The postal service is unveiling a new anti-terrorism device in central Iowa today.The main post office in Des Moines is the first in the state to get a B-D-S or Biohazard Detection System, which is now running. U.S. Postal Service spokesman Richard Watkins says “It’s a self-contained, fully-automated technology that combines air sampling with D-N-A analysis to detect biohazardous materials in the mail with extremely high reliability.” Watkins says letters are flattened as they pass through the B-D-S. When the letter is compressed at the “pinch point,” a small puff of air comes out which is tested for microscopic traces of anthrax and other toxins. The machines are being installed in several mail-handling facilities in Iowa as part of a nationwide initiative following the anthrax scares of October 2001.If it detects something hazardous, an alert is sounded, the item is isolated, the post office would be evacuated and emergency responders would be called in. Watkins says the machines are being put in nearly 300 mail centers nationwide. Facilities in Waterloo, Cedar Rapids and Sioux City will get them in the next two months, along with one more in Milan, Illinois, to serve the Quad Cities. The Des Moines office is Iowa’s busiest, handling several million pieces of mail per week.