Indoor Plants and Air Quality

Indoor air quality refers to the air quality around and within a building or home. We often might think of outdoor air quality in relation to health, but indoor air quality is a significant health factor with its own set of pollutants.

Sources of indoor air pollution can include fuel-burning combustion appliances, furniture made from pressed wood products, and tobacco. While air fresheners might help neutralize odors, they unfortunately can also be releasing pollutants. These pollutants may include formaldehyde, asbestos, lead, and VOCs.

Formaldehyde in your Home

Formaldehyde is a common pollutant and gas that can be released from burning chemicals and incense sticks, tobacco smoking, electronic cigarettes, wood-burning fireplaces, carpets, laminate, and more. The National Toxicology Program lists formaldehyde as a reasonably anticipated human carcinogen.

While measuring the concentrations of formaldehyde from these products, researchers in 2018 noted that the concentration of formaldehyde within a room is inversely corelated to the air exchange rate. What this relationship means is the greater the air circulation, possibly from a fan or open windows, the lower the indoor formaldehyde level.

Asbestos Inside Walls

Asbestos is a mineral fiber found in building insulation and fire retardant. It might be found within an attic, roofing, walls and floors around wood-burning stoves, and heat-resistant fabrics. If these materials are damaged, asbestos fibers may be released into the air.

The EPA notes that asbestos exposure increases the risk of lung disease, including lung cancer, mesothelium, and asbestosis.

Aerosolized Lead

You may think of lead in solid form but is also an air pollutant. Air emissions can occur from aircraft operations and waste incinerators. While these are not obviously inside your homes, it still remains a pesky indoor air pollutant thanks to lead paint. Thanks to EPA regulatory effects that removed lead from motor vehicle gasoline, the levels of lead in the air decreased by 98% between 1980 and 2014.

Dangerous VOCs

A large category of indoor pollutants is volatile organic compounds (VOCs). This category of compounds is released from many household products including paints, varnishes, and cleaning products. The concentration of many VOCs can be up to ten times higher indoors than outdoors.

A symptom of VOC exposure can include a headache, allergic reaction, nausea, or eye irritation. However, as the EPA notes, long-term exposure can lead to liver, kidney, and central nervous system damage. These compounds are additionally suspected to cause cancer in humans.

A study in 2021 interestingly found measuring VOCs in bile to help distinguish between pancreatic cancer and chronic pancreatitis. Pancreatitis is an infection of the pancreas and bile is a digestive fluid produced in the liver. The researchers found the measurements to have a specificity of 100% and sensitivity of 93%.

What these statistics mean is that if the VOC levels were low, the data accurately identified 100% of people without pancreatic cancer. Additionally, if the VOC levels were high, the levels accurately identified pancreatic cancer 93% of the time.

The Clean Air Study of 1989

A huge NASA study, known as the Clean Air Study, in 1989 brought indoor plants to many readers’ attention. The study showed how skilled many plants are at cleaning the air in your home.

The top plants included snake plants (Sanseviera trifasciata laurentii), English ivy (Hedera helix), peace lilies (Spathiphyllum ‘Mauna Loa’), Warneckei (Dracaena dermensis), golden pothos (Epipremnum aureum) and Janet Craig plants (Dracaena deremensis). Many of the measured pollutants mentioned in the study include those mentioned above in this post.

For example, snake plants and English ivy were found to remove benzene, formaldehyde, trichloroethylene, xylene, and toluene. All of those compounds, besides formaldehyde, are VOCs. The peace lilies removed all of those compounds plus ammonia while aloe vera could only remove benzene and formaldehyde.

The Top Potted Plants to Combat Formaldehyde

Researchers in 2011 assessed three types of potted plants’ ability to remove formaldehyde indoors. These plants included spider plant (Chlorphytum comosum), aloe (Aloe vera), and golden pothos (Epipremnum aureum).

The strength of the plant’s filtration was based on the dehydrogenase activity in the leaves and roots. Dehydrogenase is an enzyme responsible for the metabolism of formaldehyde. The higher the metabolism, the higher the removal of the compound from the indoor air.

The study found the spider plant to be the most efficient at formaldehyde removal capacity in comparison to the other two plants.

A Car Air Purifier from Plants

In 2019, researchers created an air purifier for vehicles from snake plant fibers. The results found the snake plant to be an effective purifier and reduced almost all of the smoke present from both gasoline and diesel-fueled vehicles. Now that sounds like a great way to go green!

Additional Purifying Plants

Researchers in 2009 assessed the filtration strength of 29 indoor plants. The study measured the plants over 6 hours and explored five VOCs. These VOCs included benzene, toluene, octane, trichloroethylene (TCE), and a-pinene.

The study found that removal efficiency was based on leaf area and categorized plants into superior, intermediate, and poor removal efficiency. Five plants reached the superior removal efficiency label and these included Red Ivy (Hemigraphis alternata), English Ivy (Hedera helix), Purple heart (Trasdescantia pallida) , Asparagus fern (Asparagus densiflorus), and Wax plant (Hoya carnosa).

A Take-Away

Hopefully one take-away from this article is that you should go and get an indoor plant if you do not already have one! Indoor plants can provide tremendous benefits to your indoor air health. This post shows you that a variety of plants are successful air purifiers, so you have loads of options!