Environmental risks of humanitarian demining: evidence from a war-affected region (Ukraine)

Ukraine is currently the most heavily mined country in the world, with nearly 30% of its territory affected by landmines and unexploded ordnance, which is creating long-term constraints for agricultural recovery. Humanitarian demining restores access to land but may also introduce secondary contamination by releasing and redistributing potentially toxic elements. In this study, we assessed the concentrations, spatial distributions, and ecological risks of chromium (Cr), nickel (Ni), cadmium, copper, manganese, cobalt (Co), barium and aluminium in agricultural soils from mined, manually demined, and detonation sites in southern Ukraine. Fifty topsoil samples were analysed using inductively coupled plasma optical emission spectroscopy, alongside measurements of pH, electrical conductivity, and particle size distribution. Contamination was evaluated using multiple pollution indices, including the contamination factor, enrichment factor, geoaccumulation index, pollution load index, and potential ecological risk index. The concentrations of potentially toxic elements at detonation sites substantially exceeded natural background values, with some values more than 25 times the natural background level. Manually demined sites showed greater spatial variability in the concentrations of potentially toxic elements, while mined but uncleared sites showed more stable geochemical conditions. Overall, 68% of samples exceeded regional background or regulatory threshold values for at least one element. Potential ecological risk index values indicated the ecological risk was predominantly low. Localised moderate-risk cases occurred more frequently at detonation sites than at other sites. These findings demonstrate that different demining-related land conditions generate distinct contamination patterns and highlight the need for risk-based prioritisation of post-clearance soil monitoring. Integrating geochemical diagnostics, spatial analysis, and updated environmental standards is essential for ensuring safe and sustainable post-conflict land restoration.