Content of Heavy Metals in Poultry and Local (Free Range) Chickens raised within Gwagwalada Area Council of Abuja, Nigeria

Abstract

The content of heavy metals in poultry and local (free range) chickens raised within Gwagwalada Area Council of Abuja, Nigeria was investigated. The poultry chickens were obtained from poultry farms while the local (free range) chickens were bought from the natives within the study area. Samples were prepared by wet digestion method using nitric acid and the heavy metals determined by flame atomic absorption spectrophotometry (FAAS). The mean concentration (μg/g dry weight) of heavy metals in the Poultry chickens were 3.68 ± 0.86, 0.58 ± 0.36, 0.78 ± 0.02, 4.79 ± 1.27, 77.40 ± 66.44, 2.09 ± 0.54, 1.44 ± 0.82 and 68.99 ± 23.90 for Pb, Cd, Ni, Cu, Fe, Co, Mn and Zn respectively. Also the heavy metal contents in the local chickens were 2.01 ± 1.25, ND, 1.07 ± 0.30, 3.00 ± 1.24, 108.88 ± 73.41, 1.36 ± 0.46, 13.44 ± 6.14 and 75.49 ± 24.02 μg/g dry weight for Pb, Cd, Ni, Cu, Fe, Co, Mn and Zn respectively. A Pearson correlation analysis on the heavy metals in the chicken meat revealed positive strong correlations between Zn/Fe (r = 0.867), Zn/Mn (0.764), Zn/Cu (r = 0.591), Mn/Cu (r = 0.657) and Fe/Cu (r = 0.598) at p < 0.01 significant level. This is not unusual as Fe, Cu, Mn and Zn are essential elements and constitute part of expected components of the chicken. The human risk assessment conducted on the chicken samples revealed that Estimated Daily Intake (EDI) and Target Hazard Quotient (THQ) were in the safe levels, indicating that the exposure of adult population to individual heavy metals through consumption of poultry and local (free range) chickens will not pose adverse health effects. However, the Hazard Index (HI) value for the poultry chicken is suggestive of potential adverse health effect on the consumers. Also, the HI value of local (free range) chickens cannot be ignored because the accumulation of heavy metals in the human body over time can cause serious health effects.