Arsenic vesicants exposure

Arsenic vesicants cause instantaneous irritation of the eyes, nose, throat, and skin, which provides warning of their presence. Extended exposures cause violent coughing, sneezing, and regurgitation. The odor of arsenic vesicants varies with the individual compound and ranges from odorless to fruity to flowery. Odors may not be discernable due to irritation. 

Although sublethal doses of some arsenic vesicants are rapidly detoxified by the body, many agents are not detoxified and exposures are cumulative. 

Arsenic vesicants produce immediate pain. Tissue damage occurs within minutes of exposure but clinical effects may not appear for up to 24 hours. Some agents are rapidly absorbed through the skin. Extensive skin contamination may cause systemic damage to the liver, kidneys, nervous system, red blood cells, and the brain. 

Arsenic vesicants have been thickened with various substances to enhance deployment, increase their persistency, and increase the risk of percutaneous exposure. Thickeners include polyalkyl methacrylates (methyl, ethyl, butyl, isobutyl), polyfvinyl acetate), polystyrene, plexiglas, alloprene, polychlorinated isoprene, nitrocellulose, as well as bleached montan and lignite waxes. Military thickener K125 is a mixture of methyl, ethyl, and butyl polymethacrylates. When thickened, agents become sticky with a consistency similar to honey. Typically, not enough thickener is added to affect either the color or odor of the agent. 

Immediately dangerous to life or health (IDLH) levels are the ceiling limit for respirators other than SCBAs. However, IDLH levels have not been established for arsenical vesicants. Therefore, any potential exposure to these agents should be regarded with extreme caution and the use of SCBAs for respiratory protection should be considered. 

Because of the extreme dermal hazard posed by arsenic vesicants, responders should wear a Level A protective ensemble whenever there is a potential for exposure to any liquid agent, or to an elevated or unknown concentration of agent vapor. 

Exposure of the skin to arsenic vesicants produces an immediate burning sensation. Reddening of the skin (erythema) may appear in as short a time as 5 minutes although full progression to blisters may not develop for up to 18 hours. Although blisters tend to be deeper and more painful than produced by sulfur vesicants (Chapter 3), they heal more readily. 

BAL is the standard treatment for poisoning by arsenic compounds and will alleviate some effects from exposure to arsenic vesicants. It may also decrease the severity of skin and eye lesions if applied topically within minutes after decontamination is complete (i.e., within 2-5 minutes postexposure). Additional chelating agents for the treatment of systemic arsenic toxicity include meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercapto-l-propanesulfonic acid (DMPS). 

Medical Management Immediate decontamination after exposure is the only way to prevent damage to victims, followed by symptomatic management of lesions. Hospital care tends to be supportive. It should be repeated that liquid arsenical vesicants produce more serious lesions on dermal surfaces than do liquid mustard. In toxic victims, liberal fluids by mouth or intravenous, and high-vitamin, high-protein, high-carbohydrate diets could be indicated. For those victims where shock is in evidence, provide the usual supportive measures such as intravenous administration, blood transfusions, or other vascular volume expanders should be indicated. 

Skin impacts from Arsenical Vesicant vapor occur at concentrations as low as 17 ppm (10 minute exposure). 

Eye impacts from Arsenical Vesicant vapor occur at concentrations as low as 3 ppm (10 minute exposure). Permanent eye damage may occur at concentrations as low as 18 ppm (10 minute exposure). 

LDsqS for skin exposure to liquid Arsenical Vesicants are as low as 2.8 gm per individual. 

Arsenical Vesicants produce pain immediately. Skin impacts begin appearing within minutes of exposure, although it may be up to 18 hours before the full lesion develops. Inhalation of high concentrations may be fatal in as short a time as 10 minutes. Pulmonary edema caused by inhalation of the agent vapor may be delayed for several hours. 

Vapors from Arsenical Vesicants have a density greater than air and tend to collect in low places. Liquids are persistent but are rapidly decomposed by water. These agents are absorbed into porous material, including painted surfaces, and these materials could continue to re-release vapor after exposure has ceased. Agent vapor is rapidly decomposed by moisture in the air. The rate of hydrolysis of liquid agents is limited by their low solubility in water. The liquid density of these agents is greater than that of water. 

Small Areas Decontaminate with copious amounts of full strength household bleach. Removal of porous material, including painted surfaces, that may have absorbed Arsenical Vesicant vapor may be required as these materials could continue to re-release vapor after exposure has ceased. 

Lewisite (b-chlorovinyldichloroarsine) is an arsenical vesicant but of secondary importance in the vesicant group of agents. It was synthesized in the early twentieth century and has seen little or no battlefield use (Balali-Mood et al., 2005). Lewisite is similar to mustard in that it damages the skin, eyes, and airways however, it differs from mustard because its clinical effects appear within seconds of exposure. An antidote, British anti-Lewisite (BAL), can ameliorate the effects of Lewisite if used soon after exposure. Lewisite has some advantages over mustard but also some disadvantages. 

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