Assessment of Chickens Fed with Solid Wastes in Terms of Heavy Metal Contents in Zaria Metropolis, Nigeria

The concentrations of Zn, Pb, Cu, Cd and Hg were spectrophotometrically determined in local chickens that were fed with the solid wastes for three months and dumpsite-soils in both dry and wet seasons. Dumpsite-leachates were analysed in wet season only across the sites. A total of four hundred and thirty two samples of chicken organs, leachates and soil samples were investigated. The trend in the bio-availabilities of the metal ions in the analysed samples was; soils > leachates > organs with the exception of mercury. Overall, the order of the bioavailability of these metals in the analyzed samples across the sites and seasons was; Hg > Cu > Cd > Pb > Zn. The concentrations of mercury, cadmium and lead in the chicken-organs were all above the FAO/WHO (1986) recommended limits for human consumption across the sites. However, the concentrations recorded for copper and zinc were below the safe limits some of the dumpsite chicken organs. Overall, significant differences of the metal ion concentrations in the analysed samples across sites and seasons at p<0.05 were recorded, thus, consuming chickens grown in these dumpsites might pose a serious health threats to consumers due to metal ion bioaccumulation through the food chain.