This article addresses the myths and truths about electromagnetic waves, explaining scientifically what they are, their properties, and how they affect the human body. We debunk the myth that electromagnetic waves are always harmful, and discuss how their effects can vary depending on the type of electromagnetic wave and its frequency.
We’ve all heard our mothers say, “The TV is giving off electromagnetic waves, and they’re bad for you,” when we’re glued to the TV screen watching a funny cartoon movie. My mom used to do that all the time. If I watched too much TV or played too many games on the computer, she would always tell me to stop because it was bad for me. Now that I’m in electrical engineering and have specialized in electromagnetic waves, I think back to that time and realize that she wasn’t necessarily right.
The correct physical term for electromagnetic waves is “electromagnetic waves”. Electromagnetic waves are the result of strong interactions between electric and magnetic fields, and the transmission of electrical energy in the form of waves. Let’s recall the basic principles of electricity and magnetism from science class. The presence of electric charges creates an electric field, and the movement of electric charges creates a magnetic field (moving electric charges are electric currents, and magnetic fields are created by electric currents). Electric and magnetic fields are so closely related that a sudden change in the electric field creates a magnetic field. Conversely, a sudden change in the magnetic field also creates an electric field. Remembering this principle, consider a situation where a charge suddenly moves. The sudden movement of the charge will cause the electric field to fluctuate. This will create a magnetic field, and since the magnetic field has suddenly changed, an electric field will be created again. The electric field generates a magnetic field, which in turn generates an electric field, and so on ad infinitum. Thus, the electric and magnetic fields continue to interact and generate energy, which takes the form of waves. This is electromagnetic waves, which means that any sudden movement of electric charges will generate electromagnetic waves, which will travel in all directions. As you can see, electromagnetic waves are very easy to generate.
Electromagnetic waves aren’t the dirty soot you sometimes see, they’re all around us, just like air. We can make wireless calls to friends across the country on our smartphones. If you think about this situation, which is so commonplace in the modern world, it means that electromagnetic waves carrying your friend’s voice are everywhere. Physically, those electromagnetic waves extend all the way to outer space, meaning there is no space where they don’t exist. If electromagnetic waves are harmful to the human body, we are in contact with them 24/7, from birth to death, and for the rest of our lives. How creepy is that?
The electromagnetic waves I’m talking about are not the same as the “bad” electromagnetic waves my mother was referring to. However, the properties and effects of electromagnetic waves vary depending on their frequency. The frequency is how many times the magnitude of electric and magnetic fields changes in a second. The beautiful “light” we see with our eyes is also a type of electromagnetic wave. It’s called visible light because we can see it. We put sunscreen on our faces to avoid “ultraviolet radiation,” which is an electromagnetic wave with a slightly higher frequency than visible light. Infrared radiation, which is usually emitted by longevity stone beds, is an electromagnetic wave with a slightly lower frequency than visible light. X-rays, which are used to take x-rays of broken bones, and microwaves, which are used to heat food in a microwave oven, are all the same electromagnetic wave. They just have different frequencies.
Now you know that electromagnetic waves are ubiquitous, like air. But are electromagnetic waves really as harmful as my mother says they are? First, let’s think about electromagnetic waves traveling through the human body. The human body is a better conductor of electricity than a rock or rubber. The charges of the many electrolytes on the surface and inside the body can move freely. If the frequency of the electromagnetic wave is low, the body’s charges will move right along with the electromagnetic wave’s electric field, canceling out the electric field, i.e., neutralizing it. This is how visible and ultraviolet light, which has no effect on the body, is canceled right at the surface of the body. In fact, infrared light only penetrates the human body by a few millimeters and is completely absorbed. In contrast, electromagnetic waves such as X-rays, which have a much higher frequency, change so quickly that the charge in your body can’t keep up with them and cancel them out. So the X-rays just pass through the body.
The electromagnetic waves that we often hear about in the news as being bad for us are in the low-frequency range, which has a much smaller frequency than visible light. The energy of electromagnetic waves is proportional to their frequency, and the low frequencies that are considered harmful are between 1 MHz and 50 GHz (10^10 Hz). Low frequencies are often generated by common household appliances, such as gas stoves and cell phones, and their energy is very small (one part per million) compared to visible light, which has a frequency of 10^15 Hz. It’s not the amount of energy that makes them harmful. Prolonged exposure to electromagnetic waves can disrupt electrolytes such as K+, Na+, and Cl-, which play important roles in the body, causing ionic imbalances and affecting various immune and nervous systems. However, since electromagnetic waves do not accumulate in the body like toxic substances, and their energy is very small, there is much debate in the scientific community about their dangers.
In recent years, as smartphone use has become more commonplace, there have been claims that electromagnetic radiation from smartphones is harmful. There are studies showing that smartphone electromagnetic radiation can negatively affect the fetus, and that carrying a smartphone in your pants pocket can decrease sperm count in men. The International Agency for Research on Cancer (IARC) also warned of the dangers of electromagnetic radiation in its 2011 classification of carcinogens, classifying cell phone radiation as a “Group 2B probable human carcinogen”. This fear of electromagnetic waves has led to the popularity of ‘smartphone electromagnetic blocking stickers’ and ‘electromagnetic blocking cases’. However, the World Health Organization (WHO) has stated that there are no harmful symptoms caused by electromagnetic waves from electronics, and many studies have shown that Wi-Fi signals from smartphones are not harmful to humans, so the debate continues.
Despite these controversial findings, many people believe that electromagnetic radiation is harmful. Due to the negative perceptions and ignorance of electromagnetic waves, people tend to blame electromagnetic waves without trying to determine the exact cause. Many people claim that electromagnetic radiation is harmful based on their own experiences, such as headaches, stiff shoulders, and sunken eyes from prolonged use of computers, or feeling lethargic after sleeping on an electric table. However, it’s more likely that the cause of these health problems lies elsewhere. In the case of computers, it’s the prolonged periods of time spent in a bad posture, staring intensely at one place, which leads to stiff shoulders and sunken eyes. In the case of electroplating, the body is exposed to high temperatures for long periods of time, which affects circulation. For those of us who can”t live without electronics, invisible electromagnetic waves can be a source of fear. However, the harmful effects of electromagnetic waves are still being debated, and ignorance is not the best defense.
