Abstract
1) The author first discussed the criteria necessary for the establishment of the presence of an occupational cancer and then emphasized the necessity of "descriptive" and "analytical" epidemiologic studies in view of the well-known fact that carcinogenesis is extremely species-specific. 2) Major carcinogenic agents generally accepted as responsible for occupational cancer of the skin or lung were listed and the total number of reported cases caused by such agents as calculated by Hueper and Eckardt was introduced. Similar but internationally tabulated figures were also shown for the occupational bladder cancer caused by aromatic amines. As the most prominent nature common to these carcinogenic agents, the author emphasized the significance of repeated exposueres to a trace amount of them. Since latent period, i.e. the time between the initial exposure to a carcinogen and the clinical manifestation of the cancer due to this, is prolonged so long as to exceed the average life-span when exposure is mitigated, it was suggested that a maximum allowable concentration could be decided for each occupational carcinogen. Unfortunately this has not yet been achieved mainly because of the well-known shortage of quantitative informations of such carcinogens present in occupational environments. 3) The control of the occupational cancer will be attained by three different but well-coordinated approaches, namely control of exposure, health care of the exposed, and health education. The control of exposure to a specific occupational carcinogen includes various measures such as technical and engineering developments to reduce the formation and distribution of the carcinogen, improvements in work conditions, and legal considerations. In regard to health care the author made a particular emphasis to improve the current status that neither voluntary nor enforced efforts are being made at all in behalf of exposed worker after they have left work, for instance, by retirement. Another problem is that practically no informations are yet available as to the incidence of known occupational cancers. As generally accepted, occupational cancer is definitely preventable. In order to prevent it, it is desired that the reluctant attitude to this specific type of cancer generally maintained by the industry should markedly be altered.
