Hygienic significance of the soil. Soil chemistry and sanitary and epidemiological requirements

In nature, everything is interconnected. Substances move from the atmosphere to soil and water, and from there they re-enter the atmosphere. They have an impact on flora and fauna, on our entire civilization. To avoid disaster, you need to take care of every part of a single system. The biological significance of the soil is great. It is an extensive natural area where inorganic compounds are formed, constant processes of synthesis of substances occur, organisms live.

The hygienic significance of the soil focuses on two main sources of pollution: natural and man-made. Chemicals, waste, wastewater, sludge - all this poses a threat to the environment. The hygienic and epidemiological significance of the soil lies in the possibility of transmission of intestinal (typhoid, dysentery, cholera), anaerobic (tetanus, botulism, gangrene), viral (poliomyelitis, Botkin's disease), zoonotic (anthrax, brucellosis) diseases and geohelminthiasis, enteroscariosis , hookworm). It should be remembered that the soil serves as an environment for the development of larvae of fleas, flies, mosquitoes and horse flies, dangerous to humans.

Sanitary and epidemiological significance of the soil

Sanitary and epidemiological requirements are now higher than ever. The very first measures to protect human health were aimed at sanitary protection of the soil, since people walked barefoot, slept on the ground or in dugouts, drank underground water, and ate products grown on the ground. The problem of the effect of soil on human health has historically been of great interest. The standards established in our time are based on SanPiN 2.1.7.1287-03 "Sanitary and epidemiological requirements for soil quality". Rules have been established to maintain the quality of soils, to comply with hygiene standards for living, to build and operate facilities.

The Federal Law “On the Sanitary and Epidemiological Well-Being of the Population” (1999) regulates the state of the territories of settlements and soil microflora. In the soil approved by sanitary analyzes, the total number of bacteria in 1 g does not exceed 2.5-3 million.

Hygienic assessment of soil quality is given by the content of nitrogen, carbon, chloride and the number of Khlebnikov. The cleaner the soil, the closer the number to unity. It shows the ratio of humus nitrogen and organic nitrogen in general.

Soil structure and components

The hygienic importance of soil is to promote a healthy life. Since it is part of the biosphere and the upper ball of the earth's crust, it consists of compacted solid particles, between which pores are located. They serve to transport air, steam, water or smaller particles, as well as for the development of microflora.

The chemical composition of the soil is very diverse and is represented by mineral and organic substances. In other words, humus. This is an essential component for the normal development of plants and high yields. In different natural zones, the soil can radically differ. Its formation is affected by climate, geochemical conditions, and relief. Therefore, the plant world of the planet is so diverse that it entails a variety of animal species, because the existence of fauna is inextricably linked with the flora. For convenience, there is a classification of soils by composition, which is based on the study of the ratios of sand, dust and clay in soils.

1. Single grain structure. The soil easily sags under the influence of gravity. For construction, the ratio of soil voids should be minimal. This type is very unstable and does not withstand vibration and shock.
2. Honeycomb structure. The soil consists of sand and silt particles ranging in size from 0.02 to 0.002 mm. During sedimentation, particles are attracted to each other and form compounds. Between them, a large void forms, which gives the soil friability.
3. Lumpy structure. This type of soil is due to the attraction of charged clay particles. In marine conditions, salt acts on them - an electrolyte. It promotes compaction. Although in other cases, this type has a low density.
4. A dusty structure is formed when the clay surface is reconstructed and particles are repelled from each other. Over time, it loses strength.
5. The coarse-grained structure is found in combined soils. The space between the coarse particles is filled with fine grains. Thanks to this, the soil can withstand heavy loads.
6. The matrix clay structure resembles a coarse-grained one, but fine-grained particles predominate in it. This type is very stable in nature.

Organic soil

This includes all types of influence on the soil of living things:

• The animals, mesofauna, and microorganisms that form it form holes and pores necessary for the movement of water and air. In the same way, plant roots open underground channels.
• Plants with long rod roots that penetrate deep layers and absorb nutrients. Fibrous roots, which are closer to the surface, easily decompose and multiply organic matter.
• Microorganisms, fungi and bacteria. They affect the chemical exchange between roots and soil, accumulate nutrients.
• People who control the vegetation, which leads to the destruction of territories.

Hygienic assessment of the soil takes into account the presence of all necessary components in it and the minimum amount of polluting factors.

Sources of pollution

The soil "suffers" from living creatures that carry out their activities in and on it. The main "supplier" of pollution is a person, but not only him.

Sources of pollution:

• Inorganic: industry, transport (heavy metals).
• Organic: natural waste (animal bodies, dead plants), human waste (oil, detergents, pesticides).
• Radioactive.
• Microbial agents: fungi, helminths, bacteria, spores, protozoa.

Some of them have a particularly strong effect on the hygienic value of the soil.

Nitrites and nitrates

These compounds do not stay in the soil and are quickly absorbed into the water or absorbed by the crop, that is, they enter the food. Vegetables grown in the fall with fertilizers at low air temperature and low light intensity, as a rule, contain a lot of nitrates, unlike fruits and other crops. They are dangerous to use, since studies have established a relationship between nitrates and cancer. The risk of negative consequences for the pregnant woman and the fetus is especially high. If nitrates were found in breast milk in the mother, her baby is likely to be exposed to methemoglobinemia. This is the name of the blue baby syndrome.

Heavy metals

Mercury, cadmium, lead and arsenic are considered very dangerous. Organic arsenic is a natural element in the earth, absorbed by plants and concentrated mainly in leaves. But inorganic can harm. It causes a number of pathologies in living forms.

Pesticides

This includes any mixtures and fluids intended to expel, destroy and dispose of any insects, rodents, mushrooms or weeds. First they are spread by air currents, precipitation, vapor droplets and particles. Then they are carried by water: currents, drains, spills, rains. In parallel, pesticides are deposited on animal hair, human clothing and other objects. Applying them, you need to think about the possible consequences:

• Damage to third-party organisms (bees).
• Prolonged exposure to pesticides.
• Their distribution.

Persistent Organic Pollutants (POPs)

Toxic chemicals negatively affect the environment. Firstly, they are intensively carried by wind and water. Used in one country, they can easily be transported to a neighboring one. Secondly, they do not disappear anywhere, they accumulate and can be transmitted by animals along the food chain. Among these elements: additives to paint and lubricants, aerosols against mosquitoes, waste after burning garbage and medicines. A person uses them with products with untreated water as a result of direct contact. Often this leads to impaired reproductive, behavioral, neurological, endocrine functions and a weak immune system.

Contamination of soils and the environment occurs due to the direct absorption of harmful substances into the soil and into objects close to it. Chemicals settle in the respiratory tract and are absorbed into the skin of organisms.

Helminth infections

They are caused by the activity of parasitic worms and spread through eggs contained in feces. In infected individuals, mental and physical abilities are impaired, intoxication of the body occurs. To combat helminths, in certain territories, people periodically destroy all types of worms, conduct training events and warn about prevention, take care of comfortable sanitary conditions and the availability of medicines. Recommended drugs are Albendazole (400 mg), Imebendazole (500 mg), which have passed the examinations, approved and used by millions of people. The main goal of medicine is to eliminate the incidence of helminth infections in children by 2020.

Radiation

Sources may include nuclear explosions, the disposal of radioactive waste, the extraction of radioactive ores, accidents at nuclear plants.

Household garbage

Waste is a by-product of human activity that no longer performs useful functions.

• Infectious: pathogenic substances, tampons, materials or equipment that came into contact with infected patients, excrement).
• Pathological: human tissues or fluids (body parts, blood, other biological fluids, fruits.
• Sharp: needles, syringes, scalpels, blades, broken glass.
• Pharmaceutical preparations, bottles or boxes contaminated or containing medicines.
• Genotoxic: substances with genotoxic properties (cytotoxic drugs).
• Chemicals: laboratory reagents, disinfectants, expired, solvents.
• Heavy metals: batteries, broken thermometers, pressure gauges.
• Pressure tanks (gas cans, aerosols).
• Radioactive: radioactive substances (unused fluids from radiation therapy or laboratory tests, dirty glassware, packaging, or absorbent paper).

There are several ways to solve the problem with garbage: processing, burning and falling asleep. Due to these factors, a significant part of the waste does not disappear anywhere and affects the chemical composition of the soil. Therefore, it is worthwhile to pay special attention to recycling, the search for alternative power sources in order to less exploit and deplete the land. It is also worth considering the search for its artificial counterparts. The ecological importance of the soil must be taken care of now so as not to face global cataclysms in the future.

How to save the soil

There are many simple events available to each of us:

• Plant trees to protect the earth from wind, rain and to strengthen it with roots.
• Do not compact wet ground so as not to impede the transport of air and nutrients.
• To control pollution by waste and rainwater, as well as pest and parasite control.

To preserve the natural soil, other substrates for growing crops can be used. They should perform only two functions: to support the root system and contain water, nutrients that provide growth.

Total

The hygienic significance of the soil lies in the fact that it serves as an environment for the development of microorganisms, affects the crops grown and representatives of the food chain. It absorbs waste and breaks it down into inorganic substances. The ability to self-clean helps the soil in the fight against helminth eggs and other parasites that violate the integrity of the ecosphere, but this ability is limited. Therefore, a person should carry out sanitary measures to combat pollution and soil destruction, think about possible innovations that will reduce the burden on the exploited land and save it.