and 250 times for 137 Cs, indicating a greater distribution of these radio- nuclides into the water phase at the several stations in the lagoon. The relative constancy of the ratios found for the actinide and lanthanide distribution coefficients between the particulate phases and sediments are interpreted as an indication of their intimate association with resuspended sediments which are finely divided; the high ratios for Co, Bi and Cs suggest a dissolution and/or a higher rate of removal from the sediments.