Fallout Radioactivity in Diet and Excreta ‐The Levels at Tokai District, Japan in 1962 to 1963

• Published in: JOURNAL OF RADIATION RESEARCH Vol. 5; no. 1; pp. 56 - 68
• Main Authors: FUJITA, Minoru, AKAISHI, Jun, IWAMOTO, Junko, YABE, Akira, ICHIKAWA, Yoshiko, OKAMOTO, Toshio, FUKUDA, Hiroshi
• Format: Journal Article
• Language: English
• Published: England THE JAPAN RADIATION RESEARCH SOCIETY 1964; Oxford University Press
• Subjects: Diet; Feces; Food Contamination; Food Contamination, Radioactive; Humans; Japan; OldMedline; Radioactive Fallout; Radioactivity; Urine; FECES; RADIOACTIVE FALLOUT; FOOD CONTAMINATION, RADIOACTIVE; JAPAN; URINE
• ISSN: 0449-3060; 1349-9157
• DOI: 10.1269/jrr.5.56

The levels of fission products such as 90Sr, 137Cs, 95Zr, 95Nb, 103Ru and 106Ru in diet and excreta were examined. The experiment started in May, 1962 and ended in Feb. , 1963. During the period, seven intermittent samplings of excreta and diet were made. In each sampling, excreta were collected over five consecutive days from four normal human subjects who took the same diet at that time. An exact duplicate of the diet was collected at the same time. A large NaI(T1) crystal scintillator and an 100 channel pulse height analyser were used to determine the radioactivities of γ-emitters in ashed samples, but 90Sr and 137Cs were analysed radiochemically. In general, the value of 95Nb in the diet was highest among all the radioactive fission nuclides, reaching about 60 μμc/day/person in Feb. , 1963. The level of 90Sr in the diet varied between 7. 0 and 13 μμc/day/person during the period, and that of 137Cs changed between 13 and 35 /e, ~lc/day/person. However, about 1 μμc of 90Sr was always found in 24-hr urine samples, irrespective of the contents in the diet. The activities of 137Cs in the same urine specimens, in contrast to 90Sr, changed between 10 and 31 μμc corresponding to the contents in the diet. During the period examined, the levels of 137Cs and 95Zr+95Nb in the diet varied according to the changes of the dry fallout in the atmosphere. The amount of stable potassium and calcium in the diet and excreta were also examined.