Assessment of Accumulation of Heavy Metals in Vegetables Irrigated with Water from Amba Stream in Lafia, Nasarawa State, Nigeria
| Main Authors: | Ishaleku, Y. Y., Etonihu, A. C., Uzama, D. |
|---|---|
| Format: | Article Journal |
| Terbitan: |
, 2018
|
| Subjects: | |
| Online Access: |
https://zenodo.org/record/1170638 |
Daftar Isi:
- Vegetable uptake of metals is one of the major pathways soil metals enter into the food chain and the subsequent bio-accumulated risks to human health when plant based food stuffs are consumed. This study assessed the impact of water from Amba Stream in Lafia, Nasarawa State used for irrigation. For the soil and sediment, the mean organic matter was 1.04 and 0.81% respectively. The mean pH of soil, sediment and water were 8.8, 7.1 and 6.9 respectively, while the moisture contents were 91.62 and 87.34% for soil and sediment, respectively. As expected, the soil sample had the highest concentrations of the heavy metals that ranged from 0.57 μg/g in Cd to 7.36 μg/g in Ni. The Amba stream water had higher levels of the heavy metals than the pipe-borne water used as a control, with the highest concentration of Cu (6-05 mg/l). The mean concentration of Cd in the stream water was 0.21 mg/l higher than the permissible level of 0.003 mg/l set by NAFDAC/NIS, while that in the sediments was not detected (ND). The results further showed that the concentrations of the metals were higher in the vegetables irrigated with water from the Amba stream than in the control except for Pb in spinach (0.01 μg/g) and As in water leaf (0.78 μg/g). Among the vegetables, bitter leaf had the highest concentration of Zn (3.94 μg/g) and Cu (5.09 μg/g). Arsenic (As) ranged from not detected in water leaf to 1.83μg/g in pumpkin. Cd was not detected in all the vegetables. The bioconcentration factors in the irrigated vegetables were found to be highest for Zn but lowest for Pb in the order Zn (1.04) > Cu (0.89) > As (0.71) > Pb (0.02). Although the levels of the heavy metals in vegetables are quite below the phytotoxic level that posed no imminent danger to consumers, regular monitoring of levels of these metals in water used for irrigation is essential to prevent excessive build up of these metals in the food chain