Radon problem has been widely investigated within the Romanian borders throughout the years while thoron did not attract that much of attention. However, fairly recent studies around the world have pointed out that indoor thoron should not be neglected when estimating the effective dose. Taking this into consideration a new survey is in progress, a survey that is going to provide the effective dose not only due to indoor radon but also the thoron contribution to it. Both dwellings and workplaces were selected for this investigation. The measuring method used is based on solid state nuclear track detectors with CR39 plats. A comparison exercise with Macedonian schools pointed out that both radon and thoron activity concentrations appears to be rather higher in Romanian schools with an average radon activity concentration of 89 Bq m-3 for the first versus 211 Bq m-3 for the last and respectively 19 Bq m-3 versus 80 for thoron. Notwithstanding, the Romanian dwellings presented slightly lower activity concentrations for radon, with an average of 193 Bq m-3 while thoron activity remained steady at 80 Bq m-3. However, the present paper analyzes only a low number of locations; a more substantial survey is yet in progress
