Most people through the subway, railway stations and airport security experience is that th
baggage on the parcel security machine on the conveyor belt, X-ray photos, visitors have to go through security doors, let the security officer "touch" again. Previous incident, Chengdu airport used a security machine, not only to be baggage "camera", even people have to be "photographed" the. We can not help but worry: up through this security machine, will damage health?
To answer this question, we must first understand what is radiation? Radiation, divided intoionizing radiation and non
ionizing radiation, the difference is that radiation energy is large enough to cause material ionization. Non-ionizing radiation is characterized by a longer wavelength, does not cause material ionization, such as our visible light, generally does not cause human harm. Ionizing radiation, on the contrary, such as medical X-ray, can cause material ionization. Medical X-ray, is the use of ionizing radiation in the X-ray can pass through the body's characteristics, so that doctors through X-ray through the body to observe the image of the internal structure of the human body.
Is ionizing radiation harmful to the body? The key is dose. Radiation therapy used in the
ionizing radiation, due to large doses may cause cancer; used to check, imaging diagnosis of X-ray, CT, because the dose is very low, is unlikely to cause cancer. The radiation dose unit is expressed in terms of Sv (sv), 1 Sv (sv) = 1000 mSv (milliwatts) = 1,000,000 uSv.
Public information, Chengdu airport security device produced a radiation equivalent of 0.05-0.2 uSv (micro-Sv), equivalent to a chest X-ray 1/500, or limb X-ray 1/5.
In short, the airport with this "micro dose X-ray machine" dose of hospital X-ray, CT lower, that this X-ray machine X-ray machine, due to too weak and weak, on the human body Of the harm is minimal. Micro-dose X-ray human security machine in the global application of many scenes. In fact, our living environment, there is already a certain intensity of ionizing radiation, due to high-altitude cosmic rays more, take the aircraft itself is a process of receiving additional ionizing radiation. Was shot by the airport X-ray security machine, the equivalent of an extra 35 minutes on the planet, or in high-altitude flight of the aircraft to stay 1 minute 12 seconds. If the X-ray security screening opportunity, its possibility is not higher than you in the wild stroll, meteorite impact. If you are not afraid of flying will lead to cancer, it does not have to worry about because of the plane to accept the security check it!