Radiation in dwellings and cancer in children

Indoor radiation, especially radon exposure, has been in focus in the public domain during the past several years. The growing concern among parents of children with cancer possibly having high radiation levels in their homes led us to study the levels of gamma- and alpha-radiation levels in the homes of a group of children in the county of Ostergötland. The indoor concentration of alpha-emitting radon daughters was measured by a high-voltage method. The gamma activity was measured with a standard detector scintillation meter. The yearly average for radon-daughter concentration in both cases (57 Bq/m3) and controls (61 Bq/m3) corresponds fairly well with the national average of 53 Bq/m3. The yearly average for gamma radiation (cases 0.37 mGy, controls 0.36 mGy) is much lower than the permissible upper level in dwellings (2.5 mGy/year). The values seem to be of the same order as the subtracted cosmic radiation, which is 0.24-0.26 mGy. No appreciable difference could thus be found between cases and controls either from gamma radiation or radon-daughter exposure. We cannot from our study rule out the possibility of an effect of low-level radiation in susceptible individuals, but it seems clear that children who get cancer do not live in more radioactive homes than other children.