Air cleaners

Plants can help in fight against
indoor air pollution


Monday, October 23, 2000

By Julie Bawden Davis
Inman News Features



Imagine how we'll combat indoor air pollution--one of the top five public health threats--in the next century.

Chances are you're envisioning elaborate, Space Age machinery doing the job. But the answer may be the low-tech houseplant.

Houseplants can improve indoor air quality, according to Bill Wolverton, an environmental scientist and author of "How to Grow Fresh Air:  50 Houseplants that Purify Your Home or Office. (Penguin, 1997)

(First in a two-part series. See part 2)

For almost 20 years, Wolverton worked for NASA developing technology that would allow humans to live in a closed environment on the moon or Mars.

Through this pioneering research, he discovered that houseplants are the quickest and most effective filters of common, dangerous air pollutants such as formaldehyde, benzene, xylene and ammonia.

All of these pollutants cause a number of ailments such as asthma and allergies, as well as the general condition called sick building syndrome. Wolverton and his colleagues have placed houseplants in sealed chambers and exposed them to hundreds of chemicals.

"We've found that plants literally suck these chemicals out of the air," said Wolverton, who now lives in Mississippi. "After some study, we've unraveled the mystery of how plants can act as the lungs and kidneys of buildings."

Plants clean indoor air in two ways, he said. They absorb pollutants into their leaves and transmit the toxins to their roots. There the toxins are transformed into a food source for the plant.

Plants also emit water vapors that create a pumping action that pulls dirty air down around the plant's roots, where it is also converted into food for the plant.

"The closer the plant is to you, the better," Wolverton said. "Even in large open rooms, a plant within your personal breathing zone (the 6 to 8 cubic feet surrounding you) really improves the air you breathe."

Many common houseplants do a great job of cleaning indoor air. Like large plants? Bamboo palm, rubber plant and draceana `Janet Craig' are great air cleaners.

Peace lily, golden pothos and Boston fern are good smaller choices.

Even outdoor plants brought in for a short time will clean the air.

Some plants specialize in removing certain toxins. Boston fern, for instance, does the best job of removing formaldehyde, which is found in many synthetic products, such as particleboard furniture, paints, carpeting, cleaning solutions and pesticides.

The peace lily does an especially good job of removing acetone, found in fingernail polish remover and various solvents.

If plants are so efficient at cleaning indoor air, why doesn't everyone know about it? That's because houseplants are falsely blamed for creating airborne mold and mildew, Wolverton said

"It's not plants that give off mold spores, but the soil," he said. "Plants actually reduce molds and mildews in the air."

Wolverton and his co-researchers have developed a solution to the mold issue. "We've discovered soil-free pebbles (expanded shale) that can be used to grow plants in water and eliminate the threat of mold," he said. These pebbles are available in some locations.

If you use potting soil for your houseplants, he suggests that people sensitive to mold cover the top of the soil in their pots with aquarium gravel, which will dry quickly after watering.

He is also working on introducing Eco-Planters to the United States. Eco-Planters are plant pot systems that contain activated carbon filters, fans, lights and electronic water gauges. These hi-tech planters make plants extremely more effective at cleaning indoor air and removing airborne microbes like mold spores. They are currently on the market in Japan.

"In the meantime, though, everyone should grow houseplants in a manner that won't create mold," he said. "The more houseplants you have in your home and office environment, the better."

Julie Bawden Davis is a Southern California freelance writer.

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SOME CHEMICALS

THAT POLLUTE AIR

Indoor air contains an abundance of chemicals harmful to humans.

Although many of these chemicals are released into the environment in minute amounts, when hundreds of chemicals mix, they can form a "pea soup concoction that can create a variety of health problems, including respiratory disorders such as asthma,"

said Bill Wolverton, author of "How to Grow Fresh Air."

Here are just a few chemicals and the problems they can cause.

--Acetone: This is found in nail polish remover and various solvents.  It is very drying to the skin.

--Ammonia: Found in many cleaning solutions, it can create a toxic gas if mixed with bleach.  It is also very irritating to the lungs.

--Benzene:  Suspected of causing leukemia in children, this is found in paint, varnish, gas and just about any chemical that has an odor.

--Formaldehyde: This is an especially dangerous chemical that is found in most synthetic products, such as particle-board furniture, paint, pesticides and carpeting.

It is a strong irritant and is believed to cause a condition known as multiple chemical hypersensitivity in some individuals, which leads to asthma and multiple allergies.

--Julie Bawden Davis

 

 

Copyright 2000 Inman News Features