In the first days after the Chernobyl accident, the greatest danger to the population came from the rapidly decaying isotope iodine-131.
In the first decades after Chernobyl, the biggest threat was cesium-137. This isotope deposited the most, but its half-life is 30 years.
Over time, the most dangerous consequence of the Chernobyl accident is americium-241, a decay product of plutonium-241. The danger of americium is that its quantity only increases over time. Its half-life is enormous - 433 years. And it is a source of alpha radiation, and this is a mortal threat to a living organism.
Plutonium is a heavy element. Therefore, it fell only in the territory of the Chernobyl zone and around it. It’s easy to protect yourself from plutonium: the main thing is to follow the rules of personal hygiene and economic activity.
In general, radiation is not mysticism, but the result of chemical processes. And you need to treat it scientifically, then you can live in peace. Physicist Valery Gurachevsky told Nasha Niva about the impact of radioactive isotopes.
30 years have passed since Chernobyl disaster. This is not just another round date, but also the half-life of the main radioactive isotopes that contaminated the territory of Belarus after the explosion - cesium-137 and strontium-90. From these isotopes, new substances are formed as a result of decay. How dangerous are they?
Valery Gurachevsky: The half-life period has ended - this means that half of all this type of radionuclide has turned into stable nuclides that no longer emit. In another 30 years, half of the volume that remains will decay, then another half... For the entire volume of cesium and strontium that fell as a result of the Chernobyl accident to decrease by 1024 times, 10 half-lives are needed - three hundred years. So this story will drag on for a long time.
Map of cesium-137 contamination of territories after the Chernobyl accident in 1986.
Map of cesium-137 contamination in 2015
Map of predicted contamination of territories with cesium-137 for 2026 and 2046.
From radioactive strontium-90, as a result of decay, yttrium-90 is formed, and then the stable metal zirconium. Is yttrium dangerous?
VG: Yes, yttrium-90 is also radioactive. Strontium, when decaying, releases a beta particle, resulting in yttrium. Yttrium, in turn, also emits a beta particle.
But yttrium has a very short period half-life is 64 hours; when calculating the danger for strontium, yttrium is automatically taken into account. As much as there was strontium, there would be as much yttrium. There is no accumulation. But yttrium beta radiation is more dangerous than strontium radiation for living organisms, and in fact, when we talk about the dangers of strontium, this is not entirely true. This means yttrium.
Map of territorial contamination with strontium-90 and plutonium isotopes in 2015.
The body mistakes cesium and strontium for potassium and calcium.
- What is their effect on living organisms?
VG: Strontium is in the same column of the periodic table as calcium. And living organisms define them as elements with similar properties: these substances accumulate in bones, unlike cesium-137, which (like potassium) accumulates in soft tissues. And nature has provided an excellent way to remove toxins from the soft tissues of the body - the genitourinary system. There is such a concept - the half-life from the body. For cesium this is a couple of months. This means that within a year it is almost completely eliminated from the body.
But nature did not provide such a system for bones. Therefore, what is accumulated in them is almost never removed. Beta radiation from strontium accumulated in the bones affects the red bone marrow, a hematopoietic organ. At large doses, strontium accumulated in the body can cause blood cancer. But, I repeat, we're talking about about very large doses. None of the population received such doses, only a small number of liquidators.
- How does strontium enter the body?
VG: Radionuclides, strontium in particular, enter the body through food, water, and milk.
- Where in Belarus can food products be tested for radionuclide content?
VG: In Belarus, more than 800 laboratories are engaged in radiation monitoring of food products. Almost any enterprise that produces food has a radiation control point. Radiation control points exist in the system of the Ministry of Health (sanitary and epidemiological institutions) and in large markets.
- Does strontium accumulated in bones behave the same way as in nature? Does it decay into yttrium and then into zirconium?
VG: Yes, but the concentration of this substance in the body is microscopic.
Half-life - 432 years
IN Lately they began to talk about a new radiation isotope - americium, which is formed as a result of the decay of radioactive plutonium. But first I’ll ask a question about plutonium: where did it fall out most after the Chernobyl accident?
VG: Cesium and strontium are fission fragments of uranium nuclei. But, in addition to fragments in the reactor, nuclei of transuranium elements are formed, heavier than uranium. The predominant role is played by four of their types: pluton-238, pluton-239, pluton-240 and pluton-241. They are formed in the bowels of the reactor and were released into the atmosphere after the accident. These are heavy substances: 97% of them fell within a radius of approximately 30 kilometers around Chernobyl. This is a resettled zone where it is not so easy for a person to get to. Three of these isotopes - 238, 239 and 240 - have alpha radiation. In terms of the strength of its impact on living organisms, alpha radiation is 20 times more dangerous than beta and gamma radiation.
But here's the paradox: plutonium-241 has beta radiation. It would seem that there is less harm from it. But it is precisely this that during decay turns into americium-241 - a source of alpha radiation. The half-life of plutonium-241 is 14 years. That is, two periods have already passed, and three quarters of the precipitated substance has turned into americium.
Plutonium-241 fell out the most during the Chernobyl accident - this is due to the technical characteristics of the reactor. And now it turns into americium-241. Previously, there was no americium in the 30-kilometer zone around the reactor and beyond, but now it appears. Its content also increases outside the 30-kilometer zone, where transuraniums were present, but in quantities not exceeding the permissible level. And now we need to monitor whether the americium content exceeds the permissible level or not.
Acceptable level
- What is the acceptable level?
VG: The legislation does not yet take into account americium-241, and the exact permissible limits for its content in nature have not been determined. But they should be approximately the same as for other isotopes with alpha radiation. And now we are observing an alarming situation: in zones located close to the reactor, the level of alpha radiation is growing and the size of these zones is increasing. Forecast: by 2060, there will be twice as much americium as there are now all plutonium isotopes combined. And the half-life of americium is 432 years. So this is a problem for many, many years.
Clothing will protect you from external radiation
- They write on the Internet that americium radiation has a very high penetrating ability.
VG: The penetrating power of alpha radiation is negligible. But provided that radiation affects the body from the outside. You can hide from such radiation with a sheet of paper - and the paper absorbs alpha radiation. For humans, the role of such paper is performed by the keratinized top layer of skin. Yes, and clothing must be taken into account - after all, no one runs around the zone naked. But there is also internal radiation - if a source of alpha radiation enters the body. With food, for example. And it is already dangerous, since the body has nothing to protect itself from it from the inside. 80-90% of radiation doses received by the population today, as well as radiation-related diseases, are the result of internal exposure.
- In what organs does americium accumulate?
VG: In bones, like strontium. This is a dangerous radionuclide. But, I repeat, there is no need to panic. It is necessary to conduct research and measurements.
Is it true that americium has greater volatility compared to the original plutonium and therefore it is easier for it to “capture” new territories?
VG: Volatility is approximately the same. It may have a greater ability than plutonium to move from soil to plants, but this still needs to be tested.
Radical forecast: up to the resettlement of part of the Rechitsa district
- Are there any studies being conducted on the content of americium in the soil and its distribution?
VG: Yes. This is done by the Radiation Control and Monitoring Center environment Ministry of Nature, Polesie State Radiation Reserve - it has an excellent laboratory, thanks to our Western partners. The Gomel Institute of Radiobiology and the Institute of Radiology of the Ministry of Emergency Situations also have the appropriate equipment.
But a simple farmer or the chairman of a collective farm, will he be able to test his products for americium content in the nearest of those 800 radiation control laboratories?
VG: Detection of americium is possible only in laboratories with radiochemical equipment. This is a lengthy and expensive study. But, if someone turns to the above institutions, I think they will be helped there. Most of the 800 laboratories named can determine the level of cesium-137 and potassium-40. Research on strontium is not carried out everywhere.
- Which territories of Belarus are contaminated (or may be contaminated in subsequent years) with americium?
VG: Scientists disagree about this. Some believe that the situation is very serious, and even part of the Rechitsa district may fall into the infection zone.
- And what measures can be taken to protect yourself?
VG: I repeat, this is only a version. But in extreme cases, no measures will help. Only control. And, if the situation develops as the mentioned scientists predict, it will lead to resettlement.
Main radionuclides in an emergency release
From the book by V. Gurachevsky “Introduction to Nuclear Energy. Chernobyl accident and its consequences."
Valery Gurachevsky. Candidate of Physical and Mathematical Sciences, Associate Professor. One of the initiators of the creation and head of the Center for Radiology and Product Quality in the Agro-Industrial Complex at the Belarusian State Agrotechnical University. Author of more than 100 scientific publications, several books - incl. books “Introduction to Nuclear Energy. Chernobyl accident and its consequences."
In the Polesie Radiation Reserve, americium was found in the bodies of wild boars, because boars dig the ground and eat root vegetables with the soil
Vyacheslav Zabrodsky, head of the laboratory of the Polesie State Radiation-Ecological Reserve, told NN about how the level of americium in the soil is studied. The laboratory has American alpha and gamma spectrometers from Canberra, which can be used to study the content of americium and other radioactive isotopes in soil and food.
Vyacheslav Zabrodsky next to the gamma spectrometer
Determining the level of gamma radiation in soil and sediment samples, said Vyacheslav Zabrodsky, is not an expensive process. However, alpha spectrometry requires measurements that are a thousand times more precise. The process takes about seven days and requires expensive reagents - analysis of one sample can cost about two million rubles. When asked whether a farmer who wants to test his products or soil can contact the laboratory, the manager answered positively. True, he noted, no one has yet applied.
At any point in the reserve, a small amount of americium is present in the soil, says Zabrodsky. It may also be in surrounding areas. The scientist notes that, as a consequence of nuclear tests, americium is found anywhere in the world. In a lower concentration, of course.
If americium is contained in the soil, why does it not change? the legislative framework, the standards for its content have not been determined? Perhaps this is why they are in no hurry, notes Zabrodsky, because americium has a fairly low coefficient of transition into living organisms. This is due to the fact that, for example, cesium and strontium are radiation analogs of potassium and calcium, elements that are the basis of biological life. And americium and plutonium, from which it is formed, are perceived by the body as foreign elements. And thus they remain in the soil and do not pass into plants.
And yet to get into human body this radioactive couch potato has a chance. For example, through the organisms of those whose diet includes soil.
“We conducted research on wild boars,” says Zabrodsky. - Soil makes up 2% of their diet. We even found americium and plutonium in their muscle tissue. Detection capabilities were at a minimum, but they were found.”
Can these isotopes enter the body through smoke?
Unlikely, Zabrodsky notes. “When there were fires in Khoiniki, we collected samples of smoke particles and soot. There was cesium and strontium in them, but not plutonium or americium, since it is not in wood.”
Radiation situation on the territory of the Polesie Radiation-Ecological Reserve
Dmitry Pavlov: All the plutonium fell out in a closed area
“The legislation can and should be changed,” says the head of the rehabilitation department of the affected territories of the Department for Elimination of Consequences Chernobyl nuclear power plant Dmitry Pavlov. - But first we need to evaluate the feasibility. All of our plutonium fell out in a closed area, in a nature reserve, where we do not allow tourists or walking groups. Why should the rules applicable to this territory be extended to the entire country?
Yes, there is a problem in the reserve: nuclear fuel fell out in the form of dispersed particles during the explosion. And you can pick up this particle on your shoes and move it in any direction. Therefore, there is a situation when at one point the background radiation is normal, but five meters later it is hundreds of times higher.”
But the problem with americium, Pavlov believes, is being artificially inflated: “For some reason no one compares the areas of distribution of americium and the self-purification of soils from cesium and strontium - look at the difference in areas there. Ukraine and Russia envy us because we did not abandon these territories. We don’t have as much land as in Russia to be able to abandon them. People live and work there. How can you get clean products there? For example, fertilizers are applied and they replace the cesium present in the soil.”
Map of the radiation situation in the Gomel region in 2015.
Map of the radiation situation in the Brest region in 2015.
How is strontium level in milk measured?
Dmitry Pavlov also agreed to comment on the high-profile case of milk taken for testing at a Belarusian farm 45 km from Chernobyl. In that milk, according to Associated Press journalists, a tenfold excess of strontium-90 content was detected.
The study of that milk, explained Dmitry Pavlov, was carried out on the MKS-AT1315 device produced by the Belarusian enterprise Atomtech. To determine the content of each radioactive isotope, the sample must be prepared in a special way. The simplest analysis is for cesium-137. A liter of liquid milk is enough for it; such an analysis requires 30 minutes.
Strontium analysis requires special sample preparation. Firstly, there must be at least three liters of milk. First, it is evaporated for five days and passed through a special filter. Then the dry matter remaining on the filter is burned. And from three liters of milk a couple of tens of grams of burned substance comes out. In it, the device determines the level of strontium content, and then, using calculation tables, the content of the radionuclide in the initial three liters of milk is calculated.
An analysis for strontium was not even carried out at that time, but in the measurement protocol that the journalists received, the device automatically produced numbers for all measurements possible on it. For strontium-90 and potassium-40, these numbers are arbitrary, completely random, explains Dmitry Pavlov.
Americium- 95th element of the periodic table. Synthesized in 1944 in Chicago. Named after America, just as a previously identified element with a similar outer shell of electrons was named after Europe.
Soft metal, glows in the dark due to its own alpha radiation. The isotope americium-241 accumulates in spent weapons-grade plutonium - this is responsible for the presence of alpha radiation in nuclear waste. The half-life of americium-241 is 432.2 years.
Diagram of the electron shells of the americium atom.
Analysis for americium content can only be carried out in laboratories with radiochemical equipment. This is done by the Center for Radiation Control and Environmental Monitoring of the Ministry of Nature, the Polesie State Radiation Reserve, the Gomel Institute of Radiobiology and the Institute of Radiology of the Ministry of Emergency Situations.
Prepared by Andrey Skurko
According to established tradition, the article is published “as is”.
The information is presented in places in a highly simplified form,
with assumptions
not always compatible with the opinion of narrow specialists.
The article may lack links and materials,
which will appear later.
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Thanks for understanding.
For a long time it was believed that heavy radioactive isotopes such as Plutonium-241 could not move in the radioactive cloud after Chernobyl accident long distances.
Unfortunately, it is not.
On this moment at a considerable distance from the Chernobyl nuclear power plant, in areas where fallout of Cesium-137 and Strontium-90, which have safely traveled gigantic distances by air, is traditionally observed, heavy Americium-241 is beginning to be detected.
Americium-241 is a source of alpha radiation. It is very toxic and very mobile. Fortunately, Americium-241 is also a source of gamma radiation, by which it can be detected in samples of soil, plants and animal remains using a gamma spectrometer.
In the near future, we will begin posting reviews of the analysis of samples collected by volunteers in different parts of the planet and processed using our Atom Spectra gamma spectrometers.
The main event of 2017 will be the results of analyzes of samples that will be collected in the north Russian Federation along the route of the all-terrain expedition on SHERP vehicles.
Great All-Terrain Expedition "To the East!" http://navostok.ru/
will cover a route of 10,000 km from Arkhangelsk to Petropavlovsk-Kamchatsky. The expedition route will not pass through the cleanest places in terms of radioactivity.
The expedition team will be provided with our Atom Dosimeters and information support for collecting the necessary samples for further analysis on our Atom Spectra gamma spectrometers.
Fortunately, in the process of preparing for this event, we received invaluable support from specialists involved in analyzing the consequences of the Chernobyl accident.
We will look for traces of Americium-241 in the samples.
Americium-241 is formed from the decay of Plutonium-241.
The half-life of Plutonium 241 is about 14 years. In about 280 years, Plutonium-241 will have mostly decayed.
The half-life of Americium-241 is about 430 years. In about 8,600 years, Americium-241 will have mostly decayed.
Taking into account the latest accident at the Fukushima-1 nuclear power plant, Plutonium-241 will mostly decay around the year 2300.
Taking into account the first nuclear ground test, Americium-241 will only accumulate until 2300.
This means that every 14 years Americia -241 will become larger. At the moment, only after the accident at the Chernobyl nuclear power plant, more than 75% of Plutonium-241 decayed, forming Americium-241.
This quantitative characteristic can be reassuring and misleading.
Let's consider what problems are becoming relevant right now and will affect the majority of people living on planet Earth?
1) The accumulation of Americium-241 increases the background radiation of gamma and alpha radiation in all territories where Plutonium-241 has flown.
There is a suspicion that it flew wherever cesium-137 and strontium-90 flew.
Sanpin leaves no doubt that the expected toxicity of Americium-241 compared to Plutonium-241 is 100 times higher. Sanpin screen:
2) The value of the maximum permissible concentration (MPC) for Americium-241 in the air is about 2.9 *
10 -3
Bq/m 3
(Becquerels per cubic meter), in water - about 0.69 Bq/l. The data is at this link at the end of the table page.
The MPC value for Plutonium-241 in air is about 0.14 Bq/m 3
and in water about 80 Bq/l. These data were obtained from various sources, are of an estimated nature, but in order they are similar to the truth.
3) Americium-241 is approximately 100 times more toxic than Plutonium-241.
This means that instead of a “unit” of Plutonium-241 radioactivity, 100 corresponding “units” of Americium-241 radioactivity appear.
This means that if we had a glass of water with Plutonium-241 within the MPC, then after 14 years it will have to be diluted with 10 liters of water in order to reduce the concentration of radioactive dirt to the previous level.
This means that 50 kg of Plutonium-241, which was potentially released from the Chernobyl reactor into the atmosphere, now turns into roughly 5000 kg of radioactive dirt sprayed across the planet.
4) The radioactive cloud formed after the explosion at the Chernobyl nuclear power plant scattered radioactive elements on a planetary scale.
Now there is evidence that heavy isotopes also traveled long distances in the cloud along with Cesium-137.
For example, in the fall of 2016 in Tula region Americium-241 was found in mushroom samples taken from the Chernobyl spill sites.
The measurement results are in the table below.
Map with sample numbers where samples were taken:
Map with sample numbers: 
A similar distribution of Plutonium-241 could be from all the numerous explosions and accidents that took place on the planet.
5) In general the situation looks like this:
Chernobyl dispersed radioactive isotopes across the surface of the planet. Any forest fire potentially releases a radioactive cloud into the air. Particularly serious consequences can be expected from forest fires in the 30-kilometer zone around the Chernobyl nuclear power plant and in neighboring regions, including Europe. Plants and animals are accumulators of radioactive isotopes.
Fukushima continues to dissolve radioactive isotopes in the waters of the world's oceans, thanks to global currents. Algae, marine reptiles and fish “vacuum” ocean water, increasing the concentration of radioactive isotopes in their bodies. The concentrations of isotopes inside the organisms of ocean inhabitants are 100-1000 times higher than the concentrations of isotopes in water.
6) There will never be a pre-accident level of safety.
There is no safe level of radiation activity in food and air.
It is impossible to control contaminated areas.
Yes, and it is difficult to organize this control locally (see. PS below).
All that currently seems effective for control is to regularly survey the population for internal radiation of the human body (human radiation counter - HRU). Based on the results, understand the sources and consequences of internal exposure.
What to do with sources and consequences is another vast topic.
Why are you blinking...
Over my head?
You won't wait for the fire
Smoke detector, I'm not yours...
What nonsense? Oh, yes... It's all the fire smoke detectors hanging over my head that have such an effect on me :) They are stuck in everywhere possible. Nowadays, not a single new building is put into operation without such devices, hanging in the entrances, several of them on each floor.
Actually, this device itself is very useful, you never know what might happen to your neighbors. I don’t really want to burn with them if, God forbid, they have a fire. It hangs from the ceiling for years, slowly blinking its red eye, and if suddenly there is a fire, it will make the fire alarms scream so loudly that people jump out of the windows to escape the loud siren, and they will also be saved from the fire in one fell swoop: D
Few people think about how this device works. Well, they react to heat and smoke, and thank God. People more or less familiar with technology know that detectors come with optical sensors, thermocouples, etc. and so on. And there are also slightly exotic ones - radioisotopes. But, despite their exoticism, they are quite widespread, you can find them absolutely anywhere, and you won’t even guess it, because outwardly they are no different from their non-radioisotopic counterparts. Here, for example, are two photographs: on the left is an optical smoke detector, on the right is a radioisotope one. 
You can find out what type of sensor it is by holding it in your hands and reading the information on the nameplate. And it happens that even on the nameplate they don’t write anything about the ionization chamber located inside. And sometimes they have no nameplates at all... 
But there are also exceptions. There are such smoke detectors, just by their appearance, which seem to hint, “Don’t come close to me, I’ll kill you!” As they say, guess the country of origin from the photo XD 
You can meet them in the most unexpected places, mainly in Soviet-era buildings. 
Well, or under your feet, somewhere on the street... 
By the way, if you see this miracle in such a crushed state, I do not advise you to linger in this place. Get past it as quickly as possible and as far away from it as possible. And if you are a completely respectable and law-abiding citizen, then report the dangerous find to the relevant authorities (Ministry of Emergency Situations, Radon, etc.).
Well, okay, we won’t talk in detail about this miracle of the harsh Soviet industry. These smoke detectors are so interesting and unique that I would like to write a separate article about them if I ever get my hands on one of them. It will be interesting, I promise ^_^ But I can’t promise that at least one of them will fall into my hands: D Therefore, let’s move on to a review of more modest, modern, widespread imported analogues.
And so, meet: ionization smoke detector Appollo Xp95A!!! 
As you can see, it’s a regular smoke detector; these hang absolutely everywhere you look. Having disassembled it, you can see the following picture:
A shiny metal container that looks like another smoke detector, only miniature, has an ionization chamber. And it’s not difficult to guess for yourself that this is an ionization chamber, because a trefoil is drawn on it. Everyone without exception is familiar with this icon. It also displays information about the parameters of the radioisotope source located inside the ionization chamber: type of radioisotope, specific activity.
For those who are interested in the technical details of the principle on which such radioisotope smoke detectors operate, please open this spoiler. For those who are not very interested in this, read on.
Brief information. A radioisotope detector is a smoke fire detector that is triggered due to the impact of combustion products on the ionization current of the internal ionization chamber of the detector. The operating principle of a radioisotope detector is based on the ionization of the air in the chamber when it is irradiated with a radioactive substance. When oppositely charged electrodes are introduced into such a chamber, an ionization current occurs. Charged particles “stick” to heavier smoke particles, reducing their mobility - the ionization current decreases. Its decrease to a certain value is perceived by the detector as an “alarm” signal. Such a detector is effective in smoke of any nature.
Okay, so that my conscience does not torment me further, I confess that the previous two photographs of the smoke detector are not mine, they are from a third-party resource. Why? Because I don’t have a smoke detector itself, as such. I could have purchased it for review, but I didn't. What is my policy... If you have a device that is fully working, then disassembling it and breaking it in order to see what’s inside is blasphemy :) So I did it simpler: I directly got hold of several ionization chambers, one of which I ripped apart for of this article, and I use the rest for their intended purpose - I will make smoke detectors out of them, which I will install in the garage. And the damaged sensor went into action. I'll tell you how I used it in the next article. I think it will be interesting for handmaders (homemade workers in our language) :) 
Here is the ionization chamber that will fall victim at my hands. Let's measure the conditional gamma+beta DER on its surface, as well as on the reverse side. 
As you can see, the radiometer readings are not that impressive. Only 70 and 36 microR/h. Let me remind you that the maximum permissible background, which is established by the authorized bodies, is 30 μR/h. Manufacturers care about people :) I won’t measure it separately from all sides by gamma, particle density by betta, because it will result in too many photographs and information. And it would be wrong to measure the flux density of beta particles, because the preparation itself is very small compared to the size of the radiometer sensor. The readings will be too inaccurate. Now let’s directly extract the Americium drug from the ionization chamber. I will not describe the extraction technology in detail, I will only say that it is not difficult to bend the pair of plastic tendrils that hold the source inside the chamber using pliers.
Here he is: on the left is his working side, on the right is the back.
Let's measure it closely on both sides. Conditional DER gamma+beta, on the left - the working side, on the right - the back. 
The readings increased significantly compared to those he gave while mounted in the ionization chamber. 226 μR/h is given by the working side, and some 44 μR/h - by the rear. Again they are not impressive.
By the way, americium 241 is an alpha emitter. Therefore, it would be very appropriate to measure it with an alpha-sensitive radiometer in order to fully reveal the properties of this drug. However, due to the lack of such a radiometer, we have to work with what we have and measure the daughter decay products that emit beta particles and gamma quanta. But I hope that someday I will acquire such a radiometer and work with the ionization chamber in more detail. And regarding alpha radiation, which creates the main ionization in the smoke detector chamber, I can only add that a third-party source provides the following information: the flux density of alpha particles from the surface of the drug is 650 particles per square centimeter per minute. The figure is significant, however, given the almost zero penetrating ability of alpha radiation, the external irradiation of the body by alpha is reduced to nothing.
This is where I will finish the practical part of my article. Now let's move on to the theory. For those who are interested in what physical processes undergoes the drug Americium 241, causing its radioactivity, please reveal the spoiler. Well, those who don’t particularly care about physics skip this spoiler and read on.
Americium-241 is an isotope of stable americium-243. The simple substance is a silvery-white metal. Interesting feature This isotope glows in the dark due to its own alpha radiation. Americium is highly toxic. Its toxicity is due more to its radiation properties than to its chemical ones. Let's dissolve in water. Americium-241 is obtained in three main ways:
1. During beta decay of the isotope Plutonium-241
2. When an electron is captured by a Curium-241 atom
3. During the alpha decay of Berkeley-245
Americium-241 itself is also unstable, with a half-life of 432.6 years. When decaying, americium-241 emits alpha particles, forming a daughter product - Neptunium-237, which, in turn, undergoes beta and gamma decay. Thanks to the decay of Neptunium, we can detect radiation from Americium using radiometers that are sensitive only to beta and gamma radiation.
According to tradition, in the final part of the article we talk about the dangers of all of the above.
And so, there is a smoke detector assembly, ready for use. If it hangs on the ceiling or wall, then you can completely forget that it contains the radioactive drug Americium 241, because due to its weak radioactivity it poses absolutely no danger in this state (this statement does not apply to Soviet smoke detectors, but which I hope I can tell someday :D). If you have at your disposal an ionization chamber separate from the smoke detector, then, without taking into account stochastic effect*, it also does not pose any danger due to weak radioactivity, which is almost completely shielded by the body of the ionization chamber. The main thing is not to carry this camera around all your life tied to your body)))
It’s a completely different matter if you somehow get your hands on the Americium drug from the ionization chamber, or you yourself suddenly want to disassemble it. Americium dissolves easily in water. Therefore, if it lies on dry surfaces, it will not leave a trace, but if it gets into a humid environment or into hands without protective gloves, it can pretty much ruin everything around it, and its microscopic particles will probably get inside your body if you twirl it in your bare hands . Washing your hands does not at all guarantee that there will be no traces of Americium 241 left on them. Therefore, when working directly with this metal, it is necessary to take precautions - at a minimum, wear gloves, and, at a maximum, not have anything to do with Americium 241 at all :)
Here I will end my next story, reminding you that radiation is found everywhere, and you need to be vigilant. In the next article I will talk about how, without the help of expensive equipment, using improvised means, you can visually observe the decay of Americium 241, and indeed any alpha- and beta-emitting radioisotope.
*stochastic effect is a phenomenon reflecting the individual susceptibility of each living organism to a particular dose of radiation. In other words, in order for the effects of irradiation of the body to manifest itself, some need more, and some need less...
MkR/h. The more visits to the page, the more radioactive the smoke detectors are :)
