If you live in an urban environment, you probably consider your home or office a haven from air pollution. Outside, buses may be belching black smoke, and a layer of smog could be hanging over the city. But inside, the air is clean. Right? Well, not exactly.
It turns out that indoor air pollution can be just as much a problem as the outdoor variety. According to Dr. Bill Wolverton, a retired NASA senior research scientist:
"In August 1989, the EPA released a major report on indoor air pollution to Congress. After studying businesses, homes and schools for five to six years, they concluded that the health risk from indoor air pollution is greater than that from outdoor pollution, simply because we spend 80 percent to 90 percent of our time indoors. Their findings indicated that pollution levels from indoors were estimated at anywhere from 10 to 100 times higher in modern, energy-efficient buildings than outdoors."
That's alarming news. But Dr. Wolverton has devoted the last 20 years to finding a solution. Now, working with the Foliage for Clean Air Council, he's spreading this simple message: The best way to protect yourself from indoor pollution is with houseplants.
To back it up, Dr. Wolverton has tested the effect of plants on three common indoor air pollutants:
* Formaldehyde, which is emitted by plywood, carpeting, foam insulation, furniture made with particleboard, some household cleaners and other sources.
* Benzene, a carcinogen that represents a family of solvents (xylene, toluene, etc.) and comes from paints, varnishes and lacquers, tobacco smoke, gasoline, some plastics, inks and even detergents.
* Trichloroethylene, a chlorinated compound that's believed to be a cause of liver cancer. It's in various inks, paints, lacquers, varnishes and the solvents used in dry cleaning. "So," explains Dr. Wolverton, "if you take clothes out to be dry cleaned, you may be bringing low levels of pollution into your home."
The results of experiments? "Plants were found to remove as much as 87 percent of toxic indoor air pollutants within 24 hours."
$ The best-laid plants
What are these beneficial plants? Surprisingly, they're ordinary varieties you may already have around your home.
According to a list supplied by the Foliage for Clean Air Council, philodendrons and spider plants are two potent formaldehyde fighters. English ivy and chrysanthemums battle benzene. And peace lilies and Gerbera daisies take on trichloroethylene. There are quite a few more plants on the list. If you want a copy, send a self-addressed, stamped envelope to Foliage for Clean Air Council, Dept. JC, 405 N. Washington St., Falls Church, Va. 22046. Ask for the fact sheet.
Meanwhile, here's some advice from Dr. Wolverton:
* "If you have a tightly sealed home, I'd suggest you get at least one plant per 100 square feet, minimum."
* "If you're a novice and don't know much about growing, I recommend low-maintenance plants like philodendron, golden pothos or peace lilies. If you're interested in more exotic plants, consider orchids, pot mums or azaleas."
* "Put in as many plants as you can. But don't over-water to the point where the plants might get moldy. And try not to get the rug wet when you water; it might cause mildew. (Both will affect the indoor air quality.)"
Dr. Wolverton concludes: "There is no question that if you're concerned about the quality of air in your building, you need some plants. It's worth it to keep them healthy, because they'll help keep you healthy."