cell study revives cellphone safety fears (26/10/02)
Tramès per Klaus Rudolph (Citizens'
Cancer cell study revives
cellphone safety fears
10:57 24 October 02 / Exclusive from New Scientist
The safety of cellphones has been brought into question once again by
research that suggests radio waves from the devices could promote the
growth of tumours. Paradoxically, the study suggests that the radiation
makes tumours grow more aggressively by initially killing off cancer cells.
Cell biologist Fiorenzo Marinelli and his team at the National Research
Council in Bologna, Italy, decided to investigate whether radio waves
had any effect on leukaemia cells after previous studies indicated that
the disease might be more common among mobile phone users. The life cycle
of leukaemia cells is well understood, making it relatively easy to spot
changes in behaviour.
The team exposed leukaemia cells in the lab to 900-megahertz radio waves
at a power level of 1 milliwatt, and then looked at the activity of a
gene that triggers cell suicide. Many European mobile networks operate
at 900 megahertz, and maximum power outputs are typically 2 watts, although
they regularly use only one-tenth of this power.
After 24 hours of continuous exposure to the radio waves, the suicide
genes were turned on in far more leukaemia cells than in a control population
that had not been exposed. What is more, 20 per cent more exposed cells
had died than in the controls. But after 48 hours exposure, the apparently
lethal effect of the radiation went into reverse. Rather than more cells
dying, Marinelli found that a survival mechanism kicked in. Three genes
that trigger cells to multiply were
turned on in a high proportion of the surviving cells, making them replicate
ferociously. The cancer, although briefly beaten back, had become more
Marinelli presented his results this month at the International Workshop
on Biological Effects of Electromagnetic Fields on the Greek island of
Rhodes. While the results do not show a direct health threat from mobile
phones, they provide fresh evidence that radiation from such devices could
play an important role in activating genes that might help cancer
"We don't know what the effects would be on healthy human cells,"
says Marinelli. "But in leukaemia cells the response is always the
same." Marinelli suspects the radiation may initially damage DNA,
and that this interferes with the cells' biochemical signals in a way
that ultimately triggers a defensive mechanism.
Many scientists believe that because radiation from cellphones does not
have enough energy to break chemical bonds, it cannot damage cells. The
only way damage could occur, they say, is if the radio waves heated tissues
But British research earlier in 2002, by molecular toxicologist David
de Pomerai at the University of Nottingham, showed that radio waves can
cause biological effects that are not due to heating. He found that nematode
worms exposed to radio waves showed an increase in fertility - the opposite
effect from what would be expected from heating (New Scientist print edition,
Marinelli's study is intriguing, says de Pomerai. "But I'm far from
convinced that these authors are looking at any reproducible and real
phenomena," he says. Other studies have shown mobile phone radiation
to have no effect on cell death, de Pomerai adds.
An inquiry in April 2000 by the British government found no evidence of
any health risks from mobile phones. But it still recommended that people
take a precautionary approach until further evidence emerged. In particular,
it suggested children, whose brains are still developing, should not use
mobile phones excessively.
"It's a very confused field," admits Colin Blakemore, a physiologist
at the University of Oxford and a member of the British National Radiological
Protection Board's advisory group on non-ionising radiation. People should
place more reliance on animal studies than lab-based experiments on cells,
But de Pomerai insists that a consensus is emerging that non-ionising
radiation can indirectly damage DNA by affecting its repair system. If
the DNA repair mechanism does not work as well as it should, mutations
in cells could accumulate, with disastrous consequences. "Cells with
unrepaired DNA damage are likely to be far more aggressively cancerous,"
Informant: Volker Hartenstein, Member of the Bavarian
Parlament and others
2454th Council meeting.
Luxembourg, 8 October 2002
M. Klaus Hjort Frederiksen, Minister for Employment,
Ms. Henriette Kjaer, Minister for Social Affairs and Equal Opportunities,
M. Lars Lokke Rasmussen, Minister for the Interior and Health, of the
Kingdom of Denmark.
The Council took note of information given by the Presidency on the outcome
of a technical seminar that it organised in Luxembourg on 20 September.
The aim of this seminar was to establish whether there is enough scientific
evidence of potential risks to the health and safety of workers when exposed
to electromagnetic fields and waves to justify legislative measures.
The seminar showed that there was agreement on a number of potentially
acute health effects resulting from exposure to powerful, low-frequency
electromagnetic fields and waves, as well as to sources of radio and microwave
frequencies. The Presidency intends to continue work, in close co-operation
with the forthcoming Greek Presidency and the Commission, on the preparation
of a new text for a Directive on minimum requirements for safety and health
regarding workers' exposure to electromagnetic fields and waves. This
will follow the model of the two previous texts on vibration and noise
(the former adopted in June 2002, the latter currently in conciliation
with the European Parliament).
Informant: Volker Hartenstein, Member of the