Two more Interphone studies
is the multinational series of case-control studies to assess whether
radiofrequency radiation exposure from cell phones is associated
with the cancer risk. Another two Interphone studies have been published.
(For others, see “What’s New
April, May, and September
’05). The first is from five areas of the UK, and addresses
the risk of glioma
in relation to cell phone use. The Odds
Ratio (OR) for regular phone use was 0.94, which is consistent
with no increased risk. There was a significantly increased OR of
1.24 for reported phone use on the same side as the tumour, but
there was a significantly reduced risk on the opposite side. This
is consistent with recall bias,
seen when knowledge of the tumour site influences information given
about which side of the head was usually used for phoning. The main
weakness of the study was the low response rate - 51% for patients
with glioma and 47% for controls.
second was from Germany, and looked at cases of glioma and meningioma.
Like the UK study, the overall use of a cell phone was not associated
with brain tumour risk. The ORs for glioma and meningioma were 0.98
and 0.84 respectively. Among persons who had used a cell phone for
10 years or more, the OR was 2.20, although the risk was not statistically
significant, since the 95% confidence
intervals were 0.94 and 5.11. This result was based on 12 cases.
The participation rates were 79.6% for glioma cases and 62.7 % for
Hepworth SJ, Schoemaker MJ, Muir KR, Swerdlow AJ, et al. (2006):
Mobile phone use and risk of glioma in adults: case-control study.
BMJ (published online 20 January)
J, Bohler E, Berg G, Schlehofer B, et al. (2006): Cellular phones,
Cordless phones, and the risks of glioma and meningioma (Interphone
study group, Germany). Am J Epidemiol (published on-line January
two more papers from Hardell and colleagues
and colleagues have added to their lengthy list of publications
with two recent papers. The first pools results from two separate
studies with similar methodology, and examines the risk of benign
brain tumours in users of analogue and digital cell phones, and
also in cordless phone users. Many results are reported. In the
multivariate analysis there was a statistically significant increased
risk for acoustic neuroma in analogue phone users. The OR was 2.5.
The second paper reported the results of their latest case-control
study. The paper concentrates on malignant tumours. The authors
found increased risks in all of the user groups, even after multivariate
analysis (although the risk was not statistically significant in
digital phone users). These results contrast markedly with the results
emerging from the various Interphone studies.
more on the Interphone studies, and those of Hardell et al., see
Hardell L, Carlberg M, Mild KH (2006a): Pooled analysis of two case-control
studies on the use of cellular and cordless telephones and the risk
of benign brain tumours diagnosed during 1997-2003. Int J Oncol
L, Carlberg M, Mild KH (2006b): Case-control study of the association
between the use of cellular and cordless telephones and malignant
brain tumours diagnosed during 2000-2003. Environ Res 100:232-241.
genotoxic studies with
A study by Sakuma and colleagues has failed to show and evidence
of DNA damage in cells exposed to radiofrequency radiation (RFR).
The RFR exposure was from the International Mobile Telecommunication
system (IMT-2000). The cells were exposed for either 2 or 24 hours
at SARs between 0.8 and 8 W/kg. There were no significant differences
between RFR-exposed and sham-exposed cells in the alkaline comet
assay, an indicator of DNA damage.
et al. report that RFR exposure (1.8 GHz, SAR 3 W/kg) with chemical
mutagens mitomycin C and 4-nitroquinoline-1-oxide had greater effects
on DNA damage in human lymphocytes than those seen with the chemical
found no effect on the proto-oncogene c-fos in rat brain
cells after the animals had been exposed to RFR for 60 minutes (900
MHz, SAR 4W/kg).
and colleagues used serial analysis of gene expression to assess
the effect of 2.45 GHz RFR on cultured human HL-60 cells (SAR 10
W/kg). They found that a large number of genes altered their expression
after 2 and 6 hours exposure.
more, see "Research - Toxicological
Sakuma N, Komatsubara Y, Takeda H, Hirose H, et al. (2006): DNA
breaks are not induced in human cells exposed to 2.1425 GHz band
CW and W-CDMA
modulated radiofrequency fields allocated to mobile radio base stations.
W, Jiliang H, Lifen J, Deqiang L, et al. (2005): Studying the synergistic
damage effects induced by 1.8 GHz radiofrequency field radiation
(RFR) with four chemical mutagens on human lymphocyte DNA using
comet assay in vitro. Mutat Res 578:149-157.
JW (2005): Expression of the immediate early gene, c-fos, in mouse
brain after acute global system for mobile communication microwave
exposure. Pathology 37:231-3.
S, Johnson D, Dunbar K, Dong H, et al. (2005): 2.45 GHz radiofrequency
fields alter gene expression in cultured human cells. FEBS Letters