Radioactivity of the Columbia River Effluent

Abstract

Chromium-51 and zinc-65 were detected as far as 115 and 15 kilometers, respectively, from the mouth of the Columbia River; zinc-65 also was found at a few isolated stations. Zirconium-95 and niobium-95 from atmospheric fallout occurred in the river effluent but they were most abundant in surface waters further ofJshore. Distribution of the radionuclides is controlled largely by surface currents and by upwelling of sea water near the coast.