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Note that the air concentrations are used to estimate activity concentrations in biota they are not used to estimate external dose rates from air. External dose rates for H, C, S and P are assumed to be zero in the ERICA Tool anyway (most models assume same or very low external dose rates - see Vives i Batlle et al 2007http://wiki.ceh.ac.uk/x/UoDqBg).
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Answered by Nick Beresford 05/08/2010
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