Frederik Freudenstein

Little was known about the relationship between carrying mobile phone handsets by men and their risk perception of radiofrequency-electromagnetic field (RF-EMF) exposure due to carrying handsets close to the body. This study aimed to determine where men usually carried their handsets and to assess the relationship to risk perception of RF-EMF. Participants completed a self-administered questionnaire about mobile phone use, handset carrying locations, and levels of risk perception to RF-EMF. Data were analysed using linear regression models to examine if risk perception differed by mobile phone carrying location. The participants were 356 men, aged 18–72 years. They owned a mobile phone for 2–29 years, with over three quarters (78.7%) having a mobile phone for over 20 years. The most common locations that men kept their handsets when they were ‘indoors’ were: on a table/desk (54.0%) or in close contact with the body (34.7%). When outside, 54.0% of men kept the handset in the front trouser pocket. While making or receiving calls, 85.0% of men held their mobile phone handset against the head and 15.0% either used earphones or loudspeaker. Men who carried their handset in close contact with the body perceived higher risks from RF-EMF exposure compared to those who kept it away from the body (p<0.01). A substantial proportion of men carried their mobile phone handsets in close proximity to reproductive organs i.e. front pocket of trousers (46.5%). Men who kept their handset with the hand (p < .05), and those who placed it in the T-shirt pocket (p < .05), while the phone was not in use, were more likely to perceive health risks from their behaviour, compared to those who kept it away from the body. However, whether this indicates a causal relationship, remains open.

Uncertainty is a crucial issue for any risk assessment. Consequently, it also poses crucial challenges for risk communications. Many guidebooks advise reporting uncertainties in risk assessments, expecting that the audience will appreciate this disclosure. However, the empirical evidence about the effects of uncertainty reporting is sparse and inconclusive. Therefore, based on examples of potential health risks of electromagnetic fields (EMF), three experiments were conducted analysing the effects of communicating uncertainties separately for hazard identification, risk characterisation and risk protection. The setups aimed to explore how reporting and how explaining of uncertainty affects dependent variables such as risk perception, perceived competence of the risk assessors, and trust in risk management. Each of the three experiments used a 2x2 design with a first factor presenting uncertainty descriptions (as used in public controversies on EMF related health effects) or describing a certainty conditions; and a second factor explaining the causes of uncertainties (by pointing at knowledge gaps) or not explaining them. The study results indicate that qualitative uncertainty descriptions regarding hazard identification reduce the confidence in the professional competencies of the assessors. In contrast, a quantitative uncertainty description in risk characterisation–regarding the magnitude of the risk–does not affect any of the dependent variables. Concerning risk protection, trust in exposure limit values is not affected by qualitative uncertainty information. However, the qualitative description of uncertainty regarding the adequacy of protection amplifies fears. Furthermore, explaining this uncertainty results in lower text understandability.

In the current paper, research on risk communication regarding radiofrequency electromagnetic fields (RF-EMF) of mobile communication technologies is systematically reviewed. The following databases were searched in March 2017: EBSCO (PsycInfo, Academic search premier), Medline, SCOPUS, and emf-portal.org. Of 1139 unique hits, 28 articles (including 27 studies) remained after full-text eligibility screening. The majority of studies were experiments. The quality of all studies was evaluated against standardised criteria. Studies were assigned to nine different categories of content. Categories were comprehensibility of information (four studies), information on the (non-)existence of the risk (2), information about uncertainty (3), information focussed on different health effects (3), information about the source of the information (2), information about individual risk and exposure aspects (5), information about precautionary measures (14), effects of television reports and audio-visual advertisements (4), information regarding base station siting (2). For each topic, findings were summarised and, if possible, a recommendation for risk communication practice was derived. Throughout the topics, many studies did not only analyse the main effects but also interactions with recipient characteristics. Interaction analyses suggest that especially prior risk perception shapes the individual evaluation of information about RF-EMF and has an influence on perceived credibility, interpretation of verbal descriptors of uncertainty, perceived persuasiveness of arguments and the communication´s effect on risk perception. For information about precautionary measures, the evidence was combined in a meta-analysis. Mean effects showed a significant increase of risk perception regarding mobile phones and mobile phone base stations due to information about precaution (Hedges´ g = .16, 95% confidence interval (.05; .26) for mobile phone risk perception, g = .17 (.10; .24) for base station risk perception). Strategies for dealing with the influence of prior risk perception are discussed. Finally, limitations of the current study and potential avenues for future research are outlined.