Fate of post-blast residue in soils from an armed conflict zone determined by magnetic, microbiological, and ecotoxicological assessments.

Weapon detonations generate substantial quantities of post-blast residue (PBR), which contributes iron-rich particles to soils. After deposition, these residues undergo redox transformations that produce bioavailable iron compounds, potentially increasing phytotoxic risks to agricultural crops. In the present study, soil contamination by detonation of military weapons was simulated by adding 1% of < 1 mm PBR to soil, and iron mobilization under waterlogged conditions was subsequently monitored. Scanning electron microscopy revealed two components in PBR: iron-bearing spherules and metallic fragments composed of an iron core with an oxidized surface layer. Magnetic analyses confirmed that waterlogging had a limited impact on PBR, with no significant changes in explosion-derived iron spherules; however, a decrease was observed in hematite-like phases associated with surface-corroded iron fragments. This decrease was linked to the interaction of these phases with metabolically active soil microorganisms. Following the addition of a carbon and energy source (potato) to PBR-contaminated soil, the abiotic reaction of Fe