Authored By:
Lane et alThis was a meta-analysis of three cohort studies which investigated the risk of lung cancer mortality to workers exposed to low-level radon in uranium mines. The cohort studies included were from the Czech Republic, France and Canada collectively covering exposure periods from 1953 to 1999. Exposure to workers was assessed by both the concentration of radon in the air and by the length of employment in months. This was then used to derive an exposure unit of working level month (WLM). The study was limited to workers who had received less than 100 WLM in order to investigate low-level effects. The study found was an increased excess relative risk (ERR) risk in lung cancer mortality among workers per WLM of 0.022 (95% confidence interval (CI) of 0.013-0.034). However, the authors report that this risk was no longer statistically significant at an exposure of less than 10 WLM. The authors suggest the higher exposures are compatible with a linear non-threshold model and lower exposures are not. However, the authors state that no conclusion can be made at the low exposures due to the low statistical power.
Published In:
International Archives of Occupational and Environmental Health, 2019This study demonstrates the difficulty of evaluating the risk of lung cancer mortality from low-level exposures to radon. The authors reported that at low radon exposure of less than 10 WLM the risk of lung cancer mortality was no longer significant. A working level month within a uranium mine is approximately equivalent to 10 mSv of dose (ARPANSA, 2019). However, the data by Lane et al showed that this extends further and that at less than 19 WLM there is not a statistically significantly increased risk of lung cancer mortality (1.41 relative risk with a 95% CI of 0.90–2.25). In Australia, RPS C-1 2016 sets out the requirements for the protection of occupationally exposed persons in uranium mines. A number of studies have demonstrated the additional risk of lung cancer from radon exposure is small relative to the risk from tobacco smoking (ICRP, 2010). The best way of reducing the total lung cancer risk, as well as the lung cancer risk from exposure to radon, is to avoid tobacco smoking.
