Indoor plants are everywhere—offices, homes, classrooms, and social media feeds. They’re often celebrated as natural air purifiers and low-maintenance design upgrades. But how much do they really contribute to indoor air quality? At Air Quality Consultants (AQC), we get this question a lot: Are houseplants a meaningful solution for air pollution inside your home, or is their reputation overblown?
The answer is a bit more nuanced than a simple yes or no. Let’s explore what science says about indoor plants, how they really affect your air, and when they may help—or even hurt—your indoor environment.
The Original Claim: Plants as Air Purifiers
The idea that houseplants improve indoor air quality largely stems from a 1989 NASA study, which found that certain plants could remove volatile organic compounds (VOCs) like benzene and formaldehyde from sealed chambers. This research sparked a trend that has lasted decades.
But here’s the catch: The NASA study was conducted under highly controlled, small-scale conditions—not in typical home or office environments. Follow-up studies in real-world settings have found that while plants do absorb some airborne pollutants, the amount is very small compared to what’s needed to significantly improve indoor air quality.
The Real Impact
- Minimal filtration effect: You would need dozens, if not hundreds, of plants per room to match the pollutant-removing capacity of a basic HEPA air purifier.
- Slow absorption rate: Most houseplants absorb pollutants at a slow pace, not nearly fast enough to keep up with continuous indoor sources of VOCs (from paints, cleaning products, furniture, etc.).
Where Plants Can Help
Despite the limitations, plants aren’t useless when it comes to air quality. They may offer modest benefits, especially when paired with other air quality strategies.
1. Humidity Control
Some plants can release moisture into the air through a process called transpiration, which may help raise humidity levels in very dry environments. This can improve comfort and reduce issues like dry skin or throat irritation—though too much humidity brings its own risks (more on that below).
2. Psychological Benefits
This might be the most significant value they offer. Plants can reduce stress, enhance mood, and increase focus. While not directly tied to air filtration, a more relaxed mental state can indirectly support overall well-being.
3. Dust Reduction
Large-leafed plants may help trap dust particles on their surfaces, which can be wiped away during plant care. However, this effect is modest and should not replace routine cleaning and filtration
When Plants Can Become a Problem
As much as people love their greenery, indoor plants aren’t risk-free.
1. Mold and Moisture
Overwatering plants or using poorly draining pots can lead to mold growth, which releases spores into the air and worsens indoor air quality—especially for those with allergies or asthma.
2. Pest Risks
Gnats, mites, and other pests can hitch a ride indoors and proliferate in soil, leading to frustration and potential air contamination.
3. Allergen Concerns
Some plants produce pollen or strong scents that can trigger allergic reactions or respiratory irritation in sensitive individuals.
Best Practices for Cleaner Air with Plants
If you enjoy having houseplants and want to keep them while maintaining good air quality, here’s how to strike the right balance:
- Choose low-allergen plants like snake plants, spider plants, or pothos.
- Avoid overwatering, and use pots with proper drainage to prevent mold.
- Keep leaves clean to minimize dust buildup and help plants stay healthy.
- Don’t rely on plants alone—use high-quality air purifiers, improve ventilation, and minimize indoor pollutant sources for the best results.
Complementary, Not a Cure-All
Indoor plants can be a beautiful and calming addition to any space, and they may offer small, supportive benefits for indoor air quality. But they shouldn’t be mistaken for primary air purifiers. The hype surrounding their air-cleaning powers often oversells what they can realistically do in a typical home or office.
At AQC, we recommend using plants as part of a larger air quality strategy—not the whole solution. For tailored recommendations and professional air quality assessments, reach out to our team. We’re here to help you create an indoor environment that’s not only livable, but truly healthy.
