ABSTRACT
CONTENTS 4.1 Introduction ....................................................................................................................... 150 4.2 Microwave Effects ............................................................................................................ 153
4.2.1 Detection of Microwaves ................................................................................... 153 4.2.2 Microwave Performance Disruption ............................................................... 155 4.2.3 Microwave Cognitive Effects: Animal Studies .............................................. 155
4.2.3.1 Microwave Cognitive Performance Disruption in Animals......... 155 4.2.4 Animals: Spatial Memory Replications and Confirmations ........................ 156
4.2.4.1 Introduction .......................................................................................... 156 4.2.5 Microwave Spatial Memory Experiments ...................................................... 159 4.2.6 Conclusions: Animals: Spatial Memory Replications
and Confirmations .............................................................................................. 162 4.2.7 Microwave Cognitive Effects: Human Studies ............................................. 163 4.2.8 Microwave Effects on the Electroencephalogram ........................................ 168 4.2.9 Blood-Brain Barrier Studies ............................................................................. 179 4.2.10 Electrosensitivity in Humans ........................................................................... 185 4.2.11 Future Microwave Mobile Signals and Further Research ........................... 185 4.2.12 Microwave Effects: Overall Conclusion.......................................................... 189
4.3 Extremely Low-Frequency Effects ................................................................................. 190 4.3.1 Detection of Extremely Low-Frequency Electric and Magnetic
Fields .................................................................................................................... 190 4.3.2 Extremely Low-Frequency Cognitive Effects: Animals................................ 196 4.3.3 Extremely Low-Frequency Animal Cognitive Studies: Conclusion........... 197 4.3.4 Extremely Low-Frequency Cognitive Studies: Humans .............................. 197 4.3.5 Extremely Low-Frequency Human Cognitive Studies: Conclusion .......... 198
Acknowledgment....................................................................................................................... 199 References ................................................................................................................................... 199
The human brain is comprised of more than 100 billion individual nerve cells that are functionally interconnected into systems. These systems construct our perceptions and cognitions of the world, and control how we react to the external world (Kandel et al., 2000). This chapter presents an overview of the interaction of nonionizing electromagnetic fields (EMFs) as external stimuli to the nervous systems and the behavior of humans and laboratory animals. This overview of the scientific literature specifically includes the detection of EMFs and effects of EMFs on behavioral performance and cognition. EMF detection by humans and responses of laboratory animals suggests that detection could motivate changes in behaviors. The chapter is divided into two parts, which are distinguished simply by frequency: microwave (MW) radio frequency and extremely low-frequency (ELF). This chapter extends the findings of recent reviews of the animal and human research literature (Hermann and Hossmann, 1997; D’Andrea, 1999; Cook et al., 2002; D’Andrea et al., 2003a,b; Hossmann and Hermann, 2003). Biological effects of MWs occur due to absorption of energy in the body. Microwave
absorption by water molecules has a resonant frequency in the region of 2.45 GHz that causes heating by molecular vibration and is the result of the interaction of MWs and tissue of the body. Water is the molecular component of tissue known to have a resonant frequency that could contribute to the absorption of MW energy. Heating (absolute temperature rise) is the best understood mechanism for the effective transfer of MW energy into tissue. Other tentative mechanisms for the transfer of energy from MWs into human tissue are not established as potential sources for health effects or the modification of human behavior. The accepted unit of measurement is specific absorption rate (SAR). The IEEE (Std
C95.1-2005) defines ‘‘specific absorption rate (SAR) as the time derivative of the incremental energy absorbed by (dissipated in) an incremental mass contained in a volume element of given density.’’ The ICNIRP (1998) defines ‘‘specific energy absorption rate (SAR) as the rate at which energy is absorbed in body tissues, in watt per kilogram (W/kg). SAR is the dosimetric measure that has been widely adopted at frequencies above about 100 kHz.’’ Absolute rise in temperature in the tissues of the body is also a measure of MW absorption of energy. Biological effects of ELF are known to be due to electrostimulation which is defined as
‘‘the induction of a propagating action potential in excitable tissue by an applied electrical stimulus; electrical polarization of pre-synaptic processes leading to a change in post synaptic cell activity’’ (Reilly, 1998; IEEE, Std C95.6-2002). The unit of measurement is slightly different for IEEE and ICNIRP. For the IEEE, the unit is the induced in situ electric field stimulation of the nervous system (volts per meter: V/m) (IEEE, Std C95.6-2002) and for the ICNIRP the unit is the induced current density (ampere per square meter: A/m2) that results in stimulation of the nervous system (ICNIRP, 1998). The body generates thermal noise and also electrical noise and against that background
the input of low power MW stimulation may be indistinguishable from the endogenous biological thermal noise while core temperature remains stable (Adair, 2003) and the electrical power stimulation may be indistinguishable from the endogenous electrical noise below the threshold for the generation of action potentials of nerves (Reilly, 1998). Establishing scientific evidence of the time course and dose effects for MW-induced temperature rise and ELF-induced electrical stimulation of nerves are essential. Reviewed in this chapter, these are reflected in the animal and human gradients from biological sensory detection of MWs and ELF exposures up to the level of adverse health effects on behavioral and cognitive responses.
