Of all the poisons, cyanide has the most notorious fame. The use of this cyanide by cyber criminals in detective novels is a very popular way to get rid of unwanted persons. Obviously, the widespread fame of poison is also associated with its availability at the turn of the XIX – XX centuries, when the powder could easily be bought at a pharmacy.
Meanwhile, potassium cyanide is not the most dangerous and poisonous substance - it is inferior in terms of lethal dose to such prosaic poisons as nicotine or botulinum toxin. So what is cyanide, where does it apply and how does it affect the human body? Does his fame correspond to the real state of things?
What is cyanide potassium
The poison belongs to the group of cyanide derivatives of hydrocyanic acid . The formula of cyanic potassium is KCN. The substance was first obtained by the German chemist Robert Wilhelm Bunsen in 1845, he also developed an industrial method for its synthesis.
In appearance, cyanide potassium is a colorless crystalline powder, well soluble in water. Reference books describe that potassium cyanide has a peculiar smell of bitter almond. But this characteristic of his is not always true - about 50% of people are able to feel this smell. It is believed that this is due to individual differences in the olfactory apparatus. Cyanic potassium is not a very stable compound. Since hydrocyanic acid is weak, the cyano group is easily replaced from the compound by salts of more strong acids. As a result, the cyano group evaporates, and the substance loses its toxic properties. Also, cyanides are oxidized upon access of humid air or in solutions with glucose. The latter property allows the use of glucose as one of the antidotes for poisoning with hydrocyanic acid and its derivatives.
Where does cyanide
What is cyanide for man for? It is used in the mining and processing industry and electroplating industry. Since noble metals are not able to oxidize directly with oxygen, they use potassium or sodium cyanide solutions to catalyze the process. Chronic potassium cyanide poisoning can get people and non-production. Thus, in early 2000, there were cases of toxic emissions from mining and processing enterprises in Romania and Hungary into the Danube River, as a result of which people living in the vicinity of the floodplain were injured. Employees of special laboratories who come into contact with poison as a reagent risk getting a chronic disease.
In the domestic environment, cyanides can be found in photo lab reagents and jewelry cleaners. Small amounts of potassium cyanide are used by entomologists in the stains for insects. There are also artistic paints (gouache, watercolor), which include cyanide - “Prussian blue”, “Prussian blue”, “Milori”. There, they are combined with iron and give the dye a rich azure color.
What does cyanide contain in nature? In its pure form, you will not find it, but the compound with the cyano group, amygdalin, is found in the seeds of apricots, plums, cherries, almonds, peaches; elderberry leaves and shoots. The cleavage of amygdalin produces hydrocyanic acid, which acts similarly to potassium cyanide. Fatal poisoning can be obtained from 1 gram of amygdalin, which corresponds to approximately 100 grams of apricot kernels.
The effect of potassium cyanide on humans
How does cyanide on the human body? The poison blocks the cellular enzyme, cytochrome oxidase, which is responsible for the uptake of oxygen by the cell. As a result, oxygen remains in the blood and circulates there in a form associated with hemoglobin. Therefore, in cyanide poisoning, even venous blood has bright scarlet staining. Without oxygen, the metabolic processes inside the cell stop and the body quickly dies. The effect is tantamount to, as if the poisoned person simply suffocated due to lack of air.
Cyanic potassium is poisonous if ingested, with inhalation of powder and solution vapors; It can also penetrate the skin, especially if it is damaged. The lethal dose of potassium cyanide for humans is 1.7 mg / kg of body weight. The drug belongs to the group of highly toxic substances, its use is controlled with all possible severity.
The action of cyanide is weakened in combination with glucose. Laboratory workers who are forced to come into contact with this poison while working hold a piece of sugar behind their cheeks. This allows you to neutralize microscopic doses of toxin that have accidentally entered the blood. Also, the poison is more slowly absorbed on a full stomach, which allows the body to reduce its harmful effects by oxidation with glucose and some other blood compounds. A small amount of cyanide ions, about 140 µg per liter of plasma, circulate in the blood as a natural metabolite of metabolism. For example, they are part of vitamin B12 - cyanocobalamin. And in the blood of their smokers are twice as much.
Symptoms of potassium cyanide poisoning
What are the symptoms of potassium cyanide poisoning? The effect of poison manifests itself very quickly - when inhaled almost instantly, when released into the stomach - after a few minutes. Through the skin and mucous cyanide absorbed slowly. Signs of potassium cyanide poisoning depend on the dose received and the individual sensitivity to poison.
In acute poisoning violations develop in four stages.
sore throat, scratching sensation;
- bitterness in the mouth, the notorious taste of "bitter almond" is possible;
- numbness of the oral mucosa, pharynx;
- nausea and vomiting;
- feeling of tightness in the chest.
The second stage is dyspneetic, with it signs of oxygen starvation are increasing:
- chest pressure increases;
- pulse slows, weakens;
- general weakness increases;
- pupils dilated, conjunctiva reddens, eyeballs bulge out;
- there is a feeling of fear, turning into a stunned state.
When receiving a lethal dose, the third stage begins - convulsive:
- tongue bite;
- involuntary urination and defecation;
The fourth stage, paralytic, leads to death from potassium cyanide:
- unconscious victim;
- breathing slows down;
- mucous membranes turn red, a blush appears;
- lost sensitivity and reflexes.
Death occurs in 20–40 minutes (when poison is ingested) from respiratory failure and the heart. If the victims do not die within four hours, then, as a rule, they survive. Possible consequences - residual impairment of brain activity due to oxygen starvation.
In chronic cyanide poisoning, the symptoms are largely due to intoxication with thiocyanates (rhodanides), substances of the second hazard class, into which cyanides pass into the body under the influence of sulfide groups. Thiocyanates cause pathology of the thyroid gland, adversely affect the liver, kidneys and provoke the development of gastritis.
The victim needs the prompt introduction of antidotes of potassium cyanide, of which there are several. Before the introduction of a specific antidote, it is necessary to alleviate the patient's condition - remove the poison from the stomach by washing:
- 0.1% solution of potassium permanganate;
- 2% solution of baking soda;
- 2% hydrogen peroxide solution;
- 5% sodium thiosulfate solution.
Then give a sweet warm drink.
If the victim is unconscious, only a medical professional can help him. In case of respiratory arrest, artificial respiration is performed.
If there is a chance that cyanide potassium gets on clothing, you must remove it and wash the patient's skin with water.
Take measures to maintain vital activity - a breathing tube and an intravenous catheter are inserted. Cyanic potassium is a poison to which there are several antidotes. Apply them all, because they have a different mechanism of action. The antidote is effective even in the final stages of poisoning.
- Methemoglobin formers cleave oxygen from hemoglobin and allow it to take cyanide molecules from cells. This group includes nitrogen oxides, nitrates and nitrites, nitroglycerin, amyl nitrite, methylene blue.
- Amylnitrite drip on the fleece and give a sniff every two minutes.
- Sodium nitrite is administered intravenously in the form of a 2% solution.
- Methylene blue 1% solution on a 25% glucose solution intravenously.
At the same time they are guided by the fact that the level of methemoglobin in the blood does not exceed 25–30%.
- Solutions of substances easily donating sulfur neutralize cyanides in the blood. Apply a 25% sodium thiosulfate solution.
- Glucose solution 5 or 40%.
To excite the respiratory center injected drugs "Lobelin" or "Tsititon."
Summing up, we can say the following. The toxic effect of potassium cyanide on humans consists in blocking the mechanism of cellular respiration, as a result of which death from suffocation and paralysis occurs very quickly. Can help antidote drugs - amyl nitrite, sodium thiosulfate, glucose. They are administered intravenously or inhaled.
For the prevention of chronic poisoning in the workplace, it is necessary to follow general safety measures: avoid direct contact with the poison, use protective equipment, and regularly conduct medical checkups.