Toxic (Pb, Cd, Hg) and essential (Fe, Cu, Zn, Mn) metal content of liver tissue of some domestic and bush animals in Ghana
Abstract
Accumulation of toxic metals in liver, a rich natural source of essential elements, can present health risks to regular consumers of liver. A total of 35 fresh liver samples of cow, sheep, goat, pig, grass-cutter ( Thryonomys swinderianus ), gaint rat ( Cricetomys gambianus ), red deer ( Cervus elaphus ), chicken and antelope ( Antilocapra americana ) were obtained from three different markets in Accra and Kumasi, Ghana. Samples were analyzed using atomic absorption spectrometry and an automatic mercury analyzer. Levels of iron in the grass-cutter and pig of 500.5-645.4 mg kg -1 were the highest in the animal livers examined. Mn concentrations were highest in grass-cutter and rat liver, ranging 16.5-30.2 mg kg -1 . The safe Cu and Zn permissible limits of 20 and 50 mg kg -1 were exceeded in 70 and 75% of the liver samples, respectively. Generally, for each animal group studied, at least 50% of the sample livers exceeded the Cd permissible limit of 0.5 mg kg -1 . The levels of Pb, which ranged 1.3-13.8 mg kg -1 , exceeded the proposed European Commission (EC) limit of 0.5 mg kg -1 . Care must be taken by regular consumers of the iron-rich animal livers of grass-cutter, pig and rat because they also had the highest levels of Pb (in grass-cutter and pig) and Cd (in grass-cutter, rat and pig). The liver samples analyzed for Hg had values far below the permissible limit of 0.5 mg kg -1 .