ROBINS AIR FORCE BASE, Ga. – Airman 1st Class Josue David, 78th Bioenvironmental Flight technician, records water chlorine levels in building 905 at Robins Air Force Base, Georgia, Feb. 9, 2021. Testing for contaminants and chlorine levels are among the many industrial hygiene duties the flight performs regularly. (U.S. Air Force photo by Kisha Foster Johnson)