{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,5]],"date-time":"2025-12-05T18:37:42Z","timestamp":1764959862150,"version":"3.46.0"},"reference-count":45,"publisher":"Public Library of Science (PLoS)","issue":"12","license":[{"start":{"date-parts":[[2025,12,5]],"date-time":"2025-12-05T00:00:00Z","timestamp":1764892800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>Radon, a naturally occurring radioactive gas known for its health risks, has recently gained attention for its potential protective role against COVID-19 mortality. This cross-sectional ecological study examined the relationship between indoor radon exposure and COVID-19 mortality rates across eight countries, including several European nations, the United States, and the State of Kerala, India, during the pre-vaccination period. The analyzed data on the subject were derived from recent scientific publications. The environmental aspect was represented by the variable \u201cindoor radon concentration or probability of exceeding a radon concentration in indoor air,\u201d depending on data availability. Using national radon surveys and COVID-19 mortality statistics, statistical analyses, including Spearman\u2019s correlation and Kendall Tau, were conducted between March and December 2020. The findings revealed a consistent negative correlation between radon concentrations and COVID-19 mortality rates, indicating that higher radon concentrations were associated with lower mortality rates. Regions such as Finland and Sweden, where radon exposure was relatively high, experienced significantly lower mortality. With Sweden and Finland showing a mortality risk reduction factor of respectively 1,42 and 5,47 during the first wave compared to the UK where Radon levels are very low. Although the findings are not overwhelmingly strong, the data suggest that radon exposure may have a mitigating effect on COVID-19 mortality.<\/jats:p>","DOI":"10.1371\/journal.pone.0337320","type":"journal-article","created":{"date-parts":[[2025,12,5]],"date-time":"2025-12-05T18:32:28Z","timestamp":1764959548000},"page":"e0337320","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Radon exposure and COVID-19 mortality in pre-vaccination period: What links might exist?"],"prefix":"10.1371","volume":"20","author":[{"given":"Jean Fran\u00e7ois","family":"Coudert","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ekaterina","family":"Dadachova","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gilles","family":"Maignant","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9857-7750","authenticated-orcid":true,"given":"Stephanie","family":"Jonathan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2025,12,5]]},"reference":[{"key":"pone.0337320.ref001","article-title":"Coronavirus: un premier foyer identifi\u00e9 dans le d\u00e9partement du Morbihan","volume":"2","author":"A Robert","year":"2020","journal-title":"Agence de Sant\u00e9 Bretagne."},{"key":"pone.0337320.ref002","doi-asserted-by":"crossref","first-page":"404","DOI":"10.15669\/pnst.1.404","article-title":"Simultaneous measurement of radon and thoron released from building material used in Japan","volume":"1","author":"M Nabil","year":"2011","journal-title":"Prog Nucl Sci Technol."},{"key":"pone.0337320.ref003","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1016\/j.apradiso.2009.10.003","article-title":"Internal exposure from building materials exhaling 222Rn and 220Rn as compared to external exposure due to their natural radioactivity content","volume":"68","author":"P Ulji\u0107","year":"2010","journal-title":"Appl Radiat Isot."},{"issue":"3","key":"pone.0337320.ref004","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1504\/IJLR.2004.005434","article-title":"One century of radon therapy","volume":"1","author":"K Becker","year":"2004","journal-title":"IJLR."},{"issue":"8","key":"pone.0337320.ref005","doi-asserted-by":"crossref","first-page":"894","DOI":"10.1093\/rheumatology\/39.8.894","article-title":"Long-term efficacy of radon spa therapy in rheumatoid arthritis\u2013a randomized, sham-controlled study and follow-up","volume":"39","author":"A Franke","year":"2000","journal-title":"Rheumatology (Oxford)."},{"key":"pone.0337320.ref006","volume-title":"Low-dose whole-lung radiation for COVID-19 pneumonia: planned day-7 interim analysis of an ongoing clinical trial","author":"CB Hess","year":"2020"},{"key":"pone.0337320.ref007","doi-asserted-by":"crossref","first-page":"234","DOI":"10.3390\/radiation1030020","article-title":"Low-dose radiation therapy for COVID-19: a systematic review","volume":"1","author":"SMJ Mortazavi","year":"2021","journal-title":"Radiat."},{"key":"pone.0337320.ref008","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.radmeas.2015.01.007","article-title":"The world\u2019s high background natural radiation areas (HBNRAs) revisited: a broad overview of the dosimetric, epidemiological and radiobiological issues","volume":"73","author":"A Sadiq Aliyu","year":"2015","journal-title":"Radiat Meas."},{"key":"pone.0337320.ref009","unstructured":"United Nations Scientific Committee on the Effect of the Atomic Radiations UNSCEAR. 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