Indoor air pollution is a critical environmental challenge with negative impacts on human health, especially in urban and enclosed settings. This study aimed to evaluate the tolerance of three indoor ornamental plants—Epipremnum aureum, Sansevieria trifasciata, and Syngonium podophyllum Schott—against pollutants generated by cigarette smoke and kerosene combustion. Plants were exposed under controlled indoor conditions, while particulate matter (PM₁. ₀, PM₂. ₅, PM₁₀), total volatile organic compounds (TVOCs), and carbon dioxide (CO₂) were measured before, during, and after exposure. Plant tolerance was assessed using the Air Pollution Tolerance Index (APTI), calculated from total chlorophyll content, leaf extract pH, ascorbic acid, and relative water content. Both cigarette smoke and kerosene combustion caused significant increases in all measured pollutants (p < 0.001, η2 = 0.588–0.894). Specifically, cigarette smoke increased PM₁.₀ from 71.6 ± 29.5 to 564.5 ± 174.8 μg/m3, PM₂. ₅ from 101.9 ± 53.9 to 788.4 ± 196.9 μg/m3, PM₁₀ from 68.7 ± 14.7 to 498.9 ± 154.4 μg/m3, TVOCs from 79.1 ± 60.6 to 0.53 ± 0.17 mg/m3, and CO₂ from 459.5 ± 88.8 to 1067.1 ± 281.2 ppm. Kerosene combustion increased PM₁.₀ from 70.6 ± 42.2 to 462.0 ± 183.4 μg/m3, PM₂.₅ from 101.7 ± 71.4 to 774.3 ± 249.3 μg/m3, PM₁₀ from 124.4 ± 83.6 to 796.0 ± 290.2 μg/ m3, TVOCs from 77.5 ± 61.9 to 3.0 ± 15.4 mg/m3, and CO₂ from 459.5 ± 88.8 to 1560.8 ± 412.5 ppm. Foliar applications of glycine, yeast extract, and their combination significantly enhanced plant tolerance, with S. podophyllum showing the highest APTI (101.0) and S. trifasciata moderate tolerance (77.6), while E. aureum exhibited lower tolerance (32.6). These findings indicate that selected ornamental plants can effectively mitigate indoor air pollution, whereas sensitive species such as E. aureum may serve as bioindicators for monitoring indoor air quality.
