1. THE LECTURE Sanitary-hygienic description of soil. Sanitary cleaning of settlements Author: Sopel O.N.

2. THE PLAN 1. Introduction. 2. Soil and health. 3. Problems of protecting the soil. Sanitary cleaning of settlements 4. Sanitary cleaning of settlements.

3. Soil may be defined as the fine earth covering land surfaces that has the important function of serving as a substratum of plain, animal, and human life. Soil essence of our being. Soil by volume, on the average consists of 45% mineral, 25% water, 25% air and 5% organic matter (both living and dead organisms).

5. Soils are composed of mineral matter, air, water, organic matter, and organisms. There are two general types of soils, mineral soils and organic soils. Mineral soils form from decomposed rocks or sediment derived from rocks. Organic soils form from the accumulation of plant material, usually in water-saturated, anaerobic conditions that retard decomposition. Mineral matter is described as texture and comprises half the volume of mineral soils. The other half of the soil volume is composed of voids or holes. These voids fill with water as the soil soaks up rain or flood waters, then are displaced with air as the water drains away, evaporates, or is absorbed by roots. The Composition of Soils

6. Both plants and animals help to create a soil. As they die, organic matter incorporates with the weathered parent material and becomes part of the soil. Living animals such as moles, earthworms, bacteria, fungi and nematodes are all busy moving through or digesting food found in the soil. All of these actions mix and enrich the soil. Here is a creature from each major group of soil organisms.Living animals Eastern Mole Night Crawler Nemotode (Round Worm) Root Fungus AmoebaBacteria Beetle Mite

7. There are many functions provided by soil that are important to human beings. Soil is necessary for:  dwellings  highways  airports  recreation areas  it also provides road fill  material for water retention structures  and fulfils many other essential functions.

8. S oil pollution is associated mainly with: 1. The use of chemicals, such as fertilizers and growth-regulating agents, in agriculture; 4. The soil is thus becoming increasingly polluted with chemicals, including heavy metals and products of the petroleum industry, which can reach the food chain, surface water, or ground water, and ultimately be ingested by man. 2. T he dumping on land of large masses of waste materials from the mining of coal and minerals and the smelting of metals. Toxic or harmful substances can be leached out of such materials and enter the soil; 3. The dumping on land of domestic refuse and solids resulting from the treatment of sewage and industrial wastes.

9. MAN AIR MAN water Plants MAN planctone FISHES Animals MAN The following ways of toxic, radioactive and biological agents transmission are possible

10. Biological agents Biological agents animal-soil-man pathogenic organisms of animals, transmitted to man by direct contact with soil contaminated by the wastes of infected animals man-soil-man pathogenic organisms excreted by man and transmitted to man by direct contact with contaminated soil or by the consumption of fruit or vegetables grown in contaminated soil soil-man pathogenic organisms found naturally in soil and transmitted to man by contact with contaminated soil

11. Leptospirosis Other diseases lymphocytic choriomeningi tis visceral larva migrans South American types of haemorrhagic fever, tuberculosis, salmonellosis, and tularemia Clostridium perfringens infections Animal-soil-man Animal-soil-man In a number of zoonoses (diseases of animals transmissible to man), the soil may play a major part in transmitting the infective agent from animal to man. Anthrax

12. Soil-man Soil-man Tetanus is an acute disease of man induced by the toxin of the tetanus bacillus growing an aerobically at the site of an injury. The infectious agent, clostridium tetani, is excreted by infected animals, especially horses. The immediate source of infection may be soil, dust, or animal and human faces. Mycoses Fungi and actinomycetes that grow normally as saprophytes in soil or vegetation cause most of the serious subcutaneous, deep-seated and systemic mycoses. Botulism This is a frequently fatal type of poisoning caused by bacterial toxins produced by Clostridium botulinum. The reservoir of the organism is soil and the intestinal tract of animals. The toxin is formed by the anaerobic growth of spores in food, which is the immediate source of poisoning.

13. Mechanic content of soil and it’s hygienic meaning Sanitary condition of soil depends greatly on its structure. Soil consists of dense, liquid, gas and alive components. Soil solution is water with solved gases, mineral and organic compounds. Mechanic analysis data make available the following divisions of soils: stony, gravel, cartilage, sandy (>80% sand and <10% of clay); sandy loam soil (50-80% of clay), lesser loamy soil (30-50% of clay), loamy soils (50-80% of clay), clay soils (>80% of clay), lime soils (>80% of clay), chalk soils, lessic soils (mixture of small sand particles with lime clay), black earth (>20% of humus), turf soils etc.

14. According to cleanness the soil is divided on Clean Low polluted Polluted Heavily polluted According to cleanness the soil is divided on Clean Low polluted Polluted Heavily polluted

15. Methods of sanitary analysis of soil: sanitary- physical sanitary- chemical sanitary- helminthological analysis sanitary- biological sanitary- radiological sanitary entomological

16. There are the indices of soil disperse capacity. The disperse properties of soil determine its air content: filtration capacity, water content, capillarity, hygroscopic properties, evaporation capacity. The epidemiological importance of soil depends on its capacity of infections, invasions and infestations spreading. Ecologic and epidemiological analysis of soil should include the evaluation of their biogeocenoses, the following ways of toxic, radioactive and biological agents transmission are possible: Sanitary-entomological studies determine a number of winged flies, maggots, pre-chrysalis and chrysalis. Sanitary-helminthological analysis define quantity of helminthes eggs and larvae

17. The disposal methods of choice are composting sanitary landfill incineration fields of irrigation fields of filtration agricultural fields

18. Incinerator design is improving as combustion efficiency improves and greater control is obtained over gaseous emissions; even after incineration, however, a sizeable volume of ash remains. Composting, although it has widespread popular appeal, has become increasingly uneconomical as a means of disposal, both because of the changing nature of refuse and the difficulty in disposing of the compost itself. Sanitary landfill is everywhere the most popular method of disposal. While it requires the use of relatively large areas, it can be used effectively for land reclamation purposes; when properly managed it can be inoffensive, and avoid both air pollution and, to a large extent, leaching and resulting water pollution. A modification of the process is being developed in certain areas; refuse is hauled relatively long distances by rail, and disposal is combined with strip-mining operations. Other processes, still at the experimental stage, include pulverization into a dense, homogeneous, and relatively inoffensive material.

19. Incinerator design is improving as combustion efficiency improves and greater control is obtained over gaseous emissions; even after incineration, however, a sizeable volume of ash remains. Composting, although it has widespread popular appeal, has become increasingly uneconomical as a means of disposal, both because of the changing nature of refuse and the difficulty in disposing of the compost itself. Sanitary landfill is everywhere the most popular method of disposal. While it requires the use of relatively large areas, it can be used effectively for land reclamation purposes; when properly managed it can be inoffensive, and avoid both air pollution and, to a large extent, leaching and resulting water pollution. A modification of the process is being developed in certain areas; refuse is hauled relatively long distances by rail, and disposal is combined with strip-mining operations. Other processes, still at the experimental stage, include pulverization into a dense, homogeneous, and relatively inoffensive material.

20. Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants from sewage. It includes physical, chemical and biological processes to remove physical, chemical and biological contaminants.sewage The site where the process is conducted is called a sewage treatment plant.

21. Typically, sewage treatment involves three stages, called primary, secondary and tertiary treatment.

22. Primary Treatment The wastewater that enters a treatment plant contains debris that might clog or damage the pumps and machinery. Such materials are removed by screens or vertical bars, and the debris is burned or buried after manual or mechanical removal. The wastewater then passes through a comminutor (grinder), where leaves and other organic materials are reduced in size for efficient treatment and removal later. Grit Chamber In the past, long and narrow channel-shaped settling tanks, known as grit chambers, were used to remove inorganic or mineral matter such as sand, silt, gravel, and cinders. These chambers were designed to permit inorganic particles 0.2 mm (0.008 in) or larger to settle at the bottom while the smaller particles and most of the organic solids that remain in suspension pass through. Grit Chamber In the past, long and narrow channel-shaped settling tanks, known as grit chambers, were used to remove inorganic or mineral matter such as sand, silt, gravel, and cinders. These chambers were designed to permit inorganic particles 0.2 mm (0.008 in) or larger to settle at the bottom while the smaller particles and most of the organic solids that remain in suspension pass through.

23. Sedimentation Primary sedimentation tank at a rural treatment plant

24. Secondary Treatment Secondary Sedimentation tank at a rural treatment plant

25. Trickling Filter Trickling filter bed using plastic media

26. Activated Sludge The final step in the secondary treatment stage is to settle out the biological floc or filter material and produce sewage water containing very low levels of organic material and suspended matter.

27. Stabilization Pond or Lagoon Another form of biological treatment is the stabilization pond or lagoon, which requires a large land area and thus is usually located in rural areas. Facultative lagoons, or those that function in mixed conditions, are the most common, being 0.6 to 1.5 m (2 to 5 ft) in depth, with a surface area of several acres. Anaerobic conditions prevail in the bottom region, where the solids are decomposed; the region near the surface is aerobic, allowing the oxidation of dissolved and colloidal organic matter. A reduction in BOD 5 of 75 to 85 percent can be attained.