Document YnDD3aK0Q9m6vaOjqqEDNZnN

Industrial Hyslane Planet 1272/SO Kadloloilcal Flndlnsa as Predictora of Mortality la Quebec Asbestos Workers. F. D. K. Liddell and J. C. McDonald. Brit. J. lad. Mad. 37s 237-267, August 1980. 21 refs. Two cohorts of chrysotlla miners and alllars la Quahac wara salaccad to study tha extent to which chast radiographs takaa whlls still em ployed predict mortality.' tha paper presents aalnly findings In auch tha larger cohort, vhleh consisted of A339 aen (two-thirds past workers) whoso latest radiograph had bean assessed by ons of sin expatlanced readers Into what beease tha UlCC/Clnclnnacl (O/O classification; by tha and of 1973 there had bean 1343 deaths in this cohort. Tha findings vara generally confined la tha other cohort, coaprlslag 988 currant aala workers, who had been examined in 1967-68 by questionnaires on respiratory symptoms end smoking and by lung function tests, and for whoa all six readers had assessed their 1966 radio graphs Into tha 0/C classlf lcatIon; 130 man had died by tha end of 1973. Men with any radio graphic abnormality, heavy dust exposure, or a history of cigarette smoking had relative risks (Ms) of total mortality greater than unity. Death from pneumoconiosis was associated with small parenchymal opacities, usually Irregular, of profusion 1/1 or more, and with heavy dust exposure but not with smoking. Most who died from lung cancer had evoked cigarettes, or had bean heavily exposed to dust, or both. Small parenchymal opacities vara present In most but not all the excess deaths due to lung cancer. Deaths from ocher malignant diseases showed no consistent dust or x-ray patterns. Ms of deaths from most other causes ware raised for certain radiographic features. Failures In forecasting mortality were primarily due to deaths In which asbestos-related disease was not tha primary cause but may have been a contrib uting factor. The main findings validated the V/C classification convincingly, particularly as tha films had been taken as routine and wara of modest quality. Despite objective rules for tha reading and tha fact that all six readers wara contributing to the development of tha classifi cation, there ms Inevitably some observer variation. The Importance of radiographic technique and tha need for careful control of the reading Is evident. The authors' results provide support for the use of the chest radio graph for surveillance of asbestos workers, and for environmental monitoring. Its protective value for Individual workers, however. Is limited to the extent that radiological progression continues after withdrawal from exposure, and by the carcinogenic risk associated with dust already retained. --Authors' abstract reprinted by permission 1273/80 Clearance of Asbestos Bodies from the Luns; A Personal View. K. J. Anil and P. F. Holt. Brit. J. Ind. Med. 37* 273-277, August 1980. 11 refs. In histological sections asbestos bodlss In human lungs may be either transparent, yellow. Jjbvamber lMn strongly Perls-positlva structures as described In published reports, or opaque, black struc tures, the ferreproteln coating having been converted Into haemoslderln. The transparent asbestos bodies fragment Into segaents; the black asbestos bodies disintegrate Into a nass of haemoslderln granules that sceussilata as dense deposits, particularly near to blood vessels. The presence of haemoslderln granules Indicates that asbestos bodies have broken down. When a patient has died with a mesothelioma there Is little evidence of phagocytle activity In many areas of tha lung. Whan exposure to asbestos ceased many years before a mesothelioma developed there nay be few recognisable asbestos bodies remaining In the lung. --Authors' abstract reprinted by permission 1274/80 Effect of Snoklns on Attack Kates of Pulmonary and Pleural Lesions Related to Expo sure to Asbestos Rist. 0. H. C. McMillan, et el. Brit. J. Ind .Mad. 37: 268-272, August 1980. 6 refs. In follow-up studies of samples of employees ac two of Her Majesty's Dockyards the prevalence of asbestos-related lesions In smokers and exsmokers was statistically significantly higher chan In non-smokers even when differences la age and exposure risk were considered. --Authors' abstract reprint by permission 1273/80 Carbon ?bnoxlda: Dosimetry In Occuoa tlonsl Exposures In Denver. Colorado. J. V. Jabara, et al. Arch. Environ. Health 33/ 198204, July/August 1980. 6 refs. Tha occupational carbon monoxide (CO) exposure of Denver traffic control personnel was evalua during 8-hr workahifts using three parameters: (1) 98, 8-hr time-weighted average breathing tone air samples (personal dosimetry); (2) before- and after-uorkshlft CO breath samples; and (3) 8-hr moving average, ambient CO levels during the fall and winter months. Different shifts and work experiences wara taken Into cqnaIderstion. The data revealed greater CO exposure In subjects working on the street than controls working Inside downtown buildings with raspect to breath CO concentration and breathing sons air samples. The CO concentrations In the after-uorkshlft breath samples were closely associated with the 8-hr time-weighted average CO levels. Tha graatast source of CO to the sample population was cigarette smoking, fol lowed by occupational-related soureas, and finally, the ambient background CO levels. --Authors' abstract reprinted OUi 07140 20 {f /S 0 0 0 iS j