study of cell phone use and cancer risk
et al. (2002) reported on a cohort study of cell phone users and
cancer risk. This group has now updated their findings. They followed
420,095 subscribers and linked them to the Danish Cancer Registry.
The mean time of cell phone use was 8.3 years, with a maximum of
21 years. They found no evidence of an association between tumour
risk and cell phone use.
more, see Research – Epidemiology”.
Schuz J, Jacobsen R, Olsen JH, Boice JD Jr., et al. (2006d): Cellular
telephone use and cancer risk: Update of a nationwide Danish cohort.
J Natl Cancer Inst 98:1707-1713.
negative study of RFR and the stress response
and colleagues have added to the growing number of studies that
have shown no effect of RFR exposure on the induction of indicators
of stress responses in the cell. They exposed cells to RFR at SAR
of either 2 or 20 W/kg for 30 minutes or 1 hour, and found no change
in expression of heat shock
proteins or other activators of stress responses.
more, see “Research –
Toxicology – Others – Heat shock response”.
Lee J-S, Huang T-Q, Kim T-H, Kim JY, et al. Radiofrequency radiation
does not induce stress response in human T-lymphocytes and rat primary
astrocytes. Bioelectromagnetics 2006;27:578-588.
New method proposed for estimating exposure
levels for cell phone users
of the most difficult tasks in conducting an epidemiological study
of the risks of cell phone usage is to accurately assess exposure
levels of users.
Kim and colleagues have proposed a new method to estimate quantitative
and relative RF exposure levels using a neural network model. The
parameters that were used to develop this model were average usage
time per day, total period of usage in years, SAR of the specific
phone, hands-free usage, antenna extraction, and the type of phone
(flip or folder). They used these because they believe them to be
related to RF exposure. The authors emphasize that their method
needs to be developed and updated as future research enables RF
exposure to be more accurately estimated.
Kim SC, Nam KC, Kim DW (2006): Estimation of relative exposure levels
for cellular telephone users using a neural network. Bioelectromagnetics
RFR exposure and the skin
have been few papers that have examined the effect of RFR exposure
on the skin.
Two papers, authored by the same group of researchers, have now
reported the effect of RFR exposure on the skin (Manchez 2006, Sanchez
2006). Skinless rats were exposed to either 900 or 1800 MHz RFR,
either for 2 hours at SAR of 5 W/kg, or for 2 hours per day, 5 days
a week, for 12 weeks at 900 or 1800 MHz at SAR of 2.5 or 5 W/kg.
There were no significant changes in the skin of exposed rats, when
compared with skin from an unexposed part of the same area of the
rat, or of control or sham-exposed rats.
more, see “Research –
Toxicology– Others – Skin”.
Masuda H, Sanchez S, Dulou PE, Haro E, et al. Effect of GSM-900
and -1800 signals on the skin of hairless rats: 1: 2-hour acute
exposures. Int J Radiat Biol 2006;82:669-674.
S, Masuda H, Billaudel B, Haro E, et al. Effect of GSM-900 and -800
signals on the skin of hairless rats: 11: 12-week chronic exposures.
Int J Radiat Biol 2006;82:675-680.
affects temperature in rabbits' eyes
have been varied results in experiments testing the effect of RFR
on rabbits' eyes. Kojima et al. reported that anesthesia affects
the thermoregulatory control mechanisms, and leads to increased
temperatures in the eyes of the rabbits (see "What's
New" June "04). The same group has now confirmed this
finding, and has also shown that a computational model gives results
that are in good agreement with results seen in live animals.
more, see "Research - Toxicology
Hirata A, Watanabe S, Kojima M, Hata I, et al. Computational verification
of anesthesia effect on temperature variations in rabbit eyes exposed
to 2.45 GHz microwave energy. Bioelectromagnetics 2006;27:602-612.
of the effect of ELF-modulated RF fields on brain function
and colleagues have updated a 2002 review of brain electrophysiological
and cognitive responses
to EMF exposure. Some of the review relates to ELF-modulated RF
fields. They report that there are more reports of physiological
effects than performance effects, and offer possible explanations
for these observations.
more, see “Research
– Clinical – EEG and Cognitive function”.
CM, Saucier DM, Thomas AW, Prato FS. Exposure to ELF and ELF-modulated
radiofrequency fields: The time course of physiological and cognitive
effects observed in recent studies (2001-2005). Bioelectromagnetics
effect of RFR on ROS or HSP70 levels
paper has failed to show any effect of RFR on reactive oxygen species
(ROS) or HSP70 levels. Human lymphocytes
and monocytes were
exposed to 1800 MHz RFR for 30 or 45 minutes at 2W/kg SAR for the
ROS investigation, or for 1 hour for the HSP study. No increase
was seen in ROS induction or HSP&) levels.
more, see "Research - Toxicological
M, Lupke M, Frahm J, Mattson MO, et al. ROS release and Hsp70 expression
after exposure to 1,800 MHz radiofrequency electromagnetic fields
in primary human monocytes and lymphocytes. Radiat Environ Biophys