DescriptionMEASURING ENVIRONMENTAL RADIOACTIVITY. Mrs. Melanie NEDBALEK , Austrian staff member of the Environmental Radioactivity Section of the International Atomic Energy Agency's laboratory at Seibersdorf, near Vienna, Austria, operates the atomic absorption spectral photometer to determine the quantity of cesium in a sample of plant material analyzed for radioactive cesium-137. IAEA/October 1963/No. 1262. Please credit IAEA