BIOACCUMULATION OF HEAVY METALS IN SOILS, Talinum triangulare and Celosia argentea LEAVES GROWN AROUND TEMBOGA RIVERBANK, BENIN CITY NIGERIA

Heavy metal levels in soils may result in heavy metal entry into the food chain, the study aimed at accessing concentration of heavy metals (Cd, Ni, Pb) in soils, Talinium triangulare and C. argentea leaf grown along Temboga Riverbank. Surface (0-15 cm) soil, T. triangulare and C. argentea leaf samples were collected randomly from Temboga Riverbank (RB), 60 meters from RB (60MRB) and 120 meters from RB (120MRB) in three replicates, making a total of nine soil, nine T. triangulare and nine C. argentea leaves samples. The soil, T. triangulare and C. argentea leaves samples were analyzed for some heavy metal properties using standard laboratory methods. The result showed that Cd contents of the soils was highest (0.19 mg kg-1) at 60MRB, however the levels of soil Cd and Ni, where still within tolerance levels in other locations. The results also showed that Cd content of 0.93 mg kg-1 obtained for T. triangulare leaf at 60 MRB have reached toxic level,s while the Cd content of T. triangulare leaf at RB (0.77 mg/kg) and 120MRB (0.77 mg/kg) could reach toxic levels in a short time. The Ni levels of T. triangulare and C. argentea leaves have exceeded permissible limit with values of 4.42, 2.32, 2.22 mg kg-1 and 2.88, 2.88, 2.72 mg kg-1 recorded at RB, 60MRB, 120MRB respectively. The vegetables (T. triangulare and C. argentea) leaves could be said to contains toxic levels of Ni and thus unfit for human consumption.