- 29 and 82 per cent respectively of the total disintegration rate of the gamma-emitting isotopes. species, At Ujelang, in the same wi85 accounted for 61 per cent and 64 per cent respectively of the total disintegration rate (Table 3). The presence of yi85 on the leaves at Ujelang indicates that the radioactivity found in these samples is from recent fallout (Fig. 8). In the Ujelang soil, on July 19, wi85 contributed only 17 per cent of the total radioactivity in comparison with 89 per cent for the same isotope at Belle Island corrected to the same date. Janet Island soil contained wi85 at a level of 48 per cent of the total activity corrected to July 19 (Table 3). The low value at Janet Island in comparison to that of Belle Island is due to the former island's having been washed by the water wave. The low ratio of tungsten at Ujelang Atoll in comparison to that of samples from both Belle and Janet Islands suggests that a significant part of the radioactivity in Ujelang soil was from earlier fallout, fallout, activity. containing wis | the new contributing only part of the total A similar situation was observed in the soil sample from Henry Island at Eniwetok Atoll.