Objectives: The study was performed to validate exploratory results obtained in a former study on the incidence rates of childhood malignancies in the vicinity of German nuclear power plants and to evaluate the confirmatory results of this previous study.
Methods: Incidence rates near German nuclear installations were compared to rates in control regions based on the German Childhood Cancer Registry.
Results: No exploratory result could be reproduced. This is also true for children with acute leukemia younger than 5 years who were living within a 5 km radius of an installation: an observed relative risk (RR) of 1.39 was not significantly increased (95 percent confidence interval CI: 0.69-2.57). Former confirmatory results could be confirmed again. A pooled analysis of both studies based on 2390 cases resulted in RR of 0.99 for all malignancies (CI: 0.91-1.07) and of 1.00 for acute leukemias (CI: 0.87-1.16) (children younger than 15 years of age living within a 15 km radius).
Conclusions: Results did not show significantly increased incidence rates for any subgroup with previously significant exploratory results. Therefore, it appears to be most likely that the previous results were just due to chance. Evaluating the previously confirmatory results with the combined data from the two study periods reassures that incidence rates are not increased in children younger than 15 years who are living within a 15 km radius, either for all malignancies or for acute leukemias. We conclude that at present, in Germany no further investigations of this kind are necessary.