Hygienic and epidemiological significance of soil

The soil is called the surface layer of the bark of the globe. On the health status of the population is greatly influenced by water, heat and air regime of the soil. High standing soil water affects the humidity and the microclimate of the area. The soil is heated from the sun, has an impact on the thermal properties of the surface layer of air. Thermal properties of the soil affect the thermal regime of the basement or semi-basement premises, as well as on the microclimate of premises on the first floor.
The soil used for the disposal and recycling of waste generated in the process of human activity. Contaminated soil can be a source of infectious and parasitic diseases of humans and animals. From the structure of the soil and to a certain extent depends on the degree of dust air.
The soil consists of solid particles of different size and shape (grains) and free spaces between them - then filled with air. The size of the particles and the nature of their location depends on the size of the pores and on the value of long - important hygienic properties of the soil: air permeability, moisture capacity, the ability to cleanse itself.
The flow of air into the soil has a great hygienic value, as all the oxidative processes with participation of aerobic bacteria is possible only at presence of sufficient oxygen. Between soil and the atmosphere air, there is a constant exchange arising from fluctuations in temperature and barometric pressure.
When soil contamination in surface air can be emitted methane and other gases.
Composition and structure of soil and explains the attitude of the water. Being filtered through the soil, atmospheric water in varying quantities delayed it. The soil's capacity to retain water is called consumption. Coarse-grained soil poorly retains water, most of it flows down into the aquifer. Fine-grained soil retains a significant amount of moisture, such soil is usually more raw, cold and easy sabalaceae.
In the opposite function of the diameter of pores is the capillarity of the soil - raising ground water by then. Capillarity to consider when laying the foundations of buildings, as lifting of ground water can cause wet walls.
The same consequences big hygroscopicity soil.
From a hygienic point of view, the most favourable coarse soils (sandy), permeable to air and does not hold water. Adverse fine-grained soil (clay), is able to retain moisture.
Knowledge of soil properties is necessary when choosing a land plot for construction, when the irrigated fields and other
For communal and housing construction should be selected area with pure coarse-grained soil with big air and water permeability and low intensity, humidity and capillarity.
The chemical composition of the mineral part of the soil is determined by its origin. As part of sandy soils predominate compounds of silica (SiO2), as part of the limy - calcium (Cao), in the composition of the clay soils connection, aluminium (Al2O3). Organic part of the soil is composed of the remnants of flora and fauna, exposed in the soil complex changes.
Soil settlements, especially in poor condition of purification, is constantly exposed to the danger of infection by pathogens and eggs of helminths. Pathogenic microbes into the soil with the faeces of humans and animals, with other allocations, with the corpses of men and of animals that died from infectious diseases. For the development of the majority of pathogenic bacteria in the soil environment is unfavorable, so they are relatively quickly die.
Life expectancy in the soil pathogens typhoid, dysentery, plague, tularemia, tuberculosis, polio virus, Leptospira varies from several hours to several months. At the same time, some spore-forming pathogens (germs tetanus, anthrax, gas gangrene) can live in the soil for several years.
Thus, contaminated soil in direct contact with it (earthworks, play in the sand, ingestion of contaminated vegetables) can facilitate the spread of some contagious diseases and worm infestations.
A huge amount of waste, by doing to the soil, he is neutralized due to its ability to cleanse itself.