Revue de l'Institut d'hygiene des mines最新文献

The prevalence of chronic bronchitis was compared in a group of 970 coalminers and in 538 controls by means of a standardized questionnaire and of VC and FEV1 measurements. The coaldust present in the galleries had a low content of free silica and the dust levels were lower than the maximal permissible concentrations with reference to the US standards. The socio-economic characteristics, and mean height values were identical in both groups. The controls were somewhat older than concerning bronchitis symptoms were found in the non-smokers. The non-smokers exposed to coaldust showed higher prevalences of cough and FEV1 abnormalities than their matched controls. The unfavourable effect of exposure to coaldust on the bronchi was masked by cigarette smoking.

Events leading to the start of the Pneumoconiosis Field Research in 1953 are reviewed. Research methods are outlined, progress is described, and the main results are summarised. Three medical surveys were conducted at approximately five-year intervals in 24 coal mines. A further two quinquennial surveys took place at 10 of them, thus completing 20 years' observations. Individual miners' exposures to dust have been measured throughout the periods of study and earlier exposures have been estimated. The dust exposure have been expressed as cumulative timeweighted mass concentrations of dust in the respirable range. Correlations have been demonstrated between this index of exposure and (a) risks of developing various degrees of simple pneumoconiosis, (b) the occurrence of chronic bronchitis symptoms, (c) level of breathing capacity, and (d) among miners with no pneumoconiosis, mortality attributed to respiratory diseases generally, chronic bronchitis and emphysema in particular, and to cancers of the digestive organs. Exposures to quartz amounting to less than about 10 per cent of mixed coal mine dust do not generally affect the probability of developing simple pneumoconiosis. But there is evidence that some miners may show unusual radiological changes over ten years when exposed to dust with a relatively high quartz content. Current work includes continuation of mortality studies and follow-up surveys of miners no longer working at the research collieries. The inter-disciplinary nature of the research team is emphasized and there are suggestions for further work on unresolved problems.

Chronic cough in the sense of the international definition was found in 50.5% of a group of 970 coal-miners at work without pneumoconiosis. In 14.7% of these subjects the cough was without phlegm production. Non productive cough is therefore not a rare event and this symptom may not be neglected in the natural history of chronic bronchitis in coal-miners. The changes in lung function are similar whether the cough is productive or not. In both cases endoscopic and histological features are suggestive of an established chronic inflammatory process. Allergy is not more frequent in subjects with dry cough than in those with productive cough.

The results observed with talampicilline in our clinical study confirmed the observations made by others regarding the activity and the improved tolerance for this drug versus ampicilline. The use of a high daily dosage of 3 g per day was neither a cause of more frequent nor more severe side-effects than the usually smaller posology used in other studies published in the literature.

Fenoterol aerosol (400 micrograms) and isoproterenol aerosol (200 micrograms) were compared in a double blind cross-over trial in 59 patients with reversible broncho-obstruction. Measurements of VC, FEV1, respiratory impedance (ZR), blood pressure and pulse rate as records of subjective symptoms, râles and side effects, were made over a period of 180 minutes. After fenoterol FEV1 increased significantly from the 15th minute till the first hour. After isoproterenol an increase of this parameter was obtained only at the 15th minute. The decrease in ZR was always larger with fenoterol than with isoproterenol. This difference was significant at the 2nd hour (P < .05) and at the 3rd hour (P < .01). In a group with severe obstruction the airway obstruction improved more with fenoterol than with isoproterenol (P < .01). The functional improvement induced by 400 micrograms fenoterol appeared to be more potent and of longer duration than the improvement caused by 200 micrograms isoproterenol. Moreover it appeared more rapidly after administration.

The author stresses the permanent evolution of the working conditions in the industry. He pays a particular attention to the changes which were experienced in this regard since two decades in the coal mines. The ergonomist tries to give an impartial answer to the new problems by means of a scientific approach in order to help those who are responsible for the social and technical progress. The author reminds the principles of this approach. He analyses the definition of ergonomics and shows how this discipline may be applied in the coal mines. He reminds the important role played in this regard by the ECCS, and the realizations which could be performed in the coal industry as well. A comment on the objectives and means of the 4th research ergonomic programme of the European Communities is presented.

A review is given about various epidemiologic and pathologic studies in coal workers and foundry workers, regarding the prevalence of respiratory symptoms, chronic bronchitis and pulmonary emphysema in those workers in the Rhine-Ruhr-area. It is evident that these diseases are much more frequent in dust-exposed workers than in the other population.

The results are in agreement with the hypothesis that 900 mg oral bamifylline, as a unique dose, should produce slight and temporarily bronchodilating effects. This phenomen may be discussed from the 30th minute after intake. It was significant after 2 hours and remained significant till the 4th hour. It is interesting to stress that this conclusion is in agreement with some isolated observations we could make before in our laboratory by means of injections or suppositories with the same product [9]. We did not observe facts suggesting a possible cumulative effect of the drug, when taken at a dosage of 3 times 900 mg regularly spread over the day. The drug seems to be perfectly tolerated. A 10 days' treatment with the above mentioned posology did not produce neither haematological, haepatic, renal, nor vascular side-effects which could be identified by the techniques classically used in these respective fields.

Epidemiological surveys of coal workers' pneumoconiosis are only possible by means of periodic X-ray examinations, repeated with a reasonable frequency in order to allow an identification of the first X-ray anomalies of simple pneumoconiosis in exposed workmen. Incidence studies to detect simple pneumoconiosis at its first stages and its progressive increase in cohorts of coal-miners whose dust exposure is known are indeed theoretically the best way to approach these problems. For many reasons, discussed in this paper, such incidence studies are nowadays impossible in Belgium. The survey technique used in our country is based on repeated transversal surveys. Its results are illustrated and commented.