Does personal relevance moderate communication effects? The example of risk communication about 5G-related electromagnetic fields.

Background: Technological advancements, such as the introduction of the fifth generation technology standard 5G, offer opportunities but also raise concerns. Although no evidence suggests negative effects of radiofrequency electromagnetic fields (RF-EMF) within defined exposure limits, authorities responsible for risk communication provide precautionary advice to help citizens reduce personal exposure. However, previous research indicates that precautionary information can increase risk perception and decrease trust. Methods: This cross-sectional study investigated effects of precautionary information on risk perception and trust in the context of 5G, using large general population samples in Germany and Greece. For the first time, personal relevance was examined as a potential moderating factor, using a novel approach to assess practical and thematic relevance. Participants were first surveyed on their relevance of the topic, then provided with basic information about "RF-EMF and health", and, in the experimental group, with additional precautionary information. Different measures for risk perception and trust followed. We expected higher risk perception and lower trust for the experimental group, and assumed that at lower personal relevance, this effect would be stronger. Results: Contrary to expectations, precautionary information increased just one risk perception measure and only in Germany. The anticipated moderating effect of personal relevance was not found, but relevance itself significantly predicted risk perception, with higher relevance correlating with higher risk perception. Exploratory findings revealed higher risk perception among females compared to males and in Greece compared to Germany. Conclusions: That there were only few effects of the precautionary information may be linked to the focus on actions to reduce personal exposure when using mobile devices. The results underline the importance of considering personal relevance and demographic factors in risk communication and highlight directions for future research.