Kromek Security and Defence Newsletter

Where does radiation come from?

Radioactive sources can show up in the environment, waste sites, antiques, mines, building materials and more. How do you know what’s safe and what’s not?

Ionising radiation forms a portion of the energy released by unstable nuclei (called radionuclides) undergoing radioactive decay.

The ‘ionising’ portion of ionising radiation originates from its ability to detach electrons from atoms due to the significant amount of energy they inherit from the radioactive decay process.

Ionisation can lead to damage to biological tissue, malfunctioning cells and DNA mutation. The extent of damage done is relative to the type of ionising radiation, the effected tissue, the amount of exposure in a certain time frame and the type of exposure (internal or external). The culmination of all of these variables is measured as a ‘dose’ and the amount of dose is key to the

symptoms of radiation exposure. 

Naturally-occurring vs human-made radiation

All living things are exposed to natural background radiation, which comes from three sources: 

1. Cosmic radiation directly from space, such as the energy released from the fusion of hydrogen and helium in our own Sun
2. Ionisation of the Earth’s atmosphere by cosmic rays, creating sub-atomic particles like muons, mesons and positrons 
3. Terrestrial radiation from soil, water, vegetation and the Earth’s crust

Many human-made processes result in the production of radioactive materials as well. The most significant source of human-made radiation exposure to the public is from medical procedures, which includes x-rays, nuclear medicine and radiation therapy. Some consumer products, such as building material, smoke alarms, combustible fuels, can also release varying levels of radiation. Fallout from nuclear testing and small quantities of radioactive materials released to the environment from coal and waste from nuclear power plants are also sources of radiation exposure. 

If we’re always exposed to radiation, how do we know what’s considered safe and what isn’t? 

That’s where reliable, radiation detection comes in. The ability to rapidly distinguish dangerous sources from less harmful natural or medical sources is crucial for informing next steps in decontamination and ensuring the safety of people and the environment. Take Southern Oregon Sanitation for example! They avoided an expensive 200-day shutdown by using the D3M and D5 RIID to correctly identify a misidentified radionuclide, therefore effectively mitigating the incident without wasting time and money.