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Populations living near nuclear installations
Various studies
have been carried out of cancer rates in the vicinity of nuclear
installations in recent years, mostly in Western Europe and
North
America. Doses to populations around these installations were
generally several orders of magnitude lower than those to
persons
living near the Techa River in Russia at the time of high
discharges
from the Mayak plant. There is evidence of raised cancer
risks in this latter group, although quantification is difficult.
There does not appear to have been
a general increase in rates
of adult cancers around nuclear installations. Some, but not
all,
studies have indicated increased rates of childhood cancers
and
particularly childhood leukaemia. The evidence for such increases
has tended to be strongest in the vicinity of nuclear reprocessing
plants; in particular, Sellafield and Dounreay in the UK and,
to a
lesser extent, La Hague in France. Interpretation of these
studies
has been hindered in part by small numbers of cases and by
the
ecological (correlation) study design used in many instances.
Assessments of radiation doses to those living near these
installations
do not suggest that the raised childhood leukaemia risks can
be explained on the basis of radioactive discharges. Case–control
studies generally do not demonstrate clear links with habits
that
might give rise to enhanced environmental exposures. A case–
control study around Sellafield suggested a link between childhood
leukaemia and paternal occupational radiation exposure
prior to conception. However, this has not been replicated
in
larger studies elsewhere, and may have been a chance finding.
Non-radiation factors such as population mixing have been
mentioned
as possible explanations for the raised risks, but it is unclear
whether these factors could explain all the results.
At present, specific actions are not
indicated over and above
existing guidelines on radiation exposures to members of the
public. However, continued monitoring of environmental radioactivity
and cancer rates around nuclear installations is desirable.
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