The major pollutant emitted from vehicles are Carbon monoxide, Nitrogen oxide, Hydrocarbons, Sulphur dioxide and Sulphur trioxides, tetraethyl lead and tetramethyl lead, etc. These pollutants directly affect the Avenue trees by reducing their Chlorophyll content, increasing Ascorbic acid and closing Stomata.
To evaluate the effect of vehicular pollution on avenue trees of NH-31 from Naugachhia to Begusarai (Distance 113 Km) APTI of 10 plants were calculated. APTI ranged in between 7.067 to 13.755. The minimum was of Aegle marmelos and maximum of Acacia arabica followed by Ficus benghalensis, Ficus religiosa, Azadirachta indica and Saraca indica.