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Проблемы биогеохимии и геохимической экологии, 2012, №3 (20)
Проблемы биогеохимии и геохимической экологии, 2012, №3 (20)
Draft: 631.95, pp. 77-83
B.K. Karimov1, M.F. Bekchanova1, G. Tartari2, D.A.L. Vignati2
Institute of the gene pool of plant and animal life of the Academy
of Sciences of the Republic of Uzbekistan 1
Uzbekistan, 100125 г. Tashkent, str. Datura Yuli 32
Tel. +99871-2890315; E-mail: Karimov@sarkor.uz
Water research institute, CNR Italy. Brugherio 2
20047 Milan, Italy. E-mail: tartari@irsa.cnr.it
MONITORING AND ECOTOXICOLOGICAL ESTIMATION OF
MERCURY POLLUTION LEVELS OF HUMAN AND AQUATIC ECOSYSTEMS
COMPONENTS IN THE REPUBLIC OF UZBEKISTAN
Mercury levels in bottom sediments varied between 4.0 and 26.4 μg/kg, with somewhat higher levels
in Arnasay lakes (9.6–26.4) than in the lower reach of Amudarya river (4.0–21 μg/kg). Levels of mercury in
fish varied between 28.7 and 137.7 μg/kg. Mercury content of human hair in Tashkent city varied between
42.8 and 387 (average 124) μg/kg, which was slightly lower than in Khorezm region (21.6 to 678; average
161 μg/kg). These values are much lower than the attention thresholds set by US EPA and WHO (1000 and
10000 μg/kg, respectively).
Keywords: bottom sediments, lake, mercury, water systems.
Introduction
Mercury is one of the highest priority en-
vironmental pollutants of concern. Mercury is tox-
ic, persistent, and bioaccumulates in food chains.
Mercury circulates between air, water, soil and
biota in various forms. Specific human subgroups
such as high-end consumers of fish, groups living
in industrialized areas, pregnant women, and
newborns may be at risk from accumulating ele-
vated levels of mercury threatening their health.
Air pollution can also be a significant
source of exposure to mercury. In urban areas,
power generation plants and emissions from cars
are a growing threat to air quality. High levels of
trace elements such as lead, nickel, copper, cad-
mium, manganese, mercury, tin, as well as anti-
mony, selenium, and fluorine have been found in
Uzbekistan’s atmosphere, mainly from the burn-
ing of fossil fuels, inappropriate disposal of waste
materials, and ferrous and nonferrous smelting
(Ecological review of Uzbekistan, 2008). Espe-
cially high concentrations of heavy metals were
reported for industrially developed Tashkent, Na-
voi and Fergana regions. Mercury introduced to
the atmosphere can be deposited back to terrestrial
and aquatic system where, especially in the latter
case, can be converted to methylmercury, incorpo-
rated in the food chain, accumulated in fish and
can result in high human exposure. Mercury pol-
lution has indeed received much attention and is
placed high on the political agenda in most devel-
oped countries. On the other hand, in Central
Asian countries, it has been included only recently
into the monitoring schemes. In 2001 the monitor-
ing laboratories of the State Hydrometeorological
B.K. Karimov
Doctor, Professor, Head of
Laboratory of “Ichthyolo-
gy, Hydrobiology and Aq-
uaculture”
G. Tartari
Doctor, Director of Re-
search at the Water Re-
search Institute (IRSA), of
the National Research
Council (CNR)
D.A.L. Vignati
Senior Researcher of the
Laboratory of Ecotoxico-
logal Interactions, Biodi-
versity, Ecosystems
(LIEBE)
Проблемы биогеохимии и геохимической экологии, 2012, №3 (20)
Service and Nature protection Committee of the
Republic of Uzbekistan have been supplied with
additional equipment to analyze additional specif-
ic toxic metals such as selenium, strontium, co-
balt, antimony, mercury, etc.
Materials and methods
Fish and bottom sediment samples were
collected during September-October 2009 from
two largest river basins in Central Asia: the mid-
dle reach of Syrdarya River - Arnasay Lake Sys-
tem (ALS) which includes 3 interconnected large
lakes (Eastern Arnasay, Tuzkan and Aydar and
Central Golodnosteppe Collector –CGC) and the
lower reach of Amudarya River where sampling
points included Amudarya River itself, Main col-
lector Ozerniy (MCO), collector Jirmizkol, andtap
water from drinking water supply system of the
region. Samples were also taken in upper reach of
Chirchiq River near to village Botanical of Tash-
kent region, Uzbekistan (see figure).
The bottom sediment samples were col-
lected in polyethylene plastic bags, transported to
the laboratory in Tashkent, dried at room tempera-
ture and stored frozen without further treatment.
They were then transported on ice to CNR-IRSA,
UOS Brugherio, Italy by airplane and placed
again into a refrigerator until further treatment.
Fish sampling was carried out in Arnasay
and Tuzkan lakes (ALS) using passive gill nets
(mesh size between 32 and 80 mm). Various
commercial fish species were measured (total
length - L and total weight) and divided by spe-
cies and sex whenever possible. Two to three
fishes from each sampling point were selected
(table 3). Fish muscle was taken from the dorsal
portion of the fish, above the lateral line between
the head and the dorsal fin. The 15-30 g of tissues
from 2-3 individuals of the same species and sex
were pooled together. Samples were stored at
−20°C and transported on ice CNR-IRSA, UO-
SBrugherio, Italy where they were freeze-dried.
The average content of water in dried-out fish
muscles was 80.5%. After then dry fish muscles
were homogenized in agrinder “MM 2000
Retsch” and were kept dry until analysis.
For mercury determination in human hair,
a bundle of hair was taken from the occipital re-
gion, as close as possible to the scalp, using
stainless steel scissors. Hair samples were col-
lected in polyethylene plastic bags without further
treatment. For each sample we collected the fol-
lowing information: age; occupation; sex; living
region; amount, type and frequency of fish con-
sumed; other factors which could contribute to
increase Hg body-burden (e.g., use of peculiar
cosmetics, professional exposure, living in the
vicinity of coal-power plants or cement factories,
etc). A special questionnaire was prepared for
each volunteers.
For women with long hair (> 5 cm), the
longest hair was lifted and the freshly grown hair
on the occipital region and close to the scalp was
collected. Mercury concentrations in all samples
were determined by atomic-absorption spectro-
photometer using an Automated Mercury Ana-
lyzer (AMA. 254, FKV, Bergamo) with a detec-
tion limit of0.01 ng Hg (absolute concentration).
Approximately 25–50 milligrams of hair, 40–70
mg of freeze dried sediments and 40–55 mg of
freeze dried fish muscle tissue in each replicates
(3 replicates) were used for the determinations.
Experimental results were evaluated based
on quality standards accepted in former Soviet
Republics (table 1).
Table 1 – Maximum permissible concentrations (MPC) of mercury and its compounds
Chemical form of
presence
In air of res-
idential
areas, mg/m3
In air of work-
ing zone
mg/m3
In water used for
potable purposes
mg/L
Soil,
mg/kg
Consumer pro-
ducts, mg/kg
Mercury
0,0003
0,005
0,0005
2,1 (total
content)
0,005-0,5
(e.g. Fish-0,3)
Inorganic mercu-
ry compounds
0,0003
0,05
0,0005
Organic mercury
compounds
0,005
0,0001
Not allowed
Проблемы биогеохимии и геохимической экологии, 2012, №3 (20)
Results
The range of Hg contamination in bottom
sediments varied between 4,0-26,35 μg/kg; with
slightly higher levels found in ALS (9,59-26,35
μg/kg ) than in the lower reach of AD (4,0-20,98
μg/kg) (table 2). These values are much lower
than MPC for soils – 2 100 μg/kg and below the
Consensus-Based Threshold Effect Concentration
of 180 µg/kg for sediments.
In investigated fish species average accu-
mulation levels of mercury varied between 28,7-
137,7 μg/kg (table 3) which was also lover than
MPC (300 μg/kg).
Mercury levels in human hair from volun-
teers in Tashkent city varied between 42,8-387
(arithmetic mean = 124,2) μg/kg and were slightly
higher in samples from Khorezm region -21,65-
677,68 (161,34) μg/kg. These values are much
lower than the attention thresholds set by the US
EPA and WHO (1000 and 10000 μg/kg, respec-
tively). They were also lower than levels meas-
ured for comparison in hair from volunteers work-
ing at CNR-IRSA in Brugherio: 479,43-3 417,49
(1 486,66) μg/kg (table 4).
Table 2 – Mercury concentrations in bottom sediments of water bodies in Uzbekistan
Water body
Date of samp-
ling
Place of samp-
ling
Hg, mg/kg (ppm) dry weight
Repl.1
Repl.2
Repl.3
Mean
1.CGC (Central
Golodnosteppe
Collector)
Sep.21.2009
Lower reach
0,018
0,020
0,019
0,019
2. Arnasay
reservoir
Sep. 22, 2009
Outflow
0,010
0,010
0,009
0,010
3. Lake Aydar
Sep.22, 2009
Eastern part
0,009
0,009
0,012
0,010
Проблемы биогеохимии и геохимической экологии, 2012, №3 (20)
Continuation of Table 2
Water body
Date of samp-
ling
Place of samp-
ling
Hg, mg/kg (ppm) dry weight
Repl. 1
Repl. 2
Repl. 3
Mean
4. Eastern
Arnasay
Sep.22, 2009
Hydromet
0,024
0,023
0,024
0,023
5. Lake Tuzkan
Sep.24, 2009
Western part
0,024
0,030
0,025
0,026
6. MCO (Main
collector Ozerni)
Oct.06, 2009
Fish farm
0,004
0,004
0,004
0,004
7. Amudarya
River
Oct.06, 2009
Khorazm
0,004
0,005
0,003
0,004
8. Collector
Jirmizkol
Oct.06, 2009
Khorazm
0,032
0,018
0,014
0,021
The comparison of mercury pollution rate
of human and fish consumption levels of popula-
tion will give interesting, however expected re-
sults. It is well-known that the bioaccumulation
rate of mercury in human organism correlates
positively with fish consumption level. Indeed,
people in Tashkent city consume an average 1.0
kg of fish/year and people in Italy – about 20 kg,
i.e. difference is about 20 times. In turn people in
Khorezm consume 0.5 kg of fish/year. Which is
twice lower than in Tashkent city.
Discussion
According to (Kuncova, 2004) in Kyr-
gyzstan, Tadjkistan and Russian Federation the
primary production of mercury in 2000, 2002,
2003 was 594, 300 and 250 tonnes and by-
production in 2003 – 100 tonnes. Mercury is a
main product and by-product of mining or refin-
ing of other metals (zinc, gold, silver) in Kyrgyzs-
tan (Maylisu, Khaydarkam) and other production
plants in Tajikistan).
There are very limited data concerning
pollution level of aquatic systems with mercury in
Uzbekistan. According to Z. Suleymanova (2004)
in water of small mountain river Shahimardonsay
in Uzbekistan during 2000-2003 the concentra-
tions of mercury 0,001-0,004 mg/L was observed
in water. Much lower concentrations have been
registered in the water of Zarafshan river (plain
territory) in may 2001 – 0,2–0,04 μg/L. The mer-
cury content in the environment in another former
Soviet Republic of Moldova was following: water
– less than 0,0001 mg/L, bottom sediments –
within 0,03-3,05 mg/L (Bulimaga, 2004). Al-
though water contamination was not assessed,
these values are above the water quality standard
of 50 ng/L set by the European Community for
inland waters and calls for further verification in
future studies.
For bottom sediments, contamination le-
vels in the study areas were much lower than le-
vels measured in freshwater systems in industria-
lized areas of Italy (Camusso et al., 2002; Vignati
et al., 2008). In the case of fish, R. Schoeny
(2004) summarized data for fish mercury conta-
mination for various countries and fish species
(table 5). Comparing these values with those ob-
tained for fishes living in water bodies in plain
territories of the Republic of Uzbekistan, we con-
clude that Hg pollution levels in are quite low. We
do note however that the European Community
proposes an ecological standard of 20 µg/kg total
mercury in fish, so that more data are needed to
evaluate the Hg risk in the investigated area.
Finally, fish consumption is usually the
most common route of Hg uptake by humans. Hg
levels in hair from Uzbek volunteers were low (or
even extremely low) compared with those meas-
ured in Italian volunteers. People in Tashkent city
and Khorezm consume an average of 1,0 kg and
0,5 of fish/year, while the corresponding figure
for people in Italy is about 20 kg. The results
therefore reflect the different patterns of fish con-
sumption between the two countries. However,
individuals with comparatively higher levels of
Hg (i.e., volunteer number 8 from Khorezm) can
be found and our very little database does not al-
low drawing any conclusion on the general popu-
lation exposure.
Проблемы биогеохимии и геохимической экологии, 2012, №3 (20)
Table 3 – Mercury concentrations in fish muscles from Arnasay lake system (ALS) and Khorezm fish farm of Uzbekistan
Waterbody
Date of
sampling
Specimen
Sex
Body lenth,
cm (L)
Weight, G
Hg, mg/kg (ppm) dry weght
Repl.1
Repl.2
Repl.3
Mean
1. Eastern ALS
Sep.22,
2009
Common carp -Cyprinus
carpio L.
Juvenile and
female
24 and 36
840 and
1565
0,024
0,029
0,032
0,029
2. Lake Tuzkan
Sep.24,
2009
Pike-perch -Stizostedion lu-
cioperca L.
Juveniles
21, 24 and
27
300, 410
and 506
0,100
0,109
0,112
0,108
3. Lake Tuzkan
Sep.24,
2009
Aral shemaya - Chalcalbur-
nus chalcoides aralensis
(Berg)
Juveniles
18, 18,5 and
19
167, 171
and 180
0,117
0,143
0,154
0,138
4. Lake Tuzkan
Sep.24,
2009
Roach - Rutilus rutilus ara-
lensis Berg
Unknown
15, 17 and
17,5
125, 132
and 143
0,058
0,064
0,075
0,065
5. Lake Tuzkan
Sep.24,
2009
Vostrobryushka –
Hemiculter lucidus (Pub.)
Unknown
16, 18 and
19
96, 106 and
117
0,059
0,067
0,068
0,065
6. Fish farm
Khorezm
Oct.06,
2009
Silver carp - Hypophthal-
michthus
molitrix (Valenciennes)
Unknown
40, 41 and
43
480, 520
and 600
0,065
0,073
0,071
0,070
Проблемы биогеохимии и геохимической экологии, 2012, №3 (20)
Table 4 – Mercury concentrations in human hair in Khorezm region and Tashkent city of Uzbekistan
and Brugherio city of Italy
No.
Age
Sex
Hg, mg/kg (ppm)
Repl.1
Repl.2
Repl.3
Mean
Uzbekistan, Tashkent City
1.
34
F
0,440
0,365
0,356
0,387
2.
14
M
0,063
0,044
0,046
0,051
3.
34
F
0,055
0,064
0,067
0,062
4.
31
F
0,044
0,041
0,043
0,043
5.
50
M
0,151
0,150
0,157
0,152
6.
4
M
0,052
0,043
0,055
0,050
Tashkent, mean
0,124
Uzbekistan, Khorezm
7.
23
F
0,140
0,133
0,118
0,130
8.
50
M
0,761
0,658
0,613
0,678
9.
48
F
0,096
0,075
0,083
0,085
10.
56
M
0,056
0,050
0,056
0,054
11.
47
M
0,089
0,098
0,099
0,095
12.
65
F
0,018
0,020
0,026
0,022
13.
43
F
0,065
0,071
0,060
0,065
Khorezm, mean
0,161
Italy, Brugherio
14.
40
F
2,76
2,59
2,67
15.
25
M
1,26
1,46
1,36
16.
33
M
0,522
0,489
0,506
17.
69
M
3,16
3,68
3,42
18.
29
F
1,02
0,612
0,816
19.
28
F
0,491
0,467
0,480
20.
31
F
1,14
1,16
1,16
Italy, mean
1,49
In general, the present work did not high-
light serious mercury pollution problems, but it
must be considered as a seminal work to develop
more organized and larger studies. In particular,
similar investigations are needed in the most indu-
strialized regions of Uzbekistan and in other
neighboring Republics where large sources of
mercury pollution exist.
Table 5 – Examples of Hg levels in various fish species from other regions (values obtained from UNEP,
Schoeny, 2004)
Location
Fish species
Hg concentration, ppm
Thailand
5 marine fish species
0,05-0,7
Fiji
Canned tuna
0,01-0,97
Philippines
Tilapia
0,1-0,5
Australia
Redfin perch
0,12-1,3
UK
Swordfish
0,15-2,7
Shark
1,0-2,2
Sweden
Northern pike
0,1-2,0
USA
Large mouth bass
0,1-1,4
Проблемы биогеохимии и геохимической экологии, 2012, №3 (20)
LITERATURE
1 Bulimaga Constantin. Mercury estimate in
Republic of Moldova. Regional awareness-raising
workshop on mercury pollution, a global problem
that needs to be addressed. Kiev, Ukraine, 20 – 23
July 2004. – Kiev, 2004. – P. 68-70
2 Camusso M., Galassi S., Vignati, D.
Assessment of River Po sediment quality by
micropollutants analysis. – 2002. – V. 36, P.
2491–2504
3 Charles French. Measuring and monitor-
ing mercury levels in environmental media and
biota – Overview, UNEP Chemicals. Regional
awareness-raising workshop on mercury pollu-
tion, a global problem that needs to be addressed.
Kiev, Ukraine, 20 – 23 July 2004. – Kiev, 2004. –
P. 92-93
4 Environmental Management and Monitor-
ing Plan of the Samarkand and Bukhara Water
Supply Project. – Tashkent, 2001, P. 39-41
5 Ecological review of Uzbekistan 2008. –
UNDP Uzbekistan, 2008. P. 88-91
6 Hana Kuncova. Global NGOs mercury
strategy: Eliminating use, trade, release and asso-
ciated exposure. Regional awareness-raising
workshop on mercury pollution, a global problem
that needs to be addressed. Kiev, Ukraine, 20 – 23
july 2004. – Kiev, 2004. – P. 43-46
7 Rita Schoeny. Overview of exposures and
health effects of mercury for humans and wildlife.
Regional awareness-raising workshop on mercury
pollution, a global problem that needs to be ad-
dressed. Kiev, Ukraine, 20 – 23 July 2004. – Kiev,
2004. – P. 76-81
8 Vignati D. A. L., Burdino E., Congiu A.
M., Cicala F., Pardos M., Nieddu G. F., Ugazio G.
Screening of sediment quality in 24 tributaries of
the Po river Water, Air, Soil Pollut. 190. – Italy,
2008. – P. 129–141
9 Zulfia Suleimanova. Strategy of the Re-
public of Uzbekistan on the prevention of envi-
ronmental mercury pollution. Regional aware-
ness-raising workshop on mercury pollution, a
global problem that needs to be addressed. Kiev,
Ukraine, 20 – 23 July 2004. – Kiev, 2004. – P. 62-
63 Acknowledgements: The present study
was supported by 2009 research grant of the
Landau network-Centro Volta - Cariplo Founda-
tion (Italy).
АДАМНЫҢ СЫНАППЕН ЛАСТАНУ ДЕҢГЕЙІ ЖӘНЕ ӨЗБЕКСТАН
РЕСПУБЛИКАСЫНЫҢ СУ КОМПОНЕНТТЕРІНІҢ МОНИТОРИНГІ ЖӘНЕ
ЭКОТОКСИКОЛОГИЯЛЫҚ БАҒАЛАУЫ
Б.К. Каримов, М.Ф. Бекчанова, Дж. Тартари, Д. Вигнати
Сынап концентрациясы түп шөгінділерінде 4,0 – 26,4 мг/кг аралығында аутқыды, жоғары
концентрациялар Амударья өзенінің төменгі ағысымен салыстырғанда Арнайск көлдерінде(9,6–
26,4 және 4,0–21 мг/кг) байқалды. Сынап мөлшері балықтарда 28,7 – 137,7 мг/кг аралығында
ауытқыды, ал Ташкент және Хорезмск облыстарындағы адамдардың шашында 42,8 – 387
және 21,6 - 678 μг/кг, АҚШ бекіткен ЕРА мен БДС (1000 және 10000 мг/кг, сәйкесінше)
зияндылық шектеріне қарағанда төмен болып шықты.
МОНИТОРИНГ И ЭКОТОКСИКОЛОГИЧЕСКАЯ ОЦЕНКА
УРОВНЯ РТУТНОГО ЗАГРЯЗНЕНИЯ ЧЕЛОВЕКА И КОМПОНЕНТОВ
ВОДНЫХ ЭКОСИСТЕМ РЕСПУБЛИКИ УЗБЕКИСТАН
Б.К. Каримов, М.Ф. Бекчанова, Дж. Тартари, Д. Вигнати
Концентрации ртути в донных отложениях колебались в пределах 4,0 – 26,4 μг/кг, по-
вышенные концентрации наблюдались в Арнасайских озерах по сравнению с нижним течением
реки Амударьи (9,6–26,4 и 4,0–21 μг/кг). Содержание ртути в рыбе варьировало в пределах 28,7 –
137,7 μг/кг, а в человеческом волосе из г. Ташкента и Хорезмской области в пределах 42,8 – 387 и
21,6 - 678 μг/кг, которые оказались низкими, чем границы вредности, установленные ЕРА США и
ВОЗ (1000 и 10000 μг/кг, соответственно).
