[Respiratory parameters in pneumoconiotic miners in the north French coal district (author's transl)].

The authors examine the respiratory tests performed during a two years-period in 676 pneumoconiotic miners. Spirography was normal in 8% of the cases; a mixed ventilatory impairment, with an obstructive prevalence of variable extent, was present in 2/3 of the cases. Pharmacodynamic tests in 353 subjects showed a frequent non-specific bronchial sensitivity (34.2% of the whole group). Hypoxaemia (PaO2 below 75 mmHg) with normo- or hypocapnia was observed in 379 patients; hypercapnia was relatively uncommon (9.9%) and occurred mainly in bronchitic patients. The breath holding CO lung transfer test was very often disturbed, as the diffusing capacity (DLCO) was below the predicted value in about 80% of the population. Radiofunctional comparisons were carried out in an homogeneous group of 212 subjects. The data clearly demonstrate that functional abnormalities were not exclusively seen in extensive radiological forms. As far as it goes beyond a simple ventilatory study, the measurement of the breath holding lung transfer factor for CO has proved to be a valuable element in the functional statement of anthracosilicosis. The polymorphism of the pulmonary repercussions of dust exposure explains individual differences between the results of the main investigations, and this emphasizes the need for a series of diversified tests.