Forensics chemical incidents

A comprehensive approach to a states response to a chemical terrorism includes having a plan not only for the crisis and consequence management phases of the incident, but also for all elements required for complete resolution of the event. This may include the necessity to definitively establish whether chemical agents were used, to provide supporting evidence to confirm other analyses, or to provide the forensic proof required to support a criminal prosecution. The collection and analysis of biomedical samples - blood, urine or other tissue from affected humans or animals - is one of the means for providing such information. Although current capabilities such as urinary thiodyglycol excretion or plasma cholinesterase activity can be performed, there is scope for far more sensitive and specific assessments that overcome the limitations of these approaches. 

If these methods do prove inconclusive, biomedical sample analysis may provide a unique method for establishing exposure. Due to both the complex technical requirements and the strict forensic approach used it is unlikely that this information will be available in the early phases of response to such an incident. Biomedical sample analysis does however offer another method by which proof of the use of chemical agents can be provided, and thus has a potentially significant role in the overall preparation of a capability for the response to a terrorist chemical agent attack. 

Stahl, C. J., Green, G. C., Farnum, J. B. (1985). The incident at Tuol Chrey Pathologic and toxicologic examinations of a casualty after chemical attack. Journal of Forensic Sciences, 30(2), 317-337. 

Material Selection of appropriate material for examination is mainly determined by the time that has elapsed from administration of the toxic substance to collection of the material, as well as the site of conducting examinations (a clinical or forensic laboratory, or the site of the incident, for example, during a roadside check of a driver). Various compounds occur in various materials - parent, and active and inactive metabolites. Active metabolites influence life processes, and the presence of inactive metabolites in the organism could attest to consumption of a substance a long time ago. Currently available analytical techniques are applied to detect, identify and determine chemical substances in classical biological material (i.e. blood, urine and sections of internal organs) as well as in so-called alternative materials (i.e. hair, saliva and sweat). In recent years, numerous studies aimed at... 

The importance of detection and forensic analysis of TATP is abundantly clear from the nature and number of incidents involving the material. Details of the synthesis and chemical characteristics of TATP will be presented prior to a discussion of methodologies for the analysis of this improvised explosive. 

Charles J. Stahl, Christopher C. Green, and James B. Farnum, The Incident atTuol Chrey Pathological and Toxicologic Examinations of a Casualty After Chemical Attack, Jowma/ of Forensic Sciences 30, no. 2 p. 328. 

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