What is technetium-99 used for?
Given its long half-life, 212,000 years, Tc-99 remains in the environment. Air, sea water, soils, plants, and animals contain very low concentrations of Tc-99. Organic matter in soils and sediments slows the transport of Tc-99. In the presence of oxygen, plants readily take up technetium compounds from the soils. Some plants such as brown algae living in seawater are able to concentrate Tc-99. Technetium-99 can also transfer from seawater to animals.
