Important Study Finds Inexpensive Solution to Improving Indoor Air Quality

NASA and the Associated Contractor Landscapers of America (ALCA) spent two years testing 19 different common plants for their ability to remove common pollutants from indoor air.

Most of the plants used in the study are common variety houseplants and can be seen in homes around the world. The remaining two plants listed in the findings are annual decorative plants that may be used indoors infrequently.

Of course we all know that plants produce their own food through a process called photosynthesis. Photosynthesis “cleans” our air by absorbing carbon dioxide from the atmosphere and releasing oxygen but, during this process other substances including pollutants are taken in by the plant as well. The plants absorb the substances through openings in their leaves called stomata.

So why are these houseplants so efficient at removing pollutants and improving indoor air quality?

The advantage that houseplants have over other plants is that they are adapted to tropical areas where they grow beneath dense tropical canopies and must survive in areas of low light. Because of this, these plants are ultra-efficient at capturing light, which also means that they must be very efficient in processing the gasses necessary for everyday photosynthesis. Due to this, they have greater potential to absorb other gases, including potentially harmful ones.

In the NASA study, under controlled conditions some of the houseplants were found to remove as much as 87 percent of indoor air pollutants within 24 hours.

In the study NASA and ALCA tested primarily for three common chemical pollutants: Formaldehyde, Benzene, and Trichloroethylene.

Formaldehyde is commonly used during the manufacturing process of many building materials including particle board, carpet, insulations and by-products are used in many paper items and cleaning products as well. Benzene is a common solvent found in oils and paints. Trichloroethylene is used in paints, adhesives, inks, and varnishes.

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.

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 recorded as very effective in treating Trichloroethylene.

Additionally, NASA found that the bamboo palm, Mother-in-law’s tongue, dracaena warneckii, peace lily, dracaena marginata, golden pathos, and green spider plant worked well for filtering Formaldehyde.

Some of the best plants for absorbing benzene, formaldehyde and/or trichloroethylene are listed in the chart below. Note that all the plants in the list are easily available from your local nursery.

For effective improvement of air quality, use 1 potted plant per 100 square feet of home or office space.