Disaster Preparedness Chemical WMD Chemical agents are poisonous
gases, liquids or solids that have toxic effects on people,
animals or plants. Chemical incidents are characterized by the
rapid onset of medical symptoms and easily observed signatures,
such as colored residue, dead foliage, pungent odor and dead
animals and insects. Most chemical agents cause serious injuries
or death. They are classified by their effects: nerve, blood,
choking or blister. These weapons kill by destruction or
disruption. The infamous "gases" of World War I --mustard gas,
for instance -- essentially burn away parts of the respiratory
system. More modern nerve gases --Tabun, Sarin and VX -- disrupt
the chemical processes through which one nerve cell communicates
with another. Severity of injuries depends on the type and
amount of the chemical agent used, and the duration of exposure.
Chemical agents are generally liquid when containerized but are
disseminated as an aerosol or gas. To be effective, chemical
agents must be dispers