3.4 Doses received by patients
We have no system for monitoring patient exposure, in particular because this exposure is not subject to any strict limitation, owing to its medical benefits. It is hard to accurately identify the overall exposure of medical origin, as we do not know the numbers of each type of examination practiced and the doses delivered for the same examination can vary widely. However, global statistics (UNSCEAR 2000 report, volume 1, p. 401) drawn up for 1.53 billion inhabitants of the developed countries (1991-1996 data) indicate an annual effective dose rate per inhabitant of 1.2 mSv for radiology, 0.01 mSv for dentistry and 0.08 mSv for nuclear medicine. In western Europe, for diagnostic radiological imaging, the annual effective dose per inhabitant in France was assessed at 0.7/0.8 mSv, whereas it is 0.33 mSv for the United Kingdom and 1.9 mSv for Germany.
Action plan for monitoring exposure of patients to ionising radiation.
Based on recommendations published in 2002 by the InVS, the ASN produced an Action plan at the end of 2003 designed to set up and develop monitoring of exposure of patients to ionising radiation of medical origin (PASEPRI). The multi-year plan was drafted in close collaboration with the relevant departments of the IRSN and the InVS, then submitted to the various institutional partners involved for approval. Implementation of this plan began in 2004.
It is regularly monitored by a committee chaired by the Director General of the ASN.
One of the actions included in the PASEPRI is to have the IRSN and the InVS set up an observatory of medical exposure to ionising radiation, from which the following lessons can be learned (CNAM 2002 data):
– the annual number of radiological examinations (conventional and dental radiology) would seem to stand somewhere between 55 and 66 million, of which 67% is with conventional radiology;
– the 4 most common conventional radiological examinations are radiography of the lower and upper limbs (32%), the spine (16%), the thorax (12%) and the breast (11%);
– oral radiography accounts for 85% of dental examinations;
– scanner examinations of the head and spine represent 38% and 26% respectively of the total number of scanner examinations;
– the total annual number of conventional radiography examinations (excluding dental) and scanner examinations is between 60 and 72 million, of which 92% is for conventional radiography alone;
– if we include nuclear medicine and surgical radiology examinations, the total number of examinations (excluding dental) would be somewhere between 61 and 74 million, for an average annual effective dose of between 0.66 and 0.83 mSv.

4   OUTLOOK

In addition to its regulatory and supervisory duties, the ASN closely monitors developments in research and knowledge in the field of health and ionising radiation, as well as in international radiation protection doctrine. More precisely:

a) Implementing a true scientific watch in the field of ionising radiation, in accordance with the recommendations of the Vrousos commission and the national health and environment plan, implies the provision of considerable resources, which are not currently available. In the meantime, the IRSN is required periodically to publish summaries on the research topics on which it is working.

b) Close attention must continue to be paid to the work of the ICRP, which is updating its recommendations published in 1990. New recommendation proposals are expected in 2006. The ASN will therefore closely monitor this work, particularly as the IAEA and the European Commission have announced their intention to conduct a joint updating of the international "basic standards" which underpin community directives and European regulations concerning radiation protection.

c) Exposure monitoring requires a particular effort in order to better identify the population categories or groups which are most exposed. The interest of this is three-fold: this knowledge should lead to better targeting of risk reduction efforts (optimisation), provide reliable indicators for evaluating the effectiveness of public policy and develop epidemiological surveys for an improved approach to the risk. Monitoring patient exposure and domestic radon are two priority areas for the ASN:

• thus, the national action plan to identify exposure to ionising radiation of medical origin (PASEPRI) set up by the ASN in 2004, jointly with the IRSN and the InVS, began in 2005 to contribute new and more precise data concerning estimates of the doses delivered to patients. It will continue in 2006, in association with the learned societies concerned;

• furthermore, the ASN is continuing with implementation of the action plan concerning the risks linked to radon in the home. This plan is leading to preparation of the measures necessary for including radon measurement in the residential health file required for real estate transactions. It should eventually contribute to improving understanding of radon exposure in those departments most concerned by this radioactive gas.