Verification of Exposure to Chemical Warfare Agents
Although banned by international treaty, the use of chemical warfare agents is still of concern, as highlighted by events in Syria in 2012–13. Investigations into alleged uses rely to a great extent on chemical analysis of samples obtained from the scene. Analytical methods for detection of chemical warfare agents, and their degradation and reaction products in environmental samples are well established and are practised by laboratories worldwide. Analysis of biomedical samples, for example blood and urine, in order to detect biomarkers of exposure to chemical warfare agents has received somewhat less attention. In cases where access to the scene of an alleged use in a conflict zone is not possible, but samples from casualties are available, analyses of biomedical samples are of great importance for verification of both use and exposure. If chemical warfare agents were to be used by a terrorist organisation, as occurred in Japan in the 1990s, then such analyses would be important for forensic and diagnostic purposes, and to reassure the minimally or non-exposed ‘worried well’. This chapter provides an overview of analytical methods that have been developed for verification of exposure to chemical warfare agents and details their applications in both deliberate and accidental human exposures.