Document nm4BJM9vvaeVnm8oJmZZMzGR1

454 OCCUPATIONAL TUMORS AND ALLIED DISEASES the occurrence of a malignant disease requiring an exposure time of con siderably more than io years is not eradicated within 3 years by the mere installation of an improved ventilation system in the mines. This conclusion is supported by a recent communication of Peller, who analyzed data obtained from the former Czechoslovakian Ministry of Health for 1929 to 1938, and found that the mortality from cancer among the Joachimsthal miners of the age group 35 to 44 years and 45 to 54 years was enormously greater than that of the corresponding age groups of the population of Prague and Vienna (perhaps 20 times higher), while 90 per cent of all primary cancers found among the miners were intrathoracic. There were so far 19 cases of Joachimsthal lung cancer placed on record (Lowy; Pirchan and Sicklj Beutel; Ziel) between 1926 and 1935. It is not probable that this figure represents the actual mortality from lung cancer among the miners during this period. Age. The average age at death from pulmonary malignancy is 49 years, according to Sickl (compared with 55 years in Schneeberg). The age distri bution of eleven cases for which this information is available is as follows: Years: Cases: 36-40 4^~45 21 46-50 2 5I~55 4 56-60 0 61 and over 2 In a subsequent report it was stated that the average age of the miners with lung tumors was 53 years, that is, approximately the same as the age of death of the general population. This assertion stands, however, in peculiar contrast to information supplied by Neitzel oh this subject. This investigator noted that the average age of 56 miners dying, during 1918 to 1928, was 42 years, while the average age at death for the general population in thg Joachimsthal district during this period was 59 years. This information is in agreement with data contained in the history records of miners who died from lung cancer. In these documents it is stated that the male members of the family died not infrequently at an early adult age (between 30 and 42 years) from respiratory diseases. As the male members of the population of this region often have worked for many generations in the mines, this information has a significant circumstantial value. Time of Exposure. The period of exposure, that is, the time of employment in the mines, ranged from 13 to 23 years. The distribution, according to the number of years exposed, is as follows: Years: 13 14 15 16 17 25 Cases: 221 21 1 Tyfe of Worker Affected. Of the affected workers eleven were employed underground (6 carpenters, 4 hewers and drillers, 1 mine foreman), while two worked above ground in the radium laboratories. Without an intimate knowledge of the conditions of exposure that prevailed in the mines for the