On the hazards of pesticide use and misuse in Khartoum state and some histopathological studies on the effects of carbamate insectici des on experimental a nimals. [MICROFICHE] .

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Research type: Research Paper

Authors: Abd Rabou, Abdel Fattah Nazmi H.

Abstract: In this study, the hazards of pesticide use and misuse in Khartoum State were investigated. However, some histopathological studies concerning carbaryl and carbofuran were also searched. Eleven agricultural areas in Khartoum were selected randomly and a total of 115 farmers, were interviewed to carry out this study. Crops have been infested by different types of pests and as a result, a wide range of pesticides hve been used by farmers (95 percent). Although illiteracy was 35 percent among Khartoum farmers, the majority got pesticides from markets in stead of legal centres and only few (9 percent) who read labels on products to follow such precaution measures for pesticide application. They showed poor care to the time and frequency of pesticide application as well as to dose determination. Moreover, the majority of farmers (90 percent) applied perticides by using sprayers while the test used primitive and unsafe methods such as brooms or sacks immersed into buckets containing pesticides, but of whom using sprayers, the majority didn't wash them after application which may lead to corrosion and clogging and even leaks due to residual pesticides. Protective clothing whixh often prevent conamination were highly ignored where 61 percent did not care about them and 26 percent banded their mouths and noses by their turbans. The fate of empty pesticide containers was disregardful where only 16 percent disposed of them as recommended by burning and / or burial, 61 percent threw them elsewhere, 14 percent retained them for domestic use and 9 percent stored them for later disposal. Wind direction was also ignored and the extension services were inadequate. Although 94 percent of farmers recognized pesticide hazards, only 31 peercent were suffering from many diseases or permanent symptoms which could be associated to pesticide application. Occupational and incidental victims in human being due to pesticides were evident besides other hazards to domestic animals and non-targt species were recorded. On the other hand, single acute and subacute doses of 1/1000, 1/100 and 1/10 of the LD50of the two carbamate insecticides, carbary and carbofuran were prepared and administered intraperitoneally to albino mice. Also, a diet containing carbofuran only was introduced to albino rats. Animals of acute dosed were autopsied soon after treatment. The liver, kidney, stomach, intestine and spleenwere taken and prepared histologically for subsequent histopathological studies concerning the two insecticides in question. the clinical signs were dose-dependnt and increased with acute doses. Mice showed decreased activity, solitary behaviour, ataxia, hindlimb incoordination developed later to paralysis, severe muscular tremors and convulsion, dyspnoea and finally death occurred within about 5-8 minites of dosing, while in orally treated rats it occurred mostly within 30 minutes or more. Histopathologically, the results of this study suggest that carbaryl and carbofuran affect severaltissues including the digestive tract, liver, kidney, and spleen. Although lymphocytic infiltration, blood congestion and hemorrhage were seen in most tissues. Other significant lesions wer also seen in the given orangs. The liver showed fatty change (steatosis), necrosis and hypertrophy in hepatic cells and their nuclei, hepatic cord disarray, congestion and distention of sinusoidl spaces and amyloid-like structures. The kidney showed tublas. Furthermore, shock kidney was evident in some sections. The intestinal lesions represented by necrosis and proliferation of the epithelial cells lining the villi which as a result became shorter and thicker. Edema, widening of muscularis and submucosa as wellas rupture of the internal mucosal tissues of the stomach were recorded. Ultimately, the spleen showed necrosis, unclear fibrous structures in addition to the presence of macrophages which appeared as large cells. In conclusion, the government and the public role regarding preventive measures inaddition to more related studies and researches were propesed. (115 ref.) .