[The dynamics of exposure to silicotic dusts and silicosis in a foundry]

This work presents the concentrations dynamics of dust in a cast iron foundry, in parallel with the frequency and gravity dynamics of the getting sick of silicosis. The knowing of the real risk of exposure to silicotic dust was possible through the data processing concerning the dusting degree (the average of working place), the content of silicon free-crystalline dioxide (SiO2 l.c.) for the calculation of the maximum admitted concentration (C.M.A.) and the dispersion degree of dust in a cast iron and steel foundry for the studied period (1982-1996). New cases of silicosis appeared in this period were studied and they were colligated with the age at declaration, the average length of service and the profession. The values of the dusting degree outrun the C.M.A. up to 168 times, especially at the preparation of mixture and grinding with a prevalence of particles under 3 micron (40-70%) and the Si02 l.c. content varies between 35.2% and 64.5%. From those 98 new cases of silicosis appeared in 15 years, 82.65% were traced out in the incipient phases of the disease. The average age in service and the average age increase (43.1 respective 19.8 years). The coefficients of correlation and regress (+0.286 respective +0.383) show a good correlation between the silicosis number and the age in service. The advanced stages of silicosis and age in service under 10 years were found at the foundry-workers and formators, occupations which imply a high silicotic risk. The foretelling calculations for the next 20 years show an increase of the silicosis incidence for foundry-workers.