الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Summary:-Non domestic birds are useful as bioindicators of environmental pollution because they are often at the top of food chain, ubiquitous, and many are abundant and common, making collecting possible. These birds have the advantage of being large, wide-ranging, long-lived, easily observed, and important to people. Many species are at the top of food chain where they bioaccumulate contaminants with age. Also, birds can be used as bioindicators in many ways, including contaminants level in tissues of affected birds, epidemiological field studies of effects, experimental and laboratory studies of dose and effects.<
This study was carried on cattle egrets which were collected from sharkia province to determine the level of pesticide residues in their tissues and eggs.
I- The organochlorine residues in tissues and eggs of cattle egrets:2. livers : Analysis of organochlorine residues in liver samples revealed that the mean concentrations of α-HCH, β-HCH, p,p’-DDE, dieldrin and endrin were 111.78, 33.99, 53.64, 63.71 and 756.25 ng/g wet weight, respectively. γ-HCH, p,p’-DDT, aldrin and heptachlor residues were not detected in any of examined liver samples, while o,p’-DDT and heptachlor epoxide were detected only in one liver sample with a concentrations of 35 and 192.5 ng/g wet weight, respectively. Regarding the Extraneous Maximum Residue Limits (EMRL) of organochlorine pesticides, our investigation revealed that 1 (14.3%) out of 7 examined liver samples had α-HCH over the permissible limits. Also 2 (28.6%) of examined samples had endrin above the permissible limits. While other detected organochlorine pesticides in liver tissues were within the permissible limits
2. Abdominal fats: The abdominal fat samples from investigated cattle egrets had α-HCH, β-HCH, o,p’-DDT, p,p’-DDE, endrin and heptachlor epoxide residues with amean values of 11.16, 74.55, 7.22, 8.69, 696.03 and 102.35 ng/g wet weight, respectively. While, γ-HCH, p,p’-DDT and heptachlor were detected only in one fat sample with a concentrations of 3.70, 21.85 and 67 ng/g wet weight, respectively. Other organochlorines (dieldrin and aldrin) could not be detected in all examined fat samples. Concerning EMRL of organochlorine pesticides, this study showed that 1 (14.3%) out of 7 examined fat samples had β -HCH over the permissible limits. Also 2 (28.6%) of examined samples had endrin above the permissible limits. While other detected organochlorine pesticides in fat tissues were within the permissible limits.3. Egg yolks: Organochlorines detected in egg yolk pooled samples of cattle egrets were α-HCH, β-HCH, γ-HCH, p,p’-DDE, dieldrin, heptachlor and heptachlor epoxide with amean values of 251.85, 281.29, 662.97, 138.97, 195.10, 438.92 and 588.31 ng/g wet weight, respectively. While, aldrin residue was detected in a very high concentration (2611 ng/g) but found only in one sample Study result revealed that 2 (40%) out of 5 examined egg yolk pooled samples had α-HCH, dieldrin and heptachlor residues over the permissible limits. Also 3 (60%) had γ-HCH, p,p’-DDE and heptachlor epoxide, 1 (20%) had aldrin and 4 (80%) had β-HCH with a limits exceeding the permissible limits.
By comparing the residue of organochlorines in tissues and egg yolks of cattle egrets, it was observed that the levels of all detected organochlorines in egg yolk samples are higher than those found in liver and abdominal fat tissues. It was also found that liver samples had a higher concentrations of α-HCH, o,p’-DDT, p,p’-DDE, dieldrin and heptachlor epoxide than those found in fat samples, while fat samples exceed the liver samples in the concentrations of β-HCH, p,p’-DDT and heptachlor residues.
II. The residue of pyrethroids in tissues and eggs of cattle egrets:
Estimation of the pyrethroidal residues in liver, abdominal fat and egg yolk samples of cattle egrets revealed that all analyzed pyrethroidal compounds (tetramethrin, cyhalothrin, permethrin and cypermethrin) were not detected in any of examined samples except the fenpropathrin compound that was detected in all types of samples with avariable concentrations. It was detected only in one liver sample with a concentration of 172.09 ng/g wet weight, while it was found in 3 samples of both of abdominal fat and egg yolk with a mean values of 25.34 and 320.22 ng/g wet weight, respectively. from these results we observed that egg yolk samples had the highest concentrations of fenpropathrin followed by liver sample and the lowest levels were in abdominal fat tissues. It was also observed that all detected levels of fenpropathrin were over the permissible limits in all examined samples.
The second part of this study was carried out to elucidate the toxic effect of the synthetic pyrethroid (fenpropathrin) on chromosomes of bone marrow cells and some biochemical parameters in serum of albino rats.
Thirty mature albino rats were divided into three groups each group contain 10 rats. The first and second group administered fenpropathrin orally at a dose of 150 LD50 (1.4 mg/kg b.wt.) and 1100 LD50 (0.7mg/kg b.wt.), respectively for 14 consecutive days. While the third group served as control.