Toxicity, bioaccumulation and metabolism of phenol in the freshwater fish Oreochromis mossambicus

The acute toxicity of phenol was determined to be 35.0 mg/l in Oreochromis mossambicus. The fish were exposed to two sublethal concentrations of phenol (2.3 and 3.5 mg/l) for 30 days. The effects of exposure were studied on the bioaccumulation and elimination of phenol from the kidney and biochemical parameters of liver, gill, and muscle at intervals of 10, 20, and 30 days. A statistically significant increase in phenol concentration was noted in tissues from all treated fish groups. Bioaccumulation and biochemical changes were dose and duration dependant. Recovery in fish after post exposure was observed after transferring these fish to normal tap water for 30 days. Elimination of phenol was noted, although the concentration of phenol remained significantly higher than the control after 30 days of the experiment. Total protein, total carbohydrate, and total lipids in the tissues of liver, gill, and muscle of fish decreased greatly. The longer the exposure time, the greater was the percentage reduction of organic matter of the fish exposed to the sublethal concentration of phenol.