we are Com letely satisfies that a toiers 7@ oripinally desig .ed for vse on fieh eentuniiated with radioactive asn can be lopicall) applied to fish whese racioactivity arises from ti.c ingestion of radioactive materials.) During our entire monitoring procedure we encountered only 3 tuna showing evidence of radioactivity, out of nany thevsends witch we examined. One of these fish was examined by the New York operations office of the AEC, on May 23, 19S. We siowed Mr. Hansen the results of that examination, which disci.sed the greatest activity in the bone and kidney, intermediate activity in the skin, and rather low activity in the edible portion. we aiowd Mr. Hansen data indicating that the activity in the flean was appr ximately double that of the natural rediosctivity of camed tuna. This natural activity is due to neturally-occurring radioactiver.artnant of Energy ~ Historian's Offles potassium. We also discussed briefly the sffect of canning upon tng CHIVES radioactivity of a Suna showirr some man-made radioactivity, as Cisclosed by a simulated cvning procedure conducted by our Divisions of Pharmacology znd Food. is showed that there was some loss of radiosctivity of the edible portions during the canning process. ‘2 stated trat we had not announced an otficial tolerance for radioactivity in tuna. We pointed out, however, that 4FC hai informally made some Siggestions to the Japanese w.ich res lted in their adopting the 100 cpm and later t:<¢ 500 cpm values. we said that our information si.ved that scme tuna showing evidence of radioaciiv.ty were arriving in Japan as recently as last October. e have no information as to .sindings since toat date. Te vir greategt cuncern }.as tes it’ long-lived Lasotopes such as Sr°o and SO wich er -etabolized in a fasnion sinilar to calciuz and thus ca. .3 deposited in the bone. Dering the first fow weeks after an atomic explosion, we are also concerned with radioacvive cesium, which ‘s likely to appear throughout the tissues. 6. We pointed out that whet..or the radloactivity of canned tuna constitutes danger to pitlie health devends upon soveral factors, including the activity of the tuna, the amount likely to te consumed ly any menber of the population, and such tnin7zs is the age and health of the incividual. While we would not be concerned over the effect on public bealth of an occasional tuna showing some man=made radioactivity, we would becose concerned if all tuna snowed an increase in radioactivity as meagured by field instrumemits. Zi!