Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies

Duration versus intensity of exposure on the risk of lung cancer due to radon exposure in the general population

Indoor radon causes lung cancer. The objective of this investigation is to describe lung cancer risk based both on duration and intensity of radon exposure, and to analyze if this effect could be different by sex. To do this, we used pooling information coming from very similar case-control studies on radon and lung cancer, all performed in a radon-priority area. We did a classical categorical analysis using logistic regressions to predict lung cancer risk for exposure duration, intensity of exposure and both variables combined, and we also employed generalized additive models to assess the risk of lung cancer. The results were obtained separately by sex. We included 3415 participants for whom radon measurements had been performed at their home, 1619 of whom were cases. We observed that the length and intensity of residential radon exposure might have a similar importance on lung cancer risk. For those living in dwellings with radon concentrations above 300 Bq/m3, lung cancer risk increases steadily and importantly with exposure duration, even with lengths of exposure above 40 years. We also observed that the risk of lung cancer might be higher in men compared to women. We encourage other researchers to reanalyze their data to confirm these results and also to test if the effect observed in women is replicated.

Simulation of diffusion and decay of radon/thoron exhaled from a wall and its newly created progeny. Response of a bare LR-115 detector placed on the wall

Monte Carlo techniques were used to simulate the air diffusion of exhaled radon/thoron atoms from a wall, the formation and decay of different radioactive species during transport, and the response of a bare LR-115 detector placed on the exhaling surface. The spatial distributions of radionuclide decays and the detector's partial sensitivities to radon/thoron and their progeny were determined. The simulation results were numerically validated through comparisons with published theoretical and experimental data. From the simulated experiments, the contributions of different species to the total track density and what the detector might measure in the studied configuration and assumed parameters were inferred. It was shown that near the wall, where the effective volumes of all species are located, the number of radon atoms was approximately constant, while that of thoron decreased to about 30% relative to the number of exhaled atoms, and the equilibrium factors of both gases were very low. A negligible contribution of 220Rn and 216Po to the track density is expected if the distance between detector's edges and support exceeds 5-6 times the thoron characteristic diffusion length. For similar detector and support sizes, these atoms can significantly contribute to the track density if thoron exhalation rate from wall is high. The advantages and limitations of the detector exposure method for estimating indoor radon concentrations are analyzed. Finally, a simple method is suggested for more accurate radon measurements using the bare LR-115 detector placed on a wall.

"Fusion of Horizons": Part III. Rethinking radon Risk: Scientific advances and regulatory implications (since 1990s)

This study examines the global evolution of scientific understanding regarding radon exposure and its health implications, focusing on the transition from early occupational exposure limits and epidemiological risk assessments to molecular-level attributions of radon-induced diseases. Since the early 1990s, advancements in genetic and molecular research have provided growing evidence suggesting that radon exposure may leave a distinct oncological signature, potentially allowing for more precise differentiation between radon-induced lung cancers and those caused by other factors. While this field continues to evolve, its implications extend beyond epidemiological risk assessment to include legal, medical, and regulatory frameworks. Beyond lung cancer, contemporary research has explored links between radon exposure and a range of other oncological and non-oncological diseases, including leukemia, kidney cancer, neurodegenerative disorders, and chronic respiratory conditions. The study further explores the ethical and legal consequences of these findings, particularly in the context of risk governance, compensation claims, and occupational health regulations. The paper also examines the hybrid nature of radon as both naturally occurring and anthropogenically intensified hazard, complicating risk perception and public policy responses. Additionally, the phenomenon of "contaminated communities," is discussed, wherein prolonged radon exposure disrupts social structures and contributes to psychological distress, economic losses, and legal disputes. By analyzing radon exposure through the lens of toxic disaster theory, this study outlines the sequential stages of public and regulatory responses, from initial scientific uncertainty to regulatory intervention and societal adaptation. The findings highlight a broader challenge in environmental health governance: how scientific advancements are integrated into public health policies amid economic and political constraints. Ultimately, the study underscores the need for continuous scientific inquiry and proactive policymaking to address the full spectrum of health risks associated with radon exposure.

Uncovering hidden dangers in urban housing: Sources of indoor radon and associated health risks

Radon, a naturally occurring radioactive gas, tends to accumulate indoors and can reach hazardous concentrations that pose significant health risks. Globally, radon is recognized as the second leading cause of lung cancer after smoking. Despite its well-documented dangers, significant knowledge gaps persist regarding the sources of radon exposure and the resulting health risks. In this study, we examine the spatial and temporal distribution, sources, and health impacts of indoor radon in Ohio, USA-a state characterized by diverse geological and meteorological conditions and radon concentrations significantly exceeding the national average, contributing to approximately 900 lung cancer deaths annually. Our results reveal pronounced spatial heterogeneity, with elevated radon concentrations in central urban areas, and seasonal variability, with higher levels during winter. Using statistical analysis and structural equation modeling, we identify surface radiation sources, meteorological conditions, and building materials as key drivers of indoor radon accumulation. Furthermore, Monte Carlo simulations indicate that the estimated lifetime excess cancer risk for residents in the study area is 2.29 %, approximately double the standard safety threshold. These findings underscore the urgent need to raise awareness of radon-induced carcinogenesis and to implement effective mitigation strategies to safeguard public health.

Presence, distribution, and origin of radioisotopes in rock, soil, and groundwater in Central Mexico: implications of ionizing radiation for health

Several sources of environmental radioactivity in central Mexico were investigated for their potential association with health by assessing gamma dose rates, trace elements in rocks, gamma ray energy spectra, radon and thoron activity in groundwater, soil-air, and dwellings, and previously unpublished data on uranium, thorium, and enriched-tritium concentrations dissolved in groundwater. Results of the screening studies show that the predominant rocks are ignimbrites of rhyolitic composition contain 238U and 232Th. These rocks outcrop in hills and surrounding mountains and extend to depth where they constitute a fractured aquifer, which underlies a granular one, whose constituents and permeable soils also contain 238U and 232Th and their decay series. Gross Alfa Activity and 222Rn are present in groundwater for human consumption above the Maximum Contaminant Level suggested by the US Environmental Protection Agency, reaching the lower threshold for uranium ores and mining in northern Mexico. 222Rn and 220Rn were also measured in soil-air and in dwellings. Rhyolitic-ignimbrites have been used in industrial applications since the 1960s, and milling and tailing operations contain radionuclides that can be transported by air or leached into groundwater. The combined exposure to various sources of radioactivity and metals, primarily the use and ingestion of groundwater and dust may impact the human health in the study area, in addition to the inhalation of 222Rn-220Rn and dust. Additional and detailed research should be done for long-term measurements and risk assessment for radiological protection, also considering the evaluation and combined exposure to industrial and agricultural contaminants.

Radon Exposure and Cancer Risk: Assessing Genetic and Protein Markers in Affected Populations

Radon is an inert gas produced by the radioactive decay of uranium-238, commonly found in the environment. Radon and its decay products are the main sources of human exposure to radiation from natural sources. When inhaled, radon's alpha particles impact lung tissue, potentially causing lung cancer by damaging DNA and altering oxidative processes. This review article addresses the need for a deeper understanding of the genetic and molecular changes associated with radon-induced lung cancer, aiming to clarify key genetic mutations and protein markers linked to carcinogenesis. Particular attention in recent studies has been given to mutations in tumor suppressor genes (RASSF1, TP53), oncogenes (KRAS, EGFR), and changes in the expression levels of protein biomarkers associated with inflammation, stress, and apoptosis. Identifying these markers is critical for developing effective screening methods for radon-induced lung cancer, enabling timely identification of high-risk patients and supporting effective preventive strategies. Summarizing current genetic and protein biomarkers, this review highlights the importance of a comprehensive approach to studying radon-induced carcinogenesis. Understanding these molecular mechanisms could ultimately improve early diagnostic methods and enhance therapy for cancers associated with radon exposure.

Maintaining competence in radiation protection research: a position statement by the MELODI scientific advisory committee

The aim of this position statement is to bring to the forefront the necessity for maintaining and enhancing high competence in assessing the impact of low dose and low dose rate exposure on human health and the urge for funding to achieve this within Europe. Exposure to low dose/dose rates of radiation can arise from multiple scenarios or events, including natural radiation exposure, the use of radiation in medicine, industry and energy production, terrorist actions and following a nuclear incident or war. Technological developments involving radiation are progressing rapidly and have the potential to benefit mankind and societal issues. The benefit of high dose exposure during radiotherapy is a well-funded area. However, the health consequences of exposure to low doses is not well understood and the area of radiation protection research (RPR) is poorly funded. High quality RPR is essential to allow updating of radiation safety regulations for optimal protection from natural, medical and occupational exposure and for assessment of radiation incidents. Continuous evaluation of risks is essential as technological developments result in new types of radiation exposure. We will overview the technologies and situations which can potentially lead to low dose exposure, evaluate what has been gained from RPR and the questions that still need addressing, discuss the current state of RPR in Europe and highlight the consequences of a failure to adequately fund this area. We conclude that increased funding for RPR is essential to maintain high competence and to allow adequate protection of the public to inevitable low dose radiation exposure.

Investigation into terrestrial gamma radiations and radiological safety concerns near the Dilli-Jeypore coalfield, India

This present study investigates the levels of dose rates and the potential risks of exposure to terrestrial gamma radiations in both indoors and outdoors in houses in the vicinity of the Dilli-Jeypore coalfield of Assam, India. The measurements were carried out using a highly sensitive portable Micro-R Survey Meter (UR 705). Indoor gamma dose rates have been estimated to be in the range of 49.7 ± 5.1-154.9 ± 5.1 nGy h-1, while outdoor rates varied between 49.7 ± 5.1 and 93.5 ± 5.1 nGy h-1, with an indoor to outdoor dose rate ratio of 1.21. The geometric mean of annual effective dose equivalent (AEDE) was calculated to be 0.49 ± 0.03 mSv y-1, which is slightly higher than the global recommended level of 0.48 mSv y-1. The excess lifetime cancer risk (ELCR) was estimated to range from 1.1 × 10-3 to 2.9 × 10-3, with a mean of 1.72 × 10-3.

Numerical simulations of radon diffusion-seepage in single fracture of rock

The joint roughness coefficient (JRC) of rock fractures significantly effects their seepage characteristics, which is critical in radon diffusion-seepage studies. It is worthwhile to investigate how to accurately characterize the rock fracture roughness and its effect on radon diffusion-seepage patterns within fractured porous media. In this study, the roughness of single-fracture rock is thoroughly considered and described by the Barton curve. Furthermore, this study examines the effects of pressure gradient, temperature, and water saturation on radon diffusion-seepage in fracture-containing porous media. Additionally, this study investigates the variation in seepage velocity within cracks under various pressure gradients, and further analyze the impact of roughness on radon exhalation rate in rocks. The results indicate that: (1) the JRC significantly influences the diffusion-seepage of radon in rocks. The radon exhalation rate on the low-pressure side and the seepage velocity within the fracture increase approximately by 30% and 10%, respectively. (2) The radon exhalation rate on the low-pressure side of the rock correlates positively with the JRC, whereas the radon exhalation rate in the fracture shows a negative correlation with the JRC. Concurrently, the pressure gradient, temperature and water saturation also significantly impact the radon exhalation rate. (3) The seepage velocity within the fracture increases with the rise of osmotic pressure in a fixed JRC value. AS the increase of JRC, the seepage velocity of the rock fracture decreases by approximately 7.9%-10.8%.

Silver-Exchanged Clinoptilolite-Rich Natural Zeolite for Radon Removal from Air

Radon (Rn) is a hazardous radioactive gas that poses significant health risks in enclosed indoor environments. This study investigates the potential of silver-exchanged clinoptilolite-rich natural zeolite (NZ-Ag+) for the removal of Rn from air. Natural zeolite (NZ) was thermally treated and further modified to enhance its adsorption characteristics. The thermally treated NZ (200 °C) was first exchanged in Na+ form, since Na+ is more easily exchanged in clinoptilolite with hydrated Ag+ ions than the other exchangeable cations. The modification with Ag+ was carried out at room temperature using ultrasonic processing to obtain (NZ-Ag+). The materials were characterized in terms of chemical composition, cation exchange capacity, mineralogy, total surface area, pore volume, and thermal behavior. Rn adsorption experiments were performed using a closed-circuit system, and the efficiency of NZ-Ag+ was compared with that of NZ. The results indicate that NZ-Ag+ exhibits superior Rn adsorption capacity, achieving up to 50% higher retention efficiency compared to NZ. The improved performance is attributed to enhanced adsorption facilitated by silver ion clusters interacting with radon atoms. These results suggest that silver-exchanged zeolite represents a promising material for radon mitigation in air filtration systems, with potential applications in residential and occupational settings.

Deep learning paradigms in lung cancer diagnosis: A methodological review, open challenges, and future directions

Lung cancer is the leading cause of global cancer-related deaths, which emphasizes the critical importance of early diagnosis in enhancing patient outcomes. Deep learning has demonstrated significant promise in lung cancer diagnosis, excelling in nodule detection, classification, and prognosis prediction. This methodological review comprehensively explores deep learning models' application in lung cancer diagnosis, uncovering their integration across various imaging modalities. Deep learning consistently achieves state-of-the-art performance, occasionally surpassing human expert accuracy. Notably, deep neural networks excel in detecting lung nodules, distinguishing between benign and malignant nodules, and predicting patient prognosis. They have also led to the development of computer-aided diagnosis systems, enhancing diagnostic accuracy for radiologists. This review follows the specified criteria for article selection outlined by PRISMA framework. Despite challenges such as data quality and interpretability limitations, this review emphasizes the potential of deep learning to significantly improve the precision and efficiency of lung cancer diagnosis, facilitating continued research efforts to overcome these obstacles and fully harness neural network's transformative impact in this field.

Environmental pollution and cancer

OBJECTIVE

To identify and describe pollutants with carcinogenic potential that contaminate indoor and outdoor air, food and soil.

DATA SOURCE

The descriptors environmental pollutants, occupational cancer, prevention and soil pollutants were used to conduct the research for literature review. Articles published from 2003 to 2024 in the electronic databases Pubmed Medline, Lilacs and Scielo, in Portuguese and English, were included.

SUMMARY OF FINDINGS

There are multiple sources of pollution in the external and internal environments, including motor vehicles, industrial facilities, smoke from tobacco products, agricultural activities, fires and domestic combustion devices. The most important pollutants related to chemical substances include all forms of asbestos, benzene, exhaust gases from gasoline engines, food and water contaminants, such as arsenic and inorganic arsenic compounds, in addition to persistent organic pollutants, such as dioxins. The use of fossil fuels and biomass for domestic heating are also important sources of pollution. The carcinogenic potential of pollutants varies according to the sources of pollution, climate conditions and the region's topography.

CONCLUSIONS

Global environmental pollution is an international public health problem with multiple health effects. Many environmental pollutants are proven to be carcinogenic to adults, while few causes have been scientifically established for children. Pollution is mainly caused by uncontrolled urbanization and industrialization. Preventing environmental exposure to carcinogenic pollutants requires both government regulation and community action and commitment.

Radiation adaptive response for constant dose-rate irradiation in high background radiation areas

The presented paper describes the problem of human health in regions with high level of natural ionizing radiation in various places in the world. The radiation adaptive response biophysical model was presented and calibrated for the special case of constant dose-rate irradiation. The calibration was performed for the data of residents of several high background radiation areas, like Ramsar in Iran, Kerala in India or Yangjiang in China. Studied end-points were: chromosomal aberrations, cancer incidence and cancer mortality. For the case of aberrations, among collected publications about 45% have shown the existence of adaptive response. Average reduction of chromosomal aberrations was ∼ 10%, while for the case of cancer incidence it was ∼ 15% and ∼ 17% for cancer mortality (each taking into account only results showing adaptive response). Results of the other 55% of data regarding chromosomal aberrations have been tested with the LNT (linear no-threshold) hypothesis, but results were inconsistent with the linear model. The conditions for adaptive response occurrence are still unknown, but it is postulated to correlate with the distribution of individual radiosensitivity among members of surveyed populations.

Lifetime Risks for Lung Cancer due to Occupational Radon Exposure: A Systematic Analysis of Estimation Components

Lifetime risk estimates play a key role in many areas of radiation research. Here, the focus is on the lifetime excess absolute risk (LEAR) for dying from lung cancer due to occupational radon exposure based on uranium miners cohort studies. The major components in estimating LEAR were systematically varied to investigate the variability and uncertainties of results. Major components of the LEAR calculation are baseline mortality rates for lung cancer and all causes of death, risk model and exposure scenario. Sex-averaged mortality rates were chosen from a mixed Euro-American-Asian population, in addition to mortality rates to represent heavy and light smokers. Seven radon-related lung cancer risk models derived from different uranium miners cohorts were compared. As exposure scenarios, occupational exposure of two working level months (WLM) from age 18-64 years was considered, and three scenarios from the German uranium miners cohort. Further components were modified in sensitivity analyses. The LEAR was compared to other lifetime risk measures. With a range from less than 0.6 × 10-4 to over 8.0 × 10-4, LEAR per WLM estimates were influenced heavily by the choice of risk models. Notably, mortality rates, particularly lung cancer mortality rates, had a strong impact on LEAR per WLM across all models. The LEAR per WLM exhibited only low variation to changes in exposure scenarios for all risk models, except for the BEIR VI model fitted on the pooled 11 miners study. All assessed lifetime risk measures displayed a monotonically increasing relationship between exposure and lifetime risk at low to moderate exposures, with minor differences between ELR, REID, and LEAR (all per WLM). RADS yields the largest lifetime risk estimates in most situations. There is substantial variation in LEAR per WLM estimates depending on the choice of underlying calculation components. Reference populations and mortality rates should be selected with care depending on the application of lifetime risk calculations. The explicit choice of the lifetime risk measure was found to be negligible. These findings should be taken into consideration when using lifetime risk measures for radiation protection policy purposes.

Radon exhalation rate and natural radioactivity in the building materials used in metropolitan Jakarta and its surrounding areas, Indonesia

Introduction

Creating a safe living environment involves using healthy and sustainable building materials. Humans are exposed to natural radionuclides, such as 226Ra, 232Th, and 40K decay series, found in building materials that pose a radiological hazard. This study is aimed to investigate the radionuclides content of building materials used in Jakarta and its surrounding areas. The computer code RESRAD-BUILD was used to calculate the annual effective dose received by an adult living in a typical room constructed with the studied building materials.

Methods

Samples such as sand, cement, bricks, and Autoclaved Aerated Concrete (AAC) were collected. The 222Rn surface exhalation rate was determined using the closed chamber method using RAD7, while the activity concentration of natural radionuclide was measured using a gamma spectrometer.

Results and discussion

The 222Rn surface exhalation rate varies from 4 × 10-2 to 1.6 × 100 mBq m-2 s-1 with an average of 4 × 10-1 mBq m-2 s-1. The average 222Rn exhalation rate of the building materials studied was much lower than the global average value of 1.6 × 101 mBq m-2 s-1. The average activity concentration values of 232Th (21 Bq kg-1) and 40K (217 Bq kg-1) in all building materials studied are lower than the global average values of 45 and 412 Bq kg-1. In comparison, the average activity concentration of 226Ra (34 Bq kg-1) is similar to the global average value of 32 Bq kg-1. Furthermore, the assessed radiological hazard from the measured building material has an average activity index of 0.3, while the RESRAD-BUILD estimated total annual effective dose for a typical house constructed using a mixture of the building materials was 0.11 mSv, in which indoor 222Rn alone represents 92% of the total. From the assessment results, the building materials in Jakarta and its surrounding areas do not pose significant concerns regarding radiological hazards. However, the higher contribution of 222Rn suggests the need for a large-scale indoor 222Rn survey in the study area.

Analysis of indoor radon concentration levels and trends in China

A systematic review of publicly available papers on indoor radon data from 1980 to 2023 was conducted to provide a preliminary understanding of indoor radon concentration levels and trends in China. Keywords were used to collect literature on indoor radon surveys in China during the periods of before 2000, 2000-2010 and after 2010 in the CNKI, WANFANG, VIP and PubMed databases. This paper also collected indoor radon concentration data from WHO, UNSCEAR publications and PubMed databases for other countries. A total of 37,886 indoor radon concentration data points were collected in China, covering 31 provinces. The results showed that the weighted and arithmetic mean radon concentrations in China were 29.4 Bq/m3 and 33.2 Bq/m3 (n = 17,940) before 2000, 44.7 Bq/m3 and 43.3 Bq/m3 (n = 10,692) in 2000-2010, 57.6 Bq/m3 and 60.8 Bq/m3(n = 9,254) after 2010, respectively. It indicated an increasing trend in indoor radon concentrations in China. The differences in mean indoor radon concentrations across time periods were significant (p < 0.001). In the regional analysis, the differences in indoor radon concentrations between different administrative geographic regions for each time period were significant (p < 0.05). Furthermore, the differences in indoor radon concentrations among climatic areas were significant for the periods 2000-2010 and after 2010 (p < 0.05). Additionally, this paper collected indoor radon data from 63 countries worldwide. The mean radon concentrations across the three periods-before 2000, 2000-2010 and after 2010-were 56.5 Bq/m3, 67.9 Bq/m3 and 81 Bq/m3, respectively. Meanwhile, a comparison of indoor radon concentration was made before and after 2000 among 26 countries, of which 16 countries showed an increasing trend. So, it can be seen the increase in indoor radon concentration in China is not an isolated phenomenon, and the issue of indoor radon pollution still requires further attention.

C-C motif chemokine ligand 5 contributes to radon exposure-induced lung injury by recruiting dendritic cells to activate effector T helper cells

Radon (222Rn) is a naturally occurring radioactive gas, ionizing radiation emitted by the radon induces oxidative stress and the up-regulation of inflammatory proteins, which may cause lung damage or cancer. However, the underlying pathogenesis remains to be determined. Effector T helper cells are key in mediating the host's protection and immune homeostasis. In this study we revealed that, accompanied by the activation of effector T helper cells, there is a significant increase in C-C motif chemokine ligand 5 (Ccl5) in the lung of mice after cumulative inhalation of radon at 3, 9, 21, 45, 90, and 180 working level months (WLM). In vitro experiments showed that Ccl5 attracts DC migration and promotes the activation of effector T helper cells in the Ccl5-DC and T cells co-culture model. Of particular interest, Ccl5 neutralization in vivo inhibited the migration of DC cells and the subsequent activation of effector T helper cells, which finally protected mice from radon-induced lung damage and inflammatory response. Ultimately, transcriptome sequencing and western blot analysis showed that Ccl5 activates the CCR5/PI3K/AKT/Nr4a1 pathway to increase the secretion of IL-12 and IFN-γ by DC cells, which then promotes the activation of effector T helper cells. Overall, these results indicate that Ccl5 significantly contributes to the progression of radon-induced lung damage by modulating DC to activate effector T helper cells.

Optimization Methods for Radon Progeny Measurement Based on the Three-Stage Method

In different measurement tasks, the duration allocated for radon progeny concentration measurement varies, and the requirements for measurement precision also differ. To accommodate the needs of various radon progeny concentration measurement tasks, this study takes the error in radon progeny concentration measurement as the optimization goal and the time points of the three-stage method as the optimization target, establishing an optimized three-stage method for radon progeny concentration measurement. The optimization algorithm allocates the three time periods under any total measurement time requirement, ensuring the highest measurement precision. The optimization algorithm can also optimize the measurement errors for 218Po, 214Pb, and 214Bi according to task requirements. By comparing with existing three-stage methods, when the total measurement time is 30 min, the optimization results are similar to Thomas's three-stage method; when the total measurement time is 15 min, the measurement results are consistent with the rapid three-stage method. Therefore, the optimized results of the three-stage method are reasonable and reliable, providing technical support for different radon progeny measurement tasks.

Radon Exposure and Gestational Diabetes

Importance

Understanding environmental risk factors for gestational diabetes (GD) is crucial for developing preventive strategies and improving pregnancy outcomes.

Objective

To examine the association of county-level radon exposure with GD risk in pregnant individuals.

Design, Setting, and Participants

This multicenter, population-based cohort study used data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b) cohort, which recruited nulliparous pregnant participants from 8 US clinical centers between October 2010 and September 2013. Participants who had pregestational diabetes or were missing data on GD or county-level radon measurements were excluded from the current study. Data were analyzed from September 2023 to January 2024.

Exposures

County-level radon data were created by the Lawrence Berkeley National Laboratory based on the Environmental Protection Agency's short- and long-term indoor home radon assessments. Radon exposure was categorized into 3 groups: less than 1, 1 to less than 2, and 2 or more picocuries (pCi)/L (to convert to becquerels per cubic meter, multiply by 37). Because radon, smoking, and fine particulate matter air pollutants (PM2.5) may share similar biological pathways, participants were categorized by joint classifications of radon level (<2 and ≥2 pCi/L) with smoking status (never smokers and ever smokers) and radon level with PM2.5 level (above or below the median).

Main Outcomes and Measures

The main outcome was GD, identified based on glucose tolerance testing and information from medical record abstraction. Multiple logistic regression models were used to assess the association between radon exposure and GD.

Results

Among the 9107 participants, mean (SD) age was 27.0 (5.6) years; 3782 of 9101 (41.6%) had ever used tobacco. The mean (SD) county-level radon concentration was 1.6 (0.9) pCi/L, and 382 participants (4.2%) had GD recorded. After adjusting for potential confounders, individuals living in counties with the highest radon level (≥2 pCi/L) had higher odds of developing GD compared with those living in counties with the lowest radon level (<1 pCi/L) (odds ratio [OR], 1.37; 95% CI, 1.02-1.84); after additional adjustment for PM2.5, the OR was 1.36 (95% CI, 1.00-1.86). Elevated odds of GD were also observed in ever smokers living in counties with a higher (≥2 pCi/L) radon level (OR, 2.09; 95% CI, 1.41-3.11) and participants living in counties with higher radon and PM2.5 levels (OR, 1.93; 95% CI, 1.31-2.83), though no statistically significant interactions were observed.

Conclusions and Relevance

This cohort study suggests that higher radon exposure is associated with greater odds of GD in nulliparous pregnant individuals. Further studies are needed to confirm the results and elucidate the underlying mechanisms, especially with individual-level residential radon exposure assessment.

Radon release at a rehabilitated uranium mine site and dose assessment (case of the former Beshtaugorskiy mine, North Caucasus)

The uranium mines both developed and abandoned appear to be one of the most significant sources of radon exhalation in the world. Therefore, the study of radon exposure of the population in the areas around rehabilitated uranium mines is very important. This article presents the results of the radon release studies at the rehabilitated Beshtaugorsky uranium mine site, which is now used by local people for hiking and picnicking. A dose assessment is also provided. The following parameters were measured: (i) radon flux density from the soil by the open charcoal chamber method using the beta radiometer "Camera-01"; (ii) concentration of radon and its progeny in the air using the radiometer "Alpha-AERO" based on a semiconductor detector; (iii) radon in groundwater by accumulation of radon in charcoal using the "Camera-01" equipment; (iv) content of natural radionuclides in soils and rocks by NaI(Tl) spectrometry; and (v) gamma dose rate using the Geiger-Muller counter. Measurements were taken at 38 points along the Beshtaugorskaya ring road, as well as at the mouths of abandoned adits. The measurements showed significant radon release at the mouths of the former adits and in some sections of tectonic faults. In our opinion, the abnormal radon release is due to convective thermally induced air convection in permeable zones of the mountain massif; radon transport by groundwater does not affect surface radon emissions. The most important source of radiation risk is the incompletely sealed mine openings, which periodically blow out radon-enriched air. In places around the mouth of these mines, the equivalent equilibrium concentration of radon progeny in the open air reaches 35,000-45,000 Bq/m3, and the gamma dose rate also exceeds 10 µSv/h, which is more than 30 times the permissible level. A person resting for 4 h in such an area may, in the worst case, receive a dose of more than 2 mSv. It is advisable to implement measures to prevent or reduce the time people spend in the area around the former mine openings.

Elevated airborne radioactivity downwind of a Colorado oil refinery

Airborne radioactivity from fossil fuel production systems is poorly characterized, but a recent study showed elevated ambient levels with proximity to oil and gas production wells. Here, we report year-long, high temporal resolution monitoring results of airborne alpha radioactivity from both radon gas and radon progeny attached to particulates immediately northeast of an oil refinery in Commerce City, Colorado, USA, in an environmental justice community of concern. Gas and particle-associated radioactivity contributed nearly evenly to the total alpha radioactivity. Total radioactivity levels of 30-40 Bq m-3 were 2-3 times higher than background levels (~10-15 Bq m-3) when winds were light and southwesterly, suggesting the refinery as the geographic origin. Furthermore, elevated airborne radioactivity tracked most closely with the light hydrocarbon and natural gas tracer ethane. Thus, the data imply natural gas as the radon emission carrier. Our findings are unique and suggest a need for further investigations of radon emissions from oil and gas infrastructure such as natural gas processing plants, compressor stations, petrochemical plants, and oil refineries that process oil and natural gas from unconventional production.Implications: Regulatory agencies currently do not mandate or conduct monitoring of radioactivity releases and public exposure from petroleum industry air emissions. This study reports elevated radioactivity from radon gas and nonvolatile radon decay products attached to particulate matter, at about 2-3 times above background levels in proximity to Colorado's largest oil refinery. Observations were within an environmental justice community of concern that experiences well above-average exposure to many other harmful atmospheric pollutants, suggesting potential adverse health effects from this cumulative exposure. Our findings offer actionable insights for policymakers, industry stakeholders, and affected communities alike.

The Impact of Environmental Health Determinants in Surgical Oncology

Environmental determinants of health refer to external factors in our surroundings that influence health outcomes. It is estimated that healthier environments could prevent almost one-quarter of the global burden of disease. Additionally, environmental factors, including lifestyle factors, air pollution, chemical exposures, and natural exposures, are responsible for a significant incidence of cancers and premature cancer deaths. Minority populations, low-income populations, children, and older adults are at increased risk for oncologic risks secondary to environmental factors.

Radon exposure as an occupational risk factor for lung cancer in conventional workplaces. An overview

INTRODUCTION

Radon gas has been a declared human carcinogen for more than 30 years and has been causally associated with lung cancer. Studies have shown a linear relationship between residential radon exposure and lung cancer risk.

AREAS COVERED

Initially, this risk was subjected to cohorts of underground miners and then in case-control studies in the general population.While the evidence on residential radon exposure and lung cancer risk is extensive, there is little evidence on occupational radon exposure in conventional workplaces. Studies estimating radon-attributed mortality and prevalence also consider only residential radon exposure.

EXPERT OPINION

As individuals are also exposed to radon in the workplace, further studies should incorporate an integrated assessment of radon exposure, including both residential and occupational exposure.The European Council Directive established specifications for occupational exposure to radon, indicating the reference level and making it mandatory to measure radon in the workplace. EU countries have adopted national legislation incorporating this framework, some relatively recently. These regulations create an unprecedented situation for previously and currently exposed workers. It is important that the legislation on the determination of radon concentrations in the workplace is rigorously enforced and introduced in countries where this is not yet the case.

Indoor Radon Concentrations in Severe Cold Area and Cold Area and Impact of Energy-saving Design on Indoor Radon in China

ABSTRACT

This study investigated indoor radon concentrations in modern residential buildings in the Cold Area and Severe Cold Area in China. A total of 19 cities covering 16 provinces were selected with 1,610 dwellings measured for indoor radon concentration. The arithmetic mean and geometric mean of indoor radon concentration were 68 Bq m -3 and 57 Bq m -3 , respectively. It was found that indoor radon concentrations were much higher in the Severe Cold Area than those in the Cold Area. The indoor radon concentrations showed an increasing trend for newly constructed buildings. It was estimated that the average effective dose from inhalation of indoor radon is 2.15 mSv and 1.60 mSv for the Severe Cold Area and Cold Area, respectively. The more and more rigid energy-saving design for residential buildings in the Severe Cold Area and Cold Area has an obvious impact on the increased trend of indoor radon due to extremely low air exchange rate in China.

Spectroscopic analysis of alpha particles from radioactive nuclides with CR-39 plastic nuclear track detectors

A spectroscopy method of alpha particles with the track geometry parameters in CR-39 plastic nuclear track detectors is proposed. The relationship between the track registration sensitivity and incident angle of each etch pit is analyzed. The components of alpha particles emitted from radon, thoron and 241Am can be roughly separated when the etching level is not exceeded beyond the range in CR-39. This work aims at improving the dose assessment accuracy from exposure to indoor radon and thoron.

Two-Year Experience of a Center of Excellence for the Comprehensive Management of Non-Small Cell Lung Cancer at a Fourth-Level Hospital in Bogota, Colombia: Observational Case Series Study and Retrospective Analysis

Background: This study aimed to provide a comprehensive analysis of 56 patients admitted to the Lung Cancer Clinical Care Center (C3) at Fundación Santa Fe de Bogotá (FSFB) between 2 May 2022 and 22 April 2024. The focus was on demographic characteristics, smoking history, comorbidities, lung cancer types, TNM classification, treatment modalities, and outcomes. Methods: This observational case series study reviewed medical records and included patients over 18 years with a confirmed diagnosis of non-small cell lung cancer (NSCLC). Data were collected and analyzed for demographics, comorbidities, treatment types, biomolecular profiling, and survival rates. Ethical approval was obtained, and data were anonymized. Results: The mean age was 71.8 years with a female predominance (53.6%). A history of smoking was present in 71.4% of patients. Adenocarcinoma was the most common type (75.0%), followed by squamous cell carcinoma (19.6%). At admission, the most frequent TNM stages were IA2 (17.9%) and IVA (16.1%). One-year survival was 68.8%, and 94.3% of stage I-IIIA patients underwent PET scans. Biomolecular profiling revealed 69.2% non-mutated EGFR, 90.4% ALK-negative, and various PDL-1 expression levels. Immunotherapy was received by 91.4% of patients, with Alectinib and Osimertinib being common. Grade III-IV pneumonitis occurred in 5.4% of patients. Conclusions: The study's findings align with existing literature, highlighting significant smoking history, common adenocarcinoma, and substantial use of immunotherapy. Limitations include the observational design, small sample size, and short follow-up period, impacting the generalizability and long-term outcome assessment. Future research should address these limitations and explore longitudinal outcomes and emerging therapies.

Can neotectonic faults influence soil air radon levels in the Upper Rhine Graben? An exploratory machine learning assessment

Radon (Rn) is a naturally occurring radioactive gas that poses a significant lung cancer risk. Subsurface fault zones can act as pathways for fluid and gas migration, potentially amplifying Rn accumulation. This study investigates the impact of fault zones on Rn concentrations within a 25 km2 area in the Northern Upper Rhine Graben, Germany - a region with available detailed geophysical exploration data and active neotectonic faulting. We conducted 597 Rn soil air measurements along precisely located fault zones, integrating a comprehensive range of environmental parameters. Utilizing the advanced machine learning model eXtreme Gradient Boosting (XGBoost) in conjunction with SHapley Additive exPlanations (SHAP) values, we dissected the influence of soil types, environmental factors, and proximity to fault zones on soil air Rn concentrations at a 1-meter depth. Our results reveal that clay-rich soils and cumulative 30-day precipitation are the primary drivers of elevated Rn levels. Proximity to fault zones also significantly influences Rn concentrations, though its impact is less pronounced than the factors mentioned above. Additionally, environmental factors such as wind speed, air pressure, and temperature exhibited lesser effects on Rn levels. The negligible influence of measuring devices and operating personnel increases confidence in data integrity in extensive environmental studies. This study demonstrates the effectiveness of integrating XGBoost with SHAP values to identify and quantify key factors influencing Rn concentrations. By providing a robust framework for enhancing Rn prediction models through machine learning, our findings contribute to improved risk assessments and mitigation strategies, thereby advancing public health and environmental management.

Associations Between Gestational Residential Radon Exposure and Term Low Birthweight in Connecticut, USA

BACKGROUND

Studies suggest biologic mechanisms for gestational exposure to radiation and impaired fetal development. We explored associations between gestational radon exposure and term low birthweight, for which evidence is limited.

METHODS

We examined data for 68,159 singleton full-term births in Connecticut, United States, 2016-2018. Using a radon spatiotemporal model, we estimated ZIP code-level basement and ground-level exposures during pregnancy and trimesters for each participant's address at birth or delivery. We used logistic regression models, including confounders, to estimate odds ratios (ORs) for term low birth weight in four exposure quartiles (Q1-Q4) with the lowest exposure group (Q1) as the reference.

RESULTS

Exposure levels to basement radon throughout pregnancy (0.27-3.02 pCi/L) were below the guideline level set by the US Environmental Protection Agency (4 pCi/L). The ORs for term low birth weight in the second-highest (Q3; 1.01-1.33 pCi/L) exposure group compared with the reference (<0.79 pCi/L) group for basement radon during the first trimester was 1.22 (95% confidence interval [CI] = 1.02, 1.45). The OR in the highest (Q4; 1.34-4.43 pCi/L) quartile group compared with the reference group during the first trimester was 1.26 (95% CI = 1.05, 1.50). Risks from basement radon were higher for participants with lower income, lower maternal education levels, or living in urban regions.

CONCLUSION

This study found increased term low birth weight risks for increases in basement radon. Results have implications for infants' health for exposure to radon at levels below the current national guideline for indoor radon concentrations and building remediations.

Radon-222 signatures of atmospheric dynamics in the Pech Merle Painted Cave, France: Consequences for management and conservation

Radon-222, a radioactive noble gas with a half-life of 3.8 days produced by radium-226, is a health hazard in caves, but also a powerful tracer of atmospheric dynamics. Here we show how airborne radon-222 can be analysed in a cave with multiple openings, the Pech Merle Cave in South-West France. This two-level cave hosts prehistoric remains and Gravettian paintings in its lower level. Radon concentration, monitored at 15 points with one-hour sampling intervals for more than one year, including two points for more than three years, showed mean values from 1274 ± 11 to 5281 ± 20 Bq m-3, with transient values above 15,000 Bq m-3. Seasonal variations were observed, with a weak normal cycle (low in winter) at two points in the upper level and a pronounced inverse seasonal cycle (low in summer) at the other points in the cave. The radon-222 source (effective radium-226 concentration, ECRa) was measured in the laboratory for floor deposits, soil and rock samples. While ECRa values obtained for rocks and speleothems are smaller than 1 Bq kg-1, most ECRa values for soils are larger than 10 Bq kg-1. Quantitative modelling confirms that the floor fillings inside the cave are responsible for the stationary lower concentrations, while the higher concentrations observed in winter are explained by percolation of outside air, which collects radon-222 as it passes through the soil layers. In addition, Stored Available Radon (SAR) is sufficient to account for transient variations. While air currents occur when visitors enter the cave or when the cave is deliberately ventilated, the climatic processes revealed by their radon-222 signatures appear to be essentially natural. These processes, enhanced by global climate change, could cause or accelerate the deterioration of prehistoric paintings. Radon-222 source analysis using ECRa-based modelling and SAR appears essential for the preservation of underground heritage.

Thoron exposure in the radon-thoron prone area of the Adamawa Region, Cameroon

The radon-prone area of the Adamawa region is characterized by high radon concentrations, where no low-risk area was observed. This study aims to investigate about indoor thoron concentration in this area, using RADUET detectors, thoron progeny monitors and DTPS/DRPS. The indoor thoron concentration ranged between 17 and 1000 Bq m-3, with an average of 131 Bq m-3. 36% of dwellings have thoron concentration less than 100 Bq m-3 while 28% are above 300 Bq m-3. The thoron equilibrium factor of 0.04 was found to be two times higher than the globally assumed value. Thoron progeny contributes on average to 26% (1.9 mSv y-1) of the total inhalation dose. The excess lifetime cancer risk due to thoron progeny is about 5%. These results justify that thoron cannot be neglected when assessing radiation doses. As only radon is regulated, such study will contribute to accelerate the regulation on thoron.

Lung cancer mortality attributable to residential radon in Germany

The radioactive gas radon is one of the most important risk factors for lung cancer after smoking. This article aims to estimate the annual number of lung cancer deaths attributable to residential radon exposure in Germany and its federal states using updated data and an advanced calculation method. Data on lung cancer mortality (2018-2022), smoking behavior (2017), and on the estimated distribution of radon concentration based on a radon residential study (2019-2021) in Germany are used. The risk model employed is derived from the pooled European residential radon study, indicating that excess relative risk for lung cancer increases by 16% per 100 becquerels per cubic meter (Bq/m3 ) of corrected long-term radon concentration. It is estimated that a total of around 2800 lung cancer deaths per year (95% confidence interval (CI) 900-5100) are attributable to residential radon in Germany. This represents a population attributable fraction of 6.3% (95% CI 2.1-11.4%). Notably, radon-attributable lung cancer deaths occur not only among current (41%) but also significantly among former smokers (41%) and those who have never smoked (19%). The results confirm that radon in homes is an important risk factor for lung cancer, highlighting the need for protective measures against radon for all population groups in Germany.

"The air within: reviewing the sources and health effects of indoor air pollution in households"

Air pollution in the interior of our homes is caused by diverse chemical, physical, and biological entities. This review comprehensively explores the current understanding of sources and health impacts of gaseous and particulate pollutants. Trend analysis of indoor air research worldwide revealed a quantum jump of 2.8 times in the number of publications during the last ten years. Indoor air pollutants are innumerable, but only a few are widely prevalent in most households. The qualitative complexity of pollutants translates to different health problems, including respiratory diseases, cardiovascular conditions, cancer, and deaths. There exist wide-scale disparities in the negative impacts among different economic strata, genders, and age groups; children and elderly populations are more vulnerable. In developing countries, pollutants primarily arise from traditional sources, whereas in developed countries, pollutants from non-conventional sources are comparatively significant. Only a few countries have indoor air regulations, policies, monitoring plans and effective enforcement.

Distribution of radon in large workplaces: an analysis performed on radon levels measured in UK schools

Radon is a radioactive, carcinogenic gas formed by the radioactive decay of uranium and radium that occur naturally in small amounts in all rocks and soils. It is the largest single source of radiation exposure to the UK population, contributing to more than 1 100 lung cancer deaths each year according to an analysis conducted in 2005. Regulations exist to protect employees (and other persons) where radon concentrations exceed the reference level of 300 Bq m-3. Once the reference level is exceeded, annual doses of more than the public dose limit of 1 mSv a-1are considered to be excessive. A radon measurement campaign for schools, which started in 2009, generated a large dataset, including those with high numbers of simultaneous radon measurements. Radon data between buildings (e.g. homes) have been shown to correspond broadly to the lognormal distribution, after the additive contribution of outside air has been removed. However, there are fewer studies of the distribution of radon levels within a single, large property. Radon data collected from 533 UK schools with at least 20 valid, simultaneous results were analysed against several statistical models. In approximately 50% of schools the radon levels could be represented by the lognormal distribution and in 60% by the loglogistic lognormal distribution, the latter being a better fit probably owing to its lower sensitivity to the tails of the distribution. Qualitatively, the lognormal and the loglogistic probability plots appeared to be indistinguishable. These findings indicate that the lognormal and loglogistic might be appropriate models to characterise the distribution of radon in most large workplaces. For each statistical model, the two distribution parameters can be used to provide a better estimate of the average dose to the occupants. However, caution is required when assessing doses, since the average estimator of the radon concentration does not predict the highest value and may significantly underestimate or overestimate the dose in specific areas.

Nicotine interacts with DNA lesions induced by alpha radiation which may contribute to erroneous repair in human lung epithelial cells

PURPOSE

Epidemiological studies show that radon and cigarette smoke interact in inducing lung cancer, but the contribution of nicotine in response to alpha radiation emitted by radon is not well understood.

MATERIALS AND METHODS

Bronchial epithelial BEAS-2B cells were either pre-treated with 2 µM nicotine during 16 h, exposed to radiation, or the combination. DNA damage, cellular and chromosomal alterations, oxidative stress as well as inflammatory responses were assessed to investigate the role of nicotine in modulating responses.

RESULTS

Less γH2AX foci were detected at 1 h after alpha radiation exposure (1-2 Gy) in the combination group versus alpha radiation alone, whereas nicotine alone had no effect. Comet assay showed less DNA breaks already just after combined exposure, supported by reduced p-ATM, p-DNA-PK, p-p53 and RAD51 at 1 h, compared to alpha radiation alone. Yet the frequency of translocations was higher in the combination group at 27 h after irradiation. Although nicotine did not alter G2 arrest at 24 h, it assisted in cell cycle progression at 48 h post radiation. A slightly faster recovery was indicated in the combination group based on cell viability kinetics and viable cell counts, and significantly using colony formation assay. Pan-histone acetyl transferase inhibition using PU139 blocked the reduction in p-p53 and γH2AX activation, suggesting a role for nicotine-induced histone acetylation in enabling rapid DNA repair. Nicotine had a modest effect on reactive oxygen species induction, but tended to increase alpha particle-induced pro-inflammatory IL-6 and IL-1β (4 Gy). Interestingly, nicotine did not alter gamma radiation-induced γH2AX foci.

CONCLUSIONS

This study provides evidence that nicotine modulates alpha-radiation response by causing a faster but more error-prone repair, as well as rapid recovery, which may allow expansion of cells with genomic instabilities. These results hold implications for estimating radiation risk among nicotine users.

Overview of radon gas in groundwater around the world: Health effects and treatment technologies

The natural radioactive decay of uranium in rocks and soils gives rise to the presence of radon in groundwater. The existence of radon in groundwater at activity levels way higher than the reference limits set by US-EPA and WHO was widely covered in literature. The exposure to elevated levels of radon in ground and drinking water have been reported in literature to cause adverse health impacts. The aim of the present paper is to give an overview of radon gas in groundwater followed by the safe limits suggested by international organizations and agencies such as US-EPA and WHO. The paper also discusses the health effects associated with the exposure to radon levels and the estimation of the annual effective dose through ingestion and inhalation. This is followed by the radon levels around the world as well as the corresponding annual effective doses reported in literature. The determination techniques of radon levels in water covered in literature such as liquid scintillation counting, gamma-ray spectrometry and emanometry were also discussed and reviewed in the present work. Next, the paper sheds light on the most frequently used treatment techniques such as aeration, adsorption, filtration as well as biological techniques and evaluates their efficiency in mitigating radon levels in water. The paper also highlights the main precautions and future mitigation plans for radon in groundwater as well as delved onto future research perspectives of radon. It was found out that the type of rock played a key role in determining the radon levels. For instance, granitic rock types were reported to contribute to the elevation in the groundwater radon levels due to their characteristic permeability as a result of the formed fractures as well as their natural incorporation of high levels of uranium. Some of the reported radon levels in groundwater in literature were way higher than the guidelines set by the World Health Organization (WHO) for drinking water and US-EPA alternative higher maximum contaminant level. This review paper could be of importance to researchers working on the evaluation as well as the treatment of radon gas in water as it will provide a critical and state of the art review on radon gas in groundwater.

Development of a High-Resolution Indoor Radon Map Using a New Machine Learning-Based Probabilistic Model and German Radon Survey Data

BACKGROUND

Radon is a carcinogenic, radioactive gas that can accumulate indoors and is undetected by human senses. Therefore, accurate knowledge of indoor radon concentration is crucial for assessing radon-related health effects or identifying radon-prone areas.

OBJECTIVES

Indoor radon concentration at the national scale is usually estimated on the basis of extensive measurement campaigns. However, characteristics of the sampled households often differ from the characteristics of the target population owing to the large number of relevant factors that control the indoor radon concentration, such as the availability of geogenic radon or floor level. Furthermore, the sample size usually does not allow estimation with high spatial resolution. We propose a model-based approach that allows a more realistic estimation of indoor radon distribution with a higher spatial resolution than a purely data-based approach.

METHODS

A multistage modeling approach was used by applying a quantile regression forest that uses environmental and building data as predictors to estimate the probability distribution function of indoor radon for each floor level of each residential building in Germany. Based on the estimated probability distribution function, a probabilistic Monte Carlo sampling technique was applied, enabling the combination and population weighting of floor-level predictions. In this way, the uncertainty of the individual predictions is effectively propagated into the estimate of variability at the aggregated level.

RESULTS

The results show an approximate lognormal distribution of indoor radon in dwellings in Germany with an arithmetic mean of 63  Bq / m 3 , a geometric mean of 41  Bq / m 3 , and a 95th percentile of 180  Bq / m 3 . The exceedance probabilities for 100 and 300  Bq / m 3 are 12.5% (10.5 million people affected) and 2.2% (1.9 million people affected), respectively. In large cities, individual indoor radon concentration is generally estimated to be lower than in rural areas, which is due to the different distribution of the population on floor levels.

DISCUSSION

The advantages of our approach are that is yields a) an accurate estimation of indoor radon concentration even if the survey is not fully representative with respect to floor level and radon concentration in soil, and b) an estimate of the indoor radon distribution with a much higher spatial resolution than basic descriptive statistics. https://doi.org/10.1289/EHP14171.

Actinium-225 photonuclear production in nuclear reactors using a mixed radium-226 and gadolinium-157 target

BACKGROUND

Actinium-225 is one of the most promising radionuclides for targeted alpha therapy. Its limited availability significantly restricts clinical trials and potential applications of 225Ac-based radiopharmaceuticals.

METHODS

In this work, we examine the possibility of 225Ac production from the thermal neutron flux of a nuclear reactor. For this purpose, a target consisting of 1.4 mg of 226Ra(NO3)2 (T1/2 = 1600 years) and 115.5 mg of 90 % enriched, stable 157Gd2O3 was irradiated for 48 h in the Breazeale Nuclear Reactor with an average neutron flux of 1.7·1013 cm-2·s-1. Gadolinium-157 has one of the highest thermal neutron capture cross sections of 0.25 Mb, and its neutron capture results in emission of high-energy, prompt γ-photons. Emitted γ-photons interact with 226Ra to produce 225Ra according to the 226Ra(γ, n)225Ra reaction. Gadolinium debulking and separation of undesirable, co-produced 227Ac from 225Ra was achieved in one step by using 60 g of branched DGA resin. After 225Ac ingrowth from 225Ra (T1/2 = 14.8 d), 225Ac was extracted from the 226Ra and 225Ra fraction using 5 g of bDGA resin and then eluted using 5 mM HNO3.

RESULTS

Measured activity of 225Ac showed that 6(1) kBq or 0.16(3) μCi (1σ) of 225Ra was produced at the end of bombardment from 0.9 mg of 226Ra.

CONCLUSION

The developed 225Ac separation is a waste-free process which can be used to obtain pure 225Ac in a nuclear reactor.

Airborne particle radioactivity during desert dust days in Cyprus

Mediterranean countries are often affected by desert dust storms, which have significant effects on the environment and public health. We compared airborne particle radioactivity levels during desert dust and non-dust days in Cyprus. Gross α- and β-radioactivity from Total Suspended Particle (TSP) samples, collected at two urban routine monitoring stations in Limassol and Nicosia, were available for the period 2017-2020 and 2008-2020, respectively. Radionuclides 137Cs and 40K, from TSP samples, were also available from a semi-industrial monitoring station in Nicosia during 2008-2020. Information on desert dust presence, dust origin, particulate matter (PM) levels, and solar activity (KP index and solar sunspot numbers - SSN) were also obtained. We used linear regression models adjusting for seasonality and long-term trends, and solar activity to assess the effect of dust storms on TSP gross α- and β-, and 137Cs and 40K radioactivity levels. Gross α- and β-radioactivity, and 137Cs and 40K radioactivity levels were significantly higher on days with desert dust compared to days characterized with no influence of desert dust. Levels of gross α- and β-radioactivity during dust days were higher when dust originated from the Middle East deserts than from the Sahara Desert. The same trend was observed for the ratios 137Cs to 40K and 137Cs to PM10. Conversely, ratios of TSP gross α- and β-radioactivity to PM10 were significantly lower during desert dust days in comparison to days without dust influence. This study suggests that desert dust increase both TSP gross α- and β-radioactivity, as well as 137Cs and 40K radioactivity levels. Further studies should clarify the contribution of anthropogenic and other natural sources to the emission or transportation of particles radioactivity, to better mitigate future exposures.

Radiological assessment of radon in groundwater of the northernmost Kashmir Basin, northwestern Himalaya

This study investigates the radon concentration in groundwater in Kupwara, the northernmost district of the Kashmir valley. It further assesses the annual effective dose experienced by the district's diverse population-infants, children, and adults-attributable to both inhalation of airborne radon released from drinking water and direct ingestion. In addition to this, the calculation of gamma dose rate is also carried out at each of the sampling site of radon. A portable radon-thoron monitor and a portable gamma radiation detector were respectively employed to estimate the activity concentration of radon in water samples and to measure the gamma dose rate. The radon concentration was found to exhibit variability from a minimum of 2.9 BqL-1 to a maximum of 197.2 BqL-1, with a mean of 26.3 BqL-1 and a standard deviation of 23.3 BqL-1. From a total of 85 samples, 10.6% of the samples had radon activity concentrations exceeding the permissible limits of 40 BqL-1 set by the United Nations Scientific Committee on Effects of Atomic Radiations as reported by UNSCEAR (Sources and effects of ionizing radiation, 2008) and only 1.2% of the samples have radon activity concentration exceeding the permissible limits of 100 BqL-1 set by the World Health Organization as reported by WHO (WHO guidelines for drinking-water quality, World Health Organization, Geneva, 2008). The mean of the annual effective dose due to inhalation for all age groups as well as the annual ingestion dose for infants and children, surpasses the World Health Organization's limit of 100 μSv y-1 as reported by WHO (WHO guidelines for drinking-water quality, World Health Organization, Geneva, 2008). The observed gamma radiation dose rate in the vicinity of groundwater radon sites ranged from a minimum of 138 nSv h-1 to a maximum of 250 nSv h-1. The data indicated no significant correlation between the dose rate of gamma radiation and the radon levels in the groundwater. Radon concentration of potable water in the study area presents a non-negligible exposure pathway for residents. Therefore, the judicious application of established radon mitigation techniques is pivotal to minimize public health vulnerabilities.

A Historical Survey of Key Epidemiological Studies of Ionizing Radiation Exposure

In this article we review the history of key epidemiological studies of populations exposed to ionizing radiation. We highlight historical and recent findings regarding radiation-associated risks for incidence and mortality of cancer and non-cancer outcomes with emphasis on study design and methods of exposure assessment and dose estimation along with brief consideration of sources of bias for a few of the more important studies. We examine the findings from the epidemiological studies of the Japanese atomic bomb survivors, persons exposed to radiation for diagnostic or therapeutic purposes, those exposed to environmental sources including Chornobyl and other reactor accidents, and occupationally exposed cohorts. We also summarize results of pooled studies. These summaries are necessarily brief, but we provide references to more detailed information. We discuss possible future directions of study, to include assessment of susceptible populations, and possible new populations, data sources, study designs and methods of analysis.

On the informative value of community-based indoor radon values in relation to lung cancer

BACKGROUND

Radon is a radioactive gas and a major risk factor for lung cancer (LC).

METHODS

We investigated the dose-response relationship between radon and LC risk in the International Lung Cancer Consortium with 8927 cases and 5562 controls from Europe, North America, and Israel, conducted between 1992 and 2016. Spatial indoor radon exposure in the residential area (sIR) obtained from national surveys was linked to the participants' residential geolocation. Parametric linear and spline functions were fitted within a logistic regression framework.

RESULTS

We observed a non-linear spatial-dose response relationship for sIR < 200 Bq/m3. The lowest risk was observed for areas of mean exposure of 58 Bq/m3 (95% CI: 56.1-59.2 Bq/m3). The relative risk of lung cancer increased to the same degree in areas averaging 25 Bq/m3 (OR = 1.31, 95% CI: 1.01-1.59) as in areas with a mean of 100 Bq/m3 (OR = 1.34, 95% CI: 1.20-1.45). The strongest association was observed for small cell lung cancer and the weakest for squamous cell carcinoma. A stronger association was also observed in men, but only at higher exposure levels. The non-linear association is primarily observed among the younger population (age < 69 years), but not in the older population, which can potentially represent different biological radiation responses.

CONCLUSIONS

The sIR is useful as proxy of individual radon exposure in epidemiological studies on lung cancer. The usual assumption of a linear, no-threshold dose-response relationship, as can be made for individual radon exposures, may not be optimal for sIR values of less than 200 Bq/m3.

222Rn and 220Rn levels in drinking water, emanation, and exhalation assessment, and the related health implications in the U-bearing area of Poli-Cameroon

The inherent radioactivity of radon gas presents potential exposure risks to human beings through ingestion and inhalation of its radioisotopes 222Rn (radon) and 220Rn (thoron) from water sources. Recent studies have been conducted to assess radon concentrations in different environmental matrices such as water, air, and soil, due to their detrimental impact on human health. As the main cause of lung cancer in non-smokers and an acknowledged contributor to stomach cancer when ingested, the present study aimed to preliminarily assess radon and thoron levels in the Uranium bearing area of Poli in the Faro division of Cameroon, known for its significant U-deposits. The assessment included measuring 220, 222Rn concentrations in drinking water, emanation, and exhalation, with a specific focus on evaluating the exposure of different age groups within the local population. The radon/thoron levels in water and their related exposure and cancer risk data indicated no immediate health hazards. However, continuous monitoring and prospective measures are deemed essential due to the area's abundant U-minerals. The emanation measurements showed sparsely distributed data with a singularity at Salaki, where the equipment recorded values of 8.14 × 1012 Bqm-3 and 3.27 × 1012 Bqm-3 for radon and thoron, respectively. Moreover, radon/thoron transfer coefficients from the soil to the air indicated levels below unity. While the calculated doses suggest minimum potential risk in line with WHO and UNSCEAR guidelines, the obtained results are expected to significantly contribute to the establishment of national standards for radon levels in drinking water, emanation, and exhalation. Furthermore, these findings can play a crucial role in monitoring radon/thoron levels to ensure public health safety.

Ra-226 in building materials as a source of indoor radon in high-rise residential buildings in Russian cities

The problem of indoor radon in high-rise buildings is mostly associated with exhalation from building materials. Characterization of the radon entry from building materials by diffusion is required to provide a proper control of the population indoor radon exposure. To analyze the relationship between the content of Ra-226 in building materials and the indoor radon concentration the results of the following surveys in high-rise buildings in Russian cities were used: 1) indoor radon (>1000 apartments), 2) natural radionuclides in the building materials in existing buildings by means of non-destructive field gamma spectrometry (100 apartments). The surveys were carried out in nine large cities in different climatic zones. The radon entry rate due to diffusion from building materials, D, normalized to Ra-226 activity concentration, Ra, is in the range of 0.2-0.6 (Bq/m3/h)/(Bq/kg), depending on the type of building materials and building construction. In new multi-story buildings, the typical D/Ra ratio can be assumed to be 0.4 (Bq/m3/h)/(Bq/kg). In new energy-efficient buildings, the ratio of the radon concentration to Ra-226 activity concentration is on average 2.1 times higher than in multi-story buildings of lower energy efficiency built before 2000. The average radon exhalation rate from the building materials, normalized to Ra-226 activity concentration, is estimated to be 0.25 Bq/m2/h.

Neighborhood-level socioeconomic disparities in Radon testing in North Carolina from 2010 to 2020

Radon is a naturally occurring radioactive gas that poses significant health risks to humans, including increased risk of lung cancer. This study investigates the association of neighborhood-level socioeconomic variables with radon testing and radon exposure levels in North Carolina between 2010 and 2020. Our analysis of the two largest commercial household radon tests reveals that 67% of census tracts had testing rates below 10 tests per 1000 population, indicating low testing prevalence. Low radon levels (<2 pCi/L) were detected in 74.1% of the tracts (n = 1626), while medium levels of 2-4 pCi/L and ≥4 pCi/L were observed in 17.2% (n = 378) and 1.6% (n = 36) of the tracts. A generalized spatial regression model was employed to analyze the association between neighborhood-level socioeconomic variables and radon testing rates (per 1000 households), controlling for median radon testing results. The results show a positive correlation (P-value <0.001) of testing rate with various indicators of neighborhood affluence including education level, income, and occupation. In contrast, neighborhood disadvantage, including poverty, unemployment, and public assistance, was associated with a lower radon-testing rate (P-value <0.001). These findings highlight the need for targeted interventions to address socioeconomic disparities in radon testing and promote awareness and access to testing resources in lower socio-economic neighborhoods. Improving testing rates can effectively address radon-related health risks in North Carolina and across the U.S.

Radon Exhalation Rate: A Metrological Approach for Radiation Protection

Radon, a radioactive inert gas that comes from the decay of naturally occurring radioactive species, poses a substantial health risk due to its involvement in lung cancer carcinogenesis. This work proposes a metrological approach for determining radon exhalation rates from diverse building materials. This methodology employs an electrostatic collection chamber for alpha spectrometry of radon isotopic decay products. Experimental evaluations were conducted particularly focusing on volcanic gray tuff from Sant'Agata de' Goti (Campania region, Italy), a material commonly utilized in construction, to assess radon exhalation rates. The study aligns with Legislative Decree 101/2020, a transposition of European Directive 59/2013/Euratom, highlighting the need to identify materials with a high risk of radon exhalation. Moreover, this work supports the goals of the Italian National Radon Action Plan related to the aforementioned decree, aiming to develop methodologies for estimating radon exhalation rates from building materials and improving radioprotection practices.

Radon and lung cancer: Current status and future prospects

Beyond tobacco smoking, radon takes its place as the second most significant contributor to lung cancer, excluding hereditary and other biologically related factors. Radon and its byproducts play a pivotal role in exposing humans to elevated levels of natural radiation. Approximately 10-20 % of lung cancer cases worldwide can be attributed to radon exposure, leading to between 3 % and 20 % of all lung cancer-related deaths. Nevertheless, a knowledge gap persists regarding the association between radon and lung cancer, impeding radon risk reduction initiatives globally. This review presents a comprehensive overview of the current state of research in epidemiology, cell biology, dosimetry, and risk modeling concerning radon exposure and its relevance to lung cancer. It also delves into methods for measuring radon concentrations, monitoring radon risk zones, and identifying priorities for future research.

Tackling Non-Small Cell Lung Cancer in Young Adults: From Risk Factors and Genetic Susceptibility to Lung Cancer Profile and Outcomes

Lung cancer has traditionally been associated with advanced age; however, its increasing incidence among young adults raises concerning questions regarding its etiology and unique considerations for this population. In contrast to the older population, the onset of lung cancer at younger age may be attributed to a complex interplay of incompletely understood individual susceptibility and prevalent environmental risk factors beyond tobacco smoke exposure, such as radon gas and air pollution, which are widespread globally. Consequently, this leads to distinct clinical and molecular profiles, requiring a tailored approach. Furthermore, a diagnosis of cancer represents a threatening event during the prime years of a young person's life, prompting concern about career development, social aspects, fertility aspirations, and physical independence. This poses significant additional challenges for health care professionals in a field that remains underexplored. This comprehensive review recognizes lung cancer in young adults as a distinct entity, exploring its clinical and molecular characteristics, diverse predisposing factors, and priorities in terms of quality of life, with the aim of providing practical support to oncologists and enhancing our understanding of this under-researched population.