Korpinen LH, Paakkonen RJ. Self-Report of Physical Symptoms Associated With Using Mobile Phones and Other Electrical Devices. Bioelectromagnetics. April 27, 2009 Ahead of print.
Electromagnetic hypersensitivity (EHS) is defined as non-specific symptoms associated with exposure to electromagnetic fields (EMF). Symptoms include headache, pain and warmth in the head, sensations in the eyes, on the neck or face or in the ears, vertigo and general body symptoms. However, no biologic cause for EHS has been found.
The aim of the study was to investigate self-reported physical symptoms associated with the use of mobile phones and other electrical devices.
In October, 2002, a questionnaire was sent to 15,000 Finns aged 18-65. The questionnaire asked about general demographic factors such as age, gender, education, and trade, the use of technical devices that emit EMFs, such as computers, mobile phones, and digital telephones, and an open-ended question on “other observations concerning technology and health”. Those who experienced symptoms associated with EMF exposure were identified from this open-ended question and were grouped according to symptom and device type.
The response rate was 41%, of which 1,300 (21%) answered the open-ended question about technology and health. In total, approximately 2,508 comments were made. Comments were grouped into 3 categories: (1) respondents with different self-reported symptoms associated with mobile phone use, (2) respondents who had skin symptoms after long exposure to computer screens, and (3) respondents who mentioned physical symptoms associated with use of mobile phones and other electrical devices. Category 1 included 33 respondents who experienced either one or several of: headaches, earaches, and warmth sensations. In total 0.7% of respondents were included in category 1 or 2.
Interpretation and Limitations
The authors suggest that the low rate of response to the open-ended question may be because subjects viewed the question as redundant or unclear. The symptoms reported by the subjects in this study are similar to those experienced by those with EHS in other studies. The prevalence of EHS was 0.7% in this study, which is lower than that reported in Sweden (1.5%), California (3.2%), and Switzerland (5%). However, if those who didn’t answer the open-ended question are excluded from the analysis, the prevalence of EHS in this study is 2.5%. The authors suggest that the questionnaire should be repeated, this time using more structured questions, to see if this significantly changes the results.
This study shows that physical symptoms associated with using mobile phones can be quite complex, and that people can have one clear symptom or many non-specific symptoms. The strength of the open-ended question is that the researchers didn’t impose their own assumptions on the responses, although the study design may have underestimated the prevalence of EHS.