Their anonymous faces remained hidden behind protective plastic shields as they collected samples to ensure the safety of the famous inhabitants of the congressional offices they searched.

Members of the U.S. Marines Corps' Chemical Biological Incident Response Force, better known as CBIRF, were on their first, if a bit unexpected, mission.

A specialized life-saving unit within the Marines that responds to biological and chemical threats, the 400-person force is trained to go into contaminated areas to rescue and stabilize victims exposed to dangerous airborne agents.

But on Capitol Hill, the unit collected samples, not people, working alongside the other armed forces and experts from the Environmental Protection Agency and FBI during the anthrax investigations in Washington.

The scares began Oct. 11 when Sen. Tom Daschle received a contaminated letter and congressional offices were evacuated later that week to be swept for anthrax bacteria. The Hart Senate Office Building, where Daschle's office is located, is the only of the six congressional office still closed and the Capitol remained open throughout the scare, although it is still closed to tours.

For some of the Marines in CBIRF, the anthrax scare in Washington was their first real-word mission. Although the unit had trained extensively for a biological or chemical terrorist attack, it had never been called to a potentially dangerous biological environment.

"We actually got called; we actually got to do something," said Stephan M. Howard, a medical corpsman with the Marine unit.
"I don't want to say we actually got to prove ourselves, but after going up to Capitol Hill, more people got to learn about us."
The CBIRF Marines walked the deserted halls of the Longworth House Office Building, breathing filtered air through gas masks and pumps and collecting biological samples with long vacuum hoses.

A half-empty cup of coffee sat cold on an aide's desk. An opened book lay discarded. A fax machine hummed on, unaware of the utter desertion.

"It just looked like people up and left-just left everything as is... and it had an
eerie feeling to it," Howard said.

Leaving everything was exactly what congressional members, staffers and security guards did when they evacuated their offices in Longworth more than a month ago. CBIRF was called in to collect samples that were then delivered to the EPA.

"You could get the sense that there was something big going on around you," said Corporal Jerad Alexander, who worked at a decontamination station outside the Longworth building.

Besides sampling, the Marines were responsible for decontaminating their own team and other workers on the Hill. Once a person went inside a congressional office building, he or she had to be thoroughly washed. A decontamination squad of 15 Marines clad in air-proof suits alternately sprayed diluted bleach or water on people who had gone inside.

The unit also removed contaminated mail from the P Street Postal Facility in Washington, another unusual task for the CBIRF Marines.
"Give us a mission and we'll figure out how to do it," said Col. Thomas Hammes, commander of the unit.

He said the unit's flexibility, large numbers, reconnaissance capabilities and medical staff set it apart from other biological and chemical agent response teams.
Ready to deploy within one hour of notification, CBIRF responds with an initial force of 100 people, who can set up a decontamination station at a designated site within eight minutes of arrival.

What sets the CBIRF Marines apart from other Marines is their ability to respond to tragedies in hot zones, areas that are biologically and chemically contaminated with agents such as nerve gas or smallpox.
One of the greatest stumbling blocks to responding is the very covering that protects the CBIRFs from the "hot" environment-their hazardous materials suits. The suits restrict their movements and vision. They must train to gain confidence working in the suits, to maneuver and see in the dark and to overcome the potential feeling of claustrophobia caused by wearing gas masks.

"It's a little bit harder to see, harder to move your head around," Howard said. He is a Navy corpsman who is a permanent member of the CBIRF medical team responsible for stabilizing victims exposed to dangerous agents.

"You learn how to improvise and overcome some of the disabilities put on you by the suits," he said. "I don't want to say it gets easier as you do it, but it doesn't bother you as much."

Readiness, quickness and precision are the defining characteristics of a Marine and of CBIRF, said Lt. Paul Cabellon, a spokesman for the unit.

But so is the attitude-do more with less, he said.

The barracks of CBIRF are a testimony to its sparse resources. The unit is based in Indian Head, Md., a small town with a main highway that dead-ends at the naval base.
The deployment area at CBIRF looks more like a high school gym than a high-speed response facility. The workout facility consists of two small rooms with free weights and treadmills; hand-painted murals by the Marines cover the walls. The equipment and gear is never the latest, Cabellon said.
Some Marines said they hoped their work in Washington would improve the funding and support of CBIRF.

"I was in there doing a job. I was helping these people out," Alexander said.
Since the terrorist attacks and a growing public awareness of the threats of biological and chemical terrorism, CBIRF has gained greater responsibility and prominence. In October, it was named to the 4th Marine Expeditionary Brigade, a new anti-terrorism unit. A few weeks later, it received its first assignment at Longworth. Two weeks ago, it collected samples from the Dirksen Senate Office Building.

Corpsman Howard said the biggest change for him since the Sept. 11 attacks has been the attitude of his wife.

"I guess Sept. 11 came around and just like that her views changed," he said, snapping his fingers. He explained that she wants him to leave the military because of the potential danger, but also has never been so proud of his work .