Objectives: Spinal pain is a significant occupational health issue. Whilst neck pain and low back pain have received considerable attention, thoracic spinal pain (TSP) has not. The objective of this study was to systematically identify and report the evidence describing the prevalence and correlates of TSP within occupational groups. Methods: This literature review systematically searched for reports of TSP prevalence and associated factors for TSP in working adult cohorts using nine electronic databases. Studies were evaluated for level of evidence and epidemiologic data were narratively synthesised. Results: 52 studies were identified describing 65 cohorts covering manual labourers, office workers, health professionals, manufacturing and industrial workers, drivers, military personnel and performing artists. Prevalence varied with occupational group and time period. One year prevalence of TSP ranged from 3.0-55.0%, with most occupational groups having medians around 30%. Significant odds ratios for individual (concurrent musculoskeletal disorders, exercising, pre-menstrual tension and female gender), general work-related (high work load, high work intensity, perceiving ergonomic problems in the workplace, working in some specialised areas, performing boring/tedious work tasks, certain year levels of study, employment duration, driving specialised vehicles, and a high number of flying hours), physical work-related (manual physiotherapy tasks, climbing stairs and high physical stress) and psychosocial work-related (perceived risk of injury and high mental pressure) factors were reported. Conclusions: The high median prevalence rates suggest TSP may be a significant occupational health problem. The multiple domains of associated factors point to the need for prospective research encompassing these domains to inform targeted occupational interventions.

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Objectives: The aim of this study was to enhance (i) insight in the relationship between different types of employment contract and the quality of working life, health and well-being, and (ii) our causal understanding of these relationships by comparing employees whose contract type changes across time. Methods: Analyses were based on a two-year prospective cohort study. Cross-sectional analyses were based upon a sample of 2,454 Dutch employees (2004). Longitudinal data were available for 1,865 respondents (2004-2006). We distinguished among 5 contract types, and subgroups of `Upward' (i.e., towards permanent employment) and `Downward' (towards temporary employment) movers across time. Data were analysed with analysis of variance and cross table analysis. Results: Cross-sectionally, we found differences between contract types in quality of working life: generally permanent employees had better jobs, whereas temporary agency workers and on call workers had more `bad work characteristics'. We also found a difference in health behaviour (smoking) and that psychological health was worst among temporary agency workers. In longitudinal analyses we found some evidence that a positive change in employment contract was associated with a better quality of working life and better psychological health, whereas the opposite was true for a negative contract change. Conclusions: The quality of working life, health and well-being are unequally distributed over employment contract groups. Temporary agency workers and on-call workers deserve special attention in terms of job design and human resource management.

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Objectives: In the present study, we modified a night shift system for an ambulance service so that ambulance paramedics were assured of taking a nap, and examined the effects of this new system on the fatigue and physiological function of ambulance paramedics. Methods: Ten ambulance paramedics at a fire station in the center of a large city in Japan voluntarily enrolled as subjects in this field study. They worked a 24-h shift system. There were two teams of 5 ambulance paramedics in the fire station. Three ambulance paramedics per shift usually provided the emergency services. In the traditional system, the ambulance paramedics had to deal with all emergency calls throughout a 24-h shift (T-shift). In the modified system, 2 ambulance paramedics were allotted time for naps in the 21:00-3:00 (C-shift) or 3:00-8:30 (B-shift) shift by the addition of another a firefighter (D-shift). Results: There were fewer emergency dispatches and nap time was longer in the B- and C-shifts than in the T-shift. Parasympathetic nerve activities during naps in B- and C-shifts were higher than in the T-shift. The results of critical flicker fusion frequency and 3-choice reaction time in the B-shift at 7:30 tended to be higher and shorter than that in T-shift. Conclusions: The results of this study suggest that the modified night shift which ensured time for ambulance paramedics to take long, restful power naps alleviated subjective fatigue, and improved physiological function which are often adversely affected by night workload.

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Purpose: We have developed a classification of high-resolution computed tomography (HRCT) images for screening, surveillance and epidemiological studies of respiratory diseases caused by occupational and environmental factors. The proposed classification consists of three parts: a guideline explaining the elements of the classification scheme, a reading sheet, and reference films to aid in assessing thin-section CT films. We assessed the reliability of the proposed classification system by blinded, independent trial reading. Materials and Methods: Seven independent radiologists and pulmonologists performed a trial reading to measure the reliability of the classification system using HRCT films from 27 pneumoconiosis patients and 7 normal controls. Results: The agreement was moderate to good for rounded opacities (weighted κ=0.68 and 0.64), irregular opacities (0.59, 0.48), honeycombing (0.65, 0.47), emphysema (0.76, 0.62) and large opacities (0.48, 0.52). Ground glass opacities (0.16, 0.20) showed poor to fair agreement. Intra-reader agreement of each of the seven readers was moderate to good (mean: weighted κ=0.52-0.80) for parenchymal findings, but the agreement was relatively low (mean weighted κ=0.52) for ground glass opacities. Conclusion: The proposed classification is able to describe early dust-related fibrotic changes and provide a semi-quantitative description of the HRCT features of major fibrotic changes in the parenchyma and pleura. Reliability, as measured by inter-reader agreement, was satisfactory.

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Objectives: Despite the high level of sex segregation of the labour market in Sweden and other countries, there is little knowledge on the association between sex segregation and ill-health. The aim of this study was to study associations between self-reported ill-health among women and men and the level of numerical sex segregation at their work sites and psychosocial work conditions. Methods: A cross-sectional questionnaire study was conducted among 10,000 employed persons in the County of Östergötland, Sweden. The questionnaire covered the level of numerical sex segregation at the work site, work organisation and conditions, ill-health, and demography. The proportions of individuals at sex-integrated and sex-segregated work sites reporting frequent ill-health symptoms were calculated and compared using Chi-square test statistics. Prevalence's of physical and psychosocial work aspects were calculated. Logistic regression models were used to assess the associations between sex segregation and other aspects of the work situation and health. Results: Among the men, 69% worked at male-dominated work sites, 16% at female-dominated, and 15% at sex-integrated work sites. Among the women, the equivalent rates were 8%, 75%, and 17%, respectively. Sex segregation was associated with all self-reported ill-health symptoms among the men, also when controlling for possible confounders. Other variables that were associated with self-reported ill-health symptoms were demands at work, negative expectations, and sickness presence. Conclusions: The present study generates sufficient findings to suggest that the link between sex segregation at work sites and ill-health is an important area that merits further attention.

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Objectives: Over one million ragpickers collect and sale recyclable materials from municipal solid wastes (MSW) in India for a living. Since MSW contains a host of pathogenic microorganisms, we investigated the occurrence of airway inflammation and its underlying mechanism in 52 non-smoking female ragpickers (median age 29 yr) and 42 control women matched for age, smoking habit and socioeconomic conditions in Kolkata, eastern India. Methods: Spontaneously expectorated sputum were stained using the Papanicolau method for cytology, and flow cytometry was used for measurements of surface expression of β₂ Mac-1 integrin (CD11b/CD18) on leukocytes and P-selectin on platelets. The concentrations of pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α) and chemokine interleukin-8 (IL-8) were measured in plasma by enzyme-linked immunosorbent assay. Results: Compared with controls, sputum samples of ragpickers contained significantly increased numbers of alveolar macrophages, neutrophils, eosinophils and lymphocytes, suggesting airway inflammation. Circulating neutrophils and monocytes of the ragpickers overexpressed CD11b/CD18 and their platelets had upregulated surface expression of P-selectin, implying functional activation of these cells. In addition, plasma levels of IL-8 and TNF-α were significantly increased, indicating greater trafficking of leukocytes from circulation to the tissues. Multivariate logistic regression analysis demonstrated a positive association between the ragpicking profession and leukocyte activation after controlling for potential confounders. Conclusions: Ragpickers experience leukocyte and platelet activation and airway inflammation that could make them more vulnerable to tissue damage and cardiovascular diseases.

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Objectives: The present study examined how job demands affect an intimate partner's well-being. We hypothesized that job demands have a negative influence on partner well-being through the experience of work-family conflict (WFC) and an impaired quality of the relationship (reduced social support and increased social undermining towards the partner). Methods: The participants of this study were 99 couples of dual-earner parents in Japan. Results: Consistent with hypotheses, men's job demands (i.e. overload and emotional demands) were positively related to their own reports of WFC, and indirectly to women's ratings of men's WFC. Consequently, women's ratings of men's WFC were negatively related to the quality of the relationship (i.e. decreased social support from and increased social undermining by men), which, in turn, led to women's ill-health (i.e. depressive symptoms and physical complaints). We found similar findings for the model starting with women's job demands; gender did not affect the strength of the relationships in the model. Conclusions: These findings suggest that high job demands initiate a process of work-family conflict and poor relationship quality, which may eventually affect the intimate partner's well-being in an unfavorable way.

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Objectives: This study was carried out to clarify the subchronic and chronic toxicity, and carcinogenicity of 2-amino-4-chlorophenol(ACP). Methods: Carcinogenicity, and chronic and subchronic toxicity of ACP were examined by feeding 10 rats of both sexes ACP-containing diet at a dose level of 0 (control), 512, 1,280, 3,200, 8,000 or 20,000 ppm (w/w) for 13 wk and 50 rats of both sexes at a dose level of 0, 1,280, 3,200 or 8,000 ppm for 2 yr. Results: The 13-wk oral subchronic toxicity of ACP was characterized by proliferative lesions leading to development of tumors in the forestomach and urinary bladder and by erythrocyte toxicity as evidenced by decreases in red blood cell counts, hemoglobin and hematocrit and concurrent increases in methemoglobin levels and reticulocyte counts. Both simple and papillary and/or nodular types of transitional cell hyperplasias were observed in the urinary bladder of ACP-fed male rats. The proliferative lesions appeared at higher doses of ACP after the 13-wk administration than clear erythrocyte toxicity did. The 2-yr oral administration of ACP significantly increased incidences of squamous cell papillomas and carcinomas in the forestomach of male and female rats and transitional cell carcinomas in the urinary bladder of male rats. These tumor incidences increased dose-dependently. Notably, clear signs of erythrocyte toxicity were not evident after the 2-yr administration of ACP. Conclusion: Clear evidence of carcinogenic activity of ACP was shown in male and female rats. These data might be useful for the health risk assessment of workers exposed to ACP.

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Objectives: The aim of this study was to determine factors of working conditions associated with job satisfaction among physicians in Japan. Methods: We sent a questionnaire to all the physicians who graduated from a medical school in Japan. Physicians who were satisfied with their job were determined as those who selected "very satisfied" and "satisfied" in response to the question: "Overall, are you satisfied with your job?" Working conditions were determined from 10 different aspects: income fairness, hospital resources, career satisfaction, difficulty in patient care, lack of personal time, administrative work, workload, and relationships with physician colleagues, staff and patients. Logistic regression analysis was used to explore the association between working conditions and job satisfaction. Results: Among the respondents, 209 (55.4%) men and 62 (61.4%) women were determined to be satisfied with their job. Job satisfaction was associated with income fairness for both men (corrected odds ratio 1.31, 95% confidence interval 1.09 to 1.47) and women (1.35, 1.05 to 1.53). For men, job satisfaction was associated with good hospital resources (1.45, 1.29 to 1.57), high career satisfaction (1.41, 1.23 to 1.57), good relationships with physician colleagues (1.33, 1.12 to 1.49), and good relationships with hospital staff (1.28, 1.07 to 1.45). For women, job satisfaction was associated with good relationships with patients (1.41, 1.07 to 1.56). Conclusions: Certain working conditions were important factors for job satisfaction among physicians. These factors should be discussed for improving working conditions.

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Objectives: The purpose of this study was to evaluate the work limitations and attendance rates after employees diagnosed with cancer returned to work from sick leave, and to identify the related factors for the limitations and attendance rates at a single manufacturing company in Japan. Methods: This study retrospectively analyzed 129 men and 4 women, employed in a single manufacturing industry, who returned to work after sick leave due to newly diagnosis of cancer. Limitations on work after the return to work were enforced in the workplace based on an industrial physician's evaluation. All the employees who needed measures for work were examined by the industrial physicians every 1-6 months until the termination of such work limitations. Results: Limitations on work after the return to work were enforced for 79 (59%) employees (36 employees with alteration of work, 31 with prohibition of shift work and 55 with prohibition of overtime work). A higher degree of work limitations was significantly correlated with work-related factors before sick leave (i.e. shift work, production line) as well as disease/treatment-related factors (i.e. chemotherapy, recurrence/metastasis), while the attendance rates after the return to work were not correlated with adverse work-related factors before sick leave. Conclusion: The enforcement of work limitations for employees with cancer was relatively common and was based on both disease/treatment- and work-related factors, and this phenomenon may play an important role in the return to work as well as the successful continuation of work after cancer survivors return to work.

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Objectives: The prevalence of musculoskeletal symptoms and related factors were investigated by a structured questionnaire among male steel workers at a large steel company in Korea including a number of aged employees and workers with prior acute injuries. Methods: Of an eligible 2,093 workers, 1,836 responded to the survey. Among 39 job groups, 8 major job groups (1,068 subjects) were selected to evaluate the potential risk factors of musculoskeletal symptoms. Results: The prevalence of musculoskeletal symptoms was 19.1% for the upper extremities, 7.6% for the back, and 7.7% for the lower extremities. Regardless of body part, the prevalence was 25.5%. In logistic regression analysis, among workers of 8 major job groups, those who experienced prior acute injuries were more likely to have musculoskeletal symptoms in the same region as that of the injury (for the upper extremities, odds ratio [OR] 2.19, 95% confidence interval [CI] 1.51-3.16; for the back, OR 7.35, 95% CI 4.01-13.48; for the lower extremities, OR 4.20, 95% CI 2.33-7.57), after adjusting for age, duration of employment, and job contents. Conclusions: The effect of job contents differed according to the presence of prior acute injury. Among workers with prior injuries, the relationship between job contents and musculoskeletal symptoms was not statistically significant in general. Among workers with no prior injuries, job contents was a significant variable for the musculoskeletal symptoms of the upper extremities and back, after adjusting for age and duration of employment. These findings suggest that prior acute injuries are a potential risk factor for musculoskeletal disorders in the workforce. More detailed and specific strategies for managing musculoskeletal disorders including prevention of musculoskeletal injuries is needed.

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