First UK study to map higher radon levels with increased lung cancer risk

18 May 2026

A new study led by researchers at Queen’s University Belfast, in collaboration with Trinity College Dublin, has for the first time in the UK linked national radon mapping data with cancer statistics from the Northern Ireland Cancer Registry (NICR) at a large regional scale – highlighting differences in lung cancer risk across areas with varying radon levels.

The findings have been published in Environmental Geochemistry and Health, a longstanding international journal in the field.

The study found that people living in areas classified as having the highest radon levels had more than twice the likelihood of lung cancer compared to those in lower exposure areas.

This link remained after accounting for key factors such as smoking, air pollution, age, sex, and socioeconomic conditions, suggesting that the patterns observed are not explained by these factors alone.

Radon is invisible, odourless and can build up indoors, but it can be measured with simple tests which cost around £50. The radon atlas provides a useful starting point for identifying whether testing may be advisable for a property.

Despite this, awareness of radon remains low, and many households may not realise they are living in areas where elevated levels are more likely.

The researchers say the findings reinforce the importance of checking whether a home is in an area where radon testing is recommended but also note that high radon concentrations can occur in properties mapped as low risk.

The study also highlights opportunities to improve public health approaches, including increasing awareness and encouraging testing in areas more likely to have elevated radon levels.

Current UK radon maps group areas into broad categories, rather than providing continuous estimates of radon concentration. More detailed, high-resolution mapping could allow for more precise assessment of how risk varies geographically and support more advanced epidemiological studies.

Lead author Claire Delargy, PhD Researcher from the Cancer Epidemiology and Data Research (CEDAR) Group at Queen’s University Belfast, commented: “Our findings reiterate that the radon atlas can be a practical tool for the public. Checking whether your home is in an area where testing is recommended is an important first step.

“Radon cannot be seen or smelt, but it can be measured relatively easily, and testing is the only way to know the levels in your home.”

Senior author Dr Daniel Middleton, Lecturer from the Cancer Epidemiology and Data Research (CEDAR) Group at Queen’s University Belfast, added: “This study shows that widely available radon maps can reflect differences in lung cancer risk at a population level, which has important implications for public health.

“It also highlights that moving towards more detailed, continuous estimates of radon concentration could support more advanced research and help refine how we target prevention efforts.

“However, it is important to emphasise that smoking remains the dominant cause of lung cancer. Stopping smoking is still the most effective way to reduce risk. Notably, most radon-related lung cancer patients also smoke cigarettes.”

The researchers note that the study used area-based radon estimates rather than measurements from individual homes, meaning exposure can vary within mapped areas. As a result, the findings reflect population-level patterns rather than individual risk.

Full research paper is available here.

 

source: Queen’s University Belfast News