Particulate Matter Removal of Three Woody Plant Species, Ardisia crenata, Ardisia japonica, and Maesa japonica

In this study, we investigated the physiological responses and particulate matter (PM) abatement and adsorption of three plants: Ardisia crenata, Ardisia japonica, and Maesa japonica, to determine their effectiveness as indoor air purification. When compared to control (without plants), PM was significantly and rapidly decreased by all three plants. The reduction in PM varied by species, with A. crenata being the most effective, followed closely by A. japonica, and finally M. japonica. M. japonica showed the highest rate of photosynthesis and transpiration, generating the greatest decrease in CO2 and a large increase in relative humidity. We hypothesize that the increased relative humidity in the chamber acted in a manner similar to a chemical flocculant, increasing the weight of PM via combination with airborne water particles and the creation of larger PM aggregates, resulting in a faster sedimentation rate. A. crenata had a stomatal size of ~20 μm or larger, suggesting that the PM reduction observed in this species was the result of direct absorption. In the continuous fine dust exposure experiments, chlorophyll fluorescence values of all three species were in the normal range. In conclusion, all three species were found to be suitable indoor landscaping plants, effective at reducing indoor PM.