The Incredible Hulking Science Behind Gamma Radiation

According to Dr. Peter Petric, medical physicist and radiation safety officer at BC Cancer, everyone in the world is exposed to small amounts of gamma radiation every day. This can come from outer space, the sun, and radioactive minerals in the ground, and its levels vary depending on where we live. It’s called natural background radiation.   

“In Vancouver, we have fairly low amounts of background radiation. Some of the reasons why are that we’re at sea level and have low geological radon levels,” he says. "Places with higher altitudes like Colorado or places with naturally high radon levels like Kelowna and Prince George can have background radiation levels double that of Vancouver.”  

So, are we all just biding time until we become superheroes like the Hulk, Spider-Man, Daredevil and The Fantastic Four, casually hanging from tall buildings and causing city-wide destruction in the name of fighting supervillains?  

“Unfortunately, no,” Dr. Petric laughs. “You won’t turn green and you won’t get super strong.”  

Gamma radiation is a type of ionizing electromagnetic radiation emitted by radioactive material. On the electromagnetic spectrum, gamma rays have the shortest wavelength and the highest energy.  

Although gamma radiation transmits high amounts of energy—so high that it can convert atoms or molecules into ions by detaching electrons from them—he explains that the levels we’re exposed to through background radiation are infinitesimal compared to the explosion responsible for creating the Hulk.  

Here on Earth such levels of gamma radiation cannot give anyone the power to do the Hulk Smash, hold up a mountain range with their bare hands, or tear Ultron machinery to shreds with their mouths. Instead, it can lead to fatalities, says Dr. Petric.  

He shares that exposure to high amounts of gamma radiation can be dangerous due to the DNA damage that it causes. It can make people sick with headaches, fatigue or nausea. It can also cause skin reddening and destroy bone marrow cells and the cells lining the gut.  

“An interesting thing is that DNA damage actually happens naturally every day as our cells divide. Our bodies are adapted to deal with moderate amounts of DNA damage using DNA repair mechanisms. However, these adaptations may fail from time to time if the amount of DNA damage is too severe,” he adds.   

He stresses that high sources of gamma radiation are heavily controlled and regulated. At BC Cancer and in many healthcare facilities around the world, gamma radiation is pivotal in diagnostic imaging and radiation therapy.   

Dr. Petric says that to diagnose various illnesses and diseases, gamma-emitting drugs are injected into the body and tracked with specialized scanners.  

During radiation therapy, gamma emitting drugs can also be injected into the body to destroy cancer cells and gamma irradiator machines which deliver radiation through beams of gamma rays and X-rays can be used to precisely target cancerous tumours.  

“Sometimes we also implant small, seed-like sources of gamma radiation directly into cancerous tumours. This gamma radiation exposes and destroys the cancer with minimal exposure to the surrounding normal cells,” Dr. Petric says.  

He mentions that gamma radiation is useful in manufacturing, astronomy research, and food preservation as well.   

Aboard NASA’s International Space Station, astronauts often consume food that has been freeze-dried or irradiated for preservation, including meat that has been sterilized with gamma rays for a necessary helping of beef fajitas!   

Gamma radiation may not give rise to superheroes with freakish strength or gruesome features, but as Dr. Petric tells us, it plays an even more remarkable role in our universe, aiding gamma-ray astronomy research, sterilizing food and medical equipment, and furthering advancements in cancer diagnosis and treatment.  

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