Page 18 - Chiron Calling Spring 2017

16 CHIRON CALLING
Blot, Bang, Rub – A Sinister History of Chemical Warfare:
Major Drew Tootal RAVC, SO2 Veterinary Science, Dstl Porton Down
It was early evening in Ypres on the 22nd April 1915. There was an eerie stillness in the trenches. No bird song could be heard on the gentle evening breeze, and the exhausted French Colonial soldiers talked in hushed tones to each other, if they could even bring themselves to talk at all. The day had started like so many others, with a nerve-shredding artillery bombardment from the German lines that had lasted much of the day. It was quiet now though, and the breeze felt good as it breathed across No-Man’s Land.
The sentries, previously in a low state of alert, stiffened and began murmuring to themselves as the wind changed colour, somewhere towards the German trenches. A greenish-yellow cloud was starting to drift slowly towards them. Calls down the line alerted the occupants of the trenches, and their unease turned quickly to stomach-churning fear as they rst caught the distinctive pepper and pineapple smell of the chlorine gas. The smell became stronger, stinging their eyes and burning their throats as, in their panic, they breathed the poison cloud in. With no knowledge of what it was that was attacking them, the soldiers panted in terror as the chlorine reacted with the water in their lungs, producing hydrochloric acid and destroying the fragile tissue, releasing vast quantities of uid until they nally succumbed and death took them.
A dramatisation perhaps, but based on fact. On 22 April 1915, the German Army released 168 tonnes of chlorine gas from nearly 6,000 cylinders in the rst massive, and successful, use of chemical weapons in modern warfare (Heller 1984). The resulting gas cloud caused a breach along nearly 4 miles of the French trenches, affecting nearly 10,000 soldiers, half of whom died within hours of the attack (Duffy 2009). The German Army, perhaps surprised by the effectiveness of their weapon, failed to exploit the breach and the Allies held most of their positions.
22 April 1915 was the start of what became known as the second battle of Ypres, and heralded the start of a chemical arms race with each side investigating, and utilising, ever more deadly substances in what is occasionally termed the “Chemist’s War”.
The stalemate of the trenches, availability and expense of explosives, and logistical dif culty in moving around the battlespace were all undoubtedly drivers in the development of a variety of new chemical weapons.
Choking Agents:
Choking agents are delivered as gas clouds to a populated area, causing death by damaging the lining of the lungs and causing the initiation of massive in ammation which causes the lungs to ll with uid and thus asphyxiate the casualty. They are sometimes also referred to as Lung Damaging Agents.
Following the rst use of chlorine it became apparent that its effectiveness was somewhat hit and miss, and casualty rate depended on wind direction, position in the trenches (those at the bottom of trench systems tended to be worse affected due to settling of gas), and there was a not insigni cant risk to those releasing the gas. However, its rst effective use resulted in the
Horses under gas treatment at the Vet Hospital, Abbeville (Photo courtesy of IWM)
development of more potent agents, lethal in smaller doses and in shorter timeframes. Phosgene is one such gas, colourless and with a more subtle smell, the identi cation of an attack became much more dif cult and while not as well-known as some of the other chemical agents used in World War 1 (WW1), it is thought to have caused approximately 80% of the 100,00 fatalities due to chemical weapons during wartime operations (Schneider 2016).
Blister Agents:
Agents that can be delivered in either vapour or liquid form, blister agent use became widespread during WW1. Probably the most well-known agent is sulfur mustard, often known as mustard gas. Blister agents burn any biological material they come in contact with, skin, eyes, and lungs all being affected, and not just in humans (see Figures 1 and 2). Severity of effects would depend on concentration and location of exposure. The agents would cause massive debilitating blisters on the skin, and would cause excruciating pain in the areas of lung that were exposed. Victims could be suffering the effects for weeks after an attack.
While widely used, blister agents did not cause the fatality rate of the choking agents and their effects are mainly to cause injury and debilitation, overwhelming both medical and logistical chains.
Choking agent attacks tended to be of short duration as once dispersed by the wind their toxic action would rapidly wane. Blister agents, especially when used in liquid form, were much more tenacious and could be used as area denial weapons. That said, without very effective protective equipment, the area denial would be to both sides.
Nerve Agents:
For this group of agents we travel forward in time to the 1930s, where German chemists working for large chemical corporations synthesised the rst highly toxic organophosphorus compounds. Initially developed for use as pesticides, their development from one of the rst agents Tabun (called GA) to Sarin (GB), to Soman (GD) was one of increasing toxicity. Such were their levels of production that at the end of World War 2 (WW2), many thousands of tonnes of these agents were seized by the Allies.
The interest in nerve agents continued after WW2 and led to the development of even more toxic agents, the most infamous of which was VX. This agent, developed by the Americans, was more stable than the G-series agents (G being for German under the American nomenclature) and VX (the V standing for Venom) is ten times more potent than Sarin and has the dubious honour of being the most toxic substance ever produced. The eagle-eyed will note an absence of an agent called GC. One story, which may or may not be apocryphal, is that when naming the agents, GC was already taken by the medical chain as an abbreviation for Gonococcus. This is an alternative name for Neisseria gonorrhoeae, the causative bacteria for gonorrhoea! Perhaps the powers that be decided it would be confusing, or inappropriate, to talk of GC attacks?
Nerve agents, deliverable in both liquid and gaseous form, act by disabling the chemicals at nerve endings which turn off a nerve impulse. The resulting hyperactivation results intense sweating, lling of airways with mucous and uid, blurred vison, uncontrollable vomiting, convulsions and nally death from paralysis and respiratory failure. Death can occur within minutes from the inhalation of small quantities of vapour, or within hours from a single tiny drop to the skin.
This small selection of many, many agents has an interesting timeline of usage. The rst German use of chlorine provoked outcry among many nations as the use of poison, and poison weapons, had been outlawed by the 1899 Hague Declaration Concerning Asphyxiating Gases, and the 1907 Hague Convention on Land Warfare. Germany quickly argued that the Hague treaties only banned the use of chemical shells and projectiles, and that the release of chlorine had been from gas canisters. A technicality that led to open season on chemical warfare by all sides. By the conclusion of WW1, some 1.3 million casualties were attributable to chemical warfare (Duffy 2009). The following years saw periodic small scale use but nowhere near the scale and duration of the