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

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5. GLOBAL ENVIRONMENTAL PROBLEMS
 5.1. 
 Environmental pollution and environment 
quality degradation
Life on the Earth is fragile, and every living being can continue 
to live only in the environ mental conditions optimal for its life. 
Such factors as the rise or fall of temperature above or below the 
optimum,  intensive  flow  of  electro magnetic  radiation  (ionising 
radiation) or the action of chemical substances can annihilate 
living  organisms  and  –  in  a  wider  context  –  life  itself.  Living 
organisms can also perish due to depletion of needed nutrients. 
Likewise, the impact of natural hazards and calamities can create 
unfavourable conditions for living organisms. Many times during 
the existence of the Earth, the number of species was reduced even 
by more than half as a result of various disasters. Moreover, living 
beings themselves can cause their living environ ment changes that 
have no less dramatic consequences.
The past, present and potential global threat of environ mental 
pollution and degradation can to a great extent be considered one 
of the main factors that has an effect on the formation of society’s 
environ mental  consciousness.
Environ mental pollution is quite often associated with che mi-
cal pollution, and we will deal with that in a bit more detailed 
manner below. Pollution of the environ ment by chemical sub-
stances  can  be  classified  depending  on  the  properties  and 
structure of these substances. Environ 
mental contamination 
with metals or their compounds (Cu, Pb, Co, Hg and others) and 
toxic trace elements (F, B, As, Se and others) can be marked out 
first.  Organic  pollutants,  such  as  pesticides,  can  have  a  negative 
impact on the natural environ ment. Organic substances can be 
formed as a result of the decomposition of household products, 
pest control with pesticides and herbicides as well as industrial 
pollution. The environ mental pollution threat increases if the 
organic substances that have been released into the environ ment 
are  persistent  (Persistent  Organic  Pollutants  –  POP),  i.e.,  if  they 
remain there for a long period of time (even several decades in the 
soil). Such substances as pesticide DDT, dioxins, polychlorinated 
Pollutant is any substance 
released into the envi‑
ronment as a result of 
human activity or natural 
processes that has an 
adverse impact on living 
organisms. Environmen‑
tal degradation means 
that the environment 
becomes unusable for 
its designed purposes 
or that the development 
of living organisms and 
their communities in the 
environment is impeded. 
Environmental pollution 
and degradation can be 
caused by chemical sub‑
stances, physical factors 
or the development of 
undesirable living orga‑
nisms (biological factors). 
Different substances or 
factors have different 
effects. Any chemical, 
biological or physical 
factor is called toxic if 
it causes an adverse 
biological reaction. All 
toxic substances are 
hazardous, but not all 
hazardous substances are 
toxic. Toxic substances 
can be either naturally 
occurring, or they 
can be human‑made 
(xenobiotic) – produced 
by means of synthesis 
or as by‑products in the 
process of production of 
other substances. 

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76 
ENVIRONMENT, POLLUTION, DEVELOPMENT:  THE CASE OF UZBEKISTAN
biphenyls and others belong to POPs. More or less chemically inert 
compounds  in  a  state  of  fine  particles  can  also  contaminate  the 
environ ment. Particles may form dust and aerosols in the air and 
suspensions in water.
Factors that cause environ mental degradation can be classified 
depending on their nature. The quality of the environ ment can 
deteriorate due to physical factors, for example electro magnetic 
radiation, the influence of which can be quite different depending 
on the wavelength. Short-wavelength electro magnetic radiation 
(γ-rays)  actively  affects  living  organisms,  and  its  sources  are 
radioactive elements or reactions in atomic nuclei. UV radiation, 
which  has  longer  wavelength,  may  have  a  significant  effect,  for 
example, on the human skin or growth of plankton in surface 
waters. Noise pollution, i.e. high intensity noise in the living or 
working  environ ment,  can  be  classified  among  physical  environ-
mental  pollution  factors.  Increased  amounts  of  heat  (flow  of 
energy) released into the environ ment may have quite a many-
sided negative impact (thermal pollution). For example, the 
discharge of industrial cooling waters or warm water from thermal 
power plants into the environ ment has adverse consequences, 
affecting the growth of aquatic organisms. Last but not least, living 
organisms can also cause serious environ mental pollution. They 
can be infectious agents, parasites as well as the living organisms 
whose metabolism or decay products are harmful to humans or 
other living organisms.
0
50
100
150
200
250
1995
1997
1999
2001
2002
2005
2004
2008
EU-15
EU-25
M
illion tons
CMR substances
Chronically toxic substances
Very toxic substances
Toxic substances
Hazardous substances
All kinds of chemical 
compounds are incre‑
asingly released into the 
environment (Figure 5.1). 
To date, there are 
approximately 10 million 
known chemical sub‑
stances, and a large part 
of them do not exist in 
the natural environment. 
There are approximately 
120
 
000 industrially 
produced chemical 
compounds that 
are widely used and 
10
 
000 substances 
produced in the amounts 
exceeding 500 kg per 
year. Moreover, the 
number of types of 
industrially produced 
substances is increasing 
from approximately one 
to three thousand new 
ones every year.