Lewisite , described

Lewisite 1 was used for spiking in the sixth and in the ninth proficiency test. The participants that failed to identify lewisite 1 did not describe an effective lewisite 1 sample preparation procedure (12) in their analysis report, which could indicate that no such procedure had been employed. The participants performances in the identification of lewisite 1 are summarized in Table 3. 

A special derivatization reaction is required for lewisite 1, which is so reactive that it cannot be determined by GC/MS in low quantities (e.g. below 10 ng per injection). It has been known for a long time that lewisite 1 reacts with compounds having an a, P-dithiol structure, such as 2,3-dimercaptopropanol-l (British-Anti-Lewisite (BAL) also used for medical treatment). The derivatization reaction can be performed at an analytical level and several examples have been described (29). The reaction product of lewisite 1 with 3,4-dimercaptotoluene, 2-(2-chlorovinyl)-5-methyl-l,3,2-benzodithiarsole (see (1)), is a useful derivative for GC/MS analysis. Its mass spectrum is simple with molecular ion peaks at m/z 290/292 and the base peak at m/z 229 due to the loss of the 2-chlorovinyl group (30). 

The subcommittee determined that the Army s interim RfDs for GA, GB, GD, and sulfur mustard were scientifically valid but concluded that the RfDs for VX and lewisite and the SF for sulfur mustard were too high. The bases for those conclusions are described below. Research recommendations for filling major data gaps are also presented. 

THIS CHAPTER contains a brief description of the methods used by toxicologists at Oak Ridge National Laboratory (ORNL) to derive the U.S. Army s interim reference doses (RfDs) for GA, GB, GD, VX, sulfur mustard, and lewisite. Those methods were based on the procedures outlined by the U.S. Enviromnental Protection Agency for Superfund risk assessment guidelines (EPA 1989) and for reference concentrations (EPA 1994). An alternative method, the benchmark-dose (BD) approach (Crump 1984) is also described. Because uncertainty factors are integral to both approaches, further consideration is also given to the statistical distribution and confidence associated with them. 

Lewisite (2-chlorvinyldichlorarsin) is another vesicant agent. Unlike sulfur mustard, there has never been a documented use in armed conflict. It was first synthesized and described by the Belgian priest and chemist Julius Arthur Nieuwland (Nieuwland, 1904). During World War I, the US military chemist Winford Lee Lewis suggested and initiated its development into a chemical weapon, which due to the 1918 armistice in Europe was not used on the battlefield (Vilensky and Redman, 2003). 

Snider et al. (1990) determined the elimination of lewisite from rabbits after p.c. injection. Half-life was determined, ranging from 55 to 75 h. A clearance of 120ml/h/kg was found. However, these findings only describe the overall elimination of arsenic from the organism, following a lewisite exposure. 

Potentiometric titration and colorimetric methods have been described for the determination of )5-chlorovinyldichloroarsine (Lewisite) . In the latter the organic arsenic is mineralized by refluxing with aqueous sodium hydrogen carbonate and then oxidized to... 

It is necessary to note that more or less marked asymmetry of the band 1554 cm 1 (and of the bands at 1143, 710 and 807 cm 1 as well) was observed in the spectra of all mixtures studied. Its profile may be always resolved into components with maximums at 1548 and 1554 cm 1 corresponding to p- and a-lewisite. The relative quantity of these types may be approximately described by the following relation ... 

Phenyldichlorarsine is a less severe vesicant than lewisite, although Prentiss (1937) described its vesicant actions as not inconsiderable . The effects of phenyldichlorarsine on an individual, exposed while working on it, were described in detail by Hunter (1978). There was severe blistering of one hand and two days after exposure, severe diarrhoea, vomiting and slight jaundice. This individual recovered, with intermittent vomiting and diarrhoea (which was not bloody) continuing for some days, while the skin had healed by the tenth day after exposure. Thus, the effects were not dissimilar to those of lewisite. 

Described by Beadnell (1943), without the chemical name, as a variety of lewisite with especial lung-irritant effects . 

Fig. 4-2. Agent vaporization increases in proportion to energy sources such as heat from explosive charges or from ambient heat (as measured by air or surface temperatures). Vapor persistence is then determined by weather factors such as wind and humidity. Hydrolysis rates are affected by factors such as temperature and solubility. Agents show characteristic hydrolysis rates in water, and water vapor, as described by humidity, may cause significant hydrolysis of vaporized agent. The vesicant Lewisite, for example, shows relatively rapid hydrolysis in water vapor, while the nerve agent VX is more resistant to hydrolysis.

As is reported, the first 150 tons of Lewisite was shipped by railroad to Edgewood Arsenal—probably to the Bush River Depot— to be shipped overseas. The train was described as a train like no other. Apparently, it only had an engineer on it and the rest of the crew were soldiers. It went no faster than 10 miles an hour and took four days to get to Edgewood. The Armistice came while the train was en route. Various news stories report that the load was taken out to sea and dumped, 50 miles from Baltimore. It is unclear whether that means Chesapeake Bay or just off the coast of Delaware. However, the San Francisco Journal on February 19, 1923, reported that Lewisite was dumped in Chesapeake Bay. Photos 13, 14,15, 17, and 18 in the center photo section show some of the ocean dumping of Lewisite and other chemical munitions. 

Metalloids too are able to form compounds with SH-groups. Concerning GSH among others the following arsenic compounds have been described (GS)3As from the reaction of AsjOj + GSH in methanol (40) (GS)2AsPh from PhAsCh or PhAsO 4- GSH (44) (GS)As(Ph)2 on reacting Lewisite and GSH (45). 

In any event, if you remember two representatives from each of these classes—the blister agents mustard and Lewisite, and the nerve agents sarin and VX— you will have in memory a reasonably clear list of the most likely chemical threats, both military and from possible use in terrorism. Other CW agents—an extensive list of them will follow shortly—are of course potential threats, as described below, but mustard. Lewisite, sarin, and VX—as well as we can tell right now—are the modern poisons of choice. 

Signs and symptoms of acute lewisite exposure include a rapid onset of irritation to the eyes and mucous membranes of the upper respiratory tract (lachrymation and rhinitis). In more serious cases of vapor intoxication, chest pain, nausea, vomiting, headache, weakness, convulsions, hypothermia, and hypotension occur (Sidell et al., 1997 Katos et al., 2007). Laboratory tests of the blood of persons exposed may show hemoconcentra-tion animal studies suggest elevated liver enzymes, including lactate dehydrogenase (LDH) (King et al., 1994 Sasser et al., 1999). The following sub-sections describe the effects on specific body sites. 

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