Search Results (58)

Background: Radon exposure is the second most important risk factor for lung cancer after tobacco smoking and represents a significant but often underestimated public health problem. Due to the absence of specific clinical manifestations at early stages, the identification of molecular biomarkers reflecting early radon-induced carcinogenic processes is of particular importance. The aim of this study was to identify protein biomarkers associated with radon exposure in lung cancer patients residing in settlements of the Akmola and North Kazakhstan regions of Kazakhstan. Methods: Indoor radon exposure was assessed using CR-39 detectors to measure radon concentrations in residential dwellings during summer and autumn periods. The study included 57 lung cancer patients and 73 control subjects residing in areas characterized by varying levels of radon exposure. Plasma samples were collected and analyzed using liquid chromatography–tandem mass spectrometry (LC–MS/MS) to identify differentially expressed proteins associated with lung cancer and radon exposure. Statistical analyses were performed to evaluate differences between groups and associations between radon exposure and molecular biomarkers. Results: Seasonal variability in indoor radon concentrations was observed, with several settlements demonstrating levels exceeding international reference values. Proteomic analysis identified multiple proteins differentially expressed between lung cancer patients and controls, as well as between radon-exposed and non-exposed lung cancer patients. Several proteins involved in inflammation, lipid metabolism, oxidative stress, and immune regulation pathways demonstrated significant differences in expression levels, suggesting potential associations with radon-induced carcinogenic mechanisms. LC–MS/MS proteomic profiling identified multiple differentially expressed proteins associated with lung cancer and radon exposure after false discovery rate correction. Proteins involved in inflammation, oxidative stress, immune regulation, and lipid metabolism, including ORM2, AZGP1, PRDX2, IRF7, and APOC3, demonstrated significant expression differences between radon-exposed and low-exposure groups. Conclusions: The identified protein biomarkers demonstrated significant associations with both radon exposure and lung cancer status, indicating their potential relevance for early detection and risk assessment of radon-induced lung cancer. The integration of environmental exposure assessment with proteomic profiling may provide new insights into the molecular mechanisms of radon-associated carcinogenesis and support the development of preventive strategies. Full article

Radon-222, a naturally occurring radioactive gas, is the second leading cause of lung cancer globally, after tobacco use. When inhaled, its decay products, especially polonium-218 and polonium-214, emit high-energy alpha particles that induce dense DNA damage in the bronchial epithelium. Because ambient radon measurements often vary significantly over time and across locations, they provide limited insight into individual exposure levels. This suggests the urgent need for biological markers that can accurately indicate internal dose and early signs of lung cancer development. This review offers an extensive overview of biomarkers associated with radon exposure, from internal dosimetry to early biological responses. It covers internal dose markers (e.g., radon progeny in air and ²¹⁰Po/²¹⁰Pb in bones and teeth), molecular and cytogenetic indicators of effective dose (such as chromosomal aberrations, γ-H2AX foci, and DNA adducts), and early effect markers (including somatic mutations, epigenetic changes, miRNA profiles, and autoantibody signatures). The review highlights translocations detected via FISH, discussing those that are stable over time versus those that are transient. It also evaluates the reliability and practicality of these biomarkers in occupational and residential settings, noting how smoking complicates causal inference due to overlapping mutation pathways. Finally, it suggests that integrating multi-omics technologies could improve the precision of biomarker panels. Full article

Background/Objectives: Radon is a naturally occurring radioactive gas and the leading source of natural radiation exposure worldwide; however, its systemic biological effects in children remain poorly understood. This study examined the association between cumulative indoor radon exposure and inflammatory biomarkers among children residing in rural communities of the Aqmola region in Kazakhstan. Methods: The study included 87 children and adolescents (42 exposed and 45 controls). Radon exposure was measured in residential and school environments, and a composite Radon Exposure Index (REI) was constructed to estimate cumulative exposure over time. Serum concentrations of inflammatory biomarkers, including C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-8 (IL-8), were measured using validated immunoassay methods. Multivariable linear regression models adjusted for age, sex, body mass index, pubertal development stage, and heating type were used to evaluate associations between REI and biomarker levels. Results: Children and adolescents living in the radon-exposed community had significantly higher REI values than controls (7.75 ± 0.85 vs.4.83 ± 0.41, respectively). Among the biomarkers examined, CRP, TNF-α, IL-1β, IL-8 and IL-6 were not significantly associated with radon exposure. Conclusions: These findings do not support the use of the evaluated inflammatory biomarkers as indicators of early biological effects of environmental radon exposure in this population. However, the clear exposure contrast observed between study settings underscores the ongoing public health relevance of radon as an environmental hazard. Continued efforts to monitor and mitigate radon exposure in high-risk regions remain essential, particularly in environments where children spend substantial amounts of time. Full article

Background/Objectives: Radon exposure has recently been associated with asthma morbidity, including increased airway inflammation and school absenteeism in children, though limited data on underlying biological mechanisms exist. Interleukin-6 (IL-6), a pleiotropic cytokine implicated in both Type 2-low airway inflammation and radon-related lung carcinogenesis, may represent a key mechanistic link between radon exposure and asthma morbidity. We aimed to evaluate the association between indoor radon exposure and plasma IL-6 levels in children with asthma and whether this relationship differs by allergic sensitization status. Methods: We analyzed baseline data from the School Inner-City Asthma Study, a prospective cohort of children aged 4–13 years with persistent asthma. Monthly indoor radon concentrations at each participant’s residential ZIP Code Tabulation Area were estimated using a validated spatiotemporal prediction model. Plasma IL-6 was measured from baseline blood samples. Multivariable linear mixed-effects models with random intercepts for school were used to assess the association between radon exposure and IL-6, adjusting for demographic, clinical, and socioeconomic covariates. Effect modification by allergic sensitization was evaluated using an interaction term. Results: Among 144 participants, 62.5% were allergen-sensitized. The median home radon concentration was 46.6 Bq/m³ (range 30.7–99.9), and the mean plasma IL-6 was 0.22 pg/mL (SD 0.41). A significant interaction was observed between radon exposure and allergic sensitization status (β-interaction = −0.012; p = 0.014), indicating differential effects by phenotype. Among non-sensitized children, higher radon exposure was associated with increased IL-6 levels (β = 0.0088; p = 0.044), corresponding to a 0.32 pg/mL rise in IL-6 per 37 Bq/m³ increase in radon. No significant association was observed among sensitized children. Conclusions: Indoor radon exposure is associated with higher plasma IL-6 levels in non-sensitized children with asthma, suggesting a potential IL-6–mediated pathway linking radon exposure to asthma morbidity in the Type 2-low phenotype. These findings highlight heterogeneity in environmental asthma responses and support further investigation into radon mitigation as a modifiable factor to improve asthma outcomes. IL-6 may serve as a biomarker to identify children most susceptible to radon-related airway inflammation, guiding personalized mitigation strategies and targeted interventions to improve asthma outcomes. Future studies should incorporate direct home radon measurements, comprehensive endotyping panels, and longitudinal biomarker sampling to validate these findings and elucidate whether IL-6 trans-signaling pathways mediate radon-induced airway injury in non-allergic asthma. Full article

Radon (²²²Rn₈₆), the second leading cause of lung cancer, is common in indoor air. However, radon testing is generally low throughout the US. In this study, we utilized 134,496 short-term indoor air radon test results from Georgia, USA. We investigated the association of the radon testing rate with a total of 104 different independent variables belonging to seven categories: (1) Demographic and Neighborhood Characteristics; (2) Housing Characteristics; (3) Literacy and Numeracy; (4) Employment and Economy; (5) Selected Social Factors; (6) Access to Computer/Internet; and (7) Status of Healthcare, Health, Well-being, and Lifestyle. We used Bivariate Correlation, Multivariate Ordinary Least Squares (OLS) Regression, and Factor Analysis, followed by factor score-based OLS regression. Significant negative associations of the testing rates were observed with population diversity, residential segregation, urban population density, younger population, housing age, household size, low literacy, unemployment, childcare cost burden, poverty, obesity, and the frequency of mentally and physically unhealthy days. In contrast, testing rates were positively associated with older population, home value, owner-occupied homes, higher literacy, higher institutional education, income, prevalence of social association, and life expectancy. The findings provide valuable insights for identifying the communities where socio-culturally relevant outreach activities would increase testing rates and minimize the public health consequences of environmental radon. Full article

Background: Health risks from radon exposure depend on long-term radon concentrations. This study quantified interannual variability in residential radon concentrations in Finland and evaluated its implications for exposure assessment and measurement recommendations. Methods: A random sample of 277 dwellings from the national radon registry, representative of Finnish regions, building types, and construction years, was monitored using year-long Makrofol-based track-etch detectors over four consecutive years (2021–2025). Year-to-year variability was characterized using the coefficient of variation (CV). Simulations incorporating the observed CVs, previously established seasonal correction factors, and measurement uncertainty were conducted to determine thresholds for follow-up measurements in relation to reference levels. Results: The coefficient of variation (CV) for normalized annual mean concentrations was 0.16, with 90% of dwellings exhibiting CV ≤ 0.30. Although substantial variation occurred at the individual dwelling level, no statistically significant differences in overall radon levels were observed between years. Simulations showed that applying a 100 Bq/m³ threshold for recommending follow-up measurements results in an approximately 3% false-negative rate relative to the 200 Bq/m³ reference level. Lowering the threshold to 70 Bq/m³ reduces this probability to approximately 1%. Conclusions: These findings are consistent with international studies and provide an empirical basis for recommendations on follow-up radon measurements and for quantifying uncertainties in radon exposure assessment in Finnish dwellings. Full article

Machine learning (ML) models can complement traditional measurement-based approaches by supporting large-scale screening, spatial analysis, and prioritization of buildings for testing of indoor radon, a leading cause of lung cancer among non-smokers. Originating from uranium decay in soil and rock, radon enters homes via foundation cracks and accumulates indoors, influenced by building characteristics, ventilation, urbanization, and geogenic factors. As part of the Zagreb pilot within the “Evidence Driven Indoor Air Quality Improvement” (EDIAQI) project, this is the first ML application for indoor radon analysis in Croatia. This research evaluates residential indoor radon concentrations in Zagreb using ML applied to a dataset of 80 households. Several linear regression and tree-based ensemble methods were tested. The best-performing model (GBR) achieved an R² of 0.99 on the training set and 0.57 on the test set, with an RMSE of 33 Bq/m³ and MAE of 26 Bq/m³. Although predictive performance was moderate and generalization limited, key building characteristics such as construction year, dwelling type, occupancy details, and floor level were identified as relevant variables. The results suggest that machine learning may support radon risk prioritization in urban environments, but cannot replace direct measurements for regulatory purposes. Full article

Background: Lung carcinoma remains the leading cause of cancer-related mortality worldwide, with smoking as the primary risk factor and radon exposure as the second, and the first among non-smokers. The combined effect of tobacco smoke and indoor radon increases disease risk up to 2.5 times, emphasizing the need for prevention and environmental risk assessment. Methods: This study analyzed the incidence of lung carcinoma in Bulgaria during 2013–2022 and examined its association with indoor radon exposure across different regions. Annual data were obtained from the National Statistical Institute and the National Survey of Indoor Radon Concentrations in Residential Buildings (2015–2016). Results: The average annual incidence was 43.5 per 100,000 population, showing a 3.4% annual decline, while the average prevalence was 131.7 per 100,000, decreasing by 1.4% per year. Considerable interregional variation was observed, with incidence ranging from 25.5 to 62.4 per 100,000. A moderate positive correlation was found between lung carcinoma incidence and mean indoor radon concentration, and a stronger to very strong correlation with the proportion of dwellings exceeding 300 Bq/m³ and 200 Bq/m³. Conclusions: These findings indicate a positive association between residential radon exposure and lung cancer morbidity and support maintaining the WHO-recommended reference level of 200 Bq/m³. Full article

Residential radon is a leading environmental cause of lung cancer, but circulating biomarkers linking home exposure to pathogenic biology are not well defined. We conducted an exposure-contrast study in Hang Dong District, Chiang Mai, measuring indoor radon in 48 homes and enrolling adults from <50 Bq/m³ (low) and ≥100 Bq/m³ (high) households for serum profiling. Mean indoor radon was 61.8 ± 18.4 Bq/m³ (range 34–126), with 6.2% of homes ≥100 Bq/m³. Small RNA sequencing identified 55 differentially expressed miRNAs (12 up, 43 down) in high-radon serum. Notably, miR-200b-3p, miR-200c-3p, and miR-194-5p were increased, while miR-3913-5p, miR-584-5p, miR-30a-3p, miR-22-3p, and miR-125a-5p were decreased. Target enrichment (KEGG/GO) implicated PI3K–Akt and MAPK hubs with Ras/Wnt/VEGF alongside focal adhesion/ECM–receptor/actin–cytoskeleton and immune-regulatory modules. Untargeted LC–MS metabolomics showed exposure-aligned shifts: higher PUFAs and oxylipins (e.g., AA, EPA; 9-HEPE, 8-HETE, 5,12-DiHETE), elevated acyl-carnitines (β-oxidation), and increased inosine/hypoxanthine, consistent with lipid/steroid remodeling, mitochondrial fuel reprogramming, oxidative stress, and nucleotide turnover. Integrated interpretation supports DDR/ATM → PI3K/Akt–MAPK activation with EMT/adhesion remodeling, angiogenic signaling, and immune modulation—linking residential radon to lung cancer mechanisms. Given the small sample size (n = 10), these findings should be interpreted as preliminary and hypothesis-generating, warranting validation in larger cohorts. Nevertheless, findings support household testing, remediation at ≥100 Bq/m³, and integrated exposure studies considering PM2.5 co-exposures. Full article

Purpose: To achieve a better understanding of the environmental factors that contribute to childhood cancers, so as to inform future prevention efforts. Methods: We conducted a comprehensive review of epidemiological studies on environmental risk factors and childhood cancer, which was published between January 2014 and March 2021. Potential exposure sources presented in this review include air pollution, radiation, and parental occupational exposures. We considered exposures during childhood and parental exposures occurring before the child’s conception and during pregnancy in relation to all types of childhood cancer. Results: Aggregated evidence is strong for associations between leukemia and parental/child exposure to traffic pollution, indoor paints, residential pesticides, and parental occupational/nonoccupational exposure to benzene. Evidence is also strong for associations between brain cancer and residential pesticides and parental occupational exposure to agricultural pesticides. Evidence of associations between leukemia and ionizing radiation from radon and nuclear power plants remains mixed, as does evidence of a link between electromagnetic fields (EMFs) and childhood leukemia. Conclusions: Clear associations have been demonstrated between childhood cancer and environmental factors, including parent/child exposure to traffic pollution, occupational/nonoccupational benzene, indoor paints, residential pesticides, and parental occupational exposure to agricultural pesticides. These associations can be used to inform further study of interventions and public health campaigns to reduce risk. Full article

In recent years, China has experienced a notable increase in indoor radon concentrations. However, our understanding of residential radon exposure in Central China remains limited and primarily depends on the data collected from residential buildings in Wuhan before 2003. Given this context, the current radon exposure levels in Central China must be assessed immediately, and the factors influencing them be investigated. To address this gap, our study focused on five representative areas in Central China. We monitored indoor radon concentrations in residential areas using random cluster sampling while considering various building structures. The radon levels were measured through the alpha track method, and RSKS standard detectors were deployed in two separate batches to participating households. A total of 1300 detectors were distributed across 579 households, with a recovery rate of 97.15% (1263 detectors were retrieved). The annual average indoor radon concentration in Central China ranged widely from 6.25 Bq/m³ to 310.44 Bq/m³, with an arithmetic mean of 50.20 Bq/m³, which resulted in an average annual effective dose of 2.08 mSv. Referring to World Health Organization standards, the radon concentration in approximately 8.24% of the monitored rooms exceeded the recommended action level. Our analysis indicated that radon concentration is primarily influenced by factors, such as the time of measurement, geographical location, building structure, floor materials, household fuel, and ventilation practices. Multiple regression analysis revealed that these factors collectively account for 10.80% of the variation in radon concentration. Notably, geographical location, building structure, and ventilation mode emerged as important factors. Based on these findings, our study suggests several practical measures to effectively reduce indoor radon levels, including improving ventilation, switching to cleaner fuels, and using environmentally friendly building and decoration materials. Full article

Residential exposure to radon and environmental gamma radiation poses a significant public health concern in uranium-rich regions. The Akmola Region of Kazakhstan, home to one of the world’s largest uranium tailings sites, lacks localized data on seasonal exposure variations and associated health risks. This study assessed indoor radon progeny concentrations and gamma dose rates in 62 dwellings across two settlements—Aqsu and Zavodskoy—in the Akmola Region during autumn 2023 through summer 2024. Using RAMON-02 and Alpharad Plus detectors, seasonal equivalent equilibrium volumetric activity (EEVA) of radon progeny and effective doses were calculated, stratified by presence of a cellar. In Aqsu, ambient dose equivalent rates reached up to 0.55 µSv/h, and winter median EEVA levels exceeded 130 Bq/m³ in some non-cellar homes. Seasonal effective doses peaked in spring (up to 8.82 mSv) in cellar dwellings, with annual doses reaching 23.5 mSv—substantially higher than in Zavodskoy. Although mitigation efforts have reduced exposure in some homes, several cellar dwellings in Aqsu exhibited persistently elevated EEVA, suggesting potential structural vulnerabilities or residual contamination. These findings underscore significant seasonal and structural disparities in radiation exposure and highlight the need for targeted, site-specific interventions to reduce long-term health risks in affected communities. Full article

Background: Despite the identification of various environmental factors that increase the risk of multiple sclerosis (MS), the effects of many factors on the etiology of MS remain to be elucidated. In this study, we aimed to investigate the effects of radon, a factor previously studied in relation to various other neurodegenerative diseases, on the epidemiology of MS. Methods: A door-to-door field study was conducted in residential areas with relatively high and low radon gas concentrations to determine the prevalence of MS. The study area comprises the Bolvadin and İhsaniye regions, which have different geological characteristics, such as seismic activity, active faults, and distributions of volcanic rocks. CR-39 detectors, with an accepted limit of 300 Bq/m³, were utilized to measure radon gas concentrations. During the screening field, the patients diagnosed with multiple sclerosis were confirmed with their hospital records. Mc Donald’s revised diagnostic criteria were used for multiple sclerosis diagnosis. Results: The regions were grouped into higher radon areas and lower radon areas. The İhsaniye city center, Kayıhan, Kemerkaya, Döğer, and Bolvadin city center were classified as higher radon regions, whereas Dişli, Yaylabağı, Gazlıgöl, and Özburun were identified as lower radon regions. A total of 40,841 individuals were surveyed in the field. The crude MS prevalence was 41.8/100,000 in settlements with high radon gas concentrations and 20.5/100,000 in settlements with low radon gas concentrations. Conclusions: In this study, we revealed that the prevalence of MS was greater in settlements with high radon gas concentrations than in settlements with low radon gas concentrations. These results demonstrated that radon gas is an important environmental risk factor in the etiopathogenesis of MS. Full article

Background: Radon, a naturally occurring radioactive gas, is increasingly recognized as a major risk factor for lung cancer (LC), especially among non-smokers. The objective of this study was to identify serum biomarkers for the early detection of LC in individuals at high risk due to prolonged residential radon exposure in Chiang Mai, Thailand, and to assess whether the use of single or combined biomarkers improves the sensitivity and specificity of detection. Methods: A total of 15 LC patients and 30 healthy controls (HC) were enrolled. The HC group was further stratified into two subgroups: low radon (LR, n = 15) and high radon (HR, n = 15) exposure. All participants were non-smokers or former smokers. Serum levels of cytokeratin 19 fragment (CYFRA 21-1), carcinoembryonic antigen (CEA), interleukin-6 (IL-6), interleukin-8 (IL-8), transforming growth factor-alpha (TGF-alpha), and indoleamine 2,3-dioxygenase-1 (IDO-1) were measured using the Milliplex^® Kit on a Luminex^® Multiplexing Instrument (MAGPIX^® System). Results: Serum CEA, IL-6 and IL-8 levels were significantly higher in LC patients compared to the HC group (p < 0.05). Among analyzed biomarkers, only IL-8 was significantly elevated in LC patients compared to the HR group (p = 0.04). Notably, CYFRA 21-1 was the only biomarker that significantly differed between LR and HR groups (p = 0.004). The diagnostic potential of these biomarkers was evaluated using receiver operating characteristic (ROC) analysis. Individually, IL-6 showed the highest discriminative ability for differentiating LC patients from both HC and HR groups, with high specificity but moderate sensitivity. Combining IL-6 and IL-8 improved specificity and increased the area under the ROC curve (AUC), though it did not enhance sensitivity for distinguishing LC from HC. For distinguishing LC from HR individuals, IL-6 and CYFRA 21-1 exhibited strong diagnostic performance. Their combination significantly improved diagnostic accuracy, yielding the highest AUC, sensitivity, and specificity. In contrast, CEA, IL-8, TGF-alpha, and IDO-1 demonstrated limited diagnostic utility. Conclusions: Based on the available literature, this is the first study to evaluate the combined use of IL-6 and CYFRA 21-1 as potential biomarkers for LC screening in individuals with high residential radon exposure. Our findings highlight their utility, particularly in combination, for improving diagnostic accuracy in this high-risk population. Full article

The Fernald Feed Materials Production Center (FMPC), located in Fernald, Ohio, USA, released radon (Rn) as a byproduct of the processing of uranium materials during the years from 1951 to 1989. Rn is a colorless, odorless gas that emits charged alpha radiation that interacts with cells in the lung and trachea-bronchial tree, leading to DNA damage, mutations, and tumor initiation. The purpose of this project was to use evidence collected by the Fernald Dosimetry Reconstruction Project and other sources to estimate the outdoor Rn exposure to individuals in the community immediately surrounding the FMPC during the years of plant operation. Using previously tabulated source terms, diffusion and meteorological data, and self-reported detailed residential histories, we estimated radon exposure for approximately 9300 persons who lived at more than 14,000 addresses. The results indicated that a portion of the population cohort experiences mean annual Rn exposure exceeding the U.S. Environmental Protection Agency (EPA) action limit of 4 pCiL⁻¹. These exposure estimates support the analysis of the incidence of lung cancer in the Fernald Community Cohort (FCC). Full article