Abstract

Plant species can be effectively used as filters for reducing air pollution and also as bio-indicators of urban air
quality. Physio-biochemical parameters namely Ascorbic acid, leaf extract pH, total chlorophyll content and
relative water content were measured to generate Air Pollution Tolerance Index (APTI) for seven plants each at
polluted site and controlled site. All the plants were found to be sensitive to air pollution. The APTI values were
in the range of 7.38 to 10.12 in the polluted site and 6.44 to 9.6 in control site. Aegle marmelos (10.12 and 9.6)
and Ziziphus zizyphus (7.38 and 6.44) have recorded high and low values in both the sites respectively. In
comparison between the two sites; although no significant difference between APTI values was found, all the
values were slightly higher in the polluted site than the controlled for all the six plants except in Leucaeana
leucocephala and a considerable variation was observed among the four parameters when their percentage
variations were considered. Aegle marmelos, Cassia auriculata and Bougainvillea spectabilis were found to be
tolerant towards air pollution.