- 40 - Manhattan workers resulted from aspiration of droplets of liquid solutions of plutonium into the air wherein much larger particle sizes would result. At the same time, the activity of the plutonium in the particle would be considerably less than that for a particle of Pu09. For example, it is stated that 14 of the 25 subjects with measurable body burdens of plutonium worked in the recovery Operation and that this occurred when working with solutions containing 1-40 g/liter of plutonyl nitrate to which Hj709 was being added with vigorous stirring in an open hood. This resulted in con- siderable fizzing and the discharge of droplets into the air outside the hood.- WN droplet 1 u in diameter (0,5 ur) from the solution with the highest concentration (40 g/liter) would therefore contain only 6x1074 pCi compared with a 0.07 oCi vnarticle of Pud> 71 Aower by a factor of 100). 72 (a specific activity that is In other words, the particles involved in this study do not qualify’ as hot particles. They are delivering dosages lower than 1000 rem/yr to the ete ’ * 71if/ Recall from Table IV that a 0.07 pCi, the limiting activity for a hot particle, would give a dose of 1000 rem/yr to the surrounding tissue in a lung inflated to 1/2 maximum. 72/ Of the particles of an inhaled aerosol that are deposited in the deep respiratory zone of the lung, virtually all are less than 5 u in diameter [Geesaman, UCRL-50387, Op. cit., p. A 5 u droplet from the 40 g/liter solution would correspond roughly to the limiting activity of a hot particle. 3).