<p>Industrial emissions pose significant threats to environmental health. Trees serve as biomonitors, with inherent species-specific capacity. Studies on tree species’ responses across varying pollution loads remain poorly understood. This study evaluated the responses of three common tree species (<i>Mangifera indica</i>, <i>Anthocleista vogeli</i>, and <i>Delonix regia</i>) in two industrial sites (Afam and Umuebule) and a non-industrial site (Ohaji-Egbema Forest Reserve) in Southern Nigeria, using Air Pollution Tolerance Index (APTI) and Anticipated Performance Index (API). Trees with diameter at breast height (DBH) &gt; 15&#xa0;cm were systematically sampled within a 100&#xa0;m radius. Leaves were collected in triplicates for each species. Structural attributes (DBH, crown diameter, height) were measured in situ; air quality parameters (Pm, CO, NO₂, SO₂, O₃, VOCs) were monitored diurnally for 4 months, while leaf biochemical properties (chlorophyll, relative water content, ascorbic acid, and pH) were determined in the laboratory. Results revealed elevated air pollutants concentrations at the industrial sites, particularly Umuebule. Two-way ANOVA indicated significant effects of site, time, and site × time interaction on air quality parameters and site, species, and site × species interaction effect on the biochemical parameters and APTI (<i>p</i> &lt; 0.001). Pearson correlation revealed significant association between the biochemical parameters, APTI, and air quality parameters, while structural attributes had no significant correlation with biochemical parameters except RWC. APTI and API classified <i>M. indica</i> as “excellent” species in polluted sites, <i>A. vogeli</i> as “moderate” spp. especially in drought-prone areas, and <i>D. regia</i> as “sensitive” spp. in highly polluted areas. These findings demonstrate that environmental conditions and species-specific traits determine tree responses to air pollution.</p>