ASN Report 2018

Distribution of radon activity concentrations by type of institution screened (in %), 2017/2018 campaign 3.3  ̶  Doses received by patients In France, exposure for medical purposes represents the greatest part of the artificial exposures of the public to ionising radiation. Medical exposure has been increasing over the last thirty years or so due to the rise in the number of radiological examinations – and computed tomography examinations in particular, to the ageing of the population, and to the strategies implemented to ensure better patient care, particularly in the context of patient monitoring after cancer treatment and coronary diseases. It has been regularly reviewed by IRSN since 2002. The average effective dose per inhabitant resulting from diagnostic radiological examinations has been evaluated at 1.6 mSv for the year 2012 (IRSN report 2014) for some 81.8 million diagnostic procedures performed (74.6 million in 2007), i.e. 1,247 procedures for 1,000 inhabitants per year. It is to be noted that the individual exposure in 2012 is very varied. Thus, although about one third of the French population underwent at least one procedure (excluding dental procedures), 85% of that population was either not exposed or received doses of less than 1 mSv. The average individual effective dose increased by 23% between 2007 and  2012 (it was 1.3 mSv in 2007). Conventional radiology (54%), computed tomography (10.5%) and dental radiology (34%) account for the largest number of procedures. It is the contribution of computed tomography to the effective collective dose that remains preponderant and more significant in 2012 (71%) than in 2007 (58%) whereas that of dental radiology remains very low (0.2%). In adolescents, conventional radiology and dental procedures are more numerous (1,020 and 1,220 procedures respectively for 1,000 individuals in 2012). Despite their frequency in this population, dental radiology procedures represent only 0.5% of the collective dose. Lastly, it is noteworthy that: ∙ ∙ in a sample of about 600,000 persons covered by health insurance, the analysis of the effective doses for these people who effectively underwent an examination shows that 70% of them received less than 1 mSv, 18% received between 1 and 10 mSv, 11% between 10 and 50 mSv and 1% more than 50 mSv; ∙ ∙ based on a sample of 120,000 children born between 2000 and 2015, IRSN reports (2015 report) that in 2015, 31.3% of the children in the sample were exposed to ionising radiation for diagnostic purposes (up by 2% compared with 2010). The average effective dose is estimated at 0.43 mSv and the median at 0.02 mSv (down for the average but equivalent for the median value). A large age-related disparity is noted: below 1 year of age the median value is 0.55 mSv (highest value) and between 6-10 years, the median value equals 0.012 mSv (lowest median value). The substantial uncertainties in these studies with regard to the average effective dose values per type of procedure must nevertheless be taken into account, which justifies the need for progress in estimating doses in the next exposure study of the general population. Diagram 3 0 100 200 300 400 500 600 Educational institutions Healthcare and social institutions Spas Penitentiaries Working places Number of institution screened < 400 Bq/m3 between 400 and 1,000 Bq/m3 > 1,000 Bq/m3 525 551 106 27 1 1 2 11 0 0 37 10 8 32 49 The second plan of action for controlling the doses of ionising radiation delivered to persons in medical imaging Controlling the doses delivered to patients for diagnostic or therapeutic purposes leads to measures to ensure that the principles of justification and optimisation are embraced in the exercise of medical practices that use ionising radiation. ASN’s second plan of action, published in July 2018, aims at continuing to promote a culture of radiation protection in medical professionals with the reinforcing of skills and the harmonising of practices in an updated regulatory framework. The actions address several areas, including human resources and training, quality and safety of professional practices, and equipment. ASN report on the state of nuclear safety and radiation protection in France in 2018  103 01 – NUCLEAR ACTIVITIES: IONISING RADIATION AND HEALTH AND ENVIRONMENTAL RISKS 01