B. Mandzhieva

Surface waters are subject to the greatest anthropogenic impact. Industrial wastewater from chemical, oil refineries, metallurgical, tanneries, textile and paper-pulp factories and mills spoils water especially badly.

Many environmentally hazardous substances enter water bodies, flowing down from fields, pastures and livestock farms during rains and snowmelt. These may include nitrogen compounds, pesticides, phosphorus, and the like. Particularly dangerous this type pollution due to the fact that the water flowing from the fields is not subject to any purification at all. Gas, smoke and dust compounds can become sources of pollution that cause many problems. They can settle on the surface of the water from polluted air.

Increased content organic ingredients, as a rule, leads to increased contamination of water in rivers flowing through densely populated areas.

Pollution groundwater

Pollution of ground and interstratal waters occurs mainly due to leakage of process and waste water, as well as the presence of adjacent filtering earthen structures used for collecting, storing and evaporating liquid industrial waste. Depending on the nature of production, heavy metals, aromatic substances, petroleum products and many others can enter groundwater along with wastewater. Bacterial contaminants, nitrogen compounds, surfactants included in synthetic waters can also penetrate from household water into groundwater. detergents. If used unsupervised agriculture pesticides, mineral fertilizers and pesticides, the latter, together with irrigation and atmospheric waters, pollute groundwater. The fight against contaminants entering groundwater is extremely difficult and requires expensive cleaning measures; therefore, the main means of protecting groundwater are thorough preventive measures.

Ocean Pollution

The ever-increasing load on the World Ocean leads to the gradual degradation of marine ecosystems. The seas are polluted as a result of direct discharge, the entry of pollution along with the water of rivers flowing into the seas, as a result of accidents of sea vessels, due to direct deposition various types pollution from the atmosphere and other ways. The consequence of such pollution may be their inclusion in the “food chain” through contamination of marine animals and other products of marine origin. The greatest danger is oil pollution. Petroleum products do not mix with water, but by forming a film on its surface, they prevent air exchange between water and the atmosphere. As a result of oxygen depletion in water, plankton die and, as a result, this disrupts the vital activity of other sea inhabitants - fish and waterfowl. Ocean waters, like other types of water, are also polluted by other types of industrial substances.

Thermal pollution of water bodies

When generating electrical energy, industry produces a large amount of excess heat; cooling is done using a large amount of water, which is then discharged into the environment, primarily into reservoirs. As a result, the water temperature in reservoirs increases, which has a bad effect on the ecosystems of reservoirs. Thermal pollution smoothes out seasonal temperature fluctuations in water bodies, disrupting life cycle some species of fish and plants.

The concept of rational nutrition. Physiological nutritional standards.

Rational nutrition is nutrition that ensures growth, normal development and vital activity of a person, helping to improve his health and prevent diseases. Energy value The daily diet should correspond to the body's energy expenditure.

A balanced diet includes 3 components:

ü Physiological norm;

ü Product consumption standards;

ü Power mode.

Physiological norms― these are scientifically based nutritional standards that fully cover the body’s energy expenditure and provide it with everything in the proper quantities and in the most optimal ratios.

According to current standards, there are 5 groups among men and 4 groups among women, depending on the intensity of work and daily energy consumption.

Labor intensity groups

To the first group These include mainly knowledge workers. The energy expenditure of this group ranges from 2550 to 2800 kcal. This group is divided into three age subgroups. There are groups of 18-29 years old, 30-39 years old and 40-59 years old.

Second group The population in terms of labor intensity is represented by workers engaged in light physical labor. These are engineering and technical workers whose work involves some physical effort, workers in the radio electronics, watch industries, communications and telegraphs, service industries servicing automated processes, agronomists, livestock specialists, nurses and orderlies. The energy costs of the second group are 2750-3000 kcal. This group, like the first, is divided into 3 age categories.

Third group The population in terms of labor intensity is represented by workers engaged in medium-heavy work. These are mechanics, turners, service technicians, chemists, vehicle drivers, water workers, textile workers, railway workers, surgeons, printers, foremen of tractor and field crews, grocery store sellers, etc. The energy expenditure of this group is 2950-3200 kcal.

To the fourth group include heavy physical labor workers - machine operators, agricultural workers, gas and oil industry workers, metallurgists and foundry workers, woodworking workers, carpenters and others. For them, energy consumption is 3350-3700 kcal.

Fifth group– workers engaged in particularly heavy physical labor: underground mine workers, breakers, masons, timber fellers, steelworkers, excavators, loaders, concrete workers, whose work is not mechanized, etc. This group includes only male representatives, since it is prohibited by law women's work with such intensity of work. This is particularly hard physical work, because energy consumption here ranges from 3900 to 4300 kcal.

There is a special provision on rational nutrition for persons involved in physical education and sports. Special meaning has food for people with various diseases - therapeutic nutrition. For persons employed in certain industries where certain occupationally harmful physical and chemical factors are exposed, therapeutic and preventive nutrition is used. In general, the issue of nutrition should be resolved individually.

Everyone should receive individual, balanced nutrition based on their health status. There is a concept of human nutritional status in the world. It is a state of health depending on nutrition.

Nutrition is one of the main factors determining human health. Catering for the team depends on the type of institution ( kindergarten, school, industrial institution, field camp, medical institutions, army, etc.), the number of people and the duration of their stay in this institution. In most cases medical workers They themselves take part in the organization of nutrition and exercise medical control over it in order to prevent nutritional diseases.

10. Ecological problems human nutrition. The concept of foreign substances and the food chain. Food additives, metals, carcinogens, nitro compounds, mycotoxins. Contaminants migrating from equipment, inventory, containers, etc.

Food (trophic) chain

Nutritional supplements- substances added for technological purposes to food products during production, packaging, transportation or storage to give them the desired properties, for example, a certain aroma (flavors), color (dyes), shelf life (preservatives), taste, consistency, etc. P.

Metals and other trace elements- These are the most common chemicals found in food products. They can come not only from food, but also from inhaled air and drinking water, but the alimentary (food) route is the main one. For most biomicroelements, the optimal physiological requirement has been determined.

Carcinogenic substances. Carcinogen -chemical substances, physical radiation or oncogenic viruses, the impact of which on the human or animal body increases the likelihood of malignant neoplasms. Carcinogenic polycyclic hydrocarbons are a large group of carcinogens formed during the combustion of organic substances; contains more than 200 compounds that are common pollutants environment. For example, 7 thousand tons of 3,4-benzpyrene are released into the environment annually in the world - only one representative of this group of carcinogens. Carcinogens of this group can cause cancer of the lung, gastrointestinal tract, skin and other organs in humans. Carcinogenic polycyclic hydrocarbons enter plant, fish and meat products from the environment polluted by industrial emissions, fuel combustion products from thermal power plants and vehicles. Air, water and soil pollution lead to the entry of carcinogenic polycyclic hydrocarbons into plant products. In the body of animals, polycyclic hydrocarbons quickly break down, so their content in meat, dairy and fish products is usually low.

Nitroso compounds- carcinogenic nitroso compounds can enter products from a polluted environment; they are found in small quantities in smoked, dried, canned meat and fish, dark beers, dry and salted fish, pickled and salted vegetables. However, the main thing is food contamination with precursors of nitroso compounds: nitrates and nitrites. As a result of modern agrochemical measures and the use of mineral fertilizers, vegetables and other plant products contain quite a lot of nitrates. Nitrates themselves are safe. The danger is that about 5% of nitrates are reduced in food or in the body to nitrites, which, in turn, are precursors of carcinogenic nitroso compounds. Other precursors of nitroso compounds - amines and amides - have been found in a variety of food products. As a result of nitrosation of amines and amides by nitrites, carcinogenic nitroso compounds (nitrosamines and nitrosamides) appear. The synthesis of carcinogenic nitroso compounds from precursors spontaneously occurs in products at room temperature. Processing products with smoke smoke, frying, canning and salting dramatically accelerates the formation of carcinogenic nitroso compounds in them. In contrast, storing food at low temperatures in refrigerators sharply inhibits their formation. The synthesis of carcinogenic nitrosamines and nitrosamides from food precursors also occurs in the body itself: the stomach, intestines and bladder. In the study, volunteers were given vegetable juice high in nitrates and found to have a large number of nitroso compounds. Carcinogenic nitroso compounds can cause tumors in humans of the stomach, esophagus, liver, nasal cavity, pharynx, kidneys, bladder, brain and other organs.

Contaminants migrating from equipment, inventory, containers, etc.― most often occurs through salts of heavy metals (copper, zinc, lead, etc.) that enter products from kitchen utensils, equipment, storage containers and packaging materials. In order to prevent the adverse effects on the human body of organic polymeric materials migrating into food, it is necessary to comply with the rules for using utensils and products made from them. To avoid dangerous consequences, plastic containers should be used for packaging and storing only those products for which they are intended.

Ecological problems of human nutrition. The concept of foreign substances and the food chain. Components that enter food products from fertilizers, pesticides, livestock and poultry medicines.

Foreign chemical substances (FCS) include compounds that, by their nature and quantity, are not inherent in a natural product, but can be added to improve technology, preserve or improve the quality of the product and its nutritional properties. They can form in the product as a result of technological processing and storage, and also get into it or food due to contamination. From 30 to 80% of foreign substances enter the body with food.

Food (trophic) chain- a series of relationships between groups of organisms (plants, animals, fungi and microorganisms), in which matter and energy are transferred by eating some individuals by others.

Components that enter food products from mineral and other fertilizers. Due to the use of various types of fertilizers, nitrates, nitrites, other nitrogen-containing compounds, as well as a number of metals can accumulate in plant and then animal products. Plants absorb nitrates through the root system in two ways: the reduction of nitrates to nitrites and the reduction of nitrates to ammonia. Nitrates are found in high concentrations in the roots, stems, petioles and veins of plants. Leaves and roots are richer in nitrates than fruits. Culinary processing of products reduces the concentration of nitrates (cleaning, washing, soaking products reduces it by 15-20%). When cooking vegetables, up to 80% of nitrates are washed out into the broth.

Some of the nitrates and nitrites that enter the gastrointestinal tract are metabolized by the microflora of the stomach and intestines, and the rest is absorbed. Nitrites entering the blood interact with hemoglobin, nitrosohemoglobin is formed, which is transformed into methemoglobin and partially into sulfohemoglobin. The threshold dose of nitrite ion that causes an increase in the concentration of methemoglobin is 0.05 mg per 1 kg of body weight. Prevention: reducing the use of nitrate fertilizers, work of the agrochemical service.

By chemical composition: inorganic and organic;

By purpose: insecticides (extermination of insects); acaricides (mites); lamacites (clams/slugs); nematicides (worms); fungicides (microscopic fungi-mold); herbicides (weeds); zoocides (small animals); bactericides; defoliants (stimulation of plants shedding leaves), etc. When processing agricultural crops and animals, residual amounts of pestiids can remain in food products and enter the human body, causing poisoning.

Pollution processes surface waters are caused by various factors. The main sources of pollution and clogging of water bodies are insufficiently treated wastewater from industrial and municipal enterprises, large livestock complexes, production waste from the development of ore minerals; water from mines, mines, processing and rafting of timber; discharges from water and rail transport; waste from primary flax processing, pesticides, etc.

The main ones include:

Discharge of untreated wastewater into water bodies;

Washing away pesticides with rainfall;

Gas and smoke emissions;

Leaks of oil and petroleum products

Pollutants entering natural water bodies lead to qualitative changes water, which are mainly manifested in changes in the physical properties of water, in particular, the appearance of unpleasant odors, tastes, etc.); in change chemical composition water, in particular, the appearance of harmful substances in it, the presence of floating substances on the surface of the water and their deposition at the bottom of reservoirs.

The greatest harm to reservoirs and watercourses is caused by the release of untreated wastewater into them. Wastewater is divided into three groups: waste water, or fecal water; household, including drains from the galley, showers, laundries, etc.; subshale, or oil-containing.

Fan wastewater is characterized by high bacterial contamination, as well as organic contamination (chemical oxygen consumption reaches 1500-2000 mg/l), the volume of this water is relatively small.

Domestic wastewater is characterized by low organic pollution. This wastewater is usually discharged overboard the ship as it is generated. Dumping them is prohibited only in the sanitary protection zone.

Shale waters form in the engine rooms of ships. They are characterized by a high content of petroleum products.

Industrial wastewater is contaminated mainly with waste and emissions from production. Their quantitative and qualitative composition is varied and depends on the industry and its technological processes; they are divided into two main groups: containing inorganic impurities, incl. both toxic and containing poisons. The first group includes wastewater from soda, sulfate, nitrogen-fertilizer plants, processing factories of lead, zinc, nickel ores, etc., which contain acids, alkalis, heavy metal ions, etc.

Wastewater of this group mainly changes physical properties water. Wastewater of the second group is discharged by oil refineries, petrochemical plants, organic synthesis enterprises, coke plants, etc. The wastewater contains various petroleum products, ammonia, aldehydes, resins, phenols and other harmful substances. The harmful effect of wastewater from this group lies mainly in oxidative processes, as a result of which the oxygen content in water decreases, the biochemical need for it increases, and the organoleptic characteristics of water deteriorate. The life of the population of water bodies is adversely affected by wastewater from the pulp and paper industry. Oxidation of wood pulp is accompanied by the absorption of a significant amount of oxygen, which leads to the death of eggs, fry and adult fish. Fibers and other insoluble substances clog the water and impair its physicochemical properties. Fish and their food - invertebrates - are adversely affected by moth alloys. Rotting wood and bark release various tannins into the water. Resin and other extractive products decompose and absorb a lot of oxygen, causing the death of fish, especially juveniles and eggs. In addition, moth floats heavily clog rivers, and driftwood often completely clogs their bottom, depriving fish of spawning grounds and feeding places. Great amount such dangerous pollutants as pesticides, ammonium and nitrate nitrogen, phosphorus, potassium, etc., are washed away from agricultural areas, including areas occupied by livestock complexes. For the most part, they end up in water bodies and streams without any treatment, and therefore have a high concentration of organic matter, nutrients and other pollutants.

A significant danger is posed by gas and smoke compounds (aerosols, dust, etc.) settling from the atmosphere onto the surface of drainage basins and directly onto water surfaces. The density of deposition, for example, of ammonium nitrogen per European territory Russia is estimated at an average of 0.3 t/km2, and sulfur from 0.25 to 2.0 t/km2.

Oil and petroleum products at modern stage are the main pollutants of inland waters, waters and seas, and the World Ocean. When they get into bodies of water, they create different shapes pollution: oil film floating on the water, oil products dissolved or emulsified in water, heavy fractions settled to the bottom, etc. This complicates the processes of photosynthesis in water due to the cessation of access sun rays, and also causes the death of plants and animals. At the same time, the smell, taste, color, surface tension, viscosity of water changes, the amount of oxygen decreases, and harmful substances appear. organic matter, water acquires toxic properties and poses a threat not only to humans. 12 g of oil makes a ton of water unfit for consumption. Each ton of oil creates an oil film over an area of up to 12 square meters. km. Restoration of affected ecosystems takes 10-15 years.

In addition to surface water, groundwater is also constantly polluted, primarily in areas of large industrial centers. Sources of groundwater pollution are very diverse.

Pollutants can penetrate to groundwater in various ways: through the seepage of industrial and domestic wastewater from storage facilities, storage ponds, settling tanks, etc., through the annulus of faulty wells, through absorption wells, karst sinkholes, etc.

It is important to emphasize that groundwater pollution is not limited to the area of industrial enterprises, waste storage facilities, etc., but spreads downstream to distances of up to 20-30 km or more from the source of pollution. This poses a real threat to the drinking water supply in these areas.

It should also be borne in mind that groundwater pollution negatively affects the ecological state of surface waters, the atmosphere, soils, and other components of the natural environment. For example, pollutants found in groundwater can be carried by filtration flow into surface water bodies and pollute them. As many scientists emphasize, the cycle of pollutants in the surface and groundwater system predetermines the unity of environmental and water protection measures and they cannot be broken. Otherwise, measures to protect groundwater independent of measures to protect other components of the natural environment will be ineffective.

Natural sources of pollution include highly mineralized (salty and brine) groundwater or sea water, which can be introduced into fresh, unpolluted water during the operation of water intake structures and pumping water from wells.

The main sources of pollution of surface and groundwater.

Pollution processes surface waters are caused by various factors. The main ones include: 1) discharge of untreated wastewater into water bodies; 2) washing away of toxic chemicals by rainfall; 3) gas and smoke emissions; 4) leaks of oil and petroleum products.

The greatest harm to reservoirs and watercourses is caused by release of untreated sewage- industrial and municipal.

Industrial wastewater pollute ecosystems with a wide variety of components, depending on the specifics of industries.

It should be noted that currently the volume of industrial wastewater discharges into many aquatic ecosystems not only does not decrease, but continues to grow. For example, in 1995 in lake. Baikal, instead of the planned cessation of wastewater discharge from the pulp and paper mill (pulp and paper mill) and transferring it to a closed water consumption cycle, 21% more wastewater was discharged than in 1994.

A huge amount of dangerous pollutants such as pesticides, ammonium and nitrate nitrogen, phosphorus, potassium, etc., are washed off from agricultural areas, including areas occupied by livestock complexes. For the most part, they end up in water bodies and streams without any treatment, and therefore have a high concentration of organic matter, nutrients and other pollutants.

A significant danger is posed by gas and smoke compounds (aerosols, dust, etc.) settling from the atmosphere onto the surface of drainage basins and directly onto water surfaces.

The scale of oil pollution of natural waters is enormous. Millions of tons of oil annually pollute marine and freshwater ecosystems during accidents of oil tankers, in oil fields in coastal areas, when ballast water is discharged from ships, etc.

Municipal wastewater large quantities come from residential and public buildings, laundries, canteens, hospitals, etc. This type of wastewater is dominated by various organic substances, as well as microorganisms, which can cause bacterial contamination.

Sources of groundwater pollution very diverse. Pollutants can penetrate to groundwater in various ways: through the seepage of industrial and domestic wastewater from storage facilities, sludge reservoirs, settling tanks, etc.

Groundwater pollution is not limited to the area of industrial enterprises, waste storage facilities, etc., but spreads downstream to distances of up to 20-30 km from the source of pollution. This poses a real threat to the drinking water supply in these areas.

It should also be borne in mind that groundwater pollution negatively affects the ecological state of surface waters, the atmosphere, soils, and other components of the natural environment. For example, pollutants found in groundwater can be carried by filtration flow into surface water bodies and pollute them. The cycle of pollutants in the system of surface and groundwater determines the unity of environmental and water protection measures and they cannot be broken. Otherwise, measures to protect groundwater independent of measures to protect other components of the natural environment will be ineffective.

Surface water pollution processes are caused by various factors. The main ones include: 1) discharge of untreated wastewater into water bodies; 2) washing away of toxic chemicals by rainfall; 3) gas and smoke emissions; 4) leaks of oil and petroleum products.

The greatest harm to reservoirs and watercourses is caused by the release of untreated wastewater - industrial and municipal.

Industrial wastewater pollutes ecosystems with a wide variety of components, depending on the specific industries.

A significant danger is posed by gas and smoke compounds (aerosols, dust, etc.) settling from the atmosphere onto the surface of drainage basins and directly onto water surfaces.

Municipal wastewater comes in large quantities from residential and public buildings, laundries, canteens, hospitals, etc. This type of wastewater is dominated by various organic substances, as well as microorganisms, which can cause bacterial contamination.

Sources of groundwater pollution are very diverse. Pollutants can penetrate to groundwater in various ways: through the seepage of industrial and domestic wastewater from storage facilities, sludge reservoirs, settling tanks, etc.

It should also be borne in mind that groundwater pollution negatively affects the ecological state of surface waters, the atmosphere, soils, and other components of the natural environment. For example, pollutants found in groundwater can be carried by filtration flow into surface water bodies and pollute them. The cycle of pollutants in the system of surface and groundwater determines the unity of environmental and water protection measures and they cannot be broken. Otherwise, measures to protect groundwater independent of measures to protect other components of the natural environment will be ineffective.