The respondents had clear perceptions of the kinds of change that ionizing radiation can cause to the human body, and a wide variety of answers was given to the question concerning this. The most frequent answer was cancer (mentioned by 75%), whereas mutations were mentioned by 49% and genetic damage by 36%. Other effects mentioned included birth defects, damage to cells and organs, death, sterility or decreased reproductive capacity, skin damage, hair loss and burns. The results gave no information about the extent to which the respondents imagined these effects to appear (or after what kind of doses). It is worth mentioning that the most important effect, from an expert point of view, is cancer, presumed to be initiated by mutations. Genetic effects have so far been detectable in animal experiments, not in humans.