Soil contamination by military explosives: a review of environmental fate, toxicity, and preliminary findings from war-affected Ukraine

Abstract

Explosives are recalcitrant organic pollutants persisting in war-affected soils. While well-documented at training sites, contamination in active combat zones remains understudied, posing immediate threats to agriculture and human health. This review examines the environmental fate and toxicology of key explosive classes: nitroaromatics such as 2,4,6-trinitrotoluene (TNT) and dinitrotoluene (DNT); nitramines including hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetreazocine (HMX); nitrate esters like pentaerythritol tetranitrate (PETN) and nitroglycerin (NG); and insensitive munitions including 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO), and nitroguanidine (NQ). Supplementing this review, we present preliminary soil screening data from frontline and urban areas of Ukraine (2022-2025). These compounds are highly toxic and persistent; TNT and DNT are phytotoxic and potentially carcinogenic, while RDX and HMX are highly mobile and bioaccumulate in crops. Despite being considered safer, DNAN exhibits chronic phytotoxicity and food-chain bioaccumulation. Crucially, transformation products such as aminodinitrotoluenes (ADNTs), nitroso-intermediates, and azo-dimers can exhibit greater toxicity than the parent compounds but remain largely unmonitored. Co-contamination with heavy metals suppresses biodegradation, and synergistic interactions of explosive mixtures are not very well described. The Ukrainian case study revealed extreme spatial variability of TNT, RDX, HMX, and ADNTs, with specific samples exceeding human-health risk-based screening levels. In general, explosive residues in post-conflict environments represent a significant long-term environmental and health risk, underscoring the need for improved assessment of mixture toxicity and co-contamination dynamics, and for the development of robust in situ monitoring strategies to support effective remediation of war-affected regions.