[Silicosis in Switzerland. A half century of observation. The physician's viewpoint]

In Switzerland, the first cases of silicosis were recorded by Zangger in 1900. Since 1930, patients with silicosis have been provided with certain services by the "Caisse Nationale Suisse d'Assurances" (i.e. Swiss National Insurance Fund), an organization enforcing the Occupational Accidents and Diseases Bill. However, it took another two years before an effectively organized struggle against silicosis was started. Eventually, by 1938, this specific pneumoconiosis was acknowledged as an occupational disease under Swiss Law. Thus, the CNSA has been concerned with this disease for half a century, and it seems relevant now to take stock of the situation. From 1930 to late 1980, 9690 cases of silicosis were accepted by the CNSA. Nearly one half (46%) of these silicotic patients were still alive on December 31, 1980; another third had died of silicosis and the rest of other affections not related The origin of cases has remained remarkably constant over the course of time. Underground working and the stone-working industry account for the majority of cases (70%), followed by smelting works (16%) and the ceramic industry (5%). The remaining 9% are due to various causes. Silicosis hazards have declined but still remain real. In late 1980, 1287 companies in Switzerland were being monitored from this standpoint. More than two-thirds (67%) belong to the stone-working industry (even though only 30% of hazard-exposed workers are employed in this sector), 10% are involved in underground work (10% of hazard-exposed workers), 10% are smelting industries (36% exposed) and 6% belong to the ceramic industry (17% exposed). Since 1950, the number of hazard-exposed people has fluctuated between relatively narrow limits (i.e. 15,000 and 20,000). Corresponding figures for previous periods are not known. Some facts indicate that silicosis is becoming less problematic: a) The annual incidence rate of silicosis in Switzerland has evolved in three distinct phases. From 1930 to 1940 the number of new cases recorded each year rose regularly. From 1940 to the late 1960s, the incidence levelled off (200-300 cases yearly); then, from 1974, it dropped rather sharply and less than 100 new cases have been recorded yearly since 1978 (97 in 1978, 69 in 1979 and 68 in 1980). b) The average age at diagnosis of silicosis has regularly increased. Until 1940, the average age of recorded silicotic patients was about 40. The threshold of 50 years was reached between 1953 and 1957. More recently (between 1978 and 1980) the corresponding figure was 68.2.(ABSTRACT TRUNCATED AT 400 WORDS)