CAN PATERNAL PRECONCEPTIONAL RADIATION ACCOUNT FOR THE INCREASE OF LEUKEMIA AND NON-HODGKINS-LYMPHOMA IN SEASCALE

Objective-To determine if the excess of leukaemia and non-Hodgkin's ly mphoma in Seascale is restricted to those born in the parish and wheth er it might be explained by the postulated relation with paternal prec onceptional radiation. Design-Comparison, separately for those born in the parish and those born elsewhere, of the numbers of these malignan cies observed in Seascale with those expected on the basis of referenc e rates for England and Wales. Details of paternal radiation levels we re sought for each case. Setting-The parish of Seascale in west Cumbri a. Subjects-Residents of Seascale below age 25 years in the years 1951 -91. Main outcome measures-The observed and expected numbers of cases of leukaemia and non-Hodgkin's lymphoma within Seascale among those bo rn there and among those born elsewhere. Also, the levels of any pater nal preconceptional radiation associated with each case. Results-A sig nificant excess of leukaemia and non-Hodgkin's lymphoma at ages 0-24 w as found in Seascale in those who were born there (ratio of observed t o expected cases 8.6 and 20.2 respectively; p<0.01). This also applied to those not born there (7.2 and 16.5; p < 0.01), a group often regar ded as not showing an excess. The estimates were then conservatively r ecalculated so as to overestimate the risks among those born in Seasca le and underestimate them among those born elsewhere. On this basis th e six cases in those born in Seascale compare with 0.38 expected (15.8 ; p <0.001), of which two were associated with paternal preconceptiona l lifetime levels of 100 mSv or greater and three others with levels o f 90-99 mSv. Among those born elsewhere, there were five cases (expect ed 0.74; ratio 6.7, p < 0.01), of which only one was associated with a high level of such radiation. Conclusions-Paternal preconceptional ra diation cannot be the sole cause of the excess in Seascale since it wi ll not explain the excess among those born outside Seascale. It follow s that, unless two causes are to be postulated, any single cause must be a factor other than paternal preconceptional radiation. On this bas is, the association found among those born there, if not partly due to chance, may reflect an indirect relation with the true cause. The rec ent hypothesis about such paternal radiation has originated in a subgr oup of the excess cases that have aroused concern.