One of the most dangerous items is the "Demon car," the core of the third atomic bomb, hidden deep at the bottom of the Changin nuclear power plant or the notebook from the body of the scientist Mary Kiry. After 1600 years, the radiation issue has not been completely resolved. Therefore, wear protective gear, sit tight, and be cautious when approaching the leaderboard.

1. Radiation:

Today, X-ray imaging is one of the common techniques when going to the hospital. X-rays, especially CT scans, are a common way to create endoscopic images of a patient's body. Although there is a risk of cancer from X-ray exposure, the positive benefits it brings outweigh all risks. Doctors can rely on X-ray images to make diagnoses and treatments, saving many patients' lives and playing a crucial role in many medical discoveries.

In addition, radiation is also used to inspect luggage at airports, check welds, seams, or cracks in construction. Despite the risks, with a small amount of radiation, this method brings more benefits than harm.

Did you know that the bananas you eat regularly also contain radiation? Not only bananas, but also carrots, potatoes, red meat, or beer are foods containing natural radiation. Although the amount of radiation emitted from bananas is very small, about 0.1 microsieverts compared to an X-ray, experts have also talked about unpredictable consequences if you eat too many bananas.

For example, if you eat 274 bananas in one day and continue like that for 7 years, you will face symptoms of chronic radiation exposure, equivalent to the victims of the atomic bombing in Hiroshima in 1945. However, surely no one is foolish enough to eat 294 bananas every day for 7 consecutive years. The unforeseen consequences will make you die. Even if you eat 8 million bananas at once, you may still be at risk of death from radiation. Just reading this far is enough to see that eating bananas is still a better choice than not eating.

Now, let's learn about something a little more dangerous: Marie Curie's notebook, a famous French physicist and chemist. She was the first person to receive two Nobel Prizes, but she was contaminated with radiation from direct contact with tubes containing radioactive isotopes. Marie Curie died of aplastic anemia due to radiation exposure, and to this day, her body still contains radiation. To prevent radiation from spreading to the environment, her body is placed in a coffin lined with radiation-conducting material inside.

Not only her body, but many of her personal belongings are also contaminated with radiation, including a notebook containing valuable scientific notes. This notebook is considered a treasure of the scientific world and is currently preserved in a container at the French National Library. However, according to scientists, this notebook is also an extremely dangerous threat because it is contaminated with radium 226, with a half-life of up to 1600 years. This means that it will take another 1600 years for this radiation level to decrease by half from the original. Although it has been isolated, it is still not as frightening as some items in the leaderboard below, so I only rank it as A.

2. Mixed mass:

Have you heard of the elephant's foot, a mixed mass of molten uranium, coal, concrete, and sand, created in the Chernobyl disaster on April 26, 1986? Known as the "elephant's foot," this waste mass has a strong radiation level, causing those who come into contact with it to live only a few minutes and suffer from serious health problems. Although small but powerful, a caesium 137 pellet from Australia, less than 1 cm long, contains radioactive caesium 137 with a half-life of up to 30 years. Contact with it can cause burns and adverse effects equivalent to having 10 consecutive X-rays, increasing the risk of cancer and death, especially for those with long-term exposure. Although small, fortunately, an Australian journalist found it and returned it to the government, ranking it as A.

Going back to the past, the United States dropped two atomic bombs on Japan after Japan surrendered in World War II. Although the war had ended and atomic bombs were no longer needed, scientists at the Alam National Laboratory had to manufacture the third plutonium core for the next bomb. They had to take responsibility for preserving this plutonium core, known as the "demon core" or "Demon car." In the event of a bomb's radiation, an unstoppable chain reaction of nuclear reactions will occur, with nothing to stop it. The US knew they were dealing with something very dangerous.

However, they wanted to explore further the limits that particles reach when approaching near the supercritical point. It is often said that scientists are a bit crazy and daring, and this is not wrong. This stems from a special love for science, and that is why two physicists studying with demon cores had to face death. One of them died from conducting an experiment with the demon core alone, while the other died from an unforeseen accident before conducting an experiment with the demon core. The danger of this research project is evidenced enough by its name, and I will definitely rank this demon core in the highest category.

Without a doubt, next is radium, the miraculous element discovered by two Nobel Prize-winning scientists Marie Curie and her husband Pierre Curie in 1898. Quickly becoming a cancer treatment method, radium became a special "miracle drug" with extraordinary power. A "radium craze" began, with radium being added to many daily products from toothpaste to cosmetics and even food and drinks. A manufacturer named R. Thor even mixed a very small amount of radium into water, then advertised it as a "holy water" that could improve health and cure all kinds of diseases, from asthma to the "good" period.

However, the nature of radium is a toxic element and the most expensive substance in the world at that time, with a price equivalent to $2.2 million (in today's purchasing power). American track and field athlete Eben Byers, formerly famous, drank a bottle of R. Thor every day for several years and ended up dying in 1932. It was only then that people realized that radium was not the "miracle drug" they thought it was. Luminous watches in the dark, with hands and numbers coated with a special luminous paint that glows without needing an energy source, created another kind of magic.

3. Exposure:

The luminous paints that create a magical green glow on watch hands all contain radium. Female workers in watch factories often come into contact with this paint when painting watch faces, which glow thanks to radium radiation, bringing joy and high income. However, in the end, for these people, joy is traded for pain as their bodies become the shadow of the most toxic disease, from tooth loss, hair loss, jaw necrosis, jaw fractures to eye socket cancer, forcing them to face death at a very young age. Of course, this paint deserves a high ranking, equivalent to the demon core, in the S category.

The story of the radioactive claw is related to the Chernobyl nuclear disaster when an excavator's claw in the forbidden zone was believed to have a high radiation level that could cause death with just a touch. This excavator was left in a forest on the outskirts of the city of Pripyat after being used to clean up waste from the 1986 nuclear power plant disaster. An expert used a handheld radiation detector to measure before quickly leaving the scene. The measurement results showed that the radiation attached to this device was at 39.80 microsieverts, compared to the normal level of only 0.17. Although high, because it remains stationary, it does not pose a threat to social life. For this reason, I rank it in the B category.

One of the most heavily radioactive polluted places in the world is Lake Karach, located in the Chabin region south of the Ural Mountains and has been discovered since the 18th century. This lake is certainly not a suitable place for relaxation or sunbathing.

In the 1990s, just standing on the shore of Lake Karach for an hour could expose you to radiation levels of up to 600 roentgens. This level of exposure is enough to seriously harm healthy people. Since 1951, the Mayak Production Association, one of the largest nuclear production facilities in the Soviet Union, began dumping radioactive waste into the Karach Lake area. The radiation pollution level of this lake is twice as high as Chernobyl, with accumulated radioactive waste reaching 120 million curies. The frightening thing is that even brief contact with it can lead to death. Lake Karach has become one of the most heavily radioactive polluted places in the world.

Additional information is that all smart devices such as mobile phones, Wii consoles, radios, remote controls, and GPS emit radiation. These products have now become essential items for everyone, especially Wi-Fi networks and mobile phones. They use invisible energy waves to transmit voice, text, images, and emails to the nearest mobile stations, thereby transmitting information everywhere in the world.

4. Energy waves:

Phones are like a tiny microwave oven that you carry with you, emitting radiation from phones that increases rapidly in areas with low signal coverage, with the greatest risk being at the short-range access of mobile phones, where it emits very close to the brain. However, research results also show that there is not enough evidence to confirm that mobile phones or smart devices cause cancer in humans. It is best to limit their use as long as possible when going to bed, and remember to turn off the power after use to minimize the risk, so I rank them in the E category.