First, let's clarify an important concept: a signal base station is not the same as a signal tower. A base station is a vital component of the communication network, responsible for receiving and transmitting wireless communication signals. A signal tower, on the other hand, is typically part of the base station, used for mounting antennas to ensure signal coverage. In general, signal towers and base stations are inseparable—where there is a base station, there will be a signal tower, and where there is a signal tower, there will be a base station.
Now, let's return to the main topic: radiation. When it comes to radiation, many people likely think of the devastating nuclear radiation caused by the atomic bombing of Hiroshima, the Chernobyl disaster, or even Marie Curie, the scientist who isolated radium. Due to her prolonged exposure to radiation, even her remains, along with her notebooks, need to be shielded with thick lead plates because they are still radioactive and will remain so for 1,500 years. These images understandably make people fearful of radiation. However, we need to understand that even in ancient times, long before communication technology existed, radiation was present everywhere. For example, when we sunbathe, the sun emits radiation. Solar radiation refers to the energy the sun sends out in the form of electromagnetic waves. The energy from solar radiation is mainly produced by nuclear fusion reactions occurring within the sun, which creates high temperatures that cause the sun to continuously radiate enormous energy into space. For both Earth and humanity, solar radiation is extremely important. It provides light and heat, allowing life to exist and thrive. A moderate amount of solar radiation helps the human body produce vitamin D, which benefits bone health. However, excessive solar radiation can harm the body, leading to sunburn, premature skin aging, and even skin cancer. Therefore, radiation has its limits—it should be controlled within a certain range to prevent harm, rather than blindly opposed. A powerful testament to this is the bird nests that are often found on signal towers. These birds bask in sunlight and enjoy both solar and base station radiation, raising their young without any apparent harm.
When discussing whether signal base stations and towers can harm the human body with radiation, we must first acknowledge that signal base stations do indeed emit radiation. Signal base stations rely on electromagnetic waves to communicate with mobile devices, facilitating voice calls, data transmission, and other functions. As a result, they inevitably emit electromagnetic radiation. For instance, the antennas of common 4G and 5G base stations continuously send signals into the surrounding space to cover a certain area, ensuring that mobile phones and IoT devices within that area stay connected. While signal base stations do emit radiation, there’s no need to panic. This is because the radiation from a base station decreases rapidly with distance. This happens because the electromagnetic energy emitted by the base station spreads out in all directions, following the law of energy conservation, and forms a spherical distribution. Here’s the principle:
Energy Dispersion Law: When a base station emits electromagnetic radiation, the energy spreads outward in the form of spherical waves. As the distance increases, this energy is distributed over an increasingly larger spherical surface. To illustrate, imagine the initial radiation energy is concentrated on a small "energy sphere." As the distance increases, the same amount of energy has to be spread over a larger "energy sphere," which means the energy received per unit area rapidly decreases. Mathematically, the power density of electromagnetic radiation is inversely proportional to the square of the distance. In other words, if the distance doubles, the power density reduces to a quarter of its original value; if the distance triples, the power density decreases to a ninth of its original value.
Directional Impact of Radiation: Base station antennas have specific radiation patterns, including main lobes and side lobes. The main lobe direction carries most of the radiation energy, with greater transmission distance and stronger signals. In contrast, the side lobe directions have lower radiation energy. When you move away from the main lobe direction, the radiation intensity you receive becomes weaker, and as you move farther from the base station, the radiation intensity drops even more sharply. For example, directly below the antenna, you are typically in the side lobe area where radiation is minimal, and as you move horizontally away from the base station, the radiation weakens more quickly.
Therefore, in daily life, the farther you are from a signal base station, the lower the radiation exposure. As long as you maintain a reasonable distance from the base station, the radiation impact is practically negligible.
So, what should we do if we want to stay away from base stations in daily life while maintaining a good signal for communication devices? In such cases, we can choose either outdoor antennas or indoor antennas based on our needs. Antennas play a critical role in wireless communication, broadcasting, radar, and many other fields. Their core function is to convert guided waves into free-space waves, ensuring smoother operation of the entire wireless communication link. According to research data, for common household wireless routers, the radiation power density 1 meter away from the antenna is generally less than 1 microwatt per square centimeter, which is far below the public exposure limit of 40 microwatts per square centimeter for electromagnetic radiation protection. Moreover, the energy radiated by the router antenna quickly attenuates with distance. As long as the distance is slightly increased, the radiation reduces significantly. Therefore, when using antenna devices, there is no need to overly worry about radiation posing a threat to human health, as the radiation power density is very low and the impact on health is minimal.