Many people do not even realize how many dangers the air they breathe can be fraught with. A variety of elements may be present in its composition - some are completely harmless to the human body, others are the causative agents of the most serious and dangerous diseases. For example, many people are aware of the danger that radiation, but not everyone realizes that an increased share can be easily obtained in Everyday life. Some people mistake symptoms from exposure to increased levels of radioactivity for signs of other illnesses. A general deterioration in well-being, dizziness, body aches - a person is used to associating them with completely different root causes. But this is very dangerous because radiation can lead to very serious consequences, and a person spends time fighting far-fetched diseases. The mistake of many people is that they do not believe in the possibility of obtaining radiation doses in your daily life.
What is radon?
Many people believe that they are sufficiently protected because they live far enough from workers. nuclear power plants, do not visit warships powered by nuclear fuel with excursions, and they heard about Chernobyl only from films, books, news and games. Unfortunately, it is not! Radiation is present around us everywhere - it is important to be where its quantity is within acceptable limits.
So, what can hide the ordinary air surrounding us? Do not know? We will simplify your task by giving a leading question, and immediately the answer to it:
- radioactive gas 5 letters?
- Radon.
The first prerequisites for the discovery of this element were made at the end of the nineteenth century by the legendary Pierre and Marie Curie. Subsequently, other well-known scientists became interested in their research, who were able to identify radon in its purest form in 1908, and describe some of its characteristics. During its history of official existence, this gas changed many names, and only in 1923 did the ode become known as radon- 86th element in periodic table Mendeleev.
How does radon gas enter the premises?
Radon. It is this element that can imperceptibly surround a person in his house, apartment, office. Gradually lead to a deterioration in the health of people cause very serious illness. But it is very difficult to avoid danger - one of the dangers that is fraught with radon gas, lies in the fact that it cannot be determined by color or smell. Radon nothing is released from the surrounding air, so it can imperceptibly irradiate a person for a very long time.
But how can this gas appear in ordinary rooms where people live and work?
Where and most importantly how can radon be detected?
Quite logical questions. One source of radon is the layers of soil that are located under buildings. There are many substances that release this gas. For example, ordinary granite. That is, the material that is actively used in construction work(for example, as an additive in asphalt, concrete) or is found in large quantities directly in the Earth. To the surface gas can carry groundwater, especially during heavy rains, do not forget about deep-water wells, from where many people draw invaluable liquid. Another source of this radioactive gas is food - in agriculture Radon is used to activate feed.
The main trouble is that a person can settle in an ecologically clean place, but this will not give him a full guarantee of protection from the harmful effects of radon. Gas can penetrate into his abode with food, tap water, as evaporation after rain, from the surrounding elements of the decoration of the building and the materials from which it was erected. There will not be a person every time ordering or buying something to be interested in radiation level at the place of production of the purchased products?
Outcome - radon gas can be concentrated in hazardous quantities in areas where people live and work. Therefore, it is important to know the answer to the second question posed above.
Premises at risk
Radon is much heavier than air. That is, when it enters the air, its main volume is concentrated in the lower layers of the air. Therefore, apartments of multi-storey buildings on the ground floors, private households, basements and semi-basements are considered potentially dangerous places. efficient way to get rid From this threat is the constant ventilation of the premises and the detection of the source of radon. In the first case, dangerous concentrations of radon can be avoided, which could appear randomly in the building. In the second - to destroy the source of its constant occurrence. Naturally, most people do not think much about some of the characteristics of the building materials used, and in the cold season they do not always ventilate the premises. Many basements do not have a natural or forced ventilation system at all, and therefore become a source of concentration of dangerous amounts of this radioactive gas.
87. Radioactive gas radon and the rules for protection against its effects.
Harmful effects of radon gas and methods of protection
The largest contribution to the collective radiation dose of Russians is provided by radon gas.
Radon is an inert heavy gas (7.5 times heavier than air) that is released from the soil everywhere or from some building materials (eg granite, pumice, red clay bricks). Radon has neither smell nor color, which means that it cannot be detected without special radiometer devices. This gas and its decay products emit very dangerous (α-particles that destroy living cells. Sticking to microscopic dust particles, (α-particles create a radioactive aerosol. We inhale it - this is how the cells of the respiratory organs are irradiated. Significant doses can cause lung cancer or leukemia.
Regional programs are being developed that provide for radiation inspection of construction sites, children's institutions, residential and industrial buildings, control over the content of radon in the atmospheric air. Within the framework of the program, firstly, the content of radon in the atmosphere of the city is constantly measured.
Homes should be well insulated from radon penetration. During the construction of the foundation, anti-radon protection is necessarily carried out - for example, bitumen is laid between the plates. And the content of radon in such rooms requires constant monitoring.
Exposure dose
A measure of air ionization as a result of exposure to photons, equal to the ratio the total electric charge dQ of ions of the same sign, formed by ionizing radiation absorbed in a certain mass of air, to the mass dM
Dexp = dQ / dM
The unit of measurement (off-system) is roentgen (P). At Dexp = 1 P in 1 cm3 of air at 0o C and 760 mm Hg (dM = 0.001293 g), 2.08.109 pairs of ions are formed, carrying a charge dQ = 1 electrostatic unit of the amount of electricity of each sign. This corresponds to an energy absorption of 0.113 erg/cm3 or 87.3 erg/g; for photon radiation Dexp = 1 P corresponds to 0.873 rad in air and about 0.96 rad in biological tissue.
89. Absorbed dose
The ratio of the total energy of ionizing radiation dE absorbed by a substance to the mass of the substance dM
Dab = dE/dM
Unit of measurement (SI) - Gray (Gy), corresponding to the absorption of 1 J of ionizing radiation energy of 1 kg of substance. The non-systemic unit is rad, corresponding to the absorption of 100 egr of substance energy (1 rad = 0.01 Gy).
90. Equivalent dose:
Deqv = kDabs
where k is the so-called radiation quality factor (dimensionless), which is a criterion of relative biological effectiveness in chronic irradiation of living organisms. The larger k, the more dangerous exposure for the same absorbed dose. For monoenergetic electrons, positrons, beta particles and gamma quanta k = 1; for neutrons with energy E< 20 кэВ k = 3; для нейтронов с энергией 0, 1 < E <10 МэB и протонов с E < 20 кэB k = 10; для альфа-частиц и тяжелых ядер отдачи k = 20. Единица измерения эквивалентной дозы (СИ) - зиверт (Зв), внесистемная единица - бэр (1 бэр = 0, 01 Зв) .
Sanitary protection zone of the enterprise.
Environmental assessment of industries and enterprises. Environmental impact assessment (EIA).
91. The fight against radioactive contamination of the environment can only be of a preventive nature, since there are no methods of biological decomposition and other mechanisms that can neutralize this type of contamination of the natural environment. The greatest danger is posed by radioactive substances with a half-life of several weeks to several years: this time is sufficient for the penetration of such substances into the body of plants and animals.
storage of nuclear waste seems to be the most acute problem of protecting the environment from radioactive contamination. At the same time, special attention should be paid to measures that eliminate the risk of radioactive contamination of the environment (including in the distant future), in particular, to ensure the independence of emission control authorities from the departments responsible for production atomic energy.
92.Biological pollution of the environment - bringing into the ecosystem and reproduction of alien species of organisms. Contamination by microorganisms is also called bacteriological or microbiological contamination.
Biologist. loading- 1-biotic (biogenic) and 2- microbiological (microbial)
1. distribution in the environment of biogenic substances - emissions from enterprises, production of certain types of food (meat processing plants, dairies, breweries), enterprises producing antibiotics, as well as pollution by animal corpses. B.z. leads to disruption of the processes of self-purification of water and soil. 2. occurs due to the masses. the size of microorgs in environments changed in the course of economic activity of people.
93.environmental monitoring -an information system for observing, assessing and predicting changes in the state of the environment, created to highlight the anthropogenic component of these changes against the background of natural processes.
94. The territorial bodies of the State Committee for Ecology of Russia, together with the executive authorities of the constituent entities of the Russian Federation, conducted an inventory of storage and disposal sites for production and consumption waste in more than 30 constituent entities of the Russian Federation. The results of the inventory make it possible to systematize information about the places of storage, storage and disposal of waste, to assess the degree of filling of the presence of free volumes in the places of storage and disposal of waste, to determine the types of waste accumulated in these places, including by hazard classes, to assess the conditions and condition of the places disposal of waste and the degree of their impact on the environment, as well as to make proposals for the implementation of certain measures to prevent environmental pollution by production and consumption waste.
95. One of the main problems of our time is the disposal and processing of MSW - municipal solid waste . It is still difficult to talk about cardinal changes in this area in our country. As for European countries and the USA, there people have long come to the conclusion that the resource potential of MSW should not be destroyed, but used. It is impossible to approach the problem of MSW as a fight against garbage, setting the task to get rid of it at any cost.
But even in Russia, technological lines have already been created, where secondary raw materials are washed, crushed, dried, fused and turned into granules. Using the revived polymer as a binder, it is possible to produce, including from the most tonnage and inconvenient waste for processing - phosphogypsum and lignin, beautiful bricks, paving slabs, tiles, decorative fences, curbs, benches, various household goods and construction materials .
As the first months of operation showed, the quality of the "reanimated" polymer is not worse than the primary one, and it can even be used in its "pure" form. This significantly expands the scope of its application.
96. Pesticides. Pesticides are a group of man-made substances used to control pests and plant diseases. Pesticides are divided into the following groups: insecticides - to combat harmful insects, fungicides and bactericides - to combat bacterial plant diseases, herbicides - against weeds. It has been established that pesticides, destroying pests, harm many beneficial organisms and undermine the health of biocenoses. In agriculture, there has long been a problem of transition from chemical (polluting) to biological (environmentally friendly) methods of pest control. Currently, more than 5 million tons. pesticides enter the world market. About 1.5 million tons. of these substances has already entered the composition of terrestrial and marine ecosystems by ash and water. The industrial production of pesticides is accompanied by the appearance of a large number of by-products that pollute wastewater. In the aquatic environment, representatives of insecticides, fungicides and herbicides are more common than others. Synthesized insecticides are divided into three main groups: organochlorine, organophosphorus and carbonates. Organochlorine insecticides are obtained by chlorination of aromatic and heterocyclic liquid hydrocarbons. These include DDT and its derivatives, in the molecules of which the stability of aliphatic and aromatic groups in the joint presence increases, various chlorinated derivatives of chlorodiene (eldrin). These substances have a half-life of up to several decades and are very resistant to biodegradation. In the aquatic environment, polychlorinated biphenyls are often found - derivatives of DDT without an aliphatic part, numbering 210 homologues and isomers. Over the past 40 years, more than 1.2 million tons have been used. polychlorinated biphenyls in the production of plastics, dyes, transformers, capacitors. Polychlorinated biphenyls (PCBs) enter the environment as a result of discharges from industrial Wastewater and combustion of solid
waste in landfills. The latter source delivers PBCs to the atmosphere, from where they fall out with atmospheric precipitation in all regions of the globe. Thus, in snow samples taken in Antarctica, the content of PBC was 0.03 - 1.2 kg/l.
97. Nitrates - salts of nitric acid, for example NaNO 3, KNO 3, NH 4 NO 3, Mg (NO 3) 2. They are normal metabolic products of nitrogenous substances of any living organism - plant and animal, so there are no "nitrate-free" products in nature. Even in the human body, 100 mg or more of nitrates are formed and used in metabolic processes per day. Of the nitrates that enter the body of an adult every day, 70% comes from vegetables, 20% from water and 6% from meat and canned foods. When consumed in increased amounts, nitrates in the digestive tract are partially reduced to nitrites (more toxic compounds), and the latter, when released into the blood, can cause methemoglobinemia. In addition, N-nitrosamines can be formed from nitrites in the presence of amines, which have carcinogenic activity (contribute to the formation of cancerous tumors). When taking high doses of nitrates with drinking water or food, nausea, shortness of breath, blueness of the skin and mucous membranes, and diarrhea appear after 4-6 hours. All this is accompanied by general weakness, dizziness, pain in the occipital region, palpitations. First aid - abundant gastric lavage, intake of activated charcoal, saline laxatives, fresh air. The allowable daily dose of nitrates for an adult is 325 mg per day. As you know, the presence of nitrates up to 45 mg / l is allowed in drinking water.
Gas is one of the aggregate states of matter. Gases are present not only in the air on Earth, but also in space. They are associated with lightness, weightlessness, volatility. The lightest is hydrogen. What is the heaviest gas? Let's find out.
The heaviest gases
The word "gas" comes from the ancient Greek word "chaos". Its particles are mobile and weakly bound to each other. They move randomly, filling all the space available to them. A gas can be a simple element and consist of atoms of one substance, or it can be a combination of several.
The simplest heavy gas (at room temperature) is radon, its molar mass is 222 g/mol. It is radioactive and completely colorless. After it, xenon is considered the heaviest, the atomic mass of which is 131 g / mol. The remaining heavy gases are compounds.
Among inorganic compounds, the heaviest gas at a temperature of +20 o C is tungsten (VI) fluoride. Its molar mass is 297.84 g/mol and its density is 12.9 g/l. Under normal conditions, it is a colorless gas; in humid air, it smokes and turns blue. Tungsten hexafluoride is very active, it easily turns into a liquid when cooled.
Radon
The discovery of the gas occurred during a period of research into the study of radioactivity. During the decay of some elements, scientists have repeatedly noted some substance emitted along with other particles. E. Rutherford called it an emanation.
Thus, the emanation of thorium - thoron, radium - radon, actinium - actinon was discovered. Later it was found that all these emanations are isotopes of the same element - an inert gas. Robert Gray and William Ramsay first isolated it in its pure form and measured its properties.
In the periodic table of Mendeleev, radon is an element of the 18th group with atomic number 86. It is located between astatine and francium. Under normal conditions, the substance is a gas, has no taste, smell and color.
Gas is 7.5 times denser than air. It is more soluble in water than other noble gases. In solvents, this figure increases even more. Of all the inert gases, it is the most active, easily interacting with fluorine and oxygen.
radioactive gas radon
One of the properties of an element is radioactivity. The element has about thirty isotopes: four are natural, the rest are artificial. All of them are unstable and subject to radioactive decay. radon, more precisely, its most stable isotope, is 3.8 days.
Due to its high radioactivity, the gas exhibits fluorescence. In the gaseous and liquid state, the substance is highlighted in blue. Solid radon changes its palette from yellow to red when cooled to nitrogen temperature - about -160 o C.
Radon can be very toxic to humans. As a result of its decay, heavy non-volatile products are formed, for example, polonium, lead, bismuth. They are extremely poorly excreted from the body. Settling and accumulating, these substances poison the body. After smoking, radon is the second most common cause of lung cancer.
Location and use of radon
The heaviest gas is one of the rarest elements in the earth's crust. In nature, radon is part of ores containing uranium-238, thorium-232, uranium-235. When they decay, it is released, falling into the hydrosphere and atmosphere of the Earth.
Radon accumulates in river and sea waters, in plants and soil, in building materials. In the atmosphere, its content increases during the activity of volcanoes and earthquakes, during the extraction of phosphates and the operation of geothermal power stations.
With the help of this gas, tectonic faults, deposits of thorium and uranium are found. It is used in agriculture to activate pet food. Radon is used in metallurgy, in the study of groundwater in hydrology, and radon baths are popular in medicine.
