[Fibroplastic dust and cardio-respiratory functions]

Repeated measurements of dust concentrations and work loads were made at the workplaces in iron foundries (interval 10 years) and processing of asbestos (dusts 27 years and work load 8 years). The work load was mild to moderate, rarely heavy (energy output 2.0 to 5.7 MJ in the shift) with a mean heart rate 94-106. The incidence of occupational diseases was stabilized in the foundries, increased in the asset processing plants (mostly lung cancer). Two thirds of the workers were smokers, in spite of that the workers in the foundries had their mean flow-volume curve almost identical with the standards. Their age conditioned diminution was faster especially for FEF50 and 25 and accompanied with a bigger rise of FRC and RV. Exercise testing demonstrated the same fitness as in normal population (2.7 +/- 0.7 l/min). As far as asbestos processing is concerned, a diminution of dust concentrations below the limits was found. Despite of this, an increase in lung cancer incidence was observed probably as a consequence of high dust concentrations in the past and smoking habits (2/3 of workers). The flow-volume curves were obviously smaller than the normals. With the rising of exposure to asbestos and with the advancing age (more close correlation), the deterioration of respiratory parameters (measured during 6-7 years) was two times faster. The correlations were more close for women then for men. In the man group, this deterioration was greater in the last measurements. The results of ergometer testing up to anaerobic threshold were identical with those found in normal population.