In a 1987 study, the U.S. Environmental Protection Agency (EPA) ranked indoor air pollution fourth in cancer risk among the 13 top environmental problems analyzed. The United Nations Development Program estimated that more than two million people die each year due to the presence of toxic indoor air.
Most people spend more time indoors than outdoors these days, and acording to research from the EPA and the California Air Resources Board (ARB), indoor air pollutant levels are often higher than those outdoors, and contain potentially dangerous chemicals like formaldehyde, chloroform, and styrene, in ranges two to 50 times higher than outdoor levels.
What can you do? In addition to standard safey measures like testing for radon, installing an air filter, allowing and allowing for regular ventilation, and using eco-friendly cleaners, recent research shows that several types of houseplants can help significantly reduce the levels of pollutants in your home or office.
Studies Show Plants Work
Several studies have indicated that indoor plants can help us breathe cleaner air.
- Study 1: A research team from Pennsylvania State University published the results of a study on the effects of three common houseplants on indoor ozone levels in HortTechnology. They released ozone into two chambers—one with houseplants, and one without—and found the ozone depletion rates were higher in the chambers that contained plants. Ozone is the main component of air pollution, or smog, and frequently infiltrates indoor environments. Toxic effects on humans include pulmonary edema, inflammation, and reduction of lung function.
- Study 2: In 1989, a two-year study by NASA and the Associated Landscape Contractors of America found that certain tropical plants commonly used as houseplants were effective in removing formaldehyde, benzene, and trichloroethane from the air and replacing it with breathable oxygen. Though all plants provide some benefit to air quality, the tropical ones proved more effective at processing gas and chemicals.
- Study 3: Studies over the past five years by the University of Technology, Sydney, found that installing small groups of the Janet Craig and Sweet Chico plants in offices reduced total levels of volatile organic compounds (VOCs) by up to 75 percent, and dust by 20 percent, with results consistent over the 5-12 weeks studied. Researchers estimate that six or more plants in a 1,200- to 1,500-square-foot house could achieve significant reduction of indoor air pollution.
- Study 4: Research from the Washington State University found that dust was reduced as much as 20 percent when a number of plants were placed around the perimeter of a computer lab and small office for one week.
Plants That Can Clean Up Your Indoor Air
Plants clean indoor air in two ways—by absorbing contaminants through pores on the leaves, and by metabolizing contaminants through organisms living in the soil. In fact, plants are so effective that some stores, like Lowe’s and Home Depot, are starting to label the most effective ones with tags.
Though it seems most plants will benefit indoor air, the following are those that have been shown in scientific studies and shown to work. These plants can also help maintain humidity levels and remove mold spores and bacteria from the air.
- Spider Plant: formaldehyde, xylene and toluene.
- Golden Pothos: benzene, formaldehyde, trichloroethylene, xylene and toluene.
- Snake Plant (Mother-in-Law’s Tongue): benzene, formaldehyde, trichloroethylene, xylene and toluene.
- Bamboo Palm or Reed Palm: formaldehyde, xylene, and toluene.
- Chinese Evergreen: benzene, formaldehyde.
- Peace Lily: benzene, formaldehyde, trichloroethylene, xylene, toluene, and ammonia.
- English Ivy: mold and mildew, formaldehyde, benzene, xylene, and toluene.
- Gerbera Daisies: benzene, formaldehyde, trichloroethylene.
- Red-Edged Dracaena (Dracaena Marginata): benzene, formaldehyde, trichloroethylene, xylene, and toluene.
- Warneck Dracaena: benzene, trichloroethylene, xylene, and toluene.
- Weeping Fig: formaldehyde, xylene, and toluene.
- Chrysanthemum: formaldehyde, benzene, trichloroethylene, xylene, toluene, and ammonia.
- Boston fern: formaldehyde, xylene and toluene.
- Philodendron: formaldehyde.
Do you use houseplants to clean up indoor air? Which ones?
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“Reducing Indoor Air Pollution a Serious Health Problem,” California Air Resources Board, May 2, 2001, http://www.arb.ca.gov/research/indoor/rediap.htm.
American Society for Horticultural Science (2009, September 9). Houseplants Cut Indoor Ozone. ScienceDaily. Retrieved February 25, 2013, from http://www.sciencedaily.com /releases/2009/09/090908103634.htm.
“Best Houseplants to Improve Indoor Air Quality,” Pro’s Who Know, March 1, 2010, http://proswhoknow.wordpress.com/2010/03/01/best-houseplants-to-improve-indoor-air-quality/.
“A Superhero Scrubs the Air: the Mighty Houseplant,” The Wallstreet Journal, March 14, 2011, http://online.wsj.com/article/SB10001424052748704893604576200423930895948.html.
Heather L. Papinchak, et al., “Effectiveness of Houseplants in Reducing the Indoor Air Pollutant Ozone,” HortTechnology, April-June 2009, 19(2): 286-290, http://horttech.ashspublications.org/content/19/2/286.full.pdf.