The medical industry uses technetium in diagnostic nuclear medicine to image different parts of the body, according to the University of Virginia. Technetium-99m is the most prevalent diagnostic agent in nuclear medicine, as of 2015. The biological half-life of technetium is about one day, leaving little time to do harm.
Approximately 20 million medical imaging procedures every year use technetium, notes the Royal Society of Chemistry. The element also inhibits corrosion in steel, but it's use in this capacity is limited to closed systems due to it's radioactivity. Technetium has a half-life of six hours and long eluded scientists in the past because it does not occur naturally.