67 coal miners without CWP and 37 healthy controls in this study. FSR and HRCT images for all subjects were interpreted separately by three readers. Crude agreement and Kappa values were calculated to evaluate the agreement between the two methods. Results: The overall agreement for CWP evaluation was good (crude agreement rate=87.1%, κ=0.72, 95% CI: 0.62–0.83) between FSR and HRCT in all coal miners. The sensitivity of HRCT for CWP diagnosis was 96.9% (93/96). We observed that 18 of the 67 (26.9%) miners negative for CWP by FSR were classified as category 1 by HRCT according to the lung parenchyma profusion category system reported by Bérgin et al. The difference in the profusion scores between CWP subjects and healthy controls for HRCT scans were statistically significantly higher than those for FSR. Conclusions: HRCT was more sensitive than FSR in recognition of the profusion of small opacities among coal miners. More research is needed to evaluate the role of HRCT in early diagnosis of CWP.(J Occup Health 2014; 56: 301-308)
Objectives: Participatory Action-Oriented Training (PAOT) has been known as a practical training methodology for improving health and safety at work, particularly for small- and medium-sized enterprises (SMEs). Our hypothesis is that PAOT is a better approach than a traditional local method, and the objective of this study was to evaluate the efficacy of PAOT and to make suggestions for improvement. Methods: An intervention was performed for one year at 20 volunteer SMEs. PAOT was applied in 10 factories, and a traditional local method was applied in the other 10 SMEs as a control. Two cross-sectional studies were performed consisting of a questionnaire and environmental measurements. Data were also collected on the number of factory improvements, productivity, worker income, accidents, and health costs. Results: There were significant improvements among the intervention factories in terms of work environment, number of improvements and health costs between the pre- and post- intervention phases. In terms of productivity, significant increases were seen in the civil engineering, metal, garment, and rice mill industries in the intervention group, while the metal casting and, garment industries in the control group also showed significant increase in productivity. Conclusions: The findings support the idea that a PAOT program produces better outcomes in SMEs. It is recommended that a PAOT program be widely applied to SMEs to improve health and safety. A fuller examination could be obtained with more environmental measurements taken over a much longer period of time, together with data on sickness absence and accidents that have been independently validated.(J Occup Health 2014; 56: 309-316)
Objectives: A cholangiocarcinoma outbreak among workers of an offset color proof-printing department in a printing company was recently reported. It is important to understand the clinical course leading to occupational cholangiocarcinoma development for investigation of the carcinogenesis process and for surveillance and early detection. We evaluated the changes in laboratory test results and diagnostic imaging presentation before the detection of cholangiocarcinoma. Methods: We investigated the changes in laboratory test results and diagnostic imaging presentation before the detection of cholangiocarcinoma in 2 patients because the data were available. Results The clinical courses observed in the 2 participating patients showed persistent elevation of serum γ-glutamyl transpeptidase levels with or without elevated serum levels of alanine aminotransferase and/or aspartate aminotransferase before cholangiocarcinoma detection. Dilatation of the bile ducts without tumor-induced stenosis was observed several years before cholangiocarcinoma detection and progressed gradually in both patients. The serum concentration of carbohydrate 19-9 also increased prior to cholangiocarcinoma detection in both patients. Eventually, observation of stenosis of the bile duct and a space-occupying lesion strongly suggested cholangiocarcinoma. Pathological examination of the resected specimens showed chronic bile duct injury and neoplastic lesions, such as “biliary intraepithelial neoplasia” and “intraductal papillary neoplasm of the bile duct” in various sites of the bile ducts, particularly in the dilated bile ducts. Conclusions: The changes in laboratory test results and diagnostic imaging might be related to the development of cholangiocarcinoma. It is important to monitor diagnostic imaging presentation and laboratory test results in workers with extended exposure to organic solvents.(J Occup Health 2014; 56: 317-322)
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