Document K8q7JNa6XZVDpQQDgbp7X030

-3- A report from Turner Brothers Asbestos Company, Ltd., Rochdale, England, and presented by Dr. J. F. Knox, showed a somewhat more optimistic story when suitable dust prevention regulations were Introduced and enforced in the asbestos industry. In a mortality study of workers in an asbestos factory carried out prior to the enforcement of the British Asbestos Industry Regula tions excess mortality among3t workers employed for 20 years a.-.d upwards was observed. Lung cancer in association with asbestosis was responsible for a considerable proportion of this, excess, A study of a group of workers from the same factory exposed since the regulations went into effect shows a reduction in mortality rate without an excess of lung cancer. Dr. Hammond had pointed out in his paper that the extreme rarity of pleural mesothelioma ir. the general population meant the finding of even a very few cases in a particular study in Industry wa3 highly significant; Dr. P. C. Elmes of Belfast, Ireland, tackled the problem of mesothelioma from another point of view. He had studied 42 cases of pleural mesothelioma found in hl3 department in Belfast over the past 14 years; the population at risk being about three-quarters of a million people. A positive history of exposure to asbestos at work was obtained in 52 of the cases compared with only 9 of 42 matched controls. Asbestos bodies were found in the lungs of 88# of patients with mesothelioma of the pleura, 20# of patients with carcinoma of the bronchus and 20.5# of patients dying of nonmallgnant disease. The frequency of finding of asbestos bodies in the lung is higher (27#) In men dying of non-malignant disease between 60 and 69 years of age who went into industry between 1905 and 1915 than in the 50 to 59 age group who started work between 1915 and 1925. Between 1906 and 1923 over 1000 tons a year of boiler composition were imported into Belfast compared with 60C tons a year at other times. This boiler composition was an insulat ing material containing a considerable proportion of asbestos fiber. Dr. Elmes pointed out that the latent period for the development of pleural malignancy after exposure may be up to forty years so that increasing numbers of cases arising from exposure can be expected for many years to come. Dr. Wagner, of the M.R.C. Pneumoconiosis Research Unit, Glamorgan, Wales, British Isles, noted that an association between asbestos and pulmonary malignancy was now generally accepted. More recent investigation had shown that there was an increased incidence of pleural and peritoneal mesotheliomas occurring in people occupationally or environmentally exposed to asbestos dust. In some of these cases the exposure has been extremely slight and not sufficient to produce the histological features of asbestosis. The only pathological evidence of exposure has been the presence of asbestos bodies or fibers in the air spaces. In South Africa core than 100 cases of this tumor have been confirmed histologically. PUP 0900335