GEOGRAPHICAL-DISTRIBUTION OF PRECONCEPTIONAL RADIATION-DOSES TO FATHERS EMPLOYED AT THE SELLAFIELD NUCLEAR INSTALLATION, WEST CUMBRIA

Objective-To examine whether the geographical distribution of births a ssociated with preconceptional exposure of fathers to radiation at the Sellafield nuclear installation is consistent with the suggestion tha t this exposure explains the excess of childhood lymphoid malignancy i n the adjacent village of Seascale. Design-Retrospective birth cohort study. Setting-Cumbria, West Cumbria health district, and Seascale civ il parish. Subjects-The 10 363 children born in Cumbria during 1950-89 to fathers employed at Sellafield. Main outcome measures-The doses of external whole body ionising radiation received by fathers at Sellafi eld in the total time and in the six months before conception of their children; the proportions of the collective doses associated with Sea scale and the rest of West Cumbria. Results-9256 children were born to fathers who had been exposed to radiation before the child's concepti on. Of these, 7318 had fathers who were exposed in the six months befo re conception. Overall 7% (38 person-Sv) of the collective total preco nceptional dose and 7% (3 person-Sv) of the collective dose for the si x months before conception were associated with children born in Seasc ale. Of all the children whose fathers worked at Sellafield, 842 (8%) were born in Seascale. The mean individual doses before conception wer e consistently lower in Seascale than in the rest of West Cumbria. Con clusions-The distribution of the paternal preconceptional radiation do se is statistically incompatible with this exposure providing a causal explanation for the cluster of childhood leukaemias in Seascale.