How to assess the degree of danger of soil contamination by chemicals? Terms and Definitions.
The use of unified methodological approaches will help obtain comparable data when assessing the level of soil pollution and the possible consequences of pollution, and will also make it possible to predict the quality of food products of plant origin. The accumulation of factual material on soil pollution and its indirect impact on humans will make it possible to subsequently improve the proposed guidelines.
These guidelines do not apply to the assessment of pesticide contamination.
1. General Provisions
1.1. From a hygienic point of view, the danger of soil contamination with chemicals is determined by the level of its possible negative impact on contacting media (water, air), food products and indirectly on humans, as well as on the biological activity of the soil and its self-purification processes.
1.2. The main criterion for hygienic assessment of the danger of soil pollution by harmful substances is the maximum permissible concentration (MPC) of chemicals in the soil. MPC is a comprehensive indicator of the content of chemical substances in the soil that is harmless to humans, since the criteria used in their scientific substantiation reflect all possible ways of indirect exposure of the pollutant to contact media, the biological activity of the soil and its self-purification processes. In this case, each of the exposure routes is assessed quantitatively with justification for the permissible level of substance content for each hazard indicator. The lowest reasonable level of content is limiting and is taken as the maximum permissible concentration of the substance, since it reflects the most vulnerable route of exposure to this toxicant.
1.3. To assess the danger of soil pollution, the choice of chemical substances - pollution indicators - is carried out taking into account:
Specifics of pollution sources that determine the complex of chemical elements involved in soil pollution in the studied region (Appendix 1);
Priority of pollutants in accordance with the list of maximum permissible concentrations of chemicals in soil (Table 2) and their hazard class (Appendix 2) (“Maximum permissible concentrations of chemicals in soil”, 1979, 1980, 1982, 1985, 1987);
The nature of land use (Appendix 3).
1.3.1. If it is not possible to take into account the entire complex of chemical substances that pollute the soil, the assessment is carried out based on the most toxic substances, i.e. belonging to a higher hazard class (Appendix 2).
1.3.2. If the given documents (Appendix 2) do not contain the hazard class of chemicals that are priority for the soils of the surveyed area, their hazard class can be determined by the hazard index (Appendix 4).
1.4. Soil sampling, storage, transportation and preparation for analysis are carried out in accordance with GOST 17.4.4.02-84 "Nature conservation. Soils. Methods for collecting and preparing soil samples for chemical, bacteriological and helminthological analysis."
1.5. The determination of chemical substances in soil is carried out by methods developed to justify their MPCs in soil and approved by the USSR Ministry of Health, which are published in the appendices to the “Maximum Permissible Concentrations of Chemicals in Soil (MPC)” (1979, 1980, 1982, 1985).
2.6. Assessment of soil contamination levels
There are different approaches to assessing the level of soil contamination.
For inorganic pollutants, the division of soils into categories (classes) of pollution is carried out taking into account the hazard class of the pollution component, its maximum permissible concentration and the maximum value of the permissible level of element content (Kmax) according to one of four hazard indicators. For organic pollutants, the division of soils into categories (classes) of pollution is carried out taking into account the hazard class of the substance and the multiplicity of excess of its MPC in the soil.
According to the sanitary and hygienic condition of agricultural soils, the content of chemicals in the soil is divided into acceptable; moderately dangerous; highly dangerous and extremely dangerous, and the MPC for the translocation sign of harmfulness is very important.
The grouping of soils contaminated with heavy metals is based on the methodology of the Soil Institute named after. V.V. Dokuchaev, the clarke content of the element lies. According to this method, the level of soil contamination is determined using the arithmetic or geometric progression of the clarke of the element.
To assess technogenic anomalies with a polyelement composition, total pollution indicators Z C are used, characterizing the degree of pollution by an association of elements relative to the background and reflecting the effect of exposure to a group of elements:
Where TO ci– concentration coefficient i-th element in the sample;
n– number of elements taken into account.
The concentration coefficient is defined as the ratio of the actual content of an element in the soil to the background content, and it must be greater than unity (otherwise the element is not concentrated, but dispersed). If there are no background values for comparing landscape pollution, the element clarke or MPC is taken instead.
2.7. Standardization of the quality of agricultural products
When standardizing quality food They use such an indicator as the maximum permissible concentration of a harmful substance in food, otherwise called the permissible residual amount (ARK).
Maximum permissible concentration (permissible residual amount) of a harmful substance in food (MPC, DOC)- This is the maximum concentration of a harmful substance in food products, which for an unlimited period of time (with daily exposure) does not cause diseases or deviations in human health.
For each type of product, the maximum permissible concentration for certain pollutants that can accumulate in it when receiving agricultural products, during their processing and storage is standardized. Sometimes the maximum permissible concentration also depends on the conditions and time of receipt of the product. For example, the nitrate content in vegetable products is standardized taking into account the type of crop, growing conditions (open or protected ground) and harvest time (early or late production). The content of some heavy metals in canned food is standardized taking into account their possible entry from metal containers.
Standardization of product quality is carried out on the basis of the permissible daily dose of pollutants or the limit of its annual intake, taking into account the diet of the population.
Permissible daily dose (ADI) – This is the maximum amount of a pollutant that can enter the human body with all food and water on average per day throughout life and at the same time not affect the health of a person and his offspring. The ADI is established in units of mass of pollutant per kg of body weight (mg/kg, ng/kg) or simply in units of mass of pollutant (mg, ng), with the mass of an average person being taken to be 70 kg. The World Health Organization (WHO) has developed DDIs for heavy metals, nitrates, etc.
Annual Income Limit (AGL) - this is the maximum amount of a pollutant that can enter the human body with all food and water on average per year throughout life and at the same time not affect the health of a person and his offspring. The GWP is established, for example, for anthropogenic radionuclides.
Certain limiting indicators (signs) of harmful substances have been developed that have to be taken into account when regulating the quality of agricultural products:
– organoleptic, characterizing the influence of a substance on changes in the properties of a product determined by human senses (taste, smack, smell, color, turbidity, the presence of foam and films, etc.);
– toxicological, characterizing the toxicity of a substance to humans;
– technological, characterizing the ability of a substance to degrade the quality of a product as a result of certain reactions during its production;
– hygienic, characterizing the ability of a substance to impair the beneficial properties of a product as a result of certain reactions with beneficial substances contained in the product.
Control questions.
1. What is the principle of separate rationing? How is it used in assessing air and water quality?
2. What indicators (signs) of harmfulness are used when regulating the quality of air, water, soil, and products? What is a limiting indicator (sign) of harmfulness (LPH)?
3.What is the summation effect? How is it used in assessing air and water quality?
4. What is IZA, IZV? How are they calculated?
5 What is the total indicator of soil contamination with heavy metals? How is it calculated?
6. What is DSD? GWP? How do they affect the maximum permissible concentrations of contaminants in food in different countries?
MINISTRY OF HEALTH OF THE USSR
MAIN SANITARY AND EPIDEMIOLOGICAL DEPARTMENT
METHODOLOGICAL INSTRUCTIONS
BY ASSESSING THE DEGREE OF HAZARD
SOIL POLLUTION BY CHEMICALS
SUBSTANCES
MOSCOW, 1987
The guidelines were developed by the Research Institute of General and Municipal Hygiene named after. A.N. Sysin Academy of Medical Sciences of the USSR (Prof. V.M. Perelygin, Ph.D. N.I. Tonkopiy, Ph.D. A.F. Pertsovskaya, Ph.D. V.N. Pavlov, Ph.D. Agricultural Sciences T.I. Grigorieva, G.E. Shestopalova, Candidate of Biological Sciences E.V. Filimonova, N.B. Zyabkina).
Main Sanitary and Epidemiological Directorate of the USSR Ministry of Health (A.S. Perotskaya).
Institute of Mineralogy, Geochemistry and Crystal Chemistry of Rare Elements (Candidate of Medical Sciences B.A. Revich, Doctor of Geological and Mineralogical Sciences Yu.E. Sayet, Candidate of Geographical Sciences R.S. Smirnova).
Starring:
Ufa Research Institute of Occupational Hygiene and Occupational Diseases (candidate of medical sciences L.O. Osipova, candidate of biological sciences R.F. Daukaeva, S.M. Safonnikova, G.F. Maksimova);
Dnepropetrovsk Medical Institute (Prof. M.Ya. Shelyug, Candidate of Medical Sciences E.A. Derkachev, Candidate of Medical Sciences P.I. Lakiza, Candidate of Medical Sciences B.N. Yaroshevsky);
Georgian Research Institute of Sanitation and Hygiene named after. G.M. Natadze (MD R.E. Khazaradze, N.I. Dogodnishvili, N.G. Sakvarelidze, N.A. Menagarishvili, R.G. Mzhavanadze);
Research Institute of Regional Pathology. Ministry of Health of the Kazakh SSR (candidate of medical sciences N.P. Goncharov, candidate of medical sciences I.A. Snytin).
I approve
Deputy Chief State
sanitary doctor of the USSR
EM. Saakyants
METHODOLOGICAL INSTRUCTIONS FOR ASSESSING THE DEGREE OF HAZARD OF SOIL POLLUTION BY CHEMICALS
INTRODUCTION
The main directions of economic and social development of the USSR for 1986-1990 and for the period until 2000 emphasize the need to implement measures to protect the environment and increase the efficiency of environmental measures (“Main directions of economic and social development of the USSR for 1986-1990 and for the period until 2000 year", section V).
To solve these problems, when establishing the priority of implementing hygienic and environmental measures, it is important to rank soils to the degree of danger of their contamination by chemicals and, on the basis of this, identify areas that require priority investment in monitoring soil pollution, developing comprehensive measures for their protection, when developing regional planning schemes, hygienic assessment of soils in urbanization areas and land reclamation measures.
The results of hygienic studies of soils contaminated with heavy metals, oil products and other substances made it possible for the first time to develop methodological approaches for assessing the degree of danger of soil contamination with these toxicants according to the level of their possible impact on the systems “soil - plant”, “soil - microorganisms, biological activity”, “soil - groundwater", "soil - atmospheric air" and indirectly on human health.
These guidelines are intended for sanitary and epidemiological stations, research institutes and hygienic institutions, hygiene departments of medical institutes and institutes for advanced training of doctors, agrochemical service institutions and other regulatory organizations.
The use of unified methodological approaches will help obtain comparable data when assessing the level of soil pollution and the possible consequences of pollution, and will also make it possible to predict the quality of food products of plant origin. The accumulation of factual material on soil pollution and its indirect impact on humans makes it possible to subsequently improve the proposed guidelines.
These guidelines do not apply to the assessment of soil contamination by pesticides.
1. GENERAL PROVISIONS
1.1. From a hygienic point of view, the danger of soil contamination with chemicals is determined by the level of its possible negative impact on contacting media (water, air), food products and indirectly on humans, as well as on the biological activity of the soil and its self-purification processes.
1.2. The main criterion for hygienic assessment of the danger of soil pollution by harmful substances is the maximum permissible concentration (MAC) of chemicals in the soil. MPC is a comprehensive indicator of the content of chemical substances in the soil that is harmless to humans, since the criteria used in their scientific substantiation reflect all possible ways of indirect exposure of the pollutant to contact media, the biological activity of the soil and its self-purification processes. In this case, each of the exposure routes is assessed quantitatively with justification for the permissible level of substance content for each hazard indicator. The lowest reasonable level of content is limiting and is taken as the maximum permissible concentration of the substance, since it reflects the most vulnerable route of exposure to this toxicant.
1.3. To assess the danger of soil pollution, the choice of chemicals - pollution indicators - is carried out taking into account:
Specifics of pollution sources that determine the complex of chemical elements involved in soil pollution in the studied region (Appendix);
Priority of pollutants in accordance with the list of maximum permissible concentrations of chemicals in soil (table) and their hazard class (appendix) (“Maximum permissible concentrations of chemicals in soil”, 1979, 1980, 1982, 1985, 1987);
The nature of land use (appendix).
1.3.1. If it is not possible to take into account the entire complex of chemical substances that pollute the soil, the assessment is carried out based on the most toxic substances, i.e. belonging to a higher hazard class (Appendix).
1.3.2. If the given documents (Appendix) do not contain the hazard class of chemicals that are priority for the soils of the surveyed area, their hazard class can be determined by the hazard index (Appendix).
1.4. Soil sampling, storage, transportation and preparation for analysis are carried out in accordance with GOST 17.4.4.02-84 “Nature conservation. Soils. Methods for collecting and preparing soil samples for chemical, bacteriological and helminthological analysis.”
1.5. The determination of chemical substances in the soil is carried out by methods developed to justify their MPCs in soil and approved by the USSR Ministry of Health, which are published in the appendices to the “Maximum Permissible Concentrations of Chemicals in Soil (MPC)” (1979, 1980, 1982, 1985) .
1.6. In general, when assessing the risk of soil contamination by chemicals, the following should be taken into account:
A). The more the actual levels of controlled substances in the soil (C) exceed the MPC, the greater the danger of contamination. That is, the greater the value of the hazard coefficient (Ko) exceeds 1, the higher the danger of soil contamination, i.e.
b). The higher the hazard class of the controlled substance, the higher the risk of contamination.
V). The assessment of the danger of pollution by any toxicant should be carried out taking into account the buffering capacity of the soil*, which affects the mobility of chemical elements, which determines their impact on contacting media and the availability of plants. The less buffering properties the soil has, the greater the danger of its contamination with chemicals. Consequently, at the same value of Ko, the danger of pollution will be greater for soils with an acidic pH value, lower humus content and lighter mechanical composition. For example, if K substances turned out to be equal in sod-podzolic sandy loam soil, in sod-podzolic loamy soil and chernozem, then in order of increasing risk of soil contamination they can be arranged in the following series: chernozem Ð loamy soddy-podzolic soil Ð sandy loam soddy-podzolic soil .
* “Soil buffering” is understood as a set of soil properties that determine its barrier function, determining the levels of secondary pollution by chemicals in media in contact with the soil: vegetation, surface and groundwater, atmospheric air. The main components of the soil that create buffering are fine mineral particles that determine its mechanical composition, organic matter (humus), and the reaction of the environment - pH.
1.7. The assessment of the hazard of soils contaminated with chemicals is carried out differentially for different soils (different types of land use) and is based on 2 main provisions:
1. Economic use of territories (soils of settlements, agricultural lands, recreational areas, etc.).
2. The most significant ways for these territories to impact soil pollution on humans.
In this regard, various schemes are proposed for assessing the danger of soil pollution in populated areas and soils used for growing agricultural plants.
2. HYGIENIC CONDITION OF SOILS USED FOR GROWING AGRICULTURAL PLANTS
2.1. The basis for assessing the danger of contamination of soils used for growing agricultural plants is the translocation indicator of harmfulness, which is the most important indicator in justifying the maximum permissible concentrations of chemicals in the soil. This is due to the fact that: 1) on average, 70% of harmful chemicals enter the human body with food products of plant origin; 2) the level of translocation determines the level of accumulation of toxicants in food products and affects their quality. The existing difference in the permissible levels of chemical substances for various indicators of harmfulness (Table) and the main provisions of the differential assessment of the degree of danger of contaminated soils also make it possible to give recommendations on the practical use of soils in contaminated areas.
2.2. The danger of contamination of soils used for growing agricultural plants is determined in accordance with Table. And . In table The basic principles for assessing soils and recommendations for their use and reducing the adverse effects of pollution are given. Table data are a logical addition to the table. and provide the necessary information for ranking soils by level of contamination in accordance with the principles set out in table. .
Example. The soils of the territories are contaminated with nickel, the content of mobile forms of which is 20 mg/kg in the first (1) and 5 mg/kg in the second (2). Based on table and the soil (1) should be classified as “extremely high” contamination, because the level of nickel content exceeds the permissible levels of this element for all indicators of harmfulness: translocation, migratory water and general sanitary. Such soil can only be used for industrial crops or completely excluded from agricultural use.
Soil 2 can be classified as “moderately contaminated”, because the nickel content (5 mg/kg) exceeds its maximum permissible concentration (4 mg/kg), but does not exceed the permissible level for the translocation indicator of harmfulness (6.7 mg/kg). In this case, the soil can be used for any agricultural crops while simultaneously implementing measures to reduce the availability of the toxicant - nickel - for plants.
Table 1
Schematic diagram for assessing agricultural soils contaminated with chemicals
|
Characteristics of contamination |
Possible use of the territory |
Suggested activities |
|
|
I. Acceptable |
Use for any crop |
Reducing exposure to soil pollution sources. Implementation of measures to reduce the availability of toxicants for plants (liming, application of organic fertilizers, etc.). |
|
|
II. Moderately dangerous |
Use for any crops subject to quality control of agricultural plants |
Measures similar to category I. In the presence of substances with limiting migration water or migration air indicators, the content of these substances in the breathing zone of agricultural workers and in the water of local water sources is monitored |
|
|
III. Highly dangerous |
Use for industrial crops The use of agricultural crops is limited, taking into account the hub plants |
1. In addition to the measures specified for category I, mandatory control over the content of toxicants in plants - food and feed. 2. If it is necessary to grow plants - food - it is recommended to mix them with products grown in clean soil. 3. Limiting the use of green mass for livestock feed, taking into account hub plants |
|
|
IV. Extremely dangerous |
Use for industrial crops or exclusion from agricultural use. Forest shelterbelts |
Measures to reduce the level of pollution and bind toxicants in the soil. Monitoring the content of toxicants in the breathing zone of agricultural workers and in the water of local water sources |
table 2
Maximum permissible concentrations (MAC) of chemicals in soil and permissible levels of their content according to hazard indicators
|
MPC mg/kg soil taking into account background (clark) |
Harmfulness indicators |
||||
|
translocation |
migration |
general sanitary |
|||
|
air |
|||||
|
Movable form |
|||||
|
Cobalt**) |
More than 1000.0 |
||||
|
Water soluble form |
|||||
|
Manganese |
|||||
|
Manganese + vanadium |
|||||
|
Lead + mercury |
|||||
|
Potassium chloride (K2O) |
|||||
|
Benz/a/pyrene (BP) |
|||||
|
Isopropylbenzene |
|||||
|
Alphamethylstyrene |
|||||
|
Sulfur compounds (S) |
|||||
|
hydrogen sulfide (H2S) |
|||||
|
elemental sulfur |
|||||
|
sulfuric acid |
|||||
|
More than 800.0 |
More than 800.0 |
||||
*) Mobile forms of copper, nickel and zinc are extracted from the soil with ammonium acetate buffer with pH 4.8 (copper, zinc), pH 4.6 (nickel).
**) The mobile form of cobalt is extracted from the soil with an ammonium-sodium buffer solution with pH 3.5 for gray soils and pH 4.7 for soddy-podzolic soil.
***) OFU - coal flotation waste. MPCs of OFU are controlled by the content of benzo/a/pyrene in the soil, which should not exceed the MPC of BP.
****) KGU - complex granulated fertilizer with the composition N:P:K = 64:0:15. The KSU MPC is controlled by the nitrate content in the soil, which should not exceed 76.8 mg/kg of absolutely dry soil.
*****) LCS - liquid complex fertilizers of the composition N:P:K = 10:34:0 TU 6-08-290-74 with manganese additives not exceeding 0.6% of the total mass. The maximum permissible concentration of liquid-commodity fertilizers is controlled by the content of mobile phosphates in the soil, which should not exceed 27.2 mg/kg of absolutely dry soil.
3. HYGIENIC ASSESSMENT OF SOILS IN SETTLEMENT AREAS
3.1. Assessment of the danger of soil contamination in populated areas is determined by: 1) the epidemiological significance of soil contaminated with chemicals; 2) the role of contaminated soil as a source of secondary pollution of the ground layer of atmospheric air and in its direct contact with humans; 3) the significance of the degree of soil pollution as an indicator of air pollution.
3.2. The need to take into account the epidemiological safety of the soil in populated areas is determined, as the results of our research have shown, by the fact that with an increase in the chemical load, the epidemic danger of the soil increases. In contaminated soil, against the background of a decrease in true representatives of soil microbial cenoses (antagonists of pathogenic intestinal microflora) and a decrease in its biological activity, there is an increase in positive findings of pathogenic enterobacteria and geohelminths, which were more resistant to chemical soil contamination than representatives of natural soil microbial cenoses.
3.3. Assessment of the level of epidemic danger in the soil of populated areas is carried out according to a scheme developed on the basis of the probabilistic occurrence of pathogenic enterobacteria and enteroviruses. The criterion for epidemic safety is the absence of pathogenic agents in the object under study (Table).
3.4. Assessing the adverse effects of soil pollution through its direct impact on the human body is important for cases of geophagy in children when they play on contaminated soils. This assessment was developed for the most common pollutant in populated areas - lead, the content of which in the soil is usually accompanied by an increase in the content of other elements. When the lead content in the soil of playgrounds is at a level of 500 mg/kg and its systematic presence in the soil, changes in the psychoneurological status of children can be expected (War en H.V., 1979; Dyggan M.J., Willians., 1977; - 1983).
3.5. Based on the study of the distribution of certain metals in the soil, the most common indicators of urban pollution, an approximate assessment of the danger of atmospheric air pollution can be given. Thus, when the lead content in the soil, starting from 250 mg/kg, in the area of active pollution sources, an excess of its maximum permissible concentration in the atmospheric air is observed (0.3 μg/m3), when the copper content in the soil, starting from 1500 mg/kg, is observed exceeding the maximum permissible concentration of copper in atmospheric air (2.0 μg/m3).
3.6. Assessment of the level of chemical contamination of soils as indicators of adverse effects on public health is carried out using indicators developed in conjunction with geochemical and geohygienic studies of the urban environment. Such indicators are: the concentration coefficient of a chemical substance (Kc), which is determined by the ratio of its real content in the soil (C) to the background (Cf): Kc = and the total pollution indicator (Zc).
The total pollution indicator is equal to the sum of the concentration coefficients of chemical elements and is expressed by the following formula:
Zc = - (n - 1)
where n is the number of elements to be summed.
Analysis of the distribution of geochemical indicators obtained as a result of testing soils over a regular network gives the spatial structure of pollution of residential areas and the air basin with the greatest risk to public health (Methodological recommendations for the geochemical assessment of pollution of urban areas with chemical elements, 1982).
3.7. Assessment of the danger of soil pollution by a complex of metals according to the Zc indicator, which reflects the differentiation of urban air pollution with both metals and other, most common ingredients (dust, carbon monoxide, nitrogen oxides, sulfur dioxide), is carried out according to the rating scale given in Table. . The gradations of the rating scale were developed based on a study of health indicators of the population living in areas with different levels of soil contamination.
Determination of chemical substances when assessing the level of soil pollution is recommended to be carried out using the emission analysis method.
Table 3
Scheme for assessing the epidemic danger of soils in populated areas
|
Pollution indicators (cells in soil): |
||||||
|
E. coli |
Enterococci |
Pathogenic enterobacteria |
Enteroviruses |
Helminths |
||
|
1. High-risk areas: kindergartens, playgrounds, sanitary protection zones of water bodies |
||||||
|
Polluted |
10 and |
10 and |
||||
|
Sanitary protection zones |
||||||
|
Polluted |
100 and |
100 and |
||||
Table 4
Approximate rating scale for the danger of soil pollution based on the total pollution indicator (zс)
|
Value (zc) |
Changes in population health indicators in pollution hotspots |
|
|
Acceptable |
The lowest incidence of morbidity in children and the minimum incidence of functional abnormalities |
|
|
Moderately dangerous |
Increase in overall morbidity |
|
|
Increase in overall morbidity, number of frequently ill children, children with chronic diseases, disorders of the functional state of the cardiovascular system |
||
|
Extremely dangerous |
Increased morbidity among children, impaired reproductive function of women (increased toxicosis of pregnancy, number of premature births, stillbirths, malnutrition of newborns) |
When assessing the level of soil pollution, it is recommended to determine chemical substances using the emission analysis method.
Annex 1
|
Sources of pollution |
Type of production |
Concentration factor (Kc)* |
|
|
Non-ferrous metallurgy |
Production of non-ferrous metals directly from ores and concentrates |
Lead, zinc, copper, silver |
Tin, bismuth, arsenic, cadmium, antimony, mercury, selenium |
|
Recycling of non-ferrous metals |
Lead, zinc, tin, copper |
||
|
Production of hard and refractory non-ferrous metals |
Tungsten |
Molybdenum |
|
|
Titanium production |
Silver, zinc, lead, boron, copper |
Titanium, manganese, molybdenum, tin, vanadium |
|
|
Ferrous metallurgy |
Production of alloy steels |
Cobalt, molybdenum, bismuth, tungsten, zinc |
Lead, cadmium, chromium, zinc |
|
Iron ore production |
Lead, silver, arsenic |
Zinc, tungsten, cobalt, vanadium |
|
|
Mechanical engineering and metalworking industry |
Enterprises with heat treatment of metals (without foundries) |
Lead, zinc |
Nickel, chromium, mercury, tin, copper |
|
Production of lead batteries |
Lead, nickel, cadmium |
||
|
Production of devices for the electrical and electronics industry |
Lead, antimony, zinc, bismuth |
||
|
Chemical |
Production of superphosphate fertilizers |
Strontium, zinc, fluorine |
Rare earths, copper, chromium, arsenic |
|
Plastics production |
ytrium, copper, zinc, silver |
||
|
Construction materials industry |
Cement production (when metallurgical waste is used in cement production, it is possible that other metals may also accumulate in soils) Production of concrete products |
Mercury, strontium, zinc |
|
|
Printing industry |
Type foundries, printing houses |
Lead, zinc, tin |
|
|
Municipal solid waste from large cities used as fertilizers |
Lead, cadmium, tin, copper, silver, antimony, zinc |
||
|
Sewage sludge |
Lead, cadmium, vanadium, nickel, tin, chromium, copper, zinc |
Mercury, silver |
|
|
Contaminated irrigation water |
Lead, zinc |
||
*) Kc - the concentration coefficient of a chemical element is determined by the ratio of its real content in the soil (Ci) to the background (Cf): Kc = .
Appendix 2
Classification of chemical substances entering the soil from emissions, discharges, wastes to hazard classes (according to GOST 17.4.1.02-83 “Nature conservation. Soils. Classification of chemical substances for pollution control” Gosstandart, M., 1983)
|
Hazard Class |
Chemical substance |
|||||||
|
Arsenic, cadmium, mercury, lead, selenium, zinc, fluorine, benz/a/pyrene |
Transport lands |
Agricultural land |
Forest land |
|||||
|
Pesticides (residues)*), mg/kg-1 |
||||||||
|
Heavy metals**), mg/kg-1 |
||||||||
|
Oil and petroleum products, mg/kg-1 |
||||||||
|
Volatile phenols, mg/kg-1 |
||||||||
|
Sulfur compounds**), mg/kg-1 |
||||||||
|
Detergents (anionic and cationic)**), mg/kg-1 |
||||||||
|
Carcinogenic substances**), µg/kg-1 |
||||||||
|
Arsenic, mg/kg-1 |
||||||||
|
Cyanides, mg/kg-1 |
||||||||
|
Polychloride biphenyls, µg/kg-1 |
||||||||
|
Radioactive substances |
||||||||
|
Macrochemical fertilizers*), g/kg-1 |
||||||||
|
Microchemical fertilizers*), mg/kg-1 |
||||||||
*) The choice of appropriate indicators depends on the chemical composition of agricultural chemicals used in a particular area.
**) The choice of appropriate indicators depends on the nature of emissions from industrial enterprises.
Note:
The “+” sign means that the existing indicator is required to determine the sanitary condition of soils;
The “-” sign means the indicator is optional.
The sign “±” - the indicator is required if there is a source of pollution.
Appendix 4
The hazard class of chemicals in soil, determined by the hazard index ( z)
Formula for calculating hazard class (z)
A is the atomic weight of the corresponding element;
M is the molecular weight of the chemical compound that contains this element;
S - solubility of a chemical compound in water (mg/l);
a is the arithmetic mean of six maximum permissible concentrations of chemicals in different food products (meat, fish, milk, bread, vegetables, fruits);
MPC is the maximum permissible concentration of an element in the soil.
BIBLIOGRAPHY
Soil is a special natural formation that ensures the growth of trees, crops and other plants. It is difficult to imagine life without ours. But how does modern man relate to soils? Today, human soil pollution has reached colossal proportions, so the soils of our planet are in dire need of protection and conservation.
Soil - what is it?
Protecting soils from pollution is impossible without a clear understanding of what soil is and how it is formed. Let's consider this issue in more detail.
Soil (or ground) is a special natural formation, an essential component of any ecosystem. It is formed in the upper layer of the parent rock, under the influence of the sun, water, and vegetation. Soil is a kind of bridge, a link that connects the biotic and abiotic components of the landscape.
The main processes that result in soil formation are weathering and the activity of living organisms. As a result of mechanical weathering processes, the parent rock is destroyed and gradually crushed, and living organisms fill this inanimate mass
Human soil pollution is one of the most important problems of modern ecology and environmental management, which became especially acute in the second half of the twentieth century.
Soil structure
Any soil consists of 4 main components. This:
- rock (base of soil, about 50% of the total mass);
- water (about 25%);
- air (about 15%);
- organic matter (humus, up to 10%).
Depending on the ratio of these components in the soil, the following are distinguished:
- rocky;
- clayey;
- sandy;
- humus;
- salt marshes.
The key property of soil that distinguishes it from any other component of the landscape is its fertility. This is a unique property that provides plants with the necessary nutrients, moisture and air. Thus, the soil ensures the biological productivity of all vegetation and the productivity of agricultural crops. This is why soil and water pollution is such a pressing problem on the planet.
Soil surveys
A special science deals with soil research - soil science, the founder of which is considered to be Vasily Dokuchaev, a world-famous scientist. It was he, back at the end of the 19th century, who was the first to note that soils are distributed quite naturally (latitudinal zonation of soils), and also named clear morphological characteristics of the soil.
V. Dokuchaev considered soil as a holistic and independent natural formation, which no other scientist had done before him. The scientist’s most famous work, “Russian Chernozem” of 1883, is a reference book for all modern soil scientists. V. Dokuchaev conducted a thorough study of the soils of the steppe zone of modern Russia and Ukraine, the results of which formed the basis of the book. In it, the author identified the main parent rock, relief, climate, age and flora. The scientist gives a very interesting definition of the concept: “soil is a function of the parent rock, climate and organisms, multiplied by time.”
After Dokuchaev, other famous scientists were actively involved in studying soils. Among them: P. Kostychev, N. Sibirtsev, K. Glinka and others.
The meaning and role of soil in human life
The phrase “nurse-nurse”, which we hear very often, is not symbolic or metaphorical. This is true. This is the main source of food for humanity, which, one way or another, provides about 95% of all food. The total area of all land resources on our planet today is 129 million km 2 of land area, of which 10% is arable land, and another 25% is hayfields and pastures.
They began to study soils only in the 19th century, but people have known about their wonderful property - fertility - since ancient times. It is the soil that owes its existence to all plant and animal organisms on Earth, including humans. It is no coincidence that the most densely populated areas of the planet are those with the most fertile soils.
Soils are the main resource for agricultural production. Many conventions and declarations adopted at the international level call for rational and careful management of the soil. And this is obvious, because total pollution of land and soil threatens the existence of all humanity on the planet.
The most important geographical element responsible for all processes in the biosphere. The soil accumulates a huge amount of organic matter and energy, thereby acting as a giant biological filter. This is a key link in the biosphere, the destruction of which will disrupt its entire functional structure.
In the 21st century, the load on the soil cover has increased several times, and the problem of soil pollution has become paramount and global. It is worth noting that the solution to this problem depends on the coordination of actions of all states of the world.
Land and soil pollution
Soil pollution is the process of degradation of the soil cover, during which the content of chemical substances in it significantly increases. Indicators of this process are living organisms, in particular plants, which are the first to suffer from a violation of the natural composition of the soil. In this case, the reaction of plants depends on the level of their sensitivity to such changes.
It should be noted that our state provides for criminal liability for human pollution of land. In particular, Article 254 of the Criminal Code of the Russian Federation sounds like “Damage of land.”
Typology of soil pollutants
Major soil pollution began in the twentieth century with the rapid development of the industrial complex. Soil pollution refers to the introduction of atypical components into the soil - the so-called “pollutants”. They can be in any state of aggregation - liquid, solid, gaseous or complex.
All soil pollutants can be divided into 4 groups:
- organic aromatic hydrocarbons, chlorine-containing substances, phenols, organic acids, petroleum products, gasoline, varnishes and paints);
- inorganic (heavy metals, asbestos, cyanides, alkalis, inorganic acids and others);
- radioactive;
- biological (bacteria, pathogenic microorganisms, algae, etc.).
Thus, the main soil pollution is carried out precisely with the help of these and some other pollutants. An increased content of these substances in the soil can lead to negative and irreversible consequences.
Sources of land pollution
Today we can name a large number of such sources. And their number is only increasing every year.
We list the main sources of soil pollution:
- Residential buildings and utilities. This is the main source of land pollution in cities. In this case, human contamination of the soil occurs through household waste, food debris, construction waste and household items (old furniture, clothes, etc.). In large cities, the question “where to put the garbage?” turns into a real tragedy for city authorities. Therefore, on the outskirts of cities, huge kilometer-long landfills grow up, where all household waste is dumped. In developed Western countries, the practice of recycling waste in special installations and factories has long been introduced. Moreover, a lot of money is earned there. In our country, such cases are, alas, rare.
- Factories and plants. In this group, the main sources of soil pollution are the chemical, mining and engineering industries. Cyanides, arsenic, styrene, benzene, polymer clots, soot - all these terrible substances end up in the ground in the area of large industrial enterprises. A big problem today is also the problem of recycling car tires, which cause large fires that are very difficult to extinguish.
- Transport complex. The sources of land pollution in this case are lead, hydrocarbons, soot, and nitrogen oxides. All these substances are released during the operation of internal combustion engines, then settle on the surface of the earth and are absorbed by plants. Thus, they also enter the soil cover. In this case, the degree of soil contamination will be highest along major highways and near road junctions.
- While we receive food from the earth, we at the same time poison it, no matter how paradoxical it may sound. Human contamination of the soil here occurs through the introduction of fertilizers and chemicals into the soil. This is how dangerous substances - mercury, pesticides, lead and cadmium - get into the soil. In addition, excess chemicals can be washed off fields by rain, ending up in permanent streams and groundwater.
- Radioactive waste. Soil contamination from nuclear waste poses a very great danger. Few people know that during nuclear reactions at nuclear power plants, about 98-99% of the fuel goes to waste. These are products of the fission of uranium - cesium, plutonium, strontium and other elements that are extremely dangerous. A very big problem for our country is the disposal of this radioactive waste. Every year, about 200 thousand cubic meters of nuclear waste are generated in the world.
Main types of pollution
Soil pollution can be natural (for example, during volcanic eruptions), or anthropogenic (technogenic), when pollution occurs due to human fault. In the latter case, substances and products that are not characteristic of the natural environment and negatively affect ecosystems and natural complexes enter the soil.
The process of classifying types of soil contamination is very complex; different sources provide different classifications. But still, the main types of soil pollution can be presented as follows.
Household soil pollution- soil pollution with garbage, waste and emissions. This group includes pollutants of different nature and in different states of aggregation. They can be either liquid or solid. In general, this type of pollution is not too dangerous for the soil, but excessive accumulation of household waste clogs the area and interferes with normal plant growth. The problem of household soil pollution is most acute in megalopolises and large cities, as well as in villages with an unorganized waste collection system.
Chemical soil contamination- This is, first of all, pollution with heavy metals, as well as pesticides. This type of pollution already poses a great danger to humans. After all, heavy metals tend to accumulate in a living organism. Soils are contaminated with such types of heavy metals as lead, cadmium, chromium, copper, nickel, mercury, arsenic and manganese. A major soil pollutant is gasoline, which contains a very toxic substance - tetraethyl lead.
Pesticides are also very dangerous substances for the soil. The main source of pesticides is modern agriculture, which actively uses these chemicals in the fight against beetles and pests. Therefore, pesticides accumulate in soils in huge quantities. For animals and humans they are no less dangerous than heavy metals. Thus, the highly toxic and very stable drug DDT was banned. It is capable of not decomposing in the soil for decades; scientists have found traces of it even in Antarctica!
Pesticides are very destructive to soil microflora: bacteria and fungi.
Radioactive soil contamination is soil contamination with waste from nuclear power plants. Radioactive substances are extremely dangerous because they easily penetrate the food chains of living organisms. The most dangerous radioactive isotope is strontium-90, which is characterized by a high yield during nuclear fission (up to 8%), as well as a long half-life (28 years). In addition, it is very mobile in the soil and is capable of depositing in the bone tissue of humans and various living organisms. Other dangerous radionuclides include cesium-137, cerium-144, and chlorine-36.
Volcanic soil contamination- this type of pollution belongs to the group of natural ones. It involves the release of toxic substances, soot and combustion products into the soil, which occurs as a result of volcanic eruptions. This is a very rare type of soil pollution, which is typical only for certain small areas.
Mycotoxic soil contamination- is also not man-made and is of natural origin. The source of pollution here are some types of fungi that release dangerous substances - mycotoxins. It is worth noting that these substances pose as great a danger to living organisms as all the others listed above.
Soil erosion
Erosion has been and remains a major problem for the preservation of the fertile soil layer. Every year it “eats” large areas of fertile soil, while the rate of natural restoration of the soil cover is significantly lower than the rate of erosion processes. Scientists have already thoroughly studied the features of these processes and found measures to combat them.
Erosion can be:
- water
- wind
Obviously, in the first case, the leading factor of erosion is flowing water, and in the second, wind.
Water erosion is more common and dangerous. It begins with the appearance on the earth's surface of a small, barely noticeable ravine, but after each heavy rain this ravine will expand and increase in size until it turns into a real ditch. In just one summer period, a ditch 1-2 meters deep can appear on a completely flat surface! The next stage of water erosion is the formation of a ravine. This landform is distinguished by its great depth and branched structure. Ravines catastrophically destroy fields, meadows and pastures. If you don't fight the ravine, sooner or later it will turn into a beam.
Water erosion processes are more active in the steppe region with rugged terrain, where there is very little vegetation.
Wind erosion is caused by storms and hot winds, which are capable of blowing up to 20 centimeters of the upper (most fertile) ball of soil. The wind carries soil particles over long distances, forming sediments up to 1-2 meters high in certain places. Most often they form along plantings and forest belts.
Assessment of soil contamination levels
To carry out a set of measures to protect soil cover, an adequate assessment of soil pollution is very important. It is calculated through complex mathematical calculations, after conducting a complex of detailed chemical and environmental studies. The assessment is presented by a complex pollution indicator Z c.
Soil pollution assessment is carried out taking into account several important factors:
- specifics of pollution sources;
- a complex of chemical elements - soil pollutants;
- priority of pollutants, according to the list of maximum permissible concentrations of substances;
- nature and conditions of land use.
Researchers identify several levels of soil contamination, namely:
- Acceptable (Z with less than 16).
- Moderately dangerous (Z from 16 to 38).
- Dangerous (Z from 38 to 128).
- Extremely dangerous (Z with more than 128).
Soil protection
Depending on the source of pollution and the intensity of its influence, special measures have been developed to protect the soil cover. These measures include:
- Legislative and administrative (adopting relevant laws in the field of soil protection and monitoring their implementation).
- Technological (creation of waste-free production systems).
- Sanitary (collection, disinfection and disposal of waste and soil pollutants).
- Scientific (development of new technologies for treatment facilities, assessment and monitoring of soil conditions).
- Forest reclamation and anti-erosion measures (these are measures for planting special shelterbelts along fields, construction of hydraulic structures and proper planting of crops).
Conclusion
The soils of Russia are a colossal wealth, thanks to which we have food, and production is provided with the necessary raw materials. The soil has been formed over many centuries. That is why protecting soils from pollution is the most important task of the state.
Today there are a large number of sources of soil pollution: transport, industry, cities, utilities, nuclear power plants, and agriculture. The common task of scientists, government authorities and public figures is to protect soils from the harmful effects of all these factors, or at least minimize their harmful effects on soils.
