WASHINGTON (AP) _ An expert on germ warfare is telling Americans to use a steam iron on the mail if they're afraid to open it.

Ken Alibek said the combination of heat and moisture would kill any anthrax lurking in an envelope.

``If you are scared, just iron this letter,'' he said. ``After that, they (the spores) become harmless.'' Microwaves are somewhat less effective than steam ironing because they don't emit moist heat, he said.

Alibek defected to the United States in 1992 after serving as deputy head of the huge Biopreparat venture linked to germ warfare in the former Soviet Union. The Soviet Union produced hundreds of tons of anthrax at its sprawling biological weapons facilities.

Alibek spoke Tuesday at a Capitol Hill briefing organized by Reps. Edward Markey, D-Mass., and Christopher Shays, R-Conn.