Did you know that according to the Environmental Protection Agency (EPA), indoor air quality has been shown to be 2-5 times (even up to 100 times) more polluted than outdoor air? Thanks to airtight homes, harsh cleaning chemicals, and houses filled with substances that emit volatile organic compounds (VOCs) and other pollutants, our indoor air quality can be quite poor. Inexpensive particleboard furniture, paints, varnishes, carpeting and carpet glue, and new furniture can all emit VOCs and other dangerous gases. An example of one of the more than 900 identified VOCs is formaldehyde, which is classified as a probable human carcinogen whose indoor sources include building materials, particleboard/fiberboard, tobacco smoke, household products, and fuel burning appliances1. The immediate effects of poor indoor air quality include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Exposure to VOCs specifically can lead to allergy-like symptoms, burning eyes and throat, breathing problems, headaches, and lethargy. Other long term health effects from indoor air pollutants include respiratory disease, heart disease, and cancer1. I personally experienced allergy-like symptoms and severe headaches that did not respond to medication when I moved into my new home in the middle of the winter. The headaches disappeared when the weather warmed up and we opened the windows. The EPA says indoor air quality is one of the top five major health threats to Americans and partly responsible for the current rise in asthma. Since people in industrialized nations spend 90% of their time indoors2, it’s important that we keep our indoor air as clean as possible!
The good news is that cleaning your home’s air doesn’t have to be complicated or expensive. No need to worry about a fancy air filter, which usually won’t remove VOCs anyways. Since outdoor air is cleaner than indoor air, simply open your windows. This is an especially good idea on cool summer nights–open the windows and turn off the AC. You’ll wake up to a cooler home with fresher air. But what can be done when the temperature outside doesn’t really allow for open windows? You can fill your home with air cleaning plants.
Several varieties of indoor houseplants can clean your air, removing dangerous pollutants such as formaldehyde and benzene (a known human carcinogen). According to B.C. Wolverton, Ph.D., a scientist involved in the NASA sponsored Clean Air Study3 to find ways to make the space station inhabitable, plants can remove up to 99% of toxins from polluted indoor air under controlled conditions. “We’ve taken plants, put them in sealed chambers and exposed them to literally hundreds of chemicals. We’ve found that the plants literally suck these chemicals out of the air.” Plants absorb pollutants into their leaves and convert the toxins into food for the plant4. Microbes in the plant’s roots also help clean the air, as do microorganisms in the soil3. Certain plants are better at absorbing specific chemicals. For example, rubber plants and spider plants remove formaldehyde, while chrysanthemums work well against the toxins in new paint and the benzene from new plastics. Pothos plants are good all-around air cleaners. A German study in 1994 found that one spider plant could detoxify a 100 cubic foot room of formaldehyde in six hours5. Wolverton believes that palm and fern families are among the best filters, and his personal favorite plants for ease of care and filtering capabilities include lady palm, peace lily and “Janet Craig” dracaena4. Even pretty flowering plants like mums and gerbera daises can clean your home’s air.
The following plants have all been shown to clean indoor air–aloe vera, areca palm, australian sword fern, bamboo palm, boston fern, chinese evergreen, chrysanthemum, cornstalk dracaena, devils ivy, dragon tree, dwarf date palm, english ivy, ficus alii, gerbera daisy, “janet craig” dracaena, lady palm, mums (flowering), peace lily, philodendron (including heartleaf, selloum, and elephant ear varieties), pothos, reed palm, rubber plant, striped dracaena, snake plant, spider plant, warneck dracaena, and weeping fig. NASA recommends using 15-18 good-sized plants in an 1800 square-foot home. It’s important to concentrate the plants in rooms where you spend the most time, particularly your bedroom. Also consider bringing a few potted plants to your office, as many office-buildings lack good ventilation and contain just as many, if not more, sources of air pollution as your home. Remember that even though house plants can clean the air, the EPA still recommends “source control” as the best method to improve indoor air quality. This means trying to reduce the products in your home that are producing the pollution in the first place. Research products before purchasing them, research materials before remodeling, use safer household cleaners (check here soon for an article on this topic), never use pesticides in your home, don’t use air fresheners, always provide proper ventilation when painting or cleaning, “air out” new home furnishings or products before bringing them into your home, etc. So open your windows, add potted houseplants to your home, be aware of the indoor sources of VOCs and dangerous pollutants, and hopefully we can all enjoy cleaner indoor air!
sites worth visiting:
1. http://www.epa.gov/iaq/pubs/insidest.html, Accessed 9/3/07.
2. U.S. Environmental Protection Agency, Office of Air and Radiation. Report to Congress on Indoor Air Quality, Volume II: Assessment and Control of Indoor Air Pollution, pp. I, 4-14. EPA 400-1-89-001C, 1989.
3. http://ntrs.nasa.gov/archive/nasa/ssctrs.ssc.nasa.gov/foliage_air/foliage_air.pdf, Accessed 9/3/07.
4. Wolverton, B. C. How To Grow Fresh Air: 50 Houseplants that Purify Your Home or Office. Penguin Books, 1996.
5. Giese, M. et al. Detoxification of Formaldehyde by the Spider Plant (Chlorophytum comosum L.) and by Soybean (Glycine max L.) Cell-Suspension Cultures. Plant Physiol. 1994 April; 104(4): 1301–1309.