Last Updated: 2003-05-21 16:44:45 -0400 (Reuters Health)

WASHINGTON (Reuters Health) - The Environmental Protection Agency (EPA) warned consumers Wednesday to check their attics for an asbestos-containing insulation material that may pose health risks if disturbed.

Bush Administration officials estimated that the insulation, made from a mineral called vermiculite and sold for years under the brand name Zonolite, may be present in tens of millions of houses across the country.

They urged homeowners to not to come into contact with the insulation and to avoid physically disturbing it, but did not recommend immediate removal from houses.

Handling or otherwise disturbing the insulation can mobilize asbestos fibers that pose a well-known risk of mesothelioma and other forms of lung cancer, they said.

"The message is, do not disturb," said Stephen L. Johnson, assistant administrator for the Office of Prevention, Pesticides, and Toxic Substances at EPA. "If left undisturbed, we don't believe there's any risk to consumers," he said.

Still, Johnson warned that federal regulators remain unsure about how much asbestos is contained in vermiculite attic insulation or what the actual risk of exposure is to people who live in houses where it was installed.

The EPA's warning urges consumers to check their attics for vermiculite, which looks like granular dirt or gravel. The insulation can sift through cracks in lighting fixtures and ceiling fans.

It also instructs homeowners to avoid storing boxes in attics where the insulation is present and to keep children from playing near it.

Homeowners who remodel or want to remove the insulation should also never handle the insulation themselves, but instead call on firms trained in insulation or asbestos removal, the agency said.

In attics that contain air conditioning machinery or animals that can kick up dust, "you would not want to go up there," said Kathy Skipper, director of communications at the Agency for Toxic Substances and Disease Registry.

Much of the current U.S. supply of vermiculite was culled from a mine in Libby, Montana, that was also a major source of asbestos. Preliminary EPA estimates suggest that mixing contaminated the vermiculite with as much as six percent asbestos.

The warning comes as lawmakers are preparing to introduce legislation that would ban all industrial uses of asbestos in the U.S. The bill, to be introduced tomorrow by Sen. Patty Murray, D-Wash., contains a provision directing EPA to warn consumers about potential risks associated with vermiculite.

The first Bush Administration attempted to ban asbestos in 1989, but the ban was overturned by a federal court order at the urging of the mining industry.

"What the EPA did today appears to be a modest first step," said Todd Webster, a Murray spokesperson.

Asbestos is routinely used in several products, including car brake pads and roofing shingles.

Thousands of miners, workers, and residents of Libby, Montana, have been diagnosed with cancers and other health problems blamed on asbestos inhalation. Murray is likely to push the ban when the Senate soon debates a bill designed to set up a national compensation fund for workers and others sickened by asbestos, Webster said.

EPA's complete vermiculite warning is available at www.epa.gov/asbestos/.