RESUMO
The recently developed radon film-badge makes it possible to measure radon indoors, in soil, in water and/or in aqueous media (e.g. mud). As a result of its wide response linearity, this monitor has been successfully used to measure radon in-water with concentrations from 10 to ~10 000 Bq/L. By exploiting the unique characteristics of this badge, a mini-survey has been carried out by Health Canada in which radon in water was measured from 12 private wells, as well as in tap water originating from the Ottawa River. Due to the widespread interest of different laboratories in using these passive monitors, laboratories were provided with plastic films to construct their own badges by using in-house CR-39 detectors. Monitors were then irradiated by a known radon concentration at the National Institute of Radiation Metrology (ENEA)'s radon chamber and sent back to each laboratory for processing and counting. Even though these laboratories have been using different etching- and counting-procedures, the film-badge responses varied only within ~12%.
Assuntos
Poluição do Ar em Ambientes Fechados/análise , Dosimetria Fotográfica , Cooperação Internacional , Monitoramento de Radiação/métodos , Radônio/análise , Poluentes Radioativos da Água/análise , Canadá , HumanosRESUMO
The internal alpha dose assessment (ICRP 65, 1994) depends on the value of the equilibrium factor F. This parameter is generally not measured and a mean conventional value ranging between 0.4 and 0.6 is assumed, possibly leading to a significant bias in the dose assessments. In this paper, a method for the measurement of F is reported, based on the total aerosol sampling on filters and immediate gross beta counting of 214Pb and 214Bi activities. Measurements are interpreted according to a Raabe-Wrenn and Jacobi simplified room model, leading to an estimate of the individual airborne activities of short-lived radon daughters, the removal parameter and the equilibrium factor. The method was laboratory tested and validated and it is being qualified by field surveys in different indoor environmental conditions.
