141
Static, Low-Frequency, and Pulsed Magnetic Fields
levels were measured in tissues. The GSH concentration was significantly lower in the
heart of all experimental animals compared with the control group; furthermore, the
decrease was higher in the liver of restrained animals. Superoxide dismutase activity
was found to be lower in the plasma of restrained and EMF-exposed animals compared
with unrestrained rats. There were no significant differences in CAT activity and TBARS
levels among all the experimental groups versus the control group. The authors suggest
that EMF might alter the metabolism of free radicals, decreasing SOD activity in plasma
and GSH content in heart and kidney, but does not induce lipid peroxidation. Oxidative
stress induced by movement restraint was stronger than that produced by EMF.
Goraca, Ciejka, and Piechota (2010) examined the effects of an ELF-EMF (40 Hz,
7 mT, 60 min/day for 2 weeks) on ROS generation in rat heart tissue. The results of
the study indicated that the ELF-EMF caused significant increase in TBARS and H 2 O 2
concentrations and decrease in the concentrations of GSH and total free -SH groups
in heart homogenates. Moreover, the exposure to ELF-EMF resulted in a decrease in
plasma antioxidant capacity.
Negishi et al. (2008) evaluated the hypothesis that power-frequency EMF (50 Hz,
≤350 μT, 22 h/day, 7 d/week for 30 weeks) is a significant risk factor for the occurrence of
hematopoietic neoplasia. The results showed that there was no observed sexual difference
in the cumulative proportions of mice with 7,12-dimethylbenz(a)anthracene (DMBA)induced leukemia and no relationship between EMF exposure and the occurrence of
neoplasia. These data provide no evidence to support the aforementioned hypothesis.
Emre et al. (2011) investigated the effect of an ELF-EMF (consecutive four pulse trains
of 1, 10, 20, and 40 Hz, 1.5 mT, 0.6 V/m) on oxidative stress in rat liver tissue. The results
showed significant increase in the levels of oxidative stress indicators, for example,
plasma ALT, AST, alkaline phosphatase (ALP) albumin, bilirubin, total protein, malondialdehyde (MDA), and SOD activity, and indicated significantly higher apoptotic cell
percentage but lower necrotic cell percentage in the ELF-EMF-exposed group compared
with both the unexposed and the sham control groups. However, DNA ladder analyses
did not differentiate between the groups. Although the effect of ELF-EMF on apoptosis
is not a clearly established issue, the release of extracellular calcium ion has been considered by the authors as a critical step in the process.
Raggi et al. (2008) studied the effects of the relationship between EMF and oxidative
stress in humans. The authors reported the effects of an ELF-EMF (1–100 Hz, 1–100 μT)
therapy device on oxidative status in humans. This device supplies complex magnetic
signals with specific choices of frequency, intensity, and shape that are based on Liboff’s
ICR hypothesis. Thirty-two healthy volunteers were treated using the therapy device.
A quantitative determination of oxidative stress was obtained at three time points by
measuring MDA concentrations in peripheral blood before and after the cycle and one
month following completion of the cycle. A highly significant reduction in mean MDA
(53.8%) was found at the end of treatment. One month later the mean MDA values were
found to have risen again, but there was still a significant overall reduction of 15.6%
compared with the original values.
Reddy et al. (2010) investigated the genotoxic effect of a PEMF (<1000 Hz, 1 mT, for
eight weeks) on mice. Positive control animals exposed to 1 Gy γ-radiation were also
included in the study. The extent of genotoxicity and cytotoxicity was assessed from
Static, Low-Frequency, and Pulsed Magnetic Fields
levels were measured in tissues. The GSH concentration was significantly lower in the
heart of all experimental animals compared with the control group; furthermore, the
decrease was higher in the liver of restrained animals. Superoxide dismutase activity
was found to be lower in the plasma of restrained and EMF-exposed animals compared
with unrestrained rats. There were no significant differences in CAT activity and TBARS
levels among all the experimental groups versus the control group. The authors suggest
that EMF might alter the metabolism of free radicals, decreasing SOD activity in plasma
and GSH content in heart and kidney, but does not induce lipid peroxidation. Oxidative
stress induced by movement restraint was stronger than that produced by EMF.
Goraca, Ciejka, and Piechota (2010) examined the effects of an ELF-EMF (40 Hz,
7 mT, 60 min/day for 2 weeks) on ROS generation in rat heart tissue. The results of
the study indicated that the ELF-EMF caused significant increase in TBARS and H 2 O 2
concentrations and decrease in the concentrations of GSH and total free -SH groups
in heart homogenates. Moreover, the exposure to ELF-EMF resulted in a decrease in
plasma antioxidant capacity.
Negishi et al. (2008) evaluated the hypothesis that power-frequency EMF (50 Hz,
≤350 μT, 22 h/day, 7 d/week for 30 weeks) is a significant risk factor for the occurrence of
hematopoietic neoplasia. The results showed that there was no observed sexual difference
in the cumulative proportions of mice with 7,12-dimethylbenz(a)anthracene (DMBA)induced leukemia and no relationship between EMF exposure and the occurrence of
neoplasia. These data provide no evidence to support the aforementioned hypothesis.
Emre et al. (2011) investigated the effect of an ELF-EMF (consecutive four pulse trains
of 1, 10, 20, and 40 Hz, 1.5 mT, 0.6 V/m) on oxidative stress in rat liver tissue. The results
showed significant increase in the levels of oxidative stress indicators, for example,
plasma ALT, AST, alkaline phosphatase (ALP) albumin, bilirubin, total protein, malondialdehyde (MDA), and SOD activity, and indicated significantly higher apoptotic cell
percentage but lower necrotic cell percentage in the ELF-EMF-exposed group compared
with both the unexposed and the sham control groups. However, DNA ladder analyses
did not differentiate between the groups. Although the effect of ELF-EMF on apoptosis
is not a clearly established issue, the release of extracellular calcium ion has been considered by the authors as a critical step in the process.
Raggi et al. (2008) studied the effects of the relationship between EMF and oxidative
stress in humans. The authors reported the effects of an ELF-EMF (1–100 Hz, 1–100 μT)
therapy device on oxidative status in humans. This device supplies complex magnetic
signals with specific choices of frequency, intensity, and shape that are based on Liboff’s
ICR hypothesis. Thirty-two healthy volunteers were treated using the therapy device.
A quantitative determination of oxidative stress was obtained at three time points by
measuring MDA concentrations in peripheral blood before and after the cycle and one
month following completion of the cycle. A highly significant reduction in mean MDA
(53.8%) was found at the end of treatment. One month later the mean MDA values were
found to have risen again, but there was still a significant overall reduction of 15.6%
compared with the original values.
Reddy et al. (2010) investigated the genotoxic effect of a PEMF (<1000 Hz, 1 mT, for
eight weeks) on mice. Positive control animals exposed to 1 Gy γ-radiation were also
included in the study. The extent of genotoxicity and cytotoxicity was assessed from