Objectives: The Epworth sleepiness scale (ESS) is often used for screening of sleep apnea syndrome (SAS) in the workplace. We conducted pulse oximetry for workers of a large transportation company, who were selected based on their response to a questionnaire that included ESS and breathing pattern during sleep. Methods: Pulse oximetry was performed for 803 of 3,761 male workers. A 3% oxygen desaturation index (ODI) ≥15 was defined to represent sleep disordered breathing (SDB). We evaluated the frequencies of severe snoring and sleep apnea in the past three months reported by the bed partner or a family member. The relationships between 3% ODI ≥15 and various parameters were analyzed. Results: Of the 715 workers with valid recordings, 3% ODI was ≥15 in 108. The prevalence of 3% ODI ≥15 was high among workers with a body mass index (BMI) ≥25 kg/m2, or for whom severe snoring (≥4 days/wk) or sleep apnea (≥2 days/mo) was reported, but did not correlate with ESS scores. Multivariate analysis showed that 3% ODI ≥15 correlated significantly with BMI, and reported severe snoring and sleep apnea, but not ESS scores. The prevalence of 3% ODI ≥15 was high among obese workers. ESS scores did not correlate with 3% ODI ≥15, irrespective of obesity. Conclusions: Our findings suggest that severe snoring, sleep apnea and BMI, but not ESS, are useful screening tools for SAS.
Objectives: We performed a cytotoxicity study by cell magnetometry, measured lactate dehydrogenase (LDH) activity by enzyme assay, detected DNA ladder formation, and performed morphological examination by electron microscopy in order to evaluate the safety of high temperature wool (HT wool), an asbestos substitute, using long and short chrysotile fibers (CF) as positive controls and phosphate buffered saline (PBS) as a negative control. Methods: Alveolar macrophages were isolated from male Fisher rats. Following the addition of iron oxide particles (Fe3O4) to macrophages, HT wool, long or short CF was added. Then, the remanence strength was measured for 20 min after magnetization by an external field. Percent LDH release was calculated after determining LDH activity. DNA was detected using an apoptosis detection kit. Morphological observation was performed by taking electron micrographs of macrophages in the groups treated with HT wool and long- and short-CF. Results: Rapid relaxation, an indicator of decay of cytotoxicity, was observed by cell magnetometry immediately after magnetization was ended in the groups treated with HT wool and PBS, showing that HT wool causes no harmful effect on the cytoskeleton. The CF-treated groups had higher LDH activity than the PBS- and HT wool-treated groups. No fragmentation of DNA was observed in any group. In morphological observation, cytotoxicity in macrophages was lower in the HT wool-treated groups than in the CF-treated groups. Conclusions: The results suggest that HT wool has no cytotoxicity, as evaluated by cell magnetometry, enzyme assay, DNA ladder detection and morphological examination.
Objectives: To investigate the prevalence of musculoskeletal symptoms in the upper extremity (UE) in a sample of Italian call center (CC) operators, and the relationship between the symptoms and potential workplace risk factors. Methods: During 2005-2006, 775 workers from seven CCs in the Turin area participated in a questionnaire survey of exposure to ergonomic, organizational and psychosocial factors at work, socio-demographics, lifestyle, symptoms and diseases. Musculoskeletal symptoms were defined as self-reported musculoskeletal symptoms in the UE during the previous 28 days, for which a physician was consulted and/or drugs were taken. Relative risks were estimated through Poisson regression models with the Huber-White sandwich estimator of variance. Result: Overall, 45% of workers reported UE symptoms in the last four weeks. Symptoms in the neck were the most prevalent (39%), followed by the shoulder (22%), hand-wrist (10%) and elbow (4%). Among workplace risk factors, neck-shoulder symptoms were associated with low job control, elevated noise, poor desk lighting and impossibility to lean back while sitting; whereas elbow-hand/wrist symptoms were associated with short intervals between calls, insufficient working space, lack of forearm support, job insecurity and long seniority in the CC industry. Conclusions: The high prevalence of UE symptoms in this sample was similar to that reported by other studies conducted in this industry. Our results confirm previously reported associations, such as poor characteristics of the workstation and psychological stressors. The striking difference between the set of risk factors for neck-shoulder and elbow/wrist-hand symptoms indicates that the two regions should be investigated separately.
Objectives: Thermal reconditioning characteristics of organic vapors from a respirator cartridge were studied by introducing humid air into a cartridge that had adsorbed organic vapors in order to develop a thermal reconditioning method. Methods: Five different organic vapors (methanol, 2-propanol, acetone, dichloromethane and methyl acetate), most of which have relatively weak adsorption affinity to charcoal, were used in this study. Adsorption was carried out at a temperature of 25°C. The relative humidity of the adsorption air with organic vapor was 50%. When the vapor concentration in the downstream of the respirator exceeded the breakthrough concentration, that is, the occupational exposure limits in Japan, the vapor supply was stopped. Then, desorption was started by introducing clean humid air from opposite side of the cartridge under a heated condition. When the desorbed vapor concentration fell below the limit of quantification, desorption process was ended and the next adsorption cycle was started after the temperature had returned to room temperature. This adsorption - desorption cycle was repeated more than three times. The desorption temperature was 65°C and the relative humidity of desorption air was 20%, 50% or 70% at 25°C. Results: When the relative humidity was 20%, the breakthrough times of regenerated cartridges were shorter than that of a new one, but no difference was observed in the breakthrough curves when the relative humidity was greater than 50%. Conclusion: The results suggest that the thermal reconditioning of respirator cartridges using humid air is possible for these vapors.
Objectives: To identify individual, work-related physical and psychosocial factors associated with the self-reported prevalence of musculoskeletal symptoms in the hip, knee and ankle/foot of saleswomen in department stores in Thailand. Methods: A cross-sectional survey was conducted in which 1,310 saleswomen in 18 department stores received a self-administered questionnaire. Returns were 1,200 (92%) questionnaires, and after screening for exclusion criteria, 1,189 saleswomen were found to be eligible for the study. Results: Having a child, number of working hours per day, frequency of body twisting during work and self-rated perception of light intensity in the workplace were each significantly associated with the prevalence of experiencing hip symptoms. Significant associations were found between age, number of hours per day required to stand or walk and self-rated perception of temperature in the workplace, and the prevalence of experiencing knee symptoms. The number of working hours per day and working days per week as well as frequency of working in static postures and rest breaks during work were each significantly related to the prevalence of experiencing ankle/foot symptoms. Conclusions: Among saleswomen, various individual and work-related physical factors were identified as risks and preventive factors for musculoskeletal symptoms in the lower extremities. Further research should focus on these modifiable factors in order to develop effective strategies for reducing the occurrence of such symptoms in saleswomen.
Objective: To present the pitiable working conditions of clinical waste pickers in hospitals in the Northwest region of Cameroon and associated exposure to health hazards. Methods: Observe clinical waste pickers as they carry out their functions for three days and carry out informal consultations (discussion) with the waste pickers on their working conditions, possible health risks and avenues and resources to improve the current situation. Results: Lack of immunization, protective equipment, and poor work postures, absence of support groups and lack of awareness on associated health hazards contributes to the current plight of clinical waste pickers in Cameroon. Improving hospital infrastructure and equipment is prioritized over safety and management of risks faced by the clinical waste pickers. Conclusion: Clinical waste pickers in Cameroon certainly work in poor conditions which endanger their health and those of their families. There is an urgent need for the implementation of health and safety protocols together with an overhaul of equipment currently in use.