Italy does not currently produce energy through nuclear fission processes and has no plans to build nuclear power plants; however, radioactive materials capable of generating exposure to ionizing radiation are present in the radioactive waste produced by the previous nuclear program as well as in the structures and systems of nuclear plants subjected to decommissioning. The use of ionizing radiation sources continues, as in the rest of the world, to be carried out in medicine, industry and research.
No exposure to ionizing radiation, however modest, can be considered risk-free. For this reason, in any activity involving risks associated with ionizing radiation it is necessary to guarantee an appropriate system of protection for the individuals involved.
Radiation protection, or health protection against ionizing radiation, aims to preserve the health and well-being of workers, individuals making up the population and the population as a whole, reducing the risks that may derive from exposure to ionizing radiation connected to those human activities for which the use of ionizing radiation sources is justified in relation to the benefits deriving from them to society and its members. According to its objective, it also provides for the protection of the environment as regards the returns to humans.
In relation to radiation protection, ISIN carries out preliminary activities, technical assessments, control and surveillance activities in relation to both nuclear installations and the use of ionizing radiation sources (radionuclides and X-ray machines).
In particular, the Inspectorate carries out the investigations and issues to the competent ministries the opinions required by current legislation for the activities of use of ionizing radiation sources, with regard to radiation protection and the safe management of the sources themselves; carries out the assessments of the radiological impact on workers and individuals of the population as well as accident scenarios, as part of the authorization procedures relating to nuclear installations, carrying out its surveillance at nuclear installations and at all installations where subject activities are carried out to the legislative provisions of radiation protection.
The Inspectorate also carries out technical assessments and checks on the safety of sources; in the field of radiation protection, he prepares and adopts technical positions and opinions requested by public administrations and private entities and prepares guides.
The Inspectorate provides technical and regulatory support to the Civil Protection Authorities in the context of the interventions envisaged following radiological emergencies and specific situations of national importance, also by participating in Prefectural Commissions established by the competent Prefectures, with the carrying out of on-site inspections ; carries out and adopts, from the point of view of the radiation protection of workers and the population, technical investigations and opinions concerning the remediation and safety measures of sites contaminated by radionuclides.
The ISIN also carries out checks on the monitoring of environmental radioactivity in the areas adjacent to nuclear installations, by updating the data relating to the monitoring of radioactive effluent discharges from nuclear sites in normal operating and emergency conditions, taking care of their systematic collection, evaluation and publication.
It carries out control and surveillance activities regarding exposure, deriving from work activities, to particular natural sources of radiation subject to the legislative provisions of radiation protection.
The Inspectorate ensures the functions of National Contact Point in relation to the international control system, provided for by the Code of Conduct of the International Atomic Energy Agency (IAEA) on the subject of protection (safety) and security (security) on sources radioactive as well as on the system of controls on imports and exports of sealed radioactive sources between Member States of the IAEA in accordance with the supplementary Guidance. It participates in the activities of international organizations and European Union institutions and provides technical support for the development of national and international standards on radiation protection. Inspectorate experts participate in the Examination Commissions for registration in the list of names of qualified experts and authorized doctors, for the expression of the suitability judgment for the technical operation of nuclear plants.
ISIN ensures the surveillance activities of environmental radioactivity required by current legislation. Unless there are nuclear accidents (such as that of Chernobyl and Fukushima), radioactivity in the environment has a mainly natural origin and only a small part is of artificial origin.
Natural radioactivity is of cosmic origin (cosmic rays) and of terrestrial origin, due to the primordial radionuclides present in the earth's crust since its formation.
The main source of exposure of the population to natural radioactivity of terrestrial origin is represented by the decay products of radon, a radioactive gas generated in soils and rocks that accumulates in closed environments (homes, schools, workplaces). An additional source of exposure to natural radiation can derive from products or residues from certain industrial sectors where materials containing radionuclides of natural origin (Naturally Occurring Radioactive Material - NORM) are used.
Artificial radioactivity is generated by anthropogenic activities related to the production of nuclear energy, the use of radioactive sources in the medical-diagnostic, industrial and scientific research fields and the production of war material. In the environment, artificial radioactivity is largely due to atomic tests in the atmosphere of the 1960s and nuclear accidents, in particular that of Chernobyl in 1986 and that of Fukushima in 2011, which in any case affected Italy to an extremely extreme extent. marginal (Figure 1).
Control of environmental radioactivity
In our country, the control over environmental radioactivity is regulated by Legislative Decree 101/2020. The Ministry of Ecological Transition (formerly the Ministry of the Environment and Land and Sea Protection) exercises control over environmental radioactivity, while the Ministry of Health exercises control over food and beverages for human and animal consumption.
The set of controls is divided into national and regional surveillance networks. The regional networks are managed by the individual regions. The national networks are the national RADioactivity Surveillance Network - RESORAD, the ISIN alarm networks (REMRAD and GAMMA) and the alarm network managed by the Ministry of the Interior. To these must be added the local surveillance networks of the environmental radioactivity of nuclear plants, managed by the operators of the plants themselves, over which the ISIN performs the institutional control function.
RESORAD makes use of the radiometric surveys and measurements of the regional and provincial agencies for the protection of the environment of the National System for the Protection of the Environment (SNPA) and other bodies, institutes and bodies suitably equipped such as the Experimental Zooprophylactic Institutes.
ISIN performs the technical coordination functions of RESORAD, collects and disseminates the results of the measurements carried out, manages the new SINRAD web portal (National Information System on Radioactivity) within which a specific section containing data on radioactivity is envisaged. environmental products produced by RESORAD which are transmitted to the European Commission in compliance with current legislation and the Euratom Treaty.
The main objective of the network is to monitor the space-time trend of radioactivity in the matrices of the various environmental and food compartments according to guidelines that take into account the European Commission Recommendation 2000/473/Euratom.
In June 1998 the Italian national network was able to detect, through the recording of an anomalous presence of radioactivity in the air, an accident at the Spanish foundry of Algeciras, in which a source of Cesium-137 was melted. In March 2011, RESORAD detected the first traces of radioactivity in the environment, Iodine-131, following the accident at the Fukushima nuclear power plant (Figure 2) and the only one, for analytical sensitivity, capable of providing data in environmental and food matrices in the following days.
In order to ensure the homogeneity of the surveys, of the sampling and measurement methods, the RESORAD network manual has been drawn up, which collects all the information on the structure, sampling plans, sampling and measurement methods and the flow of data of the network itself. In addition to the manual, additional reference documents, survey results and guidelines relating to issues relating to the protection of the population from exposure to ionizing radiation are available.
Radon, in the absence of accidental events, represents the main source of exposure to radioactivity of natural origin for the population. The World Health Organization, through the International Agency for Research on Cancer (IARC) has evaluated the carcinogenicity of radon since 1988 and has included it in Group 1 of human carcinogens. Estimates consolidated for decades worldwide attribute radon to the second cause of lung cancer after tobacco smoke with a risk proportional to the concentration. Radon is a radioactive gas produced by the decay of uranium, naturally present in soils and rocks with different concentrations depending on their composition. The radon emitted from the soils, in a diversified way according to the geology of the territory, is present everywhere in the air we breathe but, while outdoors it disperses and does not reach high concentrations, in closed places (indoor radon - homes, schools, work, buildings in general) accumulates reaching, in some cases, concentrations such as to involve a high risk for health. Some building materials and water are secondary sources of radon. Additional causes, such as the construction methods of buildings, with particular reference to the ground connection, and the living habits of the occupants, can affect the presence of radon. All these factors, all highly variable, contribute to a highly diversified spatial distribution of indoor radon concentration on the territory, mainly governed by local geolithology. Even between single buildings similar and close to each other, it is possible to find a strong difference in the concentration of radon.
In 2020, the Legislative Decree of 31 July 2020, n. 101 of implementation of the Directive 2013/59 / EURATOM of the European Council, which introduces important innovations in the field of prevention and protection from ionizing radiation, adapting the national legislation to what is foreseen in the European context.
For the first time in the context of protection from exposure to radon, residential environments (homes) are included in the standard, framed as existing exposure situations like workplaces. The maximum reference levels, in terms of the average annual value of the concentration of radon activity in the air, are set at 300 Bq m-3 for workplaces and for existing homes, and at 200 Bq m-3 for homes. built after 31 December 2024. A reference level in terms of annual effective dose of 6 mSv is also set for workplaces.
The provisions relating to exposure to radon in the workplace, apply in underground workplaces, in semi-underground workplaces or located on the ground floor within the priority areas (in which it is estimated that the average annual concentration of radon in the air exceeds the reference level in a significant number of buildings), in specific types of workplaces identified by the National Radon Action Plan, and in spas.
In these workplaces the operator is required to carry out the measurement of radon using recognized dosimetry services and, in the event that the aforementioned reference level is exceeded, to implement corrective measures to reduce the concentration to the lowest level. low reasonably achievable. In this context, Legislative Decree no. 101/2020 introduces for the first time the professional figure of the expert in radon remediation interventions, who must be in possession of specific requirements on the subject. If, despite the application of corrective measures, the radon concentration remains above the reference level, the operator must carry out the assessment of the annual effective doses using the radiation protection expert. In the event that the results of the assessments are higher than the reference level in terms of effective dose equal to 6 mSv / year, the operator is required to apply certain measures provided for in Title XI "Exposure of workers".
The renewed regulatory framework also provides for the implementation of the National Action Plan for radon, as part of which to identify the strategies, criteria and methods of intervention to prevent and reduce long-term risks due to exposure to radon. .
Among the functions that the new decree assigns to ISIN in the matter of radon, there are that of the collection and recording of data produced at national level by the regional and provincial agencies for the protection of the environment (ARPA APPA) and by dosimetry services, all the RADON section of the new SINRAD (National Information System on Radioactivity) web portal. Furthermore, ISIN ensures support for the competent ministries in the context of the National Action Plan for radon.
ISIN also carries out monitoring and control of indoor radon gas through its own measurement surveys.
In the 90s the ISIN, then ENEA-DISP, and the Istituto Superiore di Sanità (ISS), in collaboration with the regional health departments and with the Regional Reference Centers for the Control of Environmental Radioactivity, now merged into the ARPA APPA, carried out a national survey on the concentration of radon in about 5,000 homes, from which the national average concentration of radon was estimated to be 70 Bq m-3, a value higher than the European average of about 55 Bq m-3 and the world one equal to about 40 Bq m-3. The average concentrations measured by the Regions and the Autonomous Provinces showed values ranging from about 25 Bq m-3 to about 120 Bq m-3. Nationally, it is estimated that in about 2% of homes the average annual concentration of radon is higher than 300 Bq m-3.
The estimates of the average concentrations of radon in the Regions and Autonomous Provinces and the estimated average value for Italy from the 1990s survey still represent a national reference. In addition to the ISIN, the Regions, through the ARPA APPA, subsequently carried out many other surveys, not only in homes, but also in schools and workplaces, carrying out tens of thousands of measurements of the average annual concentration of radon. . Taking housing as a reference, however, it should be noted that the percentage of homes measured is rather small compared to the total number of homes present on the national territory.
The regional surveys were carried out using different methods and criteria which, although valid for the purposes of the classification of territorial areas, make a direct comparison complicated. In order to undertake a process of harmonization of data at national level, also with the aim of representing in a more homogeneous way among the Regions and Autonomous Provinces the spatial variability of the radon concentration and to make the information usable, the ISIN started a collection of the estimates of the average concentrations of radon in the Italian municipalities processed by the ARPA APPA and, for Lazio, by the ISIN itself.
At present, the information received and the data on average radon concentrations are available for 4,241 municipalities, with a territorial coverage corresponding to 53% of Italian municipalities, but are fragmented and concentrated mostly in the regions of northern and central Italy. Furthermore, their examination shows certain differences in the methods of carrying out radon measurement surveys essentially attributable to two main types of approaches in carrying out measurements in homes: the first for those located exclusively or mainly on the ground floor; the second for those located on different floors. The estimates of the municipal average concentrations obtained from measurements carried out exclusively or mainly on the ground floor concern over 80% of the municipalities being assessed and over 40% of all Italian municipalities.
Based on this information, ISIN has drawn up a thematic map of the municipal average concentrations of radon. The values shown in the thematic map should be consulted taking into account the information returned by the spatial query of the municipal units regarding the type of data used or estimates made. It is also important to remember that the high variability of the radon concentration between the different houses, even in the same Municipality, does not allow to use the value of the municipal average as a reliable indicator of the value of the radon concentration in a specific house located in the same Municipality. . The only way to have a reliable estimate of the radon concentration in a specific home is to carry out a direct measurement, which costs approximately, excluding any inspections, a few tens of euros.
Further activities of collection and communication of radon data carried out by ISIN are those carried out as a contact point for Italy within the European Atlas of Natural Radiation - European Indoor Radon Map project, where the Inspectorate ensures support to the European Commission for the elaboration of the spatial statistics of the data required by the Joint Research Center, aimed at the creation and continuous updating of the map of harmonized radon levels at European level.
Further information on radon is contained in the dedicated chapter within the ISIN Report The Surveillance of Environmental Radioactivity in Italy 2020.
The radiometric laboratories of the ISIN carry out measurement and investigation activities in support of the tasks and institutional activities of the Inspectorate in the field of environmental radioactivity control.
The laboratories are equipped to carry out investigations aimed at the radiometric characterization of specific sites of interest, the determination of the state of the environment, through measurements performed on environmental samples and on specific materials that may represent a source of contamination. The laboratory facility is built and authorized to receive and process samples with low activity concentrations.
The main activities are addressed:
· To technical-scientific support in the field of surveillance of nuclear installations, carried out through investigations around nuclear sites and control measures on effluents;
· To the characterization of industrial materials containing radionuclides of natural origin (NORM), with particular regard to the Reclamation Sites of National Interest (SIN) in which there are disused plants and landfills containing massive quantities of NORM;
· Technical-scientific support in cases of radiological emergencies, for the purpose of assessing the state of the environment and the health protection of the population and workers.
The laboratories also provide support to public administrations and judicial authorities in the field of radioactivity in the environment and in food and in the preparation of remediation and intervention plans in the context of contaminated sites with the presence of radioactive materials. To carry out the tasks described, the laboratories are able to perform gamma spectrometry and radiochemistry measurements (alpha spectrometry and beta counts) for non-gamma emitting radionuclides.
The Inspectorate is also equipped with a laboratory dedicated to measuring the concentration of radon gas in the air, which is mainly used for indoor investigations in places of public interest (schools, workplaces, etc.) or in private homes.
ISIN also manages the Laboratory for measuring radioactivity in atmospheric particulate matter, called ITL10, of the International Monitoring System (IMS), on behalf of the Ministry of Foreign Affairs and International Cooperation, in compliance with the Treaty on total ban of the United Nations Nuclear Experiments (CTBT).
The Treaty provides for a ban on all nuclear tests and for its entry into force it must be signed and ratified by at least 44 main member states of the 196 total. Currently, several states have not yet signed or ratified the treaty.
The International Monitoring System consists of a set of detection networks: seismic, infrasonic, hydroacoustic and radioactivity in the atmosphere.
The ITL10 laboratory is one of 16 laboratories strategically distributed on all continents capable of carrying out highly specialized and sensitive measurements of radioactivity in atmospheric particulate matter and which represent the highest technology for this type of measurement. The analyzes are able to detect and characterize traces of radionuclides in the air due to a nuclear event, wherever in the world it may occur, also estimating the date of occurrence. The additional information available to the International Monitoring System also makes it possible to establish its origin. The ITL10 laboratory was officially certified on 14 December 2016.