SOME TOXIC EFFECTS OF PETROLEUM PRODUCTS ON NIGERIAN FAVOURITE DELICACY (FRESH FISH)

*Azikiwe C. C. A., Udoye J. O. and Ifezulike C. C.

ABSTRACT

Background: Fresh fish is a Nigerian delicacy and commonly sourced from ponds, streams, rivers and oceans. Petrol and diesel are common byproducts of petroleum. These products get to end users through many channels including long distance transportation to filling stations, dispensing to motor vehicles, jerry-cans/other containers. Accidental spillages and outright pouring into fish ponds, streams, rivers and oceans are possible. African catfish thrive in hash environment but, may indeed be a potential store house of toxicity in man from these petroleum products. Aim/Objective: Aim of this project is therefore to assess some toxicological effects of petrol and diesel on fish. Methodology: A total of 80 six-weeks old African catfish of average weight of 8.0grams were purchased from the fishery Department of Nnamdi Azikiwe University, Awka, Nigeria. They were allowed two weeks acclimatization in the Laboratory before the commencement of the experiment. Acute toxicity study to determine the LD50 was done based on Lorke’s 1983, method. Chronic toxicity was done with none lethal doses of either petrol or diesel for a 14 week period. The animals were divided into 5 groups (A-E) consisting of 6 animals per group. The appropriate dose based on bi-weekly weight was daily orally administered with cannulation. They were allowed free access to feeds and water. Water in their plastic aquarium was changed daily. They were housed in our standard Laboratory environment and allowed 12 hours each of light and darkness. At the end of the 13week and beginning of the 14th week, the animals were finally weighed and sacrificed. Blood samples were collected into EDTA and plain bottles. Sampling was done via cardiac puncture and free blood flow from cut-tails. Harvested organs were stored in fixatives for future use while blood samples were sent to the Laboratory to determine Packed cell volume (PCV), Full blood count, Urea, Creatinine, electrolytes, alanine transaminase, aspartate transaminase, alkaline transaminase enzymes and bilirubin. Raw data were collated and analyzed using SPSS version 20 to determine mean, analysis of mean variance while student t-test was used to determine P-value. P-value greater than or equal to 0.05 were adjudged as insignificant. Results: LD50 for petrol was 129.6mg/kg while that of diesel was 149.7mg/kg intraperitoneaelly in African catfish. There was retardation of growth in the high dose of petrol or diesel treated groups unlike control. There was however no significant differences in weight and length in treated groups compared to control. The PCV, total white cells and Lymphocytes were significantly elevated in dose dependent fashion for either petrol or diesel compared to the negative control. All liver enzymes and electrolytes were all significantly elevated in dose dependent fashion compared to the negative control. Conclusion: This work can be concluded to have demonstrated a dose dependent liver, renal and haemotoxicological effects of petrol and diesel on African catfish and may indirectly affect humans when the fish is eaten. Recommendation: It can be recommended that fish ponds should be sited far away from filling stations and mechanic workshops while our roads should be properly maintained to reduce vehicular accidents and incidents of fall-tankers.

Keywords: Petroleum, Cat-fish, Toxicity, Fish-ponds, Nigerian delicacy; Fresh-fish.