This chemical element is the killerβs favorite weapon. He figured in many works of art and often became the cause of the death of the main political figures. They strengthened their health and removed intractable husbands. Some of its compounds can harm a person even in small amounts, but on the other hand, mineral water and some medicines containing it help restore health. The time has come to remove the aura of mystery and get to know better with this intractable and dangerous substance.
Arsenic is a chemical element known in the periodic table as arsenic. Atomic number - 33, refers to semimetals. Changing the valency to a large extent makes it possible to obtain compounds with different properties, some of which can kill a person, while others, on the contrary, can cure diseases such as cancer and leukemia.
Item Properties
The arsenic content in the earth's crust is negligible. It does not form during magmatic processes due to its volatility after heating, but arsenic compounds enter the atmosphere in large quantities during volcanic eruptions. There are about one hundred and eighty arsenic-based minerals, since this element can take on different valencies. But in nature, arsenic combined with sulfur is more common (formula As 2 S 3).
And not in nature?
In everyday life, the most common and stable is gray arsenic (formula - Ξ±-As). This is a rather fragile crystal of gray-steel color, which fades in the air and becomes covered by a film due to prolonged contact with open air. There are also yellow, black and brown modifications of the element, after heating turning into gray.
Get it by heating the rock, which contains arsen, or restore pure arsenic from its oxides.
History
First of all, arsenic is poison. But in the ancient world, people used this mineral to obtain dyes and medicines. For the first time in its pure form, arsenic was obtained by Albert the Great in the thirteenth century AD. In his works, Paracelsus also mentioned this element, but under a different name. In eastern countries, in parallel with Europeans, they also investigated the properties of this amazing substance and could even diagnose death from poisoning. But their knowledge has not reached our days.
As a separate chemical element, arsenic was introduced into the periodic table by Antoine Lavoisier.
Causes of Poisoning
Arsenic poisoning is not uncommon in our time. But this is more the fault of the accident than the targeted killing. You can run into it almost anywhere:
- outdoors: the groundwater that feeds the springs can pass through rocks containing this mineral;
- it is contained in smoke: burning industrial waste is extremely toxic;
- in seafood: since arsenic is well precipitated in cold water, then during the eruption of volcanoes located at the bottom of the oceans, it may well enter the body of fish and mollusks;
- in industry: used as an auxiliary element in the production of glass, semiconductors or other electronic devices.
In addition, deliberate arsenic poisoning cannot be ruled out as an attempted suicide or murder.
Pathogenesis of poisoning
Once in the human body through the skin, lungs or intestines, arsenic with a blood stream is carried throughout the body, penetrating into all organs and tissues. He can not overcome the blood-brain barrier, but penetrates the placenta well, poisoning the fetus. A long elimination period allows you to detect poison even a week after poisoning.
The lethal dose is from 0.05 to 0.2 grams. And it can be obtained both simultaneously and gradually, if chronic poisoning occurs. Typically, this condition is observed among workers in agriculture, fur and leather industry, as well as chemical enterprises.
Clinic
When a lethal dose gets inside, the consequences are not long in coming. Within half an hour, a person begins to feel symptoms of general intoxication, such as headache, weakness, lethargy, nausea and vomiting. They are not specific to any poison. This is just a reaction of the body to the action of a toxic substance. How to make sure that it was arsenic poisoning? Symptoms are as follows:
- cramping abdominal pain;
- diarrhea in the form of rice broth;
- persistent garlic breath;
- severe dehydration and thirst.
Depending on which system the poison affected in the first place, several forms of poisoning are distinguished: gastrointestinal, cardiovascular, urinary, nervous. In addition, as mentioned above, chronic arsenic poisoning also occurs. Symptoms in this case do not develop so rapidly and are more pronounced on the skin:
- Hyperkeratosis: excessive production of the surface layer of the skin.
- Redness or pigmentation of places with thin skin - eyelids, axillaries, temples, neck, nipples and genitals.
- Peeling and roughening of the skin.
- The appearance of white lines on the nail plates.
Urgent events
First aid for arsenic poisoning comes down to washing the stomach with plenty of water and washing it off the skin. If the person is unconscious, then after you turn him on his side, you must urgently call an ambulance. In no case give the victim a laxative or sorbents. If the poison has already managed to get into the red blood cells, these measures can help little.
In especially severe cases, it is necessary to begin cardiopulmonary resuscitation before the arrival of doctors. Signs of arsenic poisoning can be mistaken for a regular intestinal infection, so be sure to tell doctors all the details of the poisoning.
Hospital treatment
Arsenic poisoning requires hospitalization and specialist supervision. The victim needs oxygen inhalation, abundant invasive therapy to remove the remaining poison from the body. If, after analysis, it is found that the patient has reduced hemoglobin and red blood cells, then he is additionally injected with a glucose-novocaine mixture. When exhaling vapors of arsenic, swelling of the mucous membrane may develop, as a result, we have difficulty breathing. In this case, the patient should enter aminophylline, and in severe cases, also incubate to connect the artificial respiration apparatus.
Unithiol (the main active ingredient is dimercaprol), which binds to arsenic and forms insoluble compounds excreted in the urine, is considered a specific antidote. The medicine is administered at a rate of 2-3 milligrams per kilogram of weight. Repeat the procedure every six hours during the first day, and then twice a day for another couple of weeks.
The doctor needs to find out how much arsenic poisoning the patient has. Treatment will depend on the dose of the poison. Modern techniques allow you to install it quite accurately.
Forensic examination
As you know, arsenic poisoning for a long time could get away with the murderers, since it was not possible to detect the toxin in the blood or hair of a person. Historians agree that Napoleon Bonaparte died precisely from this poison, but the official version claims that the cause was untreated stomach cancer.
So that such incidents would not be repeated, and the criminal could be found, chemists and physicists from around the world, without saying a word, began to search for a way to identify arsenic in the victim's body. Robert Boyle, Olaf Bergman, Karl Scheele and James Marsh participated in this study. It was the last of them that was able to obtain pure arsenic during their experiments, which could be used as evidence. The sensitivity of the reaction could show 0.001 g of the poison content in the blood of the deceased.
After a hundred years, poisoning with arsenic compounds no longer was a mystery for the investigation, since chemists were able to achieve greater accuracy and subtlety of the procedure.
Military targets
After the First World War, when the use of poisonous gases entered the circle of means to defeat the enemy, scientists enthusiastically began to experiment with new weapons. The chemical effect of arsenic compounds or its vapor on the opponent caused abscesses, skin necrosis, swelling of the mucous membranes, and death by suffocation before the poison enters the bloodstream.
Even a slight concentration was enough to demoralize a person and kill him. One such remedy was lewisite. He had a wonderful smell of blooming geraniums, but even a drop of it could greatly damage the body. For this property, the soldiers called it the "dew of death."
Mineral water
The permissible concentration of arsenic in a liter of drinking water is 50 micrograms. But in 2002, this norm was revised, as a result of which a more stringent one was adopted - up to 10 micrograms. An alarm on this issue was sounded in Taiwan. Their artesian water contained so much arsenic that it was amazing how they still had not died out. The concentration was more than 180 times higher than the norm admissible by modern standards.
The issue of water purification and its delivery to areas of Southeast Asia with the lowest economic costs arose sharply. The simplest way was to oxidize trivalent arsenic to pentavalent and precipitate it.
Medical use
In small quantities, almost all the elements of the periodic system of D. I. Mendeleev are necessary for the normal functioning of a person, because it is not for nothing that they are present in the body. And who did not hear the phrase that in small doses, and poison is a medicine? It is known that arsenic helps to improve blood formation, accelerate metabolism and the growth rate of tissues, including bones. Microdoses even improve the immune system. In ancient times, paste from arsenic compounds was used to treat ulcers and open wounds, tonsillitis, and typhoid.
In the thirteenth century, Thomas Fowler invented a solution based on arsenic, which he called his name and used to treat mental and skin diseases. Passion for this medicine and its derivatives reached its climax at the junction of the eighteenth and nineteenth centuries. But with the introduction of new knowledge about physics, chemistry and the human body, the toxic nature of this compound was nevertheless revealed, and its use declined.
Arsenic-enriched natural mineral waters are still used to treat anemia, leukemia and some diseases of the gastrointestinal tract. In addition, it is part of the mummy used in cosmetology. Natural sources of this element are seafood, wild rice, cereals, lentils, carrots, grapes (and raisins), strawberries.