Common plants can help remove indoor air pollutants

Washington, Nov 5 : Common indoor plants such as purple waffle, English ivy, variegated wax and purple heart plant have been found tremendously effective in eliminating harmful air pollutants in homes, offices, and other indoor spaces, say researchers.

Indoor air is said to be 12 times more polluted than outdoor air due to paints, varnishes, adhesives, furnishings, clothing, solvents, building materials, and even tap water.

Lead researcher Stanley J. Kays, Department of Horticulture, University of Georgia, tested the ornamental indoor plants for their ability to remove harmful VOCs or volatile organic compounds from indoor air.

These 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.

Adding ornamental plants to indoor spaces can reduce stress, increase task performance, and reduce symptoms of ill health.

During the study, 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 said.

"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," he added.

These 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.

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 is published in HortScience.