According to hundreds of online articles, Peace Lilies aren’t just pretty houseplants – they’re also super-efficient air purifiers. But the internet is full of exaggerated health claims. Does the science support the idea that your Peace Lily will clean the air in your home or workplace? Or is this just another overhyped online trend?
Potted Peace Lilies absorb some volatile organic compounds from the air – but probably not enough to matter. Most research indicates that you’d need a ridiculous number of houseplants to make a real difference. Your building’s natural ventilation does more to clean the air than all your plants put together.
Why is this misconception so popular? And why do Peace Lilies, in particular, show up on so many lists of the “Best Air Cleaning Plants”? We’ll explain how the Spathiphyllum plant got its reputation as a living HVAC system and where the research stands today. We’ll also look at some of the real reasons why growing Peace Lilies could be good for you.
Do Peace Lilies Purify Air?
When you look for information on plants and indoor air quality, you’ll find endless references to NASA. The agency conducted a study in 1989 on whether plants could improve the air quality in space habitats. They were concerned about the buildup of volatile organic compounds, or VOCs, in indoor environments.
Not all VOCs are harmful, but many are, and they can quickly build up inside heavily insulated spaces. This can lead to a combination of health issues known as “sick building syndrome”. This is an obvious risk for astronauts living for months at a time inside a sealed space station.
The NASA study tested 10 different plants for their ability to reduce VOC concentrations in an enclosed space. Researchers placed potted plants in small chambers and injected test chemicals into the air inside. They used 3 VOCs – benzene, formaldehyde, and trichloroethylene – that are known to have harmful health effects. Air samples at 0, 6, and 24 hours after injection showed a sharp drop in concentrations of these compounds.
Spathiphyllum – Peace Lily – was one of the plant varieties tested. And they did perform better than many of their competitors, especially at removing benzene. Nearly 80% of the benzene in the Peace Lily test chamber was gone after 24 hours. This is probably why Spathiphyllum shows up on just about every online list of “air cleaning plants.”
How Many Peace Lilies Would You Need to Clean the Air?
The conclusion seems clear, doesn’t it? Get a Peace Lily and turn your home into an oasis of clean air. Not so fast. The hype about Pece Lilies ignores a crucial question in any health study: the dosage.
The NASA experiment involved sealing one plant at a time inside airtight plastic containers. The largest chambers were 30 inches wide, 30 inches deep, and 60.5 inches high. That’s not exactly a spacious penthouse apartment.
Even if you account for the difference in size between a tiny box and a full-sized home, it’s hard to draw conclusions from the NASA study. Unlike astronauts, we don’t live in sealed chambers. Even a home with amazing insulation exchanges a certain amount of air with the outdoors.
That’s the main way that our houses get rid of VOCs and other harmful gases. The amount of pollution absorbed by a few potted plants is minuscule compared to what flows out on its own.
So how many Peace Lilies would your apartment or office need before you’d see an improvement in air quality?
Since the 1989 study, there have been surprisingly few follow-up tests in real-world environments. The results of those few aren’t encouraging. The current best estimate is that you’d need one plant for every two square feet of your floor plan to accomplish anything.
If you can figure out how to cram that many houseplants into your living space, go for it! And send us pictures.
Do Peace Lilies Absorb Radiation?
The articles recommending Peace Lilies for VOC absorption are at least attempting to work from actual science. Many other online claims are much wackier. For instance, you may have stumbled on blog posts that say Peace Lilies can absorb radiation.
Well, sure. Every living thing absorbs a certain amount of the radiation passing through the environment. But your Peace Lily isn’t some kind of vortex pulling radiation out of the air. The idea doesn’t even make sense – radiation doesn’t hang around like smog. It’s always on the move, blasting through space in the form of subatomic particles or pulses of energy.
We’re bombarded by radiation all the time, mostly electromagnetic waves that pass through us with no known effect. And houseplants don’t soak up any more of the harmful type than anything else in your house. Unless you strap Peace Lilies over every inch of your body, they won’t do much to protect you. (Even then, you’d get more shielding from a sheet of lead foil.)
Some houses do have problems with radon, a radioactive gas that seeps up from the ground. But plants don’t breathe radon. There’s no evidence that a Peace Lily will do anything to reduce radon levels in your home.
Does a Peace Lily Produce Oxygen at Night?
One widely touted health benefit of houseplants is boosting your home’s oxygen content. The idea makes sense. After all, plants absorb carbon dioxide and emit oxygen, right?
People get especially excited about plants that perform a special trick called crassulacean acid metabolism, or CAM. Most plants only produce oxygen during the day, while they’re photosynthesizing. CAM plants do it at night instead. This makes them attractive bedroom plants to some people, because concentrations of CO2 tend to go up when you’re asleep with the door closed.
First things first: Peace Lilies are not CAM plants. They only generate oxygen during the day. Most CAM plants are desert dwellers that need to keep their pores shut during the day to avoid losing too much water vapor. Peace Lilies, as rainforest plants, don’t need to do this.
You shouldn’t worry about whether you have CAM or non-CAM houseplants, though. As with VOCs, the effect on oxygen levels from houseplants is too small to affect your health.
The Real Health Benefits of Peace Lilies
It seems like having houseplants nearby must be good for you somehow, even if they don’t clean your air. And it’s hard to deny that you just feel better around a big, healthy Peace Lily.
You’re right: you do feel better. And that’s why Peace Lilies are good for you.
The mental health benefits of houseplants are well-documented. People who spend time around growing things have lower stress, less anxiety, and more creativity. In hospitals, patients with plants in their rooms recover faster and need less pain medication. If you have some greenery in your office or home workspace, you’re more productive. You’re also less likely to take sick days.
Those are the advantages of simply having plants around. Growing them is even better for you. Having something to take care of is therapeutic, alleviating illnesses like depression and anxiety.
That would be a good enough reason all by itself to own houseplants. But remember that mental and physical health are linked. When your stress is lower, your blood pressure drops, your immune system works better, and you have more restful sleep. Those are just a few examples – researchers are constantly uncovering new connections between emotional and physical well-being.
But why should you grow a Spathipyhyllum in particular?
Well, because they’re gorgeous! The beauty of nature is part of its healing power. Many of the benefits we mentioned above can come from simply looking at living plants. If you find Peace Lilies attractive, then having them around is good for you.
Of course, if they’re not to your taste, there are plenty of other gorgeous houseplants for you to choose from.
Final Thoughts
A potted Peace Lily won’t do much to clean the air in your home. But that’s only because its effect is drowned out by the entire ecosystem you’re a part of. The billions of other plants growing near your home produce a tide of fresh air that’s always flowing inside.
Maybe that’s why keeping a Peace Lily near your desk makes you feel so much better. It’s a reminder that we’re never really separate from the living world around us.