The FDA looks to chlorine dioxide to clear the Hart building of Anthrax.
Anthrax cleanup under way in Senate office building
December 1, 2001WASHINGTON (CNN) -- Cleanup crews pumped toxic chlorine dioxide gas into the Hart Senate Office Building for much of the day Saturday in an attempt to kill all traces of anthrax contamination left over from a letter sent to Senate Majority Leader Tom Daschle in October, officials said.
It is the first time the process has been used to rid such a large space of anthrax, and Environmental Protection Agency officials said they hope it will be a model for future cleanup if it succeeds.
Police blocked off surrounding streets Friday in preparation to clean up the Hart building, where a staff member in the South Dakota Democrat's office opened an anthrax-laden letter more than six weeks ago.
A cleanup team began pumping chlorine dioxide into Daschle's two-floor office suite -- a space of about 3,000 square feet -- at about 3 a.m.
The gas is being created on-site from two chemicals that will be pumped into the building, where they are being blended to form a chlorine dioxide-rich mixture. That mixture will be pumped into the Daschle suite until the chlorine dioxide concentration in the air reaches levels that scientists say will be effective in killing anthrax spores.
The gas then will be sucked out of the suite and passed through a bubble chamber with a solution designed to break it down.
Richard Rupert, who is overseeing the cleanup for the EPA, said chlorine dioxide -- while extremely toxic -- breaks down naturally with exposure to daylight or even fluorescent lights. To be effective, the procedure must be undertaken in complete darkness. Workers blacked out office windows ahead of the fumigation.
To ensure the anthrax is gone after the gas is removed, so-called spore strips will be placed in the offices with a marker bacterium. The death of these bacteria will indicate that the anthrax bacteria, which are related, also are gone.
Initially, plans were to leave the chlorine dioxide in the office for about 12 hours, but that was revised upward on Saturday after it was determined that more time was needed.
"No one's ever really introduced chlorine dioxide gas into a room where there was lots of furniture and rugs. In all the tests that we've done prior to this, they were much smaller areas, not as much fabrics, desks, that sort of thing," Rupert said at a Saturday evening briefing. But otherwise, everything was proceeding as planned, he said.
Rupert said it would take five to seven days before the EPA will get final test results on whether the office is anthrax-free.
EPA officials said they had hoped to use the gas throughout the entire Hart building, which has been closed since October 17, but a peer review said that plan was too risky because of the size and shape of the large building.
Cleanup of other less contaminated parts of the building using an anti-bacterial foam, liquid chlorine dioxide and a hepavac machine is already under way, Rupert said.
In addition to Daschle's office, traces of anthrax were found in 11 Senate suites, and liquid and foam spot removers will be used to rid those offices of viable anthrax.
Rupert said cleanup of all contaminated areas of the Hart building, where 50 senators have their offices, probably will take another two to four weeks to complete.
But EPA administrator Christie Whitman has not committed to a date. At a hearing this week, she told senators that her goal is to make sure the Hart building has "no viable anthrax." However, she admitted some traces may remain as long as they pose no health risk.
Senators raised concerns about sending staff into the building, telling Whitman they were skeptical they could be sure about their safety.
"It looks to me like we'll be looking for more money to build a new building because I don't know how you're going to get all the anthrax out," Sen. Ted Stevens, R-Alaska, told Whitman.
-- CNN Congressional Correspondent Kate Snow and Producers Dana Bash and Richard Griffiths contributed to this report.
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