Biohazard workers pumped chlorine dioxide gas through the Washington offices of the Senate majority leader, Tom Daschle, yesterday in an effort to eliminate any remaining risk of anthrax contamination.
In an unprecedented fumigation operation, officials from the Environmental Protection Agency and the Centers for Disease Control and Prevention sealed off the whole of the Hart Building, home to 50 senators and their staffs, an adjacent building and an underground car park.
Several emergency teams and a hi-tech laboratory bus were on hand to check for possible toxic gas leaks. The gas had to be pumped in conditions of maximum humidity, so extra steam was provided by cranking up the building's heating systems.
Officials said they could not promise they would kill every last anthrax spore but they hoped to make workers in the Hart Building comfortable that all possible danger of infection had passed.
Much of Capitol Hill was thrown into a panic in mid-October when a letter addressed to Senator Daschle was found to contain fine anthrax powder. Thousands of people were put on antibiotics and two Washington postal workers died.
A second contaminated letter, addressed to the Senate Judiciary Committee chairman Patrick Leahy, was intercepted before it was opened. Investigators anxious to inspect the contents without risk to their own health were expected to open the letter, believed to contain billions of anthrax spores, with a small robot working inside an isolation tank at a germ warfare laboratory.Reuse content