Heavy Metal Accumulation by Telfairia occidentalis Hook f. Grown on Waste Dumpsites in South-eastern Nigeria

摘要

Leachates from waste dumpsites in Abakaliki metropolis, South eastern Nigeria has become a major source of heavy metal pollution to the soil. Cultivation of Telfaria occidentalis is practiced in these waste dumpsites due to its high organic matter inorder to increase yields. Telfaria occidentalis grown on two selected waste dumpsites in the metropolis was collected. Heavy metals (Cu, Zn, Pb and As) in their plant parts as well as in the soil were determined using digestion and Atomic Absorption Spectrophotometric methods. Heavy metal values in leaf were highest for Pb followed by shoot. Pb ranged from 0.35-0.54 mg kg~(-1), Copper ranged from 0.02-0.07 mg kg~(-1) and Zn ranged from 0.04-0.06. Transfer factors were high suggesting that consumption ofvegetables grown on the waste dumpsites is dangerous to human health. The Translocation Factor (TLF) for As, Pb and Cu was higher than 1.0 but lower than 1.0. The enrichment coefficient of Pb and As was higher than 1.0. In view of plants role in food chain, cultivation of Telferia occidentalis in waste dumpsites should be eschewed.