Comparative Performance of Different Plants as Phytoremediators for Heavy Metals Released by Varying Density Road...

Heavy metals released by traffic pollution significantly harm plant and animal health. This research aimed to determine how well different plant species can perform phytoremediation along roadsides with varying levels of traffic. Samples from 18 different native plants, along with soil and water, were collected at four locations with varying traffic intensities, identified as low (L1), moderate (L2), high (L3), and very high (L4), and tested for their phytoremediation capabilities for Pb, Cd, Ni, and Zn. For all samples, the concentration of heavy metals increased with increasing road traffic from low (L1) to very high (L4). The maximum heavy metal concentration (111.67, 7.41, 95.12 and 10.47 mg kg^-1), bioaccumulation factor (1.18, 6.18, 1.09 and 1.32), and translocation factor (0.986, 0.973, 0.989 and 1.102) for Zn, Cd, Pb, and Ni were observed for plant species Dodonaea viscosa, Cyprus rotundus, Verbesina encelioides, and Cynodon dactylon, respectively. Based on these findings, it was concluded that the species Verbesina encelioides, Cyprus rotundus, Cynodon dactylon, and Dodonaea viscosa are efficient phytoremediators for Pb, Cd, Ni, and Zn toxicity, respectively. Hence, these are recommended for phytoremediation of roadside soils polluted by vehicular emissions in ecological conditions similar to those of District Malakand.