Source of Support: None, Conflict of Interest: None
General principles of radiation protection of workers and population are applicable to medical installations, but the protection of patients deserves special considerations. Medical sources of radiation are by far the most significant contribution to the collective dose of any population; therefore efforths should be done to reduce such contribution as much as reasonably possible keeping of the same time every real benefit to the health of people. The non-thereshold linear hypotesis between risks and doses is the present support of radiation protection philosophy as recommended by the International Commission of Radiological Protection (ICRP). The present work analyze its implications on individual and collective basis. It is shown that even when a single radiological procedure con generate a "negligible" risk for a given person, the collective dose may be relevant if many people are irradiated in similar procedures and the associated detriment, expressed as the mathematical expectation of harm, may be significant. Such considerations provides basis for a better judgment of justifications and optimization of practices, particularly when generalized procedures of radiological surveillance are imposed to groups of populations. The work shows that reduction of unnecessary doses in radiation medicine results in appreciable reduction of collective doses and its associated detriment. Such reductions can be achieved by promotion and enforcement of utilizatior, of appropriate equipment and techniches as well as a good policy for training of physicions and physicist. Argentine experience on adoption of standars of quality and training programs is commented.