Research conducted by the University of Birmingham in partnership with the Royal Horticultural Society (RHS) concluded that three plants could significantly reduce pollution to improve living conditions.
In the trials, three standard and inexpensive houseplants (to make them accessible to everyone) were exposed to nitrogen dioxide, a pollutant common in most everyday settings. Each plant was placed by itself in a test chamber where nitrogen dioxide was similar to an office space.
The research showed that in one hour, all the plants could decrease pollution levels. All three houseplants could reduce nitrogen dioxide by around 20 percent for a small office space. The plants tested were the peace lily, corn, and fern arum.
There were undoubtedly some variants; for example, a plant in a room with poor ventilation would not be able to decrease pollution as effectively. But if you are in a poorly ventilated house or office, do not worry; by adding more plants to a poorly ventilated office or house, you can still achieve a 20% decrease in pollution (and even more with more plants). As a good rule of thumb, a poorly ventilated small office (15 square meters) with high levels of air pollution would require at least five houseplants to reduce pollution by 20%.
Funny enough, researchers do not fully understand how plants reduce nitrogen dioxide. According to the principal horticultural scientist at the Royal Horticultural Society, Dr. Tijana Blanusa:
“There was no indication, even during longer experiments, that our plants released the NO2 back into the atmosphere, so there is likely a biological process taking place also involving the soil the plant grows in—but we don’t yet know what that is.”
The next step in the study will seek to model air quality indoors, encompassing several more variables.