International intercomparison on glass implanted 210Po in Yugoslavian houses

Measurements of 210Po embedded in glass have been performed with passive detectors in houses of three rural communities of Yugoslavia. Field work has been initiated and carried out by the VINCA Institute of nuclear sciences, Belgrade, and analyses have been conducted by SSI (Sweden), UCD (Ireland), NRPA (Norway) and CRR (Italy). Based on 210Po concentration assessments, radon retrospective estimates have been produced. Fairly good agreement amongst laboratories resulted both for polonium and radon determinations. Comparison of radon retrospective estimates with contemporary levels has identified a small number of contemporary concentrations which are certainly not representative of the past. Retrospective measurements give clear indication of higher levels for one of the three communities (Gornja Stubla). From the analysis of retrospective and contemporary levels in different rooms of a high concentration house in Gornja Stubla, less data dispersion has come out for retrospective estimates, indicating a sort of better spatial stability of these estimates. (author)