Staff Sgt. Kathleen Couillard (right) and Airman 1st Class Dustin Monti, 28th Medical Operations Squadron bio-environmental engineering technicians, conduct a radiation scatter survey at the dental facility on Ellsworth Air Force Base, S.D., March 27, 2012. Bio-environmental engineering technicians help prevent health problems that could result from exposure to radiation by testing facilities around base for radiation emissions. (U.S. Air Force photo by Airman 1st Class Kate Thornton/Released)