Shunji MATSUDA’s research while affiliated with Gunma University and other places

A method is described for the spectrographic determination of strontium and calcium in bone ash. Two parts of carbon powder and 1 part each of potassium sulphate and bone ash were mixed, loaded into a graphite sample electrode, and burned in an interrupted a. c.-arc of 3 amperes. The line pairs were: Sr 4077.7Å/Ca 3968.4Å or 4226.7Å, Ca 3644.4Å/Ti 3642.1Å. The lower determinable limits by the present method were 10⁻⁴ for Sr/Ca-ratio and 20% for calcium, and the coefficient of variation estimated statistically were below 5.3% for calcium and 12% for Sr/Ca-ratio. Mean values of calcium content and Sr/Ca-ratio in human bone ash, 34% and 0.36 × 10⁻³, were obtained from results on 20 samples by the present method. © 1965, The Japan Society for Analytical Chemistry. All rights reserved.

Japanese soil and rice collected at 15 localities have been analyzed for cesium-137 since 1959 through 1963. The time trend of rice-levels indicates the minimum in 1960 and 1961 and the maximum in 1963, showing more than threefold value of the minimum. A higher dependency was observed of the level of cesium-137 in rice on the fallout rate than either of the cumulative ground deposit or the N-ammonium acetate extractable cesium-137 in soil. Variation with locality is great and the highest rice-level is observed on the northern Japan Sea side, the lowest in the central and southern parts, and intermediate on the northern Pacific side.

Measurements were made on the concentrations of Cs/sup 137/ and Sr/sup 90/ in the River Tonegawa and at Kiriu City in Japan. The concentrations in rain water were calculated by dividing the monthly deposits by the monthly rainfall. An attempt was made to evaluate the run-off of a radionuclide in terms of the cumulative deposition and the deposition rate on the basis of an expression of the general form: C = C/sub d/ + p/sub r/C/sub r/, where C is the concentration of a radionuclide in the river water ( mu mu C/l), C, is the concentration of the radionuclide in the rain water ( mu mu C/l) corrected for the evaporation (30% is assumed), p/sub r/ is a proportionality factor, and C/sub d/ is the concentration of the radionuclide in the river water that was derived from the cumulative deposition. The run-off by river of the ground deposits of Cs/sup 137/ and Sr/sup 90/ was estimated as 17.5 and 32 c, respectively, per annum on the basis of the mean concentrations (C/sub d/) and the total discharge of 5 x 10/sup 14/ l of river water in Japan. (P.C.H.)