Particulate Matter Capturing Ability of some Plant Species: Implication for Phytoremediation of Particulate Pollution around Rourkela Steel Plant, Rourkela, India

The particulate pollution has always been a matter of great concern because of its adverse effect on human and plant population. In the present global environmental scenario, this problem has become increasingly severe. The particulates and gaseous pollutants, alone and in combination, can cause serious setbacks to the overall physiology of plants. Results from numerous investigations of human respiratory and other diseases have shown a consistent statistical association between human exposures to the outdoor levels of particulates or dust and adverse health impacts. These hazards are more pronounced in the vicinity of industries where these particles become air-borne and inhalable. Research has shown that plant leaves being the main receptor of particulate pollution can act as biological filters, removing large quantities of particles from the urban atmosphere. This physical trait can be used to determine the level of particulate pollution in the surroundings, as well as the ability of individual plant species to intercept and mitigate particulate pollutants. In the present study, fifteen plant species (11 trees and 4 shrubs) growing around the Rourkela Steel Plant (RSP) area were selected. Particulate or dust load on leaf surfaces and leaf surface morphology as a measure of dust trapping ability of leaves were analysed. The plant species such as Alstonia scholaris, Anthocephalus indicus, Cassia auriculata, Cassia siamea, Lagerstroemia speciosa, Mimusops elengi, Peltophorum inerme and Tabebuia aurea were found to have high dust capturing capacity; Albizia lebbeck, Bougainvillea spectabilis, Ficus religiosa, Swietenia mahagoni and Thevetia nerifolia have medium, while species such as Caesalpinea pulcherima and Delonix regia have low dust capturing capacity. Results also indicate that leaf surface morphology greatly determines the dust trapping capacity of a particular plant species.