Development of a methodology for assessing radiological dose due to use of NORM sludge as fertilizer.

In Europe, the general obligation to recycle drives for increased reuse of residues containing Naturally Occurring Radioactive Material (NORM). In agriculture, this has led to the reuse of sludge produced by groundwater filtration facilities as a means of fertilization. In the frame of the RadoNorm project, a methodology was developed for dose assessment of agricultural workers and other members of the public living near agricultural fields in which NORM-containing sludge is applied. Appropriate exposure scenarios were identified and modelled for each relevant NORM decay segment of both U-238 and Th-232 series, as well as for K-40. Dose assessments were performed using the software RESRAD-ONSITE with dose coefficients for external and internal exposure taken from the latest publications from the International Commission on Radiological Protection (ICRP). The objective was to develop a generic methodology to quantify exposure and to obtain screening values - so-called Operational Levels (OLs). These OLs pertain to the activity concentration of natural radionuclides (in terms of kBq kg-1) present in sludge that is reused in agriculture, for which dose criterion of 1 mSv year-1 is complied with. OLs can be used as screening tools by an authority/operator, even non-experts in the field of radiation protection. Results showed that the most critical decay segments are Ra-226+ and Ra-228+, for which OLs of the order of 1 kBq kg-1 were estimated. For all the other radionuclides, the calculated OLs are much higher than the activity concentrations typically found in sludge from water treatment facilities, and the radiological impact expected is well-below 1 mSv year-1. The methodology and results of this study could contribute to the update of the Clearance Levels and discharge levels reported in the European guidelines RP 122 Part II and RP 135, respectively.

Resilience after a nuclear accident: readiness in using mobile phone applications to measure radiation and health indicators in various groups (SHAMISEN SINGS project).

An anonymous web-based survey was developed to check different aspects (SHAMISEN SINGS project): stakeholder awareness and perceptions of available mobile applications (apps) for measuring ionising radiation doses and health/well-being indicators; whether they would be ready to use them in the post-accidental recovery; and what are their preferred methodologies to acquire information etc. The results show that participation of the citizens would be most beneficial during post-accident recovery, providing individual measurements of external ionizing dose and health/well-being parameters, with possible follow-up. Also, participants indicated different preferences for sources to gain knowledge on ionising radiation and for the functions that an ideal app should have. The level of awareness and readiness to use apps to measure ionising radiation dose depended on two main aspects: individual differences (age & gender) and whether people were from countries affected by the previous major accidents. We concluded that stakeholders could have benefits from the data management plan: (1) it potentiates resilience at individual and community level; (2) citizens' measurements contribute to environmental monitoring and public health screening; (3) linkages between different types of data (environmental exposure, individual behavioural diaries, and measurements of health indicators) allow to perform more rigorous epidemiological studies.

A real-time system to report abnormal events involving staff in a nuclear medicine therapy unit.

A system for internal and voluntary reporting of abnormal events in a Nuclear Medicine Therapy Unit is described. This system is based on the Internet of Things and is composed of an application for mobile devices and a wireless network of detectors. The application is addressed to healthcare professionals and is intended to be a user-friendly tool to make the reporting procedure little laborious. The network of detectors allows for a real-time measurement of the dose distribution in the patient's room. The staff was involved in all stages, from the design of the dosimetry system and mobile application up to their final testing. Face-to-face interviews were carried out with 24 operators in different roles in the Unit (radiation protection experts, physicians, physicists, nuclear medicine technicians and nurses). The preliminary results of the interviews and the current state of development of the application and the detection network will be described.

Tools for harmonized data collection at exposure situations with naturally occurring radioactive materials (NORM).

Naturally occurring radioactive materials (NORM) contribute to the dose arising from radiation exposure for workers, public and non-human biota in different working and environmental conditions. Within the EURATOM Horizon 2020 RadoNorm project, work is ongoing to identify NORM exposure situations and scenarios in European countries and to collect qualitative and quantitative data of relevance for radiation protection. The data obtained will contribute to improved understanding of the extent of activities involving NORM, radionuclide behaviours and the associated radiation exposure, and will provide an insight into related scientific, practical and regulatory challenges. The development of a tiered methodology for identification of NORM exposure situations and complementary tools to support uniform data collection were the first activities in the mentioned project NORM work. While NORM identification methodology is given in Michalik et al., 2023, in this paper, the main details of tools for NORM data collection are presented and they are made publicly available. The tools are a series of NORM registers in Microsoft Excel form, that have been comprehensively designed to help (a) identify the main NORM issues of radiation protection concern at given exposure situations, (b) gain an overview of materials involved (i.e., raw materials, products, by-products, residues, effluents), c) collect qualitative and quantitative data on NORM, and (d) characterise multiple hazards exposure scenarios and make further steps towards development of an integrated risk and exposure dose assessment for workers, public and non-human biota. Furthermore, the NORM registers ensure standardised and unified characterisation of NORM situations in a manner that supports and complements the effective management and regulatory control of NORM processes, products and wastes, and related exposures to natural radiation worldwide.

A methodology for the systematic identification of naturally occurring radioactive materials (NORM).

Naturally occurring radioactive materials (NORM) are present worldwide and under certain circumstances (e.g., human activities) may give radiation exposure to workers, local public or occasional visitors and non-human biota (NHB) of the surrounding ecosystems. This may occur during planned or existing exposure situations which, under current radiation protection standards, require identification, management, and regulatory control as for other practices associated with man-made radionuclides that may result in the exposure of people and NHB. However, knowledge gaps exist with respect to the extent of global and European NORM exposure situations and their exposure scenario characteristics, including information on the presence of other physical hazards, such as chemical and biological ones. One of the main reasons for this is the wide variety of industries, practices and situations that may utilise NORM. Additionally, the lack of a comprehensive methodology for identification of NORM exposure situations and the absence of tools to support a systematic characterisation and data collection at identified sites may also lead to a gap in knowledge. Within the EURATOM Horizon 2020 RadoNorm project, a methodology for systematic NORM exposure identification has been developed. The methodology, containing consecutive tiers, comprehensively covers situations where NORM may occur (i.e., minerals and raw materials deposits, industrial activities, industrial products and residues and their applications, waste, legacies), and thus, allows detailed investigation and complete identification of situations where NORM may present a radiation protection concern in a country. Details of the tiered methodology, with practical examples on harmonised data collection using a variety of existing sources of information to establish NORM inventories, are presented in this paper. This methodology is flexible and thus applicable to a diversity of situations. It is intended to be used to make NORM inventory starting from the scratch, however it can be used also to systematise and complete existing data.

Application of the ALARA principle for radon at work: feedback from the European ALARA network.

The Council Directive 2013/59/Euratom has introduced binding requirements for the management of radon in the workplace in Member States of the European Union. How does it work in practice? In 2021, the European ALARA Network created a working group on ALARA for Radon at Work with the objective of collecting and sharing experiences from the field. A survey was developed to detail each step of the national regulations for the control of radon and to describe case studies showing implementation. This article presents a qualitative analysis of the answers received from seven countries. There are no two similar national regulations and, at each step, different provisions, protocols, techniques etc are applicable or recommended. This diversity contributes to the richness of the results and can inform about interesting and good practices, where 'good' is defined by what is appropriate in the nationally and locally prevailing circumstances. All national regulations follow a graded approach, which is a key component for the implementation of the optimisation (ALARA) principle, yet several potential weak points that may be challenging to ALARA have been identified and are discussed, namely the radon risk assessment, the focus on numerical values, uncertainties in the measurement, how to obtain economically efficient remediation, and the interface with other regulations. Strengthening collaboration between risk prevention and radiation protection actors could help to provide and build expertise on radon management in the workplace, especially when exposure is managed as a planned exposure situation.

Lessons from past radiation accidents: Critical review of methods addressed to individual dose assessment of potentially exposed people and integration with medical assessment.

The experiences of the Chernobyl and Fukushima nuclear accidents showed that dosimetry was the essential tool in the emergency situation for decision making processes, such as evacuation and application of protective measures. However, at the consequent post-accidental phases, it was crucial also for medical health surveillance and in further adaptation to changed conditions with regards to radiation protection of the affected populations. This review provides an analysis of the experiences related to the role of dosimetry (dose measurements, assessment and reconstruction) regarding health preventive measures in the post-accidental periods on the examples of the major past nuclear accidents such as Chernobyl and Fukushima. Recommendations derived from the review are called to improve individual dose assessment in case of a radiological accident/incident and should be considered in advance as guidelines to follow for having better information. They are given as conclusions.

Underground Radiobiology: A Perspective at Gran Sasso National Laboratory.

Scientific community and institutions (e. g., ICRP) consider that the Linear No-Threshold (LNT) model, which extrapolates stochastic risk at low dose/low dose rate from the risk at moderate/high doses, provides a prudent basis for practical purposes of radiological protection. However, biological low dose/dose rate responses that challenge the LNT model have been highlighted and important dowels came from radiobiology studies conducted in Deep Underground Laboratories (DULs). These extreme ultra-low radiation environments are ideal locations to conduct below-background radiobiology experiments, interesting from basic and applied science. The INFN Gran Sasso National Laboratory (LNGS) (Italy) is the site where most of the underground radiobiological data has been collected so far and where the first in vivo underground experiment was carried out using Drosophila melanogaster as model organism. Presently, many DULs around the world have implemented dedicated programs, meetings and proposals. The general message coming from studies conducted in DULs using protozoan, bacteria, mammalian cells and organisms (flies, worms, fishes) is that environmental radiation may trigger biological mechanisms that can increase the capability to cope against stress. However, several issues are still open, among them: the role of the quality of the radiation spectrum in modulating the biological response, the dependence on the biological endpoint and on the model system considered, the overall effect at organism level (detrimental or beneficial). At LNGS, we recently launched the RENOIR experiment aimed at improving knowledge on the environmental radiation spectrum and to investigate the specific role of the gamma component on the biological response of Drosophila melanogaster.

Alkali-activated concrete with Serbian fly ash and its radiological impact.

The present paper reports the results of a study on different types of fly ash from Serbian coal burning power plants and their potential use as a binder in alkali-activated concrete (AAC) depending on their radiological and mechanical properties. Five AAC mixtures with different types of coal burning fly ash and one type of blast furnace slag were designed. Measurements of the activity concentrations of 40K, 226Ra and 232Th were done both on concrete constituents (fly ash, blast furnace slag and aggregate) and on the five solid AAC samples. Experimental results were compared by using the activity concentration assessment tool for building materials - the activity concentration index I, as introduced by the EU Basic Safety Standards (CE, 2014). All five designed alkali-activated concretes comply with EU BSS screening requirements for indoor building materials. Finally, index I values were compared with the results of the application of a more accurate index - I(ρd), which accounts for thickness and density of building materials (Nuccetelli et al., 2015a). Considering the actual density and thickness of each concrete sample index - I(ρd) values are lower than index I values. As an appendix, a synthesis of main results concerning mechanical and chemical properties is provided.

A new accurate and flexible index to assess the contribution of building materials to indoor gamma exposure.

The role of building materials as a source of gamma radiation has been recognized in the new EU Basic Safety Standards Directive which introduces an index I to screen building materials of radiological concern. This index was developed to account for average concrete values of thickness and density, the main structural characteristics of building materials that have an effect on gamma irradiation. Consequently, this screening procedure could be unfit in case of significantly different density and/or thickness of the building materials under examination. The paper proposes a more accurate and flexible activity concentration index, accounting for the actual density and thickness of building materials.

Radioactivity in drinking water: regulations, monitoring results and radiation protection issues.

INTRODUCTION: Drinking waters usually contain several natural radionuclides: tritium, radon, radium, uranium isotopes, etc. Their concentrations vary widely since they depend on the nature of the aquifer, namely, the prevailing lithology and whether there is air in it or not. AIMS: In this work a broad overview of the radioactivity in drinking water is presented: national and international regulations, for limiting the presence of radioactivity in waters intended for human consumption; results of extensive campaigns for monitoring radioactivity in drinking waters, including mineral bottled waters, carried out throughout the world in recent years; a draft of guidelines for the planning of campaigns to measure radioactivity in drinking water proposed by the Environmental Protection Agency (ARPA) of Lombardia.

Thorium series radionuclides in the environment: measurement, dose assessment and regulation.

Environmental radioactivity research is more advanced for the (238)U series than for the (232)Th series, for a number of reasons. One reason is that some radionuclides of the (232)Th series are more difficult to measure than the corresponding isotopes in the (238)U series, and measurement techniques are less widely available. The (232)Th series population doses, however, are sometimes significant. This paper analyses some main radionuclides in the (232)Th series in comparison with corresponding nuclides in the (238)U series, with regard to measurement techniques, dose coefficients and regulation needs.

In situ gamma spectroscopy in environmental research and monitoring.

In situ gamma spectroscopy was introduced to determine the outdoor gamma dose rate from soil and to calculate the radionuclide concentration and the relative contribution to the dose rate. This paper reviews the most common and proven applications of in situ gamma spectroscopy-together with the most recent and innovative research outcomes obtained with this technique, particularly for its use indoors. Advantages and limitations of its utilization to assess environmental radioactivity-indoors and outdoors-are also discussed.

A method to evaluate the contribution of building material to indoor gamma dose rate through outdoor measurements: preliminary results.

Building materials can be an important source of exposure to gamma radiation indoors. In situations in which it is impossible to enter the dwellings to measure indoor gamma dose rate, as can happen in epidemiological studies and in surveys on randomly selected dwellings, it is important to obtain accurate and precise estimates of the indoor gamma dose rate. In this paper, preliminary results of a validation study of a new method, named IN-OUT, to estimate the indoor gamma dose rate attributable to the building materials are presented. This method, which is still in progress, is based on outdoor measurements, performed close to an external wall of a dwelling, and on a 'room model' elaboration, which takes into account geometrical and structural characteristics of the dwelling. The validation was performed using data--relevant to 91 dwellings, at present--collected in Latium and Campania within the framework of 'SETIL', the Italian epidemiological study on the aetiology of childhood leukaemia, lymphoma and neuroblastoma.

[Sources of natural and artificial radioactive contamination in the marine environment]. / Origini della contaminazione radioattiva naturale e artificiale dell'ambiente marino.

Sources of natural and artificial radioactive contamination in the marine environment. The Chernobyl accident produced the most severe contamination of Europe, still detectable in environmental samples, but many other sources of artificial and natural radioactivity have produced a considerable impact on the environment and a risk for the public health. In this paper a review of the most important events or industrial processes that produced contamination of the European seas is presented; moreover, attention is paid to the situation of the coastal marine environment in Italy as regards the artificial radioactivity and the human enhanced radioactivity produced by non nuclear plants.