Studies on the Radiologically Contaminated Fishes Caught at Kagoshima Sea Region

1) At the fish market in Kagoshima, the species of "the waste fish" — the fish which was enforced to cast away on account of its being contaminated by radioactivity — was Istiophorus orientalis, Coryphaena hippurus, Acanthocybium solandri, and Neothunus macroPterus. During the term from May to June most of the waste fish was consisted of Coryphaena hippurus, and since August was all most of Istiophorus orientalis that was cast away as waste fish. 2) Seasonal variation of the fishing ground in which the waste fish was caught was as follow : — After emerging from the eastern sea front of Formasa in May it shifted gradually to the north; in August and September it reached the southern coast of Kagoshima Prefecture and during the term from September to November it was almost confined within this district. On the other hand, at the western region of Oshima, the seeming lapse into disappearance of the contaminated fish during the three months of July to September was revived in October and November. But it was supposed that among these groups there were those which reversely ran down from the neighbourhood of the Saishu Island after migrating from Kagoshima to north along the Tsushima Current. 3) As to the credibility of the inspection standard of "100 count by 10 cm distance" it was confirmed that the seeming count value was comperatively unstable and not slightly influenced by the geometrical conditions of the body, namely:— the dimensions, thickness of the sample and the estimation distance (the distance between the sample and mica). 4) As to distribution of radioactivity on each tissue of the waste fish, generally, it was concentrated to liver, kidney and spleen. As to the muscle, it was stronger at the dark muscle than at the ordinary one, and in the case of the skin tissue it was concentrated to the epidermis, and in vertebra, it become stronger as the estimating part approached to the head part. 5) It was ascertained that the radioelements absorbed each tissue was most strong at III group, and that, considering from the state of decaying and the absorption curve of 8 - ray, the specific kinds of the radioelements was to be absorbed by the fish from the fission product, and that the kind of the absorbed radioelements varied with the differnce of the each organ. 6) Radioelements absorbed in the fish body had the propensity to be removed, with the lapse of time, to the special organ, especially to the kidney, and after being accumulated there, to be gradually excreted out of the body. 7) It was ascertained that it was not impossible to remove the radioactivity of the fish muscle by treating it through the process of freezing, boiling, and water extraction, and that the most part of radioactivity, when it was boiled in the water soluble protein solution of the fish meat, was to be removed to the heat coagurated part of that, and its adsorption capacity was greater than that of the egg white, Na-alginate, activated charcoal, alumina, and complex salt of ferrous ammonium sulphate