Childhood Leukaemia and Nuclear Installations

SUMMARY One of the most contentious issues in epidemiology today is the question of whether the radioactive discharges from nuclear installations can detectably raise the risk of childhood leukaemia in surrounding areas. The results of several studies suggest some association, but radiological assessments cannot explain the reported excesses of cases. An examination of the problems involved in the analysis of childhood leukaemia incidence around nuclear sites shows that studies must be performed with care. A review of the studies reveals that prior knowledge of data has influenced the structure of some of the analyses, which leads to problems of interpretation of results. Nevertheless, evidence exists of raised rates of childhood leukaemia incidence or mortality near certain installations, but the wide variety of functions associated with these establishments, and the relatively large areas over which the discharges would have to act, casts doubt on a direct causal relationship. If a non-radiological factor is involved, then its influence should be observable elsewhere. It remains to be seen whether such a factor can be detected through statistical analysis.