ASSESSING THE AIR POLLUTION TOLERANCE INDEX AND ANTICIPATED PERFORMANCE INDEX OF ROADSIDE PLANT SPECIES FOR BIOMONITORING ENVIRONMENTAL HEALTH

Abstract

Leaf surface of plants acts as a sink for the deposition of air pollutants in the urban environment andis considered an ecologically sustainable cost-effective strategy to mitigate the impact of air pollution.In this context, assessment of air pollution tolerance index (APTI) and anticipated performanceindex (API) was calculated to observe the tolerant potential of fifteen plant species along roadsideof Kathmandu valley. APTI was determined by combining the four biochemical and physiologicalparameters; Relative water content (RWC), Total chlorophyll content (TChl), Ascorbic acid content(AA) and Leaf extract pH using a pre-defined formula. Results suggested that, TChl and pH werelower, and RWC and AA were higher at heavily polluted area in comparison to the control site. TheAPTI for the species ranged between 7.57 and 11.51, ideal for sensitive species category (APTI < 16),and the plants are classified as bio indicators of air pollution. Highest mean ATPI (11.51) wasrecorded in Callistemon citrinus and lowest (7.57) was recorded in Buddleja asiatica. The API notonly takes APTI into consideration but also the biological and socio-economic aspect of the species.The API grade indicates. Ficus religiosa and N. arbor-tritis (API = 5) as good performers whileCallistemon citrinus (API=4), Nerium oleander (API=3), Bougainvillea glabra (API=3) and Buddlejaasiatica (API=3) are predicted to be moderate green belt performers. On the basis of APTI and APIassessment, the study suggest that out of fifteen species, only six plants species were identifiedas suitable green belt development. The overall results highlight the suitability of APTI and APIas simple, inexpensive, and convenient methods for recommending plant species for urban areaswith sound environmental pollution with dust load.