Document 3e04EYOpkZ3zrDB9450Qzz5x

CANCERS OF THE RESPIRATORY SYSTEM 435 i< of chemical agents are capable, in the experimental animal at least, of in fluencing the occurrence, incidence, or biological character, of pulmonary neoplasia. c. Physical Agents Physical agents which have been incriminated in the production of oc cupational tumors of the respiratory system are either of a specific type (radiating energy, radioactive substances) or they are of nonspecific char acter (mechanical trauma). I. PHYSICAL AGENTS OF DEFINED TYPE a) Radioactive Substances; Lung Cancer of the Schneeberg Miners, Joachimsi thal Miners and Workers in Radium Laboratories Historical Asfects. The occupational cancer of the organs of the lower r? respiratory tract is one of the oldest occupational tumors known. These neo plasms affect mainly the workers employed in certain mines from which 11} radioactive ores are recovered and which have been worked for many cen turies. It is only very recently that isolated cases of this type of occupational tumor have been observed among chemists, technical assistants and workers engaged in the purification and commercial handling of radioactive sub stances. The oldest known source of occupational pulmonary malignancy resulting from the exposure to radioactive ores is represented by the cobalt mines of the Schneeberg district in Saxony, Germany. The symptoms of this disease, preva lent among the miners of this region, were described by Theophrastus Bombastus von Hohenheim, called Paracelsus, who termed this ailment "mala metallorum" (1531). This disease of the miners of the Erzgebirge also was mentioned by Agricola (1521-1527 and 1546), Matthesius (1559), Pansa \ (1614), Engelschall (1725), Henckel (1729), Scheffler (1770) and Kuchen, \ meister (1869), who referred to it as "Bergkrankheit" (mountain sickness). The true nature of this fatal condition, however, was not recognized at that time and this miner's disease often was mistaken for tuberculosis of the lung (phthisis of the miners). It was not until 1879 that this occupational illness of the lungs was diagnosed properly as a malignant tumor (Harting and Hesse), but even then the correct histogenetic character was riot determined until many years later (Schmorl 1926). Following the report of Harting and Hesse, an appreciable number of investigations have dealt with this im * portant occupational disease (Cohnheim (1882)5 Aucke (1884); Arnstein : i (I9I3); Uhlig (1920); Riser(i92i); Schmorl (1923); Beyreuther ( 1924); 3 Rostoski, Saupe arid Schmorl (1926); Weber (1926); Rostoski (1928)5 Schmorl (1928)5 Rostoski and Saupe (1930)5 Schmidtmann (1930)5 Lange (I935)j Neitzel (1935)5 Dohnert (1938)). .} Among the miners, working in the uranium mines of Joachimsthal, located on the southern slope of the Erzgebirge, in the Sudetenland, it had been