Editor's Choice | This Week in BMJ | Press releases
BMJ No 7103 Volume 315 Letters Saturday 2 August 1997 Death rates from leukaemia are higher than expected in areas around nuclear sites in Berkshire and OxfordshireEditor,As a result of the report that a fire at the United States Air Force base at Greenham Common in 1958 may have caused radioactive contamination near Newbury, Green Audit (Wales) has compared the number of deaths from leukaemia in children aged 14 years and younger from 1981 to 1995 in the Newbury area with that within nearby county districts. The table shows results for the triangular area defined by Oxford, Newbury, and Reading. It is notable that the districts with significantly higher relative risks are those that contain the outfalls for licensed releases of radioisotopes from the nuclear sites at the Atomic Energy Research Establishment, Harwell; the Atomic Weapons Establishment, Aldermaston; and the Royal Ordnance Factory, Burghfield. Bithell et al, however, found no significant excess of leukaemia between 1966 and 1987 within a 25 km radius of the 23 nuclear installations that they studied.(1)
In 1989 the Committee on Medical Aspects of Radiation in the Environment reported on childhood leukaemia in west Berkshire and confirmed a significant increase in incidence (relative risk 1.3; P0.05) between 1972 and 1985.(2) The committee established that since 1948 all three nuclear sites had been releasing radioactive gases into the immediate surroundings and liquid effluents into the river Thames at Sutton Courtenay (from the Atomic Energy Research Establishment) and at Pangbourne (from the Atomic Weapons Establishment), and into the river Kennet (from the Atomic Weapons Establishment and Royal Ordnance Factory). Geographical constraints would concentrate most of the radioisotopes within the two river valleys; inhalation and ingestion could result in differential contamination of the populations. Data in the committee's report suggest that south Oxfordshire would be most strongly affected followed by Newbury, which would be a little less strongly affected, and that both these areas would be much more strongly affected than more remote districts upwind or upriver of the nuclear sites. There is no sea dilution effect in this area and the pollution is
likely to remain in the local environment, unlike releases from British
Nuclear Fuels at Sellafield. Recent measurements of plutonium-239 and
plutonium-240 confirm this. Croudace et al found soil concentrations as
high as It is possible that these radioactive emissions might have harmful
effects on those living near the sites or in areas close to the rivers
where effluents are discharged. The committee concluded that levels of
exposure were too low to cause any measurable increase in leukaemia
both at Sellafield and in west Berkshire.(2) The risk
factors that were used to support this view, however, are derived from
the studies of Hiroshima, which are of short term, high dose external
exposure. Concern has been expressed recently that these risk factors
may be unsuitable when used to measure the effects of long term, low
dose internal exposure.(4)
Chris Busby
References
1 Bithell J F, Dutton S J, Draper G J, Neary N M. Distribution of
childhood leukaemias and non-Hodgkin's lymphomas near nuclear
installations in England and Wales. BMJ 1994;309:501-5.
2 Committee on Medical Aspects of Radiation in the
Environment. Third report: the incidence of childhood
cancer in the west Berkshire and north Hampshire area in which are
situated the atomic weapons research establishment, Aldermaston and the
Royal Ordnance Factory, Burghfield. London: HMSO, 1989.
3 Croudace I W, Saunderson D C W, Warwick P E, Allyson J D. A
regional study of the radiation environment of Greenham Common, Newbury
district and surrounding areas. Southampton: Southampton
Oceanography Centre, 1997.
4 Bramhall R, ed. The health effects of low-level
radiation: proceedings of a symposium held at the House of Commons,
April 1996. Aberystwyth: Green Audit, 1997.
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||