Removal of Indoor Tobacco Smoke under Light and Dark Conditions as Affected by Foliage Plants

The efficacy of three species of indoor plants (Spathiphyllum spp., Ficus elastica and Syngonium podophyllum) for the removal of environment tobacco smoke (ETS) particulate matter (PM) in the light and dark and changes in physiological responses (photosynthesis, transpiration, respiration) of the plants to ETS was assessed. Cigarette smoke was generated in sealed chambers to give an initial concentration of ～182 ㎍ㆍm?³ and after normalization (10 min) the concentrations of various size categories (PM₁?, PM 1.0 , and PM 0.5 ) were determined. ETS PM diminished with time due to adsorption and sedimentation. However, the decrease was accelerated by the presence of indoor plants in both the light and dark. Removal efficiency varied among species and was not correlated with leaf area. Spathiphyllum spp. had the highest removal efficacy on a leaf area basis among the species tested in both light and dark conditions, and removal was more efficient in the light than in the dark. In the dark there was little difference in removal efficiency among species or in respiratory rate. The removal efficiency in the light was higher in species with higher photosynthetic rates, suggesting that photosynthesis may be involved in the accelerated removal.