The effect of aluminum on human health. Properties of aluminum Application of aluminum cations in medicine
Speaking about the importance of aluminum, we most often recall the industrial "derivatives" of this metal - mechanical engineering, technology, food industry, etc. By the way, you can read about aluminum prices on the website www.scrapmetall.ru. However, at the same time, an important and even fundamental point is overlooked - the effect of aluminum on human health and vital activity. But this metal has been used in medicine and cosmetology since ancient times, and a lack of aluminum in the body can lead to negative consequences - as well as exceeding its concentration. In modern medicine, the status of aluminum is still in question - the fact is that scientists have identified some side effects of traditional aluminum-based drugs, as a result of which recommendations have been made to refuse certain drugs. At the same time, new improved medicines and cosmetic preparations with an aluminum “base” are emerging today.
Our aluminum
Compared with some other substances, the content of the 13th element in the human body is relatively small - for an adult, this value is about 30-50 mg. Aluminum is present in almost all organs - this element is part of various biomolecules. Aluminum is directly involved in the formation of phosphate and protein complexes in the body, tissue regeneration, stimulates or inhibits (depending on concentration) digestive enzymes.
According to researchers, the daily intake of aluminum in the body should be at least 1 mcg, otherwise there is a deficiency of this element. Experiments conducted on animals have shown that a lack of aluminum in the body can cause growth retardation, impaired coordination of movements, in some cases provoke miscarriages, and reduce productivity. At the same time, an excess of aluminum (and this problem is just more relevant today) leads to dysfunction of the central nervous system, the development of Alzheimer's and Parkinson's diseases, and other negative consequences.
aluminum drugs
The most ancient "aluminum medicine" was alum - this name was given to crystalline double aluminum sulfate salts by the Slavs in the 15th century: the word "kysati" (sour), in their opinion, quite accurately reflected the specific taste of the substance. Alum was used to heal wounds and to treat various skin diseases.
Today, in dermatological practice, mainly potassium alum (K2SO4 * Al2 (SO4) 3 * 24H20) and burnt alum are used. Aluminum silicate, better known as kaolin (white clay), aluminum hydroxide and aluminum phosphate, are also widely used. The fact is that aluminum alum has astringent, bactericidal and drying properties. At the same time, they act on the skin quite gently, relieve pain, itching and burning.
There are also preparations for internal use based on aluminum. Among the most popular "aluminum" drugs are remedies for heartburn, gastritis and stomach ulcers: Antacid, Alumag, Almagel, Almagel-a, Gastal, Gastralugel, Alyugastrin and others. These drugs are being improved every year - due to new developments, their side effects are reduced and their effectiveness is enhanced. However, researchers have not yet found a replacement for the basis of such drugs - aluminum compounds.
26.98, melting point - 660°, boiling point - 2500°. Oxidizes in air, resistant to water. It is found in small amounts in the body (trace element).
aluminum preparations. In medical practice, preparations of soluble and insoluble aluminum salts are used.
The former include Burov's liquid, alum, burnt alum. They have astringent, cauterizing and action, which is based on the ability of these salts to combine with proteins to form albuminates. Water-insoluble aluminum preparations include white clay, aluminum oxide hydrate. They have an adsorbing and enveloping effect, they do not have astringent and cauterizing properties.
Burov's liquid (liquor Burovi) - 8% solution of aluminum acetate. Used in a dilution of 1:10 or more for douching in inflammatory diseases of the skin and mucous membranes.
Alum (Aluminii et Kalii sulfas, Alumen) - double sulfate salt and aluminum. Applied externally in aqueous solutions (0.5-1%) for the same indications as Burov's liquid, and in the form of pencils as a hemostatic agent for cuts. Burnt alum (Alumen ustum) is used as an astringent and drying agent (for sweating feet, etc.). Aluminum oxide hydrate (Aluminii hydroxydum, Aluminum hydroxydatum) is used as an adsorbent and enveloping agent externally in the form of powders and inside with increased acidity of gastric juice (see). See also white clay.
Aluminum oxidizes in air, resistant to water. It is a trace element of the animal body.
Aluminum preparations are divided into 2 groups. The first includes soluble aluminum salts that have astringent, cauterizing and bactericidal action, which is based on their ability to combine with proteins, forming albuminates. Of the drugs in this group, Burov's liquid, aluminum-potassium and burnt alum are used. The second group consists of aluminum preparations that are insoluble in water. They have a high degree of dispersion and have an adsorbing and enveloping effect. They do not possess astringent and cauterizing properties. This group includes white clay (aluminum silicate) and aluminum hydroxide.
Burov's liquid (Liquor Burovi) - 8% solution of aluminum acetate; used in a dilution of 1: 10, 1: 20 or more for rinsing, lotions, douching in inflammatory diseases of the skin and mucous membranes.
Aluminum-potassium alum (Alumen) - double sulfate salt of potassium and aluminum; used externally in aqueous solutions (0.5-1%) for the same indications as Burov's liquid, and in the form of pencils - for cauterization in trachoma and as a hemostatic agent for cuts (composition of hemostatic pencils: aluminum-potassium alum - 20% , aluminum sulfate - 78%, calcium oxide -2%).
Burnt alum (Alumen ustum) is obtained from aluminum-potassium alum by removing crystallization water from them (by heating); used for powders as an astringent and drying agent (for sweating feet, etc.).
White clay (Bolus alba) - aluminum silicate with a small admixture of other silicates; prescribed as an enveloping and adsorbing agent. It is applied externally in the form of powders, pastes, ointments for skin diseases, ulcers, diaper rash, burns, etc. For gastrointestinal diseases (colitis, enteritis), occasionally administered orally from 20 to 100 g (adults). It is also used as constituens in the manufacture of pills and tablets.
Aluminum oxide hydrate (Aluminium hydroxydatum, synonymous with alumina) is also used as an adsorbent and enveloping agent externally for powders and inside with increased acidity of gastric juice (see Antacids).
Aluminum as an industrial poison. Aluminum is obtained from aluminum, mainly bauxite, ores. The use of nephelines and alunites, which are especially rich in the bowels of the USSR, is very promising. Obtaining aluminum from ores is carried out in two stages: first, alumina (Al 2 O 3) is extracted from ores, and then metallic aluminum is extracted from it.
Alkaline methods are widely used in the production of alumina. At the same time, workers are exposed to bauxite dust and alumina dust, as well as an increased concentration of alkaline aerosols, high temperature, air humidity and radiant heat (V. A. Gavrilova and S. V. Miller).
Metallic aluminum is obtained by electrolysis of alumina dissolved in molten cryolite. Workers inhale air containing alumina dust. Exposure to hydrogen fluoride and pitch sublimates, high air temperature, intense radiation in summer and low air temperature in winter are also dangerous.
In the production of powders used in pyrometallurgy, pyrotechnics and as paint powder, workers are exposed to aluminum dust. Highly dispersed metallic aluminum in high concentration forms an explosive mixture with air. Alumina dust also enters the air during the smelting of bauxite in the production of artificial corundum. When inhaling the dust of metallic aluminum and its oxide, dust fibrosis of the lungs-aluminosis occurs (see Pneumoconiosis). Aluminosis was also obtained under experimental conditions by intratracheal administration of aluminum dust to white rats. However, many authors on the basis of clinical and experimental studies deny the possibility of developing aluminosis in this case. Such contradictory reports on the action of aluminum should be explained by the different properties of aluminum dust - the presence or absence of an aluminum oxide film on the surface of its particles, the different size of the surface of dust particles, their sizes, etc.
Some authors believe that aluminum is practically non-toxic. Dust of aluminum and duralumin irritates the mucous membranes of the eyes, nose and mouth. Workers involved in the production of aluminum powders often have catarrhs of the upper respiratory tract (rhinitis, laryngitis, pharyngitis), and with an increase in experience, the proportion of atrophic forms increases. With the smallest wounds and cuts of the skin, the penetration of small particles of aluminum and duralumin into them leads to purulent pustules that do not heal for a long time with a significant compaction of the tissue around.
The maximum permissible concentration for an aerosol of aluminum, aluminum oxide and its alloys in the air of working premises is 2 mg / m 3. In the manufacture and use of abrasives and in the production of aluminum by the electrochemical method (electrolysis departments), preliminary and periodic (1 time in 12 months) medical examinations are mandatory.
When examining the working electrolysis shops, special attention should be paid to the signs of chronic fluoride intoxication.
The chemical element aluminum is a light, silvery metal. Aluminum is the most common metal in the earth's crust. The physical and chemical properties of aluminum have allowed it to be widely used in modern industry and everyday life.
Chemical properties of aluminum
The chemical formula of aluminum is Al. Atomic number 13. Aluminum belongs to simple substances, since its molecule contains an atom of only one element. The outer energy level of an aluminum atom contains 3 electrons. These electrons are easily donated by the aluminum atom during chemical reactions. Therefore, aluminum has a high chemical activity and is able to displace metals from their oxides. But under normal conditions, it is quite resistant to chemical interaction, as it is covered with a strong oxide film.
Aluminum reacts with oxygen only at high temperatures. As a result of the reaction, alumina is formed. With sulfur, phosphorus, nitrogen, carbon, the interaction also occurs at high temperatures. But aluminum reacts with chlorine and bromine under normal conditions. It reacts with iodine when heated, but only if water acts as a catalyst. Aluminum does not react with hydrogen.
With metals, aluminum is able to form compounds called aluminides.
Aluminum, purified from the oxide film, reacts with water. The hydroxide, which is obtained as a result of this reaction, is a poorly soluble compound.
Aluminum readily reacts with dilute acids to form salts. But it reacts with concentrated acids only when heated, forming salts and acid reduction products.
Aluminum reacts easily with alkalis.
Physical properties of aluminum
Aluminum is a durable metal, but at the same time ductile, easily machined: punched, polished, drawn.
Aluminum is the lightest of the metals. It has a very high thermal conductivity. In terms of electrical conductivity, aluminum is practically not inferior to copper, but at the same time it is much lighter and cheaper.
Application of aluminum
For the first time aluminum metal was obtained by a Danish physicist Hans Christian Oersted in 1825. In those days, aluminum was considered a precious metal. Fashionistas loved to wear jewelry from it.
But the industrial method for producing aluminum was created much later - in 1855 by the French chemist Henri Etienne Saint-Clair Deville.
Aluminum alloys are used in almost all engineering industries. Modern aviation, space and automotive industries, shipbuilding cannot do without such alloys. The most famous alloys are duralumin, silumin, cast alloys. Perhaps the most popular of these alloys is duralumin.
When aluminum is processed by hot and cold processing, profiles, wire, pipes, tapes, sheets are obtained. Aluminum sheets or tape are widely used in modern construction. So, a special aluminum tape is used to seal the ends of various building panels in order to provide reliable protection against precipitation and dust ingress into the panel.
Since aluminum has a high electrical conductivity, it is used for the manufacture of electrical wires and electrical busbars.
Aluminum is not a precious metal. But some of its compounds are used in the jewelry industry. Probably, not everyone knows that ruby and sapphire are single crystals of aluminum oxide, in which coloring oxides are added. The red color of a ruby is given by chromium ions, and the blue color of sapphire is due to the content of iron and titanium ions. Pure crystalline alumina is called corundum.
In industrial conditions, artificial corundum, ruby and sapphire are created.
Aluminum is also used in medicine. It is part of some drugs that have an adsorbing, enveloping and analgesic effect.
It is difficult to find a branch of modern industry that does not use aluminum and its compounds.
aluminum hydride. Alum
Aluminum forms a polymer hydride (Alan ) AlH 3, which is obtained indirectly, for example, by the action of AlCl 3 on ether solutions of hydridoaluminates:
3 Li + AlCl 3 ═ 4 AlH 3 + 3 LiCl
Aluminum hydride is a white powder that decomposes when heated to release hydrogen. When AlH 3 interacts with basic hydrides in an ether solution, hydridoaluminates are formed:
LiH + AlH 3 ═ Li
Hydridoaluminates are white solids that are rapidly decomposed by water. They are strong reducing agents. Used in organic synthesis.
Potassium alum are usually much less soluble than the individual sulfates that make them up. With increasing temperature, the solubility in most cases increases very strongly. Potassium-aluminum alum KAl(SO 4) 2 12H 2 O is used in large quantities for tanning leather, as well as in dyeing as a mordant for cotton fabrics. In the latter case, the action of alum is based on the fact that the aluminum hydroxide formed as a result of their hydrolysis is deposited in the fabric fibers in a finely dispersed state and, adsorbing the dye, firmly holds it on the fiber.
The daily intake of aluminum by a human is 47 mg. Aluminum affects the development of epithelial and connective tissues, the regeneration of bone tissue, affects the exchange of phosphorus.
An excess of aluminum in the body inhibits the synthesis of hemoglobin, because due to its rather high complexing ability, aluminum blocks the active centers of enzymes involved in hematopoiesis.
The pharmacological action of aluminum salts is based on the fact that A1 3+ ions form complexes with proteins (Pr proteins) that precipitate in the form of gels:
A1 3+ + Pr → AlPr
This leads to the death of microbial cells and reduces the inflammatory response.
Alum is used for rinsing, washes and lotions in inflammatory diseases of the mucous membranes and skin. In addition, this drug is used as a hemostatic agent for cuts (clotting action).
Burnt alum is used in the form of powders as an astringent and drying agent for sweaty feet. The drying effect is due to the fact that burnt alum slowly absorbs water.
Burov's liquid also has an astringent effect - an 8% solution of aluminum acetate A1 (CH 3 COO) 3.
In living organisms with bioligands (hydroxy acids, polyphenols, carbohydrates, lipids), aluminum forms chelate complex compounds. As a rule, it forms bonds with organic ligands through oxygen atoms.
Topic: Group IV P-elements
Keywords:p-elements, carbon, silicon, allotropes of carbon, diamond, graphite, carbine, hybridization, carbides, hydrocyanic acid, cyanides, percarbides, phosgene, metal carbonyls, carbonates, hydrocarbonates, carbon disulfide, thiocarbonates, freon, silica, amorphous silicon, silicides, silicates, silane, silicic acid, silicones.
6 C 1s 2 2s 2 2p 2
14 Si 3s 2 3p 2
32 Ge 3d 10 4s 2 4p 2
50 Sn 4d 10 5s 2 5p 2
82 Pb 4f 14 5d 10 6s 2 6p 2
Similarity of elements:
– the same structure of the outer electron layer of atoms ns 2 np 2
– p-elements
– highest oxidation state +4
– typical valencies II, IV
For atoms of all elements, two valence states are possible:
1) Basic ns 2 np 2 (unexcited). More typical for Sn and Pb
2) Excited ns 1 np 3 More typical for C, Si and Ge
Acidum boricum(boric acid) H 3 BO 3. Applied externally as an antiseptic in the form of aqueous solutions (2-4%) for rinsing the mouth, throat and eyes, also prescribed as an ointment (5-10%) and powders for skin diseases.
Natrii tetraboras(Borax) - sodium tetraborate (borax) Na 2 B 4 O 7 ´10H 2 O. It is used externally as an antiseptic for douching, rinsing, lubrication in the form of aqueous solutions (1-2%), as well as in the form of ointments and powders.
Aluminum hydroxudum(aluminum hydroxide) Al(OH) 3 . Applied inside as an adsorbent, enveloping and antacid agent for increased acidity of gastric juice, peptic ulcer of the stomach and duodenum, acute and chronic hyperacid gastritis and food poisoning. Assign inside in the form of a 4% aqueous suspension. Prolonged use of Al(OH) 3 can lead to constipation, therefore it is recommended to use Al(OH) 3 in combination with MgO.
Almagel(almagel) (composition: Al(OH) 3 , MgO with the addition of D-sorbitol). It is used for gastric and duodenal ulcers, acute and chronic hyperacid gastritis, esophagitis and other gastrointestinal diseases.
GefaI (Gefal)- a medicinal product containing aluminum phosphate in the form of a white suspension. It is used as an antacid for peptic ulcer, gastritis, dyspepsia, etc.
Aluminum and Kalii sulfas- potassium-aluminum sulfate (aluminum-potassium alum) KAl (SO 4) 2 ∙ 12H 2 O. Applied externally as an astringent in the form of aqueous solutions (0.5-1%) for rinsing, washing, lotions and douching, with inflammatory diseases of the mucous membranes and skin. It is also used in the form of pencils for cauterization, with trachoma and as a hemostatic agent for cuts. Burnt (calcined) alum (KAl(SO 4) 2) is used in the composition of powders as an astringent and drying agent.
Bolus alba(white clay) Al 2 (SiO 3) 3 has healing properties, providing an enveloping effect. Assign externally in the form of powders, pastes, ointments for skin diseases, ulcers, diaper rash, burns. Inside with gastrointestinal diseases (colitis, enteritis) and intoxication.
Aluminum alloys (diosal, etc.) are used for the manufacture of metal products used in pharmacy and medical practice, including infunders intended for the preparation of infusions (infusions) and decoctions. White clay (Al 2 (SiO 3) 3 mixed with CaSiO 3 and MgSiO 3 is used as a base (constituens) for the preparation of pills and tablets.
In dental practice, boric acid is used, which is used as a mold filler when casting steel teeth. The composition of dental pastes used as an adhesive layer for dentures includes sodium metaborate (NaBO 2) mixed with aluminum hydroxide (Al (OH) 3).
Kaolin (Al 2 O 3 ∙ SiO 2 ∙ 2H 2 O) is part of the cements used as a filling material.
In pharmacoanalysis, the following boron and aluminum compounds are used: aluminum oxide for chromatography (I and II degrees of activity); boric acid, sodium tetraborate (borax) for the preparation of buffer solutions.
