WiredGov Newswire (news from other organisations)
|Printable version||E-mail this to a friend|
HPA - New estimates of cancer risks after exposure to radiation
New estimates on the risk of developing some types of cancer after exposure to ionising radiation have been published by the Health Protection Agency's Advisory Group on Ionising Radiation (AGIR).
AGIR reviewed the latest scientific evidence on the lifetime risks of developing 'solid cancers' – such as cancer of the breast, lung and colon cancer – following exposure to ionising radiation.
Professor Bryn Bridges, chairman of AGIR, said: "The new estimates are broadly in line with previous figures and have been used to calculate the cancer risks from various medical investigations that use ionising radiation; particularly CT scans and mammographic examinations which have become more common."
Professor Sir Nicholas Wald, who chaired the Working Group, added: "The benefits of a medical procedure, such as surgery, should always outweigh the risks – including the risk of radiation induced cancer from an x-ray. This needs particular consideration in medical screening for cancers among people who are not showing any symptoms."
Among the report's conclusions are risk estimates for:
Mammography screening of women for breast cancer
Computed tomography (CT) assessment of coronary artery calcification in screening for heart disease
CT scanning in colorectal and lung cancer screening
Prof Bridges said: "The benefits of CT assessments in screening for coronary artery disease and colon cancer, in particular, have not yet been established. It will be important to ensure that any benefits resulting from these procedures are not outweighed by the risks involved, however small."
Dr John Cooper, director of the HPA's Centre for Radiation, Chemical and Environmental Hazards: said: "We will continue to work with all relevant professional bodies to ensure that the risk and benefits of medical procedures involving ionising radiation are understood and appropriately managed."
Notes to editors
The report: Risk of Solid Cancers following Exposure to Ionising Radiation: Estimates for the UK Population, can be viewed here at www.hpa.org.uk/Publications/Radiation/DocumentsOfTheHPA/.
A previous AGIR report provided estimates of Leukaemia risk for the UK population (Risk of leukaemia and related malignancies following radiation exposure: estimates for the UK population. Report of an Advisory Group on Ionising Radiation. Doc NRPB, 14 (1), 1-119 (2003).
Solid cancers are those which form a discrete tumour mass – for example cancer of brain, breast, prostate, colorectum, kidney – in contrast to leukaemia or lymphomas which generally diffusely infiltrate a tissue without forming a solid mass.
Average annual ionising radiation doses in the UK population are estimated at 2.7 millisieverts per person. Of this, some 84 per cent comes from natural sources such as indoor exposure to radon, 14 per cent results from medical investigations such as x-rays while occupational exposure and nuclear weapons fallout makes up less than 1 per cent. Exposure of the UK population to man-made ionising radiation from medical and industrial uses is closely monitored and controlled.
The Life Span Study of Japanese atomic bomb survivors is the single most informative study on the risks of radiation-induced solid cancers. However, some studies of medical, occupational and environmental exposures are also informative when considering specific cancers and/or specific types of exposure