‘4 TABLE 2.5 Beta Activity in Core Samples of Soil Beta Activity (B/min /g) Island No. of Cores l-in. Increment of Soil Coring Ist 2nd 3rd 4th 5th 6th wpa : Ith 8th Likiep 1 140 40 40 nDdA@) Utirik 3 1,250 480 240 130 100 160 60 25 Rongelap 4 6,600 2,100 570 420 230 160 200 150 Busch 1 10,800 7,100 7,200 6,400 6,800 Eniaetok 1 57,000 24,000 4,300 ‘7,000 26,000 12,000 11,000 Labaredj 1 42,000 33,000 29,000 23,000 19,000 Ka belle 3 43,000 30,000 10,000 3,600 2,000 2,300 180 Lomuilal 3 53,000 48,000 26,000 20,900 14,000 1,000 Gejen 1 37,000 37,000 8,000 4,400 3,400 Lukuen 2 35,000 40,000 13,000 10,500 10,000 10,000 4,700 Bikar 3 4,000 740 250 170 120 100 27 Eniwetak 2 16,000 7,500 3,000 2,000 1,800 1,100 160 (a) 4,000° 9th 50 100 No detectable activity uptake over a long period of time may be considerable since the root systems on the islands are uniformly distributed throughout the top 14 in. of.the island profiles and are extremely dense. Very few roots were found below 14 in. and those that were noted appeared to be carryiig large amounts of water from the fresh water lens to the mother plant. The large amounts of activity found in the plant systems negates any possibility that direct fall-out could be solely responsible for the contamination. The nature of the contamination in the plants shows that although Ce!#4_pPr'44 and Ru!%_Rh!° are firmly fixed in the soil they are readily taken up by the plant systems.