Can systematic use of houseplants improve air quality at home for people with asthma? Kerri MacKay dives into the research.
If you know me, you know I’m not a big fan of natural remedies. I’d much rather see the research data.
When it comes to asthma treatments, Google can occasionally turn up some questionable results. Breathing exercises that claim to “cure” asthma, certain foods or diets “guaranteed” to help, and Himalayan salt lamps are all unfounded claims that don’t work and can even be potentially harmful.
Sometimes, though, we may discover logical, science-backed remedies worth trying, like the potential role of houseplants on indoor air quality. It might sound a little “out there,” but it’s worth considering: It’s pretty well-documented that planting trees in urban outdoor spaces decreases the presence of air pollutants.
So, could houseplants positively impact indoor air quality in a similar way? Or could making your home a bit greener perhaps not be one of the ways to manage your asthma symptoms?
Going greener: A key for indoor air quality?
Our journey to the discussion of “going green” for better air quality starts off at NASA. Yes, that NASA. A study they conducted back in 1989 explored whether or not plants could help with air quality and cleanliness aboard space shuttles. The results suggested that “virtually all plants tested” led to decreased levels of atmospheric benzene and formaldehyde, also known as air pollutants.
More recently, other studies have indicated a decrease in mercury vapors, as well. In today’s era, these vapors probably aren’t floating around your house, but accidental exposure can occur if old thermometers or fluorescent bulbs break, or if mercury is used in cultural or religious practice.
While I initially thought — and NASA did, too — that leaves might be part of the key to the air-cleaning abilities of plants, they actually suggest that plant roots and their associated microorganisms play the biggest role. (I wonder if the cactus I’ve got in my kitchen is more useful than anticipated, given its shallow network of roots in the soil!)
So, which plants do this best? In one assessment of 50 houseplants, researchers determined that the plants that can best clean common air contaminants, thrive in low-light environments, and are easy to maintain include palms, ferns, peace lilies, English ivy, and more.
University of Georgia researcher Stanley J. Kays notes that the plant you select for your home depends on the individual building, as different plants filter different compounds from the air. Considering plants in addition to air filtration systems, which filter certain pollutants, may be a better option.
Still, while the evidence is generally positive, there is simply not enough research to make a solid recommendation about whether houseplants help asthma.
Potential asthma problems
Of course, you should stay away from plants that produce pollen if that is something you’re allergic to. But even plants that are suggested for people with asthma can trigger asthma symptoms.
Dust accumulation may be an issue, especially with larger plants, but regular watering should wash this off. Mold is also a common houseplant problem, which can trigger allergy symptoms. Removing mold from plant surfaces and ensuring plants are not over-watered (which can promote mold growth in the soil) can keep plants healthy and mold levels down.
Some plants, plant pots, microorganisms in plants, and soils have the potential to contaminate air with pollutants called volatile organic compounds (VOCs). It can be difficult to tell if VOCs are present without laboratory testing. More research is needed, as their contributing role in asthma exacerbations is still uncertain.
Depending on your allergies and asthma severity, these factors may make adding more plants to your home an undesirable choice. It’s always a good idea to speak with your doctor or allergist before introducing new living things to your environment — including plants and pets — to confirm whether or not they’ll negatively affect your asthma.
So, houseplants for asthma: hope or hype?
The answer is a bit of both. Going green — at least in conjunction with a good air filter — may help keep the air in your home (or office) cleaner based on research over the past two and a half decades.
However, the presence of plants may create other asthma triggers in your environment, especially if they aren’t properly cared for. Right now, the evidence is just not there to promote house plants to help asthma. But if you don’t have significant allergies and want to test out your indoor “green thumb,” it’s possible you may notice improved indoor air quality.
Remember, always do your research, and ask your doctor for advice if you decide to make any changes to your environment based on what you read online.
The information presented is solely for educational purposes, not as specific advice for the evaluation, management, or treatment of any condition.
NPS-ALL-NP-00804 FEBRUARY 2023