Bioavailability and bioaccessibility are two important factors in determining the level
of metal toxicity in soil. Inorganic soil amendments can decrease metal bioavailability
and enhance soil quality. In this study, we used mussel shell, cow bone, and biochar to
reduce Pb toxicity in highly contaminated military shooting range soil in Korea. Watersoluble
and 1 M ammonium nitrate extractions along with a modified physiologically
based extraction test (PBET) were performed to determine Pb bioavailability and
bioaccessibility in the soil, respectively. Biologically active carbon in the soil was also
determined to evaluate the effects of the amendments on soil quality. Seed germination
and root elongation tests using lettuce (Lactuca sativa) showed increases in germination
percentage and root length in soil treated with the amendments. Biochar was most
effective in increasing seed germination (360%) and root length (189%) compared to
control. Bioavailability and bioaccessibility of Pb decreased, respectively, to 92.5% and
48.5% in mussel shell, 84.8% and 34.5% in cow bone, and 75.8% and 12.5% in biochartreated
soil compared to control. The overall results suggest that the observed reduction
in Pb availability in military shooting range soil by the amendments was related to a
decrease in Pb ecotoxicity, as indicated by seed germination and root length. Furthermore,
an increase in biologically active carbon in soil by