INTERRELATIONS BETWEEN PLUTONIUM AND SOME TRANSITION-ELEMENTS IN GULF OF BOTHNIAN SEDIMENTS

The lateral distributions of plutonium and other metals of natural and anthropogenic origin were studied in recent sediments from the Gulf of Bothnia. Nonparametric rank and multivariate factor analysis indicate that the distribution of Pu is governed by runoff processes and by the deposition of metals and organic matter in deposition basins. Plutonium is probably adsorbed onto or complexed with organic matter in the sediments. Plutonium is interrelated with Mn, As, Mo, Pb, Cd and Fe from both natural sources and industrial emissions. Ni, Co, V, and Cu followed another distribution pattern, probably due to conservative mixing in the water column and due to the absence of local sources. Activity ratios for Pu-238/Pu-239,240 suggest that atmospheric fallout is the sole source.