Issues in medical exposures.

Medical exposures account, on average, for some 14% of the background ionising radiation exposure in the UK and form the great majority of the non-natural component. In the United States of America, medical exposures comprised over 50% of the total in 2006. This is due primarily to an increase in x-ray computed tomography (CT) and positron emission tomography (PET) procedures. This paper highlights the potential problems in the use of CT scanning to investigate the asymptomatic individual, where the traditional risk/benefit considerations are less clear-cut than in conventional clinical situations. It draws on a recent COMARE report which examined the use of CT for whole body, heart, lung and colon studies. The number of PET facilities is increasing rapidly in the UK and, in addition to considerations of radiation dose to subjects, careful planning is necessary to limit doses to staff. In non-ionising radiation, a topic of keen interest at present is the use of increasingly powerful sunbeds, particularly by those aged under 18. Legislation and regulation vary widely across Europe and the Scottish Parliament has recently introduced the first UK regulation. It is suggested that further research is required into the effects of current UV systems and the reasons why tanning is thought so desirable by Caucasians. Lastly, a number of issues requiring radiobiological and epidemiological input are considered and actions to satisfy these identified.