Indoor radon and radon progeny survey at Campinas-Brazil using CR-39: Final results

In a survey performed at Campinas-SP, Brazil, the CR-39 detector was used as an alpha-spectrometer taking into account the size and the gray level of round tracks measured under an automatic optical microscopy system. The exposures were carried out in the same room of 70 dwellings during two successive periods of six months: the first one from November 1996 to May 1997 (summer exposure) and the second one from May 1997 to December 1997 (winter exposure). The results of the assessment of radon and radon progeny (RP) joint activity in the air neighboring the detector and the plated-out RP activity on the material surfaces are given.