Evaluation of Some Heavy Metals in Aerial Parts of Wild Rice Plant in Kaduna State, Nigeria

Abstract

This study was designed to evaluate the level of Cd, Co, Fe and Zn in the aerial/upper parts of wild rice plant in three locations (Gure, Kagoro, and Kaduna) of Kaduna state. HNO₃-H₂O₂ was used to digest the plant samples and analyzed using AA320N model Atomic absorption spectrophotometer. The results obtained revealed that, the concentration(mg kg^-1 dry weight basis) of the heavy metals analyzed in the upper parts of wild rice plant were 0.242, 0.028, 2.947 and 19.145 for Cd, Co Fe, and Zn respectively. Also in the grain, the concentration of metals was found to be 0.223, 0.023, 2.003 and 19.050 for Cd, Co, Fe, and Zn respectively. The ANOVA result showed that the concentration of Cd, Co and Fe were not significantly different within the plant parts while that of Zn was different at 95% confidence limit. The concentration of Zn, Fe and Co in the wild rice plant and grain were within the limits obtained in most world crops and vegetables and WHO/FAO reference standards. Although, the concentration of Cd in grain was a little higher than the recommended limit of WHO/FAO reference standard. The dietary implication of the elements, suggests that the consumption of the wild rice plant/grain analyzed may not cause much health hazard to grazing animals and human beings.

Keywords: Aerial part, Grain, Heavy metals, Wild rice