Māris kļaviņŠ, azamat azizov, JĀnis zaļoksnis environment, pollution, development: the case of uzbekistan

particles can cause allergic reactions and cause disease. 
Aerosol retention in the human respiratory system depends on 
the size distribution of particulate matter.
Pollen,  dust  of  wood,  flour  and  other  organic  substances  can 
be viewed as a special group of aerosols. Since these substances are 
organic, their composition differs significantly from the composition 
of  the  traditional  dust,  but  among  the  potential  effects  on  human 
health the ability of these aerosols to cause allergies should be noted.
Aerosols  and  dust  may  adversely  affect  the  plants,  too.  This 
effect  is  characterized  by  the  process  of  photosynthesis  inhibition 
and effects of toxic substances, as they desorb. 
In the Uzbekistan major sources of dust are – loose dusty soils 
and surfaces of salinized soils of Karakum, Kizilkum and Aralkum 
(dry part of Aral Sea) deserts. Aeolian drift of sand and salt from the 
dry bottom of Aral Sea yields 40-45 million tons/year, besides, the 
main salt and dust erosion occurs within 300 km of coastal strand. 
The amount of dust, which falls out on the soil in Juznoje Priaralje, 
is ten times bigger than in the irrigated zone. The composition of 
dust from Aral Sea includes sulfate salts up to 25-48%, chlorides – 
18-30%, carbonates – 10-20%.

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142 
ENVIRONMENT, POLLUTION, DEVELOPMENT:  THE CASE OF UZBEKISTAN
The total capacity of anthropogenic sources of solid particle 
emissions into the atmo sphere in the Republic is considerably lower 
than of the natural ones and is evaluated at 1.311 millions of tons 
per year. The share of solid particles in anthropogenic emissions 
is not high and contributes 16% for industrial sources, and 2% for 
mobile ones. The total amount of solid particles’ emissions in the 
Uzbekistan from industry is much higher than from the transport.
The main sources of entry of the industrial dust are companies 
of  State  Joint  Stock  Companies  «Uzbekenergo»,  «Uzstrojmateriali», 
«Uzchlopkoprom».  According  to  the  statistical  data  for  the  period 
from year 2000 to 2005, the total emissions of solid particles 
increased from 88.993 thousand tons to 101.09 thousand tons, but in 
year 2006 a notable decrease had been observed.
Index of total dust concentration in the atmo sphere is being 
controlled in 18 industrial cities of Uzbekistan. Excessive dust 
concentration is observed in large cities, in which lives approximately 
41% of urban population. The level of air contamination with dust 
is affected by high natural dustiness and industrial emissions. The 
city dust characteristically contains soot, which is formed during 
the combustion processes. The major mass of soot is being washed 
away by precipitation. In exhaust gasses from automobiles, which 
contribute in a certain way to dustiness of surface air, small particles 
with diameter of 0.02-0.06 µm prevail.
Higher  specific  dust  emissions  are  observed  in  cities,  where 
cement industry and coal-burning powerplants are mostly located. 
Dust settling around industrial centres contains various mineral 
compounds,  metal  oxides,  silicates,  soot,  fluorides,  arsenic  oxides, 
antimony and selenium. Among specific admixtures in dust contents 
of large industrial cities are metals like cadmium, copper, lead, 
nickel, zinc and manganese.
Since the aerosol effects on human, animal, plant and building 
condition may be adverse, and according to mass, aerosols and 
dusts must be considered the largest group of atmo spheric pollutant 
compounds, it is important to limit their emission in the main areas 
of aerosol formation, namely, industry and energy production.
To clean exhaust fumes from dust and aerosols several 
approaches can be used: 
1) The simplest method for air cleaning from dust is the 
sedimentation of dust. Only coarser dust particles (>100 µm) 
fall out sufficiently fast, and that limits the opportunities for 
using this method;
2) 
To clean the air from dust and aerosols, one can take the 
advantage of the fact that the particle inertia is larger than 
that of the gas molecules. This principle is used in cyclones 
and  dry  centrifuges.  In  this  case,  the  air  to  be  purified  is 
introduced into a conical cylinder so as to create an air swirl 

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7. AIR POLLUTION
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movement, where the heavier dust particles are thrown back 
to the cylinder wall. Cyclones are the devices for continuous 
operation.
3)  Filtration  of  the  air  to  be  purified.  Aerosols  and  dust  can 
be effectively removed by filtration of the air mixture to be 
purified through suitable, such as asbestos, fibres, synthetic 
material,  glass  fibre  fabric.  The  filtration  efficiency  is 
dependent on the filter material. 
4) Scrubbers. In this case, a liquid is sprayed in the air to be 
purified.  The  liquid  gathers  (and  if  accompanied  by  an 
appropriate reagent also reacts with) the dust and aerosol