In Europe and Latin America, products with recycled content make up about on average 20 percent of the at-home market, according to experts at the Kimberly Clark Corporation.

Environmental groups say that the percentage is even higher and that they want to nurture similar acceptance here. Through public events and guides to the recycled content of tissue brands, they are hoping that Americans will become as conscious of the environmental effects of their toilet tissue use as they are about light bulbs or other products.

Dr. Hershkowitz is pushing the high-profile groups he consults with, including Major League Baseball, to use only recycled toilet tissue. At the Academy Awards ceremony last Sunday, the gowns were designer originals but the toilet tissue at the Kodak Theater’s restrooms was 100 percent recycled.

Environmentalists are focusing on tissue products for reasons besides the loss of trees. Turning a tree to paper requires more water than turning paper back into fiber, and many brands that use tree pulp use polluting chlorine-based bleach for greater whiteness. In addition, tissue made from recycled paper produces less waste tonnage — almost equaling its weight — that would otherwise go to a landfill.

Still, trees and tree quality remain a contentious issue. Although brands differ, 25 percent to 50 percent of the pulp used to make toilet paper in this country comes from tree farms in South America and the United States. The rest, environmental groups say, comes mostly from old, second-growth forests that serve as important absorbers of carbon dioxide, the main heat-trapping gas linked to global warming. In addition, some of the pulp comes from the last virgin North American forests, which are an irreplaceable habitat for a variety of endangered species, environmental groups say.

Greenpeace, the international conservation organization, contends that Kimberly Clark, the maker of two popular brands, Cottonelle and Scott, has gotten as much as 22 percent of its pulp from producers who cut trees in Canadian boreal forests where some trees are 200 years old.

Image Various brands at a supermarket near Philadelphia. Credit... Mike Mergen for The New York Times

But Dave Dickson, a spokesman for Kimberly Clark, said that only 14 percent of the wood pulp used by the company came from the boreal forest and that the company contracted only with suppliers who used “certified sustainable forestry practices.”