On the other hand, there is no overall monitoring system able to provide an exhaustive picture of the doses received by the population as a result of nuclear activities. Consequently, compliance with the population exposure limit (effective dose set at 1 mSv per year) cannot be controlled directly. However, for BNIs, there is detailed accounting of radioactive effluent discharges and radiological monitoring of the environment is implemented around the installations. On the basis of the data collected, the dosimetric impact of these discharges on the populations in the immediate vicinity of the installations is then calculated using models simulating transfers to the environment. The dosimetric impacts vary, according to the type of installation and the lifestyles of the chosen reference groups, from a few microsieverts to several tens of microsieverts per year (μSv/year). An estimation of the doses from BNIs is presented in Table 4 which shows, for each site and per year, the estimated effective doses received by the most exposed reference population groups. There are no known estimates for nuclear activities other than BNIs owing to the methodological difficulties involved in identifying the impact of these facilities and in particular the impact of discharges containing small quantities of artificial radionuclides resulting from the use of unsealed radioactive sources in research or biology laboratories, or in nuclear medicine units. To give an example, the impact of hospital discharges could lead to doses of a several tens of microsieverts per year for the most exposed persons, particularly for certain jobs in sewage networks and wastewater treatment plants (IRSN studies 2005 and 2015). Legacy situations, such as atmospheric nuclear tests and the Chernobyl accident (Ukraine), can make a marginal contribution to population exposure. Thus, the exposure due to fall-out from nuclear tests is currently estimated at 2.3 μSv/year in metropolitan France (1.3 for strontium-90 and 1 μSv/year for carbon-14; exposure linked to caesium-137 cannot be distinguished from that due to fall-out from the Chernobyl accident). The overall exposure due to fall-out from nuclear tests and the Chernobyl accident is 46 μSv/year for people living in areas of high persistence of this fall-out and 9.3 μSv/year for people over the rest of the country, that is to say an average dose per inhabitant of 12 μSv/year for the country as a whole (IRSN 2021). With regard to the fall-out in France from the Fukushima Daiichi NPP accident, the results published for France by IRSN in 2011 showed the presence of radioactive iodine at very low levels, resulting in estimated effective doses for the populations of less than 2 μSv/year in 2011. 3.2.2 Exposure of the population to Naturally Occurring Radioactive Materials Exposure due to natural radioactivity in drinking water The results of the monitoring of the radiological quality of the tap water distributed to consumers carried out by the Regional Health Agencies (ARS) between 2008 and 2009 (DGS/ASN/IRSN report published in 2011) showed that 99.83% of the population receives tap water whose quality complies at all times with the total indicative dose of 0.1 mSv/year set by the regulations. This generally satisfactory assessment also applies to the radiological quality of bottled water produced in France (DGS/ASN/IRSN report published in 2013). Since 2019, measurement of the radon content of tap water and bottled water has been compulsory. To assist the introduction of this new provision, an instruction was drawn up in consultation with ASN and issued in 2018 to the ARS by the General 11. Order of 26 February 2019 relative to the methods of managing radon in certain buildings open to the public and dissemination of information to the people frequenting these buildings. Directorate for Health – DGS (ASN opinion 2018-AV-0302 of 6 March 2018 on radon management procedures in the sanitary control of water intended for human consumption). Exposure due to radon In France, the regulations relative to management of the radon risk, put in place in the early 2000’s for certain Public Access Buildings (PAB), were extended to certain workplaces in 2008. In 2016, radon was introduced into the indoor air quality policy. Transposition of Council Directive 2013/59/Euratom of 5 December 2013 laying down Basic Safety Standards for protection against the dangers arising from exposure to ionising radiation led to the amending of the provisions applicable to radon since 1 July 2018. A reference level of 300 Bq/m3 has been introduced. It is applicable to all situations, which enables the health risk associated with radon to be managed with an allinclusive approach. The regulations have been extended with provisions concerning the three main sectors: ∙ With regard to the general public, a significant improvement has been introduced: radon is now included in the information to be provided to buyers and tenants of real estate situated in areas where the radon potential could be the highest. ∙ In workplaces, the regulations have been extended to cover professional activities exercised on ground floor levels (only activities carried out in basements were concerned until now) and in certain specific workplaces. Whatever the radon potential zone in which the workplace is situated, radon must be considered in the risk assessment. A radon measurement can be carried out in this context if necessary. If there is a risk of reaching or exceeding the reference level of 300 Bq/m3, the employer must take action to reduce the radon activity concentration. If the action turns out to be ineffective, the employer must identify potential “radon zones” from the moment the dose received by the workers exceeds 6 mSv/year, assuming the workers are present constantly, and then implement radiation protection measures if necessary according to the level of exposure of the workers. ∙ In some PAB, the radon management methods have been adjusted, more specifically with the inclusion of day-care facilities for children under 6 years of age and an obligation to inform the public by displaying the radon measurement results(11). The type of action to be taken if the reference level of 300 Bq/m3 is exceeded is graded according to the measurement results: simple corrective actions for radon concentrations between 300 and 1,000 Bq/m3, expert assessment and remediation work if the corrective actions do not reduce the radon concentration to below the reference level or if the measurement results equal 1,000 Bq/m3 or higher. ASN issues the approvals to the organizations that measure radon in certain PAB. Fifty-two approvals were issued in 2022 (44 of level N1A and 8 of level N2), bringing the total number to 83. The list is available in the ASN Official Bulletin at asn.fr. The data transmitted to ASN each year by these organisations in their annual report concern the measurements taken in the PAB that are subject to monitoring of exposure of the public, defined in Article D. 1333‑32 of the Public Health Code (level N1A approval). The analysis of the data over the last six measuring campaigns shows a gradual reduction in the number of buildings exceeding the reference level of 300 Bq/m3 and the level of 1,000 Bq/m3 under the initial and ten-yearly measurements, which means a reduction in the exposure of the public frequenting these buildings (see Diagram 3). During the last campaign of 2021‑2022, the radon activity concentration was less than the reference level of 300 Bq/m3 in 84% of the teaching institutions measured, in 91% 112 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
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