الفهرس 
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Abstract
A total of 120 fish samples were collected from Bahr El Banat agricultural drainage, different fish farms and Al Rayaan Lake. The collected samples were represented by Clariasgariepinus from Bahr El Banat agricultural drainage, different fish farms (15 each), Mugilcephalus from different fish farms and Al Rayaan Lake (15 each), Soleasolea (30 samples) and Oreochromisniloticus from Bahr El Banat agricultural drainage, different fish farms and Al Rayaan Lake (10 each). They were analyzed for the presence of organochlorine pesticides in their muscles, 50g muscles were ground with l00 g of anhydrous sodium sulphate in presence of 150 ml of petroleum ether for two minutes, the extract was decanted through 500 ml funnel containing two Whattman filter papers. The extract was poured through column of anhydrous sodium sulphate and eluent was collected in 500 ml flask and placed in rotary evaporator to concentrate the extract. The pesticide residues were extracted from fat by using acetonitrile saturated with petroleum ether and clean up on florisil adsorbent. Clean up with 6, 15 and 50% diethylether in petroleum ether. The elute was concentrated then dissolved in 2 ml n-hexane before injection in gas chromatography apparatus (Agilent GC model 6890) equipped with an Ni63 electron capture detector for quantitative determination of organochlorine pesticides and declared that:
A-organochlorine pesticides residues in fish samples from Bahr El Banat:
The mean values of organochlorine pesticides residues in Oreochromisniloticus represented by methoxychlor 1.88±0.91 ppb.
P,p’-DDD found with mean concentration of 7.49±0.37 ppb followed by p,p’-DDE 1.69±0.56, while endrin present with a mean value of 5.73±0.18 ppb, dieldrin 0.112±0.112 ppb. Endosulfan recorded 0.528±0.18 ppb, γ-chlordane 1.032±0.35 ppb, aldrin 0.064±0.33 ppb and heptachlor epoxide 0.152±0.07 ppb.
Heptachlor was found with a mean value of 4±1.33 ppb, meanwhile δ-HCH recorded 13.03±6.52 while γ-HCH (lindane) was found with a mean value of 1.672±0.46 ppb, On the other hand p,p’-DDT and α-HCH were not detected in any of the examined Oreochromisniloticus samples from Bahr El Banat agricultural drainage.
Concerning Clariasgariepinussamples from Bahr El Banat methoxychlor found in with a mean value of 1.29±0.916 ppb, While, p,p’-DDD found in all examined samples with a mean value of 7.362±1.03, but the other metabolite p,p’ DDE found with a mean value of 2.6±0.54ppb, On the other hand p,p’-DDT was not detected in any of the analyzed samples.
Endrin recorded a mean value of 5.32±0.22 ppb. Meanwhiledieldrin recorded a mean value of 0.517±0.11 ppb and aldrin recorded 0.261±0.024 ppb, Endosulfan was detected mean value of 1.76±0.8 ppb, while heptachlor was found with a mean value of 3.33±0.213 ppb.
Heptachlor epoxide was detected with a mean value of 0.516±0.039 ppb, gamma chlordane with mean value of 164±0.232 ppb, But HCH isomers found 119.76±17.89, 1.35±0.33 and 0.24±0.09 ppb for δ, γ, and α isomer, respectively.
There were significant differences in the mean values of organochlorine pesticides residues between Oreochromis niloticusand Clarias gariepinus samples from Bahr El Banat at p≤0.05.
B-organochlorine pesticides residues in fish species from different fish farms:
The mean values of organochlorine pesticides residues in (Mugilcephalus) samples represented by methoxychlor with a mean value of 1.188±0.37 ppb. While, p,p’-DDT not detected at any of the analyzed samples, p,p-’DDD and p,p’-DDE found with mean values of 5.76±0.44 and 2.25±0.49 ppb, respectively.
Aldrin and dieldrin were found in a mean of 0.40±0.05 and 0.44±0.12 ppb, respectively. On the other aspect, endosulfan and γ-chlordane were detected with mean value of 0.65±0.12 and 1.36±0.18ppb respectively, while δ-HCH recorded 35.27±7.73 ppb followed by γ-HCH (lindane)1.38±0.3 ppb and finally the α-HCH with a mean of 0.054±0.037 ppb, respectively. Heptachlor epoxide found with mean value of 0.59±0.03 ppb, whereas heptachlor was detected with mean a value of 4.27±0.97ppb.
In concern of Oreochromisniloticus, methoxychlor was detected with a mean concentration of 1.72±0.59 ppb and p,p’-DDD recorded 8.39±2.77 ppb, On the other hand p,p’-DDT, p,p’-DDE, aldrin and all HCH isomers were undetected.
Endrin was detected with a mean value of 1.44±0.73 ppb and dieldrin with mean value of 0.184±0.12 ppb. During that, γ-chlordane and heptachlor epoxide recorded the mean values of 0.54±0.23 and 0.26±0.1 ppb, respectively. While endosulfan and heptachlor were detected with mean values of 1.3±0.87 and 1±0.67 ppb respectively.
Concerning Clariasgariepinus, methoxychlor was detected with a mean value of 0.25±0.05 ppb, p,p’-DDT found with a mean value of 0.29±0.05 ppb , while p,p’-DDD present with a mean value of 0.054±0.01 ppb, Endrin found with mean value of 0.0053±0.0053ppb and finally, heptachlor with a mean value of 0.026±0.01 ppb, On the other hand p,p’-DDE, dieldrin, endosulfan, γ-chlordane, aldrin, heptachlor epoxide and all HCH isomers(α, γ and δ) failed to be detected in the analyzed catfish samples from different farms.
There were significant differences between fish species from different farms in the mean values of most organochlorine pesticides at p≤0.05.
C-organochlorine pesticides residues in different fish species from Al Rayaan Lake:
Regarding Soleasolea, from Al Rayaan Lake, methoxychlor was detected with mean value of 11.07±7.61 ppb, At the same time p,p’-DDT, p,p’-DDD and p,p’-DDE were detected with mean values of 0.392±0.392, 2.98±0.58 and 4.65±0.218 ppb, respectively.
Endrin was found with a mean value of 7.53±0.25 ppb, Butendosulfan and γ-chlordane were detected in trace amounts of 0.196±0.095 and 0.079±0.04 ppb, respectively. Simultaneously, aldrin and dieldrin were detected with mean values of 0.638±0.067 and 0.542±0.12 ppb, respectively. Heptachlor epoxide found in lower mean value than heptachlor: 0.723±0.038 versus 1.944±0.47 ppb. during that δ-HCH recorded a mean value of 193.86±33.79 ppb, followed by α-isomer with mean value of 1.63±0.26 ppb and at last γ-HCH (lindane) with mean value of 1.24±0.41ppb.
Concerning Mugilcephalus, methoxychlor was detected with a mean value of 0.26±0.06 ppb, while the mean value of p,p’-DDT was 0.21±0.04 ppb, but p,p-DDD and p,p’-DDE were detected with mean value of 0.026±0.021 and 0.01±0.007 ppb, respectively. Endrin was detected with mean value of 0.02±0.01 ppb, aldrin was detected in a mean value 0.0053±0.005 ppb, During that heptachlor was found with mean value of 0.053±0.01 ppb while heptachlor epoxide was detected with a mean value of 0.02±0.01 ppb. At the same time dieldrin, endosulfan, γ-chlordane and α-HCH failed to be detected in any of the tested Mugilcephalus samples from Al Rayaan Lake.
Considering Oreochromisniloticus, methoxychlor was detected with a mean value of 0.768±0.39 ppb, while p,p’-DDT was detected mean with a value 0.064±0.044 ppb, At the same time p,p’-DDD and p,p’-DDE were detected in mean values of 3.65±0.99 and 2.29±0.66 ppb, respectively.
Endrin, dieldrin and aldrin were predominated by endrin 2.8±0.76, followed by dieldrin 0.528±0.14 and at last aldrin 0.28±0.07 ppb. During that endosulfan was found in a mean value of 0.08±0.039 ppb, while γ-chlordane was 0.32±0.08 ppb, while heptachlor and its epoxide form recorded 1.2±0.48 and 0.392±0.107 ppb, respectively. During that δ-HCH found in a mean value of 9.77±2.39 ppb, followed by γ-HCH (lindane) with mean value of 0.888±0.45 ppb and at last. α-HCH with mean value of 0.176±0.07 ppb.
Significant differences in levels of most analyzed organochlorine pesticides were found between fish species from Al Rayaan Lake at p≤0.05.
Among all fish species from different water sources from El Fayoum Governorate only 20% of Soleasoleafrom Al Rayaan Lakeexceeded the MRL of δ-HCH.
Public health hazards of organochlorine pesticides residues in fish was discussed and recommendations to minimize these residues in fish were done.