Are media warnings about the adverse health effects of modern life self-fulfilling? An experimental study on idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF)

Objective: Medically unsubstantiated 'intolerances' to foods, chemicals and environmental toxins are common and are frequently discussed in the media. Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) is one such condition and is characterized by symptoms that are attributed to exposure to electromagnetic fields (EMF). In this experiment, we tested whether media reports promote the development of this condition. Methods: Participants (N=147) were randomly assigned to watch a television report about the adverse health effects of WiFi (n=76) or a control film (n=71). After watching their film, participants received a sham exposure to a WiFi signal (15 min). The principal outcome measure was symptom reports following the sham exposure. Secondary outcomes included worries about the health effects of EMF, attributing symptoms to the sham exposure and increases in perceived sensitivity to EMF. Results: 82 (54%) of the 147 participants reported symptoms which they attributed to the sham exposure. The experimental film increased: EMF related worries (beta=0.19; P=.019); post sham exposure symptoms among participants with high pre-existing anxiety (beta=022; P=.008); the likelihood of symptoms being attributed to the sham exposure among people with high anxiety (beta=.31; P=.001); and the likelihood of people who attributed their symptoms to the sham exposure believing themselves to be sensitive to EMF (beta=0.16; P=.049). Conclusion: Media reports about the adverse effects of supposedly hazardous substances can increase the likelihood of experiencing symptoms following sham exposure and developing an apparent sensitivity to it. Greater engagement between journalists and scientists is required to counter these negative effects. (C) 2012 Elsevier Inc. All rights reserved.