Table of Contents
The most abundant metal on earth - Aluminum Al
Harmful effects of excessive aluminum intake
Major sources of excess aluminum in the human body
Prevention of aluminum poisoning
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The most abundant metal on earth
The most abundant metal on earth - Aluminum Al
The most abundant metal on earth
The most abundant metal on earth
The most abundant metal on earth
Many people often assume that iron Fe is the most abundant metal in the Earth's crust. In fact, the most abundant metal in the Earth's crust is Aluminum Al, followed by Iron, with Aluminum accounting for 7.45% of the total weight of the entire Earth's crust, almost twice as much as Iron! Aluminum compounds are found everywhere on the earth, such as common soil, which contains a lot of aluminum oxide Al2O3.The most important aluminum mines are alum and bauxite. The most important aluminum ores are alumina and bauxite, and our country has an abundance of aluminum ores.
Now, aluminum is very common. The coins we usually use are made of aluminum. In the kitchen, aluminum pots, aluminum lunch boxes, aluminum spoons, aluminum pots, aluminum spoons, aluminum woks ....... However, more than a hundred years ago, aluminum was considered a rare precious metal, more expensive than gold, so much so that it was classified as one of the "rare metals".
In fact, this is not surprising. Because the value of aluminum is expensive *, depends entirely on the level of the aluminum refining industry. More than a hundred years ago, people used the metal sodium Na to make aluminum. Sodium was expensive, and of course aluminum was even more expensive. It wasn't until the end of the 19th century that a new method of producing aluminum in large quantities was invented - electrolysis by passing an electric current through a molten mixture of cryolite and bauxite (alumina). That's when aluminum began to make its way to big industry and to every corner of life.
Aluminum, is a silver-white light metal (specific gravity of only 2.7). People often call aluminum "steel". Pure aluminum is very soft, can be pressed into a very thin foil, now wrapped candy, cigarettes, "silver paper", in fact, most of the aluminum foil. Pure aluminum conductivity is very good, and light, people often use it to replace copper, manufacturing wires, especially in the long-distance power transmission, more aluminum wire instead of copper wire, can reduce the poles and other equipment. Since the proletarian cultural revolution, our country vigorously develops "aluminum instead of copper", overcome the "aluminum instead of copper" technical key - aluminum welding technology, made a variety of horsepower of aluminum wire Motor, saving a lot of copper. Pure aluminum is also used in chemistry, semiconductor and electronics research and the production of optical instruments. Pure aluminum reflects light very well, so the lampshade of a searchlight is often made of pure aluminum.
However, pure aluminum is too soft, usually people always add a small amount of copper Cu, magnesium Mg, manganese Mn, etc., made of hard aluminum alloys - "hard aluminum". Aluminum and aluminum alloys are beautiful, lightweight and not easy to rust and corrosion, a wide range of uses. For example, some years ago, some statistics, an aircraft has about half a million rivets made of aluminum! Fuselage, wings, tail, propeller, engine also can not be separated from aluminum and aluminum alloy, according to statistics, aluminum and aluminum alloy accounted for about 70% of the total weight of the aircraft. If the train wagon are made of aluminum, the weight will be greatly reduced, locomotive traction efficiency can also be improved. Aluminum ships, not only fast, not be seawater erosion, and no magnetic, not for magnetic mines found, military is very important. In recent years, aluminum alloy has become an important material for manufacturing artificial satellites and rockets. In addition, in the transportation sector, aluminum is also used to manufacture high-speed locomotives, bridges, oil tanks for oil trucks, as well as ships and automobiles in some of the parts; in the construction industry, using aluminum as a skeleton, aluminum beams, hollow aluminum siding and a variety of aluminum components.
Aluminum is silver-white, but aluminum products with not long, the surface often becomes white, what is the reason? This is aluminum rust. Aluminum surface and air oxidation, generating a thin layer of oxide film - aluminum oxide. This layer of aluminum oxide is very dense, it is tightly adhered to the surface of aluminum, preventing the inside of the aluminum and oxidation continue to combine. This layer of aluminum oxide is not afraid of water immersion, not afraid of fire, melting point of up to 2050 ℃, no wonder aluminum products are difficult to rust, durable. This layer of aluminum oxide is not even afraid of nitric acid corrosion, so nitric acid plant commonly used aluminum cans to load concentrated nitric acid. However, this layer of oxide film is afraid of alkali, alkali can dissolve it, hydrochloric acid and sulfuric acid can also dissolve it. Therefore, aluminum products can not be used to hold alkaline substances, dirty and do not use grass ash to rub, grass ash is alkaline, with which to rub aluminum products, will shorten the service life. In addition, do not put acidic vegetables and other parties in the aluminum pot overnight.
Don't look at the aluminum oxide film so white, hard and beautiful gems in nature - corundum, but also aluminum oxide! He is a crystalline anhydrous aluminum oxide. Corundum's hardness is second only to diamond, often used to make metal products grinding wheels, watch bearings are mounted on the wear-resistant corundum. We often hear people talk about the "number of diamonds" in a watch, which refers to the number of corundum in the watch. In addition to watches, balances, clocks, ammeters and voltmeters also use corundum. Now, people from the bauxite mine to extract pure white alumina powder, placed in the hot furnace heating and melting, the production of artificial corundum, it is even harder than natural corundum.
Normal adult body **** contains 45 ~ 150 mg of aluminum, an average of 100 mg or so, and became a trace element in the human body. Usually, daily intake of aluminum from the general diet in the gastrointestinal tract 10 to 100 mg, the absorption rate of about 0.1%, the vast majority of fecal excretion. Normal people have the ability to excrete aluminum through the kidneys and other excretory organs when it enters the body in trace amounts.
But in recent years, research has found that the barrier effect of the human intestinal wall is not very perfect, when the person ingests too much aluminum, it will also be more into the tissue. And it is also difficult to excrete it quickly, thus stagnating in the organs.
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Ingesting too much aluminum on the human body of the harm
1. Excessive intake of aluminum is harmful to the bones
In Toronto, Canada, held a seminar on "Aluminum," Spencer confirmed that a small amount of long-term oral antacids containing aluminum on the bones of the elderly can pose a threat. To the elderly oral aluminum 30 mg, three times a day, can reduce the body's phosphorus storage, resulting in calcium deficiency. One of the reasons for this is that in the phosphorus consumption and lack of phosphorus and calcium release from the bone, fecal excretion of phosphorus increased, the amount of calcium excreted in the urine increased significantly; the second is that aluminum can form an insoluble complex with phosphate in food, so that the absorption of phosphorus is reduced; the third is that aluminum hydroxide is easy to form a complex with fluorine, so that the intake of fluorine in the food by 50%, the amount of fluorine in the skeleton to reduce the amount of fluorine deposition, the relative occurrence of fluorine deficiency Fluorine is an important regulator of mineral storage in bones. For these reasons, prolonged oral administration of aluminum hydroxide (even in small, intermittent doses) can result in calcium, phosphorus, and fluoride deficiencies, which can be seen clinically in decreased phosphate in the urine, hypercalciuria, weakness, discomfort, bone pain, and osteoporosis. It is particularly likely to occur in older people on low protein diets, taking aluminum on an empty stomach and alcoholism. Once a person's kidneys fail, the structure and function of the intestinal wall is malfunctioning, permeability increases, the barrier effect of the intestinal wall to aluminum is even lower, and the patient then undergoes the dialysis method, due to the amount of aluminum contained within the dialysis solution, even more aluminum enters the patient.
2. Able to cause damage to the brain
In recent years and found that the emergence of Alzheimer's disease is also related to the usual excessive intake of aluminum. As early as 1965, Krazow first found aluminum poisoning in the rabbit brain, the emergence of Alzheimer's disease unique neuronal fibers tangled lesions, but did not cause people to pay attention. Until 1973, he pointed out that according to the results of the cat's cerebral cortex aluminum content increased, so that the cat appeared obvious brain dysfunction, which only awakened the world alert. Once aluminum salts enter the body, they are first deposited in the brain, which may lead to brain damage and cause severe memory loss, a symptom specific to early-onset dementia. The researchers involved in the work said that experiments on rats showed measurable levels of aluminum in their brains after they were given just one glass of water treated with aluminum salts. The study of the rats found that trace amounts of aluminum mixed in with the drinking water entered the rats' brains and gradually built up there. The researchers' study of dementia patients found that 30% of the neocortical areas in the brains of such patients had aluminum concentrations greater than 4 micrograms per gram (dry weight), and that in the nuclei of neuron cells in the brains of the patients, aluminum levels were four times higher than those of healthy people, with a maximum of 30 times higher. The researchers believe that if aluminum accumulates gradually in the brain over time, it can kill the neurons and cause a person to lose their memory. Therefore, the intake of excessive aluminum will also cause loss of appetite and indigestion, affecting the intestinal absorption of phosphorus, strontium, iron, calcium and other elements.
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Major sources of excess aluminum in the human body
1. The use of aluminum cookware.
Since aluminum is a good conductor of heat, a lot of cookware is made of aluminum, which becomes one of the reasons why people consume too much aluminum. When cooking with aluminum cookware, the amount of aluminum that seeps from the cookware into the dish can generally account for about 20 percent of the daily intake of aluminum. If you use aluminum products to store acidic foods and dishes overnight, use aluminum containers to store or brew acidic beverages, or prolonged contact with salt will make the amount of aluminum in the food increased significantly, but also through food and drink will be aluminum intake. In particular, the mixing of aluminum cookware and iron cookware, such as stir-frying with aluminum pots and spatulas, under the action of salt, water, vinegar and heat, coupled with the stirring and friction of the spatula, it is easier to make aluminum into the food.
2. Aluminum in food.
(1) Vermicelli and doughnuts contain large amounts of aluminum.
The traditional vermicelli production process adds about 0.5% alum (). Alum mainly plays a role in coagulation, so that the fans, rice noodles, not for the strip, not sticky, not muddy soup. Alum contains aluminum, eat more easily in the body to form a chronic accumulation, aluminum poisoning, fans eat more, its aluminum is difficult to discharge by the kidneys. In order to make the doughnut expansion crisp, making doughnuts also added some alum, doughnuts eat more, the same threat to health.
(2) The fermentation agent contains aluminum.
The most common food containing high levels of aluminum is leavening agents, especially sodium aluminum phosphate baking powder. Home made pastry, food factory out of pastries, pancakes raw materials, cold dough contain more aluminum, and finally can make each (only) finished food products containing 5 to 15 mg of aluminum. The application of aluminum sulfate sodium salt for baking powder is also common, and each teaspoon can contain 70 mg of aluminum. If 1 to 3 teaspoons of baking powder is used, the final food can contain 5 to 15 mg of aluminum per serving (only) (equivalent to 1/4 to 3/4 of the daily intake of aluminum from the average diet). The United States in 1970 produced 18 million kilograms of aluminum phosphate sodium salt baking powder.
(3) pickles with the fixative (such as aluminum sulfate and alum) containing aluminum is very high, can obviously contaminate the pickles, and make the medium size of a cucumber contains 10 mg of aluminum.
3. Aluminum salt water purification.
It has been reported that one of the main reasons for the increase in aluminum content in tap water in North American countries is the application of alum precipitation and treatment of water. Widespread use of aluminum salts for water purification may lead to brain damage, resulting in severe memory loss, a symptom specific to Alzheimer's disease.
4. Aluminum in medicines.
Many medicines contain large amounts of aluminum. For example, the main ingredient in the treatment of stomach acid, "Gastropin", is aluminum hydroxide. Aluminum hydroxide is also found in Konpurin, which is used to treat rhinitis. The aluminum content of aluminum hydroxide is 34.6%, and long-term use of GastroSuprine can lead to excess aluminum in the body.
5. Dialysis therapy makes the body consume too much aluminum.
Dialysis therapy is an important treatment, hemodialysis, peritoneal dialysis has been widely used in clinical medicine. However, some patients, after the original lesions improved, have developed speech disorders, psychomotor disorders, depression, hallucinations, delusional mania, paroxysmal muscle spasms, mental retardation, progressive dementia, and 2/3 of the patients developed osteodystrophy. This has caused widespread concern and a number of studies have been conducted. It was later found that the cause of this disease is caused by the high concentration of aluminum in the water used for hemodialysis. Reversible dementia was also observed in some patients who had been taking oral aluminum gel for a long period of time, which caused an increase in the concentration of aluminum in the blood. It is further demonstrated that too much aluminum in the body can indeed cause dementia due to mental retardation.
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Prevention of Aluminum Poisoning
Everyone knows the importance of "prevention is better than cure," and the same rule applies to aluminum poisoning. Although normal people generally have the ability to control the absorption of aluminum, and also have the ability to excrete the aluminum inhaled into the body, and can effectively prevent what has entered the body into the brain. However, harmful effects occur beyond a certain point (e.g., large intakes) or due to old age, renal failure, and leakage from dialysis fluids into the body, brain, and bone. In these cases, the physiological barrier effect alone is not sufficient and other strong measures must be taken to prevent excessive ingestion and absorption of aluminum.
When the source of excess aluminum in the body is identified, corresponding measures can be taken to prevent aluminum poisoning.
1. Reduce the intake of aluminum from food
Eat as little as possible of vermicelli, doughnuts, and pasta made with aluminum-salted baking powder. Use yeast to ferment instead of aluminum-salt baking powder. Pickles should avoid or use less aluminum-containing substances as fixatives. Fried foods and puffed foods are high in aluminum, and children can be guided to eat less of these foods. In addition, puffed food and fried small foods generally have high fat, high calorie, high salt, high sugar, high MSG, etc. Its nutritional composition is not comprehensive, and fat, carbohydrates and protein are its main components. High-fat, high-calorie foods, will contribute to the acidification of body fluids, but also easy to bring obesity, diabetes, hypertension, hyperlipidemia and other diseases of affluence. And they all belong to the low crude fiber food, long-term consumption of large quantities of such food, if insufficient intake of crude fiber, exercise is not great, easy to cause the body fat accumulation. For children in the growth and development period, if the long-term consumption of large doses of aluminum content exceeds the standard of food, and even on the intellectual development of the impact.
Reminder: let the children drink less canned beverages experts reminded, do not let the children drink too much canned beverages, canned beverages, aluminum content than bottled beverages to be 3 to 5 times higher, so parents do not let the children drink too much canned beverages. At the same time, because most children like to snack on puffed food, parents should also pay attention to this.
2. Reduce the amount of aluminum in tap water
In order to avoid aluminum contamination of water sources, in addition to protecting the environment, it is necessary to use less aluminum-containing substances in precipitating water, making kettles and water pipes, and to use better methods of precipitating and treating water.
3. Reduce the intake of aluminum from medicines
Smaller or no use of aluminum-containing antacids, or use other antacids that do not contain aluminum to treat gastric and duodenal ulcers and digestive disorders such as high gastric acidity. In this way, on the one hand, it can prevent the patient from absorbing a large amount of aluminum, but also can prevent a large amount of aluminum with feces out of the body, polluting the environment and crops.
4. Reduce the amount of aluminum entering the human body through aluminum cookware
Less or no aluminum cooking vegetables, storage of acidic beverages, vegetables and salt, not to mention long-term storage of beverages, vinegar, salts and vegetables, to prevent aluminum poisoning and contamination, is one of the important measures.
5. Protect the environment, prevent aluminum pollution
Aluminum is originally the most abundant metal on the earth's crust, coupled with the vigorous mining of aluminum ore, aluminum refining, aluminum, aluminum, aluminum to do a variety of cookware, utensils, toys, as well as the square pan of aluminum preparations for the treatment of gastrointestinal disorders and precipitation of water with aluminum, aluminum pollution of the environment should attract the attention of everyone, to take the above measures, to minimize the aluminum environment, crops, food, water and air.
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