Fig. 7. Comparison of Cr(VI) reduction at Day 84 for sterile and nonsterile soils. Values for unreduced Cr(VI) fractions at Day 84 for nonsterile soils were obtained with first-order fits (see Fig. 5). Alpha values from t tests of significance of further Cr(VI) reduction in nonsterile soils relative to their sterile counterparts are indicated in italic type. NS, not significant.