And man
Remember!
What is the role of man in the biosphere?
Early stages of human development. Humanity's influence on the biosphere began at the moment when people moved from gathering to hunting and farming. According to scientists, already in the life of Pithecanthropus (the most ancient people), hunting was of great importance. At their sites, which are more than 1 million years old, bones of large animals are found.
Approximately 55–30 thousand years ago, during the Stone Age (Paleolithic), the economic basis of human society was hunting large animals: deer, woolly rhinoceros, mammoth, horse, aurochs, wild ox, bison and many others. Neanderthals (ancient people) already had dozens of types of stone tools that they used as daggers and spearheads, for scraping and cutting carcasses. Being skilled hunters, they drove animals to cliffs and swamps. Such actions were only possible for a coordinated team.
In the Upper Paleolithic, hunting became much more advanced, which played a huge role in the development of mankind (Fig. 172). Neoanthropes (modern humans) made tools from bone. An important innovation was the creation of a spear thrower, with the help of which the Cro-Magnons could throw spears twice as far. Harpoons made it possible to effectively catch fish. Cro-Magnons invented snares for birds and traps for animals. Hunting for large animals was improved: reindeer and ibex were pursued during their seasonal migrations. Hunting techniques using knowledge of the area (driven hunting) made it possible to kill animals in the hundreds, which led to the predatory extermination of animals. While studying Cro-Magnon sites, archaeologists discovered huge accumulations of bones. Thus, on the territory of the modern Czech Republic, the remains of the skeletons of 100 mammoths were found in one place, in a ravine near Amvrosievka in Ukraine - the skeletons of 1000 bison, and near the city of Solutre (France) - the skeletons of 10 thousand wild horses. Hunting for Cro-Magnons became a constant source of highly nutritious food.
Rice. 172. Hunting of Cro-Magnons. Rock paintings from a cave in Spain
About 10 thousand years ago, the glacier retreated, a sharp warming occurred, forests replaced the tundra in Europe, and many large animals became extinct. Such changes completed a certain stage in the economic development of mankind.
In the next era (New Stone Age), along with hunting, fishing and gathering, cattle breeding and agriculture became increasingly important. Man domesticates animals and breeds plants. The development of mineral resources begins and metallurgy is born. Humanity is increasingly using the resources of the biosphere for its needs.
With the transition to cattle breeding and agriculture, people began to destroy established natural communities. Huge herds of domestic ungulates knocked out vegetation, and semi-deserts replaced steppes and savannas. The use of fire to destroy vegetation and free up land for crops led to the replacement of forests with savannas. However, these destructions of communities have not yet had a global impact on the biosphere as a whole.
Modern era. Over the past two centuries, the pace of social development has accelerated sharply. The world's population increased significantly, industrial production increased, and more and more land was used for agricultural land. A qualitatively new stage has begun in the development of the biosphere, when human activity, transforming the Earth, has become commensurate in scale with geological processes. Vernadsky wrote that the biogeochemical role of humans in the 20th century. began to significantly exceed the role of other, most biogeochemically active organisms. There is not a single piece of land or sea left on Earth where traces of human activity cannot be found. Anthropogenic impact on the biosphere in the 20th century. took on a global character and threatened its stable existence.
According to scientists, during the entire existence of man, about 100 billion people lived on Earth. This means that approximately one in seventeen of all people who have lived on our planet is alive today. At the same time, when the Egyptian pyramids were built (about 4 thousand years ago), 50 million people lived in the world (today this is how many live in England alone), at the beginning of our era - 200 million. In the first half of the 19th century. The world's population exceeded one billion, and in the second half of the 20th century. has also more than tripled (Fig. 173).
Rice. 173. Growth of the Earth's population
Human influence on wildlife consists of direct and indirect changes in the natural environment.
Excessive exploitation and pollution of the biosphere disrupt the balanced existence of natural communities, leading to a decrease in species diversity. The construction of cities, the construction of roads and tunnels, and the construction of dams are not directly aimed at destroying existing ecosystems, but have a serious impact on nature. However, there is also a direct impact on living organisms, for example, cutting down trees.
Not so long ago, forests covered almost a third of the land. The global destruction of forest vegetation was caused by the need for new agricultural land - fields and pastures. Tropical forests are disappearing at a particularly rapid rate. According to scientists, currently about 12 million hectares of forest are cut down annually, an area equal to the territory of England, and almost as many more die due to irrational farming and selective cutting of the most valuable tree species. Deforestation greatly worsens the condition of the biosphere as a whole.
In place of the cut down forest, the shade-loving vegetation of the lower tiers disappears, and light-loving plants that are resistant to lack of moisture and elevated temperatures take root. The animal world is changing. Surface water flow increases, which leads to changes in the hydrological regime of water bodies and increases the likelihood of floods. Deforestation increases soil erosion and increases the amount of carbon dioxide in the atmosphere.
Rice. 174. Extinct species of animals: A – dodo; B – tarpan; B – great auk
But it's not just forests that are disappearing. The Eurasian steppes and US prairies, tundra and coral reef ecosystems are communities whose existence is under threat, and their numbers are growing every year.
More species have gone extinct on Earth in the last 300 years than in the previous 10 millennia. This list includes the aurochs and the dodo, Steller's cow and the wild horse tarpan, the African blue antelope and the passenger pigeon, the Turanian tiger and the great auk (Fig. 174). Scientists estimate that currently, on average, one species goes extinct every day. Thousands of animal species are on the verge of extinction or are preserved only in nature reserves. Small populations with limited habitat are especially vulnerable. So on the verge of extinction in the 90s. XX century there was a giant panda, which is found in southwest China and feeds exclusively on young bamboo shoots (Fig. 175). Population growth and the clearing of forests for agricultural land have led to the fact that the area of bamboo jungle has sharply decreased and pandas began to die of starvation. The created reserves and a special program for breeding pandas in captivity using artificial insemination made it possible to prevent the extinction of the species and increase its number to a thousand individuals.
Humanity is interested in preserving species diversity not only from an ecological point of view. Most people recognize ethical and aesthetic reasons, which are sometimes difficult to support with objective data and arguments. There are also utilitarian reasons.
In conditions when planet Earth becomes the single home of humanity, many contradictions, conflicts, and problems can outgrow local boundaries and acquire a global character.
The influence of primitive man on the environment was practically invisible. Primitive people did not have such things in everyday life that could pollute the environment to such an extent as they do now.
Today it is important to recognize the inextricable connection between nature and society, which is reciprocal. Here it is appropriate to recall the words of A.I. Herzen that “nature cannot contradict man unless man contradicts its laws.” On the one hand, the natural environment, geographical and climatic features have a significant impact on social development. These factors can accelerate or slow down the pace of development of countries and peoples and influence the social development of labor.
On the other hand, society influences the natural environment of humans. The history of mankind testifies to both the beneficial effects of human activity on the natural environment and its harmful consequences.
There is no need to prove that social life is in constant change. The German philosopher of the early 19th century, Hegel, argued that social development is a movement forward from imperfect to more perfect. The criteria for progress are the development of reason and public morality, which underlies the improvement of all aspects of social life.
Let us recall the famous words of Turgenev’s hero Bazarov: “Nature is not a temple, but a workshop, and man is a worker in it.” What this installation leads and has already led to today is well known based on specific facts.
Let me highlight just a few of them. The growth in the scale of human economic activity and the rapid development of the scientific and technological revolution have increased the negative impact on nature and led to a disruption of the ecological balance on the planet.
Consumption in the sphere of material production of natural resources has increased. In the years after the Second World War, as many mineral raw materials were used as in the entire previous history of mankind. Since the reserves of coal, oil, gas, iron and other minerals are not renewable, they will be exhausted, according to scientists, in a few decades. But even if the resources that are constantly renewed are in fact rapidly declining, deforestation on a global scale significantly exceeds the growth of wood, and the area of forests that provide oxygen to the earth decreases every year.
The main foundation of life—soils everywhere on Earth—are degrading. While the Earth accumulates one centimeter of black soil in 300 years, now one centimeter of soil dies in three years. No less dangerous is the pollution of the planet. The world's oceans are constantly being polluted due to the expansion of oil production in marine fields. Huge oil spills are detrimental to ocean life. Millions of tons of phosphorus, lead, and radioactive waste are dumped into the ocean. For every square kilometer of ocean water there are now 17 tons of various land wastes.
Fresh water has become the most vulnerable part of nature. Sewage, pesticides, fertilizers, mercury, arsenic, lead and much more find their way into rivers and lakes in huge quantities. The Danube, Volga, Rhine, Mississippi, and Great American Lakes are heavily polluted. According to experts, in some areas of the world 80% of all diseases are caused by poor quality water. Air pollution has exceeded all permissible limits.
The concentration of substances harmful to health in the air exceeds medical standards in many cities by tens of times. Acid rain, containing sulfur dioxide and nitrogen oxide, resulting from the operation of thermal power plants and factories, brings death to lakes and forests. The accident at the Chernobyl nuclear power plant showed the environmental threat posed by accidents at nuclear power plants; they are operated in 26 countries around the world. Syunkov V.Ya. Fundamentals of life safety. Moscow: Center for Innovation in Pedagogy, 2001.-159p.
Clean air disappears around cities, rivers turn into sewers, piles of garbage, landfills, and mutilated nature are everywhere - this is a striking picture of the insane industrialization of the world.
The main thing, however, is not the completeness of the list of these problems, but in understanding the reasons for their occurrence, their nature and, most importantly, in identifying effective ways and means of resolving them.
The true prospect of overcoming the environmental crisis lies in changing human production activities, his lifestyle, and his consciousness. Scientific and technological progress not only creates “overloads” for nature; In the most advanced technologies, it provides a means of preventing negative impacts and creates opportunities for environmentally friendly production. Not only an urgent need has arisen, but also an opportunity to change the essence of technological civilization and give it an environmental character. One of the directions of such development is the creation of safe production facilities. Using the achievements of science, technological progress can be organized in such a way that production waste does not pollute the environment, but returns to the production cycle as secondary raw materials. An example is provided by nature itself: carbon dioxide released by animals is absorbed by plants, which release oxygen necessary for animal respiration.
Currently, the entire territory of our planet is subject to various anthropogenic influences. The consequences of the destruction of biocenoses and environmental pollution have become serious. The entire biosphere is under increasing pressure from human activity. Environmental protection measures are becoming an urgent task.
3. The influence of primitive and modern man
on the environment
People rely on natural resources to provide their basic needs, including food, shelter and clothing, but they also compete for space occupied by natural habitats. Thus, population growth and human development affect biodiversity both directly and indirectly. Human impacts on the environment, including the use of land and other natural resources, are the most important factors behind the decline in biodiversity.
In the past, low population densities and regulated use of natural resources maintained the balance of ecosystems. However, over the last thousand years, human impact on the earth has increased.
Man began to change natural systems already at the primitive stage of the development of civilization, during the period of hunting and gathering, when he began to use fire. The domestication of wild animals and the development of agriculture expanded the area of manifestation of the consequences of human activity. As industry developed and muscle power was replaced by fuel energy, the intensity of anthropogenic influence continued to increase. In the 20th century Due to the particularly rapid rate of population growth and its needs, it has reached unprecedented levels and spread throughout the world.
The most important environmental postulates formulated in Tyler Miller's book "Living in the Environment."
1. Whatever we do in nature, everything causes certain consequences in it, often unpredictable.
2. Everything in nature is interconnected, and we all live in it together.
3. Earth's life support systems can withstand significant pressure and rough interventions, but there is a limit to everything.
4. Nature is not only more complex than we think about it, it is much more complex than we can imagine.
All human-created complexes (landscapes) can be divided into two groups depending on the purpose of their creation:
– direct – created by purposeful human activity: cultivated fields, gardening complexes, reservoirs, etc., they are often called cultural;
– accompanying – not intended and usually undesirable, which were activated or brought to life by human activity: swamps along the banks of reservoirs, ravines in fields, quarry-dump landscapes, etc.
Each anthropogenic landscape has its own history of development, sometimes very complex and, most importantly, extremely dynamic. In a few years or decades, anthropogenic landscapes can undergo profound changes that natural landscapes will not experience in many thousands of years. The reason for this is the continuous intervention of man in the structure of these landscapes, and this interference necessarily affects the man himself.
Anthropogenic changes in the environment are very diverse. By directly influencing only one of the components of the environment, a person can indirectly change the others. In both the first and second cases, the circulation of substances in the natural complex is disrupted, and from this point of view, the results of the impact on the environment can be classified into several groups.
The first group includes impacts that lead only to changes in the concentration of chemical elements and their compounds without changing the form of the substance itself. For example, as a result of emissions from motor vehicles, the concentration of lead and zinc increases in the air, soil, water and plants, many times higher than their normal levels. In this case, the quantitative assessment of exposure is expressed in terms of the mass of pollutants.
The second group - impacts lead not only to quantitative, but also qualitative changes in the forms of occurrence of elements (within individual anthropogenic landscapes). Such transformations are often observed during mining, when many ore elements, including toxic heavy metals, pass from mineral form into aqueous solutions. At the same time, their total content within the complex does not change, but they become more accessible to plant and animal organisms. Another example is changes associated with the transition of elements from biogenic to abiogenic forms. Thus, when cutting down forests, a person, cutting down a hectare of pine forest and then burning it, converts about 100 kg of potassium, 300 kg of nitrogen and calcium, 30 kg of aluminum, magnesium, sodium, etc. from biogenic form into mineral form.
The third group is the formation of man-made compounds and elements that have no analogues in nature or are not characteristic of a given area. There are more and more such changes every year. This is the appearance of freon in the atmosphere, plastics in soils and waters, weapons-grade plutonium, cesium in the seas, widespread accumulation of poorly decomposed pesticides, etc. In total, about 70,000 different synthetic chemicals are used every day in the world. About 1,500 new ones are added every year. It should be noted that little is known about the environmental impact of most of them, but at least half of them are harmful or potentially harmful to human health.
The fourth group is the mechanical movement of significant masses of elements without a significant transformation of the forms of their location. An example is the movement of rock masses during mining, both open-pit and underground. Traces of quarries, underground voids and waste heaps (steep-sided hills formed by waste rocks transported from mines) will exist on Earth for many thousands of years. This group also includes the movement of significant masses of soil during dust storms of anthropogenic origin (one dust storm can move about 25 km3 of soil).
The real scale of modern anthropogenic influence is as follows. Every year, over 100 billion tons of minerals are extracted from the depths of the Earth; 800 million tons of various metals are smelted; produce more than 60 million tons of synthetic materials unknown in nature; They introduce over 500 million tons of mineral fertilizers and approximately 3 million tons of various pesticides into the soils of agricultural lands, 1/3 of which enters water bodies with surface runoff or lingers in the atmosphere. For their needs, people use more than 13% of river flow and annually discharge more than 500 billion m3 of industrial and municipal wastewater into water bodies. The above is enough to realize the global impact of man on the environment, and therefore the global nature of the problems arising in connection with this. Let us consider the consequences of three main types of human economic activity.
1. Industry - the largest branch of material production - plays a central role in the economy of modern society and is the main driving force of its growth. Over the last century, global industrial production has increased more than 50 times, with 4/5 of this growth occurring since 1950, i.e. a period of active implementation of scientific and technological progress into production. Naturally, such a rapid growth of industry, which ensures our well-being, primarily affected the environment, the load on which has increased many times over.
2. Energy is the basis for the development of all sectors of industry, agriculture, transport, public utilities. This is an industry with very high rates of development and huge scale of production. Accordingly, the share of participation of energy enterprises in the load on the natural environment is very significant. Annual energy consumption in the world is more than 10 billion tons of standard fuel, and this figure is continuously increasing2. To obtain energy, they use either fuel - oil, gas, coal, wood, peat, shale, nuclear materials, or other primary energy sources - water, wind, solar energy, etc. Almost all fuel resources are non-renewable - and this is the first stage of impact on the environment in the energy industry - the irreversible removal of masses of substances.
3. Metallurgy. The impact of metallurgy begins with the extraction of ores of ferrous and non-ferrous metals, some of which, such as copper and lead, have been used since ancient times, while others - titanium, beryllium, zirconium, germanium - have been actively used only in recent decades (for the needs of radio engineering, electronics , nuclear technology). But since the middle of the 20th century, as a result of the scientific and technological revolution, the extraction of both new and traditional metals has sharply increased, and therefore the number of natural disturbances associated with the movement of significant masses of rocks has increased.
In addition to the main raw material – metal ores – metallurgy quite actively consumes water. Approximate figures for water consumption for the needs of ferrous metallurgy: the production of 1 ton of cast iron requires about 100 m 3 of water; for the production of 1 ton of steel – 300 m 3; for the production of 1 ton of rolled products - 30 m 3 of water.
But the most dangerous side of the impact of metallurgy on the environment is the technogenic dispersion of metals. Despite all the differences in the properties of metals, they are all impurities in relation to the landscape. Their concentration can increase tens and hundreds of times without external changes in the environment. The main danger of trace metals lies in their ability to gradually accumulate in the bodies of plants and animals, which disrupts food chains.
126
. Air exchange, air exchange rate, air conditioning. Relationship between ventilation parameters and the content of harmful substances in the air of the working area.
Calculation of the release of harmful substances and moisture.
Moisture release
The amount of moisture released by workers: W
=
,
Where n– number of people in the room; w– moisture release from one person.
Gas emissions
It is necessary to take into account gas emissions during technological operations.
Calculation of heat releases.
Heat emissions from people
The calculations use sensible heat, i.e. heat that affects the change in air temperature in the room. It is believed that a woman produces 85% of the heat generated by an adult man.
Heat release from solar radiation
For glazed surfaces: Q ost. = F ost. .
q ost. .
A ost., W,
Where F ost.– glazing surface area, m2; q ost.– heat release from solar radiation, W/m 2, through 1 m 2 of the glazing surface (taking into account the orientation to the cardinal points); A ost.– factor taking into account the nature of the glazing.
Heat emissions from artificial lighting sources
- Q osv. = N osv. .
h, W,
Heat emissions from equipment
Manual soldering irons with a power of 40 W?
- Q about. = N about. .
h
The required air flow is determined by harmful factors that cause a deviation of the air parameters in the working area from the standardized ones (the entry of harmful substances, moisture, excess heat).
Required air exchange when harmful substances enter the air of the working area
The amount of air required to dilute the concentrations of harmful substances to acceptable levels:
G = , m 3 / h,
Where IN– the amount of harmful substances released into the room in 1 hour, g/h; q 1 , q 2 – concentration of harmful substances in the supply and exhaust air, g/m3, q 2 is accepted to be equal to the maximum permissible concentration for the substance in question (lead and its inorganic compounds - 0.1.10 -4 g/m 3, hazard class - I).
Selection and configuration of ventilation systems.
Selection of ventilation systems
Since the obtained value of the amount of air will require huge expenditures of electricity and material resources, it is advisable to use a system of local suction, which will significantly reduce air exchange.
When removing harmful substances directly from the place of their release, the greatest effect of ventilation is achieved, because in this case, large volumes of air are not polluted and harmful substances released by small volumes of air can be removed. In the presence of local suction, the volume of supply air is assumed to be equal to the volume of the exhaust (minus 5% to eliminate the possibility of polluted air flowing into neighboring rooms).
Calculation of local ventilation (exhaust).
Air exchange when harmful substances enter the air of the working area
Misalignment angle j between the axes of the torch of harmfulness and suction is assumed to be 20 o for design reasons. The air flow rate for suction, which removes heat and gases, is proportional to the characteristic air flow rate in the convective flow rising above the source:
L ots. = L 0 . TO P . TO IN . TO T ,
Where L 0 – characteristic flow rate, m 3 / h; TO P– dimensionless factor, taking into account the influence of geometric and operating parameters characterizing the “source-suction” system; TO IN– coefficient taking into account the speed of air movement in the room; TO T– coefficient taking into account the toxicity of harmful emissions.
- L 0
=
,
- s
=
,
- D =
,
- TO IN
=
,
K T is determined depending on parameter C:
WITH = ,
Where M– consumption of harmful substances (7.5 - 10 -3 mg/s); L ots.1– air consumption by suction at K T = 1; MPC– maximum permissible concentration of harmful substances in the air of the working area (0.01 mg/m3); q etc.– concentration of harmful substance in the supply air, mg/m3.
Calculation of general ventilation (supply).
Since supply ventilation is designed on the principle of exhaust compensation (air exchange), to ensure a speed in the network of 6.5 m/s it is advisable to use an air duct with a cross-section of 200? 200, to ensure the required inflow, use 10 double adjustment grilles PP 200? 200.
The “fan - electric motor” set can be used the same as in the exhaust network, because the resistance (air intake grille, air filter, heater and grilles in the room) will be of the same order as in the exhaust network.
Under the influence of the equipment and technological processes used, a certain external environment is created in the work area. It is characterized by: microclimate; content of harmful substances; levels of noise, vibration, radiation; workplace illumination.
The content of harmful substances in the air of the working area should not exceed maximum permissible concentrations (MPC).
MPCs are concentrations that, when exposed to people during their daily work, except weekends, for 8 hours (or another duration, but not more than 41 hours per week) throughout their entire work experience, cannot cause diseases or diseases detectable by modern research methods or deviations in the state of health both among the workers themselves during their work activities and in the subsequent period of life, and among subsequent generations.
Maximum permissible concentrations for most substances are maximum one-time, i.e., the content of a substance in the breathing zone of workers is averaged over a period of short-term air sampling: 15 minutes for toxic substances and 30 minutes for substances with a predominantly fibrogenic effect (causing cardiac fibrillation). For highly cumulative substances, along with the maximum one-time maximum, a shift-average MPC has been established, i.e. the average concentration obtained by continuous or intermittent air sampling for a total time of at least 75% of the duration of the work shift, or the time-weighted average concentration of the duration of the entire shift in the breathing zone of workers at their places of permanent or temporary stay.
In accordance with SN 245-71 and GOST 12.1.007-76, all harmful substances, according to the degree of impact on the human body, are divided into four hazard classes:
extremely dangerous – MPC less than 0.1 mg/m3 (lead, mercury - 0.001 mg/m3);
highly hazardous – MPC from 0.1 to 1 mg/m3 (chlorine - 0.1 mg/m3; sulfuric acid - 1 mg/m3);
moderately hazardous – MPC from 1.1 to 10 mg/m3 (methyl alcohol - 5 mg/m3; dichloroethane - 10 mg/m3);
low-hazard - MPC more than 10 mg/m3 (ammonia - 20 mg/m3; acetone - 200 mg/m3; gasoline, kerosene - 300 mg/m3; ethyl alcohol - 1000 mg/m3).
Based on the nature of their impact on the human body, harmful substances can be divided into: irritants (chlorine, ammonia, hydrogen chloride, etc.); asphyxiants (carbon monoxide, hydrogen sulfide, etc.); narcotics (nitrogen under pressure, acetylene, acetone, carbon tetrachloride, etc.); somatic, causing disturbances in the functioning of the body (lead, benzene, methyl alcohol, arsenic).
When several harmful substances of unidirectional action are simultaneously contained in the air of the working area, the sum of the ratios of the actual concentrations of each of them in the air (K1, K2, ..., Kn) to their maximum permissible concentrations (MPC1, MAC2, ..., MACn) should not exceed one :
Problem 1/2
At a meat processing plant located in the suburbs, an unlined container containing G=5 tons of ammonia NH 3 ( r =0.68 t/m 3). A cloud of contaminated air moves towards the city center, where at a distance of R=1.5 km from the meat processing plant there is a store with N=70 people. Provision of gas masks X=20%.. The area is open, wind speed in the surface layer V=2 m/s, inversion.
Determine the size and area of chemical contamination, the time of approach of the infected cloud to the store, the time of the damaging effect of chlorine, the loss of people who ended up in the store.
Solution.
- 1. Determine the possible area of an ammonia spill using the formula:
Where G– mass of chlorine, t; p– chlorine density, t/m3; 0.05 – thickness of the spilled chlorine layer, m.
2. Determine the depth of the chemical contamination zone (D)
For an unbanked container, at a wind speed of 1 m/s; For G=5 t; isotherm Г 0 =0.7 km.
For this problem: with inversion for a wind speed of 2 m/s G=G 0? 0.6? 5=0.7? 0.6? 5=2.1 km.
3. Width of the chemical contamination zone (W) during inversion: W=0.03? G=0.03? 2.1=0.063 km.
4. Area of the chemical contamination zone ( S h):
5. Time of passage of contaminated air to a populated area located in the direction of the wind ( t podkh), according to the formula:
6. Time of damaging action (t pores) for ammonia, unbanked storage t pores,0 = 1.2. For a wind speed of 2 m/s, we introduce a correction factor of 0.7.
t time = 1.2? 0.7=0.84 s.
7. Possible losses of people (P) caught in the store.
For a 20% supply of gas masks, the number of affected people is P = 70? 40/100=28 people. of which 7 people had mild damage, 12 people had moderate and severe damage, and 9 people had a fatal outcome.
What actions need to be taken to ensure the safety of people in the store? How to provide first aid to an ammonia victim?
Answers:
Protection against hazardous chemicals is achieved by using individual and collective protective equipment. To eliminate the consequences of infection, facilities are degassed and personnel are sanitized. The suddenness of accidents at chemically hazardous facilities, the high speed of formation and spread of a cloud of contaminated air requires the adoption of prompt measures to protect people from hazardous chemicals.
Therefore, the protection of the population is organized in advance. A system is created and a procedure is established for notification of emergency situations occurring at facilities. Personal protective equipment is accumulated and the order of their use is determined. Protective structures, residential and industrial buildings are being prepared. Ways to move people to safe areas are being outlined. Management bodies are being prepared. The population living in areas adjacent to the enterprise is purposefully trained. To ensure timely adoption of protective measures, a warning system is activated. It is based on local systems created at chemically hazardous facilities and around them, which provide notification not only to the enterprise personnel, but also to the population of nearby areas.
Protection against hazardous chemicals is provided by filtering industrial and civil gas masks, gas respirators, insulating gas masks and civil defense shelters. Industrial gas masks reliably protect the respiratory organs, eyes and face from damage. However, they are used only where the air contains at least 18% oxygen, and the total volume fraction of vapor and gaseous harmful impurities does not exceed 0.5%.
If the composition of gases and vapors is unknown or their concentration is higher than the maximum permissible, only insulating gas masks (IP-4, IP-5) are used.
Boxes of industrial gas masks are strictly specialized in purpose (according to the composition of absorbers) and differ in coloring and markings. Some are made with aerosol filters, others without. A white vertical stripe on the box means it has a filter. To protect against chlorine, you can use industrial gas masks of brands A (the box is painted brown), BKF (protective), B (yellow), G (half black, half yellow), as well as civilian gas masks GP-5, GP-7 and children's. What if they don't exist? Then apply a cotton-gauze bandage moistened with water, or better yet, a 2% solution of baking soda.
Civilian gas masks GP-5, GP-7 and children's PDF-2D (D), PDF-2Sh (Sh) and PDF-7 reliably protect against hazardous chemicals such as chlorine, hydrogen sulfide, sulfur dioxide, hydrochloric acid, tetraethyl lead, ethyl mercaptan, phenol , furfural.
For the population, available skin protection products, complete with gas masks, are recommended. These can be ordinary waterproof capes and raincoats, as well as coats made of dense thick material, and cotton jackets. For feet - rubber boots, boots, galoshes. For hands - all types of rubber and leather gloves and mittens.
In the event of an accident involving the release of hazardous substances, civil defense shelters provide reliable protection. Firstly, if the type of substance is unknown or its concentration is too high, you can switch to complete isolation (third mode), you can also stay in a room with a constant volume of air for some time. Secondly, filter absorbers of protective structures prevent the penetration of chlorine, phosgene, hydrogen sulfide and many other toxic substances, ensuring the safe stay of people.
You need to leave the infection zone in one direction, perpendicular to the direction of the wind, focusing on the readings of a weather vane, the waving of a flag or any other piece of material, and the slope of trees in an open area. Voice information about an emergency situation should indicate where and on which streets or roads it is advisable to exit (exit) so as not to fall under an infected cloud. In such cases, you need to use any transport: buses, trucks and cars.
Time is the deciding factor. You must leave your houses and apartments for a period of time - 1-3 days: until the toxic cloud passes and the source of its formation is localized.
Medical care for those affected by hazardous chemicals
Contaminants can enter the human body through the respiratory tract, gastrointestinal tract, skin and mucous membranes. When entering the body, they cause disruption of vital functions and pose a danger to life.
According to the speed of development and nature, acute, subacute and chronic poisonings are distinguished.
Acute poisonings are those that occur within a few minutes or several hours from the moment the poison enters the body. The general principles of emergency care for damage to hazardous chemicals are:
- stopping further poison entering the body and removing what is not absorbed;
- accelerated removal of absorbed toxic substances from the body;
- use of specific antidotes (antidotes);
- pathogenetic and symptomatic therapy (restoration and maintenance of vital functions).
In case of inhalation of hazardous substances (through the respiratory tract), put on a gas mask, remove or remove from the contaminated area, rinse the mouth, if necessary, sanitize.
In case of contact with the skin - mechanical removal, use of special degassing solutions or washing with soap and water, if necessary, complete sanitization. Immediately rinse eyes with water
etc.................
Question 1. How did the activities of primitive man affect the environment?
Already more than 1 million years ago, Pithecanthropus obtained food by hunting. Neanderthals used a variety of stone tools for hunting and hunted their prey collectively. Cro-Magnons created snares, spears, spear throwers and other devices. However, all this did not make serious changes to the structure of ecosystems. Human impact on nature intensified during the Neolithic era, when cattle breeding and agriculture began to become increasingly important. Man began to destroy natural communities, without, however, yet having a global impact on the bio-sphere as a whole. Nevertheless, unregulated grazing of livestock, as well as clearing of forests for fuel and crops, already at that time changed the state of many natural ecosystems.
Question 2. To what period of development of human society does the origin of agricultural production belong?
Agriculture appeared after the end of glaciation in the Neolithic era (New Stone Age). This period is usually dated to 8-3 millennia BC. e. At this time, man domesticated several species of animals (first the dog, then the ungulates - pig, sheep, goat, cow, horse) and began to cultivate the first cultivated plants (wheat, barley, legumes).
Question 3. Name the reasons for the possible occurrence of water shortages in a number of areas of the world.
A lack of water can arise as a result of various human actions. With the construction of dams and changes in river beds, a redistribution of water flow occurs: some territories are flooded, others begin to suffer from drought. Increased evaporation from the surface of reservoirs leads not only to the formation of water shortages, but also changes the climate of entire regions. Irrigated agriculture depletes surface and soil water supplies. Deforestation on the border with deserts contributes to the formation of new territories with a lack of water. Finally, the reasons may be high population density, excessive industrial needs, as well as pollution of existing water supplies.
Question 4. How does the destruction of forests affect the state of the bio-sphere?Material from the site
Deforestation catastrophically worsens the condition of the biosphere as a whole. As a result of logging, surface water flow increases, which increases the likelihood of floods. Intensive soil erosion begins, leading to the destruction of the fertile layer and pollution of water bodies with organic substances, water blooms, etc. Deforestation increases the amount of carbon dioxide in the atmosphere, which is one of the factors increasing the greenhouse effect; the amount of dust in the air is growing; The danger of a gradual decrease in the amount of oxygen is also relevant.
Cutting down large trees destroys established forest ecosystems. They are replaced by much less productive biocenoses: small forests, swamps, semi-deserts. At the same time, dozens of species of plants and animals may disappear irrevocably.
Currently, the main “lungs” of our planet are the equatorial tropical forests and taiga. Both of these groups of eco-systems require extremely careful treatment and protection.
Didn't find what you were looking for? Use the search
On this page there is material on the following topics:
- man is part of the biosphere essay
- How does forest destruction affect the state of the biosphere?
- the impact of forest destruction on the state of the biosphere
- to what period of development of human society does the origin of agricultural production belong?
- essay on biology biosphere and man