WASHINGTON -- The poisonous gas pumped into the Hart Senate Office Building last weekend appears to have killed any remaining anthrax spores, Environmental Protection Agency officials said Tuesday.
The agency must await lab tests to confirm the preliminary results, but monitoring equipment suggested the fumigation worked on the second try. An earlier attempt failed when officials could not create the necessary levels of humidity.
"We feel very comfortable that we had a very successful fumigation," Richard Rupert, the EPA's on-scene coordinator said in an interview.
"We feel that based on the humidity numbers, the temperature and the concentration of chlorine dioxide, we were able to effectively destroy any anthrax spores."
Technicians under the environmental agency's direction began pumping chlorine dioxide gas into the heating and ventilation system of the southeast quadrant of the building at 9 a.m. Friday. The process was completed at 4:30 a.m. Monday.
The quadrant had tested positive for anthrax spores after the earlier fumigation effort. The building, where half the 100 senators have their offices, closed Oct. 17 two days after an aide to Senate Majority Leader Tom Daschle opened an anthrax-tainted letter.
Daschle said Sunday there was a reasonable possibility the building would reopen this month.
Officials are waiting for results, possibly later this week, on two types of laboratory tests.
One analysis is under way on more than 400 Band-Aid-size strips that will provide the results of the fumigation. Separate tests are checking samples taken from swabbing and vacuuming surfaces.