Industrial health
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Case Reports
Clinical, pathological and mineralogical features in two autopsy cases of workers exposed to agalmatolite dust.
An agalmatolite miner and processor showed large shadows at the bilateral hila accompanied by surrounding emphysematous changes and irregular shadows on chest X-ray films. Chest CT scans were characterized by a mixture of tiny irregular structures and small round opacities. Histopathological examination revealed massive fibrosis, which corresponded to large shadows, but only a small number of typical silicotic nodules, indicating mixed dust pneumoconiosis. ⋯ Quartz accounted for 70% of the amount of all mineral dust in both patients, but pyrophyllite accounted for 10.8% and 14.4%. The pulmonary mineral dust composition in the two patients was well consistent with the mineral composition of the raw clays in the agalmatolite mine. In the two patients, chest X-ray findings and histopathological findings of the lungs also suggested agalmatolite pneumoconiosis, which was confirmed by mineral analysis of the lungs.
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Comparative Study
Shift work-related problems in 16-h night shift nurses (2): Effects on subjective symptoms, physical activity, heart rate, and sleep.
We compared the shift work-related problems between 16-h night shift and 8-h evening/night shifts among nurses in a university hospital with respect to subjective symptoms, physical activity, heart rate (HR), and sleep. The nurses of one group (n = 20) worked a 16-h night shift under a rotating two-shift system, while those of the other group (n = 20) worked an 8-h evening or night shift under a rotating three-shift system. The 16-h night shift was staffed by three or four nurses who alternately took a 2-h nap during the shift, and had at least one day off after each shift. ⋯ No differences in subjective symptoms between the two shift schedules were observed before or after the shifts or during days off. The main sleep was longer after the shifts and during days off in the 16-h shift group than in the 8-h shift group. Our results suggest that the work-related problems in 16-h night shift nurses may not be excessively greater than those in 8-h evening/night shift nurses, as long as appropriate countermeasures are taken during and after the extended shift.
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Comparative Study
The comparative study on occupational mortality, 1980 between Japan and Great Britain.
Age-adjusted standardized mortality ratios (SMRs) and life tables in male occupational groups for all causes and major diseases such as malignant neoplasm of stomach and lung, cerebrovascular disease, ischemic heart disease, traffic accidents and suicide was compared between Japan and Great Britain. Except for traffic accidents and suicide, males in higher employment grades had lower SMRs which had also been found to be related to other social class indicators such as perinatal death rate, the frequency of work absence and current smoker's rate. ⋯ The present authors concluded that inequalities in socio-economical factors were more likely to be the primary factors for survival, and that selection such as occupation and occupation-related lifestyle might still be an important factor for the inequalities. These inequalities were more obvious in Japan, where a life expectancy was, however, best in the world.
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With objective to find out prevalence of Coal Worker's Pneumoconiosis and variation among readers in reading x-ray plates for pneumoconiosis, a retrospective epidemiological survey of Coal Worker's Pneumoconiosis was undertaken in 72 collieries of Madhya Pradesh and Orissa by re-reading of x-ray plates taken during the Periodical Medical Examination at the Occupational Health Units over a period of 5 years. Six readers, trained abroad in reading pneumoconiosis x-ray plates, were involved for the study. Each reader reported approximately one sixth of the available x-ray plates of all the collieries and classified on the 12 point scale of I. ⋯ Among the opacities, 'p' type is more prevalent (48.29%) followed by 'q' type (40.62%). There was variation amongst the different readers and ranged from 1.14% to 6.76% for reporting the prevalence of Coal Worker's Pneumoconiosis. However, when analysis of six readers for inter reader variation was conducted, that shows no abnormal deviation in the reading of any of the readers.
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The epidemiological studies performed thus far have presented only limited evidence for the carcinogenicity of trichloroethylene (TRI) to humans. However, these studies had drawbacks such as insufficient size of cohort, short observation period, and inadequate TRI exposure assessment; therefore, no concrete conclusion has been reached concerning TRI carcinogenicity to humans. Despite the limited epidemiological evidence as to the carcinogenicity of TRI, the International Agency for Research on Cancer (IARC) has changed the carcinogenicity classification of TRI from Group 3 (not classifiable as to carcinogenicity to humans) to Group 2A (probably carcinogenic to humans). ⋯ The main symptoms appearing after chronic exposure at low levels are neurological changes represented by subjective symptoms relating to central and autonomic nervous systems, or by a lowered conduction velocity of the nerves or a prolonged latency of the nerve responses. For the present, it is reasonable to use the neurological findings for establishing the reference values of TRI for both work and general environments. A value of 25 ppm (135 mg/m3) is proposed as a reference value for work environments, and 25-50 ppb (135-270 micrograms/m3) for the general environment (1/1,000 of the value for work environment).