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Electromagnetic Fields in Biological Systems
bone cavities, but this enhancement was probably unlikely to cause biological effects.
The maximum electric field enhancement of 50% was observed. Since the TMP was
a more adequate measure for the stroma cell model, the TMP change was evaluated.
According to subsequent calculation, the TMP change across the gap junctions reached
over 200 μV. Table 4.3 lists the examples of the calculated and measured current densities in a realistic human model exposed to ELF electric fields.
Table 4.3 Examples of Calculated and Measured Current Densities in Realistic
Human Models Exposed to Electric Field
Author
Current Density (mA/m 2 )
Method and Comments
Dawson, Moerloose,
and Stuchly (1997a)
The validity of the integrated twocalculation techniques was evaluated
in low resolution.
60 Hz, 1 kV/m: hybrid method
(scalar potential finite difference
[SPFD]/quasistatic finitedifference time domain [FDTD])
calculation for anatomical,
magnetic resonance imaging
(MRI)–based, 3.6-mm resolution,
heterogeneous, grounded and
ungrounded human models
Dawson, Caputa, and
Stuchly (1998a)
Calculated peak values are observed in
the head and abdomen; the effects of
conductivity variation and body
position on induced electric fields and
current densities were analyzed.
60 Hz, 1 kV/m: hybrid method
(SPFD/quasistatic FDTD)
calculation for anatomical,
MRI-based, 3.6-/7.2-mm
resolution, heterogeneous,
grounded and ungrounded
human models
Dimbylow (2000)
Calculated peak values: 0.171 × 10 −2 in
the body of grounded model and
0.474 × 10 −2 in ungrounded model;
0.100 × 10 −3 for retina in ungrounded
model
50 Hz, 1 V/m: FDM calculation for
anatomical, MRI-based, realistic,
2-mm resolution human model,
NORMAN; averaged 1 cm 2 for
retina.
González, Peratta,
and Poljak (2007)
Calculated peak values: 8–10.2 for neck
and 60 for ankle (both in human body
with arms up and open)
60 Hz, 10 kV/m: three-dimensional
BEM calculation related to an
anatomically realistic human
grounded model
Hirata et al. (2001)
Calculated average values across 1-cm 2
area: 0.25 for neck and 0.517 for legs
(in grounded adult); 0.283 for neck
and 0.508 for legs (in grounded child)
60 Hz, 1 kV/m: hybrid method
(SPFD/quasistatic FDTD)
calculation on an adult model,
and FDTD on a child model
Hirata and Fujiwara
(2007)
Calculated average values across 1-cm 2
area: 0.204 for TARO; 0.216 for
HANAKO (both for retina)
60 Hz, 1 kV/m: quasistatic FDTD
calculations on anatomical
Japanese models, TARO and
HANAKO
Potter, Okoniewski,
and Stuchky (2000)
The current density and induced fields
can be significantly higher than for the
uniform electric field exposure on a
ground plane.
60 Hz: quasistatic FDTD
calculation for anatomical,
MRI-based, 7.2-mm resolution,
heterogeneous, human model in
close proximity to power lines