Determination of Heavy Metals in Selected Tissues and Organs of Slaughtered Cattle from Akinyele Central Abattoir, Ibadan, Nigeria

Abstract

Meat and offal obtained from cattle are consumed daily as source of protein, but consumers’ knowledge on the possible exposure to heavy metals in meat and its associated health risk is generally low. Therefore, this study seeks to determine heavy metal levels in selected tissues and organs of cattle.A cross-sectional study design with laboratory analysis component was adopted. Lead, cadmium and chromium in blood, muscle, liver and kidney of cattle slaughtered in Akinyele central abattoir, Ibadan, Nigeria were studied. Samples of blood from jugular vein at slaughter, external abdominus muscles, liver apical lobes and kidney cortices were collected. Eighty samples were collected for 8 weeks and analyzed for lead, chromium and cadmium, using Atomic Absorption Spectrophotometer (AAS). Values were compared with Joint FAO/WHO guidelines. Statistical analysis was done using descriptive statistics, t-test and ANOVA. Male cattle (75%) and female (25%) with mean age of 49.5 months were used. Mean chromium residual values in blood, muscle tissue, liver and kidney were 0.62±0.00, 0.62±0.00, 1.28±0.93 and 2.33±2.99 mg/kg respectively. Chromium residues were higher in liver and kidney, while lead residues were within the permissible limit. Mean cadmium residues in blood, muscle tissue, liver and kidney were 5.67±2.08, 3.81±2.09, 5.24±2.30 and 5.71±2.31 mg/kg respectively. These values were higher than permissible limit of 0.5-1.0mg/kg. There was significant difference (P=.05) in heavy metals bioaccumulation based on tissue type and age of the cattle.The cattle meat contained levels of cadmium and chromium and this could pose health risk to consumers. Therefore, massive public health awareness on the risk associated with cadmium and chromium ingestion and measures to reduce them in meat and meat products should be advocated. Cattle rearers should also be educated on the grazing areas to be selected.

Keywords: Cattle meat and offal, lead, cadmium and chromium, abattoir