Bioaccumulation of auto-mechanic wastes in the tissues of Pellonula Afzeliusi (Johnels, 1954) collected from Agba stream Ilorin, Kwara State, Nigeria

Abstract

Hydrocarbons and heavy metals (HM) present in automobile wastes get into water bodies close to automobile mechanic villages. They deteriorate the physico-chemical qualities of such water bodies and exert toxic effects on fish and other aquatic fauna. They also pose risks to humans that consume fish from streams near such automechanic villages. There is paucity of information on the HM contents of Agba stream, Ilorin and no information on the bioaccumulation of HM in the tissues of Pellonula afzeliusi is currently available. The purpose of this study was to assess the physico-chemical qualities of water and bioaccumulation of HM in the tissues of Pellonula afzeliusi fish collected from Agba stream, Ilorin, Kwara State, Nigeria. Water and samples of Pellonula afzeliusi were collected from the upstream (station A), midstream (station B) of Agba stream located close to an auto-mechanic village and Oyun dam (control site, station C) located within the University of Ilorin. Standard methods were used to analyse oil and grease (OG), total petroleum hydrocarbon (TPH) and HM in water samples. The concentrations of TPH and HM were analysed in the skin, bone, muscle, gills, gastrointestinal tract, liver and kidney of the fish. The order of water HM concentrations indicated Zn > Cd > Ba> Fe > Pb at station A; Cd > Zn > Fe > Ba > Pb at station B, and Zn > Ba > Pb > Fe >Cd at station C. TPH and HM bioaccumulated in the tissues of fish while lead was not detected in all tissues from station C. Bioaccumulation factor varied with the highest values  t station C. The result of this study indicated heavy pollution burden in station B with lower pollution burden in station C (the control site). These call for attention of government in ensuring ecological restoration and prevention of further discharge of automobile wastes into the stream. Keywords: Automobile wastes, Heavy metals, Hydrocarbons, Bioaccumulation, Pellonula afzeliusi