Spatial variation in Heavy Metal residue in Corchorus olitorious cultivated along a Major highway in Ikorodu- Lagos, Nigeria

Abstract

This study focused on heavy metals (Lead (Pb), Zinc (Zn) and Cadmium (Cd)) contamination in the vegetable Corchorus olitorius (C.olitorius) leaves cultivated along a major road. Samples the vegetable, C. olitorius leaves) were collected from two sites, one of which is located on a major highway and the other remotely located from any form of industrial activity and which served as the control site. These samples were collected at
distances of 10, 20 and 30m from the roadside and analyzed for Pb, Zn and Cd content by atomic absorption spectrophotometer. The mean concentration of heavy metals in the studied vegetable with effect to distance from the road was compared with the permissible values given by WHO/FAO. Mean concentration of heavy metal in C. olitorius leaves ranged from 0.013 to 0.310mg/kg, 2.500 to 4.850mg/kg and 0.063 to 0.205mg/kg at 10m, 20m and 30m distances respectively from the road. In all cases, it was observed that the closer the plants were to the road, the higher the heavy metal burden. The result of this study shows that, while the concentration of heavy metals in C. olitorius leaves from the control site remains constant, (i.e. showing no sign of contamination) the concentration of heavy metals in C. olitorius leaves cultivated along major road decreased with an increasing distance from the road.