Effects of diazinon on blood parameters and histology of organs on fish

The organophosphate insecticide diazinon is used worldwide to control pests, accumulates in aquatic ecosystems, and exerts toxic effects on aquatic animals. This study aims to compile the findings from previous studies on the pesticide's effect on biochemical parameters and histopathological changes in fish to better understand what the pesticide's effect is and the real risks of diazinon. During the diazinon exposure trial, fish showed various behavioral changes such as restlessness, sudden and rapid movements, loss of balance, increased operculum activities, and paralysis. In addition, fish exposed to diazinon cause darkening of the body color and more mucus production on the body surface. Chronic exposure to lethal concentrations of diazinon causes significant hematological and biochemical changes. Biochemical blood plasma profile studies show that diazinon has a pronounced neurotoxic effect in fish. On the other hand, diazinon causes changes in both erythrocyte and leukocyte profile values. It raises the glucose levels in the plasma and brings about significant changes in the value of electrolytes in the blood. Exposure to non-lethal diazinon concentrations causes a change in normal enzyme values indicating cell damage. Histological changes are observed in vital organs such as the liver, gill, intestine, kidney, and gonads of fish exposed to diazinon. The results clearly show that the use of pesticides for agricultural purposes can be a threat to aquatic fauna and flora and humans. In addition, the presence of diazinon in freshwater reservoirs, even in small concentrations, can have detrimental effects on fish physiology and potentially hinder their survival in the natural environment.