Science and trans-science in radiation risk assessment: child cancer around the nuclear fuel reprocessing plant at Sellafield, U.K.

The assessment of health risks to the population from radionuclides in the environment is a complex and as yet incomplete science: biogeochemical mechanisms of environmental transfer and concentration are poorly understood; models of radionuclide metabolism rely largely on inconclusive and contradictory experiments with animals, and the principles by which results may be extrapolated to humans are unknown; uncertainties in the dosimetry of alpha-emitters in children and the foetus are acute; and chronic doubt persists over the magnitude of low-level dose-response for radiation carcinogenesis. To deny uncertainties of this nature is to court public distrust of scientific risk assessment; public confidence in nuclear power technologies might be strengthened through a more open discussion of the technical difficulties involved. These problems are described with reference to the assessment of cancer risks at a large nuclear facility in the north of England. The extent of uncertainties in a recent radiological risk assessment are found to be such that, should scientific concern persist over the exceptional incidence of child cancer in the locality, greater consideration should be given to a reappraisal of the risk calculation.