Medical Effects of Chemical Weapons - Operational Medicine · A chemical arms race began; virtually every British chemist was employed in research and development. Porton Down was

SEABEE OPERATIONAL MEDICAL & DENTAL GUIDE

MEDICAL EFFECTS OFCHEMICAL WEAPONS

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HISTORY AND POLICY

Chemical and biologic warfare dates back many centuries. Warring armies in the PeloponnesianWar used smoke from burning pitch to drive enemies from defensive positions. In 1347 theTartars catapulted their dead (afflicted with bubonic plague) into the city of Caffa. The Genoesedefenders became stricken and carried the disease back to Italy as they fled. In colonial times,British gave American Indians gifts of small-pox laden blankets.

Modern chemical warfare began April 22, 1915 at Ypres, Belgium when German troops releasedchlorine gas on totally unprepared French and Algerian soldiers. The subsequent German artilleryattack killed 5000 and injured 10,000; many casualties the result of gas alone. The attack wasrepeated 36 hours later against Canadian troops who rushed in to fill gaps in the trench line, withsimilar casualty statistics. Gas casualties numbered an estimated 1.3 million in WWI with 91,000deaths; the Russians were hardest hit with some half million affected. Use of CW's in WWIoccurred despite the Hague Declaration of 1899 which specifically outlawed use of poisons bybelligerents.

Development of the chlorine delivery system is attributed to German chemist Dr. Fritz Haber(who later won a Nobel prize for other work) and was facilitated by transformation of a boomingprewar dye industry in Germany.

Loos, Belgium in September, 1915 saw the first British gas counterattack and crude anti gasmeasures such as respirators and masks. Britain lagged months behind the Germans who nextinvented Phosgene gas (another product of the dye industry). Initially used in combination withchlorine, this gas was more incapacitating, had less odor and color, and was thus more surprising.Allies retaliated with Phosgene, which soon became the main British agent.

A chemical arms race began; virtually every British chemist was employed in research anddevelopment. Porton Down was opened in January, 1916 in England and various deliverysystems invented. WWI progressed, gas was increasingly used and the Germans developed yetanother generation of agent, Mustard gas. This dichlorethyl sulfide, penetrated clothing,desquamated skin and burned eyes, throat and lung. In weeks, the Germans caused morecasualties than the entire preceding year. By the end of the war, an estimated 113,000 tons ofchemicals were used.

MEDICAL EFFECTS OF CHEMICAL WEAPONS


Fig 1. Gas shells in N0-Man's Land

Fig 2. French soldier Fig 3. British gas casualtiesWith early cloth mask

Lewisite, developed by the US and ship bound to Europe when Armistice was declaredexemplified American involvement in the CW race. We saw the beginning of a strongpro-chemical lobby whose influence still persists. Post-war proliferation continued at places likeEdgewood arsenal in the U.S. and Porton Down. War research at the Down consisted of bothmass animal subjects and human "observers" (persons who would be subjected to gas anddocument their symptoms). Bodies of gas poisoned troops were returned to England and studiedmicroscopically. Major Charles Howard Foulkes, Britain's WWI "gas advisor" is said to havesampled every gas used; he turned down a postwar directorship at Porton Down, considering thejob too dangerous.



Fig 4. British machine gunners on the Somme in 1918. Note the improved masks.

British postwar R and D philosophy was based on devising the deadliest weapons possible beforeinvestigating countermeasures. 1919-1939 saw much U.S. and British technology develop andhuman research continued. French, Italian, and Japanese programs initiated and secret Germanresearch proliferated. The Russian chemical corps was established. CW's continued to see battle,used in the Russian revolution, by the British in India and by the Italians against the Abyssinians(led by emperor Haile Selassie).

Politically, the allied powers prohibited CW's by the Versailles Treaty of 1919 and specificallyprohibited the Germans from importation or manufacture for all time. The Washington Treaty 3years later expanded this concept "banning chemical weapons should be universally accepted aspart of international law binding alike to the conscience and practice of nations." May 1925 sawthe Geneva protocol internationally prohibit CW's and extend this ban to the then theoreticalbiologic weapons: this was signed by 38 nations, not including the infant USSR. Individualnations then needed to ratify the protocol, but this was not accomplished in the U.S. senate until1970. Some of the european nations did ratify early on, however this agreement only seemed toban first use and various countries continued development in the name of "defensiveness."

World unrest in the mid 1930's saw large scale chemical rearmament and joint French-Britishprojects were undertaken. Unknown to the world, Dr. Gerhard Schrader (a German insecticidechemist) discovered Tabun in 1936. This organic phosphide "nerve gas" was a superior killer andquickly found its way into the Wehrmacht.NAZI regulations of the time mandated reportingscientific discoveries of any potential military importance. Sarin was developed in 1938 and in1940 Hitler told the world of "new German weapons that would leave his enemies defenseless".



Factories were set up to employ Tabun, but were beset with problems of corrosiveness, expenseand extreme toxicity to workers. Despite this, the Germans stockpiled perhaps 70,000 tons ofTabun, including as many as 1/2 million bombs. Animal and human testing occurred; manysubjects being political prisoners or concentration camp inmates.

Hitler was averse to the use of CW's (having been a victim of gas himself during WWI) but nearthe end of WWII it appeared he may change his mind. Perhaps the fear of Allied retaliation butmore likely lack of capability by the devastated Luftwaffe prevented Tabun's use. High rankingGerman officials later claimed to have had a contingency plan to divert orders for CWdeployment should they have been issued by Hitler. This great German effort remained silent toBritish intelligence allegedly until the end of the war. This is not entirely true, since Britishsources knew of "nerve gas" two years prior to VE-day and failed to fully pursue the matter.Perhaps confident in their own chemical abilities, this could have been one of the costliestmistakes in modern history.Biological warfare was born ironically as a result of the Geneva Protocol. Japanese army majorShiro Ishii, fearing existence of such weaponry, was the compelling force behind Japan's earlywork with cholera, dysentery, anthrax, typhus, typhoid, plague, brucellosis, gas gangrene andsmallpox. The Pingfan installation in WWII developed the Uji bomb capable of spreading anthraxspores. POW's including mostly Chinese (possibly American, British and Australian) were infectedby various means and studied in various stages of disease; some being killed by morphine beforeactual disease death. Strong evidence that Japans's biologic warfare (BW) was used against theChinese prompted Allied activity.

The British BW project began in February, 1934 and by 1940 Porton Down was set up to developbiologicals as well. Britain feared Hitler would send BW's via the V-weapons, not knowing thatthe Germans were years behind in BW technology. Canadian inoculations for botulism were sentto London and many soldiers were supplied self inoculating syringes during the invasion at Normandy. Gruinard island off Scotland's coast near Aultbea was the site of anthrax experimentsled by Dr. Paul Fildes in 1942. "Anthrax Island" is still off-limits today, the result ofexperimentation without regard to safety and very long-lived anthrax spores. Here was developedthe first anthrax bomb which later led to stockpiling of 5 million "cattle cakes" at Porton Down.

Operation Anthropoid of 1941 with the assassination of Reinhard Heydrich (ruthless head of theNAZI security service and perhaps planned successor to Hitler) in mind culminated in the May1942 bombing of his auto in Czechoslovakia. One of two special "X" bombs (British term forbotulinum toxin) merely sent splinters into Heydrich who died mysteriously a week laterpresumably from botulism paralysis. Though not officially linked, Fildes later bragged tocolleagues of his involvement.

Britain and the U.S. pooled BW information much as they did with the atomic bomb. The resultswere massive stockpiling of anthrax and development of other materials termed anti-crop warfare.By the war's end the U.S. had enough material to destroy perhaps 30% of the Japanese rice crop.An anthrax bomb production plant was set up at Vigo, Indiana, however never went to



production. BW's could wipe out large population segments and thus cripple an enemy's wareffort; anthrax, however, would poison the conquered soil for generations. Brucellosis, with lowmortality and high morbidity, was viewed as a viable alternative.

The world was spared CBW's in WWII by a series of historical events that were related toconventional successes and failures; sufficient disincentive to belligerent's drive to use them. Hadthe war progressed, almost certainly would these agents have been used.

The early postwar period saw destruction of captured German and Japanese nerve gas stores.Intact factories and documents fell into Russian hands; and it became known that a new, powerfulsubstance Soman (GD) had been recovered by the Soviets. While the Allies analyzed andattempted to isolate the effects of these substances, Russian reassembly of captured equipmentand production proceeded. A spiraling impetus for proliferation was established; American beliefin a large Soviet chemical/biological capacity and Soviet belief in an expanding American nuclearability. Views that defensiveness against attack was ineffective also stimulated the research ofoffensive measures.

Japanese prisoners were offered immunity for information of their biologic POW experimentation.The extent of this information far exceeded Allied expectation, these experiments were as horrificas those of the NAZI's. This information was carefully used and kept secret for decades. TheSoviets were opposed to the immunity agreement for obvious reasons, to keep this informationout of western hands.

Allied experimentation proceeded through the 40's, 50's and 60's. Various examples includeoperations "Pandora"-1948, "Harness"-1948, "Ozone"-1953 and "Negation"-1954 whichemployed real disease dispersal in varying modes. More than 200 experiments were conducted intwo decades over real cities. "Harmless" bacteria were released over San Francisco bay in 1950and throughout the NYC subway in 1966. These demonstrations confirmed the theory ofhelplessness to biologic attack. The Tripartite agreement of 1947 between the U.S., Britain andCanada formed a secret information pool to which Australia was added in 1965.

British research changed emphasis indeed to defensiveness: gas masks, vaccines, detectiondevices, etc. Animal and frequently involuntary human experimentation did, however, persist. U.S. efforts continued in offensive weapons and the biologic facility at Pine Bluff, Ark. wasopened in 1950. From this installation BW bombs were developed and stockpiled. Anti-cropbombs were reported the following year at Camp Detrick, near Washington, D.C. Americanemphasis on "controlled" delivery of biologicals led to investigation of vectors such as mosquitos,fleas and ticks. The U.S. policy was changed in 1956 from one of retaliation to one described "thedecision for U.S. forces to use CBW rests with the president of the United States." Allegations ofU.S. use of such weapons in Korea were never suitably verified, and answered by unverifiabledenials. Specific information recovered from a Russian Army intelligence officer, Oleg Penkovsky,suggested that Soviet policy likewise was no longer confined to defensiveness.



Various developments in the pre-Vietnam war era included discovery and development of VXfrom 1952-1956 by the British and Americans. This oily, long lasting nerve agent was thestrongest yet and by 1967, 4000-5000 tons were stockpiled in the U.S. Pro-gas propagandapromoted CBW's as humane weapons,but strong opposition continued. Late 50's and early 60'sresearch with LSD and other psychochemicals attempted to define an agent that would entice theenemy to lay his weapons down and come to the front with hands up (war without death). BZ, anLSD like agent with longer duration of effect, was stockpiled at Pine Bluff. These materials hadan inherent unpredictability, however.

The early Vietnam period witnessed proposals of incapacitating diseases such as Venezuelanequine encephalomyelitis and enterotoxins. A concept of theoretical "ethnic weapon" developedbut such an agent was never found. Operation Ranch Hand employed 6 agents including agentorange to bare jungles and expose the enemy. Composed of two substances and traces of dioxin(one of the most deadly chemicals known), agent orange proved carcinogenic and teratogenic tothe vietnamese civilians and American personnel exposed. Agent orange and the potent tear gasCS were not considered CW violations by U.S. policy makers since they did not have directmortal effects. U.S. policy did change, however. The 1968 Eighteen Nation DisarmamentCommittee in Geneva prompted Nixon's 1969 denouncement of BW's. The April 4th, 1972 U.S.and U.S.S.R. meeting in Geneva removed the "defensiveness" condition to previous BWagreements: 'never in any circumstance develop, produce, stockpile of otherwise acquire or retainany biological weapons'. 80 other nations followed in this declaration. The germs at Pine Bluffwere turned into harmless sludge; Nixon had apparently ended CBW's.

Unfortunately, this treaty lacked the provision for inspection of the other side's facilities and failedto restrict CBW research. Various incidents in the 70's and early 80's evidencing Russianpossession and actual use of CBW's in certain conflicts (Yemen, Afghanistan, Southeast Asia) ledto high level U.S. military conclusions that a policy of rearmament should be adopted. Soviet andWarsaw pact "chemical troop" capabilities were viewed as extensive and the "disarmamentdecade" appeared as a time of American standstill and Russian proliferation.

The 1980's have seen British and American troop readiness facilities open and continued weaponresearch. Binary weapons (weapons that contain two inactive compounds that when mixed form atoxic substance) have been developed to increase safety. Biologicals that employ recombinantmicroorganisms (example: cobra venom gene placed into influenza virus vector) are hypothesized. Plans to discard aging and corroding stockpiles are under proposal but have met opposition fromenvironmental and other civic groups. Growing CBW technology in third world nations as cheapalternatives to conventional or nuclear development also lend support to U.S. rearmament. Themajor political changes in the "communist" world may indeed hasten another period ofdisarmament, however, it seems that the seed of CBW's planted many years ago has no directionbut to grow.

The previous discussion is a condensation of A higher form of killing the secret story of chemical



and biological warfare by Robert Harris and Jeremy Paxman, Hill and Wang, New York, 1982.Its importance is to outline the decisions and history involved in the proliferation of CBW's. Thistext also demonstrates the strengths and shortcomings of the various treaties.

WEAPON DELIVERY

As partially discussed, any method imaginable may be used to deliver CBW's: Sprays, bombs,artillery, air delivery, ICBM, wind and water. Whatever the method of delivery, one must have inmind the enemy's objective. Contamination of an area makes it inhospitable for both aggressorand friendly troops. Meteorological conditions must be considered, wind for distribution as wellas temperature and humidity factors for speed of vaporization and persistence.

AGENTS

It is, perhaps, most convenient to consider the many available agents by groups according to thephysiologic system which is affected. This helps in terms of treatment of casualties as well. Thefollowing is the list of agents for consideration of toxicities and treatments.

Lethal Agents• Nerve AgentsØ GA (Tabun)Ø GB (Sarin)Ø GD (Soman)Ø VX

• Blood AgentsØ AC (Hydrogen Cyanide)Ø CK (Cyanogen Cl or cyanide)

Incapacitating Agents• Depressants - BZ• Hallucinogens - LSD

Blister Agents• H• HD (Mustard Compounds)• HN• L (Lewisite)• CX (Phosgene Oxime)

Lung Agents• Cl (Chlorine)• CG (Phosgene)



Riot Control• CA• CS• CN• CR• DM

Routes of entry may be inhalation, skin absorption, ingestion or tissue deposit through infection ofwounds. Symptoms depend of concentration of the agent, degree and length of exposure, andother factors.

LETHAL AGENTS

One could say that all agents are lethal if given in sufficient concentration. These particular agentsare lethal at relatively low (easy to achieve) concentrations.

Nerve Agents

Nerve agents are anticholinesterase compounds which may be carbonates such asphysostigmine,pyridostigmine or organophosphates such as parathion, malathion, tabun, sarin,soman, or VX. These result in the destruction of acetylcholinesterase at the synaptic junction (theenzyme responsible for breakdown of acetylcholine). Acetylcholine remains attached to the post synaptic fiber and continual neural discharge results in muscarinic, nicotinic and CNS effects.Muscarinic effects include: miosis, salivation, sweating, hastened GI motility (vomiting, cramps,diarrhea, secretion) and bronchoconstriction with pain, wheezing and secretions. Nicotinic stimulation effects skeletal muscle; fatigue, twitching, spasm and ganglia; BP and heart ratedecrease. CNS effects are more pronounced with agents that more effectively penetrate theblood-brain barrier and include; apprehension, restlessness, loss of concentration, long terminsomnia, emotional instability at sublethal doses, central respiratory depression, coma andconvulsions.

The order of appearance of symptoms reflects the route of exposure. Skin absorption may resultin early nausea, vomiting and diarrhea, whereas vapor inhalation may induce miosis, increasedpulmonary secretions and bronchoconstriction. Convulsions may be the first sign of massiveexposure.

Treatment of Nerve Agent exposure includes:• Protection from contamination• Decontamination with M-258 Kit-Clorox and water• Ventilation of the patient



• Cholinergic Blockade - Atropine• Restoration of acetylcholinesterase enzyme-Pralidoxime chloride(2-PAM)• Other; benzodiazapines for convulsions, fluid balance, and dysrrhythmias.

Cholinergic blockade with atropine works at muscarinic sites and may require massive doses.Generally 2-10 mg are used initially and the titrated to control secretions and chest tightness(pupil measurements are not accurate). The oximes are a class of compounds that have the abilityto complex with acetylcholinesterase bound nerve agents, resulting in their removal from the enzyme (this reactivates the enzyme). Pralidoxime chloride is the drug of choice, works best atnicotinic sites, and is supplied to troops as a 600 mg autoinjector. One gram slow IV may beused; side effects may include large rise in BP. "Aging" refers to permanent attachment of a nerveagent to the enzyme molecule and oxime must be used before this permanent inactivation occurs.Various agents have differing aging half lives.

Two mg Atropine and 600 mg 2-PAM-Cl are provided to each trooper in the form ofautoinjector, to be used on exposure to nerve gas. Other compounds and combinations are beinginvestigated for effectiveness, but so far Atropine and PAM provide the best protection. CANAhas been introduced for troop field use in the event of actually poisoning, in order to providesome protection against siezure. CANA is nothing more than 10 mg. benzodiazepam, and so hasabuse potential. Use of pyridostigmine by oral pretreatment has been introduced, and usedextensively during the Gulf War as a method of tying up the enzyme system with a relatively lesslethal and reversible Carbamate "poison" to protect against the more lethal organophosphates.From Malathion to thickened Soman, each is similar in action. The differences lie in vaporpressures, relative toxicities , "aging" and other such considerations. Insecticide poisoning is afairly common occurrence in Agricultural pilots in this country, and some very interesting casehistories are found in the medical literature. You should be aware, that exposures which "aged"in this group of people, requirred literaly GRAMS of atropine over days, titrated in to keepairway spasm under control.

Blood Agents

Cyanide in its several forms is the second group in the lethal category. Cyanide is highly volatile,hydrolyses in water, is affected by strong oxidants like permanganate and is not heat stable. It istherefor not easily delivered by artillery, and requires consideration of the atmospheric condition.On the other hand, it may be quite effective if rapid dispersal and early habitability of a site weredesired.

Toxicity of CN is due to combination in the blood with Methemoglobin to formcyanmethemoglobin. CN Met Hb basically ties up the cytochrome oxidase system preventingcertain crucial oxidation-reduction reactions, and uncouples cellular respiration. CN is readilyabsorbed through skin and mucosa in liquid form and may present a threat for lethality in such ascenario. Lethality from vapor would be likely only in confined spaces. So, while its effectivenessas a lethal agent may be thus diminished, it may certainly be effective in disruption of a man's



activities.

Treatment of cyanide exposure formerly consisted of Amyl Nitrate which works by formingMethemoglobin which effectively competes with cytochrome oxidase for the CN-ions. It is nolonger available in the chemical defense kits due to its abuse potential. Battlefield treatmentconsists of 10 cc of 3% Sodium nitrite over 1 minute, followed by 50 cc of Sodium thiosulfateslowly (I.V.). Sodium nitrite is itself lethal if given too rapidly or in higher concentrations.

Trials have been underway for some time, looking at organic cobalt and some of the aminophenols which offer some promise of protection.

Incapacitating agents:

Any chemical or drug which has the capability of producing short term effects in this category isfair game. Agents such as BZ, a potent anticholinergic, LSD, a psychotropic, or other compoundwhich is capable of incapacitation may be considered. If a chemical which produces nausea, orshort term memory impairment could be used, then there would be a general debilitation anddecreased capability to perform necessary combat functions.

BZ produces a short term memory impairment, body heat build up and loss of coordination aswould any anticholinergic. LSD, of course, acts as a hallucinogen, rendering the victim incapableof proper perception and judgement.

Treatment for these exposures is largely symptomatic. Physostigmine may be of some use inanticholinergics, but will not shorten the course nor reverse the effects.

Blister agents

The compounds in this group are direct vesicants,each with its own degree of corrosiveness.

Mustards

The mustard compounds may produce only minimal symptoms initially, but as vapors tend todissolve in water, the eyes are particularly involved as well as axillary and groin areas. Seriouslung damage also occurs as vapors are inhaled. After a latent period of up to 12 hours, severe painand blistering of the eyes, and skin occur, with cough, hoarseness and copious secretionsreflecting the respiratory tract damage. In addition to these direct injuries and since mustardcompounds are alkylating agents, there is a potential for interaction with many other tissues on along term basis. Particularly sensitive are the spleen, marrow, lymphatic and hematopoieticsystems. Because of the alkylating nature of these compounds, healing is delayed for weeks ormonths.

Treatment consists of rapid and complete decontamination as soon as possible with soap, water



and mild bleach. Scrubbing should be avoided, but blisters need to be drained because thecompound remains in blister fluids in sufficient quantity to cause additional tissue damage. Fromthere, treatment is as for any other burn for skin lesions, and medical management of therespiratory injuries and eyes.

Fig 5. Mustard casualty, WW I

Lewisite

Lewisite is a direct vesicant created by the British near the end of WWI for use in the field,although the war ended before its deployment. It is a chlorovinyl arsine which has effects similarto those seen with mustard exposure, except that there is immediate pain and burning on exposureand the skin burns are deeper than with mustards. Lewisite also acts as a system poison producingrestlessness, reduction in blood pressure and temperature as well as severe diarrhea, and is notdetoxified by the body.

Treatment of Lewisite exposure is essentially the same as for mustards. British Anti-Lewisite(BAL) was developed specifically for chelation and removal of this poison from the body.

Phosgene Oxime

The symptoms produced by exposure to Phosgene Oxime are immediate and intolerable pain oncontact with rapid destruction of tissue as is characteristic of rapidly corrosive chemicals. Thiscompound is very dangerous to handle and obviously affects all tissues similarly.

Treatment consists of rapid and thorough decontamination to prevent further injury and treatmentof the damage as one would any other similar injury.



Lung agents

Chlorine

The first of the war gases to be used, it still has potential for use to produce instant tearing,respiratory irritation, and if in sufficient concentration, death from suffocation due to copioussecretions.

Phosgene (Carbonyl Chloride)

Phosgene is not only a war gas, but is to found frequently as a result of pyrolysis of a number ofvinyl compounds and foams found in electrical wiring, furniture and decorations to name a few.This gas is produced as a result of aircraft fires as the plastics and vinyls are incinerated. Thecardinal feature of phosgene exposure is a delayed onset of pulmonary edema many hours later asthe phosgene hydrolyses in the lung producing hydrochloric acid. Respiratory embarrassment mayoccur during the night after exposure and requires careful observation.

Treatment of exposure to these agents is removal from exposure, administration of oxygen,monitoring, treatment of pulmonary edema and supportive care. Use of steroids remainscontroversial as with any pulmonary edema, but may decrease mortality. Blood gases and chestx-ray are very helpful in monitoring the patient's status if such is available to you in the field.

Riot control agents

Of the several agents in this category, perhaps the best known is CS, or tear gas. These agents arenot meant to produce any injury or long term effects, nor are they intended to. Their purpose issimply to disperse crowds when it becomes necessary to control riots. Whether their mechanismof action is to produce tearing or nausea and vomiting, they share a rapid onset of action and noresidual side effects. Clearly, people with other respiratory conditions or those unable to escapehigh concentrations of these compounds would be at risk for more serious injury.

Treatment is simply removal from exposure and perhaps some local decontamination with flushingof the eyes.

CHEMICAL DETECTION ANDDECONTAMINATION EQUIPMENT

M-43 - Airborne Agent detector



A very sensitive electronic device, which may be hooked to an alarm unit, giving earlywarning of the existence of vapor.

XM-272 - Water test kit

This kit provides simple colorimetric reactions for nerve agents, cyanide, and blister agents.

M-256 - Chemical Agent Detector Ticket.

A multiple stepwise reagent test in crushable ampoules in a single card which can detectcyanide, phosgene oxime, mustard and nerve agents.

M-9 - Chemical agent detector paper.

A quick color test on heavy paper which will detect all known liquid agents, thereby beinguseful for droplet or mist evaluation. The problem is it also reacts with some solvents,lubricants, and, of course, commercial insecticides.

DS-2 - Decontaminating agentNaOH is the major of three components of this mixture, so it is somewhat corrosive toequipment and personnel. It can be used to quite rapidly decontaminate all CW agents in use.

M-291 Resin Decontaminating KitThis relatively new decontamination material is a combination of an ion exchange resin,chemical adsorbant and polystyrene polymer which serves to both neutralize and adsorbchemical contaminants from the skin.

XM-16 - A truck mounted, Jet powered, mobile, decontaminating apparatus.These units using DS-2 and water rinse may be used to quickly decontaminate large vehiclesand other pieces of equipment by simply driving them through the spray.

"FOX" VEHICLEA vehicle now manned and staffed by chemical warfare specialists, on call for use whereverchemical weapons may be detected. These vehicles use the M-43, M-256 and other standarddetection devices, but are unique in the fact that they use a min- mass spectrometer fordefinitive identification of chemical agents and recording capability.

INDIVIDUAL PROTECTIVE CLOTHING

The individual's gear is sometimes called; NBC gear, for Nuclear Biological and Chemical, CBRfor Chemical, Biological and Radiological, and is also referred to as "MOPP" gear, for MissionOriented Protective Posture. Whoever thought that one up was clearly a paper planner, trying to



use a term reflective of different chemical battleground scenarios.

Individual protective NBC clothing consists of:

1 package trousers and jacket1 pair cotton glove liners1 pair butyl rubber gloves1 pair butyl rubber overboots with tie1 Mask with filters1 Butyl rubber hood

There are variations to each piece of gear depending on tasks to be performed by individuals, sothere are several different types of masks, several different types of jackets, trousers, and so forth.The above list is what field troops are issued. Each individual is issued the gear listed and has asecond package with jacket and trousers held in reserve somewhere in the rear. Use of thisequipment in the field is where the term Mission Oriented Protective Posture (MOPP) is derived,and is supposed to give the greatest flexibility while at the same time minimizing risk of exposureshould the need arise to suit up. The time given to suit up is three minutes. However, missioncommanders may use several different levels of preparedness depending upon the threatpresented. Some of the chemical protective gear, particularly the drugs, were listed in the medicaldepartment's authorized medical allowance list. The Seabee Logistics Command is now re-organizing all gear under control of the CBR officer, which is more appropriate. Recently, CBRgear and funding was taken over by an established joint services office, which will attempt tostandardize clothing and masks throughout the services rather than each going off in differentdirections. Because of funding constraints, the new Advanced Chemical Protective Garment(ACPG) and a new mask design will be delayed, with replacements currently predicted to appearin mid-1999. Until then, there are several different masks and suits in the system. Becomeacquainted with your unit's protective gear.

MOPP Levels:

I Suit on, carry boots, gloves, and mask.II Suit on, boots on, carry gloves and mask.III Suit on, boots and mask on, carry gloves.IV All equipment on.

Aboard ship, exposure to chemical weapons results in personnel going inside, pressurization ofspaces (The citadel concept) , steering around the cloud, and then decontamination of the vesselby a team from the Damage Control Division. Meanwhile, on the inside, sailors have donned M17masks and MkIII suits as needed.

In a very simplistic way, this is the scenario for how NBC gear is supposed to work: a. alarmsounds, b. troops don protective gear, c. troops continue battle in chemical environment, and d.



friendly forces emerge victorious. The reality is that there are enormous deficiencies in protectionprovided by the equipment, and logistical problems which are equally complicated.

GEAR PROBLEMS

Mask• Filters are difficult to change at best, and next to impossible in a contaminated environment.

• Visibility through the eyepieces is poor.

• Insets for corrective lens wearers is very poor.

• Lenses fog easily

• Speech is rather unintelligible

• Hearing is slightly impaired

• Weapon sighting is very difficult

Hoods• These do not form a good seal. Vapors get in beneath hood easily.

Boots and gloves• Difficult to put on• Hot• Loss of delicate function of hands• Loss of sense of feel

Suit (Nylon/charcoal/nylon sandwich)• Bulky• Heat builds up rapidly• The suit loses its protective capacity in 14 days if the package is opened and exposed to

ambient air (the charcoal works very well), six to twelve hours in a chemical environment, orif it becomes wet, and acts like a sponge.

GENERAL LIMITATIONS ANDUSER COMPLAINTS

• Too hot/heat casualties• Unable to work/walk far• Unable to eat or drink (except M17-A1)



• Inability to relieve oneself• Respiratory exchange through filter limits high levels of exertion.

The medical department does not have sufficient personnel to deliver casualties to the aid station.This is done by ship's company or combat troops. Facility sites should be selected to takemaximum advantage of protective terrain and should be upwind of any chemical contamination. Aline must be drawn to separate dirty from clean areas, and must not be crossed by anyone who hasnot been completely decontaminated.

TRIAGE OF CASUALTIES

Casualties brought to a battalion aid station may be chemical, traumatic or both. All must besuspected of contamination which certainly complicates an already difficult situation. Unstablepatients may need to be stabilized before anything else is done. Not an easy task if he iscontaminated and in MOPP gear, and the person trying to administer to his needs is alsoencumbered by his own gear. A simple task like opening a package or starting an I.V. becomesoverwhelmingly difficult.

Once stable, the patient is decontaminated by specific procedures, undressed, and passed acrossthe clean line for definitive care. Even a moment's thought should alert you to the difficulties ofhandling even a few casualties. It is absolutely imperative that the flight surgeon participate inregularly scheduled training exercises to begin to understand the scope of the problem.

Decontamination of Casualties

The following discussion of decontamination is from the United States Army Medical ResearchInstitute of Chemical Defense: Medical Management of Chemical Casualties Handbook, SecondEdition, Chemical Casualty Care Office, Aberdeen Proving Ground, MD 21010-5425. For amore detailed discussion of specific chemicals, consult Virtual Naval Hospital CD or their websiteat www.vnh.org. Setting up a field decontamination site is covered very nicely in FM 3-5,Chapter 9.

OverviewCertification of DecontaminationMethods of Decontamination Physical Removal Chemical MethodsWound DecontaminationConclusions

Overview



Decontamination is the reduction or removal of chemical agents. Decontamination may beaccomplished by removal of these agents by physical means or by chemical neutralization ordetoxification. Decontamination of skin is the primary concern, but decontamination of eyes andwounds must also be done when necessary. Personal decontamination is decontamination of self;casualty decontamination refers to the decontamination of casualties; and personneldecontamination usually refers to decontamination of non-casualties. The most important andmost effective decontamination of any chemical exposure is that decontamination done within thefirst minute or two after exposure. This is self-decontamination, and this early action by thesoldier will make the difference between survival (or minimal injury) and death (or severe injury).Good training can save lives.

Decontamination of casualties is an enormous task. The process requires dedication of both largenumbers of personnel and large amounts of time. Even with appropriate planning and training therequirement demands a significant contribution of resources. Liquids and solids are the onlysubstances that can be effectively removed from the skin. It is generally not possible or necessaryto decontaminate vapor. Removal from the atmosphere containing the vapor is all that is required.Many substances have been evaluated for their usefulness in skin decontamination.

The most common problems with potential decontaminants are irritation of the skin, toxicity,ineffectiveness, or high cost. An ideal decontaminant will rapidly and completely decontaminateall known chemical and biological warfare agents. Furthermore, a suitable skin decontaminantmust have certain properties that are not requirements for decontaminants for equipment.Recognized desirable traits of a skin decontaminant include:

Neutralization of all agents Safety (compound to be both nontoxic and noncorrosive) Ease of application by hand Readily available Rapid action Nonproduction of toxic end products Stability in longterm storage Shortterm stability (after issue to unit/individual) Affordability Nonenhancement of percutaneous agent absorption No irritability Hypoallergenicity Ease of disposal

Decontamination issues have been explored since the beginning of modern chemical warfare.After years of research worldwide, simple principles which consistently produce good results stillapply.The first, which is without equal, is timely physical removal of the agent. To remove the substanceby the best means available is the primary objective. Chemical destruction (detoxification) of the



offending agent is a desirable secondary objective. Physical removal is imperative because none ofthe chemical means of destroying these agents do so instantaneously. While decontaminationpreparations such as fresh hypochlorite react rapidly with some agents (e.g., the halftime fordestruction of VX by hypochlorite at a pH of 10 is 1.5 minutes), the half-times of destruction ofother agents, such as mustard, are much longer. If a large amount of agent is present initially, alonger time is needed to completely neutralize the agent to a harmless substance. Decontaminationstudies have been conducted using common household products. The goal of these studies wasidentification of decontaminants for civilians as well as field expedients for the soldier. Timely useof water, soap and water, or flour followed by wet tissue wipes produced results equal, nearlyequal, or in some instances better than those produced by the use of Fuller's Earth, DutchPowder, and other compounds. (Fuller's Earth and Dutch Powder are decontamination agentscurrently fielded by some European countries.) This is easily understood because 1) no topicaldecontaminant has ever shown efficacy with penetrated agent, 2) agents in large enough quantity,especially vesicants, may begin penetrating the skin before complete reactive decontamination(detoxification) takes place, and 3) early physical removal is most important.

Military personnel may be questioned for guidance by local civilian authorities or may deal withsupply shortages in the field. Knowledge of the U.S. doctrinal solutions may not suffice in thesesituations, and awareness of alternative methods of decontamination will prove very beneficial.However, it is not so much what method is used, rather it is how and when it is used. Chemicalagents should be removed as quickly and completely as possible by the best means available.The M291 resin kit and 0.5% hypochlorite for casualty decontamination are stateoftheart. TheM291 kit is new, whereas hypochlorite has been around since World War I. The M291 kit is thebest universal dry decontaminant for skin. Fresh 0.5% hypochlorite solution with an alkaline pH isthe best available universal liquid decontaminating agent. Liquids are best for large or irregularsurface areas. Hypochlorite solutions are well suited for medical treatment facilities with adequatewater supplies. For hypochlorite to be the best universal liquid skin decontaminant it has to berelatively fresh (made daily or more frequently, particularly in a warm environment whereevaporation will occur) and at a concentration of 0.5% at an alkaline pH. Hypochlorite solutionsare for use on skin and soft tissue wounds only. Hypochlorite should not be used in abdominalwounds, in open chest wounds, on nervous tissue, or in the eye.

Surgical irrigation solutions should be used in liberal amounts in the abdomen and chest. All suchsolutions should be removed by suction instead of sponging and wiping. Only copious amounts ofwater, normal saline, or eye solutions are recommended for the eye. Contaminated wounds will bediscussed later.

The M291 resin kit is best for spot decontamination of skin only. It rapidly adsorbs the chemicalagent with carbonaceous material physically removing the agent from skin contact. Later an ionexchange resin neutralizes the offending agent by chemical detoxification. Since the M291 kit issmall and dry and easily carried by the soldier, it is well suited for field use. It will be the earlyintervention with the use of this kit that will reduce chemical injury and save life in most cases.Decontamination of the casualty using an M291 kit does not obviate the need for decontamination



at a field facility. The decontamination station is more conducive to thorough decontamination.Chemical agent transfer is a potential problem that can be resolved by a second deliberatedecontamination. Decontamination at the medical treatment facility prevents spread of the agentto areas of the body previously uncontaminated, contamination of personnel assisting the patient,and contamination of the medical facility.

Certification of DecontaminationCertification of decontamination is accomplished by any of the following: processing through thedecontamination facility; M8 paper; M9 tape; M256A1 ticket; or by the CAM (Chemical AgentMonitor). If proper procedure is followed the possibility of admitting a contaminated casualty tofield medical facility is extremely small. The probability of admitting a dangerously contaminatedcasualty is miniscule to non-existent. Fear is the worst enemy, not the contaminated soldier.

Methods of DecontaminationThree basic methods of decontamination are physical removal, chemical deactivation, andbiological deactivation of the agent. Biological deactivation has not been developed to the pointof being practical.

Physical RemovalSeveral types of physical and chemical methods are at least potentially suitable fordecontaminating equipment and material. Flushing or flooding contaminated skin or material withwater or aqueous solutions can remove or dilute significant amounts of agent. Scraping with awooden stick, i.e., a tongue depressor or popsicle stick, can remove bulk agent by physical means.For the decontamination of clothing only, adsorbents and containment materials (to be used onouter garments before their removal and disposal) have been considered. A significant advantageof most physical methods is their nonspecificity. Since they work nearly equally well on chemicalagents regardless of chemical structure, knowledge of the specific contaminating agent or agentsis notrequired.

Flushing with Water or Aqueous SolutionsWhen animal skin contaminated with GB was flushed with water (a method in which physicalremoval predominates over hydrolysis of the agent), 10.6 times more GB was required to producethe same mortality rate as when no decontamination occurred. In another study, the use of wateralone produced better results than high concentrations of hypochlorite (i.e., 5.0% or greater,which are not recommended for skin). Timely copious flushing with water physically removes theagent and will produce good results.

Adsorbent MaterialsAdsorption refers to the formation and maintenance of a condensed layer of a substance, such as achemical agent, on the surface of a decontaminant as illustrated by the adsorption of gases bycharcoal particles and by the decontaminants described in this section. Some NATO nations useadsorbent decontaminants in an attempt to reduce the quantity of chemical agent available for



uptake through the skin. In emergency situations dry powders such as soap detergents, earth, andflour, may be useful. Flour followed by wiping with wet tissue paper is reported to be effectiveagainst GD, VX and HD.

M291 ResinThe current method of battlefield decontamination by the individual soldier involves the use of acarbonaceous adsorbent, a polystyrene polymeric, and ion exchange resins (M291). The resultantblack resin is both reactive and adsorbent. The M291 Kit has been extensively tested and provenhighly effective for skin decontamination. It consists of a wallet-like carrying pouch, containing 6individual decontamination packets. Each packet contains a non-woven fiber-fill laminated padimpregnated with the decontamination compounds. Each pad provides the individual with a singlestep, non-toxic/non-irritating decontamination application, which can be used on the skin,including the face and around wounds. Instructions for use are marked on the case and packets.The individual decontamination pads are impregnated with the decontamination compound"Ambergard XE-555 Resin", which is the black, free-flowing, resin based powder. As the pad isscrubbed over the contaminated skin the chemicals are rapidly transferred into and trapped in theinterior of the resin particles. The presence of acidic and basic groups in the resin promotes thedestruction of trapped chemical agents by acid and base hydrolysis. Because the resin is black itmaps out the areas that have been decontaminated.

Chemical MethodsThree types of chemical mechanisms have been used for decontamination: water/soap wash;oxidation; and acid/base hydrolysis. HD (mustard) and the persistent nerve agent VX containsulfur molecules that are readily subject to oxidation reactions. VX and the other nerve agents(GA, GB,GD, and GF) contain phosphorus groups that can be hydrolyzed. Therefore, most chemicaldecontaminants are designed to oxidize HD and VX and to hydrolyze nerve agents (VX and the Gseries).

Water/Soap WashBoth fresh water and sea water have the capacity to remove chemical agents not only throughmechanical force but also via slow hydrolysis; however, the generally low solubility and slow rateof diffusion of CW agents in water significantly limit the agent hydrolysis rate. The predominanteffect of water and water/soap solutions is the physical removal or dilution of agents; however,slow hydrolysis does occur particularly with alkaline soaps. In the absence of hypochloritesolutions or other appropriate means of removing chemical agents, these methods are consideredreasonableoptions.

Oxidation/Hydrolysis



The most important category of chemical decontamination reactions is oxidative chlorination.This term covers the "active chlorine" chemicals like hypochlorite. The pH of a solution isimportant in determining the amount of active chlorine concentration. An alkaline solution isadvantageous.Hypochlorite solutions act universally against the organophosphorus and mustard agents.Both VX and HD contain sulfur atoms that are readily subject to oxidation. Current doctrinespecifies the use of a 0.5% sodium or calcium hypochlorite solution for decontamination of skinand a 5% solution for equipment.

HydrolysisChemical hydrolysis reactions are of two types: acid and alkaline. Acid hydrolysis is of negligibleimportance for agent decontamination because the hydrolysis rate of most chemical agents isslow, and adequate acid catalysis is rarely observed. Alkaline hydrolysis is initiated by thenucleophilic attack of the hydroxide ion on the phosphorus atoms found in VX and the G agents.The hydrolysis rate is dependent on the chemical structure and reaction conditions such as pH,temperature, the kind of solvent used, and the presence of catalytic reagents. The rate increasessharply at pH values higher than 8 and increases by a factor of four for every 10oC rise intemperature. Several of the hydrolytic chemicals are effective in detoxifying chemical warfareagents; unfortunately, many of these (e.g., NaOH) are unacceptably damaging to the skin.Alkaline pH hypochlorite hydrolyzes VX and the G agents quite well.

Wound DecontaminationAll casualties entering a medical unit after experiencing a chemical attack are to be consideredcontaminated unless there is certification of non-contamination. The initial management of acasualty contaminated by chemical agents will require removal of MOPP and decontaminationwith 0.5% hypochlorite before treatment within the field treatment facility.

Initial DecontaminationDuring initial decontamination in the decontamination areas bandages are removed and thewounds are flushed; the bandages are replaced only if bleeding recurs. Tourniquets are replacedwith clean tourniquets and the sites of the original tourniquets decontaminated. Splints arethoroughly decontaminated, but removed only by a physician. The new dressings are removed inthe operating room and submerged in a 5% solution of hypochlorite or placed in a plastic bag andsealed.

General ConsiderationsOf the agents discussed, only two types, the vesicants and nerve agents, might present a hazardfrom wound contamination. Cyanide is quite volatile so it is extremely unlikely that liquid cyanidewill remain in a wound, and it requires a very large amount of liquid cyanide to produce vaporadequate to cause effects.Mustard converts to a cyclic compound within minutes of absorption into a biological milieu, andthe cyclic compound rapidly (minutes) reacts with blood and tissue components. These reactionswill take place with the components of the wound--the blood, the necrotic tissue, and the



remaining viable tissue. If the amount of bleeding and tissue damage is small, mustard will rapidlyenter the surrounding viable tissue where it will quickly biotransform and attach to tissuecomponents (and its biological behavior will be much like an intramuscular absorption of theagent).

Although nerve agents cause their toxic effects by their very rapid attachment to the enzymeacetylcholinesterase, they also quickly react with other enzymes and tissue components. As theydo with mustard, the blood and necrotic tissue of the wound will "buffer" nerve agents. Nerveagent that reaches viable tissue will be rapidly absorbed, and since the toxicity of nerve agents isquite high (a lethal amount is a small drop) it is unlikely that casualties who have had much nerveagent in a wound will survive to reach medical care. Potential risk to the surgeon from possiblycontaminated wounds arises from agent on foreign bodies in the wound and from thickenedagents.

Thickened AgentsThickened agents are chemical agents that have been mixed with another substance (commonly anacrylate) to increase their persistency. They are not dissolved as quickly in biological fluids, norare they absorbed by tissue as rapidly as other agents. VX, although not a thickened agent, isabsorbed less quickly than other nerve agents and may persist in the wound longer than othernerve agents.Thickened agents in wounds require more precautions. Casualties with thickened nerve agents inwounds are unlikely to survive to reach surgery. Thickened HD has delayed systemic toxicity andcan persist in wounds even when the large fragments of cloth have been removed. Though thevapor hazard to surgical personnel is extremely low, contact hazard from thickened agents doesremain and should always be assumed.No country is currently known to stockpile thickened agents. In a chemicalattack, the intelligence and chemical staffs should be able to identifythickened agents and to alert the medical personnel of their use.

OffGassingThe risk from vapor offgassing from chemically contaminated shrapnel and cloth in wounds isvery low and not significant. Further, there is no vapor release from contaminated woundswithout foreign bodies. Offgassing from a wound during surgical exploration will be negligible(or zero). No eye injury will result from off-gassing from any of the agents. A chemical-protectivemask is not required for surgical personnel.

Foreign MaterialThe contamination of wounds with mustard or nerve agents is basically confined to the foreignmaterial (e.g., BDU and protective garment in the wound). The removal of this cloth from thewound effectively eliminates the hazard. There is little chemical risk associated with individualfibers left in the wound. No further decontamination of the wound for chemical agent is necessary.

Wound Contamination Assessment



The CAM (Chemical Agent Monitor) can be used to assist in locating contaminated objects withina wound; however, 30 seconds are required to achieve a bar reading. The CAM detects vapor, butmay not detect liquid (a thickened agent or liquid on a foreign body) deep within a wound. Asingle bar reading on CAM with the inlet a few millimeters from the wound surface indicates thata vapor hazard does not exist.

HypochloriteDiluted hypochlorite (0.5%) is an effective skin decontaminant for patient use. The solutionshould be made up fresh daily with a pH in the alkaline range. Plastic bottles containing 6 ouncesof calcium hypochlorite are currently fielded for this purpose. Hypochlorite solution iscontraindicated for the eye. This substance may result in corneal opacities. It is also notrecommended for brain and spinal cord injuries. Irrigation of the abdomen may lead to adhesionsand is therefore also contraindicated. The use of hypochlorite in the thoracic cavity may be less ofa problem, but the hazard is still unknown.

Wound Exploration/DebridementSurgeons and assistants are advised to wear a pair of well fitting (thin) butyl rubber gloves ordouble latex surgical gloves and to change them often until they are certain there are no foreignbodies or thickened agents in the wound. This is especially important where puncture is likelybecause of the presence of bone spicules or metal fragments.

The wound should be explored with surgical instruments rather than with fingers. Pieces of clothand associated debris must not be examined closely, but quickly disposed of in a container of 5%hypochlorite. The wound can then be checked with the CAM which may direct the surgeon tofurther retained material. It takes about 30 seconds to get a stable reading from the CAM. A rapidpass over the wound will not detect remaining contamination. The wound is debrided and excisedas normal, maintaining a no-touch technique. Removed fragments of tissue are dropped intohypochlorite. Bulky tissue such as an amputated limb should be placed in a plastic or rubber bag(chemical proof) which is then sealed. Hypochlorite solution (0.5%) may be instilled into deepnon-cavity wounds following the removal of contaminated cloth. This solution should be removedbysuction to an appropriate disposal container. Within a short time, i.e., 5 minutes, thiscontaminated solution will be neutralized and nonhazardous. Subsequent irrigation with saline orother surgical solutions should be performed.

Penetrating abdominal wounds caused by large fragments or containing large pieces of chemicallycontaminated cloth will be uncommon. Surgical practices should be effective for the majority ofwounds in identifying and removing the focus of remaining agent within the peritoneum. Whenpossible the CAM may be used to assist. Saline, hydrogen peroxide, or other irrigating solutionsdo not necessarily decontaminate agents, but may dislodge material for recovery by aspirationwith a large bore sucker. The irrigation solution should not be swabbed out manually with surgicalsponges. The risk to patients and medical attendants is minuscule. However, safe practice



suggests that any irrigation solution should be considered potentially contaminated. Followingaspiration bysuction the suction apparatus and the solution should be disposed of in a solution of 5%ypochlorite. Superficial wounds should be subjected to thorough wiping with 0.5% hypochloriteand subsequent irrigation with normal saline.

Instruments that have come into contact with possible contamination should be placed in 5%hypochlorite for 10 minutes prior to normal cleansing and sterilization. Reusable linen should bechecked with the CAM, M-8 paper, or M-9 tape for contamination. If found to be contaminated itshould be disposed of in a 5-10% hypochlorite solution.

ConclusionsDecontamination at the medical treatment facility is directed toward (1) eliminating any agenttransferred to the patient during removal of protective clothing; (2) decontaminating or containingof contaminated clothing and personal equipment; and (3) maintaining an uncontaminatedtreatment facility. Current doctrine specifies the use of 0.5% hypochlorite solution or the M291Kit for contaminated skin. These are both state-of-the-art decontamination preparations, one oldand one new.

Fabric and other foreign bodies that have been introduced into a wound have the capacity tosequester and slowly release chemical agent presenting a liquid hazard to both the patient andmedical treatment personnel. There is no vapor hazard to surgical personnel. Protective masks arenot necessary.

REFERENCES

For specific procedures in establishing field medical facilities, and decontamination stations andtheir operation, the reader is referred to the Medical Management of Chemical Casualtieshandbook (available also on the Virtual Naval Hospital CD or their website at www.vnh.org) ,FMF 4-5, Medical and Dental Support (Marine Corps) and NAVMED P-5041, Treatment ofChemical Agent Casualties and Conventional Military Chemical Casualties.

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