Toxicity evaluation of chlorpyrifos and diuron below maximum residue limits in rabbits.

Objectives: This study investigated the toxicological aspects of chlorpyrifos and diuron concentrations below maximum residue limit (MRL) in rabbits, determined their residues associated with the toxicological aspects and modeled the toxicity. Methods: Single- and repeated-dose toxicity tests were employed using white rabbits as experimental animals. In both toxicity tests, rabbit responses were evaluated by monitoring their body weight, various growth factors, activity of acetylcholinesterase (AChE), and activities of liver enzymes, alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Various kidney functions (urea, uric acid, creatinine and total protein concentration) were evaluated. Pesticide residues were also determined by GC. Results: Repeated-dose toxicity test of chlorpyrifos and diuron significantly reduced the body, liver and heart weights compared with those of the control group (p = 0.045). Both tests reduced the serum AChE, AST and ALT activities and increased ALP activity. On the other hand, the tested compounds increased the uric acid and urea concentrations and reduced the creatinine concentration in the blood serum. Chlorpyrifos was detected in blood, kidney and manure samples whereas diuron was detected in liver tissues and blood samples. Conclusions: Concentrations of chlorpyrifos and diuron far below MRL values generated various toxic effects in rabbits, indicating a possible health risk. [ABSTRACT FROM AUTHOR]