Review of plant exposure analysis and monitoring methods for chemical warfare agents

The Organization for the Prohibition of Chemical Weapons (OPCW) enforces strict regulations on the production, storage, and use of chemical warfare agents (CWAs). However, in recent decades, terrorist incidents involving the use of CWAs have remained frequent, posing a persistent and serious threat to global security. Plants have emerged as a promising medium for detecting CWAs exposure or toxic chemical leaks due to their wide availability, straightforward sample preparation, and the absence of ethical concerns associated with animal testing. When plants are exposed to CWAs or toxic chemicals, various components within their tissues can react with these agents, generating specific biomarkers of exposure; the detection of these biomarkers enables accurate traceability of CWAs exposure. Furthermore, when plants are subjected to stress from external toxic substances, their phenotypic characteristics undergo significant changes. These changes can be non-destructively analyzed using hyperspectral imaging (HSI) technology, offering rapid monitoring and early warning for laboratory analysis of chemical exposure or toxic chemical leaks. This article presents a comprehensive review of the detection of metabolites and adducts produced in plants exposed to sulfur mustards, nitrogen mustards, sarin (GB), soman (GD), VX, Russian VX (RVX), and chlorine, as well as the monitoring of plant phenotypic changes using HSI technology over the past decade. The review aims to inspire further discoveries of novel plant biomarkers and inform research related to plant exposure to CWAs.