We spend most of our lives on the axis – home-office-home. The time we seem to spend indoors accounts for nearly 87% of our lives, The National Human Activity Pattern Survey shows (1) ! We add a 6% for the traffic jam hassle in the car. And it looks like being on the outside and breathing fresh air is somehow slipping through our fingers. Besides, air in the big city metropolitans is all but fresh and clean. Still, it’s nothing compared to what we take in our lungs while relaxing in our own fortresses or seemingly clean office spaces. And though indoor pollutants are not as audible as those we literally bump into on the street, they exist. They lurk in furnishing, paints, detergents and many commercial products and severely interfere with our health. Indoor air pollutants cause 50% of illnesses globally (2)!
What if you knew there was a simple way to get a healthier indoor environment? Air purifying plants could be a natural, cost effective, and therapeutic means for improved indoor air quality. And this simple guide will lead you through the most effective ones, as proved by NASA and most recent research work.
How Safe Is the Air You Breathe At Home?
Poor air ventilation at home and other enclosed spaces lead to the build up of a number of toxic chemicals. They come from furnishing, building materials, detergents, other commercial products for personal care or hobbies, we use on a daily basis. These pollutants include but are not limited to:
Benzene is present in furnishing wax, paints, glues, synthetic fibers, rubber, oils and detergents. It can also be found in cigarette smoke and vehicle exhaust gas. This chemical evaporates quickly when exposed to air. Repeated skin contact can cause skin irritation and dermatitis. Acute inhalation can result in irritation to eyes, drowsiness, dizziness, headache, irregular heartbeat, confusion. Benzene is known to cause cancer, based on evidence from studies in both people and lab animals (3).
Trichloroethylene is used as an extraction solvent for greases, oils, fats, waxes, and tars; by the textile processing industry to scour cotton, wool, and other fabrics; in dry cleaning operations; and as a component of adhesives, lubricants, paints, varnishes, paint strippers. It is found in higher concentrations especially in homes undergoing renovation. The health effects of trichloroethylene depend on how much trichloroethylene you are exposed to and for how long. People who are overexposed to moderate amounts of trichloroethylene for a short period of time may experience headaches, dizziness, or sleepiness. The EPA and the International Agency for Research on Cancer (IARC) have determined that trichloroethylene is “carcinogenic to humans.” (4)
Found in resins used in the manufacture of composite wood products (hardwood plywood, particleboard and medium-density fiberboard); building materials; household products (glues, permanent press fabrics, paints and coatings, lacquers and finishes, and paper products); used as a preservative in some medicines, cosmetics and other consumer products (dishwashing liquids and fabric softeners). It can cause irritation of the skin, eyes, nose, and throat. High levels of exposure may cause some types of cancers.(5)
You may come in contact with xylene from a variety of consumer products. This includes gasoline, paint, varnish, shellac, rust preventives, and cigarette smoke, as well as through skin contact with lacquers, paint thinners and removers. Short-term exposure to high concentrations of xylene can cause irritation of the skin, eyes, nose, and throat; difficulty in breathing; impaired function of the lungs; delayed response to a visual stimulus; impaired memory; stomach discomfort; and possible changes in the liver and kidneys.(6)
It is found in many cleaning products, including glass and oven cleaners, floor cleaners and polishes, smelling salts. Inhalation of lower concentrations can cause coughing, and nose and throat irritation. (7)
Air Purifying Plants – Is It Just A Wishful Thinking?
Decades ago NASA made a detailed research on the ability of plants to purify air in enclosed spaces in an attempt to find the best solution for cleaner air in space stations.(8) Findings were based upon chamber studies. The results were more than impressive – removal rates up to 90% in 24 hours. The research came up with a list of plants that have the ability to neutralize the negative effects from a number of toxic chemicals released by furniture, cleaning products, varnishes etc. that build up in air due to poor ventilation. Later, new research followed to confirm these results (Wood et al. (2003)). Researchers at Penn State University proved that three common houseplants – snake plant, spider plant and golden pothos – reduced ozone in a simulated indoor environment.
Some of the studies, however, didn’t show any conclusive evidence that houseplants have the capability to remove volatile organic compounds (VOC) from indoor air. The Associated Landscape Contractors of America (ALCA) worked with Healthy Buildings International to conduct a field experiment (HBI, 1992). The authors of the study concluded that the presence of plants produced no significant reduction of pollutant concentrations in the studied office spaces. Another field study of three portable office buildings in Perth, Australia to test removal of formaldehyde by plants reached a similar conclusion. There was only an 11% reduction in formaldehyde concentrations with 20 plants in the room – a number not applicable in the real world.
There are even critical analysis pointing out that research done till now has many weaknesses and room for improvement. For example, chamber studies used concentrations that are not representative of concentrations found in actual indoor. The continuous emittance of some pollutants was not accounted for. Also, field studies don’t measure ventilation rates and ventilation typically dominates pollutant removal processes.
The jury is still out on the final verdict. More research needs to be done to confirm or deny the viability of houseplants in eliminating indoor air pollutants. In the meantime, you can choose to try or not a beautiful way to clean your indoor air.
Common Houseplants Recommended for Air-Purification (NASA)
Though growing houseplants might seem a tedious task, it is well worth the efforts. Especially if you know which types of plants to take home. The NASA report states that a house would need one healthy plant for every 10 feet x 10 feet of your home. A 2000 square foot home would require 20 plants, distributed appropriately. So, choose wisely! Top 5 air purifying house plants according to NASA:
1. Peace Lilly
A nice decorative plant and one of the top three plants for removing common household toxins according to NASA (9). While, at the same time, one of the easiest to care for.
Peace Lillies enjoy medium to low light. Don’t water them on schedule. Since they are sensitive to overwatering, check them once a week to see if the time has come for the next watering. Fertilize them 1-2 times a year. Wash or wipe down the leaves at least once a year. (10)
Filters out: formaldehyde, benzene, trichloroethylene, xylene, ammonia
CAUTION: Toxic to cats, dogs, and children.
2. Florist Chrysanthemum
Don’t ignore these charming flowering green companions when considering new additions to your indoor plants collection. They are rated highest at purifying indoor air. (11)
”Mums” are not hard to care for. But are difficult to rebloom. They only bloom for about six weeks and without the flowers their air cleaning properties won’t be the same. You can either buy a fresh pot or fertilize in the spring to try and get new flowers.
Keep the potting mix moist, at average room humidity, cooler temperatures (13-18°C) and direct sunlight.(12)
Filters out: formaldehyde, xylene, benzene, ammonia
CAUTION: Chrysanthemum leaves are poisonous. Keep out of the reach of children and pets.
3. English Ivy
A research presented to the American College of Allergy, Asthma & Immunology claims that English Ivy can help reduce the amount of mold in the air of your home and particles of airborne fecal-matter. (13)
Definitely no worries about maintenance. True ivies need bright light, but some species prefer medium to low light. Be careful not to overwater. Check the soil before each watering to make sure the soil surface is nearly dry. Fertilize your ivy once a month in the spring, summer and fall, but skip fertilizing in the winter.
Filters out: benzene, formaldehyde, trichloroethylene, xylene, and toluene (14)
CAUTION: Keep the plant away from pets and children who may eat the berries or leaves of the plant. It contains glycoside hederin and these parts of the plants are poisonous for both pets and humans.
4. Snake Plant (Sansevieria)
It is easy to care for and will generously reward you for the little effort you are to make. Place it in indirect sunlight, be careful not to overwater it (once every 7 – 10 days thoroughly, allowing the soil to dry in between waterings), use a little general purpose fertilizer monthly. And that’s the deal. What you get however, NASA claims, is a cleaner indoor air.
Filters out: benzene, formaldehyde, xylene, trichloroethylene (15)
CAUTION: Toxic when eaten, so please keep away from pets and children.
5. Red-Edged Dracaena (Dracaena marginata)
Distinguished by the purple-red edges on its green leaves, this beautiful plant grows slowly to finally reach as high as your ceiling. Choose a location with moderate sunlight, water it once or twice a week, keep the soil evenly moist, never soaked. Fertilizing twice a year, in spring and summer, with a slow-release fertilizer would be just enough for its normal growth.
Filters out: benzene, formaldehyde, trichloroethylene, xylene(16)
CAUTION: Dracaena marginata contains unknown steroidal saponins that cause drooling, vomiting, weakness, incoordination and dilated pupils (cats) when ingested.
In addition, here is a list of 9 more houseplants that will bring life and color to your home while working to improve air quality and freshen up your day.
There are many “IFs”
There are many “IFs” to using houseplants as natural air purifiers. And no conclusive evidence certain species could effectively help you get rid of all toxic substances and off gas coming from…virtually everything we use at home or in the office – from carpets to window cleaners. But studies yet show that there is a beneficial effect that is worth the attention of both consumers and scientists. Consequently, air purifying plants could be a perfect complementary means for cleaner air, in addition to:
- Keeping your floors clean
- Avoiding synthetic cleaners or air fresheners
- Reducing humidity in your air
- Maintaining good air ventilation
And if you combine it with an effective air purifier you will be much closer to breathing easy and living healthy at home.