Heavy metals accumulation in suburban roadside plants of a tropical area (Jengka, Malaysia)

Abstract

Introduction: This study aims to examine the uptake and translocation of Cd, Cu, Fe, and Pb in different parts of three roadside plant species grown in the semi-urban of Jengka, Pahang, Malaysia. Methods: Heavy metal concentrations were determined from various parts of Athyrium esculentum (AE), Chromolaena odorata (CO), and Lantana camara (LC). The bioconcentration factor (BCF) and translocation ratio of heavy metals from soils to plants were estimated. Results: Fe showed the highest metal concentration determined (< 850 mg kg−1), while Cd showed the lowest metal concentration observed (< 0.12 mg kg−1) in all plants. Heavy metal concentration in the roadside plants was higher than metal determined in the same species from an uncontaminated site. Principal component analysis (PCA) suggests anthropogenic and natural sources of heavy metal. Plant roots slightly enriched by Cd and Pb (BCF < 1), while the leaves absorbed and accumulated Cu and Fe (BCF > 1). The translocation ratio of four metals suggests that absorption of the three plants had the rank: root > stem > leaves. Conclusion: The metals in the root zone transported weakly to the stem but more strongly mobilized to leaves when available in the stems. A comprehensive study of heavy metal concentration in a variety of roadside plants in the tropical area should be done in the future ensuring the precise source and translocation mechanisms.