The main sources of pollution of water resources. Human water pollution

Water is the most valuable natural resource. Its role is participation in the process of metabolism of all substances that are the basis of any life form. It is impossible to imagine the activity of industrial, agricultural enterprises without the use of water, it is indispensable in human everyday life. Everyone needs water: people, animals, plants. For some, it is a habitat.

The rapid development of human life, the inefficient use of resources has led to the fact that e environmental problems (including water pollution) have become too acute. Their solution is in the first place for humanity. Scientists, environmentalists around the world are sounding the alarm and trying to find a solution to the world problem

Sources of water pollution

There are many reasons for pollution, and not always the human factor is to blame. Natural disasters also harm clean water bodies and disrupt the ecological balance.

The most common sources of water pollution are:

Industrial, domestic waste water. Having not passed the system of purification from chemical harmful substances, they, getting into the reservoir, provoke an ecological catastrophe.

Tertiary cleaning. Water is treated with powders, special compounds, filtered in many stages, killing harmful organisms and destroying other substances. It is used for domestic needs of citizens, as well as in the food industry, in agriculture.



- radioactive contamination of water

The main sources that pollute the oceans include the following radioactive factors:

• nuclear weapons testing;

  dumping of radioactive waste;

  major accidents (ships with nuclear reactors, Chernobyl);

  burial at the bottom of the oceans, seas of radioactive waste.

Environmental problems and water pollution are directly related to radioactive waste contamination. For example, French and British nuclear plants have infected almost the entire North Atlantic. Our country has become the culprit of the pollution of the Arctic Ocean. Three nuclear underground reactors, as well as the production of Krasnoyarsk-26, clogged the largest river, the Yenisei. It is obvious that radioactive products got into the ocean.



Pollution of world waters with radionuclides

The problem of pollution of the waters of the oceans is acute. Let us briefly list the most dangerous radionuclides that fall into it: cesium-137; cerium-144; strontium-90; niobium-95; yttrium-91. All of them have a high bioaccumulative capacity, move along food chains and concentrate in marine organisms. This creates a danger for both humans and aquatic organisms.

The water areas of the Arctic seas are heavily polluted by various sources of radionuclides. People carelessly dump hazardous waste into the ocean, thereby turning it into a dead one. Man must have forgotten that the ocean is the main wealth of the earth. It has powerful biological and mineral resources. And if we want to survive, we must urgently take measures to save him.

Solutions

Rational consumption of water, protection from pollution are the main tasks of mankind. Ways to solve environmental problems of water pollution lead to the fact that, first of all, much attention should be paid to the discharge of hazardous substances into rivers. On an industrial scale, it is necessary to improve wastewater treatment technologies. In Russia, it is necessary to introduce a law that would increase the collection of fees for discharges. The proceeds should be directed to the development and construction of new environmental technologies. For the smallest emissions, the fee should be reduced, this will serve as a motivation for maintaining a healthy environmental situation.

An important role in solving environmental problems is played by the upbringing of the younger generation. From an early age, it is necessary to teach children to respect, love for nature. To inspire them that the Earth is our big house, for the order in which each person is responsible. Water must be protected, not poured thoughtlessly, try to prevent foreign objects and harmful substances from entering the sewer.



Conclusion

In conclusion, I would like to say that Russian environmental problems and water pollution concern, perhaps, everyone. The thoughtless waste of water resources, the littering of rivers with various garbage has led to the fact that there are very few clean, safe corners left in nature.Ecologists have become much more vigilant, multiple measures are being taken to restore order in the environment. If each of us thinks about the consequences of our barbaric, consumer attitude, the situation can be corrected. Only together will humanity be able to save water bodies, the oceans and, possibly, the lives of future generations.

Oddly enough, but as civilization develops, the threat to environmental security for the entire planet grows. In particular, this concerns the pollution of water sources. It's no secret that effects of water pollution can be catastrophic for all mankind. As progress increases, the number of human needs increases, and it is possible to fully satisfy them only by increasing the volume of industrial production. But it is industrial waste that causes such sad consequences, since the current state of treatment facilities leaves much to be desired, or the necessary systems are completely absent.

According to the reports of UN experts, which are published annually on the eve of World Water Day (March 22), the number of people who get sick and die just because they use contaminated water is almost equal to the number of victims of various types of violence. And with the development of industrialization and urbanization, the degree of water pollution is only increasing. According to independent experts, at least 1.8 million children worldwide die every year from diseases caused by drinking excessively polluted water. Moreover, their age does not exceed five years.

Thus, the consequences of drinking contaminated water for humans are various intestinal and infectious diseases - cholera, typhoid, hepatitis, dysentery, gastroenteritis. In addition, water pollution leads to a deterioration in the condition of the skin, adversely affects the condition of the hair, and leads to damage to the teeth. Chlorine, which is used for drinking water in central water supply systems, very often does not react with some elements. For example, chlorine has absolutely no effect on fluorine and phenol compounds, which have a negative effect on the activity of the liver and kidneys. The kidneys and liver are the risk zone for which drinking contaminated water has the most detrimental consequences.

Negative effects of water pollution, namely, the high content of lead, cadmium, chromium, benzopyrene in it for a person is expressed in a rapid deterioration in health. The critical accumulation of these harmful elements in the body often causes oncological diseases, as well as disorders of the central and peripheral nervous systems. E. coli, enteroviruses are harmful microorganisms that have a negative impact on the functioning of the gastrointestinal tract. If water is not subjected to additional treatment, then the consequences are easy to predict - this is the development of urolithiasis and cholelithiasis, disruption of the cardiovascular system, etc. There is also a high probability of diseases with chronic nephritis and hepatitis.

In our country, today more than 50 percent of urban water supply systems have exhausted their operational resource and are in an emergency-dangerous state. This, so to speak, is a consequence of their long use. Moreover, as the results of the inspections show, the vast majority of domestic industrial enterprises do not have any kind of facilities, so they dump their waste into open water bodies. Needless to say, what consequences these actions have for nature.

Therefore, in order to avoid poisoning and other negative consequences of drinking polluted water, it is necessary to take care of its purification ourselves. Of course, this is not yet a fact that water with impurities flows from your tap, but without analysis it is impossible to say with certainty that there are no impurities in it.

As for water bodies such as rivers and lakes, pollution occurs in them due to the use of various modern chemicals and fertilizers. According to scientists, 80 percent of them did not pass any tests, so it is even difficult to say what the consequences will be.

Pollutants can enter the water at any stage of the cycle, and effects of water pollution, namely its use, may not appear immediately, but after some time, until a large number of harmful elements accumulate in the body. Therefore, it is highly recommended to take care of your health by installing water purification systems in your homes.

Most of the water resources on Earth are polluted. Even if our planet is covered with 70% water, not all of it is suitable for human use. Rapid industrialization, misuse of scarce water resources and many other factors play a role in the process of water pollution. Every year, about 400 billion tons of waste is generated worldwide. Most of this waste is dumped into water bodies. Of the total water on Earth, only 3% is fresh water. If this fresh water is constantly polluted, then the water crisis will become a serious problem in the near future. Therefore, it is necessary to take proper care of our water resources. The facts of water pollution in the world presented in this article should help in understanding the seriousness of this problem.

Facts and figures of water pollution in the world

Water pollution is a problem that affects almost every country in the world. If proper steps are not taken to control this threat, it will lead to disastrous consequences in the near future. Facts pertaining to water pollution are presented using the following points.

The rivers in the Asian continent are the most polluted. The content of lead in these rivers is 20 times higher than in the reservoirs of industrialized countries of other continents. The bacteria found in these rivers (from human waste) is three times more than the average worldwide.

In Ireland, chemical fertilizers and sewage are major water pollutants. About 30% of the rivers in this country are polluted.
Groundwater pollution is a major problem in Bangladesh. Arsenic is one of the main pollutants that affects the quality of water in this country. About 85% of the total area of ​​Bangladesh is contaminated with groundwater. This means that more than 1.2 million citizens of this country are exposed to the harmful effects of arsenic-contaminated water.
The king river in Australia, the Murray, is one of the most polluted rivers in the world. As a result, 100,000 different mammals, about 1 million birds and some other creatures died due to the acidic water present in this river.

The situation in America in relation to water pollution is not much different from the rest of the world. It is noted that about 40% of the rivers in the United States are polluted. For this reason, the water from these rivers should not be used for drinking, bathing or any similar activity. These rivers are not capable of supporting aquatic life. Forty-six percent of lakes in the US are unsuitable for supporting aquatic life.

Contaminants in water from the construction industry include: cement, gypsum, metal, abrasives, etc. These materials are much more harmful than biological waste.
The thermal pollution of water, caused by the runoff of hot water from industrial enterprises, is increasing. An increase in water temperature is a threat to the ecological balance. Many aquatic creatures lose their lives due to thermal pollution.

Drainage caused by rainfall is one of the main causes of water pollution. Waste materials such as oils, chemicals emitted from vehicles, household chemicals, etc., are major pollutants from urban areas. Mineral and organic fertilizers and pesticide residues make up the bulk of the pollutants.

Oil spills in the oceans are one of the global problems that are responsible for water pollution on a large scale. Thousands of fish and other aquatic creatures die from oil spills a year. In addition to oil, there are also huge amounts of practically non-degradable waste found in the oceans, like all kinds of plastic products. The facts of water pollution in the world speak of an impending global problem and this article should help to gain a deeper understanding about it.

There is a process of eutrophication, in which there is a deterioration of water in reservoirs to a large extent. As a result of eutrophication, excessive growth of phytoplankton begins. The level of oxygen in the water is reduced to a great extent and thus the life of fish and other living creatures of the water are endangered.

Water pollution control

It must be understood that the water we pollute can harm us in the long run. Once toxic chemicals enter the food chain, humans have no choice but to live and carry them through the body system. Reducing the use of chemical fertilizers is one of the best ways to clean water from contaminants. Otherwise, these vague chemicals will permanently pollute water bodies on earth. Efforts are being made to tackle the problem of water pollution. However, this problem cannot be completely solved because effective measures must be taken to eliminate it. Given the speed at which we are disrupting the ecosystem, it becomes necessary to follow strict regulations in reducing water pollution. Lakes and rivers on planet earth are becoming more and more polluted. Here are the facts of water pollution in the world and it is necessary to concentrate and organize the efforts of people and governments of all countries in a proper way to help minimize problems.

Rethinking the facts about water pollution

Water is the most valuable strategic resource of the Earth. Continuing the theme of the facts of water pollution in the world, we present new information provided by scientists in the context of this problem. If we take into account all water reserves, then no more than 1% of the water is clean and potable. Drinking contaminated water causes 3.4 million deaths every year, and this number is only going to increase in the future. To avoid this fate, do not drink water anywhere, and even more so from rivers and lakes. If you can't afford bottled water, use water purification methods. At a minimum, this is boiling, but it is better to use special cleaning filters.

Another problem is the availability of drinking water. So in many regions of Africa and Asia it is very difficult to find sources of clean water. Often, in order to get water, the inhabitants of these parts of the world walk several kilometers a day. Naturally, in these places, some people die not only from drinking dirty water, but also from dehydration.

Considering the facts about water, it is worth emphasizing that over 3.5 thousand liters of water are lost every day, which splashes and evaporates from river basins.

To solve the problem of pollution and lack of drinking water in the world, it needs to attract public attention and the attention of organizations that can solve it. If the governments of all countries make an effort and organize the rational use of water resources, the situation in many states will improve significantly. However, we forget that everything depends on ourselves. If people themselves save water, we can continue to enjoy this benefit. For example, in Peru, a billboard was erected with information about the problem of clean water. This attracts the attention of the population of the country and improves their awareness on this issue.

Water needs. It is clear to everyone how great is the role of water in the life of our planet and especially in the existence of the biosphere. Recall that the tissues of most plant and animal organisms contain from 50 to 90 percent water (with the exception of mosses and lichens, which contain 5-7 percent water). All living organisms need a constant supply of water from outside. A person whose tissues are 65 percent water can live for only a few days without drinking (and without food, he can live for more than a month). The biological need of man and animals for water per year is 10 times higher than their own weight. Even more impressive are the household, industrial and agricultural needs of man. So, for the production of a ton of soap, 2 tons of water are required, sugar - 9, cotton products - 200, steel - 250, nitrogen fertilizers or synthetic fiber - 600, grain - about 1000, paper - 1000, synthetic rubber - 2500 tons of water.

In 1980, mankind used 3494 cubic kilometers of water for various needs (66 percent in agriculture, 24.6 percent in industry, 5.4 percent for domestic needs, and 4 percent evaporation from the surface of artificial reservoirs). This represents 9-10 percent of the global river flow. During use, 64 percent of the withdrawn water evaporated, and 36 percent were returned to natural reservoirs.

In our country in 1985, 327 cubic kilometers of clean water were taken for household needs, and the volume of discharge was 150 cubic kilometers (in 1965 it was 35 cubic kilometers). In 1987, the USSR took 339 cubic kilometers of fresh water for all needs (about 10 percent from underground sources), that is, approximately 1,200 tons per capita. Of the total, 38 percent went to industry, 53 percent to agriculture (including dryland irrigation), and 9 percent to drinking and household needs. In 1988, about 355-360 cubic kilometers were already taken.

Water pollution. The water used by man is eventually returned to the natural environment. But, apart from evaporated water, it is no longer pure water, but domestic, industrial and agricultural wastewater, usually not treated or treated insufficiently. Thus, there is pollution of freshwater reservoirs - rivers, lakes, land and coastal areas of the seas. In our country, out of 150 cubic kilometers of sewage, 40 cubic kilometers are discharged without any treatment. And modern methods of water purification, mechanical and biological, are far from perfect. According to the Institute of Biology of Inland Waters of the USSR, even after biological treatment, 10 percent of organic and 60-90 percent of inorganic substances remain in wastewater, including up to 60 percent of nitrogen. 70-phosphorus, 80-potassium and almost 100 percent salts of toxic heavy metals.

biological pollution. There are three types of water pollution - biological, chemical and physical. Biological pollution is created by microorganisms, including pathogens, as well as organic substances capable of fermentation. The main sources of biological pollution of land waters and coastal waters of the seas are domestic sewage, which contains feces, food waste; wastewater from food industry enterprises (slaughterhouses and meat processing plants, dairy and cheese factories, sugar factories, etc.), pulp and paper and chemical industries, and in rural areas - effluents from large livestock complexes. Biological contamination can cause epidemics of cholera, typhoid, paratyphoid and other intestinal infections and various viral infections, such as hepatitis.

The degree of biological pollution is characterized mainly by three indicators. One of them is the number of E. coli (so-called lactose-positive, or LPC) in a liter of water. It characterizes the contamination of water with animal waste products and indicates the possibility of the presence of pathogenic bacteria and viruses. According to the State Standard of 1980, for example, swimming is considered safe if the water contains no more than 1000 LCP per liter. If the water contains from 5,000 to 50,000 LCPs per liter, then the water is considered dirty, and there is a risk of infection when bathing. If a liter of water contains more than 50,000 LCPs, then bathing is unacceptable. It is clear that after disinfection by chlorination or ozonation, drinking water must meet much more stringent standards.

To characterize the contamination with organic substances, another indicator is used - biochemical oxygen demand (BCD). It shows how much oxygen is required by microorganisms to process all decomposable organic matter into inorganic compounds (within, say, five days - then it is BOD 5. According to the standards adopted in our country, BOD 5 in drinking water should not exceed 3 milligrams of oxygen per liter of water.Finally, the third parameter is the content of dissolved oxygen.It is inversely proportional to the VOD.Drinking water should contain more than 4 milligrams of dissolved oxygen per liter.

Chemical pollution created by the introduction of various toxic substances into the water. The main sources of chemical pollution are blast furnace and steel production, non-ferrous metallurgy, mining, chemical industry and, to a large extent, extensive agriculture. In addition to direct discharges of wastewater into water bodies and surface runoff, it is also necessary to take into account the ingress of pollutants onto the water surface directly from the air.

In table. Table 3 shows the rates of contamination of surface waters with toxic heavy metals (according to the data of the same authors as the data on air and soil pollution by metals). These data include 30 percent of the mass of metals entering the atmospheric air.

As in air pollution, in the pollution of surface waters (and, running a little ahead, ocean waters) among heavy metals, lead holds the palm: its ratio of an artificial source to a natural one exceeds 17. Other heavy metals - copper, zinc, chromium, nickel , cadmium, an artificial source of entry into natural waters, is also larger than natural, but not as much as that of lead. Mercury pollution from the air, forests and fields treated with pesticides, and sometimes as a result of industrial discharges, poses a great danger. The runoff of water from mercury deposits or mines is extremely dangerous, where mercury can turn into soluble compounds. This threat makes reservoir projects on the Altai Katun River extremely dangerous.

In recent years, the entry of nitrates into the surface waters of land has increased significantly due to the irrational use of nitrogen fertilizers, as well as due to an increase in atmospheric emissions from vehicle exhaust gases. The same applies to phosphates, for which, in addition to fertilizers, the increasing use of various detergents serves as a source. Dangerous chemical pollution is created by hydrocarbons - oil and products of its processing, which enter rivers and lakes both with industrial discharges, especially during the extraction and transportation of oil, and as a result of washing off the soil and falling out of the atmosphere.

Dilution of sewage. To make wastewater more or less usable, it is subjected to multiple dilutions. But it would be more correct to say that at the same time, pure natural waters that could be used for any purpose, including drinking, become less suitable for this, polluted. So, if dilution by a factor of 30 is considered mandatory, then, for example, to dilute 20 cubic kilometers of sewage discharged into the Volga, 600 cubic kilometers of pure water would be needed, which is more than twice the annual flow of this river (250 cubic kilometers). To dilute all the effluents discharged into the rivers in our country, 4,500 cubic kilometers of pure water would be required, that is, almost the entire river flow in the USSR, amounting to 4.7 thousand cubic kilometers. This means that there is almost no clean surface water left in our country.

Dilution of wastewater reduces the quality of water in natural reservoirs, but usually does not achieve its main goal of preventing harm to human health. The fact is that harmful impurities contained in water in negligible concentrations accumulate in some organisms that people eat. First, toxic substances enter the tissues of the smallest planktonic organisms, then they accumulate in organisms that, in the process of breathing and feeding, filter a large amount of water (mollusks, sponges, etc.) and, ultimately, both along the food chain and in the process of breathing concentrated in the tissues of fish. As a result, the concentration of poisons in the tissues of fish can become hundreds and even thousands of times greater than in water.

In 1956, an epidemic of an unknown disease broke out in Minamata (Kyushu, Japan) with a complete breakdown of the central nervous system. People's vision and hearing deteriorated, speech was disturbed, their mind was lost, movements became uncertain, accompanied by trembling. Minamata disease affected several hundred people, with 43 deaths reported. It turned out that the chemical plant on the shore of the bay was the culprit. Careful studies, which the plant administration initially put up with all sorts of obstacles, showed that its wastewater contains mercury salts, which are used as catalysts in the production of acetaldehyde. Mercury salts are themselves poisonous, and under the action of specific microorganisms in the bay they turned into extremely poisonous methylmercury, which was concentrated in the tissues of fish by 500 thousand times. This fish poisoned people.

The dilution of industrial effluents, and especially solutions of fertilizers and pesticides from agricultural fields, often occurs already in the natural reservoirs themselves. If the reservoir is stagnant or slow-flowing, then the discharge of organic matter and fertilizers into it leads to an overabundance of nutrients - eutrophication and overgrowth of the reservoir. At first, nutrients accumulate in such a reservoir and algae, mainly microscopic blue-green, grow rapidly. After their death, the biomass sinks to the bottom, where it is mineralized with the consumption of a large amount of oxygen. Conditions in the deep layer of such a reservoir become unsuitable for the life of fish and other organisms that need oxygen. When all oxygen is exhausted, oxygen-free fermentation begins with the release of methane and hydrogen sulfide. Then there is a poisoning of the entire reservoir and the death of all living organisms (except for some bacteria). Such an unenviable fate threatens not only lakes into which domestic and industrial waste is discharged, but also some closed and semi-enclosed seas.

Damage to water bodies, especially rivers, is caused not only by an increase in the volume of discharged pollution, but also by a decrease in the ability of water bodies to self-purify. A vivid example of this is the current state of the Volga, which is more of a cascade of slow-flowing reservoirs than a river in the original sense of the word. The damage is obvious: it is the acceleration of pollution, and the death of aquatic organisms in water intake areas, and the disruption of habitual migration movements, and the loss of valuable agricultural land, and much more. And is this damage compensated by the energy produced at hydroelectric power plants? It is necessary to recalculate all the pros and cons, taking into account the modern environmental requirements of human existence. And it may turn out to be more expedient to dismantle some dams and liquidate reservoirs than to suffer losses from year to year.

physical pollution water is created by the discharge of heat or radioactive substances into them. Thermal pollution is mainly due to the fact that the water used for cooling at thermal and nuclear power plants (and, accordingly, about 1/3 and 1/2 of the energy produced) is discharged into the same reservoir. Some industries also contribute to thermal pollution. Since the beginning of this century, the water in the Seine has warmed by more than 5 °, and many rivers of France have ceased to freeze in winter. On the Moskva River within Moscow, ice floes are now rarely seen in winter, and recently, at the confluence of some rivers (for example, Setun) and discharges of thermal power plants, polynyas were observed with wintering ducks on them. On some rivers of the industrial east of the USA, in the late 60s, the water heated up to 38˚ and even up to 48˚ in summer.

With significant thermal pollution, the fish suffocates and dies, as its oxygen demand increases, and the solubility of oxygen decreases. The amount of oxygen in the water also decreases because thermal pollution leads to the rapid development of unicellular algae: the water “blooms” with subsequent decay of the dying plant mass. In addition, thermal pollution significantly increases the toxicity of many chemical pollutants, in particular heavy metals.

During the normal operation of nuclear reactors, neutrons can enter the coolant, which is mainly water, under the action of which the atoms of this substance and impurities, primarily corrosion products, become radioactive. In addition, the protective zirconium shells of fuel elements may have microcracks through which nuclear reaction products can enter the coolant. Although such wastes are weakly active, they can still increase the overall background of radioactivity. During accidents, the waste may be more active. In natural waters, radioactive substances undergo physical and chemical transformations - concentration on suspended particles (adsorption, including ion exchange), precipitation, sedimentation, transport by currents, absorption by living organisms, accumulation in their tissues. In living organisms, first of all, radioactive mercury, phosphorus, cadmium accumulate, in the soil - vanadium, cesium, niobium, zinc, sulfur, chromium, iodine remain in the water.

Pollution oceans and seas is due to the intake of pollutants with river runoff, their precipitation from the atmosphere, and, finally, due to human economic activity directly on the seas and oceans. According to data dating back to the first half of the 1980s, even in a sea such as the North Sea, where the Rhine and Elbe flow into, collecting effluent from the vast industrial zone of Europe, the amount of lead brought by rivers is only 31 percent of the total, while on atmospheric source accounts for 58 percent. the rest falls on industrial and domestic effluents from the coastal zone.

With river runoff, the volume of which is about 36-38 thousand cubic kilometers, a huge amount of pollutants in suspended and dissolved form enters the oceans and seas. According to some estimates, more than 320 million tons of iron, up to 200 thousand tons of lead, 110 million tons of sulfur, up to 20 thousand tons of cadmium, from 5 to 8 thousand tons of mercury, 6.5 million tons of phosphorus, hundreds of millions of tons of organic pollutants. Especially goes to the inland and semi-enclosed seas, in which the ratio of the catchment areas and the sea itself is greater than that of the entire World Ocean (for example, in the Black Sea it is 4.4 versus 0.4 in the World Ocean). According to minimal estimates, 367,000 tons of organic matter, 45,000 tons of nitrogen, 20,000 tons of phosphorus, and 13,000 tons of oil products enter the Caspian Sea with the flow of the Volga. There is a high content of organochlorine pesticides in the tissues of sturgeons and sprats - the main objects of the fishery. In the Sea of ​​Azov, from 1983 to 1987, the content of pesticides increased by more than 5 times. In the Baltic Sea over the past 40 years, the content of cadmium has increased by 2.4 percent, mercury - by 4, lead - by 9 percent.

Pollution coming with river runoff is unevenly distributed over the ocean. About 80-95 percent of the suspended matter and 20 to 60 percent of the dissolved matter of river runoff is lost in river deltas and estuaries and does not enter the ocean. That part of the pollution that nevertheless breaks through the areas of “avalanche sedimentation” in the mouths of the rivers moves mainly along the coast, remaining within the shelf. Therefore, the role of river runoff in the pollution of the open ocean is not as great as previously thought.

Atmospheric sources of ocean pollution for some types of pollutants are comparable to river runoff. This applies, for example, to lead, the average concentration of which in the waters of the North Atlantic has increased from 0.01 to 0.07 milligrams per liter over forty-five years and decreases with depth, directly indicating an atmospheric source. Mercury from the atmosphere comes almost as much as with river runoff. Half of the pesticides found in ocean water also come from the atmosphere. Somewhat less than with river runoff, cadmium, sulfur, and hydrocarbons enter the ocean from the atmosphere.

Oil pollution. A special place is occupied by pollution of the ocean by oil and oil products. Natural pollution occurs as a result of oil seepage from oil-bearing layers, mainly on the shelf. For example, in the Santa Barbara Strait off the coast of California (USA), an average of almost 3 thousand tons per year enters this way; this seepage was discovered as early as 1793 by the English navigator George Vancouver. In total, from 0.2 to 2 million tons of oil per year enters the World Ocean from natural sources. If we take the lower estimate, which seems to be more reliable, then it turns out that the artificial source, which is estimated at 5-10 million tons per year, exceeds the natural one by 25-50 times.

About half of artificial sources are created by human activities directly on the seas and oceans. In second place is river runoff (together with surface runoff from the coastal area) and in third place is the atmospheric source. Soviet specialists M. Nesterova, A. Simonov, I. Nemirovskaya give the following ratio between these sources - 46:44:10.

The greatest contribution to the oil pollution of the ocean is made by sea transportation of oil. Of the 3 billion tons of oil currently produced, about 2 billion tons are transported by sea. Even with accident-free transport, oil is lost during its loading and unloading, flushing and ballast waters (which fill tanks after oil is unloaded) into the ocean, as well as during the discharge of so-called bilge waters, which always accumulate on the floor of the engine rooms of any ships. Although international conventions prohibit the discharge of oil-polluted waters in special areas of the ocean (such as the Mediterranean, Black, Baltic, Red Seas, and the Persian Gulf), in the immediate vicinity of the coast in any area of ​​the ocean, impose restrictions on the content of oil and oil products in discharged waters, they still do not eliminate pollution; During loading and unloading, oil spills occur as a result of human error or equipment failure.

But the greatest damage to the environment and the biosphere is caused by sudden spills of large amounts of oil during tanker accidents, although such spills account for only 5-6 percent of the total oil pollution. The record of these accidents is as long as the history of seaborne oil shipments. The first such accident is believed to have occurred on Friday, December 13, 1907, when the seven-masted sailing schooner Thomas Lawson, carrying 1,200 tons of kerosene, crashed against the rocks off the Isles of Scilly near the southwestern tip of Great Britain in stormy weather. The cause of the accident was bad weather, which for a long time did not allow astronomical determination of the position of the vessel, as a result of which it deviated from the course, and a severe storm, which tore the schooner from its anchors, threw it onto the rocks. As a curiosity, we note that the most popular book of the writer Thomas Lawson, whose name was borne by the lost schooner, was called “Friday the 13th”.

On the night of March 25, 1989, the American tanker Exxon Valdie, which had just left the oil pipeline terminal in the port of Valdez (Alaska) with a cargo of 177,400 tons of crude oil, while passing through the Prince William Strait, ran into an underwater rock and ran aground. More than 40 thousand tons of oil poured out of eight holes in its hull, which in a few hours formed a slick with an area of ​​more than 100 square kilometers. Thousands of birds floundered in the oil lake, thousands of fish surfaced, and mammals died. Subsequently, the slick, expanding, drifted to the southwest, polluting the adjacent shores. Colossal damage was caused to the flora and fauna of the area, many local species were under the threat of complete extinction. Six months later, the Exxon oil company, having spent $1,400 million, stopped work to eliminate the consequences of the disaster, although it was still very far from the complete restoration of the ecological health of the region. The cause of the accident was the irresponsibility of the captain of the ship, who, being in a state of intoxication, entrusted the management of the tanker to an unauthorized person. The inexperienced third assistant, frightened by the ice floes that appeared near, mistakenly changed course, as a result of which the disaster occurred.

In the interval between these two events, at least a thousand oil tankers perished, and there were many more accidents in which it was possible to save the vessel. The number of accidents increased, and their consequences became more serious as the volume of maritime transport of oil increased. In 1969 and 1970, for example, there were 700 accidents of various sizes, as a result of which more than 200 thousand tons of oil ended up in the sea. The causes of accidents are very different: these are navigational errors, and bad weather, and technical problems, and the irresponsibility of personnel. The desire to reduce the cost of oil transportation led to the appearance of supertankers with a displacement of more than 200,000 tons. In 1966, the first such vessel was built - the Japanese tanker "Idemitsu-maru" (206 thousand tons), then tankers of even larger displacement appeared: "Universe Ireland" (326 thousand deadweight tons): "Niseki-maru" ( 372 thousand tons); Globtik Tokyo and Globtik London (478 thousand tons each); “Batillus” (540 thousand tons): “Pierre Guillaume” (550 thousand tons) and others. Per ton of cargo capacity, this really reduced the cost of building and operating the vessel, so it became more profitable to transport oil from the Persian Gulf to Europe, bypassing the southern the tip of Africa, rather than by conventional tankers along the shortest route - through the Suez Canal (previously such a route was forced due to the Israeli-Arab war). However, as a result, another cause of oil spills appeared: supertankers began to break quite often on very large ocean waves, which can be as long as tankers.

The hull of supertankers may not withstand if its middle part is on the crest of such a wave, and the bow and stern hang over the soles. Such accidents were noted not only in the area of ​​​​the famous “key-prollers” off South Africa, where waves dispersed by the western winds of the “Roaring Forties” go to the counter current of Cape Agulhas, but also in other areas of the ocean.

Today, the catastrophe of the century remains the accident that occurred with the supertanker Amoco Cadiz, which, near the island of Ouessant (Brittany, France), lost control due to malfunctions in the steering mechanism (and the time it took to bargain with the rescue ship) and sat on the rocks near this island. It happened on March 16, 1978. All 223,000 tons of crude oil poured out of the Amoco Cadiz tanks into the sea. This created a severe environmental disaster in the vast area of ​​the sea adjacent to Brittany and along a large stretch of its coast. Already in the first two weeks after the disaster, the spilled oil spread over a vast area, and the coast of France was polluted for 300 kilometers. Within a few kilometers from the accident site (and it happened 1.5 miles from the coast), all living things died: birds, fish, crustaceans, mollusks, and other organisms. According to scientists, never seen biological damage on such a huge area in any of the previous oil pollution. One month after the spill, 67 thousand tons of oil evaporated, 62 thousand tons reached the shore, 30 thousand tons were distributed in the water column (of which 10 thousand tons decomposed under the influence of microorganisms), 18 thousand tons were absorbed by sediments in shallow water and 46 thousand tons were collected from coast and from the surface of the water mechanically.

The main physicochemical and biological processes by which ocean waters self-purify are dissolution, biodegradation, emulsification, evaporation, photochemical oxidation, agglomeration, and sedimentation. But even three years after the accident of the Amoco Cadiz tanker, oil residues remained in the bottom sediments of the coastal zone. 5-7 years after the catastrophe, the content of aromatic hydrocarbons in bottom sediments remained 100-200 times higher than the norm. According to scientists, many years must pass to restore the complete ecological balance of the natural environment.

Accidental spills occur during offshore oil production, which currently accounts for about a third of global production. On average, such accidents make a relatively small contribution to the oil pollution of the ocean, but individual accidents are catastrophic. These include, for example, the accident at the Ixstock-1 drilling rig in the Gulf of Mexico in June 1979. The oil gusher, which escaped from control, erupted for more than six months. During this time, almost 500 thousand tons of oil ended up in the sea (according to other sources, almost a million tons). The self-cleaning time and damage to the biosphere during oil spills are closely related to climatic and weather conditions, with the prevailing water circulation. Despite the huge amount of oil spilled during the accident on the Ixstock-1 platform, which stretched in a wide strip for a thousand kilometers from the Mexican coast to Texas (USA), only an insignificant part of it reached the coastal zone. In addition, the prevalence of stormy weather contributed to the rapid dilution of oil. Therefore, this spill did not have such noticeable consequences as the Amoco Cadiz disaster. On the other hand, if it took at least 10 years to restore the ecological balance in the “catastrophe of the century” zone, then, according to scientists, self-purification of polluted waters during the Ex-son Valdez accident in Prince William Bay (Alaska) will take 5 to 15 years, although the amount of oil spilled there is 5 times less. The fact is that low water temperatures slow down the evaporation of oil from the surface and significantly reduce the activity of oil-oxidizing bacteria, which ultimately destroy oil pollution. In addition, the heavily indented rocky shores of Prince William Bay and the islands located in it form numerous “pockets” of oil that will serve as long-term sources of pollution, and the oil there contains a large percentage of the heavy fraction, which decomposes much more slowly than light oil.

Due to the action of wind and currents, oil pollution has affected essentially the entire oceans. At the same time, the degree of ocean pollution is increasing from year to year.

In the open ocean, oil is found by eye in the form of a thin film (with a minimum thickness of up to 0.15 micrometers) and tar lumps, which are formed from heavy oil fractions. If tar lumps primarily affect plant and animal marine organisms, then the oil film, in addition, affects many physical and chemical processes occurring on the ocean-atmosphere interface and in the layers adjacent to it. With an increase in ocean pollution, such an impact may become global.

First of all, the oil film increases the share of solar energy reflected from the ocean surface and reduces the share of absorbed energy. Thus, the oil film affects the processes of heat accumulation in the ocean. Despite the decrease in the amount of incoming heat, the surface temperature in the presence of an oil film increases the more, the thicker the oil film. The ocean is the main supplier of atmospheric moisture, on which the degree of moistening of the continents largely depends. The oil film makes it difficult to evaporate moisture, and with a sufficiently large thickness (about 400 micrometers) it can reduce it to almost zero. By smoothing out wind waves and preventing the formation of water splashes, which, evaporating, leave tiny particles of salt in the atmosphere, the oil film changes the salt exchange between the ocean and the atmosphere. It can also affect the amount of atmospheric precipitation over the ocean and continents, since salt particles make up a large part of the condensation nuclei needed to form rain.

Hazardous waste. According to the International Commission on Environment and Development of the United Nations, the amount of hazardous waste generated annually in the world is more than 300 million tons, with 90 percent of it occurring in industrialized countries. There was a time, and not too distant, when hazardous waste from chemical and other enterprises ended up in ordinary city dumps, dumped into water bodies, buried in the ground without taking any precautions. Soon, however, in one country after another, the sometimes very tragic consequences of the careless handling of hazardous waste began to appear more and more often. The widespread environmental movement of the public in industrialized countries has forced the governments of these countries to significantly tighten the legislation on the disposal of hazardous waste.

In recent years, the problem of hazardous waste has become truly global. Hazardous wastes have begun to cross national borders more frequently, sometimes without the knowledge of the government or the public in the recipient country. The underdeveloped countries are particularly affected by this type of trade. Some publicized egregious cases literally shocked the world community. On June 2, 1988, about 4 thousand tons of toxic waste of foreign origin were discovered in the area of ​​​​a small pore in Koko (Nigeria). The cargo was imported from Italy in five consignments from August 1987 to May 1988 using forged documents. The Nigerian government arrested the perpetrators, as well as the Italian merchant ship Piave, in order to send hazardous waste back to Italy. Nigeria withdrew its ambassador from Italy and threatened to take the case to an international court in The Hague. An inspection of the landfill showed that the metal drums contained volatile solvents and that there was a risk of fire or explosion emitting extremely toxic fumes. About 4,000 barrels were old, rusty, many bloated from the heat, and three of them were found to be highly radioactive. When loading waste for shipment to Italy on the ship "Karin B", which became infamous, loaders and crew members suffered. Some of them received severe chemical burns, others vomited blood, and one person was partially paralyzed. By mid-August, the landfill was cleared of the foreign “gift”.

In March of that year, 15,000 tons of “raw brick material” (so the documents said) were buried in a quarry on the island of Kassa opposite Conakry, the capital of Guinea. Under the same contract, another 70 thousand tons of the same cargo were soon to be delivered. After 3 months, newspapers reported that the vegetation on the island was drying up and dying. It turned out that the cargo delivered by the Norwegian company is ash rich in toxic heavy metals from household waste incinerators from Philadelphia (USA). The Norwegian consul, who turned out to be the director of the Norwegian-Guinean company - the direct culprit of what happened, was arrested. The waste has been removed.

Even a complete list of cases known to date will not be exhaustive, since, of course, not all cases are made public. On March 22, 1989, in Basel (Switzerland), representatives of 105 states signed an agreement on the control of the export of toxic waste, which will enter into force after ratification by at least 20 countries. At the heart of this treaty is an indispensable condition: the government of the host country must give written permission in advance to receive the waste. The treaty thus rules out fraudulent transactions, but legitimizes transactions between governments. The green movement has condemned the treaty and is demanding a complete ban on the export of hazardous waste. The effectiveness of the measures taken by the "greens" is evidenced by the fate of some ships that imprudently took on board a dangerous cargo. The already mentioned “Karin B” and “Deep Sea Carrier”, which exported dangerous cargo from Nigeria, could not immediately unload, a ship that left Philadelphia in August 1986 with 10 thousand tons of waste, the cargo of which was not accepted in the Bahamas, wandered the seas for a long time , nor in Honduras, Haiti, Dominican Republic, Guinea-Bissau. The dangerous cargo, carrying cyanide, pesticides, dioxin and other poisons, traveled for over a year before returning aboard the Syrian vessel Zanoobia to the port of departure of Marina de Carrara (Italy).

The problem of hazardous waste must be solved, of course, by creating waste-free technologies and decomposing waste into harmless compounds, for example, using high-temperature incineration.

radioactive waste. Of particular importance is the problem of radioactive waste. Their distinctive feature is the impossibility of their destruction, the need to isolate them from the environment for a long time. As mentioned above, the bulk of radioactive waste is generated at nuclear plants. These wastes, mostly solid and liquid, are highly radioactive mixtures of fission products of uranium and transuranium elements (except for plutonium, which is separated from waste and used in the military industry and for other purposes). The radioactivity of the mixture is on average 1.2-10 5 Curies per kilogram, which approximately corresponds to the activity of strontium-90 and cesium-137. At present, about 400 nuclear reactors of nuclear power plants with a capacity of about 275 gigawatts are operating in the world. Roughly, one gigawatt of power annually accounts for about a ton of radioactive waste with an average activity of 1.2-10 5 Curie. Thus, by mass, the amount of waste is relatively small, but their total activity is growing rapidly. So, in 1970 it was 5.55-10 20 Becquerels, in 1980 it quadrupled, and in 2000, according to the forecast, it will quintuple again. The problem of disposal of such waste has not yet been solved.

In our country, with huge reserves of fresh water, we rarely think about the value of drinking water. Meanwhile, on other continents, clean fresh water is worth its weight in gold. The neglect of water also affected the quality of the water. According to experts from the World Health Organization, it is its poor quality, non-compliance with sanitary and epidemiological standards that causes most diseases in residents of all countries. But why does something that, in fact, should give life kill us?

Only 3% is fresh water from the total volume of water, of which only 25% is easily accessible to us, because. the rest of the quantity is glaciers, icebergs. Conditionally sources of drinking water can be divided into three groups: surface (rivers, lakes), underground (artesian, mineral), artificial (the creation of human hands, there are desalination plants). It would seem that even if it is possible to desalinate water, then there should be no problems, it can also be purified using other installations.

However, pollution has not bypassed any source, and modern treatment equipment is expensive, it is difficult to use it on a city scale. And in general, it is better to deal with the cause, rather than eliminate the consequences. You need to stop spitting in the well you drink from.

Directly about the sources of pollution

In short, the main dangerous sources of water pollution are of anthropogenic origin. At the same time, harmful human activity has affected all types of waters. Pollutes water industry, agriculture, settlements.

Almost all industrial enterprises use water: as a raw material, a coolant, for washing, transportation. With water at many factories, plants remove waste. It used to be considered quite normal to dump untreated industrial effluents into natural reservoirs. Even today, some enterprises illegally dump toxic and other waste into rivers and lakes.

And in some countries there is simply no such legislation. The extractive industry also harms: waste seeps into the soil, drains into surface water bodies, and what can we say about oil spills during transportation and production.

Pesticides, potassium, phosphorus, nitrogen fertilizers, insecticides- all these toxic substances "give" us agricultural wastewater. And if on livestock farms, poultry farms, the water used can be purified before it enters the natural environment again, then how to purify the water used to irrigate the fields?

Domestic sewage, of course, passes through treatment facilities. But even modern equipment is not able to prevent the ingress of harmful substances (for example, detergents) with drains into water bodies, it does not guarantee protection against pathogenic bacteria. What remains to be demanded from obsolete purification plants that have remained since Soviet times?

Summarizing all that has been said

There are many questions, few answers, and the right ones, in general, are difficult to find. It is simply necessary that everyone realizes how important it is to start living “by the rules” right now, otherwise you will have to survive later.