Resources for a sustainable future

20/1/2010 Guardian  You reported the view that radiation risks are exaggerated, but left out vital information on radiation protection (Radiation health threat overstated – Oxford professor, 11
January).The article relied upon and extensively cited a retired ­professor of
particle physics, Wade ­Allison, who is neither a radiation ­biologist nor an
epidemiologist, and is not in my view an expert in radiation risks. Indeed, the
other three scientists quoted in the article pointedly refrained from supporting
Allison. His sole contribution to the literature is a self-published book.
An article alongside (Nuclear theory: the current consensus) states that “a
single dose below 100 millisieverts (mSv) is usually considered safe”, and later
gives Allison’s claim that “there is a threshold of about 200 mSv, below which
the body can repair all DNA ­damage caused and, therefore, which is safe”. But
there is no safe dose of ­radiation: no matter how low it is, a small risk
remains.
The linear no-threshold (LNT) theory is used by all the world’s radiation
authorities – the UN Scientific Committee on the Effects of Atomic Radiation,
the International Commission on Radiological Protection, the title=”Health Protection Agency, etc – to estimate
risks at low doses. It presumes that risks decline proportionately as you lower
the dose all the way down to zero, and that the only dose with no effect is zero
mSv.
And, yes, there is evidence that exposures to residents near nuclear facilities
cause them harm. For example, a recent German government study found large
increases in leukaemia (220%) and embryonal cancer (160%) among children living
near all German nuclear ­reactors. Its results are supported by many other
worldwide studies into child leukaemias near nuclear reactors.
Current radiation risks are based on an unsatisfactory dataset – the Japanese
survivors of the US atomic bombs in 1945. Though relevant for estimating the
risks of sudden blasts of powerful types of radiation, this data is irrelevant
for slow, long-term exposures or for weaker types of radiation which are more
common. And many studies point to the risks being higher than this data
suggests.
Then there are the unusual non-­targeted effects of radiation. These cause
changes in cells temporally and spatially distant from the cells hit by
radiation. These effects challenge the present explanation of radiation’s
effects but are unknown by the public. They are hotly discussed by radiation
biologists throughout the world, and are the ­subject of thousands of
­scientific articles. The older explanation had given considerable support to
current estimates of radiation risks. The new effects strikingly do not do this,
as they occur after very low doses of ­radiation. In other words, these new
effects raise ­serious questions about whether ­existing dose limits should be
tightened.
I do not think current radiation risks are overrated, and neither do most
­scientists in this field.
Go to: http://www.guardian.co.uk/commentisfree/2010/jan/20/evidence-nuclear-risks-not-overrated