Assessment of Metal Pollutants Bioaccumulation in Amaranthus (Amaranthus tricolor) Vegetables in Maiduguri, Nigeria

Abstract

Assessment of metal pollutants bioaccumulation in amaranthus vegetables cultivated along the bank of river Ngadda and Alau dam was carried out with the aim of establishing the health risk associated with their consumption. Samples of amaranthus vegetables were analyzed for metal pollutants namely: Aluminum (Al), Manganese (Mn), Samarium (Sm), Iron (Fe), Zinc (Zn), Cobalt (CO), Chromium (Cr), Rubidium (Rb), Barium (Ba) Scandium (Sc), Thorium (Th), Antimony (Sb) and Vanadium (V) using instrumental neutron activation analysis (INAA) techniques. Four samples from each study site were collected, analyzed for concentration values and compared with the available values of safe limit given by WHO/FAO. From the result obtained, the maximum concentrations for Al was 1508 ± 018 at sampled site A2, for Mn was 179 ± 1 at sampled site A1, for Mg was 19890 ± 537 at sampled site A3, for Fe was 655 ± 40 at sampled site A4, for Zn was  85 ± 4 at sampled site A3 for Co was 20 ± 3 at sampled site A2, for Cr was 88 ± 21 at sampled site A4, for Rb was 18 ± 1 at sampled site A4, for Sc was 15 ±1 at sampled site A4, for Th was 33 ± 5 at sampled site A4, for Sb was 18 ± 2 at sampled site A2 and for V was 2.3 ± 0.5 at sampled sites A2, A3. The result showed that the maximum concentration of Fe, Cr, Mn and Co exceed the values recommended by FAO/WHO of 425.5, 1.3, 25 and 0.3 ppm respectively. Therefore, the consumption of vegetables cultivated on farmland soils along the bank of river Ngadda and Alau dam may constitute health risk overtime as these metals can accumulate in the body.