Comparison of indoor radon concentrations measured by active charcoal-canisters and alpha track detectors

Screening measurements of radon by using active charcoal-canister, was one of the method listed in Norway for several years, but is now removed from the official list. Miljoelaboratoriet has more than ten years experience of using the method as a fist step in radon investigations. We here present two different studies, where both short-term and long-term have been used in the same rooms and two studies where short-term measurements have been used to find areas with high radon risks. As these results shows good agreement, one can ask if it is reasonable not to have the active charcoal-canister listed as a screening method. (au)