Objectives: The aim of this study was to quantify the relative contributions to surface lead contamination of boat-caulkers’ houses of three contamination modes, namely “take-home” lead from the caulker, “natural” spatial dispersal from boatyard to household and “redistribution” of accumulated lead-laden dust within the house. Methods: Boat-caulkers’ houses situated in areas surrounding boat repair yards were recruited. Caulkers’ houses that were located close together were divided into location-matched pairs, within which one was randomly assigned to be given a cleaning and designated a CL house, and the other was to be left uncleaned and designated a NCL house. Geographically isolated caulker’s houses were randomly assigned to one of the two categories. The nearest non-boatyard worker’s house (NB) was additionally recruited for each set. The surface lead loading rate (SLLR), defined as the mass of lead deposited in dust per unit area of surface per unit time, was measured over a period of 3 mo in all houses, and the data were modeled using linear mixed effects regression. Results: Adjusted values of SLLR differed only slightly between CL and NCL houses (0.96 to 1.02 times) but were between 1.65 and 2.03 times higher in CL and NCL houses than in NB houses depending on proximity to the boatyard and between 2.12 and 2.61 times higher in houses within one km of a boatyard than in more distant houses depending on category of house. Conclusions: Newly deposited dust lead likely resulted from the take-home and spatial dispersion modes. The contribution of redistribution is very small.
Objectives: We evaluated the validity of the urine dipstick test for identifying reduced glomerular filtration rate (GFR) in male workers. Methods: This study was conducted in male workers aged ≥ 40 yr. Reduced GFR was categorized as either estimated GFR (eGFR) < 60 ml/min/1.73 m2 (eGFR <60) or eGFR < 50 ml/min/1.73 m2 (eGFR < 50). Four sets of criteria were used to evaluate the GFR on the basis of proteinuria excretion, as measured using the urine dipstick test. Receiver operating characteristic curves were created based on the sensitivity and specificity and used to calculate the area under the curve (AUC) and the 95% confidence intervals (CI). Results: A total of 5,799 workers were included in this study. Use of an abnormal proteinuria criterion of 1+–3+ and a reduced GFR criterion of eGFR < 60 resulted in a sensitivity and specificity of 7.8% and 97.4%, respectively, while a reduced GFR criterion of eGFR < 50 resulted in a sensitivity and specificity of 37.8% and 97.4%, respectively. The AUC was 0.52 (95% CI, 0.48–0.55) for eGFR < 60 and 0.70 (95% CI, 0.59–0.80) for eGFR < 50. Conclusions: In this study, 92.2% of participants with an eGFR < 60 and 62.2% of participants with an eGFR < 50 were overlooked in the urine dipstick test. These results suggest that the urine dipstick test only is not sufficient enough to identify reduced GFR and that both a urine dipstick test and other measures of GFR are required to reliably identify reduced GFR.
Objectives: The aim of this study was to determine ultraviolet (UV) action spectra for cell killing of primary porcine lens epithelial cells (LECs) that can be used to establish guidelines for evaluation of the hazard of cataract due to UV exposure in the workplace. Methods: Primary porcine LECs were exposed to different doses (radiant exposure) of UV at 17 different wavelengths from 235 nm to 311 nm. At 2 days after exposure, cell viability was assessed by measuring crystal violet staining of the cells and lactate dehydrogenase release into the culture medium. The exposure dose required to kill 50% of cells (LD50) was determined from the dose-effect relationship obtained at each wavelength and was used to construct action spectra. Results: The action spectra had a broad minimum in the approximate range of 250–280 nm, indicating that UV is most hazardous to porcine LECs within this wavelength range. The spectra rose steeply at both longer and shorter wavelengths. These action spectra are consistent with the in vivo action spectra for opacities in the rabbit lens and for light scattering in the rat lens, taking the transmittance of the ocular media into account. Conclusions: These results will help to determine a UV hazard function for cataract formation, which can be used to draft guidelines for evaluation of the hazard of cataract due to UV exposure in the workplace.
Objectives: The aim of this study was to clarify the pulmonary toxicity of copper indium gallium diselenide (CIGS) solar cells on 62 8-wk-old rats. Methods: Male Wistar rats were given 0.5, 5 or 50 mg/kg of CIGS particles, intratracheally, 3 times for a week. Control rats were given vehicle, distilled water, only. These rats were euthanized 0, 1 or 3 wk after the final instillation serially, and toxicological effects were determined. Results: None of the CIGS-treated groups exhibited suppression of body weight gain compared with the control group. The relative lung weight in the CIGS 5 mg/kg-treated and 50 mg/kg-treated groups were significantly increased compared with that in the control group throughout the observation period. Although serum copper (Cu) and selenium (Se) concentrations were not affected by instillations of CIGS particles, the indium (In) levels increased with the passage of time in the CIGS 5 mg/kg-treated and 50 mg/kg-treated groups. However, the serum gallium (Ga) levels decreased in the CIGS 50 mg/kg-treated group from 0 to 3 wk. The content of each metal in the lung increased depending on the dose instilled and was constant during observation periods. Histopathologically, foci of slight to severe pulmonary inflammatory response and exudation were present among all the CIGS-treated groups, and the severity of these lesions worsened with the passage of time. Conclusion: The present results clearly demonstrate that CIGS particles caused subacute pulmonary toxicity and that dissolution of CIGS particles in the lung was considerably slow when repeated intratracheal instillations were given to rats.
Objectives: The aim of this study was to validate the Japanese version of the Recovery Experience Questionnaire (REQ-J), which assesses how individuals unwind and recuperate from work during leisure time (i.e., psychological detachment, relaxation, mastery and control). Methods: The translated and back-translated REQ was administered via the Internet to 2,520 Japanese employees from various occupations. Exploratory and confirmatory factor analyses were conducted to evaluate factorial validity. The relationship with potential predictors and consequences of recovery experiences were investigated to evaluate construct validity. Internal consistency was examined to evaluate its reliability. Results: A series of confirmatory factor analyses revealed that the hypothesized four-factor model fit the data best. Construct validity was generally supported by expected correlations of recovery experiences with possible predictors and consequences. Cronbach’s alpha coefficient for each of the four subscales was sufficient (0.85—0.89). Conclusions: This study confirmed that the REQ-J is an adequate measure of recovery experiences that can be used in the Japanese context.
Objectives: The purposes of this study were to identify the relationships among acculturative stress, work-related psychosocial factors and depression in Korean-Chinese migrant workers living in Korea and to determine whether work-related psychosocial factors mediate the relationship between acculturative stress and depression. Methods: A descriptive correlational cross-sectional design was used. A convenience sample of 200 Korean-Chinese full-time migrant workers was recruited, and 170 completed questionnaires were included in the analysis. Acculturative stress was assessed by Sandh and Asrabadi’s Acculturative Stress Scale. Work-related psychosocial factors were assessed by job demand, insufficient job control and interpersonal conflict measures from the Korean Occupational Stress Scale. Depression was assessed by the Center for Epidemiologic Studies Depression Scale. Self-administered or face-to-face surveys were conducted by trained data collectors. Multiple regression and path analysis were used. Results: Roughly 30% of the sample met the criteria for depression. Female workers had significantly higher depression scores than male workers. Acculturative stress and work-related psychosocial factors significantly predicted 26.3% of the variance in depression. A path model revealed the mediating effect of job demand on the relationship between acculturative stress and depression. Conclusions: Our results indicate that work-related psychosocial factors are salient factors that lead to depression among Korean-Chinese migrant workers living in Korea. The results suggest that occupational health-care professionals should promote the prevention and management of depression in this population and highlight the importance of acculturation context in the development of interventions designed to reduce work-related stress.
Objectives: The prevalence of metabolic syndrome (MS) has been remarkably increasing worldwide. However, few studies have examined the effect of lifestyle intervention among subjects with MS. We investigated the effect of a six-month lifestyle modification program on the prevalence of MS and its associated biomarkers among Japanese men with MS. Methods: Subjects were randomly assigned to either the intervention (n=53) or control (n=54) group. Subjects in the intervention group received a lifestyle modification program focused on exercise and diet behavior from a trained occupational health nurse at the baseline and at one and three months. The effect of intervention was assessed by differences in changes in the prevalence of MS, its components and associated biomarkers between the two groups. Results: Of the 107 participants, 102 completed the survey at the end of six months (intervention group, n=49; control group, n=53). During the study period, the prevalence of MS decreased to 65.3% and 62.3% in the intervention group and control group, respectively. However, the difference between the two groups was not statistically significant (p=0.75). A significant reduction in body weight, waist circumference and glycated hemoglobin was observed in the intervention group compared with the control group. In the intervention group, time spent on physical activity was increased by nearly one hour per week, and the intakes of cereals and sugar and sweeteners were significantly decreased. Conclusions: Although the tailor-made lifestyle modification program among men with MS did not provide an additional benefit in decreasing the prevalence of MS, it may help weight control and improve glucose metabolism.
Objectives: The aim of this study was to investigate the relation between work-family conflict and burnout, and the mediating role of psychological capital (PsyCap) in the relation between work-family conflict and burnout, among Chinese doctors. Methods: This cross-sectional study was performed during the period of September/October 2010. A questionnaire that comprised work-family conflict assessed by the work-family conflict scale, PsyCap assessed by the PCQ-24 scale and burnout assessed by the Maslach Burnout Inventory-General Survey (MBI-GS), as well as age and gender, was distributed to 1,300 doctors in Liaoning Province, China. A total of 1,011 effective respondents became our final study subjects. Hierarchical linear regression analyses were performed by using SPSS 17.0 to explore the mediating role of PsyCap in the relation between work-family conflict and burnout. Results: Both work interfering family conflict (WIF) and family interfering work conflict (FIW) were positively related with emotional exhaustion and cynicism among both male and females doctors. However, WIF was positively related with professional efficacy only among male doctors, whereas FIW was negatively related with professional efficacy among both male and female doctors. PsyCap partially mediated the relation between WIF and professional efficacy among male doctors and partially mediated the relations of FIW with emotional exhaustion, cynicism and professional efficacy among female doctors. Conclusions: Work-family conflict was associated with burnout among Chinese doctors. PsyCap was a mediator between work-family conflict and burnout. PsyCap might be a positive resource to reduce the negative effect of work-family conflict on burnout of doctors, especially female doctors, in China.
Objectives: The objectives of this study were to determine the prevalence of and differences in certain health complaints, including physical symptoms and psychological distress, among workers in different occupational categories and to explore the associations between occupational category and each complaint. Methods: A cross-sectional study was conducted using a self-administered questionnaire. A total of 1,628 workers representing seven occupational categories from ten companies in different industries submitted completed questionnaires. The self-administered questionnaire contained three parts: personal data, physical symptoms and psychological distress. Physical symptoms were measured using nine questions developed by a panel of ten general practitioners; the questions included nine common physical symptoms across main organ systems. Psychological distress was measured using the Chinese Health Questionnaire. Results: Muscle pain (44.7%) and dizziness (30.1%) were the most common symptoms reported by participants, and 16.6% of participants suffered from psychological distress. Significant differences in physical symptoms and psychological distress were found among workers in different occupational categories (Χ2=53.59, p<0.001). Compared with service workers, office workers and managers had higher prevalence rates of physical symptoms; office workers also showed a higher prevalence of psychological distress. Conclusions: The study merits attention in terms of prevention of health problems in the workplace by focusing on a set of physical symptoms and psychological distress (not merely morbidity). Occupational category should be taken into consideration when planning workplace health promotion. Our findings highlight the need for health promotion programs that specifically target office workers and managers.
Objectives: Operation of handheld power tools results in exposure to hand-arm vibrations, which over time lead to numerous health complications. The objective of this study was to evaluate protective equipment and working techniques for the reduction of vibration exposure. Methods: Vibration transmissions were recorded during different work techniques: with one- and two-handed grip, while wearing protective gloves (standard, air and anti-vibration gloves) and while holding a foam-covered tool handle. The effect was examined by analyzing the reduction of transmitted vibrations at the wrist. The vibration transmission was recorded with a portable device using a triaxial accelerometer. Results: The results suggest large and significant reductions of vibration with appropriate safety equipment. Reductions of 85.6% were achieved when anti-vibration gloves were used. Conclusions: Our results indicated that transmitted vibrations were affected by several factors and could be measured and significantly reduced.
Background: The six-item Perceived Workplace Environment Scale (PWES) is a self-report instrument designed to measure employees’ perceptions of the extent to which their workplace environment supports employee physical activity. A Chinese version is needed to facilitate workplace physical activity research in Chinese speaking countries. Objectives: This paper describes the translation process and the psychometric properties of the newly translated Chinese version of the PWES (PWES-C). Methods: The PWES in English was translated into Chinese using a modified committee approach with the consideration of cross-cultural equivalence. Psychometric properties were examined by a cross-sectional survey of 466 male and 109 female Taiwanese information technology (IT) professionals from three IT companies in northern Taiwan. Results: Content validity of the newly translated PWES-C was supported by a panel of experts. Internal consistency reliability was high (Cronbach’s alpha=0.88), and no significant ceiling and floor effects were observed for the PWES-C. Construct validity was supported by examining the factor structure of the PWES-C using a confirmatory factor analysis, and the results suggest a single-factor structure. Conclusions: The PWES-C is a reliable and valid measure of perceived workplace physical activity environments in Taiwanese IT professionals. The scale could be used by employers to document employees’ perception of the workplace environment.