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THE LECTURE Soil and health. Bases of the sanitary cleaning of the inhabited places. Author: Sopel O.N. THE PLAN 1. Introduction. 2. Soil and health. Problems of protecting the soil. 3. Hygiene of dwelling. Microclimate, heating, ventilation. 4. Hygiene of natural and artificial illumination in apartments 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). The Composition of Soils 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. 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. Eastern Mole Nemotode (Round Worm) Amoeba Root Fungus Bacteria Night Crawler Beetle Mite 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. Soil pollution is associated mainly with: 1. The use of chemicals, such as fertilizers and growth-regulating agents, in agriculture; 3. The dumping on land of domestic refuse and solids resulting from the treatment of sewage and industrial wastes. 2. The 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; 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. The following ways of toxic, radioactive and biological agents transmission are possible SOIL SOIL SOIL MAN AIR water planctone SOIL Plants MAN MAN FISHES Animals MAN MAN Biological agents 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 animal-soil-man pathogenic organisms of animals, transmitted to man by direct contact with soil contaminated by the wastes of infected animals soil-man pathogenic organisms found naturally in soil and transmitted to man by contact with contaminated soil Man-soil-man Enteric bacteria and protozoa can contaminate the soil as a result of: unsanitary excreta disposal practices; the use of night soil or sewage sludge as a fertilizer, the direct irrigation of agricultural crops with sewage. Soil and crops can become contaminated with the bacterial agents of cholera, salmonellas, bacillary dysentery (shigellosis) and typhoid and paratyphoid fever, or with the protozoan agent of amoebiasis. Parasitic worms (helminthes) Soil-transmitted parasitic worms or geo-helminthes are characterized by the fact that their eggs or larvae become infective after a period of incubation in the soil. 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. Leptospirosis Other diseases visceral larva migrans lymphocytic choriomeningi tis Anthrax listeriosis, Clostridium perfringens infections South American types of haemorrhagic fever, tuberculosis, salmonellosis, and tularemia Soil-man Mycoses Fungi and actinomycetes that grow normally as saprophytes in soil or vegetation cause most of the serious subcutaneous, deep-seated and systemic mycoses. 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. Botulism 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. Mechanic content of soil and it’s hygienic meaning Sanitary condition of soil depends greatly on its structure. 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. According to cleanness the soil is divided on Clean Polluted Low polluted Heavily polluted sanitarychemical sanitary entomological sanitarybiological Methods of sanitary analysis of soil: sanitaryhelminthological analysis sanitaryphysical sanitaryradiological Dwelling influences a man’s health by volume area microclimate other indexes The dwelling includes the work place, the place for rest and sleep. Absences of necessary sanitary-hygienic standards in apartment are negatively reflected on such physiological organism functions Breathing Heat exchange Higher nervous activity. The death rate among inhabitants of apartments with a great number of people is in 1,5 - 2 people residing spacious apartments. times higher than among Pulmonary tuberculosis is the most typical illness of very small apartments. Very easily can spread such infections as: grippe measles scarlet fever diphtheria coughing chicken pox The dwelling, which corresponds to hygienic norms, is : • ought to be sufficiently spacious, • dry, • to have a favorable microclimate, • clean air, • to be well lighted by sunrays. In Ukraine the lowest level of dwelling space per person is 2 13-15 m . The dwelling functions for people are: satisfaction of physiological needs (sleeping, personal hygiene, eating, physical training and sport) communication and cultural activity (rest, entertainments, communication of family members) education and bringing up of children housekeeping (cooking, cleaning, washing) professional activity, self-education, amateur activities. Natural and artificial lighting in dwellings The sun‘s rays render a thermal, physiological and bacteriological effects. Therefore residential, industrial and public buildings should be provided with daylight. This phenomenon depends upon percentage of light absorption by walls of different coloring. white wallpapers absorb only 8% of light, yellow – 10%; blue – 15% dark brown from 87% to 96%.T The white color and light tone are mirrored by sun rays on 70-90 of %, yellow color - on 50 %, green - on 50-60 of %, blue, violet on 10-11 of %, black - on 1 %. Types of insolation mode of locations Insolar mode Orientation windows on the world sides Time of insolation (hour) % insolation square in room Maximum South-East 5-6 South-West 80 Moderate South, East 3-5 40-50 Minimum North-East North-West <3 < 30 Orientation of the windows on the world sides in some rooms: hospital wards (patient room) - on the South or South-East ; operation room - on the North; reanimation room - on the North, North West, North-East; - classroom-on the South, South- East or East The day lighting in room depends on: •distance between buildings, •height of the building, •proximity and height of green plantations. Factors that influences on intensity and duration of daylight of rooms are: 1. The size of the windows, 2. Form of the windows, 3. Disposition of the windows. The upper edge of windows is necessary to be as higher as it is possible. The size of the windows Hygiene has established standards of a glass area of windows to regulate amount of day light in rooms. It is recommended to have a glass area of windows (not windows area) which would be equal, for dwelling, not less than ⅛ of area of a floor. Light coefficient (LC) is a ratio of a glass area of windows to area of a floor. For living rooms LC = 1:6 - 1:8, For hospital wards, the doctor’s rooms, study rooms 1:5 - 1:6, for operation rooms, laboratory 1:3 - 1:4, for corridor 1:10 - 1:12. form and disposition of the windows The best in form of the window are the rectangular windows, and the upper edge of the window should be placed from a ceiling on 20-30cm, for maximum receipt of light to the depth of rooms. Coefficient of Depth (DC) This is an attitude of distance from the window to the opposite wall to distance from the upper edge of the window to a floor. The hygienic norm DC is not than 2. DC = distance from the window to the opposite wall / distance from the upper edge of the window to a floor Coefficient of natural illumination The basic lighting engineering parameter for a normalization of daylight is coefficient of natural illumination (CNI). CNI = lighting indoors / lighting outdoor This ratio of lighting indoors to simultaneous lighting outdoor, is expressed in %. For living rooms CNI should be not less than 0,5 %, for hospital wards not less than 1 %, for study room - not less than 1,5 %, for operational room - not less than 2,5 %. The angle of incidence of light rays The angle of incidence of light rays is an angle between a horizontal surface of a table, and line conducted from this surface to the upper edge of the window. The more erectly direction of light rays, i.e. the more angle, the lighting is more. For lighting of workplace the angle of incidence according to hygienic norms should be not less than 27. The angle of opening The angle of opening of light rays is an angle between a horizontal surface of a table, and line conducted from this surface to the upper edge of the object with darken the window (building or tree). Hygienic norm for the angle of opening is not less than 5. Diagram for determination of the angle of incidence and the angle of opening The angle of opening calculation: tg =BC/AB (see table of tangents), - the angle of incidence; tg =BD/AB (see table of tangents), - the angle of shading; , is the angle of opening. distance between buildings At contamination of glasses Light coefficient The daylight in rooms depends on: colorings of a ceiling, floor, walls Coefficient of natural illumination Coefficient of depth Angle of opening of light rays Angle of incidence of light rays Description of natural illumination of dwelling Index Coefficient of day lighting (DLC) Light coefficient (LC) Angle of incidence of light rays Angle of opening Depth Coefficient (DC) Rates not less 0,75 % not less 1/6-1/8 not less 27 0 not less 5 0 not greater 2 The sources of artificial lighting. incandescent bulb luminescent lamp Incandescent Lamp Components of a Fluorescent Lamp A fluorescent lamp consists of a phosphor-coated tube, starter, and ballast. There are 3 types of luminescence lamp: •- daylight luminescence lamp, •- white-light luminescence lamp, -warm-white-light luminescence lamp. The light from such lamps can be made to approximate the quality of daylight The efficiency of the fluorescent lamp is high Important advantages of Fluorescent lamps Fluorescent tube taking 40 watts of energy produces as much light as a 150-watt incandescent bulb. Fluorescent lamps produce less heat than incandescent bulbs for comparable light production The defect of luminescence lamp cyanotic skin “evening effect” stroboscopic effect Fluorescent lamps The defect of the daylight luminescence lamp is that human skin in this light looks unhealthy, cyanotic That`s why they are not used in hospital and school rooms. Comparing with daylight lamps the spectrum of white-light luminescence lamps is richer with yellow rays. During lighting with such lamps high workability of an eye is kept and skin looks better. Used at schools, apartments, hospitals. Spectrum of warm-white-light lamps is rich with yellow and pink rays and decreases eye`s workability, but considerably improves colour of skin. Used for illumination of stations, cinemes, underground Description of artificial light for dwelling Living place Level of least illumination (lux) By incandescence lamps By luminescent lamps 75 100 100 100 Closet, bathroom Hall 30 50 50 50 Stairs 10 50 Dwelling room Kitchen LUXMETR Microclimate of dwelling places Temperature In winter temperature in apartment has to be 18-20 0C (for moderate latitude). Relative humidity (with air temperature 18-200С) has to be 40-60 %. Speed of air has to be not more then 0,2-0,3 m/s Acceptable microclimate - person can wear light clothes and shoes, stay for a long time without many moves and have no unpleasant feelings such as freezing or overheating. Chemical structure of air The most important part of air for man is Oxygen. Carbon dioxide Contents of carbon dioxide gas in atmospheric air is relatively permanent - 0,03-0,04 %. СО2 does not congest in air and excludes from it with rainfalls (1l of rain-water contains about 1-2 ml СО2), reacts with seawater, forming carbon dioxide salts and, usually, collapses by chlorophyll plants. A concentration of СО2 in air in closed, badly ventilated dwellings rises up because of peoples’ breathing. Change of content and properties of air while breathing Atmospheric Breathed out air air Oxygen СО2 Temperatur e 21 % 15,5-16 % 0,03-0,04 % 2,5-5 % different 35-370 Maximum admissible concentration of СО2 in dwelling air is 0,1%. Air ventilation can be considered: good if the concentration of СО2 in air is lesser than 0,07 %; satisfactory when concentration of СО2 in air is 0,1 % the concentration of 0,15 % is admissible only for short time staying (for example, in cinemas). As air is cleaner, it contains more light electric negatives ions. In village the amount of such ions is equal 1000 ions per 1 ml of air, on some healthresorts (in mountains and by sea) amount of light electric negatives ions reaches 3000-4000 ions per 1 ml of air, and in some big industrial cities amount of such ions falls down to 300-100 ions. Sources of Indoor Air Pollution Lead Asbstosis Carbon Monoxide Nitrogen Dioxide Pesticides Radon Respirable Particles Secondhand Smoke Stoves, Heaters, Fireplaces, and Chimneys Carbon Monoxide (CO) Carbon monoxide is an odorless, colorless and toxic gas. At lower levels of exposure, CO causes mild effects that are often mistaken for the flu. These symptoms include: headaches, dizziness, disorientation, nausea fatigue. Levels CO in Homes Admissible concentration of carbon oxide gas in house is 0,002 mg per liter of air. Middle amount of carbon oxide gas in air attached to yellow flame is 0,045 mg per litre of air. Middle amount of carbon oxide gas in air attached to blue flame is 0,001 mg per litre of air.