What’s in it for me? Busting the myths and confronting fears around radiation to make better choices.

Radiation, like mythical beasts of old, gets a bad rap mostly by virtue of being invisible. In the human psyche, what cannot be seen is often more terrifying than clearly visible threats.

“But what about those mushroom clouds and nuclear winters I’ve heard so much about? Those certainly aren’t mythical!” Like electricity before it, the harnessing of enormous power sources in the 19th and 20th centuries has unleashed some truly horrific consequences. Some things you can’t just un-see.

But once irrational fears or existential dread are at play, it can be hard to judge the magnitude of any risk. Perhaps worse, the general level of fear and ignorance around the topic of radiation has also left some real risks unacknowledged. Believe it or not, radiation’s usefulness in medicine has led to a doubling of background radiation exposure in the United States since 1980. Many other countries have seen similar rises.

In this Blink, we’ll tackle some basic science of radiation in layman’s terms, including the discovery of particle, or nuclear, radiation and its many uses. Spoiler alert: instead of dry, dusty science it’s full of curiosity and wonder. We’ll chart a course through revolutionary medical treatments that save countless lives each year. To the rise of nuclear fission and fusion, and yes, even atomic bombs and thermonuclear weapons.

Along the way, we’ll encounter some of the pioneers of broadcasting, medicine and physics, and meet both innocent and not-so-innocent victims of early radiation science. Revealing how some lived long and healthy lives, while others did not, can help all of us understand the real costs and benefits of nuclear science.

In these blinks, you’ll learn

  • How an accident with charged electrons made radio possible
  • What ram testicles taught us about cancer treatment
  • How even scientists sometimes see things that aren’t there, because they really, really want them to be true


The start of playing with radiation

“I’ve seen the light!” It’s such a simple expression, but it reveals much about the near mystical importance of light for humans. From sunsets to sparkles on the water, light and its refracted parts, –also known as colours– cause delight. These light rays? They’re radiation. In fact, it’s the radiation you can see with your naked eyes, because it excites special molecules in your retina. This visible light falls in the middle of the energy spectrum, sandwiched between Infrared energy below, and Ultraviolet above.

Light, like all radiation, is energy on the move, and it moves in waves. From the longest, or radio waves, at the bottom of the spectrum, to the shortest, or gamma rays, at the top, all are just energy moving through space. Thanks to Einstein, we know that all electromagnetic radiation travels at a constant speed: the speed of light. But like waves on the ocean, the crests of each wave can be closer together or farther apart. Short, frequent waves carry more energy at the same speed, while slow, rolling waves carry less.

Electricity, too, is energy on the move. While we harness it now for almost everything, before the 19th century it was a destructive force of nature, lightning started fires and could kill in an instant. When electricity was first introduced to homes for electric light, it was seen as incredibly dangerous. More dangerous, ironically, than the gas lamps and candles that regularly burned down houses.

The discovery and early transmission of radio waves, however, didn’t generate the same fear, even though it was linked to electricity.

As a young man of 20, radio pioneer Guglielmo Marconi discovered the work of Heinrich Hertz, who had detected radio waves in his laboratory back in 1888. The discovery went almost unnoticed by the world, but when Hertz died in 1894, Marconi saw the discovery lauded in the press, and immediately understood its potential. Marconi jumped in and began exploring the possibility of using long wavelength electromagnetic, or radio, waves to transmit messages wirelessly.

But it was another discovery in 1891 by the French Scientist Édouard Branly, that opened the door to radio communications. Imagine the scene: playing around in his lab with electric sparks one day, Branly notices that the sparks of electricity made some metal fillings sealed in a nearby glass tube jump up and line up from end to end. Once the electricity stops, a quick tap on the tube makes them crumble into a pile again. Some strange force made them defy gravity and organise themselves into a line! But what? The force is so strong it works even if the spark is on the other end of the room.

Soon, any scientist with a sealed tube of metal filings is trying it out. Even better, they discover that by placing a bell right next to the tube, the filings could move the glass and tap the bell as they jumped up. It wasn’t long before scientists were blowing their friends’ minds by ringing a bell with a spark from another room and showing that energy can transmit through seemingly empty space.

Marconi saw the potential to use electrical energy to transmit waves further and further. On December 12, 1901, he successfully transmitted a signal from Poldhu, England to St. John’s, Canada. Decades later, most homes had a radio receiver.

Oddly enough, through this process, Marconi and his team never worried about the potential dangers of radio wave exposure even knowing energy waves could be dangerous. The electricity they used terrified them, but the radio waves never did. Looking back, Marconi himself realised this was short sighted, but history proved him right.

Why? It’s all about wavelength, which we’ll get into next.


Wavelength is the key

It’s Christmas Day, 1895. In Germany, professor Wilhelm Conrad Roentgen feels troubled. Days earlier he made a revolutionary discovery, but it was so disturbing, he hoped it might be a mistake. His discovery? He found that invisible rays could pass through solid objects. Even seeing it with his own eyes he had his doubts.

Little did he, nor any other scientist at the time, know about the work of Hermann von Helmholtz, another German scientist. In 1893 Helmholtz had predicted that, if there were rays with wavelengths shorter than visible light, those rays could pass through matter. If Roentgen had known that, he might have relaxed a bit and enjoyed his holiday.

Roentgen was one of those old-fashioned scientists who believed discovery came with constant experimentation. A few days before Christmas, he’d noticed that while he was experimenting with electricity at one end of the room, his fluorescent screen on the other end was emitting a strange glow. The screen was just coated with a fluorescent chemical, but it seemed to react to the electricity from a distance. Roentgen couldn’t understand why.

Unlike light, he couldn’t bend the effect with a prism, or block the effect by inserting something between the source and the screen—unless he inserted metal. Wood was transparent to these unknown rays, but coins or other metal objects were not. He called them “x” like mathematicians would, indicating an unknown ray.

Soon he was placing coins into wooden boxes and “seeing” inside when the rays passed from the spark to his screen through the wood. In one of these experiments, his hand blocked the beam, and what he saw on the screen astonished him: the bones of his hand. While the flesh didn’t block these new X rays – the bones of his hand did.

Within days he told his wife in confidence, brought her to the laboratory and showed her the results. She too was astonished, and a bit worried about what she saw.

But lucky for us, once confident in his discovery, Roentgen was quick to see its benefits for medical science. He immediately published his methods and sent out a few images, making sure every scientist or physician could duplicate his results. Just a few months later, a successful surgery to remove a bullet in a patient’s leg was completed after using an X-ray to locate the object near the bone. The patient was spared amputation, and the practice of medical X-rays was born.


A cautious approach pays off

Luckily for Roentgen, he had protected himself from these unknown rays early on. Perhaps because he was a cautious man, or perhaps because the image of bones on a fluorescent screen seemed like an omen of death. Still, not everyone was so cautious.

American inventor and businessman Thomas Edison was quick to pursue X-ray experiments in his own commercial laboratory. Edison’s involvement in bringing electric light to households had been both ruthless and cruel. But it put him at the forefront of innovation. Sadly, it was the experiments with these new waves that showed how dangerous X-ray exposure can be. Edison’s assistant, Clarence Dally, had volunteered to have his hands bombarded with X-Rays again and again to show how X-rays worked. Hand ulcers showed him how high exposure could burn the skin. But these ulcers grew cancerous, and spread from his hands, up the arms and to his chest, and eventually caused his death.

That brings us back to the topic of energy waves. Remember: shorter, faster waves carry more energy. And longer, slower waves carry less energy. At that point, it became clear that wavelengths longer than those of visible light are generally safe, like radio waves, microwaves and infrared. However, any wavelengths shorter than those of visible light carry so much energy that they interfere with the atoms and living cells, like Ultraviolet, X-rays, and Gamma rays.

Gamma rays carry enough energy to rip particles from the nucleus of other atoms as they pass through. Scientists call this ionising radiation because ionisation is essentially changing the electrical charge of an atom by removing particles from it. Molecules missing either electrons or protons are called ions, and their uneven charge tends to be unstable and they break down further. These chain reactions in cells can cause mutations and potentially even cell death.

So Marconi was correct, radio waves couldn’t hurt him or his colleagues. While Edison, who clearly knew the risks of electricity, chose to assume wavelengths shorter than visible light were equally safe. Edison himself nearly lost his eyesight after too many observations, but as we’ll see in the coming chapters, there were even more costs in scientific discovery.


Radiation is everywhere—and so are the risks

The discovery of new wavelengths of energy happened at the same time as other discoveries. In France, scientist Antoine Becquerel was fascinated by Roentgen’s experiments, but more drawn to fluorescence, or light-emitting chemicals. He also loved photography, and wanted to capture fluorescence on film like light. So, he sealed films in dark covers and sprinkled them with minerals coated in fluorescent chemicals. He thought fluorescence was like X-rays and could pass through the covering and expose the film.

Sadly for him, none of his fluorescence experiments worked out until he tried the mineral Uranium. Without exposure to light, but WITH exposure to uranium, the photographic films were exposed and showed an image even without light. Oddly enough, the uranium hadn’t been treated with fluorescent chemicals at all—it seemed to emit an as-yet-undiscovered kind of ray. In 1903, he shared the Nobel Prize for this discovery with the famed scientific team, Marie and Pierre Curie.

But what was this new kind of ray? At last we come to the most common association of the current topic: particle radiation, also known as nuclear radiation.

But why nuclear? This refers to the nucleus, or centre, of an atom, so it’s a good idea at this point to review the basic atomic structure.

Atoms are essential collections of smaller particles organised by charge: Ok. So, to break it down – the centre, or nucleus, holds a positive charge. That positive charge comes from the protons in the nucleus. Meanwhile the electrons, or negatively charged particles, orbit around the nucleus like planets in a solar system. Balancing the charges in the nucleus are neutrons, or neutral particles, that carry neither a positive or negative charge and keep things stable.

With large atoms like Uranium, which has 92 protons, or Radium which has 88, the positive charge at the nucleus builds up even with the neutrons trying to regulate. And so, occasionally a particle will fly out and spontaneously the atom will decay into another state. In the process, the particle carries energy, and energy waves are generated.

The ionising radiation referred to earlier was dangerous because it carried enough energy to rip particles out of an atom and leave it unstable. For DNA and other complex molecules, this is dangerous. But it is precisely the capacity to kill cells with higher wavelengths of particles, or nuclear radiation, that actually introduced helpful treatments to Western medicine.


The introduction of nuclear radiation to medicine.

Fun fact: until the 1890s you were as likely to be killed by medicine as you were by any disease. Doctors injected mercury or used bloodletting regularly, and killed patients in the process.

Perhaps no one saw both the benefits and risks of the new nuclear science for medicine as clearly as Chicago physician Emil Herman Grubbe. At only 7, Grubbe was brought along to Edison’s new light bulb demonstration at the McVicker Theatre. At 20, he was working for a lightbulb manufacturer. His company wanted to make special scientific equipment, called Crookes tubes, for commercial sale. These small glass and metal instruments could send streams of electrons through the air, and Grubbe’s work life involved countless experiments with them. He considered his burned and blistered hands from the X-rays they emit to be the cost of discovery.

But Grubbe was also studying medicine in the evenings, and his professors noticed his bandaged hands. One, Dr. John Gilman thought that if X-rays were so good at destroying healthy tissue, they might be good at killing diseased tissues like tumours. And so, nuclear medicine was born, just one month after Roentgen’s Christmas-time X-ray discovery.

Incredibly, Grubbe began treating patients with X-rays just two days later. The first patients were beyond available medicine, essentially terminal. Still, the X-rays managed to reduce their pain, and are still used as pain relief for cancer patients today. But patients who were referred to Dr. Grubbe at earlier stages of their disease benefited more from treatments: tumours shrank and metastasis slowed.

Harnessing the radiation properties of minerals like uranium and radium was not far behind. Marie and Pierre Curie’s refinement of radium and many published findings had led to a fashion trend for radioactivity. The soft glow of radium was the height of modern fashion for things like watch dials and clock faces that were visible in the dark. Firms like the Waterbury Clock Company happily jumped on the trend.

The glowing detail was radium-infused paint and done by hand— with a tiny paint brush by the mostly female workers at the factory. Since the fine brush tips often dried, they wet them with their lips between brushstrokes. Ingesting tiny amounts of radium with each tiny lick turned out to be disastrous.

Turns out, when a body absorbs radium it quickly travels to the bones and is deposited there like calcium. Over time, the radiation it emits destroys the bones. The workers suffered as their bones crumbled and cancers ensued, eventually receiving a payout from the Company. But the most important change their story made was about safety: everyone stopped licking brushes, and painting moved under ventilation that kept workers from breathing it in. With these small changes, radium was safely used for many years to come.

And remember that special equipment Grubbe was making at the lightbulb factory? The tubes that can fire electrons? Well, it turns out that if you fire a lot of electrons at an atom like radium or uranium, you can split it into smaller ones. You can even do the opposite – fire lots of electrons at smaller molecules and force them together.

In both processes, called fission and fusion, tiny amounts of matter—a gram or less—could release unbelievable amounts of power. Even a gram of matter yields more than 90 trillion joules of energy.

How much is that? Well, about the same energy needed to heat 1,000 homes for a year. Or about 10,000 lightning bolts. Or the energy released in a single atomic bomb. A point that will become all too relevant next.


The effects of Hiroshima

It’s a warm morning on August 6, 1945, and Dr. Terufumi Sasaki is settling into a day’s work at the Red Cross Hospital, just outside the city centre in Hiroshima, Japan. By 8:15, he’s heading down the hallway to deliver a patient’s blood specimen to the lab. Suddenly, he sees a bright flash of light.

An atomic bomb just detonated at the center of Hiroshima. At ground zero, the temperature was hotter than the surface of the sun. Heat from the bomb ignites fires, which engulf about 4 square miles of the city center. The blast radius was circular, just under a mile across.

Just five hundred feet beyond this radius, Dr. Sasaki quickly learns he’s one of only 6 doctors at the hospital to survive the initial blast. Why so lucky? The hallway was the best place he could have been in that moment—it shielded most of the initial shockwave and kept flying glass from hitting him. But the hospital was soon overwhelmed with others who weren’t so lucky.

Many had cuts and traumatic injuries, but a few had strange burns—images of flowers or objects—on their skin beneath their clothing. Sasaki knew overexposure to X-rays caused strange burns, but radiation sickness is almost unknown in 1945. Sasaki and his colleagues are among the first to witness it, and see it roll through in three waves.

First, some patients close to the blast, but without obvious burns or trauma, die quickly. They slip into a coma and die within 48 hours. After a few days, the surviving patients start to vomit and their hair falls out. Sadly, many of them die, too. After about a month, other survivors show symptoms like anaemia, exhaustion and vitamin deficiencies, but have a good prognosis if they get treatment for these.

But why? Looking for answers to these symptoms leads us back to the early experiments in nuclear medicine.

In those days, Doctors like Grubbe had based treatment on the fact that tumour cells were more sensitive to radiation than healthy ones because they divided more quickly. But this is why that second wave of patients died: human intestines are also lined with fast-dividing cells. These cells died during exposure, and never recovered.

The third wave of patients – those who were only partially dosed with radiation, revealed that bone marrow, too, was sensitive to radiation. Essentially these folks, at a distance of just a few hundred metres past the fatal zone, developed anaemia as a result of lost marrow. Deep in the bones, marrow makes red blood cells, which live for about 30 days, so it wasn’t until about a month later that their inability to make new ones caused anaemia.

Like Grubbe predicted decades earlier, the risks of radiation all come down to the dose. Even in an atomic blast, your proximity to a source of radiation is a powerful tool in mitigating the risks. The hallway of the hospital building was enough to shield Dr. Sasaki from many harmful effects. Were he standing before a window during the blast, instead of a wall, his story would have been quite different.


Final summary

Radiation is just energy on the move, and it travels in waves. The faster, shorter energy waves above visible light carry more energy and can cause damage as they move, while slower, longer waves below visible light are harnessed for things like radio transmission.

Through radiation, humanity has unlocked modern medicine, harnessed atomic power, and probed the secrets of the universe. But ignorance about radiation and its risks still keep many from making wise decisions about radiation in medicine or nuclear power. Limiting exposure, shielding sources and safe handling of radiation materials can go a long way toward multiplying the benefits, while vastly limiting the risks.