## 2 Methods  
The presented survey was conducted in August 2014 by the professional survey company SSI in seven European countries. Participation was voluntary. Data was evaluated anonymously. The online study had a total of 2454 participants, with 1809 respondents remaining after quality control (German sample \(n=274\), French sample \(n=243\), Spanish sample \(n=241\), Portuguese sample \(n=290\), Romanian sample \(n=276\), Serbian sample \(n=291\), and UK sample \(n=194\)). The age distribution was balanced with a mean age of approx. 40 years, with 49.1% male and 50.9% female. The mean education of the respondents was 15.2 years. Regarding employment, most of the respondents were in paid work (57%, including employees, self-employed, and working for the family business), 11.3% of the respondents were unemployed and actively looking for a job, and 9.0% were studying. The surveys--consisting of 33 questions--started with a short introduction describing the topic and the background of the study, as well as the confidential handling of their personal information. The background information was presented as: \"_The background of the survey is the project LExNet: Low EMF Exposure Future Networks. Seventeen leading telecommunication operators, vendors, research centres and academic institutions from the EU cooperate in LExNet throughout 10 European countries. The reduction of exposure to radio frequency electromagnetic fields is examined and it is analysed technically in the project as well as how this will be accepted by the user_\". Before respondents answered the first question, some additional information on RF EMFs was presented: \"_FOR YOUR INFORMATION: Electromagnetic fields (EMF) are produced and emitted by electrical devices. Mobile phones and base stations use EMF for transmission of voice and data._\"  
All questions were translated into languages of the participating countries (German, French, Spanish, Portuguese, Dutch, Romanian, Montenegrin, Serbian) and double-checked with re-translation back into English. Demographic, political, and economic background-related items were partially adapted from the survey platform \"European Social Survey\" [24]. The dataset used and analyzed during the current study is available from the corresponding author on reasonable request. For a detailed analysis, three groups were formed according to the subjects' responses regarding the components of RF EMF risk perception, i.e., concern, thematic relevance, and discursive relevance (see Table 1). The grouping of the study subjects into one of the three groups is based on the following assignment: (1) Not and less concerned group: subjects who scored \(\leq\)3 on the 5-point Likert scale for concerns, as well as for thematic and discursive relevance (\(n=931\)); (2) not enduringly concerned: subjects that responded with 4 = \"fairly concerned\" and 5 = \"very concerned\" regarding concerns about the potential health effects of electromagnetic fields, but \(\leq\)3 on questions regarding relevance (\(n=548\)); (3) enduringly concerned: subjects who scored \(\geq\)4 for concerns and 4 = \"often\" or 5 = \"very often\" on thematic relevance (\(n=228\)). Due to the small of number of subjects who are concerned, and for whom RF EMF risks are thematically and discursively relevant, we have abstained from building a further group. To measure the respondents' personal perceived daily RF EMF exposure, a simple item was created and asked at the beginning of the questionnaire: \"Think about your daily life, to which degree do you think you are exposed to electromagnetic fields from electronic devices (like mobile phones, WiFi router) and base stations?\", using a 5-point Likert scale from 1 = \"Not at all\", to 5 = \"To a very high degree\".