Common house plants like Peace Lily, Corn Plant and Fern Arum placed into a test chamber containing levels of NO2 similar to an office situated next to a busy road were able to remove around half the NO2 in the chamber over the course of an hour. The latest research led by scientists from the University of Birmingham found that common houseplants can reduce levels of  nitrogen dioxide (NO2) – a common pollutant – by as much as 20 percent. Dr Christian Pfrang, who led the research, said that the plants they chose showed strikingly similar abilities to remove NO2 from the atmosphere despite being very different from each other.