HISTOPATHOLOGICAL ASSESSMENT OF PESTICIDES EXPOSURE ON TILAPIA FISH: IMPLICATIONS FOR HEALTH MONITORING AND ENVIRONMENTAL RISK ASSESSMENT

Abstract

Histopathological investigations are crucial tools in toxicology research and water pollution monitoring. Using light microscopy, this study assessed the effects of lambda-cyhalothrin on the kidney, liver, and gill tissues of Oreochromis niloticus. In a 28-day period, fish were subjected to sub-lethal amounts of lambda-cyhalothrin (0.24 ppb and 0.36 ppb). Histological analysis showed that, while tissues in the control group remained normal, exposed fish exhibited significant pathological changes. Changes in the gill tissues were noted necrosis, edema, inflammation, epithelial hyperplasia, shorter secondary lamellae, and lamellar fusion. Large sinusoidal gaps contracted, melanomacrophages were present, inflammation, micronuclei cluster development, and tubular epithelial necrosis were all seen in kidney tissues. Large sinusoidal gaps, micronuclei clusters, pyknotic nuclei, and fibrosis were also visible in the liver tissues. The study of biochemical consequences, showed significant abnormalities in lipid metabolism, as seen by increased levels of triglycerides, LDL, VLDL, and cholesterol and decreased HDL. Increased liver enzymes (ALT, AST) and changed protein levels indicated hepatotoxicity, but hyperglycemia and thyroid hormone abnormalities suggested endocrine disturbance. Increased levels of creatinine and urea suggested nephrotoxicity. These results demonstrate the organ and metabolic toxicological effects of lambda-cyhalothrin, highlighting the need for strict environmental regulation and monitoring to reduce ecological concerns in aquatic ecosystems.