Radioprotection 2025, 60( 1), 76 – 83 © G. Taino et al., Published by EDP Sciences, 2025 https:// doi. org / 10.1051 / radiopro / 2024041
Available online at: www. radioprotection. org
ARTICLE
Medical surveillance of workers exposed to radon: new perspectives in lung cancer prevention
G. Taino 1, A. Delogu 1, R. Pintucci 1, L. Semborowski 1, E. Oddone 1, 2,*, A. Osuchowski 1 and F. Solazzo 1
1 Istituti Clinici Scientifici Maugeri IRCCS, Hospital Occupational Medicine Unit( UOOML), Institute of Pavia, Pavia, Italy. 2 Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy.
Received: 24 July 2023 / Accepted: 26 August 2024
Abstract – Radon is produced by the radioactive decay of Radium 226( 226 Ra), in turn produced by radioactive decay of Uranium 238( 238 U), found in ores such as lave, tables, granites and pozzolane. Lung cancer is still a disease with a high mortality rate responsible, worldwide, for about one in five deaths due to cancer. The health surveillance of workers exposed to Radon is aimed at the prevention and early diagnosis of lung cancer, which represents, in Italy, the second most frequent neoplasm in men( 15 %) and the third in women( 12 %). At present, however, screening strategies are proposed only in populations at high risk of developing the disease, as it is difficult to find a single very sensitive and highly specific biomarker. This situation implies that healthy subjects are subjected to Computed Tomography( CT) scan only after the onset of symptoms, leading to often late diagnosis, without a survival benefit. Currently the most promising biomarker is micro-RNA( miRNA, MSC), associated with Low Dose Computed Tomography( LDCT) scan. An optimization in the future of these tools and the cost-benefit ratio will open their use in early diagnosis, as well as their use also in the health surveillance of those exposed to Radon.
Keywords: Lung cancer / Radon / radioprotection
1 Introduction
Radon( Rn) is a noble gas, inert, odorless, tasteless and colorless at standard temperature and pressure. Radon is produced by the radioactive decay of Radium 226( 226 Ra), in turn produced by radioactive decay of Uranium 238( 238 U), found in ores such as lave, tables, granites and pozzolane. 222 Rn’ s half-life is 3.8 days, decaying into radioactive
daughters. Especially worth of note are two unstable isotopes of Polonium( 218 Po and 214 Po) which, being electrically charged may react with particulate pollution and, once inhaled, reach the lower respiratory tract. Polonium isotopes alpha decay and are the culprit of cellular damage. Other daughters are unstable, beta-decaying, isotopes of lead and bismuth and are less harmful. Alpha particles are Helium nuclei and being both highly charged and heavy have a very short mean free path. Because of this they can reach only the most superficial layer of the skin and therefore are of lesser concern in case of external exposure, but become a major hazard in case of internal contamination( such as from skin injuries, ingestion or inhalation)( Bochicchio et al., 2005; Darby et al., 2005; Krewski et al., 2005; UNSCEAR, 2006).
* Corresponding Author: enrico. oddone @ unipv. it
Epidemiological surveys showed a strong link to lung cancer and on the basis of these results Radon was acknowledged as carcinogen in Group I( sufficient evidence of carcinogenicity in humans) according to International Agency for the Research on Cancer( IARC)( IARC 1988); therefore, further epidemiological studies were designed to investigate home exposure.
The main results are the following: – incidence of lung cancer is directly related to Radon concentration; – risk of lung cancer increases proportionally to the length of exposure;
– the risk increase mirrors the“ usual” epidemiology for lung cancer, with lower incidence up the age of 45 years, and increasing incidence up the 65;
– being equal Radon concentration and exposure length, the risk for lung cancer is much higher among smokers( approximately 25 times related risk among those smoking 1pack / day vs. not smokers)( Darby et al., 2005); this demonstrates that Radon is especially dangerous for smokers.
Epidemiological studies performed in 11 European Countries including Italy showed how, with 30-years long exposure, the risk for lung cancer is increased by 16 % every
This is an Open Access article distributed under the terms of the Creative Commons Attribution License( https:// creativecommons. org / licenses / by / 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.