The aim of the study was to determine the effectiveness of an extension-oriented exercise program in the prevention and management of low back/neck pain in nursery school teachers. A Cluster Randomized Controlled Trial was utilized. Seventy-one nursery school teachers working in nine school buildings were randomly divided into two groups, with each school as a unit of randomization. All the teachers in both groups received an ergonomic brochure; teachers in the experimental group also received an extension-oriented exercise program, conducted by a physical therapist. Data were collected at baseline and at a two-month follow-up. The primary outcome measure recorded was the level of disability (Roland Morris Disability Questionnaire and Oswestry Disability Index), while secondary outcome measure included the evaluation of cervical and lumbar physical discomfort (Visual Analogue Scale). At follow-up, a significant improvement was registered in the experimental group as compared to the control group for all the outcomes evaluated. In conclusion an extension-oriented exercise program may be a useful strategy to prevent low back and neck complaints and to reduce consequent LBP functional disability among nursery school teachers.
This study was aimed at clarifying the effect of exposure to N-methyl-2-pyrrolidone (NMP) on workers' health. Fifteen male NMP-exposed workers and 15 referent male workers were recruited for this study. Exposure concentrations were assessed by determining NMP in the breathing zones and urinary NMP. Clinical examinations, motor and sensory nerve conduction velocities in the dominant arm, and neurobehavioral tests were carried out. The subjects were asked to complete self-administered questionnaires for subjective symptoms and psychological assessment. The mean NMP exposure concentrations ranged from 0.14 to 0.26 ppm, and urinary NMP levels at the end of each workday ranged from 0.17 to 0.22 mg/l, throughout the work week. In terms of clinical data, motor and sensory nerve conduction velocities, neurobehavioral tests, and subjective symptom assessments, there were no differences and no dose-dependent changes in either the means or the prevalence of abnormal findings between NMP-exposed and referent workers.
Epidemiological studies have found a consistent inverse relationship between increased body mass index (BMI) and sleep duration. These studies have not controlled for the role that job related factors such as shift work and working hours may have on this relationship. A cross sectional survey of shift and day workers (N=346; 292 males and 59 females) was employed to investigate the association between obesity, job related factors and sleep duration. Mean age for the overall sample was 41.1 yr (±11.1). Mean BMI was significantly higher in shift workers than in day workers (p<.001). Mean BMI (12.60 h±0.41) was also significantly (p<.001) higher in the group working long daily hours followed by medium working hours (10.95 h±0.56) and short working hours (8.72 h±0.56). Obese individuals worked significantly longer hours (p<.001) and slept 18 min less per day (p<.06) compared to those with a normal BMI. The adjusted odds ratio (OR) indicated the most significant predictor of obesity was long working hours (OR=2.82, CI: 1.10-7.19), followed by being older (OR=2.05, CI: 1.17-3.59) and short sleep duration (OR=1.92, CI: 1.03-3.55). The limitations of the study are discussed.
To explore characteristics of the development of coal workers' pneumoconiosis (CWP) at present and trend in the future, we investigated 16,154 coal miners exposed to dust for at least 1yr in the Tiefa Colliery in China. Occupational categories were divided into tunneling, mining, combining and helping. Four cohorts (before 1958, 1958-, 1968-, and after 1978) were created according to years of first exposure. Life-Table Method was used to calculate cumulative incidence rates of CWP adjusted by duration of dust exposure and predict the number of the new CWP patients. Results indicated that cumulative incidence rates of CWP in four cohorts were 26.65%, 18.94%, 1.15%, and 0.06%, respectively (Χ2=493.57, p<0.0001). The 55-yr cumulative rate of CWP of tunneling miners (25.90%) or that of combining miners (14.53%) was statistically higher than that of mining miners (7.26%) or that of helping miners (0.89%). The number of new CWP patients predicted in future was approximately 77. New CWP patients predicted would mainly occur among coal miners with first dust exposure in 1958-1967 and those working at tunneling. Most of them could be diagnosed in the age group from 45 to 75 and in the period of the next 20 yr from 2008 to 2028.
The number of foreign workers in Japan, especially temporary workers, has been increasing recently. However, little is known about the mental health status of the foreign workers working temporarily in Japan. We examined the depressive symptoms in 81 Chinese factory workers and attempted to identify the determining factors. The subjects were requested to complete individual questionnaires on sociodemographic variables (sex, age group, and residence period in Japan), working condition variables (number of working days per week and working hours per day), health administration variables (health checkups and health education), a social support variable (interpreters at workplace), and health behavior variables (alcohol consumption, current smoking, and regular exercise). The 20-item Center for Epidemiologic Studies Depression scale (CES-D) was used to measure the depressive symptoms. Of all the subjects, 95% and 84% received health checkups and health education, respectively, at their workplaces. The results of multiple linear regression analysis showed that long working hours per day were significantly associated with high CES-D score. Further, we found that older age (30-49 yr) was marginally associated with high CES-D score. Health administration considering working time and age would be important for decreasing depressive symptoms among foreign workers.
The objective of this study was to evaluate the effects of pretreatment of ethanol (EtOH) and phenobarbital (PB), which are known to affect the metabolism of xenobiotics, in the formation of hemoglobin adducts in rats administered with benzidine (BZ) and Direct Black 38 (DB38). The experimental rats were divided into BZ and DB38 groups; each group was subdivided into control, EtOH, and PB groups. Blood samples were separated into hemoglobin and plasma immediately after obtaining and basic hydrolysis was done to convert the adducts into aromatic amines. Hydrolyzed BZ, monoacetylbenzidine (MABZ), and 4-aminobiphenyl (4ABP) were separated by reversed-phase liquid chromatography without derivatization. Then, quantitative analyses were performed using a high performance liquid chromatograph equipped with an electrochemical detector. The amount of metabolites was expressed in the hemoglobin binding index (HBI). As a result, the formations of hemoglobin in BZ-, MABZ-, and 4ABP-HBI of BZ-EtOH and BZ-PB groups were increased compared with those of BZ-control group. In DB38 group, all of HBIs except for BZ-HBI were increased more than those of DB38-control group regardless of the pretreatment. These results are attributable to the fact that EtOH and PB induced N-hydroxylation is related to the formation of hemoglobin adducts. They indicate that EtOH not only increases the adduct formation by inducing N-hydroxylation but also induces N-acetylation. PB induced N-hydroxylation and increased the adduct formation in BZ group, but decreased the adduct formation in DB38 group due to decreasing azo reduction. These results suggest that the effects of EtOH or PB should be considered in biochemical monitoring of BZ and DB38 for the assessment of intermittent exposure to BZ and DB38.
Almost all studies of sleepy driving are carried out in driving simulators and with monotonous road conditions (no interaction with other cars). The present study investigated indicators of sleepy driving in a more challenging scenario after a night awake. 17 participants drove a high fidelity moving base driving simulator experiment while sleepiness was monitored physiologically and behaviourally. Short periods of situations of free driving (no other vehicles) alternated with short periods of following another vehicle (car following) with and without the possibility to overtake. The result showed that a night of prior sleep loss increased sleepiness levels at the wheel (eye closure duration and lateral variability) compared to after a night of normal sleep. Blink duration while overtaking was significantly lower compared to the other situations, it was at the same level as after night sleep. Speed when passing a stopped school bus was not significantly affected by sleepiness. However the warning caused a more rapid reduction of speed. In conclusion, a moderately challenging driving contest did not affect sleepiness indicators, but a very challenging one did so (overtaking). This suggests that it is important to monitor the driving situation in field operational tests of sleepy driving.
Exposure to whole-body vibration (WBV) is an occupational hazard for operators of industrial vehicles, such as earth-moving machines. Quantification of WBV exposure in terms of impact on health forms one aspect of the Standard ISO 2631-1 (1997). Regarding assessment of risk to health, ISO 2631-1 (1997) states that if WBV components below 1 Hz are not `relevant nor important' then they can be excluded from the assessment. In this paper the influence of sub-1 Hz components in WBV acquired from a sample of 46 earth moving machines is evaluated in terms of their contribution to ISO 2631-1 WBV exposure dose metrics: frequency weighted r.m.s. and the vibration dose value (VDV). For the majority of machines, a high proportion of the horizontal (x- and y-axis) WBV r.m.s. and VDV values was generated by sub-1 Hz vibration components; there was a much lower proportion of the vertical (z-axis) vibration generated by such components.
The aim of this study was to investigate the prevalence of cardiovascular risk factors in a sample of Taiwanese healthcare workers. Two thousand thirty-four hospital employees, 30yr of age and older, were recruited and underwent physical examinations and laboratory testing in December 2003. The study subjects were classified into four job categories, i.e., physicians, nursing staff, medical technicians, and non-medical workers. Various cardiovascular risk factors, including blood biochemical parameters, body-mass index (BMI), and blood pressure were measured for each worker. The odds ratios of having abnormal cardiovascular risk factors as a function of certain jobs were estimated from multivariate logistic regression. Overweight and obesity were independently associated with an increased prevalence of cardiovascular risk factors. Additionally, compared to non-medical workers, medical technicians had a significantly greater prevalence of hypertension, with an odds ratio of 1.74 (95% CI=1.05-2.91). The results suggest a need for managing hypertensive disorders among medical technicians, and urged that the health conditions of hospital employees should not be overlooked.
The transfection assay is an important tool for evaluating the health effects of industrial chemicals, with the reporter gene expression as an indicator. However, heavy metals often influence the expression of the reference plasmids used to correct variations in transfection efficiency between assay plates, reducing the reliability of this assay. We found that the target of heavy metals is the reporter, rather than the promoter used in the reference plasmid. Of the reporters we tested, luciferase (Luc) enzyme activity was affected by heavy metals, whereas gene product levels of the chloramphenicol acetyltransferase (CAT) or β-galactosidase (βGal) gene were not. Neither heavy metals nor extracts from cells exposed to heavy metals showed an effect when directly added to the Luc enzyme, suggesting that heavy metals act through an indirect mechanism. These data indicate that the use of CAT or βGal as a reporter is appropriate for a reliable assay of heavy metal effects.
Occupational noise has been recognized as hazardous for the human beings. A high noise level in forging shops is considered to lower the labour productivity and cause illness however occupational noise is being accepted as an integral part of the job. The present study has been carried out in 5 small scale hand tool forging units (SSI) of different sizes in Northern India in Punjab. Noise levels at various sections were measured. OSHA norms for hearing conservation has been incorporated which includes an exchange rate of 5 dB (A), criterion level at 90dB (A), criterion time of 8 h, threshold level=80dB (A), upper limit=140 dB (A) and with F/S response rate. Equivalent sound pressure level (Leq) has been measured in various sections of these plants. Noise at various sections like hammer section, cutting presses, punching, grinding and barrelling process was found to be >90 dB (A), which is greater than OSHA norms. A cross-sectional study on the basis of questionnaire has been carried out. The results of which revealed that 68% of the workers are not wearing ear protective equipments out of these 50% were not provided with PPE by the company. About 95% of the workers were suffering speech interference though high noise annoyance was reported by only 20%. It has been established that the maximum noise exposure is being taken by the workers as they are working more than 8h a day for six days per week. More than 90% workers are working 12 to 24 h over time per week which lead to very high noise exposure i.e. 50 to 80% per week higher than exposure time/week in USA or European countries15, 16).
We examined smoking prevalence among dentists in Hyogo, Japan, as smoking would influence their smoking cessation interventions to encourage their patients to stop smoking. In 2003, a self-administered questionnaire was mailed to all members of the Hyogo Dental Association (HDA) in Japan. Of the 1,133 members of the HDA, 327 were current smokers (28.9%). Smoking prevalence among HDA members was significantly higher than that among Japan Medical Association (JMA) members in 2004, as previously reported (16.2%) (p<0.01). Although smoking prevalence among HDA members decreased overall in 2003 in comparison with 2000, smoking prevalence among dentists aged 20-39 yr increased. These findings indicate that smoking was more prevalent among dentists in Hyogo Prefecture than among Japanese medical doctors. It is important to promote smoking cessation among Japanese dentists so that dentists will be more likely to encourage their patients to quit smoking.
The traditional cyclone with spray scrubber was developed for the removal of airborne silica particles from local exhaust ventilation (LEV). The objective of this research is to evaluate the efficiency of this process for removing silica particles in LEV. After designing and installing a traditional cyclone and spray scrubber, air samples were obtained at the inlet and outlet of the apparatus. The mass of each collected sample was determined gravimetrically using EPA method. The efficiency of the cyclone with spray scrubber for the removal of dust particles from the LEV system was determined to be in the range of 92-99%. There was a high correlation between the inlet concentration of dust particles and the efficiency of the apparatus. The total pressure across the system was 772.17-1120.90 Pa. It was concluded that a traditional cyclone with a spray scrubber can effectively remove a very high percentage of the incoming silica particles from an LEV. The total pressure drop across the current process is less than the pressure drop across other treatment equipment, which means that our process can effectively remove silica particles while using less electricity than other processes.
Between 1992 and 2005, 72 cases of occupational hypersensitive pneumonitis were reported to the Czech National Registry of Occupational Diseases. This represented 0.24% of all occupational diseases reported in the Czech Republic during that period. The greatest number of cases occurred in 1997 (10 cases), of which men constituted 58.3% (42 cases) and women 41.7% (30 cases). The most prevalent cases were farmer's lung (50 cases), malt worker's lung (7 cases) and chemical worker's lung (6 cases). Agriculture was the most common economic activity (total 48 cases), with cattleman and dairyman (total 26 cases) the most frequent occupations; less common were tractor driver (8 cases) and maltster (7 cases). Typical case reports after different exposures are presented. A peak in frequency was observed in the age groups of 45-49 and 50-54yr (20.8% and 19.4% of cases, respectively) and within the first four years of employment (22.2% of cases). Median age was 48yr and median exposure 12.5yr. Incidence was in the range of 0.00-0.20 per 100,000 workers, which appears rather low. Due to the difficult diagnostics of hypersensitive pneumonitis, the actual number of cases is undoubtedly higher, and this disease is probably under-reported.