REASSESSMENT OF RADIATION EXPOSURES OF UNDERGROUND NON-URANIUM MINE WORKERS IN WESTERN AUSTRALIA

In the 1990, radon and radon progeny was reported to contribute approximately 70% of the average 1.4 + 1.0-mSv annual dose across 26 Western Australian underground non-uranium mines. The Western Australian underground mining workforce has expanded significantly, and parameters used to calculate doses have changed significantly, warranting a review of the 1990's data. The review concludes that doses received by the contemporary mining workforce has increased on average, by 5.4%, with annual dose estimates ranging from 0.53 to 3.56 mSv, with a mean of 1.33 mSv. Doses in 12 of the 23 underground mines exceed 1 mSv and are required to comply with radiation safety legislation. It is estimated that 5400 underground workers will fall into the greater than 1-mSv category. The collective dose to the underground worker population has increased by 4.5 times from 3060 man mSv (2173 workers) to 13 669 man mSv (8597 workers).