[Interpretation of early radiological changes in the diagnosis of pneumoconiosis among coal miners]. / Interpretacja wczesnych zmian radiologicznych w diagnostyce pylicy górników kopaln wegla kamiennego.

Apart from certain changes which are typical for pneumoconiosis, the radiological picture of the lungs of sigma coal miners does frequently show some irregular small opacities of s, t and u types. The role and specificity of these changes in the early diagnosis of pneumoconiosis has not been too well defined by now. A 10-year study (conducted at 2 or 3 year intervals) was carried out among 150 miners from 2 mines characterized by different dust loading. Some irregular changes in the miners' lungs were observed. The control group derived from the same mines comprised 115 miners with no radiological changes found in their lungs. The evolution of radiological changes took place in 55.3% of the miners and was more intensive in the heavily dusted mine. Radiological changes were revealed in 38.3% of the controls. It was indicated that pneumoconiosis results much more frequently (38.6%) from the evolution of the irregular changes rather than directly from the proper radiological picture of the lungs (5.3%). In 44.7% of the subjects the changes of s, t and u type did not undergo any evolution, which may be due to their non-specific characteristics. The evolution of irregular opacities is dominating in the patients with bronchitis and emphysema. No significant correlation between smoking and the progress of irregular opacities was found. The observation of the further exposure to the dusts did not produce any clear results. The progress of the changes of s, t and u type was observed more frequently in those still working under ground, but more cases of pneumoconiosis were found in the miners who stopped working. This fact indicates that the further exposure affects the s, t and u type changes and confirms the observations by other authors concerning the manifestation of pneumoconiosis after the break of exposure. The results of the 10-year study prove that the miners with this sort of changes are exposed to a higher risk of pneumoconiosis, although the answer concerning specificity of irregular changes in the radiological picture has not yet been found.

[Evaluation of the effectiveness of medical prevention of pneumoconiosis based on studies of its incidence in selected coal mines]. / Ocena skutecznosci profilaktyki medycznej pylic w oparciu o badania chorobowosci w wybranych kopalniach wegla kamiennego.

In a group of 3,938 persons--pit miners of 3 coal mines--employed over 8 years, full-size X-ray pictures of the chest have been taken and through a special questionnaire information has been collected on the length of employment, workstation, risk of dustiness, exposure to fibrogenic dusts outside the mine. Basing on the studies, the mean annual incidence of pneumoconiosis in particular mines has been calculated. The data has been compared with the mean annual incidence rate of pneumoconiosis calculated for 10 years prior to epidemiological studies and based on the primary selection by means of small-size pictures. This comparison indicated that the full-size pictures revealed 3-7 times more pneumoconioses as compared to the hitherto applied system. The comparison of full-size and small-size X-ray pictures demonstrated that the lesions visible in full-size pictures have not been registered in small-size pictures in as many as half of the cases. The obtained results indicate that the effectiveness of the hitherto applied system of medical prevention of pneumoconiosis is insufficient. A change in this system is indispensable; miniature roentgenography should be replaced by full-size X-ray pictures.