A review of radiation doses and associated parameters in Western Australian mining operations that process ores containing naturally occurring radionuclides for 2018–19

Abstract

Naturally occurring radionuclides (NORs) are encountered in varying concentrations in a wide range of commodities that are mined and processed in Western Australia (WA), including mineral sands, coal, phosphate ores, sandblasting materials, and the production of bauxite, titanium dioxide pigment, copper, zinc, lead, tin, tantalum and the refining of zircon. Because they have the potential for workers to receive annual doses in excess of 1 mSv, 14 mining operations in WA are required to submit an annual report of worker doses to the regulatory authority. This research provides a summary of the workforce demographics and radiation doses reported by mining operations for the 2018–19 reporting period in order to establish a benchmark against which to compare future worker exposures. The 2018–19 data is compared to that presented in the last peer-reviewed research, published in 1994 in order to evaluate changes in worker dose profiles over the intervening period. In 1992–93, the collective effective dose received by 1496 workers across seven mining operations was 2824 man.mSv, whereas in 2018–19 it had decreased to 784 man.mSv for 1474 workers in 13 operations. The maximum committed effective dose (CED) decreased by 76%, from 18 mSv (36% of the annual limit) in 1992–93 to 4.4 mSv (22% of the derived annual limit) in 2018–19. The mean CED decreased by 49%, from 1.8 mSv in 1992–93 to 0.97 mSv in 2018–19. As a result of revised DC’s published in ICRP-137 and ICRP-141, the impacts upon the mean CED per unit intake of alpha activity arising from inhalation of insoluble NORs-containing dusts, and contribution to CED from inhalation of radon, thoron and their progeny will require evaluation for individual mining operations in the WA mining industry.

A review of radiation doses and associated parameters in Western Australian mining operations (2018–20)

“…Subsequent to the publication of Ralph et al (2020a), one RE (#13) submitted an annual report, and REs #9, #11, #15, #16, #22 and #23 provided additional data. This data has been assimilated into this research, and as a result, the information reported in parentheses in table 2, and for 2018-19 in tables 3 and 4 do not align directly with the information provided in Ralph et al (2020a).…”

“…All 17 REs provided data on the size of their workforce REs for the 2019-20 reporting period. Ralph et al (2020a) reported that in the 2018-19 reporting period 1474 workers were employed by those REs that had submitted workforce data. Subsequently, two REs (#1 and #13) provided their workforce data for 2018-19, increasing the workforce by 50, to 1524 as shown in table 3.…”

“…This research compares data for the 2019-20 reporting period against that for 2018-19 reported by Ralph et al (2020a) who found that for the 2018-19 reporting period the collective effective dose (CED) to the 1474 workers employed by 13 REs was 784 man.mSv. The mean ED was 0.97 mSv, with a maximum reported ED of 4.4 mSv (22% of the derived annual limit of 20 mSv).…”

“…This paper aims to follow up the research by Ralph et al (2020a) and profile the estimates of radiation doses to WA mine workers, working for REs in the 2019-20 annual reporting period. The dose profile is then used to evaluate the impact of revised DCs for members of the 238 U and 232 Th decay series on the dose estimates to WA mine workers by comparison to the 2018-19 annual reporting period, which preceded implementation of the revised DCs.…”

A Review of Radon Exposure in Non-uranium Mines—Estimation of Potential Radon Exposure in Canadian Mines

“…The radon-induced lung cancer is not specific only for uranium miners, because radon is a naturally occurring radioactive gas generated by the decay of uranium-bearing minerals in all rocks and soils in varying concentrations. For example, radon and γ-ray exposures were measured in 26 non-uranium mines in Australia ( Ralph et al 2020a ). The results showed that, on average, exposure to radon progeny in non-uranium mines contributed to 71% of the total annual effective dose, ranging from 43% to 93% in different mines.…”