2. What are the current guidelines for radiation protection?
Radiation protection is based on three principles:
- Justification: any radiation introduced should produce more good than harm to the individual or to society.
- Optimisation: exposure should be as low as possible.
- Dose limitation: individual doses for non-medical applications should not exceed set limits. For workers, the limit is 50 mSv in a single year with a maximum of 100 mSv in a consecutive five-year period. For members of the public, the current limit is 1 mSv of radiation exposure from man-made sources per year. The doses from security screening are very likely to fall below this limit but they should still be justified and optimised.
From a legal point of view, exposures from security scanners used to fall under the category of “medico-legal procedures”, which include exposure to radiation without a medical reason. Under a new directive, these have been re-classified as “non-medical imagining exposures” and the justification and optimisation principles have been strengthened. Individuals should consent to the screening before it takes place and should be offered an alternative that does not involve ionising radiation. However, countries can pass laws so that in some cases screening can be carried out without consent.
It is not clear whether exposure to staff that are required to be screened such as airline crews, airport workers or couriers, can be regarded as occupational. Under the current framework they are considered as being part of the general public so the annual dose limit of 1 mSv would apply. More...