Wallace D, Eltiti S, Ridgewell A, Garner K, Russo R, Sepulveda F, Walker S, Quinlan T, Dudley S, Maung S, Deeble R, Fox E. Do TETRA (Airwave) Base Station Signals Have a Short-Term Impact on Health and Well-Being? A Randomized Double-Blind Provocation Study. Environ Health Perspect. Jan 14,2010 Ahead of print.
In the UK, a new communication system “Airwave”, based on Terrestrial Trunked Radio (TETRA) is currently being introduced for the police and emergency services. Some police officers attribute various health symptoms to using their Airwave handset. Others attribute unusual symptoms to TETRA base station signals. Also, some people in the general population believe that they suffer from “electrosensitivity”’ i.e. they believe that their symptoms are caused by electromagnetic fields from electrical equipment in general. Little scientific information is available on possible health effects of TETRA. In 2001, the Advisory Group on Non-Ionizing Radiation (AGNIR), based on its review of available scientific evidence, concluded that TETRA was unlikely to pose a health risk. However, AGNIR recommended that well-designed laboratory studies be conducted. Only two studies have been published since then, one reporting no effects of TETRA handsets on calcium physiology in the brain and the other – no effect on blood pressure or on any other physiological parameters.
This was the first study of short-term health effects of TETRA base stations. Its objective was to assess effects of TETRA signals on health and well-being of “electrosensitive” individuals and of members of the general public who do not report such problems.
Before testing, all participants completed the electromagnetic hypersensitivity questionnaire in order to assess their state of health and to determine whether they attributed their symptoms to EMFs. TETRA base station signals were tested on “electrosensitive” individuals and healthy controls under open provocation and double-blind conditions. A total of 51 individuals with self-reported electrosensitivity and 132 age- and gender matched controls participated in an open provocation test, 48 “electrosensitive” individuals and 132 controls participated in the double-blind tests. At the open provocation tests, both the experimenter and the participants knew when the base station was “on” and when it was “off”. Exposure conditions for the double-blind tests were preprogrammed by an external consultant. A range of objective (heart rate, skin conductance and blood pressure) and subjective (visual analogue scales and symptom scales) indicators of well-being were measured and the ability to detect the presence or absence of the signal was determined.
Visual Analogue Scales.
In the open provocation test, “electrosensitive” individuals experienced greater anxiety, tension, arousal, discomfort and fatigue and less relaxation than controls, regardless of exposure condition (TETRA or sham). Regardless of group (“sensitive” or control) the participants felt worse during TETRA exposure compared to sham. However, no significant differences between groups or exposure conditions were observed under double-blind conditions.
In the open provocation test, sensitive participants experienced a greater severity and number of symptoms than controls. For control individuals, there was no difference between TETRA and sham exposure conditions in symptom severity or number of symptoms. In contrast, “electrosensitive” participants reported significantly more symptoms and higher symptom severity during TETRA compared to sham exposure. Under double-blind conditions, “electrosensitive” individuals reported more symptoms and greater symptom severity than controls regardless of exposure conditions.
Objective physiological parameters.
“Electrosensitive” participants had higher heart rate compared to controls regardless of exposure conditions both in the open provocation and in the double-blind test. No other significant differences were observed. Neither group was able to detect when the TETRA base station was “on” and when it was “off”.
Interpretation and Conclusion
The results of this study suggest that it is the awareness of the exposure to TETRA base station signal, but not the exposure itself that causes symptoms in the “electrosensitive” individuals. This is in line with findings of other studies on TETRA handset signals and on GSM and UMTS signals. Taken together, these studies suggest that short-term exposure to radiofrequency fields has no negative effect on human health.