What are the hazards of wireless networks to the human body?

With the vigorous development of the Internet industry, wireless Internet is basically covered in many developed areas of my country, whether it is shopping malls or streets, which has brought great convenience to people's access to network information. However, there is a saying on the Internet that the human body is easily affected by the long-term exposure to wireless networks. Is there any real basis for this statement? What are the hazards of wireless networks to the human body?

The question of whether WiFi wireless networks are harmful to the human body has been raised time and again. Simply put, the answer is no. In fact, to rephrase your question: suppose you also ask about baby alarms, radio-controlled cars, cordless phones, Bluetooth headsets, burglar alarms, etc., which also use unlicensed wireless frequencies and do not cause you any concern.

For example, “Is leaving a baby alarm at home the same as leaving the microwave door open?” A more detailed answer is: The strength of a wireless network signal is 100,000 times weaker than that of a microwave oven. A microwave oven is a directional wireless device that operates at a very high voltage and has a very short range. The operating voltage of a wireless router is much lower. At the same time, it transmits signals in all directions and has a relatively long operating distance.

Radio signals, like light, sound waves and gravity, obey the inverse square law: for every doubling of distance, the energy is reduced by one quarter. In other words, the signal strength decays rapidly with distance. At normal distances, the signal strength of a wireless network is too weak to be of any concern: it's just part of the "radio smoke" formed by radio, TV signals, alternating current, household motors, and the vast universe. As my colleague Charles Arthur has pointed out, the wavelength of wireless network signals is the same as the wavelength of the cosmic background radiation: 12 cm. If you're still worried, just don't go out.

As Guardian readers know, the electromagnetic spectrum ranges from the very long wavelengths of radio signals to the extremely short wavelengths of gamma rays, including the wavelength range of visible light. It is well known that ionizing radiation with wavelengths shorter than visible light, such as ultraviolet rays, X-rays and gamma rays, is harmful. The ultraviolet rays in sunlight are of course harmful, so apply sunscreen. However, non-ionizing radiation with wavelengths longer than visible light is harmless. Including infrared, microwaves and radio waves. Because they use the 2.45 GHz frequency band, wireless network signals, baby alarms and mobile phones all fall within the range of microwave wavelengths. After the microwave band comes the radio band used for television and radio signals, and then long-wave signals.

Regarding the harm of wireless networks to the human body, due to space limitations, I will give you a brief introduction today! Of course, I still want to emphasize that, generally speaking, as long as we do not have long-term exposure to wireless network transmitters, there is basically no harm, especially for us adults. However, parents with children at home must pay attention and try to turn off wireless networks when they are free, so as to facilitate the healthy growth of children.