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Percutaneous Absorption of Chemicals from Fabric (Textile) *
Published in Robert N. Phalen, Howard I. Maibach, Protective Gloves for Occupational Use, 2023
J. L. Bormann, A. S. F. Acipayam, H. I. Maibach
Military personnel may be exposed to chemicals as a means of attack through chemical warfare. Chemicals in the organophosphate family, such as Agent VX, are widely studied. Agent VX is a chemical warfare agent with lethal properties when dermally absorbed. Due to the lethality of Agent VX, parathion, a common pesticide with similar chemical properties as VX, was used to estimate percutaneous penetration of the more lethal Agent VX when transferred from clothing.1 Standard army issue coat, hot weather woodland camouflage, combat pattern, 50% nylon and 50% cotton (American Apparel, Inc.) was utilized as the uniform material. Arms, head, and neck were unprotected by the military uniform. Parathion absorption was measured at 1, 8, and 96 hours after contact with the contaminated fabric, or, in the case of naked skin, after chemical contamination with no uniform barrier.
Chemical and Biological Threats to Public Safety
Published in Frank A. Barile, Barile’s Clinical Toxicology, 2019
Soman, a methylphosphonofluoridic acid ester, is miscible with organic solvents and water. It is readily absorbed through the skin. Soman is the most toxic of the three “G” agents and one of the most toxic compounds ever synthesized, with fatalities occurring with an oral dose of 10 μg/kg in humans. Sarin, a methylphosphonofluoridic acid ester, and tabun, a dimethylphosphonofluoridic acid ester, are also miscible with organic solvents and water and are readily absorbed through the skin (tabun possesses a bitter almond smell). Recently, however, VX (methylphosphonothioic acid ester) has emerged as a more toxic nerve agent. Its chemical and biological properties satisfy the requirements for VX as a chemical bioterrorist threat. The odorless, tasteless, oily liquid was originally developed in the United Kingdom in the 1950s. Unlike more volatile aromatic and aliphatic hydrocarbons, heating VX liquid renders it suitable for inhalation, dermal, or ocular contact with the airborne vapors. Contamination of food and water supplies is also possible. Of concern is its ability to accumulate in physiological compartments, its slow metabolic degradation, and its high density, enabling it to spread throughout low-lying areas.
Toxicokinetics of Nerve Agents
Published in Brian J. Lukey, James A. Romano, Salem Harry, Chemical Warfare Agents, 2019
Marcel J. van der Schans, Hendrik P. Benschop, Christopher E. Whalley
With the analytical methodology available, it appeared possible to measure nerve agents at the toxicologically relevant level. This capability made it possible to measure the toxicokinetics of nerve agents after a variety of exposure routes at several doses and to determine the time period for which acutely toxic levels exist. The relevance of such studies has been shown, since the persistence of nerve agent in vivo is longer than anticipated, with the percutaneous exposure to VX being the most remarkable. It is evident that these studies can be used for the development of strategies for the timely administration of antidotes in the case of nerve agent intoxication. For example, the efficacy of HuBuChE as a scavenger for nerve agents was demonstrated by toxicokinetic studies.
Efficient agent degradation within skin is important for decontamination of percutaneously exposed VX
Published in Cutaneous and Ocular Toxicology, 2021
Lina Thors, Elisabeth Wigenstam, Johanna Qvarnström, Anders Bucht
Medical management of victims percutaneously exposed to nerve agents might be greatly affected by the remaining intact agent within the skin after decontamination36,37. Low volatile nerve agents, such as VX, are suggested to form depots in the deeper layers of the skin, which may cause continuous agent release and sustained symptoms7–9. Therefore, efficient removal of nerve agents requires skin decontamination procedures that have the ability to reach agents within the skin. This study aimed to evaluate procedures using RSDL, TRSDL, and soapy water for their ability to remove VX from human skin and to reduce the agent amount penetrating through the skin.
Inhibition of cholinesterases following percutaneous intoxication with V agents in rats
Published in Toxin Reviews, 2021
Jiri Bajgar, Kamil Kuca, Jiri Kassa
This parameter is characterized by bimolecular rate constant of inhibition (ka, M·min−1) or other derived constants, for example, I50, pI50, etc. Bimolecular rate constants for interaction of soluble rat brain AChE and VX (1.26 × 106) or its diethyl derivative (1.0 × 106) were described (Bajgar and Patocka 1977), too. There are not very high differences in the inhibition potency in vitro among V agents when phosphorus head in their molecules is the same. On the other hand, small differences for the blood cholinesterase inhibition observed in our experiments and characterized as t0.5 decreased in the following manner: et–but > et–et > VX. As for normal AChE activity in tissues, it is on the large scale and dependent on different factors, for example, age etc. (Strauss et al.2017): low activity in the blood and diaphragm was observed, relatively high activity in the brain parts was detected. This non-uniformity was also described earlier in literature for the brain parts (Gupta 2004, Hajek et al.2009, Bajgar 2012, Strauss et al.2017). For V agents, it was not observed relationship among AChE activity in the brain parts of died and survived animals as it was demonstrated for G agents (Bajgar et al.2008). On the other hand, AChE activity in the diaphragm of survived rats was significantly higher than that in died animals. It is corresponding to the described mechanism of death as peripheral in case of V agents intoxication (Bajgar and Voicu 2009, Bajgar 2012), an interval between occurrence of the first blood ChE inhibition is interesting. It supports a hypothesis that VX penetrates easier through the skin than remaining two V derivatives.
Pulmonary toxicity following inhalation exposure to VX in anesthetized rats: Possible roles for compromised immunity and oxidative stress-induced lung injury
Published in Experimental Lung Research, 2018
The current effort was designed to determine the direct inhalational effects of one of the most toxic nerve agents, VX. This effort differs from earlier work in that we tested lower exposure doses such as 17.1 mg/m3 or 31.6 mg/m3 of the published LCt50.11 We occasionally observed VX-induced cholinergic responses such as lacrimation, hypersecretion, fasiculations, temporary seizures, and in some instances, fatalities, which in this study ranged from approximately 14% to 27% for the 17.1 mg/m3 or 31.6 mg/m3 VX-exposed groups, respectively.