The use of radioactive trace substances and ionizing radiation is common in biomedical research. The basic work is normally carried out in the laboratory and using animal models in order to study chemical, physiological and metabolic processes as well as the turnover of pharmaceuticals. Such investigations are a necessary part of the introduction of new diagnostic and therapeutic methods. In all investigations involving exposure of humans, a careful estimation of the radiation dose to the patient should be made. The associated risk should then be weighted against the benefit for the patient or the society.
According to the Basic Safety Standards (BSS), the exposure of humans for medical research is deemed to be not justified unless it is:
The estimated risks of the irradiation should be explained to those individuals involved who knowingly incur doses while voluntarily helping (other than in their occupation) in the care, support or comfort of patients undergoing medical diagnosis or treatment (BSS II.26 and II.27).
When selecting subjects for a research project the following general principles should be taken into account:
In addition, when employees who work with radiation are considered as possible volunteers for research, the researcher must ensure that, as volunteers, they are aware of the additional risk arising from their exposure to radiation at work. The legitimate right of the employee to refuse participation in the research project should be respected.
No. However, appropriate dose constraints should be authorized for each research programme and the protection should be carefully optimized. For research projects involving use of ionizing radiation, the ICRP and WHO recommend the use of categories of risk arranged according to the radiation dose and estimated level of risk to be received by the subject. The risk may then be evaluated with regard to the expected benefit. These categories are listed in the following table.
|Level of Risk||Trivial||Minor to intermediate||Moderate|
|Total detriment||~ 10-6 or less||~ 10-5||~ 10-4||~ 10-3 or more|
|Range of effective doses (adults), mSv||< 0.1||0.1 - 1||1 - 10||> 10a|
|Anticipated level of benefit to society||Minor to intermediate||Intermediate to moderate||Substantial|
a To be kept below deterministic thresholds except for therapeutic experiments.