The First Attempt to Reevaluate Radon and Thoron Exposure in Gansu Province Study Using Radon-Thoron Discriminating Measurement Technique

Although the epidemiological studies provide evidence for an increased risk of lung cancer risk associated with residential radon, an issue of radon-thoron discrimination remains to be solved. In this study, an updated evaluation of lung cancer risk among the residents in Gansu, China was performed where one of the major epidemiological studies on indoor radon demonstrated an increased risk of lung cancer. We analyzed data from a hospital-based case-control study that included 30 lung cancer cases and 39 controls with special attention to internal exposure assessment based on the discriminative measurement technique of radon isotopes. Results from the analyses showed non-significant increased lung cancer risks; odds ratios (ORs) adjusted for age, smoking, and total income were 0.35 (95% CI: 0.07–1.74) and 0.27 (95% CI: 0.04–1.74) for groups living in residences with indoor radon concentrations of 50–100 Bq m−3 and over 100 Bq m−3, respectively, compared with those with < 50 Bq m−3 indoor radon concentrations. Although the small sample size hampers the usefulness of present analyses, our study suggests that reevaluation of lung cancer risk associated with residential radon in the epidemiological studies will be required on the basis of precise exposure assessment.

A Potential Serum Biomarker for Screening Lung Cancer Risk in High Level Environmental Radon Areas: A Pilot Study

Radon is a major cause of lung cancer (LC) deaths among non-smokers worldwide. However, no serum biomarker for screening of LC risk in high residential radon (HRR) areas is available. Therefore, the aim of this study was to determine diagnostic values of serum carcinoembryonic antigen (CEA), cytokeratin 19 fragment (Cyfra21-1), human epididymis protein 4 (HE4), interleukin 8 (IL-8), migration inhibitory factor (MIF), tumor nuclear factor-alpha (TNF-α) and vascular endothelial growth factors (VEGF) occurring in high radon areas. Seventy-five LC non-smoker patients and seventy-five healthy controls (HC) were enrolled in this study. Among the HC groups, twenty-five HC were low residential radon (LRR) and fifty HC were HRR. Significantly higher (p < 0.0004) serum levels of CEA, Cyfra21-1, IL-8 and VEGF were found in the LC compared with the LRR and HRR groups. More importantly, significantly higher levels (p < 0.009) of serum CEA, Cyfra21-1 and IL-8 were observed in HRR compared with the LRR group. Likewise, a ROC curve demonstrated that serum CEA and Cyfra21-1 could better distinguish LC risk from HRR groups than IL-8. These results indicated that serum CEA and Cyfra21-1 were significantly increased in the HRR group and may be considered as potential biomarkers for individuals at high-risk to develop LC.

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

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

Residencial radon and small cell lung cancer: A case control study.

e20566 Background: Residential radon is the second most important risk factor for lung cancer. We aim to asses the effect of residential radon exposure on the risk of SCLC in general population. Methods: A multicentric hospital-based case-control study was designed including 10 hospitals from Spain and Portugal. Incident cases with pathological diagnosis of SCLC were prospectively recruited. Controls consisted in patients undergoing non-complex surgery unrelated to tobacco consumption. All study participants were sent a radon detector. Results: A total of 375 cases and 902 controls were recruited. 24.5% of cases were women. The median age at diagnosis was 66 for cases. 6.4% of the cases were younger than 50 years. Tobacco consumption was higher in cases compared to controls. Residential radon concentrations were higher than 147 Bq/m3 in 161 SCLC cases (42.9%). Median residential radon concentration was also higher in SCLC cases compared to controls (152.5 Bq/m3 vs 142 Bq/m3). Those people exposed to more than 147 Bq/m3 and heavy smokers showed an OR of 72,62 (95%CI 17.95 - 499.41) compared to never-smokers with less than 50 Bq/m3. Conclusions: radon exposure seems to increase the risk of small cell lung cancer. There is a significant lung cancer risk departing from 148 Bq/m3 and there is also a linear dose-response pattern. Tobacco consumption may also produce an important effect modification for radon exposure. Those individuals exposed to high radon concentrations and heavy smokers can have a very high risk of this cancer type compared with their low exposed and never-smoking counterparts. It is necessary to increase radon awareness among citizens and administrations in order they can establish the necessary protective and mitigation measures against residential radon. Effect modification between residential radon exposure and tobacco consumption on the risk of small cell lung cancer.[Table: see text]

P661 Radon exposure and inflammatory bowel disease in a radon prone area

Background Inflammatory Bowel Disease (IBD) is a multifactorial pathology with an increasing incidence. There are environmental factors, many unknown, that participate in its development. There is no study having assessed a possible relationship with residential radon exposure, which is very high in the study area. The aim of this study was to analyze if residential radon concentration measured at a municipal level is associated with a higher incidence of IBD and its characteristics (clinical or demographic). Methods We performed an ecological study where we included all incident cases of IBD in the area of Santiago de Compostela between January and December 2017 in order to estimate municipal incidence rates. Radon levels at a municipal level were obtained from the Galician Radon Map and correlated with demographic factors and type of IBD. We used the Spearman’s correlation coefficient to test the existence of any association. Results 96 patients were included, 63 (65.6%) with Ulcerative Colitis, 29 (30.25) with Crohn’s Disease and 4 (4.2%) with indeterminate colitis. Median age was 41 (IQR: 33.5 to 56 years), and 50.0% were women. The incidence rate per 100.000 inhabitants-year in the study area was 21.6 cases. The median radon concentration was 104.9Bq/m3 (IQR: 91.0 to 154.6), without statistically significant differences in function of the location of the house (rural vs. urban) nor the type of edification (flat vs house), p &gt;0.05. There were no statistically significant differences on the type of IBD developed (ulcerative colitis, Crohn’s disease or indeterminate colitis) regarding radon levels either (p&gt;0.05). There were no statistically significant differences (p&gt;0.05) between radon and sex of IBD cases. No correlation between radon levels and age of the individuals was observed (Spearman’s rho = -0.13, p-value 0.2), nor radon levels variation by age groups (p&gt;0.05). There was no correlation between radon concentration and cumulative incidence of IBD at municipal level (Spearman’s rho = 0.13, p-value 0.5), as it is shown in figure 1. Conclusion In the area of Santiago de Compostela there is a higher incidence of IBD in comparison with previous studies taking western countries as reference. It is possible that some environmental risk factors, could be responsible of this difference. In this study we have not found any correlation with municipal average radon concentration and incidence of IBD or any of its types.