EFFECTS OF FALLOUT RADIATION T T T T T l T j _t PLATELETS x10° 30 285 ® 10 0 ! 10 1 20 i 30 —_t ! 40 50 AGE (YR) 60 70 80 boFFG Fig. 3. Seattergram of individual 1958 platelet counts, males, plotted against age with mean curves of the 3-vear and 4-year comparison population males plotted according to age. to 3700 cells/mm’ in the unexposed people), and recovery of this blood element is considered almost complete. A seattergram of the individual counts plotted according to age and accumulative distribution curves, however, showed more of the counts to be low than in the unexposed population. 4. Platelets There was a steady reduction in the platelets in the peripheral blood after expo- sure, reaching a low of about 30% of the unexposed group by the fourth week (Nig. 2). A rapid recovery trend was then followed by a fluctuating, slow recovery pattern, the males showing slower recovery than the females. Even at + vears postexposure platelet production does not appear to have recovered completely. The counts were higher than a year ago, but compared with mean unexposedlevels they were about 12% lower in the males (greater than 10 years of age) and 9% lower in the females. A scattergram (Fig. 3) shows individual counts in the males und the mean curve of the controls plotted against age. The counts are preponderantly below the control curve. This trend is not so marked in the females. 3, Hosinophils and Monocytes ” one CPE Btat Wosinophils and monocytes showed depression and recovery roughlyparalleling that of the neutrophils. Eosinophilia is present in all the populations studied.