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 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.

Radiocaesium activity concentrations in the fruit-bodies of macrofungi in Great Britain and an assessment of dietary intake habits.

Radiocaesium activity concentrations in the fruit-bodies of some species of macrofungi are higher than in many other foodstuffs. The consumption of fruit-bodies contributes significantly to radiocaesium intake of humans in some countries. In the United Kingdom, the collection of wild fungi has generally been considered to be of minor importance and there are few data on consumption rates or radiocaesium activity concentrations in most edible species.

Dose due to man-made radionuclides in terrestrial wild foods near Sellafield.

Radiological dose implications for consumers of wild foods around Sellafield have been assessed. Habits were surveyed from 72 households, mostly within a few kilometres of Sellafield. A few people were included who lived further away but collect wild foods close to Sellafield.

The determination of 129I in milk and vegetation using neutron activation analysis.

A new method has been developed to measure 129I in the environment with detection limits below 10 mBq/kg of vegetation and 10 mBq/l of cows' milk. The method is based on extraction of 129I from the milk or vegetation sample, onto an ion exchange resin. An inactive carrier of 127I is added to the sample before separation, to monitor losses throughout the entire procedure.