Radon mapping in Piedmont (North-West Italy): a radio-geo-lithological approach

Background: In this work a radon mapping method implemented in Piedmont, an Italian Region in the Northern part of the country, is presented and discussed. Methods: The method is based on a "mixed approach", combining together an experimental approach, based on a large set of experimental radon measurements performed with nuclear track detectors, and an empirical model, based on the geo-lithological characteristics of soils and rocks. This approach was named as "radio-geo-lithological" because the identification of geo-lithological units was defined considering not only the usual geological classification of the territory but also the radioactivity content of the most widespread rocks and soils of Piedmont. Results and Conclusion: This method allowed to classification of all municipalities of Piedmont (1181), thus permitting the identification of the Radon Priority Areas, a provision required by the new Italian law (Legislative Decree 101/2020), implementing the European Basic Safety Standards (Euratom Directive 59/2013)

The Underground Karst Laboratories of Bossea Cave: more than 50 years of collaborations and research

The Bossea Cave, Piedmont, is the first show cave of Italy, opened to the pubblic in 1874. The cavity develops for about 2800 m in the tectonic contact between the Middle Triassic carbonate rocks, and Permotriassic metavolcanics. A main water collector (Mora River) and several water supplies are present inside the cave. Different underground karst laboratories to study hydrogeology, climatology, radon activity and subterranean biology are located in the cave, managed by a multidisciplinary group from Struttura Operativa Bossea C.A.I., DIATI - Politecnico di Torino, and Biologia Sotterranea Piemonte - Gruppo di Ricerca, working together with ARPA Piemonte, ARPA Valle d’Aosta and INRiM. The first laboratory was built in 1969 by volunteers of Gruppo Speleologico Alpi Marittime; over the years, more than 60 sophisticated data logger and sensors were positioned in different touristic and non-touristic areas of the cavity, thanks to the contribution of volunteers, associations and public authorities. The hydrogeological research concerns both the flow hydrodynamics and the water geochemistry. Mora River is continuously monitored since 1983, and water sampling under different hydrodynamic conditions are carried out to chemical analyses. Tracing experiments from surface watercourses to spring waters have been done to understand the recharge area of the karst aquifer. Different environmental parameters are continously monitored in the cave, such as air circulation, air, rock and water temperature, relative humidity, air and water CO2 concentration. Rainfall and snowmelt are monitored too, above and inside the cave, evidencing the infiltration events. Radon (222Rn) derive from the radioactive 238U decay, spreading rapidly into the cave atmosphere and waters. The gas exchange dynamics between rock, water and atmosphere are studied, testing also different equipments for the radon monitoring. Subterranean biology investigations started in 1970, discovering over the years more than 125 different species of hypogeal fauna in the system (75 in the last 30 years), of which four endemics, and six new species to science. A strong contribution to the dissemination of the results was done by the operators, organizing training courses, activities for schools, environmental education, seminars, conferences, and online updates. The fundamental collaboration with the cave managers has allowed to carry out innovative research in this cavity, and to disseminate the discoveries to a not purely scientific or speleological pubblic. Research allows a greater knowledge of the peculiarities and problems of the system, considering the cave not only a tourist attraction, but an important ecosystem to preserve

European Atlas of Natural Radiation

Natural ionizing radiation is considered as the largest contributor to the collective effective dose received by the world population. The human population is continuously exposed to ionizing radiation from several natural sources that can be classified into two broad categories: high-energy cosmic rays incident on the Earth’s atmosphere and releasing secondary radiation (cosmic contribution); and radioactive nuclides generated during the formation of the Earth and still present in the Earth’s crust (terrestrial contribution). Terrestrial radioactivity is mostly produced by the uranium and thorium radioactive families together with potassium. In most circumstances, radon, a noble gas produced in the radioactive decay of uranium, is the most important contributor to the total dose. This Atlas aims to present the current state of knowledge of natural radioactivity, by giving general background information, and describing its various sources. This reference material is complemented by a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources. It is a compilation of contributions and reviews received from more than 80 experts in their field: they come from universities, research centres, national and European authorities and international organizations. This Atlas provides reference material and makes harmonized datasets available to the scientific community and national competent authorities. In parallel, this Atlas may serve as a tool for the public to: • familiarize itself with natural radioactivity; • be informed about the levels of natural radioactivity caused by different sources; • have a more balanced view of the annual dose received by the world population, to which natural radioactivity is the largest contributor; • and make direct comparisons between doses from natural sources of ionizing radiation and those from man-made (artificial) ones, hence to better understand the latter.JRC.G.10-Knowledge for Nuclear Security and Safet

European Atlas of Natural Radiation

Natural ionizing radiation is considered as the largest contributor to the collective effective dose received by the world population. The human population is continuously exposed to ionizing radiation from several natural sources that can be classified into two broad categories: high-energy cosmic rays incident on the Earth’s atmosphere and releasing secondary radiation (cosmic contribution); and radioactive nuclides generated during the formation of the Earth and still present in the Earth’s crust (terrestrial contribution). Terrestrial radioactivity is mostly produced by the uranium and thorium radioactive families together with potassium. In most circumstances, radon, a noble gas produced in the radioactive decay of uranium, is the most important contributor to the total dose.This Atlas aims to present the current state of knowledge of natural radioactivity, by giving general background information, and describing its various sources. This reference material is complemented by a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources. It is a compilation of contributions and reviews received from more than 80 experts in their field: they come from universities, research centres, national and European authorities and international organizations.This Atlas provides reference material and makes harmonized datasets available to the scientific community and national competent authorities. In parallel, this Atlas may serve as a tool for the public to: • familiarize itself with natural radioactivity;• be informed about the levels of natural radioactivity caused by different sources;• have a more balanced view of the annual dose received by the world population, to which natural radioactivity is the largest contributor;• and make direct comparisons between doses from natural sources of ionizing radiation and those from man-made (artificial) ones, hence to better understand the latter.Additional information at: https://remon.jrc.ec.europa.eu/About/Atlas-of-Natural-Radiatio

Evaluation of the Terrestrial ²²²Rn Flux from ²¹⁰Pb Deposition Measurements

The study of the 222Rn terrestrial flux (Bq/(m2·s) or Bq/(m2·h)) is a complex issue involving both radiation-protection and environmental aspects. While the radiation-protection aspects are quite obvious—it has been well known for several decades that soil is the major source of indoor radon—environmental issues such as the correlation with conventional pollutants (PM2.5, PM10, NOX, etc.) and the use of radon for the esmation of the natural component of GHG (CO2) emissions are relatively less discussed in spite of their growing relevance. In this work we present a method for the estimation of the average value of 222Rn flux from HPGe γ-spectrometry 210Pb measurements performed on wet and dry deposition samples gathered monthly in the period 2006–2020. The results obtained with this technique give an average radon flux in the period Φ = 57 ± 27 Bq/(m2·h), the value of which is comparable with those coming from other methods and direct radon flux measurements as well. The method can thus be used to obtain a worldwide map of the radon flux

Main results of the international intercomparison of passive radon detectors under field conditions in Marie Curie's tunnel in Lurisia (Italy)

In recent years a large number of radon intercomparison exercises has been organized; most of them took place in radon chambers, in reference atmosphere of the parameter to control (i.e. radon gas) under temperature, humidity and atmospheric pressure stable conditions. In 2014, in the tunnel belonging to the Lurisia spas complex (Lurisia, Piedmont, Italy), with natural high concentrations of uranium and radon gas, an intercomparison exercise has been held to give to radon measurement services and laboratories the possibility to test their passive systems under field conditions, which are less controlled and much more challenging. The response of laboratories was very positive: 46 participants from 10 European countries and 3 non-European countries. Generally about 80% of results of participants were considered acceptable even if it was observed a global trend of a substantial underestimation of the actual radon concentration

Metrological aspects of international intercomparison of passive radon detectors under field conditions in Marie Curie's tunnel in Lurisia

In 2014, an intercomparison exercise of passive radon detectors under field conditions in the Marie Curie's tunnel belonging to the Lurisia spas complex (Lurisia, Piedmont, Italy) has been held. Radon activity concentration in the tunnel was measured with six radon active monitors, previously calibrated at ENEA-INMRI facilities. In the present paper, a synthesis of the metrological aspects of the intercomparison is given. Indeed particular attention was paid to metrological characterization of radon monitors and their response upon ambient conditions. Correction factors have been defined to be applied when measurements are performed in severe environmental conditions. In particular, it has been found that monitors are particularly sensitive to the effect of air density: the AlphaGUARD (AG-SAPHYMO, GmbH) efficiency decreases with the air density, while for the MR1 PLUS (Tesys, Italy), the opposite applies. When the reference monitors were placed into the Marie Curie's tunnel, to the recorded average radon concentrations correction factors were applied. After the correction the difference between data coming from AG and MR1 PLUS is within the 1.7%

Chapter 5: Radon

Natural ionising radiation is considered the largest contributor to the collective effective dose received by the world’s population. Man is continuously exposed to ionising radiation from several sources that can be grouped into two categories: first, high-energy cosmic rays incident on the Earth’s atmosphere and releasing secondary radiation (cosmic contribution); and, second, radioactive nuclides generated when the Earth was formed and still present in its crust (terrestrial contribution). Terrestrial radioactivity is mostly produced by the uranium (U) and thorium (Th) radioactive families together with potassium (40K), a long-lived radioactive isotope of the elemental potassium. In most cases, radon (222Rn), a noble gas produced by radioactive decay of the 238U progeny, is the major contributor to the total dose. This European Atlas of Natural Radiation has been conceived and developed as a tool for the public to become familiar with natural radioactivity; be informed about the levels of such radioactivity caused by different sources; and have a more balanced view of the annual dose received by the world’s population, to which natural radioactivity is the largest contributor. At the same time, it provides reference material and generates harmonised data, both for the scientific community and national competent authorities. Intended as an encyclopaedia of natural radioactivity, the Atlas describes the different sources of such radioactivity, cosmic and terrestrial, and represents the state-of-the art of this topic. In parallel, it contains a collection of maps of Europe showing the levels of natural sources of radiation. This work unfolds as a sequence of chapters: the rationale behind; some necessary background information; terrestrial radionuclides; radon; radionuclides in water and river sediments; radionuclides in food; cosmic radiation and cosmogenic radionuclides. The final chapter delivers the overall goal of the Atlas: a population-weighted average of the annual effective dose due to natural sources of radon, estimated for each European country as well as for all of them together, giving, therefore, an overall European estimate. As a complement, this introductory chapter offers an overview of the legal basis and requirements on protecting the public from exposure to natural radiation sources. In Europe, radiation has a long tradition. Based on the Euratom Treaty, the European Atomic Energy Community early established a set of legislation for protecting the public against dangers arising from artificial ('man-made') ionising radiation, but this scope has since been extended to include natural radiation. Indeed, the recently modernised and consolidated Basic Safety Standards Directive from 2013 contains detailed provisions on the protection from all natural radiation sources, including radon, cosmic rays, natural radionuclides in building material, and naturally occurring radioactive material