New Tests For Anthrax Negative

John Tucker, who works at a facility that handles government mail, fills out paperwork to receive a screening for anthrax at the D.C. General Hospital campus. (Nikki Kahn -- The Washington Post)

But even at the Pentagon, there was concern that some procedures were not followed properly. Workers did not hold up delivery of an estimated 8,000 pieces of mail that flowed Thursday and Friday throughout the building. Standard procedure requires mail to be held until daily tests are completed, and military officials said complacency might have played a role after years of negative results.

The assessments came during a long day for security officials, who held their collective breath pending conclusive test results from samples taken from the Pentagon's Remote Delivery Facility in Arlington and the Skyline office building complex of defense workers and contractors at Baileys Crossroads in Fairfax.

The incident began before 10:30 a.m. Monday when a defense contractor responsible for daily biohazard monitoring at the Pentagon mailroom reported a positive alert for anthrax from a sensor filter sampled Thursday. The facility, which also handles food and other deliveries to the Pentagon, was shuttered; 263 employees submitted swab samples to medical personnel, and Arlington emergency crews were called.

About 2:30 p.m. at the Baileys Crossroads complex, which receives mail from the Pentagon facility four miles away, a sensor gave an alert in an eighth-floor mailroom at Skyline Five Place. About 800 workers were locked down in three buildings for almost six hours. Dozens were decontaminated, and workers who had left were told to wash exposed skin, jewelry and eyeglasses and seal their clothing in a plastic bag.

Pentagon officials said they are continuing to investigate but have found no connection between the alerts at the two facilities, calling the situation an apparent coincidence. Defense officials are working with Fairfax County and the FBI to determine when the buildings may reopen, pending additional tests.

Postal officials expressed relief that the mail was not involved. Postal Service spokesman Gerry McKiernan said this morning that the V Street facility was reopening at noon, and about 240,000 pieces of government mail held there will be delivered. He said officials are also advising employees at the center who began taking antibiotics that they can discontinue the medication.

The test that produced the confirmed positive finding of anthrax was performed by the U.S. Army Medical Research Institute of Infectious Diseases at Fort Detrick and completed about 4 a.m. yesterday, a top military official said. The polymerase chain reaction test is accurate to "very, very close" to 100 percent in confirming the presence of the molecular signature of anthrax bacteria, he said. But all subsequent lab culture tests, used to determine if there were any live or viable bacteria, were negative.

Officials said the Pentagon incident did not bear the signature of the 2001 attacks, when anthrax spores were found in more than two-thirds of tests at mail facilities in Brentwood and New Jersey.

Authorities have not recovered any mail believed to have triggered the sensors, and they said there were no threats to lend credence to a possible attack. That, coupled with the many negative test results, provided federal officials with the confidence to say there was no health risk.

Staff writers Dan Eggen, Manny Fernandez, Allan Lengel, John Mintz and Jamie Stockwell contributed to this report.