Public and Environmental Health Research Unit (PEHRU), London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK, antonio.gasparrini@lshtm.ac.uk.

Background Several papers have reported state-wide projections of mesothelioma deaths, but few have computed these predictions in selected exposed groups. Objective To predict the future deaths attributable to asbestos in a cohort of railway rolling stock workers. Methods The future mortality of the 1,146 living workers has been computed in term of individual probability of dying for three different risks: baseline mortality, lung cancer excess, mesothelioma mortality. Lung cancer mortality attributable to asbestos was calculated assuming the excess risk as stable or with a decrease after a period of time since first exposure. Mesothelioma mortality was based on cumulative exposure and time since first exposure, with the inclusion of a term for clearance of asbestos fibres from the lung. Results The most likely range of the number of deaths attributable to asbestos in the period 2005-2050 was 15-30 for excess of lung cancer, and 23-35 for mesothelioma. Conclusion This study provides predictions of asbestos-related mortality even in a selected cohort of exposed subjects, using previous knowledge about exposure-response relationship. The inclusion of individual information in the projection model helps reduce misclassification and improves the results. The method could be extended in other selected cohorts.

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The retrospective assessment of morbidity rates and cancer pathology risks in workers of asbestosis-cement enterprises of Ukraine has been made. It was established that annual cancer morbidity among workers makes 88,1 per 100 000 of workers (RR = 0.26, CI 95 % 0.06-1.01). The most often cancer pathology was located in digestive organs (48.1%), respiratory organs (18.5%) (lung cancer–11.1%). The mesothelioma of pleura, peritoneum and pericardium were not found. The risks (odds ratio–OR) of cancer morbidity were increased for such organs as: respiratory organs (OR = 2.37), skin (OR = 1.78), digestive organs (OR = 1.34).

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Formerly Japan National Railways Central Health Institute.

Asbestos has been an indispensable insulating material for railway industries, especially steam locomotives (SLs). This review (1928-1987) consists of three parts. 1) Pleural plaques: Since the 1970s, pleural plaques have been regarded as evidence of past asbestos inhalation, and more recently recognized as a risk factor of asbestos-related malignancies. For diagnostic criteria on plain radiographs, the modified ILO 1980 International Classification of Radiographs of Pneumoconioses was used. Most cases had pleural plaques with normal lungs. Large plant workers showed a significantly higher rate of plaques than workers in smaller plants. Bilateral plaques were dominant followed by the left, then the right lung, and chest wall plaques were dominant over the diaphragm. The manifestation of pleural plaques was more correlated to years since the onset of the asbestos exposure than the sum of asbestos work years, although the result was not significant. The boilermen of railway ferry steamers had a significantly higher plaque rate than other seamen. CT studies on plaques started in 1978. 2) Asbestos-related malignancies: Five retrospective cohort studies 1960-1970 were made on primary lung cancer incidence and mortality among 350,000 active railway men with smoking information. The follow-up period was 20 yr at the longest. Almost all plant workers showed a tendency of higher incidence or mortality than the controls. Two cases of mesothelioma were reported in 1980. 3) Pneumoconioses: Most studies (1928-1975) had relatively low prevalence rates among SL-related workers.

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