Ordinary potted house plants can potentially make a significant contribution to reducing air pollution in homes and offices, according to new research led by the University of Birmingham and in partnership with the Royal Horticultural Society (RHS).

During a series of experiments monitoring common houseplants exposed to nitrogen dioxide (NO2) – a common pollutant – researchers calculated that in some conditions, the plants could be able to reduce NO2 by as much as 20%.

The researchers tested three houseplants commonly found in UK homes, easy to maintain and not overly expensive to buy. They included peace lily (Spathiphyllum wallisii), corn plant (Dracaena fragrans) and fern arum (Zamioculcas zamiifolia).

Each plant was put, by itself, into a test chamber containing levels of NO2 comparable to an office situated next to a busy road.

Over a period of one hour, the team calculated that all the plants, regardless of species, were able to remove around half the NO2 in the chamber. The performance of the plants was not dependent on the plants’ environment, for example whether it was in light or dark conditions, and whether the soil was wet or dry.

“The plants we chose were all very different from each other, yet they all showed strikingly similar abilities to remove NO2 from the atmosphere. This is very different from the way indoor plants take up CO2 in our earlier work, which is strongly dependent on environmental factors such as nighttime or daytime, or soil water content,” said lead researcher Christian Pfrang.