Interaction between occupational radon exposure and tobacco smoke: a systematic review

ABSTRACT

Introduction

The risk of lung cancer from radon exposure was small compared to tobacco smoking (BEIR VI), but the relationship between these two carcinogenic agents has yet to be quantitatively estimated. The objective of this systematic review was to evaluate the last evidences on the role of radon occupational exposures and tobacco smoke on lung cancer risk.

Areas covered

Thirteen articles were selected using two different databases, PubMed and Scifinder, and were limited to those published from 2010 to 2021. The reference list of selected studies was reviewed to identify other relevant papers.

Expert opinion

Seven papers included in this systematic review did not deal with the multiplicative or the additive type of interaction between radon exposure and smoking habit. Six papers discussed the nature of this interaction with a prevalence of the sub-multiplicative model compared to the additive one. Altogether, smoking adjustment did not significantly change lung cancer risk. The included studies might constitute a starting point for updating the models for risk assessment in occupational and residential scenarios, promoting concomitantly the exposure reduction to radon and other cofactors, as recently introduced by Italian Legislative Decree number 101 of 31 July 2020, an application of Euratom Directive 59/2013.

Plain Language Summary

This paper offers an updated overview on lung cancer risk due to occupational exposure to radon together with tobacco smoking habits. It evidences the quantitative role of smoking on radon exposure and discusses their interaction. The results show that smoking adjustments do not significantly modify lung cancer risk at both high and low radon concentrations.

KEYWORDS:

• Radon
• lung cancer risk
• exposure
• interaction
• multiplicative interaction
• additive interaction
• occupational risk management

Article highlights

• Radon is a lung carcinogen agent, but more information is needed on the role of smoking as a modifier of the radon-lung cancer association.

• To investigate associations between radon and smoke exposure and lung cancer incidence, we analysed the results of six cohort studies and seven case–control studies, published in the last decade.

• Seven studies did not reveal any additive or multiplicative interaction when they were assessed, while five case–control studies and one cohort study evaluated an additive or multiplicative interaction.

• The results showed that smoking adjustments do not significantly modify lung cancer risk at both high and low radon concentrations.

• However, radon exposure at work should be monitored particularly in radon prone-areas, given that it is possible that workers might have high radon exposure also at home.

Acknowledgments Remembering Matteo

We would like to remember Prof. Matteo Goldoni (1973-2022), Professor of Medical Statistics at University of Parma.

Declaration of interests

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/17476348.2022.2108795

Additional information

Funding

This paper was not funded.