I · Air · Explainer · 4 min
Do plants improve air quality?
What the famous NASA study found, and why it does not translate to your living room.
By Colpo d’Aria Editorial · Published September 24, 2026 · Last reviewed October 1, 2026
The short answer
Not in any measurable way at home. Keep plants because they are beautiful; do not rely on them to clean the air.
Where the idea comes from
A 1989 NASA study found that some plants removed VOCs from small, sealed test chambers. The result was accurate for those chambers and has been repeated ever since as if it applied to homes.
Why it does not scale
A 2019 review of three decades of studies by Cummings and Waring estimated that it would take between 10 and 1,000 plants per square meter to match the VOC removal of ordinary air exchange in a building. Homes already replace their air far faster than a few pots on a windowsill can clean it.
What plants can do—and cannot
- They can make a room feel calmer and more alive, which is its own value.
- They cannot meaningfully remove particles, VOCs or CO₂ at household scale.
- Overwatered soil can add humidity and mold spores, which is worth considering in a bedroom or for allergy sufferers.
What actually works
Remove the source, ventilate, and use correctly sized filtration for particles. Activated carbon, in meaningful quantity, handles some odors and VOCs.