CHAPTER1 Gross Activity A. Land Plants Graphs 2 and 3 indicate the general levels of activity of edible plants (pandanus, papaya, breadfruit, arrowroot), and coconut meat and milk at Rongelap Atoll together with their decline of activity with time.’ ? Tables 4, 5 and 6 show the analyses by HASL.*: ® than other edible plants, but the rate of decline of activity has been less than for other edible land plants due principally to the higher per- centage uptake of this longer-lived Cs'*”. Table 1—Summary of Gross Beta Activity in Miscellaneous Plant Samples = whale “FF cM Solem * os *, “asadSeae Tables 1 and 2 show the analyses made by NRDLfor their first survey in February 1955. Table 3 is based on the February 1956 survey.‘ The highinitial activity of the “edible plants”’ (Graph 2) was probably due to surface contamination caused by the direct fallout. The rise in activity after a year after the fallout occurred may be due to (a) sampling and counting variances, (b) the ability of some plants to concentrate Cs? (see Section Radiochemical Analysis), (c) the increased availability of the radioactive fallout material to the plants, or (d) a combination of these factors. Initially the activity in the coconut milk and meat was less AVERAGE ACTIVITY (uc/g x 10) « > PLant MatEerian ISLAND Likiep Utirik Rongelap; Busch Enifaetok) Labaredj| Kabelle Lukuen Gejen Lomutlal) Bikar Eniwetak Grass_.-..-..-----..-----..x 400 3000 420 5300 1900 2100 68, 000 5600 180 400 Coconut leaf.....-.....-----|.-..---. W00 fnew 750 1800 670 |------- fe fede ee Coconut frond stem........./-.-.---of-2 fe. fee fe eee fee ef ee ¥40 J_.-.---.--]---..--.--]--------]------ 2 Coconut shell.........-...-. weer ene|e one e ene fee een eee fee eee eee eee ee fee ee eee V7 joie ee 150 |_-.-22-_-- |e fe Coconut husk....._.-...-.--] 17 L5 8B j---2 22] yr 1]0 |.-..------ 8.4 j----.----. Coconut sprout.._.------..-| 2.2 --e} we eee 8 |.----.-.|---.------|---------110 |.-----. eee ee fee ee fee ee Jone eee eee Sprouted coconut reots_-..-|..-.....|---.--. 2. 72 ).-----~-[----------|--. ------740 on feeee e ee e ee ee ee fee een penne een ee Scaevola leaf.....-...-.---.-]-.---.--f------- ef fe fee 120 |-_.-....100 200 6.7 60 Beaevola trunk sectlon_.....}.------ ||| ee ee [eee eee ee eee 2 -.--.---.-Arrowroot Stem.....-.-..--.|..--.---]--------219 |---| fee ef ef ee Arrowroot leaf.......-.--..-).-..----|--------BY [oe ee fe ee ef nee eee [eee nen fe eee ee been ene ee eee ee Pumpkin._...-......--.-..2.0 [..--..--.. 35 [o.oo [ eee fee ee ee pee ee ee fen en ee ee fe ee ee beeen fone e eee Limes. -_-...--2-..--------ZO fee ee fee ne ee cn fee eee ene ee ween fee eee cee ene eee ene [pene eee p eee ee enon Taro........-------.--.--2-LY joe fee ee ee eee ee ene nee pee eee fee een eee [eee ee nf ee eee ee eee Banana......---.--.--------46 |... oe]. eee eee Vines... 22-2 ee fn ee fe eee ee fee fee eee [eee e cece fe eee eee fee een eee 490 |...0...-}.--22--340 * Wet weight. © As determined on basis 0:01 standards and empirical scattering and absorption corrections. *Collections made about February 1, 1955. Data reported as of March 1, 1955.