In the late 1980s, a study by NASA and the Associated Landscape Contractors of America (ALCA) resulted in excellent news for homeowners and office workers everywhere. The study concluded that common houseplants such as bamboo palms and spider plants not only make indoor spaces more attractive, they also help to purify the air!
Newer homes and buildings, designed for energy efficiency, are often tightly sealed to avoid energy loss from heating and air conditioning systems. Moreover, synthetic building materials used in modern construction have been found to produce potential pollutants that remain trapped in these unventilated buildings.
Chemicals are released into the air within the home through a number of catalysts which are common to the home, (and often undetected as health threats) including upholstery, curtains, plywood, particle board, stains and varnished, paints, paper towels, tissues, carpets, permanent-press clothing, fabrics, construction materials, modern synthetic furniture, computers, electrical equipment, and other household products, synthetic materials and chemicals in, or around the home.
The trapped pollutants result in what is often called the Sick Building Syndrome. Symptoms of SBS include allergies, asthma, irritations of the eyes, nose and throat, fatigue, headache, nervous system disorders, respiratory congestion and sinus congestion.
While it’s a well-known fact that plants convert carbon dioxide into oxygen through photosynthesis, the NASA/ALCA study showed that many houseplants also remove harmful elements such as trichloroethylene, benzene, and formaldehyde from the air.
While NASA found that some of the plants were better than others for absorbing these common pollutants, all of the plants had properties that were useful in improving overall indoor air quality.
NASA also noted that some plants are better than others in treating certain chemicals.
For example, English ivy, gerbera daisies, pot mums, peace lily, bamboo palm, and Mother-in-law’s Tongue were found to be the best plants for treating air contaminated with Benzene. The peace lily, gerbera daisy, and bamboo palm were very effective in treating Trichloroethylene.
Additionally, NASA found that the bamboo palm, Mother-in-law’s tongue, dracaena warneckei, peace lily, dracaena marginata, golden pathos, and green spider plant worked well for filtering Formaldehyde.
After conducting the study, NASA and ALCA came up with a list of the most effective plants for treating indoor air pollution.
The recommended plants can be found below. Note that all the plants in the list are easily available from your local nursery.
1. Philodendron scandens `oxycardium’, heartleaf philodendron 2. Philodendron domesticum, elephant ear philodendron 3. Dracaena fragrans `Massangeana’, cornstalk dracaena 4. Hedera helix, English ivy 5. Chlorophytum comosum, spider plant 6. Dracaena deremensis `Janet Craig’, Janet Craig dracaena 7. Dracaena deremensis `Warneckii’, Warneck dracaena 8. Ficus benjamina, weeping fig 9. Epipiremnum aureum, golden pothos 10. Spathiphyllum `Mauna Loa’, peace lily 11. Philodendron selloum, selloum philodendron 12. Aglaonema modestum, Chinese evergreen 13. Chamaedorea sefritzii, bamboo or reed palm 14. Sansevieria trifasciata, snake plant 15. Dracaena marginata , red-edged dracaena
For an average home of under 2,000 square feet, the study recommends using at least fifteen samples of a good variety of these common houseplants to help improve air quality. They also recommend that the plants be grown in six inch containers or larger.
Here is a list of resources for more information on this important study:
PDF files of the NASA studies related to plants and air quality: http://ntrs.nasa.gov/archive/nasa/ssctrs.ssc.nasa.gov/foliage_air/foliage_air.pdf