Insulation workers in Belfast. 3. Mortality 1940-66

Abstract

. (1971). Brit. J. industr. Med., 28,[226][227][228][229][230][231][232][233][234][235][236]. Insulation workers in Belfast. 3. Mortality 1940-66. One hundred and seventy men were identified as making up the total population of insulation workers in Belfast in 1940. This is an analysis of all the information about deaths that has emerged from tracing these men up to the end of 1966. Five remain untraced, and the mortality experience of the remainder is compared with that of other men in Northern Ireland over the period. There were 98 deaths when only 37 were expected. The number of deaths occurring exceeded those expected throughout the period 1940-66 and the increase was statistically significant during the period 1950-55 and onwards. There was an especially high mortality (compared with other Northern Ireland males) due to cancer of the lung, mesothelioma of the pleura and peritoneum, cancer of the gastrointestinal tract, and fibrotic lesions of the lungs. The ratio of observed over expected deaths was 2-6 for all causes, 3 9 for all cancers, and 17-6 for cancers of the lower respiratory tract and pleura. Those men finally classified as dying from lung cancer showed evidence of lung fibrosis whereas those classified as dying from mesothelioma did not. Comparisons within the group failed to show any relationship between age at first exposure or duration of exposure and the excessive mortality. There were too few non-smokers to show the significance of smoking.The first two studies Langlands, Wallace, and Simpson, 1971) were concerned with the health of men still employed as insulators; the third study is an attempt to evaluate the deaths which have occurred in this occupational group. For a complete picture of the occupational hazard it would also be necessary to find out the proportion of men who had to leave this occupation for medical reasons other than death. But records giving the reasons why men changed to lighter work or became unemployed were nonexistent and information about those who drew sickness benefit was scanty and hard to come by. Therefore, it was decided to restrict the enquiry to the frequency and causes of death. As there were no specific regulations concerning the handling of asbestos in Northern Ireland up to the time of the enquiry, there were no official records of the numbers of men employed. Because of this lack of official recognition, few patients were referred to the pneumoconiosis panels and no special arrangements were in existence for recording the causes of death in this group. The enquiry was conducted in three stages-the identification of the population at risk, the identification of the men who had died and, finally, the analysis of the information which could be obtained about these deaths.To define the population at risk, a preliminary investigation of the employers' and trades union records was made. Work on the other two studies had indicated that these records were not complete and became progressively less so the further back they were traced. But other work on the mali...

Asbestos, radiation and oncogenic transformation

“…More recently, numerous epidemiological and clinical studies have firmly established the correlation between exposure to asbestos fibres and the development of certain malignant neoplasms. These include bronchogenic carcinoma, pleural and peritoneal mesothelioma (McDonald & McDonald, 1977;Wagner et al, 1960;Selikoff et al, 1979), and to a lesser extent various gastrointestinal, oropharyngeal and laryngeal cancers (Selikoff, 1974;Elmes & Simpson, 1971).…”

Epidemiology of asbestos-related diseases.

“…Elmes and Simpson (42) have extended their earlier report (37) times increased risk of respiratory cancer mortality among retired men who had worked as production or maintenance employees in the asbestos industry and who had been exposed to mixed fibers. Among men with mixed exposure to crocidolite and chrysotile in the asbestos cement industry, the rate was 6.1 times the expected rate.…”

“…Epidemiologic studies of the already defined populations have consistently shown an excess risk of other cancers, especially of the gastrointestinal tract (22,37,58,74,76,80,94); however, it has been less than that of lung cancers.…”

“…Mortality studies of defined populations of asbestosmanufacturing, insulating and shipyard workers have provided the most concrete evidence concerning the association between bronchial cancer, pleural, and peritoneal mesotheliomas and exposure to asbestos. Reports have come from several countries: England (36,37), Germany (38), the United States (39), The Netherlands (40), and Italy (41).…”

Digestive System Cancer among Persons Subjected to Occupational Inhalation of Asbestos Particles: A Literature Review with Emphasis on Dose Response

“…Elmes and Simpson (6) give data by age with age roughly correlated with duration of employment as'insulation workers. From the data given I estimate SMR for digestive system cancers -300, 95% confidence limits, .…”