CONTENT OF SOME HEAVY METALS IN FORAGE GRASS IN KAGARA NORTH CENTRAL, NIGERIA

Y. Salawu, Sani Ibn Yakubu*, M. Garba, M. A. Usman1 and A. I. Yakasai

ABSTRACT

This work was designed to investigate the concentrations of zinc, copper, lead, nickel and arsenic in forage grass being grazed by cattle around Kagara in Rafi Local Government Area of Niger state, North Central Nigeria at five different grazing pastures sites around the town. There have been serious indiscriminate local gold mining activities in those communities by the inhabitants leading to possible environmental pollution particularly by heavy metals. These heavy metals can be transported, dispersed to and accumulated in plants being fed on by the grazing animals and these animals form part of human diet as our main source of protein. The samples collected were analyzed after wet digestion for levels of the heavy metals by Atomic Absorption Spectrometry. The trend of the metal levels was Zn> Cu >Pb> Ni > As. The mean concentrations obtained in mg/kg were in the range of 11.129 to 22.322 for zinc, 7.352 to 15.182 for copper, 4.732 to18.173 for lead, 1.904 to 2.811 for nickel and 0.188 to 0.852 for arsenic. Forage grass examined in this study were relatively not safe for grazing by animals due to high forage lead level. Consumption of lead contaminated animals and their products constitute serious risk to public health.

Keywords: Heavy metals, forage grasses, grazing animals.