Spatiotemporal Differences and Ecological Risk Assessment of Heavy Metal Pollution of Roadside Plant Leaves in Baoji City, China

Abstract

The concentration of heavy metals in plants’ leaves can effectively indicate the spatiotemporal differences of environmental pollution, providing a scientific basis for the monitoring of urban air quality. The concentration of Ni, Cu, Cd, Pb and Zn in the leaves of five different species (Ophiopogon japonicus, Ligustrum vicaryi, Platanus acerifolia, Sophora japonicaand Cedrusdeodara) were measured, which were from I, II, III, IV (0.05 m, 0.25 m, 1 m, 4 m) at different times (May and November) in the green belt of Baoji city. The degree of heavy metal pollution and potential ec ological risk were analyzed. The results revealed that the concentration of Zn, Cu and Pb in roadside plant leaves was relatively high. In May, the heavy metal concentration was the highest in the leaves of C.deodara, whereas this was the case for S. japonica in November. Arbors were more effective at capturing particles from the atmosphere than low plants. At the same height, areas with high levels of heavy metal pollution in May were basically the same as that in November, and areas with high levels of pollution were affected by traffic and industry. The pollution index and the comprehensive index of potential ecological risk of element Cd were the highest, indicating that the potential harm of Cd to the environment should receive more attention from the Government.