Musculoskeletal disorders (MSDs) are a significant cause of morbidity in healthcare workers. The influence of shift work and long work hours on risk for MSDs is an area that needs further exploration. The purpose of this report is to assess research progress and gaps across studies that examined the relationship between demanding work schedules and MSD outcomes. A literature search identified 23 peer-reviewed publications in the English language that examined MSDs and long work hours, shift work, extended work shifts, mandatory overtime, or weekend work. Eight studies that examined long work hours and had some controls for physical job demands reported a significant increase in one or more measures of MSDs. Fourteen studies examining shift work had incomparable methods and types of shift work, and therefore, no clear trends in findings were identified. A small number of studies examined mandatory overtime, work on weekends and days off, and less than 10 h off between shifts. Given the complexity of the work schedule research topic, relatively few studies have adequately examined the relationship of work schedules and musculoskeletal outcomes. The review discusses research gaps including methodological issues and suggests research priorities.
Asbestos is a fibrous silicate which is recognized as causing a variety of lung disorders including malignant mesothelioma of the pleura, lung cancer and asbestosis. Asbestos use has been banned in most developed countries but exposure still occurs under strict regulation in occupational settings and also occasionally in domestic settings. Although the hazards of asbestos are well known in developed countries, awareness of its adverse health effects is less in other parts of the world, particularly when exposure occurs in non-occupational settings. Experience of asbestos use and its adverse heath effects in developed countries such as Australia have resulted in development of expertise in the diagnosis and treatment of asbestos-related diseases as well as in screening and this can be used to help developing countries facing the issue of asbestos exposure.
Effects of nine social life indicators on age-adjusted and age-specific annual suicide mortality of male and female Japanese population in the years 1953-96 were investigated by multiple regression analysis on time series data. Unemployment rate was significantly related to the age-adjusted mortality in both males and females. Also, female labour force participation was positively related to the male mortality; persons and 65 and above was inversely related to the male mortality. Results on the age-specific mortality indicated that: during the 44 yr, (1) unemployment significantly related with the mortality of young, middle-aged and elderly males and young females; (2) female labour force participation significantly related with the mortality of young and elderly males and young females; aged population significantly related with the mortality of middle-aged and elderly males; (4) young population significantly related with the mortality of young and middle-aged males and females; (5) divorce significantly related with the mortality of middle-aged and elderly males and young males and females; (6) persons employed in primary industries significantly related with the mortality in middle-aged males and young males and females; and (7) population density significantly related with the mortality of middle-aged males and young females.
Absorbed power characteristics of seated human subjects under fore-aft (x-axis) and lateral (y-axis) vibration are investigated through measurements of dynamic interactions at the two driving-points formed by the body and the seat pan, and upper body and the backrest. The experiments involved: (i) three back support conditions (no back support, and back supported against a vertical and an inclined backrest); (ii) three seat pan heights (425, 390 and 350 mm); and three magnitudes (0.25, 0.5 and 1.0 m/s2 rms acceleration) of band limited random excitations in 0.5-10 Hz frequency range, applied independently along the x- and y- axes. The force responses, measured at the seat pan and the backrest are applied to characterize total energy transfer reflected on the seat pan and the backrest. The mean responses suggest strong contributions due to back support, and direction and magnitude of vibration. In the absence of a back support, the seat pan responses dominated in lower frequency bands centered at 0.63 and 1.25Hz under both directions of motion. Most significant interactions of the upper body against the back support was observed under fore-aft vibration. The addition of back support caused the seat pan response to converge to a single primary peak near a higher frequency of 4 Hz under x- axis, with only little effect on the y-axis responses. The back support serves as an additional source of vibration to the occupant and an important constraint to limit the fore-aft movement of the upper body and thus relatively higher energy transfer under. The mean responses were further explored to examine the Wd frequency-weighting used for assessing exposure to horizontal vibration. The results show that the current weighting is suited for assessing the vibration exposure of human subjects seated only without a back support.
Mercury, an occupational and environmental contaminant, is a well-recognized health hazard. The thymus is a target for inorganic mercury (Hg2+); thymic function is impaired in Hg2+ intoxication and is partially restored by simultaneous L-arginine supplementation. The nitric oxide (NO)-nitric oxide synthase (NOS) pathway and metallothioneins (MTs) were studied to investigate the role of L-arginine in thymic function restoration after mercury exposure. Mice received a higher and a lower dose of inorganic mercury, with and without L-arginine supplementation. Saline-treated mice were used as controls. Thymus weight and thymulin were measured as indices of thymic function. Mice treated with Hg2+ alone displayed an accumulation of metal in the thymus, reduced NOS activity, a lower plasma nitrite plus nitrate concentration and an increased MTs expression compared with control mice. L-arginine supplementation was associated with lower Hg2+ concentrations in the organ and partial preservation of other measures. Reduced accumulation of Hg2+ in mice dosed with L-arginine was probably related to greater NO production and NO-MTs interactions.
The main purpose of this study is to discuss and explore the safety and health management in semiconductor industry. The researcher practically investigates and interviews the input, process and output of the safety and health management of semiconductor industry by using the questionnaires and the interview method which is developed according to the framework of the OHSAS 18001. The result shows that there are six important factors for the safety and health management in Taiwan semiconductor industry. 1. The company should make employee clearly understand the safety and health laws and standards. 2. The company should make the safety and health management policy known to the public. 3. The company should put emphasis on the pursuance of the safety and health management laws. 4. The company should prevent the accidents. 5. The safety and health message should be communicated sufficiently. 6.The company should consider safety and health norm completely.
A simple direct injection method for analysis of polycyclic aromatic hydrocarbons (PAHs) or other organic components of particulate matter by gas chromatography/mass spectrometry (GC/MS) was developed. This method uses a small custom brass capsule to insert a particulate sample deposited on a quartz fiber filter or powdery sample directly into a GC injector inlet. This approach was applied in the analysis of PAHs in diesel emissions and other particulate samples, which are introduced into the GC and analyzed by MS using selected ion monitoring mode. Quantitation is based on the concentration of PAHs in a standard reference material (SRM), which are certified by US National Institute of Standard Technology to avoid matrix effects on extraction efficiency. A standard filter is prepared by deposition of small amount of SRM of diesel particulate or ambient PM on quartz fiber filter. By this method, the linearity for 12 kinds of PAHs (3 to 6 rings) was demonstrated from 0.022 mg to 0.65 mg of SRM 1650. The linearity of BaP, for example, was confirmed from 0.028 to 0.845 ng. The reproducibility of this method determined by analyzing the standard filter was 15.4%. By selecting an appropriate SRM as a standard material, this method is applicable for analyzing PAHs in fine particulate matter of less than 1 µm from various origins. Preliminary results for a series of ambient particulate matter, roadside PM, diesel soot and sidestream smoke, are presented. This method enables analysis of organic chemical substances, for example PAHs, in PM without any pretreatment using organic solvent, and without any expensive modification of GC instrument.
This study aimed to examine the status of time spent working and sleeping by resident doctors before the introduction of the New Training System for Residents in Japan. A time-budget survey was conducted over a 4-wk period on 102 residents at the Shiga University of Medical Science Hospital, and the response rate among residents was 76% of a total of 2,722 person-days. The average number of hours spent sleeping was the lowest and spent in the hospital including commuting time was the highest in residents of the surgery department, at 4.4 h and 18.9 h, respectively. Forty percent of residents reported dozing off at work, with the incidence rate being highest in residents of the surgery department (0.7 times/person-day). Dozing appeared to occur in response to the lack of sleep and fatigue, since the same residents slept longer on nights before days they reported not dozing off than on nights before days when they did doze off. Strong correlations were observed between the number of sleeping and working hours and between working hours and the number of patients in a resident's care. In order to maintain high standards of training and to get sufficient sleep it is therefore necessary for residents to manage their work and the number of patients in their care.
Sleep problems are often under-diagnosed, but may have a profound impact on work performance. The purpose of this study was to validate the Dutch version of the Occupational Impact of Sleep Questionnaire (OISQ). A total of 555 adults with a regular daytime job completed the OISQ. In addition, they also completed the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and the SLEEP-50 questionnaire. 443 surveys were included in the analysis (220 men and 223 women). The Dutch OISQ had high reliability (Chronbach's alpha=0.96). OISQ scores correlated significantly with scores on the SLEEP-50 questionnaire, ESS, and PSQI (p<0.0001). Mean score on the OISQ was 14.0. Poor sleepers (OISQ score around 20) had approximately double the OISQ score as good sleepers (OISQ score around 10), irrespective of this classification was based on self-ratings, PSQI-scores or SLEEP-50 scores. The Dutch OISQ is a suitable tool to examine the occupational impact of sleep.
To examine the relationship between cardiovascular risk factors and prevalence of carotid atherosclerosis in Japanese middle-aged men with multiple risk factors, 110 Japanese men aged 36 to 60 yr were recruited based on the presence of all of the following factors detected during a screening survey: 1) body mass index (BMI) ≥ 25kg/m2; 2) systolic blood pressure (SBP) ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg; 3) serum levels of triglycerides (TG) ≥ 150mg/dl and/or total cholesterol (T-ChoL) levels ≥ 220 mg/dl and/or high density lipoprotein cholesterol (HDL-C) levels < 40 mg/dl; and 4) fasting serum glucose ≥ 110 mg/dl and/or hemoglobin A1C ≥ 5.6%. After adjustment for age and cardiovascular risk factors, the odds ratio (95% confidence interval) of carotid atherosclerosis associated with a 1-SD increment in HDL-C was 0.4 (95%CI: 0.2 to 0.9). We also detected a borderline association for anti-hypertension medication use, an indicator for advanced hypertension, with an odds ratio of 2.7 (95%CI: 1.0 to 7.4) after multivariable adjustment. The other risk factors, i.e. BMI, SBP, T-ChoL, TG, diabetes, smoking and drinking status did not show significant associations with carotid atherosclerosis. In conclusion, low HDL-C and advanced hypertension were significant correlates of carotid atherosclerosis for middle-aged Japanese men with multiple risk factors.
Dramatic changes in workplace structure and environment have increased the importance of psychosocial factors and job insecurity in working life. Job insecurity is shown to have a negative impact on mental and physical health. Health care transformation in Turkey increases the threat of job insecurity for many workers in the health care sector. Therefore the aim of this cross-sectional study was to determine the effects of perceived job insecurity on perceived depression and anxiety in nurses working in the private health sector in Izmir, Turkey. There were 16 private hospitals in Izmir of which 11 accepted to participate. Perceived quantitative (5 items) and qualitative (4 items) job insecurity were measured by means of structured questionnaires. The hospital anxiety and depression scale was used to evaluate subjective anxiety and depression. Job strain was assessed by the Demand-Control-Support Questionnaire. Χ2 and logistic regression tests were used for analysis. A total number of 462 nurses were surveyed. Perceived anxiety (OR: 2.2, 95% CI: 1.2-3.9) and depression (OR: 2.5, 95% CI: 1.6-4.1) were significantly associated with qualitative job insecurity. Similarly quantitative job insecurity was associated with perceived anxiety (OR: 3.4, 95% CI: 1.9-6.2) and depression (OR: 2.2, 95% CI: 1.4-5.6) in nurses. It has been concluded that qualitative and quantitative job insecurity significantly affected perceived anxiety and depression levels in nurses working in private hospitals. Prevention oriented research is needed for policy development.
The purpose of the present study was to examine the effects of different types of personal cooling equipments (PCE) on the alleviation of heat strain during red pepper harvest simulated in a climatic chamber. The experiment consisted of eight conditions: 1) Control, 2) Neck cooling scarf A with a cooling area of 68 cm2, 3) Neck cooling scarf B (cooling area 154 cm2), 4) Brimmed hat with a frozen gel pack, 5) Cooling vest (cooling area 606 cm2), 6) Hat+Neck Scarf B, 7) Hat+Vest, and 8) Hat+Neck Scarf B+Vest. Twelve subjects worked a red pepper harvest simulated in a climatic chamber of WBGT 33℃. The result showed that rectal temperature (Tre) was effectively maintained under 38℃ by wearing PCE. Mean skin temperature (Tsk) and heart rate (HR) became more stable through wearing PCE. When wearing the ‘Hat+Scarf B+Vest’, particularly, Tsk and HR quickly decreased to the comfort level during the mid-rest stage. We confirmed that the vest with a cooling area of only 3.3% body surface area (BSA) was effective in alleviating heat strain in a simulated harvest work. Furthermore, the heat strain of farm workers can be considerably eliminated by the combination of the cooling vest, a scarf, and a brimmed hat, with the total cooling area of 4.2% BSA.
Prolonged exposure to hand-arm vibration (HAV) due to use of hand-held power tools leads to an increased occurrence of symptoms of disorders in the vascular, neurological, and osteo-articular systems of the upper limbs called hand-arm vibration syndrome (HAVS). Biodynamic responses of the hand-arm system to vibration can be suggestive parameters that give us better assessment of exposure to HAV and fundamental data for design of low-vibration-exposure power tools. Recently, a single axis hand-arm vibration system has been installed in the Japan National Institute of Occupational Safety and Health (NIOSH). The aims of this study were to obtain the fundamental dynamic characteristics of an instrumented handle and to validate the performance and measurement accuracy of the system applied to dynamic response measurement. A pseudo-random vibration signal with a frequency range of 5-1,250 Hz and a power spectrum density of 1.0 (m/s2)2/Hz was used in this study. First the dynamic response of the instrumented handle without any weight was measured. After this measurement, the dynamic response measurement of the handle with weights mounted on the handle was performed. The apparent mass of a weight itself was obtained by using the mass cancellation method. The mass of the measuring cap on the instrumented handle was well compensated by using the mass cancellation method. Based on the 10% error tolerance, this handle can reliably measure the dynamic response represented by an apparent mass with a minimum weight of 2.0 g in a frequency range of 10.0 to 1,000 Hz. A marked increase in the AM magnitude of the weights of 15 g and 20g in frequency ranges greater than 800 Hz is attributed not to the fundamental resonance frequency of the handle with weights, but to the fixation of the weight to the measuring cap. In this aspect, the peak of the AM magnitude can be reduced and hence should not be an obstacle to the biodynamic response measurement of the human hand-arm system. On the basis of the results obtained in this study, we conclude that this hand-arm vibration test system can be used to measure biodynamic response parameters of the human hand-arm system.
Trichloroethylene is a widely-used industrial solvent that is absorbed through the digestive or respiratory tracts or cutaneously. It has a selective tropism for the cardiovascular and central nervous systems and may cause death due to cardiac arrest or neurological sequelae. We present the case of a 25-yr-old women who was exposed to trichloroethylene in the workplace for 18 months and who developed a disabling myoclonic encephalopathy. Non-toxicological causes were excluded. Although the exposure ceased, the disease progressed with thalamic and cerebellar involvement. The patient, who had only a partial response to symptomatic treatment, suffered severe limitations in the activities of daily living and was registered as permanently disabled due to a work-related disability.