increased risk of acoustic neuroma in cell phone users
A new research
paper has provided further evidence that cell phone users are not
at increased risk of developing acoustic neuroma, a tumour that
grows on the auditory nerve (the eighth cranial nerve). The study
examined 106 cases that were seen at the one centre in Copenhagen
that sees all patients with this disorder in Denmark. Each case
was matched with 2 controls, and the use of cell phones prior to
diagnosis was examined. The relative risk of acoustic neuroma was
0.90. A relative risk of 1 or less indicates no increased risk.
studies have also concluded that there is no increased risk of this
tumour in cell phone users. The exception to this was a study by
Hardell and colleagues in Sweden that did find an increased risk.
Several reviewers have criticized the Swedish study on methodological
grounds. For more, see "Research
The Danish group
is the first to report findings from the international case-control
study that is underway at present (see "Research
Programs - IARC).
Christensen HC, Schuz J, Kosteljanetz M, Skovgard H, et al.(2004):
Cellular telephone use and risk of acoustic neuroma. Am J Epidemiol
and mobile phones (1)
Expert Group on Mobile Phones (IEGMP) in the UK, in its 2000 report,
are currently unrecognised adverse health effects from the use of
mobile phones, children may be more vulnerable because of their
developing nervous system, the greater absorption of energy in the
tissues of the head, and a longer lifetime of exposure".
Fields Committee of the Health Council of the Netherlands has reviewed
the scientific evidence and could not find data to back the statement
of the IEGMP. The Committee concluded that
"no major changes in head development occur after the second
year of life that might point at a difference in electromagnetic
susceptibility between children and adults. The Health Council therefore
sees no reason to recommend limiting the use of mobile phones by
van Rongen E, Roubos EW, van Aernsbergen LM, Brussaard G, et al.
(2004): Mobile phones and children: Is precaution warranted? Bioelectromagnetics
and mobile phones (2)
This topic is
also explored in a recent publication. The authors used a computational
technique to estimate the Specific Absorption Rate (SAR) in heads
of different sizes. They concluded:
"higher SAR in children's brains can be expected depending
on whether the thickness of their skulls and surrounding tissues
actually depends on size".
Reference: Martinez-Burdalo M, Martin A, Anguiano
M, Villar R (2004): Comparison of FDTD-calculated specific absorption
rate in adults and children when using a mobile phone at 900 MHz
and 1800 MHz. Physics in Medicine and Biology 49:345-354.
Another study on brain function
A recent study
has shown that exposure to EMFs from a cell phone at 902MHz frequency
was associated with a decrease in reaction time. This was more prominent
in a group who had received the exposure for 45 minutes before embarking
on the tests of brain function, compared to those who had the RFR
exposure during performance of the tests.
have shown changes in reaction times with exposure to RFR, though
the results have not been consistent. For more, see "Research
- Clinical Experiments - cognitive function".
Curcio G, Ferrara M, de Gennaro L, Cristiani R, et al. (2004): Time-course
of electromagnetic field effects on human performance and tympanic
temperature. Neuroreport 15:161-164.
increase in ODC activity with RFR
(ODC) is an enzyme
that is involved in the growth of normal and cancer cells. Several
studies have shown increased ODC levels in laboratory experiments
after exposure to RFR. A recent paper reports an attempt to replicate
one of these studies. In contrast to the earlier study, there was
no increase of ODC activity after exposure to RFR from a cell phone
with a frequency of 835 MHz. If sufficient power was used to cause
increased temperature in the tissues, a decrease in ODC activity,
rather than an increase, was observed.
For more, see
"Research - Toxicological Experiments
Desta, A. B., Owen RD, Cress LW (2003): Non-thermal exposure to
radiofrequency energy from digital wireless phones does not affect
ornithine decarboxylase activity in L929 cells. Radiat.Res.160:488-491.