Houseplants That Clean the Air

Indoor air pollution is the result of the accumulation of toxic gasses and particulate matter in amounts that can cause health problems. Air pollution can even lead to some diseases. Everyday sources of indoor air pollution include smoke from tobacco and cooking oils and volatile organic compounds (VOCs). VOCs such as formaldehyde are emitted from items such as interior paint, vinyl flooring and mini-blinds, shower curtains, carpeting, and manufactured-wood furniture.

Today's air-tight well-insulated homes and offices may help to keep the energy bills down but can severely limit the amount of outdoor air that enters a building. Since the energy crisis of the 1970's buildings have become increasingly air-tight - but at the same time occurrences of health problems such as asthma have increased dramatically. Studies show that Americans spend more than 90 percent of their time indoors, but conventionally built structures often have no built-in mechanical ventilation system to bring in outside air.

Formaldehyde, carbon monoxide, benzene, and nitrogen dioxide are a few chemicals that can accumulate in our interior spaces and make the air unhealthy to breathe. According to the EPA indoor air is typically higher in several of these pollutant chemicals than air outside. Luckily, houseplants can be an effective all-natural way to clean indoor air.

A study conducted by NASA in the mid 1980's - originally designed to find ways to purify air in space stations and vehicles - concluded that several varieties of houseplants removed toxic gasses from indoor air. The study's authors found that the plants studied removed not only carbon monoxide from the air during photosynthesis but also reduced concentrations of formaldehyde, benzene, and trichloroethylene.

The amount of these toxins removed naturally by plants is substantial. In a second NASA study involving spider plants the plants removed almost all of the nitrogen dioxide present in the study chamber over a period of just 6 hours.

All of the houseplants recommended to improve indoor air quality can be easily found at your local nursery. For maximum effect, it is recommended to have one air-cleaning houseplant for each 100 square feet of interior living space.

Below is a list of the houseplants shown to be effective in the NASA studies:

• Bamboo palm, Chamaedorea seifritzii
• Chinese evergreen, Aglaonema modestum
• English ivy
• Fiscus, Benjamina
• Gerbera daisy, Transvaal daisy
• Dracaena 'Janet Craig'
• Dracaena 'Marginata'
• Corn cane, Dracaena massangeana
• Mother-in-law's tongue, Sansevieria laurentii
• Peace lily, Spathiphyllum 'Mauna Loa'
• Pot mum, Chrysanthemum
• Dracaena 'Warneckei'
• Spider plant

Some of the plants studied were more effective at removing certain toxins than others. For example, Bamboo palm, Dracaena 'Janet Craig', Mother-in-law's tongue, Dracaena Marginata, Peace lily, green spider plant, and golden pathos are most effective at removing formaldehyde from the air. Gerbera daisy, pot mum, Peace lily, Bamboo palm, Dracaena Warneckei, English ivy and Mother-in-law's tongue are best at removing benzene. The plants most effective at cleaning trichloroethylene from the air are Gerbera daisy, Dracaena Marginata, Peace lily, Dracaena 'Janet Craig' and Bamboo palm.

Most homes and workplaces have several sources of potential indoor air pollutants. From your pressed-wood bookcase to your office's copy machine, common items release unhealthy gasses that can accumulate and lead to health issues. Use the natural air-cleaning power of plants to purify the air you breathe while greening and beautifying your space.

Houseplants are just one way to help clean indoor air of pollutants. For additional ideas, see 10 Ways to Improve Indoor Air Quality.