Experts can test to identify Co-60 in urine, even at very low concentrations, and determine their levels of concentration in the human body.
Detecting and Responding to Co-60 Exposure
Co-60, the lost radioactive source in Vung Tau, is a man-made radioactive isotope of Cobalt that can cause cancer if exposure occurs. It is a gamma-ray emitting source, and external exposure to a large source of Co-60 can cause skin burns, acute radiation syndrome, or even death.
Radioactive nuclides can be applied in the medical field. (Illustration: www-nds.iaea.org)
Co-60 undergoes radioactive decay, emitting beta particles and strong gamma rays, eventually decaying into non-radioactive nickel. The half-life of Co-60 is 5.27 years, which is a short enough period to concentrate remediation measures for contaminated areas. In some cases, a contaminated area may only be reused after 10 to 20 years.
The man-made radioactive isotope of Cobalt can be released into the environment through leaks or spills from nuclear power plants, or in solid waste from these facilities. The U.S. Nuclear Regulatory Commission (NRC) only allows a very small amount of Co-60 to be released into the air or dumped into sewers. It may be present in a doctor’s office, but only when there is special laboratory equipment available.
How is Co-60 Exposure Occurred?
Exposure to Co-60 primarily occurs intentionally during necessary medical examinations or treatments. These forms of exposure are tightly controlled to avoid negative health impacts and maximize the benefits of medical treatment.
In contrast, accidental exposure can occur when a radioactive source is lost, or when medical and industrial radiation processing is improperly handled. Although relatively rare, exposure can also happen due to negligence in management at metal recycling facilities or steel mills.
When medical or industrial radioactive sources are lost or stolen, they are referred to as “orphan sources.” Scientists warn that in some situations, we might handle them unknowingly and inadvertently come into contact. Radioactive sources often have metal casings, making them easily confused with scrap metal and undetectable during transport to recycling facilities.
Humans can absorb Co-60 through contaminated food or water or inhale radioactive dust. However, the main concern regarding Co-60 arises when exposed externally to strong gamma rays. This can occur if there is contact with an “orphan source” or with waste from a nuclear reactor.
A doctor adjusting the helmet of a Gamma Knife device used for radiation therapy. The Gamma Knife device uses Co-60 as a radiation source. (Photo: University of South Carolina Gamma Knife Center)
Detection and Response to Exposure
If released into the environment, radioactive materials can pose dangers to humans. According to CNN, experts even consider Co-60 to be one of the “candidates” for making dirty bombs. In a speech in 2012, the director of the International Atomic Energy Agency (IAEA) warned that a dirty bomb made from Co-60 detonating in a city could cause panic as well as environmental and economic damage.
According to the U.S. Environmental Protection Agency, to determine if one is near a radioactive source, special equipment is necessary. If radioactive contamination is suspected, experts can test for Co-60 in urine, even at very low concentrations, and assess its concentration levels in the human body.
Whole-body counting techniques can detect gamma radiation emitted from Co-60 in the body. Other methods can include handheld devices that detect contamination on skin and hair, as well as technologies that identify contamination in soft tissues, blood, bones, or feces.
According to Fox News, anyone who comes into direct contact with Co-60 is at risk of death. People living near a radioactive source may experience milder effects such as skin burns, blisters, or gastrointestinal issues, including vomiting and dizziness.
“If someone is exposed (externally) to gamma rays, treating the patient is only an external concern and will not endanger medical staff or caregivers. However, if the container is broken or if there is direct contact, they will be exposed to radiation,” said James O’Donnell, a nuclear medicine expert in Cleveland, Ohio, USA.
Most hospitals are equipped with methods to respond to exposure and techniques to limit the risk of contact for doctors, healthcare staff, or patients. In hospitals, when radiation detectors signal the presence of radiation, safety protocols require halting all other activities, using absorbent paper, covering objects with lead shields, isolating individuals from hazardous areas, and decontaminating patients.
For radiation sources, protective casings are often made of hard materials and are designed to be robust, preventing them from being easily opened or breached. At the Rajasthan Nuclear Power Plant in India, experts use robotic arms to handle Co-60. Outside the radioactive source, they place thick glass barriers nearly two meters high and cover them with lead to prevent leakage.
