Andrew Yule, Science Officer – Monitoring and Emergency Response Section Radiation Health Services (Australian Radiation Protection and Nuclear Safety Agency)
For several decades, radon progeny dosimetry was a relatively simple endeavour due to the ICRP recommendation to use the dose conversion convention (in ICRP publication 65) to calculate the radiation dose from any exposure to radon progeny. The ICRP now recommend the use of dose conversion factors (DCFs) based on the ICRP respiratory system model (in ICRP publication 137), which has raised many important questions about radon progeny dosimetry. While various aspects of these changes are under active consideration around the world, ARPANSA has focused on the practical impact of the changes. This has involved attempting to answer the following questions:
How do you actually measure the DCF?
Do the DCF’s suggested by the ICRP match real world conditions?
Are the recommended DCF’s still appropriate as mining technology advances?
Is there a place for site specific dose conversion factors, and if so where?
In order to address these questions, we have developed new equipment and methods to provide accurate data in real world situations. Despite the challenges involved in working with nano-scale aerosols we have made significant progress which will be of interest to those involved in radon progeny measurement, dosimetry and regulation.