Risk Assessment of Heavy Metals in Soil and Vegetables of Selected Dumpsites in Port-Harcourt Metropolis

The study to evaluate the concentration of heavy metals in soils and vegetables (Vernonia amygdalina, and Telfairia occidentalis) was carried out in selected dumpsites in Port Harcourt Metropolis. Heavy metals were analyzed following standard methods using Perkin-Elmer model 403 Atomic Absorption Spectrophotometer. Data revealed that the levels of heavy metals in soil samples from Sites I and II were below the safe limits with the exception of Fe, whereas in the vegetables (Vernonia amygdalina) the concentration of Mn was above safe limit in all sites while Cu was above safe limit in Site I. Telfairia occidentalis revealed that Mn was above safe limit in Sites I and II, while Pb was above safe limit in Site I and Fe was above safe limit in Sites I and III. Levels of the 6 metals in the soils ranged between 2.93 to 3247.91 mg/kg (site I), 1.03 to 206.69 mg/kg (site II) and 1.42 to 4189.70 mg/kg (site III). The levels of metals in the vegetable (Vernonia amygdalina) were in the ranges of 4.70 to 212.63 mg/kg at Site I, 0.71 to 263.41 mg/kg at Site II and 1.18 to 171.95 mg/kg at site III with Transfer Factor been highest for Cu and V in Site I, V and Mn in Site II and Cu, V and Pb in site III. The metals in Telfairia occidentalis were between 71 to 1929.9 mg/kg at Site I, 3.24 to 1735.03 mg/kg at site II and 4.55 to 250.74 mg/kg at Site III while Transfer Factor was highest for Pb and Cu in Site I, V and Fe in Site II and V, Cu, Pb in Site III. The daily intake of Fe was above the Oral reference dose, while the HQ for both Vegetables were above 1 with the exception for Zn in all sites and Cu in Site I in Vernonia amygdalina and in all Sites for Telfairia occidentalis which reflects that the consumption of vegetables from the dumpsites may pose a potential health risks to inhabitants.