Where does polonium 210 go in fertilizers. Why was polonium needed? Tea with polonium

In 1898, while studying uranium pitch from Bohemia, containing up to 75% uranium, Curie-Sklodowska noticed that the pitch had a significantly higher radioactivity than pure uranium preparations isolated from the same pitch. This suggested that the mineral contains one or more new elements of high radioactivity. In July of the same year, Curie-Sklodowska made a complete analysis of uranium pitch, carefully monitoring the radioactivity of each product isolated from it. The analysis turned out to be very difficult, since the mineral contained several elements. Two fractions had increased radioactivity; one of them contained bismuth salts, the other - barium salts. A product was isolated from the bismuth fraction, the activity of which was 400 times higher than that of uranium. Curie-Sklodowska came to the natural conclusion that such a high activity is due to the presence of salts of some hitherto unknown metal. She named it polonium (Polonium) in honor of her homeland Paul (lat. Polonia - Poland). However, for several years after this discovery, the existence of polonium was considered controversial. In 1902, Markwald checked the analysis of uranium resin on a large amount of the mineral (about 2 tons). He isolated the bismuth fraction, discovered a "new" element in it, and named it radiotellurium (Radiotellurium), since, being highly radioactive, the metal was similar to tellurium in other properties. As Markwald determined, the radiotellurium salt he isolated was a million times more active than uranium and 1000 times more active than polonium. The element has an atomic weight of 212 and a density of 9.3. Mendeleev at one time predicted the existence of an element with such properties and, based on its supposed position in the periodic system, called the element dwi-tellurium. In addition, Markwald's findings have been confirmed by several researchers. However, Rutherford soon established that radiotellurium is one of the radioactive decay products of the uranium series, and named the element Ra-F (Radium-F). Only a few years later it became apparent that polonium, radiotellurium and radium-F are one and the same element, with alpha and gamma radiation and a half-life of about 140 days. As a result, it was recognized that the priority of the discovery of a new element belongs to the Polish scientist, and the name proposed by her was left.

In London, the Litvinenko murder case brought the topic of polonium poisoning back to the front pages of the media. We are talking about this chemical element with a doctor of chemical sciences, head of the Laboratory of the Radioisotope Complex of the Institute for Nuclear Research of the Russian Academy of Sciences Boris Zhuikov. Interviewed Natalia Demina.

In 2006-2007, you repeatedly commented on polonium poisoning on Ekho Moskvy, NTV and other Russian and foreign media. After all, many at first did not understand what had happened. It was argued that this substance was illogical to use, and in general the very fact of poisoning with polonium was questioned?

Yes, there was such a point of view. For example, Lev Fedorov, Doctor of Chemistry, President of the Union for Chemical Safety, said on the air of Ekho Moskvy: “How can you poison with polonium-210? This is what I'm not going to use... Now, if I thought about how to poison a person, then the last thing I would call polonium ... Naturally, the person who would drag it across the borders had to be dragged in a lead container ”.

A participant in the discussion that took place on the television program “Sunday Evening with Vladimir Solovyov” on December 3, 2006, in which I participated, Maxim Shingarkin, an artilleryman by training, claimed that Litvinenko was not poisoned, but inhaled himself with polonium while working in a secret laboratory on the territory Great Britain. ( Subsequently, M. Shingarkin became an adviser to the chairman of the Federation Council Committee on Science and Education, a consultant to the Commission under the President of the Russian Federation for the modernization and technical development of the Russian economy, and now he is a deputy of the State Duma, Andrei Lugovoi's ally in the LDPR faction - Polit.ru).

It is difficult to understand: the people who said this - they simply do not understand this area at all or are biased. Already in my first comment on this topic, I said that polonium-210 is a fairly suitable substance for poisoning, and the most likely method of poisoning is oral administration: throw a capsule with a soluble shell into tea or coffee, because it is sufficiently absorbed through the stomach . And literally the next day they reported that they found a teapot contaminated with polonium, from which Litvinenko drank tea. Represent my position? ( laughing).

Have you had experience with polonium in your practice?

Yes, many years ago, when I worked as a researcher at the Joint Institute for Nuclear Research in Dubna, I dealt with polonium-210 and other isotopes of polonium, in microquantities. In general, I have worked with radioactive isotopes of almost all elements. This was the direction - we were looking for new, undiscovered elements in a complex mixture of products of various nuclear reactions and in natural samples. Right now, my main focus is on radioactive isotopes for nuclear medicine, isotopes that are injected into the human body to diagnose and treat various diseases.

Do you know people who are now related to polonium?

Yes, but by the nature of their service, they are unlikely to agree to give you a frank interview, they have their own rules.

Well it is clear. After all, what relates to polonium is probably a secret?

No, the very properties of polonium, its behavior, methods of production and application have long been no secret, everything has been published. There are also a number of publications on the effects of polonium on animals. The specialist can understand and correctly interpret what is relevant in this case.

How expensive is polonium to manufacture?

Talk about the high cost of polonium-210 is a myth. I know the price it's selling for, but I probably shouldn't divulge it. In any case, it is very small. Of course, manufacturers of a particular drug - a source of radioactive radiation, convenient for use, can request a decent amount, but this, as they say, is "cheat". Polonium itself is cheap. Also, the source used, although obviously made by professionals, is poorly made, made by bad professionals.

Where can such a conclusion come from?

According to its properties, polonium easily diffuses through organic shells and, in general, spreads easily. In such cases, the source is made with a multilayer coating. The people who made the sample either did not know this, or were too lazy, or hoped that the presence of polonium would not come up at all. So the performers decently inherited.

If polonium is so inconvenient to use, why was it used?

On the contrary, in principle, polonium-210 is a very convenient substance for poisoning, namely for covert poisoning, and not for provocation. Initially, it is very difficult to detect if you do not do special analyzes (alpha spectrometry). And no one was going to do special analyzes, since this substance had not been used for poisoning before - at least it was not found. Polonium-210 differs from other radioactive isotopes in that it emits almost exclusively alpha particles with an energy of 5.3 MeV, which are absorbed even by a sheet of paper. Gamma radiation, which is usually detected using Geiger counters, is extremely weak, making up only one hundred-thousandth part. Accordingly, introducing it to England is not a problem, lead containers are not needed for such quantities, and it is safe to perform various operations with a sufficiently sealed capsule.

There were opinions that the polonium was used for provocation. In my opinion, such talk is absolute nonsense. There was no provocation, there was an attempted covert assassination. For provocation, it would be advisable to use any other radionuclide, for example, americium-241 - it would be easier to detect, it is more accessible (it is used everywhere in smoke detectors).

How then was this polonium discovered?

Yes, they found it, they might not find it. This is an interesting story, I followed the developments on the Internet. Litvinenko's symptoms were consistent with radiation injury. However, nothing was detected by a conventional counter that registers gamma radiation. A very weak line of gamma radiation with an energy of 803 keV could only be noticed as a result of long-term measurements using a good gamma spectrometer. At first, this radiation was erroneously attributed to radioactive thallium (thallium-206), which is produced by the decay of alpha-active bismuth-210m.

But then this version was recognized as erroneous, since this isotope of bismuth has too long a half-life, and they began to consider the possibility of having other alpha emitters. After that, urine was analyzed for the presence of alpha-active radionuclides and polonium was found, moreover, in huge quantities. The assumption that the British scientists were "prompted" about polonium-210 by some provocateurs seems to me extremely unlikely. Everything was done consistently and quite logically.

Why not use the usual chemical poison?

All groups of chemical poisons are known, it would be easier to detect them. Even when “disappearing” poisons are used, some traces of their use remain.

And polonium was unknown?

Unknown as a poison. Of course, there were cases, very few, of poisoning at work. But in production, after all, they are poisoned by anything.

But now...

Now you don't have to worry and don't carry the alpha counter with you. No one else will use polonium for this purpose. I am sure about that. The story became too popular, and even I was harassed with a request to check something... Another thing is the old cases that occurred even before the poisoning of Litvinenko, for example, the mysterious death of Yuri Shchekochikhin, the attempted poisoning of Anna Politkovskaya...

But after all, so many years have passed, is there really anything left? After all, the half-life of polonium-210 is 138 days?

Yes, this means that in 10 years its quantity decreases by 100 million times. Polonium-210 will remain, but in very small quantities. It is estimated that at least 1-3 billion becquerels (decays per second) were injected into Litvinenko for the second time. This is very high activity, even too high activity: as a result, a person can die in a few days. But in the polonium-210 produced at the reactor, there should be a small admixture of another, long-lived isotope - polonium-209 (half-life of 102 years).

At first, it is very difficult to detect it because of the background of the 210th. But after the collapse - then you should try. It is possible, of course, to produce polonium-210 without admixture 209, but it will be really very expensive and difficult. It is unlikely that these people who made the drug would do such things. Although, who knows?

There were opinions that Yasser Arafat was poisoned with polonium. What have the studies shown?

A detailed study by Swiss scientists (the report was published) showed that there are no weighty grounds to talk about poisoning in this case, although the authors themselves first drew a different conclusion from their results. The report provides quite convincing data that some excess of polonium (which really was) was most likely of natural origin - obviously, the result of the decay of radon-222, which is abundant in the dungeons where Arafat often stayed. An autopsy revealed a corresponding amount of another decay product of radon - lead-210. No polonium-209 has been found. Thus, Arafat received many orders of magnitude lower dose of polonium-210 than Litvinenko, and this could not have been the cause of death.

At public hearings, information was heard that Litvinenko was killed the second or third time. Apparently, the killers wanted to insure?

Yes, this fact has long been known and published in the scientific literature. It was reliably established by the distribution of polonium in Litvinenko's body. Moreover, the first dose administered was much less. Litvinenko would have died later anyway, and then, probably, nothing would have been discovered at all. But apparently the customers were impatient ...

Tell me, if as a result of such detailed studies it was possible to determine the nature of the introduction of polonium into Litvinenko, then probably it would be possible to determine the role of A. Lugovoy and D. Kovtun, suspected by the British?

Of course of course. They were studied, as far as I know, at the Medical Biophysical Center. A.I. Burnazyan. It was reported that Lugovoy was found to have polonium, but detailed results that would help shed light on the role of this person are unknown. They didn't go to the UK.

But was there a danger of hitting the performers and hitting those around them? Information appeared in the British media that Lugovoy even brought his son to the last meeting and gave him to shake hands with Litvinenko ...

There was some danger, taking into account the fact that the performers, apparently, were not properly instructed. But still, it is not at all as dangerous as ingestion of polonium, and does not pose a danger to life. Lugovoy himself said that someone had soiled him. And whether he got dirty or he did something himself - this could be seen. And the fact that they followed him and deliberately left traces is just stupidity, it is unrealistic to organize it so that it is not revealed.

In your opinion, is everything that the lawyer of the Litvinenko family and the British investigating authorities said is true?

At least in what is connected with the behavior of polonium, there are no contradictions. Only wrong is that its use has created a great threat to others. Small amounts of polonium, which can contaminate people in contact with Litvinenko, can be detected, but they are practically harmless to health. As a result, according to the Health Protection Agency, only 52 people received an increased dose, but not enough to significantly increase their risk even in the future. The real danger would be if only someone finished drinking tea for Litvinenko. And it's also wrong that polonium-210 is very expensive, unless it's ultra-high purity. I have already said about this above. It is simply inaccessible, and its distribution is well controlled by government agencies.

Do you see any inconsistencies in what the British investigators say?

There are no discrepancies that could not be explained on the basis of the physical and chemical properties of polonium. On the contrary, as soon as the opponents begin to put forward some objections, these objections do not fit in with the scientific data at all.

Thanks for the interview.

The scientific aspects of the Litvinenko case were analyzed by Dr. chem. sciences, head. Laboratory of the Radioisotope Complex of the Institute for Nuclear Research of the Russian Academy of Sciences.

Is it possible to determine the origin of polonium in a technical way? Theoretically it is possible, but practically it is very difficult. Each nuclear reactor (in a certain irradiation channel) is characterized by its own neutron spectrum. The presence of fast neutrons leads to the formation, along with polonium-210 (half-life - 138.4 days), small amounts of polonium-209 (half-life - 102 years, alpha particle energy - 4.9 MeV) by nuclear reaction (n, 2n) from the accumulated polonium-210, and also in smaller quantities of polonium-208 (2.9 years).

Thus, according to such a "nuclear clock", in principle, it is possible to determine the place and date of production of polonium. However, this is not easy, and in certain cases impossible. It depends on how much polonium was found and where: the ratio between stable lead-206 formed from polonium-210 and background lead, the content of which in the natural mixture of isotopes is 24.1%, is important. You will need a special mass separator to separate polonium isotopes (or a long exposure to decay polonium-210), as well as calibration samples of polonium from the reactor, made in the same irradiation mode.

Russian polonium is produced at the All-Russian Research Institute of Experimental Physics in Sarov. Irradiation of bismuth at the reactor is carried out, apparently, in another place - P / O "Mayak" in the city of Ozersk, Chelyabinsk region. The method for producing polonium-210 is not secret, so it can be produced at any other reactors where there is a special channel for irradiating targets in order to obtain isotopes. Such reactors are located in several countries of the world. Power reactors are generally not suitable for this, although some of them have a channel for irradiating targets. More than 95% of the polonium-210 was reported to be produced in Russia.

There are also other methods for obtaining polonium, but they are practically not used now, since they are much less productive and more expensive. One of these methods, used by Marie Curie, is chemical isolation from uranium ores (polonium-210 is found in the decay chain of uranium-238). Actually, polonium was discovered in 1898. Polonium-210 can also be obtained at charged particle accelerators by nuclear reactions 208 Pb (A, 2 n) or 209 Bi (d, n). At the same time, far from any accelerator is suitable for obtaining polonium-210. This requires an alpha particle or deuteron accelerator. There are not many such accelerators in the world. They exist in Russia and the UK. However, as far as I know, in Britain, the Amersham accelerator has long been tuned out for alpha particles and is constantly working exclusively on the production of medical isotopes for diagnostics. In a number of places I visited abroad, colleagues told me that their plants were inspected to see if they were producing polonium.

At one time, JSC Techsnabexport sold polonium-210 to the UK (to Reviss). But this was five years before the unfortunate events, and, as colleagues told me, the company was very carefully checked after that. Products containing polonium are not officially supplied to the UK from the USA and Russia. Polonium-210 was previously obtained at the Oak Ridge National Laboratory (USA), but now it is not produced there in significant quantities, but, on the contrary, some is received from Russia.

The work of both reactors and accelerators is strictly controlled. If someone still plans to produce polonium illegally, with the existing control system, this can easily be discovered.

Nuclear physical properties

As already mentioned, the half-life of polonium is 138.4 days. This means that every 138 days its activity decreases by 2 times, and in two years - by about 40 times. Such a half-life is very convenient for the use of a radionuclide as a poison.

Polonium-210, when decaying, emits alpha particles with an energy of 5.3 MeV, which have a short range in solids. For example, aluminum foil tens of microns thick completely absorbs such alpha particles. The gamma radiation that could be detected by Geiger counters is extremely weak: gamma rays with an energy of 803 keV are emitted with a yield of only 0.001% per decay. Polonium-210 has the lowest gamma constant of all common alpha active radionuclides. So, for americium-241 (widely used, for example, in smoke detectors), the gamma constant is 0.12, and Po is 5 10 -5 Rxcm 2 / hxmCi. In this case, the dose coefficient and, consequently, radiotoxicity are quite comparable.

Thus, even without a protective shell, it is extremely difficult to remotely detect the amount of polonium-210 sufficient for poisoning using a conventional counter, since the radiation level is comparable to the natural background (see Fig. 2). Thus, polonium-210 is very convenient for clandestine transportation, and there is no need even to use lead containers. However, special care must be taken during transport to avoid depressurization of the container (see below).
Rice. 2. Gamma radiation (dose rate) of polonium-210 depending on its activity and distance to the detector (1 mCi - 3.7 × 10 7 Bq) It is not at all advisable to use polonium-210 for provocations, since it can only be detected with the help of special equipment, which is not normally used.

The 803 keV gamma line can only be detected by long measurements using a good gamma spectrometer, and the semiconductor detector should be located very close to the source. There is evidence that this is how the increased radioactivity was found in Litvinenko at first, but at first the radiation was erroneously attributed to radioactive thallium (thallium-206), which is obtained by the decay of bismuth-210m (see the diagram in Fig. 1).

This was reported on the Internet even before polonium was identified. But then this version was recognized as erroneous, since this isotope of bismuth has too long a half-life, and they began to consider the possibility of having other alpha emitters. After that, urine was analyzed for the presence of alpha-active radionuclides and polonium was found, moreover, in huge quantities. The assumption that some provocateurs “told” the British experts about polonium-210 seems to me taken from the ceiling. British scientists did everything consistently and quite logically.

On the surface, the alpha activity of polonium-210 can be detected using an alpha counter, which is usually used only for special purposes, and not for routine checks for radioactive contamination. However, to determine that the radiation refers specifically to polonium-210, more complex equipment, usually stationary, is required - an alpha spectrometer. Activity on the order of 1 Bq (decay per second) on the surface can be easily registered. If alpha activity is detected, then sample preparation is already performed (for example, using chemical isolation) and a line in the 5.3 MeV alpha spectrum is detected on the alpha spectrometer, which characterizes this particular alpha-active radionuclide.

Chemical properties

Polonium can exist in various chemical forms, but in this case it is most likely to be in the form of soluble compounds (for example, nitrates, chlorides, sulfates), while a significant part of it in solution can also be in colloidal form. It is important that polonium is sorbed to a large extent from neutral and slightly acidic solutions on various surfaces, in particular, on metal and glass (maximum sorption is at pH ~ 5). It is difficult to completely wash it with conventional methods. Therefore, it is not at all surprising that a teapot and a cup from which polonium was consumed were discovered.
Rice. 3. 3d-graphic of the Metropolitan Police of London, characterizing the contamination in the kettle, from which Litvinenko was poisoned. From green (low) to purple (high). From the site www.litvinenkoinquiry.org Actually polonium in microquantities begins to sublimate only at temperatures of about 300 ° C. But it can also pass into the environment together with water vapor in which it is contained, and in the process with recoil nuclei.

Polonium diffuses rather easily in plastic and other organic substances; sources based on it are made with a multilayer coating. And if the ampoule was depressurized, then even the smallest traces of it can be detected with the help of an alpha counter.

Polonium is a polyvalent element that is prone to the formation of various complexes and can form various chemical

forms. In this regard, part of it is quite easily distributed in the natural environment. Therefore, it is quite understandable that traces of polonium have spread, and they can trace the source of polonium contamination.

Biological impact and radiation safety

Biological studies of the effects of polonium on animals were carried out in our country mainly in the 60s at the Institute of Biophysics in the laboratory of Professor Yu.I. Moskalev, there are several publications.

It has long been known that polonium-210 is one of the most dangerous radionuclides. The levels of human exposure to polonium-210 are shown in the table (data on experiments with animals are recalculated by us for the mass of a person).

The absorption of this substance through the gastrointestinal tract is estimated from 5 to 20%. Through the lungs is more effective, but such an introduction is extremely inconvenient for latent poisoning, since this can greatly pollute those around you and the performers. Only about 2% per day is absorbed through the skin, and this use of polonium for poisoning is also ineffective.

Polonium is distributed in the body to all organs, but, of course, not quite evenly. And it is excreted from the body with any biological substances: feces, urine, sweat ... The half-life, according to various sources, is from 50 to 100 days. One industrial accident was reported in our country, which led to the death of a person 13 days after the ingestion of 530 MBq (14 mCi) of polonium.

According to indirect data (according to the impact), the amount of polonium introduced into Litvinenko could be (0.2−4)x10 9 Bq (becquerels), that is, disintegrations per second), by mass it is 1−25 μg, practically invisible amount.

If polonium was contained in a cup of tea, for example, ~10 9 Bq per 100 g, then up to 0.01-0.10 ml, that is, up to 10 5 -10 6 Bq. This does not pose a serious danger to human life, although it exceeds the permissible pollution standards. Such an amount can be easily detected, and an activity of the order of 1 Bq is also detected.

In the Litvinenko story, according to the Health Protection Agency, the following happened:

120 people were likely exposed to polonium but received doses below 6 mSv (millisieverts), which poses no health risk;
17 people received a dose above 6 mSv, but not so significant as to cause any disease in the near future, the increase in the risk of disease in the distant future is probably very small. However, the highest dose

not life-threatening, received, of course, the wife of Alexander Litvinenko Marina, with whom he had the most contact.

The allowable dose for professionals working with radioactivity in Russia is 20 mSv/yr. not elevated. Only exposure to an effective dose of more than 200 mSv during the year is considered potentially dangerous. Thus, claims that the use of polonium created a great danger to others is an exaggeration.

Character impact	Activity, Bq (decay/ with)
When smoking 365 packs (per year, one pack per day)	22−175
Modern Russian standards - the limit of annual intake with food	110
Old Russian norms (1996) - the limit of annual intake with food	830
US Regulations - Dietary Limit	1100
Minimum significant activity allowed for use without restrictions (modern norms)	10 000
Old Soviet norms (1976) - limit of annual food intake	400 000
Chronic lesion leading to 100% death in 6-12 months. (intra-abdominal administration):	8 000 000
Activity corresponding to receiving a dose of 15 sievert (radiation sickness of the fourth degree):	40 000 000
Acute exposure leading to human death in 10-30 days (intra-abdominal administration):	80 000 000
The same when administered through the gastrointestinal tract	400 000 000- 800 000 000
Introduced in Litvinenko (according to various data from the Western press)	170 000 000- 4 000 000 000

The question was raised in the press whether polonium-210 had been used as a poisonous substance before and whether this could be established. In particular, the poisons that may have poisoned Y. Shchekochikhin and tried to poison A. Politkovskaya remained unknown. If polonium-210 was present in these cases, then over the past time it has decayed to a level below the background level. However, exhumation may reveal polonium-209, which could be present as an impurity (see above).

The hypothesis that Yasser Arafat was poisoned with polonium-210 was practically not confirmed. Some excess of polonium-210 can be explained by natural causes - inhalation of radon-222 during the long stay of the Palestinian leader in the bunker. Polonium-210 is a decay product of radon. A corresponding amount of lead-210, which is also a decay product of radon, was found in Arafat's body.

Application

So far, polonium-210 has been used for the following purposes.

To create autonomous sources of energy generated as a result of alpha decay. The Soviet Lunokhod and some satellites of the Kosmos series were equipped with such devices.
As a source of neutrons, in particular, for the initiators of a nuclear explosion in atomic bombs. Neutrons are produced when beryllium is irradiated with alpha particles and initiate a nuclear explosion when the mass of uranium-235 or plutonium-239 becomes critical. Also, such sources were used for neutron activation analysis of natural samples and materials.
As a source of alpha particles in the form of applicators for the treatment of certain skin diseases. Now it is practically not used for such purposes, since there are much more suitable radionuclides.
As an air ionizer in antistatic devices such as the Staticmaster manufactured by Calumet in the USA. These materials are not exported to the UK, and in order to extract the polonium-210 needed for poisoning, many such devices would have to be processed, which requires a radiochemical laboratory.

The photo was taken two days before Litvinenko's death (November 23, 2006). From www.litvinenkoinquiry.org Findings related to Litvinenko's death

Conclusions of a technical nature that may be essential for solving a crime can be divided into two groups: quite certain and those that are very likely, but for an unambiguous statement, an investigation is required not only in the UK, but also in Russia.

well defined

Polonium-210 is a covert poison. Its main difference from other radioactive substances is the difficulty of initial detection. Accordingly, it is pointless to use it for provocation, there are much more accessible and suitable radionuclides for this.
Polonium-210 is a substance that can be conveniently surreptitiously transported in quantities sufficient to cause poisoning. It is also easy to discreetly introduce it into a person’s drink. Other methods of administration (for example, airborne spraying or skin injection) are less effective, unreliable, difficult, and very dangerous for the poisoner.
Accidental contamination with polonium-210 by negligence is almost improbable, since such a degree of contamination requires a huge amount that can only exist in places of mass production of polonium in a plant, and this can be easily determined by the distribution of polonium on the human body.
None of the published allegations by the UK investigating authorities contain technical contradictions.

Very likely, but needs to be confirmed

It is most likely that the polonium-210 was produced in Russia. It could have been brought to the UK from Russia or the USA, where this substance is officially supplied. Other sources are not excluded in principle, but it would be practically impossible to hide such production. Polonium-210 has long been discontinued in the UK.
Extraction from antistatic devices in the US requires a special radiochemistry lab, which is extremely difficult to conceal under the current US control system. In other countries, such antistatic devices are practically not used.
It is possible to determine the origin of polonium by analysis only under certain circumstances (sufficient quantities and concentration, absence of background lead, sufficient exposure before analysis, availability of a special mass separator and samples for comparison). Under favorable conditions, it is also possible to establish in which production cycle it was obtained.
The substance was not stolen. This is extremely difficult to organize under the existing control system. Previously, several facts of the loss of polonium were recorded, but all of them were disclosed, since it is not a big problem to reveal them.

Polonium is an element all of whose isotopes (types of atoms) are radioactive. It is also a chalcogen, that is, it is found in nature - it is part of the earth's crust. He's also incredibly dangerous. Especially its isotope - polonium-210. However, first things first.

Half life

As already mentioned, polonium-210 is a very dangerous substance. It is highly toxic and has a half-life of 138 days and 9 hours. This value refers to the time during which the substance decays approximately into a ratio of ½. Let's apply this term, by the way, not to all systems. And exclusively to exponentially decaying.

It is important to note that all particles do not decay in two such periods. After all, each stage of half-life reduces the number of surviving particles by 2 times. And it is also worth knowing that the activity of a substance is proportional to the number of its atoms.

Toxicity

The element under consideration has a very high specific activity - as much as 166 TBq / g. This term refers to the number of radioactive decays carried out per unit time - a spontaneous change in the composition or internal structure of atomic nuclei.

This substance emits only alpha particles - positively charged, formed by 2 protons and 2 neutrons. But even despite this, it is forbidden to take it with your hands. Touching this soft silvery-white metal, a person is guaranteed to earn radiation damage to the skin at least. And it is highly likely that it will spread throughout the body. Because the isotope easily penetrates through the skin.

It is also dangerous at a distance that exceeds the length of overcoming alpha particles. This is because they begin to heat up on their own, as a result of which they pass into an aerosol state.

This is about the toxicity and decay of polonium-210. But there are also isotopes 208 and 209 - more long-lived. 208 has a half-life of 2.898 years. And the 209th has 103 years at all. They are less toxic. And there is practically no information about the remaining isotopes and their radiotoxicity, since they are short-lived.

There is a concept of maximum permissible concentration - this is a legally approved sanitary and hygienic standard. It allows the content in the environment of certain elements in a strictly defined quantity that is safe for flora, fauna and humans.

And even such a toxic substance as polonium-210, the photo of which is presented below, has MPC. Its content in water bodies is permissible in the amount of 11.1.10 −3 Bq/l. In the air of working premises, it can be found in a concentration of 7.41.10 −3 Bq/m³. That is why they work with this isotope exclusively in sealed boxes.

Along with the allowable limits, there is also a lethal dose. For an adult, only 0.1-0.3 GBq is enough. This is from 0.6 to 2 micrograms. That is, 0.000002 grams of an isotope that enters the body through the lungs can kill. A lethal outcome in the oral case occurs with a larger amount of the substance - from 6 to 18 mgc (0.000006 - 0.000018 grams).

Naturally, the radioactive isotope of polonium-210 has no antidote. Although experiments are being carried out. There is evidence that 2,3-dimercaptopropanol, which is a detoxifying drug with sulfhydride components, has been successfully used as an antidote during experiments with rats.

Animals were intravenously injected with a lethal dose of the isotope. And in one part of the experimental group, it was taken out with the help of the indicated means, while others were left to die. 90% of rats injected with 2,3-dimercaptopropanol survived. All others, including those poisoned and not cured, died in the next 1.5 months.

Properties and characteristics

They also need to be told. If we consider this radioactive substance as an element, then we can distinguish the following properties and features:

The mass of the polonium-210 nucleus is about 208.9824 atomic units (g/mol).
The formula for the arrangement of electrons in the shells of an atom (configuration) looks like this: [Xe] 4f 14 5d 10 6s 2 6p 4 .
The radius of an atom, which indicates the distance between the nucleus and the farthest electron orbit, is 176 picometers. 1 pc = 1 trillionth of a meter.
The covalent radius, denoting half the distance between the nuclei of an atom with a covalent bond, is 146 pc.
The ion radius (size) is (+6e) 67 pm.
Electronegativity on the Pauling scale is 2.3. This term implies the ability of some atoms to attract the electrons of others. By the way, fluorine has the highest indicator - 9.915.
The electrode potential (electromotive force) is as follows: Po ← Po 3 + 0.56 V and Po ← Po2 + 0.65 V.
The oxidation states are as follows: -2, +2, +4 and +6.
The ionization energy (the lowest required to remove an electron from a free atom) is 813.1 (8.43) kJ/mol or eV.
The density of the substance under normal conditions is approximately 9.5 g/cm 3 .
The melting point of this soft metal is only 254 °C.
Polonium boils at 962°C.
The specific heat of melting and evaporation is 10 and 102.9 kJ/mol, respectively.
The molar heat capacity is 26.4 J/(K*mol).
The molar volume is 22.7 cm³/mol.

And a few more words should be said about the crystal lattice of this soft metal. This is a geometric image, which is introduced to analyze the structure of substance crystals. Polonium has a cubic structure, and the parameters are 3.35 angstroms.

Sources of polonium

Few people know, but this isotope was found in tobacco used in the manufacture of cigarettes. And, accordingly, in tobacco smoke. Manufacturers, of course, prefer to remain silent about this. But this information was still clarified and disclosed.

The article was first published in an American publication called the American Journal of Public Health. It was written by a group of researchers, which included specialists from the Mayo Clinic (Rochester) and scientists from Stanford University.

The article says that cigar manufacturers discovered more than forty years ago that radioactive polonium-210 was found in tobacco. They tried by all available methods to remove it from the production, but to no avail.

In order to avoid greater awareness of potential buyers about this fact, the companies did not report the results of their internal research. This is evidenced by internal documents of tobacco industry concerns.

The Swiss newspaper Le Temps, in turn, writes that the desire to hide this information was so strong that the manufacturers hushed it up even when it turned out that the concentration of polonium-210 was two to three times lower than the estimates made initially.

Scientists believe that on cigarette packs, in this regard, it is necessary to depict a sign that would warn of radioactive danger.

Receiving metal

Much has been said above about the molar mass of polonium-210, its physicochemical properties and other features. It will not be superfluous to tell about how this metal is obtained.

In nature, its isotopes are included in the radioactive natural series 238 U, and are also present in uranium ores. But due to the short period of alpha decay, polonium-210 does not accumulate in significant amounts. The concentration is within the acceptable range.

To obtain this substance from the ore, it is necessary to extract radium from it - a silvery-white shiny alkaline earth metal, which is highly reactive. Its residues are dissolved with hydrochloric acid, after which polonium is precipitated with hydrogen sulfide. Along with it, bismuth also stands out - a shiny metal with a pink tint.

The next step is the separation of polonium. This process uses the method of fractional crystallization of compounds that have different solubility and different properties.

To date, polonium-210 can be obtained in nuclear reactors, where bismuth is irradiated with neurons. And the longest-lived isotope is extracted by bombarding the pink metal with protons.

In simple terms, obtaining radioactive polonium is not so easy. According to experts, there are only 40-50 reactors in the world that can produce this substance. Some of them are nuclear facilities located on the territory of the former USSR, as well as Germany and Australia.

Usage

Above, it has been sufficiently told about the various properties of this semimetal, as well as about the composition of the polonium-210 nucleus. 84 is the number under which the element is located, but it was entered first in the periodic table due to the uniqueness shown in many indicators.

Where is it applied? Polonium was the first radioactive metal used in space exploration. Approximately 40 years ago, it was applicable in the thermoelectric elements of satellites. However, the half-life of polonium-210 is only 138 days, which is not enough. Therefore, it was replaced with plutonium-238.

The metal was also used in neutron sources. However, even there it was replaced by tritium, a superheavy radioactive isotope of hydrogen.

In addition, polonium was used as an antistatic agent in printing devices. It was added to reduce the static electrification characteristic of polymeric materials. But now this is no longer necessary.

In general, the production of this material has long been discontinued in many countries. In Britain, it was completed in the 1960s. In the US, in the 1970s. In Canada, production ended before the early 1980s, and only in China did it last until the 1990s. The last polonium produced was made in Sarov, a closed Russian scientific city in the Nizhny Novgorod region.

Poisoning. Symptoms

Even winning a billion dollars in the lottery is easier than finding polonium somewhere. After all, its production is classified by the government, and every microgram of the extracted substance is strictly controlled. However, if this somehow happened, then you need to act immediately.

Poisoning with polonium-210 has no obvious signs. But from the very first contact, the substance provokes the development of radiation sickness, which is accompanied by symptoms of radioactive damage. The same signs appear that are observed in case of poisoning with other highly toxic metals. Namely:

Diarrhea, nausea, vomiting.
Hypertension and tachycardia.
Decay and fatigue.
Delusions, hallucinations and disturbances of consciousness.

These are common signs. After a while it starts:

Hair loss.
Rapid aging of the body.
Organ failure (begins with the liver and kidneys).
Complete defeat of the immune system and the leukocyte formula responsible for it.
Lack of bone marrow and lymph.

Polonium-210, once in the body, through the blood evenly "diverges" throughout the body. Homogeneous concentration is observed after a couple of hours after the incident. Metabolic processes are immediately disrupted, convulsions and psychosis, problems with motor skills may appear. Heart attacks, bloody stools, pressure drops, partial or complete blindness - all these are the consequences of poisoning.

How to act?

Whether or not a person can be saved from harmful contact with this substance does not depend on the half-life of polonium-210, and not even on how much metal or fumes were affected. And from treatment and timely assistance. Here's how to proceed:

When touching metal, immediately wash this area of the body using a large amount of washing powder or laundry soap.
If the isotope enters the esophagus, it is necessary to immediately induce vomiting. Since seconds count, subcutaneous injections of apomorphine are used for this. And taking a laxative - the introduction of an enema of sodium sulfate and magnesium.

Naturally, before this it is necessary to call an ambulance. In such cases, qualified medical care is paramount.

Within six months or a year, the isotope can be excreted from the body by the kidneys. But during this time it will accumulate and cause harm (baldness, for example).

If the substance has managed to be absorbed into the tissue of the organs, doctors use chemical compounds from oxathiol and unitiol. These drugs can "extract" the polonium-210 and bring it out. For at least a week, the victim will have to lie under a dropper.

Cases of poisoning

Only two are known to history. One happened in 2006 - 43-year-old Alexander Valterovich Litvinenko, a lieutenant colonel of the Soviet and Russian state security, who was in London at that time, was poisoned with polonium-210.

On the night of November 23, his condition deteriorated sharply, and he died less than a day later. Alexander's body was not opened for a long time, because there was a fear of exposure of doctors to radiation. Detailed investigations were carried out. Within their framework, it was possible to detect traces of radiation in those places where Alexander was before he became ill.

The second case is not so clear cut. Polonium-210 was found in the personal belongings of a Palestinian National Authority chairman named Yasser Arafat, who died in 2004.

An exhumation of his body was even carried out, and the Swiss side of the international commission, as a result of research, confirmed that this was an isotope poisoning. But then they changed their mind. As a result, the Russian, French and Swiss sides came to the conclusion that there was no evidence confirming the fact of polonium poisoning, and the case was closed.

The poisoning of Alexander Litvinenko would have required, according to British experts, considerable technical knowledge and skill.

Litvinenko died on 23 November due to a lethal dose of radiation from the polonium-210 isotope found in his system.

Since then, traces of the isotope have been found at five locations in London, including a sushi bar and a hotel where the ex-FSB officer used to frequent.

However, polonium-210 belongs to a class of radioactive substances, the detection and production of which presents significant difficulties.

This isotope occurs naturally in nature and in the human body at extremely low concentrations. In order to obtain sufficient quantities of this substance for criminal use, complex equipment and special knowledge are required.

Professor Nick Priest, one of the few British physicists with direct experience with polonium-210, told the BBC that just one milligram of the isotope would be enough to kill Litvinenko.

Polonium-210 emits a powerful burst of alpha particles. Unlike gamma radiation, alpha particles penetrate a relatively short distance, to a depth of only a few cells in biological tissues.

However, alpha particles have initially high energy, giving off which they are able to cause great damage to cellular structures.

"If you put this substance in a test tube or flask, it is impossible to recognize it by external signs," says Dr. Frank Barnaby, a nuclear physicist at the University of Oxford. "That's what makes it an almost perfect poison."

But if such a tube is opened, then polonium-210 spreads very easily through the air with water vapor and pollutes the environment.

At least three methods are known for obtaining this isotope. Polonium-210 can be extracted from uranium ore, from reactor-enriched uranium, or from another radium-226 isotope.

The fruit of Marie Curie's efforts

Polonium was discovered by Marie Curie in 1897 by chemical extraction from the mineral uranium oxide. The researcher gave the element its name in honor of her homeland - Poland.

According to physicist Nick Priest, this method is not able to produce enough of the isotope needed to kill an adult human.

To obtain the required amount requires the use of a nuclear reactor, he said.

According to him, the most realistic way to obtain polonium-210 is to irradiate the element bismuth with neutrons in such a reactor, resulting in the isotope bismuth-210.

This isotope has a short half-life, after which it decays into polonium-210 and thallium-206.

As Nick Priest points out, there were reports of small amounts of radioactive thallium in Litvinenko's body, which could be an indirect sign of polonium production in the reactor.

Thallium-206 has a very short half-life, so there should be traces of bismuth-210 in polonium, which in turn gives us thallium.

This can occur in the case of incomplete separation of bismuth from polonium at the final stage of the process.

Obtaining polonium from the radium-226 isotope is considered a difficult process because this radium isotope produces hard penetrating radiation.

Lunar rovers walked on it

According to experts, there are only 40-50 reactors in the world capable of producing polonium-210. All available data points to sources outside the UK.

Among them are several nuclear facilities in the former Soviet Union, as well as in Australia and Germany.

"There is only one reactor in Britain that could produce this isotope, and I'm sure the physicists working on it didn't do that," says Nick Priest.

Polonium is used in various measuring devices, but it is not easy to extract it from them.

In the past, polonium, like beryllium, was used as an initiator of a nuclear reaction in atomic bombs produced in the USA, Great Britain and the USSR. In addition, Soviet lunar rovers in the 70s were equipped with isotope batteries based on polonium-210.

The culprits are harder to find

The Litvinenko case brings us back to the topic of illegal trade in Russian radioactive substances. Since 1995, the IAEA has maintained a database of recorded episodes of the spread of nuclear waste and radioactive materials. According to last year's data, a total of 827 such episodes were registered.

The IAEA has no data on the presence of the isotope polonium-210 on the black market, but there have been unconfirmed reports in this regard.

On Tuesday, Sergei Kiriyenko, head of Rosatom, dismissed suggestions that the polonium-210 that killed Litvinenko could have been smuggled out of Russia. According to him, Russia exports only 8 grams of polonium-210 per month, and all this amount is sent to the United States. Exports to the UK were discontinued five years ago.

Theoretically, Litvinenko's investigators could trace the origin of polonium-210, but to do so, residual traces of other isotopes must first be found.

But even if such data were obtained, it would not necessarily lead to the discovery of the culprit, especially in the case of theft of such materials. According to many physicists, polonium-210 was chosen as the murder weapon precisely because of its high toxicity and difficulty in detecting.