14 March 2013
Evidence suggests that the risk of developing cancer or tissue damage after exposure to ionising radiation varies among people because of genetic and lifestyle factors, according the Health Protection Agency’s independent Advisory Group on Ionising Radiation (AGIR).
An AGIR report concludes that there is strong evidence that smoking substantially increases the risk of developing lung cancer after exposure to ionising radiation; an effect particularly marked in people exposed to radon gas. There is also evidence that genetic factors affect the way people react to ionising radiation, although further research is needed to confirm this and identify all the genes responsible.
The conclusions raise ethical issues that will need careful consideration and could have implications for advice given to smokers who undergo radiotherapy, work with ionising radiation or are accidentally exposed.
Professor Bryn Bridges, chairman of AGIR, said: “Smoking may well be important when considering future risks in exposed people. It is an appropriate time to start to consider how knowledge of lifestyle factors such as smoking might be incorporated into occupational, medical and public radiation protection.
“Identification and understanding of the various factors that contribute to radiosensitivity is improving but remains incomplete. There is currently no simple predictive test of individual radiosensitivity, although such tests may be available in the future.”
The maximum amount of radiation that someone receives during radiotherapy is limited by current dose thresholds set to limit damage to healthy tissue among the most sensitive people. Identification of patients who are more sensitive would allow higher doses to be used among the rest of the population and lead to improved control of the cancer.
However, because there is currently no valid predictive test, AGIR concludes that a move from the current population based approach to a more tailored, individual approach to radiation protection would not at present be justified.
Dr John Cooper, director of the HPA’s Centre for Radiation, Chemical and Environmental Hazards, said “We welcome this report from AGIR and will take its recommendations into consideration in formulating our research programme as we move into Public Health England.”
Last reviewed: 14 March 2013