Two types of methods based on a particular principle allow enhancing and sustaining workers' alertness all along their night work. The first one rather consists in arousing workers by exposing them to stimulant environment conditions (light or noise…) or by giving them natural or pharmacological reactivating substances (caffeine or amphetamines…) for example. The second principle consists in increasing workers' possibilities for resting and allowing them to have short sleep periods or Short Rest Periods (SRP) in an adapted area at the workplace. In order to use these techniques in real work situations, after a critical review taking into account both efficiency, advantages and disadvantages but also applicability and acceptability, the SRP technique stands out as the most efficient method as it has a certain number of advantages with regard to our initial objective.
In order to prevent low back pain (LBP) during dishwashing, we developed three types of aid with a thick cushion for supporting the shins and evaluated the effects of the standing aid on the subjective discomfort and muscle activities. Nine female volunteers were asked to wash plates in each of four working postures: (a) without the standing aid, (b) with the round type of aid, (c) with the small rectangular type of aid, and (d) with the large rectangular type of aid. With the three types of aid, the subjects were instructed to support the shins with the standing aid and to support the abdomen with the edge of a kitchen counter. In the three postures with the standing aid, 21.5 ± 10.0% of the weight was supported with the standing aid and the kitchen counter. The subjective discomfort was milder and the muscle activity level in the low back was lower in the three postures with the standing aid than in the posture without the aid. It was thought that the round type of aid would be more effective in decreasing the discomfort in many of body regions and the muscle load on the low back than either of the rectangular types of aid. Therefore, it was suggested that the standing aid had the desired effect in decreasing discomfort and muscle load on the low back during dishwashing.
Objective: The present study was aimed at clarifying the effect of vibration syndrome (VS) on the peripheral nervous system in the lower extremities of patients with VS due to rock-drill work. Methods: Fifty-three patients with VS due to previous exposure to vibration from rockdrilling work and 55 age-matched controls were examined for sensory nerve conduction velocities in the medial plantar nerve (SCV-P). The patient group was divided into three subgroups, outdoor rock-drill workers with vibration-induced white finger (VWF) (N=10), tunnel workers with VWF (N=27) and tunnel workers without VWF (N=16). Results: ANOVA of SCV-P for the four groups showed F=3.23 (dF=3, 104, p=0.0253). A significant difference was found between the controls and outdoor rock-drill workers with VWF group (p=0.0261) by multiple comparison using Scheffe's method. Conclusion: These findings suggest that peripheral nervous system function in the lower extremities of patient with VS is affected by cold exposure and circulatory disturbance manifested as VWF.
The present research was conducted in a stone quarry of marble located in northeast of Iran. Time weighted average of total dust, respirable dust, and crystalline silica (α-quartz) concentration in workers' breathing zone were monitored by using both gravimetric and XRD methods. The results showed that the employees working in hammer drill process had the highest exposure to the total and respirable dust: 107.9 ± 8.0 mg/m3, 11.2 ± 0.77 mg/m3 respectively, while the cutting machine workers had the lowest exposure (9.3 ± 3.0 mg/m3, 1.8 ± 0.82 mg/m3). The maximum concentration of α-quartz in total and respirable dust were detected equal to 0.670 ± 8.49 × 10-2 and 5.7 × 10-2 ± 1.6 × 10-2 mg/m3 respectively, which belonged to the exposure of the workers of hammer drill process. The prevalence of skin and respiratory symptoms were higher in hammer drill workers, however, respiratory symptoms showed no significant prevalence. Regarding the average age of workers (31.6 ± 1.9 yr) and average of their work history (3.8 ± 1.0 yr), these results were predictable.
To clarify the effects of changing shift schedules from a full-day to a half-day before a night shift, 12 single nurses and 18 married nurses with children that engaged in night shift work in a Japanese hospital were investigated. Subjects worked 2 different shift patterns consisting of a night shift after a half-day shift (HF-N) and a night shift after a day shift (D-N). Physical activity levels were recorded with a physical activity volume meter to measure sleep/wake time more precisely without restricting subjects' activities. The duration of sleep before a night shift of married nurses was significantly shorter than that of single nurses for both shift schedules. Changing shift from the D-N to the HF-N increased the duration of sleep before a night shift for both groups, and made wake-up time earlier for single nurses only. Repeated ANCOVA of the series of physical activities showed significant differences with shift (p<0.01) and marriage (p<0.01) for variances, and age (p<0.05) for a covariance. The paired t-test to compare the effects of changing shift patterns in each subject group and ANCOVA for examining the hourly activity differences between single and married nurses showed that the effects of a change in shift schedules seemed to have less effect on married nurses than single nurses. These differences might due to the differences of their family/home responsibilities.
A cross-sectional study on 6, 676 workers consisting of 4, 243 males and 2, 433 females aged 20-58 yr in a metal product factory was conducted to elucidate the relationship between work characteristics, e.g. job demand/control/support, sedentary job, overtime work and shift work, and waist to hip ratio (WHR) as well as body mass index (BMI) taking alcohol consumption, smoking, exercise and other psychosocial factors such as education and marital status into account. By a stepwise multiple regression analysis, BMI was associated with shift work, marital status and sedentary job for males, and with exercise but inversely associated with education for females. WHR was also associated with shift work, alcohol consumption, marital status and sedentary job but inversely associated with exercise for males, and with sedentary job, marital status and education but inversely associated with smoking for females. These results suggest that work characteristics such as sedentary job and shift work should also be considered when trying to prevent increases in BMI and WHR.
The purpose of the study is to evaluate influences of the introduction of 30% co-payments on potential visit behavior using a questionnaire in order to determine whether “employment state of the spouse” and “number of dependent children”. as indicators of economic backgrounds, affect visits to physicians in a health insurance society. The subjects were 1, 674 insured consisting of 1, 165 males and 509 females, who underwent a regular health examination in July 2002, in a health insurance society. In the survey, they were asked whether the subject “will reduce” or “will not reduce” visits to physicians due to the increase in co-payments in the health insurance system scheduled in 2003. Multivariate analyses showed that “employment state of the spouse” was significantly related to the reduction in visits for myocardial infarction or stroke, cancer or heart disease, and hypertension and diabetes mellitus. Concerning “number of dependent children”. it was related to the risk of reducing visits to physicians for myocardial infarction or stroke, trauma or fracture, cancer or heart disease, and low back pain or knee pain. Finally, upper limit expenditures of co-payments of physicians to visits due to hypertension and diabetes mellitus were related to “number of dependent children”. The study results suggest that “employment state of the spouse” and “number of dependent children” are significant factors to affect potential visits to physicians after the introduction of 30% co-payments.
The purposes of this study were to assess fatigue among elderly citrus farmers and indicating countermeasures to reduce the workload of agricultural work and the work-related stress among elderly citrus farmers. The Fatigue Questionnaire for Farmers developed by the Rural Life Research Institute, Japan was used after a modification by the addition of items related to dietary life. It was found that some of the factors causing fatigue among citrus farmers differed between men and women. There was a clear correlation between agricultural work load and the severity of fatigue. Among these elderly farmers, the qualitative aspect of work stress had much more effect on fatigue than the quantitative aspect. And, the fact that social support impossibility for them deepened their sense of dissatisfaction with work and social life indicated the importance of social support for them. The study suggested that the modified questionnaire as shown to be useful in the assessment of fatigue among agricultural workers; however, it needs to be simplified. Further study using the simplified fatigue questionnaire is needed for further clarification of fatigue and its underlying factors among agricultural workers.
The effects of seat-back angle and accelerometer height at the seat-back on seat-back xaxis frequency-weighted root-mean-square (r.m.s.) acceleration have been investigated in field experiments. Experiment 1 investigated the range and variability, of frequency-weighted r.m.s. acceleration at the same measurement position, where the seat-back angle was 24 degrees from vertical on the floor and the accelerometer height was 38 cm up from the seat cushion surface. Experiment 2 investigated ranges of frequency-weighted r.m.s. acceleration between the reference position, which was the position used in experiment 1, and test positions at different seat-back angles, 4 degrees ahead of and 4 degrees behind the reference position. Experiment 3 investigated the range of frequency-weighted r.m.s. acceleration between the reference position which was the same as in experiments 1 and experiment 2, and test positions at different accelerometer heights at the seatback from a seat cushion surface, 2.5 cm higher, 2.5 cm lower and 5 cm lower than the reference position. This investigation clarifies that different seat-back angles and accelerometer heights at the seat-back affect the frequency-weighted r.m.s. acceleration at these measurement positions, which is beyond the exposure values at which people are able to distinguish different vibration acceleration magnitudes.
Toluene is a neurotoxic organic solvent widely used in industry. Acute toluene administration in rats induced a significant increase in the numbers of neural cells immunostained for p75NTR in several brainstem regions, such as the raphe magnus and the nucleus of the solitary tract, as well as in the lateral reticular, gigantocellular, vestibular and ventral cochlear nuclei, without any in the facial and spinal trigeminal nuclei and the dorsal horn of the spinal cord. These data suggest that p75NTR could be involved in toluene-induced neurotoxic efffects in the rat brainstem.
The purpose of this study was to examine the influence of waterproof covering on finger skin temperature (FST) and hand pain during immersion test for diagnosing hand-arm vibration syndrome complying with the proposal of the International Organization for Standardization (ISO/CD14835-1, 2001) for measurement procedure. Six healthy male subjects took part in the immersion tests and immersed their both hands into water at 12°C for 5 min, repeatedly with two types of waterproof covering (polyethylene and natural rubber gloves) or without hand covering (bare hands) during immersion. The FST data from middle fingers and subjective pain scores for hand pain were analyzed. Statistically significant differences in FST among three conditions were observed showing the highest FST with natural rubber gloves, followed by the FST with polyethylene gloves and the lowest with bare hands. Significant differences in pain score among three conditions were observed during immersion showing the lowest pain score with natural rubber gloves, followed by the pain score with polyethylene gloves and the highest with bare hands. Immersion test with polyethylene gloves instead of bare hands during immersion seems to be suitable for reducing subject suffering.
A 25-year-old man, a field operator in a petroleum refinery was found unconscious. He was exposed to hydrogen sulfide and presented with Glasgow Coma Score of 5, severe hypoxemia on arterial blood gas analysis, normal chest radiography, and normal blood pressure. On hospital day 7, his mental state became clear, and neurologic examination showed quadriparesis, profound spasticity, increased tendon reflexes, abnormal Babinski response, and bradykinesia. He was also found to have decreased memory, attention deficits and blunted affect, which suggested general cognitive dysfunction, but which improved soon. MRI scan showed abnormal signals in both basal ganglia and motor cortex, compatible with clinical findings of motor dysfunction.