Concentrations of Trace Metals in Three Leafy Vegetables (Telfairia occidentalis, Amaranthus viridis and Pterocarpus erinaceus) during the Dry Season in Enugu, Nigeria

Abstract

Aims: To investigate the trace metals, manganese (Mn), Nickel (Ni), chromium (Cr), cobalt (Co), zinc (Zn) and iron (Fe) in vegetable samples (Telfairia occidentalis, Amaranthus viridis and Pterocarpus erinaceus) from three senatorial zones in Enugu state, Nigeria during dry season period. Place of Study: The leaf samples were collected from three senatorial zones (Enugu north, Enugu west and Enugu east) of Enugu State Nigeria. Methodology: The samples were collected fresh in January, February and March. Prior to analysis, each of the collected samples were dried at room temperature, pulverized using a ball mill and stored at room temperature. They were digested using the wet digestion method and individual metals analyzed using atomic absorption spectrophotometer. Results: The results of the findings revealed that the concentrations of trace metals in the plant tissues were in the following decreasing order Fe > Zn > Mn > Cr > Co > Cd. Amaranthus viridis had the highest accumulation of trace metals while P. erinaceus had the least. Enugu East senatorial zone had the highest accumulation of Mn and Co in all the vegetable samples while Enugu West senatorial zone showed the highest accumulation of Ni, Cr, Zn and Fe in all the plant tissues. Enugu north senatorial zone had the least level of trace metals accumulation in the three plant tissues. Manganese contamination could be a result of mining, battery and automobile fume pollution which dissolve into the soil and are absorbed by plants more effectively during dry seasons. Conclusion: To mitigate the unwanted increase of these metals in vegetables during the dry season, it is necessary to strengthen environmental waste disposal laws.