Common plants can eliminate indoor air pollutants

Nov 04, 2009
Hemigraphis alternata, or purple waffle plant, one of the highest rated ornamentals for removing indoor air pollutants. Credit: Photo courtesy of Dr. Stanley Kays

Air quality in homes, offices, and other indoor spaces is becoming a major health concern, particularly in developed countries where people often spend more than 90% of their time indoors. Surprisingly, indoor air has been reported to be as much as 12 times more polluted than outdoor air in some areas. Indoor air pollutants emanate from paints, varnishes, adhesives, furnishings, clothing, solvents, building materials, and even tap water.

A long list of , or VOCs [including benzene, xylene, hexane, heptane, octane, decane, trichloroethylene (TCE), and methylene chloride], have been shown to cause illnesses in people who are exposed to the compounds in indoor spaces. Acute illnesses like asthma and nausea and chronic diseases including cancer, neurologic, reproductive, developmental, and respiratory disorders are all linked to exposure to VOCs. Harmful indoor pollutants represent a serious health problem that is responsible for more than 1.6 million deaths each year, according to a 2002 report.

Stanley J. Kays, Department of Horticulture, University of Georgia, was the lead researcher of a study published in HortScience that tested ornamental indoor plants for their ability to remove harmful VOCs from indoor air. According to Kays, some indoor plants have the ability to effectively remove harmful VOCs from the air, and not only have the ability to improve our physical health, but also have been shown to enhance our psychological health. Adding these plants to indoor spaces can reduce stress, increase task performance, and reduce symptoms of ill health.

The ability of plants to remove VOCs is called "phytoremediation". To better understand the phytoremediation capacity of ornamental plants, the research team tested 28 common indoor ornamentals for their ability to remove five volatile indoor pollutants. "The VOCs tested in this study can adversely affect indoor air quality and have a potential to seriously compromise the health of exposed individuals," Kays explained. "Benzene and toluene are known to originate from petroleum-based indoor coatings, cleaning solutions, plastics, environmental tobacco smoke, and exterior exhaust fumes emanating into the building; octane from paint, adhesives, and building materials; TCE from tap water, cleaning agents, insecticides, and plastic products; and alpha-pinene from synthetic paints and odorants."

During the research study, plants were grown in a shade house for eight weeks followed be acclimatization for twelve weeks under indoor conditions before being placed in gas-tight glass jars. The plants were exposed to benzene, TCE, toluene, octane, and alpha-pinene, and air samples were analyzed. The plants were then classified as superior, intermediate, and poor, according to their ability to remove VOCs.

Of the 28 species tested, Hemigraphis alternata (purple waffle plant), Hedera helix (English ivy), Hoya carnosa (variegated wax plant), and Asparagus densiflorus (Asparagus fern) had the highest removal rates for all of the VOCs introduced. Tradescantia pallida (Purple heart plant) was rated superior for its ability to remove four of the VOCs.

The study concluded that simply introducing common ornamental plants into indoor spaces has the potential to significantly improve the quality of indoor air. In addition to the obvious health benefits for consumers, the increased use of indoor plants in both ''green'' and traditional buildings could have a tremendous positive impact on the ornamental plant industry by increasing customer demand and sales.

More information: The complete study and abstract are available on the ASHS electronic journal web site: http://hortsci.ashspublications.org/cgi/content/abstract/44/5/1377

Source: American Society for Horticultural Science

Explore further: New research reveals fish are smarter than we thought

add to favorites email to friend print save as pdf

Related Stories

Houseplants cut indoor ozone

Sep 08, 2009

Ozone, the main component of air pollution, or smog, is a highly reactive, colorless gas formed when oxygen reacts with other chemicals. Although ozone pollution is most often associated with outdoor air, ...

Probing Question: Is indoor air pollution really a problem?

Apr 30, 2009

A popular television commercial from the 1970s shows a Native American man in buckskin and feathers paddling his canoe through ink-black waters, past refineries billowing smoke. He comes aground on a litter-strewn shoreline ...

Recommended for you

Science casts light on sex in the orchard

13 hours ago

Persimmons are among the small club of plants with separate sexes—individual trees are either male or female. Now scientists at the University of California, Davis, and Kyoto University in Japan have discovered ...

Four new dragon millipedes found in China

14 hours ago

A team of speleobiologists from the South China Agriculture University and the Russian Academy of Sciences have described four new species of the dragon millipedes from southern China, two of which seem to ...

Scientist creates automatic birdsong recognition app

18 hours ago

Dr Dan Stowell, an EPSRC Research Fellow in QMUL's School of Electrical Engineering and Computer Science, has used a grant from Queen Mary Innovation to develop a prototype for an app that turns his research ...

New research reveals fish are smarter than we thought

18 hours ago

(Phys.org) —A new study from researchers in our Department of Psychology with colleagues at Queen Mary University of London has reported the first evidence that fish are able to process multiple objects ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Caliban
1 / 5 (1) Nov 04, 2009
Had always understood this to be the case- somewhat surprised to hear that this is(possibly) the first such study. Trials should be made with a wider variety of houseplants, as some do better than others based on the temperature and light conditions indoors.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.