The Ground Wave Emergency Network (GWEN) is a communication system under development by the Air Force for which a Final Environmental Impact Statement was issued in September 1987. In 1990, members of Congress asked the Air Force to evaluate recent evidence that exposure to electromagnetic fields results in adverse biological effects and to assess the significance of the evidence in the context of potential health effects of the low-frequency (LF) and ultra-high-frequency (UHF) radiation emitted by the GWEN system. The release of federal funds to bring the entire system of GWEN transmitters and relay stations into operation was delayed until the Air Force responded to the Congressional request for information. The Air Force established a contract with the National Research Council (NRC) to convene a committee of independent scientists to address the questions raised by Congress, and this report is the result of the work of the committee, the Committee on Assessment of the Possible Health Effects of Ground Wave Emergency Network.
In correspondence with NRC before establishment of the GWEN committee, the Air Force raised several questions related to the interaction of electromagnetic fields with living systems. Briefly stated, the questions raised by the Air Force were as follows:
Is there epidemiological evidence relevant to the risk of significant environmental impact associated with GWEN electromagnetic fields?
Is there evidence of tumor-promoting effects of electromagnetic fields, and if so, is it relevant to a carcinogenic risk to the public associated with the operation of GWEN?
What is known about the effects of electromagnetic fields on membrane properties, biological signal transduction, Ca2+ binding to membranes, and Ca2+ transport into cells? Is there evidence of ion cyclotron resonance interactions or other physical interactions that could influence biosystems? If these interactions have been shown to exist, is the evidence strong and do the observed bioeffects constitute a health risk?
What is the relevance of previous studies on shock and burn hazards to the operation of GWEN?
This report addresses all those questions. To accomplish its task within the broader framework of a comprehensive report, the committee has prepared a report that progresses from interaction mechanisms of electromagnetic fields to their biological and human health effects, and then to an analysis of risk and exposure reduction options. This report describes the physical characteristics of GWEN fields, mechanisms of electromagnetic field interactions with the human body, animal and tissue interactions of electromagnetic fields, human health effects of the fields, existing exposure standards and guidelines, and risk analysis and management. The committee has tried to relate the findings of laboratory studies and human epidemiological surveys to the possible health and environmental effects of GWEN fields. The committee has answered the Air Force's specific questions within the broader context of interaction mechanisms, biological effects and human health effects of electromagnetic fields.