Assessments of glass implanted 210po in Yugoslavian houses: results of an international intercomparison and critical analysis of methods

Measurements of 210Po embedded in glass have been performed with passive detectors in houses ofthree rural communities of Yugoslavia. Field work has been initiated and carried out by the VincaInstitute, Belgrade and analyses have been conducted by SSI (Sweden), UCD (Ireland), NRPA(Norway) and CRR (Italy). Based on 210Po concentration assessments, radon retrospective estimateshave been produced. Fairly good agreement amongst laboratories resulted both for polonium andradon determinations. Comparison of radon retrospective estimates with contemporary levels haspointed a small number of contemporary concentrations which are certainly not representative of thepast. Retrospective measurements give clear indication of higher levels for one of the threecommunities (Gornja Stubla). From the analysis of retrospective and contemporary levels in differentrooms of a high concentration house in Gornja Stubla, less data dispersion has come out forretrospective estimates, indicating a sort of better space stability of these estimates. The effects of UVradiation on detectors (CR-39) used for embedded 210Po assessments have been investigated by CRR.UV levels have been recorded at various objects (suitable for 210Po assessments) in an Italian houseand detectors on portions of the same glass have been exposed to different UV illuminance values. Ithas been observed that damages to the CR-39 surface, that do not permit detectors analysis, appear forUV levels typical of dwelling objects exposed to direct sunlight, but attention has also to be paid withregard to objects not in direct sunlight.