Given the difficulty of observing a small excess of
cancer cases against the large number that would occur
in the absence of exposure to ionising radiation, the
potential public health impact of nuclear weapons
testing can only be predicted by models. Risk modelling
studies of exposure to ionising radiation from the
Nevada Test Site in the USA suggest that an extra
49 000 (95% CI 11 300–212 000) cases of thyroid cancer
would be expected to occur among US residents alive
at the time of the testing—an excess of about 12%
over the 400 000 cases of thyroid cancer expected to
develop in the absence of fallout.20 Almost all of the
radiation-related cases of thyroid cancer would be
among individuals younger than 20 years during the
period 1951–57.20 In addition, there could be as many
as 11 000 deaths from non-thyroid cancers related
to fallout among those US residents, with leukaemia
making up 10% of the total.20 Large uncertainties are
inherent in these projections.
Although exposure to ionising radiation from nuclear
weapons testing occurred some 50–60 years ago, a
substantial fraction (less than half) of the predicted
total number of excess radiation-related cancers are yet
to occur since the risk persists for many decades after
exposure.11,20 The effect of nuclear testing on the world’s
overall cancer burden has been small, although very
substantial to those individuals affected by it.