Radon Hazard in Central Italy: Comparison among Areas with Different Geogenic Radon Potential

Radon (222Rn) is a natural radioactive gas formed in rocks and soil by the decay of its parent nuclide (238-Uranium). The rate at which radon migrates to the surface, be it along faults or directly emanated from shallow soil, represents the Geogenic Radon Potential (GRP) of an area. Considering that the GRP is often linked to indoor radon risk levels, we have conducted multi-disciplinary research to: (i) define local GRPs and investigate their relationship with associated indoor Rn levels; (ii) evaluate inhaled radiation dosages and the associated risk to the inhabitants; and (iii) define radon priority areas (RPAs) as required by the Directive 2013/59/Euratom. In the framework of the EU-funded LIFE-Respire project, a large amount of data (radionuclide content, soil gas samples, terrestrial gamma, indoor radon) was collected from three municipalities located in different volcanic districts of the Lazio region (central Italy) that are characterised by low to high GRP. Results highlight the positive correlation between the radionuclide content of the outcropping rocks, the soil Rn concentrations and the presence of high indoor Rn values in areas with medium to high GRP. Data confirm that the Cimini–Vicani area has inhalation dosages that are higher than the reference value of 10 mSv/y.

Rising Canadian and falling Swedish radon gas exposure as a consequence of 20th to 21st century residential build practices

Radioactive radon gas inhalation is a major cause of lung cancer worldwide and is a consequence of the built environment. The average radon level of properties built in a given period (their ‘innate radon risk’) varies over time and by region, although the underlying reasons for these differences are unclear. To investigate this, we analyzed long term radon tests and buildings from 25,489 Canadian to 38,596 Swedish residential properties constructed after 1945. While Canadian and Swedish properties built from 1970 to 1980s are comparable (96–103 Bq/m3), innate radon risks subsequently diverge, rising in Canada and falling in Sweden such that Canadian houses built in the 2010–2020s have 467% greater radon (131 Bq/m3) versus Swedish equivalents (28 Bq/m3). These trends are consistent across distinct building types, and regional subdivisions. The introduction of energy efficiency measures (such as heat recovery ventilation) within each nation’s build codes are independent of radon fluctuations over time. Deep learning-based models forecast that (without intervention) the average Canadian residential radon level will increase to 176 Bq/m3 by 2050. Provisions in the 2010 Canada Build Code have not significantly reduced innate radon risks, highlighting the urgency of novel code interventions to achieve systemic radon reduction and cancer prevention in Canada.

A Novel Strategy for the Assessment of Radon Risk Based on Indicators

Among the physical pollutants affecting indoor air, the radioactive gas radon may turn out to be the most hazardous. Health effects related to radon exposure have been investigated for several decades, providing major scientific evidence to conclude that chronic exposures can cause lung cancer. Additionally, an association with other diseases, such as leukemia and cancers of the extra-thoracic airways, has been advanced. The implementation of a strategy to reduce the exposure of the population and minimize the health risk, according to the European Directive 59/2013/Euratom on ionizing radiations, is a new challenge in public health management. Starting from an understanding of the general state-of-the-art, a critical analysis of existing approaches has been conducted, identifying strengths and weaknesses. Then, a strategy for assessing the radon exposure of the general population, in a new comprehensive way, is proposed. It identifies three main areas of intervention and provides a list of hazard indicators and operative solutions to control human exposure. The strategy has been conceived to provide a supporting tool to authorities in the introduction of effective measures to assess population health risks due to radon exposure.

Designing an Indoor Radon Risk Exposure Indicator (IRREI): An Evaluation Tool for Risk Management and Communication in the IoT Age

The explosive data growth in the current information age requires consistent new methodologies harmonized with the new IoT era for data analysis in a space–time context. Moreover, intuitive data visualization is a central feature in exploring, interpreting, and extracting specific insights for subsequent numerical data representation. This integrated process is normally based on the definition of relevant metrics and specific performance indicators, both computed upon continuous real-time data, considering the specificities of a particular application case for data validation. This article presents an IoT-oriented evaluation tool for Radon Risk Management (RRM), based on the design of a simple and intuitive Indoor Radon Risk Exposure Indicator (IRREI), specifically tailored to be used as a decision-making aid tool for building owners, building designers, and buildings managers, or simply as an alert flag for the problem awareness of ordinary citizens. The proposed methodology was designed for graphic representation aligned with the requirements of the current IoT age, i.e., the methodology is robust enough for continuous data collection with specific Spatio-temporal attributes and, therefore, a set of adequate Radon risk-related metrics can be extracted and proposed. Metrics are summarized considering the application case, taken as a case study for data validation, by including relevant variables to frame the study, such as the regulatory International Commission on Radiological Protection (ICRP) dosimetric limits, building occupancy (spatial dimension), and occupants’ exposure periods (temporal dimension). This work has the following main contributions: (1) providing a historical perspective regarding RRM indicator evolution along time; (2) outlining both the formulation and the validation of the proposed IRREI indicator; (3) implementing an IoT-oriented methodology for an RRM indicator; and (4) a discussion on Radon risk public perception, undertaken based on the results obtained after assessment of the IRREI indicator by applying a screening questionnaire with a total of 873 valid answers.

Social Determinants of Health, Environmental Exposures and Home Radon Testing

Home radon testing is a primary lung cancer prevention strategy, yet the majority of Americans have not tested their home. This descriptive, ecological study uses 54,683 observed radon values collected in Kentucky homes from 1996 to 2016 to examine the association of county-level social determinants of health and environmental exposures on home radon testing rates. Multivariate linear regression analysis indicates that as median home value, rurality, and radon risk potential increased, counties experienced an increase in annual home radon testing rates. As adult smoking prevalence increased, counties experienced a decrease in annual rates of residential radon testing. These findings indicate that counties with low median home values, high adult smoking prevalence, and high incidence of lung cancer may benefit most from prevention interventions aimed at promoting home radon testing, adopting radon- and smoke-free home policies, and integrating radon risk reduction messaging into tobacco cessation and lung cancer screening programs.

Radon Health Impact Assessment and Risk Communication in Sardinia Region

<p>INTRODUCTION</p><p>Following the recommendations of the National Prevention Plan, the Sardinia Region Department of Hygiene, Health and Social Security has promoted a programme dedicated to protecting the population from exposure to radon gas. The plan included: radon monitoring activities during a dedicated campaign based on geological mapping; radon Health Impact Assessment, HIA; drafting of “Guidelines for the construction/renovation of buildings”; community involvement and a radon risks communication campaign.</p><p>OBJECTIVES</p><p>To present the development of the HIA based on radon environment monitoring data and the communication process.</p><p>METHODS</p><p>Radon risk mapping combined the knowledge of geological composition of Sardinia Island and the results obtained by monitoring with dedicated devices.</p><p>HIA was implemented calculating cases attributable (CA) to radon exposure, combining the following parameters: Relative Risk (available by literature); mortality rate of lung cancer prevalence/incidence rate (baseline); exposed population size; radon concentration target.</p><p>The radon monitoring campaign required a widespread communication activity, while the results communication activity, based on a dedicated plan, involved multiple stakeholders.</p><p>RESULTS</p><p>On the basis of radon concentration data estimated by ARPAS, the HIA procedure estimated lung cancer deaths attributable to radon in areas of different exposure and throughout Sardinia. In the whole region, with an average concentration of 116 Bq/m3, radon-attributable cases were estimated at 143 out of 832 total expected deaths (attributable fraction 17.2%); in the area most at risk, including 49 municipalities, with an estimated average concentration of 202 Bq/m3, radon-attributable deaths were 13 out of 55 total (attributable fraction 23.6%).</p><p>The parameters of the algorithm and the results were presented and discussed with the local working groups.</p><p>A specific radon monitoring activity developed in schools helped to focus the efforts on the protection of school goers as vulnerable and susceptible groups. Urgent renovation and improvement activities in school and in other public administration buildings throughout the region were carried out.</p><p>Six guided discussions and four training sessions during six months were held to develop HIA and communication activities. A meeting to present the work was held in Nuoro town in October 2019, where information material was distributed and public attention raised around the issue.</p><p>The communication process aggregated several stakeholders including: civil servants in the field of health and the environment; public administrators; health professionals committed to spread knowledge about radon-free building.</p><p>CONCLUSIONS</p><p>The objectives of the regional program were focused to: - protect Sardinian population from radon risk, with special reference to vulnerable and susceptible subjects, particularly radon exposed smokers; - spread knowledge about risks; - inform about the opportunities to reduce risks.</p><p>Results indicate that the health of populations living in radon-exposed areas can be significantly improved by reducing exposure to radon and synergistic risk factors. It is essential to strengthen awareness-raising activities using historical and acquired knowledge and to monitor progress in order to reinforce further action, as these activities should be planned for the long term.</p>

Climate impact on radon risk for silty loam soils

<p>Radon isotope <sup>222</sup>Rn constitutes a natural source of radioactivity, which is worldwide extended and can be found, regardless its concentration in almost all soils of the Earth surface. Inhale radon gas is a risk for human health and the World Health Organization, WHO, has concluded the doubtless correlation between long exposure to radon gas and lung cancer; even more, the US-EPA considers it as the second most important cause of lung cancer in USA., The adoption of preventive measurements during building construction is extending in many developed countries because long exposure to radon gas take place mainly in poorly ventilated basements. Generally, these measures are based on radon risk associated exclusively with radon production by soils, but less attention are devoted to the impact of soil gas permeability and, even more, of the variable soil gas permeability because of the different degrees of soil water contents. Soil water content affects soil permeability to both water and vapor phases, and it must be taken into consideration when defining the risk associated to the presence of radon. In the present study, we show the importance of different climate conditions on soil water content and in turn on the gas permeability. We tested with the radon potential risk of building sites of the Czech Republic, which combines both the radon concentration in soil and soil gas permeability (Neznal et al, 2004). According to the Köppen classification, the present study considers different climatic scenarios: Bsk, hot semiarid climate, typical from many regions in South Europe; Csa, temperate Mediterranean climate with dry hot summers and moderate winters, also common in South Europe; Cfb, oceanic humid climate with great extension in France and UK; and finally Dfb, humid continental climate with cool winters and moderate summers, typical from central Europe.</p><p>Soil water content for each scenario was simulated using HYDRUS. Average values were obtained from a 100-year temporal series.  The top most 1-m thick layer was considered as the representative for the soil water content. Results demonstrate the necessity to consider water content when defining the radon risk and their interannual variability, especially for those climates with very clear different precipitation patterns along the different seasons.</p>

COMMUNICATION STRATEGIES FOR INFORMATION ABOUT RADON RISKS

The article analyzes and determines the most effective directions of communication strategies and specific approaches to the choice of ways to inform the population about radon risks. Communicating with the public about radon risks is an integral part of the national radon action plan, and radon risk communication is a specific requirement of the IAEA's Basic Safety Standards. An effective risk communication strategy provides for a multi-stakeholder information flow involving stakeholders (all stakeholders) - representatives of communities living at risk, regulators, experts, radiation safety inspectors, and should focus on informing different audiences and recommending appropriate protective measures. It is also very important to take into account both the demographic and socio-economic context of the population and the use of quantitative and qualitative approaches to information. National and regional departments, local health authorities and non-profit organizations should work together to share knowledge, experience, resources and ideas that will stimulate radon measurements and protective actions. An effective component of a radon risk communication campaign is to identify target audiences that need to be informed and persuaded to take the necessary protection measures, and raising public awareness of the need to reduce radon levels in homes should be a key communication strategy. In the process of risk communication, an important aspect is the approach to the choice of ways of informing and developing the content of information messages. The effectiveness of communications will increase significantly if you join existing other information campaigns, such as energy efficiency, smoking control, labor protection and the like. Communication should be an ongoing process and should be carried out at all stages of the implementation of the radon action plan.