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

Number of days when the maximally permissible concentration of 
dust in air was exceeded, %
 City
2008
2009
2010
Almalik
21
19
14
Bukhara
38
43
44
Gulistan
21
22
26
Navoi
30
8
4
Nukus
71
73
69
Taskhent
22.74
9.32
13.15
Aerosols which enter the atmo spheric air can serve as catalysts 
for various chemical reactions, such as zinc and iron oxide-
containing aerosols can catalyze the oxidation of sulfur dioxide into 
sulfur trioxide.
Overall, the chemical transformations that occur with aerosols 
can significantly alter their properties and composition. For example, 
cement production dust, when released into the atmo 
sphere, 
significantly reduces the sulfur and nitrogen oxide content, forming 
the respective calcium and magnesium salts, and thus affecting pH 
of the atmo spheric precipitation. 
Dust and aerosol particles also are electrically charged. Aerosol 
and  dust  chemical  composition  can  differ  quite  considerably 
depending  on  their  source.  Aerosols  may  consist  of  water-soluble 
ions  or  particles  which  are  almost  water  insoluble.  At  the  same 
time, the aerosol composition analysis allows to identify the sources 
of  aerosols.  Aerosols  of  natural  origin  are  mostly  composed  of 
potassium, aluminium, silicon, sodium, iodine, iron, chlorine and 

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140 
ENVIRONMENT, POLLUTION, DEVELOPMENT:  THE CASE OF UZBEKISTAN
carbon compounds. Heavy metals and complex organic substances 
in the aerosol composition suggest that their formation has occurred 
due to human activity. 
Atmo spheric aerosols and dust can significantly affect the Earth’s 
climate. This is evidenced both by the Earth’s long-term climate 
change analysis and the impact on the climate of dust spillage in the 
atmo sphere from the eruption of volcanoes. 
Dust and aerosol effects on the human body are determined by 
the particle size (Figure 7.19). Coarser particles (dust) are mainly 
detained in the nasal cavity and upper respiratory tract, but 
especially  fine  particles  (with  sizes  of  less  than  10  micrometres) 
reach the lung alveoli, and may even fall into the blood 
circulatory system. Airborne dust and aerosol inhalation can cause 
inflammatory processes in the respiratory system, increase the risks 
for the development into respiratory diseases, particularly chronic, 
and suppress the immune system.
0.01  0.1 
1.0 
10 
100