Exposure to Mobile Phone Electromagnetic Fields and Subjective Symptoms: A Double-Blind Study CATERINA CINEL,PHD, RICCARDO RUSSO,PHD, ANGELA BOLDINI,PHD, AND ELAINE FOX,PHD Objectives: The objective of this study was to examine whether acute exposure to radio frequency electromagnetic fields (REFs) emitted by mobile phone may affect subjective symptoms. Methods: Three large groups of volunteers (total 496) were exposed to REFs emitted by mobile phones in one session and sham signals in a different session. REF and sham exposure sessions were counterbalanced and double blinded. Participants were exposed to either Global System for Mobile Communication (GSM) or unmodulated signals, and the mobile phone was positioned either on the left or on the right side of the head. Before and after REF and sham exposure participants completed a questionnaire to rate five symptoms. Any changes in the severity of the symptoms after REF exposure were compared with changes after sham exposure. Results: For one group of participants (N = 160), it was found that dizziness was affected by GSM exposure, but this was not consistently found with the other two groups of participants. No other significant effects were found. Conclusions: We did not find consistent evidence suggesting that exposure to mobile phone REFs affect subjective symptoms. Even though we acknowledge that more research is needed, we believe that our results give an important contribution to the research on mobile phone use and subjective symptoms. Key words: radio frequency electromagnetic fields, REF exposure, subjective symptoms, mobile phones. REF = radio frequency electromagnetic field; GSM = Global System for Mobile Communication; CW = continuous wave; SAR = specific energy absorption rate; SD = standard deviation. INTRODUCTION T he use of mobile phones has often been associated with particular subjective symptoms such as headache, fatigue, rash, or warmth sensations on the skin (particularly in the area around the ear). Thus, in recent years, scientists have been trying to establish whether symptoms such as these can be triggered specifically by the radio frequency electromagnetic fields (REFs) emitted by mobile phones (1). As it is often the case with studies on the effects of electromagnetic fields on human health, this is a very controversial area of research and there are no conclusive studies as yet (2). A way of investi- gating this issue is by examining symptoms or sensations experienced by mobile phone users (3–5). Hocking (5) inter- viewed 40 mobile phone users and found that the majority (88%) suffered of cranial symptoms such as heat or dull pain on temple, ear or occiput when using a mobile phone. Typi- cally symptoms started a few minutes after commencing a call. Other symptoms frequently reported were transient ef- fects on vision, such as blurring (31%) and sensation of nausea or dizziness (43%). The same symptoms did not occur when using ordinary handsets. In a more recent survey, Balikci et al. (3) compared symptoms reported by mobile phone users and nonusers and found that the use of mobile phone may increase the severity of symptoms such as headache, irritation, clicking sounds in ears and others. While studies examining the symp- toms of mobile users in everyday life are essential to reveal effects related to prolonged daily exposure to mobile phones, a) they do not necessarily reveal an association between subjective symptoms and REFs exposure, b) they may lack accurate experimental control, as in those kind of studies it is very difficult to have control of variables other than REFs that can trigger particular symptoms, and c) volunteers can be biased when judging the severity of the symptoms related to mobile phone use. An alternative way of testing whether or not mobile phones REFs produce subjective symptoms is by exposing individuals, under strict experimental control and under double-blind conditions (i.e., when both participants and experimenter are unaware of the exposure condition) to REFs and sham signals, in different sessions, for a given period of time, and then ask them to report about particular symptoms they are experiencing (6). Hietanen et al. conducted a study using a similar method (7). They recruited a group of volunteers who reported themselves as being sensitive to cellular phones. In several sessions, participants were exposed to either REFs or sham signals and were then questioned about any particular symptoms. The symptoms reported were not aggravated by REFs exposure. The study also investigated whether participants were able to sense mobile phone REF emission and it was found that no one could distinguish between exposure conditions. Recently, other studies have shown no relations at all between exposure to mobile phone REFs and subjective symptoms (6,8,9), not even those studies that have focused on individuals claiming to be hypersensitive to REFs. Even though some scientists came to the conclusions that nocebo effects (8) or psychological factors (9) may affect reports of symptoms, generally it is acknowledge that more research is needed (10). In the present study, we investigated whether exposure to mobile phone REFs can affect five symptoms (headache, dizziness, fatigue, itching or tingling of skin, and sensation of warmth on skin). The choice of symptoms was based on what has been previously reported in the literature. In two different sessions, volunteers were exposed to active REF and sham signals, and asked to rate the above symptoms. Exposure conditions (real exposure and sham exposure) were double blinded. Testing under double-blind conditions seems impor- tant since many effects reported under single-blind conditions From the Department of Psychology, University of Essex, United Kingdom (C.C., R.R., E.F.); and Department of Psychology, University of Valencia, Spain (A.B.). Address correspondence and reprint requests to Caterina Cinel, Department of Psychology, University of Essex, Colchester CO4 3SQ, United Kingdom. E-mail: ccinel@essex.ac.uk This work was supported by a grant from the Mobile Telecommunications and Health Research Programme (Grant ref. RUM9) to Riccardo Russo and Elaine Fox. The views expressed in the publication are those of the authors and not necessarily those of the funders. Received for publication July 23, 2007; revision received October 10, 2007. DOI: 10.1097/PSY.0b013e31816521f1 345 Psychosomatic Medicine 70:345–348 (2008) 0033-3174/08/7003-0345 Copyright © 2008 by the American Psychosomatic Society