ASN Report 2022

in proposing screening kits to the inhabitants of a given region to raise their awareness of the radon risk. Lastly, line 3 aims to take better account of the management of the radon risk in buildings. In order to help members of building trade organisations improve their skills, these organisations have recently developed training courses dealing with methods to prevent and reduce concentration levels and various media to address the needs. The various French-language aids have been listed. To complete the offering, a guide intended for professionals and private individuals will establish prevention recommendations for new constructions and remedial measures in existing buildings. The progress made in understanding the effectiveness of construction standards in reducing radon concentrations in indoor air shall be consolidated. A system of specific indicators, chosen according to their relevance and the data available for monitoring them, has been put in place. Monitoring how these indicators evolve over several years will enable the effectiveness of the national strategy deployed under the national action to be determined. 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. It has been regularly reviewed by IRSN since 2002. Although exposure has been increasing for the last 30 years, it has tended to stabilise since 2012, whereas at the same time the number of medical procedures has greatly increased. Nuclear medicine, the third-biggest contributor to the collective effective dose, is the discipline that saw the greatest increase between 2012 and 2017, in terms of both frequency and contribution to the collective effective dose. The average effective dose per inhabitant resulting from diagnostic radiological examinations was evaluated at 1.53 mSv for the year 2017 (IRSN ExPRI study 2020) for some 85 million diagnostic procedures performed in 2017 (81.6 million in 2012), i.e. 1,187 procedures for 1,000 inhabitants per year. It is to be noted that as before, the individual exposure in 2017 is very varied. Consequently, although about 32.7% of the French population underwent at least one procedure (dental procedures excluded), half the patients received a dose of 0.1 mSv or less, 75% received 1.5 mSv or less, while the most exposed 5% of patients received a dose exceeding 18.1 mSv. Conventional radiology (55.1 %), computed tomography (12.8%) and dental radiology (29.6 %) 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 2017 (75%) than in 2012 (71%), whereas that of dental radiology remains very low (0.3%). In adolescents, conventional radiology and dental procedures are the most numerous (about 1,000 procedures for 1,000 individuals in 2017). Despite their frequency, these procedures in this population represent only 0.5% of the collective dose. Lastly, it will be noted that: ∙ A national headcount estimated at more than 30,000 patients was exposed to a cumulative effective dose of more than 100 mSv in 2017 due to multiple computed tomography examinations. This figure reaches 500,000 if a cumulative period of six years is considered. This highly exposed population seems to be increasing in size regularly and relatively rapidly since 2012. Although most people in this population are old, a quarter of them are aged under 55 years. The question of possible radiation-induced effects is therefore raised for this specific population. It is worth pointing out that these patients are MANAGEMENT OF THE RADON RISK, NEW ISSUE 2022, INTENDED FOR THE REGIONAL AUTHORITIES In 2022, in partnership with the DGS and the Scientific and Technical Centre for Building (CSTB), ASN updated the guide for the regional authorities entitled Management of the Radon Risk. As the radon regulations changed in 2018, particularly with regard to PAB and informing the public, the guide as a whole needed to be updated. The purpose of this guide is to assist the regional authorities in fulfilling their regulatory obligations regarding management of the radon risk, notably by giving the floor to the authorities involved in monitoring radon in PAB and residential buildings. The guide is divided into three parts corresponding to the different roles of the regional authorities as: ■ owner or operator of the PAB subject to radon monitoring. This part details each step of the process: from the initial measurement to the corrective actions or works to be implemented and the verification of the effectiveness of these actions. The presentation of the regulations is supplemented by operational recommendations; ■ municipality or agglomeration participating in informing the population about major risks; ■ stakeholder of a proactive policy vis‑à‑vis the radon exposure risk. This part contains a wealth of advice on measures the authorities can take to encourage private individuals to measure the radon concentration in their home. An appendix provides numerous links giving free access to further information, such as the webinars of the National Centre of the Regional Public Authorities (CNFPT), guides on prevention methods in new buildings and reduction of radon concentration in existing buildings, along with examples of remediation work. 0.46 % Penitentiaries 29% Some health care, social and medico-social facilities 59% Educational institutions 11% Day-care facilities for children under 6 years of age 0.20% Spas TOTAL 100% DIAGRAM Distribution of N1A measurements per building category in the measuring campaigns from 2016-2017 to 2021-2022 5 114 ASN Report on the state of nuclear safety and radiation protection in France in 2022 • 01 • Nuclear activities: ionising radiation and health and environmental risks 01