The geochemical association of plutonium in sediments from the marine
ecosystem of Palomares has been studied. A sequential leaching techniq
ue using selective extractants has been employed to determine the perc
entages of Pu in the following forms: (a) readily available, (b) excha
ngeable and adsorbed to specific sites, (c) associated with organic ma
tter, (d) sesquioxides, (e) residual. Plutonium was found to be associ
ated mainly with phases (c), (d) and (e), and therefore, appears to be
relatively inmobile and not readily available to bottom feeding biota
. The effect of different source terms on Pu distribution is also disc
ussed.