Great the people who should be wiped out are now protected. Wednesday, June 26, 2002 WASHINGTON â€” Call it another sign of the times: The first of 20,000 gas masks â€” enough for all lawmakers, their aides and other employees and even tourists in the event of a chemical or biological attack â€” have begun arriving at the U.S. Capitol. One-hour training sessions for congressional employees on how to use the quick masks will begin next week when lawmakers are out of town for a weeklong July Fourth holiday, Capitol Police Chief Terrance W. Gainer said Wednesday. "It's simply an escape hood, it's not meant to do any work," Gainer said of the devices, explaining that the masks are intended solely to protect employees and visitors just long to evacuate the Capitol and nearby office buildings in the event of a biological or chemical attack. The mask includes a yellow hood that fits over the head with a plastic face covering, a nosepiece clamp and a fitted mouthpiece with a filter attached for stopping chemical gases and biological agents. The masks are used by paramedics, firefighters and police officers who first respond to emergencies. Gainer said the devices, each costing about $100, are good for two minutes up to an hour at filtering out anthrax spores or toxic gases, depending on the temperature and how hard a person is breathing. The masks are ineffective against radiological agents, he said. The masks will be stored in each congressional office and at all entrances to the Capitol and its office buildings. They would be issued only upon an alert and police officers will be trained to quickly instruct tourists and other visitors on how to put them on, Gainer said. Capitol Police officers have been equipped with the masks since 1997. After anthrax letters addressed to lawmakers were discovered in the Capitol complex last fall, additional masks were ordered for congressmen and senators. Gainer said a decision was made to order another 20,000 of them because the Capitol already has been subjected to a bioterrorist attack and would be a likely target for another one. "It's just being cautious," he said. "There's not one shred of information that ties this to July Fourth or any specific threat." Anthrax-tainted mail sent to the Capitol last fall killed two postal workers. Before the terrorist attacks, about 10,000 visitors walked the Capitol's halls on a busy day. Some took guided tours, but many roamed freely. Then came Sept. 11 and anthrax, which frightened away many of the city's visitors. Returning tourists are finding the Capitol a much more security-minded place. No more self-guided tours of the building, for example. About 1,000 people take the public tour; others take private tours arranged by congressional offices or see only the House and Senate chambers. Outside, concrete barriers and metal posts now ring the sprawling Capitol grounds. Another 700 officers have been added to the Capitol Police force. Security is tight around a construction zone on the east side where a $368 million, three-story visitors center is being built underground.