Safety officials in charge of warning the public if there is a release from the chemical weapons stockpile at the Pine Bluff Arsenal say the alert system is being updated. Sirens, tone alert radios and roadside signs are being improved as part of the effort. Testing is continuing on 58 sirens that were installed within a nine-point-five-mile radius of the arsenal, an area called the Immediate Response Zone. Testing should begin soon on four additional sirens. Electronic signs are scheduled to be placed at several locations to help motorists in any evacuation. In addition, the programming of 15-thousand new tone alert radios is to be complete in January. The radios will be distributed to people in the radius.