Abstract

The air pollution tolerance indices of 10 plants growing around the vicinity of Umuebulu Gas flare Station in Oyigbo Local Government Area of Rivers State, Nigeria were analyzed. Plant samples were randomly collected from the vicinity of the gas station. A composite sample of eight leaves for each plant was used for laboratory analysis. Four physiological and biochemical parameters: leaf relative water content (RWC), ascorbic acid content (AAC), total leaf chlorophyll (TLC) and pH of leaf extract were used to compute the Air pollution tolerance indices (APTI). Results showed order of tolerance as Psidium guajava (0.10%) > Puerenia phaseoloides (0.36%) > Mallotus oppositifolus (3.23%) > Musa paradisiaca (6.80%) > Telfairia occidentalis (7.01%) > Cymbopogon citratus (9.18%) > Talinum triangulare (9.36%) > Vernonia  amygdalina (12.34%) > Manihot esculenta (14.61%) > Ocimum gratissimum (36.53%); showing Psidium guajava as the most tolerant species while Ocimum gratissimum as the most sensitive species to air pollution stress. Therefore, plants with high and low APTI can serve as tolerant and sensitive species for air pollution biomonitor, respectively.

Key words: Air pollution, relative water content, chlorophyll content, ascorbic acid, pH, tolerance, sensitivity

Abbreviation

ES, Experimental; CS, control site; RWC, relative water content; AAC, ascorbic acid content; TLC, total leaf chlorophyll; APTI, air pollution tolerance indices