Cinel C, Russo R, Boldini A, Fox E. (2008). Exposure to mobile phone electromagnetic fields and subjective symptoms: a double-blind study. Psychosom Med 70(3):345-348.
Surveys of mobile phone users have revealed that some of these people report subjective symptoms such as headache, fatigue, rash, or warm sensations on the skin (particularly around the ear) when using their mobile phones in everyday life.
The objective of this research was to investigate the association between exposure to radiofrequency electromagnetic fields (REF) that are emitted during mobile phone use and subjective symptoms under controlled experimental conditions.
Study participants were 496 volunteers studying or working at the University of Essex, United Kingdom. In two different sessions separated by about a week, subjects were exposed to either 40 minutes of REF signals or 40 minutes of ‘sham’ signals. The source of the signals was a mobile phone mounted next to the subjects’ ear. During the experiment, neither the subjects nor the researchers knew which signal (REF or sham) had been emitted from the mobile phone so that this knowledge could not influence their responses (double-blind design). Subjects completed one of three tests of memory, attention, and listening skills while under REF exposure. Before and after exposure, subjects were asked to rate the strength of the following sensations or symptoms they were experiencing: headache, dizziness, fatigue, itching or tingling of skin (specify location), sensation of warmth on skin (specify location), and any other symptoms.
Participants rated on average their symptoms as more severe after both REF and sham exposure. There was no difference between the symptoms experienced after REF and sham exposure for most subjects. Participants who performed one of the three types of mental tests during exposure reported a significantly increased sensation of dizziness following REF exposure but not sham exposure.
The authors suspect that subjects’ symptoms worsened following exposure to both REF and sham signals due to the difficulty of the mental tasks the subjects were asked to perform and not due to the exposures themselves. The finding that only one group of subjects and not the other two groups experienced an increase in dizziness following REF exposure and not sham exposure is surprising. Only the mental test and not the exposure conditions varied between the three groups. No other studies have found that dizziness is associated with REF exposure. For these reasons, the authors concluded that this finding is not scientifically meaningful and may be a statistical error.
Exposure to mobile phone REF’s is not associated with uncomfortable symptoms or sensations among the general population. These results are consistent with previous studies. More research is needed on the effects of long-term exposure to mobile phone REF’s (such as would occur with frequent daily mobile phone use) and on the effects in children.