Houseplants and your health
July 8, 2024—A home full of plants is a beautiful sight. And the common belief that plants purify the air can tempt plant-lovers to add just one more pot of greenery to their collection. But in reality, houseplants do not improve indoor air quality.
Flawed research
In 1989, a NASA study reported that potted plants remove carbon dioxide and volatile organic compounds (VOCs) from the air. VOCs can cause serious health problems, such as cancer. Additional studies came to the same conclusion.
But in 2019, new research was published that debunked these beliefs. According to the American Lung Association (ALA), the earlier studies were conducted under laboratory conditions that can't be replicated at home—for example, placing one plant in an airtight chamber and injecting just one VOC into the air. In that environment, plants do remove VOCs over a period of hours or days.
But our homes and offices aren't sealed environments like a space station. Instead, air flows constantly throughout the rooms, being replaced with air from the outdoors. That's true even in newer buildings with closed windows and heavy insulation.
To replicate the effects found in these earlier studies, you would have to cram hundreds of houseplants into your home. According to the ALA, you'd need about 680 plants in a 1,500-square-foot space.
Helpful or harmful?
You can't count on houseplants to clear the air in your home—but that doesn't mean they don't affect your health and well-being. And many people simply enjoy caring for plants, whether or not there's any health benefit.
However, although more research is needed, some studies suggest that houseplants do affect our health and well-being.
Not all of those effects are positive. According to the ALA, houseplants can:
- Trigger asthma and allergies. To avoid this, don't overwater your plants, which can cause mold to grow on the soil. Check that your plants are in soil that drains well, and avoid flowering plants, which produce pollen.
- Gather dust. Dust can not only irritate your respiratory system, it also can carry harmful substances like lead and pesticides. Dust your plants' leaves with a damp cloth every week.
- Carry insects. Mites, mealybugs and aphids could irritate your respiratory system. If you find insects on your plants, pick them off or spray the plant with water. You can also try insecticides with low amounts of chemicals.
Houseplants can have positive effects, too, says AARP. Research suggests that:
- Just looking at plants can help you relax.
- Gardening may help lower cognitive decline and blood pressure.
- Plants may help you focus and be more attentive.
- Growing herbs and other edible plants can help you eat more healthfully.
Breathe easier
Want to improve your indoor air quality? Houseplants aren't the answer, but some simple strategies can help you handle seven common air-quality concerns.
Sources
- AARP. "6 Chic Ways to Use Plants in Your Home Decor - and Why You Should." https://www.aarp.org/home-family/your-home/info-2024/incorporate-plants-into-home-decor.html.
- AARP. "Boost Your Health with an Indoor Garden." https://www.aarp.org/home-family/your-home/info-2019/houseplants-health.html.
- American Heart Association. "Homegrown Foods from the Garden Make Family Meals Healthier." https://www.heart.org/en/healthy-living/healthy-eating/cooking-skills/meal-planning/homegrown-meals.
- American Lung Association. "Actually, Houseplants Don't Clean the Air." https://www.lung.org/blog/houseplants-dont-clean-air.
- National Library of Medicine. "Effects of Indoor Plants on Human Functions: A Systematic Review with Meta-Analyses." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9224521/.
- National Library of Medicine. "Potted Plants Do Not Improve Indoor Air Quality: A Review and Analysis of Reported VOC Removal Efficiencies." https://pubmed.ncbi.nlm.nih.gov/31695112/.