-10- The lagoon sediments contain sr29, RuL06 | cel44 and Eut55, The radioactivity is associated mainly with the fines and is concentrated in the top two to four inches, dropping off rapidly with depth. Radioisotopes other than naturally occurring K40 were not detected in sea water although larger samples and more sensitive techniques undoubtedly would have revealed their presence. In sum, on land, fission products, the present distribution of long-lived sr?9 and csi37, very much as they are now. can be expected to remain The levels of radioactivity will be reduced primarily by physical decay of the radionuclides so long as other factors such as changed agricultural practices or a catastrophic storm do not occur. In the lagoon, the levels of radioactivity will decline more rapidly than on land because of the presence of shorter-lived radionuclides, tion of sr?°, with the excep- ‘The latter does not enter the marine food web to any significant extent and may remain as a tag useful in evaluating the long-term effects of physical forces in the lagoon.

Select target paragraph3