We report a high sensitivity study of actinides content in water and sediment matrices performed for the first time along the Garigliano river, near the nuclear power plant currently undergoing decommissioning, and in the marine environment surrounding the river mouth up to a depth of 100 m. Ultrasensitive accelerator mass spectrometry measurements were carried out to estimate the absolute values of 236U, 238U, 239Pu, and 240Pu concentrations and 236U/238U, and 239Pu/240Pu ratios. The accuracy of the measurements and the spatial distribution of the radionuclides enable us to discriminate the anthropogenic from the natural radionuclide’s contribution to the environmental radioactivity. The results indicate that the contribution to the anthropogenic contamination of past power plant operations is, in most of the examined environmental compartments, negligible compared to fallout. High resolution γ-ray spectrometry measurements for 137Cs and 40K show interesting correlations with the actinides results.

Tuscany, with its mixed geology, offers a great variety of stones that are used to build entire villages. In this paper, two of these building materials are considered: Rosso Ammonitco and Pietra Serena. In particular, the activity concentration of 226 Ra, 232 Th and 40 K have been analysed in order to estimate the value of the gamma index. In addition to this, the X-ray fluorescence spectroscopy has been carried out to obtain a chemical characterization of the stones. Although these kind of stones are not subjected to radiological characterization, the approach used was the one reported in Radiation Protection 112, also implemented in the Italian Legislative Decree 101/2020, because of their lithographical peculiarity and their employment in construction.

The reaction Be(p7,γ)8B plays an important role in the Sun, where it determines the high energy component of the solar neutrino spectrum. The importance of this reaction triggered several experiments over the last decades. A combined analysis of their results produces an overall consistent picture for the energy dependence of the cross section, while an inflation of the quoted uncertainties is needed to accommodate the observed discrepancy in the absolute scale of the different data sets. The origin of this discrepancy needs to be understood for a reliable estimate of the astrophysical rate of Be(p7,γ)8B and its uncertainty. In addition, there is a question about possible common systematic effects, considering that all measurements performed so far share the same experimental approach, i.e. an intense proton beam impinging on a Be7 radioactive target. A direct measurement using a radioactive Be7 ion beam on a pure hydrogen gas target has been since long envisioned as a way to improve the situation. First attempts showed the feasibility of an experiment based on the use of a recoil mass separator to collect reaction products with high efficiency, but failed to reach a useful statistical significance because of the low beam intensity. Here we present the results obtained using the intense Be7 beam available at the Tandem Accelerator Laboratory at CIRCE, University of Campania, Italy coupled to the recoil mass separator ERNA in the energy range Ecm=367 to 812 keV. Our results are compatible only with a part of previous measurements, in particular those indicating a low value of the astrophysical S-factor at zero energy S17, thus exacerbating the discrepancy between existing measurements. The analysis of our data together with the results of previous data provides an estimate S17(0)=20.0±0.8 eV⋅b, where systematic uncertainties are inflated to obtain a statistically compatible data set.

The possible damaging effects on human health of inhaled radon and its decay products are of interest to workers and the public. In particular, radon in thermal environments often occurs in high concentrations. Therefore, investigations and remedial actions are important to reduce activity concentration values and associated risk. This work concerns the analysis of two surveys of radon gas activity concentration carried out in 2006/2007 and 2019/2020 at twenty thermal spas on the island of Ischia (Italy). Annual measurements were carried out in workplaces located in the basement and ground floor using passive CR-39 detectors. In the spas involved in both surveys, the effectiveness of the remedial actions, implemented by the owners, was assessed obtaining an average percentage reduction of 74%. Considerations were made about the annual effective dose, and the location of the spas taking into account the geological setting of the volcanic nature of the island.

Using Monte Carlo (with Geant4) and COMSOL simulations, the authors have defined a useful tool to reproduce the alpha spectroscopy of 222Rn, 220Rn and their ionized daughters by measurement systems based on electrostatic collection on a silicon detector, inside a metallic chamber. Several applications have been performed: (i) simulating commercial devices worldwide used, and comparing them with experimental theoretical results; (ii) studying of realization of new measurement systems through investigation of the detection efficiency versus different chamber geometries. New considerations and steps forward have been drawn. The present work is a novelty in the literature concerning this research framework.

For a healthy indoor environment, it is important to understand which materials and factors favor the generation of high levels of indoor radon. A preliminary multivariate statistical analysis was carried out on two datasets concerning indoor radon and building materials in the Campania Region using Principal Component Analysis (PCA) and the k-means partitional analysis technique. A total of 13 parameters related to building materials were used. The results show the greater contribution of building materials of volcanic origin to the concentration of indoor radon and thoron activity and the different influence of the parameters of the 31 materials analyzed. The same analyses applied to the indoor radon values of 694 rooms in the Campania Region were equally effective in assessing the structural characteristics of indoor environments that most influence indoor radon levels. The study provided an effective assessment of the influence on radon activity of several environmental parameters, which are often not adequately considered.

Radiological characterization of tuff of Ciglio area in Ischia Island was performed to assess the potential radiological hazard associated with its use. For this purpose, high resolution gamma-ray spectroscopy was used. In five green tuff samples was measured the activity concentration of natural gamma-ray emitting radionuclides 226Ra, 232Th and 40K so, the mean gamma index was calculated. The mean value of the gamma index resulted lower than the reference level and it meets the dose criterion for the safety use of green tuff as building material.

222Rn gas represents the major contributor to human health risk from environmental radiological exposure. In confined spaces radon can accumulate to relatively high levels so that mitigation actions are necessary. The Italian legislation on radiation protection has set a reference value for the activity concentration of radon at 300 Bq/m3. In this study, measurements of the annual radon concentration of 62 bank buildings spread throughout the Campania region (Southern Italy) were carried out. Using devices based on CR-39 solid-state nuclear track detectors, the 222Rn level was assessed in 136 confined spaces (127 at underground floors and 9 at ground floors) frequented by workers and/or the public. The survey parameters considered in the analysis of the results were: floor types, wall cladding materials, number of openings, door/window opening duration for air exchange. Radon levels were found to be between 17 and 680 Bq/m3, with an average value of 130 Bq/m3 and a standard deviation of 120 Bq/m3. About 7% of the results gave a radon activity concentration above 300 Bq/m3. The analysis showed that the floor level and air exchange have the most significant influence. This study highlighted the importance of the assessment of indoor radon levels for work environments in particular, to protect the workers and public from radon-induced health effects.

This is the first paper to report a potential map of radon (222Rn) distribution in the Campania region of southern Italy, using the geostatistical kriging interpolation method using QGIS® software. The response variable is the 222Rn indoor measurements, whereas proxy variables used as predictors are: geology, faults, soils permeability, meteorological/climatic parameters, 238U distribution, 222Rn emanation coefficients and exhalation rates, 226Ra in building materials and gamma dose rate in dwellings. The map shows high radon potential areas in correspondence to the main volcanic centres and the faults network of the region. The map is a useful instrument to identify radon-prone areas and evaluate radon risk level for the population.

The study concerns the analysis of 220Rn (thoron) recorded in the surface soil in two sites of the Campi Flegrei caldera (Naples, Southern Italy) characterized by phases of volcanic unrest in the seven-year period 1 July 2011–31 December 2017. Thoron comes only from the most surface layer, so the characteristics of its time series are strictly connected to the shallow phenomena, which can also act at a distance from the measuring point in these particular areas. Since we measured 220Rn in parallel with 222Rn (radon), we found that by using the same analysis applied to radon, we obtained interesting information. While knowing the limits of this radioisotope well, we highlight only the particular characteristics of the emissions of thoron in the surface soil. Here, we show that it also shows some clear features found in the radon signal, such as anomalies and signal trends. Consequently, we provide good evidence that, in spite of the very short life of 220Rn compared to 222Rn, both are related to the carrier effect of CO2, which has significantly increased in the last few years within the caldera. The hydrothermal alterations, induced by the increase in temperature and pressure of the caldera system, occur in the surface soils and significantly influence thoron’s power of exhalation from the surface layer. The effects on the surface thoron are reflected in both sites, but with less intensity, the same behavior of 222Rn following the increasing movements and fluctuations of the geophysical and geochemical parameters (CO2 flux, fumarolic tremor, background seismicity, soil deformation). An overall linear correlation was found between the 222−220Rn signals, indicating the effect of the CO2 vector. The overall results represent a significant step forward in the use and interpretation of the thoron signal.

In this paper, an in-depth and systematic study of the radiological characterization of three types of Puglia region natural limestones (Pietra Leccese, Pietra Mazzara and Carparo) was carried out. The investigation was performed by XRF spectroscopy for a chemical analysis, and gamma spectroscopy of the specific activity concentration of natural radionuclides 226Ra, 232Th, and 40K. Although the limestone does not fall within the category included by Italian Legislative Decree 101/2020, the gamma index was calculated using the results of the gamma spectroscopy measurements. For Pietra Mazzara and Carparo stones, the gamma index was found to be less than the reference value; conversely Pietra Leccese was found to be higher. To obtain a more complete evaluation of the external exposure, radium equivalent activity and external radiation hazard were calculated for all analyzed stones. The results suggest the need to broadly consider the radiological risk for these stones, and for limestone more generally, when used as a building material.

The characterization of natural radioactivity content in thirty-one natural building materials representative of the Campania region (South Italy) was carried out. High resolution gamma-ray spectrometry for the determination of the Ra-226, Th-232 and K-40 activity concentrations was used. Commonly-used radiation hazard indexes were computed to evaluate the human exposure to gamma-radiation. The results are compared to limit values established by the 2013/59/Euratom Directive and by UNSCEAR: the comparison proves the high natural radioactivity content and the radiation exposure hazard coming from some samples of volcanic origin. The emanated fraction and the exhalation rate of the Rn-222 and of the Rn-220 from the investigated materials were also measured with the alpha-spectrometry of the ionized radon daughters. This study is justified by the ever-growing public concern about radon risk associated to building materials from Campania region, locally widely used and exported worldwide. The results show interesting differences about the radioactivity content and the capacity to generate radon, among the different materials. This work contributes to enriching knowledge about natural radioactivity in natural building materials used in Italy. (C) 2020 Elsevier Ltd. All rights reserved.

This is a seven-year study (1/7/2011-31/12/2017) of radon monitoring at two sites of Campi Flegrei caldera (Neaples, Southern Italy) that in the last 70 years experienced repeated phases of volcanic unrest. The sites are equipped with devices for radon detection, based on the spectrometry analysis of the α-particles of radon daughters. A hybrid method, as combination of three known methods, is applied for the identification of residuals (anomalies) and trends of the time series of Radon. The results are compared with the following indicators of current caldera unrest: the tremor caused by the major fumarolic vent registered by a seismic station; the cumulative of background seismicity; the maximum vertical deformation acquired by GPS networks during the current phase of uplift; the temperature-pressure of the hydrothermal system estimated based on gas geo-indicators. The comparisons show strong correlation among independent signals and suggest that the extension of the area affected by current Campi Flegrei crisis is larger than the area of seismicity and of intense hydrothermal activity from which the radon stations are 1–4 km away. These results represent an absolute novelty in the study of a such calderic area and mark a significant step forward in the use and interpretation of the radon signal.

The interest in the measurement of thoron (220Rn) activity concentration in air has recently increased, with the attention for the development of standards useful for the calibration of measuring instruments. Due to its short half-life (55.8 s), consolidated techniques for the realization and the use of controlled atmospheres of radon (222Rn) are not effective in the case of thoron. New adequate methodology are required. A method for the measurement of the thoron reference activity based on the direct detection of the alpha particles produced by the decay of 220Rn, from natural samples containing 232Th, is here proposed. The possibility of observing an acceptable spectrum is entrusted to the realization of measurement chambers small enough to reduce as much as possible the energy loss of the alpha particles before they reach the Silicon detector. Such a chamber was realized and used with a known thoron atmosphere in a controlled environment. The experimental results are compared with those obtained from the simulation with the Monte Carlo method: (i) the alpha spectra coming directly from thoron atoms exhibit similar shape with a linear trend plus an exponential trend on the left side of the 220Rn peak, depending from the distance between source and detector; (ii) the corresponding 220Rn detection efficiency values are compatible considering the uncertainties. An investigation was conducted to study the shape of the 220Rn spectra vs the different volume of chambers, through Monte Carlo simulations. The results show: (i) the linear part of the spectra shape goes to reduce with the increasing of the height of the chamber; (ii) the 220Rn detection efficiency decreases with the increasing of the height of the chamber.

Radiological risk affects the quality of the environment in buildings since population and workers can be potentially exposed to high levels of radiation. Radon gas emanating from both subsoil and building materials represents the most important source of radiation exposure for people. This study investigates the sustainability concept of a small rural village of Ischia Island, named Ciglio, in relation to radiation protection legislation concerning the radiological risk for workers. Radon activity concentration was measured in typical green-tuff dwellings and in water samples collected from a local waterfall E-Perm devices. Moreover, for green tuff as building material, the radon emanation coefficient was calculated by gamma spectroscopy. The results highlight the importance of performing environmental radon monitoring and investigating the radon content of building materials, especially in geographical areas characterized by traditional use of typical stones for constructions. In conclusion, the sustainable development of rural buildings is possible if the radiological risk for inhabitants and workers is assessed in line with the national radiation protection legislation.

The most used passive detectors for Radon measurement are the CR39s, both for the good stability of the material and for the practicality of use. But, commercial reading systems are expensive and not always fast. The aim of the present work was the development of a method for a rapid, efficient and economic evaluation of the result of the indoor Radon measurement performed with CR39 detectors. The analysis and acquisition of detector images were performed using a photo scanner and the free ImageJ software. Several groups of CR-39 detectors were exposed, developed and analysed. Calibration curve was obtained in a wide range of exposure values (200-12 000 kBq.h.m(-3)) to allow the procedure to be applied in all possible measurement environments. Furthermore, a statistical study was carried out on the shape and size of nuclear tracks after chemical development. The dependence of the track size on Radon exposure was effective in showing the trace saturation effect as well.

The results of radioactivity content of samples of different types of soils and building materials characteristic of the Campania volcanic region (South Italy) have been reported and discussed. This characterization has been carried out by performing: i) gamma-ray spectrometry measurement, using a hyperpure germanium detector in very low background conditions, for the determination of the activity concentration of Ra-226, Th-232 and K-40; ii) alpha-spectrometry of ionized descendants of Rn-222, collected in an electrostatic cell, to measure the emanated fraction of this radioactive gas. Materials of different characteristic and origin have been studied. Results prove the high radioactivity of the samples coming from this volcanic region, underlining the differences among their radioactivity content and their capacity to generate radon.

This paper reports the analysis of soil 222Rn data recorded over 7-years in the volcanic caldera of Campi Flegrei (Naples-Italy). The relationship between Radon activity concentration and several geophysical, geochemical and meteorological parameters, influencing the gas emissions, is estimated by the Artificial Neural Network (ANN) method. The analysis goals are: the estimation (replication) of the Radon time series from influencing parameters, the forecasting of an unknown part of it, and the search for anomalies. Results prove: (i) the effectiveness of the ANN method; (ii) Radon follow the periods of agitation of the caldera, demonstrated by the comparison with previous works using different methods.

The present work concerns a detailed analysis of Radon time series to differentiate endogenous from exogenous phenomena which provide anomalous signals. Two-year data from two sites in Czech Republic and in Italy are analyzed in order to contribute to the prevention of natural hazards. A new hybrid forecasting method is implemented and tuned for the identification of Radon anomalies in the time series. It is based on the combination of Multiple Linear Regressions, Empirical Mode Decomposition and Support Vector Regression methods that decompose the signal and analyze the components to distinguish the variations due to Radon originated in depths from those due to environmental parameters. The possible correlations with fumarolic tremors in the Italian site and the faults microdisplacements in the Czech site have been studied, as well as with the earthquakes that have influence on two studied areas. Results show that: (i) the used method is very effective considering the calculated statistical uncertainties; (ii) the outer temperature is the main influencing Radon driving force; (iii) the extracted Radon anomalies due to endogenous phenomena are well correlated with fault displacements, fumarolic tremors, and with earthquakes under a characteristic delay time for each area; (iv) significant correlations among earthquake magnitude and depth with fault displacement and fumarolic tremor are found.

In this study the radon-222 activity concentration in drinking water over a large area of the western Campania region was investigated. Water samples were collected over a period of three years between May 2017 and May 2019 in compliance with Italian legislation. The measurement of radon activity concentration using electret detector (E-Perm (R) system) in short-short term configuration was performed. The purpose has been to identify the sampling points and report them on a map, studying the presence of any correlations between variations in the concentration of activity, seasonality and specific characteristics of the plant. The results obtained revealed that the concentrations of radon activity in the drinking water of the investigated sites are below the parameter value established by the law. Furthermore, activity concentration of radon in well water does not depend on seasonality, unlike the tanks, for which there is a relationship with the temperature that must be studied separately on the basis of the single tank.