300 BULLETIN OF THE TORREY BOTANICAL CLUB [Vou. 91 c 110,000 a 4 t 5 TESLA A a: = - =x © Py] = tocar “I 1000, L ’ 2 f | i 3 ~ ‘ 2 al = ~ ef > J = E 1 > - 5 29 5” | ° 100}— a TOTAL SOIL PLANT e L r } ° > “100 = _ 5 < _ z < ] 2 , . 10 o 44. SOL FRACTION|: e i 2 4 I I 20 40 DISTANCE FROM 1 60 GROUND i i 80 ZERO Ll 4 100 (MILES) a 16 20 Fig. 6. Soil and plant contamination in relation to distance from ground zero and the activity of particles < 44y in diameter. From Lindberg et al. (1959). used for this purpose, but the analysis of data may be confounded by the presence of natural radionuclides and of fission products previously deposited on thesoil.