This report (HPA-RPD-006) describes a long-term study of the transfer of radionuclides from soil to fruit.
This report brings together the results of long-term studies of the uptake of selected radionuclides by perennial fruit crops. Over a nine-year period, apples, blackcurrants, gooseberries and strawberries have been grown in an area of land that has been reclaimed from the sea in north-west England and provided an opportunity for field research because of the authorised discharges of radionuclides from Sellafield. Apples have also been grown over periods of up to six years in an established lysimeter facility where three diverse soil types have been artificially contaminated.
The results indicated that, when radionuclide uptake occurs only via transfer from soil, then any storage of activity in plant parts such as branches does not result in increased transfer to fruit in later years. In these circumstances, soil:crop transfer parameters derived from short-term experiments would also be applicable in the longer term, at least for radiological assessment purposes. In terms of soil:crop transfer factors, changes should be considered for the default values for isotopes of caesium, plutonium and americium currently assumed in the dynamic foodchain model FARMLAND. The current value for strontium should be retained.