In coastal marine sediments from western North America there is a continuing increase in 239+240Pu concentrations from the early 1950's to the present. Most of these transuranic isotopes have entered our surroundings following nuclear weapons testing from direct stratospheric fallout which went through a maximum around 1963. Since no maximum level in the sediments corresponding to the maximum stratospheric fallout was observed, another source of plutonium to these deposits was sought. It has been identified through the analyses of atmospheric aerosols as crustal rock debris transferred from the continents to the oceans by winds. A transport of soil debris, containing sorbed artifical radionuclides, to the oceans by winds and/or by rivers may explain the greater 90Sr fluxes to the marine environment, compared to those of the continents, after this fission product in nuclear explosions.