The first step to having clean indoor air starts with opening windows every day to air out the house. Rain or shine, airing out the house for a short while (10-15 minutes is all that is required) is the key. Try to do this before 9am and after 4pm, when the air is heavier, so less toxins and pollution come into your homes.
Next step is choosing which indoor plants you bring into your home. Not all plants are created equal! Some are more effective than others at keeping your house air clean. There have been several studies conducted on the effects of indoor plants. In the late 1980s, the National Aeronautics and Space Administration (NASA) conducted many studies evaluating the beneficial effects of plants indoors.
The NASA study notes: Two of the key ingredients which have contributed to today’s potentially serious indoor air pollution problems are tightly constructed buildings with dramatically reduced ventilation rates and the radical change in the nature of building materials and household furnishings. Add to this, new household products such as cleaning and polishing solutions, insecticides, glues, personal hygiene and health care products, along with numerous electronic devices and radon gas and you have the ingredients for serious health problems…” “Indoor air pollution and ‘sick building syndrome’ can contribute to symptoms such as allergies, asthma, eye, nose and throat irritations, headaches, fatigue, sinus and respiratory congestion. “
Given the amount of time we spend indoors, whether at work or at home, (or in some cases, both!), we can be spending an awfully large amount of time with these hundreds or so of pollutants!
If these all sounds a bit scary, here is the good news. Plants live and grow thanks to a photosynthetic process. This process requires a continuous exchange of gaseous substances between plant leaves and the surrounding atmosphere. The most common gaseous substances exchanged are carbon dioxide, oxygen and water vapor. A plant’s leaves normally give off water vapors and oxygen, and take in carbon dioxide. The NASA study provides evidence that plant leaves can also take in other gaseous substances from the surrounding atmosphere through tiny openings (stomates) on their leaves. In fact, both plant leaves and roots can be used in removing trace levels of toxic vapors.
The most common air pollutants found indoors are formaldehyde, benzene, and trichloroethylene. Formaldehyde is used in many building materials, including particle board and foam insulations. It is also found in many cleaning products. Benzene is a common solvent found in oils and paints. Trichloroethylene is used in paints, adhesives, inks, and varnishes.
The advantage that houseplants have over other plants is that they are adapted to tropical areas where they grow beneath dense tropical canopies and must survive in areas of low light. These plants are thus ultra-efficient at capturing light, which also means that they must be very efficient in processing the gases necessary for photosynthesis. Because of this fact, they have greater potential to absorb other gases, including potentially harmful ones. NASA also noted that some plants are better than others in treating certain chemicals.
For example, English ivy, gerbera daisies, pot mums, peace lily, bamboo palm, and mother- in-law's tongue were found to be the best plants for treating air contaminated with benzene. The peace lily, gerbera daisy, and bamboo palm were very effective in treating trichloroethylene.
Additionally, NASA found that the bamboo palm, mother-in-law's tongue, dracaena warneckei, peace lily, dracaena marginata, golden pathos, and green spider plant worked well for filtering formaldehyde.
Here is a list of some plants that are among the most effective all-around.
- Areca palm
- Reed palm
- Dwarf date palm
- Boston fern
- Janet Craig, Warneck, and/or cornstalk dracaena
- English ivy
- Spider plant
- Australian sword fern
- Peace Lily
- Rubber plant
- Weeping fig
- Bamboo Palm
- Chinese Evergreen
If you have pets you will need to be more careful what plants you choose for your home. Avoid growing these 12 houseplants that are considered toxic for pets:
- Aloe Vera
- Boston ivy
- Dumb cane
- English ivy
- German ivy
- India rubber plant
- Potted chrysanthemum
- Weeping fig
Keep in mind that you will need approximately 1 plant for every 8-9 square meters of space. Plants can also offer additional benefits such as stress reduction, increased productivity and creativity, as well as noise reduction.
Once you’ve got the plants figured out, keep your environment healthy by avoiding air fresheners (plug-ins, sprays, candles, etc). Toxic-free candles can be found at bio stores and you can also try beeswax candles.
Some good resources:
- Your Naturally Healthy Home, by Alan Berman.
- Plantes depolluantes Boudassou edition LaRousse
This article was originally publushed in the March 2011 edition of the Sunbeams Newsletter.