A survey of trace metals in vegetation, soil and lower animal along some selected major roads in metropolitan city of Lagos

The concentration of trace metals (Cd, Cu, Pb and Zn) in a total of 144 samples of grass, soil and lower animal ( earthworm, Lybrodrilus violaceous) were collected and analysed for their metallic content. Levels of cadmium ranged from 0.01 - 0.07 mu g g(-1); 0.01 - 0.12 mu g g(-1) and from trace- 0.05 mu g g(-1) dry weight for plant, soil and animal samples respectively. Mean concentration of copper ranged 0.10 - 1.48 mu g g(-1); 0.10 - 2.90 mu g g(-1) and 0.01 - 0.08 mu g g(-1) for samples in similar order as above. The levels of Pb varied from 0.01 - 0.14 mu g g(-1); 0.02 - 0.23 mu g g(-1) and from trace- 0.07 mu g g(-1) while that of Zn ranged from 0.19 - 1.80 mu g g(-1); 0.51 - 3.35 mu g g(-1) and 0.01 - 0.08 mu g g(-1) also in the same order of samples as mentioned above. Levels of metals in soil samples were higher than the background levels with the exception of Zn but lower than European Union (EU) limits. The results generally revealed the presence of metals in plant and animal samples and metal dynamics up the food chain is highly possible. Acceptable recoveries of the spiking experiment validate the experimental protocol.