Ionising radiation is a recognized cancer-causing factor, and studies of individuals exposed to acute, high doses of ionising radiation provide the main quantitative basis for radiation protection guidelines.
A multinational cohort study has been conducted to assess the effect of protracted low dose, low dose rate exposure to ionising radiation on the risk of cancer mortality. The study, which includes cohorts of workers in the nuclear industry across France, the UK, and the US, offers a direct estimate of the association between low dose exposure to ionising radiation and solid cancer mortality, with implications for radiation protection in various settings.
- Objective: To evaluate the effect of protracted low dose exposure to ionising radiation on cancer risk.
- Design: Multinational cohort study.
- Setting: Cohorts of workers in the nuclear industry in France, the UK, and the US.
- Participants: 309,932 workers with individual monitoring data for external exposure to ionising radiation.
- Total Follow-up: 10.7 million person years.
- 103,553 deaths recorded, with 28,089 due to solid cancers.
- Estimated rate of mortality due to solid cancer increased by 52% per Gy, lagged by 10 years.
- Restricting analysis to low cumulative dose range approximately doubled the estimate of association.
- Exclusion of deaths from lung and pleural cancer had a modest effect on the estimated magnitude of association.
- Evidence suggests a steeper slope for the dose-response association in the low dose range.
- Results can help strengthen radiation protection, especially for low dose exposures in medical, occupational, and environmental settings.
Did You Know?
The study’s estimated rate of mortality due to solid cancer increased by 52% per Gy of radiation dose, a figure that is larger than estimates currently informing radiation protection.