Assessment of Soil and Vernonia amygdalina Cultivated in Port Harcourt, Nigeria

Background and Objective: Vernonia amygdalina is a vegetable used by habitats of Port Harcourt for both food and medicinal purposes. It is cultivated in most homes, its bioaccumulation of toxicants has been speculated. This study evaluated the heavy metals concentration and risk assessment of soil and Vernonia amygdalina (bitter leaf) cultivated in Abuloma-Trans Amadi, Port Harcourt. Materials and Methods: The soil and bitter leaf (BL) samples were taken randomly from 3 locations, U-(Control), Abuloma-1 and Abuloma-2. They were analyzed for heavy metals using atomic absorption spectroscopy. Transfer factor (TF), contamination factor (CF) and pollution load index (PLI) were evaluated using standard models. One-way Analysis of Variance (ANOVA) was used to determine the mean and standard deviation, the Turkey’s post hoc Test was also carried out at a 95% confidence level (p≤0.05). Results: Soil samples had Fe and Mn concentrations above WHO permissible limit. Soil Abuloma-1&2 TF was in the order Co>Fe>Ni>Mn>Cu, BL Abuloma 1, Mn>Cu>Ni>Fe>Co while BL Abuloma-2, Cu>Mn>Ni>Fe>Co. Soil samples CF for Abuloma 2 had moderate contamination while Moderate and considerable CF were observed in the BL samples. The PLI for soil samples was highest in Abuloma-1 (0.003868 mg kg‾¹), for BL samples, Abuloma-2 had the highest pollution index (1.907 mg kg‾¹). Conclusion: The findings of this study revealed heavy metal contamination of both soil and bitter leaf cultivated in the study, therefore, suggesting a thorough monitoring/regulation of the industrial activities in the Abuloma/Trans Amadi Industrial area of Port Harcourt.