August 21, 2020

expert reaction to Russian opposition figure Alexei Navalny falling ill, which allies claim is due to poisoning

The Russian opposition politician Alexei Navalny has been admit to hospital with illness which his family and supporters claim is due to poisoning.

Prof Alastair Hay, Emeritus Professor of Environmental Toxicology, University of Leeds, said:

Hearing of his symptoms, how likely is it he has been poisoned?

“I don’t know the full range of symptoms. But signs, i.e. how he appears, and what he complains of give valuable clues as to the possible cause.

What sort of substance could have been used – would it have to have been something that would have been administered without him knowing (i.e. tasteless/colourless)?

“Yes, you would want to mask the taste, otherwise someone will spit out what they have taken into their mouth. If someone has a sweet tooth and likes sugar in their tea, the sweetness of the sugar would be a great disguise. If sugar is not a possibility it becomes more complicated. But some teas have strong tastes too and may help to disguise a poison. We are of course focusing on the tea. Are there other possibilities? As to substance, if you wanted it to be undetected you would use something very potent. If it is to be absorbed, make sure it is taken up from the gut very readily and is effective after absorption. Many substances are.

How could it impact his nervous system?

“It depends. Organophosphate compounds (OPs), particularly nerve agents, like sarin, or the Novichoks, attack nerves directly, by blocking a crucial enzyme acetylcholinesterase, which controls message from nerves to muscles. If this enzyme is inhibited, muscles go into spasm and are unable to expand and contract as normal. This will affect all muscles, and those that control your breathing are the most crucial. So, someone may be unable to breathe normally and poor oxygenation could kill them or make them comatose through poor oxygenation of the brain. OPs have direct effects on the brain too. Opiates depress breathing and poor oxygenation may affect the brain, and on top of possible vomiting, cause someone to choke and die.

How difficult is it to treat cases like this – where doctors are uncertain of what’s caused the illness?

“This is where intensive care is essential. It is all about maintaining vital functions, ensuring someone can breathe, is well ventilated, that the heart keeps pumping, maintaining fluid balance, ensuring the blood chemistry stays within the normal ranges, watching glucose levels etc, until you identify the cause and can treat it more specifically.

How likely is this to be a case of poisoning, given evidence of past events where dissidents/critics of Russia have been poisoned?

“You would have to rule poisoning out. This means exhaustive tests and with sophisticated equipment which a regional hospital may not have. Remember, Porton Down discovered the Novichok in the Scripals’ case. A hospital lab would in all probability not have been able to find it and certainly if they had no assay or test for OPs.”

https://www.bbc.co.uk/news/world-europe-53857563

Declared interests

None received.