Fig. 3. Concentration of ⁵⁴Mn, ⁶⁵Zn, ⁵⁷Co, and ¹³⁴Cs measured in the soil matrix (unstained) and in preferential flow paths (stained). Mean and standard error are given. The symbols *, **, and *** indicate significance at the 0.05, 0.01, and 0.001 probability levels, respectively; while n.s. is not significant and n.d. is not detectable.