From Rainforests to Kitty Litter

Breathing Silica, Washing Vegetables and Saving Habitat

What are the health effects of clumping cat litter on humans? Are there any negative side effects from breathing the actual litter?

—Andy and Taeja Klukas, Maple Grove, MN

Clay-based cat litters contain crystalline silica, the main component in sand, rock and mineral ores. A possible health threat from clay-based litters is posed by silica dust, which can be kicked up and breathed in by both cats and humans. Prolonged exposure to silica dust causes silicosis, a non-cancerous but sometimes fatal lung disease. Crystalline silica dust is also a suspected carcinogen, associated with bronchitis and tuberculosis. Although exposure to this dust is of great concern to those working in mines or on construction sites, the effects on cat owners exposed while cleaning their cat’s litter box are virtually unknown.

Illustration: Tom Garcia

However, respiration problems are not the only thing to consider when purchasing litter for your cat. All cats clean their fur and paws, which can be coated with clay litter from using the litter box. Clumping litters in particular can be harmful to your pet because, once ingested, the litter expands and absorbs moisture in the intestines, causing blockages and dehydration, and preventing the absorption of nutrients. For this reason, the ASPCA recommends not using clumping litter for kittens.

Aware of the possible risks of silica dust and other side effects from clay litters, many cat owners are opting for healthier, more environmentally-sound alternatives. Dust-free litters like Feline Pine or Swheat Scoop are biodegradable, less harmful if ingested by pets, and produce no dangerous respirable dusts. They both contain no chemical additives, fragrances or dyes, are completely flushable, and can even be used as compost or mulch.


Centers for Disease Control and Prevention
1600 Clifton Road NE
Atlanta, GA 30333
Tel. (404) 639-3311

How many of our rainforests are protected around the world?

—Adriano Adamson Paiva, Bahia, Brazil

According to biologist Norman Myers, “Rainforests are the finest celebration of nature ever known on the planet.” As complex, well-integrated ecosystems, rainforests cover less than two percent of the Earth’s surface, yet produce about 70 percent of the world’s oxygen and house 40 to 50 percent of all life forms on our planet.

Janet Abramovitz, senior researcher at the Worldwatch Institute in Washington, D.C., identifies three different types of rainforests. There are about 4.2 million square miles of tropical moist forest, of which eight percent is protected, and 76,000 square miles of tropical mangrove forest, of which nine percent is protected. And only five percent of the 300,000 square miles of the third type, tropical dry forest, is protected. It’s worth noting that many of these forests are protected only on paper; on the ground, they may not necessarily be protected at all.

Thousands of acres of rainforest are disappearing every day in different parts of the world, along with the unique animal species and plants living there. Major causes of this destruction are logging, cattle ranching, mining, oil extraction, hydroelectric dams and subsistence farming.

Some things you can do to help as a consumer are to choose cereals, cookies, nuts and other goods made from sustainably-harvested rainforest products that advertise their support for rainforest preservation, and avoid buying rainforest woods such as mahogany and teak.


Rainforest Action Network
221 Pine Street, Suite 500
San Francisco, CA 94104
Tel. (415) 398-4404

Is there any organic material that can wash away the pesticides on our fresh fruits and vegetables before we eat them?

—Michelle, Chalmette, LA

Several products on the market now are designed to remove pesticide residues, including Organiclean’s natural wash made from fruit extracts. The company says the wash, which has not been scientifically tested, cleans the surface of the fruit or vegetable. An Organiclean representative says that soap makes a poor cleanser because it can penetrate the porous skin of produce and leave harmful deposits. Emily Headen of the Environmental Working Group (EWG) prefers plain old water to remove surface contamination, though she adds that there are systemic pesticides (absorbed into the flesh of the food) that can’t be washed away either by water or by an organic wash. Consumers Union recently reported that a diluted wash of dish detergent, followed by a tap water rinse, reduced pesticide residues to zero in 53 percent of the samples tested.

Unfortunately, says EWG, washing and peeling by no means ensures that fruits and vegetables are 100 percent free of chemicals. The alternative is to buy certified, organically-grown, pesticide-free produce.


Environmental Working Group
1718 Connecticut Avenue NW, Suite 600
Washington, DC 20009
Tel. (202) 667-6982

10877 Wilshire Boulevard, 12th Floor
Los Angeles, CA 90024
Tel. (888) 834-9274