Radiation is, when you think about it, really scary. You should actually be terrified of it. And also, it isn’t nearly as dangerous as you probably think it is.
Radiation is a very cool thing. It is completely invisible, impossible to control and gives us a window into a realm that is otherwise unexplorable. But it is also an uncontrollable force of nature that can, and will, kill you if you are not careful. But it is also a force that is massively misunderstood.
Firstly, there is no such thing as ‘radiation’. There are many types of radiation, only some of which are harmful. The majority of them fit onto this scale here.
You will notice that yes, that is the electromagnetic spectrum. Light, radio waves and infrared are all in fact forms of radiation. But these are all non-ionising radiation types. You can shine as many radio waves as you want on a cell, it won’t mutate.
But then there are the bad guys.
There are, broadly speaking, 5 types of radiation that are ionising. In other words, there are 5 types of radiation that can do all the things that radiation is famous for – giving you cancer, sterilising you, giving you radiation sickness and killing you. They occur in varying amounts and are various degrees of dangerous. Let’s go.
Alpha radiation is, technically speaking, the most dangerous type of radiation. It consists of a bundle of 2 protons and 2 neutrons, flung at high speed away from a radioactive element. It is highly ionising, and can rip your DNA to shreds if it gets close enough – hense cancer-causing.
The good news? Alpha radiation has pitiful penetration. It can’t get through skin or paper, and is stopped by a few centimetres of air. So as long as you don’t swallow any or get it into a pore, you should be fine around alpha sources. But if this stuff (elements like polonium) get into your blood…
Alexander Litvinenko was poisoned in 2006, probably by Russian intelligence services, who put 10 micrograms of polonium in his drink. 6 days later, no more Litvinenko. Don’t go around eating alpha sources.
Beta radiation is less dangerous than alpha, but is still pretty nasty stuff. It is a high-energy, high-speed electron emitted from the nucleus of an atom, when a neutron decays into a proton and an electron. And if that sounds nonsensical to you, you understand it perfectly.
Gamma. Gamma is nasty. (By the way, X-rays are identical to gamma rays in every way, but just less nasty). Gamma rays are low power, so it would take a hell of a lot of gamma radiation to see any effects. The bad news?
You cannot hide from gamma. Gamma can go through a metre of concrete, no problem. The lead-lined suits that people seem to be so fond of, that won’t do a thing. You can hide behind a) a few metres of lead or b) a few metres of solid concrete.
Neutron radiation is the weirdest type of radiation, and the level of damage it does is hard to judge. Neutron radiation isn’t actively harmful, but it has a secret weapon: it can turn other substances radioactive. If you get hit by a wave of neutron radiation, your entire body will become one massive radiation source.
So what does radiation actually do to your body? The main thing that radiation does to the body in the long term is rip your DNA to shreds. When you have damaged DNA, your cells either can’t reproduce or they reproduce with errors – they become tumours. That’s why radiation sickness damages the parts of your body that contain rapidly reproducing cells – hair, stomach lining, blood cells. Hence your hair falls out, you start throwing up and your immune system goes down the drain. And if the radiation dose is high enough, the blood-brain barrier dissolves and you die. Quickly and painfully.
But it takes a really high dose to do that to someone. Usually, you will just get an increased cancer risk and might feel a bit ill. But radiation isn’t an instant-kill thing.
Which is a good thing, given how we are exposed to radiation all the time.
We get roughly 3 milliSieverts of radiation per year that we live on Earth. We get more in space, and more if you work or live near a nuclear source – a reactor or a processing plant. But that is a pretty insignificant amount, given how a lethal radiation dose is about 2 Sieverts. Radiation, in small doses, is much less dangerous than we think. In fact, our body is remarkably resiliant when it comes to surviving radiation, even in huge dosages.
Citation: Tsutomu Yamaguchi.
Yamaguchi was an engineer working for Mitsubishi in 1945. He was in Hiroshima outside the company headquarters, having finished drawing up plans for a new 5,000 ton oil tanker. He was within 1.5 miles of the epicentre of the Little Boy nuclear bomb. But remarkably, he survived the blast with only minor injuries. Later that week, he returned to his home town. Nagasaki. Yamaguchi is one of only a handful of people to have been in the blast radius of both bombs. And his wife was in the Nagasaki blast as well. Between them, they survived 3 nuclear explosions. And then went on to have children.
And those children, remarkably, are fine. They have had no higher cancer incidence than the rest of Japan, they have no birth defects. They are fine. Our bodies are remarakbly good at withstanding the most adverse conditions and still being able to procreate. Maybe less so if you snack on an alpha source, but good news all the same.