(caAsean AECD-3446 -92- vegetation, the general pattern of which is similar for each of the three islands, The radius of similar zones, however, on the three islands varies, In brief, the’ zones occur as follows: (1) a zone of little vegetation: Engebi to 400 yards radius, Aomon to 300 yards radius, Runit to 250 yards radius; (2) a zone of scattered clumps of plants: Engebi - 400 to 500 yards, Aomon - 300 to 409 Runit - 250 to 300 yards; (3) a zone of rather continuous plants, many of which =: show chlorosis (not sharply delimited on the outer edge); (4) a zone where disty. ecological habitats are a more important factor in exclusion of plants than bom) °=& effects. “3 SUMMARY (1) The amount of radioactive fission products absorbedbythe roots, translocated through the plant and deposited internally within the tissues of the coconut palms at Bikini and Eniwetok Atolls is very small, Activity was not en. countered which was in excess of twice that found in the control material from or in crop plants grown in the agricultural soils of the Columbia Plateau in Washing: ton State, (2) Significant radioactivity persists on the dead leaf bases and in the acte~:<, mulation of debris located in the axils of the leaf bases in those areas where "falladt of radioactive materials was expected, Counts ran as high as 8,100 cpm/100 mg * of ash on Romuk Island, the highest encountered on Bikini Atoll and 530, 000 : c/min/mg ash on Aitsu, the highest for Eniwetok Atoll. This weight of ash corres®::- (3) Ca”~ 45 was formed by the n-y reaction with Ca” 44 in the coral sands of " Runit Island, andtherefore presumably on Engebi and Aomon. Ca*5 wasthen” absorbedby the plants and resides within them as a componentofthe total calcium” of the plants. The activities within Portulaca oleracea due to ca* were 734 , d/min/gm of fresh tissues on March 14, 1950, or approximately 1500 d/min/g™ a fresh tissue in August, 1949, (Plant taken 30 yards from tower base.) (4) Fission products are scattered at random over the low-growing plant in the vicinity of the bomb craters. Their origin is presumably from the soil face, having been splashed upon the plants by the action of raindrops on the soll,x,