Radiation is present in the environment naturally and we are all exposed to some extent. The effect this radiation has on humans depends on the type, source and level of radiation and on the age of the patient. Legislation guides dose limits for staff and public and the dose reference levels (DRLs) for patients undergoing medical exposure. DRLs give an idea of the doses for standard-sized patients, but the dose may be larger for larger patients. Strictly, there are no dose limits for patients but the key guiding principle for patient, staff and public doses is ALARP (As Low As Reasonably Practicable).
This chapter covers the sources of radiation to staff, how the dose received is measured and how to protect against radiation exposure.