~- 33 In the period from March 1954 to October 1955 the levels of radioactivity in the land plants were generally higher in the northern islands of theatoll, which was in accord with the survey meter readings and the radioactivity in the soils. The activity in the land plants, however, declined at a faster rate than that in the scils for the period March 1954 to January 1955, after which the rate of decline appeared to be slower in the land plants. The rate of decline at Kabelle and Labaredj Islands is presented in Figure 11 for island soil and in Figure 12 for coconut meat and milk. The activity in the coconuts does not appear to be declining appreciably with time, but since it is due mostly to Cs137, it does not present a health problem at this time. (The average level for coconuts in October 1955 was approximately 4.5 x io? uc/ g of wet tissue, which is less than 1 percent of the tolerance level), Edible plants other than coconuts have been found to contain levels of sr?° which are above the tolerance level as defined in the Radiological Health Handbook, Among these plants are Pandanus, squash, and possibly arrowroot. milk is very low» 8. papaya, Morinda, The level of sr?° in coconut meat and Thus it can be stated that certain plants are selec- tively absorbing this isotope, while others are not. Another indication of selective uptake of radioactive materials from the soil is shown by the difference in the decay slopes of coconut meat and milk. They are not only different from one another, but also are different from the decay slopes of other plants and soils, the average slope of which logarithmically is about -1.25. The decay slopes for different samples of coco- nut meat and milk taken from Kabelle and Rongelap Islands are presented