Distribution of Some Heavy Metals in the Tissues of Arm, Thigh, Kidney and Liver after Continuous Feeding of Rabbits with Diet Contaminated with Crude Oil

Aims: This experiment was conducted to assess the distribution of these heavy metals in the tissues of rabbits from the continuous feeding of diets contaminated with crude oil.

Study Design: Completely randomized design (CRD).

Place and Duration of Study: University of Benin Teaching and Research Farm for a period of 9 months.

Methodology: The experiment was carried out using 40 rabbits of New Zealand breed obtained from the University of Benin Teaching and Research Farm, Nigeria. The rabbits were divided into four treatments with each treatment having ten replicates. A single diet was formulated based on the nutrient requirement of growing rabbits and partitioned into Diets A, B, C and D with 0, 15, 30 and 45 mL of crude oil added to every 3 kg of the feed. Analysis of heavy metals in the tissues was based on standard procedures.

Results: The highest level of cobalt recorded in the arm was found among the highest dosed rabbits (45 mL) which differed significantly from the groups that received lower or no dosage. No traces of nickel and cadmium were found in any of the tissues. The dose-related increase in the distribution of lead and copper in the thigh was observed. Generally, the kidney and liver had an increasing accumulation of the heavy metals with increasing crude oil contamination in the diets except for nickel and cadmium that were not also detected.

Conclusion: It was therefore concluded that crude oil ingestion could result in increased accumulation of heavy metals in the tissues of arm, thigh, kidney and liver of growing rabbits.