Radioactive Sources are Beneficial
Some of them are produced in nuclear facilities; some in accelerators
source: https://www.iaea.org/newscenter/news/what-are-radioactive-sources
Radioactive sources contain radioactive material of a particular radionuclide (an unstable form of an element emitting radiation), which can vary based on the application for which the source was manufactured. These sources emit ionizing radiation, typically in the form of alpha and beta particles, gamma rays or neutron radiation. Click here to learn more about radiation.
Until the 1950s, only radionuclides of natural origin, such as Radium-226 – an isotope of radium used to treat some types of cancers – were available for use. Today, radionuclides artificially produced in nuclear facilities and accelerators - emphasis mine -, including Caesium-137, Colbalt-60, and Iridium-192, are extensively used. Around the world, these radioactive sources are used for medical, industrial, agricultural, research and educational purposes.
Some examples of the application of radioactive sources include killing bacteria in food, sterilizing medical supplies and equipment, treating cancer and other diseases, mapping underground sources of water, integrity testing of mechanical structures and measuring soil density for construction projects.
Read about the use of ionizing radiation for pest control and sterilization.
When I had prostate cancer, I got a PET scan to be sure I had no metastasis of cancer anywhere else in my body. I'll spare the details, but I got injected with a measured amount of Fluorine, F18, which was bonded in sugar molecules, the idea being that cancer takes in whatever sugar it can. (A good argument for minimal or no sugar intake, as a cancer preventative.) The F18 decays, emitting an electron-positron pair (positrons being the P in PET), which immediately unite, changing both particles into energy, specifically high-energy gamma rays. These emitted rays (Emitted as in the E in PET) are detected by an MRI-like machine which creates a 3-D picture, or tomography (the T in PET). I got more radiation in the first hour after injection than I had received over four years in the Navy's nuclear power program, but F18 has a 1.8-hour half life, so there was effectively no radiation after the first 16 hours. I don't recommend more than about one PET scan per year, to allow the body to repair damage done by the 6 MeV gammas, and recover.
I guess the point is that radiation can be used for good, but it must be used in controlled ways.