特に中国核実験による放射性降下塵の食品汚染

抄録

Since 1961, the area of Fukuoka City as well as other areas of Japan has been polluted by radioactive fallout brought about mainly by the fission and fusion bomb test in Red China. In this area periodic measurements of radioactive fallout deposits were measured on the Standard Diet proposed by the Department of Welfare in Japan. In addition measurements were taken on several kind of vegetables (well washed), dairies, row milk, short necked clam and the Tapes Philippiarium. Results obtained from these surveys are as follows:
1) The level of radioactivity of the fallout deposited on the vegetables resulting from the 1st, 2nd and 5th tests of the atmic bomb in Red China increased remarkably from 10 times to 200. This is much higher than that of the usual amount of fallout on vegetables. Especially noted was that a somewhat higher level of radioactivity than normal level was maintained for several months during the time of the 5th test.
2) Increase and decrease of radioactivity on seasonal vegetables fluctuated approximately with those of the radioactive fallout deposited on the vegetables. The level of radioactivity on the vegetables increased sharply from normal level measured on them after the test.
3) Although radioactivity level on the vegetables had increased from the usual level, the level measured on dairy and row milk did not fluctuate remarkably during the test.
4) The degree of radioactivity in the short necked clam with shell removed fluctuated considerably more than the usual level, eg. 0.5 to 38.9. However there was no evidence of increase of radioactivity in the clam after the test.
5) The degree of radioactivity in the Standard Diet in Japan increased slightly in 1967 compared to that of former years.
6) Giant particles of radioactive fallout precipitated on spinach just after the fifth test of the Atomic Bomb in Red China were discovered by means of autoradiography. Removal of these particles could not be completely successfully accomplished with a soapless soap.