study of the effects of RF radiation on blood flow in the brain
A recent publication
reported on the effects of radiofrequency radiation, emitted by
a mobile phone, on blood flow in the human brain. The blood flow
was measured by a PET scan. The subjects were examined while performing
a memory task. While there was a relative decrease in regional blood
flow in the part of the brain associated with hearing, it was thought
that this was likely due to an auditory signal from the battery
of the active mobile phone, rather than to the EMF from the phone.
There was no change in the brain area most likely to be exposed
A previous study
of brain blood flow, by Huber and colleagues, which was reported
in "What's New" in February
2003, showed increased blood flow in the brain on the same side
as exposure to a pulse-modulated electromagnetic field.
For more, see
"Research - Clinical -
Reference: Haarala C, Aalto S, Hautzel H,
Julkunen L, et al. (2003): Effects of a 902 MHz mobile phone on
cerebral blood flow in humans: A PET study. NeuroReport 14:2019-2023.
effect of RF radiation on melatonin production in rats
studies, by Vollrath and colleagues (1997) and Heikkinen and colleagues
(1999), showed no effect of exposure to RF radiation on melatonin
production in laboratory animals. Another study has shown similar
results. Bakos and colleagues exposed the animals to either 900
or 1800 MHz frequency radiation for 2 hours a day for 14 days, and
found no change in the amount of urinary melatonin produced during
the night. Most studies in humans have failed to show any effect
of RF radiation on melatonin production. These results are of particular
interest because some researchers have speculated that disturbed
melatonin production may influence cancer formation. For more, see
"Research - Toxicological
Experiments - Others" and "Research
- Clinical experiments - Hormone secretion".
Bakos J, Kubinyi G, Sinay H, Thuróczy G (2003): GSM modulated
radiofrequency radiation does not affect 6-sulfatoxymelatonin excretion
of rats. Bioelectromagnetics 24:531-534.
about results of study
In March 2003
"What's New" we reported a
study by Mashevich and colleagues that suggested that RF radiation
can induce changes in chromosomes of cells. In the latest issue
of the journal "Bioelectromagnetics" there is correspondence
about the validity of the findings. The debate centres on whether
or not the cells could have been exposed to excessive heating.
Chou C-K, Swicord M (2003): Comment on "Exposure of human peripheral
blood lymphocytes to electromagnetic fields associated with cellular
phones leads to chromosomal instability" by Mashevich et al.
R, Barbul A (2003): Reply to the Comment. Bioelectromagnetics 24:583-585.
The US government
has announced plans for a $10 million study of potential health
risks associated with cell phones.
It has also
been reported that the Danish Minister of Science and Technology
is planning a new study into the relationship between radiation
given off by cell phones and possible health effects.