Silicosis, Coal-mine Pneumoconiosis in Connection with Tuberculosis in Slovakia in a Longitudinal Survey

Overview

The investigation was aimed at the evaluation of silicosis, coal-miner pneumoconiosis and silicotuberculosis (sitb) in the periodof 1977- 96. The authors draw attention to the fact that the number of sitb cases notified at occupational diseases in Slovakia, i.e.202 cases over 20 years, decreased significantly (from 83 cases in the period 1977 - 1981 to 16 cases in 1992 - 1996).While in the first, five-year period of observation, sitb and pneumoconioses in coal-miners with active sitb constituted 21.1% ofnotified cases of pneumoconioses (silicoses and coal-miner pneumoconiosis), the incidence was 8.8% in the period of 1992 - 1996.In 175 workers in the Mid-Slovakia region (41.7 % from ore mines, 33.1% from coal mines, the rest from mixed exposure inmetal industries, tunnelling and stonecutting) the mean age at the subgroup of pneumoconiosis notification with an X-ray picture ofsmall opacities was 55.5 ± 9.9 years (mean ± S.D., n = 146). It became obvious that in he period of 1992 - 1996, smoking minerswere affected in notified silicosis significantly earlier than non-smokers (at the age of 53.1 ± 1.5 versus 57.9 ± 1.7 years, mean ±S.E., p < 0.05). The mean age at notification of sitb and coal-miner pneumoconiosis with active tb was 63.6 ± 9.6 years (mean ±S.D., nsitb n = 23), difference at the age of notified pneumoconiosis with small opacities being significant at P < 0.001). In view ofthe systemic follow up examinations over the last 20 years, only six cases of pneumoconioses have been notified displaying X-rayopacities classified as A, B, C (according to ILO) at the average age of 65.7 ± 5.9 years (mean ± S.D.). The mean years ofexposure to fibrogenic dust at the time of notification of the different forms of fibroconioses did not differ (23 versus 21.9 versus23.6, respectively).The authors draw attention to the fact that the incidence of sitb is different than the registered one. In the period of 1987 - 96observation in the Mid-Slovakia region, clinical signs of tuberculosis were subsequently found in further 38 patients, 3.8 years afterthe original notification of pneumoconioses without tb. In 14 of them (36.8%), positive Mycobacterium tuberculosis was detected inthe sputum. It became obvious that the all-life epidemiological attention regarding tuberculosis is required in subjects affected bypneumoconioses.

Key words:
pneumoconiosis, silicotuberculosis, years of exposure, late tuberculosis in silicosis, smoking, influence upon earlier xray expression of pneumoconiosis