Variation in Formaldehyde Removal Efficiency among Indoor Plant Species

The efficiency of volatile formaldehyde removal was assessed in 86 species of plants representing five general classes (ferns, woody foliage plants, herbaceous foliage plants, Korean native plants, and herbs). Phytoremediation potential was assessed by exposing the plants to gaseous formaldehyde (2.0 mu L.L-1) in airtight chambers (1.0 m(3)) constructed of inert materials and measuring the rate of removal. Osmunda japonica, Selaginella tamariscina, Davallia mariesii, Polypodium formosanum, Psidium guajava, Lavandula spp., Pteris dispar, Pteris multifida, and Pelargonium spp. were the most effective species tested, removing more than 1.87 mu g.m(-3.)cm(-2) over 5 h. Ferns had the highest formaldehyde removal efficiency of the classes of plants tested with 0. japonica the most effective of the 86 species (i.e., 6.64 mu g.m(-3).cm(-2) leaf area over 5 h). The most effective species in individual classes were: ferns-Osmudu japonica, Selaginella tamariscina, and Davallia mariesii; woody foliage plants-Psidium guajava, Rhapis excels, and Zamia pumila; herbaceous foliage plants-Chlorophytum bichetii, Dieffenbachia 'Marianne', Tillandsia cyanea, and Anthurium andraeanum; Korean native plants-Nandina domestica; and herbs-Lavandula spp., Pelargonium spp., and Rosmarinns officinalis. The species were separated into three general groups based on their formaldehyde removal efficiency: excellent (greater than 1.2 mu g.m(-3) formaldehyde per cm(2) of leaf area over 5 h), intermediate (1.2 or less to 0.6), and poor (less than 0.6). Species classified as excellent are considered viable phytoremediation candidates for homes and offices where volatile formaldehyde is a concern.