الفهرس 
ACKNOWLEDGMENTOnly 14 pages are availabe for public view
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Abstract
In Egypt the main reason for water pollution is industrial effluents, chemical
processes, agricultural and sewage wastes. This is because the factories,
manufacturers and farmers are throwing industrial, agricultural and animal wastes
into streams and River Nile that lead to environmental and health problems. For
instance, chemical fertilizers cause to increase the amount of nutrient in the water
that provide suitable environment to grow algae in water. This contributes to
diminish the quantity of oxygen in the water, which lead to death of aquaculture
animals. However, water pollution will leads to contamination of soil which cause
problems that related to human health and fish (Abeera, 2013).
The present study was performed to estimate some heavy metals pollutants
(lead, Cadmium and Aluminium) in water and Tilapia nilotica muscles and gills
from Sohag governorate – Egypt. 30 water samples, 60 muscles and 60 gills
samples of Tilapia nilotica (Oreochromis niloticus) were collected from 6 districts
in Sohag Governorate (summer, 2011) (DarEl-salam, Gerga1, Gerga2, Akhmim,
Maraga and Tahta) which located on River Nile, Upper Egypt. Fish samples
average weight 200-500 gm .
Collected samples were examined organoleptically then analyzed for the
content of the mentioned heavy metals using Atomic Absorption Spectrometer
(AAS) Graphite tube/Wall Technique.
The obtained results revealed that the mean levels of lead in the examined
water samples from Maraga, Tahta, Akhmim, Gerga2, Gerga1and Dar El-salam
districts were 0.065±0.02, 0.084±0.05, 0.112±0.05, 0.586±0.471, 0.872±0.345,
1.48±0.495 ppm, respectively.
The mean levels of lead in the examined muscle samples from Maraga ,Tahta,
Akhmim, Gerga2, Gerga1 and Dar El-salam districts were 0.568±0.3, 1.092±0.79,
7.148±3.9, 17.55±6.71, 18.26±4.03, 23.71±4.58 ppm, respectively. The mean levels of lead in the examined gills samples from Maraga ,Tahta,
Akhmim, Gerga2, Gerga1 and Dar El-salam districts were 1.245±0.575 ,
1.604±1.49 , 17.764±14.79 , 18.209±2.52 , 21.847±2.858 and 26.322±13.11
ppm, respectively.
For cadmium the obtained results revealed that the mean level of cadmium in
the examined water samples from Dar El-salam district was 0.213±0.037 ppm. The
mean level of Cd in Gerga1 was 0.003±0.0005 ppm. While in Gerga2, Akhmim,
Maraga and Tahta Cd levels not detected.
The mean levels of Cd in the examined muscle samples from DarEl-salam
district was 0.139±0.015 ppm. The mean level of Cd in Gerga1 was 0.014±0.015
ppm. While in Gerga2, Akhmim , Maraga and Tahta Cd levels not detected.
The mean levels of Cd in the examined gill samples from Akhmim, Gerga2,
Gerga1 and Dar El-salam districts were 0.176±0.029, 0.194±0.3, 1.811±2.63,
2.158±3.14 ppm respectively. While in Gerga2 and Akhmim Cd levels in the
examined gills not detected.
For Aluminium the obtained results revealed that the mean level of Al in the
examined water samples from Maraga , Akhmim, Tahta, Gerga2, Gerga1 and
Dar El-salam districts were 0.0001±0.00001, 0.0004±0.0001, 0.0007±0.00009,
0.054±0.007, 0.056±0.017 and 0.089±0.015 ppm respectively.
The mean levels of Al in the examined muscle samples from Maraga, Tahta,
Akhmim, Gerga2, Gerga1 and DarEl-salam were 0.055±0.030, 0.058±0.059,
0.070±0.056, 0.080±0.044, 0.108±0.157, 0.262±0.162 ppm respectively.
The mean levels of Al in the examined gills samples from Maraga, Tahta,
Akhmim, Gerga2, Gerga1 and DarEl-salam districts were 0.058±0.025,
0.071±0.050, 0.173±0.118, 0.255±0.221, 0.283±0.208 and 0.291±0.213 ppm
respectively. The results of water samples indicated that that Pb concentrations in
DarElsalam, Gerga1 and Gerga2 were higher than the maximum Egyptian
recommended limit for Pb (0.1 ppm) in water (EOSQC, 1993) and exceeded the
limits set by FAO/WHO (1985/1992) (0.5 ppm). Only in Akhmim Pb levels were
higher than the maximum Egyptian recommended limit for Pb (0.1 ppm) in water
(EOSQC, 1993). The levels of Pb obtained in our study from Maraga and Tahta
districts were the lowest among the 6 districts and below permissible limits.
For Cd the results of water samples in DarElsalam was higher than the
maximum Egyptian recommended limit for Cd (0.1 ppm) in water (EOSQC, 1993)
and exceeded the limits set by FAO/WHO (1985/1992) (0.05 ppm). The levels of
Cd obtained in our study from Gerga1 district were below the permissible limits.
For Al the results of water samples in all studied districts were below the
maximum WHO (1992) (0.2 ppm) in water. The levels of Al obtained in our study
from Dar El-salam district was the highest among the 6 districts and below the
permissible limits.
The results of muscles samples indicated that Pb concentrations in all districts
were higher than the maximum Egyptian recommended limit for Pb (0.1 ppm) in
muscle (EOSQC, 1993) and exceeded the limits set by FAO/WHO (1985/1992)
(0.5 ppm).
For Cd the results of muscles samples in Dar Elsalam was higher than the
maximum Egyptian recommended limit for Cd (0.1 ppm) in muscle (EOSQC,
1993) and exceeded the limits set by FAO/WHO (1985/1992) (0.05 ppm).The
levels of Cd obtained in our study from Gerga1 district were below the permissible
limits.
For Al the results of muscles samples in Dar El-salam district were higher than
the maximum WHO (1992) (0.2 ppm) in muscle, while in other districts were
below the permissible limits.
The results of gills samples indicated that Pb concentrations in all districts
were higher than the maximum Egyptian recommended limit for Pb (0.1 ppm) in
gills (EOSQC, 1993) and exceeded the limits set by FAO/WHO (1985/1992) (0.5
ppm).
For Cd the results of gills samples in Dar Elsalam, Gerga1, Gerga2 and
Akhmim were higher than the maximum Egyptian recommended limit for Cd (0.1
ppm) in gills (EOSQC, 1993) and exceeded the limits set by FAO/WHO
(1985/1992) (0.05 ppm).
For Al the results of gills samples in DarEl-salam, Gerga1 and Gerga2
districts were higher than the maximum WHO (1992) (0.2 ppm) in gills, while in
Akhmim, Maraga and Tahta were below the permissible limits.
Comparing our result with the permissible limit of EOSQC, 1993 in water samples,
muscles and gills samples of T.nilotica fish, for each one of the estimated metals (77
and 17) , (90 and 17) and (95 and 27)% of the examined samples exceeded the
permissible limits for Pb and Cd respectively. While comparing with permissible limit
of FAO/WHO, 1985 and1992, (40 , 17 and 0) , (85 , 32 and 12) and (91.7 , 27 and
32)% of the examined samples exceeded the permissible limits for Pb , Cd and Al
respectively.
The sources of environmental contamination as well as the public health
significance of the estimated heavy metals were discussed.