Article publication date:
September 2022
Authored by:
Zablotska et al.
Summary:
This study assessed the association between the exposures to radon and gamma (γ) radiation and the incidence of lung cancer in a cohort of uranium mine workers in Canada. The cohort of 16,752 workers (~ 92% male) employed during 1932-1980 received exposures to radon and γ-ray radiation and were followed for the development of new lung cancer from 1969 to 1999. The mean (+/-SD) cumulative total dose to the lung in the cohort was 931.65 (+/-1990.90) millisieverts. The cohort data was linked to the Canadian Cancer Data Base, which had more than 82% of the lung cancers confirmed by histology or cytology. Incidence of lung cancer analysis was restricted to male workers (n=15,351), who contributed to a total of 367,253 person-years. The study found that lung cancer incidence was significantly higher in the workers compared with the general Canadian male population. Risks of lung cancer (n=594, 34% squamous cell, 16% small cell, 17% adenocarcinoma) increased with increasing radon exposure. No significant difference in risks by different histologic lung cancer types was found.
Link to:
Published in:
Cancer
Commentary by ARPANSA:
The study provides an update on the risk of lung cancer following exposure to radon and γ-ray radiation in an occupational mining setting. The overall conclusion of increased risk of lung cancer among radon-exposed mining workers is consistent with other cohort studies (Lane et al., 2019). Though comparable data from Australia are limited, an Australian study (Peters et al., 2013) has shown an elevated risk of lung cancer among underground mining workers. In Australia, occupational exposure to radon in the uranium mining and milling industry is low and regulated to minimise cancer risk. The Code for Radiation Protection in Planned Exposure Situations sets out the requirements for the protection of occupationally exposed persons in uranium mines. Though an additional risk of lung cancer from radon exposure has been established, the risk is much smaller compared to that from tobacco smoking (ICRP, 2010). Avoiding tobacco smoking ultimately reduces the total lung cancer risk, including that from radon exposure.
