Can you eat the food swept by the subway security detector? Will there be radiation residue?

Can you eat the food swept by the subway security detector? Will there be radiation residue?

People who take the subway to work and school in big cities frequently have their backpacks subject to subway security checks, as do people who often need to take high-speed trains. This has caused many people to murmur mentally, and forget the things they wear in their bags. Can the food still be eaten after passing the scanner? Will there be any radiation inside?

Let's first understand what radiation refers to.

Radiation refers to the energy emitted from a certain radiation source. Light and heat emitted from the sun to the earth also belong to radiation; microwaves in microwave ovens, X-rays emitted from X-ray security devices, and of course gamma rays emitted by radioactive elements are also radiation.

One type of radiation is electromagnetic radiation. If the electromagnetic radiation is converted into a picture according to the wavelength, then the long-wave radio is at one end of the electromagnetic radiation spectrum, the gamma rays are at the other end, there are X-rays in the middle, and visible light that we can see with the naked eye.


Another type of radiation is ionizing radiation. The human body is actually in an environment of ionizing radiation all the time. Ionizing radiation can damage DNA and cause gene mutations and cancer. In the natural environment, the main source of ionizing radiation is radon gas, as well as radiation from cosmic rays. In addition, smoke sensors in many buildings also contain trace amounts of radioactive materials.

In fact, since each of us lives in background radiation composed of electromagnetic radiation and ionizing radiation, each person is exposed to 36,000 millisieverts of radiation from the environment every year. The radiation generated by natural radiation sources accounts for the human body’s exposure to radiation. 80% of the total radiation.

If you eat a banana every day for a year, you will receive about 0.0365 millisievert of radiation. Those who fly frequently also receive more ionizing radiation (from more exposure to cosmic rays) than those who do not fly frequently.

So, will there be any radiation residue in the food that has been X-ray scanned at the airport, subway or train station?

The short answer is no.

Regarding this question, Kelly Classic, a radiologist at the Mayo Medical Center, said, “There are two types of radiation that need to be distinguished in this question. Exposure to radioactive materials."

During radiation exposure, energy in the form of photons passes through your body or your bag, which does not make your body or your bag radioactive.

However, if you receive a large dose of X-ray radiation, a molecule called free radical will be produced in the cell, and a large number of free radicals are harmful to the cell. The food irradiation disinfection method mentioned below relies on this trick to kill bacteria and other harmful organisms.

radiation residue

Of course, repeated exposure to X-rays will indeed damage DNA, cause genetic mutations, and induce cancer. This is the reason for limiting the number of medical X-ray exposures that the human body receives each year. But food is not a living thing. It does not need to worry about DNA damage causing cancer, because it has no life.

The most important thing is that after the subway scanner scans, neither your bag nor yourself will be radioactive, which is completely different from the radioactive material leakage caused by the Fukushima nuclear power plant accident.

X-ray Safeagle

Can you eat the food swept by the subway security detector? Will there be radiation residue?-Safeagle

contact us