Each of us has such experience, that is, in the airport, subway station, railway station, bus station and other places need to pass the security check.
Does the radiation of security equipment affect our health? Will the fetus in pregnant women abdomen be affected by the radiation of security inspection equipment? And so on, a series of problems have followed. Today, let’s talk about the radiation of security equipment with you.
The three most common security inspection equipment:
1. Hand held metal detector. Security personnel are holding it in their hands and scanning around our bodies.
2. Walk through metal detector (security gate). The security gate we walk through is actually a metal detector, not an x-ray device, so we don't have to worry about radiation when we pass through the security gate.
3. X-ray security inspection system (security machine). That is, our luggage needs to pass through the security equipment. The security inspection machine is a channel type X-ray machine, which will produce a certain dose of X-ray in the work.
Is the radiation of security inspection machine terrible?
X-ray baggage scanner, security inspection machine is a kind of equipment to detect objects, with various types. The most common one is the channel type X-ray machine. Through the working mode of line scanning, the X-ray image is obtained when the article passes through the security inspection machine, and the image is processed by the computer, and the recognizable image is displayed on the computer screen. This is similar to the X-ray examination in the hospital, but the X-ray dose of the security inspection machine is far lower than that of the medical X-ray equipment, and the tube current is 0.4-1.2ma.
The internal ray of the detector is basically direct, all sealed in the security detector. There is a small amount of scattering in the X-ray, but the lead curtain at the entrance and exit of the security detector can basically block it. In addition, the four walls inside the security detector are all thick lead walls. As long as the lead curtain is not lifted up substantially, the radiation can not be detected around the security detector. Only when the luggage passes through, it will be electrified instantaneously and the radiation will be produced.
Therefore, there must be a certain dose of X-ray when the security inspection machine works, but if the human body does not enter, it will not be exposed to the radiation. The key issue is whether there is radiation leakage around the security inspection machine. If there is a leakage, it may have a certain impact on the staff who have long-term contact, but the impact on passing passengers is not significant. Generally speaking, a qualified security inspection machine should be safe. Its standard leakage dose is 0.05 μ Gy / h (1Gy is about 1000msv or 1SV), which is close to the natural radioactive background.
Are security staff and pregnant women safe?
The staff of China Nuclear and radiation administration center have done the test. At the side of the machine 5-10 cm away from the surface of the security inspection machine, the data obtained by the staff using hand-held instruments are 0.1 μ SV / h to 0.2 μ SV / h, which is similar to the value measured in the natural environment. In other words, there is no radiation leakage on the side of the machine. The staff also put the detector at about 10 cm of the luggage entrance and exit of the machine. The values measured here are slightly higher, ranging from 0.7 μ SV / h to 0.8 μ SV / h.
The staff of the security inspection machine concluded that the radiation leakage at the luggage entrance and exit of the security machine was the highest, and the farther away from the security machine, the smaller the radiation leakage. According to the basic standard for protection against ionizing radiation and safety of radiation sources, the artificial radiation dose of the public should not exceed 1msv in a year. According to the calculation, a person standing at the entrance and exit of the security inspection machine about 10 cm in 52 days will not reach this amount. However, the average annual dose of occupational personnel is not more than 20msv according to the national regulations, and the staff have to stay for 2.85 years to reach this amount.
We can say that the radiation value of the security inspection machine is actually very low, which is not enough to cause radiation damage to human body. Pregnant women will not have an impact on their babies when passing through the security inspection machine, so there is no need to worry and panic.
All x-ray scanning systems CETC supplying meet the Chinese national radiation permit as well as the national related standard GB15208-2018 and strictly follow the instruction of all applicable international radiation safety standards. Therefore, all passengers using CETC’s x-ray scanning system are totally safe.
