Dahmen N, Ghezel-Ahmadi D, Engel A. Blood laboratory findings in patients suffering from self-perceived electromagnetic hypersensitivity (EHS) Bioelectromagnetics Mar 3, 2009 Ahead of print.
Individuals with electromagnetic hypersensitivity (EHS) describe adverse health effects when exposed to devices emitting electric and/or magnetic fields (EMF) of low intensity, such as mobile phones, mobile phone base stations, cordless phones, and power lines. Health effects are usually non-specific and include sleep disturbances, headache, nervousness or distress, general anxiety, depression, fatigue or problems in concentrating, memory problems, respiratory problems, gastrointestinal symptoms, dry eyes, photosensitivity, palpitations, loss of weight, increased sweating, and heat intolerance. However, these symptoms usually appear without any physiological basis. Many of these symptoms are found in disorders common in the general population, such as thyroid dysfunction, chronic liver disease, anaemia, chronic kidney disease, and chronic inflammatory processes. The authors hypothesize that EHS sufferers may be ill-attributing their symptoms to electromagnetic field exposure when they are in fact suffering from a common disorder.
To analyze clinical laboratory findings in subjects suffering from electromagnetic hypersensitivity and in controls to screen for common disorders.
A total of 132 electromagnetic hypersensitivity patients (90 females) aged 18-65 years were recruited from German electromagnetic hypersensitivity self-help groups or by local advertisement. A total of 101 controls (67 females) were matched to the patients on age, sex, and Body Mass Index (BMI). All participants were seen by an experienced psychiatrist and were free of acute psychiatric disorders. A blood sample was taken to measure the function of various body organs.
More electromagnetic hypersensitivity patients than controls had levels of thyroid function below the reference value (6.1% vs. 0.9%). Both measures of liver function were elevated in 20.9% and 12.4% of electromagnetic hypersensitivity individuals respectively while they were elevated in 11% and 5.9% of controls. No indication of anaemia was found in the electromagnetic hypersensitivity group. Measures of kidney function were similar between the two groups, with the exception of mean sodium levels which were slightly higher in the electromagnetic hypersensitivity group. There was no difference between patients and controls in measures of inflammation, with 10 subjects in each group having levels above threshold.
Implications and Limitations
Lower measures of thyroid function among electromagnetic hypersensitivity patients could mean that they suffer from thyroid gland dysfunction, or that there is a link between EMF exposure and thyroid function. Few studies have been done on this topic and more research is necessary. Values of liver function for the vast majority of all participants fell within the normal range, which suggests that liver affectations may play a role in only a small minority of electromagnetic hypersensitivity patients. The lack of association between electromagnetic hypersensitivity individuals and anaemia is in accordance with previous findings on the effects of EMF on blood parameters. None of the measures of kidney function were of clinical relevance, suggesting that kidney dysfunction is not of major concern in electromagnetic hypersensitivity. Measures of inflammation were elevated in the electromagnetic hypersensitivity group. The potential link between immune function and EMFs is unclear and immune suppressive and stimulatory effects have been reported, as have null effects. It is also difficult to discriminate between potential EMF effects, the effects of stress, and potential pre-existing abnormalities.
The authors identified thyroid dysfunction, liver dysfunction and chronic inflammatory processes in a small fraction of electromagnetic hypersensitivity sufferers, which may explain some of their symptoms, with differences between cases and controls for some measures of organ function.