Screening of Capitol for Anthrax Begins

Federal environmental specialists have begun screening the Capitol and several office buildings for anthrax spores with the hope that Congress can resume a full schedule next week, the Environmental Protection Agency said Friday.

Several government agencies are pitching in to ensure that the Capitol complex is free of anthrax after 28 Senate staffers tested positive in preliminary tests for exposure to the bacteria. The anthrax was sent in a letter to Senate Majority Leader Tom Daschle (D-S.D.).

The cleanup teams, including three EPA experts and six contract workers, will wear protective suits made of Tyvek--the material used in soft express-mail packages--and full facemasks with respirators, EPA spokeswoman Tina Kreisher said.

The EPA is releasing few details about the operation; the timetable is unclear, although the work likely has begun and will continue through the weekend.

Experts in such cleanups said the inspectors need to ensure that they test the right areas so they don’t miss any spores and use the right chemicals for cleanup.

“It’s a horrendous job,” said Manuel S. Barbeito, a retired biological safety professional.

The risk, Barbeito said, is that anthrax spores can linger in the environment for decades. “It’s a spore. It doesn’t decay.”

However, to contract the deadliest form of the disease, inhalation anthrax, an individual would have to breathe thousands of spores into the lungs, experts said.

“Once they’ve taken up the initial [spore-containing] package, there probably is not enough left over to cause disease,” said Calvin Chue, a senior scientist at Johns Hopkins University’s Center for Civilian Biodefense Studies.

The EPA considers the job of cleaning the Capitol “manageable,” said Bonnie Piper, another EPA spokeswoman. Piper declined to comment specifically about the work underway at the complex. But she described the general approach to such jobs.

First, she said, the teams of experts devise a plan to sample material from walls, floors, ceilings, equipment, furniture, ventilation systems and ducts.

Barbeito said experts need to do a bit of detective work to decide where to take samples. This might include retracing the steps of people believed to have come into direct contact with the material, testing elevator buttons, desks and doorknobs along the way.

The sampling is done with swabs that have been moistened with a saline solution, Barbeito said. These cultures are placed on petri dishes and allowed to grow.

“You use common sense” in deciding where to test, said one infectious disease expert who has been advising Capitol Hill physicians since the anthrax was discovered there.

“You swab a desk or an envelope. You look for air filters--the obvious things,” the specialist said.

The tests are not perfect, he said, and scientists do not know their rate of accuracy, partly because “we’ve never screened so many places or people before.”

The EPA then analyzes the data from the samples to develop a cleanup plan, Piper said. “The goal is to eliminate and kill any anthrax spores present.”

To accomplish that, various products are used. A soy emulsion is best for cleaning fabrics; bleach is best for floors, walls and surfaces, experts said. An oxidizing foam, developed by Scandia National Laboratory, also can be used. The solvents are rubbed on the surfaces, allowed time to work and then the surfaces are wet-vacuumed with a very fine filter, Piper added.

The area is wiped down a second time with alcohol or soap and water, and allowed to dry. Any cloths used in the process are soaked in bleach and disposed of as biomedical waste, Piper said.

Another product used to decontaminate anthrax is formaldehyde gas, which is used to fumigate rooms, Barbeito said. But formaldehyde gas has drawbacks because residue can remain behind in porous materials.

In the Capitol operation, crews may start cleaning as they go rather than wait for all the results of the tests, which will take at least 24 hours, EPA officials said.

“People want to get back to work,” said Hays Griswold, an EPA coordinator at the site.

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Times staff writer Marlene Cimons contributed to this report.