The House suspended work and three Senate office buildings were closed yesterday as congressional leaders announcedthat 26 Senate staffers and five police officers had been exposed to anthrax spores that arrived in the office mailof Senate Majority Leader Thomas A. Daschle on Monday.

It was believed to be the first time since British troops burned the Capitol in 1814 that danger to lawmakers forceda congressional recess.

The letter sent to Daschle was found to contain a highly refined form of anthrax, suggesting it was produced byexperts. The particles are so tiny, they can float a considerable distance through the air on the smallest of aircurrents, without detection.

Producing germs that can spread as a mist has been the main technical challenge facing bioweapons programs throughoutthe 20th century.

Almost simultaneously, New York Gov. George E. Pataki announced that anthrax microbes had been detected in hisManhattan office.

Meanwhile, Centers for Disease Control announced yesterday that preliminary testing indicates the strain of anthraxthat infected workers at American Media Inc in Florida, is almost identical to the strain that arrived in a lettersent to NBC.

Guest:

• Dr. Leonard Cole, author of ??The Eleventh Plague: The Politics of Biological and Chemical Warfare.