Radiation exposure to the population of Perth, Western Australia

This study focussed on the population of Perth, Western Australia. The relative amounts of ionising radiation exposure received from all major sources have been assessed. The intention is to compare the results to previous population dose studies completed in the United Kingdom. The main conclusions are as follows: 1) the proportion of the radiation dose to the Perth population arising from natural sources is about 88%. This is about the same as the UK (87%); 2) the estimated Perth population dose (2.5 mSv) is identical to the United Kingdom estimate (2.5 mSv). However, the relative contribution from some of the component sources show considerable variation, and; 3) exposure from radon is the major contributor (47 %) to the total dose received in the UK. In Perth, the major contributor has been found to be gamma radiation (33 %). The major factors influencing these variations appear to be the different underlying geology of the two regions, and the different levels of radioactivity in their respective building construction materials. Annual dose due to radon exposure in Perth has been found to be about 0.7 mSv. This is significantly lower than the exposure of the UK population (1.2 mSv). Annual dose due to gamma exposure in Perth has been determined to be about 0.83 mSv. This is significantly higher than the UK dose (0.35 mSv). 23 refs., 4 tabs