0211_clean air

Foliage plants are not only beautiful and fun but they are also the latest word in a healthy environment. Research now shows that houseplants play an important role in cleaning the air we breathe, both indoors and out ! Houseplants can be very beneficial in our lives. They purify and renew our stale indoor air by filtering out toxins, pollutants and the carbon dioxide we exhale - replacing them with life sustaining oxygen.

Plants produce their own food through a process called photosynthesis. This means they take in carbon dioxide from the atmosphere and release oxygen. Photosynthesis "cleans" our air by absorbing carbon dioxide and by taking in certain other pollutants, as well. Under controlled conditions, in the NASA study, certain houseplants were found to remove as much as 87 percent of indoor air pollutants within 24 hours.

Some plants even also produce oxygen at night, from the carbon dioxide they took up the previous day. Some of those plants are Zygocactus (Christmas cactus & Easter cactus), Sanseveria, Dendrobium, Aloe Vera and Moth Orchid (Phalaenopsis). In private life such plants belong in the sleeping room, where they can do their work at night.

Although it should be safe to presume that all plants are capable of removing toxins from our air, research by NASA 20 years ago already showed that some house plants are more efficient in filtering out toxins than others. Philodendrons, Spider plants (Chlorophytum comosum), and Pothos (Epipremnum aureum or Scindapsus aureus) were found to be the most efficient in the removal of formaldehyde.

The NASA researchers suggest that for the test plants to be effective "air cleaners" it is necessary to use 1 potted plant per 100 square feet of home or office space. Indeed, it would appear that plants have many useful qualities, including one of making our indoor air cleaner to breathe (Information obtained from The Foliage For Clean Air Council and National Academy of Sciences). The more vigorous the plant, the more air it can filter. Keep in mind that plants will not do much to alleviate tobacco smoke or dust in the air (although it seems that Bromeliads can feed on tobacco smoke).

Gerbera Daisies and Chrysanthemums were found to be effective in the removal of benzene, a known carcinogen. Plants with fuzzy leaves were best at removing particulate pollutants such as smoke and grease particles.

Most of those pollutant removing plants have dark leaves and need little light. Specially recommended for their capacities are Big single-leaf plants such as Peace Lily (Spatiphyllum) and Flamingo Flowers (Anthurium).

Until recently, indoor air pollution was not considered a health threat; most homes and public buildings leaked so much that air often was replaced every couple of hours. But during the 1970's, after energy shortages occurred, more and more of us began to insulate our houses and office buildings to conserve energy and lower heating and cooling costs. As a result, indoor air might linger for five hours or more allowing pollutants to accumulate. And as an extra threat, much outdoor air pollution caused by "the economy" has been added.

Researchers are just beginning to understand how, just like outdoor chemical air pollution, indoor pollutants such as cigarette smoke, for example, can also harm humans. The effects range from skin and eye irritations to headaches and allergies. Some of the pollutants may even be carcinogenic. According to the NASA study, the plants listed below proved effective in removing certain air pollutants.

Pollutant	Source	Plants that Remove Pollutant
Benzene	Inks, oils, paints, plastics, rubber, dyes, detergents, gasoline, pharmaceutical, tobacco smoke, synthetic fibers	English Ivy, Dracaena marginata, Janet Craig, Warneckei, Chrysanthemum, Gerbera Daisy, Peace lily, Fern
Formaldehyde	Foam insulation, plywood, pressed-wood products, grocery bags, waxed paper, fire retardants, adhesive binders in floor coverings, cigarette smoke, natural gas	Azalea, Philodendron, Spider plant, Golden Pothos, Bamboo palm, Corn plant, Chrysanthemum, Mother-in-law's tongue
Trichloroethylene	Primarily used in the metal degreasing and dry cleaning industries; also in printing inks, paints, lacquers, varnishes, adhesives	Gerbera Daisy, Chrysanthemum, Peace lily, Warneckei, Dracaena marginata. Fern

It is difficult to answer this question about oxygen ; much will depend on the health of the plant, its size, and the light levels where it is growing. In general, more light means more photosynthesis and more oxygen production. However, some plants such as tropical foliage plants are better adapted to low light conditions and therefore best for increasing indoor oxygen levels. Plants not as well adapted to shade will tend to deplete the oxygen because they will be respiring (releasing carbon dioxide) as well as photosynthesizing (producing oxygen). Whether or not they are net producers or consumers depends on the light level and shade adaptability of the plants.

If the light conditions are very low, philodendron and other plants like it will produce more oxygen. In brighter light, other plants will do better. Most home conditions are such that the period of bright light is very limited, thus limiting maximum photosynthesis. So the answer to this question is : it will also depend on your light conditions at home - intensity and duration.

N.A.S.A.Study shows: Plants clean the air inside our Buildings, offices and homes.