An investigative screening of heavy metal contamination of Amaranthus spp grown along Ibi river-bank,Taraba State, Nigeria

Abstract

Agricultural activities around river bank are popular practice in most riverine areas in Nigeria. Vegetables are the commonest agricultural commodity that are grown around the river bank and are averagely the most consumed food product in Nigeria. An investigative screening of metallic contamination of Amaranthus spp grown in three farms around river Ibi bank showed a level of metallic deposition: Cadmium (Cd), (2.25±0.63, 3.28±0.55, 2.51±0.03) ppm; Lead (Pb), (1.83±0.51, 0.54±0.03, 1.06±0.13) ppm; Mercury (Hg), (0.53±0.01, 1.03±0.01, 0.66±0.01) ppm; Arsenic (As), (0.50±0.72, 0.51±0.06, 0.62±0.15) ppm and Chromium (Cr), (4.26±0.51, 2.66±0.22, 1.75±0.38) ppm. Descending order of the mean concentrations of the trace metals detected from analyzed sample of Amaranthus spp from the three locations are as follows; Farm A: Cr>Cd>As>Pb>Hg, Farm B: Cd>Cr>Hg>Pb>As, Farm C: Cd>Cr>Pb>Hg>As. Amaranthus spp cultivated along Ibi river bank has shown a reasonable amount of deposition of heavy metals, therefore, are not totally safe. The metallic content in Amaranthus spp sample collected in farms along Ibi river bank ranges; 0.50±0.72 to 4.26±0.51 in sample A, 0.51±0.06 to 3.28±0.55 in sample B and 0.62±0.15 to 2.51±0.03 in sample C. The metallic deposition detected from analyzed Amaranthus spp showed values that are above the World Health Organization set permissible limit (Pb-0.3ppm; Cd-0.2 ppm; As-0.5ppm; Hg-0.5ppm; Cr-0.5ppm). Bioaccumulation of these metallic substances in the human system as a result of long-term consumption of the vegetables poses a deleterious health effect. This study aimed at ascertaining the food safety of agricultural products cultivated around Ibi river bank.