Survivor, salty roads and car-free cities. (Ask E).

I really enjoy the Survivor TV series, but what is the environmental impact of the TV crews working in those remote areas?

--Rachel Maxwell, Port Washington, NY

Though the TV show Survivor ensures the survival of its contests, some feel it fails to offer the same guarantee to the environment. As the third Survivor series was being taped in the Kenyan Shaba National Reserve, members of the local Waso Trust Land Project began to complain that vegetation and animals living in the park were being disrupted by the filming. Local environmentalists said in a press statement, "The presence of more than 200 workers and the heavy commercial trucks supplying provisions and other operations in the reserve has scared away all the animals."

Survivor II, which was filmed in Australia, has a much better record, in part because of strict conditions imposed on the filmmakers. Ian Sinclair of the Queensland Department of Natural Resources (DNR) explained to the Wired news service that the terms of the show's lease included guaranteed waste collection and protection of local flora and fauna: In an interview with the Australian Broadcasting Corporation, he added, "The impacts were pretty minimal. All rubbish was removed. No vegetation was destroyed. The tracks and the bare area that were reseeded are probably the only visible signs of impact from the use of the area by Survivor II." But as Australian Survivor competitor Colby Donaldson showed when he illegally picked up pieces of coral, local environmental laws may not always be followed. CONTACT: Queensland DNR, (011)61-7-3896-3111, www.dnr.qld.gov.au.

--Y.Z.

What is the least environmentally damaging way to de-ice pavement?

--Heidi David, Concord, NH

Although salt and various salt derivatives melt ice and make raveling safer, they are damaging to the environment. According to the New York Times, salty runoff can poison fish and aquatic organisms and will sensitive vegetation. It also causes corrosion of metals, damage to concrete and risks to people and animals with high blood pressure. Zev Ross, conservation coordinator for the River Alliance of Wisconsin, says, "Salting the roads affects every facet of the surrounding environment."

However, conscientious consumers can effectively use deicers with minimal impact, says materials consultant Henry Kirchner. Snow should be cleared away first, and just enough deicer should be applied to break the bonds between the ice and the pavement. The ice should then be chipped off and moved away from water supplies and vegetation. Properly constructed and water-sealed surfaces are easier to keep ice-free.

For small jobs, it may be feasible to use more potent, less environmentally toxic de-icers like magnesium chloride (85 cents per gallon) or calcium magnesium acetate ($675 a ton) instead of rock salt ($30 a ton). These stronger compounds can be strategically applied before a storm to block ice from forming.

Sand and kitty litter can be used to provide temporary traction, but these materials may dog surface water and bury plants, says the New York Times. Although many researchers are experimenting with even more benign de-icers, including by-products of corn and cheese processing, none of these compounds are currently available to consumers. CONTACT: The Salt Institute, [phone], www.saltinstitute.org; Pacific Northwest Snowfighters, [phone], www.ws dot.wa.gov/fossc/maint/pns.

--B.H.

Are there any car-free cities?

--Elizabeth Vales, Cleveland, OH

Carfree.com has an extensive listing of car-free locations throughout the world. The website breaks these places into three categories: those completely or predominantly car free, those with large areas that are car free, and those with limited automobile traffic. In the United States, essentially car-free locations include Mackinac Island, a resort island on Lake Huron that uses horses and buggies for its transportation, and Fire Island in New York, which uses a combination of boats and wagons.

Many other sites are located in Europe, the largest being Venice, where a canal system takes the place of streets and transportation occurs by foot or boat. Giethoorn, located in the Netherlands, also relies on canal-boat transportation. Various alpine resorts in Switzerland, such as Zermatt and Barunwald, are car free as well. A unique location is Louvain la Neuve, a university town in Belgium with streets for automobiles lying beneath separate streets for pedestrians. Mont-Saint-Michel and Ile de Porquerolles, islands off France, are also car free.

Outside of the United States and Europe, car-free places exist in numerous cities in Morocco and in China (Gulangya Island, Cheung Chau Island and other islands off Hong Kong). CONTACT: Carfree.com, www.carfree.com.

--C.S.