Hygienic value of pollution of atmospheric air of the closed premises
Atmospheric air always contains certain quantity of a dust and microorganisms. The dust maintenance fluctuates over a wide range: from 0,01 mg/m 3 to several tens in mg in 1 m. the Source of this dust are lifted by a wind or moving transport soil particles. Besides, in atmosphere the space dust always contains. It is known, that on 1 km 2 surfaces of the Earth for a year drops out nearby 70 g a space dust. Eruption of volcanoes increases quantity of a dust in air. More powerful source of air pollution by a dust is the smoke from burning of coal, peat and other kinds of fuel, and also the industrial enterprises on which on a course of technological process occurs considerable pyleobrazovanie.
The Dust concerns aerodisperse systems - dust parts (a disperse phase) are distributed in air (the disperse environment). In aerodisperse systems of a particle of a dust get ability to be in a suspension. It is caused by considerable crushing of substances and the small sizes of formed particles. As a rule, diameter of particles does not exceed 100 microns (from 0,01 to 100 microns).
The Firm substance at transition in a disperse condition gets new properties as its specific surface and superficial forces increase. Therefore in aerodisperse systems coagulation processes (curling, a condensation) and adsorptions of particles of substance easily develop.
Degree of a dispersion of dust particles has the big hygienic value as it defines duration of stay of parts of a dust in air and their action on an organism. The less sizes of dust particles, the longer they are in a suspension in air, by that are carried away from an emission source further. Besides, smaller particles of a dust get into breath bodies while large motes are late basically in the top respiratory ways. The smallest particles can cause defeats of bronchial tubes and lungs. Except bodies of breath the dust can amaze and a mucous membrane of eyes, causing an inflammation konjunktivy.
The dust Maintenance in air fluctuates depending on time of days (communication with features of activity of the person), speeds of movement of air, its temperature and humidity, and also from degree of an accomplishment and the hygienic maintenance of the occupied places. The dust being in air pollutes clothes, a skin, osteklenie windows, dwelling. Some kinds of a dust possess toxic properties. For example, lead, myshjakovaja and a soda dust meet in air of the industrial enterprises is more often.
The Dust can influence health of the person an indirect route as, being in a suspension and being kernels of condensation, motes promote formation of fogs. The dust and fogs, absorbing a considerable part of solar radiation, worsen a light climate of the occupied places. The dust, settling on an external surface osteklenija windows, worsens natural illumination of dwellings.
Maximum permissible daily average concentration of not toxic dust in air should not exceed 0,15, as much as possible single - 0,5 mg/m ; 3 .
Microorganisms get to atmospheric air with a soil dust and their quantity in direct ratio air dust contents. With a soil dust they can be transferred on the big distances. The steadiest against influence of factors of environment are activators of a tetanus, a gas gangrene, a botulism, and also egg gelmintov. In the winter when the soil is covered by snow, the quantity of microorganisms decreases.
Among the microorganisms which are in air, special danger represent pathogenic - activators of a flu, a measles, a scarlet fever, a tuberculosis, etc. the Part of these microorganisms perishes from drying and action of ultra-violet radiation of a sunlight. Therefore air of the closed premises (infectious hospitals, surgical branches etc. is more dangerous.).
Correct and sufficient air exchange, damp cleaning of premises, and also disinfection of air is necessary For the prevention of bacterial air pollution of premises by means of chemical preparations (propilenglikol, trietilenglikol) and an irradiation bactericidal lamps (БУВ-15, БУВ-30). These lamps should not render direct influence on eyes of people, therefore them establish in apertures of doors. They work during 2-3 ch a day.
For the purpose of preventive maintenance of aerogene infections carry out the regular microbiological control of air of premises, reveal sources of bacterial air pollution and use subjects. Objects of the given research are hospitals, polyclinics, sanatoria, children's combines, drugstores, and also places of a congestion of people - cinemas, rest houses, concert halls, sports palaces.
Air of premises is considered pure if in 1 m 3 it is found out no more than 1500 microorganisms, polluted - if their quantity reaches to 2500 (A.I.Shafir, 1958). For operational and dressing the general obsemenennost before work should not exceed air accordingly 500 and 750, after work - 1000 and 1500 microorganisms in 1 m 3 (V.A.Jaroshenko, 1964). Pathogenic kokkovaja the flora should not be found out in 250 m 3 air. In other hospital premises air is considered pure if find out no more than 3500 microorganisms in 1 m 3 in the summer and no more than 5000 winter. At detection of pathogenic microorganisms air is considered polluted and epidemiologicheski dangerous.
Air pollution by gaseous substances can occur in the course of disintegration of organic nitrogenous substances (ammonia) and as a result rotting of albumens (hydrogen sulphide).
Air in large industrial regions is Most polluted, the Basic sources of air pollution are the industrial enterprises, boiler, thermal power station, railway and motor transport.
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