Article review date
November 2024
Article publication date
September 2024
Summary
This systematic review and meta-analysis assessed the association between radon exposure and health effects other than lung cancer in human populations. A total of 129 studies, published during 1990-2023, were included in the review and 40 studies were used in the meta-analysis. Risk estimates such as risk ratio (RR) per 100 units (Bq/m3 or Working level Month) of increased radon exposure level were calculated with a 95% confidence interval (CI). A range of health outcomes, including cancers (except lung cancer) and non-cancerous diseases were considered in the evaluation. The quality of the included studies were jointly evaluated using the New-castle Ottawa Scale (NOS) and the UNSCEAR’s approach of assessing quality of studies (including ecological studies) (UNSCEAR, 2017, p 48, table 3).The meta-analyses generally showed no statistically significant positive association for any health outcomes. Some of the estimated risk ratios were positive with the significance level near the threshold for statistical significance including lympho-hematological cancer incidence in children (RR = 1.01; 95% CI: 1.00-1.03; p = 0.08); malignant melanoma mortality in adults in the general population (RR = 1.10; 95% CI: 0.99-1.21; p = 0.07); liver cancer mortality (RR = 1.04; 95% CI: 1.00-1.10; p = 0.06), and intestine and rectal cancer mortality combined among mine workers (RR = 1.02; 95% CI: 1.00-1.04; p = 0.06). The included studies had moderate to high quality scores. In conclusion, this review showed an absence of statistically significant associations between radon exposure and potential health outcomes other than lung cancer however, these effects cannot be ruled out.
Published in
Frontiers in Public Health
Link to study
ARPANSA commentary:
The overall conclusion of the review indicates no significant association between radon exposure and a range of health outcomes other than lung cancer in children and adult populations. Importantly, this review contributes to the body of knowledge on the potential health effects (both malignant and non-malignant diseases) of radon exposure in occupational and residential settings. Comparison of the findings of this review with other studies was not possible due to a lack of similar published reviews. Of the epidemiological studies included (except those on miners related to occupational radon) in this review, a majority of them related to children and adults were ecological studies, which may lead to ecological fallacy. There were several methodological limitations of the included studies, such as assessment of radon exposure and health outcomes as well as accounting for potential confounders which may alter the risk estimation. Therefore, further well-designed epidemiological research using robust radon exposure assessment tools and methods are needed to evaluate the potential risk of radon exposure for a range of population health outcomes. Some limitations of the study were: the inclusion of few studies in the meta-analysis of the exposure-risk relationships may have resulted in a lack of statistical power, significant heterogeneity was estimated in studies on occupational exposure to radon which limits the interpretation of the risk estimates and meta-regressions/in-depth sensitivity analyses was not done to evaluate the sources of heterogeneity due to the limited number of included studies. The review also did not conduct a certainty in evidence assessment which is another limitation.
According to the Australian Radiation Protection and Nuclear Safety Agency’s (ARPANSA) nationwide survey of Australian homes, the average radon exposure level in Australian homes is much lower than the global average. Consequently, residential radon exposure is not expected to be a significant contributor to any health risk other than lung cancer in Australia. ARPANSA has a fact sheet on ionising radiation exposure doses, including natural sources such as radon, and health. The International Commission on Radiological Protection has published guidance on radiological protection against radon exposure.
