Soil is a special natural formation that provides the growth of trees, crops and other plants. It is difficult to imagine life without our fertile soil. But how does modern man relate to soils? Today, human pollution of the soil has reached tremendous proportions, so the soils of our planet are in dire need of protection and protection.
Soil - what is it?
Soil protection from pollution is impossible without a clear understanding of what soil is and how it is formed. Let's consider this question in more detail.
Soil (or soil) is a special natural formation, an essential component of any ecosystem. It is formed in the upper layer of the parent rock, under the influence of the sun, water, and also vegetation. The soil is a kind of bridge, a link that connects the biotic and abiotic components of the landscape.
The main processes that result in the formation of soil are weathering and the vital activity of living organisms. As a result of mechanical weathering processes, the parent rock is destroyed and gradually crushed, and living organisms fill this inanimate mass with organic substances.
Human pollution of the soil is one of the main problems of modern ecology and nature management, which is especially acute in the second half of the twentieth century.
Soil structure
Any soil consists of 4 main components. It:
- rock (soil base, about 50% of the total mass);
- water (about 25%);
- air (about 15%);
- organic matter (humus, up to 10%).
Depending on the ratio of these components in the soil, the following types of soils are distinguished:
- rocky;
- clayey;
- sandy;
- humic;
- salt marshes.
A key property of the soil that distinguishes it from any other component of the landscape is its fertility. This is a unique property that satisfies plants in essential nutrients, moisture and air. Thus, the soil provides biological productivity of all vegetation and crop yields. That is why pollution of soil and water is such an acute problem on the planet.
Soil cover studies
Soil research is carried out by a special science - soil science , the founder of which is considered to be Vasily Dokuchaev - a world-famous scientist. It was he who, at the end of the 19th century, was the first to note that soils spread along the earth's surface quite naturally (latitudinal zonality of soils), and also called clear morphological features of the soil.
V. Dokuchaev considered the soil as an integral and independent natural formation, which none of the scientists had done before. The scientist’s most famous work, The Russian Black Soil of 1883, is a handbook for all modern soil scientists. V. Dokuchaev conducted a thorough study of the soils of the steppe zone of modern Russia and Ukraine, the results of which formed the basis of the book. In it, the author identified the main factors of soil formation: mother rock, topography, climate, age and flora. The scientist gives a very interesting definition of the concept: "soil is a function of the parent rock, climate and organisms, multiplied by time."
After Dokuchaev, other well-known scientists were actively studying the soil. Among them: P. Kostychev, N. Sibirtsev, K. Glinka and others.
The value and role of soil in human life
The phrase “land-nurse”, which we hear very often, is not symbolic or metaphorical. It really is. This is the main source of food for humanity, which, one way or another, provides about 95% of all food. The total area of all the land resources of our planet today is 129 million km 2 land area, of which 10% is occupied by arable land, and another 25% - hayfields and pastures.
They began to study soils only in the 19th century, but people knew about their wonderful property - about fertility, since ancient times. It is the soil that owes its existence to all plant and animal organisms on Earth, including humans. It is no coincidence that the regions with the most fertile soils are the most densely populated territories of the planet.
Soil is the main resource of agricultural production. Many conventions and declarations adopted at the international level call for a rational and careful attitude to the soil. And this is obvious, because the total pollution of lands and soils threatens the existence of all mankind on the planet.
Soil cover is the most important element of the geographic shell of the Earth, responsible for all processes in the biosphere. The soil accumulates a huge amount of organic matter and energy, thereby fulfilling the role of a giant biological filter. This is a key link in the biosphere, the destruction of which will violate its entire functional structure.
In the 21st century, the load on the soil cover has increased several times, and the problem of soil pollution is becoming of paramount and global importance. It is worth noting that the solution to this problem depends on the coordination of actions of all states of the world.
Pollution of land and soil
Soil pollution is called the process of degradation of the soil cover, in which the content of chemicals in it increases significantly. Indicators of this process are living organisms, in particular, plants, which are the first to suffer from a violation of the natural composition of the soil. In this case, the reaction of plants depends on the level of their sensitivity to such changes.
It should be noted that our state provides for criminal liability for human pollution of land. In particular, Article 254 of the Criminal Code of the Russian Federation sounds like "Damage to the land."
Typology of soil pollutants
The main soil pollution began in the twentieth century with the rapid development of the industrial complex. Soil pollution is understood as introducing into the soil atypical components for it - the so-called "pollutants". They can be in any state of aggregation - liquid, solid, gaseous or complex.
All soil pollutants can be divided into 4 groups:
- organic (pesticides, insecticides, herbicides, aromatic hydrocarbons, chlorine-containing substances, phenols, organic acids, petroleum products, gasoline, varnishes and paints);
- inorganic (heavy metals, asbestos, cyanides, alkalis, inorganic acids and others);
- radioactive;
- biological (bacteria, pathogens, algae, etc.).
Thus, the main soil pollution is carried out precisely with the help of these and some other pollutants. The increased content of these substances in the soil can lead to negative and irreversible consequences.
Sources of land pollution
To date, a large number of such sources can be called. And their number is only increasing every year.
We list the main sources of soil pollution:
- Residential buildings and utilities. This is the main source of urban land pollution. In this case, human pollution of the soil occurs through household waste, food debris, construction waste and household items (old furniture, clothing, etc.). In large cities, the question "where to put the garbage?" turns into a real tragedy for the city authorities. Therefore, on the outskirts of cities, huge kilometer landfills grow where all household waste is dumped. In developed countries of the West, the practice of recycling garbage in special plants and plants has long been introduced. Moreover, a lot of money is earned there. In our country, so far, such cases, alas, are isolated.
- Factories and plants. In this group, the main sources of soil pollution are the chemical, mining and engineering industries. Cyanides, arsenic, styrene, benzene, clumps of polymers, soot - all these terrible substances fall into the ground in the area of large industrial enterprises. A big problem now is the problem of recycling car tires, which cause large fires that are very difficult to put out.
- Transport complex. Sources of land pollution in this case are lead, hydrocarbon, soot, and nitrogen oxides. All these substances are released during the operation of internal combustion engines, then settle on the surface of the earth and are absorbed by plants. Thus, they fall into the soil cover. At the same time, the degree of soil pollution will be as high as possible along major highways and near road junctions.
- Agro-industrial complex. Receiving food from the earth, we at the same time poison it, no matter how paradoxical it may sound. Human pollution of the soil here occurs through the introduction of fertilizers and chemicals into the ground. That is how terrible substances for it — mercury, pesticides, lead and cadmium — fall into the ground. In addition, excess chemicals can be washed away from the fields by rains, falling into permanent streams and groundwater.
- Radioactive waste. Soil pollution by nuclear industry waste poses a very great danger. Few people know that during nuclear reactions at nuclear power plants about 98-99% of the fuel goes to waste. These are the products of the fission of uranium - cesium, plutonium, strontium and other elements that are unusually dangerous. A very big problem for our country is the disposal of this radioactive waste. Each year around 200 thousand cubic meters of nuclear waste are generated in the world.
The main types of pollution
Soil pollution can be natural (for example, during volcanic eruptions), or anthropogenic (man-caused) when pollution occurs through human fault. In the latter case, substances and products that are not characteristic of the natural environment and adversely affect ecosystems and natural complexes fall into the ground.
The process of classifying the types of soil contamination is very complex; different classifications are made in different sources. But still, the main types of soil pollution can be represented as follows.
Domestic soil pollution is soil pollution with garbage, waste and emissions. This group includes pollutants of a different nature and in a different state of aggregation. They can be either liquid or solid. In general, this type of pollution is not too dangerous for the soil, however, excessive accumulation of household waste clogs the area and prevents the normal growth of plants. The most acute problem of household soil pollution is in megacities and large cities, as well as in villages with an unimpaired garbage collection system.
Chemical pollution of soils is, first of all, pollution by heavy metals, as well as pesticides. This type of pollution is already a great danger to humans. After all, heavy metals have the property of accumulating in a living organism. Soils are contaminated with heavy metals such as lead, cadmium, chromium, copper, nickel, mercury, arsenic and manganese. Gasoline, which contains a very toxic substance - tetraethyl lead, acts as a great soil pollutant.
Pesticides are also very dangerous substances for the soil. The main source of pesticides is modern agriculture, which actively uses these chemicals to control bugs and pests. Therefore, pesticides accumulate in soils in huge quantities. For animals and humans, they are no less dangerous than heavy metals. So, it was banned highly toxic and very stable drug DDT. It is capable of not decomposing in the soil for decades, scientists have found its trace even in the Antarctic!
Pesticides are very harmful to soil microflora: bacteria and fungi.
Soil radioactive contamination is the contamination of soils by the waste of nuclear power plants. Radioactive substances are extremely dangerous, as they easily penetrate the food chains of living organisms. The most dangerous radioactive isotope is considered to be strontium-90, which is characterized by a high yield during nuclear fission (up to 8%), as well as a long (28 years) half-life. In addition, it is very mobile in the ground and is able to be deposited in the bone tissue of humans and various living organisms. Among other dangerous radionuclides can also be called cesium-137, cerium-144, chlorine-36.
Volcanic soil pollution - this type of pollution belongs to the group of natural. It consists in the entry into the soil of toxic substances, soot and combustion products, which occurs as a result of volcanic eruptions. This is a very rare type of soil pollution, which is characteristic only for certain small territories.
Mycotoxic soil pollution is also not technogenic and has a natural origin. The source of pollution here are some types of mushrooms that release dangerous substances - mycotoxins. It is worth noting that these substances pose the same great danger to living organisms as all the others listed above.
Soil erosion
Erosion has been and remains a major problem for the preservation of the fertile soil layer. Every year it “eats” large areas of fertile soil, while the rate of natural restoration of the soil cover is much lower than the rate of erosion processes. Scientists have already thoroughly studied the features of these processes and found measures to combat them.
Erosion may be:
Obviously, in the first case, the leading factor in erosion is flowing water, and in the second, wind.
Water erosion is more common and dangerous. It begins with the appearance on the earth's surface of a small, barely noticeable ravine, but after each heavy rain this ravine will expand and increase in size until it turns into a real moat. In just one summer period, a ditch 1-2 meters deep can appear on an absolutely flat surface! The next stage of water erosion is the formation of a ravine. This form of relief is characterized by great depth and branching structure. Gullies catastrophically destroy fields, meadows and pastures. If you do not fight the ravine, sooner or later it will turn into a beam.
Water erosion processes are more active in the steppe region with rough terrain, where there is very little vegetation.
The cause of wind erosion are storms and dry winds, which can blow up to 20 centimeters of the upper (most fertile) ball of soil. The wind carries particles of soil over long distances, forming in certain places sediments up to 1-2 meters high. Most often they form along plantings and forest belts.
Assessment of soil pollution
An adequate assessment of soil pollution is very important for a set of measures to protect the soil cover. It is calculated by complex mathematical calculations, after a complex of detailed chemical and environmental studies. The assessment is represented by a comprehensive indicator of pollution Z s .
Soil pollution assessment is carried out taking into account several important factors:
- specificity of pollution sources;
- a complex of chemical elements - soil pollutants;
- priority of pollutants, according to the list of maximum permissible concentrations of substances;
- nature and conditions of land use.
Researchers identify several levels of soil pollution, namely:
- Valid (Z with less than 16).
- Moderately hazardous (Z s from 16 to 38).
- Dangerous (Z s from 38 to 128).
- Extremely dangerous (Z with over 128).
Soil protection
Depending on the source of pollution and the intensity of its influence, special measures have been developed to protect the soil cover. These measures include:
- Legislative and administrative (adoption of relevant laws in the field of soil protection, and control over their implementation).
- Technological (creation of non-waste production systems).
- Sanitary (collection, disinfection and disposal of waste and soil pollutants).
- Scientific (development of new technologies of treatment facilities, assessment and monitoring of soil conditions).
- Reclamation and anti-erosion (these are measures for planting special shelterbelts along fields, construction of hydraulic structures and proper planting of crops).
Conclusion
The soil of Russia is an enormous wealth, thanks to which we have food products, and production is provided with the necessary raw materials. Soil has been formed over many centuries. That is why the protection of soils from pollution is the most important task of the state.
Today, there are a large number of sources of soil pollution: these are transport, industry, cities, utilities, nuclear power plants, and agriculture. The task of scientists, state authorities and public figures is common - to protect the soil from the harmful effects of all these factors, or at least minimize their harmful effect on the soil.