Appraisal of Heavy Metals (Lead and Cadmium) in the Muscle and Internal Organs of Cattle Slaughtered in Ibadan

Abstract

This study appraised the levels of two heavy metals: lead (Pb) and cadmium (Cd) in the muscle, liver, kidney, intestine, lungs and heart of cattle slaughtered for sale in the Akinyele Meat Market of Oyo State, Nigeria. The objectives of the study were to assess the distribution of these metals in the different parts of the body of cattle and compared their concentration with international guidelines. Thirty samples made up of six each of muscle, liver, kidney, intestine, heart and lungs were procured from the Akinyele meat market in Oyo State. The samples were pulverized and 0.5g weighed out for acid digestion with 2mL of 3:2 HNO3 /HClO4. Each digestate was made up to the 10 mL mark with de-ionized water, and analysed for the heavy metals (Pb and Cd) with a GBC Avanta ver 2.0 Atomic Absorption Spectrophotometer (AAS) model A6600. Results showed that range of detectable values in parts per million (ppm) metals were: Pb (0.00-0.81ppm), Cd (0.24-0.81ppm) in muscle; Pb (0.00-0.92ppm), Cd (0.00-0.03ppm) in heart; Pb (0.00-0.50ppm), Cd (0.40-7.65ppm) in kidney; Pb (0.00-0.28ppm), Cd (0.00-0.88ppm) in liver; Pb (0.00-0.03ppm), Cd (0.00-0.88ppm) in lungs and Pb (0.00-7.51ppm), Cd (0.10-0.65ppm) in the intestine. The results when compared with the World Health Organization (WHO) permissible limit of 0.01ppm for Pb and 0.05 ppm for Cd showed that the heavy metal concentration in most parts of the cows sampled exceeded the safety limit and are therefore potentially harmful if consumed. The study therefore show the need for regular biomonitoring programmes for heavy metal concentration in cattle in order to safeguard public health.