Monitoring and surveillance programmes for radionuclides in exposed sediment should be designed to provide: (a) the data required on the concentrations of radionuclides in the sediments of the areas of interest for comparisons to be made with recommended or statutory limits and for dose assessment purposes; (b) the data in a form which can be readily compared with similar measurements made elsewhere and at other times; (c) sufficient information on other environmental factors to enable the results to be extrapolated appropriately in space and time; and (d) information which can be reported and will demonstrate to the public that their interests are being fully protected. In addition, the programmes should preferably help to increase our understanding of environmental processes.