HEAVY METAL ANALYSIS AND HISTOPATHOLOGICAL STUDIES OF BUBULCUS IBIS (CATTLE EGRETS) IN OKO-OBA, ALIMOSHO, LAGOS STATE, NIGERIA

Abstract

Heavy metal pollution poses a significant threat to ecosystems and organisms, including avian species that serve as bio indicator due to its bioaccumulation and toxic effects on living organisms. This study examined the levels of cadmium (Cd), lead (Pb), copper (Cu), and mercury (Hg) in the feathers, liver, and chest muscles of Bubulcus ibis (Cattle Egrets) collected from Oko-Oba, Lagos State, Nigeria . Utilizing feathers, liver, and chest muscles, alongside environmental samples from sediment and water, we performed physicochemical, histopathological, and atomic absorption spectroscopic analyses to determine contamination levels .The highest mean concentrations of heavy metals in feathers were observed for Pb (4.40 ± 0.69 mg/kg) and Cu (4.13 ± 0.85 mg/kg), while Hg showed the highest mean in liver tissues (0.40 ± 0.27 mg/kg). In water samples, Pb recorded a mean concentration of 2.76 ± 0.45 mg/L, and Hg was detected at 0.97 ± 0.14 mg/L. Sediment samples exhibited maximum mean concentrations for Pb (2.37 ± 0.66 mg/kg) and Cd (0.89 ± 0.40 mg/kg). Results revealed substantial bioaccumulation of Pb and Cu, particularly in chest muscles, and elevated Hg concentrations in feathers. Histopathological analyses revealed significant tissue damage, including sloughing and lymphocytic infiltration in intestinal tissues. The results indicate a significant bioaccumulation of Pb and Cu in avian tissues and highlight the role of Bubulcus ibis as a bio indicator of heavy metal contamination. These findings underscore the ecological health risks associated with heavy metal contamination, reinforcing the importance of periodic monitoring and conservation strategies to mitigate the effects on local avian populations and ecosystem health.