According to NASA, plants help us in 2 different ways: with their leaves and with their soil.
Without going into the technical specifics of the ways NASA did its study (which were rigorous and scientific, as you can imagine).
NASA studied 12 different plants and 3 different chemicals. The chemicals that were studied were trichloroethlene (TCE), benzene, and formaldehyde. Since then, other studies have identified xylene, toluene and ammonia as chemicals that houseplants can remove from the air.
NASA sealed the various house plants–which are common house plants that can be found at garden centers, big box stores and even supermarkets (more about which ones later) in plexiglass containers measuring 30″ in height, width and depth. There was a fan to circulate the air and the inserted contaminant. Each plant was left in the chamber for 24 hours.
The plants were selected and provided by the Associated Landscape Contractors of America (which became the Professional Landcare Network, known as PLANET, and then became the National Association of Landscape Professionals.) These were the plants that were selected:
Bamboo Palm, Chinese Evergreen, English Ivy, Ficus (benjamina variety), Gerber Daisy, 4 different types of dracena (‘Janet Craig,’ marginata, massangeana, known as Mass cane or corn cane and warneckei), snake plant, peace lily, and something they called “pot mum” which I think we would now call florist chrysanthemum.
In addition, in the tests for formaldehyde, they used banana, spider plant, golden pothos, aloe vera, and 3 kinds of philodendron (heart leafed, elephant ear [aka domesticum] and lacy tree [aka selloum]).
They were kept in whatever pots they were purchased in (which must have been rather small if they were shut up in 30″ containers) and were fed Miracle-Gro™ plant food (presumably in accordance with label instructions.)
In other words, fairly common plants that are still readily available (as, of course is Miracle-Gro™) were used for these experiments. And while none of us is going to go around sealing plants up in boxes with fans, I think we can achieve similar results in having these plants clean the air in our homes. I’ll report over the next weeks over which plants worked best for what chemicals.