Fig. 9.2. Classes of physical processes in biological tissue exposed to EMFs: Types 1-4 can occur in
living and nonliving tissue They are thermodynamically closed in the sense that they are directly
proportional to the applied EMF. The biological consequences, if any, are thermodynamically open
because they can occur only if metabolic energy is also present- that is, if the system is alive. For Type
5, in contrast, both the physical process and the biological consequence can be thermodynamically
open. As an example, we have depicted a metabolically maintained superconducting region in a cell
organelle. State S
1
is associated with one biological function and S
2
-induced by the presence of the
EMF- with a different function.
Electronic excitation involves the transition of electrons to a higher energy level following the
absorption of electromagnetic energy. If the electrons are bound to enzyme molecules, for example,
then the excited molecules might behave differently in a metabolic reaction, thereby resulting,
ultimately, in a biological effect. Since, however, the thermal energy at 37°C is about 0.02 electron
volts (ev), it has traditionally been argued that photons having a lower energy would not produce
electron excitation- hence, no biological effects-because molecules with energy states less than 0.02 ev
would already be excited as a result of thermal motion. This view, although popular, is not correct
because the thermal energy is only the average energy of a collection of molecules: at any given time,
some molecules are in a state of less than 0.02 ev. The salient -and presently unexplored- questions
associated with Type-I processes relate to the density of states that are hv ev (h is Planck's constant, v
is the frequency of the EMF) below a specific average energy, and to the minimum change in the
density of such states that would be required to produce a biological effect.
Type-2 processes involve electronic, atomic, and orientational polarizations produced when a
material is exposed to an EMF: the total dipole moment of a group of molecules depends on these
polarization properties and on the strength of the local electrical field. EMF-induced alterations in
dipole moments could theoretically account for biological effects. For example, Figure 9.2 depicts a
material containing a linear array of permanent dipoles. In the absence of an EMF, the dipoles remain
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