OCCUPATIONAL AND ENVIRONMENTAL LINKS TO MESOTHELIOMA DEATHS OCCURRINGIN LEEDS DURING 1971-1987

Background Growing public concern that a Leeds asbestos factory wh ich closed in 1958 was responsible for a perceived excess of mesothelioma deaths in former workers and in people who lived or had attended a sc hool near the factory prompted us to undertake a retrospective descrip tive study of Leeds-related mesothelioma deaths occurring between 1971 and 1987. The aims of the study were to determine the number of cases of mesothelioma deaths and types of asbestos exposure (direct, indire ct and environmental) with a Leeds connection (a Leeds address at birt h or death), and to investigate the role played by the factory in thes e deaths. Methods Information on the mesothelioma cases was obtained m ainly from the National Mesothelioma Registry, the Yorkshire Regional Cancer Registry and the Leeds Coroners' records, supplemented with det ailed interviews with surviving relatives in about a third of the case s. Results Two hundred and ten mesothelioma deaths were identified, of whom 180 died in Leeds. Of these 180 cases, 26 per cent had a direct or an indirect occupational link with the factory, 48 per cent had dir ect or indirect links to other jobs with a likely occupational exposur e to asbestos, 21 per cent had no currently recognized asbestos exposu re, and 5 per cent had an unknown exposure history. Of the 25 cases wh ich had been labelled by the Coroner and news media as occurring direc tly as the result of 'environmental' exposure from the factory, 20 wer e found to have had direct or indirect occupational exposure to asbest os. The possibility of environmental exposure could not be excluded in the other five 'environmental' cases. There was under-recording of th e number of mesothelioma cases by the local regional cancer registry a nd the National Mesothelioma Registry. Conclusion A minority of Leeds mesothelioma cases had a direct or indirect occupational link to the p articular factory, but most deaths occurred In people employed in othe r occupations where contact with asbestos was likely or possible. Howe ver, the finding in our study of a number of mesothelioma cases with n o known exposure to asbestos via occupational or household contact rou tes points to the need for a further controlled study to estimate the risks of non-occupational asbestos exposure. There is also a need for improved identification of mesothelioma deaths and regular data exchan ge between the National Mesothelioma Registry and regional cancer regi stries to ensure case completeness.