A radioactive element of group VI of the periodic system of Mendeleev. Polonium was discovered in 1898 by Marie Sklodowska-Curie and Pierre Curie. The name was given in honor of Poland.
M. Curie found that some samples of uranium resin ore are more radioactive than uranium itself. Consequently, this ore should have contained substances more radioactive than uranium. These substances (elements) were isolated. Polonium first, then radium.
The longest-lived natural isotope is 210 Po. The half-life of 210 Po is 138.376 days, i.e. during this time, the initial amount of 210 Po is halved. After this time, half of the 210 Po nuclei are converted into nuclei of the stable lead isotope 206 Pb. The transformation of 210 Po into 206 Pb occurs as a result of α-decay
210 Po → 206 Pb + α.
Figure: 1. Scheme of decay of 210 Po. |
Those. In addition to lead nuclei (206 Pb), the decay of 210 Po also produces helium 4 He nuclei, which are usually called α (alpha) particles. Moreover, 210 Po is practically a pure α-emitter. Alpha decay, if it does not occur to the ground or only to the ground state of the final nucleus, is accompanied by gamma radiation. In the overwhelming majority of cases, 210 Po decays into the ground state of 206 Pb with the emission of alpha particles with an energy of 5.3 MeV, and only an insignificant fraction (0.00122%) of 210 Po nuclei decays into an excited (803 keV) state of 206 Pb, which decays with the emission of gamma quanta. It is possible to detect gamma radiation accompanying such alpha decay only in a precision experiment.
The 210 Po isotope is not only the longest-lived among natural, i.e. existing on Earth, not artificially obtained isotopes of polonium, but also the most widespread. It is constantly formed due to a chain of isotope decays, which starts with 238 U and ends with 206 Pb.
238 U → 234 Th → 234 Pa → 234 U → 230 Th → 228 Ra → 222 Rn → 218 Po → 214 Pb → 214 Bi → 214 Po → 210 Pb → 210 Bi → 210 Po → 206 Pb.
Half-life (T 1/2) 238 U 4.5 billion years. In a natural uranium mixture, 238 U contains more than 99%. The number of nuclei (N) of isotopes of uranium (238 U) and polonium (210 Po) in a natural mixture and their half-lives (T 1/2) satisfies the relation
N (238 U) / N (210 Po) \u003d T 1/2 (238 U) / T 1/2 (210 Po).
Similar relations are valid for all isotopes of the chain of successive decays, since they are in the so-called secular equilibrium , when the number of decays per unit time is the same for all isotopes. How many isotope nuclei are formed as a result of the previous decay per unit of time, the same number of them decays. Thus, 1 ton of uranium ore contains only about 100 micrograms of polonium. Basically it is 210 Po. All other natural isotopes of polonium are even less (and by many). Polonium can be isolated from uranium ores by processing waste from uranium production. However, in order to obtain a noticeable amount of polonium, an unthinkable amount of such waste would have to be processed. 210 Po is obtained in nuclear reactors by irradiation with bismuth neutrons as a result of the reaction
209 Bi (n, γ) 210 Bi.
210 Bi undergoes beta decay and turns into 210 Po. The half-life of 210 Bi is 5.013 days.
Besides 210 Po, two more artificially radioactive polonium isotopes have relatively long half-lives - 208 Po (T 1/2 \u003d 2.898 g) and 209 Po (T 1/2 \u003d 102 g). These isotopes can be produced by bombarding lead or bismuth targets with beams of alpha particles, protons, or deuterons accelerated in a cyclotron. 209 Po is available from Oak Ridge National Laboratory with permission from the United States Atomic Energy Commission (A.E.C.) for approximately $ 3200 per μCi (microcurie) *. Such a source will have 6 ·
10 -8 g 209 Po. All other polonium isotopes have half-lives from 8.8 days (206 Po) to fractions of a microsecond ().
The various types of ionizing radiation (α, β, γ) have markedly different penetrating powers. Alpha particles from radioactive isotopes flying through matter easily pick up electrons and turn into helium atoms. So in order to turn into helium, 210 Po alpha particles need only fly less than 4 cm in air, less than 50 microns in biological tissue, and less than 30 microns in aluminum. Thus, alpha radiation from radioactive sources cannot be detected by conventional dosimeters that use Geiger counters. Alpha particles of such energies will not pass through the counter body, even if its surface is smeared with an alpha radioactive isotope. It is enough to place a clean α-emitter in a sealed package with walls no thicker than a sheet of paper (the main thing is that the radioactive preparation does not "spill out" from it), and more sensitive devices, such as semiconductor or scintillation detectors, cannot detect its radiation ... The latter can help fix alpha radiation if they are in close proximity to an "open" source of radioactive contamination.
In fig. 2 shows the characteristics of the scintillation contamination detector LB 124 SCINT manufactured by BERTHOLD TECHNOLOGIES GmbH & Co.
Radioactive sources 210 Po are used both in scientific researchand in technology. During work on the Manhattan project, the polonium-beryllium neutron source was supposed to be used as a fuse atomic bomb... Neutrons in such a source are obtained as a result of the interaction of alpha particles from the decay of 210 Po with beryllium, the reaction 9 Be (α, n). However, later this decision was abandoned. The specific energy release of polonium is high - 140 W / g. A capsule containing 0.5 g of polonium is heated to 500 ° C. This property is used to create thermoelectric sources on its basis, which, in particular, are used in spacecraft. Polonium is also used in static electricity dissipation devices. Some devices of this kind may contain polonium with an activity of up to 500 μCi (about 0.1 micrograms). This amount is theoretically enough to kill 5,000 people. However, this polonium is securely packaged and requires sophisticated technology and in-depth knowledge to extract it for malicious purposes. As a rule, the activity of the sources offered on the market is low. Thus, you can purchase a 210 Po source with an activity of 0.1 μCi (microcurie) for $ 69. A source with this activity emits 3700 particles per second. The mass of 210 Po in such a source is about 2 ·
10-11 g.
Alpha radiation from radioactive sources cannot penetrate the skin.However, alpha-emitting nuclides pose a great danger when entering the body through the respiratory and digestive organs, open wounds and burn surfaces, and not only due to ionizing radiation, but also simply as toxic substances. The maximum permissible dose load on the body when 210 Po gets inside is only 0.03 μCi (6.8. 10 -12 g). With the same weight, 210 Po is about 2.5. 10 11 times more toxic than hydrocyanic acid. Once in the human body, polonium spreads through the bloodstream through the tissues. Polonium is eliminated from the body mainly in feces and urine. Most of all it is displayed in the first few days. In 50 days, about half of the polonium ingested is excreted. The presence of polonium in people infected with it is identified by the weak gamma radiation of secretions. Ingestion of one hundred thousandth of a milligram of polonium into the human body is fatal in 50% of cases. Polonium is a very volatile metal; in air in 45 hours, 50% of it evaporates at a temperature of 55 ° C.
* Units of activity - 1 Ci (Curie) \u003d 3.7. 10 10 decays per second, 1 Ci \u003d 10 3 mCi \u003d 10 6 μCi. 1 Bq \u003d 1 decay per second.
| Polonium isotopes | |||
|---|---|---|---|
| A | T 1/2 | Decay fashion | Radioactive row |
| 190 | 2.53 ms | α, EZ 0.1% | |
| 191 | 22 ms | α | |
| 192 | 33.2 ms | α 99.5%, EZ0.5% | |
| 194 | 0.392 s | α | |
| 195 | 4.64 s | α 75%, EZ 25% | |
| 196 | 5.8 s | α 98%, EZ2% | |
| 197 | 1.4 m | EZ 56%, α 44% | |
| 198 | 1.87 m | α 57%, EZ 43% | |
| 199 | 4.58 m | EZ 92.5%, α 7.5% | |
| 200 | 10.9 m | EZ 88.9%, α 11.1% | |
| 201 | 15.3 m | EZ 98.4%, α 1.6% | |
| 202 | 44.7 m | EZ 98.08%, α 1.92% | |
| 203 | 36.7 m | EZ 99.89%, α 0.11% | |
| 204 | 3.53 h | EZ 99.34%, α 0.66% | |
| 205 | 1.66 h | EZ 99.96%, α 0.04% | |
| 206 | 8.8 d | EZ 94.55%, α 5.45% | |
| 207 | 5.80 h | EZ 99.98%, α 0.02% | |
| 208 | 2.898 g | α, EZ | |
| 209 | 102 g | α 99.52%, EZ 0.48% | |
| 210 | 138.376 d | α | 238 U |
| 211 | 0.516 s | α | 235 U |
| 212 | 0.299 μs | α | 236 U |
| 213 | 3.65 μs | α | 237 Np |
| 214 | 164.3 μs | α | 238 U |
| 215 | 1.781 ms | α, β - 0.00023% | 235 U |
| 216 | 0.145 s | α | 236 U |
| 217 | 1.47 s | α\u003e 95%, β -<5% | 237 Np |
| 218 | 3.10 m | α 99.98%, β - 0.02% | 238 U |
| 219 | 2 m | α ?,β - ? | |
MOSCOW, December 11 - RIA Novosti. The discussion in the media about the properties of polonium-210 found in the body of ex-FSB officer Alexander Litvinenko contains a large amount of inaccurate information, which ultimately leads to "confusion of the situation," an expert in the field of nuclear physics told RIA Novosti.
Litvinenko, who fled to the UK in 2000 and received a British passport in October this year, died on 23 November at University College London hospital. Specialists from the British Health Protection Agency found traces of the radioactive element polonium-210 in his body.
Traces of polonium were found in places that Mr Litvinenko visited, in particular a restaurant and hotel in central London.
“In such complex issues as the handling of a radioactive isotope and the consequences of human injury with polonium-210, unfortunately, many consider themselves experts, inventing incredible things. In the beginning, there was implausible information spread by the media that a person poisoned with polonium-210 could leave after traces of themselves. This is nonsense, no sweating can take polonium-210 outside, "- said the expert.
A similar opinion was expressed to RIA Novosti earlier by the director of the Institute for Strategic Stability of Rosatom, Viktor Mikhailov. He stated that it is impossible for a person affected by polonium-210 to leave traces of the isotope behind.
"What traces? This is ridiculous! A person affected by polonium-210 cannot leave traces, unless he was carrying this polonium-210 in his hands," Mikhailov said.
According to him, "the isotope polonium-210 has alpha radiation and since it was inside a person, it cannot leave traces."
The UK Health Protection Agency issued an official statement at the end of November stating that "the risk of contamination with this substance (polonium-210) is minimal."
"The risk of injury from radiation sickness appears only if this substance has penetrated inside: you inhaled it, took it into your mouth or got it into an open wound. It does not pose a threat as long as it remains outside. Most of the traces of the substance can be removed simply by washing your hands using a washing machine or dishwasher, "the British agency said in a statement.
According to an expert in the field of radiation medicine, the development of radiation sickness from getting polonium-210 into the human body is almost inevitable. "But everything depends on the dose of the isotope and on the characteristics of the victim's organism. If the dose is extremely small, then the presence of polonium-210 can be recorded, but the health risk will be minimal," the expert told RIA Novosti.
Another expert - in the field of nuclear physics - recalled that "element 84 - polonium - the first element inscribed in the periodic table after the discovery of radioactivity." "It is the first in the order of atomic numbers and the lightest of the elements with no stable isotopes," he said.
Polonius was discovered by Pierre and Marie Curie and got its name on July 13, 1898 in honor of the historical homeland of Mary - Poland. It occurs naturally, but its concentration in uranium ores is 100 trillion times less than that of uranium.
Polonium is a soft, silvery-white metal slightly lighter than lead. It enters the human body with food and tobacco smoke
Isotopes are varieties of the same radioactive element. For example, polonium exists in variants such as polonium (P) P-210 with a half-life of 138 days, P-208 with a half-life of two years, and P-209 with a half-life of 103 years. According to the expert, the most important from the point of view of science is the isotope polonium-210 - a pure alpha emitter.
"The alpha particles emitted by it are decelerated in the metal and, running only a few micrometers in it, waste their atomic energy, which turns into heat, which, in turn, can be used for heating or converted into electricity," the expert said.
This energy is already being used both on Earth and in space. The P-210 isotope is used in the power plants of some artificial satellites. In particular, he flew beyond the Earth on the Soviet satellites Kosmos-84 and Kosmos-90.
Pure alpha emitters - and polonium-210 - have several obvious advantages over other radiation sources, including the fact that such emitters require practically no special protection measures: the penetrating power and path length of alpha particles are minimal. At one time, the radioactive isotope polonium-210 served as the fuel for the "stove" installed on the "Lunokhod-2".
Similar devices are used on Earth. Besides them, polonium-beryllium and polonium-boron sources of neutrons are important. These are sealed metal ampoules, which contain a ceramic pellet made of boron carbide or beryllium carbide coated with polonium-210. A flux of neutrons from the nucleus of a boron or beryllium atom generates alpha particles emitted by polonium.
Such neutron sources are lightweight and portable, completely safe to operate, and very reliable. A brass ampoule with a diameter of 2 cm and a height of 4 cm - a Soviet polonium-beryllium neutron source - gives up to 90 million neutrons every second.
Among other mundane things of polonium, mention should be made of its use in standard electrode alloys, which are needed for the glow plugs of internal combustion engines. The alpha particles emitted by polonium-210 reduce the voltage required to generate a spark and make it easier to start the engine.
An expert in the field of radiation medicine said that despite the presence of only alpha radiation from the P-210, from which "in principle, you can protect yourself with a simple barrier," they work with polonium only in sealed boxes, since it is one of the most dangerous radioelements.
The expert noted that today, with a high degree of probability, it can be said that Litvinenko died of acute radiation sickness.
“There are many questions in the history of his death, and every day there are more and more of them, but it is clear that the data we know through the official statements of the British authorities on the course of Litvinenko’s illness and the causes of his death most likely indicate damage from radiation disease, "he said.
"Although, of course, it is impossible to give an absolutely accurate answer without making the official results of the autopsy public," the expert emphasized.
He said that it is possible to talk about acute radiation injury to the human body when receiving a radioactive dose of radiation over 0.5 sievert (Sv).
Sievert is a unit of measure for effective and equivalent dose. The most commonly used fractional unit of a sievert is its thousandth - millisievert.
1 Sievert is equal to 1000 millisieverts (mSv). Equivalent dose is the absorbed dose in an organ or tissue multiplied by the appropriate weighting factor for a given type of radiation. The biological effectiveness of various types of ionizing radiation is taken into account, since at the same absorbed dose, alpha, beta and gamma radiation have a different effect.
The non-systemic unit of the equivalent dose is rem - the biological equivalent of an X-ray. 1 Sv is equal to 100 rem.
"Negative effects appear immediately or after a few days, in particular, the immune system weakens, the gastrointestinal tract, lungs and other internal organs, as well as the central nervous system suffer," the expert said.
At doses from 1 to 2 sievert, radiologists believe that a fifth of the victims may be fatal. At doses over 7 sievert, the survival rate is zero.
As previously reported in some media outlets, there is a reactor in Russia at the Mayak plant in the Urals, where special bismuth targets were irradiated at one time in order to obtain intermediate raw materials, from which pure polonium-210 is isolated.
Rosatom told RIA Novosti that the reactor used to produce polonium-210 was decommissioned two years ago.
Some British media reported that the polonium that could have been poisoned in London by Litvinenko was produced in the city of Zheleznogorsk, Krasnoyarsk Territory. This information was questioned by the ex-head of the RF Ministry of Atomic Energy Viktor Mikhailov, who noted that British specialists could not quickly determine the place of manufacture of polonium-210.
"I think that it is impossible so quickly, since the discovery of traces of polonium-210, without exchanging information with countries that can produce polonium, to determine the place of production of this radioactive isotope," Mikhailov said.
Krasnoyarsk nuclear specialists have also completely rejected suggestions that the polonium-210 discovered in the UK could have been produced in the Krasnoyarsk Territory.
According to the management of the mining and chemical combine operating in the closed city of Zheleznogorsk, which has been producing weapons-grade plutonium for almost half a century, the named isotope "has never been present in the technological chains of local enterprises."
Earlier, the head of Rosatom, Sergei Kirienko, said at a press conference that Russia exports polonium-210 to the United States on a monthly basis, carrying out deliveries under strict control.
The US Federal Nuclear Regulatory Commission (Nuclear Regulatory Commission), in turn, said that samples of polonium-210 available on the free market in the United States are not dangerous. According to the commission's spokesman David McIntyre, the danger is posed neither by educational and scientific samples of the isotope polonium-210, which are freely sold via the Internet, nor by technical devices and devices for combating static electricity containing this radioactive element sold through retail trade.
"If you want to disassemble the device, any amount (polonium-210) will be difficult to retrieve and still be in harmless form," McIntyre said, stressing that anti-static devices sold in the US market could be "an extremely unlikely source." radioactive polonium-210 so that it can be used to poison humans.
The American company United Nuclear issued a statement in which it said that the volume of polonium-210 in its samples is so small that about 15,000 such samples will need to be purchased to accumulate a lethal dose of this radioactive isotope. With a price tag of $ 69 per sample, the total cost of such a purchase would be over $ 1 million, which, of course, would immediately cause alarm both because of the huge amount and because of the large number of orders for a company that usually sells no more than one- two samples per quarter.
At the same time, Michael Levy, an expert on science and technology at the Political Science Council on Foreign Relations, whom the ABC contacted for comments, does not consider extracting polonium-210 from samples and devices available on the free market in the United States to be so difficult. With basic chemical knowledge and over-the-counter equipment costing a couple hundred dollars, polonium-210 is quite recoverable, considering also the fact that "vendors show engineering diagrams of their appliances on the Internet," he said.
At the same time, Levy questioned the assertions that appeared in the British and American media that polonium-210 can only be obtained in the most complex laboratories operating at nuclear complexes. "The idea that you would have to have access to the Russian nuclear complex is silly," said Levy, who agrees with experts who are surprised by the choice of polonium-210 as a poison to kill a person.
"There are undoubtedly more proven and reliable ways to kill people. You should not be so afraid of polonium, since there are many other ways to kill people, quietly slipping something into the drink," Levy said.
Chairman of the Federation Council Committee on Defense and Security Viktor Ozerov, in turn, denied all accusations against the Russian special services that could allegedly have been involved in Litvinenko's death.
"I doubt that our intelligence services are so unprofessional to spread poison across twenty London offices and endanger the lives of ordinary people," he said.
In 1898, while investigating a uranium tar from Bohemia, containing up to 75% uranium, Curie-Sklodowska noticed that the tar had a significantly higher radioactivity than pure uranium preparations isolated from the same tar. This made it possible to assume 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 the uranium tar, carefully monitoring the radioactivity of each product isolated from it. The analysis turned out to be very difficult, as 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 (Latin Polonia - Poland). However, for several years after this discovery, the existence of polonium was considered controversial. In 1902, Markwald checked the analysis of uranium tar on a large amount of the mineral (about 2 tons). He isolated the bismuth fraction, found a "new" element in it and named it Radiotellurium, since, being highly radioactive, the metal was similar in other properties to tellurium. As Markwald determined, the radiotellurium salt he isolated is a million times more active than uranium and 1,000 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 table, called the element dvitellurium. 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 a number of uranium, and named the element Ra-F (Radium-F). It was only a few years later that it became apparent that polonium, radiotellurium and radium-F are 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 retained.
who discovered polonium?
Alternative descriptionsPierre (1859-1906) French physicist, Nobel Prize 1903
Unit of measurement of radioactivity
Who helped Maria Sklodowska discover radium
French physicist, one of the founders of the theory of radioactivity
Physicists spouses
Family of Nobel Physicists
French physicist
French physicist who discovered and studied piezoelectricity
First woman to receive a Nobel Prize
First female professor
French physicist, Nobel laureate (1903), creator of the doctrine of radioactivity
She and her husband discovered polonium
Family of physicists-"nobels"
Maria Sklodowska ...
A couple of famous physicists
I discovered polonium with my husband
Unit of radioactivity
Pierre and Maria Sklodowska
Pierre and Maria
Measure of radioactivity
Famous French physicists - husband and wife
... "Chemical" spouses
Famous French physicist
Discovered radium and polonium
Pierre, who discovered radioactivity
Radiation measure
The couple who discovered radium
A married couple of physicists
Physicists, Pierre and Maria
Pierre from physicists
Discovered radium
Pierre and Maria Sklodovskaya
Polonium discoverers
Discoverers of radium
Discovered radium and polonium
Joliot ... - (1897-1956), French physicist, daughter of P. Curie and M. Sklodowska-Curie
Scientists Pierre and Maria
Unit of activity of radioactive isotopes
French physicist, one of the founders of the theory of radioactivity (1859-1906, Nobel Prize 1903)
French scientist, Nobel laureate in physics
In London, the Litvinenko murder case brought the topic of the use of polonium for poisoning back to the front pages of the media. We talk about this chemical element with the 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 have repeatedly made comments about polonium poisoning on Echo of Moscow, 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 polonium poisoning 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 Echo of Moscow: “How can you poison with polonium-210? This I will not put my mind to .... Now, if I were thinking how to poison a person, then the last one I would call polonium ... Naturally, the person who would drag it across the borders, he had to drag it in a lead container ".
A participant in the discussion that took place in the television program "Sunday Evening with Vladimir Solovyov" on December 3, 2006, in which I participated, Maxim Shingarkin, an artilleryman by training, argued that Litvinenko was not poisoned, but he himself breathed polonium while working in a secret laboratory on the territory Great Britain. ( later M. Shingarkin became an advisor 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, an associate of Andrei Lugovoi in the LDPR faction - "Polit.ru").
It's hard to understand: the people who said this - they simply do not understand this area at all or are engaged. Already in my first commentary 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 in tea or coffee, because it is sufficiently absorbed through the stomach ... And literally the next day, they reported that they found a kettle contaminated with polonium, from which Litvinenko drank tea. Can you imagine my position? ( Laughs).
Have you had any 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 trace amounts. 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. Now I deal most of all with radioactive isotopes for nuclear medicine, isotopes that are introduced into the human body for the diagnosis and treatment of 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 secret?
No, the very properties of polonium, its behavior, production methods and applications have long been no secret, everything is 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 to a given case.
How expensive is polonium to manufacture?
Talk about the high cost of polonium-210 is a myth. I know the price at which it sells, but I probably shouldn't divulge it. In any case, it is very small. Of course, manufacturers of a specific drug - a source of radioactive radiation, convenient for use, can ask for a decent amount, but this, as they say, is a "cheat". Polonium itself is cheap. Also, the source used, although obviously made by professionals, is badly done, made by bad professionals.
Where can you make such a conclusion?
Polonium, by its properties, diffuses easily through organic shells and generally 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 inherited decently.
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, precisely for latent 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 was not previously used for poisoning - 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. On the other hand, gamma radiation, which is usually detected using Geiger counters, is extremely weak, only one hundred thousandth part. Accordingly, it is not a problem to bring it to England, 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 polonium was used for provocation. In my opinion, such conversations are absolute nonsense. There was no provocation, there was a secret murder attempt. For provocation, it would be advisable to use any other radionuclide, for example, americium-241 - it would be easier to detect, it is more readily available (it is used everywhere in smoke detectors).
How, then, was this polonium discovered?
Yes, they did, they might not. This is an interesting story, I followed the development of events on the Internet. Litvinenko's symptoms were consistent with radiation damage. However, nothing was found with an ordinary counter that registers gamma radiation. A very weak 803 keV gamma-ray line could be seen only as a result of long-term measurements using a good gamma spectrometer. At first, this radiation was mistakenly 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 a too long half-life, and they began to consider the possibility of the presence of other alpha emitters. After that, the 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 logically enough.
Why didn't they use the usual chemical poison?
All groups of chemical poisons are known and would be easier to detect. Even when “disappearing” poisons are used, some traces of their use remain.
Was polonium unknown?
Unknown as poison. Of course, there have been very few cases of industrial poisoning. 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. Nobody will use polonium anymore for this purpose. I am sure about that. The story became too popular, and even I was pulled with a request to check something ... It's another matter - old cases that happened before the poisoning of Litvinenko, for example, the mysterious death of Yuri Shchekochikhin, the attempt to poison Anna Politkovskaya ...
But 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 number decreases 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 a second time. This is a very high activity, even too high activity: as a result, a person can die in a few days. But the polonium-210 produced in the reactor must contain a small admixture of another, long-lived isotope - polonium-209 (half-life 102 years).
It is very difficult to detect it at first due to the background of the 210th. But after the collapse - then you should try. It is possible, of course, to make polonium-210 without admixture of 209, but this will be really very expensive and difficult. It is unlikely that these people who made the drug would be engaged in such things. Although, who knows?
There were opinions that Yasser Arafat was poisoned with polonium. What did the research show?
A detailed study by Swiss scientists (the report has been published) showed that there is no good reason to talk about poisoning in this case, although the authors themselves first drew a different conclusion from their results. The report provides fairly convincing evidence that some excess polonium (which really was) was most likely of natural origin - obviously the result of the decay of radon-222, which is abundant in the undergrounds where Arafat often stayed. An autopsy revealed a corresponding amount of another radon decay product - lead-210. And no polonium-209 was found. Thus, Arafat received many orders of magnitude less dose of polonium-210 than Litvinenko, and this could not be the cause of death.
At public hearings, information was heard that Litvinenko was killed the second or third time. Apparently, the killers wanted to hedge?
Yes, this fact has long been known and published in scientific literature. It has been 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 at all would have been discovered. 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 perhaps it would be possible to determine the role of the British suspects A. Lugovoi and D. Kovtun?
Of course of course. They were studied, as far as I know, at the Medical Biophysical Center named after A.I. Burnazyan. It was reported that polonium was found in Lugovoi, but detailed results that would help shed light on the man's role are unknown. And they did not go to the UK.
Was there a danger of injury to the performers and injury to those around them? The British media reported that Lugovoi even brought his son to the last meeting and gave him to shake hands with Litvinenko ...
There was some danger, given that the performers were apparently not properly instructed. But still, it is not at all as dangerous as taking polonium orally, and does not pose a danger to life. Lugovoi himself said that someone had dirty 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 so that it is not revealed.
In your opinion, everything that the lawyer of the Litvinenko family said, and the British investigating authorities, is it true?
At least as far as the behavior of polonium is concerned, there is no contradiction. It is only wrong that its use has created a great threat to others. Small amounts of polonium that can contaminate people in contact with Mr 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 of illness in the future. The real danger would be if only someone finished their tea for Litvinenko. And it is also wrong that polonium-210 is very expensive, unless it is ultra-high purity. I have already mentioned this above. It is simply not readily available, and its distribution is fairly well controlled by government agencies.
Do you see any inconsistencies in what the British investigators say?
There are no discrepancies that cannot be explained based on the physical and chemical properties of polonium. On the contrary, as soon as opponents begin to put forward some objections, these objections do not fit with scientific data at all.
Thanks for the interview.