Green Guru
Advice for the eco-minded.
By Susan Cosier

What are some ways to deice my front steps without killing nearby plants?
—Jacqueline Fox, Hartsdale, NY

When temperatures dip below freezing and walkways become ice slicks, lots of people pour on the salt. But their plants will pay for it. Sodium pulls water away from plant roots and burns them; in the long term it also ruins soil structure, turning dirt into powdery dust. And who wants to add more salt to the water running off into streams and rivers? Potassium chloride and calcium chloride deicers are slightly better, says Kurt Morrell, the director of arboretum grounds and gardens at the New York Botanical Garden, because the chemicals aren’t as harsh. But if you’re planning to use chloride deicers, it’s best to treat your soil in November or December with gypsum, a limelike material that counteracts the effects of soluble salts. The bottom line: No deicing material is good for plants, says Morrell. As an alternative to such chemical products, you can spread sand, gravel, or ash to gain some traction. (These products don’t melt ice—and they can still alter the physical properties of soils.) If you must deice, practice that old adage “everything in moderation.” People often cover their sidewalk with a deicer, then, after it works, toss salt-covered snow onto a flower bed or lawn. “A lot of the time it’s the first shovel that’s causing damage,” says Morrell. In addition to practicing some restraint, you might want to check out products like Combo Therm (widely available at hardware stores) that form a brine beneath snow, discouraging ice from forming in the first place. If you apply it before the snow falls, chances are you’ll use less.
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Could you tell me if polystyrene is biodegradable or recyclable?
—Barbara Grimm, Atlanta, GA

Digging through a box of polystyrene peanuts for a present has become part of the Christmas morning fun. Deciding what to do with the packing material afterward has not. About two million tons of polystyrene—a.k.a. Styrofoam—is produced in the United States each year, and most of it ends up in landfills. Nothing to be jolly about.

Even though it’s lightweight (mainly because it’s 98 percent air) and a good insulator, polystyrene is one of the least environmentally friendly products on the planet. If the tiny pieces that break off aren’t properly disposed of, they can wind up in rivers and oceans, where birds and other animals often mistake them for food. Not to mention, the components in polystyrene are downright nasty; studies show they can change DNA structure, damage nervous systems, and may cause cancer.

Polystyrene doesn’t biodegrade either. Ever. That’s why alternatives—paper, cardboard, and even new-age packaging made from sugarcane—and many reusable materials, such as washable lunch trays, are a better way to go.

If you have no choice this holiday but to deal with leftover polystyrene used to package, say, a new pair of speakers, you can reuse it or recycle it. Visit the Alliance of Foam Packaging Recyclers website for places to send it. If your gift comes packed in peanuts, contact the Plastic Loose Fill Council, a trade association, which manages the Peanut Hotline (800-828-2214). Some stores and recycling programs also accept polystyrene.
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Is there a green product for ceiling insulation? I don’t like the idea of using fiberglass in my crawl space.
—Carol Helene, Miami, FL

The best thing you can do to keep warm this winter is pile on another blanket—on your house, that is. Since up to 50 percent of the energy used in a home is for heating and cooling, insulation will help keep your energy use in check. The U.S. Environmental Protection Agency and the Department of Energy estimate that homeowners can save up to 20 percent on heating and cooling costs if a house is properly insulated and sealed. Your concern about the dangers of fiberglass are understandable; for a long time this material was thought to be carcinogenic because of the tiny sand, glass, and other materials embedded in it. Even though fiberglass still carries a warning label that says the product may cause cancer, especially if not properly installed, the National Lung Association says exposure to its fibers does not pose a higher risk for the disease. That aside, buying eco-friendly insulation helps support a budding industry that aims to protect natural resources and keep residents feeling healthy. Options suggested by some green building specialists include shredded newspaper (cellulose) or cotton blue jean scraps, says Nadav Malin, the vice president of BuildingGreen, a Vermont company that publishes information on sustainable design. You might weigh the costs and benefits of those products against more expensive wool batts and foams made from petroleum or a soy-based polyurethane. (If chemicals are a concern, realize that most insulation today, including the eco-friendly options, has been treated with flame retardants. Also see GreenHomeGuide.)

No matter what material you go with, one simple rule applies: The denser and thicker the material, the better the insulation, or R value. Attics should be R-50 in cold climates, says the Rocky Mountain Institute, a nonprofit environmental group that focuses on energy efficiency, and R-30 in hotter regions of the country. No matter what you use, “one of the crucial things to do when you insulate is to fill every nook and cranny,” says André Desjarlais of the Oak Ridge National Laboratory. That will surely keep you feeling cozy and comfortable all year long.
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Send your most vexing questions to greenguru@audubon.org.

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