BIOMONITORING OF HEAVY METALS POLLUTION IN THE UNIVERSITY OF LAGOS, AKOKA CAMPUS ENVIRONMENT USING THE MOSS DICRANIUM SCORPARIUM HEDW

Abstract

The level of atmospheric heavy metal deposition in University of Lagos, Akoka campus was investigated using the moss Dicranum scorparium Hedw. Moss samples were collected from unplastered perimeter walls and rock surfaces at ten sampling sites labeled A-J: UBA Park (A), Ransome Kuti (B). Makama Hall (C), Faculty of Law (D), Moremi Car Park (E), Medical Centre (F), Ozoluwa BQs (G), High Rise Buildings (H), Honors Hall (I), Lagoon Front (J). A control sampling was done at First Estate, Amuwo-Odofin LGA. The concentrations of Cadmium (Cd), Lead (Pb), Nickel (Ni), Copper (Cu) and Zinc (Zn) were determined using Atomic Absorption Spectrophotometer (AAS) Perkin Elmer AA 800. The results obtained confirmed the presence of heavy metal in this order Zn > Pb > Cd > Cu > Ni. The concentration of Zn, Cd and Pb were greater than the FME and UNEP threshold limiting values.  The analysis of the anthropogenic influence of the pollutants on the environment revealed that Zn (4.24mg/L) despite its highest abundance is a moderate contaminant in the study locations. Contamination factor (CF) suggests that locations B, D, F, G and J are seriously contaminated (C5) while locations A, C, E, H, and I are extremely contaminated (C6). The index of geo-accumulation revealed that all the studied locations are in the I_geo7 category indicating extremely pollution with the assayed metals. The difference in the occurrence of anthropogenic activities was seen to be the major factor responsible for the variations in the concentration of heavy metals accumulated by the mosses.