Last Updated: Jul 23, 2021
When we think of “fresh air”, most of us remember a time we spent hiking through the rainforests of the Pacific Northwest or meandering beside a cool stream buried deep in the woods in our local state park. The crisp smell of freshness and abundant oxygen provided by the natural world differs vastly from the smog-infested air of our cities and the staleness of the air inside our homes and workplaces. Might there be a way to mimic the freshness of the air in the natural world inside our homes?
On a global scale, the World Health Organization estimates that over four million people die each year because of exposure to extreme levels of indoor air pollutants. While many of those cases are related to families in the developing world who are exposed to carbon monoxide through cooking indoors with firewood or charcoal, indoor air quality in the United States has its challenges. A study by the Environmental Protection Agency (EPA) found that the air quality inside homes was routinely 2 to 5 times worse than the air outside the home, even for people living in heavily congested urban areas. This makes indoor air pollution a top five environmental risk to overall public health.
Everything from your furniture to your mattress to paint on your walls might very well be leaching dangerous VOCs into the air you breathe, and many of those chemical compounds, like formaldehyde, are human carcinogens. Couches and other household furniture manufactured before 2006 most likely contain PBDEs and other chemical flame-retardants that used to be mandated by law. These flame-retardants have been shown to possibly cause thyroid hormone disruption, neurodevelopmental deficits, and cancer. Even commonly used consumables like hairspray, shampoo, cleaning sprays, and air fresheners can negatively impact indoor air quality.
With so many different chemicals potentially floating around the air in our homes, many people resort to indoor air fresheners to disguise that chemical smell while mimicking the “fresh air” smell of the natural world. Unfortunately, studies have shown that the chemicals in many of these air fresheners can react with formaldehyde and other VOCs that might be in your home to increase the potency of the VOCs themselves. This can thus lead to respiratory irritation and airflow limitation in people who breathe in that air.
Besides opening up every window and door in the home (not a great idea for energy efficiency in the wintertime), or using an energy-efficient HRV or ERV, how can we go about improving the air quality in our home in a natural and sustainable manner?
Most of us remember from our sixth-grade biology class that plants convert light into energy through photosynthesis. We might even remember that opposite to us, humans, plants breathe in carbon dioxide while exhaling oxygen.
The tiny, invisible pores on the surface of the leaves of plants have the ability to absorb a wide variety of gasses in the surrounding air. While plants are mainly after carbon dioxide to fuel their own growth, they have the ability to absorb a wide range of other gasses, including dangerous VOCs that might be lurking inside our homes.
Plants have been shown to be able to absorb chemical VOCs such as benzene, formaldehyde, and even acetone, that strong-smelling chemicals always present in the air in nail salons. Biologically speaking, the plants you place around your home can purify the air in two main ways. Firstly, they have the ability to pull certain contaminants from the air, metabolize them through their “breathing process” and then release harmless byproducts back into the air. Secondly, plants can even incorporate other toxic chemicals (like certain heavy metals) into their plant tissue, thus sequestering them from the air and the surrounding environment.
Nowhere has the power of plants to purify indoor air been better documented than through the NASA Clean Air Study. Astronauts aboard the space shuttle and international space station obviously do not get a lot of fresh air. The air quality inside an airtight container floating through space was seen as a potential health problem. Beginning in 1989, NASA conducted an in-depth study to determine which plants have the ability to purify indoor air of a wide range of contaminants and air pollutants. The results of their study led to a detailed list of the best plants for purifying indoor air, and they recommended that at least one plant per 100 square feet was enough to purify indoor air efficiently.
Before heading to your local nursery to purchase a bunch of random houseplants and flowers to decorate your home, we offer simple suggestions about which plants are best for certain areas of the home based on their air-purifying potential.
The Bamboo Palm is a beautiful plant and is one of the best rated by the NASA Clean Air Study to get rid of a wide variety of pollutants such as formaldehyde, xylene, and toluene, which can be found in certain kitchen appliances and furniture.
Spider Plants can remove formaldehyde, xylene, and toluene from the air. This plant is non-toxic to humans and pets, making it a great option for the area in your home where you prepare your meals.
The Snake Plant is unique in that it absorbs CO2 throughout the day and releases large amounts of oxygen during the nighttime hours. It is believed that these plants produce enough oxygen that a human could survive in a completely airtight room with only 6-8 of these plants as the sole producers of oxygen.
Certain mattresses like Memory Foam might very well release VOCs like acetone into your bedroom. The Dracaena is a unique plant and does a fantastic job getting rid of excess acetone in the air.
The Boston Fern is a plant that prefers to grow in cool, moist areas with indirect sunlight, and most basements offer these growing conditions. In addition, the Boston Fern purifies the air of formaldehyde and xylene. Since most basements have limited ventilation, a couple of these ferns placed throughout your basement can help to get rid of the VOCs off-gassing from your furniture, paint, and other sources.
The Peace Lily is a flowering plant that usually only needs watering once per week, which means you won’t have to worry about excess water getting your computer or office papers wet. This plant removes a wide variety of common household VOCs including benzene, formaldehyde, acetone, ammonia, and trichloroethylene.
Tobias runs an agroecology farm and a natural building collective in the mountains of El Salvador. He specializes in earthen construction methods and uses permaculture design methods to integrate structures into the sustainability of the landscape.