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Abstract
Summary
Fertilizers have been widely and increasingly produced to improve soil and feed livestock and consequently increase food production needed for outstripping population growth. Unfortunately, during manufacturing of phosphate fertilizers, some toxic substances are released into the environment or traces of them are being contained by the fertilizers themselves. Cadmium and fluoride are among the toxic substances released from phosphate fertilizers’ factories have significant importance.
In the present study, blood and tissue samples were taken from goats reared in the vicinity of Mangabad Super phosphate factory to evaluate the toxopathological and biochemical alterations induced by the factory emissions. Chemical analysis revealed significant increase in the levels of cadmium and fluoride in the blood and different tissue samples. Cadmium was found significantly higher in the blood, liver, kidneys, lungs, heart and spleen while fluoride levels were only significantly increased in liver, bone and heart compared to controls. Goats exposed to the factory emissions showed significant increase in the levels of AST and ALT and urea indicating liver and kidney damage, respectively.
Histopathological examination showed clear implication of blood vasculature through the body. In this context, it was found blood vessel degeneration, perivascular edema, thrombosis and hemorrhages in different body systems. Vascular damage is considered one of the important mechanisms mediating cadmium toxicity, most hazardous element released during manufacturing of phosphate fertilizers. It could result in increase vascular permeability leading to edema seen in different tissues, initiate thrombosis which consequently caused ischemic changes. The latter perhaps mediated degenerative and necrotic changes in the parenchymatous organs.
Most pounced histopathological findings in the liver were vacuolar and fatty degeneration, necrobiotic changes, activation of Kupffer cells and fibrocytic changes. Acivation of Kupffer cells might be playing a major role in the mechanism of cadmium induced hepatotoxicity through releasing some proinflammatory cytokines within the liver. In the Kidney, there were glomerular swelling, periglomerular fibrosis, necrobiotic changes of renal tubular epithelium and fibroblastic changes in the interstitium. Glomerulo- and interstitial nephritis perhaps resulted from immune reaction against cadmium-metallothionein bound complexes. Major pulmonary lesions constituted of alveolar emphysema, bronchiolitis and interstitial pneumonia. Cardiac lesions formed of degeneration and necrosis of myocardial fibers, myocardiolysis and perivascular and interstitial fibrosis. Periosteal thickening, enlargment of bone trabiculae and narrowing of bone cavities were seen in some of exposed-goats. Brain sections showed neuronal degeneration and necrosis, microglial reaction and demyelination. Skin of some exposed-goats showed epidermal atrophy and hyperkeratosis, partial to complete loss of the epithelial sheath of hair follicle or complete loss of hair follicles in the dermis, cystic dilatation of sweet glands, myxedema and eosinophilic infiltration in the dermis. In spleen, there were some evidence of lymphocytic exhaustion, thickening of follicular artery and hemosiderosis. Testicular epithelium appeared degenerated in some cases and atrophied in others.
Thus, the present study can conclude that the environmental pollution due to cadmium and fluorine emission from Mangbad super phosphate factory produces adverse pathological effects on goats reared in the area around the factory. These pathological alterations are partially mediated by damage of vasculature resulting in thrombosis and ischemia.