Document X7qm5njeN94nZ6xBObD7knjnd

Period 1924-30 1931-40 1941-50 1951-60 1961-64 1924-64 11 MALES Asbestosis all deaths Asbestosis with lung cancer *$> with cancer of lung 15 - NIL 66 13 19.7 92 21 22.8 144 45 31.3 113 62 54.7 428 141 32.9 Table 1 F EMALES Asbestosis all deaths Asbestosis with lung cancer 7- 82 5 45 5 40 11 26 7 200 28 % with cancer of lung NIL 6.1 11.1 27.5 26.9 14.0 4.4 Mesothelioma 4.4.1. Ocurrne_o Diseas^: Mesothelioma, is the most disturbing of the three diseases attributable to asbestos for two reasons. Firstly, in contrast to bronchial carcinoma, it can occur in people with minimal fibrosis, i.e. only after a brief exposure, which may be as little as three months. Some authorities even believe that a single brief exposure might be sufficient. Secondly, there is a very long time lag between the original exposure and the clinical appearance of the cancer. Thirty years is estimated to be an average time. . .2 Cause f_Diseaej_ The most up to date information on the likely agent responsible for this type of pleural neoplasm was presented in a press hand-out issued by Dr. Wagner in February of this year. He wrote: "On current evidence from South Africa, Australia and Britain, it would appear that Crocidolite is mainly implicated in the development of mesotheliomas. However, cases have occurred in the U.S. (l6 in number between 196? and 1965) Canada (6 in number, 1952-1964) and a few in Britain, in which people con cerned appear to have only been exposed to Chrysotile." At present in South Africa a continuous search is being made to detect any cases of mesothelial tumour coming from the Amosite and Chrysotilemining areas; so far, none has been discovered. This search has also been carried out in Czechoslovakia where only Russian Chrysotile is in use; again, no diagnosis of mesothelial tumours is reported. Dr. Gilson, Research Director of the M.R.C. Pneumoconiosis Research Unit, and his colleague. Dr. Wagner, have both stated in a number of papers that their major task at present is to "establish whether only one type of asbestos is responsible for the development of these tumours, and if other varieties can be exonerated". 1Co*U1Z