Toxicity lewisite

Table 2. Summary of Effect Levels for Lewisite Toxicity Studies 9...

Similar to the mustard agents, exposure prevention is the first line of defense against lewisite. Rapid decontamination is especially relevant to lewisite exposure due to the rapid development of pain (1-2 min) associated with lewisite exposure. Unlike other vesicants, an effective antidote for lewisite toxicity exists in the form of British anti-lewisite (BAL 2,3-dimercaptopropanol) which binds with arsenicals, thereby countering the lewisite-induced damage. Such chelation therapy is associated with notable side effects (e.g. renal effects) and requires carefiil medical management. More effective analogs of BAL have been developed with less significant side effects. 

King, J.R., Riviere, J.E., Monteiroriviere, N.A. (1992). Characterization of lewisite toxicity in isolated perfused skin. Toxicol. Appl. Pharmacol. 116 189-201. 

Nelson, P., Sawyer, T.W. (2006). Therapeutic effects of hypothermia on lewisite toxicity. Proceedings of the U.S. Army Medical Defense Bioscience Review, Hunt Valley, MD, 154 pp. 

Lewisite, a vesicant with HD-Uke properties, causes a similar constellation of signs and symptoms involving the skin, eyes, and airways as well as systemic effects (e.g. increased capillary permeability) after absorption. However, it does not produce immunological suppression like mustard. Another difference is that the management of lewisite toxicity includes an antidote, British Anti-Lewisite (BAL) (Yue/u/.,2003). 

Table 31. Summary of effect levels for lewisite toxicity studies.

It hydrolyses in acidic medium to form HC1 and nonvolatile (solid) chlorovinylarsenious oxide, which is a less potent vesicant than Lewisite L-2. Hydrolysis in alkaline medium, as in decontamination with alcoholic caustic or carbonate solution, produces acetylene and trisodium arsenate (Na3AS04). Therefore, decontaminated solution would contain toxic arsenic. 

Rapid hydrolysis aids in lowering the duration of effectiveness of toxic chemical agents. For example, in the presence of water or water vapor, lewisite (L) rapidly hydrolyzes. Therefore, it has a shorter duration of effectiveness than distilled mustard (HD). 

New substances (hydrolysis products) form when an agent or compound reacts with water. In certain cases hydrolysis does not completely destroy the toxicity of an agent or compound. The resulting hydrolysis products may also be toxic. Examples include lewisite and other agents containing arsenic. 

Agency for Toxic Substances and Disease Registry. "Blister Agents Lewisite (L) and Mustard-Lewisite Mixture (HL) ToxFAQs." April 2002. 

Lewisite (C04-A002) has been mixed with sulfur mustard (C03-A001) to prevent the sulfur mustard from freezing in the shell as well as to enhance its toxicity. 

Human toxicity values have not been established or have not been published. Although L2 acts primarily as a vomiting/sternatory agent, it does have limited vesicant power similar to Lewisite (C04-A002). 

BAL British Anti-Lewisite. Dimercaprol, a treatment for toxic inhalations. 

In pure liquid form, lewisite causes blindness, immediate destruction of lung tissue, and systemic blood poisoning. It is absorbed through the skin like distilled mustard, but is much more toxic to the skin. Skin exposure results in immediate pain a rash forms within 30 minutes. Severe chemical burns are possible. Blistering of the skin takes up to 13 hours to develop. Lewisite does not dissolve in human sweat. It commingles with sweat, then flows to tender skin areas such as the inner arm, buttocks, and crotch. 

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