Though you wouldn’t necessarily associate NASA with indoor plants, the research institute did a study in the late ’80s on plant abilities to purify the air, to solve the indoor pollution problem and find the best air-purifying plants for our homes.
Indoor air pollution
What are the sources of air pollution? Most likely your first thoughts would be things like exhaust from burning coal or driving a car. But, perhaps counterintuitively, the air indoors is as much as 30 times more toxic than the air outside.
A healthy home environment is vital to a person’s well-being, and houseplants contribute to it more than you might think. Their main benefit is acting as an air purifier, so it sounds only reasonable that NASA did a Clean Air Study, that found which are the best indoor plants at removing benzene, formaldehyde, trichloroethylene, xylene, and ammonia from our surroundings – chemicals that have been linked to adverse health effects like headaches, dizziness, eye irritation, and others.
Dr. B.C. Wolverton led the study about 27 years ago, and according to its results, The Florist’s Chrysanthemum and Peace Lily are the best plants for purifying the air. NASA also recommended to have at least one plant per 100 square feet (about 10 square meters), and although this research is quite old, it is still regarded by many as the most comprehensive and accurate to date.
But how did he came to this results?
The research at NASA
The solution to indoor pollution, born out by NASA research, is to bring some of the outside in: plants and associated microorganisms in the soil around them are “nature’s life-support system,” notes a study published by Stennis Space Center in 1989.
So get some houseplants – that’s easy. But the study, led by B.C. Wolverton, head of Stennis’ Environmental Research Lab, was interested in how to maximize the air-scrubbing ability of those plants. After all, space habitats present the toughest possible challenge for ensuring safe, breathable air, since they’re entirely closed systems in an airless vacuum. There’s no chance to get some fresher air by opening a window, and even if engineers were able to build a habitat free from any of the toxins and chemical pollutants we find on Earth, nonetheless “man’s own waste products would cause indoor air pollution problems”, notes Wolverton.
Wolverton screened a dozen common houseplants from the Gerbera Daisy to the Bamboo Palm, and tested their ability to remove a variety of household toxins, like formaldehyde, from a sealed chamber. The goal was to find which plants did the best job with different pollutants.
An astonishing finding
But perhaps the most important result of this study, and one that surprised the researchers, was just how, and what part of, the plant was doing the bulk of the filtering: the roots and soil. As part of the experiment, the researchers removed all the leaves and learned that the air-purifying effect was only a tiny bit less than before.
Wolverton and his team used the results to create a design for a plant pot with an activated carbon filter to maximize its air-purifying abilities, based in part on wastewater treatment studies.
The design also incorporated an electric fan beneath the pot to draw in more air and direct it into the soil, where the carbon and roots could do their filtering: “smoke, organic chemicals, pathogenic microorganisms (if present), and possibly radon are absorbed by the carbon filter,” the study notes.
“Plant roots and their associated microorganisms then destroy the pathogenic viruses, bacteria, and the organic chemicals, eventually converting all these air pollutants into new plant tissue,” it continues.
Today it is more clearer than ever that air quality needs to be constantly monitored and that air pollutions is stilla problem to be tackled, both inside and outside our houses.
If you want to be a part of the change, starting from your own home, scroll down below to check the infographic on air-purifying plants, then go to your nearest florist’s and get yourself some fresh air!
And if you can’t buy some of these plants, maybe because you don’t have the time to tend to them: did you know there is a paint that transformes your walls into a forest? We talked about it here!
Read the full articles and more here:
- Multiple authors, 2017, NASA Reveals A List Of The Best Air-Cleaning Plants For Your Home (https://www.boredpanda.com/best-air-filtering-houseplants-nasa/)
- Nasa Spinoff, 2019, NASA Plant Research Offers a Breath of Fresh Air (https://spinoff.nasa.gov/Spinoff2019/cg_7.html)
- B. C. Wolverton, Anne Johnson, Keith Bounds, 1989 (acquired in 2013), Interior Landscape Plants for Indoor Air Pollution Abatement (https://ntrs.nasa.gov/citations/19930073077)
- Wikipedia – Multiple authors, NASA Clean Air Study page (https://en.wikipedia.org/wiki/NASA_Clean_Air_Study)