Warning! Radiation ahead
A short conversation about the world’s most feared word
You know the word—perhaps you don’t remember where you heard it first, you may not be able to define it, but it tugs at a little corner of your mind that makes you uneasy. Images of scientists in hazmat suits, mushroom clouds, and black and yellow signs flood your brain. Radiation IS bad. However, radiation lets a doctor see a baby still in the womb, makes plants grow, and is the only reason you can read this article.
See, radiation is the transmission of energy from one object to another without them touching. Hearing a dog bark or feeling the warmth of the sun are as much manifestations of radiation as getting an X-ray. Radiation has no inherent danger: it is simply energy in motion.
In your everyday life, you are coexisting with radiation in many ways. The ones you should know right now are electromagnetic, particle, and acoustic radiation.
Electromagnetic radiation is the one we have most contact with: it is carried by particles called photons, which depending on their energy, create the electromagnetic spectrum. Microwaves, visible light, and x-rays are all the same phenomenon at different energies.
Particle radiation is carried by fast-moving particles with mass—protons, electrons, etc. Reactor cores, nuclear weapons, and bananas (yes, bananas) all produce particle radiation. Some particles cannot really penetrate more than a sheet of paper, while others need several meters of concrete to be stopped.
Acoustic radiation is carried by pressure waves and is the only type of radiation that needs a material—like air, water, or the ground—to exist. Earthquakes, for example, are an acoustic wave that moves through the ground. Also, every sound you’ve ever heard has come to you through acoustic radiation.
Then, why have you only heard that radiation is dangerous?
Well, the truth is that not all radiation is created equal. When a subatomic particle is travelling with enough energy it can knock off one of the electrons in an atom. This process is called ionization and it can change the electrical properties of the atoms, which can, in turn, disrupt the structure of molecules.
This radiation is called ionizing radiation. The energy required to ionize an atom is about 10 electronvolts—which is 24 orders of magnitude smaller than the energy needed to boil a cup of water. This may sound ridiculous, but you need to keep in mind that atoms are so tiny that it would be like hitting a baseball with a skyscraper.
If ionizing radiation hits the DNA in a cell, it can ionize one of its components creating damage in the molecule. From here three things can happen: your body fixes the damage, your cell dies, or the damage causes a mutation. One mutation is unlikely to cause a problem, but as mutations accumulate there is a chance one of them could turn into cancer.
So what is the verdict, dangerous or not?
Frustratingly, it depends. Radiation is a mechanism—some forms of radiation are dangerous, and some simply aren’t.
Now, you may be thinking: “Well, yeah obviously. Everyone knows that when people talk about radiation they don’t talk about music or the light of a candle, they mean the dangerous kind.” And you’d be right, people do mean the dangerous kind; the issue is that not everyone knows what the dangerous kind is. A blanket concern for radiation doesn’t protect you, it makes you scared of getting the x-ray your dentist needs, makes you vote against nuclear energy projects, or makes you forgo cancer treatment because radiation IS bad.
I didn’t mention all the types of radiation or how small exposures to the “bad” radiation may actually be necessary because those are conversations that deserve their own space. For now, I want you to understand that the word radiation is more complex and interesting than what you may think.
Stay radioactive and I’ll see you soon,
Alan Padilla