Indoor radon measurements with Kodak track film - some results

Measurements have been made of the indoor radon and radon daughter concentrations in several thousand Swedish houses. The investigation was concentrated on houses with building materials of concrete containing uranous alum shale. The detectors were Kodak LR-115-11 track films. The exposure time was one month. It is found that the RnD-concentrations are slightly higher in the basement storey of detached houses. The RnD-levels in apartment houses are lower than in single unit houses. The seasonal variation of the RnD-levels have been studied and the results show equal or lower RnD-levels in the summer in comparison with the winter levels. (author)