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Infrared (IR) beams. Hygienic requirements to natural lighting (illumination). Hygienic requirements to artificial illumination.
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Infrared (IR) beams.
Length of wave more 760 nm. A main effect - thermal - strengthening oscillatory and rotational movements of molecules in fabrics. Strengthen biological effects UVR.
Allocate 2 parts in IR-beams:
а) Long-wave IR-beams - more than 1500 nm.
b) Short-wave IR-beams - 760 - 1500 nm.
Biological effects of IR-beams:
Hyperemia skin and internal bodies, increase gas exchange in fabrics, strengthening secretory function of kidneys, soothing action, resolve the inflammatory centers - are applied in physiotherapy.
At excessive intensity IR - irradiation:
а) Heating brain environments - heatstroke and thermal faint,
b) Damage by short-wave IR-beams crystalline lens - cataract
c) Burns on skin different degree of weight.
Hygienic requirements to natural lighting (illumination).
At estimation natural illumination in premise take into account:
- Orientation windows on the sides of light (points),
- The distance up to the next buildings, plants - in norm distance between buildings - 1, 5 of it heights, trees - is not closer 10m up to building schools,
- The sizes, amount, the form of windows in premise, % of bindings - up to 25 % area of window,
- Presence extraneous subjects at windows - green plants etc. - is not recommended in schools.
Quantity indicators of natural illumination:
1) Light factor (LF) - the relation of the total area of windows in a room to the area of a floor. In inhabited rooms LF 1/8-1/10, in hospital wards and cabinets of doctors LF 1/5-1/6, in classes schools 1/4-1/5, in operational 1/2-1/4.
2) FNI - factor of natural illumination - the relation of light exposure at workplace in Lux (by luxmeter) to light exposure in open-air in Lux, expressed in %. Inhabited rooms 0, 5-0, 75 %, wards - 1 %, classes - 1, 5 %, operational - 1, 6-2%.
3) Corner of falling - not less than 27 degree.
4) Corner of aperture - not less than 5 degree.
The device for estimation of light exposure – LUXMETER (Describtion – see in Manual for practical lesson)
Hygienic requirements to artificial illumination.
The common requirements to artificial illumination:
- It should be sufficient on level of light exposure,
- To come nearer on spectrum to natural light,
- To be uniform in space - to not create sharp contrasts in light exposure - faster comes exhaustion because of light adaptation,
- To be uniform in time,
- To not blind bodies of sight.
The main parameter sufficiency of artificial illumination - light exposure of surfaces in lux. It is measured by luxmetr with the help of photocell.
Systems of artificial illumination:
- General - in inhabited room 40-50 Lx, in class 150 Lx, in operational 300 Lx (norms for incandescent electric lamps, - for luminescent lamps in 2 times more),
- Local - in inhabited room 100 Lx, in class - is not present, in operational 3000 -10000 Lx,
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- Mixed - local and common illumination together.
Sources of artificial illumination:
- Candles, etc. - non-uniformity illumination in time, air pollution in premises,
- Incandescent electric lamps - the spectrum differs from natural light (many red beams)
- Luminescent lamps - non-uniformity in time, differences in spectrum (many blue beams).
Types of the lighting fixtures:
- Fixtures of direct light - high contrasts in illumination, blinding of eyes
- Fixtures of reflected light - more powerful light source is necessary
- Fixtures of diffused light (dairy spheres) - it is the best way.
THEME № 13. HYGIENIC REQUIREMENTS TO QUALITY OF DRINKING WATER.
Value water for the person.
Water has huge physiological, hygienic and economic value for the person.
Kinds of water use:
- Drinking - the most important kind of water use for the health of the population, for it kind is the most rigid requirements to water quality. On the data the WHO, 80 % of all diseases on the Earth are connected to poor-quality water or connected with the bad sanitary conditions of life caused by deficiency of clean water.
- household - for maintenance normal sanitary conditions of life of the population and prevention infections. Requirements as to drinking water.
- Recreational - reservoirs and the water areas used for rest, aquatic sport, etc. - rigid requirements to water quality
- Balneologic water use - baths, souls, inhalations etc. - high requirements to water quality,
- Industrial - use water in technological processes on manufacture - special requirements to water quality,
- Meliorative - irrigation the grounds in agriculture etc. - special requirements to water quality,
- Fish-breeding - for cultivation fishes. Requirements sometimes even are higher, than for the person - sensitive kinds of fishes. At pollution reservoirs toxicants can collect in fish and cause diseases in people.
- Transport - sailing charter, ports etc.
Problems fresh water on the Earth.
Only 3 % stocks of water on a planet is the fresh waters (other – seawater) intensively used for the above-stated kinds of water use. Thus stocks of fresh waters are allocated very non-uniformly and are available in enough only on 20 % densety populated territories, in other places - deficiency of water.
In addition to deficiency of fresh water, fresh-water reservoirs have the biggest anthropogenous pollution, what frequently makes their unsuitable for water consumption.
UNESCO gives forecasts about real threat of water famine for mankind. A cardinal way of the decision water problem – distillation of sea waters, but it is very expensive, besides the seas and oceans are considerably polluted and at boiling toxic and cancerogenic substances can be formed.
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