15 3x10 3 T T T 4 10° Cs” SPIKE 2 » 10° $ S 7 t qo S 10} : S 1 SPIKE Sb.’ : SOIL 7 Rr 2 tir 10° Fig. 6. 9 -10" ! 0.5 t 1.0 MEV i 1.5 . Gamma-ray spectrum of a 3 to i0-inch depth increment from old soil compared with the gamna spectra of Sb 5 and csl37, 22