China is one of ancient countries with nearly 5,000 yr history of civilization, with land area of 9,600,000 km2, including 4 municipalities, 23 provinces, 5 autonomous regions and 2 special administrative regions. There are 56 nations and 1.37 billion peoples (2010, November). In 2010, GDP was 40120.2 billion Yuan, and per capita GDP was 3,600 dollars. Employment population nearly reached 780 million peoples, including a total of 226 million migrant workers. At present, China is in the rapid development period of industrialization, urbanization and globalization, and workers face the traditional and novel dual occupational hazards. Also, prevention and control of occupational disease faces severe situations and challenges.
In the USA, national worker protection legislation was enacted in 1970. The legislation required that research, recommendations and guidance be developed to aid employers and workers, that workplace health and safety standards be adopted, that employer comply with those rules and that the government police employer compliance, and that assistance be offered to employers and workers to help them maintain a safe and healthful workplace. In the 40 yr since passage of the Occupational Safety and Health Act of 1970, worker injury, illness and fatalities have declined but not been eliminated. Efforts to accelerate the standards adoption process are much discussed in the USA along with how to protect workers from emerging hazards like nanotechnology. New strategies which seek to eliminate not only the causes of work-related injury and illness, but also more broadly, worker injury and illness, are on the horizon.
The 60-film set was developed by experts (Expert Group) for examining 8 indices: sensitivity (X1) and specificity (X2) for pneumoconiosis, sensitivity(X3) and specificity for (X4) large opacities, sensitivity (X5) and specificity (X6) for pleural plaque, profusion increment consistency for small opacities (X7), and shape differentiation for small opacities (X8) of physicians’ reading skills on pneumoconiosis X-ray according to ILO 2000 Classification. The aim of this study was to assess the appropriateness of the exam film set for evaluating physicians’ reading skills. 29 physicians (A1-Group) and 24 physicians (A2-Group) attended the 1st and 2nd “Asian Intensive Reader of Pneumoconioses” (AIR Pneumo) training course, respectively, and 22 physicians (B-Group) attended Brazilian training course. After training, they took examination of reading 60-film exam set. The examinees’ reading results in terms of 8 indices were compared between the examinee groups and the Expert Group by parametric unpaired t-test. The Examinee Group consisting of A1-Group, A2-Group and B-Group was inferior to the Expert Group in all indices. There was no significant difference for X7 of A1-Group, X7 and X8 of A2-Group (p>0.05) compared with the Expert Group. There was a significant difference in X8 at p<0.05 between A1-Group and A2-Group, in X3 at p<0.05 between A1-Group and B-Group, in both X1 and in X3 at p<0.05 between A2-Group and B-Group. Accordingly, the 60-film set providing 8 indices designed might be a good method for evaluation of the physicians’ reading proficiency at different training settings.
The detrimental effect of chronic chromium (Cr) exposure on the prostate has never been studied. Here, we report the prostate specific antigen (PSA) changes in occupational chromate exposed workers. In this study, eighty six male occupational chromate exposed workers and forty five age-matched controls were recruited. The concentration of Cr in urine (U-Cr), serum total PSA (tPSA), free PSA (fPSA), high sensitive C reactive protein (Hs-CRP) and peripheral white blood cells count (WBC) were measured. The results show that the U-Cr, serum tPSA, Hs-CRP and WBC were significantly higher in Cr exposed workers when compared to the controls. Contrastively, the serum fPSA level in Cr exposed workers was lower than controls. A significant positive correlation between U-Cr and serum tPSA was observed. Multiple linear regression analysis revealed that serum tPSA and fPSA level was statistically associated with the serum Hs-CRP and U-Cr concentration in Cr exposed workers. These observations suggested that chronic Cr exposure could produce potential prostate injury and the nonspecific inflammation at least might be one of the reasons to explain the elevated concentration of tPSA in chronic occupational chromate exposed workers.
The flow and leakage characteristics of the air-curtain fume hood under high temperature operation (between 100°C and 250°C) were studied. Laser-assisted flow visualization technique was used to reveal the hot plume movements in the cabinet and the critical conditions for the hood-top leakage. The sulfur hexafluoride tracer-gas concentration test method was employed to examine the containment spillages from the sash opening and the hood top. It was found that the primary parameters dominating the behavior of the flow field and hood performance are the sash height and the suction velocity as an air-curtain hood is operated at high temperatures. At large sash height and low suction velocity, the air curtain broke down and accompanied with three-dimensional flow in the cabinet. Since the suction velocity was low and the sash opening was large, the makeup air drawn down from the hood top became insufficient to counter act the rising hot plume. Under this situation, containment leakage from the sash opening and the hood top was observed. At small sash opening and high suction velocity, the air curtain presented robust characteristics and the makeup air flow from the hood top was sufficiently large. Therefore the containment leakages from the sash opening and the hood top were not observed. According to the results of experiments, quantitative operation sash height and suction velocity corresponding to the operation temperatures were suggested.
Occupation can influence the prevalence of metabolic syndrome. Age and gender could interact with the association between occupation and metabolic syndrome. This study aimed to investigate the prevalence of metabolic syndrome among the Korean working population and determine whether the prevalence differed according to occupation, age and gender. We conducted a cross-sectional study in Korean adults using the Third Korean National Health and Nutrition Examination Survey (KNHANES III). The analysis included 3,288 workers over 19 yr old. The prevalence odds ratios (PORs) of metabolic syndrome among representative types of occupations were estimated after stratification for age and gender by logistic regression. Female manual workers had a higher prevalence of metabolic syndrome than female non-manual workers among those younger than age 50 (POR=1.95, 95%CI=1.12–3.40). However, female manual workers aged 50 and older had a lower prevalence of metabolic syndrome than female non-manual workers (POR=0.36, 95%CI=0.22–0.59). Manual occupations can be a risk factor for metabolic syndrome, but this correlation is limited to younger female workers. The effects of occupation on the prevalence of metabolic syndrome were different between older and younger workers, which could be due to longitudinal transition of socio-cultural structure.
Because poor sleep quality can reduce quality of life and increase prevalence of illness in workers, interventions are becoming increasingly important for businesses. To evaluate how sleep quality is affected by one-on-one behavioral modification when combined with group education, we conducted a randomized, controlled trial among day-shift white-collar employees working for an information-technology service company in Japan. Participants were randomly allocated to groups receiving either sleep hygiene group education (control group), or education combined with individual sleep modification training (one-on-one group). Occupational health professionals carried out both procedures, and sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). PSQI scores were obtained before and after the intervention period, and changes in scores were compared across groups after adjustments for age, gender, job title, smoking and drinking habits, body-mass index, and mental health as assessed using K6 scores. The average PSQI score for the control group decreased by 0.8, whereas that of the one-on-one group decreased by 1.8 (difference of 1), resulting in a significantly greater decrease in score for the one-on-one group (95% confidence interval: 0.02 to 2.0). These results show that, compared to sleep hygiene group education alone, the addition of individual behavioral training significantly improved the sleep quality of workers after only three months.
In Japan, mergers of cities, towns, and villages have occurred rapidly as a result of the Special Law on the Merger of Municipalities, enacted in 2005. These mergers may impact civil servants’ psychological adjustment. We developed the Municipal Merger Stress Questionnaire (MMSQ) to measure the impact of the municipal mergers and collected responses from 570 employees who had experienced a municipal merger (Study 1). We examined the relationships among the impact of municipal merger, Stress Responses, Self-concept (self-esteem and interpersonal dependency), and Social Support (Study 2). Two factors (Increased Workload and Worthlessness) were derived from the MMSQ in Study 1. Additionally, a structural equation model showed that the impact of the loss of value of their job (Worthlessness) related to the psychological stress responses, while job discretion did not differentiate an entire stress situation in Study 2. The result implies that psychological aspects of interventions focused on worthlessness are required to maintain good mental health of public servants at workplaces.
29 physicians (A1-Group) and 24 physicians (A2-Group) attending the 1st and 2nd “Asian Intensive Reader of Pneumoconiosis” (AIR Pneumo) training course, respectively, and 22 physicians (B-Group) attending the Brazilian training course took the examination of reading the 60-film set. The objective of the study was firstly to investigate the factor structure of physicians’ proficiency of reading pneumoconiosis chest X-ray, and secondly to examine differences in factor scores between groups. Reading results in terms of the 8-index of all examinees (Examinee Group) were subjected to the exploratory factor analysis. A 4-factor was analyzed to structure the 8-index: the specificity for pneumoconiosis, specificity for large opacities, specificity for pleural plaque and shape differentiation for small opacities loaded on the Factor 1; the sensitivity for pneumoconiosis and sensitivity for large opacities loaded on the Factor 2; the sensitivity for pleural plaque loaded on the Factor 3; the profusion increment consistency loaded on the Factor 4. 4-Factor scores were compared between each other of the three groups. The Factor 2 scores in A1 and A2 groups were significantly higher than in B-Group. Four factors could reflect four aspects of reading proficiency of pneumoconiosis X-ray, and it was suggested that 4-factor scores could also assess the attained skills appropriately.
Various applications of multiwalled carbon nanotubes (MWCNT) have been developed. One of these applications is an efficient sheet heating element that is woven from MWCNT-coated yarn. In this research, we assessed the exposure to MWCNT and/or the probability of particle release from broken MWCNT-coated yarn during the weaving process. This was accomplished using particle concentrations, microscopic observation, and carbon analysis. In the weaving process, neither an increase in the number of particles nor a difference in particle-size distribution was observed. In the scanning electron micrographic observation, nanosize MWCNT particles were not detected, but there were micron-size particles containing MWCNT as fragments of the yarn. Carbon analysis showed the concentration of micron-size particles containing MWCNT did not exceed 0.0053 mg-C/m3 around the loom. This value was much lower than the respirable dust mass concentration. Most of micron-size particles seemed to originate from polyester yarn without MWCNT coating. It is recommended that workers use conventional (even not specialized for nanoparticles) personal protective equipment such as respirators and gloves to prevent exposure to respirable-size MWCNT-containing particles. The probability of MWCNT fall-off from the MWCNT-coated yarn was not detected by transmission electron microscopic observation of MWCNT-coated yarn before or after the weaving process.
The objectives of this study are to determine the prevalence of hand-arm vibration syndrome (HAVS) and the characteristics of the vibrotactile perception threshold (VPT) among users of hand-held vibrating tools working in a tropical environment. A cross sectional study was done among 47 shipyard workers using instruments and a questionnaire to determine HAVS related symptoms. The vibration acceleration magnitude was determined using a Human Vibration Meter (Maestro). A P8 Pallesthesiometer (EMSON-MAT, Poland) was used to determine the VPT of index and little finger at frequencies of 31.5 Hz and 125 Hz. The mean reference threshold shift was determined from the reference threshold shift derived from the VPT value. The results show a moderate prevalence of HAVS (49%) among the shipyard workers. They were exposed to the same high intensity level of HAVS (mean = 4.19 ± 1.94 m/s2) from the use of vibrating hand-held tools. The VPT values were found to be higher for both fingers and both frequencies (index, 31.5 Hz = 110.91 ± 7.36 dB, 125 Hz = 117.0 ± 10.25 dB; little, 31.5 Hz = 110.70 ± 6.75 dB, 125 Hz = 117.71 ± 10.25 dB) compared to the normal healthy population with a mean threshold shift of between 9.20 to 10.61 decibels. The frequency of 31.5 Hz had a higher percentage of positive mean reference threshold shift (index finger=93.6%, little finger=100%) compared to 125 Hz (index finger=85.1%, little finger=78.7%). In conclusion, the prevalence of HAVS was lower than those working in a cold environment; however, all workers had a higher mean VPT value compared to the normal population with all those reported as having HAVS showing a positive mean reference threshold shift of VPT value.