Medical Aspects of Chemical Warfare (2008) - The Black Vault

Medical Aspects of Chemical WarfareFig. 4-16. Agent vaporization increases in proportion toenergy sources, such as heat from explosive charges or fromambient heat (as measured by air or surface temperatures).Vapor persistence is then determined by weather factorssuch as wind and humidity. Hydrolysis rates are affectedby factors such as temperature and solubility. Agents showcharacteristic hydrolysis rates in water, and water vapor, asdescribed by humidity, may cause significant hydrolysis ofvaporized agent. The vesicant lewisite, for example, showsrelatively rapid hydrolysis in water vapor, while the nerveagent VX is more resistant to hydrolysis..studies provide epidemiological data on CS, such asthe 1969 and 1971 Himsworth reports. 82,83 Additionally,the National Institutes of Health provides dataon carcinogen bioassays on both CS and chloroacetophenone.84 Unfortunately, little is known about thelong-term effects of many of these agents, an area ofincreasing medical concern. Chemical smoke agentsare used to obscure objects or areas from observationor from engagement by weapons with electroopticalcontrol systems. They are usually not toxic in fieldconcentrations, but may cause eye or respiratory irritationin higher concentrations. Some smokes haveadverse chronic exposure effects.Other compounds with military applications includeagents used in flame warfare, such as thickenersfor napalm and incendiary materials, and herbicides(defoliants). Other highly toxic industrial chemicalsalso pose a potential risk to the military. The disasterin Bhopal, India, in December 1984, when an estimated8,000 people died and another 30,000 were injured frombreathing methylisocyanate and chlorine released inan industrial accident, is just one of many examples ofthe devastating effect of poisonous gases. 85Chlorine and phosgene are industrial compoundsTable 4-2Modern Chemical Warfare AgentsUS Army CodeAgentCyanideACHydrogen cyanideCKCyanogen chlorideNerve agentsGA (tabun) Ethyl N,N-dimethyl-phosphoramidocyanidateGB (sarin) Isopropyl-methylphosphonofluoridateGD (soman) 1,2,2-Trimethylpropyl methylphosphonofluoridateGFCyclohexyl-methylphosphonofluoridateVXo-Ethyl S-[2-(diisopropylamino)ethyl]methylphosphonothiolateLung agentsCG (phosgene) Carbonyl chlorideDP (diphosgene) Trichloromethyl chloroformateVesicantsHD (mustard) bis-2-Chloroethyl sulfideL (Lewisite) 2-Chlorovinyl dichloroarsineHlmustard-lewisite mixtureIncapacitating agentsBZ3-Quinuclidinyl benzilate (QNB)Tear gasCN2-Chloro-1-phenylethanoneCS2-ChlorobenzalmalononitrileVomiting gasDM (Adamsite) 10-Chloro-5,10-dihydrophenarsazinethat have been and could again be used as militaryweapons. Medical personnel should be prepared forsuch chemical emergencies when military missionsare in close proximity to industry. During World WarI, the list of chemical agents was expanded to includemustard, phosgene, adamsite, and cyanide.Physical Properties of Chemical AgentsThe physical properties of an agent and its formulationalso present important threat considerations.Selection of agents and agent formulations can be usedto affect differential impacts with respect to droplet sizeand liquid deposition, agent persistence, and agentvolatility. The classic chemical warfare agents have awide range of volatility (Table 4-3), and volatility canbe a determinant in deciding which agents to use. 86Agents such as HCN and sarin are relatively volatile;134