Anastasia Ksenofontova, Dmitry Alekseev
Global climate change has led to significant changes in the Arctic flora: over the past 30 years, the height of shrubs characteristic of these latitudes has increased by 8 cm. Russian and foreign scientists came to these conclusions by tracking, using images from space and field research, how the plants of Alaska and Canada were changing , Iceland, Scandinavia and the highlands of the North-West Caucasus. It turned out that tall tree-like shrubs began to displace mosses, grasses and lichens. According to experts, this accelerates the release of methane contained in permafrost, which provokes further climate change. However, a number of Russian experts believe that the studied areas do not reflect processes in the entire Arctic.
- globallookpress.com
- Ivan Dementievsky
An international group of researchers, which included Russian specialists from Moscow State University, found that global warming is leading to rapid changes in the Arctic flora. According to scientists, this disrupts the functioning of the local ecosystem: melting accelerates, resulting in the release of what is “preserved” in it. This, in turn, provokes new climate changes.
Trees instead of bushes
During the study, which lasted 30 years, experts studied the vegetation of the Arctic tundra in the territories of Alaska, Canada, Iceland, Scandinavia and the highlands of the Northwestern Caucasus. Using satellite images and field research, scientists were able to track how the functional characteristics of plants have changed over the past three decades: leaf canopy height, leaf area, wood density. The study revealed that all these parameters directly depend on the state of the ecosystem.
“Our study is unique in its scale: no one has ever analyzed the relationship between plant traits and climatic parameters over such a vast territory and over such a long period,” explained one of the authors of the study, head of the Department of Geobotany, Faculty of Biology, Moscow State University, Vladimir Onipchenko. “It was quite surprising for us to find that the biggest impact of rising temperatures is on plant height.”
The Arctic is home to hundreds of species of low-growing shrubs and grasses that play an important role in the carbon cycle. However, based on satellite imagery and field research, scientists have found that over the past 30 years, the height of shrubs has increased by about 8 cm, which is quite significant for Arctic vegetation.
There is another trend: plants characteristic of more southern latitudes are gradually taking over the Arctic tundra. Thus, the common fragrant spikelet, common on the European plains, is now found in Iceland.
The researchers concluded that if the growth rate of shrubs does not slow down, the average height of vegetation cover in the Arctic could increase by 20-60% before the end of the 21st century.
- Common fragrant spikelet
- Wikimedia
Such an increase, according to scientists, will lead to the melting of permafrost and an increase in average annual temperatures in the Arctic.
“Short plants hold more snow, which insulates the soil from cold and heat. Tall bushes cannot cope with this task. As a result, the growth of tundra vegetation will accelerate the thawing of permafrost and the release of greenhouse gases into the atmosphere,” said the lead author of the study, an employee of the University of Edinburgh, Anna Bjorkman.
Vicious circle
According to experts, the height of a plant is directly related to its ability to accumulate carbon, and the area of leaves is directly related to the rate of photosynthesis. The higher the plants become, the more active the cycle of substances and metabolic processes in the Arctic ecosystem occur.
“About 30-50% of the world’s carbon reserves are “conserved” in the form of methane compounds in permafrost. As the climate warms, methane compounds break down and the gas enters the atmosphere. We found that the changing vegetation cover of the Arctic plays a large role in the release of carbon,” said Bjorkman.
According to her, if permafrost thawing intensifies, then the volume of greenhouse gas emissions into the atmosphere will simultaneously increase.
“Thus, the process of global warming will accelerate,” the specialist noted.
However, some Russian scientists were skeptical about the results of the study. In their opinion, there are more significant indicators indicating the acceleration of global warming, for example, a reduction in the area of ice cover.
“It happens that scientists get too carried away with the search for new factors provoking climate change. I don’t think that the transformation of vegetation cover in the Arctic will affect the rate of methane release from permafrost,” Gennady Menzhulin, a professor at the Department of Climatology and Environmental Monitoring at St. Petersburg State University, said in an interview with RT.
The expert also emphasized that the increase in the height of shrubs is not observed in all areas of the Arctic, so it is not entirely correct to transpose the study’s conclusions to the entire region.
Mercury is poison!
Completed the presentation
physical education and life safety teacher
MBOU Grekovo-Stepanovskaya secondary school
Bedenko Galina Mikhailovna
Mercury
- Each of us has a medical thermometer at home, in other words, a thermometer. But it is so fragile, made of thin glass, and if there are also children in the apartment who could carelessly break it... We all know that a thermometer contains mercury. And a parent’s nightmare is coming home from work to see a broken thermometer on the floor and a small number of characteristic shiny balls-drops of metallic mercury. Is this mercury dangerous for humans, is it dangerous if it gets into the internal environment of an apartment, is there a danger from the thermometer for children?
If the thermometer breaks...
Is a broken thermometer dangerous for human health if it happens in an apartment?
If the mercury was collected immediately, then no, it is not dangerous. If not immediately, but after some period of time, then it’s also not scary. 1 gram of metallic mercury is a small amount to cause an increase in vapor concentration to critical levels. Intensive ventilation - and the air is almost clean.
Danger exists in the following cases:
1. mercury got on upholstered furniture, carpets, parquet cracks, children's toys, clothes, and rolled under baseboards.
2. The mercury was not collected, but was spread on the soles of slippers or boots throughout the apartment by an inattentive or careless tenant or a child.
3. mercury entered the digestive tract of a person (usually a child).
The worst case is the third. In such a situation, the clinical picture of poisoning appears immediately: Vomiting, choking, blue discoloration and other signs that are impossible not to notice. An ambulance must be called immediately.
In the first case, the danger is that the pile of the carpet and upholstered furniture very well absorbs small drops of mercury, which can be completely invisible in the structure of the fabric but, nevertheless, actively evaporate into the internal air of the room.
The same is true in the second case: mercury gets into the cracks of the parquet, into the pores of the linoleum throughout the apartment and evaporates evenly, filling the internal air with toxic fumes.
What to do if the thermometer is broken
1.Ventilate the room, put on protective equipment
2. Collect with wet cotton wool, paper, suck with a syringe, syringe, sweep with a brush or using a copper plate, wire into a jar of water
3. Transfer to a special service or civil defense headquarters
Is one broken thermometer enough to “poison” the air in an apartment?
No. If the thermometer is broken in the apartment and the mercury is not removed, then the concentration of vapors usually does not exceed the maximum permissible concentration.
What not to do
1.Do not touch with bare hands or inhale vapors for a long time.
2. You cannot collect mercury with a vacuum cleaner, broom, or magnet.
3. You cannot wash mercury down the drain, throw it in a garbage chute, or on the street.
How dangerous is mercury in indoor air?
According to Russian sanitary standards (SanPiN), the permissible maximum concentration of mercury in the indoor air of a residential premises is 0.0003 mg/m 3 . According to doctors, in a healthy adult, signs of chronic mercury poisoning begin to occur when this concentration of MPC is exceeded in the air of a living room 2-3 times. However, for children, 1.5 times the excess is enough .
It is worth considering that if the apartment you live in is not new, then there is a possibility that the thermometers in it have already been broken and the remaining vapors of the “old” mercury may, together with the “new” one, exceed the MPC level.
How long will mercury remain in the apartment if it is not collected?
Under ideal conditions (good ventilation), mercury in such an amount (less than 1 gram) will evaporate in a few months without causing harm to human health.
First actions
1. The very first thing to do if the thermometer breaks is to remove all its inhabitants from the room. Let children and animals spend some time outside or with friends, otherwise they may accidentally touch the silver balls and swallow them.
3.If you do not want to call the Ministry of Emergency Situations when the device breaks, and intend to cope on your own, then you need to wear gloves and a cotton-gauze bandage. The bandage is moistened in a solution of soda and water (a large spoon of soda per glass).
4.Put plastic bags on your shoes so you don’t have to dispose of your slippers later.
5.If you don’t have a bandage, you can quickly make one at home from a bandage folded in several layers. Or you can just go to the nearest pharmacy and buy a bandage and disposable shoe covers.
6.First, they collect the fragments of the broken thermometer from the floor, and then proceed to the mercury.
Mercury Collection Tools
How to collect mercury from the floor. Do not throw it in the household waste bin. Usually a container of water (jar) is used, since water prevents the evaporation of mercury. You need to take a jar that you can screw on with a lid. Here's how you can collect liquid metal that has scattered on the floor in small balls:
- rubber syringe;
- syringe;
- wet cotton wool;
- wet newspaper;
- copper plate;
- brush.
- We collect all the collected mercury from a broken thermometer in a jar of water, and after cleaning, you can also put your tool with which you collected the toxic metal. The jar is sealed and handed over to the employees of the sanitary and epidemiological service.
- Instead of a jar, mercury balls can be swept into a paper envelope with a brush or tassel, and then the remains can be collected with wet newspaper. All the mercury that you collected after the thermometer has broken is finally placed in an airtight container, a strong plastic bag or a rubber glove.
Wet cleaning
Try to collect all the mercury without using a vacuum cleaner (!!!), treat the floor and objects on which mercury has fallen with a solution of potassium permanganate (concentration is at your discretion), or with a chlorine-containing preparation. In the future, it is advisable to regularly wash the floor with a chlorine-containing preparation (several times) and intensive ventilation.
Carpet and furniture
In some cases, mercury from the thermometer can end up on the carpet. What should be done and what remedies should be used in this sad case?
The first thing you want to do when a device with mercury breaks is to collect everything with a vacuum cleaner. However, it will spread the already formed fumes throughout the room, plus the mercury inside will heat up and begin to evaporate intensively, and then you will have to clean the vacuum cleaner itself(or throw it away).
The carpet must be taken outside; if you live in your own home, you can leave it for several days to ventilate.
- If you break the device and mercury gets on the furniture, you need to wipe it with a strong solution of potassium permanganate, although this may cause some surfaces to become stained. Ventilate the room well every day and do not sit in it for a long time. Over time, the mercury will evaporate and disappear.
How not to collect mercury
Many people try to collect mercury from the floor with a broom or vacuum cleaner. This cannot be done, because then the metal will be very difficult to remove from the twigs of the broom, as well as from the inside of the vacuum cleaner. While a broom is easy to dispose of, the situation is different with a vacuum cleaner. If you subsequently use a vacuum cleaner that is poorly cleaned of mercury, you will spread harmful metal fumes throughout your home.
Some people have a desire to collect mercury from a broken thermometer with a magnet, but this will not yield anything, since, despite its metallic luster, mercury is diamagnetic. Moreover, when you try to collect the balls with a magnet, they may roll to the side. A diamagnetic substance actually interacts with a magnetic field, only very weakly and is not attracted, but repelled from the magnet.
- Let us explain why you should not throw mercury and a thermometer that has broken into the trash can or into the toilet. If you do this, the mercury will move from your home into the surrounding atmosphere. It can settle on sewer pipes and get into the ground and air, end up on car wheels, etc. Of course, a small amount of it is unlikely to harm the environment, but if all people do this, then in the end we ourselves will create an environment hazardous to our health. Let's at least think a little and take care of ourselves.
Why is mercury dangerous?
Mercury is a liquid metal that we most often see in a liquid state at home. The fact that this substance was toxic was known back in ancient times, so they treated it with caution. The vapors of this liquid metal can cause severe poisoning.
When the body is exposed to mercury or its compounds, diseases of the nervous system, kidneys, eyes, and skin occur, the immune system deteriorates, and general health deteriorates. Young children are highly susceptible to its influence.
If it seems to you that you don’t feel anything when you are constantly near a broken thermometer, then this feeling is deceptive. The fact is that mercury can accumulate in the body, that is, it is a cumulative poison, and over time the poisoning will make itself felt. You will feel headaches and weakness, and regular pills will not help you.
Don't throw away used batteries ki
Why are the substances in the battery dangerous for humans? Lead n accumulates mainly in the kidneys. It also causes brain diseases and nervous disorders. Cadmium n accumulates in the liver, kidneys, bones and thyroid gland. It is a carcinogen, meaning it causes cancer. Mercury V Affects the brain, nervous system, kidneys and liver. Causes nervous disorders, blurred vision, hearing, musculoskeletal disorders, and respiratory system diseases. Children are the most vulnerable. Metallic mercury is poison. According to the degree of impact on the human body, mercury belongs to the 1st hazard class - “extremely hazardous substances”. Regardless of the route of entry into the body, mercury accumulates in the kidneys.
Damage from used batteries
1. According to scientists, the harm of used batteries is much worse than we can imagine: one battery, for example, can turn more than 400 liters of water into poison and pollute about 20 square meters of soil. Of course, the harm from batteries also extends to people, in whose bodies toxic waste can cause irreversible damage and diseases such as cancer, brain disease, kidney disease and liver disease.
2. Another reason why you should not throw away batteries is the presence of lead dioxin and other equally dangerous dioxins in their composition, which, if ignited, can affect the body of a person located at a distance of several tens of kilometers.
Do not throw away batteries
1. Most of us, having learned why we should not throw away batteries, wonder: if they are so dangerous, then where should we throw away the batteries so that they do not cause so much harm? The answer to this question is categorical - batteries should not be thrown away! In addition, batteries should not be burned, thrown into bodies of water, or buried in the ground. How to dispose of batteries in this case?
2. Recycling batteries is extremely expensive, so there are only a few recycling plants in the world that process batteries into environmentally friendly waste.
3. Remember, even the safest batteries, according to manufacturers, can cause irreparable harm not only to the environment around you, but also to you personally, your family and every inhabitant of our planet. Therefore, recycling batteries is your responsibility, compliance with which will allow us to enjoy life on a clean earth. In the meantime, place used batteries in a plastic bottle with a tight-fitting cap.
Perhaps mercury is one of the few chemical elements that has a lot of interesting properties, as well as the widest scope of application in the entire history of mankind. Here are just some interesting facts about this chemical element.
First of all, mercury is the only metal and the second substance (along with bromine) that remains in a liquid state at room temperature. It becomes solid only at a temperature of –39 degrees. But raising it to +356 degrees causes the mercury to boil and turn into toxic steam. Due to its density, it has a high specific gravity (see the article The heaviest metals in the world). So, 1 liter of the substance weighs more than 13 kilograms.
Cast iron core floats in mercury
In nature, it can be found in its pure form - interspersed with small drops in other rocks. But most often mercury was extracted by burning the mercury mineral cinnabar. Also, the presence of mercury can be found in sulfide minerals, shales, etc.
Due to its color, in ancient times this metal was even identified with living silver, as evidenced by one of its Latin names: argentum vivum. And this is no wonder, because being in its natural state - liquid, it is able to “run” faster than water.
Due to its excellent electrical conductivity, mercury is widely used in the manufacture of lighting fixtures and switches. But mercury salts are used in the manufacture of various substances, from antiseptics to explosives.
Humanity has been using mercury for more than 3,000 years. Due to its toxicity, it was actively used by ancient chemists to extract gold, silver, platinum and other metals from ore. This method, called amalgatation, was later forgotten and was returned to only in the 16th century. Perhaps it was thanks to him that the mining of gold and silver by the colonizers of South America at one time reached colossal proportions.
A special place in the use of mercury in the Middle Ages was its use in mystical rituals. Sprayed red cinnabar powder, according to shamans and magicians, was supposed to scare away evil spirits. “Living silver” was also used to extract gold alchemically.
But mercury became a metal only in 1759, when Mikhail Lomonosov and Joseph Brown were able to prove this fact.
Despite its toxicity, mercury was actively used by ancient healers in the treatment of various diseases. Based on it, medications and potions were made to treat various skin diseases. It was part of diuretics and laxatives and was used in dentistry. And the yogis of ancient India, according to the notes of Marco Polo, drank a drink based on sulfur and mercury, which extended their life and gave them strength. There are also known cases of Chinese healers making “immortality pills” based on this metal.
In medical practice, there are known cases of using mercury in the treatment of volvulus. According to doctors of those times, due to its physical properties, “liquid silver” was supposed to pass through the intestines, straightening them. But this method did not take root, as it had very disastrous results - patients died from intestinal rupture.
Today in medicine, mercury can only be found in thermometers that measure body temperature. But even in this niche it is gradually being replaced by electronics.
But despite the attributed beneficial properties, mercury also has destructive properties on the human body. So, according to scientists, the Russian Tsar Ivan the Terrible became a victim of mercury “treatment”. During the exhumation of his remains, modern experts established that the Russian sovereign died as a result of mercury intoxication, which he received during treatment for syphilis.
The use of mercury salts was also disastrous for medieval hat makers. Gradual poisoning by mercury vapor became the cause of dementia, called the mad hatter's disease. This fact was reflected in Lewis Carroll's Alice in Wonderland. The author perfectly depicted this illness in the image of the Mad Hatter.
But using mercury for the purpose of suicide, on the contrary, was not successful. There are known facts when people drank it or made intravenous mercury injections. And they all remained alive.
Uses of mercury
In the modern world, mercury has found wide application in electronics, where components based on it are used in all kinds of lamps and other electrical equipment; it is used in medicine for the production of certain medicines and in agriculture for seed processing. Mercury is used to produce paint that is used to paint ships. The fact is that colonies of bacteria and microorganisms can form on the underwater part of the ship, which destroy the hull. Mercury-based paint prevents this destructive effect. This metal is also used in oil refining to regulate the temperature of the process.
But scientists don't stop there. Today, a lot of work is being done to study the beneficial properties of this metal with its subsequent use in mechanics and the chemical industry.
Mercury: 7 Quick Facts
- Mercury is the only metal that, under normal conditions, is in a liquid state.
- It is possible to make alloys of mercury with all metals except iron and platinum.
- Mercury is a very heavy metal because... has enormous density. For example, 1 liter of mercury has a mass of about 14 kg.
- Metallic mercury is not as poisonous as is commonly believed. The most dangerous are mercury vapor and its soluble compounds. Metallic mercury itself is not absorbed in the gastrointestinal tract and is excreted from the body.
- Mercury cannot be transported on airplanes. But not because of its toxicity, as it might seem at first glance. The thing is that mercury, in contact with aluminum alloys, makes them brittle. Therefore, an accidental spill of mercury can damage the aircraft.
- The ability of mercury to expand evenly when heated has found wide application in various kinds of thermometers.
- Remember the Mad Hatter from Alice in Wonderland? So before, such “hatters” actually existed. The thing is that the felt used to make hats was treated with mercury compounds. Gradually, mercury accumulated in the master’s body, and one of the symptoms of mercury poisoning is severe mental disorder; in other words, hatters often ended up going crazy.
Introduction Mercury (lat. Hudrargyrum) is a chemical element of group 2 of Mendeleev’s periodic system; atomic number 80, atomic mass 200.59. Mercury is a heavy (density 13.52 g/cm3) silvery-white metal, the only metal that is liquid under normal conditions. When heated, mercury expands quite strongly, conducts electricity and heat poorly - 50 times worse than silver. Many metals dissolve well in mercury to form an amalgam.
Obtaining mercury Mercury ores containing mercury in the form of cinnabar are subjected to oxidative roasting. HgS + O2 = Hg + SO2 The roasting gases, after passing through the dust collection chamber, enter a tubular refrigerator made of stainless steel or Monel metal. Liquid mercury flows into iron receivers. To purify, raw mercury is passed in a thin stream through a high (1 - 1.5 m) vessel with 10% HNO3, washed with water, dried and distilled in vacuum. Methods have been developed for extracting mercury by electrolysis of sulfide solutions.
Distribution of Mercury in nature Mercury is one of the very rare elements. It is found in approximately the same quantities in igneous rocks. Its migration in the gaseous state and in aqueous solutions plays an important role in geochemistry. Mercury is predominantly dispersed in the earth's crust; precipitates from hot underground waters, forming mercury ores (their mercury content is several percent). 35 mercury minerals are known; the most important of them is cinnabar HgS. In the biosphere, mercury is mainly dissipated and only in minor amounts. quantities are sorbed by clays and silts (in clays and shales on average 4.10–5%). Sea water contains 3.10–9% mercury. Native mercury, found in nature, is formed during the oxidation of cinnabar into sulfate and the decomposition of the latter, during volcanic eruptions (rarely), hydrothermally (is released from aqueous solutions).
Historical background Native mercury was known 2000 years before. e. peoples of India and China. They, as well as the Greeks and Romans, used cinnabar (natural HgS) as a coloring, medicinal and cosmetic product. Alchemists considered mercury the main component of all metals. “Fixation” of mercury (transition into a solid state) was recognized as the first condition for its transformation into gold. Solid mercury was first obtained in December 1759 by St. Petersburg academicians I. A. Braun and M. V. Lomonosov. Scientists managed to freeze mercury in a mixture of snow and concentrated nitric acid. In Lomonosov's experiments, hardened mercury turned out to be malleable, like lead. The news of the “fixation” of mercury created a sensation in the scientific world of that time; it provided one of the most convincing evidence that mercury is a metal like all others.
Application Mercury is widely used in the manufacture of scientific instruments (barometers, thermometers, pressure gauges, vacuum pumps, etc.), in mercury lamps, switches, rectifiers; as a liquid cathode in the production of caustic alkalis and chlorine by electrolysis, as a catalyst in the synthesis of acetic acid, in metallurgy for the amalgamation of gold and silver, in the manufacture of explosives; in medicine (calomel, sublimate, organomercury and other compounds), as a pigment (cinnabar), in agriculture (organic mercury compounds) as a seed protectant and herbicide, and also as a component of the paint of sea ships (to combat fouling of their organisms ). Mercury and its compounds are toxic, so working with them requires taking the necessary precautions.
Poisoning The main danger is metallic mercury vapor, the release of which from open surfaces increases with increasing air temperature. When inhaled, mercury enters the bloodstream. In the body, mercury circulates in the blood, combining with proteins; partially deposited in the liver, kidneys, spleen, brain tissue, etc. The toxic effect is associated with disruption of the brain (primarily the hypothalamus). Mercury is eliminated from the body through the kidneys, intestines, sweat glands, etc. Acute poisoning with mercury and its vapors is rare. In chronic poisoning, emotional instability, irritability, decreased performance, sleep disturbance, trembling of fingers, decreased sense of smell, and headaches are observed. A characteristic sign of poisoning is the appearance of a blue-black border along the edge of the gums.
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