The radiation emitted by the plane is equivalent to 10 X-ray? Can pregnant women still fly?

You can often see rumors on the Internet that when an airplane is cruising at high altitude, it will receive more cosmic radiation than on the ground. The amount of radiation by plane is equivalent to taking 10 x-rays in the hospital …

Is that really the case? Can pregnant mothers still fly?

Before discussing the harm of radiation, let's first understand the unit for measuring radiation dose-SV.

However, in daily life, the unit of sieverts is too large, and generally a smaller unit of millisieverts (mSV) is used, which is suitable for calculating human radiation dose.

According to China's Basic Standards for Protection of Ionizing Radiation and Safety of Radiation Sources, on the basis of removing natural background radiation and medical radiation, the average effective radiation dose that the general public can bear every year is limited to 1 millisieverts.

What do you mean?

Natural background radiation, that is to say, you do nothing every year, but also suffer from radiation.

It includes light from the universe and so on. As long as you live on the earth, you must bear this natural radiation.

The natural radiation dose per person per year is about 2.4 millisieverts.

That is to say, apart from miscellaneous and inevitable radiation, it is absolutely safe as long as a person's annual additional radiation dose does not exceed 1 millisieverts.

The United Nations Scientific Committee on the Effects of Atomic Radiation has calculated that the dose of ionizing radiation to the human body during the flight of 10 hour is about 0.03 millisieverts.

To reach the limit of 1 millisievert, the plane needs to fly for more than 330 hours. Take Boeing 737-800 as an example. According to its cruising speed of 800 km/h, to reach the public radiation limit, the plane needs to fly around the earth six times, which is not enough for ordinary people.

In the hospital, the dose of CT scanning is about 2 msv ~10 msv; X-ray cardiopulmonary examination is usually done, and the primary radiation is basically around 0.2mSv.

In other words, the radiation produced by a chest CT is equivalent to hundreds of flights from Beijing to Shanghai, and an X-ray examination is roughly equivalent to the radiation produced by dozens of flights.

Therefore, the statement that "the radiation received by an airplane is equivalent to 10 X-ray chest x-rays" is totally untenable.

But when flying, the radiation received by the human body is indeed stronger than that on the ground.

Because the plane is at high altitude, the air will become thin.

When the shielding effect of the atmosphere is weakened, the human body receives more radiation.

Studies have shown that the dose of cosmic rays to the human body will double for every two kilometers increase in the flying height of the plane.

However, these are all within the human body's tolerance. Otherwise, the stewardess's little sister will fly in the sky all day, and it will be in big trouble.

So can pregnant mothers fly?

The Nuclear Regulatory Commission of the United States suggested that the radiation dose of pregnant women should be less than 5mSv per year, far below the recommended value of the upper limit of 50mSv for adults.

So as long as it is not too frequent, it is no problem for pregnant women to fly.