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NASA Research on Living Plants Indoors

indoor plants remove potentially harmful gases and pollutants from the air

Common houseplants are more than just common. They beautify our homes and offices, and they also release oxygen and assist in cleaning our indoor environment. NASA research shows that indoor plants remove potentially harmful gases and pollutants from the air.

In 1973, NASA scientists identified 107 volatile organic compounds (VOCs) in the air inside a Skylab space station. The VOC chemicals, such as benzene, formaldehyde, and trichloroethylene, are all known irritants and potential carcinogens. When these chemicals are trapped and unable to circulate, they cause people to become ill with symptoms such as scratchy throat and burning red eyes. This is called “sick building syndrome.”

Under the direction of B.C. “Bill” Wolverton, NASA tested a solution to VOCs by creating a BioHome, a tightly sealed building constructed with synthetic materials. Upon entering the BioHome, one experienced “sick building syndrome” until a substantial variety of houseplants were added. Another analysis of the air quality was conducted, and most VOCs were gone. Individual symptoms of “sick building syndrome” were also gone.

In the mid-1980s, Wolverton and his NASA researchers conducted studies where they placed potted foliage plants in sealed Plexiglas chambers. Studies showed that the plants were particularly effective at reducing common VOCs, including formaldehyde. Formaldehyde is commonly found in carpet backing, grocery bags, paper towels, particle board, plywood, foam insulation, paneling, and other substances.

Wolverton served in his field for over 30 years and retired as a senior research scientist at NASA. After retirement, he continued his work on air quality.

At the turn of the century, NASA and the Associate Landscape Contractors of America (ALCA) reported on a 2-year indoor plant study where indoor plants were once again proven to be a valuable weapon against indoor air pollution.

Eleven popular indoor plants were placed separately in sealed, Plexiglas chambers. Chemicals were injected into the chambers. Golden pothos, philodendron, and spider plant were most effecting in removing formaldehyde molecules. Flowering plants such as chrysanthemums and gerbera daisy did best at removing benzene from the atmosphere.

Wolverton said the study further proves that indoor plants provide air purification, and he said more research needs to be done in the future.

“Plants take substances out of the air through the tiny openings in their leaves,” said Wolverton. “But research in our laboratories has determined that plant leaves, roots and soil bacteria are all important in removing trace levels of toxic vapors.”

Wolverton is the author of How to Grow Fresh Air: 50 Houseplants That Purify Your Home and Office and Growing Clean Water: Nature’s Solution to Water Pollution.