Reliable assessment of the consequences of releasing radionuclides to the environment calls for an understanding of the transport of radionuclides from source to man. Over the past 50 years, a substantial store of data from experiment and observation has accumulated but, in many cases, the data are of insufficient accuracy. The question which the Environmental Transfer Action Group set out to answer was 'what do we know and what do we need to know about the movement and fate of radionuclides in the environment?' The following subjects are discussed: (i) soil-to-plant transfer, (ii)...

Reliable assessment of the consequences of releasing radionuclides to the environment calls for an understanding of the transport of radionuclides from source to man. Over the past 50 years, a substantial store of data from experiment and observation has accumulated but, in many cases, the data are of insufficient accuracy. The question which the Environmental Transfer Action Group set out to answer was 'what do we know and what do we need to know about the movement and fate of radionuclides in the environment?' The following subjects are discussed: (i) soil-to-plant transfer, (ii) human metabolic studies with plutonium and (iii) intercomparison exercises with models; other topics will be presented by other speakers. The Action Group will have achieved its objective if it provides answers or initiates work which ultimately leads to improved input data to support calculations associated with the impact of radionuclides discharged to the environment.