Healthy Houseplants

By Veronica Sliva

Indoor air pollution is an ever-increasing concern to us. Building techniques have improved over time, and today our tightly sealed homes are more energy efficient than ever before. But the downside of this efficiency is that harmful gases released from synthetic materials such as paint, carpeting, and plastics remain in the trapped air, becoming harmful to our health. When airborne pollutants interfere with the exchange of gases, symptoms such as burning eyes, itchy throat, or other respiratory problems begin to appear.

Scientific studies

Did you know that you can reduce indoor pollution with houseplants? A study commissioned by NASA (National Aeronautics and Space Administration) tested houseplants in sealed chambers for their ability to clean the air. The testing concluded that several common houseplants removed certain pollutants. Another NASA study reported that houseplants removed up to 87 per cent of toxic indoor air within 24 hours. Since then other research has also reported similar findings. For example, a German study reported that one spider plant could detoxify a 100-cubic-foot room polluted with formaldehyde in just six hours. The results are certainly compelling.

Virtually all plants are powerful air cleaners

Here's how it works: Carbon dioxide enters through the leaves, and the process of photosynthesis - a series of complex chemical reactions - releases oxygen into the air. More simply put, the plant acts as a filter by removing pollutants from the air and replacing the air with oxygen in a more pure form.

The pollutants and the purifiers

Benzene

Benzene or benzol is a colourless and flammable liquid. It's also a carcinogen. Benzene is a commonly used industrial solvent found in gasoline, ink, oils, paints, and plastics. It's also used in the manufacture of detergents, pharmaceuticals, synthetic rubber, and dyes.

Exposure to benzene can cause dizziness, nervousness, headaches, and anemia, and it irritates both the eyes and skin.

Plants that remove benzene are Chinese Evergreen, Gerbera Daisy, Chrysanthemum, Peace Lily, Bamboo Palm, Striped Dracaena, English Ivy, and Snake Plant.

Formaldehyde

Formaldehyde is an important chemical widely used in the manufacture of building materials and numerous household products. Formaldehyde is hard to avoid. It's found in virtually all indoor environments and commonly occurs in insulation, particle board, and paper products. It is also used to add permanent-press qualities to clothing, in glues and adhesives, and as a preservative in some paint products, sometimes in combination with other chemicals. Many household cleaning products contain formaldehyde.

Formaldehyde irritates the mucous membrane of the upper respiratory system and can increase the risk of asthma.

Plants that remove formaldehyde are Chinese Evergreen, Bamboo Palm, Dracaena Janet Craig, Snake Plant, Red-edged Dracaena, Peace Lily, Spider Plant, Golden Pothos, and Heartleaf Philodendron.

Trichloroethylene (TCE)

Trichloroethylene or TCE has a wide variety of industrial uses, including as a solvent to remove grease from metal parts and in spot removers, inks, paints, varnishes, and adhesives.

Inhaling small amounts may cause headaches, lung irritation, dizziness, poor coordination, and difficulty concentrating. Breathing it for long periods may cause nerve, kidney, and liver damage. Breathing in large amounts of TCE may cause impaired heart function, unconsciousness, and death.

Plants that remove TCE are Gerbera Daisy, Chrysanthemum, Red-edged Dracaena, Peace Lily, Dracaena Janet Craig, and Bamboo Palm.

Homes are healthy plant friendly

In a typical home of about 1,800 square feet, 15 to 20 of these houseplants can purify the interior. The recommended air-cleaning plants are native to tropical or sub-tropical forests where they receive filtered light through the taller trees. This means that they adapt well to lower-light conditions, making them perfectly suited to the light we can offer them in our homes.

The Air Cleaners

Refer to the following list for details about specific houseplants that can help you keep the air in your home clean:

Chinese Evergreen (Aglaonema modestum)

One of the easiest houseplants to grow; tolerates low light

Water thoroughly and let the soil dry out between waterings

Bamboo Palm (Chamaedorea sefritzii)

Thrives in medium to high light and likes average room temperatures with lots of humidity

Water well from spring to fall and moderately during winter

Chrysanthemum

Keep cool and moist

If in bud, fertilize every two weeks

When they start to wither and die, it's best to replace them

Spider Plant (Chlorophytum comosum)

Likes average temperatures with bright light, but can tolerate medium light

Water thoroughly and let the soil dry outbetween waterings

Dracaena Janet Craig (Dracaena deremensis) and Striped Dracaena (Dracaena deremensis 'Warneckii')

Prefers bright light, but not direct sun

Water thoroughly and let the soil dry out between waterings

Red-edged Dracaena (Dracaena marginata)

Easy to grow in bright to medium light

Likes average home temperatures

Golden Pothos (Epipiremnum aureum)

Climbing or trailing vine

An excellent choice for less-than-optimum conditions because it tolerates low light and infrequent watering

Gerbera Daisy or African Daisy

Indoors requires bright light to flower

Keep soil slightly moist

English Ivy (Hedera helix)

Prefers temperatures from 18.5°C in the day to 7°C at night

Water thoroughly and let the soil dry out between waterings

Heartleaf Philodendron (Philodendron scandens 'oxycardium')

Easy to grow, happy in home temperatures and humidity

Good for low-light situations

Let soil dry out between waterings

Snake Plant (Sansevieria trifasciata)

This plant tolerates almost any amount of neglect, but with a little attention can be lovely

Does well in all light situations

Do not overwater

Peace Lily (Spathiphyllum)

Easy to grow

Tolerates low-light conditions and blooms in medium light

Keep soil slightly moist