Contents
And so, when we have found out the main types of ionizing radiation (radiation), we can talk about how it is dangerous and where it can get to us. For simplicity, we will consider three types of the most common radiation, alpha, beta and gamma. Radiation can affect living beings, including you and me from two sides.
The effect of radiation (ionizing radiation) outside.
Outside, for example, if these are X-ray installations for fluorography, when flying on an airplane, when passing near radiation sources (for example, near industrial flaw detectors) or in the case when a radioactive substance dropped out as a result of a radioactive accident (for example, during Chernobyl or Fukushima), which settled on the ground and irradiates a person or got on clothes and also irradiates, but from a closer distance. It is worth noting here that there are also materials and substances that naturally have radioactivity, and at the same time are very common in our life. Such substances include:
Thorium.

Thorium-an element very common in the soil, is radioactive. But, basically, it does not make a significant contribution to the radioactive background.
Kalium.
Kaliumis a very common element in the soil, it is used as fertilizers, it is contained in large enough quantities in bananas. It should be noted that potassium in certain amounts is also useful for humans. Of course, under normal conditions, all this radioactivity is hardly noticeable and is determined by special, sensitive installations. But there are cases when there may be radiation from a trailer loaded with bananas that is noticeable with a conventional dosimeter. Do not be afraid, bananas are not harmful in normal quantities (from the point of view of radiation).

Radium.
Radium is also found in the soil, in a number of building materials, can form radon gas, which is harmful to humans, so in Russia all newly built houses are checked for its content.
I would also like to note that gamma radiation comes from granite, granite slabs (natural), which can be detected using conventional dosimeters.

The effect of radiation (ionizing radiation) from the inside.
From the inside, this is a very dangerous case, it happens that during radiation disasters, radioactive substances get into the soil, into the atmosphere and water, then in various ways, these substances get into the human body. Everything is clear with water and air, I will tell you an example of how a radioactive substance can get into the body again.
- For example, a radioactive cloud passed over a field, and floated out on it, along with rain or just dust settled.
- On this field, grass grew or sprouted, which was either covered with a layer of radioactive dust, or absorbed some of the substances from the ground.
- This grass was eaten by a cow, which then gave milk, or… sorry for the rudeness, I went for meat.
- Everything, now together with milk, cheese made from milk or cow meat, radioactive substances will end up in the human body.
This is a very dangerous moment. Inside the body, each substance enters its own organs. Usually, you can understand where a radioactive substance (or radionuclide) will fall with the help of the periodic table of Mendeleev. This is done simply, we find a radioactive substance, for example, radium, and look at the column in which it is located, there is calcium in this column. Therefore, radium will get into the bones. The most striking and terrible example of this was the “Radium Girls” in America in 1917-1926. They worked in a factory where they applied radium paint to the dials of watches and instruments so that they would glow in the dark. They did this with simple brushes, and that the brush would not be loosened, it was placed in the mouth, thereby eating part of the paint. I can’t say for sure whether they knew at that moment that radium when ingested is dangerous or not, but… All these girls finished very badly, you can read about them or watch them. https://en.wikipedia.org/wiki/Radium_Girls
Also with radioactive iodine, well, everything is generally simple here, iodine in any case gets into the thyroid gland. The whole trouble of radionuclides that have got into the human body is that they are not particularly excreted, i.e. they have got into the bones, will remain in the bones, constantly irradiating them and everything that is nearby has got into the thyroid gland – will irradiate the thyroid gland until the end of days, or until the complete disintegration of the substance.

The effect of radiation (ionizing radiation) for medical purposes.
During medical interventions, this is still a special kind of radiation, doctors accurately calculate the dose of radiation that a person will receive, whether it is external or internal radiation.
Conclusion.
If you came to this page from a search engine and you still do not understand what radiation is, I recommend looking at this page: https://radiation-info.com/2021/08/15/what-is-radiation-or-ionizing-radiation/
Contacts: https://radiation-info.com/2021/08/15/about-me/
Related articles from Wikipedia:
About Radium: https://en.wikipedia.org/wiki/Radium
About Kalium: https://en.wikipedia.org/wiki/Potassium
About the Theory: https://en.wikipedia.org/wiki/Thorium
And remember, in these articles I try to explain clearly and simply very complex things that you, dear reader, were able to understand the processes surrounding us a little more. The situations, models, and statements I have described may be inaccurate, in favor of a simpler description and understanding. For more accurate data, I recommend contacting professionals.