Effect On Plants Due To Air Pollution Exposure

Plants absorb and accumulate pollutants from the air and help to reduce the pollution level in the atmosphere. Plants provide a  large leaf area for impingement. Certain changes in morphological, anatomical, and physiological characteristics of plants have been reported when plants experienced air pollution exposure. 

The rate and the total amount of pollutants taken up from the air can affect photosynthesis, respiration, growth, yield, leaf conductance, and leaf longevity. All of these factors in trees adversely affect the canopy carbon fixation and biosynthesis of chlorophyll. 

Air pollutants affect the plants even in very low concentrations (0.1 to 55 ppm). But, plant species differ in their sensitivity level to air pollutants. Plant's symptoms in response to air pollution are of two types chronic and acute depend upon the extent of exposure. Chronic injury results from low-level pollutant exposure. 

Chronic symptoms usually do not kill the tissue. Chronic symptoms characterized by stripping, yellowing, dwarfing, or growth loss. An acute injury is due to plant exposure to a
high level of pollutants. Acute symptom characterized by dead tissue in a particular area. Sometimes whole leaf or even plant death also occurs. 

Loss of chlorophyll, bronzing, and reddening of the leaves is the commonly associated symptoms related to ozone exposure; whereas, upon the long exposure of SO₂, broad-leaved species produced dark brown inter-veinal bifacial necrosis spots on the leaf lamina.