Determination of Toxic Metals in Fruits of Abelmoschus esculentus Grown in Contaminated Soils with Different Irrigation Sources by Spectroscopic Method

Heavy metal contamination of food crops irrigated with municipal wastewater is a growing problem worldwide. In this direction, heavy metal accumulations in Abelmoschus esculentus crops were irrigated with three different water regimes (municipal wastewater, groundwater, and canal water) as well as in soil and the water sources were determined. Also, transfer factors, enrichment coefficients, pollution load indices, and health risk indices were assessed to understand the metal transportation and accumulation through the food chain. The concentrations of heavy metals in soil, water and plant samples were analysed by atomic absorption spectrophotometer equipped with a graphite furnace and D corrector (Perkin–Elmer Model 503). Heavy metal concentrations in the irrigation water samples ranged between 0.513–0.951 for Mo, 0.256–0.615 for As, 0.266–0.606 for Se, 41.604–54.642 for Fe, 0.285–0.753 for Cu, 0.255–0.619 for Zn, 4.684–5.212 for Ni, 3.792–5.526 for Pb, 0.035–0.065 for Cd and 2.635–4.608 for Co mg/L. The contents of Mo, As, Se, Fe, Cu, Zn, Ni, Pb, Cd and Co in soil samples ranged from 5.03 to 7.80, 34.27 to 38.96, 2.41 to 2.54, 4.77 to 5.94, 2.89 to 3.36, 1.76 to 3.63, 35.02 to 37.32, 25.10 to 28.12, 2.42 to 3.20, and 5.76 to 5.99 mg/kg, respectively, and the contents of Mo, As, Se, Fe, Cu, Zn, Ni, Pb, Cd and Co in A. esculentus samples ranged from 7.003 to 9.291, 2.800 to 3.585, 0.378 to 0.485, 39.718 to 44.048, 11.791 to 19.840, 28.203 to 37.051, 6.085 to 9.330, 4.885 to 7.061, 3.375 to 4.198, and 0.128 to 0.328 mg/kg, respectively. The range values of metal accumulation in A. esculentus samples were lower than the maximum permissible limits in plant samples except for Mo and Cd. Statistically, Se, Fe, Zn, Ni, Cd and Co concentrations did not vary significantly at all sites, while As, Mo, Cu, and Pb concentrations varied significantly in the vegetable samples.