Scientists studying the effectiveness of indoor plants for the passive removal of ozone, found houseplants make "at best, modest contributions of about 0.9–9% to indoor ozone removal effectiveness," they reported in 2017 in the journal Building and Environment. The tests, performed in a laboratory to simulate the effects on a typical U.S. home, found houseplants barely affected the environment. To make a meaningful difference to the air quality of your home, you'd need to fill a room from top to bottom with plants, they suggest.
