Hey Mr. Green,
What is the greenest kitty litter for my indoor cat? --Carol (submitted via e-mail)
Cats themselves are a much bigger environmental menace than kitty litter. They're an invasive species that kills hundreds of millions of birds and mammals each year, robbing food from native predators like hawks and owls. So I salute you for keeping your feline where it belongs: inside.
The greenest cat litter is made of recycled paper, followed by sawdust, wheat chaff, oat hulls, or other biological materials. But more than half the litter in the United States is made of bentonite--a stripmined clay that leads right to Dick Cheney, which may explain why he raked around in Iraq like it was his personal litter box. Halliburton, where Cheney was CEO, produces about one-sixth of the 3 million tons of bentonite sold each year, of which 1.7 million tons go into cat litter. Quite a waste of a substance that can be used in iron smelting, environmental cleanup, and wine clarifying.
Neither bentonite nor silica gel litter should be flushed en masse, as they can gum up plumbing, but flushing a few particles probably won't cause trouble. Most municipal sewage systems can handle pet waste, but it should not be flushed where sea otters live, since studies have found some of these animals to be infected with toxoplasmosis, a parasitic disease carried in cat feces. Because this parasite can severely harm human embryos, pregnant women should avoid handling cat waste.