Why Organic Chemistry is Dangerous Quiz

Answer: Sarin

Sarin was named after the scientists at IG Farben who discovered it - Gerhard Schrader, Otto Ambros, Gerhard Ritter and von der Linde. Like other nerve agents, it blocks acetylcholinesterase, the enzyme which catalyzes the breakdown of acetylcholine, a neurotransmitter. Asphyxia due to the inability to control muscles involved in breathing is the main cause of death from exposure to sarin. Atropine can be used as an antidote to sarin but can cause severe side effects.

Sarin can be prepared using trimethoxy phosphorus or methylphosphonyl difluoride as the starting material. Since sarin has a short shelf life, it is usually stored as two precursor compounds. Sarin has a median lethal dose of 172 microgram per kilogram.

Sarin was used in the Iran-Iraq war of the 1990s as well as in the Syrian Civil War that started in 2013.

The Chemical Weapons Convention of 1993 outlawed the production or stockpiling of sarin.

Answer: Diphtheria

Diphtheria is caused by the bacterium Corynebacterium diphtheriae. The median lethal dose of diphtheria toxin is 0.1 microgram per kilogram. It usually causes death by killing the tissues in the liver or heart. Diphtheria toxin can also cause inflammation of the middle layer of the heart. The patient may bleed profusely, as there is a high chance of a reduction in the number of platelets.

The gene of the toxin is encoded by a virus which infects bacteria. Such a virus is also called a bacteriophage. Diphtheria is an airborne disease that spreads through droplet infection. Diphtheria can be generally prevented through vaccination in infants.

The swollen neck results in a cough that sounds like a bark. Mumps also leads to a swollen neck, but mumps is a viral disease due to infection of the salivary glands.

Answer: Constituents of the thickening agent used

Napalm consists of a fuel, such as gasoline, which causes the burns. The other constituent of napalm is a thick gelling agent, which makes napalm stick to skin. This gelling agent consists of precipitates of aluminium salts of naphthenic acid and palmitic acid, hence the name. It was first manufactured by scientists at Harvard University.

Napalm can cause severe burns, which can be reach beneath the dermis or can remain superficial. On combustion, napalm releases large amounts of carbon dioxide and carbon monoxide. The carbon monoxide released causes death by asphyxia. Napalm also causes death through dehydration of the body.

Napalm is an infamous symbol of the Vietnam War. The picture of the Vietnamese girl Phan Thi Kim Phuc running naked after being burned by napalm reminds us of the horrors of the war. Napalm has also been used by Israel in the Six-Day War, Iran and Iraq during the Persian Gulf conflict, and by France in the First Indo-China War and the Algerian War.

Answer: Tetanus

Clostridium tetani is a gram-positive bacterium that is usually found as spores in the soil and in the intestines of various animals such as cattle and dogs. It usually enters the body through a cut or puncture by an object which is contaminated. Rusted objects can be a source of the bacteria.

Tetanospasmin, the toxin, is highly potent and has a median lethal dose of about 2.5 nanogram per kilogram. It binds to terminals of peripheral nervous system neurons and ultimately reaches the central nervous system. The spasms occur as the toxin blocks the release of inhibitory neurotransmitters such as glycine and impairs the functioning of the alpha motor neurons. Severe spasms can even cause bone fractures.

Tetanus is usually prevented through the DPT vaccine given to infants. This contains the toxin inactivated by formaldehyde due to which it no longer can harm body cells, but the immune system can recognise it and produce antibodies.

Answer: Frog

'Batrachos' is the Greek word for frog. The frogs in which batrachotoxin is found are collectively called poison dart frogs, with the most poisonous being the golden arrow frog. The toxin is released by skin glands located on the back of the frog. The toxin is however not produced by the frog. It comes from the consumption of arthropods which are rich in alkaloids. Batrachotoxin is also found in certain beetles and birds such as the pitohui.

The median lethal dose of this toxin is 2-7 microgram per kilogram. Batrachotoxin acts on the sodium ion channel by making it more permeable to sodium ions. This depolarisation of the nerve channel effectively paralyses the nerve. This further causes the muscles to become paralysed. It is also a cardiotoxin and can cause arrhythmia and fibrillation in the ventricles.

The Noanamá Chocó and Emberá Chocó tribes of Colombia produce poison darts with Batrachotoxin.

Answer: Agent Orange

Agent Orange damages the genes of people who come into contact with it. This increases the probability of developing leukemia, lymphoma or cancer in later life. The children of these people have a greater probability of being born with deformities, including cleft palates and extra fingers or toes.

When sprayed over an area, Agent Orange causes widespread deforestation and loss of animal diversity. The soil becomes contaminated by the compound, and biomagnification occurs as it is non-biodegradable. Large areas of cropland in Vietnam were destroyed due to the usage of Agent Orange.

2,3,7,8-Tetrachlorodibenzodioxin is a common impurity in Agent Orange and is the most toxic compound. The main two compounds present in Agent Orange are synthetic auxins. The median lethal dose of this third compound is 20 microgram per kilogram.

Answer: Castor Oil Plant

Ricin is produced in the endosperm of the castor oil plant. The same seeds which contain ricin are crushed and pressed to produce castor oil.

The median lethal dose of ricin is around 22 microgram per kilogram. Although ricin is a protein, it cannot be digested by peptidases, which act upon other proteins. Ricin usually causes death due to the accumulation of fluid in the lungs, causing respiratory failure.

Ricin is far more toxic if inhaled or injected rather than direct consumption. Ingestion of ricin usually causes inflammation and internal bleeding in the mucus layer of the gastrointestinal tract. Patients who survive ricin poisoning usually develop severe organ damage, as the tissues in organs like the livers can be killed.

Ricin gets denatured at temperatures above 80 degrees Celsius. Ricin is less toxic than botulinum toxin or tetanus toxin, but is easier to produce. Castor is grown on a large scale worldwide, for both ornamental purposes as well as to produce castor oil, which is used to counter alopecia.

Answer: Mustard Gas

Mustard gas can be manufactured using ethene, and disulphur dichloride or sulphur dichloride, as the starting reactants. It can also be prepared using hydrochloric acid and thiodiglycol.

Mustard gas causes alkylation of guanine as it readily loses one chlorine atom. This blocks cell division, resulting in death. Alternatively, the damage caused to DNA is severe enough to cause cancer. People who survive mustard gas attack have a high probability of developing cancer later in their lives. Mustard gas is highly soluble in fats, and absorbed into the body easily. The production of free radicals can harm various organ tissue.

Mustard gas causes severe chemical burns, and can lead to blindness. It can also cause internal haemorrhage and deposition of fluids in the respiratory system. Mustard gas is stored as an aerosol, and the liquid droplets turn into vapour once released. It was used by ISIS in its battles, a century after its first usage in World War I.

Answer: British Anti-Lewisite (BAL)

Lewisite can be prepared by the addition reaction of arsenic trichloride and acetylene. Lewisite gas can penetrate ordinary clothing and rubber. The compound acts as a suicide inhibitor of pyruvic dehydrogenase in the Tricarboxylic acid cycle in respiration. In other words, it prevents the natural degradation of the enzyme.

Lewisite gas can cause severe chemical burns and cause the death of liver tissue. The damage of capillaries can in turn cause damage of the kidneys. Damage to the cornea can also cause blindness.

British Anti-Lewisite is also known as dimercaprol. It is also used to treat arsenic, mercury, gold or lead poisoning. It treats the metal poisoning by chelating with the metal ions, or forming a cyclical structure through coordinate bonds. BAL injections are given intramuscularly.

Answer: Botulinum toxin

Botulinum toxin is produced by the bacterium Clostridium botulinum, infection with which causes the disease botulism. The toxin blocks the function of nerves and muscles, which lead to paralysis without other cause, and can also lead to death. This happens as several proteins needed for nerve functioning get cleaved by the botulinum toxin.

Botulism can lead from consumption of improperly canned food or from wound infection, especially from drug injections. The human median lethal dose of botulinum toxin is around 2 nanogram per kilogram intravenously.

However, botulinum toxin can be used in medicine to treat disorders involving overactive muscle movement, by relaxing the muscles. The same principle is used in the common cosmetic technique 'Botox', which reduces facial wrinkles by relaxing the clenched facial muscles.