ASSESSMENT OF AIR POLLUTION TOLERANCE INDEX IN SELECTED AREAS ALONG EPE ROADSIDE LAGOS STATE NIGERIA

Rapid urbanization and increased vehicular activities in Nigeria have led to a significant rise in roadside air pollution, posing risks to human health, environmental sustainability, and biodiversity. Plants, being continuously exposed to atmospheric contaminants, act as natural bioindicators and can be evaluated for their sensitivity or tolerance through the Air Pollution Tolerance Index (APTI). This study assessed the tolerance levels of three commonly occurring tree species Azadirachta indica, Ficus exasperata, and Newbouldia laevis—collected along the Epe roadside, Lagos State, Nigeria, while relatively unpolluted samples from Lagos State University (LASU) Epe campus were used as control. Biochemical parameters including leaf pH, ascorbic acid content, relative water content (RWC), and total chlorophyll were quantified following standard analytical protocols. These variables were integrated into the APTI formula to categorize the species as sensitive or tolerant. The findings revealed interspecific variations in APTI values, with Azadirachta indica exhibiting the highest tolerance, reflecting its potential resilience and suitability for urban afforestation and roadside plantation. In contrast, Ficus exasperata and Newbouldia laevis displayed moderate to low tolerance, indicating their susceptibility to vehicular emissions and utility as Bioindicators for air quality monitoring. Statistical analysis further confirmed significant differences (p < 0.05) among the species across the studied biochemical parameters. This study provides valuable baseline data on the air pollution mitigation potential of selected plant species in Epe, contributing to sustainable environmental management practices.