Q. What are chemical war fare agents (Chemical weapons)? How they are harmful to human health and environment? [43 BPSC/2001]
Ans:
Chemical war fare agents or Chemical weapons are specialised munitions that deliver chemicals that inflict death or injury on humans through chemical actions. Because they are relatively cheap and easy to produce, chemical weapons are referred to as the “poor man’s bomb”. Among the most commonly used chemical weapons are mustard gas, phosgene, chlorine, and the nerve agents Sarin and VX. ©crackingcivilservices.com
Important types:
- Non-lethal:
- Harassing agents:These are substances that are not intended to kill or injure. They are often referred to as Riot Control Agents (RCAs).
- Tear agents: These sensory irritants produce immediate pain to the eyes and irritate mucous membranes. e.g. Benzyl chloride, Benzyl bromide
- Vomiting agents: These sensory irritants are also termed sternators or nose irritants. They irritate the mucous membranes to produce congestion, coughing, sneezing etc.
- Malodorants: These are compounds with a very strong and unpleasant smell.
- Incapacitating agents: produce debilitating effects with limited probability of permanent injury or loss of life.
- Riot control agents: Cause tears, coughing and irritation to eyes, nose, mouth and skin; constrict airway and shut eyes; teargas and pepper spray are examples of such agents.
- Lethal agents:
- producing chemical casualties without regard to long-term consequences or loss of life. e.g.
- Blister agents: These are chemical compound that irritates and causes injury to the skin.
- Examples: sulphur mustard, nitrogen mustard , phosgene oxime, Lewisite.
- Blood agents ( metabolic poisons): Cyanide destroys ability of blood tissues to utilise oxygen, causing them to ‘starve’ and strangling the heart. Examples include hydrogen cyanide, cyanogen chloride, Arsine, VX
- Choking agents (lung irritants and cause injury to the lung-blood barrier resulting in Asphyxia). Examples include chlorine, phosgene, diphosgene and chloropicrin.
- Nerve agents: Disrupt the chemical communications through the nervous system. The eventual exhaustion of muscles leads to respiratory failure and death.e.g. ‘Sarin gas,’ ‘Mustard gas,tabun, and soman etc.
- The most dangerous of these are nerve agents (GA, GB, GD, and VX) and vesicant (blister) agents.
Some chemical war fare agents and its harmful effect to human health and environment:
- Sarin: Odourless, colourless agent is extremely potent. Even trace amounts can kill humans, but its threat after being released in the atmosphere is short-lived.
- The UN had confirmed the use of Sarin in the deaths of hundreds in a rebel-held Damascus suburb in 2013.
- It was originally developed in 1938 in Germany as a pesticide.
- It can contaminate food, water, and agricultural products in liquid spray form. It can be dispersed using water spray.
- Sarin is known to cause death in freshwater fishes which still have adequate amounts to pose a threat to persons upon consumption.
- Mustard gas: It was widely used in World War I, and gets its name from its distinctive odour of rotten mustard.
- It is slow acting, and about 5% to 10% of people exposed to it usually die.
- It can contaminate food, water, and agricultural products in liquid spray form.
- During the Iran-Iraq war, Iraq used mustard gas and Sarin over Kurdish population. The attack is thought to have killed up to 5,000 civilians.
- VX: It is odourless, and appears as a brownish oily substance.
- It is very persistent once in the atmosphere, it is slow to evaporate, and thus tends to cause prolonged exposure.
- This is the nerve agent that was used in the assassination of Kim Jong-nam, half-brother of North Korean leader Kim Jong-un this February, 2017.
- Novichok: These are dispersed in ultra-fine powder instead of gas or vapour. is said to be 5-8 times more lethal than VX nerve agent and its effects are rapid, usually within 30 seconds to 2 minutes.
- Chlorine gas: It isa choking agent. Its greenish-yellow clouds of gas cause shortness of breath, wheezing, respiratory failure, irritation in the eyes, vomiting, and sometimes death.
- Napalm and Agent Orange is a chemical defoliant which was used by USA during Vietnam war to open forests. Napalm also constituted a vast amount of environmental destruction in the quest to rob the enemy of their cover and concealment.
- Napalm is a form of gelled petroleum that burns extremely hot and for long periods of time. It was used extensively to clear forests by burning them to the ground.
- Tabun is a nerve agent. An amount of between 1 to 10 mL in contact with skin can be fatal. Eye exposure causes pinpoint pupils, redness of the membrane, pain and irritation of the eye, blurred vision, nausea and vomiting. Ingestion results in nausea, vomiting, diarrhea, abdominal pain, and cramping.
- It can contaminated the air, water, food, and agricultural products as a liquid spray. Tabun can be dispersed using water spray.
- Severe intoxication is manifested by salivation, involuntary defecation and urination, sweating, lacrimation, bradycardia and hypotension, respiratory depression, collapse, convulsions, and death. The proximal cause of death is respiratory failure.
- The nerve agents have very high potency to contaminate water as small quantities can produce toxic symptoms from ingestion
- If Mustard gas spilled into seawater, it would sink and remain on the bottom, where it would slowly dissolve.
- Mustard gas is considered fairly persistent in the environment.
- Mustard gas is extremely toxic to all species, but its environmental action is limited by its low solubility. Fish are the most sensitive species. Large quantities of Mustard gas would persist underwater for considerable periods and retain blister-forming properties.
- Handling and transporting munitions and containers from the storage area to the destruction facility has to be conducted in compliance with the strictest safety measures to prevent any accidental release of chemical agents, which could endanger either the personnel, the civilian population or the environment.
- Spillage and leakage of these chemicals also leads to land and air contamination. Where these chemicals can remain contaminated for an extended period of time depending on the concentration.
- During World War II, the U.S. Army Chemical Corps developed more effective flamethrowers and herbicides to help clear the way through the jungle. The resulting deforestation caused the death of entire ecosystems and continues to affect the islands to this day.
Under the Chemical Weapons Convention (1993), there is a legally binding, worldwide ban on the production, stockpiling and use of chemical weapons. It seeks to limit availability of chemicals that can be used as tools of mass destruction.Notwithstanding, large stockpiles of chemical weapons continue to exist, usually justified as a precaution against putative use by an aggressor.
The Prohibition of Chemical Weapons (OPCW) is an implementing body of the Chemical Weapons Convention. The OPCW is authorized to perform inspections to verify that signatory states are complying with the convention.
The use of these weapons anywhere, at any time, by anybody, under any circumstances is unjustifiable. The efforts in the OPCW should be aimed at eliminating all the possibilities of any future use of chemical weapons.The use of these weapons anywhere, at any time, by anybody, under any circumstances is unjustifiable. The efforts in the OPCW should be aimed at eliminating all the possibilities of any future use of chemical weapons. ©crackingcivilservices.com
