Doctor, it is said that a dental X-ray is equivalent to an hour at the Chernobyl nuclear power plant?
Doctor, I heard that a whole-body CT radiation is equivalent to staying in the place with the strongest radiation on the earth for several hours.
We doctors are often asked by patients who are examined whether such radiation is very strong and whether such radiation is dangerous.
Yes, it is quite strong, but it cannot be compared with one place because:
The strongest radiation in the world is in the lungs of smokers!
Why? Today, Dr. Clove recommended a very interesting video to explain the matter.
There is a video channel called Veritasium, which is an English science and education program and is very popular on YouTube. Founder Derek Muller is a physicist. Let’s follow him to explore the place with the highest radiation level in the world.
Tools and units for measuring radiation
Radiation is divided into ionizing radiation (such as X-ray) and non-ionizing radiation (such as mobile phones and microwave ovens). Ionizing radiation is measured here.
Geiger counter is a classic tool for measuring ionizing radiation. Its measurement unit is Sieverts.
Doctors need to be concerned that if someone receives more than 2 sieverts of radiation at one time, they may die immediately…
In order to make it easier for everyone to understand, we use the number of bananas per unit area to express the radiation intensity.
Bananas are chosen because bananas are rich in potassium, which contains about 0.0117% of radioactive potassium-potassium 40, and the half-life of potassium 40 is as long as 1.25 billion years (the life span of the earth is 4.5 billion years).
Every time you eat a banana, you are exposed to about 0.1 microsieverts of radiation, which is one tenth of a million sieverts (very little! Don’t be wrong about bananas! ).
In other words, if you want to reach 2 sieverts of lethal radiation at a time, you only need to eat 20 million bananas at one time (and do not survive).
So, how high is the radiation level in the high radiation area we are talking about?
As long as you are on earth, you cannot avoid radiation.
Because there is ionizing radiation in water, soil, rocks, air and even outside the atmosphere, it can be said that we cannot avoid ionizing radiation.
When it comes to the [most] radiation in the world, besides units, of course, reference should also be considered.
In ordinary daily life, we can regard this inevitable radiation amount as a reference background data (also called background data). The natural radiation background level in the world is 0.1 ~ 0.2 microsieverts/hour, which can be roughly regarded as-2 bananas.
Taking this background as a reference, let’s take a look at what we think is the high radiation area.
Hiroshima, Japan
The world’s first atomic bomb exploded about 600 meters above the dome and directly destroyed the whole city.
Today, 70 years later, the radiation intensity here is 0.3 microsieverts per hour, which is about-3 bananas.
Czech Republic, World’s First Uranium Mine
The Czech Republic has the world’s first mine to discover uranium (a radioactive element). The materials used by Madame Marie Curie’s research also came from here.
Now, the uranium mine has been completely mined, with only a small amount of uranium, which can emit twinkling light under ultraviolet light.
In spite of this, the radiation level of uranium ore is still only about 10 times of the general background level, which is about 17 bananas.
Madame Curie Laboratory
Perhaps we have known Madame Curie and her great experiments since childhood, but have you seen her office?
There are also places in Madame Curie’s laboratory where the radiation dose is very high, such as… door handles and chair backs. We can still detect particles in these places. We can imagine a scene where she may come to open the door and then pull open the chair and sit down after completing the experiment. These places are now recorded.
The radiation level in these places is about ten times the background level, which is about 15 bananas.
United States, Nuclear Explosion Test Site
Trinity Bomb Test Site in New Mexico, USA, is the world’s first atomic bomb test site.
At that time, the whole area was flattened by the huge energy released by the atomic bomb, and the temperature was so high that even the sand on the ground was hot to melt into small green glass-like stones.
This is the only place in the world where these special stones will appear. Therefore, these special minerals are even named after this place Trinite.
The radiation intensity of these small stones that witnessed the nuclear explosion test is about-21 bananas.
An airplane in flight
Until the previous measurement site, the place we measured was more or less related to the experiment.
However, there is one place that everyone did not think of, that is, the radiation intensity of the plane in flight is also very high.
It turns out that the higher the plane rises, the thinner the air layer protecting us, so the higher the radiation dose we receive in the plane.
In an airplane, the radiation intensity is about 2 microsieverts per hour at 33,000 feet. When the altitude is higher and closer to the earth’s poles, the radiation intensity is even higher, reaching up to 3 microsieverts per hour.
Chernobyl Nuclear Power Station
The Chernobyl nuclear power plant exploded on April 26, 1986. At that time, extremely high heat was generated inside the reactor, which blew the entire roof of the nuclear power plant off. Radioisotopes entered the air with dust and blew it to the whole of Europe.
Within a few years of the accident, up to several meters of surface soil on this land was shoveled away and transported to more remote places for deep burial. Therefore, even if radiation data are measured here, there will not be much danger for a while.
Even so, if you stay here for one hour, there will be 5 microsieverts of radiation, which is the same as the radiation received by a dental X-ray examination, and can be regarded as about 50 bananas.
Fukushima Isolation Zone, Japan
On March 11, 2011, off the coast east of Miyagi Prefecture in Japan, a 9.0 magnitude earthquake occurred and caused a strong tsunami. A series of equipment damage, core meltdown and radiation release occurred at the Fukushima Daiichi nuclear power plant.
This series of incidents is considered to be the most serious radiation incident since the Chernobyl nuclear accident in 1986.
In order to avoid radiation damage to residents’ health, the Japanese cabinet issued an emergency shelter instruction the day after the accident, requiring residents within 10 kilometers of the Fukushima nuclear power plant to evacuate immediately.
The accident was still lighter than that of the Chernobyl nuclear power plant. It is said that the radiation level of the accident was only 10% of that of the Chernobyl accident. The same way to deal with the radiation problem, their main method of removing radiation was to collect and bury shallow soil.
However, due to the short time and less decay, the radiation level is still around 5 ~ 10 microsieverts per hour, so the radiation level for one hour in Fukushima is about-100 bananas.
The basement of Pripiat Hospital
Next, we came to Pripiat Hospital, which has now been abandoned. Wild shrubs with tendrils and branches have blocked the way into the hospital.
It has been 30 years since the hospital last provided services, and the patients they received last time were all firefighters who put out the fire in the Chernobyl nuclear accident.
In the basement of this hospital, there are hidden fire suits that firefighters took off at that time. Because these fire suits were all seriously polluted, they were hidden deep in this abandoned hospital.
Just outside the door, the radiation intensity of 500 microsieverts per hour can already be recorded. Upon entering the door, the data soared to 1,500 microsieverts. If converted into bananas… Sorry, I can’t count it.
Yes, this is one of the places with the strongest radiation on the earth. If you stay in this place for one hour, you will receive 2,000 microsieverts of radiation, which is worth a whole year compared with the natural background radiation.
However, this is not the place with the highest radiation level! Let’s go to the ultimate goal!
The last stop…
A CT scan will receive a radiation intensity of 7,000 microsieverts.
It is estimated that residents around Fukushima will be exposed to 10,000 microsieverts of radiation in their lifetime.
If workers are engaged in radiation-related work, they will be exposed to an average of 50,000 microsieverts of radiation every year.
Of course, because the radiation from outer space is unstoppable, astronauts on duty on the space station will receive 80,000 microsieverts of radiation within six months.
However, they are not the ones who receive the most ionizing radiation…
It’s… Smokers!
Cigarettes contain radioactive polonium and lead, so every smoker’s lungs are exposed to an average of about 160,000 microsieverts of radiation every year!
If bananas are still used for comparison, the smallest frame in the above figure is the average radiation background data per person, and the amount of radiation smokers receive from inside to outside every year is the outermost frame.
Well, the next time a patient asks you about the hazards of radioactive examination, please tell them at the same time as well as tell them about it:
Smokers’ lungs are exposed to such great radiation! Really worried about radiation, please give up smoking first.
On radiation, the two most common questions
1. Microwave ovens, mobile phones, computers, such daily necessities have radiation?
The answer is, yes, but it is safe radiation. Don’t worry.
Take microwave oven as an example, it uses the thermal effect of electromagnetic wave and is also a kind of radiation, but it is harmless [non-ionizing radiation].
If you are not too close and do not cram yourself into the microwave oven, there will be no damage.
As for mobile phones and computers, instead of worrying about radiation, it is better to worry about whether they will explode.
2. Is what radiation harmful to people?
The answer is in the previous article, it is those [ionizing radiation]. Only unprotected ionizing radiation is to be worried about.
In our life, we generally do not have the opportunity to come into contact with a large amount of ionizing radiation, only in a few cases, such as X-ray related medical examinations.
However, the amount of radiation in routine examinations is strictly limited and usually does not reach the level of obvious damage to health, so the necessary examination must be done. After all, the damage detected by the examination is negligible compared with the failure to detect the risk of the disease.
Finally, I would like to mention the typical representative of ionizing radiation-smoke.
Really afraid of radiation, start by quitting smoking!