MISAWA AIR BASE, Japan – Maj. David Kempisty, 35th Aerospace Medicine Squadron installation radiation safety officer, shuts off a high-volume air sampler stationed on Misawa Air Base’s flightline April 29. The HVAS is used to detect radioactive particles in the air by collecting 1,000 cubic-feet of air every 50 minutes and trapping the particles on filter paper. Major Kempisty has been monitoring radiation levels here at Misawa since the earthquake and he has not detected any radiation above the normal background levels. (U.S. Air Force photo/Tech. Sgt. Phillip Butterfield)