AbstractThe accident in the nuclear power plant at Chernobyl led to a fall‐out and wash‐out of radionuclides, especially radiocesium, with a broad geographic variation in the South‐German State of Bavaria. For a younger adult, the additional effective lifetime dose from external exposure and ingestion of radiocesium varies between 1.2 mSv and 8.7 mSv, depending on the region. This is about 2%, respectively 16%, of the natural lifetime gamma dose. In none of the Bavarian regions with different levels of radiation exposure has the incidence of congenital heart defects in Bavarian children increased since the time of the accident. The results indicate that geographically no effects on such malformations can be attached to the additional radiation exposure resulting from the Chernobyl acc