Plants Soak Up Indoor Pollution

A home that's full of green plants greets you with an unmistakably different feeling. The air is alive and clean, crackling with positive energy. The plants seem to be giving off not only oxygen but also good vibrations.

But plant-filled homes feet different not only because of what the plants are giving off, but because of what they are taking in. Many house plants literally consume the chemical pollutants that pervade modern homes and may be responsible for health problems from sore throats to cancer. For less than the price of one doctor visit for a sore throat, house plants can clean the air in your home and make it safer for you to breathe.

Modern homes can be a minefield of chemical hazards. Carpets, furniture, insulation, paint, and even fireplaces can emit hazardous gases.

Formaldehyde is released from a host of household furnishings, including synthetic carpeting, particleboard (used to make bookcases, desks, and tables), foam insulation, upholstery, curtains, and even so-called air fresheners. When present at levels above 0.1 parts per million parts of air, it can cause a wide range of symptoms from burning sensations in the eyes, nose, and throat, to nausea, coughing, and even skin rashes. Xylene, benzene, and carbon monoxide are among the other invisible gases that can cause a similar array of symptoms. In a study by the U.S. Environmental Protection Agency (EPA), an 800-cubic-foot room (10 feet by 10 feet by 8 feet) contained pollution levels of approximately 1,808 micrograms of formaldehyde, 112 micrograms of xylene, and 67 micrograms of benzene.

Common house plants such as the Boston fern, English ivy, and spider plant are inexpensive, ecologically sound, aesthetically pleasing ways to filter toxins from your home, particularly during these winter months when you are likely to spend most of your time closed up indoors with the windows shut. A single Boston fern can remove 1,800 micrograms of formaldehyde from the air (nearly the total amount found in the EPA study) in about an hour.

Some plants, of course, are especially good at filtering certain pollutants. The areca palm, for example, is the most effective filter of xylene. Other plants, such as Boston ferns, chrysanthemums, and dwarf date palms, are better at removing formaldehyde.

The Foliage for Clean Air Council, a communications clearinghouse for information on the use of foliage to improve indoor air quality, recommends a minimum of two plants per 100 square feet of floor space in an average home with eight- to ten-foot ceilings. Fill your home with as many plants as you can.

If you're not ready to fill your house with plants, start on a smaller scale by selecting plants that are known to remove the most worrisome pollutants. Four species were particularly efficient in filtering formaldehyde, benzene, xylene, and carbon monoxide. Introducing these plants into your home can significantly reduce the concentration of these chemicals and possibly hundreds of others. Although the calculations of the buildup and dispersion of pollutants in a home are complex, these plants can drastically improve the air you breathe. The actual rates at which the plants clean the air will vary depending on the size of the plant, the temperature, and how polluted the air is, among other things.

BOSTON FERN

Nephrolepsis exaltata bostoniensis

Type: Hanging perennial

Main Pollutant Removed: Formaldehyde, at a rate of 1,863 micrograms per hour.

Other Pollutants Removed: Xylene, at a rate of 208 micrograms per hour

Recommended Placement in Home: If you've recently bought new furniture or carpeting, place one or two Boston ferns in each of the appropriate rooms.

Cost: An eight- to ten-inch hanging plant costs $10 to $25.

Care: They are easy to grow in medium to bright light. As with most plants, water them only when the soil feels dry.

ENGLISH IVY

Hedera helix

Type: Hanging perennial.

Main Pollutant Removed: Benzene; the plant removed 90 percent from a sealed chamber.

Other Pollutants Removed: Formaldehyde, at a rate of 1,120 micrograms per hour. Xylene, at a rate of 131 micrograms per hour.

Recommended Placement in Home: These are especially effective in a room that has been freshly painted or carpeted. They're also beneficial in a room that contains plastic equipment or furnishings (computers, printers, fax machines) or ink.

Cost: A five-inch potted plant costs from $5 to $30.

Care: These plants are easy to grow in bright light.

ARECA PALM

Chrysalidocarpus lutescens

Type: Upright perennial.

Main Pollutant Removed: Xylene, at a rate of 654 micrograms per hour.

Other Pollutants Removed: Formaldehyde, at a rate of 938 micrograms per hour.

Recommended Placement in Home: Areca palms can be used effectively in virtually any room, but are especially useful in those that are carpeted or contain freshly varnished furniture.

Cost: A ten-inch potted Areca palm costs $20 to $50.

Care: These plants grow well in the sun. They need year-round warmth, ample humidity, and filtered sunlight.

SPIDER PLANT

Chlorophytum comosum

Type: Trailing perennial.

Main Pollutant Removed: Carbon monoxide; the plant removed over 96 percent of this potentially deadly gas.

Other Pollutants Removed: Xylene, at a rate of 268 micrograms per hour. Formaldehyde, at a rate of 560 micrograms per hour.

Recommended Placement in Home: These are useful in kitchens with gas stoves or in rooms with fireplaces, where carbon monoxide may accumulate.

Cost: A ten-inch hanging spider plant costs between $10 and $15.

Care: They are easy to grow in bright to medium light.

JANET CRAIG/STRIPED DRACAENA

Dracaena deremensis

Type: Upright perennial.

Main Pollutants Removed: Formaldehyde, at a rate of 1,361 micrograms per hour. Xylene, at a rate of l54 micrograms per hour.

Recommended Placement in Home: These are especially effective in newly carpeted or newly furnished rooms.

Cost: An eight- to ten-inch potted Janet Craig costs $15 to $50.

Care: This plant needs bright to medium light, and can reach heights of fifteen feet, although it is best kept smaller.

Home