CONTROVERSES 
NUCLEAIRES !
ACTUALITE INTERNATIONALE
2004
Source ADIT: Plutonium cancer risk questioned,
New Scientist issue 17
July 2004
PLUTONIUM may be many times
more dangerous than previously thought. The cancer risk from exposure inside
the body could be 10 times higher than is allowed for in calculating international
safety limits.
The danger is highlighted
in a report written by radiation experts for the UK government, which has
been leaked to New Scientist. The experts are unanimous in saying that
low-level radiation emitted by plutonium may cause more damage to human
cells than previously believed. Their opinion could provoke a rethink of
the guidelines on exposure to radiation.
Several tonnes of plutonium
have been released into the environment over the last 60 years by nuclear
weapons tests and nuclear plants.
Concern over the harmfulness
of plutonium is growing because of discoveries about the subtle effects
of low-level radiation. Researchers in Europe and North America have shown
that the descendants of cells that seem to survive radiation unharmed can
suffer delayed damage, a phenomenon called "genomic instability" (New
Scientist, 20 January 2001, p 4). Cells adjacent to those that are
irradiated can also sustain damage, known as "the bystander effect". And
an increase was found in the number of mutations in small pieces of DNA
called mini-satellites that are passed from one generation to the next.
The fear is that these effects could trigger cancers and other ill effects.
The report, which is due to
be published in the next few months, has been drawn up by the Committee
Examining Radiation Risks from Internal Emitters (CERRIE). The committee
includes 12 specialists from the UK government's National Radiological
Protection Board, the nuclear industry, universities and environmental
groups.
All members of the committee
agree that the margin of uncertainty over the risks of plutonium and similar
radionuclides inside the body "could extend over at least an order of magnitude".
This "should be borne in mind by those making judgements and policy decisions
on low-level internal radiation", says CERRIE's chairman, Dudley Goodhead,
the former director of the UK Medical Research Council's Radiation and
Genome Stability Unit at Harwell in Oxfordshire.
Written by Rob Edwards
Pour plus d'information, veuillez contacter :
Claire Bowles
New Scientist
claire.bowles@rbi.co.uk
0207 331 2751
Posté par :
New Scientist
UK CONTACT - Claire Bowles, New Scientist Press
Office, London:
Tel: +44(0)20 7331 2751 or email claire.bowles@rbi.co.uk
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