Indoor radon is a natural radioactive gas and is one of the leading causes of lung cancer. Despite multiple policy and communication interventions to increase radon testing and mitigation, the uptake of these measures remains insufficient. A participatory research design was applied in Belgium and Slovenia to probe the barriers and facilitators homeowners experience regarding radon protective behavior on the one hand and co-designing communication tools on the other hand. The results show that there remains a need for interventions on all levels (i.e., policy, economic interventions, and communication). Moreover, results indicated a need for a communication strategy that follows the different steps between awareness and performing mitigation measures. Further, involving the target group in the early stages of intervention design was beneficial. Future research is needed to test the effectiveness of the proposed communication strategies in a controlled setting.

Indoor radon is a natural radioactive gas that enters homes through cracks in the foundations. It is one of the leading causes of lung cancer. Although radon can be detected with an indoor radon test and can be mitigated by means of either ventilation or professional measures, testing and mitigating rates of the at-risk population remain insufficient. The objective of this study is to systematically review the current level of evidence regarding the design and effectiveness of mass media campaigns to address the health risks of indoor radon to homeowners. The results show that informative tone of voices prevailed, other components, such as emotional or social components, were often not included. Furthermore, the focus was mostly on intention and less on behavior itself, and on testing instead of mitigation. Further research is needed to test effective and innovative communication strategies to increase protective behavior concerning indoor radon.

This study investigates the effectiveness of different social media communication strategies in promoting radon information-seeking behaviors and intentions to test for radon. Guided by the Elaboration Likelihood Model, the study explores the interaction between the peripheral and the central routes of persuasion in promoting radon protection behaviors across four European countries: Austria, Belgium, Ireland, and Slovenia (N=1,677). The "Radon Buster campaign," containing Facebook advertisements and a website, was specifically developed for this study. An online survey experiment evaluated the impact of the Facebook advertisements on radon information-seeking intentions and the impact of the website on radon testing intentions. Participants were randomly assigned to one of three experimental conditions (narratives, humor, or norm nudges), or included in a prior-exposure control group, followed by interaction with the website. The results show a direct positive effect of the exposure and appreciation of the posts on information-seeking intentions. However, mixed effects were found regarding the moderation of website appreciation and counterarguing on the effect of the website on the intention to test. Overall, the findings underscore the importance of engaging communication strategies that are designed to evoke both peripheral and central route processing to effectively promote radon awareness and testing behaviors.

Radon poses a significant health risk when present indoors. It is the second leading cause of lung cancer, after smoking. Effective communication strategies are essential for raising awareness about radon and encouraging individuals to test and mitigate. However, current approaches, which primarily focus on statistical information, have not proven sufficiently effective. The aim of this study was therefore to assess the impact of narratives—compared to statistical texts—on personal and general risk perception and intentions to adopt radon protective behaviour. Additionally, the mediating role of psychological distance was investigated, building on the risk convergence model. Using a between-subject design, an online experiment was conducted with three conditions: a narrative condition (N = 124), a statistical condition (N = 126), and a control condition (N = 133). The study revealed that narratives are effective in influencing personal and general risk perception. They also played a pivotal role in encouraging behavioural intentions, such as the intention to seek information, intention to test and mitigate. This underlines the importance of different communication strategies in shaping risk perception and behavioural intent. These findings contribute to the development of more effective communication strategies for reducing radon-related health risks and enhancing overall public health.

Radon, a naturally occurring radioactive gas, is the second leading cause of lung cancer worldwide. Despite the severe health risks, radon testing and mitigation remain insufficient. This issue is situated on multiple levels, ranging from the individual to the political, economic, social, and physical environment. While effective communication is essential to bridge this gap, radon health communication remains underexplored. This dissertation examines how strategic, theory- and evidence-based communication can enhance public engagement with radon-related behaviours. In the first phase of this research, the current communication was analysed. A systematic review of radon-related mass media interventions reveals that most campaigns rely on informational messaging, often failing to evoke personal relevance or emotional engagement. Moreover, in focus group workshops homeowners emphasised the need for communication strategies that extend beyond awareness-raising, addressing practical concerns such as financial support and regulatory measures. Participants also suggest tailoring messages to different behavioural stages, using approaches such as humour, personal letters, and testimonials. In the second phase, communication materials were developed and tested. An online experiment compared the impact of narrative-based and statistical messages on risk perception and behavioural intentions. Findings indicate that narratives are more effective in increasing personal and general risk perception while also strengthening intentions to seek information, test for radon, and consider mitigation. These results inform the development of a large-scale social media campaign, Radon Buster, designed to motivate individuals to take action. The campaign, implemented across Austria, Belgium, Ireland, and Slovenia, uses Facebook ads incorporating narratives, humour, and social norm nudges to attract attention and drive engagement. A controlled online survey experiment finds that exposure to these ads positively influences information-seeking intentions. A subsequent live Facebook study demonstrates strong audience engagement, with click-through rates and interaction metrics suggesting that social media can serve as an effective platform for radon risk communication. Overall, the findings highlight that radon communication must go beyond merely providing information, but should engage audiences, and align the messages with the decision-making process. While no one-size-fits-all solution exists, integrating social, emotional, and cognitive factors can enhance the effectiveness of communication strategies. This dissertation underscores the importance of a multi-level approach, combining stakeholder-targeted messaging with broader environmental interventions to ensure radon risk communication translates into meaningful action.