CAPITOL COMPLEX Officials hunt for poison letters

A ricin-tainted letter to the White House was intercepted in November.
WASHINGTON (AP) -- Unopened mail is being collected throughout the Capitol complex by investigators searching for letters that could be contaminated with the deadly poison ricin.
Three Senate office buildings remained closed after a white powder determined to be ricin was found in an office of Senate Majority Leader Bill Frist on Monday, a little more than two years since Congress grappled with another potentially lethal toxin, anthrax.
Meanwhile, a law enforcement official revealed that another letter containing ricin and bound for the White House had been intercepted in November.
Ongoing tests
Tests were ongoing on the ricin found by a young worker in Frist's fourth-floor mailroom in the Dirksen Senate Office Building. Authorities want to learn whether it was sufficiently potent and in a powder fine enough to kill people.
Even without final test results, House Speaker Dennis Hastert said, "It's serious enough that they're picking up everybody's mail."
No illnesses had been reported by late Tuesday, said Dr. John Eisold, the Capitol physician. Tests of air filters showed the toxin had not circulated through the buildings' ventilation systems, said Senate Democratic leader Tom Daschle of South Dakota.
Health experts expressed optimism that casualties would be averted in the new attack. "As each minute ticks by, we are less and less concerned about the health effects," said Dr. Julie Gerberding, director of the Centers for Disease Control and Prevention in Atlanta.
Watching for symptoms
But dozens of Senate workers were being monitored and health officials urged Senate staff to watch for swiftly developing fever, coughs or fluid in the lungs over the next two or three days. When inhaled in sufficient quantities or injected, ricin can be fatal -- and there is no known vaccine or cure.
The postal facility that processes Congress' mail also was shut. In 2001, two postal workers in Washington were among five people who died from anthrax exposure.
Senators debated a highways bill Tuesday, but votes were canceled. Frist said that voting in the Senate would resume today but that all three Senate office buildings would remain closed, perhaps all week.
The letter or package that might have carried ricin into Frist's office had not been identified, investigators said. No extortion, threat or complaint letter had been found in the office, said a second law enforcement source, also speaking on condition of anonymity.
Intercepted letter
The ricin-laced letter addressed to the White House in November had been detected at an offsite mail processing facility, the law enforcement official said, speaking on condition of anonymity.
The investigation into that letter continues, and there have been no arrests, the official said.
Authorities determined the letter posed no threat to health because of the ricin's low potency and granular form.
The letter was similar to another letter containing ricin that showed up in October at a postal facility serving Greenville-Spartanburg International Airport, according to a senior law enforcement official, speaking on condition of anonymity.
The author of both letters complained about new regulations requiring certain amounts of rest for truck drivers, the official said.
There was widespread agreement among lawmakers that Congress responded more effectively this week than to the anthrax-laced letters that were sent to two senators in 2001.
But even Frist acknowledged that things were "not perfect." Chief among senators' complaints were that authorities were too slow to alert them.
"We weren't notified promptly enough yesterday," said Sen. Tom Harkin, D-Iowa, who said one of his aides worked well into the evening in the Dirksen building.
"But that's OK. People make mistakes."
Quarantined workers
One aide who was quarantined said many co-workers had already gone home. This aide said those quarantined were asked to telephone colleagues who had left and tell them to shower and put their clothes into a bag.
Senate aides said 40 to 50 people were quarantined and decontaminated with showers, though Frist's office said the number was 24, plus an uncertain number of Capitol police officers who took precautionary showers after their shifts.
Sen. Lindsey Graham, R-S.C., emerging from a luncheon meeting with Frist, Eisold and Capitol police chief Terrance Gainer, said the three had expressed concern.
Officials worry
"There was something specific about this that made them worry," Graham said. "Somebody knew what they were doing. ... Frist said the type, the way it was presented indicated that people understood it goes into the air and gets into lungs."
Powder found in an envelope at a mail processing center in Wallingford, Conn., where anthrax was discovered in 2001 has tested negative for ricin and appears to be wood ash, officials said Tuesday night.