Alexei Navalny's poisoning: what happened at Tomsk airport

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Ambulance transport for the seriously ill Navalny in Omsk

The mug in the man's right hand is bright red and the contents appear to be quite hot. In any case, Alexei Navalny just seems to be blowing when DJ Pavel Lebedev takes his photo at the airport in the Siberian city of Tomsk last Thursday. It is one of the last pictures for the time being that shows the Kremlin critic in good health. Navalny plans to take flight S7 2614 back to Moscow shortly and has a cup of tea in a café at Bogashevo airport beforehand. It is the first and only food that he ate that day, people around him later say.

On the bus out to the waiting Boeing 737, Navalny is apparently in a good mood again for a selfie. But the 44-year-old suddenly feels very bad on the plane. On Lebedev's Instagram channel, video clips can be seen in which crew members with medical equipment rush to the rear in the center aisle of the aircraft, probably to the toilet. Loud screams can be heard in the cabin, apparently from Navalny.

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Navalny (in the center of the picture) on the way to the plane in Tomsk

Since Monday there has been at least one indication of the substance that caused such massive problems to the opposition politician. Navalny, who is now being treated in Berlin after an emergency stop in the hospital in the city of Omsk, has apparently been poisoned with a substance "from the active ingredient group of cholinesterase inhibitors". This is what the treating doctors report in a statement.

Cholinesterase inhibitors are substances that permanently block an enzyme in the human body's nervous system. They can be absorbed through the gastrointestinal tract, lungs and skin. The substances interrupt the transmission of impulses in certain parts of the nervous system and between nerve cells and muscle cells. The result: symptoms of poisoning such as pupil constriction, involuntary urine and stool leakage, respiratory depression, slow pulse, cramps and - depending on the dose - death.

"A number of chemical substances can have these effects, including in particular organic phosphoric acid esters and phosphonic acid esters," said Geneva-based chemical weapons expert Ralf Trapp when asked by SPIEGEL. "These groups of substances include a number of pesticides, but also the chemical nerve warfare agents developed for military purposes - including tabun, sarin, soman, the V-warfare agents, the so-called novichoks, and some carbamates."

Russians do not claim to have found any cholinesterase inhibitors

"These substances have also been used in assassinations," says Trapp. One example is the targeted attacks on Kim Jong Nam in Malaysia in 2017 - with the warfare agent VX - and on the Skripal family in Salisbury a year later. In this case the neurotoxin Novichok was used. It is not currently possible to say which substance Navalny actually came into contact with. "The specific substance is not yet known," says the Charité statement. At the hospital in Omsk, the doctors there insist that they looked for cholinesterase inhibitors in their prominent patient. However, these were not found in the analyzes.

"That does not automatically mean that the Russians are telling the truth. The different results can possibly be explained by the analytical method used," Ralf Stahlmann told SPIEGEL. The physician was director of the Institute for Clinical Pharmacology and Toxicology at the Charité in Berlin for many years, but is not involved in Nawalny's current treatment.

Atropine doesn't help against all symptoms

At the Charité, the patient from Russia is currently being treated in an artificial coma in the intensive care unit. According to the information from the attending physicians, he received the antidote atropine. He is said to have already received this in the Omsk hospital. This substance, which occurs naturally in thorn apple and deadly nightshade, helps the body deal better with the consequences of cholinesterase inhibitors. Among other things, the heart rate is accelerated.

The enzyme blocked by the poisoning does not get the atropine going again. "The substance works quickly and effectively against a number of symptoms, but not against all," explains the toxicologist Stahlmann. This is because only certain receptors respond to it at all.

There are various drugs for reactivating cholinesterase, including so-called oximes. These are being researched at the Bundeswehr University in Munich, among others. This is because cholinesterase inhibitors could also serve as weapons for terrorists, for example. "Oximes are only effective if they are given immediately after poisoning," says Stahlmann. With the patient Navalny it is now probably too late for that.

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Police officer at the Charité emergency room in Berlin

How long the apparently poisoned politician has to spend in an artificial coma, whether he will ever be completely healthy again, these questions cannot be answered seriously at the moment. Some cholinesterase inhibitors can cause severe nerve damage weeks after ingestion. The consequences of massive poisoning can be drastic. "There are indications of long-term neuropsychiatric damage caused by such substances," says the toxicologist Stahlmann. "However, the effect is not the same for all cholinesterase inhibitors and also depends on the dose." The weapons expert Trapp also says: "Long-term damage to the nervous system and other organs can also occur after acute poisoning."

"The chemistry of these substances is not too complex"

If Navalny, as it appears, has actually been actively poisoned, the question of responsibility arises. "It is a bit suspicious that someone who vehemently opposes the Russian state gets so sick," said British chemical weapons expert Hamish de Bretton-Gordon in the Guardian.

Does an attack with cholinesterase inhibitors now need a sophisticated infrastructure that only a state can have? "The chemistry of these substances is not too complex," says the toxicologist Stahlmann. "For some of the substances you don't need sophisticated technology to manufacture them. The synthesis is easy, and handling is rather difficult." Anyone who wants to murder with such poisons must therefore be careful not to become a victim themselves.

Some Alzheimer's drugs, such as donepezil, galantamine or rivastigmine, also act as cholinesterase inhibitors, as does the pesticide parathion - or E 605 for short - which is banned in the European Union. to trigger symptoms of poisoning like the one at Navalny. So was it actually a chemical warfare agent? "One thing surprises me," says Stahlmann. "It seems like some time has passed between taking the tea and the onset of symptoms. That doesn't really go with these substances." This could possibly be an indication that the poison was not in the tea mug, but that Navalny came into contact with it later, perhaps on the plane.

The Belgian Jean-Pascal Zanders is like his Geneva colleague Trapp a freelance chemical weapons expert. He too is closely following the Navalny case. For years Zanders has maintained a database in which he collects documents on biological and chemical weapons. When SPIEGEL approached him after the Charité statement on the condition of the patient from Russia and his treatment in Berlin, Zanders said he had just sorted the text into his database. Under the keyword "nerve poison".