After analyzing decades of research, a Drexel environmental engineering professor is debunking the myth that potted plants can help purify indoor air.
Plants can help spruce up a home or office space, but claims about their ability to improve the air quality are vastly overstated, according to research out of Drexel University. A closer look at decades of research suggesting that potted plants can improve the air in homes and offices reveals that natural ventilation far outpaces plants when it comes to cleaning the air.
“This has been a common misconception for some time. Plants are great, but they don’t actually clean indoor air quickly enough to have an effect on the air quality of your home or office environment,” said Michael Waring, PhD, an associate professor of architectural and environmental engineering in Drexel’s College of Engineering.
Waring and one of his doctoral students, Bryan Cummings, reviewed a dozen studies, spanning 30 years of research, to draw their conclusions and recently published findings in Nature'sJournal of Exposure Science and Environmental Epidemiology. The central finding is that the natural or ventilation air exchange rates in indoor environments, like homes and offices, dilutes concentrations of volatile organic compounds — the air pollution that plants are allegedly cleaning —much faster than plants can extract them from the air.
The high-profile experiment that seemed to create the myth of houseplants as air purifiers happened in 1989 when NASA, in search of ways to clean the air on space stations, declared that plants could be used to remove cancer-causing chemicals from the air.
But the problem with this experiment, and others like it, is that they were conducted in a sealed chamber in a lab — a contained environment that has little in common with a house or office — and the data from these studies was not interpreted further to reflect what the findings would be if the plant were in a real indoor environment with natural or ventilation air exchange.
