In this blog post, we will examine whether electromagnetic waves emitted from TVs and computers are truly harmful to our bodies, based on scientific evidence. Let’s take a look at the misconceptions and truths about electromagnetic waves.
Everyone has probably heard their mother say, “The electromagnetic waves from the TV are harmful to your health,” while staring intently at the TV screen as a child, engrossed in an exciting cartoon. My mother was no exception. She would always mention the electromagnetic waves when I watched TV for too long or got absorbed in computer games, telling me to stop because it was bad for my health.
Now that I’m studying electrical engineering and have gained professional knowledge about electromagnetic waves, I realize that my mother’s concerns weren’t entirely unfounded. Electromagnetic waves are more accurately described as “electromagnetic radiation.” Electromagnetic radiation is the transfer of electrical energy in the form of waves, created by the strong interaction between electric and magnetic fields. Let’s recall the basic principles of electricity and magnetism we learned in science class.
When there is a charge, an electric field is generated, and when a charge moves, a magnetic field is generated (the movement of a charge is called current, and a magnetic field is generated by current). Electric fields and magnetic fields are closely related, so when an electric field suddenly changes, a magnetic field is generated. Conversely, when a magnetic field suddenly changes, an electric field is generated. Remember this principle and consider a situation where a charge suddenly moves. When a charge suddenly moves, the electric field will fluctuate. This will generate a magnetic field, and since the magnetic field has suddenly changed, an electric field will be generated again. Since an electric field has been generated, a magnetic field will be generated again, and this process repeats infinitely. As a result, the electric and magnetic fields interact and continue to be generated, taking the form of waves. This is what electromagnetic waves are. In other words, whenever a charge suddenly moves, electromagnetic waves are inevitably generated and spread in all directions. As such, electromagnetic waves are very easy to generate.
Electromagnetic waves are not the smoky fumes we sometimes see, but rather exist everywhere around us, just like air. We can make wireless calls to our friends on our smartphones anywhere in the country. If we think about this situation, which is so commonplace for modern people, it means that electromagnetic waves carrying our friends’ voices exist everywhere. Physically, these electromagnetic waves extend into outer space. In other words, there is no space where electromagnetic waves do not exist. If electromagnetic waves are harmful to the human body, we are exposed to them 24 hours a day, from the moment we are born until we die. How terrifying is that?
The electromagnetic waves mentioned here are not the same as the “bad” electromagnetic waves referred to by the author’s mother. However, electromagnetic waves vary in their characteristics and effects depending on their frequency. Frequency refers to how many times the strength of the electric and magnetic fields changes per second. The beautiful “light” we see with our eyes is also a type of electromagnetic wave. Since it is visible to the eye, it is called visible light. To avoid ultraviolet rays, which are electromagnetic waves with slightly higher frequencies than visible light, we apply sunscreen to our faces. Infrared rays, which are often said to come from long-life stone beds, are electromagnetic waves with slightly lower frequencies than visible light. X-rays used to take X-ray images when bones are broken and microwaves used to heat food in a microwave oven are all the same type of electromagnetic wave. The only difference is the frequency of the electromagnetic waves.
Now we know that electromagnetic waves are everywhere, just like air. But are electromagnetic waves really as harmful to the body as my mother said? Let’s first consider electromagnetic waves that pass through the human body. The human body is a conductor that conducts electricity much better than rocks or rubber. The charges in the numerous electrolytes on the body’s surface and inside it can move freely. When the frequency of electromagnetic waves is low, the charges in the human body move immediately in response to the electric field of the electromagnetic waves, canceling out the electric field. In other words, this neutralizes the electromagnetic waves. Visible light and ultraviolet rays, which have no effect on the human body, are immediately absorbed at the body’s surface in this way. In fact, infrared rays penetrate only a few millimeters into the human body and are completely absorbed. On the other hand, electromagnetic waves with much higher frequencies, such as X-rays, change too quickly for the body’s charges to keep up with the changes, so they are not neutralized. Therefore, X-rays pass through the body unimpeded.
The electromagnetic waves commonly referred to as harmful to the body in the news are those in the low-frequency range, which have much lower frequencies than visible light. The energy of electromagnetic waves is proportional to their frequency, and low-frequency waves considered harmful have frequencies ranging from 1 MHz to 50 GHz (10^10 Hz). Low-frequency electromagnetic waves are primarily generated by common household appliances such as gas stoves and mobile phones. When compared to visible light, which has a frequency of 10^15 Hz, the energy of low-frequency electromagnetic waves is extremely minimal, amounting to only one-hundred-thousandth of the energy of visible light. The claim that electromagnetic waves are harmful is not due to the size of their energy. Prolonged exposure to electromagnetic waves can disrupt important electrolytes such as K+, Na+, and Cl- within the human body, causing ion imbalance and potentially affecting various immune and nervous systems. However, electromagnetic waves do not accumulate in the body like toxic substances, and due to their very low energy, there is significant debate within the academic community regarding their risks.
With the widespread use of smartphones, claims have been made that smartphone electromagnetic fields are harmful to the body. Research has also been published suggesting that smartphone electromagnetic fields have negative effects on fetuses and that carrying a smartphone in a pants pocket can reduce sperm count in men. Additionally, the International Agency for Research on Cancer (IARC) classified mobile phone electromagnetic fields as a “Group 2B possible carcinogen” in its 2011 classification of carcinogens, warning of the potential risks of electromagnetic fields. This fear of electromagnetic fields led to a trend where “smartphone electromagnetic field blocking stickers” and “electromagnetic field blocking cases” were widely sold.
However, the World Health Organization (WHO) has stated that there are no harmful symptoms caused by electromagnetic fields from electronic devices, and numerous studies have shown that Wi-Fi signals from smartphones are not harmful to the human body, keeping the debate ongoing. Despite these conflicting research findings, many people still believe that electromagnetic fields are harmful. People tend to easily blame electromagnetic fields as the culprit due to their negative perceptions and lack of knowledge about them, rather than trying to identify the actual cause.
Many people claim that prolonged computer use causes headaches, stiff shoulders, and blurred vision due to electromagnetic fields, or that sleeping on an electric blanket leaves them feeling sluggish, citing their own experiences as evidence that electromagnetic fields are harmful to the body. However, the causes of such health issues are more likely to lie elsewhere rather than in electromagnetic fields. In the case of computer use, prolonged poor posture and focusing on one area can cause shoulder stiffness and blurred vision. Electric blankets, on the other hand, can affect blood circulation due to prolonged exposure to high temperatures. In modern society, where living without electronic devices is impossible, invisible electromagnetic waves can be a source of fear. However, in the face of ongoing debates about the harmful effects of electromagnetic waves, it is important to avoid fear based on ignorance.
