66 N-10 Studies on intake by inhalation concentrated on plutonium-239,-240 at Bikini Island (Shinn et al 1980). In calculating the results, it was assumed that a person would He exposed to maximurz dust conditions for 5 hours per day throughout life (tilling fields), an unrealistic assumption bound to gife very high exposures (tilling deposits 1.5 x 10-3 picocuries per hgur in the lungs). To obtain the Rongelap dose, it was assumed by Robison @t al (1982b) that the distribution of particle sizes and of radioguclides was practically the same on Bikini and Rongelap Islands. Thérefore, the inhalation dose on Rongelap would be to that on Bikini ag the transuranic specific activity of Rongelap soil (0-5 cm) was fo that of Bikini Island. Island Specific activity in top 5 ca of soil in 1978 Bikini a/ plutonium-239,-240 americiua-241 Rongelap b/ plutoniun-239,-240 anericius~241 a/ b/ c/ pci/g Inhalation 30-yemr dose to bone marrow ren ij 8.7 033 035 3.2 -010 1.0 -005 Robison et al (1982a, pp. 8, 12, 44, 56). Robison et al (1982p, pp. 12, 14, 47, B10, B13). The dose throughout the bone would be about 4 times as great The dose is greater for a growing child. Robison et al (1992a) used a factor of 2.8 to convert the adult inhalation dose to that forjthe age period 0-30 years (.042 rem). The dose to the adult lung is congidered to be about 2.5 times that to the narrow. Dr. Robison (personal communication, 1988) has reviewed thege dose estimates according to the more recent ICRP factors. He has rediced dust consumption by a factor of 3.5, which would reduce the dose proportionally. This is still a liberal allowance for every dayfof life from birth to death, but in any case a much more reasonable one.] The net result is a reduction in dose for plutonium by a factor of about] 3, and for americium by a factor of 4.