Plants as Natural Air Purifiers

Most people know that trees and plants enhance the quality of the air outdoors by consuming carbon dioxide, converting it into food for themselves and releasing oxygen as a byproduct into the atmosphere. But new research from the University of Georgia now shows that certain plants are extremely effective at removing harmful volatile organic compounds from indoor air, suggesting they can play a critical role in improving the healthiness of homes and offices, too.

I recently spoke to Professor Stanley Kays, one of the authors of the study, and he told me that among 28 plants the research group tested, five “super ornamentals” scored especially high in removing contaminants from the air through a process called phytoremediation. These include the purple waffle plant (Hemigraphis alternataa), English ivy (Hedera Helix), variegated wax plant (Hoya cornosa), asparagus fern (Asparagus densiflorus) and the purple heart plant (Tradescantia pallida).

“The more leaves a plant has and the bigger they are, the more effective it is in removing toxins from the air over time,” says Kays, noting the purple waffle plant as the real star among the super ornamentals. “The idea that plants take up volatile compounds isn’t as much of a surprise as the poor indoor air quality we measured inside of some of the homes we tested,” he says. “We found unexpectedly high levels of benzenes and a potpourri of other contaminants that can seriously compromise the health of those exposed.”

These volatile organic compounds emanate from all kinds of furnishings and building materials,

such as foams, carpets, plastics, drywall, paint and insulation among other things, and contribute to indoor environments that can be up to 100 times more polluted than outdoor environments. They can also cause a whole host of serious illnesses, including asthma, cancer, and neurological disorders.

When I asked him how many plants would be ideal to help purify toxic indoor air, he said told me it would depend on the types of and volume of VOCs actually in the air. “But even one plant would be helpful,” he said. I think I’ll go to the flower market and try to find one.