Công nghệ xử lý rác MBT - CD.08 (Mechanic Bio Treatment)

BIOMARKERS AS INDICATOR FOR WATER
POLLUTION
WITH HEAVY METALS IN RIVERS, SEAS AND
OCEANS
M.NAGEEB
RASHED
Faculty of Science, 81528 Aswan, South Valley University,
Egypt
E-mail m n r a s h e d @h o t m a il. co m Fax 002 097 480
449
Water is one of our most important natural resources, and there are many conflicting
demands upon it. Skilful management of our water bodies is required if they are to be
used for such diverse purpose as domestic and industrial supply, crop irrigation,
transport, recreation , sport and commercial fisheries, power generation and waste
disposal. Water pollution is most commonly associated with the discharge of effluents
from sewers or sewage treatment plants, drains and factories to the water body of rivers,
seas and marines. In the attempt to define and measure the presence and effects of
pollutants epically the metals in rivers and oceans, the biological markers have attracted
a great deal of interest. The principle behind the biomarker approach is the analysis of
an organism metal content and compared the metal concentration with the background
metal levels. In this review, the data were collected from different literatures around the
world in using the aquatic organisms as biological indicator for metal pollution in
aquatic system.
INTRODUCATION
Water Pollution with metals
The aquatic environment with its water quality is considered the main factor controlling
the state of health and disease in both man and animal. Nowadays, the increasing use of
the waste chemical and agricultural drainage systems represents the most dangerous
chemical pollution. The most important heavy metals from the point of view of water
pollution are Zn, Cu, Pb, Cd, Hg, Ni and Cr. Some of these metals (e.g. Cu, Ni, Cr and
Zn) are essential trace metals to living organisms, but become toxic at higher

concentrations. Others, such as Pb and Cd have no known biological function but are
toxic elements.
Source of pollution with metals
Metals have many sources from which they can flow into the water body, these sources
are:
I Natural Sources: Metals are found throughout the earth, in rocks, soil and introduce
into the water body through natural processes, weathering and erosion.
II Industrial Sources: Industrial processes, particularly those concerned with the
mining and processing of metal ores, the finishing and plating of metals and the
manufacture of metal objects. Metallic compounds which are widely used in other
industries as pigments in paint and dye manufacture; in the manufacture of leather,
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rubber, textiles , paint, paper and chromium factories which are built close to water
for shipping.
III Domestic Wastewater: Domestic wastewater contains substantial quantities of
metals. The prevalence of heavy metals in domestic formulations, such as cosmetic
or cleansing agents, is frequently overlooked.
IV Agricultural Sources: Agricultural discharge contains residual of pesticides and
fertilizers which contains metals.
V Mine runoff and solid waste disposal areas.
VI Atmospheric pollution: Acid rains containing trace metals as well as SPM input to
the water body will cause the pollution of water with metals.
Biological markers (biomarkers or bioindicators)
In the attempt to define and measure the effects and presence of pollutants on aquatic
system, biomarkers have attracted a great deal of interest. The principle behind the
biomarker approach is the analysis of an organism to their metal contents in order to
monitor the metal excess in their tissues. Various aquatic organisms occur in rivers,
lakes, seas and marines potentially useful as biomarkers of metal pollutants, including
fish, shellfish, oyster, mussels, clams, aquatic animals and aquatic plants and algae.
FISH AS BIOMARKER

Fish have been used for many years to indicate whether water are clean or polluted. Fish
are excellent biological markers of metals in water.
Fish from Lakes: Nasser Lake
Tilapia nilotica is one of the aquatic organisms affected by heavy metals, so in many
cases, Tilapia nilotica was used as metal biological marker in toxicological studies in
which it was substantiated with the highest sensitivity to toxic effect (Patin, 1984).
Rashed (2001a, b) studied Co, Cr, Cu, Fe, Mn, Ni, Sr, Pb, Cd and Zn in different tissues
of fish (Tilapia nilotica) from Nasser lake to assess both the water pollution with these
metals and the lethal level of these metals in fish. Fish samples were collected from two
Kohrs in Nasser Lake ( Kohr Kalabsha and Kohr El-Ramel) .The fish tissues includes
muscle, gill, stomach, intestine , liver, veritable column and scales .The fish ages were 1,
1.5 , 2, 2.5 and 3 years. This study resulted in that fish scales exhibited the highest
concentrations of Cd, Pb, Co,Cr,Ni and Sr (0.088,0.95,0.29,0.30,0.25 and 3.21 µg/g DW
respectively). Whole fish contains the higher concentrations of the studied metals
compared to the previous study by Awadallah et al.(1985) in the same fish from Nasser
Lake, and this mean the increase in metal pollution in Lake water as the results of man
activities (Table 1). This increasing in metal concentration was as the result of increasing
pollution loads to the Lake from agricultural wastes, which include chemical pesticide
and fertilizers. These agricultural wastes reached the Lake body from the agricultural
farms on the beach of the Lake. The source of Pb in the Lake water and fish was resulted
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from gasoline contains Pb from the fishery boats and tour ships travels from Aswan to
Sudan (Mohamed et al.1990).
Table 1. Metal concentrations in Tilapia nilotica and water from Nasser Lake in years
1980 to 2000
Metals Lake Water (µg//l)
1985* 2000***
Fish (µg/g)
1985** 2000***
Difference

Water Fish
(µg//l) (µg/g)
Cd
Co
Cr
Cu
Fe
Pb
12
142
167
189
75
0.001
10
185
240
220
142
0.005
ND
0.095
0.082
0.099
0.104
0.095
0.034
0.25
0.29
0.27

6.45
0.33
2 --
43 0.155
73 0.108
11 0.171
67 6.35
0.004 0.235
* Sherief et al. (1980) ** Awadallah et al. (1985) *** Rashed (
2001a,b)
Lake Mariut and Lake Edku
Adham et al. (1999) used fish as bioindicator for assessing metal pollution in Delta
Lakes (Lake Maryut and Lake Edku ). Lake Edku is grouped 25 the site highest in metal
concentrations. Compared to Lakes Maryut and Edku, the Nile water displayed lower
levels of metal contamination. Lillo (1976) reported that bolti from Mariut Lake
contained less Fe content compared to Nile bolti fish and concluded that the source was
from the factories discharge. El- Nabwi et al. (1987) studied the concentration of Pb in
fish, Tilapia nilotica, from Maryut Lake and found that Pb concentration was 0.42 ppm.
Fish from River Nile
River Nile is the main source for potable water and as the result of man activities in and
on the river body it become loaded by metal pollution. Fish in the River Nile was used as
biological marker for the River pollution by metals . Mohamed et al. (1990 ) used
Tilapia nilotica fish as a biomarker for the Nile water pollution with metals at the
discharge. Point of fertilizer factory with the Nile. Ag,Au,Ca, Cr,Cu,
Fe,K,Mg,Mn,Na,Ni,Pb,Sr and Zn were determined in tilapia nilotica fish collected from
the Nile area at the point of fertilizer discharge to the Nile and south and north this
point. The results revealed that fish near the point of the factory discharge possess the
highest levels of metals as the result of pollution with metals.
Other study for using fish as biomarker for water pollution with metals was
conducted (Khallaf et al., 1994). Two species of fresh water fish (Tilapia nilotica ,named

Bolti, and Karmout ) caught from River Nile at Hawamdia and Kafer El-Zayat , at North
Egypt and also from governmental fish farms (Abbassa and Barseik) were used to detect
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the presence of industrial wastes especially heavy metals as environmental pollution in
the river track and its accumulation in edible fish tissues. The result reveals that heavy
metals in different water samples except Cu and Zn were more than the recommended
permissible levels (Table2). Iron level in Hawamdia and Kafer-El-Zayat tilapia nilotica
samples (63.4 and 54.7 µg/g respectively) was more than its permissible levels, these
may be due to the discharge of the adjacent chemical factories that used Fe in their
processing. Karmout fish from the same locations ( Kafer El-Zayat and Hawamdia ) had
lower concentration of Cu,Zn,Ni,Cd and Pb than bolti, while Fe present in higher
concentration in bolti than in Karmout.
Comparing the fish metals from Abbassa and Barseik fish farms, where no
pollution, with the same fish spices from Hawamdia and Kafer-El-Zayat river Nile, it
seems that fish of farms exhibit lower concentration of Cu,Ni,Zn,Fe and Co than those
from River Nile. This indicates that the fish especially Bolti was highly
responsible for metal pollution.
Table 2. Heavy metal concentrations in different samples of water (mg/l) and fish (µg/g)
from the River Nile and fish farms (Khallaf et al.,
1994)
Sites/ spices Cu Zn Ni Cd Fe Pb
Hawamdia (Nile)
Water
Bolti
Karmout
0.26
2.49
2.10
0.13
5.08

2.09
0.04
3.38
2.69
0.03
0.05
0.14
0.22
54.7
4.90
3.43
0.047
0.17
Kafer-El-
Zayat(Nile)
Water
Bolti
Karmout
0.16
0.87
1.13
0.15
3.80
1.32
0.16
4.04
0.92
0.07
0.12
0.13

0.36
63.9
8.80
2.89
0.05
0.25
Abbassa (Farm)
Water
Bolti
Karmout
0.16
0.87
1.13
0.15
0.39
1.17
0.07
1.04
ND
0.01
0.03
0.02
0.25
10.4
ND
1.9
0.046
0.18
Barseik (Farm)
Water

Bolti
Karmout
0.24
0.34
0.61
0.12
1.79
0.46
0.13
2.35
4.20
0.06
0.06
0.13
0.27
5.90
4.30
3.81
0.048
0.20
Permissible level*
Water
Fish
1
20
5
40
0.01
10
0.01

0.5
0.3
30
0.1
2
* Permissible level as recommended by Egyptian Organization for Standardization
(1993)
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Fish as Metal Biomarker for Water Pollution in Worldwide
Arsenic as biomarker for water pollution was assessed by Takatsu and Uchiumi (1998)
in which the contents of the metal in the tissues of the fish, Tribolodon hakonsis , from
Lake Usoriko, located in Aomori Prefecture, Japan, were examined . It was discovered
that large amounts of As were accumulated in the eye tissues. This might be partly
related to the fact that the lake water contains a relatively large amount of As. Mercury
levels in muscle of some fish species from Dique channel, Colombia was measured to
assess the water pollution with Hg (Olivero et al.1997). The highest values of Hg (105
µg/kg) found in fish from the Dique channel were lower than those found in fish species
from the Lower Gallego and Cince Rivers in Spain (Raldua and Pedrocchi, 1996). In the
Tapajos River, an Amazon water body highly exploited by gold mining activities, the
average value for Hg in muscle of Carnivorous fish was 690 µg/kg, almost ten times
higher than those found in the Dique channel (Malm et al., 1995). They also concluded
that, however the highest Hg concentration did not reach the limits level internationally
accepted for considering a fish not acceptable for human consumption (WHO, 1990).
Kalfakakon and Akrida-Demertai (2000) reported that Ca,Mg,Fe,Cu,Zn and Pb
exhibited bio-accumulation from water to fish. They demonstrate that metal
concentrations in fish are higher than in water, which indicates the bio-accumulation.
They study on the transfer of Cd,Pb,Cu and Zn through the trophic chain of Ioannina
Lake (Pamvotis,Greece) ecosystem and investigate the environmental pollution from
heavy metals on the trophic chain of the lake. The concentration of Fe,Zn,Cu and Pb
were measured in water, aquatic plants , fish and lake organisms .Aquatic plants show a

gradual increase in their concentration in relation to the water and fish ( Table 3 )
Table 3. Heavy metal concentrations in water, aquatic plants, fish and organisms from
Ioannina Lake
Items/
Metal conc.
Fe Zn Cu Pb
Water (mg/l)
Aquatic plant
(µg/g)
Fish
(µg/g)
Organisms
(µg/g)
6.1
8.0
0.61
0.40
0.0
ND*
0.63
0.58
0.01
ND
41
25
0.2
ND
3.0
2.13
*ND, Not

detected
AQUATIC PLANTS
Aquatic plants in relation to their ability to sequester heavy metals have received
extensive interest. This interest has focused primarily on aquatic plants as biomarkers of
heavy metal pollution. Aquatic plants provide a viable alternative for metals remediation
if proper disposal of spent plants can be employed (Jackson et al., 1994).
Aquatic plants from River Nile
Ali and Soltan (1999) used free-floating (Eichhornia crassipes), non-rooted-submerged
(Ceratophyllum demersum ) and rooted-submerged (Potamogeton crispus) aquatic plants