ABSTRACT
Air pollution in general, and suspended particulate matter (PM) in particular, is a serious environmental threat for all biological life forms on earth. In urban spaces particularly, PM pollutants have profound effects on physiology, biochemistry, and overall development of green plants. PM accumulation on plants depends on pollution sources and kinds of pollutants present in the air. Morphological features such as texture of leaf, trichomes present on the leaves, and size and length of petiole also affects the PM accumulation on leaves. Various biochemical parameters like sugar and protein content, pigment concentration and composition, and ascorbic acid content are impacted by PM pollutants. In addition, physiological parameters like pH of the leaf sap and water content of the leaf are also impacted. The kind of PM—namely, heavy metals and polycyclic aromatic hydrocarbons (PAHs)—affects the morphology of plants, like the number and size of the leaves, leaf area, number and structure of stomata. All these properties together contribute to the tolerance of plants to different pollutants. In this chapter, an attempt has been made to look into the harmful impact of PM on plants and evaluating characteristics that make them suitable as biomonitors for air pollution.
