How big is the real radiation of the subway X-ray security inspection machine?

How big is the real radiation of the subway X-ray security inspection machine?


Rumor: The internal radiation of such security screening machines that often appear in railway stations, airports, and subway stations is very strong. Many passengers rush to get their bags before they come out in a hurry. This is very dangerous, and you should try to stay away from that. The black shielding bar, wait for it to close before picking it up, because the shaky shielding bar will also shake out a small amount of radiation.

X-ray security

The baggage X-ray security inspection instrument is the same as the medical X-ray diagnostic instrument. It must irradiate the inspected object through X-rays to obtain the internal image of the object. Resolution of medical diagnosis level. According to the national standard GB15208.1-2005, the single inspection dose of the X-ray security inspection instrument should not be greater than 5µGy (current radiation energy, absorbed dose unit), and at any position 5 cm away from the outer surface of the device (including the entrance and exit of the device) ), the X-ray dose should be less than 5µGy/hour, this standard is the same as that of the US FDA.

In fact, the radiation dose of X-ray security cameras used in subways and airports is much lower than the national standards. Taking the X-ray security inspection equipment used in the Shanghai Metro as an example, according to the data provided by the company’s official website, its single inspection dose is 0.534µGy, and the radiation dose at 5 cm of the outer surface is 0.788µGy/hour, which is about the upper limit specified by the national standard. 1/10.

X-ray security

According to the data reported by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the radiation dose of a medical X-ray chest X-ray examination is 50 µGy. It takes about 100 scans to reach the radiation dose received by a chest X-ray—not to mention that such a situation simply cannot happen.

Some people may ask, I take the subway every day. If the number of times increases, will the accumulated amount be harmful? We do not have clear data on the amount of radiation dose received by ordinary passengers every year due to security checks. However, compared with ordinary passengers, the security inspection device operators will obviously receive more radiation, especially the airport baggage security inspection personnel, who often need to manually load or unload the security inspection device. In 2003, the U.S. Centers for Disease Control and Prevention conducted a large-scale radiation dose survey on baggage security inspectors at six major airports in the United States. The results of the survey report showed that the vast majority (89%) of airport baggage inspectors accepted their work on an annual basis. The radiation dose is 120µGy, and the remaining few personnel are basically less than 600µGy.

According to the data reported by the United Nations Scientific Committee on the Effects of Atomic Radiation, the general public, with the exception of natural radiation and medical radiation, receives an annual upper limit of radiation dose of 1000 µGy. Even airport baggage security personnel receive much less radiation dose due to work than this upper limit. The American Society of Health Physics also pointed out that the radiation dose of luggage X-ray security inspection equipment is much smaller than that of medical X-ray machines, and it has been fully shielded so that even pregnant women can safely perform luggage X-ray security inspections.

X-ray security

Conclusion: Exaggerate the facts. The internal radiation of the X-ray security inspection device used in the airport subway is not "very powerful", and the dose is much smaller than that of the X-ray equipment used for medical diagnosis, and the radiation around the machine is very weak, even full-time operators do not need protection. Although reaching into the shielding strip to take the bag does increase the amount of radiation received to a certain extent, it should be avoided as much as possible, but it is not a "very dangerous" thing.

Radiation dose received by common daily activities (unit: mSv)
Flying from Tokyo to New York (round trip), the amount of cosmic radiation received is 0.2
The average amount of cosmic radiation received per person per year in the world is 0.39
The world’s average annual radiation dose per person is 0.48
The average annual food radiation dose per person in the world is 0.29
The average amount of radon radiation in the air received per person per year in the world is 1.26
Take a chest X-ray once, the amount of radiation absorbed is 0.05
The target value (one year) of radiation near the nuclear power plant is 0.05 (the actual value is below this target value)


How big is the real radiation of the subway X-ray security inspection machine? - Safeagle

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