Document z3De5BD7g5R4ozMn24K65X4R

436 OCCUPATIONAL TUMORS AND ALLIED DISEASES known for many years that a respiratory disease commonly occurred which was symptomatically similar to that observed in the Schneeberg district. These mines have been worked for several centuries. The knowledge of. this sim ilarity apparently induced Harting and Hesse in 1879 to inquire of the officials of the Joachimsthal mines, whether the occurrence of pulmonary malignancy among the miners of Joachimsthal had been observed. The answer received was negative. When this inquiry was repeated by Uhlig in 1920, the official answer still stated that no instances of pulmonary malignancy had been ob served among the miners employed in the uranium mines at Joachimsthal. It was not until 1926 that Lowy reported from Prague the first two cases of pulmonary malignancy among the miners of Joachimsthal. An investigation started subsequently revealed that this condition was apparently as common among the Joachimsthal miners as it had been shown to be among the Schneeberg miners fifty years previously. From the evidence disclosed at that occasion, it became relatively certain that many miners had died from this disease during past centuries. Additional reports on the occurrence of lung can cer among the miners in Joachimsthal and the various aspects of this condition were published by Sickl (1928); Lowy (1929); Beutel (1931); Pirchan and Sickl (1932)5 Stocklasa (1933) j Humphris (1934)5 Parade and Paschke (1934)5 Ziel' (1935) j Tschelnitz (1935); Governmental Commission of Czechoslovakia (1935). The observations made in Joachimsthal had shown already that not only the miners of the uranium ores were victims of pulmonary malignancy, but that also some of the chemists and workers employed in the radium labora tories, where the ores were purified and processed for the isolation of the various radioactive products, were sufferers from this neoplasm. Reports of recent years (Neitzel (1935)} Teleky (1937)} Baader (1937)) indicate that similar cases' have been found among the employees of other laboratories engaged in the purification and commercial preparation and handling of radioactive substances. It is remarkable that no information is available as to the existence of similar conditions among the miners of radioactive ores in the Belgian Congo at Katanga and at Great Bear Lake in northern Canada. An emphatic denial* as to the occurrence of pulmonary malignancy among the miners at Katanga as well as . among the workers and technicians engaged in the purification of the African ores in the laboratories situated at Oolen (Belgium), was made by DeLaet in 1934. The presence of pulmonary malignancy among radium miners and workers also was not mentioned by Jacobs in his description of this plant operated by the Belgian concern. DeLaet even stressed the fact that the workers handling the ores were exposed to the inhalation of massive amounts of the dust. It may be possible that the statement of DeLaet in regard to the absence of lung cancer is correct, as the Belgian mines and laboratories have been in operation only for twelve years and in view of the