Plants rated top indoor air 'cleaners'

ATHENS, Ga., Nov. 5 (UPI) -- U.S. scientists say they have come up with five ornamental plants that do a superior job of removing indoor air pollutants.

The study of 28 types of plants, published in HortScience, found Hemigraphis alternata, known as purple waffle plant; Hedera helix or English ivy; Hoya carnosa or variegated wax plant; and Asparagus densiflorus or Asparagus fern had the highest removal rates for all five volatile organic compounds introduced.

Tradescantia pallida or Purple heart plant was rated superior for its ability to remove four of the volatile organic compounds.

Study leader Stanley J. Kays of the University of Georgia in Athens placed plants in gas-tight glass jars, exposing them to benzene, octane, toluene and alpha-pinene. The researchers analyzed air samples and then classified plants as superior, intermediate and poor in their ability to remove the five volatile organic compounds from the air.

"The volatile organic compounds tested in this study can adversely affect indoor air quality and have a potential to seriously compromise the health of exposed individuals," Kays said in a statement.

Kays said benzene and toluene are known to originate from petroleum-based indoor coatings, cleaning solutions, plastics, environmental tobacco smoke and exterior exhaust fumes seeping into buildings; 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.