Untitled

Abstract

Chromium concentration in Black-headed oriole Oriolus brachyrhynchus was carried out using Atomic Absorption Spectrometry (AAS) to determine the bioaccumulation level in the feather, liver heart, skin, carcass, nestling feather and egg so as to say which of these parts carried more contaminant. A total of 30 birds were trapped using mist net and 150 of these parts were obtained. A total of 9 eggs and 9 nestling were also collected from different nest in the study areas for investigation. Descriptive statistics were used to express chromium concentration mg/kg in the selected parts. Chromium concentration in the different organs of the bird caught in the three sample sites are as follows: feather has the highest mean values of 18.20±2.54mg/kg at Daudu, liver; 6.25±2.38mg/ kg at Daudu, heart; 691±0.23mg/kg at Buruku, skin; 4.43±2.0mg/kg at Daudu, carcass; 28.49±2.68mg/kg at Buruku, egg; 0.42±0.34mg/kg at Daudu and nestling feather; 28.22±3.32mg/kg at Buruku. A significant correlation (r 2 =0.824) existed between the skin and the carcass at (P˂0.01) and also (r 2 =0.668) between feather and skin at (P˂0.05). Similar correlation of (r 2 =0.721) existed between feather and the carcass at (P˂0.05), while the weight of feather correlated (r 2 =0.662) with that of the heart at (P˂0.05). In addition, a negative correlation (r 2 = -0.702) existed between the weight of skin and that of the heart at (P˂0.05). Chromium concentration has the highest mean value of 8.87±1.35mg/kg in maize at Daudu, and in rice; 5.72±2.61mg/kg at Daudu, while guinea corn; 6.92±1.39mg/kg also at Daudu. The concentration in soil and water was highest at Daudu with a mean of 27.04mg/kg and 0.61mg/l respectively. However, chromium concentration in the bird species in the study areas is still within permissible limit of WHO standard of 50mg/kg, but far above WHO permissible level for crop 1.30mg/kg and water 0.1mg/l which calls for concern, as cereals are the major food consumed by the people in the study areas. This calls for continuous monitoring.