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Radiation Protection Dosimetry 45:65-71 (1992)
© 1992 Oxford University Press
The Alpha Track Method Used in the Swedish Radon Epidemiological Study
An alpha track radon detection system has been developed primarily for use in the extensive nationwide case-control study, to be reported in 1992, on the relationship between radon in dwellings and the occurrence of lung cancer. The choice of method was founded on a literature survey and information gathered through contacts with groups in different countries. The system chosen is based on a CR-39 alpha track detector material, a holder originally developed at the National Radiological Protection Board (NRPB), UK chemical etch and automatic read-out by an image analysis system. The system was completed in 1989. Radon levels in about 9000 homes have been measured. System details are presented, particularly those with special relevance to accuracy. The results of a recent calibration are presented including 1500 detectors. The method developed fulfils the demands of the epidemiological study. The uncertainty ranges from 5 to 10% in a wide range of radon levels. The detection limit is 10 Bq.m-3. The experience gained has been used by Swedish commercial companies as well as by colleagues abroad. The development of the system is an example of fruitful international collaboration.