Table |. Per Cent Abundance and Relative Maximum Permissible Concentration of Fallout Radioisotopes of Biological Interest Per cent abundanceat: 1) Relative Fission One One One Ten products week month year years 5,88 2.1 6.7 2.7 === 50 days 5190 eee wee 1.8 21.8 28 years 1 y99 w-- wee 1.8 21.8 64 hours 200 y%l 2.4 7.6 3.9 --- 58 days 300 zr95 2.5 8.2 7.300 -<- 65 days 600 Nb?5 --- 4.1 18.0. --- 35 days i, 000 Rul06 --- ee 2.4 --- 365 days 100 Rn106 --- =e 2.4 --- 2 hours * jist 6.3 --- --- 8 days 20 (or 1.5 18.2 27 years 200 BalSim 1.5 18.2 3 mins. * ..- 3.7 --- MPC Half lite?) values?) 100 1) Hunter and Ballou (1951) 2) Strominger, Hollander and Seaborg (1958) 3) MPC values relative to Sr90; based upon values from 69 for which MPC for Sr®9 ig 1078 ye/ce * A short-lived daughter for which hazard is negligible in comparison to hazard for parent Handbook