24. Soil as an object of analysis. Sources of soil pollution. Criteria and indicators of soil quality.

Soil and soils provide a medium for the production of food and clothing, as well as a source of drinking water. In addition, the earth is the environment where we are destined to live. That is why clean land - clean soil and soil - is so important for human health.

The soil is constantly under the influence of human activities, represented in the form of agricultural production, industry, mining of various minerals, landfills, accumulation of pollutants that are formed primarily in atmospheric emissions during the production of heat and energy, industrial activities, traffic, waste burning, etc. P. Deterioration of soil quality or contamination with chemicals harmful to human health can occur as a result of exposure to any of these human activities.

In addition to reckless soil management (use of pesticides and disposal of waste in landfills), impacts are noted mainly as an undesirable result of a wide range of activities, including releases and leaks of chemicals, as well as the accumulation of an increasing number of pollutants generated and distributed in the air.

Soil is the richest natural resource of any country

mmol-equiv/l). The hardness of surface waters is subject to noticeable seasonal fluctuations, usually reaching the highest value at the end of winter and the lowest during the flood period.

High hardness worsens the organoleptic properties of water, giving it a bitter taste and affecting the digestive organs. The value of the total hardness in drinking water should not exceed 10.0 mmol-eq / l. Water hardness is expressed as the number of mmol-eq of calcium and magnesium in 1 liter of water.

The total hardness is determined by complexometric titration. Complexometric titration is based on the formation of complex compounds of metal ions with inorganic and organic ligands. The most widely used complexometric titration, which uses special reagents - complex - derivatives of aminopolycarboxylic acids. Most often, complexon III is used as a titrant - disodium salt of ethylenediaminetetraacetic acid Na 2 H 2 Y - EDTA (trilon B). Schematically, the formation of a complex compound can be represented as follows Me 2+ + H 2 Y 2 - = MeY 2 + 2H + ; Me 3+ + H 2 Y 2 - = MeY - + 2H +; Me 4+ + H 2 Y 2 \u003d MeY + 2H +.

These equations show that one metal atom, regardless of its valency, binds one complex molecule. Titration with complexone III should be carried out when determining

There are several methods for disposal of dehydrated sludge:

burial in special places, while the sediment should not penetrate into groundwater;

composting together with municipal solid waste;

incineration (the disadvantage of this method is atmospheric pollution);

use as fertilizers (the disadvantage of the method is the problem of heavy metals).

So the cleaning problem Wastewater generates, in turn, new problems, forming a vicious circle. Unfortunately, there are not so many alternatives to this. In addition to the introduction of new production technologies that do not pollute water, it is necessary to improve methods that exclude the discharge of industrial effluents into rivers and lakes; improve wastewater treatment by solving the problem of disposal of by-products.

Water pollution by radioactive substances poses a great danger. Scales river pollution, lakes take on such dimensions that the latter lose their ability to self-purify. Pollution of water systems is a greater danger than air pollution. This is explained by the following reasons:

the processes of regeneration and self-purification proceed in the aquatic environment more slowly than in the air;

sources of water pollution are more diverse;

natural processes carried out in the aquatic environment exposed to pollution are more sensitive

thermal barriers are formed on the ways of fish migrations;

species diversity decreases.

Experts have established that in order to prevent irreversible violations of the ecological balance, the temperature of the water in the reservoir in the summer as a result of the discharge of polluted waters should not rise by more than 3 ° C compared to average monthly temperature hottest year in 10 years.

2. Organoleptic indicators. Organoleptic indicators include color, turbidity, smell, taste and taste, foaminess. International standards ISO 6658 and others set specific requirements for tasters and tasting methods. For example, there are three qualification levels for tasters: consultant, qualified consultant and expert. Before the study of smell and taste, preliminary tests of a sample free of foreign smell or taste are carried out, and such a sample is included in a series of analyzed samples as a coded sample.

Chroma- a natural property of natural water, due to the presence of humic substances and complex iron compounds. The color of water can be determined by the properties and structure of the bottom of the reservoir, the nature of aquatic vegetation, soils adjacent to the reservoir,

character is divided into two groups, describing it subjectively according to their feelings:

natural origin (from living and dead organisms, from the influence of soils, aquatic vegetation): earthy, putrefactive, moldy, grassy, ​​etc.

artificial origin. Such odors usually change significantly during water treatment: petroleum products, acetic, phenolic, etc.

The odor intensity is evaluated on a 5-point scale (GOST 3351). For drinking water, an odor of no more than 2 points is allowed.

insoluble or colloidal particles of various origins. The turbidity of the water also determines some other characteristics of the water:

The presence of sediment, which may be absent, insignificant, noticeable, large, very large (mm).

Suspended substances, or coarsely dispersed impurities, are determined gravimetrically after filtering the sample, by the weight gain of the dried filter. This indicator is usually not very informative and is important mainly for wastewater.

Transparency, measured as the height of a column of water through which a standard font can be seen on white paper.

Turbidity is determined photometrically or visually - according to the degree of turbidity of a column 10-12 cm high. In the latter case, the sample is qualitatively described as follows: transparent, slightly opalescent, opalescent, slightly cloudy, cloudy, very cloudy (GOST 1030).

foaminess the ability of water to retain artificially created foam is considered. This indicator can be used to qualitatively assess the presence of substances such as natural and artificial surfactants. Foaminess is determined mainly in the analysis of waste and polluted natural waters. The test is positive if the foam persists for more than 1 minute (pH 6.5 -8.5).

3. pH. For all living things in water, the minimum possible pH value is 5, rain having a pH<5,5, считается кислотным. В питьевой

of the above are determined by phenolphthalein, the second - by methyl orange.

The alkalinity of natural waters due to their contact with atmospheric air and limestone is mainly due to the content of bicarbonates and carbonates in them, which make a significant contribution to the mineralization of water. Compounds of the first group can also be found in waste and contaminated surface waters.

Similar to alkalinity, sometimes, mainly in the analysis of waste and process water, determine acidity water. The acidity of water is due to the content in water of substances that react with hydroxoanions. These connections include:

Strong acids: hydrochloric (HCl), nitric (HNO 3), sulfuric (H 2 SO 4).

Weak acids: acetic (CH 3 COOH), sulfurous (H 2 SO 3), carbonic (H 2 CO 3), hydrogen sulfide (H 2 S), etc.

Cations of weak bases: ammonium (NH 4 +), cations of organic ammonium compounds.

The acidity of a water sample is measured in mol-eq / l or mmol-eq / l and is determined by the amount of strong alkali (usually KOH or NaOH solutions with a concentration of 0.05 or 0.1 mol-eq / l) are used to neutralize the solution. Similarly to the alkalinity index, free and total acidity are distinguished.

pass into carbonates, which precipitate, carbonate hardness is called temporary or removable. The hardness remaining after boiling is called constant. The results of the determination of hardness are usually expressed in mmol-eq / l.

Under natural conditions, ions of calcium, magnesium and other alkaline earth metals that cause hardness enter the water as a result of the interaction of dissolved carbon dioxide with carbonate minerals and other processes of dissolution and chemical weathering of rocks. The source of these ions is also microbiological processes occurring in soils in the catchment area, in bottom sediments, as well as wastewater from various enterprises.

Water hardness varies widely. Water with a hardness of less than 4 mmol-eq/l is considered soft, from 4 to 8 mmol-eq/l - medium hardness, from 8 to 12 mmol-eq/l - hard and above 12 mmol-eq/l - very hard. The total hardness ranges from units to tens, sometimes hundreds of mmol-eq/l, and the carbonate hardness is up to 70-80% of the total hardness. Hardness due to calcium ions usually predominates (up to 70%); however, in some cases, magnesium hardness can reach 50-60%. The hardness of sea water and oceans is much higher (tens and hundreds

lennom pH of the solution, tk. this determines the stability of the complex, as well as the change in the color of the indicator. The required pH value of the medium is created by adding buffer solutions. To indicate the end point of the titration in the method of complexometry, metal-chromic indicators are used (eriochrome black T, murexide, xylenol orange, etc.). These indicators form complexes with metal ions that are less stable than the complex of a metal ion with EDTA. Therefore, at the end of the titration, complexone III displaces the indicator from its complex with the metal (the metal binds to a more stable complex with EDTA). In this case, the color changes, the solution turns into a color characteristic of the indicator at a given pH of the solution.

6. Dry residue is the mass of the residue obtained by evaporating the filtered water sample and dried at 103-105°C or 178-182°C.

This value should express the total amount of substances dissolved in the sample, inorganic and organic. The results obtained, however, satisfy this requirement only approximately, at whichever of these two temperatures the residue is dried.

If the residue was dried at 103-105°C, then it will retain all or almost all of the water of crystallization of the salts forming

and, first of all, it is a bridge between animate and inanimate nature. It consists of products of weathering and decay of bedrock, water, organic matter, and various gases. Thousands of different microorganisms and insects live in it, maintaining the ecological balance of undisturbed soils. Improper exploitation of the soil causes its irrevocable destruction due to mining, salinization, industrial waste pollution and, finally, erosion. Natural soil erosion proceeds slowly, but under the influence of economic activity, soil erosion increases many times over. As a result of erosion, 27% of agricultural land has been lost over 100 years. Deforestation contributes to soil destruction.

The most common is water erosion, which causes enormous damage to the economy. This form of erosion is typical of areas where improper tillage practices are practiced. The annual washout of soil on the globe reaches 25 billion tons. This soil ends up in rivers and then in the oceans. The decrease in the productivity of agricultural land and the accumulation of sedimentary material in the lower reaches of the rivers leads to a complication of navigation, floods, and flooding of reservoirs. A serious cause of soil erosion can be storm flows, strong winds, prolonged droughts, which, however, are not the main danger. Erosion occurs, as a rule, due to the introduction of agricultural systems

production, designed without taking into account the susceptibility of soils to washout or deflation. Therefore, the problem of protecting soils from erosion is closely connected with the problems of overcoming backwardness in agriculture.

Sources of pollution. Soil, unlike air and water, is most heavily polluted. Various physical, chemical and biological processes take place in the soil, which are disturbed as a result of pollution. Soil pollution is associated with air and water pollution. Solid and liquid industrial, agricultural and domestic wastes enter the soil. The main pollutants are metals and their compounds, radioactive substances, fertilizers and pesticides.

Industrial and commercial activities for a long time lead to the formation of a large number of contaminated areas. Poor handling of chemicals and petroleum products results in the release and leakage of chemicals and petroleum products into the surrounding soil and soil.

Most of the contaminated sites are located in urban areas, which creates a potential threat to the local population due to soil and ground contamination. Moreover, residential buildings were built in these areas at a time when there were no serious reasons for general concern about soil pollution problems, so the construction was carried out without observing any protective measures against the effects of harmful substances.

The following sources of soil pollution can be identified:

absorbed by plants. In the latter case, these substances also penetrate the soil.

Spread of pollution formed in the air.

Soil quality, especially in urban areas, is affected by air emissions from vehicle operation, waste and fuel combustion in thermal and power plants. The impact of pollution on the state of the air basin is determined by the diffusion of pollutants over vast areas of urban areas. Some of these pollutants pose a risk to human health (especially children's health) due to the presence of heavy metals (mainly lead) in them, as well as polycyclic aromatic hydrocarbons in the surface soil layer. It is assumed that an area of ​​about 200 km 2 is exposed to pollution accumulated from the air. Of this area, it is estimated that approximately 20 km 2 is used for socially significant needs - for the construction of housing, kindergartens and public sports and entertainment areas.

Self-purification of soils practically does not occur, toxic substances accumulate, contributing to a change in the chemical composition of soils. From the soil, toxic substances through food enter the human body and cause various diseases. Heavy metals also accumulate in soils: mercury, lead, copper, iron, chromium, etc. A large amount of waste is generated during mining. big

consumption of contaminated fish; through water for bathing; use of textiles produced from agricultural raw materials (linen and cotton).

The most serious ways of external influence are: ingress of soil into the digestive system (children); skin contact with soil; inhalation of air vapors (evaporation in indoor areas); contact with drinking water; consumption of agricultural products from contaminated soils.

The routes of external influences listed above are considered first of all, and soil quality criteria are established taking into account the direct impact of the soil (ingestion through the digestive system and (or) skin contacts with the soil).

Soil quality criteria designed to impact particularly vulnerable and sensitive groups of land users, such as private horticulture and horticulture, kindergartens or sports and recreation and playgrounds. The focus on protecting babies is due to the fact that children are considered the most vulnerable group that is exposed to soil (direct ingestion of soil, contact through hands and mouth), and also because exposure to some chemical pollutants may be biologically more sensitive than for an adult. The calculation of soil quality criteria is based on standard input data. Another factor in establishing criteria for soil quality was the ability to bioaccumulate substances in the soil.

the notification relates to activities in relation to such sites. However, despite indications of small amounts of contaminants in vegetables grown in lightly contaminated soil, notifications and recommendations are given to stop growing vegetables in contaminated areas, because it is almost impossible to grow them without open ground that directly affects people. especially for children.

Threshold limits can only be used for immobile and sufficiently persistent chemicals and are only defined for the group of 10 metals and polycyclic aromatic hydrocarbons.

The cut-off value and performance criterion are identical where the performance criterion has been set to prevent acute toxic effects. The limit threshold may be ten times higher than the quality criterion for those cases where the soil quality criterion is set to prevent toxic chronic exposure. The main idea is that, in general, public information and risk reduction measures should result in a reduction in average toxic exposure to children. However, these measures will not necessarily provide protection for single cases of severe exposure to soil by ingestion. This means that the limit threshold cannot be increased from the value of the performance criterion if the basis for setting the performance criterion is

An important role in the analysis of soils is played by remote methods, which make it possible to obtain data on large-scale changes. These are methods using space means - satellites "Meteor", "Meteor-Nature", in the USA - "Landsat". Already in the 70s of the last century, images were received from the Soviet Meteor satellite, which made it possible to fairly accurately judge the change in the state of pasture vegetation in the republics of Central Asia. Extensive information about various natural resources, processes occurring on the surface of the Earth, comes from other space systems. Significant results in the assessment of anthropogenic impacts were obtained on the basis of the integrated use of information provided by space, ground-based systems, and aerial photography.

The information received from satellites and used in the organization of environmental monitoring also includes data on the state of forests, agricultural land, vegetation on land, phytoplankton at sea, the earth's surface, redistribution of water resources, pollution of the atmosphere, seas and land. To obtain such information, for example, satellites of the Meteor-Priroda system are equipped with multispectral scanners, spectrometers and microwave radiometers, which are capable of isolating aerosol plumes of anthropogenic origin in the area of ​​cities and industrial centers, places of surface contamination

25. Air as an object of analysis. Sources of air pollution. Criteria for sanitary and hygienic assessment of the air condition. Methods for determining pollutants in the atmosphere. Determination of inorganic and organic compounds.

The atmosphere is a part of the biosphere and is a gaseous form. the shell of the Earth, rotating with it as a whole. This shell is layered. Each layer has its own name and characteristic physical and chemical features. Conventionally, the atmosphere is divided into two large components: upper and lower. Of greatest interest to us is the lower part of the atmosphere, mainly the troposphere, since it is where the main meteorological phenomena that affect pollution occur. atmospheric air.

The troposphere contains most of the cosmic and anthropogenic dust, water vapor, nitrogen, oxygen and inert gases. It is practically transparent to short-wave solar radiation passing through it. At the same time, the water vapor, carbon dioxide and ozone contained in it quite strongly absorb the thermal radiation of our planet, as a result of which the troposphere heats up. This heating causes vertical movement of air currents, condensation of water vapor, formation of clouds and precipitation. The distribution of temperatures in the surface layer of the atmosphere is the most important reason for the formation of the climate and its characteristics. The composition of the gases of the lower part of the atmosphere

allowable concentrations in the atmospheric air of more than 500 substances.

Hygienic standards should provide a physiological optimum for human life, and in this regard, high demands are made on the quality of atmospheric air in our country. In view of the fact that short-term exposure to harmful substances that are not detected by smell can cause functional changes in the cerebral cortex and in the visual analyzer, the values ​​of maximum single maximum allowable concentrations (MAC mr) are introduced. permissible concentrations (MPC cc).

Thus, for each substance, two standards are established: the maximum single maximum allowable concentration (MPC mr) (averaged over 20-30 minutes) in order to prevent reflex reactions in humans and the average daily maximum allowable concentration (MPC cc) in order to prevent general toxic, mutagenic, carcinogenic and other effects with unlimited long-term breathing.

The values ​​of MPC mr and MPC ss for the most common impurities in the atmospheric air are given in Table. 7. In the rightmost column of the table, the hazard classes of substances are given. These classes are designed for continuous inhalation of substances without changing their concentration over time. In real conditions, significant increases in impurity concentrations are possible, which can lead to

hygienic hazard of a substance, you can use the indicator of the approximate-safe maximum single level of air pollution (SHPL).

Methods for determining pollutants in the atmosphere. To determine particulate matter in the air, instrumental methods are used based on measuring the optical properties of air, which are measured in units of visibility (km) or transparency (µg/m3). To measure the opacity coefficient - the reflection coefficient (pollution) requires fairly simple equipment. For automatic analysis of gas mixtures with high reflection coefficients and high sensitivity, gas analyzers based on optical-acoustic spectroscopy are used. A discretely tunable CO 2 laser produces a beam of light that is interrupted and passed through a cuvette containing an air sample. The setup is equipped with IR detectors connected to an electronic signal recording system and a mini-computer. The limit of detection is 10 -7%. Air quality analysis is based on the collection of particles from aerosols or air by filtration to determine mass concentration and composition. For this, large volume samplers with filters made of glass fiber or inert cellulose esters with pore sizes from 8 to 0.01 µm are used. Continuous sampling lasts from 24 hours to 1 month. This is how average results are obtained. Even within 24 hours, the composition of the sample may change as weather conditions change. For example, rain increases humidity,

capable of harming human health, animals, vegetation, or causing a deterioration in the aesthetic perception of the environment (for example, in the presence of dust, dirt, unpleasant odors or lack of sunlight as a result of air smoke). Since all living things very slowly adapt to these new microcomponents, chemicals serve as an objective factor in adverse effects on the natural environment and human health.

Sources of air pollution. Discharge of pollutants can be carried out in various environments: atmosphere, water, soil. Emissions to the atmosphere are the main sources of subsequent pollution of waters and soils on a regional scale, and in some cases on a global scale.

Industrial sources of atmospheric air pollution are divided into sources of emission and sources of emissions. The former include technological devices (installation devices, etc.), during the operation of which impurities are released. To the second - pipes, ventilation shafts, aeration lamps and other devices with the help of which the admixture enters the atmosphere.

Industrial emissions are divided into organized and unorganized. Organized industrial emissions enter the atmosphere through specially constructed gas ducts, air ducts and pipes, which makes it possible to use appropriate installations for purification from pollutants. unorganized

Residential buildings and household enterprises. This is mainly household and construction waste, food waste, feces, waste from heating systems, waste from public institutions (hospitals, canteens, shops, etc.).

Industrial enterprises. Solid and liquid industrial wastes contain certain substances that have a toxic effect. These are salts of non-ferrous and heavy metals, cyanides, compounds of arsenic, beryllium, wastes of benzene, phenol, methanol, etc.

Thermal power engineering. The formation of slag during the combustion of coal, as well as the release into the atmosphere of soot, sulfur oxides, which ultimately end up in the soil.

Agriculture. Fertilizers, pesticides used in agriculture and forestry to protect plants from pests and diseases.

Intensive use of agricultural land leads to deterioration of soil quality. The applied pesticides, applied sludge and fertilizers have an impact on the state of agricultural land. The use of pesticides on farmland is considered a problem due to the risk of surface leaching and contamination infiltrating into groundwater. The accumulation of heavy metals in the topsoil can be a direct or indirect source of threat to human health.

Transport. During the operation of internal combustion engines, oxides of nitrogen, carbon, lead, hydrocarbons and other substances are released that settle on the soil or

the amount of waste is also obtained during the enrichment of phosphate raw materials. Thermal power plants produce 70 million tons of ash and slag per year. Annual costs for the maintenance and operation of ash dumps amount to tens of millions of rubles.

MPC standards for soil pollution have not yet been finally established. However, a wide range of pollutants can already be determined using chemical, physical and other methods.

Impact on a person. The degree of human exposure to environmental factors present in soil and soil (harmful chemicals) depends on the degree of land use, the concentration of pollution in soil and soil, and the degree of risk of pollution of other environmental components (groundwater and air).

Ways of influence of environmental factors of the soil can be divided into two types: direct impact and indirect or indirect impact.

Direct exposure to soil and soil pollutants through: ingestion of soil particles (dust), skin contact, inhalation of soil/dust particles, inhalation of substances evaporating from the soil (especially indoors).

Indirect (indirect) impact through: consumption of contaminated crops grown on contaminated soils; consumption of contaminated livestock products (from animals bred on contaminated soils); consumption of contaminated drinking water (direct drinking, skin contact, inhalation of aerosols);

For urban areas, the quality criteria are usually exceeded for several substances (especially lead and polycyclic aromatic hydrocarbons). Therefore, a new indicator has been introduced in the soil regulations for cases of land use for particularly sensitive needs and vulnerable groups of the population, the so-called “limit threshold”.

If the value of the maximum threshold concentration is exceeded in areas used for residential development, children's institutions or children's and sports and recreation areas, then measures must be taken to eliminate pollution. If the concentration of pollutants is between the limiting threshold value and the indicator of the quality criterion, then the local authorities inform and explain the situation to the public, landowners and land users of the territory.

The aim of this approach is to define sanitary and epidemiological requirements and measures to eliminate the impact of pollution through the soil and thereby achieve the same level of protection that is usually provided when soil quality criteria are met. The discrepancy between the limiting threshold value of the pollutant concentration and the indicator of the quality criterion is called the "residential notification interval".

The basic principle is to avoid open, bare areas of the ground surface, which in such a case can lead to direct exposure of the soil to children,

soil adopted a sharp strong toxic effects of the pollutant.

Soil quality indicators. Almost always there is a need to determine soil moisture. To do this, a sample of soil is placed in a beaker and adjusted to constant weight. For clayey, high-humus soils with high humidity, 15-20 g of soil are selected, a sample of organic soils is 15-50 g. The determination is carried out twice, the heating temperature is 105 ± 2°C for 8 hours. Sandy soils are heated for 3 hours at 105 ± 2°C, gypsum soils are heated for 8 hours at 80 ± 2°C. The duration of subsequent drying is 1 hour for sandy soils and 2 hours for other soils.

When concentrating the substances under study by extracting them from the soil with liquid solvents, the concentration of the substance in the soil is calculated by the formula C = a V 1 /V in, where a- the content of the substance found in the test volume of the solution, μg; V1 V - volume of sample solution taken for analysis, ml; in- mass of the studied soil, g.

If the analyte in the sample solution is defined as a concentration (µg/ml), then the concentration of the substance in the soil (C, mg/kg) is calculated using the formula C = a V/v, where a- concentration of the analyte in the sample solution, µg/ml; V - volume of the test sample, ml; in - mass of the studied soil, g.

waters, etc. Data from the Salyut and Mir space stations make it possible to interpret the received information in a qualified manner and photograph the fields of anthropogenic impacts, including pollution. It is shown that under certain meteorological conditions the territory of Europe is covered with a haze of anthropogenic presence. Anthropogenic changes on land are caused not only by the impact of pollution, but also by total urbanization, the expansion of agricultural land, deforestation, and open mining. With the help of satellite imagery, the total effect of anthropogenicity is determined, against which its individual components (for example, plumes of pollution) can be distinguished.

At present, there is already extensive experience in using satellite information to study environmental anthropogenic changes and identify the causes of these changes.

unchanged: the mixture formed by gases is called air (Nitrogen - 78.09%, Oxygen - 20.95, Argon - 0.93, Carbon dioxide - 0.03, etc.) The average relative molecular weight of dry air is 28.966 kg / mol .

Emission of some gaseous substances (10 6 t/day)

According to the table. natural sources emit more harmful substances, however, anthropogenic intake is the most dangerous. This is due to the fact that harmful substances of anthropogenic origin accumulate in the human habitat. In addition, specific harmful substances that did not previously exist in natural conditions are now becoming an integral part of the atmospheric air, its microelements.

Air is considered clean if none of the microcomponents is present in concentrations

industrial emissions enter the atmosphere in the form of non-directional gas flows as a result of equipment leaks, the absence or poor operation of gas extraction equipment at the places of loading, unloading or storage of the product. Fugitive emissions are typical for treatment facilities, tailings, ash dumps, loading and unloading areas, loading and unloading racks, tanks and other facilities.

The main sources of industrial air pollution include energy, metallurgy, building materials, chemical and oil refining industries, and fertilizer production.

Sanitary criteria- hygienic condition assessmentair. Substances in the air enter the human body mainly through the respiratory system. Inhaled polluted air through the trachea and bronchi enters the alveoli of the lungs, from where impurities enter the blood and lymph.

In our country, work is underway on hygienic regulation (rationing) of the permissible level of impurities in the atmospheric air. The substantiation of hygienic standards is preceded by multifaceted complex studies on laboratory animals, and in the case of assessing the body's olfactory reactions to the effects of pollutants, on volunteers. In such studies, the most modern methods developed in biology and medicine are used. At present, the maximum

a short time interval to a sharp deterioration in a person's condition.

In places where resorts are located, in the territories of sanatoriums, rest houses and in recreation areas of cities with a population of more than 200 thousand people, the concentration of impurities that pollute the atmospheric air should not exceed 0.8 MPC.

A situation may arise when there are simultaneously substances in the air that have a summed (additive) effect. In this case, the sum of their concentrations (C), normalized to MPC, should not exceed one according to the following expression: C 1 / MPC 1 + C 2 / MPC 2 + C 3 / MPC 3< = 1

Harmful substances with a summation of action include, as a rule, similar in chemical structure and nature of the effect on the human body, for example: sulfur dioxide and sulfuric acid aerosol; sulfur dioxide and hydrogen sulfide; sulfur dioxide and nitrogen dioxide; sulfur dioxide and phenol; sulfur dioxide and hydrogen fluoride; sulfur dioxide and trioxide, ammonia, nitrogen oxides; sulfur dioxide, carbon monoxide, phenol and converter dust.

At the same time, many substances, when simultaneously present in atmospheric air, do not have a summation of action, i.e. maximum allowable concentrations are stored for each substance separately, for example: carbon monoxide and sulfur dioxide; carbon monoxide, nitrogen dioxide and sulfur dioxide; hydrogen sulfide and carbon disulfide.

When there are no MPC values, for evaluation

causing a change in particle dispersion. Much attention is paid to sampling in 1 hour or less, which allows you to quickly get information about the source of air pollution and identify peak particle levels. Several rapid micromethods are available for taking small air samples (200 ml) and collecting 1-2 µg of the sample. An example is the direct determination of lead macroparticles in air by flameless atomic absorption spectroscopy. The diameter of the disc filters was less than 3 mm, and the time for sampling and chemical analysis was less than 5 min per determination. For the study of sediment on the filter, rapid sampling, the industry produces a variety of equipment and filters. For any case, you can choose a filter with a precisely defined pore structure. The following methods are used to study the collected material: microscopic identification (use of visible light); microscopy in incident light, in transmitted light; electron microscopy and electron microprobe spectroscopy; chemical drop analysis; infrared spectroscopy; UV-visible spectrophotometry; flame and emission spectroscopy; X-ray fluorescence spectroscopy; x-ray diffraction analysis and radiochemistry.

Most atmospheric analysis methods

pollution is based on the use of gas chromatography, atomic absorption, polarography. The concentration of the test substances in the air (in µg/l or mg/l) is calculated by the formula C \u003d a / V, where a - mass of the substance found in the sample, μg; V - the volume of the studied air sample, reduced to normal conditions, l (0 ° C, 101080 Pa) and equal to V = 273 P V t /( 273 + t)· 101080, where R- atmospheric pressure during sampling, Pa; t- air temperature at the sampling point, °С; V t , is the volume of air sampled for analysis at a temperature t, l.

When concentrating analyzed substances from air into liquid absorption media or onto solid sorbents, fractions of the volume of sample solutions can be used in the analysis. In this case, the concentration of substances in the air is calculated by the formula C = a*V1/ V2* V, where V1 is the total volume of the sample solution, ml; V2 - the volume of the sample solution used for analysis, ml, or according to the formula C = inV1/ V, where in- concentration of the analyte in the sample solution, µg/ml.

1. Determination of inorganic compounds. The inorganic part of the air includes gases, metals and their compounds. Many standards are limited to the total metal content, and only in recent years has attention begun to be paid to the chemical nature of the compounds. This is due to the fact that the chemical nature of the substance is important in the analysis of the component and in determining the limit

with pores of a certain size. The precipitate obtained on the filter is dissolved and analyzed by any suitable method. The methods are simple, do not require expensive equipment, but at the same time they are time-consuming and do not give sufficiently accurate and reproducible results.

2. Determination of organic substances. When fuel is burned (cars, aircraft, technological processes), organic smoke is formed, containing methane, hexane, heptane, pentane, octane and acetylene. In this case, along with aliphatic compounds, aromatic compounds are also formed: benzene, xylene, chlorobenzene and cyclohexane. As a result of human activity, a significant amount of organic substances appears in the air: aerosol stimulants, pesticides, herbicides, fungicides and preservatives. Chemical methods for the analysis of organic substances depend on the type of organic compound, its concentration, and basis.

The general procedure for collecting a volatile organic compound in air involves the use of special absorbent solutions, which can be acidic, alkaline or neutral depending on the chemical properties of the analyzed product. Water, alcohol, or a solution with a reagent is often used as scavengers, giving a characteristic product with the analyte. The solutions may be in two or more bubblers connected in series.

Instrumental methods are most often used to determine organic compounds. They include,

receive a fire alarm.

Atmospheric and elevated pressure liquid chromatography (HPLC) is rapidly developing for the determination of various organic contaminants. A liquid chromatograph consists of a chromatographic column, a pump and an associated detector. A suitable solvent is fed into the column, and the sample is separated into its components. High pressure pumps are used to reduce the separation time (several minutes). The development of the method is accompanied by the improvement of columns, pumps and detectors. Recently, high performance liquid chromatography has been successfully used. For example, using this method, it is possible to determine formaldehyde, acetaldehyde, propionic and butyric aldehydes in biological fluids in their joint presence.

Thin layer chromatography (TLC). Method for the semi-quantitative analysis of non-volatile organic and inorganic compounds. It is used to determine the components of particulate matter that pollute the air. In TLC, a glass plate supports the adsorbent layer and a spot of the analyzed mixture is applied near one edge of the plate. The edge located below the spot is immersed in the selected solvent, which moves due to capillary forces in the adsorbent layer. With a good selection of the mixture-solvent-adsorbent system, contaminants move through the layer and are separated. After

Soil Quality Control Methods

The thin soil cover of the earth is a biological absorber capable of destroying harmful substances that enter it from the atmosphere and from industrial enterprises. Phenols, dioxides, heavy metals, organic and inorganic compounds represent a great environmental hazard. You can examine the soil for the presence of toxic substances using special equipment, including Expert 003, B 1200 and other photometers. The level of radioactive contamination of the soil is determined by laboratory gamma spectrometric analysis using SRP-88 or Bella devices. Research helps to check the soil for the presence of pathogenic microflora, as well as pesticides, fungicides, herbicides, etc.

Fertility Options

Soil productivity indicators determined by simple methods are also important. You can find out about the ability of the soil to absorb and retain moisture, without which plants are doomed to death, by collecting it in a room. If it crumbles when it falls, then the moisture capacity is 30-50%, does not roll - no more than 25%, retains its shape - 75-90%. Humus, beneficial microorganisms and nutrients are responsible for the biological activity of the earth. You can determine its level by burying filtered paper in different areas. The more the leaf decays in a month, the richer the soil. The mechanical composition of the soil is determined by the rolling of a wet ball with a diameter of 4 cm. The figure did not work out? The ground is dominated by sand. If you managed to build:

• cord - sandy loamy soil;
• unbreakable ring - light loam;
• bagel with cracks - heavy loam.

The acidity of the soil is determined by means of special litmus paper, as well as by the prevailing plants. Horsetail and sorrel indicate that the earth is very acidic, clover inhabits soil with moderate indicators, and field mustard and white sandman choose alkaline soils. With the help of a sieve with cells from 0.5 to 1 mm, the degree of coarseness of the soil fractions is revealed. In this case, the sample should be taken at a depth of 10-15 cm. The best porosity has a soil with 80% of particles from 0.5 to 1 mm, 5% - more than 1 mm and 15% - less than 0.5 mm. In conclusion, it is necessary to say about the ripeness of the earth, that is, about its readiness for processing. As a rule, good soil does not dust, crumble or stick to the shovel.

In the USSR, only one standard was established that determines the permissible level of soil pollution with harmful chemicals - MPC for the arable soil layer. The principle of rationing the content of chemical compounds in the soil is based on the fact that their entry into the body occurs mainly through the media in contact with the soil. The basic concepts relating to the chemical contamination of soils are defined by GOST 17.4.1.03-84. Protection of Nature. Soils. Terms and definitions of chemical pollution.

The principle of soil pollution control is to check the compliance of pollutant concentrations with established norms and requirements in the form of MPC and APC (approximately permissible amount).

The concept of MPC for soil is somewhat different from that for other environments. MPC of pollutants in soil - the maximum mass fraction of a soil pollutant that does not cause direct or indirect effects, including individual effects on the environment and human health. For example, MPC for pesticides in soil is the maximum content of pesticide residues at which they migrate to adjacent environments in amounts that do not exceed hygienic standards, and also do not adversely affect the biological activity of the soil itself.

In addition to MPC, in the normalization of impacts, a temporary standard is used - OPC - the maximum approximate allowable amount, which is obtained by calculation. The DCS is reviewed every three years or replaced by MPCs.

MPCs and AECs for soil chemicals have been developed and approved in the Russian Federation for approximately 200 substances. They serve as a criterion for classifying soils according to the impact of chemical pollutants on them, as well as for ranking pollutants into hazard classes for soils.

Soil pollution, as well as other natural environments, is combined (multiple), and therefore, in the chemical control of pollution, it becomes necessary to identify priority pollutants that are subject to control in the first place. When determining priority pollutants, their hazard classes are taken into account.

MPCs are developed mainly on the basis of the principles, techniques and methods of toxicology: they establish such concentrations in media in contact with the soil (plants, water, air) that do not pose a danger to human health and do not adversely affect the general sanitary indicators of the soil. In this case, the following indicators of harmfulness are used.

General sanitary indicator of harmfulness for soil. characterizes the effect of a substance on the self-cleaning ability of the soil and soil microbiocenosis in quantities that do not change these processes.

Translocation indicator of harmfulness. It characterizes the ability of substances to pass from the arable layer of soil through the root system of plants and accumulate in its green mass and fruits in an amount not exceeding the MPC for this substance in food products.

Migratory air indicator of harmfulness. It characterizes the ability of a substance to pass from the arable soil layer into the atmospheric air and surface water sources in an amount that does not exceed the MPC value for atmospheric air during migration.

The soil pollution regulation system, in comparison with other systems, is not considered to be sufficiently successful. For many chemicals MPCs have not been developed due to the fact that their fate is very difficult. Basically, the assessment is made by comparison with background concentrations.

It should be noted that MPC standards for pesticides in the Russian Federation (and in the former USSR) are in most cases more stringent than in other countries.

Monitoring and control of sweat pollution is carried out in the Russian Federation by the GOS of Roshydromet and other departments. Types of observations are established taking into account the nature of pollution in the region and the priority of pollutants.

health indicators. For all types of lands of the unified state land fund, control of the sanitary condition of soils is carried out. Under the sanitary condition is understood the totality of the physicochemical and biological properties of the soil, which determine its safety in epidemiological and hygienic terms.

The purpose of control is to prevent soil pollution by household and industrial emissions and waste, as well as substances purposefully used in agriculture and forestry.

The list of controlled indicators includes sanitary-bacteriological, sanitary-helminthological and sanitary-entomological indicators. These are the sanitary number (the ratio of protein nitrogen to total organic nitrogen), concentrations of ammonium and nitrate nitrogen, chlorides, pesticide residues and other pollutants (heavy metals, oil and oil products, phenols, sulfur compounds), carcinogens, radioactive substances, macro - and microfertilizers, thermophilic bacteria, bacteria of the Escherichia coli group, pathogenic microorganisms, eggs and larvae of helminths and flies. 2 The presence of organisms that characterize sanitary and bacteriological indicators indicates specific organic, fecal and other types of pollution.

List of indicators for different types of land use: settlements, resorts and recreation areas, zones of water supply sources, territories of enterprises, farmland and forests - is different.

Indicators of the sanitary state of soils are used not only for their intended purpose, but also to assess the suitability of a disturbed fertile soil layer for earthing.

biological indicators. The degree of soil contamination depends both on the anthropogenic load and on other factors: the ability of soils to self-purify, decompose, and transform pollutants during mineralization and humification.

Various groups of organisms are involved in the destruction of chemicals in the soil, including bacteria, fungi, actinomycetes, and plants. The latter absorb and process pollutants in the course of their metabolism. The ability to self-cleanse is determined primarily by the activity of soil microflora and other soil organisms, physical and chemical conditions and soil properties.

Anthropogenic impacts: fertilization, pesticide treatment, land reclamation and desiccation, as well as environmental factors (temperature, precipitation, topography of the territory) affect the activity of soil, microflora and fauna.

In ecological studies of soils, various biological indicators are used:

"respiration", indicators of cellulose-decomposing activity, activity of enzymes (urease, dehydrogenase, phosphatase), the number of fungi, yeast, etc. Usually several indicators are used, since their "sensitivity" to various pollutants differs significantly.

In assessing the ecological state of soils in works to identify zones of ecological trouble, the main indicators are Criteria for physical degradation, chemical and biological contamination. A sign of biological degradation (as a result of toxic effects) is a decrease in the level of active microbial mass; less accurate is soil respiration.

As a complex indicator of toxic soil pollution, it is recommended to use the phytotoxicity indicator. Phytotoxicity- biotest integral indicator, which is understood as a property of soil previously contaminated (for example, with herbicides) to suppress seed germination, growth and development of higher plants. The phytotoxicity indicator has been used along with traditional indicators in the development of MPCs for herbicides (a group of pesticides that are used in agriculture to control weeds) since 1982. When biotesting, the decrease in the number of seedlings compared to the control is considered an indicator of the presence of soil phytotoxicity.

The maximum permissible concentration in the arable soil layer (MPC n) is the concentration of a harmful substance in the upper, arable soil layer, which should not have a direct or indirect negative effect on the environment in contact with the soil and on human health, as well as on the self-cleaning ability of the soil.

MPC standards are designed for substances that can migrate into the atmospheric air or groundwater, reduce yields or deteriorate the quality of agricultural products.

Currently, the Institute of Human Ecology is conducting research aimed at substantiating individual MPC standards for various types of soils. Thus, in the near future it should be expected that the features of the migration and transformation of harmful substances in soils will be reflected in the rationing system.

The assessment of the level of chemical pollution of soils in settlements is carried out according to the indicators developed during the associated geochemical and hygienic studies of the environment of cities. Such indicators are the concentration coefficient of the chemical element K c and the total pollution index Z c .

The concentration coefficient is defined as the ratio of the actual content of the element in the soil C to the background Cf: K s \u003d C / C f.

Since soils are often contaminated with several elements at once, the total pollution index is calculated for them, reflecting the effect of the impact of a group of elements:

where K si- concentration factor i-th element in the sample; n- number of considered elements.

The total pollution index can be determined both for all elements in one sample, and for a site of the territory based on a geochemical sample.

Assessment of the danger of soil pollution by a complex of elements according to the indicator Zc is carried out according to an assessment scale, the gradations of which are developed on the basis of a study of the state of health of the population living in territories with different levels of soil pollution.

Table. Indicative rating scale for the danger of soil pollution

by total

Maximum Permissible Concentrations of Some Chemical Substances in Soil

Oil and oil products, mg/kg

Volatile phenols, mg/kg

Arsenic, mg/kg

Polychlorinated biphenyls, µg/kg

Lactose-positive Escherichia coli (Koli form), index

Enterococci (fecal streptococci), index

Pathogenic microorganisms (according to epidemiological indications), index

Eggs and larvae of helminths (viable), ind./kg

Cysts of intestinal pathogenic protozoa, ind./100 g

Larvae and pupae of synanthropic flies, ind./in the soil area 20 ´ 20 cm

Notes: * the choice of a specific indicator depends on the nature of the means of chemicalization of agriculture used ; ); *** allowed to determine fecal forms

The sign “+” means that it is mandatory to determine the indicator when determining the sanitary condition of soils, the sign “-” is an optional indicator, the sign “ ± » - indicator is obligatory in the presence of a source of pollution.

Annex 3

List of pollution sources and chemical elements,
accumulation of which is possible in the soil in the zones of influence of these sources

Note."O" - mandatory control, " W» - optional control.

Industry: A - alloy steel plant; B - non-ferrous metal plant; C- alloy plant;D- processing of secondary color; E - battery production; F- radiator production; G- electrical production; H - precision engineering; I- production of household products; J- heavy engineering; K - light engineering; L- production of plastics; M- production of paints; N- road network of filling stations. Appendix 6

Schematic diagram of the assessment of agricultural use soils contaminated with chemicals ()

Appendix 7

Maximum Permissible Concentrations (MACs) of Inorganic Chemical Substances in Soil and Permissible Levels of Their Content in Terms of Harm

Notes.MPCs should be adjusted in accordance with the newly developed documents.

1) MPC OFU are controlled by the content of benzo (a) pyrene in the soil, which should not exceed the MPC of benzo (a) pyrene.

2) MPC KSU composition NPK(64:0:15) are controlled by the content of nitrates in the soil, which should not exceed 76.8 mg/kg abs. dry soil.

3) MPC HCS composition NPK(10:4:0) TU 6-08-290-74 with the addition of manganese not more than 0.6% of the total mass is controlled by the content of mobile phosphates in the soil, which should not exceed 27.2 mg/kg abs. dry soil. 5 . GOST 17.4.4.02 -84 “Nature protection. The soil. Methods for the selection and preparation of soil samples for chemical, bacteriological and helminthological analysis.

6 . GOST 17.4.3.06-86 (ST SEV 5101-85) “Nature protection. Soils. General requirements for the classification of soils according to the influence of chemical pollutants on them.

7. Guidelines for assessing the degree of danger of soil pollution by chemicals No. 4266-87. Approved Ministry of Health of the USSR 13.03.87.

8. Estimated indicators of the sanitary condition of soils in populated areas No. 1739-77 Approved. Ministry of Health of the USSR 7.07.77.

9. Guidelines for the sanitary and microbiological study of soil No. 1446-76. Approved Ministry of Health of the USSR 4.08.76.

10. Guidelines for the sanitary and microbiological study of soil No. 2293-81. Approved Ministry of Health of the USSR 19.02.81.

11. Guidelines for helminthological examination of objects external environment and sanitary measures to protect against pollution by helminth eggs and neutralize them from sewage, soil, berries, vegetables, household items No. 1440-76. Approved Ministry of health of the USSR.

12. Guidelines according to geochemical assessment of pollution of urban areas chemical elements. - M.: IMGRE, 1982.

13. List of maximum allowable concentrations (MPC) of chemicals in soil No. 6229-91. Approved Ministry of Health of the USSR 11/19/91.

14 . Approximately permissible concentrations (APC) of heavy metals and arsenic in soils: GN 2.1.7.020-94 (Addendum No. 1 to the list of MPC and AEC No. 6229-92). Approved GKSEN RF 27.12.94.

15. Guidelines for assessing the degree of pollution of atmospheric air in settlements with metals by their content in the snow cover and soil No. 5174-90. Approved Ministry of Health of the USSR 15.05.90.

16 . Guidelines for the fight against flies No. 28-6.3. Approved Ministry of Health of the USSR 01/27/84.

18 . Maximum Permissible Concentrations of Chemical Substances in Soil (MPC): Ministry of Health of the USSR. - M., 1979, 1980, 1982, 1985, 1987.

19. Method for measuring the mass fraction of acid-soluble forms of metals (copper, lead, zinc, nickel, cadmium) in soil samples by atomic absorption analysis: Guidelines: RD 52.18.191-89. Approved SCCM USSR. - M., 1989.

20. Dmitriev M.T., Kaznina N.I., Pinigina I.A.: Handbook: Sanitary-chemical analysis of pollutants in the environment. - M.: Chemistry, 1989.

21. Methods of soil microbiology and biochemistry./ Ed. prof. D.G. Zvyagintsev. - M.: MGU, 1980.

22 . GOST 26204-84, 26213-84 “Soils. Methods of Analysis".

23. GOST 26207-91 “Soils. Determination of mobile forms of phosphorus and potassium by the method of Kirsanov in the modification of TsINAO.

24 . The procedure for determining the parameters of damage from land pollution by chemicals. Approved Chairman of the Federation Committee on Land Resources and Land Management 11/10/93 Ministry of Environmental Protection and Natural Resources 11/18/93. Agreed by: 1st Deputy Minister of Agriculture of the Russian Federation on September 6, 1993, Chairman of the RF SCSEN on September 14, 1993 and President Russian Academy Agricultural Sciences 8.09.93.