Childhood leukaemia and Sellafield: the legal cases

A media report of an excess of childhood leukaemia cases in the village of Seascale near the Sellafield nuclear installation in West Cumbria, England, and the subsequent finding that an association with relatively high doses of radiation received occupationally by fathers employed at Sellafield before the conception of their children could be sufficient to account for these excess cases, precipitated two legal cases heard in the High Court, London, during 1992-93. It was claimed that exposure to ionising radiation as a result of operations at Sellafield was the cause or a material contributory cause of an infant leukaemia and a non-Hodgkin's lymphoma in a young adult, whose fathers had received comparatively large preconceptional doses at Sellafield. The two cases were considered concurrently in a trial lasting 90 days, during which time evidence was heard from many expert witnesses from around the world. Of particular importance was the epidemiology and genetics evidence which provided the basis of learned discussions as to how a novel statistical association should be assessed scientifically and specifically whether a causal interpretation could be sustained. The cases provide a fascinating insight into the critical evaluation of scientific evidence. In the end, the judge found that the evidence was `decisively' against preconceptional irradiation being a material contributory cause of either the two specific cases or the Seascale excess.