B83. Yano, N. FansrsLeveorgtosy RADIOACTIVE DUST IN THis AIR. g ics ‘ (Tonys) 7, mc. 2, Yel (1956). abdGeothys An electric precipitator is :sed to collect dust in the air because its collection efficiency for radioe active substances is up to 10 tines that cf the impactor of filter-paper types. About 10 cu. m. of air is filtered duri:ig 5 hours, and the trapped dust is :easured more than 24 hours after collection to avoid the influences of naturally active substances. ew dl The avezage radioactivity of the air is approximatee ly 10749 c./ee. During the period of observation & peaks occurred. The dates and maximum levels of artificial activity, Respectively, are November abd 4-10, 1 19 s 1-2 x 107 uc./l.}3 April 1l-13, 1955, 4.3 x 1079 uc./le3 November 25-8, 1955, _maximnm unknown; and March 22-5, 1956, l= x 107? uc./l. The presumed dates and pleces of detonation corres- ponding to the peaks are October 31, 195% northwest of Japan; March 29, 1955, Nevada, U. S. A; November 22, 1955, near L. Baikal, U. S. S. R.3; and March 13-15, 1956 unknown. 84. Yatazawa, Michihike and Yanazaki, Yoshio ABSORFTION OF FISGION PRODUCTS BY PLANTS (PART V) ABSORPTION OF GROSS FISSION PRODUCTS. Soiland Flant Food 2, 158-163 (1956). 85. Yatazawa, Michihiko RADIOACTIVE CONTAMINATION OF PLANTS IN JAPAN COVERED WITH RAIN.OUT FROM H-BOMB DETONATIONS IN MARCH-MAY 195% AT BIKINI ATOLL, MARSHALL ISLAND. (PART II) a RADIOACTIVE ELEMENTS OF CONTAMINATED PLANTS. Soi] | and Plant Food 1, 23-4 (1955). Following a fallout estimated at 0.2 microcurie/l. ; Trifolium repens, Astragalus sinicus, and Rumex japonicus were harvested and analyzed for radio= activity. Most of the radioactivity (2300 - 4%700 counts/min./50 g. plant ash) was associated with oxalate precipitate. A small amoung of activity ir. the Zn BEpup is attributed to Zn produced by > recetion 2n°? (n,y) from Zn employed in the mech- @nical parts of the borb. Sr-Ba radioactivity was C.l that of the rare earth group. Distribution of the radisactive ele:ents was nearly the same as that found or tre No. 5 Pukuryueharu.e -2he