Assessment of heavy metals residues in broiler chickens from different farms in Mbikko, Njeru municipality

Abstract

Heavy metals are elements having relatively high density and are toxic at low concentration; they are divided into essential and non-essential heavy metals. They exist naturally within the atmosphere resulting from human and anthropogenic activities. Environmental pollution has increased recently. The pollutants come from different sources and they contain a variety of heavy metals like Iron (Fe), Copper (Cu), Lead (Pb), Zinc (Zn) and Cadmium (Cd). These heavy metals are bio-accumulated in chicken which is later consumed by humans and cause health problems. In this research, ten broiler birds at finishing stage were sampled from different farmers in Mbikko parish and analyzed to determine the presence and levels of Cu, Pb, and Cd in thigh muscle tissues and liver tissues. The samples were analyzed using an atomic absorption spectrometer at Uganda Industrial Research Institute (UIRI). Findings showed heavy metal concentrations of copper and lead. Results revealed that 100% of all thigh muscle and liver tissue samples screened were contaminated with traces of copper with 1.819±0.257 and 0.705±0.454 mean ± SD concentrations (mg/Kg), ranging from 1.556 to 2.310 and 0.281 to 1.618 respectively. While only 20% of the screened samples had residues of lead, with 0.092±0.206 mean ± SD and 0.610 mg/Kg maximum concentration in both thigh muscles and liver tissues. No residues of Cadmium were found at detectable levels (were less than 0.02, the LOD). Moreover, all thigh muscle samples and only 20% liver tissues samples were contaminated with unacceptable levels of copper as the concentrations were more than the permissible maximum residue levels (1.00 mg/Kg). Similarly, 20% of both liver and thigh muscle samples (all positive samples) had beyond permissible levels of lead (0.1 mg/Kg) set by FAO/WHO.