IARC 60th Anniversary - 19-21 May 2026
Session : Lung Cancer Screening, Early Detection, and Prevention: Addressing the Leading Cause of Cancer Deaths
Lung cancer risk in relation to indicative radon atlas metrics in Northern Ireland: a population-based case-control study using secondary data
DELARGY C. 1, COLEMAN H. 1, CROWLEY Q. 2, BENNETT D. 3, ELIO J. 4, FITZPATRICK D. 3, MITCHELL H. 3, WALLACE S. 1, ALHATTAB R. 1, SCOTT A. 1, MCGUINNESS B. 1, HUNTER R. 1, MCKAY G. 1, MIDDLETON D. 1
1 Centre for Public Health, Queen's University Belfast, Belfast, United Kingdom; 2 Geology, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland; 3 Northern Ireland Cancer Registry, Centre for Public Health, Queen's University Belfast, Belfast, United Kingdom; 4 Western Norway University of Applied Sciences, Bergen, Norway
Background
Radon is a well-established lung carcinogen, yet uncertainty remains about whether area-based measures of radon exposure accurately reflect population-level lung cancer risk.
Objectives
This study, the first of its kind in the UK, aimed to investigate the association between a nationwide indicative radon atlas and lung cancer risk in Northern Ireland, a region in which lung cancer screening programmes are under design.
Methods
A population-based case-control study was conducted. Primary lung cancer cases (n= 1,687) form the Northern Ireland Cancer Registry diagnosed in 2006 and 2014 were compared with 8,094 non-lung cancer controls from a large cohort, The Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA). Radon exposure data were extracted from the Indicative Atlas of Radon, which categorises 1 km2 areas by the percentage of households exceeding 200 Bq/m3. Exposure data were linked to participants by postcode. Logistic regression models adjusted for age, sex, smoking status, deprivation and PM2.5 exposure were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for lung cancer.
Results
Individuals residing in high radon exposure areas (30-100% of households exceeding 200 Bq/m3) had a greater than two-fold LC risk (adjusted OR: 2.24, 95% CI: 1.27, 3.96) compared to residents in all other areas. This association was revealed after adjusting for PM2.5. The results indicate that area-based radon classifications can still capture meaningful differences in lung cancer risk at a population level.
Conclusion
This study provides the first UK-based evidence that an indicative radon atlas can reflect underlying population lung cancer risk associated with radon exposure. These findings support the continued use of atlas-derived radon metrics in epidemiological research and in informing public health interventions, including targeted lung cancer screening and radon remediation efforts. However, the results also highlight limitations inherent to atlas-based radon classification, most notably spatial misclassification and inability to capture within-area variability