Cancer mortality after low dose exposure to ionising radiation in workers in France, the United Kingdom, and the United States (INWORKS): cohort study

Abstract

Objective To evaluate the effect of protracted low dose, low dose rate exposure to ionising radiation on the risk of cancer. Design Multinational cohort study. Setting Cohorts of workers in the nuclear industry in France, the UK, and the US included in a major update to the International Nuclear Workers Study (INWORKS). Participants 309 932 workers with individual monitoring data for external exposure to ionising radiation and a total follow-up of 10.7 million person years. Main outcome measures Estimates of excess relative rate per gray (Gy) of radiation dose for mortality from cancer. Results The study included 103 553 deaths, of which 28 089 were due to solid cancers. The estimated rate of mortality due to solid cancer increased with cumulative dose by 52% (90% confidence interval 27% to 77%) per Gy, lagged by 10 years. Restricting the analysis to the low cumulative dose range (0-100 mGy) approximately doubled the estimate of association (and increased the width of its confidence interval), as did restricting the analysis to workers hired in the more recent years of operations when estimates of occupational external penetrating radiation dose were recorded more accurately. Exclusion of deaths from lung cancer and pleural cancer had a modest effect on the estimated magnitude of association, providing indirect evidence that the association was not substantially confounded by smoking or occupational exposure to asbestos. Conclusions This major update to INWORKS provides a direct estimate of the association between protracted low dose exposure to ionising radiation and solid cancer mortality based on some of the world’s most informative cohorts of radiation workers. The summary estimate of excess relative rate solid cancer mortality per Gy is larger than estimates currently informing radiation protection, and some evidence suggests a steeper slope for the dose-response association in the low dose range than over the full dose range. These results can help to strengthen radiation protection, especially for low dose exposures that are of primary interest in contemporary medical, occupational, and environmental settings.

Book review: Attribution of radiation health effects and inference of radiation risks—considerations for application of the IAEA safety standards, IAEA Safety Reports Series No. 122

“…Empirically, several pertinent studies have been published subsequent to UNSCEAR Report 2012, and were thus not taken into account in the IAEA Report. These include new results from the LSS [5], the INWORKS study of nuclear workers [6,7], a pooled analysis of studies on leukaemia after low-dose exposure [8], the EPI-CT study on cancer after computed tomography exams during childhood [9,10], and the PUMA study based on pooled cohorts of miners exposed to Radon and its progeny [11]. These studies set up cohorts with up to hundreds of thousands of participants accruing millions of person-years of follow-up.…”

Nuclear power and environmental injustice

“…Exposure to radiation is hazardous to health, even at low levels (Beyea, 2012;National Research Council, 2006). Therefore, when people come into contact with these wastes, they are at higher risk of developing cancers and a range of other health effects (Little et al, 2023;Richardson et al, 2023). A particular complication is that some of these radioactive substances have extremely long half-lives, and remain hazardous for hundreds of thousands of years.…”

Extended analysis of solid cancer incidence among nuclear industry workers in the UK 1955–2011: comparison of workers first hired in earlier and later periods

“…However, the US study found that the risk estimates were significantly greater for those 56% of workers first hired in 1960 or later in comparison with the full cohort of 101 363 workers, for all solid cancers combined and for certain individual site-specific solid cancers, such as lung, colon, and pleural cancer. A combined analysis of mortality data for 309 932 workers from the UK, the USA and France in the recent International Nuclear Workers Study (INWORKS) [4] also found higher risks for solid cancers among those 77% of workers first hired after 1957 and even more so among those 61% first hired after 1964.…”