Evidence of Heavy Metals Distribution in Placenta in Association with Residual Levels in Some Dams’ Organs from Bodija abattoir, Oyo State, Nigeria

Abstract

Heavy metals have been known to be causing serious detrimental effect on the health of livestock and human populace in general. However, little study had been carried out on the ability of heavy metal to cross placental barrier, which has already been bio-accumulated in the dam. Therefore, this study aimed at showing the evidence of placental barrier crossing by selected heavy metals. The study was carried out in Bodija abattoir, Ibadan, Oyo-state, Nigeria, located on latitude 70⁰20N, longitude 30⁰5E. A cross-sectional study design was adopted and lasted for 6 weeks. Samples were collected from kidney cortices, apical lobe of dam’s liver and a portion of fetal placenta. 12 sample each from liver, kidney and the placenta which were analyzed using Atomic Absorption Spectrophotometer (AAS). Results were subjected to descriptive statistics, t-test and correlation using SPSS17.0 package.From this study cadmium (Cd) and lead (Pb) residues were not found in the samples, while chromium (Cr) was found in all the samples (100% prevalence) and the total prevalence for the heavy metals in the study was 33.4%. The mean chromium (Cr) residual values in placenta, kidney and liver were 0.89±0.66mg/kg, 1.32±0.94mg/kg and 1.00±0.87 mg/kg respectively. The correlation between chromium (Cr) in the dam’s kidney and placenta was 0.3, while for the dam’s liver and placenta was 0.6.  In comparison with permissible limit, the residual level in kidney 1.32±0.94, liver 1.00±0.87 and placenta 0.89±0.66, were within the permissible limit. The study revealed that chromium (Cr) residue was a major challenge in the organs sampled. Liver of the dam had the highest level of bioaccumulation and stronger correlation in the distribution to the placenta. It is therefore recommended that attention should be paid on the disposal of chromium (Cr) residues on the grazing floor where the bulk of the residues were from.

Keywords: Heavy metals, Liver, Kidney, Placenta and cattle.