Prolonged low-level radiation exposure increases risk of cancer death

In collaboration with the Press Association

A major international study has found further evidence of a link between prolonged exposure to low-level ionising radiation and a small increased risk of dying from cancer.

“The findings highlight the importance of monitoring radiation exposure in nuclear workers, and the need to follow safety precautions to minimise exposure” - Dr Jana Witt, Cancer Research UK

The researchers behind the study – coordinated by the International Agency for Research on Cancer (IARC) – said the findings reinforce the importance of radiation protection standards.

Previous research has focused on the effects of ionising radiation following high-dose acute exposure, such as in Japanese atomic bomb survivors. 

But the latest study included more than 300,000 people who had worked in nuclear industries - from France, the UK and the US – for an average of 12 years.

Published in The BMJ, the results accounted for things such as age, length of employment and job role.

Based on the analysis, the researchers estimated that around 209 of the 19,064 deaths from cancers other than leukaemia identified during the study were associated with radiation exposure.

Dr Jana Witt, health information officer at Cancer Research UK, said the findings add to what is known about low-level radiation exposure, but stressed that most workers in the study were only exposed to very low levels of radiation that would only marginally increase their risk of dying from cancer.

“This large, international study adds to our understanding of how long-term exposure to low levels of ionising radiation – which radiation workers in the nuclear industry may be exposed to – can affect the risk of dying from cancer,” she said.

“The findings highlight the importance of monitoring radiation exposure in nuclear workers, and the need to follow safety precautions to minimise exposure,” she added.

Dr Ausrele Kesminiene, a study co-author and IARC researcher, said the findings reinforce an important link between increasing radiation dose and risk of dying from solid cancers.

But Cancer Research UK’s Dr Witt cautioned that the study is not without its flaws.

“The researchers didn’t have any information on whether workers were smokers, which is a major cause of cancer death. They also didn’t have information on how many workers developed cancer overall, or what types of treatment they had,” she said.

“More studies like this are needed to confirm how low levels of ionising radiation affect the risk of cancer, including how they affect risks of different types of cancer,” she added.

IARC director, Dr Christopher Wild, also stated that follow-up studies, particularly those looking at this same group of people, would be crucial to confirm the findings.

“Many questions remain about the impact of radiation on health. The continued monitoring of this cohort in the future will play a key role in better understanding the link between cancer and radiation,” he said.


  • Richardson, D., et al. (2015). Risk of cancer from occupational exposure to ionising radiation: retrospective cohort study of workers in France, the United Kingdom, and the United States BMJ DOI: 10.1136/bmj.h5359