Modelling and experimental studies on the transfer of radionuclides to fruit

Although fruit is an important component of the diet, the extent to which it contributes to radiological exposure remains unclear, partially as a consequence of uncertainties in models and data used to assess transfer of radionuclides in the food chain. A Fruits Working Group operated as part of the IAEA BIOMASS (BIOsphere Modelling and ASSessment) programme from 1997 to 2000, with the aim of improving the robustness of the models that are used for radiological assessment. The Group completed a number of modelling and experimental activities including: (i) a review of experimental, field and modelling information on the transfer of radionuclides to fruit; (ii) discussion of recently completed or ongoing experimental studies; (iii) development of a database on the transfer of radionuclides to fruit; (iv) development of a conceptual model for fruit and (v) two model intercomparison studies and a model validation study. The Group achieved significant advances in understanding the processes involved in transfer of radionuclides to fruit. The work demonstrated that further experimental and modelling studies are required to ensure that the current generation of models can be applied to a wide range of scenarios.     

The role of fruit in the diet

Data on the production and consumption of fruit are reviewed in the context of modelling the transfer of radionuclides to fruit, and the assessment of the consequent risks to the consumers. Mean consumption rates vary widely from country to country, from 150 g per day fresh weight to about 500 g per day. Consumption also varies with age, socio-economic class, and climate. In some countries there is a trend towards increased consumption of fruit, associated with a growing interest in a healthy diet, and these trends have been associated with changes in the incidence of cardio-vascular diseases and some forms of cancer. Assessment of the effects of radionuclides in fruit needs to take into account the use of wild growing fruits, the increasing trade in fruit between countries, and the contribution from natural radionuclides in fruit.