الفهرس 
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Abstract
The problems and risks of intensive and misuse of pesticides need to offer a suitable system for hazard assessment of such chemicals under local conditions. Since these systems widely used now as a basic requirement for take the decisions regarding to prevent adverse effects against health and environment. So, the aim of the present study is to propose a hazard evaluation model which can be used as a tool for management handling and use of pesticides. To get the required data for establishing the model, serial of experiments were designed and carried out for two insecticides, i.e. chlorpyrifos as a chemical conventional insecticide and abamectin as a novel insecticide. The experiments included the following: br - Determination of toxicity data (LD50, LOEL and NOEL) against rats and test biochemical and histopathological effects of the two tested insecticides against rats. br - Assessment the phytotoxic effects of the two tested pesticides against Vicia faba . br - Genotoxicity assessment of the two tested insecticides against insect model (Drosophilla sp), mammalian model, (Experimental rats) and plant model (allium cepa). br - Toxicity measurement of the two tested insecticides against non-target organisms honey bees (Adult Apis melifra) and hymenopteran egg parasitoid (Trichogramma sp). br - Studying the environmental fate of the two tested insecticides on (plants leaves surfaces) and in (water and bacteria Pseudomonas fluorescence liquid media). br - Suggestion of simple hazard evaluation model for the two tested insecticides based on the obtained results. br The obtained results can be summarized as follows: br 1- Determination of toxicity data against rats (LD50 LOEL and NOEL) and test biochemical and histopathological effects of the two tested insecticides against rats br Toxicity results showed that the acute and sub-chronic risks of chlorpyrifos cause higher adverse effects against rats than abamectin. Histopathological effects on specific organs of Sprague Dawlly rats (liver and kidney) indicated the same trend. While the effect of abamectin on the brain and testes had a highly significant interaction among time and dose. Data concerning the effect on the selected biochemical parameters in relation to liver function (AST, ALT); kidney function (creatinine), and AChE activity indicated generally that chlorpyrifos was more toxic than abamectin. br 2- Assessment the phytotoxic effects of the two tested insecticides against Vicia faba . br Results of laboratory and semi-field bioassays showed that chloropyrophos had highly phytotoxic effects at most dose rates. The increasing of used dose leading to seed inhibition, plant vegetative reduction into shoot weight, tall, leaves area, necrosis and plant constituents as total. In the contrary results indicate that abamectin did not had any phytotoxicity effect Vicia faba plants. br 3- Genotoxicity assessment of the tested pesticides against insect model (Drosophilla sp), mammalian model, (Experimental rats) and plant model (allium cepa). br Results of genetic risk assessment showed that abamectin was not cytotoxic but chlorpyrifos at 2LOEL and LC50 concentration was cytotoxic. Comparing the number of cell/1000 with the negative control using the Mann-Whitney test showed that chlorpyrifos and abamectin were genotoxic (P,-lt;0.05) induced chromosomal aberrations.On the other hand chlorpyrifos cause a higher adverse mutagenic effects against drosophila than abamectin. Moreover, in Sprague Dawlly bone marrow a significant (P -lt; 0.01) effect of durations on induction of MN was observed for all the concentrations of chlorpyrifos more than abamectin in general. br 4- Toxicity measurement of the tested pestiades against non-target organisms honey bees (Adult Apis melifra) and hymenopteran egg parasitoid (Trichogramma sp). br Results on honey bees (Apis melifera) showed that abamectin had higher toxic effect than chloropyrophos. In the contrary the lower of (LOEL) of chloropyrophos indicated that sublethal doses of such insecticide expected to be cause higher adverse effects against honey bees than abamectin. Considering the toxicity against Trichogramma spp data of laboratory and field tests showed adverse effects were increased gradually with increasing the exposed dose. Data of initial toxicity showed that chlorpyrifos is more toxic at most dose rates level to Trichogramma spp. than abamectin. br 5- Studying the environmental fate on (plants leaves surfaces) and in (water and bacteria Pseudomonas sp. liquid media). br The obtained data indicated rapid dissipation of abamectin than chlorpyrifos residues. The half life periods were 0.631 and 2.198 days, after spray on treated leaves of Vicia faba; 1.51 and 6.11 in water and 1 and 4.95 days in liquid culture of Pseudomonas fluorescence bacteria and, respectively. Index values (LD50 Index plant, LD50 Index pseudomonas fluorescence and LD50 Index water) were 28.70, 51.2 and 15.68 %, respectively. Values support the conclusion that abamectin is more degradable than chloropyriphos . br 6- Suggestion of simple hazard evaluation model of the two tested by using the extracted obtained results of a serious experiments. br Hazard evaluation model was suggested. The hazard evaluation model was established depending on Score System Index (SSI) values of acute LC50, LD50, IC50, EC50, DT50 and chronic LOEL, Hazard Index (HI) and Risk quotient (RQ) (HI) and acute RQ LC50 and chronic RQ LOEL had been carried out for scoring range of non-target organism’s adverse effects and pesticides persistence. The (SSI) building on 50% of scores for pest and 50% for non- target organisms to achieve the environmental balance. The 50% which belong non target pests divided into ten parameters with 1-5 scores. The total scores of each insecticide used to classify hazard in five categories. Considering the obtained data of the previous assessments for the two tested insecticides, the recorded scores showed that abamectin (SSI) =13/50 in second category (low hazard) while chlorpyrifos (SSI) =25/50 in third category (Moderately hazard).