Persistence of A-234 nerve agent on indoor surfaces

Understanding the fundamental physical characteristics of extremely toxic compounds and their behavior across different environments plays a crucial role in assessing their danger. Additionally, this knowledge informs the development of protocols for gathering forensic evidence related to harmful chemicals misuse. In 2018, former Russian spy Sergei Skripal and his daughter were poisoned in Salisbury, England, with a substance later identified as the unconventional nerve agent A-234. Contamination with the compound was found on items inside Skripal's home. The aim of this paper was to determine the persistence of A-234 on selected indoor surfaces. Ceramics, aluminum can, laminated chipboard, polyvinyl chloride (PVC) floor tile, polyethylene terephthalate (PET) bottle, acrylic paint and computer keyboard were used as matrices. The decrease in surface contamination and further fate of the compound was monitored for 12 weeks. Persistence determination involved optimizing the wipe sampling method. Simultaneously, evaporation from the surface and permeation of the contaminant into the matrix were closely monitored. The experimental findings indicate that the nerve agent exhibits remarkable persistence, particularly on impermeable surfaces. Notably, the process of A-234 evaporation plays a minor role in determining its fate, with detectable concentrations observed solely above solid, non-porous surfaces such as ceramics and aluminum can. The surface persistence half-life varied significantly, ranging from 12 min to 478 days, depending on the material. The article has implications for emergency response protocols, decontamination strategies, public health and crime scene investigations.