Concepts of Risk
Sources of Exposure
- Exposure 1
- Exposure 2
- Exposure 3
An individual is exposed to many sources of radiation whilst living their normal lives. Such as the list below:
- From the sky: 100,000 cosmic ray neutrons, 400,000 secondary cosmic rays every hour
- From the air: 30,000 atoms disintegrate in lungs every hour emitting alpha or beta particles and some gamma rays
- From food and drink: 15 million potassium-40 atoms + 7,000 natural uranium atoms disintegrate inside us every hour
- From soil and building mateials: 200 million gamma rays pass through the average individual each hour
Source: NRPB is now the Radiation Protection Division of the HPA
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The radiation exposure also varies with sea level (shielding effect of the atmosphere).
X-ray doses compared with natural radiation
Source: NRPB is now the Radiation Protection Division of the HPA
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Medical Exposure
It can be stated that many routine nuclear medicine and radiological procedures have the same degree of risk or safety as many everyday activities which are taken for granted. In medicine there is a risk in all forms of treatment.
Although risks for nuclear medicine do not generally outweigh the potential benefit from having the investigation, laying undue emphasis on the risk when talking to a patient may cause them concern.
It may therefore be preferable to speak in terms of relative safety, comparing the nuclear medicine procedure with a well known radiological procedure.
