Plant Leaves as Bio-Indicator for Lead (Pb) Pollution Along Road Sides and Industrial Areas in Ibadan Metropolis

Heavy metal pollution still poses a serious threat to human and the environment especially in urban settlement where industrial and vehicular activities are most prevalent. This study was carried out to investigate the level of heavy metal pollution in two local government areas in Ibadan metropolis using the leaves of plants as bio-indicators. Composite samples of Tridax procumbens (Tridax plant), Chromolaena odorata (Siam weed), Pennisetum purpureum (Elephant grass), were collected from different sites in industrial areas, along roadsides in these local government areas and control site during dry season and were digested according to standard procedures. The lead concentration in the digested samples were determined using Atomic Absorption Spectrophotometer. Result of the analysis shows a significant level of lead in the leaf samples. Leaves of Tridax procumbens were found to be the most tolerant specie and therefore the most suitable bioindicator for lead pollution among the three plant species selected.