39 . Beagles. Physies igh June n of Bas: diological ugh June Atherton, d Radon (7 (1958), ‘trometry, HO. H. Com- and Bats al Labo- Report, ‘etention > (1958). abolism: iple but Theoret. ie Variahe Dog, unlikely. However, metabolites do travel along the ray tracheids, tritiated water enters heartwood, and in coitwoods fission products are found in wood formed prior to the existence of bomb fallout.‘® This paper reports on the use of *1°Pb tracer to estimate the rates of radial translocation of lead in trees. Also measured was 7!°Po, which gives an indication of the transport of this nuclide. These nuclides occur in nature and are derived from the °8U chain which de- exvs to “°6Ra and then through a chain of short-lived daughters to 2°Pb, which has a 21.4-year half-life. This nuclide then decays to 5-day 7!°Bi and finally to TABLE 14. which, nd acmeasent of ted by y and 2s and ncient ced at lina s type 1s 28 Bar 1-2 0 1.5 48 as GS 7 5-6 7-8 9-11 12-14 xs Ys 15-16 17-18 lls 12S 38 indiod is 0.83 + 0.10 2.09 + 0.29 5.5 7.5 10.0 13.0 0.261 0.221 0.184 0,207 0.202 0.176 0.239 0.2388 0.77 0.80 1.29 1.15 19-20 15.5 17.5 19.5 0.192 + 0.017 0.221 + 0.017 0.268 + 0.020 0.170 + 0.026 063 + 0.11 2)-23 24-25 22.0 24.5 0.2690 + 0.018 0.266 + 0.022 0.238 + 0.025 0.254 + 0.040 0.88 + 0.11 0.95 + 0.17 3.5 0.214 + 0.019 26.5 28.5 33.0 36.0 38-39 0.271 0.250 0.208 0.240 38.5 + + + + + + + + 0.024 0.017 0.017 0.017 0.021 0.020 0.017 0.019 0.148 + 0.018 0.192 + 0.026 + + + + 0.042 0.023 0.025 0.032 0.280 + 0.027 0.269 + 0.026 0.196 0.227 0.221 0.081 + + + + + + + + 1.46 + 0.19 122 + 0.15 0.027 0.043 0.03 0.03 0.72 0.91 1.06 0.34 0.266 + 0.048 + + + + 0.12 0.19 0.20 0.16 1.86 + 0.38 0.178 + 0.019 0.202 + 0.019 0.157 + 0.042 0.164 + 0.043 0.88 + 0.26 0.81 + 0.22 20S JES 2S 44-45 46-47 48-49 44.5 46.5 48.5 0.142 + 0.017 0.179 + 0.019 0.058 + 0.011 0.167 + 0.018 0.216 + 0.042 0.110 + 0.042 0.076 + 0.026 0.146 + 0.041 1.562 + 0.34 0.62 + 0,24 1.31 + 0.51 0.87 + 0,26 JEN 25S §2-53 54-55 52.5 54.5 0.138 + 0.018 0.124 + 0.017 0.103 + 0.014 0.194 + 0.044 0.146 + 0.041 0.126 + 0.035 1.41 + 0.37 1.18 + 0.37 58-59 60-61 38.5 60.5 02.5 65.0 0.119 0.0902 0.080 0.085 0.146 0.104 0.125 0.086 1.22 + 0.38 71.5 75.0 78.5 0.077 + 0.031 0.88 + 0.38 0.069 + 0.010 0.055 + 0.009 0.051 + 0.008 0.064 + 0.026 0.071 + 0.028 0.089 + 0.021 0.92 + 0.39 1.29 + 0.47 0.76 + 0.42 0.045 + 0.007 0.061 + 0.007 0.042 + 0.012 0.048 + 0.012 0.93 + 0.30 0.79 + 0.22 0.046 + 0.021 0.082 + 0.017 0.92 + 0.44 | 1.08 + 0.23 50-51 PAS 278 28S 30 SS 318 KNE ENE ENE 338 3008 oF 38 Center 50.5 56-57 | 56.5 62-03 62-07 64-05 70-73 - 73-17 77-80 78 79 80 84-86 88-92 90-95 100 ; 64.5 85.0 90.0 92.5 100.0 0.016 0.013 0.012 0.010 0.087 + 0.018 | 78.0 79.0 80.0 + + + + ' ~ ~ | ; 0.053 + 0.007 0.085 + 0.007 0.050 + 0.008 0.086 + 0.010 0.057 £ 0.008 + + + + 1.22 + 0.38 0.041 0.083 0.031 0.017 1.14 + 0.40 1.56 + 0.44 1.01 + 0.23 0.0386 + 0.012 0.69 + 0.24 0.086 + 0.021 0.073 + 0.0L} Mean 0.265 + 0.016 0.082 + 0.009 0.17 0.12 0.18 0.18 40.5 42.5 23S RapCa 0.90 + 0.15 40-41 42-43 3308 S48 iving Ratiosponmen Iss 19 8 ments yf the on of »°Pb, 7°Po ann #6Ra 2ONCENTRATIONS IN Hiexory 0.192 + 0.021 0.329 + 0.029 26-27 28-29 32-34 35-37 17s 328 roots excretion, and that the input rates are constant, the “40Ph, concentration would decrease with its 21.4-year radioactive half-life as one goes from the younger to the older wood (outer rings toward the center). 0.233 + 0.014 0.157 + 0.017 3-4 138 4s los lis iounts r the rable 222Rn, may be easily translocated, the “!°Pb moves through the biosphere independently of its predecessors. Although the origins of the stable and radioactive lead in the tree may differ, one would expect that after entry their metabolic behaviors would be similar, if not identical. Thus, if we assume no circulation, no Sinplenunber] Ageing, ateanase, umn nciig ary mpo,pctiedty IOS n par; could: 138-day 7°Po. Because of their different chemistries and because the radioactive rare gas intermediate, 2.15 + 0.63 | 1.28 £ 0.32 ! — 1.11 + 0.34 (S.D.) : .