This chemical element is the killer's favorite weapon. He appeared in many works of art and often became the cause of the death of major political figures. They strengthened their he alth and removed intractable husbands. Some of its compounds can harm a person even in small quantities, but on the other hand, mineral waters and some medicines containing it help restore he alth. It's time to remove the aura of mystery and get to know this intractable and dangerous substance.
Arsenic is a chemical element known in Mendeleev's periodic system as arsene. Atomic number - 33, refers to semimetals. A change in valence over a wide range makes it possible to obtain compounds of different properties, some of which can kill a person, while others, on the contrary, cure diseases such as cancer and leukemia.
Element Properties
The content of arsenic in the earth's crust is negligible. It is not formed during magmatic processes due to its volatility after heating, but during volcanic eruptions, arsenic compounds enter the atmosphere in large quantities. There are about a hundredeighty minerals based on arsenic, since this element can take on different valencies. But in nature, arsenic combined with sulfur is more common (formula As2S3).
Not in nature?
In everyday life, the most common and stable is gray arsenic (formula - α-As). This is a rather fragile steel-gray crystal, which tarnishes in air and becomes covered with a film due to prolonged contact with open air. There are also yellow, black and brown modifications of the element, which turn into gray after heating.
Get it by heating the rock that contains arsenic, or restore pure arsenic from its oxides.
History
First of all, arsenic is a poison. But in the ancient world, people used this mineral to make dyes and medicines. For the first time in its pure form, arsenic was obtained by Albert the Great in the thirteenth century AD. Paracelsus also mentioned this element in his works, 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 these days. But this is more the fault of an accident than a targeted murder. Encounter ayou can use it almost anywhere:
- in nature: groundwater that feeds springs can pass through rocks containing this mineral;
- contained in smoke: burning industrial waste is extremely toxic;
- in seafood: since arsenic is well deposited in cold water, during the eruption of volcanoes located at the bottom of the oceans, it may well enter the body of fish and shellfish;
- in industry: used as an auxiliary element in the production of glass, semiconductors or other electronic devices.
In addition, intentional arsenic poisoning as an attempted suicide or murder cannot be ruled out.
Pathogeny of poisoning
Getting into the human body through the skin, lungs or intestines, arsenic is carried through the bloodstream through the body, penetrating into all organs and tissues. It cannot cross the blood-brain barrier, but it crosses the placenta well, poisoning the fetus. The long elimination period makes it possible to detect poison even a week after poisoning.
The lethal dose is between 0.05 and 0.2 grams. And it can be obtained both simultaneously and gradually, if chronic poisoning occurs. Usually this condition is observed in workers in agriculture, the fur and leather industries, as well as chemical enterprises.
Clinic
When a lethal dose is ingested, the consequences are not long in coming. Within half an hour, a person begins to feel the symptoms of a generalintoxications such as headache, weakness, lethargy, nausea and vomiting. They are not specific to any poison. It is simply the body's reaction to the action of a toxic substance. How to make sure that it was arsenic poisoning? Symptoms are as follows:
- cramping abdominal pain;
- rice water diarrhea;
- persistent garlic breath;
- severe dehydration and thirst.
Depending on which system was affected by the poison in the first place, there are several forms of poisoning: gastrointestinal, cardiovascular, urinary, nervous. In addition, as mentioned above, there is also chronic arsenic poisoning. Symptoms in this case develop less rapidly and are more pronounced on the skin:
- Hyperkeratosis: Excessive production of the surface layer of the skin.
- Redness or pigmentation of thin skin areas - eyelids, armpits, temples, neck, nipples and genitals.
- Skin peeling and coarsening.
- The appearance of white lines on the nail plates.
Urgent measures
First aid for arsenic poisoning is to wash the stomach with plenty of water and wash it off the skin. If a person is unconscious, then after you turn him over on his side, you need to urgently call an ambulance. In no case do not give the victim a laxative or sorbents. If the poison has already entered the red blood cells, these activities will not be of much help.
In especially severecases, it is necessary to start cardiopulmonary resuscitation before the arrival of doctors. Signs of arsenic poisoning can be mistaken for a common intestinal infection, so be sure to tell the doctors all the details of the poisoning.
Inpatient treatment
Arsenic poisoning requires hospitalization and observation by specialists. The victim needs oxygen inhalation, abundant invasive therapy to remove the remnants of the poison from the body. If, after the tests, 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 arsenic vapors, mucosal edema may develop, as a result, we have difficulty breathing. In this case, the patient should be injected with aminophylline, and in severe cases, also incubated to connect the artificial respiration apparatus.
Unithiol (the main active ingredient is dimercaprol), which binds to arsenic and forms insoluble compounds that are excreted in the urine, is considered a specific antidote. The drug is administered at the rate of 2-3 milligrams per kilogram of body 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 severe the patient's arsenic poisoning is. Treatment will depend on the dose of poison. Modern techniques allow you to set it quite accurately.
Forensics
As you know, arsenic poisoning could get away with murderers for a long time, since it was not possible to detecttoxin in a person's blood or hair. Historians agree that Napoleon Bonaparte died from this poison, but the official version claims that untreated stomach cancer was the cause.
In order to prevent such incidents from recurring and the criminal could be found, chemists and physicists from all over the world, without saying a word, began looking for a way to detect arsenic in the victim's body. Robert Boyle, Olaf Bergman, Carl Scheele and James Marsh participated in this study. It was the last of them who was able to obtain pure arsenic during his experiments, which could be used as evidence. The sensitivity of the reaction could show 0.001 g of poison in the blood of the deceased.
A hundred years later, poisoning with arsenic compounds was no longer a secret for the investigation, as chemists were able to achieve greater accuracy and subtlety of the procedure.
Military targets
After the First World War, when the use of poison gases entered the circle of means to defeat the enemy, scientists enthusiastically began to experiment with new weapons. Chemical exposure of the enemy to arsenic compounds or its vapors caused abscesses, necrosis of the skin, swelling of the mucous membranes and death from suffocation before the poison entered the bloodstream.
Even a slight concentration was enough to demoralize a man and kill him. One such remedy was lewisite. He had a wonderful smell of flowering geraniums, but even a drop of it could greatly damage the body. For this property, the soldiers called it "the dew of death."
Mineral waters
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. The alarm on this issue was sounded in Taiwan. Their artesian water contained so much arsenic that it was amazing they hadn't died out yet. The concentration was more than 180 times higher than the norm by modern standards.
The question of water purification and its delivery to the regions of Southeast Asia with the lowest economic costs arose. The easiest way was to oxidize trivalent arsenic to pentavalent arsenic and precipitate it.
Medical use
In small quantities, almost all elements of the periodic system of D. I. Mendeleev are necessary for the normal functioning of a person, because it is not in vain that they are present in the body. And who has not heard the phrase that in small doses and poison is a medicine? It is known that arsenic helps to improve hematopoiesis, speed up the metabolism and growth rate of tissues, including bones. Microdoses even improve the immune system. In ancient times, arsenic compound paste was used to treat ulcers and open wounds, tonsillitis, and relapsing fever.
In the thirteenth century, Thomas Fowler invented an arsenic-based solution, which he named after himself and used to treat mental and skin diseases. The fascination with this medicine and its derivatives reached its peak at the turn of the eighteenth and nineteenth centuries. But with the introduction of new knowledge about physics, chemistry and the human bodyafter all, the toxic nature of this compound was revealed, and its use began to decline.
Natural mineral water enriched with arsenic is 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 include seafood, wild rice, cereals, lentils, carrots, grapes (and raisins), strawberries.
