~33- stems, flowers and leaves was the same. In these tissues the level of radioactivity was high one week after the Nectar test, dropped rapidly, and then leveled off at about 100 days post Nectar, much like the decline of radioactivity in the green leaves of Scaevola in the tissues of a coconut (Fig. The radioactivity (Cocos nucifera) rapid rate for the entire period, shown in Figure 10. 9). declined at a similar to the decline The fluctuations in the plot showing the rate of decline for the bunchgrass (Lepturus) make a com- parison with other plants difficult. Soil The gross beta radioactivity of the top two inches of soil collected at Belle Island during the study period is given in Table 5 and is presented graphically in Figure 9. The beta radioactivity of the soil after the Nectar detonation decreased to the pre-Nectar level in about 150 days at a rate which approximates the rate of decay of mixed fisSion products for thig period (15) , The rapid decrease in radioactivity of the soil samples was followed by a period of approximately one year in which the radioactivity in subseguent samples decreased at a slower rate, These data in-~ dicate that some of the radioisotopes with short half lives