Determination of heavy metals in selected tissues and organs of slaughtered cattle in Akinyele central abattoir, Ibadan, Nigeria

Meat and offal from cattle are source of protein consumed daily but Consumers’ knowledge on the possible exposure to toxic heavy metals in meat and its associated health risk is generally low. This study aimed at assessing heavy metal levels in selected tissues and organs of slaughtered cattle.

Lead, cadmium and chromium in blood from jugular vein at slaughter, external abdominus muscles, liver apical lobes and kidney cortices of cattle slaughtered in Akinyele central abattoir, Ibadan, Nigeria were studied. Eighty samples were analyzed using Atomic Absorption Spectrophotometer (AAS). Statistical analysis was done using descriptive statistics, t-test and ANOVA.

Cadmium were found in 63 samples and lead in 17 samples. Mean chromium residual values in blood, muscle tissue, liver and kidney for cattle were (0.62±0.00, 0.62±0.00, 1.28±0.93 and 2.33±2.99 mg/kg). Chromium residues were higher in liver and kidney of the cattle. Cadmium values in blood, muscle tissue, liver and kidney of cattle were (5.67±2.08, 3.81±2.09, 5.24±2.30 and 5.71±2.31 mg/kg). These values were higher than WHO permissible limit of 0.5-1.0mg/kg. Mean lead residual values in blood, muscle, liver and kidney were within the permissible limits. There was significant difference (P<0.05) in cadmium, lead and chromium concentration based on tissue type and age.

The cattle meat contained levels of cadmium and chromium and this could pose health risk to consumers. Therefore, cattle should not be exposed to feeds or environmental discharges that are sources of cadmium and chromium, so as to reduce the associated health risks of cadmium and chromium bioaccumulation in meat.