neutron flux accompanying the detonation. It was not detected in samples collected one year after the detonation; this points to an enormous concentrating capacity of Tridacna Gigas. 79. World Federation of Scientific Workers. Federation of Scientific Workers. 40p. UNMEASURED HAZARDS. (1956). 80. World Health Organization (United Mations). Release, WHO/11, (March 13, 1957). 3p. London, World GENETIC EFFECTS OF RADIATION. Press 81. Yamada, Kinjiro, Tozawa, Harumi, Amano, Keishi, and Takase, Akira. STUDIES ON THE RADIOACTIVITY IN CERTAIN PELAGIC FISH. Il. SEPARATION AND CONFIRMATION OF Zn® IN THE MUSCLE TISSUE OF A SHIPJACK. Bulletin of the Japanese Soctety of Scientific Fisheries 20, No. 10, 921-26 (1955). Ashed sample of the muscle tissue of shipjack, which were caught by “Shunkotsu-Maru” on June 19th near Bikini Atoll was used for the present study. lon-exchanger method, using Dowex 50, was applied to separate radioactive elements with 0.2 N HCl, 0.5% oxalic acid and 5% ammonium citrate (pH 3.53, 4.18, 4.60, 5.02, 5.63, and 6.42) as the eluents. Elution curve of the ashed muscle is shown in Figure 1. Appreciable amounts of cathionic radioactive elements were separated by 0.5% oxalic and by 5% ammonium citrate at the pH of 4.18 and also anionic radioactive elements were obtained by 0.2 N HCl. As the fraction, which can be withdrawn by ammonium citrate as pH 4.18, was proved the most active; further analysis was undertaken according to the schemecited in Figures 2 and 5. In addition to this chemical separation, absorption curve of this specimen with tin foil was examined simultaneously (Figure 3) and thus the radioactive zn® was confirmed to be present in the fish muscle. Although it was difficult to detect radioactivity in rare-earth and alkaline-earth groups in the muscle tissue, attempts are being made for more precise examination. 82. Yamazaki, Fumio and Kakehi, K. ESTIMATE OF RADIATION DOSES RECEIVED BY THE INDIVIDUAL ABOARD A CONTAMINATED FISHING BOAT. Radiotsotopes (Japan) 3, No. 1, 4-6 (1954). A dose was estimated to be 120 r in 24 hours or 270 r in 13 days when calculated according to tt. pr 240 r in 24 hours or 440 r in 13 days when calculated according to t!4, observed value of decay, and supposing exposure to the radiation began 6 hours after the explosion had occurred on Bikini. 83. Yano, N. RADIOACTIVE DUST IN THE AIR. Papers in Meteorology and Geophysics (Tokyo) 7, No. 1, 34-41 (1956). An electric precipitator is used to collect dust in the air becauseits collection efficiency for radioactive substances is up to 10 times that of the impactor of filter paper types. About 10 m3of air is filtered during 5 hours, and the trapped dust is measured more than 24 hours after collection to avoid the influences of naturally active substances. The average radioactivity of the air is approximately 107" curie/cc. During the period of observation 4 peaks occurred. The dates and maximum levels of artificial activity, respec- tively, are November 4-10, 1954, 1.2 x 1077 uc/liter; April 11-13, 1955, 4.3 x 107° uc/liter; November 25-8, 1955, maximum unknown; and March 22-5, 1956, 1.0 x 107" pe/liter. The presumed dates and places of detonation corresponding to the peaks are October 31, 1954 northwest of Japan; March 29, 1955, Nevada, U.S.A.; November 22, 1955, near L. Baikal, U.S.S.R.; and March 13-15, 1956 unknown. 84. Yatazawa, Michihiko and Yamazaki, Yoshio. ABSORPTION OF FISSION PRODUCTS BY PLANTS (PART V) ABSORPTION OF GROSS FISSION PRODUCTS. Soil and Plant Food (Tokyo) 2, 158-163 (1956). 85. Yatazawa, Michihiko. RADIOACTIVE CONTAMINATION OF PLANTSIN JAPAN COVERED WITH RAIN-OUT FROM H-BOMB DETONATIONS IN MARCH—MAY 1954 AT BIKINI ATOLL, MARSHALL ISLAND. (PART II) RADIOACTIVE ELEMENTS OF CONTAMINATED PLANTS. Soil and Plant Food (Tokyo) 1, 23-4 (1955). Following a fallout estimated at 0.2 micromicro/liter Trifolium repens, Astragalus Sinicus, and Rumex japonicus were harvested and analyzed for radioactivity. Most of the 166