The first indication of a possible relationship between living close to a nuclear installation and the risk of childhood leukaemia came from the United Kingdom in 1983. A cluster of childhood leukaemia in the town of Seascale which is located close to Sellafield was reported in a TV documen-tary. Since then almost 200 studies have been carried out in order to investi-gate the occurrence of childhood leukaemia around nuclear installations. Recently, the issue of childhood leukaemia gained new attention due to a large study that was carried out in Germany.
For children aged below 5 years living within 5 km of a nuclear plant there was a significantly increased risk for leukaemia. On the other hand, the reported overall conclusion from all studies performed are that clusters of leukaemia around nuclear installations are rare, only three well documented clusters, and three possible cases, have been found. The reason for the ob-served clusters remains unknown. In particular, it has been difficult to find a relation to radiation doses attributable to the normal discharges of radioac-tive substances.
Understandably, the issue of a possible increased frequency of childhood leukaemia near nuclear installations has attracted considerable public atten-tion. In order for the Swedish Radiation Safety Authority (SSM) to judge the needs for any further studies or other actions on this issue, Professors Wojcik and Feychting were asked to submit this brief overview of the present state-of-the art findings regarding childhood leukaemia in the vicinity of nuclear installations. Their report, together with other available information on childhood leukaemia, will be input for any decision about further actions to be taken by SSM.