(smoking, foodstuffs) and living habits (air travel). Diagram 1 shows an estimate of the respective contributions to the average total dose of the different sources of exposure to ionising radiation for the French population, considering firstly the radon dose coefficient stipulated by the current regulations, and secondly with the dose coefficient that was in effect until 31 December 2023. 3.1 DOSES RECEIVED BY WORKERS 3.1.1 Monitoring occupational exposure to ionising radiation The system for monitoring the external exposure of persons liable to be exposed to ionising radiation, working in BNIs or in small-scale nuclear facilities for example, has been in place for several decades. This system is based primarily on the mandatory wearing of passive dosimeters for workers liable to be exposed and enables compliance with the regulatory limits applicable to workers to be checked. These limits concern the total exposure (since 2003, the annual limit expressed in terms of effective dose has been 20 mSv for 12 consecutive months), obtained by adding the dose due to external exposure to that resulting from any internal contamination; other limits, called “equivalent dose limits”, are defined for the external exposure of certain parts of the body such as the hands and the lens of the eye (see “References” heading on asn.fr). The recorded data allow the identification of the cumulative exposure dose for a given period which cannot exceed three months, for each worker, including those from outside contractors. They are grouped together in the Ionising radiation exposure monitoring information system (Siseri) managed by IRSN and are published annually. The results of worker exposure to ionising radiation presented below are taken from the IRSN 2022 assessment entitled La radioprotection des travailleurs – exposition professionnelle aux rayonnements ionisants en France (Worker radiation protection – occupational exposure to ionising radiation in France). From the methodological aspect, as in the five preceding years, the IRSN 2022 assessment of external exposure was based exclusively on data from individual monitoring of the external exposure of workers recorded in the Siseri database. Until 2016, the assessments were produced exclusively by aggregating the annual summaries provided by the dosimetry organisations. Consequently, external exposure results for 2022 are not directly comparable with those established since 2017. Nevertheless, in order to establish trends, the results for the years 2015 and 2016 have been reassessed applying the new methodological approach (see Table 3). Tables 1 and 2 present, per area of activity and for the year 2022, the breakdown of the populations monitored, the collective dose (the collective dose is the sum of the individual doses received by a given group of persons), and the number of times the annual limit of 20 mSv was exceeded. They show a large disparity in the breakdown of doses depending on the sector. For example, the medical (including dental) and veterinary activities sector, which comprises a significant share of the population monitored (59.5%), accounts for only 11.4% of the collective dose; on the other hand, the nuclear industry, which represents just 20.7% of the headcount, accounts for 48.7% of the collective dose. Moreover, the sector concerned by exposure to natural radioactivity (excluding military aircrew), which represents just 5.7% of the total headcount, accounts for 33.2% of the collective dose. The non-nuclear industry and the research sectors represent 4.1% and 2.7% of the headcount respectively and account for 3.2% and 0.4% of the collective dose respectively. Table 3 shows that for external exposure, the total number of workers(7) monitored in 2022 was 386,080, a 1.5% decrease compared with 2021. The collective dose is 88.4 man-Sv, a figure that is 7% higher than that for 2021, which in turn was 14% up on that of 2020, but nevertheless without reaching the value of 2019 (112.3 man-Sv). This increase concerns all areas of activity but can be explained chiefly by the recovery of air traffic with the improved health situation following the Covid-19 pandemic. With regard to the dosimetry of the extremities (fingers and wrists), 27,598 workers were monitored in 2022, down by 2.6% compared with 2021 (i.e. 7.1% of the total number of persons monitored). With regard to dosimetric monitoring of the lens of the eye, it had been increasing since 2015, and has been stabilising since 2021. It concerned 5,906 workers in 2022. In 2022, six cases of exceeding the regulatory limit of 20 mSv for the effective whole body dose were registered, of which two were confirmed by the occupational physician. Four of the cases were registered in the medical sector (three in diagnostic radiology and one in radiotherapy), of which one – confirmed by the occupational physician – corresponds to the accumulation of several doses in 2022 (external exposure of 20 mSv over twelve sliding months); the other three cases were retained by default, as there was no feedback from the occupational physician on the conclusions of the investigation. The fifth case was registered in the research sector for accumulations of several doses in 2022 and was confirmed by the occupational physician. The sixth case however, which was registered in the non-nuclear industry sector, was not confirmed by the occupational physician. Alongside this, two cases of exceeding the regulatory limit for the equivalent dose to the skin of 500 mSv were registered, the first in the medical sector, in nuclear medicine, with a dose estimated at 2.1 Sv and the second in the research sector (cumulative dose of 500 mSv). Lastly, one exceedance of the regulatory limit for the equivalent dose to the extremities, confirmed by the occupational physician, was registered in the medical sector (FGIPs) with the cumulative doses attaining 502.9 mSv. To conclude, as in the preceding years, the assessment of monitoring of workers exposed to ionising radiation in France in 2022 published by IRSN in June 2023, shows the overall effectiveness of the prevention system introduced in facilities where sources of ionising radiation are used, because for nearly 92.7% of the population monitored, the annual dose remained below 1 mSv (effective annual dose limit for the public due to nuclear activities). The regular reduction in the number of the most heavily exposed workers over the last ten years should also be noted. Exceedances of the regulatory limit values remain exceptional. Monitoring of exposure of the lens of the eye with, for this tissue, compliance with the new limit, constitutes the main objective of radiation protection in the immediate years and more specifically in the area of interventional radiology. 7. The total number of workers monitored comprises all the workers, including those working in military and defence activities. ASN Report on the state of nuclear safety and radiation protection in France in 2023 107 • 01 • Nuclear activities: ionising radiation and health and environmental risks 01 05 15 08 11 04 14 06 07 13 AP 03 10 02 09 12
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