Is Your Home's Air Unhealthy? Try Plants
Plants Can Remove Harmful Indoor Airborne Contaminants, Study Says
Dec. 4, 2009 -- Certain plants can remove dangerous airborne contaminants
commonly found in homes, new research suggests.
The contaminants plants can remove from the air include harmful volatile
organic compounds such as benzene, toluene, octane, alpha-pinene, and
trichloroethylene (TCE), the researchers say in a study published in the August
issue of HortScience.
Of 28 indoor plants tested, Stanley Kays, PhD, of the University of Georgia
and his horticultural team identified five “super ornamentals” that had the
highest rates of contaminant removal, a process called phytoremediation.
These are the red ivy (Hemigraphis alternata), English ivy (Hedera
helix), variegated wax plant (Hoya cornosa), asparagus fern
(Asparagus densiflorus), and the purple heart (Tradescantia
pallida), the study says.
The scientists placed the plants in glass, gas-tight containers, exposing
them to common volatile organic compounds found indoors. And the plants did a
good job of removing the airborne contaminants.
Researchers say there may be thousands of plants capable of removing
Volatile organic compounds are likely wafting about in every house, Kays
tells WebMD. They’re given off by home furnishings, carpets, plastics, cleaning
products, building materials such as drywall, paint, solvents, adhesives, and
even tap water, Kays says.
The pollutants have been linked to many illnesses, including asthma, cancer,
and reproductive and neurological disorders, and claim 1.6 million lives a
year, he says, attributing that number to the World Health Organization.
Air inside homes and offices is often a concentrated source of such
pollutants, in some cases up to 100 times more polluted than outdoor air, Kays
No one yet knows why some plants are effective at remediation, but he and
other scientists are digging for answers.
“We also want to determine the species and number of plants needed in a
house or office to neutralize problem contaminants,” he says in a news release.
“The idea that plants take up volatile compounds isn’t as much of a surprise as
the poor air quality we measured inside some of the homes we tested.”
There is no affordable way for average consumers to determine the air
quality of their homes, Kays says.
He tells WebMD that not all volatile organic compounds are toxic, and that
some plants emit toxins, too. But placing some common ornamentals indoors has
the potential to improve air quality, he says.
“In reality, you are much more in danger from these compounds inside than
outside,” he tells WebMD. “All houses have these compounds. Even computers give
them off. It would be advantageous then to have a few plants in your house.
They also keep humidity at fairly constant levels.”
But there is no magic list on the horizon, he says.
“You might have some plants that are good with benzenes but not with
formaldehyde, which comes from upholstery, carpet, a lot of sources,” he tells
Hopefully, he says, in a few years there will be an affordable test that can
alert people to the contaminants in their homes, and a list of the best plants
to help clean the air.
“Ideally, we’d have an extension service that would send out a packet that
would do the test for you to send back and get recommendations,” he tells
He says scientists in Korea are “substantially ahead of us in
phytoremediation research,” and one with whom he is collaborating, Kwang Jin
Kim, PhD, of the National Horticultural Institute in Seoul, has evaluated the
ability of 86 species to remove indoor formaldehyde.